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Sample records for short locked nucleic

  1. Locked nucleic acid

    DEFF Research Database (Denmark)

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic...

  2. Short (16-mer locked nucleic acid splice-switching oligonucleotides restore dystrophin production in Duchenne Muscular Dystrophy myotubes.

    Directory of Open Access Journals (Sweden)

    Vanessa Borges Pires

    Full Text Available Splice-switching antisense oligonucleotides (SSOs offer great potential for RNA-targeting therapies, and two SSO drugs have been recently approved for treating Duchenne Muscular Dystrophy (DMD and Spinal Muscular Atrophy (SMA. Despite promising results, new developments are still needed for more efficient chemistries and delivery systems. Locked nucleic acid (LNA is a chemically modified nucleic acid that presents several attractive properties, such as high melting temperature when bound to RNA, potent biological activity, high stability and low toxicity in vivo. Here, we designed a series of LNA-based SSOs complementary to two sequences of the human dystrophin exon 51 that are most evolutionary conserved and evaluated their ability to induce exon skipping upon transfection into myoblasts derived from a DMD patient. We show that 16-mers with 60% of LNA modification efficiently induce exon skipping and restore synthesis of a truncated dystrophin isoform that localizes to the plasma membrane of patient-derived myotubes differentiated in culture. In sum, this study underscores the value of short LNA-modified SSOs for therapeutic applications.

  3. A locked nucleic Acid-based nanocrawler

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Pasternak, Karol; Campbell, Meghan A

    2013-01-01

    Herein we introduce a novel fluorescent LNA/DNA machine, a nanocrawler, which reversibly moves along a directionally polar complementary road controlled by affinity-enhancing locked nucleic acid (LNA) monomers and additional regulatory strands. Polyaromatic hydrocarbon (PAH) dyes attached to 2...

  4. Biological activity and biotechnological aspects of locked nucleic acids

    DEFF Research Database (Denmark)

    Lundin, Karin E; Højland, Torben; Hansen, Bo

    2013-01-01

    Locked nucleic acid (LNA) is one of the most promising new nucleic acid analogues that has been produced under the past two decades. In this chapter, we have tried to cover many of the different areas, where this molecule has been used to improve the function of synthetic oligonucleotides (ONs). ...

  5. Locked nucleic acid (LNA): High affinity targeting of RNA for diagnostics and therapeutics

    DEFF Research Database (Denmark)

    Kauppinen, S.; Vester, Birte; Wengel, Jesper

    2005-01-01

    Locked nucleic acid (LNA) is a nucleic acid analogue containing one or more LNA nucleotide monomers with a bicyclic furanose unit locked in an RNA mimicking sugar conformation. This conformational restriction results in unprecedented hybridization affinity towards complementary single stranded RN...

  6. Enhanced anti-HIV-1 activity of G-quadruplexes comprising locked nucleic acids and intercalating nucleic acids

    DEFF Research Database (Denmark)

    Pedersen, Erik Bjerregaard; Nielsen, Jakob Toudahl; Nielsen, Claus

    2011-01-01

    Two G-quadruplex forming sequences, 50-TGGGAG and the 17-mer sequence T30177, which exhibit anti-HIV-1 activity on cell lines, were modified using either locked nucleic acids (LNA) or via insertions of (R)-1-O-(pyren-1-ylmethyl)glycerol (intercalating nucleic acid, INA) or (R)-1-O-[4-(1......-pyrenylethynyl)phenylmethyl]glycerol (twisted intercalating nucleic acid, TINA). Incorporation of LNA or INA/TINA monomers provide as much as 8-fold improvement of anti-HIV-1 activity. We demonstrate for the first time a detailed analysis of the effect the incorporation of INA/TINA monomers in quadruplex forming...

  7. Cleavage and protection of locked nucleic acid-modified DNA by restriction endonucleases

    DEFF Research Database (Denmark)

    Crouzier, Lucile; Dubois, Camille; Wengel, Jesper

    2012-01-01

    Locked nucleic acid (LNA) is one of the most prominent nucleic acid analogues reported so far. We herein for the first time report cleavage by restriction endonuclease of LNA-modified DNA oligonucleotides. The experiments revealed that RsaI is an efficient enzyme capable of recognizing and cleaving...

  8. The free energy of locking a ring: Changing a deoxyribonucleoside to a locked nucleic acid.

    Science.gov (United States)

    Xu, You; Villa, Alessandra; Nilsson, Lennart

    2017-06-05

    Locked nucleic acid (LNA), a modified nucleoside which contains a bridging group across the ribose ring, improves the stability of DNA/RNA duplexes significantly, and therefore is of interest in biotechnology and gene therapy applications. In this study, we investigate the free energy change between LNA and DNA nucleosides. The transformation requires the breaking of the bridging group across the ribose ring, a problematic transformation in free energy calculations. To address this, we have developed a 3-step (easy to implement) and a 1-step protocol (more efficient, but more complicated to setup), for single and dual topologies in classical molecular dynamics simulations, using the Bennett Acceptance Ratio method to calculate the free energy. We validate the approach on the solvation free energy difference for the nucleosides thymidine, cytosine, and 5-methyl-cytosine. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

  9. Rapid genotyping using pyrene-perylene locked nucleic acid complexes

    DEFF Research Database (Denmark)

    Kumar, Santhosh T.; Myznikova, Anna; Samokhina, Evgeniya

    2013-01-01

    We have developed an assay for single strand DNA and RNA detection which is based on novel pyrene-perylene FRET pairs attached to short LNA/DNA probes. The assay is based on ratiometric emission upon binding of target DNA/RNA by three combinations of fluorescent LNA/DNA reporter strands. Specific...... geometry of the pyrene fluorophore attached to the 2'-amino group of 2'-amino-LNA in position 4 allows for the first time to efficiently utilize dipole-dipole orientation parameter for sensing of single-nucleotide polymorphisms (SNPs) in nucleic acid targets by FRET. Using novel probes, SNP detection......-perylene FRET pairs, e.g., in imaging and clinical diagnostics....

  10. Highly Efficient Synthesis of Allopurinol Locked Nucleic Acid Monomer by C6 Deamination of 8-Aza-7-bromo-7-deazaadenine Locked Nucleic Acid Monomer

    DEFF Research Database (Denmark)

    Kosbar, Tamer Reda El-Saeed; Sofan, M.; Abou-Zeid, L.

    2013-01-01

    An allopurinol locked nucleic acid (LNA) monomer was prepared by a novel strategy through C6 deamination of the corresponding 8-aza-7-bromo-7-deazaadenine LNA monomer with aqueous sodium hydroxide. An 8-aza-7-deazaadenine LNA monomer was also synthesized by a modification of the new synthetic...... the required LNA monomers....

  11. Application of locked nucleic acid-based probes in fluorescence in situ hybridization

    DEFF Research Database (Denmark)

    Fontenete, Sílvia; Carvalho, Daniel R; Guimarães, Nuno

    2016-01-01

    of nucleic acid mimics used as mixmers in LNA-based probes strongly influence the efficiency of detection. LNA probes with 10 to 15 mers showed the highest efficiency. Additionally, the combination of 2′-OMe RNA with LNA allowed an increase on the fluorescence intensities of the probes. Overall......Fluorescence in situ hybridization (FISH) employing nucleic acid mimics as probes is becoming an emerging molecular tool in the microbiology area for the detection and visualization of microorganisms. However, the impact that locked nucleic acid (LNA) and 2′-O-methyl (2′-OMe) RNA modifications have...

  12. Survivin mRNA antagonists using locked nucleic acid, potential for molecular cancer therapy

    DEFF Research Database (Denmark)

    Fisker, Niels; Westergaard, Majken; Hansen, Henrik Frydenlund

    2007-01-01

    We have investigated the effects of different locked nucleic acid modified antisense mRNA antagonists against Survivin in a prostate cancer model. These mRNA antagonists were found to be potent inhibitors of Survivin expression at low nanomolar concentrations. Additionally there was a pronounced ...

  13. Synthetic oligonucleotide antigens modified with locked nucleic acids detect disease specific antibodies

    DEFF Research Database (Denmark)

    Samuelsen, Simone V; Solov'yov, Ilia A.; Balboni, Imelda M.

    2016-01-01

    New techniques to detect and quantify antibodies to nucleic acids would provide a significant advance over current methods, which often lack specificity. We investigate the potential of novel antigens containing locked nucleic acids (LNAs) as targets for antibodies. Particularly, employing...... molecular dynamics we predict optimal nucleotide composition for targeting DNA-binding antibodies. As a proof of concept, we address a problem of detecting anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We test the best...... that the novel method is a promising tool to create antigens for research and point-of-care monitoring of anti-DNA antibodies....

  14. Scaffolding along Nucleic Acid Duplexes Using 2'-Amino-Locked Nucleic Acids

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Wengel, Jesper

    2014-01-01

    -LNA nucleotides. By application of different chemical reactions, modification of 2'-amino-LNA scaffolds can be efficiently performed in high yields and with various tags, postsynthetically or during the automated oligonucleotide synthesis. The choice of a synthetic method for scaffolding along 2'-amino-LNA mainly....../DNA probes bind nucleic acid targets with advantages of high affinity and specificity. Thus, molecular motion of nanodevices and programmable self-assembly of chemically modified LNA/DNA nanomaterials can be followed by bright fluorescence signaling from the functionalized LNA units. Another appealing aspect...

  15. Characterizing Slow Chemical Exchange in Nucleic Acids by Carbon CEST and Low Spin-Lock Field R1ρ NMR Spectroscopy

    Science.gov (United States)

    Zhao, Bo; Hansen, Alexandar L.; Zhang, Qi

    2016-01-01

    Quantitative characterization of dynamic exchange between various conformational states provides essential insights into the molecular basis of many regulatory RNA functions. Here, we present an application of nucleic-acid-optimized carbon chemical exchange saturation transfer (CEST) and low spin-lock field R1ρ relaxation dispersion (RD) NMR experiments in characterizing slow chemical exchange in nucleic acids that is otherwise difficult if not impossible to be quantified by the ZZ-exchange NMR experiment. We demonstrated the application on a 47-nucleotide fluoride riboswitch in the ligand-free state, for which CEST and R1ρ RD profiles of base and sugar carbons revealed slow exchange dynamics involving a sparsely populated (p ~ 10%) and shortly lived (τ ~ 10 ms) NMR “invisible” state. The utility of CEST and low spin-lock field R1ρ RD experiments in studying slow exchange was further validated in characterizing an exchange as slow as ~60 s−1. PMID:24299272

  16. Characterizing slow chemical exchange in nucleic acids by carbon CEST and low spin-lock field R(1ρ) NMR spectroscopy.

    Science.gov (United States)

    Zhao, Bo; Hansen, Alexandar L; Zhang, Qi

    2014-01-08

    Quantitative characterization of dynamic exchange between various conformational states provides essential insights into the molecular basis of many regulatory RNA functions. Here, we present an application of nucleic-acid-optimized carbon chemical exchange saturation transfer (CEST) and low spin-lock field R(1ρ) relaxation dispersion (RD) NMR experiments in characterizing slow chemical exchange in nucleic acids that is otherwise difficult if not impossible to be quantified by the ZZ-exchange NMR experiment. We demonstrated the application on a 47-nucleotide fluoride riboswitch in the ligand-free state, for which CEST and R(1ρ) RD profiles of base and sugar carbons revealed slow exchange dynamics involving a sparsely populated (p ~ 10%) and shortly lived (τ ~ 10 ms) NMR "invisible" state. The utility of CEST and low spin-lock field R(1ρ) RD experiments in studying slow exchange was further validated in characterizing an exchange as slow as ~60 s(-1).

  17. Locked vs. unlocked nucleic acids (LNA vs. UNA): contrasting structures work towards common therapeutic goals

    DEFF Research Database (Denmark)

    Campbell, Meghan A; Wengel, Jesper

    2011-01-01

    Oligonucleotide chemistry has been developed greatly over the past three decades, with many advances in increasing nuclease resistance, enhancing duplex stability and assisting with cellular uptake. Locked nucleic acid (LNA) is a structurally rigid modification that increases the binding affinity...... of a modified-oligonucleotide. In contrast, unlocked nucleic acid (UNA) is a highly flexible modification, which can be used to modulate duplex characteristics. In this tutorial review, we will compare the synthetic routes to both of these modifications, contrast the structural features, examine...... the hybridization properties of LNA and UNA modified duplexes, and discuss how they have been applied within biotechnology and drug research. LNA has found widespread use in antisense oligonucleotide technology, where it can stabilize interactions with target RNA and protect from cellular nucleases. The newly...

  18. Synthesis of locked cyclohexene and cyclohexane nucleic acids (LCeNA and LCNA) with modified adenosine units

    Czech Academy of Sciences Publication Activity Database

    Šála, Michal; Dejmek, Milan; Procházková, Eliška; Hřebabecký, Hubert; Rybáček, Jiří; Dračínský, Martin; Novák, Pavel; Rosenbergová, Šárka; Fukal, J.; Sychrovský, Vladimír; Rosenberg, Ivan; Nencka, Radim

    2015-01-01

    Roč. 13, č. 9 (2015), s. 2703-2715 ISSN 1477-0520 R&D Projects: GA ČR GPP207/12/P625 Institutional support: RVO:61388963 Keywords : locked nucleosides * locked nucleic acids * bicyclo[3.2.1]octene Subject RIV: CC - Organic Chemistry Impact factor: 3.559, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/ob/c4ob02193b

  19. Mapping photothermally induced gene expression in living cells and tissues by nanorod-locked nucleic acid complexes.

    Science.gov (United States)

    Riahi, Reza; Wang, Shue; Long, Min; Li, Na; Chiou, Pei-Yu; Zhang, Donna D; Wong, Pak Kin

    2014-04-22

    The photothermal effect of plasmonic nanostructures has numerous applications, such as cancer therapy, photonic gene circuit, large cargo delivery, and nanostructure-enhanced laser tweezers. The photothermal operation can also induce unwanted physical and biochemical effects, which potentially alter the cell behaviors. However, there is a lack of techniques for characterizing the dynamic cell responses near the site of photothermal operation with high spatiotemporal resolution. In this work, we show that the incorporation of locked nucleic acid probes with gold nanorods allows photothermal manipulation and real-time monitoring of gene expression near the area of irradiation in living cells and animal tissues. The multimodal gold nanorod serves as an endocytic delivery reagent to transport the probes into the cells, a fluorescence quencher and a binding competitor to detect intracellular mRNA, and a plasmonic photothermal transducer to induce cell ablation. We demonstrate the ability of the gold nanorod-locked nucleic acid complex for detecting the spatiotemporal gene expression in viable cells and tissues and inducing photothermal ablation of single cells. Using the gold nanorod-locked nucleic acid complex, we systematically characterize the dynamic cellular heat shock responses near the site of photothermal operation. The gold nanorod-locked nucleic acid complex enables mapping of intracellular gene expressions and analyzes the photothermal effects of nanostructures toward various biomedical applications.

  20. Development of bis-locked nucleic acid (bisLNA) oligonucleotides for efficient invasion of supercoiled duplex DNA

    DEFF Research Database (Denmark)

    Moreno, Pedro M D; Geny, Sylvain; Pabon, Y Vladimir

    2013-01-01

    In spite of the many developments in synthetic oligonucleotide (ON) chemistry and design, invasion into double-stranded DNA (DSI) under physiological salt and pH conditions remains a challenge. In this work, we provide a new ON tool based on locked nucleic acids (LNAs), designed for strand invasi...

  1. A Locked Nucleic Acid Probe Based on Selective Salt-Induced Effect Detects Single Nucleotide Polymorphisms

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2015-01-01

    Full Text Available Detection of single based genetic mutation by using oligonucleotide probes is one of the common methods of detecting single nucleotide polymorphisms at known loci. In this paper, we demonstrated a hybridization system which included a buffer solution that produced selective salt-induced effect and a locked nucleic acid modified 12 nt oligonucleotide probe. The hybridization system is suitable for hybridization under room temperature. By using magnetic nanoparticles as carriers for PCR products, the SNPs (MDR1 C3435T/A from 45 volunteers were analyzed, and the results were consistent with the results from pyrophosphoric acid sequencing. The method presented in this paper differs from the traditional method of using molecular beacons to detect SNPs in that it is suitable for research institutions lacking real-time quantitative PCR detecting systems, to detect PCR products at room temperature.

  2. Ultraselective electrochemiluminescence biosensor based on locked nucleic acid modified toehold-mediated strand displacement reaction and junction-probe.

    Science.gov (United States)

    Zhang, Xi; Zhang, Jing; Wu, Dongzhi; Liu, Zhijing; Cai, Shuxian; Chen, Mei; Zhao, Yanping; Li, Chunyan; Yang, Huanghao; Chen, Jinghua

    2014-12-07

    Locked nucleic acid (LNA) is applied in toehold-mediated strand displacement reaction (TMSDR) to develop a junction-probe electrochemiluminescence (ECL) biosensor for single-nucleotide polymorphism (SNP) detection in the BRCA1 gene related to breast cancer. More than 65-fold signal difference can be observed with perfectly matched target sequence to single-base mismatched sequence under the same conditions, indicating good selectivity of the ECL biosensor.

  3. Short locking time and low jitter phase-locked loop based on slope charge pump control

    International Nuclear Information System (INIS)

    Guo Zhongjie; Liu Youbao; Wu Longsheng; Wang Xihu; Tang Wei

    2010-01-01

    A novel structure of a phase-locked loop (PLL) characterized by a short locking time and low jitter is presented, which is realized by generating a linear slope charge pump current dependent on monitoring the output of the phase frequency detector (PFD) to implement adaptive bandwidth control. This improved PLL is created by utilizing a fast start-up circuit and a slope current control on a conventional charge pump PLL. First, the fast start-up circuit is enabled to achieve fast pre-charging to the loop filter. Then, when the output pulse of the PFD is larger than a minimum value, the charge pump current is increased linearly by the slope current control to ensure a shorter locking time and a lower jitter. Additionally, temperature variation is attenuated with the temperature compensation in the charge pump current design. The proposed PLL has been fabricated in a kind of DSP chip based on a 0.35 μm CMOS process. Comparing the characteristics with the classical PLL, the proposed PLL shows that it can reduce the locking time by 60% with a low peak-to-peak jitter of 0.3% at a wide operation temperature range. (semiconductor integrated circuits)

  4. Synthesis, hybridization characteristics, and fluorescence properties of oligonucleotides modified with nucleobase-functionalized locked nucleic acid adenosine and cytidine monomers.

    Science.gov (United States)

    Kaura, Mamta; Kumar, Pawan; Hrdlicka, Patrick J

    2014-07-03

    Conformationally restricted nucleotides such as locked nucleic acid (LNA) are very popular as affinity-, specificity-, and stability-enhancing modifications in oligonucleotide chemistry to produce probes for nucleic acid targeting applications in molecular biology, biotechnology, and medicinal chemistry. Considerable efforts have been devoted in recent years to optimize the biophysical properties of LNA through additional modification of the sugar skeleton. We recently introduced C5-functionalization of LNA uridines as an alternative and synthetically more straightforward approach to improve the biophysical properties of LNA. In the present work, we set out to test the generality of this concept by studying the characteristics of oligonucleotides modified with four different C5-functionalized LNA cytidine and C8-functionalized LNA adenosine monomers. The results strongly suggest that C5-functionalization of LNA pyrimidines is indeed a viable approach for improving the binding affinity, target specificity, and/or enzymatic stability of LNA-modified ONs, whereas C8-functionalization of LNA adenosines is detrimental to binding affinity and specificity. These insights will impact the future design of conformationally restricted nucleotides for nucleic acid targeting applications.

  5. Next-generation bis-locked nucleic acids with stacking linker and 2'-glycylamino-LNA show enhanced DNA invasion into supercoiled duplexes

    DEFF Research Database (Denmark)

    Geny, Sylvain; Moreno, Pedro M D; Krzywkowski, Tomasz

    2016-01-01

    Targeting and invading double-stranded DNA with synthetic oligonucleotides under physiological conditions remain a challenge. Bis-locked nucleic acids (bisLNAs) are clamp-forming oligonucleotides able to invade into supercoiled DNA via combined Hoogsteen and Watson-Crick binding. To improve the b...

  6. Hybridization-Based Detection of Helicobacter pylori at Human Body Temperature Using Advanced Locked Nucleic Acid (LNA) Probes

    Science.gov (United States)

    Fontenete, Sílvia; Guimarães, Nuno; Leite, Marina; Figueiredo, Céu; Wengel, Jesper; Filipe Azevedo, Nuno

    2013-01-01

    The understanding of the human microbiome and its influence upon human life has long been a subject of study. Hence, methods that allow the direct detection and visualization of microorganisms and microbial consortia (e.g. biofilms) within the human body would be invaluable. In here, we assessed the possibility of developing a variant of fluorescence in situ hybridization (FISH), named fluorescence in vivo hybridization (FIVH), for the detection of Helicobacter pylori. Using oligonucleotide variations comprising locked nucleic acids (LNA) and 2’-O-methyl RNAs (2’OMe) with two types of backbone linkages (phosphate or phosphorothioate), we were able to successfully identify two probes that hybridize at 37 °C with high specificity and sensitivity for H. pylori, both in pure cultures and in gastric biopsies. Furthermore, the use of this type of probes implied that toxic compounds typically used in FISH were either found to be unnecessary or could be replaced by a non-toxic substitute. We show here for the first time that the use of advanced LNA probes in FIVH conditions provides an accurate, simple and fast method for H. pylori detection and location, which could be used in the future for potential in vivo applications either for this microorganism or for others. PMID:24278398

  7. Locked Nucleic Acid-Based In Situ Hybridization Reveals miR-7a as a Hypothalamus-Enriched MicroRNA with a Distinct Expression Pattern

    DEFF Research Database (Denmark)

    Herzer, S; Silahtaroglu, A; Meister, B

    2012-01-01

    , a part of the brain that controls vital bodily functions, we employed locked nucleic acid (LNA) - fluorescent in situ hybridization (FISH). The expression pattern of the mature miRNAs miR-7a, miR-7b, miR-137 and miR-153 in mouse brain tissue sections was investigated. Whereas all studied miRNAs were......R-7a expression was particularly prominent in the subfornical organ, suprachiasmatic, paraventricular, periventricular, supraoptic, dorsomedial and arcuate nuclei. Identical expression patterns for miR-7a was seen in mouse and rat hypothalamus. By combining LNA-FISH with immunohistochemistry...

  8. Reliable allele detection using SNP-based PCR primers containing Locked Nucleic Acid: application in genetic mapping

    Directory of Open Access Journals (Sweden)

    Trognitz Friederike

    2007-02-01

    Full Text Available Abstract Background The diploid, Solanum caripense, a wild relative of potato and tomato, possesses valuable resistance to potato late blight and we are interested in the genetic base of this resistance. Due to extremely low levels of genetic variation within the S. caripense genome it proved impossible to generate a dense genetic map and to assign individual Solanum chromosomes through the use of conventional chromosome-specific SSR, RFLP, AFLP, as well as gene- or locus-specific markers. The ease of detection of DNA polymorphisms depends on both frequency and form of sequence variation. The narrow genetic background of close relatives and inbreds complicates the detection of persisting, reduced polymorphism and is a challenge to the development of reliable molecular markers. Nonetheless, monomorphic DNA fragments representing not directly usable conventional markers can contain considerable variation at the level of single nucleotide polymorphisms (SNPs. This can be used for the design of allele-specific molecular markers. The reproducible detection of allele-specific markers based on SNPs has been a technical challenge. Results We present a fast and cost-effective protocol for the detection of allele-specific SNPs by applying Sequence Polymorphism-Derived (SPD markers. These markers proved highly efficient for fingerprinting of individuals possessing a homogeneous genetic background. SPD markers are obtained from within non-informative, conventional molecular marker fragments that are screened for SNPs to design allele-specific PCR primers. The method makes use of primers containing a single, 3'-terminal Locked Nucleic Acid (LNA base. We demonstrate the applicability of the technique by successful genetic mapping of allele-specific SNP markers derived from monomorphic Conserved Ortholog Set II (COSII markers mapped to Solanum chromosomes, in S. caripense. By using SPD markers it was possible for the first time to map the S. caripense alleles

  9. A locked nucleic acid antisense oligonucleotide (LNA silences PCSK9 and enhances LDLR expression in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Nidhi Gupta

    2010-05-01

    Full Text Available The proprotein convertase subtilisin/kexin type 9 (PCSK9 is an important factor in the etiology of familial hypercholesterolemia (FH and is also an attractive therapeutic target to reduce low density lipoprotein (LDL cholesterol. PCSK9 accelerates the degradation of hepatic low density lipoprotein receptor (LDLR and low levels of hepatic PCSK9 activity are associated with reduced levels of circulating LDL-cholesterol.The present study presents the first evidence for the efficacy of a locked nucleic acid (LNA antisense oligonucleotide (LNA ASO that targets both human and mouse PCSK9. We employed human hepatocytes derived cell lines HepG2 and HuH7 and a pancreatic mouse beta-TC3 cell line known to express high endogenous levels of PCSK9. LNA ASO efficiently reduced the mRNA and protein levels of PCSK9 with a concomitant increase in LDLR protein levels after transfection in these cells. In vivo efficacy of LNA ASO was further investigated in mice by tail vein intravenous administration of LNA ASO in saline solution. The level of PCSK9 mRNA was reduced by approximately 60%, an effect lasting more than 16 days. Hepatic LDLR protein levels were significantly up-regulated by 2.5-3 folds for at least 8 days and approximately 2 fold for 16 days. Finally, measurement of liver alanine aminotransferase (ALT levels revealed that long term LNA ASO treatment (7 weeks does not cause hepatotoxicity.LNA-mediated PCSK9 mRNA inhibition displayed potent reduction of PCSK9 in cell lines and mouse liver. Our data clearly revealed the efficacy and safety of LNA ASO in reducing PCSK9 levels, an approach that is now ready for testing in primates. The major significance and take home message of this work is the development of a novel and promising approach for human therapeutic intervention of the PCSK9 pathway and hence for reducing some of the cardiovascular risk factors associated with the metabolic syndrome.

  10. Active mode-locking of mid-infrared quantum cascade lasers with short gain recovery time.

    Science.gov (United States)

    Wang, Yongrui; Belyanin, Alexey

    2015-02-23

    We investigate the dynamics of actively modulated mid-infrared quantum cascade lasers (QCLs) using space- and time-domain simulations of coupled density matrix and Maxwell equations with resonant tunneling current taken into account. We show that it is possible to achieve active mode locking and stable generation of picosecond pulses in high performance QCLs with a vertical laser transition and a short gain recovery time by bias modulation of a short section of a monolithic Fabry-Perot cavity. In fact, active mode locking in QCLs with a short gain recovery time turns out to be more robust to the variation of parameters as compared to previously studied lasers with a long gain recovery time. We investigate the effects of spatial hole burning and phase locking on the laser output.

  11. Comparative crystallization and preliminary X-ray diffraction studies of locked nucleic acid and RNA stems of a tenascin C-binding aptamer

    International Nuclear Information System (INIS)

    Förster, Charlotte; Brauer, Arnd B. E.; Brode, Svenja; Schmidt, Kathrin S.; Perbandt, Markus; Meyer, Arne; Rypniewski, Wojciech; Betzel, Christian; Kurreck, Jens; Fürste, Jens P.; Erdmann, Volker A.

    2006-01-01

    Locked nucleic acid (LNA) nucleotides are RNA analogues with a useful additional conformational constraint; the current investigation will provide the first crystallographic view of an all-LNA duplex. The pharmacokinetic properties of an aptamer against the tumour-marker protein tenascin-C have recently been successfully improved by the introduction of locked nucleic acids (LNAs) into the terminal stem of the aptamer. Since it is believed that this post-SELEX optimization is likely to provide a more general route to enhance the in vitro and in vivo stability of aptamers, elucidation of the structural basis of this improvement was embarked upon. Here, the crystallographic and X-ray diffraction data of the isolated aptamer stem encompassed in a six-base-pair duplex both with and without the LNA modification are presented. The obtained all-LNA crystals belong to space group P4 1 2 1 2 or P4 3 2 1 2, with unit-cell parameters a = b = 52.80, c = 62.83 Å; the all-RNA crystals belong to space group R32, with unit-cell parameters a = b = 45.21, c = 186.97 Å, γ = 120.00°

  12. Status and trends of short pulse generation using mode-locked lasers based on advanced quantum-dot active media

    International Nuclear Information System (INIS)

    Shi, L W; Chen, Y H; Xu, B; Wang, Z C; Jiao, Y H; Wang, Z G

    2007-01-01

    In this review, the potential of mode-locked lasers based on advanced quantum-dot (QD) active media to generate short optical pulses is analysed. A comprehensive review of experimental and theoretical work on related aspects is provided, including monolithic-cavity mode-locked QD lasers and external-cavity mode-locked QD lasers, as well as mode-locked solid-state and fibre lasers based on QD semiconductor saturable absorber mirrors. Performance comparisons are made for state-of-the-art experiments. Various methods for improving important characteristics of mode-locked pulses such as pulse duration, repetition rate, pulse power, and timing jitter through optimization of device design parameters or mode-locking methods are addressed. In addition, gain switching and self-pulsation of QD lasers are also briefly reviewed, concluding with the summary and prospects. (topical review)

  13. Spatially resolved determination of the short-circuit current density of silicon solar cells via lock-in thermography

    International Nuclear Information System (INIS)

    Fertig, Fabian; Greulich, Johannes; Rein, Stefan

    2014-01-01

    We present a spatially resolved method to determine the short-circuit current density of crystalline silicon solar cells by means of lock-in thermography. The method utilizes the property of crystalline silicon solar cells that the short-circuit current does not differ significantly from the illuminated current under moderate reverse bias. Since lock-in thermography images locally dissipated power density, this information is exploited to extract values of spatially resolved current density under short-circuit conditions. In order to obtain an accurate result, one or two illuminated lock-in thermography images and one dark lock-in thermography image need to be recorded. The method can be simplified in a way that only one image is required to generate a meaningful short-circuit current density map. The proposed method is theoretically motivated, and experimentally validated for monochromatic illumination in comparison to the reference method of light-beam induced current.

  14. Conformationally locked aryl C-nucleosides: synthesis of phosphoramidite monomers and incorporation into single-stranded DNA and LNA (locked nucleic acid)

    DEFF Research Database (Denmark)

    Babu, B. Ravindra; Prasad, Ashok K.; Trikha, Smriti

    2002-01-01

    . The phosphoramidite approach was used for automated incorporation of the LNA-type beta-configured C-aryl monomers 17a-17e into short DNA and 2'-OMe-RNA/LNA strands. It is shown that universal hybridization can be obtained with a conformationally restricted monomer as demonstrated most convincingly for the pyrene LNA...... monomer 17d, both in a DNA context and in an RNA-like context. Increased binding affinity of oligonucleotide probes for universal hybridization can be induced by combining the pyrene LNA monomer 17d with affinity-enhancing 2'-OMe-RNA/LNA monomers....

  15. A sensitive detection method for MPLW515L or MPLW515K mutation in chronic myeloproliferative disorders with locked nucleic acid-modified probes and real-time polymerase chain reaction.

    OpenAIRE

    Alessandro, Pancrazzi; Paola, Guglielmelli; Vanessa, Ponziani; Gaetano, Bergamaschi; Alberto, Bosi; Giovanni, Barosi; Alessandro M, Vannucchi

    2008-01-01

    Acquired mutations in the juxtamembrane region of MPL (W515K or W515L), the receptor for thrombopoietin, have been described in patients with primary myelofibrosis or essential thrombocythemia, which are chronic myeloproliferative disorders. We have developed a real-time polymerase chain reaction assay for the detection and quantification of MPL mutations that is based on locked nucleic acid fluorescent probes. Mutational analysis was performed using DNA from granulocytes. Reference curves we...

  16. Short-circuit current density imaging of crystalline silicon solar cells via lock-in thermography: Robustness and simplifications

    International Nuclear Information System (INIS)

    Fertig, Fabian; Greulich, Johannes; Rein, Stefan

    2014-01-01

    Spatially resolved determination of solar cell parameters is beneficial for loss analysis and optimization of conversion efficiency. One key parameter that has been challenging to access by an imaging technique on solar cell level is short-circuit current density. This work discusses the robustness of a recently suggested approach to determine short-circuit current density spatially resolved based on a series of lock-in thermography images and options for a simplified image acquisition procedure. For an accurate result, one or two emissivity-corrected illuminated lock-in thermography images and one dark lock-in thermography image have to be recorded. The dark lock-in thermography image can be omitted if local shunts are negligible. Furthermore, it is shown that omitting the correction of lock-in thermography images for local emissivity variations only leads to minor distortions for standard silicon solar cells. Hence, adequate acquisition of one image only is sufficient to generate a meaningful map of short-circuit current density. Beyond that, this work illustrates the underlying physics of the recently proposed method and demonstrates its robustness concerning varying excitation conditions and locally increased series resistance. Experimentally gained short-circuit current density images are validated for monochromatic illumination in comparison to the reference method of light-beam induced current

  17. A ratiometric electrochemical biosensor for the exosomal microRNAs detection based on bipedal DNA walkers propelled by locked nucleic acid modified toehold mediate strand displacement reaction.

    Science.gov (United States)

    Zhang, Jing; Wang, Liang-Liang; Hou, Mei-Feng; Xia, Yao-Kun; He, Wen-Hui; Yan, An; Weng, Yun-Ping; Zeng, Lu-Peng; Chen, Jing-Hua

    2018-04-15

    Sensitive and selective detection of microRNAs (miRNAs) in cancer cells derived exosomes have attracted rapidly growing interest owing to their potential in diagnostic and prognostic applications. Here, we design a ratiometric electrochemical biosensor based on bipedal DNA walkers for the attomolar detection of exosomal miR-21. In the presence of miR-21, DNA walkers are activated to walk continuously along DNA tracks, resulting in conformational changes as well as considerable increases of the signal ratio produced by target-respond and target-independent reporters. With the signal cascade amplification of DNA walkers, the biosensor exhibits ultrahigh sensitivity with the limit of detection (LOD) down to 67 aM. Furthermore, owing to the background-correcting function of target-independent reporters termed as reference reporters, the biosensor is robust and stable enough to be applied in the detection of exosomal miR-21 extracted from breast cancer cell lines and serums. In addition, because locked nucleic acid (LNA) modified toehold mediate strand displacement reaction (TMSDR) has extraordinary discriminative ability, the biosensor displays excellent selectivity even against the single-base-mismatched target. It is worth mentioning that our sensor is regenerative and stable for at least 5 cycles without diminution in sensitivity. In brief, the high sensitivity, selectivity and reproducibility, together with cheap, make the proposed biosensor a promising approach for exosomal miRNAs detection, in conjunction with early point-of-care testing (POCT) of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A locked nucleic acid (LNA-based real-time PCR assay for the rapid detection of multiple bacterial antibiotic resistance genes directly from positive blood culture.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA-based quantitative real-time PCR (LNA-qPCR method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1-10 colony forming units (CFU per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4% were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.

  19. Antisense locked nucleic acids targeting agrA inhibit quorum sensing and pathogenesis of community-associated methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Da, F; Yao, L; Su, Z; Hou, Z; Li, Z; Xue, X; Meng, J; Luo, X

    2017-01-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with nonnosocomial skin and soft tissue infections due to its virulence, which is mainly controlled by the accessory gene regulator (agr) quorum sensing (QS) system. In this study (KFF) 3 K peptide-conjugated locked nucleic acids (PLNAs) targeting agrA mRNA were developed to inhibit agr activity and arrest the pathogenicity of CA-MRSA. Two PLNAs were designed, and synthesized, after predicting the secondary structure of agrA mRNA. The influence on bacterial growth was tested using a growth curve assay. RT-qPCR, haemolysis assay, lactate dehydrogenase release assay and chemotaxis assay were used to evaluate the effects of the PLNAs on inhibiting agr QS. A mouse skin infection model was employed to test the protective effect of the PLNAs in vivo. None of the PLNAs were found to be bacteriostatic or bactericidal in vitro. However, one PLNA, PLNA34, showed strong ability to suppress expression of agrA and the effector molecule RNAIII in USA300 LAC strain. Furthermore, PLNA34 inhibited the expression of virulence genes that are upregulated by agr, including hla, psmα, psmβ and pvl. The haemolytic activity of the supernatants from PLNA34-treated bacteria was also dramatically reduced, as well as the capacity to lyse and recruit neutrophils. Moreover, PLNA34 showed high levels of protection in the CA-MRSA mouse skin infection model. The anti-agrA PLNA34 can effectively inhibit the agr QS and suppress CA-MRSA pathogenicity. agrA is a promising target for the development of antisense oligonucleotides to block agr QS. Journal of Applied Microbiology © 2016 The Society for Applied Microbiology.

  20. Establishment of real time allele specific locked nucleic acid quantitative PCR for detection of HBV YIDD (ATT mutation and evaluation of its application.

    Directory of Open Access Journals (Sweden)

    Yongbin Zeng

    Full Text Available BACKGROUND: Long-term use of nucleos(tide analogues can increase risk of HBV drug-resistance mutations. The rtM204I (ATT coding for isoleucine is one of the most important resistance mutation sites. Establishing a simple, rapid, reliable and highly sensitive assay to detect the resistant mutants as early as possible is of great clinical significance. METHODS: Recombinant plasmids for HBV YMDD (tyrosine-methionine-aspartate-aspartate and YIDD (tyrosine-isoleucine-aspartate-aspartate were constructed by TA cloning. Real time allele specific locked nucleic acid quantitative PCR (RT-AS-LNA-qPCR with SYBR Green I was established by LNA-modified primers and evaluated with standard recombinant plasmids, clinical templates (the clinical wild type and mutant HBV DNA mixture and 102 serum samples from nucleos(tide analogues-experienced patients. The serum samples from a chronic hepatitis B (CHB patient firstly received LMV mono therapy and then switched to LMV + ADV combined therapy were also dynamically analyzed for 10 times. RESULTS: The linear range of the assay was between 1×10(9 copies/μl and 1 × 10(2 copies/μl. The low detection limit was 1 × 10(1 copies/μl. Sensitivity of the assay were 10(-6, 10(-4 and 10(-2 in the wild-type background of 1 × 10(9 copies/μl, 1 × 10(7 copies/μl and 1 × 10(5 copies/μl, respectively. The sensitivity of the assay in detection of clinical samples was 0.03%. The complete coincidence rate between RT-AS-LNA-qPCR and direct sequencing was 91.2% (93/102, partial coincidence rate was 8.8% (9/102, and no complete discordance was observed. The two assays showed a high concordance (Kappa = 0.676, P = 0.000. Minor variants can be detected 18 weeks earlier than the rebound of HBV DNA load and alanine aminotransferase level. CONCLUSIONS: A rapid, cost-effective, high sensitive, specific and reliable method of RT-AS-LNA-qPCR with SYBR Green I for early and absolute quantification of HBV YIDD (ATT coding for isoleucine

  1. High affinity γPNA sandwich hybridization assay for rapid detection of short nucleic acid targets with single mismatch discrimination.

    Science.gov (United States)

    Goldman, Johnathan M; Zhang, Li Ang; Manna, Arunava; Armitage, Bruce A; Ly, Danith H; Schneider, James W

    2013-07-08

    Hybridization analysis of short DNA and RNA targets presents many challenges for detection. The commonly employed sandwich hybridization approach cannot be implemented for these short targets due to insufficient probe-target binding strengths for unmodified DNA probes. Here, we present a method capable of rapid and stable sandwich hybridization detection for 22 nucleotide DNA and RNA targets. Stable hybridization is achieved using an n-alkylated, polyethylene glycol γ-carbon modified peptide nucleic acid (γPNA) amphiphile. The γPNA's exceptionally high affinity enables stable hybridization of a second DNA-based probe to the remaining bases of the short target. Upon hybridization of both probes, an electrophoretic mobility shift is measured via interaction of the n-alkane modification on the γPNA with capillary electrophoresis running buffer containing nonionic surfactant micelles. We find that sandwich hybridization of both probes is stable under multiple binding configurations and demonstrate single base mismatch discrimination. The binding strength of both probes is also stabilized via coaxial stacking on adjacent hybridization to targets. We conclude with a discussion on the implementation of the proposed sandwich hybridization assay as a high-throughput microRNA detection method.

  2. A new general model for predicting melting thermodynamics of complementary and mismatched B-form duplexes containing locked nucleic acids: application to probe design for digital PCR detection of somatic mutations.

    Science.gov (United States)

    Hughesman, Curtis; Fakhfakh, Kareem; Bidshahri, Roza; Lund, H Louise; Haynes, Charles

    2015-02-17

    Advances in real-time polymerase chain reaction (PCR), as well as the emergence of digital PCR (dPCR) and useful modified nucleotide chemistries, including locked nucleic acids (LNAs), have created the potential to improve and expand clinical applications of PCR through their ability to better quantify and differentiate amplification products, but fully realizing this potential will require robust methods for designing dual-labeled hydrolysis probes and predicting their hybridization thermodynamics as a function of their sequence, chemistry, and template complementarity. We present here a nearest-neighbor thermodynamic model that accurately predicts the melting thermodynamics of a short oligonucleotide duplexed either to its perfect complement or to a template containing mismatched base pairs. The model may be applied to pure-DNA duplexes or to duplexes for which one strand contains any number and pattern of LNA substitutions. Perturbations to duplex stability arising from mismatched DNA:DNA or LNA:DNA base pairs are treated at the Gibbs energy level to maintain statistical significance in the regressed model parameters. This approach, when combined with the model's accounting of the temperature dependencies of the melting enthalpy and entropy, permits accurate prediction of T(m) values for pure-DNA homoduplexes or LNA-substituted heteroduplexes containing one or two independent mismatched base pairs. Terms accounting for changes in solution conditions and terminal addition of fluorescent dyes and quenchers are then introduced so that the model may be used to accurately predict and thereby tailor the T(m) of a pure-DNA or LNA-substituted hydrolysis probe when duplexed either to its perfect-match template or to a template harboring a noncomplementary base. The model, which builds on classic nearest-neighbor thermodynamics, should therefore be of use to clinicians and biologists who require probes that distinguish and quantify two closely related alleles in either a

  3. Short pulse generation in a passively mode-locked photonic crystal semiconductor laser

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Blaaberg, Søren; Mørk, Jesper

    2010-01-01

    We present a new type of passively mode-locked laser with quantum wells embedded in photonic crystal waveguides operating in the slow light regime, which is capable of emitting sub picosecond pulses with widely controllable properties......We present a new type of passively mode-locked laser with quantum wells embedded in photonic crystal waveguides operating in the slow light regime, which is capable of emitting sub picosecond pulses with widely controllable properties...

  4. Kinetics of end-to-end collision in short single-stranded nucleic acids.

    Science.gov (United States)

    Wang, Xiaojuan; Nau, Werner M

    2004-01-28

    A novel fluorescence-based method, which entails contact quenching of the long-lived fluorescent state of 2,3-diazabicyclo[2.2.2]-oct-2-ene (DBO), was employed to measure the kinetics of end-to-end collision in short single-stranded oligodeoxyribonucleotides of the type 5'-DBO-(X)n-dG with X = dA, dC, dT, or dU and n = 2 or 4. The fluorophore was covalently attached to the 5' end and dG was introduced as an efficient intrinsic quencher at the 3' terminus. The end-to-end collision rates, which can be directly related to the efficiency of intramolecular fluorescence quenching, ranged from 0.1 to 9.0 x 10(6) s(-1). They were strongly dependent on the strand length, the base sequence, as well as the temperature. Oligonucleotides containing dA in the backbone displayed much slower collision rates and significantly higher positive activation energies than strands composed of pyrimidine bases, suggesting a higher intrinsic rigidity of oligoadenylate. Comparison of the measured collision rates in short single-stranded oligodeoxyribonucleotides with the previously reported kinetics of hairpin formation indicates that the intramolecular collision is significantly faster than the nucleation step of hairpin closing. This is consistent with the configurational diffusion model suggested by Ansari et al. (Ansari, A.; Kuznetsov, S. V.; Shen, Y. Proc.Natl. Acad. Sci. USA 2001, 98, 7771-7776), in which the formation of misfolded loops is thought to slow hairpin formation.

  5. Tungsten diselenide for mode-locked erbium-doped fiber lasers with short pulse duration

    Science.gov (United States)

    Liu, Wenjun; Liu, Mengli; OuYang, Yuyi; Hou, Huanran; Ma, Guoli; Lei, Ming; Wei, Zhiyi

    2018-04-01

    In this paper, a WSe2 film prepared by chemical vapor deposition (CVD) is transferred onto a tapered fiber, and a WSe2 saturable absorber (SA) is fabricated. In order to measure the third-order optical nonlinearity of the WSe2, the Z-scan technique is applied. The modulation depth of the WSe2 SA is measured as being 21.89%. Taking advantage of the remarkable nonlinear absorption characteristic of the WSe2 SA, a mode-locked erbium-doped fiber laser is demonstrated at 1557.4 nm with a bandwidth of 25.8 nm and signal to noise ratio of 96 dB. To the best of our knowledge, the pulse duration of 163.5 fs is confirmed to be the shortest compared with previous mode-locked fiber lasers based on transition-metal dichalcogenides SAs. These results indicate that WSe2 is a powerful competitor in the application of ultrashort pulse lasers.

  6. Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 Triggered Isothermal Amplification for Site-Specific Nucleic Acid Detection.

    Science.gov (United States)

    Huang, Mengqi; Zhou, Xiaoming; Wang, Huiying; Xing, Da

    2018-02-06

    A novel CRISPR/Cas9 triggered isothermal exponential amplification reaction (CAS-EXPAR) strategy based on CRISPR/Cas9 cleavage and nicking endonuclease (NEase) mediated nucleic acids amplification was developed for rapid and site-specific nucleic acid detection. CAS-EXPAR was primed by the target DNA fragment produced by cleavage of CRISPR/Cas9, and the amplification reaction performed cyclically to generate a large number of DNA replicates which were detected using a real-time fluorescence monitoring method. This strategy that combines the advantages of CRISPR/Cas9 and exponential amplification showed high specificity as well as rapid amplification kinetics. Unlike conventional nucleic acids amplification reactions, CAS-EXPAR does not require exogenous primers, which often cause target-independent amplification. Instead, primers are first generated by Cas9/sgRNA directed site-specific cleavage of target and accumulated during the reaction. It was demonstrated this strategy gave a detection limit of 0.82 amol and showed excellent specificity in discriminating single-base mismatch. Moreover, the applicability of this method to detect DNA methylation and L. monocytogenes total RNA was also verified. Therefore, CAS-EXPAR may provide a new paradigm for efficient nucleic acid amplification and hold the potential for molecular diagnostic applications.

  7. Demonstration of Hepatitis C Virus RNA with In Situ Hybridization Employing a Locked Nucleic Acid Probe in Humanized Liver of Infected Chimeric Mice and in Needle-Biopsied Human Liver

    Directory of Open Access Journals (Sweden)

    Kazuya Shiogama

    2013-01-01

    Full Text Available Background. In situ hybridization (ISH with high sensitivity has been requested to demonstrate hepatitis C virus (HCV RNA in formalin-fixed, paraffin-embedded (FFPE sections of the liver. Methods. ISH employing a locked-nucleic-acid- (LNA-modified oligonucleotide probe and biotin-free catalyzed signal amplification system (CSAII was applied to HCV-RNA detection in the liver tissue. Nested reverse-transcription polymerase chain reaction (RT-PCR was performed for HCV genotyping using total RNA extracted from FFPE sections. The target tissues included FFPE tissue sections of humanized livers in HCV-infected chimeric mice (HCV genotypes 1a, 1b, and 2a and noninfected and of needle-biopsied livers from HCV-infected patients. Results. HCV-RNA was demonstrated with the ISH technique in HCV-infected liver tissues from both chimeric mice and 9 (82% of 11 patients with HCV infection. The HCV signals were sensitive to RNase. Nested RT-PCR confirmed the genotype in 8 (73% of 11 livers (type 1b: 6 lesions and type 2a: 2 lesions. HCV-RNA was not identified in chronic hepatitis B lesions, fatty liver, autoimmune hepatitis, and hepatocellular carcinoma. Conclusion. ISH using the LNA-modified oligonucleotide probe and CSAII was applicable to detecting HCV-RNA in routinely prepared FFPE liver specimens.

  8. Detection of single-nucleotide polymorphisms using an ON-OFF switching of regenerated biosensor based on a locked nucleic acid-integrated and toehold-mediated strand displacement reaction.

    Science.gov (United States)

    Gao, Zhong Feng; Ling, Yu; Lu, Lu; Chen, Ning Yu; Luo, Hong Qun; Li, Nian Bing

    2014-03-04

    Although various strategies have been reported for single-nucleotide polymorphisms (SNPs) detection, development of a time-saving, specific, and regenerated electrochemical sensing platform still remains a realistic goal. In this study, an ON-OFF switching of a regenerated biosensor based on a locked nucleic acid (LNA)-integrated and toehold-mediated strand displacement reaction technique is constructed for detection of SNPs. The LNA-integrated and methylene blue-labeled capture probe with an external toehold is designed to switch on the sensing system. The mutant-type DNA probe completes complementary with the capture probe to trigger the strand displacement reaction, which switches off the sensing system. However, when the single-base mismatched wild-type DNA probe is presented, the strand displacement reaction cannot be achieved; therefore, the sensing system still keeps the ON state. This DNA sensor is stable over five reuses. We further testify that the LNA-integrated sequence has better recognition ability for SNPs detection compared to the DNA-integrated sequence. Moreover, this DNA senor exhibits a remarkable discrimination capability of SNPs among abundant wild-type targets and 6000-fold (m/m) excess of genomic DNA. In addition, it is selective enough in complex and contaminant-ridden samples, such as human urine, soil, saliva, and beer. Overall, these results demonstrate that this reliable DNA sensor is easy to be fabricated, simple to operate, and stable enough to be readily regenerated.

  9. One-Step Nucleic Acid Amplification in Breast Cancer Sentinel Lymph Node: A Single Institutional Experience and a Short Review

    OpenAIRE

    Brambilla, Tatiana; Fiamengo, Barbara; Tinterri, Corrado; Testori, Alberto; Grassi, Massimo Maria; Sciarra, Amedeo; Abbate, Tommaso; Gatzemeier, Wolfgang; Roncalli, Massimo; Di Tommaso, Luca

    2015-01-01

    Sentinel lymph node (SLN) examination is a standard in breast cancer patients, with several methods employed along its 20 years history, the last one represented by one-step nucleic acid amplification (OSNA). The latter is a intra-operative molecular assay searching for CK19 mRNA as a surrogate of metastatic cells. Our 3 years experience with OSNA (1122 patients) showed results overlapping those recorded in the same institution with a morphological evaluation (930 patients) of SLN. In detail,...

  10. "Clickable" LNA/DNA probes for fluorescence sensing of nucleic acids and autoimmune antibodies

    DEFF Research Database (Denmark)

    Jørgensen, Anna S; Gupta, Pankaj; Wengel, Jesper

    2013-01-01

    Herein we describe fluorescent oligonucleotides prepared by click chemistry between novel alkyne-modified locked nucleic acid (LNA) strands and a series of fluorescent azides for homogeneous (all-in-solution) detection of nucleic acids and autoimmune antibodies.......Herein we describe fluorescent oligonucleotides prepared by click chemistry between novel alkyne-modified locked nucleic acid (LNA) strands and a series of fluorescent azides for homogeneous (all-in-solution) detection of nucleic acids and autoimmune antibodies....

  11. A sensitive detection method for MPLW515L or MPLW515K mutation in chronic myeloproliferative disorders with locked nucleic acid-modified probes and real-time polymerase chain reaction.

    Science.gov (United States)

    Pancrazzi, Alessandro; Guglielmelli, Paola; Ponziani, Vanessa; Bergamaschi, Gaetano; Bosi, Alberto; Barosi, Giovanni; Vannucchi, Alessandro M

    2008-09-01

    Acquired mutations in the juxtamembrane region of MPL (W515K or W515L), the receptor for thrombopoietin, have been described in patients with primary myelofibrosis or essential thrombocythemia, which are chronic myeloproliferative disorders. We have developed a real-time polymerase chain reaction assay for the detection and quantification of MPL mutations that is based on locked nucleic acid fluorescent probes. Mutational analysis was performed using DNA from granulocytes. Reference curves were obtained using cloned fragments of MPL containing either the wild-type or mutated sequence; the predicted sensitivity level was at least 0.1% mutant allele in a wild-type background. None of the 60 control subjects presented with a MPLW515L/K mutation. Of 217 patients with myelofibrosis, 19 (8.7%) harbored the MPLW515 mutation, 10 (52.6%) with the W515L allele. In one case, both the W515L and W515K alleles were detected by real-time polymerase chain reaction. By comparing results obtained with conventional sequencing, no erroneous genotype attribution using real-time polymerase chain reaction was found, whereas one patient considered wild type according to sequence analysis actually harbored a low W515L allele burden. This is a simple, sensitive, and cost-effective procedure for large-scale screening of the MPLW515L/K mutation in patients suspected to have a myeloproliferative disorder. It can also provide a quantitative estimate of mutant allele burden that might be useful for both patient prognosis and monitoring response to therapy.

  12. Understanding the effect of locked nucleic acid and 2'-O-methyl modification on the hybridization thermodynamics of a miRNA-mRNA pair in the presence and absence of AfPiwi protein.

    Science.gov (United States)

    Kumar, Santosh; Mapa, Koyeli; Maiti, Souvik

    2014-03-18

    miRNAs are some of the key epigenetic regulators of gene expression. They act through hybridization with their target mRNA and modulate the level of respective proteins via different mechanisms. Various cancer conditions are known to be associated with up- and downregulation of the oncogenic and tumor suppressor miRNAs, respectively. The levels of aberrantly expressed oncogenic miRNAs can be downregulated in different ways. Similarly, restoration of tumor suppressor miRNAs to their normal levels can be achieved using miRNA mimics. However, the use of miRNA mimics is limited by their reduced biostability and function. We have studied the hybridization thermodynamics of the miRNA 26a (11-mer, including the seed sequence) guide strand with the mRNA (11-mer) target strand in the absence and presence of AfPiwi protein. We have also inserted locked nucleic acids (LNAs) and 2'-O-methyl-modified nucleotides into the guide strand, in a walk-through manner, to assess their effect on the binding efficiency between guide and target RNA. Insertion of LNA and 2'-O-methyl-modified nucleotides into the guide strand helped to strengthen the binding affinity irrespective of the position of insertion. However, in the presence of AfPiwi protein, these modifications reduced the binding affinity to different extents depending on the position of insertion. Insertion of a modification leads to an increase in the enthalpic contribution with an increased unfavorable entropic contribution, which negatively compensates for the higher favorable enthalpy.

  13. One-Step Nucleic Acid Amplification in Breast Cancer Sentinel Lymph Node: A Single Institutional Experience and a Short Review.

    Science.gov (United States)

    Brambilla, Tatiana; Fiamengo, Barbara; Tinterri, Corrado; Testori, Alberto; Grassi, Massimo Maria; Sciarra, Amedeo; Abbate, Tommaso; Gatzemeier, Wolfgang; Roncalli, Massimo; Di Tommaso, Luca

    2015-01-01

    Sentinel lymph node (SLN) examination is a standard in breast cancer patients, with several methods employed along its 20 years history, the last one represented by one-step nucleic acid amplification (OSNA). The latter is a intra-operative molecular assay searching for CK19 mRNA as a surrogate of metastatic cells. Our 3 years experience with OSNA (1122 patients) showed results overlapping those recorded in the same institution with a morphological evaluation (930 patients) of SLN. In detail, the data of OSNA were almost identical to those observed with standard post-operative procedure in terms of patients with positive SLN (30%) and micrometastatic/macrometastatic involvement of SLN (respectively, 38-45 and 62-55%). By contrast, when OSNA was compared to the standard intraoperatory procedure, it was superior in terms of accuracy, prompting the use of this molecular assay as a very valid, and reproducible for intra-operative evaluation of SLN. Further possibilities prompting the use of OSNA range from adhesion to quality control programs, saving of medical time, ability to predict, during surgery, additional nodal metastasis, and molecular bio-banking.

  14. Short pulse generation from a passively mode-locked fiber optical parametric oscillator with optical time-stretch.

    Science.gov (United States)

    Qiu, Yi; Wei, Xiaoming; Du, Shuxin; Wong, Kenneth K Y; Tsia, Kevin K; Xu, Yiqing

    2018-04-16

    We propose a passively mode-locked fiber optical parametric oscillator assisted with optical time-stretch. Thanks to the lately developed optical time-stretch technique, the onset oscillating spectral components can be temporally dispersed across the pump envelope and further compete for the parametric gain with the other parts of onset oscillating sidebands within the pump envelope. By matching the amount of dispersion in optical time-stretch with the pulse width of the quasi-CW pump and oscillating one of the parametric sidebands inside the fiber cavity, we numerically show that the fiber parametric oscillator can be operated in a single pulse regime. By varying the amount of the intracavity dispersion, we further verify that the origin of this single pulse mode-locking regime is due to the optical pulse stretching and compression.

  15. Short locked nucleic acid antisense oligonucleotides potently reduce apolipoprotein B mRNA and serum cholesterol in mice and non-human primates

    DEFF Research Database (Denmark)

    Straarup, Ellen Marie; Fisker, Niels; Hedtjärn, Maj

    2010-01-01

    -life as longer oligonucleotides. Pharmacology studies in both mice and non-human primates were conducted with a 13-mer LNA oligonucleotide against apoB, and the data showed that repeated dosing of the 13-mer at 1-2 mg/kg/week was sufficient to provide a significant and long lasting lowering of non...... using the LNA chemistry. Conclusively, we present a 13-mer LNA oligonucleotide with therapeutic potential that produce beneficial cholesterol lowering effect in non-human primates....

  16. Automatic locking radioisotope camera lock

    International Nuclear Information System (INIS)

    Rosauer, P.J.

    1978-01-01

    The lock of the present invention secures the isotope source in a stored shielded condition in the camera until a positive effort has been made to open the lock and take the source outside of the camera and prevents disconnection of the source pigtail unless the source is locked in a shielded condition in the camera. It also gives a visual indication of the locked or possible exposed condition of the isotope source and prevents the source pigtail from being completely pushed out of the camera, even when the lock is released. (author)

  17. High-speed clock recovery and demodulation using short pulse sources and phase-locked loop techniques

    DEFF Research Database (Denmark)

    Zibar, Darko

    2007-01-01

    clocktiming jitter, i.e. 3.5 ps at 40 Gb/s and 0.5 ps at 160 Gb/s. In the last part of the thesis, a novel phase-locked coherent optical phase demodulator with feedback and sampling, to be used in phase-modulated radio-over-fibre optical links, is also presented, theoretically investigated and experimentally...... demonstrated. It is experimentally shown that the proposed approach results in 18 dB of spur-free-dynamic range improve- ment compared to a traditional demodulator without feedback. A new time-domain, large signal, numerical model of the phase locked coherent demodulator is developed and shown...... loop with noise at a bit-rate of 160 Gb/s. It has been shown that it is important to reduce the time delay in the loop since it results in the increased timing jitter of the recovered clock signal. We also investigate the requirement for the free-running timing jitter of the local electrical...

  18. Air lock

    International Nuclear Information System (INIS)

    Palkovich, P.; Gruber, J.; Madlener, W.

    1974-01-01

    The patent refers to an air lock system preferably for nuclear stations for the transport of heavy loads by means of a trolley on rails. For opening and closing of the air lock parts of the rails are removed, e.g. by a second rail system perpendicular to the main rails. (P.K.)

  19. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  20. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  1. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  3. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  4. Portable nucleic acid thermocyclers.

    Science.gov (United States)

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.

  5. Short-term incubation in vitro with precursors of nucleic acids on human primary tumors and metastases of carcinoma of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, M; Kubli, F; Volm, M; Fournier, D V; Reus, W [Heidelberg Univ. (Germany, F.R.). Frauenklinik; Deutsches Krebsforschungszentrum, Heidelberg (Germany, F.R.). Inst. fuer Experimentelle Pathologie)

    1978-04-01

    A technique of short-term tests in vitro by means of the incubation of tumor cell suspensions is utilized as a radioactive-biochemical method for pretherapeutic determination of the resistance in human cancers of the breast. Cell suspensions from primary tumors and metastases reveal individually different responses to cytostatics in vitro. It is possible, therewith, to differentiate two tumor collectives related to in vivo resistant or in vivo sensitive tumors. The responses of the primary lesion and the axillary lymphatic metastasis of the same carcinoma may in single cases also differ in vitro, according to clinical experience with the therapy of breast cancer. A distinct relation can be shown between the histological type of a carcinoma and its in vitro capacity of resistance.

  6. Caged molecular beacons: controlling nucleic acid hybridization with light.

    Science.gov (United States)

    Wang, Chunming; Zhu, Zhi; Song, Yanling; Lin, Hui; Yang, Chaoyong James; Tan, Weihong

    2011-05-28

    We have constructed a novel class of light-activatable caged molecular beacons (cMBs) that are caged by locking two stems with a photo-labile biomolecular interaction or covalent bond. With the cMBs, the nucleic acid hybridization process can be easily controlled with light, which offers the possibility for a high spatiotemporal resolution study of intracellular mRNAs. © The Royal Society of Chemistry 2011

  7. A New Analogue of Locked Cyclohexane Nucleic Acids

    Czech Academy of Sciences Publication Activity Database

    Šála, Michal; Dejmek, Milan; Procházková, Eliška; Hřebabecký, Hubert; Rybáček, Jiří; Dračínský, Martin; Novák, Pavel; Rosenbergová, Šárka; Rosenberg, Ivan; Nencka, Radim

    2015-01-01

    Roč. 47, č. 17 (2015), s. 2654-2662 ISSN 0039-7881 R&D Projects: GA ČR GPP207/12/P625; GA ČR GA13-26526S Institutional support: RVO:61388963 Keywords : nucleosides * bicyclic compounds * oligonucleotides * carbocycles * medicinal chemistry Subject RIV: CC - Organic Chemistry Impact factor: 2.652, year: 2015

  8. Nucleic acids in circulation

    Indian Academy of Sciences (India)

    Elevated blood levels of extracellular nucleic acids have been reported in various disease conditions; such as ageing and age-related degenerative disorders, cancer; acute and chronic inflammatory conditions, severe trauma and autoimmune disorders. In addition to genomic DNA and nucleosomes, mitochondrial DNA is ...

  9. Molecular Structure of Nucleic Acids

    Indian Academy of Sciences (India)

    Molecular Structure of Nucleic Acids. A Structure for Deoxyribose Nucleic Acid. J. D. Watson and F. H. C. Crick. Medical Research Council Unit for the Study of the Molecular Structure of Biological. Systems, Cavendish Laboratory, Cambridge. April 2. We wish to suggest a structure for the salt of deoxyribose nucleic acid ...

  10. Generation of “gigantic” ultra-short microwave pulses based on passive mode-locking effect in electron oscillators with saturable absorber in the feedback loop

    International Nuclear Information System (INIS)

    Ginzburg, N. S.; Denisov, G. G.; Vilkov, M. N.; Zotova, I. V.; Sergeev, A. S.

    2016-01-01

    A periodic train of powerful ultrashort microwave pulses can be generated in electron oscillators with a non-linear saturable absorber installed in the feedback loop. This method of pulse formation resembles the passive mode-locking widely used in laser physics. Nevertheless, there is a specific feature in the mechanism of pulse amplification when consecutive energy extraction from different fractions of a stationary electron beam takes place due to pulse slippage over the beam caused by the difference between the wave group velocity and the electron axial velocity. As a result, the peak power of generated “gigantic” pulses can exceed not only the level of steady-state generation but also, in the optimal case, the power of the driving electron beam.

  11. Short (

    NARCIS (Netherlands)

    Telleman, Gerdien; den Hartog, Laurens

    2013-01-01

    Aim: This systematic review assessed the implant survival rate of short (<10 mm) dental implants installed in partially edentulous patients. A case report of a short implant in the posterior region have been added. Materials and methods: A search was conducted in the electronic databases of MEDLINE

  12. Protective air lock

    International Nuclear Information System (INIS)

    Evans, H.W.

    1976-01-01

    A device suitable for preventing escape and subsequent circulation of toxic gases is described. An enclosure is sealed by a surrounding air lock, and an automatic mechanism partially evacuates the enclosure and air lock. The enclosure ventilating mechanism can be disconnected so that a relatively undisturbed atmosphere is created in the enclosure

  13. Bicycle Parking and Locking

    DEFF Research Database (Denmark)

    Larsen, Jonas

    2017-01-01

    . This article contributes with new insights into parking and locking - ‘moorings’ - to cycling literature. It presents an ethnography of ‘design moorings’ and practices associated with parking and locking bikes. The main case study is the very pro-cycling city of Copenhagen. Yet to explore what is unique about...

  14. Origin of nucleic acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of nucleic acids is the first event after the birth of membranes which made it possible to assure the perenniality of information. The complexity of these molecules has led some scientists to propose that they were not prebiotic but rather derived a more simple and achiral primitive ancestor. This hypothesis suggests that ribose possesses properties that allowed the formation of certain polysaccharides which evolved to RNA. The first step of the hypothesis is the selection and concentration of ribofuranose. This sugar has chelating properties and its alpha-ribofuranose is favoured in the chelating position. The density of the sugar with a heavy cation is greater than water and thus the complex can escape the UV radiation at the surface of the ocean. The particularity of ribose is to be able to form a homochiral regular array of these basic chelating structures with pyrophosphite. These arrays evolve towards the formation of polysaccharides (poly ribose phosphate) which have a very organized structure. These polysaccharides in turn evolve to RNA by binding of adenine and deoxyguanine which are HCN derivatives that can react with the polysaccharides. The primitive RNA is methylated and oxidized to form prebiotic RNA with adenosine, cytidine, 7methyl-guanosine and ribothymidine as nucleic bases. The pathway of biosynthesis of DNA form RNA will be studied. I suggest that the appearance of DNA results form the interaction between prebiotic double stranded RNA and proteins. DNA could be a product of RNA degradation by proteins. The catabolism of RNA to DNA requires a source of free radicals, protons and hydrides. RNA cannot produce free radicals, which are provided by the phenol group of the amino acid tyrosien. Protons are provided by the medium and hydrides are provided by 7-methyl-guanosine which can fix hydrides coming from hydrogen gas and donate them for the transformation of a riboside to a deoxyriboside. This pathway suggests that DNA appeared at

  15. Nucleic Acid-Based Nanoconstructs

    Science.gov (United States)

    Focuses on the design, synthesis, characterization, and development of spherical nucleic acid constructs as effective nanotherapeutic, single-entity agents for the treatment of glioblastoma multiforme and prostate cancers.

  16. Novel (Phenylethynyl)pyrene-LNA Constructs for Fluorescence SNP Sensing in Polymorphic Nucleic Acid Targets

    DEFF Research Database (Denmark)

    Astakhova, Irina Kira; Samokhina, Evgeniya; Babu, B Ravindra

    2012-01-01

    We describe fluorescent oligonucleotide probes labeled with novel (phenylethynyl)pyrene dyes attached to locked nucleic acids. Furthermore, we prove the utility of these probes for the effective detection of single-nucleotide polymorphisms in natural nucleic acids. High-affinity hybridization......DNA and RNA gene fragments. Target sequences were obtained by analysis of 200 clinical samples from patients currently receiving anti-HIV/AIDS combination therapy at the Russian Federal AIDS Center. Using these fluorescent oligonucleotides, we were able to detect the target mutation despite all the challenges...

  17. Identifying a base in a nucleic acid

    Science.gov (United States)

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  18. ''Old'' locked inflation

    International Nuclear Information System (INIS)

    Liu, Yang; Piao, Yun-Song; Si, Zong-Guo

    2009-01-01

    In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ''saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ''waterfall field'' φ. Instead of rolling down along the potential, the φ field will tunnel to end the inflation stage like in old inflation, by which the saddle inflation could be avoided. Further, we study a cascade of old locked inflation, which can be motivated by the string landscape. Our model is based on the consideration of making locked inflation feasible so as to give a working model without slow roll; It also can be seen as an effort to embed the old inflation in string landscape

  19. Quantum noise locking

    International Nuclear Information System (INIS)

    McKenzie, Kirk; Mikhailov, Eugeniy E; Goda, Keisuke; Lam, Ping Koy; Grosse, Nicolai; Gray, Malcolm B; Mavalvala, Nergis; McClelland, David E

    2005-01-01

    Quantum optical states which have no coherent amplitude, such as squeezed vacuum states, cannot rely on standard readout techniques to generate error signals for control of the quadrature phase. Here we investigate the use of asymmetry in the quadrature variances to obtain a phase-sensitive readout and to lock the phase of a squeezed vacuum state, a technique which we call noise locking (NL). We carry out a theoretical derivation of the NL error signal and the associated stability of the squeezed and anti-squeezed lock points. Experimental data for the NL technique both in the presence and absence of coherent fields are shown, including a comparison with coherent locking techniques. Finally, we use NL to enable a stable readout of the squeezed vacuum state on a homodyne detector

  20. LOCKS AND KEYS SERVICE

    CERN Multimedia

    Locks and Keys Service

    2002-01-01

    The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group

  1. Locke and botany.

    Science.gov (United States)

    Anstey, Peter R; Harris, Stephen A

    2006-06-01

    This paper argues that the English philosopher John Locke, who has normally been thought to have had only an amateurish interest in botany, was far more involved in the botanical science of his day than has previously been known. Through the presentation of new evidence deriving from Locke's own herbarium, his manuscript notes, journal and correspondence, it is established that Locke made a modest contribution to early modern botany. It is shown that Locke had close and ongoing relations with the Bobarts, keepers of the Oxford Botanic Garden, and that Locke distributed seeds and plant parts to other botanists, seeds of which the progeny almost certainly ended up in the most important herbaria of the period. Furthermore, it is claimed that the depth of Locke's interest in and practice of botany has a direct bearing on our understanding of his views on the correct method of natural philosophy and on the interpretation of his well known discussion of the nature of species in Book III of his Essay concerning human understanding.

  2. Soni-removal of nucleic acids from inclusion bodies.

    Science.gov (United States)

    Neerathilingam, Muniasamy; Mysore, Sumukh; Gandham, Sai Hari A

    2014-05-23

    Inclusion bodies (IBs) are commonly formed in Escherichia coli due to over expression of recombinant proteins in non-native state. Isolation, denaturation and refolding of these IBs is generally performed to obtain functional protein. However, during this process IBs tend to form non-specific interactions with sheared nucleic acids from the genome, thus getting carried over into downstream processes. This may hinder the refolding of IBs into their native state. To circumvent this, we demonstrate a methodology termed soni-removal which involves disruption of nucleic acid-inclusion body interaction using sonication; followed by solvent based separation. As opposed to conventional techniques that use enzymes and column-based separations, soni-removal is a cost effective alternative for complete elimination of buried and/or strongly bound short nucleic acid contaminants from IBs. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Accelerated digestion of nucleic acids by pepsin from the stomach of chicken.

    Science.gov (United States)

    Liu, Y; Zhang, Y; Guo, H; Wu, W; Dong, P; Liang, X

    2016-10-01

    Nucleic acids have become an important nutritional supplement in poultry feed; however, the digestion of nucleic acids in poultry is unclear. The objective of this study was to investigate the digestion of nucleic acids by chicken pepsin in vitro. The extracted pepsinogen from the stomach of the chicken was purified to homogeneity. Upon activation at pH 2.0, chicken pepsinogen was converted to its active form. Nucleic acids, including λ-DNA, salmon sperm DNA and single-strand DNA (ssDNA), can be used as substrates and digested into short-chain oligonucleotides by pepsin. Interestingly, the digestion of the nucleic acids was inhibited when pepsin was treated by alkaline solution (pH 8.0) or pepstatin A. Also, the digestion of the nucleic acids was not affected by the addition of haemoglobin or bovine serum albumin. The results suggested that nucleic acids could be digested by chicken pepsin. Thus pepsin may have a role in digesting nucleic acids in vivo. Nucleic acids added to poultry fed may be digested, starting from the stomach.

  4. Pressure locking test results

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1996-12-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  5. Pressure locking test results

    International Nuclear Information System (INIS)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D.

    1996-01-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, open-quotes Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.close quotes Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; we will publish the results of our thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions

  6. Histidine-Containing Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  7. Cleaving Double-Stranded DNA with Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1997-01-01

    Peptide nucleic acids and analogues of peptide nucleic acids are used to form duplex, triplex, and other structures with nucleic acids and to modify nucleic acids. The peptide nucleic acids and analogues thereof also are used to modulate protein activity through, for example, transcription arrest......, transcription initiation, and site specific cleavage of nucleic acids....

  8. Positioning and locking apparatus

    Science.gov (United States)

    Hayward, M.L.; Harper, W.H.

    1985-06-19

    A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

  9. Roller Locking Brake

    Science.gov (United States)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  10. Locks and Keys Service

    CERN Multimedia

    Claude Ducastel

    The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333

  11. Innovation and Lock-in

    DEFF Research Database (Denmark)

    Cantner, Uwe; Vannuccini, Simone

    2016-01-01

    This study focuses on a well-known but yet elusive concept: (technological) lock-in. We summarize what is known about the nature of lock-in and offer a critical view on history-dependent processes based on recent contributions to the literature. We discuss if lock-ins are really inescapable......, especially when innovation is concerned. Also, we address the question if lock-in is a well-defined concept at all. To offer a fresh view on lock-in and to tackle the issues just raised, we employ the replicator dynamics model. By making a parallel between monopolization in the replicator dynamics...... and the occurrence of lock-ins, we show that the convergence of a system to a given outcome can be reversed, under certain conditions. We highlight the need for a more precise demarcation of the conceptual boundaries of lock-in and path dependence, both from the formal and the empirical side, and suggest...

  12. Data port security lock

    Science.gov (United States)

    Quinby, Joseph D [Albuquerque, NM; Hall, Clarence S [Albuquerque, NM

    2008-06-24

    In a security apparatus for securing an electrical connector, a plug may be fitted for insertion into a connector receptacle compliant with a connector standard. The plug has at least one aperture adapted to engage at least one latch in the connector receptacle. An engagement member is adapted to partially extend through at least one aperture and lock to at least one structure within the connector receptacle.

  13. Avoiding lock-in

    DEFF Research Database (Denmark)

    Henriksen, Ingrid

    1999-01-01

    The paper investigates the initial phase of the cooperative organisation of agricultural processing firms in Denmark. It argues that the variations observed can be explained within the framework of the theory of industrial organisation. The focus is on the success of cooperative creameries. In 19...... of gathering information and of preserving and transporting a perishable product, were ideally suited to overcome the problems of potential lock-in and of asymmetric information...

  14. Multiplexed microfluidic approach for nucleic acid enrichment

    Science.gov (United States)

    VanderNoot, Victoria A.; Langevin, Stanley Alan; Bent, Zachary; Renzi, Ronald F.; Ferko, Scott M.; Van De Vreugde, James L.; Lane, Todd; Patel, Kamlesh; Branda, Steven

    2016-04-26

    A system for enhancing a nucleic acid sample may include a one pump, a denaturing chamber; a microfluidic hydroxyapatite chromatography device configured for performing hydroxyapatite chromatography on the nucleic acid sample, a sample collector, and tubing connecting the pump with the denaturing chamber, the hydroxyapatite chromatography device and the sample collector such that the pump may be used to move the nucleic acid sample from the denaturing chamber to the hydroxyapatite chromatography device and then to the sample collector.

  15. Double-Stranded Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2001-01-01

    A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker.......A novel class of compounds, known as peptide nucleic acids, form double-stranded structures with one another and with ssDNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  16. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Science.gov (United States)

    2010-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

  17. Crystallization and X-ray diffraction analysis of an ‘all-locked’ nucleic acid duplex derived from a tRNASer microhelix

    International Nuclear Information System (INIS)

    Behling, Katja; Eichert, André; Fürste, Jens P.; Betzel, Christian; Erdmann, Volker A.; Förster, Charlotte

    2009-01-01

    A completely ‘all-locked’ nucleic acid duplex was designed from an E. coli tRNA Ser microhelix. The helix consists exclusively of LNA building blocks and was crystallized. The crystals diffracted to 1.9 Å resolution. Modified nucleic acids are of great interest with respect to their nuclease resistance and enhanced thermostability. In therapeutical and diagnostic applications, such molecules can substitute for labile natural nucleic acids that are targeted against particular diseases or applied in gene therapy. The so-called ‘locked nucleic acids’ contain modified sugar moieties such as 2′-O,4′-C-methylene-bridged β-d-ribofuranose and are known to be very stable nucleic acid derivatives. The structure of locked nucleic acids in single or multiple LNA-substituted natural nucleic acids and in LNA–DNA or LNA–RNA heteroduplexes has been well investigated, but the X-ray structure of an ‘all-locked’ nucleic acid double helix has not been described to date. Here, the crystallization and X-ray diffraction data analysis of an ‘all-locked’ nucleic acid helix, which was designed as an LNA originating from a tRNA Ser microhelix RNA structure, is presented. The crystals belonged to space group C2, with unit-cell parameters a = 77.91, b = 40.74, c = 30.06 Å, β = 91.02°. A high-resolution and a low-resolution data set were recorded, with the high-resolution data showing diffraction to 1.9 Å resolution. The crystals contained two double helices per asymmetric unit, with a Matthews coefficient of 2.48 Å 3 Da −1 and a solvent content of 66.49% for the merged data

  18. Comparative evaluation of three commercial systems for nucleic acid extraction from urine specimens.

    Science.gov (United States)

    Tang, Yi-Wei; Sefers, Susan E; Li, Haijing; Kohn, Debra J; Procop, Gary W

    2005-09-01

    A nucleic acid extraction system that can handle small numbers of specimens with a short test turnaround time and short hands-on time is desirable for emergent testing. We performed a comparative validation on three systems: the MagNA Pure compact system (Compact), the NucliSens miniMAG extraction instrument (miniMAG), and the BioRobot EZ1 system (EZ1). A total of 75 urine specimens submitted for polyomavirus BK virus detection were used. The human beta-actin gene was detected on 75 (100%), 75 (100%), and 72 (96%) nucleic acid extracts prepared by the miniMAG, EZ1, and Compact, respectively. The miniMAG produced the highest quantity of nucleic acids and the best precision among the three systems. The agreement rate was 100% for BKV detection on nucleic acid extracts prepared by the three extraction systems. When a full panel of specimens was run, the hands-on time and test turnaround time were 105.7 and 121.1 min for miniMAG, 6.1 and 22.6 min for EZ1, and 7.4 and 33.7 min for Compact, respectively. The EZ1 and Compact systems processed automatic nucleic acid extraction properly, providing a good solution to the need for sporadic but emergent specimen detection. The miniMAG yielded the highest quantity of nucleic acids, suggesting that this system would be the best for specimens containing a low number of microorganisms of interest.

  19. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  20. Nucleic acid drugs: a novel approach

    African Journals Online (AJOL)

    Administrator

    Nucleic acid base sequence of proteins plays a crucial role in the expression of gene. The gene is responsible for the synthesis of proteins and these proteins, which are synthesized, are responsible for the biological process and also for dreadful diseases as well. Once if the nucleic acid sequence is altered, we would be ...

  1. Synthetic Procedures for Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  2. Breaking Carbon Lock-in

    DEFF Research Database (Denmark)

    Driscoll, Patrick Arthur

    2014-01-01

    This central focus of this paper is to highlight the ways in which path dependencies and increasing returns (network effects) serve to reinforce carbon lock-in in large-scale road transportation infrastructure projects. Breaking carbon lock-in requires drastic changes in the way we plan future...

  3. Multiplexed Detection of Attomoles of Nucleic Acids Using Fluorescent Nanoparticle Counting Platform.

    Science.gov (United States)

    Pei, Xiaojing; Yin, Haoyan; Lai, Tiancheng; Zhang, Junlong; Liu, Feng; Xu, Xiao; Li, Na

    2018-01-16

    The sensitive multiplexed detection of nucleic acids in a single sample by a simple manner is of pivotal importance for the diagnosis and therapy of human diseases. Herein, we constructed an automatic fluorescent nanoparticle (FNP) counting platform with a common fluorescence microscopic imaging setup for nonamplification multiplexed detection of attomoles of nucleic acids. Taking the advantages of the highly bright, multicolor emitting FNPs and magnetic separation, the platform enables sensitive multiplexed detection without the need for extra fluorescent labels. Quantification for multiplex DNAs, multiplex microRNAs (miRNA), as well as a DNA and miRNA mixture was achieved with a similar dynamic range, a limit of detection down to 5 amol (5 μL detection volume), and a 81-115% spike recovery from different biological sample matrices. In particular, the sensitivity for multiplex miRNA is by far among the highest without using amplification or the lock nucleic acid hybridization enhancement strategy. Results regarding miRNA-141 from four different cell lines were agreeable with those of the quantitative reverse transcription polymerase chain reaction. Simultaneous detection of miRNA-141 and miRNA-21 in four different cell lines yielded consistent results with publications, indicating the potential for monitoring multiplex miRNA expression associated with the collaborative regulation of important cellular events. This work expands the rule set of multiplex nucleic acid detection strategies and shows promising potential application in clinical diagnosis.

  4. Homodyne locking of a squeezer.

    Science.gov (United States)

    Heurs, M; Petersen, I R; James, M R; Huntington, E H

    2009-08-15

    We report on the successful implementation of an approach to locking the frequencies of an optical parametric oscillator (OPO)-based squeezed-vacuum source and its driving laser. The technique allows the simultaneous measurement of the phase shifts induced by a cavity, which may be used for the purposes of frequency locking, as well as the simultaneous measurement of the sub-quantum-noise-limited (sub-QNL) phase quadrature output of the OPO. The homodyne locking technique is cheap, easy to implement, and has the distinct advantage that subsequent homodyne measurements are automatically phase locked. The homodyne locking technique is also unique in that it is a sub-QNL frequency discriminator.

  5. Nucleic Acid Aptamers Against Proteases

    DEFF Research Database (Denmark)

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø

    2011-01-01

    , directed against blood coagulation factors, are in clinical trials as anticoagulant drugs. Several of the studies on protease-binding aptamers have been pioneering and trend-setting in the field. The work with protease-binding aptamers also demonstrates many interesting examples of non-standard selection......Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing...... small molecule protease inhibitors of sufficient specificity has proved a daunting task. Aptamers seem to represent a promising alternative. In our review, we concentrate on biochemical mechanisms of aptamer selection, proteinaptamer recognition, protease inhibition, and advantages of aptamers...

  6. Circulating nucleic acids and evolution.

    Science.gov (United States)

    Anker, Philippe; Stroun, Maurice

    2012-06-01

    J.B. Lamarck in 1809 was the first to present a theory of evolution. He proposed it was due to the adaptation of species to environmental changes, this adaptation being acquired by the offspring. In 1868, Darwin suggested that cells excrete gemmules, which circulate through the body and reach the gonads where they are transmitted to the next generation. His main argument came from graft hybrids. In the fifties and sixties, Russian geneticists, rejecting neo-Darwinism, said that acquired characteristics were the basis of evolution. The main experiments on which they based their theory were the transmission of hereditary characteristics by a special technique of grafting between two varieties of plants. We repeated this kind of experiment and also succeeded in obtaining hereditary modifications of the pupil plants that acquired some characteristics of the mentor variety. Rather than adopting the views of the Russian scientists, we suggested that DNA was circulating between the mentor and pupil plants. Hirata's group have shown recently, by using molecular techniques such as cloning, RFLP PCR and sequencing some genes of their graft hybrids of pepper plants, that transfer of informative molecules from the mentor to the pupil plant does exist. Nucleic acids are actively released by cells; they circulate in the body. They can transform oncogenically or trigger antibody response but the only genetic transformation showing that DNA can go from the soma to the germen comes from graft hybrids. This suggests that circulating nucleic acids, in this case DNA, like Darwin's gemmules, play a role in the mechanism of evolution.

  7. Molecular structure and interactions of nucleic acid components in nanoparticles: ab initio calculations

    International Nuclear Information System (INIS)

    Rubin, Yu.V.; Belous, L.F.

    2012-01-01

    Self-associates of nucleic acid components (stacking trimers and tetramers of the base pairs of nucleic acids) and short fragments of nucleic acids are nanoparticles (linear sizes of these particles are more than 10 A). Modern quantum-mechanical methods and softwares allow one to perform ab initio calculations of the systems consisting of 150-200 atoms with enough large basis sets (for example, 6-31G * ). The aim of this work is to reveal the peculiarities of molecular and electronic structures, as well as the energy features of nanoparticles of nucleic acid components. We had carried out ab initio calculations of the molecular structure and interactions in the stacking dimer, trimer, and tetramer of nucleic base pairs and in the stacking (TpG)(ApC) dimer and (TpGpC) (ApCpG) trimer of nucleotides, which are small DNA fragments. The performed calculations of molecular structures of dimers and trimers of nucleotide pairs showed that the interplanar distance in the structures studied is equal to 3.2 A on average, and the helical angle in a trimer is approximately equal to 30 o : The distance between phosphor atoms in neighboring chains is 13.1 A. For dimers and trimers under study, we calculated the horizontal interaction energies. The analysis of interplanar distances and angles between nucleic bases and their pairs in the calculated short oligomers of nucleic acid base pairs (stacking dimer, trimer, and tetramer) has been carried out. Studies of interactions in the calculated short oligomers showed a considerable role of the cross interaction in the stabilization of the structures. The contribution of cross interactions to the horizontal interactions grows with the length of an oligomer. Nanoparticle components get electric charges in nanoparticles. Longwave low-intensity bands can appear in the electron spectra of nanoparticles.

  8. Payload Launch Lock Mechanism

    Science.gov (United States)

    Young, Ken (Inventor); Hindle, Timothy (Inventor)

    2014-01-01

    A payload launch lock mechanism includes a base, a preload clamp, a fastener, and a shape memory alloy (SMA) actuator. The preload clamp is configured to releasibly restrain a payload. The fastener extends, along an axis, through the preload clamp and into the base, and supplies a force to the preload clamp sufficient to restrain the payload. The SMA actuator is disposed between the base and the clamp. The SMA actuator is adapted to receive electrical current and is configured, upon receipt of the electrical current, to supply a force that causes the fastener to elongate without fracturing. The preload clamp, in response to the fastener elongation, either rotates or pivots to thereby release the payload.

  9. Developing nucleic acid-based electrical detection systems

    Directory of Open Access Journals (Sweden)

    Gabig-Ciminska Magdalena

    2006-03-01

    Full Text Available Abstract Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and requirements for an ideal detector suitable for nucleic acid analysis include high sensitivity and high specificity protocol that can be completed in a relatively short time offering at the same time low detection limit. Moreover, systems that can be miniaturized and automated present a significant advantage over conventional technology, especially if detection is needed in the field. Electrical system technology for nucleic acid-based detection is an enabling mode for making miniaturized to micro- and nanometer scale bio-monitoring devices via the fusion of modern micro- and nanofabrication technology and molecular biotechnology. The electrical biosensors that rely on the conversion of the Watson-Crick base-pair recognition event into a useful electrical signal are advancing rapidly, and recently are receiving much attention as a valuable tool for microbial pathogen detection. Pathogens may pose a serious threat to humans, animal and plants, thus their detection and analysis is a significant element of public health. Although different conventional methods for detection of pathogenic microorganisms and their toxins exist and are currently being applied, improvements of molecular-based detection methodologies have changed these traditional detection techniques and introduced a new era of rapid, miniaturized and automated electrical chip detection technologies into pathogen identification sector. In this review some developments and current directions in

  10. 49 CFR 236.765 - Locking, mechanical.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus by...

  11. Inter-comb synchronization by mode-to-mode locking

    Science.gov (United States)

    Chun, Byung Jae; Kim, Young-Jin; Kim, Seung-Woo

    2016-08-01

    Two combs of fiber femtosecond lasers are synchronized through the optical frequency reference created by injection-locking of a diode laser to a single comb mode. Maintaining a mHz-level narrow linewidth, the optical frequency reference permits two combs to be stabilized by mode-to-mode locking with a relative stability of 1.52  ×  10-16 at 10 s with a frequency slip of 2.46 mHz. This inter-comb synchronization can be utilized for applications such as dual-comb spectroscopy or ultra-short pulse synthesis without extra narrow-linewidth lasers.

  12. Escaping carbon lock-in

    International Nuclear Information System (INIS)

    Unruh, G.C.

    2002-01-01

    This article explores the climate policy implications of the arguments made in ''Understanding carbon lock-in'' (Unruh, 2000), which posited that industrial countries have become locked-into fossil fuel-based energy systems through path dependent processes driven by increasing returns to scale. Carbon lock-in arises through technological, organizational, social and institutional co-evolution, ''culminating'' in what was termed as techno-institutional complex (TIC). In order to resolve the climate problem, an escape from the lock-in condition is required. However, due to the self-referential nature of TIC, escape conditions are unlikely to be generated internally and it is argued here that erogenous forces are probably required. (author)

  13. Globalizing carbon lock-in

    International Nuclear Information System (INIS)

    Unruh, Gregory C.; Carrillo-Hermosilla, Javier

    2006-01-01

    This paper extends the arguments surrounding carbon lock-in elaborated in Unruh (Energy Policy 28 (2000) 817; 30 (2002) 317) to countries currently undergoing industrialization. It argues that, for numerous reasons, industrializing countries are unlikely to leapfrog carbon intensive energy development. On the contrary, carbon lock-in may be globalizing and could further constrain climate change mitigation options. It is then argued that many policy recommendations ignore carbon lock-in, possibly limiting their potential for successful implementation. The paper then discusses four policy approaches that appear to have advantages given lock-in conditions. It is recognized, however, that relative ease of implementation does not necessarily equate with superiority. Instead, it is merely a path dependent outcome of past development decisions. Pursuing policies on the basis of relative implementation ease may help address the issue of climate change, but could also result in sub-optimal outcomes along other dimensions of sustainable development

  14. Research of mechanism of density lock

    International Nuclear Information System (INIS)

    Wang Shengfei; Yan Changqi; Gu Haifeng

    2010-01-01

    Mechanism of density lock was analyzed according to the work conditions of density lock. The results showed that: the stratification with no disturbance satisfied the work conditions of density lock; fluids between the stratification were not mixed at the condition of connected to each other; the density lock can be open automatically by controlled the pressure balance at the stratification. When disturbance existed, the stratification might be broken and mass would be transferred by convection. The stability of stratification can be enhanced by put the special structure in density lock to ensure the normal work of density lock. At last, the minimum of heat loss in density lock was also analyzed. (authors)

  15. Nanoparticulate systems for nucleic acid delivery

    NARCIS (Netherlands)

    Varkouhi, A.K.

    2011-01-01

    Development of carrier systems with controllable physicochemical and delivery properties has opened up the possibility of nanomedicines containing nucleic acids. In the last decades, much effort has been dedicated to two exciting approaches in biomedicine, namely gene and RNA interference

  16. Nucleic acids, proteins, and chirality

    Science.gov (United States)

    Usher, D. A.; Profy, A. T.; Walstrum, S. A.; Needels, M. C.; Bulack, S. C.; Lo, K. M.

    1984-01-01

    The present investigation is concerned with experimental results related, in one case, to the chirality of nucleotides, and, in another case, to the possibility of a link between the chirality of nucleic acids, and that of peptides. It has been found that aminoacylation of the 'internal' hydroxyl group of a dinucleoside monophosphate can occur stereoselectively. However, this reaction has not yet been made a part of a working peptide synthesis scheme. The formation and cleavage of oligonucleotides is considered. In the event of the formation of a helical complex between the oligonucleotide and the polymer, 1-prime,5-prime-bonds in the oligomer are found to become more resistant towards cleavage. The conditions required for peptide bond formation are examined, taking into account the known structures of RNA and possible mechanisms for prebiotic peptide bond formation. The possibility is considered that the 2-prime,5-prime-internucleotide linkage could have played an important part in the early days of biological peptide synthesis.

  17. Molecular radiobiology of nucleic acids

    Energy Technology Data Exchange (ETDEWEB)

    Fuciarelli, A F

    1987-01-01

    In addition to radiolytic adenine release, radiolysis of adenosine 5'-monophosphate, in the absence of oxygen, can result in the formation of 8-hydroxyadenosine 5'-monophosphate and both the (R)- and (S)-epimer of 8,5'-cycloadenosine 5'-monophosphate. The mononucleoside derivatives of these modified nucleotides were also observed in irradiated solutions of adenosine and in the enzyme hydrolysates of irradiated solutions of polyadenylic acid (poly A) using high-performance liquid chromatography (HPLC). In an effort to detect 8,5'-cyclo(deoxy) adenosine formation in irradiated nucleic acids, polyclonal antiserum were raised with specificity to the 8,5'-cycloadenosine 5'-monophosphate moiety and used in an enzyme-linked immunosorbent assay (ELISA). The 8,5'-cyclo(deoxy)adenosine moiety could be detected in nitrous oxide-saturated aqueous solutions containing unhydrolyzed poly A at 10 Gy and DNA at 200 Gy using the colorimetric ELISA. Correlation of product yield measured by ELISA with HPLC analysis of irradiated, enzyme-hydrolyzed solutions of poly A revealed that the ELISA was precisely reflecting changes in the combined yield of (R)- and (S)-8,5'-cycloadenosine.

  18. Hew Locke: House of Cards

    OpenAIRE

    Reckitt, Helena; Joyce, Julie; Locke, Hew

    2004-01-01

    ‘Hew Locke: House of Cards’ featured a selection of the artist's portraits of British royalty in various media, and his response to other trappings of the monarchy and empire. The show included works previously exhibited at the Luckman Gallery, Los Angeles, in tandem with a newly commissioned coat of arms, and other recent works. \\ud \\ud Locke draws from everyday sources, ranging from items found in London's Brixton Market to discount fabric shops and thrift stores. Other sources of inspirati...

  19. John locke on personal identity.

    Science.gov (United States)

    Nimbalkar, Namita

    2011-01-01

    John Locke speaks of personal identity and survival of consciousness after death. A criterion of personal identity through time is given. Such a criterion specifies, insofar as that is possible, the necessary and sufficient conditions for the survival of persons. John Locke holds that personal identity is a matter of psychological continuity. He considered personal identity (or the self) to be founded on consciousness (viz. memory), and not on the substance of either the soul or the body.

  20. John Locke on Personal Identity**

    OpenAIRE

    Nimbalkar, Namita

    2011-01-01

    John Locke speaks of personal identity and survival of consciousness after death. A criterion of personal identity through time is given. Such a criterion specifies, insofar as that is possible, the necessary and sufficient conditions for the survival of persons. John Locke holds that personal identity is a matter of psychological continuity. He considered personal identity (or the self) to be founded on consciousness (viz. memory), and not on the substance of either the soul or the body.

  1. Biomechanics of far cortical locking.

    Science.gov (United States)

    Bottlang, Michael; Feist, Florian

    2011-02-01

    The development of far cortical locking (FCL) was motivated by a conundrum: locked plating constructs provide inherently rigid stabilization, yet they should facilitate biologic fixation and secondary bone healing that relies on flexible fixation to stimulate callus formation. Recent studies have confirmed that the high stiffness of standard locked plating constructs can suppress interfragmentary motion to a level that is insufficient to reliably promote secondary fracture healing by callus formation. Furthermore, rigid locking screws cause an uneven stress distribution that may lead to stress fracture at the end screw and stress shielding under the plate. This review summarizes four key features of FCL constructs that have been shown to enhance fixation and healing of fractures: flexible fixation, load distribution, progressive stiffening, and parallel interfragmentary motion. Specifically, flexible fixation provided by FCL reduces the stiffness of a locked plating construct by 80% to 88% to actively promote callus proliferation similar to an external fixator. Load is evenly distributed between FCL screws to mitigate stress risers at the end screw. Progressive stiffening occurs by near cortex support of FCL screws and provides additional support under elevated loading. Finally, parallel interfragmentary motion by the S-shaped flexion of FCL screws promotes symmetric callus formation. In combination, these features of FCL constructs have been shown to induce more callus and to yield significantly stronger and more consistent healing compared with standard locked plating constructs. As such, FCL constructs function as true internal fixators by replicating the biomechanical behavior and biologic healing response of external fixators.

  2. Method of Identifying a Base in a Nucleic Acid

    Science.gov (United States)

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    1999-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  3. Hybridization and sequencing of nucleic acids using base pair mismatches

    Science.gov (United States)

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  4. Probe kit for identifying a base in a nucleic acid

    Science.gov (United States)

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2001-01-01

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  5. Outdraft at Lock Approach, Tom Bevill Lock and Dam, Alabama: Hydraulic Model Investigation

    National Research Council Canada - National Science Library

    Lynch, Gary

    2001-01-01

    .... The lock is connected to the dam with a 150-ft abutment wall. A strong crosscurrent or outdraft existing in and around the upstream lock entrance causes difficulty for tow traffic navigating the lock...

  6. Evaluation of locked nucleic acid-modified small interfering RNA in vitro and in vivo

    NARCIS (Netherlands)

    Mook, Olaf R.; Baas, Frank; de Wissel, Marit B.; Fluiter, Kees

    2007-01-01

    RNA interference has become widely used as an experimental tool to study gene function. In addition, small interfering RNA (siRNA) may have great potential for the treatment of diseases. Recently, it was shown that siRNA can be used to mediate gene silencing in mouse models. Locally administered

  7. Locked nucleic acid inhibits amplification of contaminating DNA in real-time PCR

    DEFF Research Database (Denmark)

    Hummelshoj, Lone; Ryder, Lars P; Madsen, Hans O

    2005-01-01

    and real-time PCR, the addition of LNA showed blocking of the amplification of genomic XBP1 but not cDNA XBP1. To test the effect of melting temperature (Tm) on the LNA, we investigated the number of LNA nucleotides that could be replaced with DNA nucleotides and still retain the blocking activity. More...

  8. Efficient reverse transcription using locked nucleic acid nucleotides towards the evolution of nuclease resistant RNA aptamers

    DEFF Research Database (Denmark)

    Crouzier, Lucile; Dubois, Camille; Edwards, Stacey L

    2012-01-01

    We found that SuperScript® III Reverse Transcriptase is an efficient enzyme for the recognition of LNA nucleotides, making it a prime candidate to be used in de novo selection of LNA containing RNA aptamers....

  9. Assessing carbon lock-in

    International Nuclear Information System (INIS)

    Erickson, Peter; Kartha, Sivan; Lazarus, Michael; Tempest, Kevin

    2015-01-01

    The term ‘carbon lock-in’ refers to the tendency for certain carbon-intensive technological systems to persist over time, ‘locking out’ lower-carbon alternatives, and owing to a combination of linked technical, economic, and institutional factors. These technologies may be costly to build, but relatively inexpensive to operate and, over time, they reinforce political, market, and social factors that make it difficult to move away from, or ‘unlock’ them. As a result, by investing in assets prone to lock-in, planners and investors restrict future flexibility and increase the costs of achieving agreed climate protection goals. Here, we develop a straight-forward approach to assess the speed, strength, and scale of carbon lock-in for major energy-consuming assets in the power, buildings, industry, and transport sectors. We pilot the approach at the global level, finding that carbon lock-in is greatest, globally, for coal power plants, gas power plants, and oil-based vehicles. The approach can be readily applied at the national or regional scale, and may be of particular relevance to policymakers interested in enhancing flexibility in their jurisdictions for deeper emissions cuts in the future, and therefore in limiting the future costs associated with ‘stranded assets’. (letter)

  10. Coupled optical resonance laser locking.

    Science.gov (United States)

    Burd, S C; du Toit, P J W; Uys, H

    2014-10-20

    We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to coupled transitions of ions in the same spectroscopic sample, by detecting only the absorption of the UV laser. Separate signals for locking the different lasers are obtained by modulating each laser at a different frequency and using lock-in detection of a single photodiode signal. Experimentally, we simultaneously lock a 369 nm and a 935 nm laser to the (2)S(1/2) → (2)(P(1/2) and (2)D(3/2) → (3)D([3/2]1/2) transitions, respectively, of Yb(+) ions generated in a hollow cathode discharge lamp. Stabilized lasers at these frequencies are required for cooling and trapping Yb(+) ions, used in quantum information and in high precision metrology experiments. This technique should be readily applicable to other ion and neutral atom systems requiring multiple stabilized lasers.

  11. Detection of nucleic acid sequences by invader-directed cleavage

    Science.gov (United States)

    Brow, Mary Ann D.; Hall, Jeff Steven Grotelueschen; Lyamichev, Victor; Olive, David Michael; Prudent, James Robert

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The 5' nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based by charge.

  12. Automatic locking knee brace joint

    Science.gov (United States)

    Weddendorf, Bruce (Inventor)

    1995-01-01

    This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis together. In addition, the tang is biased away from the clevis. Consequently, when there is no axial force (i.e., body weight) on the tang, the tang is free to pivot within the clevis. However, when an axial force is exerted on the tang, the tang is pushed into the clevis, both sets of teeth engage, and the tang and the clevis lock together.

  13. Novel Biochip Platform for Nucleic Acid Analysis

    Directory of Open Access Journals (Sweden)

    Juan J. Diaz-Mochon

    2012-06-01

    Full Text Available This manuscript describes the use of a novel biochip platform for the rapid analysis/identification of nucleic acids, including DNA and microRNAs, with very high specificity. This approach combines a unique dynamic chemistry approach for nucleic acid testing and analysis developed by DestiNA Genomics with the STMicroelectronics In-Check platform, which comprises two microfluidic optimized and independent PCR reaction chambers, and a sequential microarray area for nucleic acid capture and identification by fluorescence. With its compact bench-top “footprint” requiring only a single technician to operate, the biochip system promises to transform and expand routine clinical diagnostic testing and screening for genetic diseases, cancers, drug toxicology and heart disease, as well as employment in the emerging companion diagnostics market.

  14. PWR integral tie plate and locking mechanism

    International Nuclear Information System (INIS)

    Flora, B.S.; Osborne, J.L.

    1980-01-01

    A locking mechanism for securing an upper tie plate to the tie rods of a nuclear fuel bundle is described. The mechanism includes an upper tie plate assembly and locking sleeves fixed to the ends of the tie rods. The tie plate is part of the upper tie plate assembly and is secured to the fuel bundle by securing the entire upper tie plate assembly to the locking sleeves fixed to the tie rods. The assembly includes, in addition to the tie plate, locking nuts for engaging the locking sleeves, retaining sleeves to operably connect the locking nuts to the assembly, a spring biased reaction plate to restrain the locking nuts in the locked position and a means to facilitate the removal of the entire assembly as a unit from the fuel bundle

  15. Fractures of the distal tibia treated with polyaxial locking plating.

    Science.gov (United States)

    Gao, Hong; Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

    2009-03-01

    We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial infections and evidence of delayed wound healing. Using the American Orthopaedic Foot and Ankle Society ankle score, the average functional score was 87.3 points (of 100 total possible points). Our results show the polyaxial locking plates, which offer more fixation versatility, may be a reasonable treatment option for distal tibia fractures with very short metaphyseal segments.

  16. The variable finesse locking technique

    International Nuclear Information System (INIS)

    Acernese, F; Al-Shourbagy, M

    2006-01-01

    Virgo is a power recycled Michelson interferometer, with 3 km long Fabry-Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark fringe. In this way, a good fraction of light escapes through the antisymmetric port and the power build-up inside the recycling cavity is extremely low. The benefit is that all the degrees of freedom are controlled when they are almost decoupled, and the linewidth of the recycling cavity is large. The interferometer is then adiabatically brought on to the dark fringe. This technique is referred to as variable finesse, since the recycling cavity is considered as a variable finesse Fabry-Perot. This technique has been widely tested and allows us to reach the dark fringe in few minutes, in an essentially deterministic way

  17. Coupled optical resonance laser locking

    CSIR Research Space (South Africa)

    Burd, CC

    2014-10-01

    Full Text Available We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to coupled transitions of ions in the same spectroscopic sample, by detecting only the absorption of the UV laser. Separate signals for locking the different...

  18. Advances phase-lock techniques

    CERN Document Server

    Crawford, James A

    2008-01-01

    From cellphones to micrprocessors, to GPS navigation, phase-lock techniques are utilized in most all modern electronic devices. This high-level book takes a systems-level perspective, rather than circuit-level, which differentiates it from other books in the field.

  19. 49 CFR 236.705 - Bar, locking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Bar, locking. 236.705 Section 236.705..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.705 Bar, locking. A bar in an interlocking machine to which the locking dogs are attached. ...

  20. Bilateral locked facets in the thoracic spine

    NARCIS (Netherlands)

    M.H.A. Willems; Braakman, R. (Reinder); B. van Linge (Bert)

    1984-01-01

    textabstractTwo cases of traumatic bilateral locked facets in the thoracic spine are reported. Both patients had only minor neurological signs. They both made a full neurological recovery after surgical reduction of the locked facets. Bilateral locked facets are very uncommon in the thoracic spine.

  1. 49 CFR 236.761 - Locking, electric.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means of...

  2. 49 CFR 236.105 - Electric lock.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except forced...

  3. 49 CFR 236.757 - Lock, electric.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric. 236.757 Section 236.757... Lock, electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  4. 49 CFR 236.768 - Locking, time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined time...

  5. Diode-pumped mode-locked femtosecond Tm:CLNGG disordered crystal laser.

    Science.gov (United States)

    Ma, J; Xie, G Q; Gao, W L; Yuan, P; Qian, L J; Yu, H H; Zhang, H J; Wang, J Y

    2012-04-15

    A diode-end-pumped passively mode-locked femtosecond Tm-doped calcium lithium niobium gallium garnet (Tm:CLNGG) disordered crystal laser was demonstrated for the first time to our knowledge. With a 790 nm laser diode pumping, stable CW mode-locking operation was obtained by using a semiconductor saturable absorber mirror. The disordered crystal laser generated mode-locked pulses as short as 479 fs, with an average output power of 288 mW, and repetition rate of 99 MHz in 2 μm spectral region. © 2012 Optical Society of America

  6. Tidal locking of habitable exoplanets

    Science.gov (United States)

    Barnes, Rory

    2017-12-01

    Potentially habitable planets can orbit close enough to their host star that the differential gravity across their diameters can produce an elongated shape. Frictional forces inside the planet prevent the bulges from aligning perfectly with the host star and result in torques that alter the planet's rotational angular momentum. Eventually the tidal torques fix the rotation rate at a specific frequency, a process called tidal locking. Tidally locked planets on circular orbits will rotate synchronously, but those on eccentric orbits will either librate or rotate super-synchronously. Although these features of tidal theory are well known, a systematic survey of the rotational evolution of potentially habitable exoplanets using classic equilibrium tide theories has not been undertaken. I calculate how habitable planets evolve under two commonly used models and find, for example, that one model predicts that the Earth's rotation rate would have synchronized after 4.5 Gyr if its initial rotation period was 3 days, it had no satellites, and it always maintained the modern Earth's tidal properties. Lower mass stellar hosts will induce stronger tidal effects on potentially habitable planets, and tidal locking is possible for most planets in the habitable zones of GKM dwarf stars. For fast-rotating planets, both models predict eccentricity growth and that circularization can only occur once the rotational frequency is similar to the orbital frequency. The orbits of potentially habitable planets of very late M dwarfs ([InlineEquation not available: see fulltext.]) are very likely to be circularized within 1 Gyr, and hence, those planets will be synchronous rotators. Proxima b is almost assuredly tidally locked, but its orbit may not have circularized yet, so the planet could be rotating super-synchronously today. The evolution of the isolated and potentially habitable Kepler planet candidates is computed and about half could be tidally locked. Finally, projected TESS planets

  7. Fractures of the Distal Tibia Treated with Polyaxial Locking Plating

    OpenAIRE

    Gao, Hong; Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

    2008-01-01

    We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial in...

  8. 49 CFR 236.766 - Locking, movable bridge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. ...

  9. Chemical consequences of irradiating nucleic acids

    International Nuclear Information System (INIS)

    Ward, J.F.

    1976-01-01

    On the basis of literature data, a discussion is presented of the DNA damage which would be produced in a cellular environment and an attempt is made to place this damage in perspective as a potential hazard in food irradiation. The topics discussed are radiation damage mechanisms, OH reactions with DNA, base products, sugar products, and evaluation of damage from irradiated nucleic acids

  10. Miniaturized isothermal nucleic acid amplification, a review.

    Science.gov (United States)

    Asiello, Peter J; Baeumner, Antje J

    2011-04-21

    Micro-Total Analysis Systems (µTAS) for use in on-site rapid detection of DNA or RNA are increasingly being developed. Here, amplification of the target sequence is key to increasing sensitivity, enabling single-cell and few-copy nucleic acid detection. The several advantages to miniaturizing amplification reactions and coupling them with sample preparation and detection on the same chip are well known and include fewer manual steps, preventing contamination, and significantly reducing the volume of expensive reagents. To-date, the majority of miniaturized systems for nucleic acid analysis have used the polymerase chain reaction (PCR) for amplification and those systems are covered in previous reviews. This review provides a thorough overview of miniaturized analysis systems using alternatives to PCR, specifically isothermal amplification reactions. With no need for thermal cycling, isothermal microsystems can be designed to be simple and low-energy consuming and therefore may outperform PCR in portable, battery-operated detection systems in the future. The main isothermal methods as miniaturized systems reviewed here include nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), helicase-dependent amplification (HDA), rolling circle amplification (RCA), and strand displacement amplification (SDA). Also, important design criteria for the miniaturized devices are discussed. Finally, the potential of miniaturization of some new isothermal methods such as the exponential amplification reaction (EXPAR), isothermal and chimeric primer-initiated amplification of nucleic acids (ICANs), signal-mediated amplification of RNA technology (SMART) and others is presented.

  11. Recent progress in nucleic acids isotachophoresis

    Czech Academy of Sciences Publication Activity Database

    Datinská, Vladimíra; Voráčová, Ivona; Schlecht, U.; Berka, J.; Foret, František

    2018-01-01

    Roč. 41, č. 1 (2018), s. 236-247 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : isotachophoresis * nucleic acids * sample preparation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.557, year: 2016

  12. Nucleic acid secondary structure prediction and display.

    OpenAIRE

    Stüber, K

    1986-01-01

    A set of programs has been developed for the prediction and display of nucleic acid secondary structures. Information from experimental data can be used to restrict or enforce secondary structural elements. The predictions can be displayed either on normal line printers or on graphic devices like plotters or graphic terminals.

  13. Recent progress in nucleic acids isotachophoresis

    Czech Academy of Sciences Publication Activity Database

    Datinská, Vladimíra; Voráčová, Ivona; Schlecht, U.; Berka, J.; Foret, František

    2018-01-01

    Roč. 41, č. 1 (2018), s. 236-247 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : isotachophoresis * nucleic acid s * sample preparation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.557, year: 2016

  14. Smart Sensing Based on DNA-Metal Interaction Enables a Label-Free and Resettable Security Model of Electrochemical Molecular Keypad Lock.

    Science.gov (United States)

    Du, Yan; Han, Xu; Wang, Chenxu; Li, Yunhui; Li, Bingling; Duan, Hongwei

    2018-01-26

    Recently, molecular keypad locks have received increasing attention. As a new subgroup of smart biosensors, they show great potential for protecting information as a molecular security data processor, rather than merely molecular recognition and quantitation. Herein, label-free electrochemically transduced Ag + and cysteine (Cys) sensors were developed. A molecular keypad lock model with reset function was successfully realized based on the balanced interaction of metal ion with its nucleic acid and chemical ligands. The correct input of "1-2-3" (i.e., "Ag + -Cys-cDNA") is the only password of such molecular keypad lock. Moreover, the resetting process of either correct or wrong input order could be easily made by Cys, buffer, and DI water treatment. Therefore, our system provides an even smarter system of molecular keypad lock, which could inhibit illegal access of unauthorized users, holding great promise in information protection at the molecular level.

  15. Performance of arm locking in LISA

    International Nuclear Information System (INIS)

    McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

    2009-01-01

    For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time

  16. Analysis on fault current limiting and recovery characteristics of a flux-lock type SFCL with an isolated transformer

    International Nuclear Information System (INIS)

    Ko, Seckcheol; Lim, Sung-Hun; Han, Tae-Hee

    2013-01-01

    Highlights: ► Countermeasure to reduce the power burden of HTSC element consisting of the flux-lock type SFCL was studied. ► The power burden of HTSC element could be decreased by using the isolated transformer. ► The SFCL designed with the additive polarity winding could be confirmed to cause less power burden of the HTSC element. -- Abstract: The flux-lock type superconducting fault current limiter (SFCL) can quickly limit the fault current shortly after the short circuit occurs and recover the superconducting state after the fault removes. However, the superconducting element comprising the flux-lock type SFCL can be destructed when the high fault current passes through the SFCL. Therefore, the countermeasure to control the fault current and protect the superconducting element is required. In this paper, the flux-lock type SFCL with an isolated transformer, which consists of two parallel connected coils on an iron core and the isolated transformer connected in series with one of two coils, was proposed and the short-circuit experimental device to analyze the fault current limiting and the recovery characteristics of the flux-lock type SFCL with the isolated transformer were constructed. Through the short-circuit tests, the flux-lock type SFCL with the isolated transformer was confirmed to perform more effective fault current limiting and recovery operation compared to the flux-lock type SFCL without the isolated transformer from the viewpoint of the quench occurrence and the recovery time of the SFCL

  17. Is John Locke a democrat?

    DEFF Research Database (Denmark)

    Svensson, Palle

      Over recent years there has been a tendency to present John Locke as an equalitarian democrat (Ashcraft) and being close to the political views of the levellers (Waldron). This is not a completely new interpretation (Kendall, 1941), but contrasts with the prevalent view presented in textbooks (......, criteria for a democratic process, and the institutions of polyarchy. The conclusion has implications for the relationship between political liberalism and constitutionalism on the one hand and democracy on the other....

  18. Nucleic Acid Aptamers Against Biotoxins: A New Paradigm Toward the Treatment and Diagnostic Approach

    DEFF Research Database (Denmark)

    Lauridsen, Lasse Holm; Veedu, Rakesh N.

    2012-01-01

    Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody-based therape......Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody......-based therapeutic and diagnostic approach currently employed against biotoxins pose major limitations such as the requirement of a live animal for the in vivo enrichment of the antibody species, decreased stability, high production cost, and side effects. Aptamer technology is a viable alternative that can be used...

  19. Dynamics of Tidally Locked, Ultrafast Rotating Atmospheres

    Science.gov (United States)

    Tan, Xianyu; Showman, Adam P.

    2017-10-01

    Tidally locked gas giants, which exhibit a novel regime of day-night thermal forcing and extreme stellar irradiation, are typically in several-day orbits, implying slow rotation and a modest role for rotation in the atmospheric circulation. Nevertheless, there exist a class of gas-giant, highly irradiated objects - brown dwarfs orbiting white dwarfs in extremely tight orbits - whose orbital and hence rotation periods are as short as 1-2 hours. Spitzer phase curves and other observations have already been obtained for this fascinating class of objects, which raise fundamental questions about the role of rotation in controlling the circulation. So far, most modeling studies have investigated rotation periods exceeding a day, as appropriate for typical hot Jupiters. In this work we investigate the dynamics of tidally locked atmospheres in shorter rotation periods down to about two hours. With increasing rotation rate (decreasing rotation period), we show that the width of the equatorial eastward jet decreases, consistent with the narrowing of wave-mean-flow interacting region due to decrease of the equatorial deformation radius. The eastward-shifted equatorial hot spot offset decreases accordingly, and the westward-shifted hot regions poleward of the equatorial jet associated with Rossby gyres become increasingly distinctive. At high latitudes, winds becomes weaker and more geostrophic. The day-night temperature contrast becomes larger due to the stronger influence of rotation. Our simulated atmospheres exhibit small-scale variability, presumably caused by shear instability. Unlike typical hot Jupiters, phase curves of fast-rotating models show an alignment of peak flux to secondary eclipse. Our results have important implications for phase curve observations of brown dwarfs orbiting white dwarfs in ultra tight orbits.

  20. Digital Microfluidics for Nucleic Acid Amplification

    Directory of Open Access Journals (Sweden)

    Beatriz Coelho

    2017-06-01

    Full Text Available Digital Microfluidics (DMF has emerged as a disruptive methodology for the control and manipulation of low volume droplets. In DMF, each droplet acts as a single reactor, which allows for extensive multiparallelization of biological and chemical reactions at a much smaller scale. DMF devices open entirely new and promising pathways for multiplex analysis and reaction occurring in a miniaturized format, thus allowing for healthcare decentralization from major laboratories to point-of-care with accurate, robust and inexpensive molecular diagnostics. Here, we shall focus on DMF platforms specifically designed for nucleic acid amplification, which is key for molecular diagnostics of several diseases and conditions, from pathogen identification to cancer mutations detection. Particular attention will be given to the device architecture, materials and nucleic acid amplification applications in validated settings.

  1. Rapid hybridization of nucleic acids using isotachophoresis

    Science.gov (United States)

    Bercovici, Moran; Han, Crystal M.; Liao, Joseph C.; Santiago, Juan G.

    2012-01-01

    We use isotachophoresis (ITP) to control and increase the rate of nucleic acid hybridization reactions in free solution. We present a new physical model, validation experiments, and demonstrations of this assay. We studied the coupled physicochemical processes of preconcentration, mixing, and chemical reaction kinetics under ITP. Our experimentally validated model enables a closed form solution for ITP-aided reaction kinetics, and reveals a new characteristic time scale which correctly predicts order 10,000-fold speed-up of chemical reaction rate for order 100 pM reactants, and greater enhancement at lower concentrations. At 500 pM concentration, we measured a reaction time which is 14,000-fold lower than that predicted for standard second-order hybridization. The model and method are generally applicable to acceleration of reactions involving nucleic acids, and may be applicable to a wide range of reactions involving ionic reactants. PMID:22733732

  2. Nucleic acid protocols: Extraction and optimization

    Directory of Open Access Journals (Sweden)

    Saeed El-Ashram

    2016-12-01

    Full Text Available Yield and quality are fundamental features for any researchers during nucleic acid extraction. Here, we describe a simplified, semi-unified, effective, and toxic material free protocol for extracting DNA and RNA from different prokaryotic and eukaryotic sources exploiting the physical and chemical properties of nucleic acids. Furthermore, this protocol showed that DNA and RNA are under triple protection (i.e. EDTA, SDS and NaCl during lysis step, and this environment is improper for RNase to have DNA liberated of RNA and even for DNase to degrade the DNA. Therefore, the complete removal of RNA under RNase influence is achieved when RNase is added after DNA extraction, which gives optimal quality with any protocols. Similarly, DNA contamination in an isolated RNA is degraded by DNase to obtain high-quality RNA. Our protocol is the protocol of choice in terms of simplicity, recovery time, environmental safety, amount, purity, PCR and RT-PCR applicability.

  3. Nucleic acid compositions and the encoding proteins

    Science.gov (United States)

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  4. Nucleic Acid Templated Reactions for Chemical Biology.

    Science.gov (United States)

    Di Pisa, Margherita; Seitz, Oliver

    2017-06-21

    Nucleic acid directed bioorthogonal reactions offer the fascinating opportunity to unveil and redirect a plethora of intracellular mechanisms. Nano- to picomolar amounts of specific RNA molecules serve as templates and catalyze the selective formation of molecules that 1) exert biological effects, or 2) provide measurable signals for RNA detection. Turnover of reactants on the template is a valuable asset when concentrations of RNA templates are low. The idea is to use RNA-templated reactions to fully control the biodistribution of drugs and to push the detection limits of DNA or RNA analytes to extraordinary sensitivities. Herein we review recent and instructive examples of conditional synthesis or release of compounds for in cellulo protein interference and intracellular nucleic acid imaging. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  5. Construction of tunable peptide nucleic acid junctions.

    Science.gov (United States)

    Duan, Tanghui; He, Liu; Tokura, Yu; Liu, Xin; Wu, Yuzhou; Shi, Zhengshuang

    2018-03-15

    We report here the construction of 3-way and 4-way peptide nucleic acid (PNA) junctions as basic structural units for PNA nanostructuring. The incorporation of amino acid residues into PNA chains makes PNA nanostructures with more structural complexity and architectural flexibility possible, as exemplified by building 3-way PNA junctions with tunable nanopores. Given that PNA nanostructures have good thermal and enzymatic stabilities, they are expected to have broad potential applications in biosensing, drug delivery and bioengineering.

  6. Optimizing the specificity of nucleic acid hybridization.

    Science.gov (United States)

    Zhang, David Yu; Chen, Sherry Xi; Yin, Peng

    2012-01-22

    The specific hybridization of complementary sequences is an essential property of nucleic acids, enabling diverse biological and biotechnological reactions and functions. However, the specificity of nucleic acid hybridization is compromised for long strands, except near the melting temperature. Here, we analytically derived the thermodynamic properties of a hybridization probe that would enable near-optimal single-base discrimination and perform robustly across diverse temperature, salt and concentration conditions. We rationally designed 'toehold exchange' probes that approximate these properties, and comprehensively tested them against five different DNA targets and 55 spurious analogues with energetically representative single-base changes (replacements, deletions and insertions). These probes produced discrimination factors between 3 and 100+ (median, 26). Without retuning, our probes function robustly from 10 °C to 37 °C, from 1 mM Mg(2+) to 47 mM Mg(2+), and with nucleic acid concentrations from 1 nM to 5 µM. Experiments with RNA also showed effective single-base change discrimination.

  7. Phase-locked Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1991-01-01

    Detailed experimental characterization of the phase-locking at both DC and at microwave frequencies is presented for two closely spaced Josephson soliton (fluxon) oscillators. In the phase-locked state, the radiated microwave power exhibited an effective gain. With one common bias source......, a frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. The interacting soliton oscillators were modeled by two inductively coupled nonlinear transmission lines...

  8. Hydrostatic self-locking bevel differential gear; Hydrostatisch selbstsperrendes Kegelraddifferentialgetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Kalmbach, K.

    2001-07-01

    The product range of the rail vehicle industry comprises the construction of railroad material for long-distance and short-distance transport. This includes, for example, locomotives and cars, subway, light railway and tramway cars as well as rail vehicle equipment. The development of the industry is determined by the demand for transport services and government actions for the extension of railways and procurement of suitable vehicle types. In contrast to road vehicles, differential gears are only used in a negligible percentage of rail vehicles. Primarily in the short-distance rail transport sector, the demand for differential gears is growing due to increased drive power, smaller wheel diameters, lower vehicle mass with higher load capacity, the introduction of low-floor technology as well as the requirement of employing ever more quiet vehicles. In hydrostatic self-locking differential gears, oil is supplied to the gears within the differential gearbox. They only rotate relative to each other when the differential gear performs a compensation movement. In this case, oil is transported in the tooth space to the meshing of the gears, where it is displaced due to the meshing and must drain through tight gaps. The pressure generated by this process acts against the compensation movement of the gear, and the drive torque is transmitted to the wheel that has the higher friction. The achievable locking torque is linearly dependent on the differential speed of the drive wheel. This locking effect is achieved without wear-prone components and works automatically without active external intervention. The design space required corresponds to that of conventional differential gears, as the locking effect is integrated in the existing design. (orig.)

  9. Use of Nucleic Acid Analogs for the Study of Nucleic Acid Interactions

    Directory of Open Access Journals (Sweden)

    Shu-ichi Nakano

    2011-01-01

    Full Text Available Unnatural nucleosides have been explored to expand the properties and the applications of oligonucleotides. This paper briefly summarizes nucleic acid analogs in which the base is modified or replaced by an unnatural stacking group for the study of nucleic acid interactions. We also describe the nucleoside analogs of a base pair-mimic structure that we have examined. Although the base pair-mimic nucleosides possess a simplified stacking moiety of a phenyl or naphthyl group, they can be used as a structural analog of Watson-Crick base pairs. Remarkably, they can adopt two different conformations responding to their interaction energies, and one of them is the stacking conformation of the nonpolar aromatic group causing the site-selective flipping of the opposite base in a DNA double helix. The base pair-mimic nucleosides can be used to study the mechanism responsible for the base stacking and the flipping of bases out of a nucleic acid duplex.

  10. Microcontroller-based locking in optics experiments

    International Nuclear Information System (INIS)

    Huang, K.; Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J.

    2014-01-01

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments

  11. Safety lock for radiography exposure device

    International Nuclear Information System (INIS)

    Gaines, T.M.

    1982-01-01

    A safety lock for securing a radiation source in a radiography exposure device is disclosed. The safety lock prevents the inadvertent extension of the radiation source from the exposure device. The exposure devices are used extensively in industry for nondestructive testing of metal materials for defect. Unnecessary exposure of the radiographer or operator occurs not infrequently due to operator's error in believing that the radiation source is secured in the exposure device when, in fact, it is not. The present invention solves this problem of unnecessary exposure by releasingly trapping the radiation source in the shield of the radiography exposure device each time the source is retracted therein so that it is not inadvertently extended therefrom without the operator resetting the safety lock, thereby releasing the radiation source. Further, the safety lock includes an indicator which indicates when the source is trapped in the exposure device and also when it is untrapped. The safety lock is so designed that it does not prevent the return of the source to the trapped, shielded position in the exposure device. Further the safety lock includes a key means for locking the radiation source in the trapped position. The key means cannot be actuated until said radiation source is in said trapped position to further insure the safety lock cannot be inadvertently locked with the source untrapped and thus still extendable from the exposure device

  12. Phase locking between Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1990-01-01

    We report observations of phase-locking phenomena between two Josephson soliton (fluxon) oscillators biased in self-resonant modes. The locking strength was measured as a function of bias conditions. A frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. Two coupled...... perturbed sine-Gordon equations were derived from an equivalent circuit consisting of inductively coupled, nonlinear, lossy transmission lines. These equations were solved numerically to find the locking regions. Good qualitative agreement was found between the experimental results and the calculations...

  13. Microcontroller-based locking in optics experiments.

    Science.gov (United States)

    Huang, K; Le Jeannic, H; Ruaudel, J; Morin, O; Laurat, J

    2014-12-01

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

  14. Microcontroller-based locking in optics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Huang, K. [Laboratoire Kastler Brossel, UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Collège de France, 4 place Jussieu, 75005 Paris (France); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J., E-mail: julien.laurat@upmc.fr [Laboratoire Kastler Brossel, UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Collège de France, 4 place Jussieu, 75005 Paris (France)

    2014-12-15

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

  15. Double pass locking and spatial mode locking for gravitational wave detectors

    CERN Document Server

    Cusack, B J; Slagmolen, B; Vine, G D; Gray, M B; McClelland, D E

    2002-01-01

    We present novel techniques for overcoming problems relating to the use of high-power lasers in mode cleaner cavities for second generation laser interferometric gravitational wave detectors. Rearranging the optical components into a double pass locking regime can help to protect locking detectors from damage. Modulator thermal lensing can be avoided by using a modulation-free technique such as tilt locking, or its recently developed cousin, flip locking.

  16. Soybean phytase and nucleic acid encoding the same

    OpenAIRE

    1999-01-01

    Isolated soybean phytase polypeptides and isolated nucleic acids encoding soybean phytases are provided. The invention is also directed to nucleic acid expression constructs, vectors, and host cells comprising the isolated soybean phytase nucleic acids, as well as methods for producing recombinant and non-recombinant purified soybean phytase. The invention also relates to transgenic plants expressing the soybean phytase, particularly expression under seed-specific expression control elements.

  17. Comparing the Overhead of Lock-based and Lock-free Implementations of Priority Queues

    DEFF Research Database (Denmark)

    Passas, Stavros; Karlsson, Sven

    2011-01-01

    . In this paper, we compare a lock-free implementation of a priority queue with a lock-based implementation. We perform experiments with processors of different generations and observe large performance differences for lock-free data structures depending on the processor generation. The lock-free implementation...... performs much better on the most recent processor generation. We investigate this performance trend, using a set of micro-benchmarks and show a significant difference in the overhead of atomic operations between processor generations. The lock-free implementation executes approximately three times as many...

  18. Past, Present, Future Erosion at Locke Island

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.

    2006-08-08

    This report describes and documents the erosion that has occurred along the northeast side of Locke Island over the last 10 to 20 years. The principal cause of this erosion is the massive Locke Island landslide complex opposite the Columbia River along the White Bluffs, which constricts the flow of the river and deflects the river's thalweg southward against the island.

  19. An automatic mode-locked system for passively mode-locked fiber laser

    Science.gov (United States)

    Li, Sha; Xu, Jun; Chen, Guoliang; Mei, Li; Yi, Bo

    2013-12-01

    This paper designs and implements one kind of automatic mode-locked system. It can adjust a passively mode-locked fiber laser to keep steady mode-locked states automatically. So the unsteadiness of traditional passively mode-locked fiber laser can be avoided. The system transforms optical signals into electrical pulse signals and sends them into MCU after processing. MCU calculates the frequency of the signals and judges the state of the output based on a quick judgment algorithm. A high-speed comparator is used to check the signals and the comparison voltage can be adjusted to improve the measuring accuracy. Then by controlling two polarization controllers at an angle of 45degrees to each other, MCU extrudes the optical fibers to change the polarization until it gets proper mode-locked output. So the system can continuously monitor the output signal and get it back to mode-locked states quickly and automatically. States of the system can be displayed on the LCD and PC. The parameters of the steady mode-locked states can be stored into an EEPROM so that the system will get into mode-locked states immediately next time. Actual experiments showed that, for a 6.238MHz passively mode-locked fiber lasers, the system can get into steady mode-locked states automatically in less than 90s after starting the system. The expected lock time can be reduced to less than 20s after follow up improvements.

  20. Commonwealth Edison Company pressure locking test report

    Energy Technology Data Exchange (ETDEWEB)

    Bunte, B.D.; Kelly, J.F.

    1996-12-01

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology.

  1. Commonwealth Edison Company pressure locking test report

    International Nuclear Information System (INIS)

    Bunte, B.D.; Kelly, J.F.

    1996-01-01

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology

  2. Helicase-dependent amplification of nucleic acids.

    Science.gov (United States)

    Cao, Yun; Kim, Hyun-Jin; Li, Ying; Kong, Huimin; Lemieux, Bertrand

    2013-10-11

    Helicase-dependent amplification (HDA) is a novel method for the isothermal in vitro amplification of nucleic acids. The HDA reaction selectively amplifies a target sequence by extension of two oligonucleotide primers. Unlike the polymerase chain reaction (PCR), HDA uses a helicase enzyme to separate the deoxyribonucleic acid (DNA) strands, rather than heat denaturation. This allows DNA amplification without the need for thermal cycling. The helicase used in HDA is a helicase super family II protein obtained from a thermophilic organism, Thermoanaerobacter tengcongensis (TteUvrD). This thermostable helicase is capable of unwinding blunt-end nucleic acid substrates at elevated temperatures (60° to 65°C). The HDA reaction can also be coupled with reverse transcription for ribonucleic acid (RNA) amplification. The products of this reaction can be detected during the reaction using fluorescent probes when incubations are conducted in a fluorimeter. Alternatively, products can be detected after amplification using a disposable amplicon containment device that contains an embedded lateral flow strip. Copyright © 2013 John Wiley & Sons, Inc.

  3. Nucleic acid interactions with pyrite surfaces

    International Nuclear Information System (INIS)

    Mateo-Marti, E.; Briones, C.; Rogero, C.; Gomez-Navarro, C.; Methivier, Ch.; Pradier, C.M.; Martin-Gago, J.A.

    2008-01-01

    The study of the interaction of nucleic acid molecules with mineral surfaces is a field of growing interest in organic chemistry, origin of life, material science and biotechnology. We have characterized the adsorption of single-stranded peptide nucleic acid (ssPNA) on a natural pyrite surface, as well as the further adsorption of ssDNA on a PNA-modified pyrite surface. The characterization has been performed by means of reflection absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM) and X-ray photoemission spectroscopy (XPS) techniques. The N(1s) and S(2p) XPS core level peaks of PNA and PNA + DNA have been decomposed in curve-components that we have assigned to different chemical species. RAIRS spectra recorded for different concentrations show the presence of positive and negative adsorption bands, related to the semiconducting nature of the surface. The combination of the information gathered by these techniques confirms that PNA adsorbs on pyrite surface, interacting through nitrogen-containing groups of the nucleobases and the iron atoms of the surface, instead of the thiol group of the molecule. The strong PNA/pyrite interaction inhibits further hybridization of PNA with complementary ssDNA, contrary to the behavior reported on gold surfaces

  4. Nucleic acid interactions with pyrite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mateo-Marti, E. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain)], E-mail: mateome@inta.es; Briones, C.; Rogero, C. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain); Gomez-Navarro, C. [Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049-Madrid (Spain); Methivier, Ch.; Pradier, C.M. [Laboratoire de Reactivite de Surface, UMR CNRS 7609. Universite Pierre et Marie Curie, 4, Pl Jussieu, 75005-Paris (France); Martin-Gago, J.A. [Centro de Astrobiologia (CSIC-INTA), Ctra. Ajalvir, Km. 4, 28850-Torrejon de Ardoz, Madrid (Spain); Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049-Madrid (Spain)

    2008-09-03

    The study of the interaction of nucleic acid molecules with mineral surfaces is a field of growing interest in organic chemistry, origin of life, material science and biotechnology. We have characterized the adsorption of single-stranded peptide nucleic acid (ssPNA) on a natural pyrite surface, as well as the further adsorption of ssDNA on a PNA-modified pyrite surface. The characterization has been performed by means of reflection absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM) and X-ray photoemission spectroscopy (XPS) techniques. The N(1s) and S(2p) XPS core level peaks of PNA and PNA + DNA have been decomposed in curve-components that we have assigned to different chemical species. RAIRS spectra recorded for different concentrations show the presence of positive and negative adsorption bands, related to the semiconducting nature of the surface. The combination of the information gathered by these techniques confirms that PNA adsorbs on pyrite surface, interacting through nitrogen-containing groups of the nucleobases and the iron atoms of the surface, instead of the thiol group of the molecule. The strong PNA/pyrite interaction inhibits further hybridization of PNA with complementary ssDNA, contrary to the behavior reported on gold surfaces.

  5. EQUATORIAL SUPERROTATION ON TIDALLY LOCKED EXOPLANETS

    International Nuclear Information System (INIS)

    Showman, Adam P.; Polvani, Lorenzo M.

    2011-01-01

    The increasing richness of exoplanet observations has motivated a variety of three-dimensional (3D) atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or 'superrotating', jet stream at the equator. When the radiative and advection timescales are comparable, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been subsequently observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing Rossby waves induced by the day-night thermal forcing. The strong longitudinal variations in radiative heating-namely intense dayside heating and nightside cooling-trigger the formation of standing, planetary-scale equatorial Rossby and Kelvin waves. The Rossby waves develop phase tilts that pump eastward momentum from high latitudes to the equator, thereby inducing equatorial superrotation. We present an analytic theory demonstrating this mechanism and explore its properties in a hierarchy of one-layer (shallow-water) calculations and fully 3D models. The wave-mean-flow interaction produces an equatorial jet whose latitudinal width is comparable to that of the Rossby waves, namely the equatorial Rossby deformation radius modified by radiative and frictional effects. For conditions typical of synchronously rotating hot Jupiters, this length is comparable to a planetary radius, explaining the broad scale of the equatorial jet obtained in most hot-Jupiter models. Our theory illuminates the dependence of the equatorial jet

  6. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody

    2008-01-01

    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  7. Neglected locked vertical patellar dislocation

    Science.gov (United States)

    Gupta, Rakesh Kumar; Gupta, Vinay; Sangwan, Sukhbir Singh; Kamboj, Pradeep

    2012-01-01

    Patellar dislocations occurring about the vertical and horizontal axis are rare and irreducible. The neglected patellar dislocation is still rarer. We describe the clinical presentation and management of a case of neglected vertical patellar dislocation in a 6 year-old boy who sustained an external rotational strain with a laterally directed force to his knee. Initially the diagnosis was missed and 2 months later open reduction was done. The increased tension generated by the rotation of the lateral extensor retinaculum kept the patella locked in the lateral gutter even with the knee in full extension. Traumatic patellar dislocation with rotation around a vertical axis has been described earlier, but no such neglected case has been reported to the best of our knowledge. PMID:23162154

  8. Neglected locked vertical patellar dislocation

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Gupta

    2012-01-01

    Full Text Available Patellar dislocations occurring about the vertical and horizontal axis are rare and irreducible. The neglected patellar dislocation is still rarer. We describe the clinical presentation and management of a case of neglected vertical patellar dislocation in a 6 year-old boy who sustained an external rotational strain with a laterally directed force to his knee. Initially the diagnosis was missed and 2 months later open reduction was done. The increased tension generated by the rotation of the lateral extensor retinaculum kept the patella locked in the lateral gutter even with the knee in full extension. Traumatic patellar dislocation with rotation around a vertical axis has been described earlier, but no such neglected case has been reported to the best of our knowledge.

  9. Unusual Cause of Knee Locking

    Directory of Open Access Journals (Sweden)

    Gazi Huri

    2013-01-01

    Full Text Available We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI and arthroscopy confirmed the intrasubstance tear of popliteus tendon and synovitis. The ruptured part of the tendon was debrided, and the inflammatory tissue around the tendon, which may lead to pseudolocking, was gently removed with a shaver in order to regain the normal ROM. The patient was discharged with full ROM and weight bearing first day after the surgery. To our knowledge, this is the first case demonstrating intrasubstance tear of popliteus tendon causing pseudolocking of the knee.

  10. MAZ-binding G4-decoy with locked nucleic acid and twisted intercalating nucleic acid modifications suppresses KRAS in pancreatic cancer cells and delays tumor growth in mice

    DEFF Research Database (Denmark)

    Cogoi, Susanna; Zorzet, Sonia; Rapozzi, Valentina

    2013-01-01

    and stability, two polycyclic aromatic hydrocarbon units (TINA or AMANY) were inserted internally, to cap the quadruplex. The most active G4-decoy (2998), which had two para-TINAs, strongly suppressed KRAS expression in Panc-1 cells. It also repressed their metabolic activity (IC50 = 520 nM), and it inhibited...... cell growth and colony formation by activating apoptosis. We finally injected 2998 and control oligonucleotides 5153, 5154 (2 nmol/mouse) intratumorally in SCID mice bearing a Panc-1 xenograft. After three treatments, 2998 reduced tumor xenograft growth by 64% compared with control and increased...

  11. Nucleic Acid Therapy: from humble beginnings a dynamic technology

    CSIR Research Space (South Africa)

    Millroy, L

    2011-02-01

    Full Text Available The term “nucleic acid therapy” encompasses a wide range of technologies for the treatment of a range of plant and animal ailments. As the name implies, it makes use of nucleic acid (either DNA or RNA) as a therapeutic agent. There are six branches...

  12. Peptide Nucleic Acids Having 2,6-Diaminopurine Nucleobases

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than a corresponding DNA strand, and exhibit increased sequence specificity and binding affinity. The peptide nucleic acids of the invention comprise ligands selected from a group...

  13. Gene Targeting and Expression Modulation by Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    Peptide nucleic acids (PNA) are artificial structural mimics of nucleic acids capable of sequence specific hybridization to both RNA and DNA. Thus they have obvious potential as gene targeting agents for drug discovery approaches. An overview with emphasis on recent progress on RNA "interference...

  14. Non-enzymatic Polymerization of Nucleic Acids from Monomers

    DEFF Research Database (Denmark)

    Dörr, Mark; Löffler, Philipp M. G.; Monnard, Pierre-Alain

    2012-01-01

    synthesis of long nucleic acid polymers or to sequence-specifically amplify nucleic acid polymers, respectively. Starting from molecular requirements, details of the polymerization mechanisms and strategies are first presented and then compared. Finally, we discuss the relevance of these strategies...

  15. EGVII endoglucanase and nucleic acids encoding the same

    Science.gov (United States)

    Dunn-Coleman, Nigel [Los Gatos, CA; Goedegebuur, Frits [Vlaardingen, NL; Ward, Michael [San Francisco, CA; Yao, Jian [Sunnyvale, CA

    2009-05-05

    The present invention provides an endoglucanase nucleic acid sequence, designated egl7, and the corresponding EGVII amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding EGVII, recombinant EGVII proteins and methods for producing the same.

  16. MEANS AND METHODS FOR CLONING NUCLEIC ACID SEQUENCES

    NARCIS (Netherlands)

    Geertsma, Eric Robin; Poolman, Berend

    2008-01-01

    The invention provides means and methods for efficiently cloning nucleic acid sequences of interest in micro-organisms that are less amenable to conventional nucleic acid manipulations, as compared to, for instance, E.coli. The present invention enables high-throughput cloning (and, preferably,

  17. Peptide Nucleic Acids Having Amino Acid Side Chains

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting...

  18. No Snowball on Habitable Tidally Locked Planets

    Science.gov (United States)

    Checlair, Jade; Menou, Kristen; Abbot, Dorian S.

    2017-08-01

    The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

  19. No Snowball on Habitable Tidally Locked Planets

    Energy Technology Data Exchange (ETDEWEB)

    Checlair, Jade; Abbot, Dorian S. [Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Menou, Kristen, E-mail: jadecheclair@uchicago.edu [Centre for Planetary Sciences, Department of Physical and Environmental Sciences, University of Toronto at Scarborough, Toronto, ON M1C 1A4 (Canada)

    2017-08-20

    The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO{sub 2} outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

  20. No Snowball on Habitable Tidally Locked Planets

    International Nuclear Information System (INIS)

    Checlair, Jade; Abbot, Dorian S.; Menou, Kristen

    2017-01-01

    The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO 2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

  1. Correlations between locked modes and impurity influxes

    Energy Technology Data Exchange (ETDEWEB)

    Fishpool, G M [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Lawson, K D [UKAEA Culham Lab., Abingdon (United Kingdom)

    1994-07-01

    An analysis of pulses that were disturbed by medium Z impurity influxes (Cl, Cr, Fe and Ni) recorded during the 91/92 JET operations, has demonstrated that such influxes can result in MHD modes which subsequently ``lock``. A correlation is found between the power radiated by the influx and the time difference between the start of the influx and the beginning of the locked mode. The growth in the amplitude of the locked mode itself can lead to further impurity influxes. A correlation is noted between intense influxes (superior to 10 MW) and the mode ``unlocking``. (authors). 4 refs., 4 figs.

  2. The Advanced Thread-Locking Mechanism

    Science.gov (United States)

    Weiss, Wolfgang

    2005-12-01

    Locking of threaded members is accomplished by a wide variety of engineering solutions. Generally, in terms of separate locking devices or by built-in locking features such as friction generating means.In regard of space flight vehicles, threaded joints are subject to severe vibration loads during launch, maneuvering, and reentry. This requires fastening systems which are capable to join structural members and attach accessories or equipment in a secure manner. However, manned spacecraft and especially payload components will be subject to installation activity during orbital or interstellar flight maintenance, repair, or mission modification. This, in turn, requires fast separation and engaging of the concerned fasteners, yet providing performance characteristics for high reliable and safe joints.The further described Advanced Thread Locking Mechanism (ATLM) has been developed to combine the merits of both, safe joining technique and a fast installation process. The ATLM uses a freewheel which is securely installed in one part of the threaded member and releasable coupled with the engaged counterpart. While screwing the threaded members together, once coupled, the freewheel will allow free mating of the threaded members including torquing to the desired value. The moment, the pair of threaded fasteners is forced to unscrew (by intended or unintended occurrence of torque in the undoing direction) the freewheel does lock instantly. Disengaging the coupling between the members of the threaded joint takes a separate release action.Owing to the nature of the ATLM, there are a number of design variants ready for implementation.Threaded fasteners in ATLM design are highly recommended for mechanical joints subject to fastening and unfastening during Extra Vehicular Activity (EVA) in course of space flight operations. This is justified through:1. Threaded members mate free running, thus, torque values preset at the wrenching tool are not influenced by varying prevailing

  3. Short-term outcome of patients with closed comminuted femoral ...

    African Journals Online (AJOL)

    Short-term outcome of patients with closed comminuted femoral shaft fracture treated with locking intramedullary sign nail at Muhimbili Orthopaedic Institute in Tanzania. Billy T. Haonga, Felix S. Mrita, Edmundo E. Ndalama, Jackline E. Makupa ...

  4. Quantitative thermodynamic predication of interactions between nucleic acid and non-nucleic acid species using Microsoft excel.

    Science.gov (United States)

    Zou, Jiaqi; Li, Na

    2013-09-01

    Proper design of nucleic acid sequences is crucial for many applications. We have previously established a thermodynamics-based quantitative model to help design aptamer-based nucleic acid probes by predicting equilibrium concentrations of all interacting species. To facilitate customization of this thermodynamic model for different applications, here we present a generic and easy-to-use platform to implement the algorithm of the model with Microsoft(®) Excel formulas and VBA (Visual Basic for Applications) macros. Two Excel spreadsheets have been developed: one for the applications involving only nucleic acid species, the other for the applications involving both nucleic acid and non-nucleic acid species. The spreadsheets take the nucleic acid sequences and the initial concentrations of all species as input, guide the user to retrieve the necessary thermodynamic constants, and finally calculate equilibrium concentrations for all species in various bound and unbound conformations. The validity of both spreadsheets has been verified by comparing the modeling results with the experimental results on nucleic acid sequences reported in the literature. This Excel-based platform described here will allow biomedical researchers to rationalize the sequence design of nucleic acid probes using the thermodynamics-based modeling even without relevant theoretical and computational skills. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Intumescent features of nucleic acids and proteins

    International Nuclear Information System (INIS)

    Alongi, Jenny; Cuttica, Fabio; Blasio, Alessandro Di; Carosio, Federico; Malucelli, Giulio

    2014-01-01

    Highlights: • The combustion resistance of DNA and caseins to different heat fluxes was studied. • Upon heating, DNA and caseins exhibited an intumescent behaviour. • The char derived from DNA was more stable and coherent than that from caseins. - Abstract: Are nucleic acids and proteins intumescent molecules? In order to get an answer, in the present manuscript, powders of deoxyribose nucleic acids (DNA) and caseins have been exposed to different heat fluxes under a cone calorimeter source and to the direct application of a propane flame. Under these conditions, DNA and caseins exhibited a typical intumescent behaviour, generating a coherent expanded cellular carbonaceous residue (char), extremely resistant to heat exposure. The resulting volumetric expansion as well as the resistance of the formed char turned out to be dependent on (i) the chemical structure of the chosen biomacromolecule, (ii) the evolution of ammonia and (iii) the adopted heat flux in cone calorimetry tests (namely, 25, 35, 50 and 75 kW/m 2 ). The presence of ribose units within the DNA backbone determined the formation of highly expanded and coherent residues as compared to those obtained from caseins. Indeed, under a heat flux of 35 kW/m 2 , when a carbon source (i.e. common cane sugar) was added to caseins, the resulting char was similar to that formed by DNA. Furthermore, the char expansion was ascribed to the evolution of ammonia released by these biomacromolecules upon heating, as detected by thermogravimetry coupled to infrared spectroscopy, and confirmed by scanning electron microscopy experiments performed on the bubbles present in the residues of flammability tests

  6. Intumescent features of nucleic acids and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Alongi, Jenny, E-mail: jenny.alongi@polito.it; Cuttica, Fabio; Blasio, Alessandro Di; Carosio, Federico; Malucelli, Giulio

    2014-09-10

    Highlights: • The combustion resistance of DNA and caseins to different heat fluxes was studied. • Upon heating, DNA and caseins exhibited an intumescent behaviour. • The char derived from DNA was more stable and coherent than that from caseins. - Abstract: Are nucleic acids and proteins intumescent molecules? In order to get an answer, in the present manuscript, powders of deoxyribose nucleic acids (DNA) and caseins have been exposed to different heat fluxes under a cone calorimeter source and to the direct application of a propane flame. Under these conditions, DNA and caseins exhibited a typical intumescent behaviour, generating a coherent expanded cellular carbonaceous residue (char), extremely resistant to heat exposure. The resulting volumetric expansion as well as the resistance of the formed char turned out to be dependent on (i) the chemical structure of the chosen biomacromolecule, (ii) the evolution of ammonia and (iii) the adopted heat flux in cone calorimetry tests (namely, 25, 35, 50 and 75 kW/m{sup 2}). The presence of ribose units within the DNA backbone determined the formation of highly expanded and coherent residues as compared to those obtained from caseins. Indeed, under a heat flux of 35 kW/m{sup 2}, when a carbon source (i.e. common cane sugar) was added to caseins, the resulting char was similar to that formed by DNA. Furthermore, the char expansion was ascribed to the evolution of ammonia released by these biomacromolecules upon heating, as detected by thermogravimetry coupled to infrared spectroscopy, and confirmed by scanning electron microscopy experiments performed on the bubbles present in the residues of flammability tests.

  7. Roald Dahl and the complete locked-in syndrome: "Cold dead body, living brain"

    DEFF Research Database (Denmark)

    Kondziella, Daniel

    2017-01-01

    they no longer have any motor output at all. Of note, Roald Dahl, the internationally acclaimed children book author, described this complete locked-in syndrome in one of his short stories, William and Mary (1959), almost half a century before the medical community became aware of this devastating condition......The classical locked-in syndrome in which partially preserved eye movements allow for communication is well-recognized by most neurologists. Yet, it is much less well-known that patients exist who are clearly conscious but have lost all means of communicating it to the outside world because...

  8. Arm locking with Doppler estimation errors

    Energy Technology Data Exchange (ETDEWEB)

    Yu Yinan; Wand, Vinzenz; Mitryk, Shawn; Mueller, Guido, E-mail: yinan@phys.ufl.ed [Department of Physics, University of Florida, Gainesville, FL 32611 (United States)

    2010-05-01

    At the University of Florida we developed the University of Florida LISA Interferometer Simulator (UFLIS) in order to study LISA interferometry with hardware in the loop at a system level. One of the proposed laser frequency stabilization techniques in LISA is arm locking. Arm locking uses an adequately filtered linear combination of the LISA arm signals as a frequency reference. We will report about experiments in which we demonstrated arm locking using UFLIS. During these experiments we also discovered a problem associated with the Doppler shift of the return beam. The initial arm locking publications assumed that this Doppler shift can perfectly be subtracted inside the phasemeter or adds an insignificant offset to the sensor signal. However, the remaining Doppler knowledge error will cause a constant change in the laser frequency if unaccounted for. Several ways to circumvent this problem have been identified. We performed detailed simulations and started preliminary experiments to verify the performance of the proposed new controller designs.

  9. Optical double-locked semiconductor lasers

    Science.gov (United States)

    AlMulla, Mohammad

    2018-06-01

    Self-sustained period-one (P1) nonlinear dynamics of a semiconductor laser are investigated when both optical injection and modulation are applied for stable microwave frequency generation. Locking the P1 oscillation through modulation on the bias current, injection strength, or detuning frequency stabilizes the P1 oscillation. Through the phase noise variance, the different modulation types are compared. It is demonstrated that locking the P1 oscillation through optical modulation on the output of the master laser outperforms bias-current modulation of the slave laser. Master laser modulation shows wider P1-oscillation locking range and lower phase noise variance. The locking characteristics of the P1 oscillation also depend on the operating conditions of the optical injection system

  10. Improving generalized inverted index lock wait times

    Science.gov (United States)

    Borodin, A.; Mirvoda, S.; Porshnev, S.; Ponomareva, O.

    2018-01-01

    Concurrent operations on tree like data structures is a cornerstone of any database system. Concurrent operations intended for improving read\\write performance and usually implemented via some way of locking. Deadlock-free methods of concurrency control are known as tree locking protocols. These protocols provide basic operations(verbs) and algorithm (ways of operation invocations) for applying it to any tree-like data structure. These algorithms operate on data, managed by storage engine which are very different among RDBMS implementations. In this paper, we discuss tree locking protocol implementation for General inverted index (Gin) applied to multiversion concurrency control (MVCC) storage engine inside PostgreSQL RDBMS. After that we introduce improvements to locking protocol and provide usage statistics about evaluation of our improvement in very high load environment in one of the world’s largest IT company.

  11. Automatic NMR field-frequency lock-pulsed phase locked loop approach.

    Science.gov (United States)

    Kan, S; Gonord, P; Fan, M; Sauzade, M; Courtieu, J

    1978-06-01

    A self-contained deuterium frequency-field lock scheme for a high-resolution NMR spectrometer is described. It is based on phase locked loop techniques in which the free induction decay signal behaves as a voltage-controlled oscillator. By pulsing the spins at an offset frequency of a few hundred hertz and using a digital phase-frequency discriminator this method not only eliminates the usual phase, rf power, offset adjustments needed in conventional lock systems but also possesses the automatic pull-in characteristics that dispense with the use of field sweeps to locate the NMR line prior to closure of the lock loop.

  12. Interband optical pulse injection locking of quantum dot mode-locked semiconductor laser.

    Science.gov (United States)

    Kim, Jimyung; Delfyett, Peter J

    2008-07-21

    We experimentally demonstrate optical clock recovery from quantum dot mode-locked semiconductor lasers by interband optical pulse injection locking. The passively mode-locked slave laser oscillating on the ground state or the first excited state transition is locked through the injection of optical pulses generated via the opposite transition bands, i.e. the first excited state or the ground state transition from the hybridly mode-locked master laser, respectively. When an optical pulse train generated via the first excited state from the master laser is injected to the slave laser oscillating via ground state, the slave laser shows an asymmetric locking bandwidth around the nominal repetition rate of the slave laser. In the reverse injection case of, i.e. the ground state (master laser) to the first excited state (slave laser), the slave laser does not lock even though both lasers oscillate at the same cavity frequency. In this case, the slave laser only locks to higher injection rates as compared to its own nominal repetition rate, and also shows a large locking bandwidth of 6.7 MHz.

  13. QPSK regeneration without active phase-locking

    DEFF Research Database (Denmark)

    Kjøller, Niels-Kristian; Da Ros, Francesco; Røge, Kasper Meldgaard

    2016-01-01

    QPSK regeneration without active phase stabilization is investigated in numerical simulations. We propose an improved scheme for phase-locking free QPSK regeneration showing significant improvements in the error vector magnitude of the signal.......QPSK regeneration without active phase stabilization is investigated in numerical simulations. We propose an improved scheme for phase-locking free QPSK regeneration showing significant improvements in the error vector magnitude of the signal....

  14. Automatic locking orthotic knee device

    Science.gov (United States)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  15. Peptide nucleic acid probe for protein affinity purification based on biotin-streptavidin interaction and peptide nucleic acid strand hybridization.

    Science.gov (United States)

    Tse, Jenny; Wang, Yuanyuan; Zengeya, Thomas; Rozners, Eriks; Tan-Wilson, Anna

    2015-02-01

    We describe a new method for protein affinity purification that capitalizes on the high affinity of streptavidin for biotin but does not require dissociation of the biotin-streptavidin complex for protein retrieval. Conventional reagents place both the selectively reacting group (the "warhead") and the biotin on the same molecule. We place the warhead and the biotin on separate molecules, each linked to a short strand of peptide nucleic acid (PNA), synthetic polymers that use the same bases as DNA but attached to a backbone that is resistant to attack by proteases and nucleases. As in DNA, PNA strands with complementary base sequences hybridize. In conditions that favor PNA duplex formation, the warhead strand (carrying the tagged protein) and the biotin strand form a complex that is held onto immobilized streptavidin. As in DNA, the PNA duplex dissociates at moderately elevated temperature; therefore, retrieval of the tagged protein is accomplished by a brief exposure to heat. Using iodoacetate as the warhead, 8-base PNA strands, biotin, and streptavidin-coated magnetic beads, we demonstrate retrieval of the cysteine protease papain. We were also able to use our iodoacetyl-PNA:PNA-biotin probe for retrieval and identification of a thiol reductase and a glutathione transferase from soybean seedling cotyledons. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Experimental Warming Decreases the Average Size and Nucleic Acid Content of Marine Bacterial Communities

    KAUST Repository

    Huete-Stauffer, Tamara M.; Arandia-Gorostidi, Nestor; Alonso-Sá ez, Laura; Moran, Xose Anxelu G.

    2016-01-01

    Organism size reduction with increasing temperature has been suggested as a universal response to global warming. Since genome size is usually correlated to cell size, reduction of genome size in unicells could be a parallel outcome of warming at ecological and evolutionary time scales. In this study, the short-term response of cell size and nucleic acid content of coastal marine prokaryotic communities to temperature was studied over a full annual cycle at a NE Atlantic temperate site. We used flow cytometry and experimental warming incubations, spanning a 6°C range, to analyze the hypothesized reduction with temperature in the size of the widespread flow cytometric bacterial groups of high and low nucleic acid content (HNA and LNA bacteria, respectively). Our results showed decreases in size in response to experimental warming, which were more marked in 0.8 μm pre-filtered treatment rather than in the whole community treatment, thus excluding the role of protistan grazers in our findings. Interestingly, a significant effect of temperature on reducing the average nucleic acid content (NAC) of prokaryotic cells in the communities was also observed. Cell size and nucleic acid decrease with temperature were correlated, showing a common mean decrease of 0.4% per °C. The usually larger HNA bacteria consistently showed a greater reduction in cell and NAC compared with their LNA counterparts, especially during the spring phytoplankton bloom period associated to maximum bacterial growth rates in response to nutrient availability. Our results show that the already smallest planktonic microbes, yet with key roles in global biogeochemical cycling, are likely undergoing important structural shrinkage in response to rising temperatures.

  17. Experimental Warming Decreases the Average Size and Nucleic Acid Content of Marine Bacterial Communities

    KAUST Repository

    Huete-Stauffer, Tamara M.

    2016-05-23

    Organism size reduction with increasing temperature has been suggested as a universal response to global warming. Since genome size is usually correlated to cell size, reduction of genome size in unicells could be a parallel outcome of warming at ecological and evolutionary time scales. In this study, the short-term response of cell size and nucleic acid content of coastal marine prokaryotic communities to temperature was studied over a full annual cycle at a NE Atlantic temperate site. We used flow cytometry and experimental warming incubations, spanning a 6°C range, to analyze the hypothesized reduction with temperature in the size of the widespread flow cytometric bacterial groups of high and low nucleic acid content (HNA and LNA bacteria, respectively). Our results showed decreases in size in response to experimental warming, which were more marked in 0.8 μm pre-filtered treatment rather than in the whole community treatment, thus excluding the role of protistan grazers in our findings. Interestingly, a significant effect of temperature on reducing the average nucleic acid content (NAC) of prokaryotic cells in the communities was also observed. Cell size and nucleic acid decrease with temperature were correlated, showing a common mean decrease of 0.4% per °C. The usually larger HNA bacteria consistently showed a greater reduction in cell and NAC compared with their LNA counterparts, especially during the spring phytoplankton bloom period associated to maximum bacterial growth rates in response to nutrient availability. Our results show that the already smallest planktonic microbes, yet with key roles in global biogeochemical cycling, are likely undergoing important structural shrinkage in response to rising temperatures.

  18. Nucleic acid detection system and method for detecting influenza

    Science.gov (United States)

    Cai, Hong; Song, Jian

    2015-03-17

    The invention provides a rapid, sensitive and specific nucleic acid detection system which utilizes isothermal nucleic acid amplification in combination with a lateral flow chromatographic device, or DNA dipstick, for DNA-hybridization detection. The system of the invention requires no complex instrumentation or electronic hardware, and provides a low cost nucleic acid detection system suitable for highly sensitive pathogen detection. Hybridization to single-stranded DNA amplification products using the system of the invention provides a sensitive and specific means by which assays can be multiplexed for the detection of multiple target sequences.

  19. Theoretical investigation of injection-locked high modulation bandwidth quantum cascade lasers.

    Science.gov (United States)

    Meng, Bo; Wang, Qi Jie

    2012-01-16

    In this study, we report for the first time to our knowledge theoretical investigation of modulation responses of injection-locked mid-infrared quantum cascade lasers (QCLs) at wavelengths of 4.6 μm and 9 μm, respectively. It is shown through a three-level rate equations model that the direct intensity modulation of QCLs gives the maximum modulation bandwidths of ~7 GHz at 4.6 μm and ~20 GHz at 9 μm. By applying the injection locking scheme, we find that the modulation bandwidths of up to ~30 GHz and ~70 GHz can be achieved for QCLs at 4.6 μm and 9 μm, respectively, with an injection ratio of 5 dB. The result also shows that an ultrawide modulation bandwidth of more than 200 GHz is possible with a 10 dB injection ratio for QCLs at 9 μm. An important characteristic of injection-locked QCLs is the nonexistence of unstable locking region in the locking map, in contrast to their diode laser counterparts. We attribute this to the ultra-short upper laser state lifetimes of QCLs.

  20. Phase-locking and bistability in neuronal networks with synaptic depression

    Science.gov (United States)

    Akcay, Zeynep; Huang, Xinxian; Nadim, Farzan; Bose, Amitabha

    2018-02-01

    We consider a recurrent network of two oscillatory neurons that are coupled with inhibitory synapses. We use the phase response curves of the neurons and the properties of short-term synaptic depression to define Poincaré maps for the activity of the network. The fixed points of these maps correspond to phase-locked modes of the network. Using these maps, we analyze the conditions that allow short-term synaptic depression to lead to the existence of bistable phase-locked, periodic solutions. We show that bistability arises when either the phase response curve of the neuron or the short-term depression profile changes steeply enough. The results apply to any Type I oscillator and we illustrate our findings using the Quadratic Integrate-and-Fire and Morris-Lecar neuron models.

  1. Computation of the lock-in ranges of phase-locked loops with PI filter

    OpenAIRE

    Aleksandrov, Konstantin D.; Kuznetsov, Nikolay; Leonov, Gennady A.; Neittaanmäki, Pekka; Yuldashev, Marat V.; Yuldashev, Renat V.

    2016-01-01

    In the present work the lock-in range of PLL-based circuits with proportionallyintegrating filter and sinusoidal phase-detector characteristics are studied. Considered circuits have sinusoidal phase detector characteristics. Analytical approach based on the methods of phase plane analysis is applied to estimate the lock-in ranges of the circuits under consideration. Obtained analytical results are compared with simulation results.

  2. Assays for urinary biomarkers of oxidatively damaged nucleic acids

    DEFF Research Database (Denmark)

    Weimann, Allan; Broedbaek, Kasper; Henriksen, Trine

    2012-01-01

    Abstract The analysis of oxidized nucleic acid metabolites can be performed by a variety of methodologies: liquid chromatography coupled with electrochemical or mass-spectrometry detection, gas chromatography coupled with mass spectrometry, capillary electrophoresis and ELISA (Enzyme-linked immun...

  3. Nanopore biosensors for detection of proteins and nucleic acids

    NARCIS (Netherlands)

    Maglia, Giovanni; Soskine, Mikhael

    2014-01-01

    Described herein are nanopore biosensors based on a modified cytolysin protein. The nanopore biosensors accommodate macromoiecules including proteins and nucleic acids, and may additionally comprise ligands with selective binding properties.

  4. Nucleic acid and nucleotide-mediated synthesis of inorganic nanoparticles

    Science.gov (United States)

    Berti, Lorenzo; Burley, Glenn A.

    2008-02-01

    Since the advent of practical methods for achieving DNA metallization, the use of nucleic acids as templates for the synthesis of inorganic nanoparticles (NPs) has become an active area of study. It is now widely recognized that nucleic acids have the ability to control the growth and morphology of inorganic NPs. These biopolymers are particularly appealing as templating agents as their ease of synthesis in conjunction with the possibility of screening nucleotide composition, sequence and length, provides the means to modulate the physico-chemical properties of the resulting NPs. Several synthetic procedures leading to NPs with interesting photophysical properties as well as studies aimed at rationalizing the mechanism of nucleic acid-templated NP synthesis are now being reported. This progress article will outline the current understanding of the nucleic acid-templated process and provides an up to date reference in this nascent field.

  5. Computational Approaches to Nucleic Acid Origami.

    Science.gov (United States)

    Jabbari, Hosna; Aminpour, Maral; Montemagno, Carlo

    2015-10-12

    Recent advances in experimental DNA origami have dramatically expanded the horizon of DNA nanotechnology. Complex 3D suprastructures have been designed and developed using DNA origami with applications in biomaterial science, nanomedicine, nanorobotics, and molecular computation. Ribonucleic acid (RNA) origami has recently been realized as a new approach. Similar to DNA, RNA molecules can be designed to form complex 3D structures through complementary base pairings. RNA origami structures are, however, more compact and more thermodynamically stable due to RNA's non-canonical base pairing and tertiary interactions. With all these advantages, the development of RNA origami lags behind DNA origami by a large gap. Furthermore, although computational methods have proven to be effective in designing DNA and RNA origami structures and in their evaluation, advances in computational nucleic acid origami is even more limited. In this paper, we review major milestones in experimental and computational DNA and RNA origami and present current challenges in these fields. We believe collaboration between experimental nanotechnologists and computer scientists are critical for advancing these new research paradigms.

  6. Continuously tunable nucleic acid hybridization probes.

    Science.gov (United States)

    Wu, Lucia R; Wang, Juexiao Sherry; Fang, John Z; Evans, Emily R; Pinto, Alessandro; Pekker, Irena; Boykin, Richard; Ngouenet, Celine; Webster, Philippa J; Beechem, Joseph; Zhang, David Yu

    2015-12-01

    In silico-designed nucleic acid probes and primers often do not achieve favorable specificity and sensitivity tradeoffs on the first try, and iterative empirical sequence-based optimization is needed, particularly in multiplexed assays. We present a novel, on-the-fly method of tuning probe affinity and selectivity by adjusting the stoichiometry of auxiliary species, which allows for independent and decoupled adjustment of the hybridization yield for different probes in multiplexed assays. Using this method, we achieved near-continuous tuning of probe effective free energy. To demonstrate our approach, we enforced uniform capture efficiency of 31 DNA molecules (GC content, 0-100%), maximized the signal difference for 11 pairs of single-nucleotide variants and performed tunable hybrid capture of mRNA from total RNA. Using the Nanostring nCounter platform, we applied stoichiometric tuning to simultaneously adjust yields for a 24-plex assay, and we show multiplexed quantitation of RNA sequences and variants from formalin-fixed, paraffin-embedded samples.

  7. Dioxaphosphorinane-constrained nucleic Acid dinucleotides as tools for structural tuning of nucleic acids.

    Science.gov (United States)

    Catana, Dan-Andrei; Renard, Brice-Loïc; Maturano, Marie; Payrastre, Corinne; Tarrat, Nathalie; Escudier, Jean-Marc

    2012-01-01

    We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure. The syntheses of all the members of the D-CNA family are described, and we emphasize the effect on secondary structure stabilization of a couple of diastereoisomers of α,β-D-CNA exhibiting wether B-type canonical values or not.

  8. Assembly of barcode-like nucleic acid nanostructures.

    Science.gov (United States)

    Wang, Pengfei; Tian, Cheng; Li, Xiang; Mao, Chengde

    2014-10-15

    Barcode-like (BC) nanopatterns from programmed self-assembly of nucleic acids (DNA and RNA) are reported. BC nanostructures are generated by the introduction of open spaces at selected sites to an otherwise closely packed, plain, rectangle nucleic acid nanostructure. This strategy is applied to nanostructures assembled from both origami approach and single stranded tile approach. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Nucleic acid-functionalized transition metal nanosheets for biosensing applications.

    Science.gov (United States)

    Mo, Liuting; Li, Juan; Liu, Qiaoling; Qiu, Liping; Tan, Weihong

    2017-03-15

    In clinical diagnostics, as well as food and environmental safety practices, biosensors are powerful tools for monitoring biological or biochemical processes. Two-dimensional (2D) transition metal nanomaterials, including transition metal chalcogenides (TMCs) and transition metal oxides (TMOs), are receiving growing interest for their use in biosensing applications based on such unique properties as high surface area and fluorescence quenching abilities. Meanwhile, nucleic acid probes based on Watson-Crick base-pairing rules are also being widely applied in biosensing based on their excellent recognition capability. In particular, the emergence of functional nucleic acids in the 1980s, especially aptamers, has substantially extended the recognition capability of nucleic acids to various targets, ranging from small organic molecules and metal ions to proteins and cells. Based on π-π stacking interaction between transition metal nanosheets and nucleic acids, biosensing systems can be easily assembled. Therefore, the combination of 2D transition metal nanomaterials and nucleic acids brings intriguing opportunities in bioanalysis and biomedicine. In this review, we summarize recent advances of nucleic acid-functionalized transition metal nanosheets in biosensing applications. The structure and properties of 2D transition metal nanomaterials are first discussed, emphasizing the interaction between transition metal nanosheets and nucleic acids. Then, the applications of nucleic acid-functionalized transition metal nanosheet-based biosensors are discussed in the context of different signal transducing mechanisms, including optical and electrochemical approaches. Finally, we provide our perspectives on the current challenges and opportunities in this promising field. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Universal spin-momentum locked optical forces

    Energy Technology Data Exchange (ETDEWEB)

    Kalhor, Farid [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada); Thundat, Thomas [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada); Jacob, Zubin, E-mail: zjacob@purdue.edu [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada); Birck Nanotechnology Center, Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47906 (United States)

    2016-02-08

    Evanescent electromagnetic waves possess spin-momentum locking, where the direction of propagation (momentum) is locked to the inherent polarization of the wave (transverse spin). We study the optical forces arising from this universal phenomenon and show that the fundamental origin of recently reported non-trivial optical chiral forces is spin-momentum locking. For evanescent waves, we show that the direction of energy flow, the direction of decay, and the direction of spin follow a right hand rule for three different cases of total internal reflection, surface plasmon polaritons, and HE{sub 11} mode of an optical fiber. Furthermore, we explain how the recently reported phenomena of lateral optical force on chiral and achiral particles are caused by the transverse spin of the evanescent field and the spin-momentum locking phenomenon. Finally, we propose an experiment to identify the unique lateral forces arising from the transverse spin in the optical fiber and point to fundamental differences of the spin density from the well-known orbital angular momentum of light. Our work presents a unified view on spin-momentum locking and how it affects optical forces on chiral and achiral particles.

  11. A novel mode-locking technique

    International Nuclear Information System (INIS)

    Chen Shaoh; Chen Youming; Chen Taolue; Si Xiangdong; Yang Yi; Deng Ximing

    1993-01-01

    A novel mode-locked Nd:YAG oscillator has been developed by using an ultrafast photoconductive feedback controlled loop, and mode-locked pulses with a duration of 100ps have been obtained. The energy instability of the pulse trains is ±5%. In this type of mode-locking technology, a type of deep-level doped GaAs (Cr-doped) photoconductive switch, which has a fast response in time and is free of avalance process, is used to drive a Pockels' cell to realize mode-locking. The dark resistance of this type of photoconductive switch is 6 orders of magnitude higher than that of the intrinsic single-crystal silicon, and it can reach a level as high as 10 9 ohms. Consequently, it is able to withstand longterm operation at several thousand DC volts. By means of the photoconductive ohmic switch characteristics, the authors have designed a positive feedback control network which has a very fast response time, and can couple a voltage of up to a thousand volts. Using this unit in a Nd:YAG laser, they have successfully realized a very stable mode-locked pulse train with pulse width shorter than 100 ps. The operation principle, and the results of the preliminary experiments are presented here. 1 ref., 3 figs

  12. Single-stranded nucleic acids promote SAMHD1 complex formation.

    Science.gov (United States)

    Tüngler, Victoria; Staroske, Wolfgang; Kind, Barbara; Dobrick, Manuela; Kretschmer, Stefanie; Schmidt, Franziska; Krug, Claudia; Lorenz, Mike; Chara, Osvaldo; Schwille, Petra; Lee-Kirsch, Min Ae

    2013-06-01

    SAM domain and HD domain-containing protein 1 (SAMHD1) is a dGTP-dependent triphosphohydrolase that degrades deoxyribonucleoside triphosphates (dNTPs) thereby limiting the intracellular dNTP pool. Mutations in SAMHD1 cause Aicardi-Goutières syndrome (AGS), an inflammatory encephalopathy that mimics congenital viral infection and that phenotypically overlaps with the autoimmune disease systemic lupus erythematosus. Both disorders are characterized by activation of the antiviral cytokine interferon-α initiated by immune recognition of self nucleic acids. Here we provide first direct evidence that SAMHD1 associates with endogenous nucleic acids in situ. Using fluorescence cross-correlation spectroscopy, we demonstrate that SAMHD1 specifically interacts with ssRNA and ssDNA and establish that nucleic acid-binding and formation of SAMHD1 complexes are mutually dependent. Interaction with nucleic acids and complex formation do not require the SAM domain, but are dependent on the HD domain and the C-terminal region of SAMHD1. We finally demonstrate that mutations associated with AGS exhibit both impaired nucleic acid-binding and complex formation implicating that interaction with nucleic acids is an integral aspect of SAMHD1 function.

  13. Hersendood. Mackies leibniziaanse herinterpretatie van Lockes theorie van persoonsidentiteit

    OpenAIRE

    De Vleeschouwer, Gregory

    2009-01-01

    In his book, 'Problems from Locke', John Leslie Mackie presents a theory of personal identity (pi) that is meant to be a supplement and correction of Locke's pi-theory. In a first part I introduce the criterion of pi that was standard before Locke's pi-theory. By showing in a second part how Locke reacted against this traditional criterion, I show wherein the singularity of Locke's pi-theory exists. In a third part I explain how Leibniz is moved by the same solicitude as Locke, but also how h...

  14. Multipulse dynamics of a passively mode-locked semiconductor laser with delayed optical feedback

    Science.gov (United States)

    Jaurigue, Lina; Krauskopf, Bernd; Lüdge, Kathy

    2017-11-01

    Passively mode-locked semiconductor lasers are compact, inexpensive sources of short light pulses of high repetition rates. In this work, we investigate the dynamics and bifurcations arising in such a device under the influence of time delayed optical feedback. This laser system is modelled by a system of delay differential equations, which includes delay terms associated with the laser cavity and feedback loop. We make use of specialised path continuation software for delay differential equations to analyse the regime of short feedback delays. Specifically, we consider how the dynamics and bifurcations depend on the pump current of the laser, the feedback strength, and the feedback delay time. We show that an important role is played by resonances between the mode-locking frequencies and the feedback delay time. We find feedback-induced harmonic mode locking and show that a mismatch between the fundamental frequency of the laser and that of the feedback cavity can lead to multi-pulse or quasiperiodic dynamics. The quasiperiodic dynamics exhibit a slow modulation, on the time scale of the gain recovery rate, which results from a beating with the frequency introduced in the associated torus bifurcations and leads to gain competition between multiple pulse trains within the laser cavity. Our results also have implications for the case of large feedback delay times, where a complete bifurcation analysis is not practical. Namely, for increasing delay, there is an ever-increasing degree of multistability between mode-locked solutions due to the frequency pulling effect.

  15. Discretely tunable micromachined injection-locked lasers

    International Nuclear Information System (INIS)

    Cai, H; Yu, M B; Lo, G Q; Kwong, D L; Zhang, X M; Liu, A Q; Liu, B

    2010-01-01

    This paper reports a micromachined injection-locked laser (ILL) to provide tunable discrete wavelengths. It utilizes a non-continuously tunable laser as the master to lock a Fabry–Pérot semiconductor laser chip. Both lasers are integrated into a deep-etched silicon chip with dimensions of 3 mm × 3 mm × 0.8 mm. Based on the experimental results, significant improvements in the optical power and spectral purity have been achieved in the fully locked state, and optical hysteresis and bistability have also been observed in response to the changes of the output wavelength and optical power of the master laser. As a whole system, the micromachined ILL is able to provide single mode, discrete wavelength tuning, high power and direct modulation with small size and single-chip solution, making it promising for advanced optical communications such as wavelength division multiplexing optical access networks.

  16. Weak-light phase locking for LISA

    International Nuclear Information System (INIS)

    McNamara, Paul W

    2005-01-01

    The long armlengths of the LISA interferometer, and the finite aperture of the telescope, lead to an optical power attenuation of ∼10 -10 of the transmitted to received light. Simple reflection at the end of the arm is therefore not an optimum interferometric design. Instead, a local laser is offset phase locked to the weak incoming beam, transferring the phase information of the incoming to the outgoing light. This paper reports on an experiment to characterize a weak-light phase-locking scheme suitable for LISA in which a diode-pumped, Nd:YAG, non-planar ring oscillator (NPRO) is offset phase locked to a low-power (13 pW) frequency stabilized master NPRO. Preliminary results of the relative phase noise of the slave laser shows shot noise limited performance above 0.4 Hz. Excess noise is observed at lower frequencies, most probably due to thermal effects in the optical arrangement and phase-sensing electronics

  17. Using river locks to teach hydrodynamic concepts

    Science.gov (United States)

    Carvalho-Santos, Vagson L.; Mendes, Thales C.; Silva, Enisvaldo C.; Rios, Márcio L.; Silva, Anderson A. P.

    2013-11-01

    In this work, the use of a river lock as a non-formal setting for teaching hydrodynamical concepts is proposed. In particular, we describe the operation of a river lock situated at the Sobradinho dam, on the São Francisco River (Brazil). A model to represent and to analyse the dynamics of river lock operation is presented and we derive the dynamical equations for the rising of the water column as an example to understand the Euler equation. Furthermore, with this activity, we enable the integration of content initially introduced in the classroom with practical applications, thereby allowing the association of physical themes to content relevant in disciplines such as history and geography. In addition, experiences of this kind enable teachers to talk about the environmental and social impacts caused by the construction of a dam and, consequently, a crossover of concepts has been made possible, leading to more meaningful learning for the students.

  18. Using river locks to teach hydrodynamic concepts

    International Nuclear Information System (INIS)

    Carvalho-Santos, Vagson L; Mendes, Thales C; Silva, Enisvaldo C; Rios, Márcio L; Silva, Anderson A P

    2013-01-01

    In this work, the use of a river lock as a non-formal setting for teaching hydrodynamical concepts is proposed. In particular, we describe the operation of a river lock situated at the Sobradinho dam, on the São Francisco River (Brazil). A model to represent and to analyse the dynamics of river lock operation is presented and we derive the dynamical equations for the rising of the water column as an example to understand the Euler equation. Furthermore, with this activity, we enable the integration of content initially introduced in the classroom with practical applications, thereby allowing the association of physical themes to content relevant in disciplines such as history and geography. In addition, experiences of this kind enable teachers to talk about the environmental and social impacts caused by the construction of a dam and, consequently, a crossover of concepts has been made possible, leading to more meaningful learning for the students. (paper)

  19. John Locke and the right to resistance

    Directory of Open Access Journals (Sweden)

    Jovanov Ilija D.

    2015-01-01

    Full Text Available John Locke was a great thinker and many works have been devoted to clear up his theories. One of the most significant, stated in his principal work, Two Treatises of Government, is the theory of the right to resistance. It was a bit revolutionary then, and to a large extent it is today. Domination of legal positivism is negation of that, by Locke, natural right. However, the fact is that in recent times the resistance to the established power occurs in a number of countries and in different forms, so that the idea of the right to resistance becomes live question again. In this regard it is interesting to consider Locke's viewpoint on this important issue and to determine whether his theory on the resistance is applicable in modern societies.

  20. SWITCHED REFERENCE PHASE LOCK LOOP (SRPLL)

    International Nuclear Information System (INIS)

    KERNER, T.

    2001-01-01

    The Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) has two beam synchronous event links (BSL), one for each ring, which use the 28 MHz ring low level rf to distribute event codes synchronously with a precise phase relationship to the beam. During a cogging reset just before injection, the low level rf sine wave is interrupted which causes the BSL receivers to lose lock. Lock loss in turn causes false triggers and other undesirable-effects on the beam position monitors (BPM), ionization profile monitors (IPM), the tune meter and various experiments which use the BSLs. To rectify these problems, a SRPLL has been inserted between the beam synchronous master and the low level rf source. The SRPLL inserts a frequency and phase continuous splice over the dead-band gap in the rf source created during a cogging reset. The splice removes the gap and prevents the distributed BSL receivers from losing lock

  1. Hybridization-Based Detection of Helicobacter pylori at Human Body Temperature Using Advanced Locked Nucleic Acid (LNA) Probes

    DEFF Research Database (Denmark)

    Fontenete, Sílvia; Guimarães, Nuno; Leite, Marina

    2013-01-01

    The understanding of the human microbiome and its influence upon human life has long been a subject of study. Hence, methods that allow the direct detection and visualization of microorganisms and microbial consortia (e.g. biofilms) within the human body would be invaluable. In here, we assessed...

  2. High-Order Frequency-Locked Loops

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In very recent years, some attempts for designing high-order frequency-locked loops (FLLs) have been made. Nevertheless, the advantages and disadvantages of these structures, particularly in comparison with a standard FLL and high-order phase-locked loops (PLLs), are rather unclear. This lack...... study, and its small-signal modeling, stability analysis, and parameter tuning are presented. Finally, to gain insight about advantages and disadvantages of high-order FLLs, a theoretical and experimental performance comparison between the designed second-order FLL and a standard FLL (first-order FLL...

  3. Mode-locked silicon evanescent lasers.

    Science.gov (United States)

    Koch, Brian R; Fang, Alexander W; Cohen, Oded; Bowers, John E

    2007-09-03

    We demonstrate electrically pumped lasers on silicon that produce pulses at repetition rates up to 40 GHz. The mode locked lasers generate 4 ps pulses with low jitter and extinction ratios above 18 dB, making them suitable for data and telecommunication transmitters and for clock generation and distribution. Results of both passive and hybrid mode locking are discussed. This type of device could enable new silicon based integrated technologies, such as optical time division multiplexing (OTDM), wavelength division multiplexing (WDM), and optical code division multiple access (OCDMA).

  4. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek

    2014-09-01

    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  5. John Locke on persons and personal identity

    OpenAIRE

    Boeker, Ruth

    2013-01-01

    John Locke claims both that ‘person’ is a forensic term and that personal identity consists in sameness of consciousness. The aim of my dissertation is to explain and critically assess how Locke links his moral and legal account of personhood to his account of personal identity in terms of sameness of consciousness. My interpretation of Locke’s account of persons and personal identity is embedded in Locke’s sortal-dependent account of identity. Locke’s sortal-dependent ac...

  6. Optimal database locks for efficient integrity checking

    DEFF Research Database (Denmark)

    Martinenghi, Davide

    2004-01-01

    In concurrent database systems, correctness of update transactions refers to the equivalent effects of the execution schedule and some serial schedule over the same set of transactions. Integrity constraints add further semantic requirements to the correctness of the database states reached upon...... the execution of update transactions. Several methods for efficient integrity checking and enforcing exist. We show in this paper how to apply one such method to automatically extend update transactions with locks and simplified consistency tests on the locked entities. All schedules produced in this way...

  7. Prediction of molecular alignment of nucleic acids in aligned media

    International Nuclear Information System (INIS)

    Wu Bin; Petersen, Michael; Girard, Frederic; Tessari, Marco; Wijmenga, Sybren S.

    2006-01-01

    We demonstrate - using the data base of all deposited DNA and RNA structures aligned in Pf1-medium and RDC refined - that for nucleic acids in a Pf1-medium the electrostatic alignment tensor can be predicted reliably and accurately via a simple and fast calculation based on the gyration tensor spanned out by the phosphodiester atoms. The rhombicity is well predicted over its full range from 0 to 0.66, while the alignment tensor orientation is predicted correctly for rhombicities up to ca. 0.4, for larger rhombicities it appears to deviate somewhat more than expected based on structural noise and measurement error. This simple analytical approach is based on the Debye-Huckel approximation for the electrostatic interaction potential, valid at distances sufficiently far away from a poly-ionic charged surface, a condition naturally enforced when the charge of alignment medium and solute are of equal sign, as for nucleic acids in a Pf1-phage medium. For the usual salt strengths and nucleic acid sizes, the Debye-Huckel screening length is smaller than the nucleic acid size, but large enough for the collective of Debye-Huckel spheres to encompass the whole molecule. The molecular alignment is then purely electrostatic, but it's functional form is under these conditions similar to that for steric alignment. The proposed analytical expression allows for very fast calculation of the alignment tensor and hence RDCs from the conformation of the nucleic acid molecule. This information provides opportunities for improved structure determination of nucleic acids, including better assessment of dynamics in (multi-domain) nucleic acids and the possibility to incorporate alignment tensor prediction from shape directly into the structure calculation process. The procedures are incorporated into MATLAB scripts, which are available on request

  8. Navigation Study, Colorado Locks, Colorado River, Matagorda, Texas

    National Research Council Canada - National Science Library

    McCollum, Randy

    2000-01-01

    A 1:70 physical navigation model was built to replicate the Matagorda Locks, approximately one mile of the GIWW east of the locks, approximately one-half mile of the Colorado River north of the GIWW...

  9. Robust tilt and lock mechanism for hopping actuator

    Energy Technology Data Exchange (ETDEWEB)

    Salton, Jonathan R.; Buerger, Stephen; Dullea, Kevin J.; Marron, Lisa C.; Salisbury, Curt Michael; Spletzer, Barry Louis

    2017-02-07

    A tilt and lock apparatus that includes a tilt servomechanism, a spiral torsion spring, a lock wheel, and a lock hook is described herein. The spiral torsion spring is mechanically coupled to the tilt servomechanism and the lock wheel (which includes an opening). When a shaft is positioned through the opening, rotation of the lock wheel is in unison with rotation of the shaft. An external surface of the lock wheel includes one or more grooves. The lock hook includes a head that engages and disengages the grooves. The lock wheel is stationary when the head engages one of the grooves and is rotatable when the head disengages the grooves. The head and the grooves are geometrically aligned when engaged to prevent creation of a force that acts to disengage the head responsive to an applied force acting on the shaft.

  10. Locking Lasers to RF in an Ultrafast FEL

    International Nuclear Information System (INIS)

    Wilcox, R.; Huang, G.; Doolittle, L.; White, W.; Frisch, J.; Coffee, R.

    2010-01-01

    Using a novel, phase-stabilized RF-over-fiber scheme, they transmit 3GHz over 300m with 27fs RMS error in 250kHz bandwidth over 12 hours, and phase lock a laser to enable ultrafast pump-probe experiments. Free-electron lasers (FELs) are capable of producing short-duration (< 10fs), high-energy X-ray pulses for a range of scientific applications. The recently activated Linac Coherent Light Source (LCLS) FEL facility at SLAC will support experiments which require synchronized light pulses for pump-probe schemes. They developed and operated a fiber optic RF transmission system to synchronize lasers to the emitted X-ray pulses, which was used to enable the first pump-probe experiments at the LCLS.

  11. Locks at reactor safety containments of nuclear power plants

    International Nuclear Information System (INIS)

    1978-12-01

    The rule is to be applied for material access locks. A material access lock as defined by this rule is a pressure resistant and technically gas-tight hollow body that is connected with the containment and has got two doors, the inner door of which connects the lock chamber with the interior of the containment and the outer door connects the lock chamber with the outside. It serves exclusively for transferring material or objects. (orig./HP) [de

  12. Performance Monitoring System: Summary of Lock Statistics. Revision 1.

    Science.gov (United States)

    1985-12-01

    2751 84 4057 4141 526 798 18 1342 5727 19 5523 3996 4587 8583 1056 1630 35 2721 6536LOCK A DAMI 2 AUXILIARY I Ins NO DATA RECORDD FOR THIS LOCK- " LOCK I...TOTAL (KTOMS) ’ - (AVt OPNP ETC) ’’ ,q [ " ARKANSAS RIVER "" FORRELL LOCK IP 7A/3TRC 9/N83 UPBOUID STATISTICS ISO 53 42 M6 553 356 909 221 41 21 M8

  13. Multiprocessor Real-Time Locking Protocols for Replicated Resources

    Science.gov (United States)

    2016-07-01

    assignment problem, the ac- tual identities of the allocated replicas must be known. When locking protocols are used, tasks may experience delays due to both...Multiprocessor Real-Time Locking Protocols for Replicated Resources ∗ Catherine E. Jarrett1, Kecheng Yang1, Ming Yang1, Pontus Ekberg2, and James H...replicas to execute. In prior work on replicated resources, k-exclusion locks have been used, but this restricts tasks to lock only one replica at a time. To

  14. Lock-free parallel garbage collection

    NARCIS (Netherlands)

    H. Gao; J.F. Groote (Jan Friso); W.H. Hesselink (Wim)

    2005-01-01

    htmlabstract This paper presents a lock-free parallel algorithm for mark&sweep garbage collection (GC) in a realistic model using synchronization primitives compare-and-swap (CAS) and load-linked/store-conditional (LL/SC) offered by machine architectures. Mutators and collectors can simultaneously

  15. A Mode Locked UV-FEL

    CERN Document Server

    Parvin, Parviz

    2004-01-01

    An appropriate resonator has been designed to generate femtosecond mode locked pulses in a UV FEL with the modulator performance based on the gain switching. The gain broadening due to electron energy spread affects on the gain parameters, small signal gain (γ0) and saturation intensity (Is), to determine the optimum output coupling as small.

  16. CMOS switched current phase-locked loop

    NARCIS (Netherlands)

    Leenaerts, D.M.W.; Persoon, G.G.; Putter, B.M.

    1997-01-01

    The authors present an integrated circuit realisation of a switched current phase-locked loop (PLL) in standard 2.4 µm CMOS technology. The centre frequency is tunable to 1 MHz at a clock frequency of 5.46 MHz. The PLL has a measured maximum phase error of 21 degrees. The chip consumes

  17. Phase locking of optically coupled lasers

    International Nuclear Information System (INIS)

    Glova, A F

    2003-01-01

    A review of studies of the properties of radiation from optically coupled lasers is presented. The methods for phase locking the fields in optically coupled lasers of different types are considered and the methods for supermode selection and correction of the radiation pattern are discussed. (review)

  18. 49 CFR 236.742 - Dog, locking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Dog, locking. 236.742 Section 236.742 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog...

  19. A New Perspective on Job Lock

    Science.gov (United States)

    Huysse-Gaytandjieva, Anna; Groot, Wim; Pavlova, Milena

    2013-01-01

    This paper analyses the situation when employees fail to adapt to overall job dissatisfaction. By combining the existing knowledge in economics on job lock and in psychology on employees' feeling of being "stuck" at work, the paper explains why some employees fail to adapt when dissatisfied with their job. Thus, the paper aims to expand…

  20. Locks & keys service moves to building 55

    CERN Multimedia

    2012-01-01

    Please note that as of July 12 Locks & keys service will be at building 55 second floor. The opening hours are as follows: 08:30 am to 12:30 pm - 1:30 pm to 5:30 pm. The procedures and rules relating to applications for key and cylinder have not changed. GI-IS Group

  1. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  2. Commercial mode-locked vertical external cavity surface emitting lasers

    Science.gov (United States)

    Head, C. Robin; Paboeuf, David; Ortega, Tiago; Lubeigt, Walter; Bialkowski, Bartlomiej; Lin, Jipeng; Hempler, Nils; Maker, Gareth T.; Malcolm, Graeme P. A.

    2018-02-01

    This paper presents the latest efforts in the development of commercial optically-pumped semiconductor disk lasers (SDLs) at M Squared Lasers. Two types of SDLs are currently being developed: an ultrafast system and a continuous wave single frequency system under the names of Dragonfly and Infinite, respectively. Both offer a compact, low-cost, easy-to-use and maintenance-free tool for a range of growing markets including nonlinear microscopy and quantum technology. To facilitate consumer uptake of the SDL technology, the performance specifications aim to closely match the currently employed systems. An extended Dragonfly system is being developed targeting the nonlinear microscopy market, which typically requires 1-W average power pulse trains with pulse durations below 200 fs. The pulse repetition frequency (PRF) of the commonly used laser systems, typically Titanium-sapphire lasers, is 80 MHz. This property is particularly challenging for mode-locked SDLs which tend to operate at GHz repetition rates, due to their short upper state carrier lifetime. Dragonfly has found a compromise at 200 MHz to balance mode-locking instabilities with a low PRF. In the ongoing development of Dragonfly, additional pulse compression and nonlinear spectral broadening stages are used to obtain pulse durations as short as 130 fs with an average power of 0.85 W, approaching the required performance. A variant of the Infinite system was adapted to provide a laser source suitable for the first stage of Sr atom cooling at 461 nm. Such a source requires average powers of approximately 1 W with a sub-MHz linewidth. As direct emission in the blue is not a viable approach at this stage, an SDL emitting at 922 nm followed by an M Squared Lasers SolTiS ECD-X doubler is currently under development. The SDL oscillator delivered >1 W of single frequency (RMS frequency noise <150kHz) light at 922 nm.

  3. A photovoltaic module diagnostic setup for lock-in-thermography and lock-in electroluminescence imaging

    DEFF Research Database (Denmark)

    Parikh, Harsh; Spataru, Sergiu; Sera, Dezso

    2018-01-01

    Electroluminescence (EL) imaging and infrared (IRT) thermography techniques have become indispensable tools in recent years for health diagnostic of PV modules in solar industry application. Complementary to these imaging methods, lock-in techniques can effectively remove noise by periodically...... modulating the input signal and averaging it over a desired number of periods. We propose a combined lock-in EL and lock-in IRT diagnostic setup for accurate analysis of different types of faults occurring in a solar module. The setup is built around a Goldeye CL-033 high-speed SWIR camera, which can acquire...... experimental work on a (36/72) cell solar module using combined (EL) or (IRT) lock-in-thermography. The setup allows one to investigate the different technological problems that can occur when performing PV diagnostics in drone-based inspections....

  4. Navigation Study of Lower Lock Approach, John Day Lock and Dam, Columbia River, Oregon

    National Research Council Canada - National Science Library

    Wilson, Donald

    2001-01-01

    Representatives of the Columbia River Towing Association reported recent structural and/or operational changes at John Day Lock and Dam have created difficult navigation conditions for tows entering...

  5. Dioxaphosphorinane-Constrained Nucleic Acid Dinucleotides as Tools for Structural Tuning of Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Dan-Andrei Catana

    2012-01-01

    Full Text Available We describe a rational approach devoted to modulate the sugar-phosphate backbone geometry of nucleic acids. Constraints were generated by connecting one oxygen of the phosphate group to a carbon of the sugar moiety. The so-called dioxaphosphorinane rings were introduced at key positions along the sugar-phosphate backbone allowing the control of the six-torsion angles α to ζ defining the polymer structure. The syntheses of all the members of the D-CNA family are described, and we emphasize the effect on secondary structure stabilization of a couple of diastereoisomers of α,β-D-CNA exhibiting wether B-type canonical values or not.

  6. 30 CFR 56.12068 - Locking transformer enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

  7. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Science.gov (United States)

    2010-07-01

    ... damage by their operations to the lock or other structures. They must use great care not to strike any.... All tow lines or hawsers must be hauled as short as practicable for safe handling of tows. (15) Crew... sufficient number of men to handle lines in mooring craft and to move barges and other craft into and out of...

  8. Nucleic acids for the rational design of reaction circuits.

    Science.gov (United States)

    Padirac, Adrien; Fujii, Teruo; Rondelez, Yannick

    2013-08-01

    Nucleic acid-based circuits are rationally designed in vitro assemblies that can perform complex preencoded programs. They can be used to mimic in silico computations. Recent works emphasized the modularity and robustness of these circuits, which allow their scaling-up. Another new development has led to dynamic, time-responsive systems that can display emergent behaviors like oscillations. These are closely related to biological architectures and provide an in vitro model of in vivo information processing. Nucleic acid circuits have already been used to handle various processes for technological or biotechnological purposes. Future applications of these chemical smart systems will benefit from the rapidly growing ability to design, construct, and model nucleic acid circuits of increasing size. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Locked modes and magnetic field errors in MST

    International Nuclear Information System (INIS)

    Almagri, A.F.; Assadi, S.; Prager, S.C.; Sarff, J.S.; Kerst, D.W.

    1992-06-01

    In the MST reversed field pinch magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance, the disturbance locks to an impulsive field error generated at a sawtooth crash, the error fields grow monotonically after locking (perhaps due to an unstable interaction between the modes and field error), and over the tens of milliseconds of growth confinement degrades and the discharge eventually terminates. Field error control has been partially successful in eliminating locking

  10. Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

    Science.gov (United States)

    McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

    2014-01-01

    We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

  11. Nucleic acid aptamers: an emerging frontier in cancer therapy.

    Science.gov (United States)

    Zhu, Guizhi; Ye, Mao; Donovan, Michael J; Song, Erqun; Zhao, Zilong; Tan, Weihong

    2012-11-04

    The last two decades have witnessed the development and application of nucleic acid aptamers in a variety of fields, including target analysis, disease therapy, and molecular and cellular engineering. The efficient and widely applicable aptamer selection, reproducible chemical synthesis and modification, generally impressive target binding selectivity and affinity, relatively rapid tissue penetration, low immunogenicity, and rapid systemic clearance make aptamers ideal recognition elements for use as therapeutics or for in vivo delivery of therapeutics. In this feature article, we discuss the development and biomedical application of nucleic acid aptamers, with emphasis on cancer cell aptamer isolation, targeted cancer therapy, oncology biomarker identification and drug discovery.

  12. Methods of introducing nucleic acids into cellular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Lajoie, Marc J.; Gregg, Christopher J.; Mosberg, Joshua A.; Church, George M.

    2017-06-27

    A method of introducing a nucleic acid sequence into a cell is provided where the cell has impaired or inhibited or disrupted DnaG primase activity or impaired or inhibited or disrupted DnaB helicase activity, or larger or increased gaps or distance between Okazaki fragments or lowered or reduced frequency of Okazaki fragment initiation, or the cell has increased single stranded DNA (ssDNA) on the lagging strand of the replication fork including transforming the cell through recombination with a nucleic acid oligomer.

  13. A Pitfall in Fixation of Distal Humeral Fractures with Pre-Contoured Locking Compression Plate

    Directory of Open Access Journals (Sweden)

    Prakash Jayakumar

    2015-04-01

    Full Text Available Anatomically precontoured locking plates are intended to facilitate the fixation of articular fractures and particularly those associated with osteoporosis. Fractures of the distal humerus are relatively uncommon injuries where operative intervention can be exceptionally challenging. The distal humeral trochlea provides a very narrow anatomical window through which to pass a fixed-angle locking screw, which must also avoid the olecranon, coronoid, and radial fossae. We describe 3 patients (ages 27, 49, and 73 years with a bicolumnar fracture of the distal humerus where very short distal locking screws were used. Intra-articular screw placement was avoided but loss of fixation occurred in two patients and a third was treated with a prolonged period of immobilization. We postulate that fixed-angle screw trajectories may make it difficult for the surgeon to place screws of adequate length in this anatomically confined region, and may lead to insufficient distal fixation. Surgical tactics should include placement of as many screws as possible into the distal fragment, as long as possible, and that each screw pass through a plate without necessarily locking in.

  14. Wall locking and multiple nonlinear states of magnetic islands

    International Nuclear Information System (INIS)

    Persson, Mikael; Australian National Univ., Canberra, ACT

    1994-01-01

    The nonlinear evolution of magnetic islands is analysed in configurations with multiple resonant magnetic surfaces. The existence of multiple nonlinear steady states, is discussed. These are shown to be associated with states where the dynamics around the different rational surfaces are coupled or decoupled and in the presence of a wall of finite resistivity may correspond wall-locked or non-wall-locked magnetic islands. For the case of strong wall stabilization the locking is shown to consist of two different phases. During the first phase the locking of the plasma at the different rational surfaces occurs. Only when the outermost resonant magnetic surface has locked to the inner surfaces can the actual wall locking process take place. Consequently, wall locking, of a global mode, involving more than one rational surface, can be prevented by the decoupling of the resonant magnetic surfaces by plasma rotation. Possible implications on tokamak experiments are discussed. (author)

  15. Power spectrum of an injection-locked Josephson oscillator

    International Nuclear Information System (INIS)

    Stancampiano, C.V.; Shapiro, S.

    1975-01-01

    Experiments have shown that a Josephson oscillator, exposed to a weak narrow-band input signal, exhibits behavior characteristic of an injection-locked oscillator. When in lock, Adler's theory of injection locking describes the experimental observations reasonably well. The range of applicability of the theory is extended to the out-of-lock regime where a spectrum of output frequencies is observed. Obtaining the theoretical output power spectrum requires solving a differential equation having the same form as the equation describing the resistively shunted junction model of Stewart and of McCumber. Experimental measurements of the output spectrum of a nearly locked Josephson oscillator are shown to be in reasonable agreement with the theory. Additional results discussed briefly include the observation of a frequency dependence of the locked Josephson oscillator output and experiments in which a Josephson oscillator-mixer was injection locked by a weak signal at the rf

  16. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  17. Probing the transition state for nucleic acid hybridization using phi-value analysis.

    Science.gov (United States)

    Kim, Jandi; Shin, Jong-Shik

    2010-04-27

    Genetic regulation by noncoding RNA elements such as microRNA and small interfering RNA (siRNA) involves hybridization of a short single-stranded RNA with a complementary segment in a target mRNA. The physical basis of the hybridization process between the structured nucleic acids is not well understood primarily because of the lack of information about the transition-state structure. Here we use transition-state theory, inspired by phi-value analysis in protein folding studies, to provide quantitative analysis of the relationship between changes in the secondary structure stability and the activation free energy. Time course monitoring of the hybridization reaction was performed under pseudo-steady-state conditions using a single fluorophore. The phi-value analysis indicates that the native secondary structure remains intact in the transition state. The nativelike transition state was confirmed via examination of the salt dependence of the hybridization kinetics, indicating that the number of sodium ions associated with the transition state was not substantially affected by changes in the native secondary structure. These results propose that hybridization between structured nucleic acids undergoes a transition state leading to formation of a nucleation complex and then is followed by sequential displacement of preexisting base pairings involving successive small energy barriers. The proposed mechanism might provide new insight into physical processes during small RNA-mediated gene silencing, which is essential to selection of a target mRNA segment for siRNA design.

  18. Spherical Nucleic Acids as Intracellular Agents for Nucleic Acid Based Therapeutics

    Science.gov (United States)

    Hao, Liangliang

    Recent functional discoveries on the noncoding sequences of human genome and transcriptome could lead to revolutionary treatment modalities because the noncoding RNAs (ncRNAs) can be applied as therapeutic agents to manipulate disease-causing genes. To date few nucleic acid-based therapeutics have been translated into the clinic due to challenges in the delivery of the oligonucleotide agents in an effective, cell specific, and non-toxic fashion. Unmodified oligonucleotide agents are destroyed rapidly in biological fluids by enzymatic degradation and have difficulty crossing the plasma membrane without the aid of transfection reagents, which often cause inflammatory, cytotoxic, or immunogenic side effects. Spherical nucleic acids (SNAs), nanoparticles consisting of densely organized and highly oriented oligonucleotides, pose one possible solution to circumventing these problems in both the antisense and RNA interference (RNAi) pathways. The unique three dimensional architecture of SNAs protects the bioactive oligonucleotides from unspecific degradation during delivery and supports their targeting of class A scavenger receptors and endocytosis via a lipid-raft-dependent, caveolae-mediated pathway. Owing to their unique structure, SNAs are able to cross cell membranes and regulate target genes expression as a single entity, without triggering the cellular innate immune response. Herein, my thesis has focused on understanding the interactions between SNAs and cellular components and developing SNA-based nanostructures to improve therapeutic capabilities. Specifically, I developed a novel SNA-based, nanoscale agent for delivery of therapeutic oligonucleotides to manipulate microRNAs (miRNAs), the endogenous post-transcriptional gene regulators. I investigated the role of SNAs involving miRNAs in anti-cancer or anti-inflammation responses in cells and in in vivo murine disease models via systemic injection. Furthermore, I explored using different strategies to construct

  19. Polymerase chain reaction system using magnetic beads for analyzing a sample that includes nucleic acid

    Science.gov (United States)

    Nasarabadi, Shanavaz [Livermore, CA

    2011-01-11

    A polymerase chain reaction system for analyzing a sample containing nucleic acid includes providing magnetic beads; providing a flow channel having a polymerase chain reaction chamber, a pre polymerase chain reaction magnet position adjacent the polymerase chain reaction chamber, and a post pre polymerase magnet position adjacent the polymerase chain reaction chamber. The nucleic acid is bound to the magnetic beads. The magnetic beads with the nucleic acid flow to the pre polymerase chain reaction magnet position in the flow channel. The magnetic beads and the nucleic acid are washed with ethanol. The nucleic acid in the polymerase chain reaction chamber is amplified. The magnetic beads and the nucleic acid are separated into a waste stream containing the magnetic beads and a post polymerase chain reaction mix containing the nucleic acid. The reaction mix containing the nucleic acid flows to an analysis unit in the channel for analysis.

  20. 1.34 µm picosecond self-mode-locked Nd:GdVO4 watt-level laser

    Science.gov (United States)

    Han, Ming; Peng, Jiying; Li, Zuohan; Cao, Qiuyuan; Yuan, Ruixia

    2017-01-01

    With a simple linear configuration, a diode-pumped, self-mode-locked Nd:GdVO4 laser at 1.34 µm is experimentally demonstrated for the first time. Based on the aberrationless theory of self-focusing and thermal lensing effect, through designing and optimizing the resonator, a pulse width as short as 9.1 ps is generated at a repetition rate of 2.0 GHz and the average output power is 2.51 W. The optical conversion efficiency and the slope efficiency for the stable mode-locked operation are approximately 16.7% and 19.2%, respectively.

  1. Effect of the doped fibre length on soliton pulses of a bidirectional mode-locked fibre laser

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, H; Alwi Kutty, N A; Zulkifli, M Z; Harun, S W [Photonics Research Center (Department of Physics), University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-08-31

    A passively bidirectional mode-locked fibre laser is demonstrated using a highly concentrated erbium-doped fibre (EDF) as a gain medium. To accomplish mode-locked operation in a short cavity, use is made of carbon nanotubes (CNTs) as a saturable absorber. Soliton pulses are obtained at a wavelength of 1560 nm with a repetition rate ranging from 43.92 MHz to 46.97 MHz and pulse width stretching from 0.56 ps to 0.41 ps as the EDF length is reduced from 60 cm to 30 cm. (lasers)

  2. Harmonic mode-locking and sub-round-trip time nonlinear dynamics of electro-optically controlled solid state laser

    Science.gov (United States)

    Gorbunkov, M. V.; Maslova, Yu Ya; Petukhov, V. A.; Semenov, M. A.; Shabalin, Yu V.; Tunkin, V. G.

    2018-03-01

    Harmonic mode-locking in a solid state laser due to optoelectronic control is studied numerically on the basis of two methods. The first one is detailed numeric simulation taking into account laser radiation fine time structure. It is shown that optimally chosen feedback delay leads to self-started mode-locking with generation of desired number of pulses in the laser cavity. The second method is based on discrete maps for short laser pulse energy. Both methods show that the application of combination of positive and negative feedback loops allows to reduce the period of regular nonlinear dynamics down to a fraction of a laser cavity round trip time.

  3. Three Alternative Symbol-Lock Detectors

    Science.gov (United States)

    Shihabi, Mazen M.; Hinedi, Sami M.; Shah, Biren N.

    1993-01-01

    Three symbol-lock detectors proposed as alternatives in advanced receivers processing non-return-to-zero binary data signals. Two perform operations similar to those of older square-law and absolute-value types. However, integrals computed during nonoverlapping symbol periods and, therefore, only one integrator needed in each such detector. Proposed detectors simpler, but performances worse because noises in overlapping samples correlated, whereas noises in nonoverlapping samples not correlated. Third detector is signal-power-estimator type. Signal integrated during successive half symbol cycles, and therefore only one integrator needed. Half-cycle integrals multiplied to eliminate effect of symbol polarity, and products accumulated during M-cycle observation period to smooth out estimate of signal power. If estimated signal power exceeds threshold, delta, then lock declared.

  4. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery....... Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard...

  5. Mode-locking via dissipative Faraday instability.

    Science.gov (United States)

    Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K

    2016-08-09

    Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

  6. Quantum locking of mirrors in interferometers.

    Science.gov (United States)

    Courty, Jean-Michel; Heidmann, Antoine; Pinard, Michel

    2003-02-28

    We show that quantum noise in very sensitive interferometric measurements such as gravitational-wave detectors can be drastically modified by quantum feedback. We present a new scheme based on active control to lock the motion of a mirror to a reference mirror at the quantum level. This simple technique allows one to reduce quantum effects of radiation pressure and to greatly enhance the sensitivity of the detection.

  7. Dither Cavity Length Controller with Iodine Locking

    Directory of Open Access Journals (Sweden)

    Lawson Marty

    2016-01-01

    Full Text Available A cavity length controller for a seeded Q-switched frequency doubled Nd:YAG laser is constructed. The cavity length controller uses a piezo-mirror dither voltage to find the optimum length for the seeded cavity. The piezo-mirror dither also dithers the optical frequency of the output pulse. [1]. This dither in optical frequency is then used to lock to an Iodine absorption line.

  8. A nucleic acid dependent chemical photocatalysis in live human cells

    DEFF Research Database (Denmark)

    Arian, Dumitru; Cló, Emiliano; Gothelf, Kurt V

    2010-01-01

    Only two nucleic acid directed chemical reactions that are compatible with live cells have been reported to date. Neither of these processes generate toxic species from nontoxic starting materials. Reactions of the latter type could be applied as gene-specific drugs, for example, in the treatment...

  9. Nucleic Acid Amplification as used in the Diagnosis and ...

    African Journals Online (AJOL)

    Nucleic Acid Amplification as used in the Diagnosis and Management of Viral Diseases: A Review. ... Bayero Journal of Pure and Applied Sciences ... are highly unculturable, fastidious or hazardous to the laboratory personnel and diagnosis depends on serological methods or culture in an expensive bio-safety level.

  10. Watson-Crick hydrogen bonding of unlocked nucleic acids

    DEFF Research Database (Denmark)

    Langkjær, Niels; Wengel, Jesper; Pasternak, Anna

    2015-01-01

    We herein describe the synthesis of two new unlocked nucleic acid building blocks containing hypoxanthine and 2,6-diaminopurine as nucleobase moieties and their incorporation into oligonucleotides. The modified oligonucleotides were used to examine the thermodynamic properties of UNA against unmo...... unmodified oligonucleotides and the resulting thermodynamic data support that the hydrogen bonding face of UNA is Watson-Crick like....

  11. Structure, stability and behaviour of nucleic acids in ionic liquids

    Science.gov (United States)

    Tateishi-Karimata, Hisae; Sugimoto, Naoki

    2014-01-01

    Nucleic acids have become a powerful tool in nanotechnology because of their conformational polymorphism. However, lack of a medium in which nucleic acid structures exhibit long-term stability has been a bottleneck. Ionic liquids (ILs) are potential solvents in the nanotechnology field. Hydrated ILs, such as choline dihydrogen phosphate (choline dhp) and deep eutectic solvent (DES) prepared from choline chloride and urea, are ‘green’ solvents that ensure long-term stability of biomolecules. An understanding of the behaviour of nucleic acids in hydrated ILs is necessary for developing DNA materials. We here review current knowledge about the structures and stabilities of nucleic acids in choline dhp and DES. Interestingly, in choline dhp, A–T base pairs are more stable than G–C base pairs, the reverse of the situation in buffered NaCl solution. Moreover, DNA triplex formation is markedly stabilized in hydrated ILs compared with aqueous solution. In choline dhp, the stability of Hoogsteen base pairs is comparable to that of Watson–Crick base pairs. Moreover, the parallel form of the G-quadruplex is stabilized in DES compared with aqueous solution. The behaviours of various DNA molecules in ILs detailed here should be useful for designing oligonucleotides for the development of nanomaterials and nanodevices. PMID:25013178

  12. Circulating nucleic acids as a new diagnostic tool

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Markéta; Plzák, J.; Strnad, Hynek; Betka, J.

    2010-01-01

    Roč. 15, č. 2 (2010), s. 242-259 ISSN 1425-8153 R&D Projects: GA MŠk 2B06106 Institutional research plan: CEZ:AV0Z50520514 Keywords : circulating nucleic acids * diagnostics * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.455, year: 2010

  13. Mosaic protein and nucleic acid vaccines against hepatitis C virus

    Science.gov (United States)

    Yusim, Karina; Korber, Bette T. M.; Kuiken, Carla L.; Fischer, William M.

    2013-06-11

    The invention relates to immunogenic compositions useful as HCV vaccines. Provided are HCV mosaic polypeptide and nucleic acid compositions which provide higher levels of T-cell epitope coverage while minimizing the occurrence of unnatural and rare epitopes compared to natural HCV polypeptides and consensus HCV sequences.

  14. Assessment for Melting Temperature Measurement of Nucleic Acid by HRM.

    Science.gov (United States)

    Wang, Jing; Pan, Xiaoming; Liang, Xingguo

    2016-01-01

    High resolution melting (HRM), with a high sensitivity to distinguish the nucleic acid species with small variations, has been widely applied in the mutation scanning, methylation analysis, and genotyping. For the aim of extending HRM for the evaluation of thermal stability of nucleic acid secondary structures on sequence dependence, we investigated effects of the dye of EvaGreen, metal ions, and impurities (such as dNTPs) on melting temperature ( T m ) measurement by HRM. The accuracy of HRM was assessed as compared with UV melting method, and little difference between the two methods was found when the DNA T m was higher than 40°C. Both insufficiency and excessiveness of EvaGreen were found to give rise to a little bit higher T m , showing that the proportion of dye should be considered for precise T m measurement of nucleic acids. Finally, HRM method was also successfully used to measure T m s of DNA triplex, hairpin, and RNA duplex. In conclusion, HRM can be applied in the evaluation of thermal stability of nucleic acid (DNA or RNA) or secondary structural elements (even when dNTPs are present).

  15. DNA-like double helix formed by peptide nucleic acid

    DEFF Research Database (Denmark)

    Wittung, P; Nielsen, Peter E.; Buchardt, O

    1994-01-01

    Although the importance of the nucleobases in the DNA double helix is well understood, the evolutionary significance of the deoxyribose phosphate backbone and the contribution of this chemical entity to the overall helical structure and stability of the double helix is not so clear. Peptide nucleic...

  16. A DNA origami nanorobot controlled by nucleic acid hybridization

    KAUST Repository

    Torelli, Emanuela

    2014-03-20

    A prototype for a DNA origami nanorobot is designed, produced, and tested. The cylindrical nanorobot (diameter of 14 nm and length of 48 nm) with a switchable flap, is able to respond to an external stimulus and reacts by a physical switch from a disarmed to an armed configuration able to deliver a cellular compatible message. In the tested design the robot weapon is a nucleic acid fully contained in the inner of the tube and linked to a single point of the internal face of the flap. Upon actuation the nanorobot moves the flap extracting the nucleic acid that assembles into a hemin/G-quadruplex horseradish peroxidase mimicking DNAzyme catalyzing a colorimetric reaction or chemiluminescence generation. The actuation switch is triggered by an external nucleic acid (target) that interacts with a complementary nucleic acid that is beard externally by the nanorobot (probe). Hybridization of probe and target produces a localized structural change that results in flap opening. The flap movement is studied on a two-dimensional prototype origami using Förster resonance energy transfer and is shown to be triggered by a variety of targets, including natural RNAs. The nanorobot has potential for in vivo biosensing and intelligent delivery of biological activators. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A DNA origami nanorobot controlled by nucleic acid hybridization.

    Science.gov (United States)

    Torelli, Emanuela; Marini, Monica; Palmano, Sabrina; Piantanida, Luca; Polano, Cesare; Scarpellini, Alice; Lazzarino, Marco; Firrao, Giuseppe

    2014-07-23

    A prototype for a DNA origami nanorobot is designed, produced, and tested. The cylindrical nanorobot (diameter of 14 nm and length of 48 nm) with a switchable flap, is able to respond to an external stimulus and reacts by a physical switch from a disarmed to an armed configuration able to deliver a cellular compatible message. In the tested design the robot weapon is a nucleic acid fully contained in the inner of the tube and linked to a single point of the internal face of the flap. Upon actuation the nanorobot moves the flap extracting the nucleic acid that assembles into a hemin/G-quadruplex horseradish peroxidase mimicking DNAzyme catalyzing a colorimetric reaction or chemiluminescence generation. The actuation switch is triggered by an external nucleic acid (target) that interacts with a complementary nucleic acid that is beard externally by the nanorobot (probe). Hybridization of probe and target produces a localized structural change that results in flap opening. The flap movement is studied on a two-dimensional prototype origami using Förster resonance energy transfer and is shown to be triggered by a variety of targets, including natural RNAs. The nanorobot has potential for in vivo biosensing and intelligent delivery of biological activators. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Surface plasmon resonance sensing of nucleic acids: A review

    Czech Academy of Sciences Publication Activity Database

    Šípová, Hana; Homola, Jiří

    -, č. 773 (2013), s. 9-23 ISSN 0003-2670 R&D Projects: GA MŠk(CZ) LH11102 Institutional support: RVO:67985882 Keywords : Surface plasmon resonance * Nucleic acid * Biosensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 4.517, year: 2013

  19. Peptide nucleic acids and their potential applications in biotechnology

    DEFF Research Database (Denmark)

    Buchardt, O.; Egholm, M.; Berg, R.H.

    1993-01-01

    Peptide nucleic acids (PNAs) are novel DNA mimics in which the sugar-phosphate backbone has been replaced with a backbone based on amino acids1-3. PNAs exhibit sequence-specific binding to DNA and RNA with higher affinities and specificities than unmodified DNA. They,are resistant to nuclease...

  20. Geometric properties of nucleic acids with potential for autobuilding

    International Nuclear Information System (INIS)

    Gruene, Tim; Sheldrick, George M.

    2011-01-01

    Algorithms and geometrical properties are described for the automated building of nucleic acids in experimental electron density. Medium- to high-resolution X-ray structures of DNA and RNA molecules were investigated to find geometric properties useful for automated model building in crystallographic electron-density maps. We describe a simple method, starting from a list of electron-density ‘blobs’, for identifying backbone phosphates and nucleic acid bases based on properties of the local electron-density distribution. This knowledge should be useful for the automated building of nucleic acid models into electron-density maps. We show that the distances and angles involving C1′ and the P atoms, using the pseudo-torsion angles η' and θ' that describe the …P—C1′—P—C1′… chain, provide a promising basis for building the nucleic acid polymer. These quantities show reasonably narrow distributions with asymmetry that should allow the direction of the phosphate backbone to be established

  1. Delivery Systems for In Vivo use of Nucleic Acid Drugs

    Directory of Open Access Journals (Sweden)

    Resende R.R

    2007-01-01

    Full Text Available The notorious biotechnological advance of the last few decades has allowed the development of experimental methods for understanding molecular mechanisms of genes and new therapeutic approaches. Gene therapy is maturing into a viable, practical method with the potential to cure a variety of human illnesses. Some nucleic-acid-based drugs are now available for controlling the progression of genetic diseases by inhibiting gene expression or the activity of their gene products. New therapeutic strategies employ a wide range of molecular tools such as bacterial plasmids containing transgenic inserts, RNA interference aptamers. A nucleic-acid based constitution confers a lower immunogenic potential and as result of the high stringency selection of large molecular variety, these drugs have high affi nity and selectivity for their targets. However, nucleic acids have poor biostability thus requiring chemical modifications and delivery systems to maintain their activity and ease their cellular internalization. This review discusses some of the mechanisms of action and the application of therapies based on nucleic acids such as aptamers and RNA interference as well as platforms for cellular uptake and intracellular delivery of therapeutic oligonucleotides and their trade-offs.

  2. Boronic acid-based autoligation of nucleic acids

    DEFF Research Database (Denmark)

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible bo....... Evidence suggests that geometric and steric factors are key features for controlling the equilibria. Graphical Abstract: [Figure not available: see fulltext.]...

  3. Predicting nucleic acid binding interfaces from structural models of proteins.

    Science.gov (United States)

    Dror, Iris; Shazman, Shula; Mukherjee, Srayanta; Zhang, Yang; Glaser, Fabian; Mandel-Gutfreund, Yael

    2012-02-01

    The function of DNA- and RNA-binding proteins can be inferred from the characterization and accurate prediction of their binding interfaces. However, the main pitfall of various structure-based methods for predicting nucleic acid binding function is that they are all limited to a relatively small number of proteins for which high-resolution three-dimensional structures are available. In this study, we developed a pipeline for extracting functional electrostatic patches from surfaces of protein structural models, obtained using the I-TASSER protein structure predictor. The largest positive patches are extracted from the protein surface using the patchfinder algorithm. We show that functional electrostatic patches extracted from an ensemble of structural models highly overlap the patches extracted from high-resolution structures. Furthermore, by testing our pipeline on a set of 55 known nucleic acid binding proteins for which I-TASSER produces high-quality models, we show that the method accurately identifies the nucleic acids binding interface on structural models of proteins. Employing a combined patch approach we show that patches extracted from an ensemble of models better predicts the real nucleic acid binding interfaces compared with patches extracted from independent models. Overall, these results suggest that combining information from a collection of low-resolution structural models could be a valuable approach for functional annotation. We suggest that our method will be further applicable for predicting other functional surfaces of proteins with unknown structure. Copyright © 2011 Wiley Periodicals, Inc.

  4. PYRENE INTERCALATING NUCLEIC ACIDS WITH A CARBON LINKER

    DEFF Research Database (Denmark)

    Østergaard, Michael E.; Wamberg, Michael Chr.; Pedersen, Erik Bjerregaard

    2011-01-01

    geminally attached. Fluorescence studies of this intercalating nucleic acid with the pyrene moieties inserted as a bulge showed formation of an excimer band. When a mismatch was introduced at the site of the intercalator, an excimer band was formed for the destabilized duplexes whereas an exciplex band...

  5. Karyotype and nucleic acid content in Zantedeschia aethiopica Spr ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-07-03

    Jul 3, 2012 ... Analysis of karyotype, nucleic deoxyribonucleic acid (DNA) content and sodium dodecyl sulfate polyacrylamide ... base pairs) for Z. aethiopica and 1144.26 ± 0.05 picograms (equivalent to 1144.26 mega base pairs) for Z. elliottiana. ... ml ice-cold nuclei-isolation buffer A of the Partec high resolution. DNA kit ...

  6. Localization of Bovine Papillomavirus Nucleic Acid in Equine Sarcoids.

    Science.gov (United States)

    Gaynor, A M; Zhu, K W; Dela Cruz, F N; Affolter, V K; Pesavento, P A

    2016-05-01

    Bovine papillomaviruses (BPV1/BPV2) have long been associated with equine sarcoids; deciphering their contribution has been difficult due to their ubiquitous presence on skin and in the environment, as well as the lack of decent techniques to interrogate their role in pathogenesis. We have developed and characterized an in situ hybridization (ISH) assay that uses a pool of probes complementary to portions of the E5, E6, and E7 genes. This assay is highly sensitive for direct visualization of viral transcript and nucleic acid in routinely processed histopathologic samples. We demonstrate here the visualization of BPV nucleic acid in 18 of 18 equine sarcoids, whereas no detectable viral DNA was present in 15 of 15 nonsarcoid controls by this technique. In nearly 90% (16/18) of the sarcoids, 50% or more of the fibroblastic cell nuclei distributed throughout the neoplasm had detectable hybridization. In the remaining 2 cases, fewer than half of the fibroblastic cells contained detectable hybridization, but viral nucleic acid was also detected in epithelial cells of the sebaceous glands, hair follicles and epidermis. A sensitive ISH assay is an indispensable addition to the molecular methods used to detect viral nucleic acid in tissue. We have used this technique to determine the specific cellular localization and distribution of BPV in a subset of equine sarcoids. © The Author(s) 2015.

  7. Nucleic acid detection with surface plasmon resonance using cationic latex

    NARCIS (Netherlands)

    de Vries, E.F.A.; Schasfoort, Richardus B.M.; van der Plas, J.; Greve, Jan

    1994-01-01

    An affinity sensor based on Surface Plasmon Resonance (SPR) was used to detect nucleic acids. SPR is an optical technique that is able to detect small changes in the refractive index of the immediate vicinity of a metal surface. After a specific amplification of DNA, achieved using the polymerase

  8. Programmable Self-Locking Origami Mechanical Metamaterials.

    Science.gov (United States)

    Fang, Hongbin; Chu, Shih-Cheng A; Xia, Yutong; Wang, Kon-Well

    2018-04-01

    Developing mechanical metamaterials with programmable properties is an emerging topic receiving wide attention. While the programmability mainly originates from structural multistability in previously designed metamaterials, here it is shown that nonflat-foldable origami provides a new platform to achieve programmability via its intrinsic self-locking and reconfiguration capabilities. Working with the single-collinear degree-4 vertex origami tessellation, it is found that each unit cell can self-lock at a nonflat configuration and, therefore, possesses wide design space to program its foldability and relative density. Experiments and numerical analyses are combined to demonstrate that by switching the deformation modes of the constituent cell from prelocking folding to postlocking pressing, its stiffness experiences a sudden jump, implying a limiting-stopper effect. Such a stiffness jump is generalized to a multisegment piecewise stiffness profile in a multilayer model. Furthermore, it is revealed that via strategically switching the constituent cells' deformation modes through passive or active means, the n-layer metamaterial's stiffness is controllable among 2 n target stiffness values. Additionally, the piecewise stiffness can also trigger bistable responses dynamically under harmonic excitations, highlighting the metamaterial's rich dynamic performance. These unique characteristics of self-locking origami present new paths for creating programmable mechanical metamaterials with in situ controllable mechanical properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Tibiotalocalcaneal arthrodesis using a humeral locking plate].

    Science.gov (United States)

    Cabrera Méndez, M P; Gamba, C; Hernández, E; Molano, J; Andrade, J C

    2016-01-01

    To describe the results of tibiotalocalcáneal arthrodesis (TTC) using a humeral locking plate. A retrospective, observational study was conducted between January 2007 and December 2013 in the Hospital Militar Central de Bogotá. The study included patients with symptomatic osteoarthritis diagnosed clinically and radiologically, and who underwent TTC arthrodesis using a humeral locking plate with a minimum follow up of 6 months. The total number patients was 35, of whom 7 (20%) were women and 28 (80%) men, with a mean age 36.3 years (19.77). 74% with post-traumatic arthritis, most of them secondary to gunshot wounds and fragmentation weapons, and neuropathic in 20%. An autogenous graft was used in 13 cases, and 14 cases using both, with a mean consolidation time of 4.37 months. Complications include, delayed union in 3 cases, and surgical site infection in 4. The postoperative functionality (AOFAS) mean was 66.7/100 points, with a score of 2.35 on a visual analogue pain scale. TTC arthrodesis using a humeral locking plate is a suitable option for fixing this type of arthrodesis, with a low rate of complications, and postoperative results that revealed satisfactory improvement in pain and consolidation. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

  10. Electricity-free, sequential nucleic acid and protein isolation.

    Science.gov (United States)

    Pawlowski, David R; Karalus, Richard J

    2012-05-15

    Traditional and emerging pathogens such as Enterohemorrhagic Escherichia coli (EHEC), Yersinia pestis, or prion-based diseases are of significant concern for governments, industries and medical professionals worldwide. For example, EHECs, combined with Shigella, are responsible for the deaths of approximately 325,000 children each year and are particularly prevalent in the developing world where laboratory-based identification, common in the United States, is unavailable (1). The development and distribution of low cost, field-based, point-of-care tools to aid in the rapid identification and/or diagnosis of pathogens or disease markers could dramatically alter disease progression and patient prognosis. We have developed a tool to isolate nucleic acids and proteins from a sample by solid-phase extraction (SPE) without electricity or associated laboratory equipment (2). The isolated macromolecules can be used for diagnosis either in a forward lab or using field-based point-of-care platforms. Importantly, this method provides for the direct comparison of nucleic acid and protein data from an un-split sample, offering a confidence through corroboration of genomic and proteomic analysis. Our isolation tool utilizes the industry standard for solid-phase nucleic acid isolation, the BOOM technology, which isolates nucleic acids from a chaotropic salt solution, usually guanidine isothiocyanate, through binding to silica-based particles or filters (3). CUBRC's proprietary solid-phase extraction chemistry is used to purify protein from chaotropic salt solutions, in this case, from the waste or flow-thru following nucleic acid isolation(4). By packaging well-characterized chemistries into a small, inexpensive and simple platform, we have generated a portable system for nucleic acid and protein extraction that can be performed under a variety of conditions. The isolated nucleic acids are stable and can be transported to a position where power is available for PCR amplification

  11. Self-locking degree-4 vertex origami structures.

    Science.gov (United States)

    Fang, Hongbin; Li, Suyi; Wang, K W

    2016-11-01

    A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.

  12. Programming the Assembly of Unnatural Materials with Nucleic Acids

    Science.gov (United States)

    Mirkin, Chad

    Nature directs the assembly of enormously complex and highly functional materials through an encoded class of biomolecules, nucleic acids. The establishment of a similarly programmable code for the construction of synthetic, unnatural materials would allow researchers to impart functionality by precisely positioning all material components. Although it is exceedingly difficult to control the complex interactions between atomic and molecular species in such a manner, interactions between nanoscale components can be directed through the ligands attached to their surface. Our group has shown that nucleic acids can be used as highly programmable surface ligands to control the spacing and symmetry of nanoparticle building blocks in structurally sophisticated and functional materials. These nucleic acids function as programmable ``bonds'' between nanoparticle ``atoms,'' analogous to a nanoscale genetic code for assembling materials. The sequence and length tunability of nucleic acid bonds has allowed us to define a powerful set of design rules for the construction of nanoparticle superlattices with more than 30 unique lattice symmetries, tunable defect structures and interparticle spacings, and several well-defined crystal habits. Further, the nature of the nucleic acid bond enables an additional level of structural control: temporal regulation of dynamic material response to external biomolecular and chemical stimuli. This control allows for the reversible transformation between thermodynamic states with different crystal symmetries, particle stoichiometries, thermal stabilities, and interparticle spacings on demand. Notably, our unique genetic approach affords functional nanoparticle architectures that, among many other applications, can be used to systematically explore and manipulate optoelectronic material properties, such as tunable interparticle plasmonic interactions, microstructure-directed energy emission, and coupled plasmonic and photonic modes.

  13. Frequency-Locked Detector Threshold Setting Criteria Based on Mean-Time-To-Lose-Lock (MTLL) for GPS Receivers.

    Science.gov (United States)

    Jin, Tian; Yuan, Heliang; Zhao, Na; Qin, Honglei; Sun, Kewen; Ji, Yuanfa

    2017-12-04

    Frequency-locked detector (FLD) has been widely utilized in tracking loops of Global Positioning System (GPS) receivers to indicate their locking status. The relation between FLD and lock status has been seldom discussed. The traditional PLL experience is not suitable for FLL. In this paper, the threshold setting criteria for frequency-locked detector in the GPS receiver has been proposed by analyzing statistical characteristic of FLD output. The approximate probability distribution of frequency-locked detector is theoretically derived by using a statistical approach, which reveals the relationship between probabilities of frequency-locked detector and the carrier-to-noise ratio ( C / N ₀) of the received GPS signal. The relationship among mean-time-to-lose-lock (MTLL), detection threshold and lock probability related to C / N ₀ can be further discovered by utilizing this probability. Therefore, a theoretical basis for threshold setting criteria in frequency locked loops for GPS receivers is provided based on mean-time-to-lose-lock analysis.

  14. From perception to action: phase-locked gamma oscillations correlate with reaction times in a speeded response task

    Directory of Open Access Journals (Sweden)

    Körner Ursula

    2007-04-01

    Full Text Available Abstract Background Phase-locked gamma oscillations have so far mainly been described in relation to perceptual processes such as sensation, attention or memory matching. Due to its very short latency (≈90 ms such oscillations are a plausible candidate for very rapid integration of sensory and motor processes. Results We measured EEG in 13 healthy participants in a speeded reaction task. Participants had to press a button as fast as possible whenever a visual stimulus was presented. The stimulus was always identical and did not have to be discriminated from other possible stimuli. In trials in which the participants showed a fast response, a slow negative potential over central electrodes starting approximately 800 ms before the response and highly phase-locked gamma oscillations over central and posterior electrodes between 90 and 140 ms after the stimulus were observed. In trials in which the participants showed a slow response, no slow negative potential was observed and phase-locked gamma oscillations were significantly reduced. Furthermore, for slow response trials the phase-locked gamma oscillations were significantly delayed with respect to fast response trials. Conclusion These results indicate the relevance of phase-locked gamma oscillations for very fast (not necessarily detailed integration processes.

  15. Flux-lock type of superconducting fault current limiters: A comprehensive review

    Science.gov (United States)

    Badakhshan, M.; Mousavi G., S. M.

    2018-04-01

    Power systems must be developed and extended to supply the continuous enhancement of demands for electrical energy. This development of systems in addition to the integration of distributed generation (DG) units to the power systems results higher capacity of system. Hence, short circuit current of network is confronted with persistent increasing. Since exploration of high temperature superconducting (HTS) materials, superconducting fault current limiters (SFCLs) have attracted a lot of attention all over the world. There are different types of SFCLs. Flux-lock type of SFCL because of its characteristics in fault current limitation is an important category of SFCLs. This paper aims to present a comprehensive review of research activities and applications of Flux-lock type of SFCLs in power systems.

  16. Selected topics in photochemistry of nucleic acids. Recent results and perspectives

    International Nuclear Information System (INIS)

    Loeber, G.; Kittler, L.

    1977-01-01

    Recent results on the following photoreactions of nucleic acids are reported: photochemistry of aza-bases and minor bases, formation of photoproducts of the non-cyclobutane type, formations of furocoumarin-pyrimidine photoadducts, fluorescence of dye-nucleic acid complexes and their role in chromosomal fluorescence staining, and mechanisms of the photochemical reaction. Results are discussed with respect to: (i) photobiological relevance of light-induced defects in nucleic acids; (ii) possibilities of achieving higher selectivity of light-induced defects in nucleic acids; (iii) the use of nucleic acid photochemistry to analyze genetic material. An extensive bibliography is included. (author)

  17. The strength of polyaxial locking interfaces of distal radius plates.

    Science.gov (United States)

    Hoffmeier, Konrad L; Hofmann, Gunther O; Mückley, Thomas

    2009-10-01

    Currently available polyaxial locking plates represent the consequent enhancement of fixed-angle, first-generation locking plates. In contrast to fixed-angle locking plates which are sufficiently investigated, the strength of the new polyaxial locking options has not yet been evaluated biomechanically. This study investigates the mechanical strength of single polyaxial interfaces of different volar radius plates. Single screw-plate interfaces of the implants Palmar 2.7 (Königsee Implantate und Instrumente zur Osteosynthese GmbH, Allendorf, Germany), VariAx (Stryker Leibinger GmbH & Co. KG, Freiburg, Germany) und Viper (Integra LifeSciences Corporation, Plainsboro, NJ, USA) were tested by cantilever bending. The strength of 0 degrees, 10 degrees and 20 degrees screw locking angle was obtained during static and dynamic loading. The Palmar 2.7 interfaces showed greater ultimate strength and fatigue strength than the interfaces of the other implants. The strength of the VariAx interfaces was about 60% of Palmar 2.7 in both, static and dynamic loading. No dynamic testing was applied to the Viper plate because of its low ultimate strength. By static loading, an increase in screw locking angle caused a reduction of strength for the Palmar 2.7 and Viper locking interfaces. No influence was observed for the VariAx locking interfaces. During dynamic loading; angulation had no influence on the locking strength of Palmar 2.7. However, reduction of locking strength with increasing screw angulation was observed for VariAx. The strength of the polyaxial locking interfaces differs remarkably between the examined implants. Depending on the implant an increase of the screw locking angle causes a reduction of ultimate or fatigue strength, but not in all cases a significant impact was observed.

  18. Delay differential equations for mode-locked semiconductor lasers.

    Science.gov (United States)

    Vladimirov, Andrei G; Turaev, Dmitry; Kozyreff, Gregory

    2004-06-01

    We propose a new model for passive mode locking that is a set of ordinary delay differential equations. We assume a ring-cavity geometry and Lorentzian spectral filtering of the pulses but do not use small gain and loss and weak saturation approximations. By means of a continuation method, we study mode-locking solutions and their stability. We find that stable mode locking can exist even when the nonlasing state between pulses becomes unstable.

  19. Analysis of peer-to-peer locking of magnetrons

    International Nuclear Information System (INIS)

    Pengvanich, P.; Lau, Y. Y.; Cruz, E.; Gilgenbach, R. M.; Hoff, B.; Luginsland, J. W.

    2008-01-01

    The condition for mutual, or peer-to-peer, locking of two magnetrons is derived. This condition reduces to Adler's classical phase-locking condition in the limit where one magnetron becomes the ''master'' and the other becomes the ''slave.'' The formulation is extended to the peer-to-peer locking of N magnetrons, under the assumption that the electromagnetic coupling among the N magnetrons is modeled by an N-port network.

  20. Locking of metacarpophalangeal joints in a patient with acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Y.; Tanaka, N.; Isoya, Eiji [Dept. of Orthopaedic Surgery, Soseikai General Hospital, Kyoto (Japan)

    1999-11-01

    A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking. (orig.)

  1. Locking of metacarpophalangeal joints in a patient with acromegaly

    International Nuclear Information System (INIS)

    Tani, Y.; Tanaka, N.; Isoya, Eiji

    1999-01-01

    A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking. (orig.)

  2. An Evaluation of Coarse-Grained Locking for Multicore Microkernels

    OpenAIRE

    Elphinstone, Kevin; Zarrabi, Amirreza; Danis, Adrian; Shen, Yanyan; Heiser, Gernot

    2016-01-01

    The trade-off between coarse- and fine-grained locking is a well understood issue in operating systems. Coarse-grained locking provides lower overhead under low contention, fine-grained locking provides higher scalability under contention, though at the expense of implementation complexity and re- duced best-case performance. We revisit this trade-off in the context of microkernels and tightly-coupled cores with shared caches and low inter-core migration latencies. We evaluate performance on ...

  3. Triptycene: A Nucleic Acid Three-Way Junction Binder Scaffold

    Science.gov (United States)

    Yoon, Ina

    Nucleic acids play a critical role in many biological processes such as gene regulation and replication. The development of small molecules that modulate nucleic acids with sequence or structure specificity would provide new strategies for regulating disease states at the nucleic acid level. However, this remains challenging mainly because of the nonspecific interactions between nucleic acids and small molecules. Three-way junctions are critical structural elements of nucleic acids. They are present in many important targets such as trinucleotide repeat junctions related to Huntington's disease, a temperature sensor sigma32 in E. coli, Dengue virus, and HIV. Triptycene-derived small molecules have been shown to bind to nucleic acid three-way junctions, resulting from their shape complementary. To develop a better understanding of designing molecules for targeting different junctions, a rapid screening of triptycene-based small molecules is needed. We envisioned that the installation of a linker at C9 position of the bicyclic core would allow for a rapid solid phase diversification. To achieve this aim, we synthesized 9-substituted triptycene scaffolds by using two different synthetic routes. The first synthetic route installed the linker from the amidation reaction between carboxylic acid at C9 position of the triptycene and an amine linker, beta-alanine ethyl ester. This new 9-substituted triptycene scaffold was then attached to a 2-chlorotrityl chloride resin for solid-phase diversification. This enabled a rapid diversification and an easy purification of mono-, di-, and tri-peptide triptycene derivatives. The binding affinities of these compounds were investigated towards a (CAG)˙(CTG) trinucleotide repeat junction. In the modified second synthetic route, we utilized a combined Heck coupling/benzyne Diels-Alder strategy. This improved synthetic strategy reduced the number of steps and total reaction times, increased the overall yield, improved solubilities of

  4. Universal nucleic acids sample preparation method for cells, spores and their mixture

    Science.gov (United States)

    Bavykin, Sergei [Darien, IL

    2011-01-18

    The present invention relates to a method for extracting nucleic acids from biological samples. More specifically the invention relates to a universal method for extracting nucleic acids from unidentified biological samples. An advantage of the presently invented method is its ability to effectively and efficiently extract nucleic acids from a variety of different cell types including but not limited to prokaryotic or eukaryotic cells and/or recalcitrant organisms (i.e. spores). Unlike prior art methods which are focused on extracting nucleic acids from vegetative cell or spores, the present invention effectively extracts nucleic acids from spores, multiple cell types or mixtures thereof using a single method. Important that the invented method has demonstrated an ability to extract nucleic acids from spores and vegetative bacterial cells with similar levels effectiveness. The invented method employs a multi-step protocol which erodes the cell structure of the biological sample, isolates, labels, fragments nucleic acids and purifies labeled samples from the excess of dye.

  5. Progress as Compositional Lock-Freedom

    DEFF Research Database (Denmark)

    Carbone, Marco; Dardha, Ornela; Montesi, Fabrizio

    2014-01-01

    A session-based process satisfies the progress property if its sessions never get stuck when it is executed in an adequate context. Previous work studied how to define progress by introducing the notion of catalysers, execution contexts generated from the type of a process. In this paper, we refine...... such definition to capture a more intuitive notion of context adequacy for checking progress. Interestingly, our new catalysers lead to a novel characterisation of progress in terms of the standard notion of lock-freedom. Guided by this discovery, we also develop a conservative extension of catalysers that does...

  6. Locking classical correlations in quantum States.

    Science.gov (United States)

    DiVincenzo, David P; Horodecki, Michał; Leung, Debbie W; Smolin, John A; Terhal, Barbara M

    2004-02-13

    We show that there exist bipartite quantum states which contain a large locked classical correlation that is unlocked by a disproportionately small amount of classical communication. In particular, there are (2n+1)-qubit states for which a one-bit message doubles the optimal classical mutual information between measurement results on the subsystems, from n/2 bits to n bits. This phenomenon is impossible classically. However, states exhibiting this behavior need not be entangled. We study the range of states exhibiting this phenomenon and bound its magnitude.

  7. Advanced frequency synthesis by phase lock

    CERN Document Server

    Egan, William F

    2011-01-01

    "An addendum to the popular Frequency Synthesis by Phase Lock, 2nd ed, this book describes sigma-delta, a frequency synthesis technique that has gained prominence in recent years. In addition, Simulink will be employed extensively to guide the reader. Fractional-n, the still-used forerunner to sigma-delta, is also discussed. Sequences of simulated results allow the reader to gain a deeper understanding while detailed appendices provide information from various stages of development. Simulation models discussed in the chapters that are available online."--Provided by publisher.

  8. Saint Lawrence Seaway Additional Locks Study. Appendices.

    Science.gov (United States)

    1982-07-01

    1790320 1945 2370 27000 LO 710 i...l.I27.121.710.0443 23.00.769 12.229.146 2,3231.503 2.5~06.000 2.239.100 23.760.400 23.019.2002 3.413200 P.. Capita...1955. - ,. XISING EISENHOWER LOCK G ISO Se-s SP*c.--2 2, 13 TIL ANDBDROC ~~~~~~ AREA LIISO9TL AD All b 22 CORPS OF ENGINEERS BUFFAL0 NY RUFFALO DISTR

  9. Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

    Energy Technology Data Exchange (ETDEWEB)

    Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan, E-mail: lining@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-05-01

    This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 mum RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm{sup 2}. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

  10. Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

    International Nuclear Information System (INIS)

    Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan

    2009-01-01

    This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 μm RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm 2 . The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

  11. A quantitative measure of chirality inside nucleic acid databank.

    Science.gov (United States)

    Pietropaolo, Adriana; Parrinello, Michele

    2011-08-01

    We show the capability of a chirality index (Pietropaolo et al., Proteins 2008;70:667-677) to investigate nucleic acid structures because of its high sensitivity to helical conformations. By analyzing selected structures of DNA and RNA, we have found that sequences rich in cytosine and guanine have a tendency to left-handed chirality, in contrast to regions rich in adenine or thymine which show strong negative, right-handed, chirality values. We also analyze RNA structures, where specific loops and hairpin motifs are characterized by a well-defined chirality value. We find that in nucleosome the chirality is exalted, whereas in ribosome it is reduced. Our results illustrate the sensitivity of this descriptor for nucleic acid conformations. Copyright © 2011 Wiley-Liss, Inc.

  12. Devices, systems, and methods for detecting nucleic acids using sedimentation

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Chung-Yan; Schaff, Ulrich Y.; Sommer, Gregory J.

    2017-10-24

    Embodiments of the present invention are directed toward devices, systems, and method for conducting nucleic acid purification and quantification using sedimentation. In one example, a method includes generating complexes which bind to a plurality of beads in a fluid sample, individual ones of the complexes comprising a nucleic acid molecule such as DNA or RNA and a labeling agent. The plurality of beads including the complexes may be transported through a density media, wherein the density media has a density lower than a density of the beads and higher than a density of the fluid sample, and wherein the transporting occurs, at least in part, by sedimentation. Signal may be detected from the labeling agents of the complexes.

  13. Microfluidic "Pouch" Chips for Immunoassays and Nucleic Acid Amplification Tests.

    Science.gov (United States)

    Mauk, Michael G; Liu, Changchun; Qiu, Xianbo; Chen, Dafeng; Song, Jinzhao; Bau, Haim H

    2017-01-01

    Microfluidic cassettes ("chips") for processing and analysis of clinical specimens and other sample types facilitate point-of-care (POC) immunoassays and nucleic acid based amplification tests. These single-use test chips can be self-contained and made amenable to autonomous operation-reducing or eliminating supporting instrumentation-by incorporating laminated, pliable "pouch" and membrane structures for fluid storage, pumping, mixing, and flow control. Materials and methods for integrating flexible pouch compartments and diaphragm valves into hard plastic (e.g., acrylic and polycarbonate) microfluidic "chips" for reagent storage, fluid actuation, and flow control are described. We review several versions of these pouch chips for immunoassay and nucleic acid amplification tests, and describe related fabrication techniques. These protocols thus offer a "toolbox" of methods for storage, pumping, and flow control functions in microfluidic devices.

  14. Silicon Dioxide Thin Film Mediated Single Cell Nucleic Acid Isolation

    Science.gov (United States)

    Bogdanov, Evgeny; Dominova, Irina; Shusharina, Natalia; Botman, Stepan; Kasymov, Vitaliy; Patrushev, Maksim

    2013-01-01

    A limited amount of DNA extracted from single cells, and the development of single cell diagnostics make it necessary to create a new highly effective method for the single cells nucleic acids isolation. In this paper, we propose the DNA isolation method from biomaterials with limited DNA quantity in sample, and from samples with degradable DNA based on the use of solid-phase adsorbent silicon dioxide nanofilm deposited on the inner surface of PCR tube. PMID:23874571

  15. Poly(alkylene oxide) Copolymers for Nucleic Acid Delivery

    Science.gov (United States)

    2012-07-17

    Poly(alkylene oxide) Copolymers for Nucleic Acid Delivery Swati Mishra1,#, Lavanya Y. Peddada1,#, David I. Devore3,4, and Charles M. Roth1,2...Neil Raju for assistance with figures. Biographies Swati Mishra received her Ph.D. in Biomedical Engineering and Biotechnology from the University of...Kleiman N, Anderson RD, Gottlieb D, Karlsberg R, Snell J, Rocha- Singh K. Results from a phase II multicenter, double-blind placebo-controlled study of Del

  16. Preparative concentration of nucleic acids fragments by capillary isotachophoretic analyzer

    Czech Academy of Sciences Publication Activity Database

    Datinská, Vladimíra; Voráčová, Ivona; Berka, J.; Foret, František

    2018-01-01

    Roč. 1548 (2018), s. 100-103 ISSN 0021-9673 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GBP206/12/G014; GA MŠk(CZ) 8F17003 Institutional support: RVO:68081715 Keywords : DNA * isotachophoresis * nucleic acids * sample preparation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  17. Histidine-lysine peptides as carriers of nucleic acids.

    Science.gov (United States)

    Leng, Qixin; Goldgeier, Lisa; Zhu, Jingsong; Cambell, Patricia; Ambulos, Nicholas; Mixson, A James

    2007-03-01

    With their biodegradability and diversity of permutations, peptides have significant potential as carriers of nucleic acids. This review will focus on the sequence and branching patterns of peptide carriers composed primarily of histidines and lysines. While lysines within peptides are important for binding to the negatively charged phosphates, histidines are critical for endosomal lysis enabling nucleic acids to reach the cytosol. Histidine-lysine (HK) polymers by either covalent or ionic bonds with liposomes augment transfection compared to liposome carriers alone. More recently, we have examined peptides as sole carriers of nucleic acids because of their intrinsic advantages compared to the bipartite HK/liposome carriers. With a protocol change and addition of a histidine-rich tail, HK peptides as sole carriers were more effective than liposomes alone in several cell lines. While four-branched polymers with a primary repeating sequence pattern of -HHK- were more effective as carriers of plasmids, eight-branched polymers with a sequence pattern of -HHHK- were more effective as carriers of siRNA. Compared to polyethylenimine, HK carriers of siRNA and plasmids had reduced toxicity. When injected intravenously, HK polymers in complex with plasmids encoding antiangiogenic proteins significantly decreased tumor growth. Furthermore, modification of HK polymers with polyethylene glycol and vascular-specific ligands increased specificity of the polyplex to the tumor by more than 40-fold. Together with further development and insight on the structure of HK polyplexes, HK peptides may prove to be useful as carriers of different forms of nucleic acids both in vitro and in vivo.

  18. System for portable nucleic acid testing in low resource settings

    Science.gov (United States)

    Lu, Hsiang-Wei; Roskos, Kristina; Hickerson, Anna I.; Carey, Thomas; Niemz, Angelika

    2013-03-01

    Our overall goal is to enable timely diagnosis of infectious diseases through nucleic acid testing at the point-of-care and in low resource settings, via a compact system that integrates nucleic acid sample preparation, isothermal DNA amplification, and nucleic acid lateral flow (NALF) detection. We herein present an interim milestone, the design of the amplification and detection subsystem, and the characterization of thermal and fluidic control and assay execution within this system. Using an earlier prototype of the amplification and detection unit, comprised of a disposable cartridge containing flexible pouches, passive valves, and electrolysis-driven pumps, in conjunction with a small heater, we have demonstrated successful execution of an established and clinically validated isothermal loop-mediated amplification (LAMP) reaction targeting Mycobacterium tuberculosis (M.tb) DNA, coupled to NALF detection. The refined design presented herein incorporates miniaturized and integrated electrolytic pumps, novel passive valves, overall design changes to facilitate integration with an upstream sample preparation unit, and a refined instrument design that automates pumping, heating, and timing. Nucleic acid amplification occurs in a two-layer pouch that facilitates fluid handling and appropriate thermal control. The disposable cartridge is manufactured using low-cost and scalable techniques and forms a closed system to prevent workplace contamination by amplicons. In a parallel effort, we are developing a sample preparation unit based on similar design principles, which performs mechanical lysis of mycobacteria and DNA extraction from liquefied and disinfected sputum. Our next step is to combine sample preparation, amplification, and detection in a final integrated cartridge and device, to enable fully automated sample-in to answer-out diagnosis of active tuberculosis in primary care facilities of low-resource and high-burden countries.

  19. Solid-state NMR studies of nucleic acid components

    Czech Academy of Sciences Publication Activity Database

    Dračínský, Martin; Hodgkinson, P.

    2015-01-01

    Roč. 5, č. 16 (2015), s. 12300-12310 ISSN 2046-2069 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : NMR spectroscopy * nucleic acid s * solid-state NMR Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/ra/c4ra14404j

  20. Preparative concentration of nucleic acids fragments by capillary isotachophoretic analyzer

    Czech Academy of Sciences Publication Activity Database

    Datinská, Vladimíra; Voráčová, Ivona; Berka, J.; Foret, František

    2018-01-01

    Roč. 1548, MAY (2018), s. 100-103 ISSN 0021-9673 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GBP206/12/G014; GA MŠk(CZ) 8F17003 Institutional support: RVO:68081715 Keywords : DNA * isotachophoresis * nucleic acids * sample preparation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  1. Nucleic acid components from strontium-90 exposed miniature swine

    International Nuclear Information System (INIS)

    Frazier, M.E.

    1976-01-01

    The reverse transcriptase associated with porcine type C virus particles was used to generate a tritium-labeled DNA product complementary to the viral RNA template. Results of nucleic acid hybridization experiments indicate this 3 H-DNA (probe) was copied from heteropolymeric regions of the procine viral RNA. Probe prepared from this porcine type C virus contains sequences that possess some homology in sequence to RNA isolated from viruses known to cause similar diseases in other animals

  2. Ion-pair chromatography of nucleic acid derivatives

    International Nuclear Information System (INIS)

    Perrone, P.A.; Brown, P.R.

    1985-01-01

    Little work has been done on the ion-pair chromatography of nucleic acid constituents, although there is a great potential for the use of this technique in the field. Since the classic work in 1949, nucleotides, as well as nucleosides and bases, have been separated by ion-exchange chromatography. However, ion exchange is a difficult mode and most researchers prefer the use of reversed-phase whenever possible. Although reversed-phase is now the method of choice, ionic compounds like nucleotides and some of the more polar bases are not adequately retained by many systems of this type. In addition, it is difficult to analyze simultaneously members of all three classes of nucleic acid compounds (bases, nucleosides, and nucleotides) using a reversed-phase system, even with gradient elution. Ion pairing can be a useful technique because, theoretically, the separation of nonionic bases and nucleosides along with the ionic nucleotides can be achieved. Additionally, each group of compounds may be separated isocratically. In this chapter, they will discuss ion-pair chromatography as applied to nucleic acid constituents. The current theories, advantages and disadvantages, a limited number of applications, and potential for future work are presented

  3. The role of immunostimulatory nucleic acids in septic shock

    Science.gov (United States)

    Bleiblo, Farag; Michael, Paul; Brabant, Danielle; Ramana, Chilakamarti V; Tai, TC; Saleh, Mazen; Parrillo, Joseph E; Kumar, Anand; Kumar, Aseem

    2012-01-01

    Sepsis and its associated syndromes represent the systemic host response to severe infection and is manifested by varying degrees of hypotension, coagulopathy, and multiorgan dysfunction. Despite great efforts being made to understand this condition and designing therapies to treat sepsis, mortality rates are still high in septic patients. Characterization of the complex molecular signaling networks between the various components of host-pathogen interactions, highlights the difficulty in identifying a single driving force responsible for sepsis. Although triggering the inflammatory response is generally considered as protective against pathogenic threats, the interplay between the signaling pathways that are induced or suppressed during sepsis may harm the host. Numerous surveillance mechanisms have evolved to discriminate self from foreign agents and accordingly provoke an effective cellular response to target the pathogens. Nucleic acids are not only an essential genetic component, but sensing their molecular signature is also an important quality control mechanism which has evolved to maintain the integrity of the human genome. Evidence that has accumulated recently indicated that distinct pattern recognition receptors sense nucleic acids released from infectious organisms or from damaged host cells, resulting in the modulation of intracellular signalling cascades. Immunoreceptor-mediated detection of these nucleic acids induces antigen-specific immunity, secretion of proinflammatory cytokines and reactive oxygen/nitrogen species and thus are implicated in a range of diseases including septic shock. PMID:22328944

  4. Immune activation by nucleic acids: A role in pregnancy complications.

    Science.gov (United States)

    Konečná, B; Lauková, L; Vlková, B

    2018-04-01

    Cell-free self-DNA or RNA may induce an immune response by activating specific sensing receptors. During pregnancy, placental nucleic acids present in the maternal circulation further activate these receptors due to the presence of unmethylated CpG islands. A higher concentration of cell-free foetal DNA is associated with pregnancy complications and a higher risk for foetal rejection. Cell-free foetal DNA originates from placental trophoblasts. It appears in different forms: free, bound to histones in nucleosomes, in neutrophil extracellular traps (NETs) and in extracellular vesicles (EVs). In several pregnancy complications, cell-free foetal DNA triggers the production of proinflammatory cytokines, and this production results in a cellular and humoral immune response. This review discusses preeclampsia, systemic lupus erythematosus, foetal growth restriction, gestational diabetes, rheumatoid arthritis and obesity in pregnancy from an immunological point of view and closely examines the different pathways that result in maternal inflammation. Understanding the role of cell-free nucleic acids, as well as the biogenesis of NETs and EVs, will help us to specify their functions or targets, which seem to be important in pregnancy complications. It is still not clear whether higher concentrations of cell-free nucleic acids in the maternal circulation are the cause or consequence of various complications. Therefore, further clinical studies and, even more importantly, animal experiments that focus on the involved immunological pathways are needed. © 2018 The Foundation for the Scandinavian Journal of Immunology.

  5. Molecular modeling of nucleic Acid structure: electrostatics and solvation.

    Science.gov (United States)

    Bergonzo, Christina; Galindo-Murillo, Rodrigo; Cheatham, Thomas E

    2014-12-19

    This unit presents an overview of computer simulation techniques as applied to nucleic acid systems, ranging from simple in vacuo molecular modeling techniques to more complete all-atom molecular dynamics treatments that include an explicit representation of the environment. The third in a series of four units, this unit focuses on critical issues in solvation and the treatment of electrostatics. UNITS 7.5 & 7.8 introduced the modeling of nucleic acid structure at the molecular level. This included a discussion of how to generate an initial model, how to evaluate the utility or reliability of a given model, and ultimately how to manipulate this model to better understand its structure, dynamics, and interactions. Subject to an appropriate representation of the energy, such as a specifically parameterized empirical force field, the techniques of minimization and Monte Carlo simulation, as well as molecular dynamics (MD) methods, were introduced as a way of sampling conformational space for a better understanding of the relevance of a given model. This discussion highlighted the major limitations with modeling in general. When sampling conformational space effectively, difficult issues are encountered, such as multiple minima or conformational sampling problems, and accurately representing the underlying energy of interaction. In order to provide a realistic model of the underlying energetics for nucleic acids in their native environments, it is crucial to include some representation of solvation (by water) and also to properly treat the electrostatic interactions. These subjects are discussed in detail in this unit. Copyright © 2014 John Wiley & Sons, Inc.

  6. Recent Developments in Peptide-Based Nucleic Acid Delivery

    Directory of Open Access Journals (Sweden)

    Tobias Restle

    2008-07-01

    Full Text Available Despite the fact that non-viral nucleic acid delivery systems are generally considered to be less efficient than viral vectors, they have gained much interest in recent years due to their superior safety profile compared to their viral counterpart. Among these synthetic vectors are cationic polymers, branched dendrimers, cationic liposomes and cellpenetrating peptides (CPPs. The latter represent an assortment of fairly unrelated sequences essentially characterised by a high content of basic amino acids and a length of 10-30 residues. CPPs are capable of mediating the cellular uptake of hydrophilic macromolecules like peptides and nucleic acids (e.g. siRNAs, aptamers and antisenseoligonucleotides, which are internalised by cells at a very low rate when applied alone. Up to now, numerous sequences have been reported to show cell-penetrating properties and many of them have been used to successfully transport a variety of different cargos into mammalian cells. In recent years, it has become apparent that endocytosis is a major route of internalisation even though the mechanisms underlying the cellular translocation of CPPs are poorly understood and still subject to controversial discussions. In this review, we will summarise the latest developments in peptide-based cellular delivery of nucleic acid cargos. We will discuss different mechanisms of entry, the intracellular fate of the cargo, correlation studies of uptake versus biological activity of the cargo as well as technical problems and pitfalls.

  7. Short philtrum

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003302.htm Short philtrum To use the sharing features on this page, please enable JavaScript. A short philtrum is a shorter than normal distance between ...

  8. Reconfigurable Braille display with phase change locking

    Science.gov (United States)

    Soule, Cody W.; Lazarus, Nathan

    2016-07-01

    Automatically updated signs and displays for sighted people are common in today’s world. However, there is no cheap, low power equivalent available for the blind. This work demonstrates a reconfigurable Braille cell using the solid-to-liquid phase change of a low melting point alloy as a zero holding power locking mechanism. The device is actuated with the alloy in the liquid state, and is then allowed to solidify to lock the Braille dot in the actuated position. A low-cost manufacturing process is developed that includes molding of a rigid silicone to create pneumatic channels, and bonding of a thin membrane of a softer silicone on the surface for actuation. A plug of Field’s metal (melting point 62 °C) is placed in the pneumatic channels below each Braille dot to create the final device. The device is well suited for low duty cycle operation in applications such as signs, and is able to maintain its state indefinitely without additional power input. The display requires a pneumatic pressure of only 24 kPa for actuation, and reconfiguration has been demonstrated in less than a minute and a half.

  9. Tom Bevill Upper Lock Approach, Tennessee-Tombigbee Waterway, Alabama: Hydraulic Navigation Investigation

    National Research Council Canada - National Science Library

    Winkler, Michael

    2003-01-01

    .... The lock is connected to the dam with a 150-ft abutment wall. A strong crosscurrent or outdraft existing in and around the upstream lock entrance causes difficulty for tow traffic navigating the lock...

  10. Improved Inhibition of Telomerase by Short Twisted Intercalating Nucleic Acids under Molecular Crowding Conditions

    DEFF Research Database (Denmark)

    Agarwal, Tani; Pradhan, Devranjan; Géci, Imrich

    2012-01-01

    Human telomeric DNA has the ability to fold into a 4-stranded G-quadruplex structure. Several G-quadruplex ligands are known to stabilize the structure and thereby inhibit telomerase activity. Such ligands have demonstrated efficient telomerase inhibition in dilute conditions, but under molecular...

  11. Scaling laws for mode lockings in circle maps

    International Nuclear Information System (INIS)

    Cvitanovic, P.; Shraiman, B.; Soederberg, B.

    1985-06-01

    The self-similar structure of mode lockings for circle maps is studied by means of the associated Farey trees. We investigate numerically several classes of scaling relations implicit in the Farey organization of mode lockings and discuss the extent to which they lead to universal scaling laws. (orig.)

  12. 30 CFR 57.12068 - Locking transformer enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Locking transformer enclosures. 57.12068 Section 57.12068 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Electricity Surface Only § 57.12068 Locking transformer enclosures. Transformer enclosures shall be kept...

  13. Investigation on Locking and Pulling Modes in Analog Frequency Dividers

    Directory of Open Access Journals (Sweden)

    Antonio Buonomo

    2013-01-01

    Full Text Available We compare the main analytical results available to estimate the locking range, which is the key figure-of-merit of LC frequency dividers based on the injection locking phenomenon. Starting from the classical result by Adler concerning injection-locked oscillators, we elucidate the merits and the shortcomings of the different approaches to study injection-locked frequency dividers, with particular emphasis on divider-by-2. In particular, we show the potential of a perturbation approach which enables a more complete analysis of frequency dividers, making it possible to calculate not only the amplitude and the phase of the locked oscillation, but also the region where it exists and is stable, which defines the locking region. Finally, we analyze the dynamical behaviour of the dividers in the vicinity of the boundary of the locking region, showing that there exists a border region where the occurrence of the locking or the pulling operation mode is possible, depending on the initial conditions of the system.

  14. Lock-In Agreements in Venture Capital Backed UK IPOs

    NARCIS (Netherlands)

    Espenlaub, S.; Goergen, M.; Khurshed, A.; Renneboog, L.D.R.

    2002-01-01

    This paper examines the impact of venture-capital backing of UK companies issuing shares at flotation on the characteristics of the lock-in agreements entered into by the existing shareholders, and on the abnormal returns realised around the expiry of the directors' lock-in agreements.The study

  15. Aktuaalsetest tendentsidest elektroakustilise muusika alal Eestis / Gerhard Lock

    Index Scriptorium Estoniae

    Lock, Gerhard, 1978-

    2007-01-01

    Elektroakustilise muusika lähiajaloost, elektroakustilist muusikat viljelevatest Eesti heliloojatest. Age Hirv, Raun Juurikas, Liis Jürgens, Andrus Kallastu, Tatjana Kozlova, Ülo Krigul, Margo Kõlar, Märt-Matis Lill, Gerhard Lock, Hans-Gunter Lock, Malle Maltis, Jüri Reinvere, Mart Siimer, Mirjam Tally, Toomas Trass, Lauri-Dag Tüür oma muusikast

  16. Phase-locking regimes of photonic crystal nanocavity laser arrays

    DEFF Research Database (Denmark)

    Skovgård, Troels Suhr; Kristensen, Philip Trøst; Mørk, Jesper

    2011-01-01

    -difference time-domain calculations, the typical coupling strength is extracted for realistic structures. Phase-locking regimes are identified, and their stability with respect to parameter variation is investigated. The results suggest that quantum well devices are not well suited for phase-locked nanocavity...

  17. ELB-trees - Efficient Lock-free B+trees

    DEFF Research Database (Denmark)

    Bonnichsen, Lars Frydendal; Karlsson, Sven; Probst, Christian W.

    2014-01-01

    As computer systems scale in the number of processors, data structures with good parallel performance become increasingly important. Lock-free data structures promise improved parallel performance at the expense of higher complexity and sequential execution time.We present ELBtrees, a new lock-fr...

  18. Selenium Derivatization of Nucleic Acids for Phase and Structure Determination in Nucleic Acid X-ray Crystallography

    Directory of Open Access Journals (Sweden)

    Zhen Huang

    2008-03-01

    Full Text Available Selenium derivatization (via selenomethionine of proteins for crystal structure determination via MAD phasing has revolutionized protein X-ray crystallography. It is estimated that over two thirds of all new crystal structures of proteins have been determined via Se-Met derivatization. Similarly, selenium functionalities have also been successfully incorporated into nucleic acids to facilitate their structure studies and it has been proved that this Se-derivatization has advantages over halogen strategy, which was usually used as a traditional method in this field. This review reports the development of site-specific selenium derivatization of nucleic acids for phase determination since the year of 2001 (mainly focus on the 2’-position of the ribose. All the synthesis of 2’-SeMe modified phosphoramidite building blocks (U, C, T, A, G and the according oligonucleotides are included. In addition, several structures of selenium contained nucleic acid are also described in this paper.

  19. Optical Injection Locking of Vertical Cavity Surface-Emitting Lasers: Digital and Analog Applications

    Science.gov (United States)

    Parekh, Devang

    With the rise of mobile (cellphones, tablets, notebooks, etc.) and broadband wireline communications (Fiber to the Home), there are increasing demands being placed on transmitters for moving data from device to device and around the world. Digital and analog fiber-optic communications have been the key technology to meet this challenge, ushering in ubiquitous Internet and cable TV over the past 20 years. At the physical layer, high-volume low-cost manufacturing of semiconductor optoelectronic devices has played an integral role in allowing for deployment of high-speed communication links. In particular, vertical cavity surface emitting lasers (VCSEL) have revolutionized short reach communications and are poised to enter more markets due to their low cost, small size, and performance. However, VCSELs have disadvantages such as limited modulation performance and large frequency chirp which limits fiber transmission speed and distance, key parameters for many fiber-optic communication systems. Optical injection locking is one method to overcome these limitations without re-engineering the VCSEL at the device level. By locking the frequency and phase of the VCSEL by the direct injection of light from another laser oscillator, improved device performance is achieved in a post-fabrication method. In this dissertation, optical injection locking of VCSELs is investigated from an applications perspective. Optical injection locking of VCSELs can be used as a pathway to reduce complexity, cost, and size of both digital and analog fiber-optic communications. On the digital front, reduction of frequency chirp via bit pattern inversion for large-signal modulation is experimentally demonstrated showing up to 10 times reduction in frequency chirp and over 90 times increase in fiber transmission distance. Based on these results, a new reflection-based interferometric model for optical injection locking was established to explain this phenomenon. On the analog side, the resonance

  20. High-energy harmonic mode-locked 2 μm dissipative soliton fiber lasers

    International Nuclear Information System (INIS)

    Yang, Nan; Tang, Yulong; Xu, Jianqiu

    2015-01-01

    High-pulse-energy harmonic mode-locking in 2 μm Tm-doped fiber lasers (TDFLs) is realized, for the first time, by using a short piece of anomalous dispersion gain fiber and the dissipative soliton mode-locking mechanism. Appropriately designing the cavity dispersion map and adjusting the cavity gain, stable harmonic mode-locking of the dissipative soliton TDFL from the 2nd to the 4th order is achieved, with the pulsing repetition rates and pulse energy being 43.4, 65.1, 86.8 MHz, and 6.27, 4.32 and 3.29 nJ, respectively. The harmonic laser pulse has a pulse width of ∼30 ps and a center wavelength of ∼1929 nm with a spectral bandwidth of ∼3.26 nm, giving a highly chirped laser pulse. Two types of soliton molecules are also observed in this laser system. (letter)

  1. Phase locking of vortex cores in two coupled magnetic nanopillars

    Directory of Open Access Journals (Sweden)

    Qiyuan Zhu

    2014-11-01

    Full Text Available Phase locking dynamics of the coupled vortex cores in two identical magnetic spin valves induced by spin-polarized current are studied by means of micromagnetic simulations. Our results show that the available current range of phase locking can be expanded significantly by the use of constrained polarizer, and the vortices undergo large orbit motions outside the polarization areas. The effects of polarization areas and dipolar interaction on the phase locking dynamics are studied systematically. Phase locking parameters extracted from simulations are discussed by theoreticians. The dynamics of vortices influenced by spin valve geometry and vortex chirality are discussed at last. This work provides deeper insights into the dynamics of phase locking and the results are important for the design of spin-torque nano-oscillators.

  2. Spatially resolved detection of mutually locked Josephson junctions in arrays

    International Nuclear Information System (INIS)

    Keck, M.; Doderer, T.; Huebener, R.P.; Traeuble, T.; Dolata, R.; Weimann, T.; Niemeyer, J.

    1997-01-01

    Mutual locking due to the internal coupling in two-dimensional arrays of Josephson junctions was investigated. The appearance of Shapiro steps in the current versus voltage curve of a coupled on-chip detector junction is used to indicate coherent oscillations in the array. A highly coherent state is observed for some range of the array bias current. By scanning the array with a low-power electron beam, mutually locked junctions remain locked while the unlocked junctions generate a beam-induced additional voltage drop at the array. This imaging technique allows the detection of the nonlocked or weakly locked Josephson junctions in a (partially) locked array state. copyright 1997 American Institute of Physics

  3. Monolithic Hybrid and Passive Mode-Locked 40GHz Quantum Dot Laser Diodes

    DEFF Research Database (Denmark)

    Thompson, M. G.; Larsson, David; Rae, A. R.

    2006-01-01

    For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs.......For the first time hybrid and passive mode-locking jitter performance is investigated in 40GHz quantum-dot mode-locked lasers. Record low passive mode-locking jitter of 219fs is presented, along with promising hybrid mode-locking results of 124fs....

  4. Comparative nucleic acid transfection efficacy in primary hepatocytes for gene silencing and functional studies

    Directory of Open Access Journals (Sweden)

    Morral Núria

    2011-01-01

    Full Text Available Abstract Background Primary hepatocytes are the best resource for in vitro studies directed at understanding hepatic processes at the cellular and molecular levels, necessary for novel drug development to treat highly prevalent diseases such as non-alcoholic steatohepatitis, cardiovascular disease and type 2 diabetes. There is a need to identify simple methods to genetically manipulate primary hepatocytes and conduct functional studies with plasmids, small interfering RNA (siRNA or microRNA (miRNA. New lipofection reagents are available that have the potential to yield higher levels of transfection with reduced toxicity. Findings We have tested several liposome-based transfection reagents used in molecular biology research. We show that transfection efficiency with one of the most recently developed formulations, Metafectene Pro, is high with plasmid DNA (>45% cells as well as double stranded RNA (>90% with siRNA or microRNA. In addition, negligible cytotoxicity was present with all of these nucleic acids, even if cells were incubated with the DNA:lipid complex for 16 hours. To provide the proof of concept that these conditions can be used not only for overexpression of a gene of interest, but also in RNA interference applications, we targeted two liver expressed genes, Sterol Regulatory Element-Binding Protein-1 and Fatty Acid Binding Protein 5 using plasmid-mediated short hairpin RNA expression. In addition, similar transfection conditions were used to optimally deliver siRNA and microRNA. Conclusions We have identified a lipid-based reagent for primary hepatocyte transfection of nucleic acids currently used in molecular biology laboratories. The conditions described here can be used to expedite a large variety of research applications, from gene function studies to microRNA target identification.

  5. Locking of intrinsic angular momentum in collision complexes

    International Nuclear Information System (INIS)

    Berengolts, Alexander.

    1995-04-01

    A concept of locking of the intrinsic angular momentum of a fragment of a collision complex to a body-fixed axis is widely used in the description of heavy-particle dynamics. The aim of this work is to provide a semiclassical description of the locking phenomenon which occur in diatomic and three atomic collision complexes. The first part of this work is devoted to the semiclassical study of the locking of the electronic angular momentum that occurs in slow collisions of two atoms, one in the spherically symmetric state and the other in state with j= 1. Here we calculate explicitly the complete locking matrix for different types of interatomic interactions. The elements of this matrix directly enter into the semiclassical expression for the different cross sections of polarized atoms. Limitations to the notion of the the locking radius and slipping probability are discussed in connection with the steepness of the interaction. Numerical calculations confirm analytical result: the optimal criterion for determination of the locking radius is a condition for the accumulated phase difference between two molecular states. Analytical expressions are suggested for the locking angle and the slipping probability. Implication of the locking approximation for calculation of the quasiclassical scattering matrix is discussed. The second part considers the locking of the rotational angular momentum of a diatom in the decomposition of a triatomic complexes. We discuss here cases J = 1,2,3 and 4, but restrict ourselves to calculation of the so-called dynamic orientation of the diatomic fragment. The letter represents one of the characteristics of the locking matrix which in principle can be measured experimentally. The orientation is created as a result of the interplay between the adiabatic interaction in the atom- diatom exit channel and the rotationally non adiabatic coupling in the perturbed rotor region

  6. Heterogeneous Silicon III-V Mode-Locked Lasers

    Science.gov (United States)

    Davenport, Michael Loehrlein

    Mode-locked lasers are useful for a variety of applications, such as sensing, telecommunication, and surgical instruments. This work focuses on integrated-circuit mode-locked lasers: those that combine multiple optical and electronic functions and are manufactured together on a single chip. While this allows production at high volume and lower cost, the true potential of integration is to open applications for mode-locked laser diodes where solid state lasers cannot fit, either due to size and power consumption constraints, or where small optical or electrical paths are needed for high bandwidth. Unfortunately, most high power and highly stable mode-locked laser diode demonstrations in scientific literature are based on the Fabry-Perot resonator design, with cleaved mirrors, and are unsuitable for use in integrated circuits because of the difficulty of producing integrated Fabry-Perot cavities. We use silicon photonics and heterogeneous integration with III-V gain material to produce the most powerful and lowest noise fully integrated mode-locked laser diode in the 20 GHz frequency range. If low noise and high peak power are required, it is arguably the best performing fully integrated mode-locked laser ever demonstrated. We present the design methodology and experimental pathway to realize a fully integrated mode-locked laser diode. The construction of the device, beginning with the selection of an integration platform, and proceeding through the fabrication process to final optimization, is presented in detail. The dependence of mode-locked laser performance on a wide variety of design parameters is presented. Applications for integrated circuit mode-locked lasers are also discussed, as well as proposed methods for using integration to improve mode-locking performance to beyond the current state of the art.

  7. Light-emitting self-assembled peptide nucleic acids exhibit both stacking interactions and Watson-Crick base pairing.

    Science.gov (United States)

    Berger, Or; Adler-Abramovich, Lihi; Levy-Sakin, Michal; Grunwald, Assaf; Liebes-Peer, Yael; Bachar, Mor; Buzhansky, Ludmila; Mossou, Estelle; Forsyth, V Trevor; Schwartz, Tal; Ebenstein, Yuval; Frolow, Felix; Shimon, Linda J W; Patolsky, Fernando; Gazit, Ehud

    2015-04-01

    The two main branches of bionanotechnology involve the self-assembly of either peptides or DNA. Peptide scaffolds offer chemical versatility, architectural flexibility and structural complexity, but they lack the precise base pairing and molecular recognition available with nucleic acid assemblies. Here, inspired by the ability of aromatic dipeptides to form ordered nanostructures with unique physical properties, we explore the assembly of peptide nucleic acids (PNAs), which are short DNA mimics that have an amide backbone. All 16 combinations of the very short di-PNA building blocks were synthesized and assayed for their ability to self-associate. Only three guanine-containing di-PNAs-CG, GC and GG-could form ordered assemblies, as observed by electron microscopy, and these di-PNAs efficiently assembled into discrete architectures within a few minutes. The X-ray crystal structure of the GC di-PNA showed the occurrence of both stacking interactions and Watson-Crick base pairing. The assemblies were also found to exhibit optical properties including voltage-dependent electroluminescence and wide-range excitation-dependent fluorescence in the visible region.

  8. Shareholder Lock-In Contracts : Share Price and Trading Volume Effects at the Lock-In Expiry

    NARCIS (Netherlands)

    Angenandt, P.P.; Goergen, M.; Renneboog, L.D.R.

    2005-01-01

    This paper unveils the diversity in lock-in agreements of firms listed on the Nouveau Marche stock exchange in France.We give the main economic reasons why shareholders adopt lock-in agreements that are more stringent than legally required.We relate the abnormal returns and the abnormal volume at

  9. Locked and proteolysis-based transcription activator-like effector (TALE) regulation.

    Science.gov (United States)

    Lonzarić, Jan; Lebar, Tina; Majerle, Andreja; Manček-Keber, Mateja; Jerala, Roman

    2016-02-18

    Development of orthogonal, designable and adjustable transcriptional regulators is an important goal of synthetic biology. Their activity has been typically modulated through stimulus-induced oligomerization or interaction between the DNA-binding and activation/repression domain. We exploited a feature of the designable Transcription activator-like effector (TALE) DNA-binding domain that it winds around the DNA which allows to topologically prevent it from binding by intramolecular cyclization. This new approach was investigated through noncovalent ligand-induced cyclization or through a covalent split intein cyclization strategy, where the topological inhibition of DNA binding by cyclization and its restoration by a proteolytic release of the topologic constraint was expected. We show that locked TALEs indeed have diminished DNA binding and regain full transcriptional activity by stimulation with the rapamycin ligand or site-specific proteolysis of the peptide linker, with much higher level of activation than rapamycin-induced heterodimerization. Additionally, we demonstrated reversibility, activation of genomic targets and implemented logic gates based on combinations of protein cyclization, proteolytic cleavage and ligand-induced dimerization, where the strongest fold induction was achieved by the proteolytic cleavage of a repression domain from a linear TALE. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Locked nucleoside analogues expand the potential of DNAzymes to cleave structured RNA targets

    Directory of Open Access Journals (Sweden)

    Wengel Jesper

    2006-06-01

    Full Text Available Abstract Background DNAzymes cleave at predetermined sequences within RNA. A prerequisite for cleavage is that the DNAzyme can gain access to its target, and thus the DNAzyme must be capable of unfolding higher-order structures that are present in the RNA substrate. However, in many cases the RNA target sequence is hidden in a region that is too tightly structured to be accessed under physiological conditions by DNAzymes. Results We investigated how incorporation of LNA (locked nucleic acid monomers into DNAzymes improves their ability to gain access and cleave at highly-structured RNA targets. The binding arms of DNAzymes were varied in length and were substituted with up to three LNA and α-L-LNA monomers (forming LNAzymes. For one DNAzyme, the overall cleavage reaction proceeded fifty times faster after incorporation of two α-L-LNA monomers per binding arm (kobs increased from 0.014 min-1 to 0.78 min-1. Conclusion The data demonstrate how hydrolytic performance can be enhanced by design of LNAzymes, and indicate that there are optimal lengths for the binding arms and for the number of modified LNA monomers.

  11. Mode-locked Pr3+-doped silica fiber laser with an external cavity

    DEFF Research Database (Denmark)

    Shi, Yuan; Poulsen, Christian; Sejka, Milan

    1994-01-01

    We present a Pr3+-doped silica-based fiber laser mode-locked by using a linear external cavity with a vibrating mirror. Stable laser pulses with a FWHM of less than 44 ps, peak power greater than 9 W, and repetition rate up to 100 MHz are obtained. The pulse width versus cavity mismatch ΔL and pump...... power have been investigated. With a short piece of nonlinear fiber included in the external cavity, laser pulses of 45 ps have been measured...

  12. An elevator for locked drilling pipes

    Energy Technology Data Exchange (ETDEWEB)

    Gurbanov, R.S.; Abbasov, E.M.; Ismailov, A.A.; Mamedov, Yu.S.; Safarov, A.A.

    1983-01-01

    An elevator is proposed, which includes a body with a door. To reduce the probability of gas shows in a well with high speed lowering and lifting of the column of locked drilling pipes through providing the possibility of feeding a drilling mud in this case into the mine, the elevator is equipped with a pneumatic cylinder with a two way hollow rod, on one face of which a sealing element is mounted for sealing the drilling pipe and on the other, an adapter for feeding the drilling mud. The rod is linked with the sleeve of the pneumatic cylinder, which is rigidly linked with the body with the capability of axial movement without rotation.

  13. Gapless Color-Flavor-Locked Quark Matter

    DEFF Research Database (Denmark)

    Alford, Mark; Kouvaris, Christoforos; Rajagopal, Krishna

    2004-01-01

    In neutral cold quark matter that is sufficiently dense that the strange quark mass M_s is unimportant, all nine quarks (three colors; three flavors) pair in a color-flavor locked (CFL) pattern, and all fermionic quasiparticles have a gap. We argue that as a function of decreasing quark chemical...... potential mu or increasing M_s, there is a quantum phase transition from the CFL phase to a new ``gapless CFL phase'' in which only seven quasiparticles have a gap. The transition occurs where M_s^2/mu is approximately equal to 2*Delta, with Delta the gap parameter. Gapless CFL, like CFL, leaves unbroken...... a linear combination Qtilde of electric and color charges, but it is a Qtilde-conductor with a nonzero electron density. These electrons and the gapless quark quasiparticles make the low energy effective theory of the gapless CFL phase and, consequently, its astrophysical properties are qualitatively...

  14. Solving nucleic acid structures by molecular replacement: examples from group II intron studies

    International Nuclear Information System (INIS)

    Marcia, Marco; Humphris-Narayanan, Elisabeth; Keating, Kevin S.; Somarowthu, Srinivas; Rajashankar, Kanagalaghatta; Pyle, Anna Marie

    2013-01-01

    Strategies for phasing nucleic acid structures by molecular replacement, using both experimental and de novo designed models, are discussed. Structured RNA molecules are key players in ensuring cellular viability. It is now emerging that, like proteins, the functions of many nucleic acids are dictated by their tertiary folds. At the same time, the number of known crystal structures of nucleic acids is also increasing rapidly. In this context, molecular replacement will become an increasingly useful technique for phasing nucleic acid crystallographic data in the near future. Here, strategies to select, create and refine molecular-replacement search models for nucleic acids are discussed. Using examples taken primarily from research on group II introns, it is shown that nucleic acids are amenable to different and potentially more flexible and sophisticated molecular-replacement searches than proteins. These observations specifically aim to encourage future crystallographic studies on the newly discovered repertoire of noncoding transcripts

  15. A low-cost, high-performance, digital signal processor-based lock-in amplifier capable of measuring multiple frequency sweeps simultaneously

    International Nuclear Information System (INIS)

    Sonnaillon, Maximiliano Osvaldo; Bonetto, Fabian Jose

    2005-01-01

    A high-performance digital lock-in amplifier implemented in a low-cost digital signal processor (DSP) board is described. This lock in is capable of measuring simultaneously multiple frequencies that change in time as frequency sweeps (chirps). The used 32-bit DSP has enough computing power to generate N=3 simultaneous reference signals and accurately measure the N=3 responses, operating as three lock ins connected in parallel to a linear system. The lock in stores the measured values in memory until they are downloaded to the a personal computer (PC). The lock in works in stand-alone mode and can be programmed and configured through the PC serial port. Downsampling and multiple filter stages were used in order to obtain a sharp roll off and a long time constant in the filters. This makes measurements possible in presence of high-noise levels. Before each measurement, the lock in performs an autocalibration that measures the frequency response of analog output and input circuitry in order to compensate for the departure from ideal operation. Improvements from previous lock-in implementations allow measuring the frequency response of a system in a short time. Furthermore, the proposed implementation can measure how the frequency response changes with time, a characteristic that is very important in our biotechnological application. The number of simultaneous components that the lock in can generate and measure can be extended, without reprogramming, by only using other DSPs of the same family that are code compatible and work at higher clock frequencies

  16. A low-cost, high-performance, digital signal processor-based lock-in amplifier capable of measuring multiple frequency sweeps simultaneously

    Energy Technology Data Exchange (ETDEWEB)

    Sonnaillon, Maximiliano Osvaldo; Bonetto, Fabian Jose [Laboratorio de Cavitacion y Biotecnologia, San Carlos de Bariloche (8400) (Argentina)

    2005-02-01

    A high-performance digital lock-in amplifier implemented in a low-cost digital signal processor (DSP) board is described. This lock in is capable of measuring simultaneously multiple frequencies that change in time as frequency sweeps (chirps). The used 32-bit DSP has enough computing power to generate N=3 simultaneous reference signals and accurately measure the N=3 responses, operating as three lock ins connected in parallel to a linear system. The lock in stores the measured values in memory until they are downloaded to the a personal computer (PC). The lock in works in stand-alone mode and can be programmed and configured through the PC serial port. Downsampling and multiple filter stages were used in order to obtain a sharp roll off and a long time constant in the filters. This makes measurements possible in presence of high-noise levels. Before each measurement, the lock in performs an autocalibration that measures the frequency response of analog output and input circuitry in order to compensate for the departure from ideal operation. Improvements from previous lock-in implementations allow measuring the frequency response of a system in a short time. Furthermore, the proposed implementation can measure how the frequency response changes with time, a characteristic that is very important in our biotechnological application. The number of simultaneous components that the lock in can generate and measure can be extended, without reprogramming, by only using other DSPs of the same family that are code compatible and work at higher clock frequencies.

  17. Photochemical reactions of nucleic acids and their constituents of photobiological relevance

    International Nuclear Information System (INIS)

    Saito, I.; Sugiyama, H.; Matsuura, T.

    1983-01-01

    A review is given of the papers published from 1977 to May 1983 on the UV-induced photochemical reactions of nucleic acids and their constituents of photobiological relevance where the structures of photoproducts have been fully characterized. Among the topics discussed are photoadditions relevant to nucleic acid-protein photocrosslinking, photoreactions with psoralens and nucleic acids and photochemical reactions of polynucleotides. (U.K.)

  18. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Science.gov (United States)

    Cary, Robert E.

    2015-12-08

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  19. BIOPHYSICAL PROPERTIES OF NUCLEIC ACIDS AT SURFACES RELEVANT TO MICROARRAY PERFORMANCE

    OpenAIRE

    Rao, Archana N.; Grainger, David W.

    2014-01-01

    Both clinical and analytical metrics produced by microarray-based assay technology have recognized problems in reproducibility, reliability and analytical sensitivity. These issues are often attributed to poor understanding and control of nucleic acid behaviors and properties at solid-liquid interfaces. Nucleic acid hybridization, central to DNA and RNA microarray formats, depends on the properties and behaviors of single strand (ss) nucleic acids (e.g., probe oligomeric DNA) bound to surface...

  20. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Robert B.

    2018-04-17

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  1. Nucleic acid binding and other biomedical properties of artificial oligolysines

    Directory of Open Access Journals (Sweden)

    Roviello GN

    2016-11-01

    Full Text Available Giovanni N Roviello,1 Caterina Vicidomini,1 Vincenzo Costanzo,1 Valentina Roviello2 1CNR Istituto di Biostrutture e Bioimmagini, Via Mezzocannone site and Headquarters, 2Centro Regionale di Competenza (CRdC Tecnologie, Via Nuova Agnano, Napoli, Italy Abstract: In the present study, we report the interaction of an artificial oligolysine (referred to as AOL realized in our laboratory with targets of biomedical importance. These included polyinosinic acid (poly rI and its complex with polycytidylic acid (poly I:C, RNAs with well-known interferon-inducing ability, and double-stranded (ds DNA. The ability of the peptide to bind both single-stranded poly rI and ds poly I:C RNAs emerged from our circular dichroism (CD and ultraviolet (UV studies. In addition, we found that AOL forms complexes with dsDNA, as shown by spectroscopic binding assays and UV thermal denaturation experiments. These findings are encouraging for the possible use of AOL in biomedicine for nucleic acid targeting and oligonucleotide condensation, with the latter being a key step preceding their clinical application. Moreover, we tested the ability of AOL to bind to proteins, using serum albumin as a model protein. We demonstrated the oligolysine–protein binding by CD experiments which suggested that AOL, positively charged under physiological conditions, binds to the protein regions rich in anionic residues. Finally, the morphology characterization of the solid oligolysine, performed by scanning electron microscopy, showed different crystal forms including cubic-shaped crystals confirming the high purity of AOL. Keywords: nucleic acid binding, polyinosinic acid, double-stranded nucleic acids, oligolysine, circular dichroism

  2. Ionizing radiation induced attachment reactions of nucleic acids and their components

    International Nuclear Information System (INIS)

    Myers, L.S. Jr.

    1975-01-01

    An extensive bibliographic review is given of experimental and theoretical data on radiation-induced attachment reactions of nucleic acids and their components. Mechanisms of these reactions are reviewed. The reactions with water, formate, and alcohols, with amines and other small molecules, and with radiation sensitizers and nucleic acid-nucleic acid reactions are discussed. Studies of the reaction mechanisms show that many of the reactions occur by radical-molecule reactions, but radical-radical reactions also occur. Radiation modifiers become attached to nucleic acids in vitro and in vivo and there are indications that attachment may be necessary for the action of some sensitizers. (U.S.)

  3. Advances in nucleic acid-based diagnostics of bacterial infections

    DEFF Research Database (Denmark)

    Barken, Kim Bundvig; Haagensen, Janus Anders Juul; Tolker-Nielsen, Tim

    2007-01-01

    Methods for rapid detection of infectious bacteria and antimicrobial-resistant pathogens have evolved significantly over the last decade. Many of the new procedures are nucleic acid-based and replace conventional diagnostic methods like culturing which is time consuming especially with fastidious...... of these pathogens is important to isolate patients and prevent further spreading of the diseases. Newly developed diagnostic procedures are superior with respect to turnaround time, sensitivity and specificity. Methods like multiplex real time PCR and different array-based technologies offer the possibility...

  4. Fluorescently labeled bionanotransporters of nucleic acid based on carbon nanotubes

    International Nuclear Information System (INIS)

    Novopashina, D.S.; Apartsin, E.K.; Venyaminova, A.G.

    2012-01-01

    We propose an approach to the design of a new type of hybrids of oligonucleotides with fluorescein-functionalized single-walled carbon nanotubes. The approach is based on stacking interactions of functionalized nanotubes with pyrene residues in conjugates of oligonucleotides. The amino- and fluorescein-modified single walled carbon nanotubes are obtained, and their physico-chemical properties are investigated. The effect of the functionalization type of carbon nanotubes on the efficacy of the sorption of pyrene conjugates of oligonucleotides was examined. The proposed noncovalent hybrids of fluorescein-labeled carbon nanotubes with oligonucleotides may be used for the intracellular transport of functional nucleic acids.

  5. Spectrofluorometric study on photochemical interaction between chlorpromazine and nucleic acids

    International Nuclear Information System (INIS)

    Fujita, H.; Hayashi, H.; Suzuki, K.

    1981-01-01

    Near-UV irradiation of a mixture of chlorpromazine and single-stranded nucleic acids produced a non-dialyzable photoproduct which emitted characteristic fluorescence at around 520 nm. The same fluorescent species was also formed by the photoreaction with purine nucleotides but not with pyrimidine nucleotide. The highest photoreactivity was observed with GMP. Smaller amounts of the species were formed in a solution with a high salt concentration than in that with a low salt concentration. A higher rate was observed under anaerobic conditions than under aerobic conditions. (author)

  6. Nucleic acid constructs containing orthogonal site selective recombinases (OSSRs)

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Joshua M.; Anderson, J. Christopher; Dueber, John E.

    2017-08-29

    The present invention provides for a recombinant nucleic acid comprising a nucleotide sequence comprising a plurality of constructs, wherein each construct independently comprises a nucleotide sequence of interest flanked by a pair of recombinase recognition sequences. Each pair of recombinase recognition sequences is recognized by a distinct recombinase. Optionally, each construct can, independently, further comprise one or more genes encoding a recombinase capable of recognizing the pair of recombinase recognition sequences of the construct. The recombinase can be an orthogonal (non-cross reacting), site-selective recombinase (OSSR).

  7. Obituary: Martha Locke Hazen, 1931-2006

    Science.gov (United States)

    Williams, Thomas R.; Willson, Lee Anne

    2007-12-01

    Longtime Harvard Curator of Astronomical Photographs and AAVSO officer Martha Hazen passed away on 23 December 2006 at Hingham, Massachusetts, after a short illness due to acute myelogenous leukemia. One of four children of Harold Locke and Katherine (neé Salisbury) Hazen, Martha was born in Cambridge, Massachusetts, on 15 July 1931, and raised in the Town of Belmont, near Cambridge, where she lived for most of her life. Her father coined the term "servo-mechanism" while serving as an engineering professor and dean for graduate students at the Massachusetts Institute of Technology. Her mother majored in chemistry at Mount Holyoke College. After receiving an A.B. in astronomy from Mount Holyoke College in 1953, Martha earned a Ph.D. in astronomy in 1958 from the University of Michigan, defending a dissertation on the distribution of intensity in elliptical galaxies in the Virgo cluster. Martha's marriage to William Liller in 1959, and the births of two children, inevitably slowed down her progress in observational astronomy. As a research fellow of the Harvard College Observatory, Martha continued to observe two to three weeks a year in Chile, and to reduce those observations and publish the results for sixteen years. Martha's first publication, at least as far as Astrophysics Data System includes the literature, was with Alice Farnsworth on the 1952 occultations of stars by the Moon, published in the Astronomical Journal (1953). In 1958 she joined L. R. Doherty and D. H. Menzel on a short note about the calculation of line profiles in a stratified atmosphere, her only theory paper. Martha's most cited paper is "The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster," (ApJ, 132, p.306, 1960). There she acknowledges Allan Sandage for suggesting the problem and providing some of the data. Her second most cited paper is "Photometric histories of QSOs - Two QSOs with large light amplitude," (Liller, M. H. & Liller, W., ApJ (Letters), 199, p. L133-L

  8. Certain features of FELs with short bunches

    International Nuclear Information System (INIS)

    Lebedev, A.N.

    2006-01-01

    The report is devoted to physics of free electron lasers operating in the short-wave domain where the bunch length could be less than the undulator length in the proper frame. Then the current component of the signal is locked within the bunch as in a cavity, while the electromagnetic component propagates freely. In contrast with gyrotrons where this regime can be of interest only for wavelengths comparable with the bunch length, we consider short waves in a bunch of arbitrary profile. Both amplification of an external harmonic signal and SASE regime, i.e. selective amplification of proper noises, are investigated

  9. Injection locking of optomechanical oscillators via acoustic waves

    Science.gov (United States)

    Huang, Ke; Hossein-Zadeh, Mani

    2018-04-01

    Injection locking is a powerful technique for synchronization of oscillator networks and controlling the phase and frequency of individual oscillators using similar or other types of oscillators. Here, we present the first demonstration of injection locking of a radiation-pressure driven optomechanical oscillator (OMO) via acoustic waves. As opposed to previously reported techniques (based on pump modulation or direct application of a modulated electrostatic force), injection locking of OMO via acoustic waves does not require optical power modulation or physical contact with the OMO and it can easily be implemented on various platforms. Using this approach we have locked the phase and frequency of two distinct modes of a microtoroidal silica OMO to a piezoelectric transducer (PZT). We have characterized the behavior of the injection locked OMO with three acoustic excitation configurations and showed that even without proper acoustic impedance matching the OMO can be locked to the PZT and tuned over 17 kHz with only -30 dBm of RF power fed to the PZT. The high efficiency, simplicity and scalability of the proposed approach paves the road toward a new class of photonic systems that rely on synchronization of several OMOs to a single or multiple RF oscillators with applications in optical communication, metrology and sensing. Beyond its practical applications, injection locking via acoustic waves can be used in fundamental studies in quantum optomechanics where thermal and optical isolation of the OMO are critical.

  10. Key-lock colloids in a nematic liquid crystal.

    Science.gov (United States)

    Silvestre, Nuno M; Tasinkevych, M

    2017-01-01

    The Landau-de Gennes free energy is used to study theoretically the effective interaction of spherical "key" and anisotropic "lock" colloidal particles. We assume identical anchoring properties of the surfaces of the key and of the lock particles, and we consider planar degenerate and perpendicular anchoring conditions separately. The lock particle is modeled as a spherical particle with a spherical dimple. When such a particle is introduced into a nematic liquid crystal, it orients its dimple at an oblique angle θ_{eq} with respect to the far field director n_{∞}. This angle depends on the depth of the dimple. Minimization results show that the free energy of a pair of key and lock particles exhibits a global minimum for the configuration when the key particle is facing the dimple of the lock colloidal particle. The preferred orientation ϕ_{eq} of the key-lock composite doublet relative to n_{∞} is robust against thermal fluctuations. The preferred orientation θ_{eq}^{(2)} of the dimple particle in the doublet is different from the isolated situation. This is related to the "direct" interaction of defects accompanying the key particle with the edge of the dimple. We propose that this nematic-amplified key-lock interaction can play an important role in self-organization and clustering of mixtures of colloidal particles with dimple colloids present.

  11. Brain communication in the locked-in state.

    Science.gov (United States)

    De Massari, Daniele; Ruf, Carolin A; Furdea, Adrian; Matuz, Tamara; van der Heiden, Linda; Halder, Sebastian; Silvoni, Stefano; Birbaumer, Niels

    2013-06-01

    Patients in the completely locked-in state have no means of communication and they represent the target population for brain-computer interface research in the last 15 years. Although different paradigms have been tested and different physiological signals used, to date no sufficiently documented completely locked-in state patient was able to control a brain-computer interface over an extended time period. We introduce Pavlovian semantic conditioning to enable basic communication in completely locked-in state. This novel paradigm is based on semantic conditioning for online classification of neuroelectric or any other physiological signals to discriminate between covert (cognitive) 'yes' and 'no' responses. The paradigm comprised the presentation of affirmative and negative statements used as conditioned stimuli, while the unconditioned stimulus consisted of electrical stimulation of the skin paired with affirmative statements. Three patients with advanced amyotrophic lateral sclerosis participated over an extended time period, one of which was in a completely locked-in state, the other two in the locked-in state. The patients' level of vigilance was assessed through auditory oddball procedures to study the correlation between vigilance level and the classifier's performance. The average online classification accuracies of slow cortical components of electroencephalographic signals were around chance level for all the patients. The use of a non-linear classifier in the offline classification procedure resulted in a substantial improvement of the accuracy in one locked-in state patient achieving 70% correct classification. A reliable level of performance in the completely locked-in state patient was not achieved uniformly throughout the 37 sessions despite intact cognitive processing capacity, but in some sessions communication accuracies up to 70% were achieved. Paradigm modifications are proposed. Rapid drop of vigilance was detected suggesting attentional

  12. Injection locking of optomechanical oscillators via acoustic waves.

    Science.gov (United States)

    Huang, Ke; Hossein-Zadeh, Mani

    2018-04-02

    Injection locking is an effective technique for synchronization of oscillator networks and controlling the phase and frequency of individual oscillators. As such, exploring new mechanisms for injection locking of emerging oscillators is important for their usage in various systems. Here, we present the first demonstration of injection locking of a radiation pressure driven optomechanical oscillator (OMO) via acoustic waves. As opposed to previously reported techniques (based on pump modulation or direct application of a modulated electrostatic force), injection locking of OMO via acoustic waves does not require optical power modulation or physical contact with the OMO and it can be easily implemented on various platforms to lock different types of OMOs independent of their size and structure. Using this approach we have locked the phase and frequency of two distinct modes of a microtoroidal silica OMO to a piezoelectric transducer (PZT). We have characterized the behavior of the injection locked OMO with three acoustic excitation configurations and showed that even without proper acoustic impedance, matching the OMO can be locked to the PZT and tuned over 17 kHz with only -30 dBm of RF power fed to the PZT. The high efficiency, simplicity, and scalability of the proposed approach paves the road toward a new class of photonic systems that rely on synchronization of several OMOs to a single or multiple RF oscillators with applications in optical communication, metrology, and sensing. Beyond its practical applications, injection locking via acoustic waves can be used in fundamental studies in quantum optomechanics where thermal and optical isolation of the OMO are critical.

  13. A scalable lock-free hash table with open addressing

    DEFF Research Database (Denmark)

    Nielsen, Jesper Puge; Karlsson, Sven

    2016-01-01

    and concurrent operations without any locks. In this paper, we present a new fully lock-free open addressed hash table with a simpler design than prior published work. We split hash table insertions into two atomic phases: first inserting a value ignoring other concurrent operations, then in the second phase......Concurrent data structures synchronized with locks do not scale well with the number of threads. As more scalable alternatives, concurrent data structures and algorithms based on widely available, however advanced, atomic operations have been proposed. These data structures allow for correct...

  14. Control of photon storage time using phase locking.

    Science.gov (United States)

    Ham, Byoung S

    2010-01-18

    A photon echo storage-time extension protocol is presented by using a phase locking method in a three-level backward propagation scheme, where phase locking serves as a conditional stopper of the rephasing process in conventional two-pulse photon echoes. The backward propagation scheme solves the critical problems of extremely low retrieval efficiency and pi rephasing pulse-caused spontaneous emission noise in photon echo based quantum memories. The physics of the storage time extension lies in the imminent population transfer from the excited state to an auxiliary spin state by a phase locking control pulse. We numerically demonstrate that the storage time is lengthened by spin dephasing time.

  15. Testing ultrafast mode-locking at microhertz relative optical linewidth.

    Science.gov (United States)

    Martin, Michael J; Foreman, Seth M; Schibli, T R; Ye, Jun

    2009-01-19

    We report new limits on the phase coherence of the ultrafast mode-locking process in an octave-spanning Ti:sapphire comb.We find that the mode-locking mechanism correlates optical phase across a full optical octave with less than 2.5 microHZ relative linewidth. This result is at least two orders of magnitude below recent predictions for quantum-limited individual comb-mode linewidths, verifying that the mode-locking mechanism strongly correlates quantum noise across the comb spectrum.

  16. Temperature-insensitive laser frequency locking near absorption lines

    International Nuclear Information System (INIS)

    Kostinski, Natalie; Olsen, Ben A.; Marsland, Robert III; McGuyer, Bart H.; Happer, William

    2011-01-01

    Combined magnetically induced circular dichroism and Faraday rotation of an atomic vapor are used to develop a variant of the dichroic atomic vapor laser lock that eliminates lock sensitivity to temperature fluctuations of the cell. Operating conditions that eliminate first-order sensitivity to temperature fluctuations can be determined by low-frequency temperature modulation. This temperature-insensitive gyrotropic laser lock can be accurately understood with a simple model, that is in excellent agreement with observations in potassium vapor at laser frequencies in a 2 GHz range about the 770.1 nm absorption line. The methods can be readily adapted for other absorption lines.

  17. Testing ultrafast mode-locking at microhertz relative optical linewidth

    OpenAIRE

    Martin, Michael J.; Foreman, Seth M.; Schibli, T. R.; Ye, Jun

    2008-01-01

    We report new limits on the phase coherence of the ultrafast mode-locking process in an octave-spanning Ti:sapphire comb. We find that the mode-locking mechanism correlates optical phase across a full optical octave with less than 2.5 micro Hz relative linewidth. This result is at least two orders of magnitude below recent predictions for quantum-limited individual comb-mode linewidths, verifying that the mode-locking mechanism strongly correlates quantum noise across the comb spectrum.

  18. Tilt-tuned etalon locking for tunable laser stabilization.

    Science.gov (United States)

    Gibson, Bradley M; McCall, Benjamin J

    2015-06-15

    Locking to a fringe of a tilt-tuned etalon provides a simple, inexpensive method for stabilizing tunable lasers. Here, we describe the use of such a system to stabilize an external-cavity quantum cascade laser; the locked laser has an Allan deviation of approximately 1 MHz over a one-second integration period, and has a single-scan tuning range of approximately 0.4  cm(-1). The system is robust, with minimal alignment requirements and automated lock acquisition, and can be easily adapted to different wavelength regions or more stringent stability requirements with minor alterations.

  19. Development of the Lock Protocol for DEPSKY Storage System

    Directory of Open Access Journals (Sweden)

    NASCIMENTO, P. S.

    2015-06-01

    Full Text Available Data management in environments based on several clouds (cloud-of-clouds should be dependable and secure. DEPSKY may assure that characteristics through mechanisms as cryptography and data replication, however DEPSKY does not support concurrent writing, a desirable functionality for many applications. This paper presents the development and a performance analysis of a lock algorithmfor DEPSKY storage system. The paper also presents validation test and performance test of the algorithm. Such protocol allows concurrent writing, through a low contention lock mechanism that uses lock filesfi to dene who is allowed to write in a data unit.

  20. Squeezing in an injection-locked semiconductor laser

    Science.gov (United States)

    Inoue, S.; Machida, S.; Yamamoto, Y.; Ohzu, H.

    1993-09-01

    The intensity-noise properties of an injection-locked semiconductor laser were studied experimentally. The constant-current-driven semiconductor laser producing the amplitude-squeezed state whose intensity noise was reduced below the standard quantum limit (SQL) by 0.72 dB was injection-locked by an external master laser. The measured intensity-noise level of the injection-locked semiconductor laser was 0.91 dB below the SQL. This experimental result indicates that a phase-coherent amplitude-squeezed state or squeezed vacuum state together with a reference local oscillator wave can be generated directly by semiconductor laser systems.

  1. Dynamics of Linker Residues Modulate the Nucleic Acid Binding Properties of the HIV-1 Nucleocapsid Protein Zinc Fingers

    Science.gov (United States)

    Zargarian, Loussiné; Tisné, Carine; Barraud, Pierre; Xu, Xiaoqian; Morellet, Nelly; René, Brigitte; Mély, Yves; Fossé, Philippe; Mauffret, Olivier

    2014-01-01

    The HIV-1 nucleocapsid protein (NC) is a small basic protein containing two zinc fingers (ZF) separated by a short linker. It is involved in several steps of the replication cycle and acts as a nucleic acid chaperone protein in facilitating nucleic acid strand transfers occurring during reverse transcription. Recent analysis of three-dimensional structures of NC-nucleic acids complexes established a new property: the unpaired guanines targeted by NC are more often inserted in the C-terminal zinc finger (ZF2) than in the N-terminal zinc finger (ZF1). Although previous NMR dynamic studies were performed with NC, the dynamic behavior of the linker residues connecting the two ZF domains remains unclear. This prompted us to investigate the dynamic behavior of the linker residues. Here, we collected 15N NMR relaxation data and used for the first time data at several fields to probe the protein dynamics. The analysis at two fields allows us to detect a slow motion occurring between the two domains around a hinge located in the linker at the G35 position. However, the amplitude of motion appears limited in our conditions. In addition, we showed that the neighboring linker residues R29, A30, P31, R32, K33 displayed restricted motion and numerous contacts with residues of ZF1. Our results are fully consistent with a model in which the ZF1-linker contacts prevent the ZF1 domain to interact with unpaired guanines, whereas the ZF2 domain is more accessible and competent to interact with unpaired guanines. In contrast, ZF1 with its large hydrophobic plateau is able to destabilize the double-stranded regions adjacent to the guanines bound by ZF2. The linker residues and the internal dynamics of NC regulate therefore the different functions of the two zinc fingers that are required for an optimal chaperone activity. PMID:25029439

  2. Radiation-induced electron migration in nucleic acids

    International Nuclear Information System (INIS)

    Fuciarelli, A.F.; Sisk, E.C.; Miller, J.H.; Zimbrick, J.D.

    1994-01-01

    Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to non-random types of damage along DNA manifested distal to the sites of the initial energy deposition. Radiation-induced electron migration in nucleic acids has been examined using oligonucleotides containing 5-bromouracil (5-BrU). Interaction of 5-BrU with solvated electrons results in release of bromide ions and formation of uracil-5-yl radicals. Monitoring either bromide ion release or uracil formation provides an opportunity to study electron migration processes in model nucleic acid systems. Using this approach we have discovered that electron migration along oligonucleotides is significantly influenced by the base sequence and strandedness. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution, which compares with mean migration distances of 6-10 bp for Escherichia coli DNA irradiated in solution and 5.5 bp for E. coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5' to 3' direction along a double-stranded oligonucleotide containing a region of purine bases adjacent to the 5-BrU moiety. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation. (Author)

  3. Nucleic acid helix structure determination from NMR proton chemical shifts

    Energy Technology Data Exchange (ETDEWEB)

    Werf, Ramon M. van der; Tessari, Marco; Wijmenga, Sybren S., E-mail: S.Wijmenga@science.ru.nl [Radboud University Nijmegen, Department of Biophysical Chemistry, Institute of Molecules and Materials (Netherlands)

    2013-06-15

    We present a method for de novo derivation of the three-dimensional helix structure of nucleic acids using non-exchangeable proton chemical shifts as sole source of experimental restraints. The method is called chemical shift de novo structure derivation protocol employing singular value decomposition (CHEOPS) and uses iterative singular value decomposition to optimize the structure in helix parameter space. The correct performance of CHEOPS and its range of application are established via an extensive set of structure derivations using either simulated or experimental chemical shifts as input. The simulated input data are used to assess in a defined manner the effect of errors or limitations in the input data on the derived structures. We find that the RNA helix parameters can be determined with high accuracy. We finally demonstrate via three deposited RNA structures that experimental proton chemical shifts suffice to derive RNA helix structures with high precision and accuracy. CHEOPS provides, subject to further development, new directions for high-resolution NMR structure determination of nucleic acids.

  4. Molecular polarization potential maps of the nucleic acid bases

    International Nuclear Information System (INIS)

    Alkorta, I.; Perez, J.J.

    1996-01-01

    Ab initio calculations at the SCF level were carried out to compute the polarization potential map NM of the nucleic acid bases: cytosine, thymine, uracil, adedine, and guanine. For this purpose, the Dunning's 9s5p basis set contracted to a split-valence, was selected to perform the calculations. The molecular polarization potential (MPP) at each point was evaluated by the difference between the interaction energy of the molecule with a unit point charge and the molecular electrostatic potential (MEP) at that point. MEPS and MPPS for the different molecules were computed with a density of 5 points/Angstrom 2 on the van der Waals surface of each molecule, defined using the van der Waals radii. Due to the symmetry of the molecules, only half the points were computed. The total number of points calculated was 558 for cytosine, 621 for thymine, 526 for uracil, 666 for adenine, and 699 for guanine. The results of these calculations are analyzed in terms of their implications on the molecular interactions between pairs of nucleic acid bases. 23 refs., 5 figs., 1 tab

  5. Evolution of sequence-defined highly functionalized nucleic acid polymers

    Science.gov (United States)

    Chen, Zhen; Lichtor, Phillip A.; Berliner, Adrian P.; Chen, Jonathan C.; Liu, David R.

    2018-03-01

    The evolution of sequence-defined synthetic polymers made of building blocks beyond those compatible with polymerase enzymes or the ribosome has the potential to generate new classes of receptors, catalysts and materials. Here we describe a ligase-mediated DNA-templated polymerization and in vitro selection system to evolve highly functionalized nucleic acid polymers (HFNAPs) made from 32 building blocks that contain eight chemically diverse side chains on a DNA backbone. Through iterated cycles of polymer translation, selection and reverse translation, we discovered HFNAPs that bind proprotein convertase subtilisin/kexin type 9 (PCSK9) and interleukin-6, two protein targets implicated in human diseases. Mutation and reselection of an active PCSK9-binding polymer yielded evolved polymers with high affinity (KD = 3 nM). This evolved polymer potently inhibited the binding between PCSK9 and the low-density lipoprotein receptor. Structure-activity relationship studies revealed that specific side chains at defined positions in the polymers are required for binding to their respective targets. Our findings expand the chemical space of evolvable polymers to include densely functionalized nucleic acids with diverse, researcher-defined chemical repertoires.

  6. Generation of short optical pulses for laser fusion. M.L. report No. 2451

    International Nuclear Information System (INIS)

    Kuizenga, D.J.

    1975-06-01

    This report considers some of the problems involved in generating the required short pulses for the laser-fusion program. Short pulses are required to produce the laser fusion, and pulses produced synchronously with this primary pulse are required for plasma diagnostics. The requirements of these pulses are first described. Several methods are considered in order to generate pulses at 1.064 μ to drive the Nd:Glass amplifiers to produce laser fusion. Conditions for optimum energy extraction per short pulse for Nd:YAG and Nd:Glass lasers are given. Four methods are then considered to produce these pulses: (1) using a fast switch to chop the required pulse out of a much longer Q-switched pulse; (2) active mode locking; (3) passive mode locking; and (4) a combination of active and passive mode locking. The use of cavity dumping is also considered to increase the energy per short pulse

  7. Passively mode-locked diode-pumped Tm3+:YLF laser emitting at 1.91 µm using a GaAs-based SESAM

    Science.gov (United States)

    Tyazhev, A.; Soulard, R.; Godin, T.; Paris, M.; Brasse, G.; Doualan, J.-L.; Braud, A.; Moncorgé, R.; Laroche, M.; Camy, P.; Hideur, A.

    2018-04-01

    We report on a diode-pumped Tm:YLF laser passively mode-locked with an InGaAs saturable absorber. The laser emits a train of 31 ps pulses at a wavelength of 1.91 µm with a repetition rate of 94 MHz and a maximum average power of 95 mW. A sustained and robust mode-locking with a signal-to-noise ratio of ~70 dB is obtained even at high relative air humidity, making this system attractive for applications requiring ultra-short pulses in the spectral window just below 2 µm.

  8. ''Old'' locked inflation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Piao, Yun-Song [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Si, Zong-Guo, E-mail: liuyangbyf@mail.sdu.edu.cn, E-mail: yspiao@gucas.ac.cn, E-mail: zgsi@sdu.edu.cn [Department of Physics, Shandong University, Jinan 250100 (China)

    2009-05-15

    In this paper, we revisit the idea of locked inflation, which does not require a potential satisfying the normal slow-roll condition, but suffers from the problems associated with ''saddle inflation''. We propose a scenario based on locked inflation, however, with an alternative evolution mechanism of the ''waterfall field'' {phi}. Instead of rolling down along the potential, the {phi} field will tunnel to end the inflation stage like in old inflation, by which the saddle inflation could be avoided. Further, we study a cascade of old locked inflation, which can be motivated by the string landscape. Our model is based on the consideration of making locked inflation feasible so as to give a working model without slow roll; It also can be seen as an effort to embed the old inflation in string landscape.

  9. Towards automatic proofs of lock-free algorithms

    OpenAIRE

    Fejoz , Loïc; Merz , Stephan

    2008-01-01

    International audience; The verification of lock-free data structures has traditionally been considered as difficult. We propose a formal model for describing such algorithms. The verification conditions generated from this model can often be handled by automatic theorem provers.

  10. Experimental study on working characteristics of density lock

    International Nuclear Information System (INIS)

    Sun Furong; Yan Changqi; Gu Haifeng

    2011-01-01

    The working principle of density lock was introduced in this paper, and the experimental loop was built so that researches on working performance of density lock in the system were done at steady-state operation and pump trip conditions. The results show that at steady-state operation conditions, density lock can keep close in a long run, which will separate passive residual heat removal circuit from primary circuit. As a result, passive residual heat removal circuit is in the non-operating conditions, which dose not influence normal operation of reactors. At the pump trip conditions, density lock can be automatically opened quickly, which will make primary and passive residual heat removal system communicated. The natural circulation is well established in the two systems, and is enough to ensure removal of residual heat. (authors)

  11. Active stabilization of a diode laser injection lock

    Energy Technology Data Exchange (ETDEWEB)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep [Department of Physics, University of Washington, P.O. Box 351560, Seattle, Washington 98195-1560 (United States)

    2016-06-15

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser’s transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.

  12. Active stabilization of a diode laser injection lock.

    Science.gov (United States)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep

    2016-06-01

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser's transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.

  13. Development of thermal actuators with multi-locking positions

    Science.gov (United States)

    Luo, J. K.; Zhu, Y.; Fu, Y. Q.; Flewitt, A. J.; Spearing, S. M.; Miao, J. M.; Milne, W. I.

    2006-04-01

    To reduce power consumption and operation temperature for micro-thermal actuators, metal-based micro-mechanical locks with multi-locking positions were analyzed and fabricated. The micro-locks consist of two or three U-shaped thermal actuators. The devices were made by a single mask process using electroplated Ni as the active material. Tests showed that the metal based thermal actuators deliver a maximum displacement of ~20µm at a much lower temperature than that of Si-based actuators. However Ni-actuators showed a severe back bending, which increases with increasing applied power. The temperature to initiate the back bending is as low as ~240°C. Back bending increases the distance between the two actuators, and leads to locking function failure. For practical application, Ni-based thermal actuators must be operated below 200°C.

  14. Microbiocidal effects of various taurolidine containing catheter lock solutions

    NARCIS (Netherlands)

    Olthof, E.D.; Nijland, R van; Gulich, A.F.; Wanten, G.J.A.

    2015-01-01

    BACKGROUND & AIMS: We have recently shown that a catheter lock solution containing taurolidine dramatically decreases catheter-related bloodstream infections (CRBSI) in patients on home parenteral nutrition (HPN) when compared to heparin. Since several taurolidine formulations are commercially

  15. Clinical Outcomes after Open Locked Intramedullary Nailing of ...

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... above who presented within 2 weeks of sustaining closed femoral shaft fractures ... tweak, and build upon the work non-commercially, as long as the author is ... was compressed, and proximal locking screws were then.

  16. Self-mode-locked Nd3+:YAG laser

    International Nuclear Information System (INIS)

    Komarov, A K; Komarov, K P; Kuch'yanov, Aleksandr S

    2003-01-01

    Self-mode-locking was observed in a Nd 3+ :YAG laser with a negative feedback without introducing any nonlinear elements into the laser cavity. The laser generates during pumping 300 - 500-ps single pulses on an axial period. (lasers)

  17. Mode-Locked Semiconductor Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Oxenløwe, Leif Katsuo

    2005-01-01

    We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized....

  18. Development of Phase Lock Loop System for Synchronisation of a ...

    African Journals Online (AJOL)

    Akorede

    KEYWORDS: Phase locked loop (PLL), grid synchronisation, simulations, PI regulator, hybrid system. .... system. AC. - D. C co nv erter. DC-DC converter. DC. - AC co nverter. Load ... The box named Discrete Transfer Fcn is the PI-regulator.

  19. Actuator assembly including a single axis of rotation locking member

    Science.gov (United States)

    Quitmeyer, James N.; Benson, Dwayne M.; Geck, Kellan P.

    2009-12-08

    An actuator assembly including an actuator housing assembly and a single axis of rotation locking member fixedly attached to a portion of the actuator housing assembly and an external mounting structure. The single axis of rotation locking member restricting rotational movement of the actuator housing assembly about at least one axis. The single axis of rotation locking member is coupled at a first end to the actuator housing assembly about a Y axis and at a 90.degree. angle to an X and Z axis providing rotation of the actuator housing assembly about the Y axis. The single axis of rotation locking member is coupled at a second end to a mounting structure, and more particularly a mounting pin, about an X axis and at a 90.degree. angle to a Y and Z axis providing rotation of the actuator housing assembly about the X axis. The actuator assembly is thereby restricted from rotation about the Z axis.

  20. Firearm Safety Locks: Federal Agency Implementation of the Presidential Directive

    National Research Council Canada - National Science Library

    1998-01-01

    ... deaths among children ages 5 to 14. In order to have the federal government serve as an example of gun safety, the President required that a safety lock device be provided with each handgun issued to federal law enforcement officers...

  1. Active stabilization of a diode laser injection lock

    International Nuclear Information System (INIS)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep

    2016-01-01

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser’s transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.

  2. Design and Performance Test of Locking Curved-Nut

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Min Cheol; Kang, Ho Sung; Kim, Do Yeop; Lee, Suk Yong; Lee, Eung Suk [Chungbuk Nat’l Univ., Cheongju (Korea, Republic of); Jeong, Hui Jong [Viblock Company, Cheongwon (Korea, Republic of)

    2017-03-15

    Many types of locking nut are commercializing in the various industries where has heavy vibration. Because Nut's loosing causes a serious accident. But the most locking nuts are too expensive as the complicate manufacturing process. In this study, we design the new type of locking nut, 'Curved-Nut' that is relatively simple making process. We study a relation between the elastic energy and the nut loosing mechanism. So it is analysed, the elastic energy of Curved-Nut comparing with the locking test. The Curved-Nut was manufactured on the commercial nut using a milling tool with horizontal cutting, one or two time under the nut. As the result, the more elastic energy the more prevent the loosing of the nut. We verified the performance of the loosing nut using the vibration testing equipment (NAS3350).

  3. Short communication

    African Journals Online (AJOL)

    abp

    2017-09-04

    Sep 4, 2017 ... Face-to-face interviews were conducted using a standardized ... Short communication. Open Access ... clinic during the time of the study and were invited to participate in the study. .... consume them. This is another ...

  4. SHORT COMMUNICATION

    African Journals Online (AJOL)

    PROF P.T. KAYE

    . SHORT COMMUNICATION. Formation and Structural Analysis of Novel Dibornyl Ethers. Perry T. Kaye*, Andrew R. Duggan, Joseph M. Matjila, Warner E. Molema, and. Swarnam S. Ravindran. Department of Chemistry, Rhodes University, Grahamstown, ...

  5. Vortex locking in direct numerical simulations of quantum turbulence.

    Science.gov (United States)

    Morris, Karla; Koplik, Joel; Rouson, Damian W I

    2008-07-04

    Direct numerical simulations are used to examine the locking of quantized superfluid vortices and normal fluid vorticity in evolving turbulent flows. The superfluid is driven by the normal fluid, which undergoes either a decaying Taylor-Green flow or a linearly forced homogeneous isotropic turbulent flow, although the back reaction of the superfluid on the normal fluid flow is omitted. Using correlation functions and wavelet transforms, we present numerical and visual evidence for vortex locking on length scales above the intervortex spacing.

  6. Enforced Electrical Neutrality of the Color-Flavor Locked Phase

    International Nuclear Information System (INIS)

    Rajagopal, Krishna; Wilczek, Frank

    2001-01-01

    We demonstrate that quark matter in the color-flavor locked phase of QCD is rigorously electrically neutral, despite the unequal quark masses, and even in the presence of an electron chemical potential. As long as the strange quark mass and the electron chemical potential do not preclude the color-flavor locked phase, quark matter is automatically neutral. No electrons are required and none are admitted

  7. Active Stabilization of a Diode Laser Injection Lock

    OpenAIRE

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep

    2016-01-01

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser's transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudde...

  8. Covering all the bases : Coarse-grained model design and application for nucleic acids

    NARCIS (Netherlands)

    Uusitalo, Jaakko Juhani

    2016-01-01

    Nucleic acids play a crucial role in the storage, transportation and expression of our genetic information. They have also become an interesting tool for many applications in nanotechnology. Studying biomolecular systems containing nucleic acids using experimental and imaging techniques has its

  9. Novel fluorescent nanoparticles for ultrasensitive identification of nucleic acids by optical methods

    DEFF Research Database (Denmark)

    Mulberg, Mads Westergaard; Taskova, Maria; Thomsen, Rasmus P.

    2017-01-01

    For decades, the detection of nucleic acids and their interactions at low abundances has been a challenging task. Present nucleic acid diagnostics are primarily based on enzymatic reactions including sequencing, polymerase-chain reaction and microarrays. However, the use of enzymatic amplificatio...

  10. Bis-Pyrene-Modified Unlocked Nucleic Acids: Synthesis, Hybridization Studies, and Fluorescent Properties

    Czech Academy of Sciences Publication Activity Database

    Perlíková, Pavla; Ejlersen, M.; Langkjaer, N.; Wengel, J.

    2014-01-01

    Roč. 9, č. 9 (2014), s. 2120-2127 ISSN 1860-7179 Grant - others:European Research Council(XE) FP7-268776 Institutional support: RVO:61388963 Keywords : fluorescence * nucleic acid hybridization * oligonucleotides * pyrenes * unlocked nucleic acids Subject RIV: CC - Organic Chemistry Impact factor: 2.968, year: 2014

  11. BGL6 beta-glucosidase and nucleic acids encoding the same

    Science.gov (United States)

    Dunn-Coleman, Nigel [Los Gatos, CA; Ward, Michael [San Francisco, CA

    2009-09-01

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl6, and the corresponding BGL6 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL6, recombinant BGL6 proteins and methods for producing the same.

  12. Technique for Determining Lock Coefficient of Differential "Quif"

    Directory of Open Access Journals (Sweden)

    A. B. Fominyh

    2015-01-01

    Full Text Available Increasing the traction qualities of cars on the black ice and snow-covered roads is a relevant task. There are two ways to solve this task, i.e. optimize distribution of the power stream between the driving wheels of the car; introduce a differential (differentials of the increased friction in transmission.Now, an installation of the increased friction differential in transmission is the most widespread measure to increase traction properties of cars. The differential of design "Quif" is one of such differentials. To estimate the efficiency degree of using such a differential is possible either experimentally or theoretically. In case of theoretically determined usefulness of this differential design, as an estimate indicator of the differential installation in transmission a coefficient of lock is accepted.The article considers an algorithm and a technique to calculate a lock coefficient of the differential design "Quif" allowing us to define numeric values of the lock coefficient of such differential at designing stage. It also considers how the lock coefficient depends on the gearing angle and tilt angle of the gear wheel teeth of differential. The given estimating algorithm of designated parameter of differential has more logical and compact structure with regard to the known ones. The lock coefficient values calculated by the offered technique differ from the experimental data by no more than 12%. Taking into account abovementioned, the presented technique for calculating lock coefficient of differential "Quif" is advisable for practical application.

  13. Pressure locking and thermal binding of gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, E.M.

    1996-12-01

    Pressure locking and thermal binding represent potential common mode failure mechanisms that can cause safety-related power-operated gate valves to fail in the closed position, thus rendering redundant safety-related systems incapable of performing their safety functions. Supplement 6 to Generic Letter 89-10, {open_quotes}Safety-Related Motor-Operated Gate Valve Testing and Surveillance,{close_quotes} provided an acceptable approach to addressing pressure locking and thermal binding of gate valves. More recently, the NRC has issued Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves,{close_quotes} to request that licensees take certain actions to ensure that safety-related power-operated gate valves that are susceptible to pressure locking or thermal binding are capable of performing their safety functions within the current licensing bases. Over the past two years, several plants in Region I determined that valves in certain systems were potentially susceptible to pressure locking and thermal binding, and have taken various corrective actions. The NRC Region I Systems Engineering Branch has been actively involved in the inspection of licensee actions in response to the pressure locking and thermal binding issue. Region I continues to maintain an active involvement in this area, including participation with the Office of Nuclear Reactor Regulation in reviewing licensee responses to Generic Letter 95-07.

  14. Experimental implementation of phase locking in a nonlinear interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong; Jing, Jietai, E-mail: jtjing@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China); Marino, A. M. [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019 (United States)

    2015-09-21

    Based upon two cascade four-wave mixing processes in two identical hot rubidium vapor cells, a nonlinear interferometer has been experimentally realized [Jing et al., Appl. Phys. Lett. 99, 011110 (2011); Hudelist et al., Nat. Commun. 5, 3049 (2014)]. It has a higher degree of phase sensitivity than a traditional linear interferometer and has many potential applications in quantum metrology. Phase locking of the nonlinear interferometer is needed before it can find its way into applications. In this letter, we investigate the experimental implementation of phase locking of the relative phase between the three beams at different frequencies involved in such a nonlinear interferometer. We have utilized two different methods, namely, beat note locking and coherent modulation locking. We find that coherent modulation locking can achieve much better phase stability than beat note locking in our system. Our results pave the way for real applications of a nonlinear interferometer in precision measurement and quantum manipulation, for example, phase control in phase-sensitive N-wave mixing process, N-port nonlinear interferometer and quantum-enhanced real-time phase tracking.

  15. Locked doors in acute inpatient psychiatry: a literature review.

    Science.gov (United States)

    van der Merwe, M; Bowers, L; Jones, J; Simpson, A; Haglund, K

    2009-04-01

    Many acute inpatient psychiatric wards in the UK are permanently locked, although this is contrary to the current Mental Health Act Code of Practice. To conduct a literature review of empirical articles concerning locked doors in acute psychiatric inpatient wards, an extensive literature search was performed in SAGE Journals Online, EBM Reviews, British Nursing Index, CINAHL, EMBASE Psychiatry, International Bibliography of the Social Sciences, Ovid MEDLINE, PsycINFO and Google, using the search terms 'open$', 'close$', '$lock$', 'door', 'ward', 'hospital', 'psychiatr', 'mental health', 'inpatient' and 'asylum'. A total of 11 empirical papers were included in the review. Both staff and patients reported advantages (e.g. preventing illegal substances from entering the ward and preventing patients from absconding and harming themselves or others) and disadvantages (e.g. making patients feel depressed, confined and creating extra work for staff) regarding locked doors. Locked wards were associated with increased patient aggression, poorer satisfaction with treatment and more severe symptoms. The limited literature available showed the urgent need for research to determine the real effects of locked doors in inpatient psychiatry.

  16. [Oligonucleotide derivatives in the nucleic acid hybridization analysis. I. Covalent immobilization of oligonucleotide probes onto the nylon].

    Science.gov (United States)

    Dmitrienko, E V; Pyshnaia, I A; Pyshnyĭ, D V

    2010-01-01

    The features of UV-induced immobilization of oligonucleotides on a nylon membranes and the effectiveness of enzymatic labeling of immobilized probes at heterophase detection of nucleic acids are studied. Short terminal oligothymidilate (up to 10 nt) sequences are suggested to attach to the probe via a flexible ethylene glycol based linker. The presence of such fragment enhances the intensity of immobilization and reduces UV-dependent degradation of the targeted (sequence-specific) part of the probe by reducing the dose needed for the immobilization of DNA. The optimum dose of UV-irradiation is determined to be ~0.4 J/cm(2) at the wavelength 254 nm. This dose provides high level of hybridization signal for immobilized probes with various nucleotide composition of the sequence specific moiety. The amide groups of the polyamide are shown to play the key role in the photoinduced immobilization of nucleic acids, whereas the primary amino groups in the structure of PA is not the center responsible for the covalent binding of DNA by UV-irradiation, as previously believed. Various additives in the soaking solution during the membrane of UV-dependent immobilization of probes are shown to influence its effectiveness. The use of alternative to UV-irradiation system of radical generation are shown to provide the immobilization of oligonucleotides onto the nylon membrane.

  17. Revealing Nucleic Acid Mutations Using Förster Resonance Energy Transfer-Based Probes

    Directory of Open Access Journals (Sweden)

    Nina P. L. Junager

    2016-07-01

    Full Text Available Nucleic acid mutations are of tremendous importance in modern clinical work, biotechnology and in fundamental studies of nucleic acids. Therefore, rapid, cost-effective and reliable detection of mutations is an object of extensive research. Today, Förster resonance energy transfer (FRET probes are among the most often used tools for the detection of nucleic acids and in particular, for the detection of mutations. However, multiple parameters must be taken into account in order to create efficient FRET probes that are sensitive to nucleic acid mutations. In this review; we focus on the design principles for such probes and available computational methods that allow for their rational design. Applications of advanced, rationally designed FRET probes range from new insights into cellular heterogeneity to gaining new knowledge of nucleic acid structures directly in living cells.

  18. Autoantibody Profiling in Lupus Patients using Synthetic Nucleic Acids

    DEFF Research Database (Denmark)

    Klecka, Martin; Thybo, Christina; Macaubas, Claudia

    2018-01-01

    specificity and reproducibility. Applying the ELISA tests to serological studies of pediatric and adult SLE, we identified novel clinical correlations. We also observed preferential recognition of a specific synthetic antigen by antibodies in SLE sera. We determined the probable basis for this finding using...... computational analyses, providing valuable structural information for future development of DNA antigens. Synthetic nucleic acid molecules offer the opportunity to standardize assays and to dissect antibody-antigen interactions.......Autoantibodies to nuclear components of cells (antinuclear antibodies, ANA), including DNA (a-DNA), are widely used in the diagnosis and subtyping of certain autoimmune diseases, including systemic lupus erythematosus (SLE). Despite clinical use over decades, precise, reproducible measurement of a...

  19. Nucleic Acid-Based Approaches for Detection of Viral Hepatitis

    Science.gov (United States)

    Behzadi, Payam; Ranjbar, Reza; Alavian, Seyed Moayed

    2014-01-01

    Context: To determining suitable nucleic acid diagnostics for individual viral hepatitis agent, an extensive search using related keywords was done in major medical library and data were collected, categorized, and summarized in different sections. Results: Various types of molecular biology tools can be used to detect and quantify viral genomic elements and analyze the sequences. These molecular assays are proper technologies for rapidly detecting viral agents with high accuracy, high sensitivity, and high specificity. Nonetheless, the application of each diagnostic method is completely dependent on viral agent. Conclusions: Despite rapidity, automation, accuracy, cost-effectiveness, high sensitivity, and high specificity of molecular techniques, each type of molecular technology has its own advantages and disadvantages. PMID:25789132

  20. Mfold web server for nucleic acid folding and hybridization prediction.

    Science.gov (United States)

    Zuker, Michael

    2003-07-01

    The abbreviated name, 'mfold web server', describes a number of closely related software applications available on the World Wide Web (WWW) for the prediction of the secondary structure of single stranded nucleic acids. The objective of this web server is to provide easy access to RNA and DNA folding and hybridization software to the scientific community at large. By making use of universally available web GUIs (Graphical User Interfaces), the server circumvents the problem of portability of this software. Detailed output, in the form of structure plots with or without reliability information, single strand frequency plots and 'energy dot plots', are available for the folding of single sequences. A variety of 'bulk' servers give less information, but in a shorter time and for up to hundreds of sequences at once. The portal for the mfold web server is http://www.bioinfo.rpi.edu/applications/mfold. This URL will be referred to as 'MFOLDROOT'.

  1. Multi-chamber nucleic acid amplification and detection device

    Science.gov (United States)

    Dugan, Lawrence

    2017-10-25

    A nucleic acid amplification and detection device includes an amplification cartridge with a plurality of reaction chambers for containing an amplification reagent and a visual detection reagent, and a plurality of optically transparent view ports for viewing inside the reaction chambers. The cartridge also includes a sample receiving port which is adapted to receive a fluid sample and fluidically connected to distribute the fluid sample to the reaction chamber, and in one embodiment, a plunger is carried by the cartridge for occluding fluidic communication to the reaction chambers. The device also includes a heating apparatus having a heating element which is activated by controller to generate heat when a trigger event is detected. The heating apparatus includes a cartridge-mounting section which positioned a cartridge in thermal communication with the heating element so that visual changes to the contents of the reaction chambers are viewable through the view ports.

  2. Nucleic Acid-Based Therapy Approaches for Huntington's Disease

    Directory of Open Access Journals (Sweden)

    Tatyana Vagner

    2012-01-01

    Full Text Available Huntington's disease (HD is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date.

  3. 2011 Rita Schaffer lecture: nanoparticles for intracellular nucleic acid delivery.

    Science.gov (United States)

    Green, Jordan J

    2012-07-01

    Nanoparticles are a promising technology for delivery of new types of therapeutics. A polymer library approach has allowed engineering of polymeric particles that are particularly effective for the delivery of DNA and siRNA to human cells. Certain chemical structural motifs, degradable linkages, hydrophobicity, and biophysical properties are key for successful intracellular delivery. Small differences to biomaterial structure, and especially the type of degradable linkage in the polymers, can be critical for successful delivery of siRNA vs. DNA. Furthermore, subtle changes to biomaterial structure can facilitate cell-type gene delivery specificity between human brain cancer cells and healthy cells as well as between human retinal endothelial cells and epithelial cells. These polymeric nanoparticles are effective for nucleic acid delivery in a broad range of human cell types and have applications to regenerative medicine, ophthalmology, and cancer among many other biomedical research areas.

  4. Nucleic acids--genes, drugs, molecular lego and more.

    Science.gov (United States)

    Häner, Robert

    2010-01-01

    Chemically modified nucleic acids find widespread use as tools in research, as diagnostic reagents and even as pharmaceutical compounds. On the background of antisense research and development, the synthesis and evaluation of modified oligonucleotides was intensively pursued in the early to mid nineties in corporate research of former Ciba. Most of these efforts concentrated on the development of sugar and/or backbone-modified derivatives for pharmaceutical applications. Additionally, oligonucleotide metal conjugates were investigated with the goal to develop artificial ribonucleases. Since the turn of the millennium also the potential of non-nucleosidic and non-hydrogen bonding building blocks has increasingly been recognized. Such derivatives possess unique properties that may have an impact in the fields of materials and genetic research. In this brief account, we take a personal look back on some past as well as some recent results.

  5. Nucleic acid probes in the diagnosis of human microbial pathogens

    International Nuclear Information System (INIS)

    Hyypia, T.; Huovinen, P.; Holmberg, M.; Pettersson, U.

    1989-01-01

    The development of effective vaccines and antimicrobial drugs against infectious diseases has been among the most successful achievements in modern medicine. The control of these diseases requires efficient diagnostic methods for the evaluation of the prevalence of diseases and for initiation of specific treatment. Virtually all known microbes can be specifically identified today but in many cases further development is needed for more accurate, rapid, easy-to-use, and inexpensive diagnostic assays. Cell culture facilities are needed for the isolation of viruses in clinical specimens. Any gene of any known microorganism can be cloned in a vector and produced in large amounts economically and then used in diagnostic assays for the identification of the pathogen. The application of the nucleic acid hybridization methods in detection of human pathogens has received considerable attention during the past few years. This paper presents examples of this application of gene technology

  6. Peptide nucleic acid (PNA) antisense effects in Escherichia coli

    DEFF Research Database (Denmark)

    Good, L; Nielsen, P E

    1999-01-01

    Antisense peptide nucleic acid (PNA) can be used to control cell growth, gene expression and growth phenotypes in the bacteria Escherichia coli. PNAs targeted to the RNA components of the ribosome can inhibit translation and cell growth, and PNAs targeted to mRNA can limit gene expression with gene...... and sequence specificity. In an E. coli cell extract, efficient inhibition is observed when using PNA concentrations in the nanomolar range, whereas micromolar concentrations are required for inhibition in growing cells. A mutant strain of E. coli that is more permeable to antibiotics also is more susceptible...... to antisense PNAs than the wild type. This chapter details methods for testing the antisense activities of PNA in E. coli. As an example of the specific antisense inhibition possible, we show the effects of an anti-beta-galactosidase PNA in comparison to control PNAs. With improvements in cell uptake...

  7. Integrated Microfluidic Nucleic Acid Isolation, Isothermal Amplification, and Amplicon Quantification

    Directory of Open Access Journals (Sweden)

    Michael G. Mauk

    2015-10-01

    Full Text Available Microfluidic components and systems for rapid (<60 min, low-cost, convenient, field-deployable sequence-specific nucleic acid-based amplification tests (NAATs are described. A microfluidic point-of-care (POC diagnostics test to quantify HIV viral load from blood samples serves as a representative and instructive example to discuss the technical issues and capabilities of “lab on a chip” NAAT devices. A portable, miniaturized POC NAAT with performance comparable to conventional PCR (polymerase-chain reaction-based tests in clinical laboratories can be realized with a disposable, palm-sized, plastic microfluidic chip in which: (1 nucleic acids (NAs are extracted from relatively large (~mL volume sample lysates using an embedded porous silica glass fiber or cellulose binding phase (“membrane” to capture sample NAs in a flow-through, filtration mode; (2 NAs captured on the membrane are isothermally (~65 °C amplified; (3 amplicon production is monitored by real-time fluorescence detection, such as with a smartphone CCD camera serving as a low-cost detector; and (4 paraffin-encapsulated, lyophilized reagents for temperature-activated release are pre-stored in the chip. Limits of Detection (LOD better than 103 virons/sample can be achieved. A modified chip with conduits hosting a diffusion-mode amplification process provides a simple visual indicator to readily quantify sample NA template. In addition, a companion microfluidic device for extracting plasma from whole blood without a centrifuge, generating cell-free plasma for chip-based molecular diagnostics, is described. Extensions to a myriad of related applications including, for example, food testing, cancer screening, and insect genotyping are briefly surveyed.

  8. Current and future developments in nucleic acid-based diagnostics

    International Nuclear Information System (INIS)

    Viljoen, G.J.; Romito, M.; Kara, P.D.

    2005-01-01

    The detection and characterization of specific nucleic acids of medico-veterinary pathogens have proven invaluable for diagnostic purposes. Apart from hybridization and sequencing techniques, polymerase chain reaction (PCR) and numerous other methods have contributed significantly to this process. The integration of amplification and signal detection systems, including on-line real-time devices, have increased speed and sensitivity and greatly facilitated the quantification of target nucleic acids. They have also allowed for sequence characterization using melting or hybridization curves. Rugged portable real-time instruments for field use and robotic devices for processing samples are already available commercially. Various stem-loop DNA probes have been designed to have greater specificity for target recognition during real-time PCR. Various DNA fingerprinting techniques or post amplification sequencing are used to type pathogenic strains. Characterization according to DNA sequence is becoming more readily available as automated sequencers become more widely used. Reverse hybridization and to a greater degree DNA micro-arrays, are being used for genotyping related organisms and can allow for the detection of a large variety of different pathogens simultaneously. Non-radioactive labelling of DNA, especially using fluorophores and the principles of fluorescence resonance energy transfer, is now widely used, especially in real-time detection devices. Other detection methods include the use of surface plasmon resonance and MALDI-TOF mass spectrometry. In addition to these technological advances, contributions by bioinformatics and the description of unique signatures of DNA sequences from pathogens will contribute to the development of further assays for monitoring presence of pathogens. An important goal will be the development of robust devices capable of sensitively and specifically detecting a broad spectrum of pathogens that will be applicable for point

  9. Sensitive determination of nucleic acids using organic nanoparticle fluorescence probes

    Science.gov (United States)

    Zhou, Yunyou; Bian, Guirong; Wang, Leyu; Dong, Ling; Wang, Lun; Kan, Jian

    2005-06-01

    This paper describes the preparation of organic nanoparticles by reprecipitation method under sonication and vigorous stirring. Transmission electron microscopy (TEM) was used to characterize the size and size distribution of the luminescent nanoparticles. Their average diameter was about 25 nm with a size variation of ±18%. The fluorescence decay lifetime of the nanoparticles also was determined on a self-equipped fluorospectrometer with laser light source. The lifetime (˜0.09 μs) of nanoparticles is about three times long as that of the monomer. The nanoparticles were in abundant of hydrophilic groups, which increased their miscibility in aqueous solution. These organic nanoparticles have high photochemical stability, excellent resistance to chemical degradation and photodegradation, and a good fluorescence quantum yield (25%). The fluorescence can be efficiently quenched by nucleic acids. Based on the fluorescence quenching of nanoparticles, a fluorescence quenching method was developed for determination of microamounts of nucleic acids by using the nanoparticles as a new fluorescent probe. Under optimal conditions, maximum fluorescence quenching is produced, with maximum excitation and emission wavelengths of 345 and 402 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-19.0 μg ml -1 for calf thymus DNA (ct-DNA) and 0.3-19.0 μg ml -1 for fish sperm DNA (fs-DNA). The corresponding detection limits are 0.25 μg ml -1 for ct-DNA and 0.17 μg ml -1 for fs-DNA. The relative standard deviation of six replicate measurements is 1.3-2.1%. The method is simple, rapid and sensitive with wide linear range. The recovery and relative standard deviation are very satisfactory.

  10. El concepto de Derecho en Locke

    Directory of Open Access Journals (Sweden)

    Diego Alejandro Fernández Peychaux

    2011-01-01

    Full Text Available El siguiente artículo aspira a ser un aporte para la comprensión del modo en que John Locke establece la relación entre los hombres y la sociedad. De acuerdo con la tradición contractualista en la que el autor se inscribe, se pretende recorrer un camino con dos etapas. En la primera, se busca establecer bien el significado del concepto de derecho, bien su relación con los deberes que surgen de la ley de naturaleza. En un segundo momento, se buscará identificar la relación existente entre los derechos/deberes y el concepto de inalienabilidad, para así comprender no ya la relación interna de los derechos/deberes individuales, sino cómo interactúan estos con los del prójimo y la comunidad en la que viven los hombres. Para ello se buscará argumentar que la inalienabilidad de los derechos del hombre, excluido el derecho a la vida, no se fundamenta en el propio derecho, sino en la relación de este con el bien más fundamental que buscan preservar, n.b. autopreservación. De este modo, se establece una suerte de escala de derechos, donde a medida que se desciende se amplía el poder de enajenación, siempre y cuando represente un aumento de las expectativas de mejorar las posibilidades de preservación.

  11. Quantum Dot-Fullerene Based Molecular Beacon Nanosensors for Rapid, Highly Sensitive Nucleic Acid Detection.

    Science.gov (United States)

    Liu, Ye; Kannegulla, Akash; Wu, Bo; Cheng, Li-Jing

    2018-05-15

    Spherical fullerene (C 60 ) can quench the fluorescence of a quantum dot (QD) through energy transfer and charge transfer processes, with the quenching efficiency regulated by the number of proximate C 60 on each QD. With the quenching property and its small size compared with other nanoparticle-based quenchers, it is advantageous to group a QD reporter and multiple C 60 -labeled oligonucleotide probes to construct a molecular beacon (MB) probe for sensitive, robust nucleic acid detection. We demonstrated a rapid, high-sensitivity DNA detection method using the nanosensors composed of QD-C 60 based MBs carried by magnetic nanoparticles (MNPs). The assay was accelerated by first dispersing the nanosensors in analytes for highly efficient DNA capture resulting from short-distance 3-dimensional diffusion of targets to the sensor surface and then concentrating the nanosensors to a substrate by magnetic force to amplify the fluorescence signal for target quantification. The enhanced mass transport enabled a rapid detection (< 10 min) with a small sample volume (1-10 µl). The high signal-to-noise ratio produced by the QD-C 60 pairs and magnetic concentration yielded a detection limit of 100 fM (~106 target DNA copies for a 10 µl analyte). The rapid, sensitive, label-free detection method will benefit the applications in point-of-care molecular diagnostic technologies.

  12. Short Stature

    DEFF Research Database (Denmark)

    Christesen, Henrik Boye Thybo; Pedersen, Birgitte Tønnes; Pournara, Effie

    2016-01-01

    -scale, non-interventional, multinational study. The patient cohort consisted of 5996 short pediatric patients diagnosed with growth hormone deficiency (GHD), Turner syndrome (TS) or born small for gestational age (SGA). The proportions of children with baseline height standard deviation score (SDS) below......The use of appropriate growth standards/references is of significant clinical importance in assessing the height of children with short stature as it may determine eligibility for appropriate therapy. The aim of this study was to determine the impact of using World Health Organization (WHO) instead...... of national growth standards/references on height assessment in short children. Data were collected from routine clinical practice (1998-2014) from nine European countries that have available national growth references and were enrolled in NordiNet® International Outcome Study (IOS) (NCT00960128), a large...

  13. Measuring a Fiber-Optic Delay Line Using a Mode-Locked Laser

    Science.gov (United States)

    Tu, Meirong; McKee, Michael R.; Pak, Kyung S.; Yu, Nan

    2010-01-01

    The figure schematically depicts a laboratory setup for determining the optical length of a fiber-optic delay line at a precision greater than that obtainable by use of optical time-domain reflectometry or of mechanical measurement of length during the delay-line-winding process. In this setup, the delay line becomes part of the resonant optical cavity that governs the frequency of oscillation of a mode-locked laser. The length can then be determined from frequency-domain measurements, as described below. The laboratory setup is basically an all-fiber ring laser in which the delay line constitutes part of the ring. Another part of the ring - the laser gain medium - is an erbium-doped fiber amplifier pumped by a diode laser at a wavelength of 980 nm. The loop also includes an optical isolator, two polarization controllers, and a polarizing beam splitter. The optical isolator enforces unidirectional lasing. The polarization beam splitter allows light in only one polarization mode to pass through the ring; light in the orthogonal polarization mode is rejected from the ring and utilized as a diagnostic output, which is fed to an optical spectrum analyzer and a photodetector. The photodetector output is fed to a radio-frequency spectrum analyzer and an oscilloscope. The fiber ring laser can generate continuous-wave radiation in non-mode-locked operation or ultrashort optical pulses in mode-locked operation. The mode-locked operation exhibited by this ring is said to be passive in the sense that no electro-optical modulator or other active optical component is used to achieve it. Passive mode locking is achieved by exploiting optical nonlinearity of passive components in such a manner as to obtain ultra-short optical pulses. In this setup, the particular nonlinear optical property exploited to achieve passive mode locking is nonlinear polarization rotation. This or any ring laser can support oscillation in multiple modes as long as sufficient gain is present to overcome

  14. Wavelength-stepped, actively mode-locked fiber laser based on wavelength-division-multiplexed optical delay lines

    Science.gov (United States)

    Lee, Eunjoo; Kim, Byoung Yoon

    2017-12-01

    We propose a new scheme for an actively mode-locked wavelength-swept fiber laser that produces a train of discretely wavelength-stepped pulses from a short fiber cavity. Pulses with different wavelengths are split and combined by standard wavelength division multiplexers with fiber delay lines. As a proof of concept, we demonstrate a laser using an erbium doped fiber amplifier and commercially available wavelength-division multiplexers with wavelength spacing of 0.8 nm. The results show simultaneous mode-locking at three different wavelengths. Laser output parameters in time domain, optical and radio frequency spectral domain, and the noise characteristics are presented. Suggestions for the improved design are discussed.

  15. Explicit ions/implicit water generalized Born model for nucleic acids

    Science.gov (United States)

    Tolokh, Igor S.; Thomas, Dennis G.; Onufriev, Alexey V.

    2018-05-01

    The ion atmosphere around highly charged nucleic acid molecules plays a significant role in their dynamics, structure, and interactions. Here we utilized the implicit solvent framework to develop a model for the explicit treatment of ions interacting with nucleic acid molecules. The proposed explicit ions/implicit water model is based on a significantly modified generalized Born (GB) model and utilizes a non-standard approach to define the solute/solvent dielectric boundary. Specifically, the model includes modifications to the GB interaction terms for the case of multiple interacting solutes—disconnected dielectric boundary around the solute-ion or ion-ion pairs. A fully analytical description of all energy components for charge-charge interactions is provided. The effectiveness of the approach is demonstrated by calculating the potential of mean force for Na+-Cl- ion pair and by carrying out a set of Monte Carlo (MC) simulations of mono- and trivalent ions interacting with DNA and RNA duplexes. The monovalent (Na+) and trivalent (CoHex3+) counterion distributions predicted by the model are in close quantitative agreement with all-atom explicit water molecular dynamics simulations used as reference. Expressed in the units of energy, the maximum deviations of local ion concentrations from the reference are within kBT. The proposed explicit ions/implicit water GB model is able to resolve subtle features and differences of CoHex distributions around DNA and RNA duplexes. These features include preferential CoHex binding inside the major groove of the RNA duplex, in contrast to CoHex biding at the "external" surface of the sugar-phosphate backbone of the DNA duplex; these differences in the counterion binding patters were earlier shown to be responsible for the observed drastic differences in condensation propensities between short DNA and RNA duplexes. MC simulations of CoHex ions interacting with the homopolymeric poly(dA.dT) DNA duplex with modified (de

  16. Short Review

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Rühli, Frank

    2015-01-01

    modality in ancient mummy research. The aim of this short review is to address the advantages and pitfalls of this particular technique for such unique samples. We recommend that when results of X-ray examination of mummies are presented, the specific recording data should be listed, and any given finds...

  17. Short fusion

    CERN Multimedia

    2002-01-01

    French and UK researchers are perfecting a particle accelerator technique that could aid the quest for fusion energy or make X-rays that are safer and produce higher-resolution images. Led by Dr Victor Malka from the Ecole Nationale Superieure des Techniques Avancees in Paris, the team has developed a better way of accelerating electrons over short distances (1 page).

  18. Short communication

    African Journals Online (AJOL)

    UPuser

    Short communication. Polymorphisms of the CAST gene in the Meishan and five other pig populations in China. Q.S. Wang. 1. , Y.C. Pan. 1#. , L.B. Sun. 2 and H. Meng. 1. 1 Department of Animal Science, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai. 201101, P.R. China. 2 Shanghai Institute of ...

  19. SHORT COMMUNICATION

    African Journals Online (AJOL)

    a

    ______. *Corresponding author. E-mail: vani_chem@yahoo.com. SHORT COMMUNICATION. OXIDATION OF L-CYSTINE BY CHROMIUM(VI) - A KINETIC STUDY. Kalyan Kumar Adari, Annapurna Nowduri and Vani Parvataneni*. Department of Inorganic and Analytical Chemistry, School of Chemistry, Andhra University,.

  20. Short communication

    NARCIS (Netherlands)

    Pantophlet, Andre J.; Gilbert, M.S.; Gerrits, W.J.J.; Vonk, R.J.

    2017-01-01

    Heavy veal calves (4-6 mo old) often develop problems with insulin sensitivity. This could lead to metabolic disorders and impaired animal growth performance. Studies in various animal species have shown that the supplementation of short-chain fructo-oligosaccharides (scFOS) can improve insulin

  1. BIOPHYSICAL PROPERTIES OF NUCLEIC ACIDS AT SURFACES RELEVANT TO MICROARRAY PERFORMANCE.

    Science.gov (United States)

    Rao, Archana N; Grainger, David W

    2014-04-01

    Both clinical and analytical metrics produced by microarray-based assay technology have recognized problems in reproducibility, reliability and analytical sensitivity. These issues are often attributed to poor understanding and control of nucleic acid behaviors and properties at solid-liquid interfaces. Nucleic acid hybridization, central to DNA and RNA microarray formats, depends on the properties and behaviors of single strand (ss) nucleic acids (e.g., probe oligomeric DNA) bound to surfaces. ssDNA's persistence length, radius of gyration, electrostatics, conformations on different surfaces and under various assay conditions, its chain flexibility and curvature, charging effects in ionic solutions, and fluorescent labeling all influence its physical chemistry and hybridization under assay conditions. Nucleic acid (e.g., both RNA and DNA) target interactions with immobilized ssDNA strands are highly impacted by these biophysical states. Furthermore, the kinetics, thermodynamics, and enthalpic and entropic contributions to DNA hybridization reflect global probe/target structures and interaction dynamics. Here we review several biophysical issues relevant to oligomeric nucleic acid molecular behaviors at surfaces and their influences on duplex formation that influence microarray assay performance. Correlation of biophysical aspects of single and double-stranded nucleic acids with their complexes in bulk solution is common. Such analysis at surfaces is not commonly reported, despite its importance to microarray assays. We seek to provide further insight into nucleic acid-surface challenges facing microarray diagnostic formats that have hindered their clinical adoption and compromise their research quality and value as genomics tools.

  2. Nucleic Acid Extraction from Synthetic Mars Analog Soils for in situ Life Detection.

    Science.gov (United States)

    Mojarro, Angel; Ruvkun, Gary; Zuber, Maria T; Carr, Christopher E

    2017-08-01

    Biological informational polymers such as nucleic acids have the potential to provide unambiguous evidence of life beyond Earth. To this end, we are developing an automated in situ life-detection instrument that integrates nucleic acid extraction and nanopore sequencing: the Search for Extra-Terrestrial Genomes (SETG) instrument. Our goal is to isolate and determine the sequence of nucleic acids from extant or preserved life on Mars, if, for example, there is common ancestry to life on Mars and Earth. As is true of metagenomic analysis of terrestrial environmental samples, the SETG instrument must isolate nucleic acids from crude samples and then determine the DNA sequence of the unknown nucleic acids. Our initial DNA extraction experiments resulted in low to undetectable amounts of DNA due to soil chemistry-dependent soil-DNA interactions, namely adsorption to mineral surfaces, binding to divalent/trivalent cations, destruction by iron redox cycling, and acidic conditions. Subsequently, we developed soil-specific extraction protocols that increase DNA yields through a combination of desalting, utilization of competitive binders, and promotion of anaerobic conditions. Our results suggest that a combination of desalting and utilizing competitive binders may establish a "universal" nucleic acid extraction protocol suitable for analyzing samples from diverse soils on Mars. Key Words: Life-detection instruments-Nucleic acids-Mars-Panspermia. Astrobiology 17, 747-760.

  3. BIOPHYSICAL PROPERTIES OF NUCLEIC ACIDS AT SURFACES RELEVANT TO MICROARRAY PERFORMANCE

    Science.gov (United States)

    Rao, Archana N.; Grainger, David W.

    2014-01-01

    Both clinical and analytical metrics produced by microarray-based assay technology have recognized problems in reproducibility, reliability and analytical sensitivity. These issues are often attributed to poor understanding and control of nucleic acid behaviors and properties at solid-liquid interfaces. Nucleic acid hybridization, central to DNA and RNA microarray formats, depends on the properties and behaviors of single strand (ss) nucleic acids (e.g., probe oligomeric DNA) bound to surfaces. ssDNA’s persistence length, radius of gyration, electrostatics, conformations on different surfaces and under various assay conditions, its chain flexibility and curvature, charging effects in ionic solutions, and fluorescent labeling all influence its physical chemistry and hybridization under assay conditions. Nucleic acid (e.g., both RNA and DNA) target interactions with immobilized ssDNA strands are highly impacted by these biophysical states. Furthermore, the kinetics, thermodynamics, and enthalpic and entropic contributions to DNA hybridization reflect global probe/target structures and interaction dynamics. Here we review several biophysical issues relevant to oligomeric nucleic acid molecular behaviors at surfaces and their influences on duplex formation that influence microarray assay performance. Correlation of biophysical aspects of single and double-stranded nucleic acids with their complexes in bulk solution is common. Such analysis at surfaces is not commonly reported, despite its importance to microarray assays. We seek to provide further insight into nucleic acid-surface challenges facing microarray diagnostic formats that have hindered their clinical adoption and compromise their research quality and value as genomics tools. PMID:24765522

  4. Multi-shell model of ion-induced nucleic acid condensation

    Energy Technology Data Exchange (ETDEWEB)

    Tolokh, Igor S. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061 (United States); Drozdetski, Aleksander V. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Pollack, Lois [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853-3501 (United States); Baker, Nathan A. [Advanced Computing, Mathematics, and Data Division, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912 (United States); Onufriev, Alexey V. [Department of Computer Science, Virginia Tech, Blacksburg, Virginia 24061 (United States); Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2016-04-21

    We present a semi-quantitative model of condensation of short nucleic acid (NA) duplexes induced by trivalent cobalt(III) hexammine (CoHex) ions. The model is based on partitioning of bound counterion distribution around single NA duplex into “external” and “internal” ion binding shells distinguished by the proximity to duplex helical axis. In the aggregated phase the shells overlap, which leads to significantly increased attraction of CoHex ions in these overlaps with the neighboring duplexes. The duplex aggregation free energy is decomposed into attractive and repulsive components in such a way that they can be represented by simple analytical expressions with parameters derived from molecular dynamic simulations and numerical solutions of Poisson equation. The attractive term depends on the fractions of bound ions in the overlapping shells and affinity of CoHex to the “external” shell of nearly neutralized duplex. The repulsive components of the free energy are duplex configurational entropy loss upon the aggregation and the electrostatic repulsion of the duplexes that remains after neutralization by bound CoHex ions. The estimates of the aggregation free energy are consistent with the experimental range of NA duplex condensation propensities, including the unusually poor condensation of RNA structures and subtle sequence effects upon DNA condensation. The model predicts that, in contrast to DNA, RNA duplexes may condense into tighter packed aggregates with a higher degree of duplex neutralization. An appreciable CoHex mediated RNA-RNA attraction requires closer inter-duplex separation to engage CoHex ions (bound mostly in the “internal” shell of RNA) into short-range attractive interactions. The model also predicts that longer NA fragments will condense more readily than shorter ones. The ability of this model to explain experimentally observed trends in NA condensation lends support to proposed NA condensation picture based on the multivalent

  5. Locking screw apparatus and method for underwater remote replacement

    International Nuclear Information System (INIS)

    Balog, L.J.

    1987-01-01

    A method is described for locking in place a screw which secures together first and second structures in the internal region of a nuclear reactor core. The first structure has a screw bore with a counterbore portion formed in an outer surface. The method comprises the steps of: forming a lateral recess in the counterbore portion and spaced from the outer surface, providing an elongated screw having an enlarged shoulder flange and an angular drive head with a lateral width substantially less than that of the counterbore portion, disposing the screw through the screw bore in threaded engagement with the second structure and with the shoulder rotatably seated in the counterbore portion. This provides a locking member having an angular opening and disposing it in the counterbore portion against the flange with the drive head received in the opening for engagement with the locking member to prevent rotation. This deforms a portion of the locking member into the recess for engagement to prevent movement of the locking member with respect to the first structure

  6. Evolution of the Generic Lock System at Jefferson Lab

    International Nuclear Information System (INIS)

    Brian Bevins; Yves Roblin

    2003-01-01

    The Generic Lock system is a software framework that allows highly flexible feedback control of large distributed systems. It allows system operators to implement new feedback loops between arbitrary process variables quickly and with no disturbance to the underlying control system. Several different types of feedback loops are provided and more are being added. This paper describes the further evolution of the system since it was first presented at ICALEPCS 2001 and reports on two years of successful use in accelerator operations. The framework has been enhanced in several key ways. Multiple-input, multiple-output (MIMO) lock types have been added for accelerator orbit and energy stabilization. The general purpose Proportional-Integral-Derivative (PID) locks can now be tuned automatically. The generic lock server now makes use of the Proxy IOC (PIOC) developed at Jefferson Lab to allow the locks to be monitored from any EPICS Channel Access aware client. (Previously clients had to be Cdev aware.) The dependency on the Qt XML parser has been replaced with the freely available Xerces DOM parser from the Apache project

  7. Locked-in: the syndrome as depicted in literature.

    Science.gov (United States)

    Haan, Joost

    2013-01-01

    Protagonists who are locked-in can be found throughout fiction, probably because being locked-in serves as a strong philosophical metaphor for human existence. In this chapter, three protagonists who are locked-in due to physical/medical reasons will be described. The fictitious stories of Noirtier from The Count of Monte Cristo by Alexandre Dumas and that of Madame Raquin from Thérèse Raquin by Émile Zola are followed by the real-life story of Jean-Dominique Bauby's The Diving Bell and the Butterfly. Dumas' Noirtier is considered the first description of the locked-in syndrome in literature, and Madame Raquin appears to be locked-in also, but her description leaves many questions. Bauby's autopathography is chosen from many several similar discourses as it contains cross-references to Noirtier, Dumas' prototype of the syndrome, but also because it is of high literary value. The similarities and remarkable differences between these three case reports of this existentialistically important state of being will be highlighted, with an emphasis on the focus of their narratives. © 2013 Elsevier B.V. All rights reserved.

  8. Mutual phase-locking of planar nano-oscillators

    Directory of Open Access Journals (Sweden)

    K. Y. Xu

    2014-06-01

    Full Text Available Characteristics of phase-locking between Gunn effect-based planar nano-oscillators are studied using an ensemble Monte Carlo (EMC method. Directly connecting two oscillators in close proximity, e.g. with a channel distance of 200 nm, only results in incoherent oscillations. In order to achieve in-phase oscillations, additional considerations must be taken into account. Two coupling paths are shown to exist between oscillators. One coupling path results in synchronization and the other results in anti-phase locking. The coupling strength through these two paths can be adjusted by changing the connections between oscillators. When two identical oscillators are in the anti-phase locking regime, fundamental components of oscillations are cancelled. The resulting output consists of purely second harmonic oscillations with a frequency of about 0.66 THz. This type of second harmonic generation is desired for higher frequency applications since no additional filter system is required. This transient phase-locking process is further analyzed using Adler's theory. The locking range is extracted, and a criterion for the channel length difference required for realizing phased arrays is obtained. This work should aid in designing nano-oscillator arrays for high power applications and developing directional transmitters for wireless communications.

  9. APR1400 Locked Rotor Transient Analysis using KNAP

    International Nuclear Information System (INIS)

    Lee, Dong-Hyuk; Kim, Yo-Han; Ha, Sang Jun

    2007-01-01

    KEPRI (Korea Electric Power Research Institute) has developed safety analysis methodology for non-LOCA (Loss Of Coolant Accident) analysis of OPR1000 (Optimized Power Reactor 1000, formerly KSNP). The new methodology, named KNAP (Korea Non-LOCA Analysis Package), uses RETRAN as the main system analysis code for most transients. For locked rotor transient DNBR analysis, UNICORN-TM code is used. UNICORN-TM is the unified code of RETRAN, MASTER and TORC. The UNICORN-TM has 1-D and 3-D neutron kinetics calculation capability. For locked rotor DNBR analysis, 1-D neutron kinetics is used. In this paper, we apply KNAP methodology to APR1400 (Advanced Power Reactor 1400) locked rotor analysis and compare the results with those in the APR1400 SSAR(Standard Safety Analysis Report). The locked rotor transient is one of the 'decrease in reactor coolant system flow rate' events and the results are typically described in the chapter 15.3.3 of SAR (Safety Analysis Report). In this study, to confirm the applicability of the KNAP methodology and code system to APR1400, locked rotor transient is analyzed using UNICORN-TM code and the results are compared with those from APR1400 SSAR

  10. Complication with Removal of a Lumbar Spinal Locking Plate

    Directory of Open Access Journals (Sweden)

    Brooke Crawford

    2015-01-01

    Full Text Available Introduction. The use of locking plate technology for anterior lumbar spinal fusion has increased stability of the vertebral fusion mass over traditional nonconstrained screw and plate systems. This case report outlines a complication due to the use of this construct. Case. A patient with a history of L2 corpectomy and anterior spinal fusion presented with discitis at the L4/5 level and underwent an anterior lumbar interbody fusion (ALIF supplemented with a locking plate placed anterolaterally for stability. Fifteen months after the ALIF procedure, he returned with a hardware infection. He underwent debridement of the infection site and removal of hardware. Results. Once hardware was exposed, removal of the locking plate screws was only successful in one out of four screws using a reverse thread screw removal device. Three of the reverse thread screw removal devices broke in attempt to remove the subsequent screws. A metal cutting drill was then used to break hoop stresses associated with the locking device and the plate was removed. Conclusion. Anterior locking plates add significant stability to an anterior spinal fusion mass. However, removal of this hardware can be complicated by the inherent properties of the design with significant risk of major vascular injury.

  11. APR1400 Locked Rotor Transient Analysis using KNAP

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Hyuk; Kim, Yo-Han; Ha, Sang Jun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2007-07-01

    KEPRI (Korea Electric Power Research Institute) has developed safety analysis methodology for non-LOCA (Loss Of Coolant Accident) analysis of OPR1000 (Optimized Power Reactor 1000, formerly KSNP). The new methodology, named KNAP (Korea Non-LOCA Analysis Package), uses RETRAN as the main system analysis code for most transients. For locked rotor transient DNBR analysis, UNICORN-TM code is used. UNICORN-TM is the unified code of RETRAN, MASTER and TORC. The UNICORN-TM has 1-D and 3-D neutron kinetics calculation capability. For locked rotor DNBR analysis, 1-D neutron kinetics is used. In this paper, we apply KNAP methodology to APR1400 (Advanced Power Reactor 1400) locked rotor analysis and compare the results with those in the APR1400 SSAR(Standard Safety Analysis Report). The locked rotor transient is one of the 'decrease in reactor coolant system flow rate' events and the results are typically described in the chapter 15.3.3 of SAR (Safety Analysis Report). In this study, to confirm the applicability of the KNAP methodology and code system to APR1400, locked rotor transient is analyzed using UNICORN-TM code and the results are compared with those from APR1400 SSAR.

  12. CLIMATE INSTABILITY ON TIDALLY LOCKED EXOPLANETS

    International Nuclear Information System (INIS)

    Kite, Edwin S.; Manga, Michael; Gaidos, Eric

    2011-01-01

    Feedbacks that can destabilize the climates of synchronously rotating rocky planets may arise on planets with strong day-night surface temperature contrasts. Earth-like habitable planets maintain stable surface liquid water over geologic time. This requires equilibrium between the temperature-dependent rate of greenhouse-gas consumption by weathering, and greenhouse-gas resupply by other processes. Detected small-radius exoplanets, and anticipated M-dwarf habitable-zone rocky planets, are expected to be in synchronous rotation (tidally locked). In this paper, we investigate two hypothetical feedbacks that can destabilize climate on planets in synchronous rotation. (1) If small changes in pressure alter the temperature distribution across a planet's surface such that the weathering rate goes up when the pressure goes down, a runaway positive feedback occurs involving increasing weathering rate near the substellar point, decreasing pressure, and increasing substellar surface temperature. We call this feedback enhanced substellar weathering instability (ESWI). (2) When decreases in pressure increase the fraction of surface area above the melting point (through reduced advective cooling of the substellar point), and the corresponding increase in volume of liquid causes net dissolution of the atmosphere, a further decrease in pressure will occur. This substellar dissolution feedback can also cause a runaway climate shift. We use an idealized energy balance model to map out the conditions under which these instabilities may occur. In this simplified model, the weathering runaway can shrink the habitable zone and cause geologically rapid 10 3 -fold atmospheric pressure shifts within the habitable zone. Mars may have undergone a weathering runaway in the past. Substellar dissolution is usually a negative feedback or weak positive feedback on changes in atmospheric pressure. It can only cause runaway changes for small, deep oceans and highly soluble atmospheric gases. Both

  13. CLIMATE INSTABILITY ON TIDALLY LOCKED EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Kite, Edwin S.; Manga, Michael [Department of Earth and Planetary Science, University of California at Berkeley, CA 94720 (United States); Gaidos, Eric, E-mail: edwin.kite@gmail.com [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2011-12-10

    Feedbacks that can destabilize the climates of synchronously rotating rocky planets may arise on planets with strong day-night surface temperature contrasts. Earth-like habitable planets maintain stable surface liquid water over geologic time. This requires equilibrium between the temperature-dependent rate of greenhouse-gas consumption by weathering, and greenhouse-gas resupply by other processes. Detected small-radius exoplanets, and anticipated M-dwarf habitable-zone rocky planets, are expected to be in synchronous rotation (tidally locked). In this paper, we investigate two hypothetical feedbacks that can destabilize climate on planets in synchronous rotation. (1) If small changes in pressure alter the temperature distribution across a planet's surface such that the weathering rate goes up when the pressure goes down, a runaway positive feedback occurs involving increasing weathering rate near the substellar point, decreasing pressure, and increasing substellar surface temperature. We call this feedback enhanced substellar weathering instability (ESWI). (2) When decreases in pressure increase the fraction of surface area above the melting point (through reduced advective cooling of the substellar point), and the corresponding increase in volume of liquid causes net dissolution of the atmosphere, a further decrease in pressure will occur. This substellar dissolution feedback can also cause a runaway climate shift. We use an idealized energy balance model to map out the conditions under which these instabilities may occur. In this simplified model, the weathering runaway can shrink the habitable zone and cause geologically rapid 10{sup 3}-fold atmospheric pressure shifts within the habitable zone. Mars may have undergone a weathering runaway in the past. Substellar dissolution is usually a negative feedback or weak positive feedback on changes in atmospheric pressure. It can only cause runaway changes for small, deep oceans and highly soluble atmospheric

  14. In vivo efficacy and off-target effects of locked nucleic acid (LNA) and unlocked nucleic acid (UNA) modified siRNA and small internally segmented interfering RNA (sisiRNA) in mice bearing human tumor xenografts

    NARCIS (Netherlands)

    Mook, O. R. F.; Vreijling, Jeroen; Wengel, Suzy L.; Wengel, Jesper; Zhou, Chuanzheng; Chattopadhyaya, Jyoti; Baas, Frank; Fluiter, Kees

    2010-01-01

    The clinical use of small interfering RNA (siRNA) is hampered by poor uptake by tissues and instability in circulation. In addition, off-target effects pose a significant additional problem for therapeutic use of siRNA. Chemical modifications of siRNA have been reported to increase stability and

  15. A Digital Phase Lock Loop for an External Cavity Diode Laser

    Science.gov (United States)

    Wang, Xiao-Long; Tao, Tian-Jiong; Cheng, Bing; Wu, Bin; Xu, Yun-Fei; Wang, Zhao-Ying; Lin, Qiang

    2011-08-01

    A digital optical phase lock loop (OPLL) is implemented to synchronize the frequency and phase between two external cavity diode lasers (ECDL), generating Raman pulses for atom interferometry. The setup involves all-digital phase detection and a programmable digital proportional-integral-derivative (PID) loop in locking. The lock generates a narrow beat-note linewidth below 1 Hz and low phase-noise of 0.03rad2 between the master and slave ECDLs. The lock proves to be stable and robust, and all the locking parameters can be set and optimized on a computer interface with convenience, making the lock adaptable to various setups of laser systems.

  16. Carbon composite micro- and nano-tubes-based electrodes for detection of nucleic acids

    Directory of Open Access Journals (Sweden)

    Huska Dalibor

    2011-01-01

    Full Text Available Abstract The first aim of this study was to fabricate vertically aligned multiwalled carbon nanotubes (MWCNTs. MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition. Further, three carbon composite electrodes with different content of carbon particles with various shapes and sizes were prepared and tested on measuring of nucleic acids. The dependences of adenine peak height on the concentration of nucleic acid sample were measured. Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids. Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode.

  17. Short Communication

    African Journals Online (AJOL)

    huis

    Short Communication. QTL analysis of production traits on SSC3 in a Large White×Meishan pig resource family. B. Zuo. 1. , Y.Z. Xiong. 1#. , Y.H. Su. 2. , C.Y. Deng. 1. , M.G. Lei. 1. , F.E. Li. 1. , R. Zheng. 1 and S.W. Jiang. 1. 1 Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture & Key Lab of Agricultural ...

  18. Adaptive Injection-locking Oscillator Array for RF Spectrum Analysis

    International Nuclear Information System (INIS)

    Leung, Daniel

    2011-01-01

    A highly parallel radio frequency receiver using an array of injection-locking oscillators for on-chip, rapid estimation of signal amplitudes and frequencies is considered. The oscillators are tuned to different natural frequencies, and variable gain amplifiers are used to provide negative feedback to adapt the locking band-width with the input signal to yield a combined measure of input signal amplitude and frequency detuning. To further this effort, an array of 16 two-stage differential ring oscillators and 16 Gilbert-cell mixers is designed for 40-400 MHz operation. The injection-locking oscillator array is assembled on a custom printed-circuit board. Control and calibration is achieved by on-board microcontroller.

  19. Restitution in the context of institutional lock-in

    Directory of Open Access Journals (Sweden)

    Załęczna Magdalena

    2014-01-01

    Full Text Available This article presents the problem of lack of restitution in Poland in the political, social and economic context. The author presents the theory of institutional lock-in, referring to the hitherto course of the political, social and economic transformation processes in Poland. She is focusing on the research problem in form of an institutional lock-in on the route to general restitution process. The author examines the path shaping and path dependence to understand the current negative attitude toward restitution presented by the government and society. The author also indicates the costs caused by lack of restitution. Through analysis of past attempts of restitution regulations the author indicates the most important flashpoints. A hypothesis constructed by the author focuses on the negative effects of institutional lock-in, lack of restitution increases transaction costs influencing the Polish economy. The study is based on the legal documents and the results of public opinion polls.

  20. Beating quantum limits in interferometers with quantum locking of mirrors

    International Nuclear Information System (INIS)

    Heidmann, Antoine; Courty, Jean-Michel; Pinard, Michel; Lebars, Julien

    2004-01-01

    The sensitivity in interferometric measurements such as those made by gravitational-wave detectors is ultimately limited by the quantum noise of light. We discuss the use of feedback mechanisms to reduce the quantum effects of radiation pressure. Recent experiments have shown that it is possible to reduce the thermal motion of a mirror by cold damping. The mirror motion is measured with an optomechanical sensor based on a high-finesse cavity, and reduced by a feedback loop. We show that this technique can be extended to lock the mirror at the quantum level. In gravitational-wave interferometers with Fabry-Perot cavities in each arm, it is even possible to use a single feedback mechanism to lock one cavity mirror on the other. This quantum locking greatly improves the sensitivity of the interferometric measurement. It is furthermore insensitive to imperfections such as losses in the interferometer

  1. Injection Locking of a Semiconductor Double Quantum Dot Micromaser.

    Science.gov (United States)

    Liu, Y-Y; Stehlik, J; Gullans, M J; Taylor, J M; Petta, J R

    2015-11-01

    Emission linewidth is an important figure of merit for masers and lasers. We recently demonstrated a semiconductor double quantum dot (DQD) micromaser where photons are generated through single electron tunneling events. Charge noise directly couples to the DQD energy levels, resulting in a maser linewidth that is more than 100 times larger than the Schawlow-Townes prediction. Here we demonstrate a linewidth narrowing of more than a factor 10 by locking the DQD emission to a coherent tone that is injected to the input port of the cavity. We measure the injection locking range as a function of cavity input power and show that it is in agreement with the Adler equation. The position and amplitude of distortion sidebands that appear outside of the injection locking range are quantitatively examined. Our results show that this unconventional maser, which is impacted by strong charge noise and electron-phonon coupling, is well described by standard laser models.

  2. Stability improvement for coil position locking of joule balance

    Science.gov (United States)

    Bai, Yang; Liu, Yongmeng; Lu, Yunfeng; Hu, Pengcheng; Wang, Dawei; Li, Zhengkun; Tan, Jiubin; Zhang, Zhonghua

    2017-08-01

    The relative vertical position locking precision between the exciting and suspended coils is an important uncertainty for the Planck constant traceability in joule balance. In order to improve the relative vertical position locking precision, several stability experiments are conducted. The stability characteristics of the suspended and exciting coils are measured using a six-axis laser interferometer system; meanwhile, the effectiveness of the active vibration isolation table is measured using a vibration measurement sensor. The piezoelectric ceramic actuators with PID controller are used to compensate the relative vertical displacement drifts while a six-axis laser interferometer system is used to measure the positions of two coils. Experimental results show that the relative vertical position is stably locked.

  3. Magnetized color flavor locked state and compact stars

    CERN Document Server

    Felipe, R Gonzalez; Martinez, A Perez

    2010-01-01

    The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model, taking into account the variation of the strange quark mass, the baryon density, the magnetic field, as well as the bag and gap parameters. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The mass-radius relation for such stars is also studied.

  4. Wavenumber locking and pattern formation in spatially forced systems

    International Nuclear Information System (INIS)

    Manor, Rotem; Meron, Ehud; Hagberg, Aric

    2009-01-01

    We study wavenumber locking and pattern formation resulting from weak spatially periodic one-dimensional forcing of two-dimensional systems. We consider systems that produce stationary or traveling stripe patterns when unforced and apply forcing aligned with the stripes. Forcing at close to twice the pattern wavenumber selects, stabilizes, or creates resonant stripes locked at half the forcing wavenumber. If the mismatch between the forcing and pattern wavenumber is high we find that the pattern still locks but develops a wave vector component perpendicular to the forcing direction and forms rectangular and oblique patterns. When the unforced system supports traveling waves, resonant rectangular patterns remain stationary but oblique patterns travel in a direction orthogonal to the traveling waves.

  5. The lock-in effect and the greening of automotive cooling systems in the European Union.

    Science.gov (United States)

    Bjørnåvold, Amalie; Van Passel, Steven

    2017-12-01

    As of 2017, the sale and use of the refrigerants most commonly used in automotive cooling systems - hydrofluorocarbons - are entirely banned in all new vehicles placed on the market in the European Union. These refrigerants have been recognised as potent greenhouse gases and, therefore, direct contributors to climate change. It is within this regulation-driven market that the technologies for a sustainable solution have been developed. However, this paper argues that the market for automotive cooling systems has been 'locked-in', which means that competing technologies, operating under dynamic increasing returns, will allow for one - potentially inferior technology - to dominate the market. Whilst such a situation is not uncommon, this paper discusses the way that regulation has reinforced a patented monopoly in 'picking winners': to the advantage of a synthetic chemical, R-1234yf, as opposed to the natural solution, which is CO 2 . By developing a generic conceptual framework of path dependence and lock-in, the presented evidence seeks to show how a snowballing effect has led to the intensification of differences in market share. We also argue that the automotive industry is potentially promoting short-term fixes, rather than long-term, sustainable and economically viable solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. 75 FR 5071 - Mississippi L&D 21, LLC, Mississippi River No. 21 Hydropower Company Lock + TM

    Science.gov (United States)

    2010-02-01

    ... Lock + \\TM\\ Hydro Friends Fund XXXII, LLC; Notice of Preliminary Permit Applications Accepted for..., Lock + TM Hydro Friends Fund XXXII, LLC (Lock + Hydro) filed an application for a preliminary permit...

  7. Phase-locked flux-flow Josephson oscillator

    DEFF Research Database (Denmark)

    Ustinov, A. V.; Mygind, Jesper; Oboznov, V. A.

    1992-01-01

    We report on the observation of large rf induced steps due to phase-locking of unidirectional flux-flow motion in long quasi-one-dimensional Josephson junctions. The external microwave irradiation in the frequency range 62–77 GHz was applied from the edge of the junction at which the fluxons enter....... The dependence of the amplitude of the phase-locked step on external magnetic field and microwave power has been measured. The observed zero-crossing steps have potential application in Josephson voltage standards. A simple model for the flux-flow as determined by the microwave driven boundary gate at the edge...

  8. Cyclotomy and Ramanujan sums in quantum phase locking

    International Nuclear Information System (INIS)

    Planat, Michel; Rosu, Haret C.

    2003-01-01

    Phase-locking governs the phase noise in classical clocks through effects described in precise mathematical terms. We seek here a quantum counterpart of these effects by working in a finite Hilbert space. We use a coprimality condition to define phase-locked quantum states and the corresponding Pegg-Barnett type phase operator. Cyclotomic symmetries in matrix elements are revealed and related to Ramanujan sums in the theory of prime numbers. The employed mathematical procedures also emphasize the isomorphism between algebraic number theory and the theory of quantum entanglement

  9. Positioning and locking device for fuel pin to grid attachment

    International Nuclear Information System (INIS)

    Frick, T.M.; Wineman, A.L.

    1976-01-01

    A positioning and locking device for fuel pin to grid attachment provides an inexpensive means of positively positioning and locking the individual fuel pins which make up the driver fuel assemblies used in nuclear reactors. The device can be adapted for use with a currently used attachment grid assembly design and insures that the pins remain in their proper position throughout the in-reactor life of the assembly. This device also simplifies fuel bundle assembly in that a complete row of fuel pins can be added to the bundle during each step of assembly. 8 claims, 8 drawing figures

  10. Microwave phase locking of Josephson-junction fluxon oscillators

    DEFF Research Database (Denmark)

    Salerno, M.; Samuelsen, Mogens Rugholm; Filatrella, G.

    1990-01-01

    Application of the classic McLaughlin-Scott soliton perturbation theory to a Josephson-junction fluxon subjected to a microwave field that interacts with the fluxon only at the junction boundaries reduces the problem of phase locking of the fluxon oscillation to the study of a two-dimensional fun......Application of the classic McLaughlin-Scott soliton perturbation theory to a Josephson-junction fluxon subjected to a microwave field that interacts with the fluxon only at the junction boundaries reduces the problem of phase locking of the fluxon oscillation to the study of a two...

  11. Lock-in imaging with synchronous digital mirror demodulation

    Science.gov (United States)

    Bush, Michael G.

    2010-04-01

    Lock-in imaging enables high contrast imaging in adverse conditions by exploiting a modulated light source and homodyne detection. We report results on a patent pending lock-in imaging system fabricated from commercial-off-theshelf parts utilizing standard cameras and a spatial light modulator. By leveraging the capabilities of standard parts we are able to present a low cost, high resolution, high sensitivity camera with applications in search and rescue, friend or foe identification (IFF), and covert surveillance. Different operating modes allow the same instrument to be utilized for dual band multispectral imaging or high dynamic range imaging, increasing the flexibility in different operational settings.

  12. Pre-Extreme Automotive Anti-Lock Brake Systems

    Directory of Open Access Journals (Sweden)

    V. G. Ivanov

    2004-01-01

    Full Text Available Designing of systems ensuring active safety of automobiles with intellectual functions requires usage of new control principles for wheel and automobile operation. One of such principles is a preextreme control strategy. Its aim is to ensure wheel work in pre-extreme, stable area of «tire grip coefficient wheel slip coefficient» dependence. The simplest realization of pre-extreme control in automotive anti-lock brake systems consists in the threshold and gradient algorithms. A comparative analysis of these algorithms which has been made on simulation results of bus braking with various anti-lock brake systems has revealed their high efficiency.

  13. Relaxation towards phase-locked dynamics in long Josephson junctions

    DEFF Research Database (Denmark)

    Salerno, M.; Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1995-01-01

    We study the relaxation phenomenon towards phase-locked dynamics in long Josephson junctions. In particular the dependence of the relaxation frequency for the equal time of flight solution on the junction parameters is derived. The analysis is based on a phase-locked map and is compared with direct...... numerical experiments performed both on the map and on the perturbed sine-Gordon equation. As an interesting result we find that very close to a bifurcation the relaxation frequency is exactly equal to the half of the step frequency, i.e., the frequency characterizing the period-one solution....

  14. Pyrazine Nucleic Acids: From Small Molecules to Proto-Informational Polymers

    Science.gov (United States)

    Wong, S. B.; Gately, M.; Young, E.; Krishnamurthy, R.; Weber, A. L.; Campbell, T.

    2017-07-01

    Pyrazine nucleosides are derivable from amino acid amides and pentoses under plausibly prebiotic conditions. Pyrazines share features similar to adenine or thymine, and may behave as an informational polymer when polymerized as pyrazine nucleic acid.

  15. Gene Therapy for Advanced Melanoma: Selective Targeting and Therapeutic Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Joana R. Viola

    2013-01-01

    Full Text Available Despite recent advances, the treatment of malignant melanoma still results in the relapse of the disease, and second line treatment mostly fails due to the occurrence of resistance. A wide range of mutations are known to prevent effective treatment with chemotherapeutic drugs. Hence, approaches with biopharmaceuticals including proteins, like antibodies or cytokines, are applied. As an alternative, regimens with therapeutically active nucleic acids offer the possibility for highly selective cancer treatment whilst avoiding unwanted and toxic side effects. This paper gives a brief introduction into the mechanism of this devastating disease, discusses the shortcoming of current therapy approaches, and pinpoints anchor points which could be harnessed for therapeutic intervention with nucleic acids. We bring the delivery of nucleic acid nanopharmaceutics into perspective as a novel antimelanoma therapeutic approach and discuss the possibilities for melanoma specific targeting. The latest reports on preclinical and already clinical application of nucleic acids in melanoma are discussed.

  16. Nucleic acid polymeric properties and electrostatics: Directly comparing theory and simulation with experiment.

    Science.gov (United States)

    Sim, Adelene Y L

    2016-06-01

    Nucleic acids are biopolymers that carry genetic information and are also involved in various gene regulation functions such as gene silencing and protein translation. Because of their negatively charged backbones, nucleic acids are polyelectrolytes. To adequately understand nucleic acid folding and function, we need to properly describe its i) polymer/polyelectrolyte properties and ii) associating ion atmosphere. While various theories and simulation models have been developed to describe nucleic acids and the ions around them, many of these theories/simulations have not been well evaluated due to complexities in comparison with experiment. In this review, I discuss some recent experiments that have been strategically designed for straightforward comparison with theories and simulation models. Such data serve as excellent benchmarks to identify limitations in prevailing theories and simulation parameters. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. THE VARIATION OF NUCLEIC ACIDS CONTENT AFTER SIMAZIN TREATMENT ON VICIA SATIVA L.

    Directory of Open Access Journals (Sweden)

    Odeta Grama-Tiganasu

    2005-08-01

    Full Text Available Simazin has in certain conditions stimulatory effects on nucleic acids biosynthese. The biosyntese and mitotic division stimulation sugest the possibility to use simazin like growing and germination stimulator.

  18. [Blood Test Patterns for Blood Donors after Nucleic Acid Detection in the Blood Center].

    Science.gov (United States)

    Men, Shou-Shan; Lv, Lian-Zhi; Chen, Yuan-Feng; Han, Chun-Hua; Liu, Hong-Yu; Yan, Yan

    2017-12-01

    To investigate the blood test patterns for blood donors after nucleic acid detection in blood center. The collected blood samples after voluntary blood donors first were detected by conventional ELISA, then 31981 negative samples were detected via HBV/HCV/HIV combined nucleic acid test of 6 mixed samples(22716 cases) or single samples(9265 cases) by means of Roche cobas s201 instrument. The combined detection method as follows: the blood samples were assayed by conventional nucleic acid test of 6 mixed samples, at same time, 6 mixed samples were treated with polyethylene glycol precipitation method to concentrate the virus, then the nucleic acid test of blood samples was performed; the single detection method as follows: firstly the conventional nucleic acid test of single sample was performed, then the positive reactive samples after re-examination were 6-fold diluted to simulate the nucleic acid test of 6-mixed samples. The positive rate of positive samples detected by combined nucleic acid test, positive samples detected by nucleic acid test of mixed virus concentration and positive samples detected by single nucleic acid test was statistically analyzed. In addition, for HBV + persons the serological test yet should be performed. In 22 716 samples detected by nucleic acid test of 6 mixed samples (MP-6-NAT) , 9 cases were HBV + (0.40‰, 9/22716); at same time, the detection of same samples by nucleic acid test of mixed sample virus concentration showed 29 cases of HBV + (1.28‰, 29/22716). In 9265 samples detected by single nucleic acid test(ID-NAT) 12 cases showed HBV + (1.30‰, 12/9265), meanwhile the detection of these 12 samples with HBV + by 6-fold dilution for virus concentration found only 4 samples with HBV + . In serological qualified samples, ID-NAT unqualified rate was 1.28‰, which was higher than that of MP-6-NAT(0.4‰) (χ 2 =8.11, P0.05). In 41 samples with HBsAg - HBV DNA + detected by ELISA, 36 samples were confirmed to be occult HBV

  19. The association between low-grade inflammation, iron status and nucleic acid oxidation in the elderly

    DEFF Research Database (Denmark)

    Broedbaek, Kasper; Siersma, Volkert Dirk; Andersen, Jon T

    2011-01-01

    This study applied a case-control approach to investigate the association between low-grade inflammation, defined by high values within the normal range of C-reactive protein (CRP) and interleukin-6 (IL-6), and urinary markers of nucleic acid oxidation. No differences in excretion of urinary...... markers of nucleic acid oxidation between cases and controls were found and multivariable linear regression analysis showed no association between urinary markers of nucleic acid oxidation and inflammatory markers. Post-hoc multivariable linear regression analysis showed significant associations between...... suggest that low-grade inflammation only has a negligible impact on whole body nucleic acid oxidation, whereas iron status seems to be of great importance....

  20. Membrane Protected Apoptotic Trophoblast Microparticles Contain Nucleic Acids

    Science.gov (United States)

    Orozco, Aaron F.; Jorgez, Carolina J.; Horne, Cassandra; Marquez-Do, Deborah A.; Chapman, Matthew R.; Rodgers, John R.; Bischoff, Farideh Z.; Lewis, Dorothy E.

    2008-01-01

    Microparticles (MPs) that circulate in blood may be a source of DNA for molecular analyses, including prenatal genetic diagnoses. Because MPs are heterogeneous in nature, however, further characterization is important before use in clinical settings. One key question is whether DNA is either bound to aggregates of blood proteins and lipid micelles or intrinsically associated with MPs from dying cells. To test the latter hypothesis, we asked whether MPs derived in vitro from dying cells were similar to those in maternal plasma. JEG-3 cells model extravillous trophoblasts, which predominate during the first trimester of pregnancy when prenatal diagnosis is most relevant. MPs were derived from apoptosis and increased over 48 hours. Compared with necrotic MPs, DNA in apoptotic MPs was more fragmented and resistant to plasma DNases. Membrane-specific dyes indicated that apoptotic MPs had more membranous material, which protects nucleic acids, including RNA. Flow cytometry showed that MPs derived from dying cells displayed light scatter and DNA staining similar to MPs found in maternal plasma. Quantification of maternal MPs using characteristics defined by MPs generated in vitro revealed a significant increase of DNA+ MPs in the plasma of women with preeclampsia compared with plasma from women with normal pregnancies. Apoptotic MPs are therefore a likely source of stable DNA that could be enriched for both early genetic diagnosis and monitoring of pathological pregnancies. PMID:18974299