18 research outputs found
Design, Fabrication, and Experimental Demonstration of Junction Surface Ion Traps
We present the design, fabrication, and experimental implementation of
surface ion traps with Y-shaped junctions. The traps are designed to minimize
the pseudopotential variations in the junction region at the symmetric
intersection of three linear segments. We experimentally demonstrate robust
linear and junction shuttling with greater than one million round-trip shuttles
without ion loss. By minimizing the direct line of sight between trapped ions
and dielectric surfaces, negligible day-to-day and trap-to-trap variations are
observed. In addition to high-fidelity single-ion shuttling, multiple-ion
chains survive splitting, ion-position swapping, and recombining routines. The
development of two-dimensional trapping structures is an important milestone
for ion-trap quantum computing and quantum simulations.Comment: 9 pages, 6 figure
Integration of fluorescence collection optics with a microfabricated surface electrode ion trap
We have successfully demonstrated an integrated optical system for collecting
the fluorescence from a trapped ion. The system, consisting of an array of
transmissive, dielectric micro-optics and an optical fiber array, has been
intimately incorporated into the ion-trapping chip without negatively impacting
trapping performance. Epoxies, vacuum feedthrough, and optical component
materials were carefully chosen so that they did not degrade the vacuum
environment, and we have demonstrated light detection as well as ion trapping
and shuttling behavior comparable to trapping chips without integrated optics,
with no modification to the control voltages of the trapping chip.Comment: 14 pages, 12 figure
Reduction of heating rate in a microfabricated ion trap by pulsed-laser cleaning
Laser-cleaning of the electrodes in a planar micro-fabricated ion trap has
been attempted using ns pulses from a tripled Nd:YAG laser at 355nm. The effect
of the laser pulses at several energy density levels has been tested by
measuring the heating rate of a single 40Ca+ trapped ion as a function of its
secular frequency. A reduction of the electric-field noise spectral density by
~50% has been observed and a change in the frequency dependence also noticed.
This is the first reported experiment where the "anomalous heating" phenomenon
has been reduced by removing the source as opposed to reducing its thermal
driving by cryogenic cooling. This technique may open the way to better control
of the electrode surface quality in ion microtraps
Characterization of PAN-1, a Carbapenem-Hydrolyzing Class B β-Lactamase From the Environmental Gram-Negative Pseudobacteriovorax antillogorgiicola.
The gene encoding the metallo-β-lactamase (MβL) PAN-1 was identified in the genome of the environmental Gram-negative species Pseudobacteriovorax antillogorgiicola. PAN-1 shares 57% amino-acid identity with the acquired MβL SPM-1, its closest relative. Kinetic parameters performed on purified PAN-1 showed it displayed a hydrolytic activity toward most β-lactams including carbapenems but spared cefepime and aztreonam. These results further highlight that environmental bacterial species may be reservoirs of MβL encoding genes
Exploring the diversity and metabolic potential of actinomycetes from temperate marine sediments from Newfoundland, Canada
Marine sediments from Newfoundland, Canada were explored for biotechnologically promising Actinobacteria using culture-independent and culture-dependent approaches. Culture-independent pyrosequencing analyses uncovered significant actinobacterial diversity (H′—2.45 to 3.76), although the taxonomic diversity of biotechnologically important actinomycetes could not be fully elucidated due to limited sampling depth. Assessment of culturable actinomycete diversity resulted in the isolation of 360 actinomycetes representing 59 operational taxonomic units, the majority of which (94 %) were Streptomyces. The biotechnological potential of actinomycetes from NL sediments was assessed by bioactivity and metabolomics-based screening of 32 representative isolates. Bioactivity was exhibited by 41 % of isolates, while 11 % exhibited unique chemical signatures in metabolomics screening. Chemical analysis of two isolates resulted in the isolation of the cytotoxic metabolite 1-isopentadecanoyl-3β-d-glucopyranosyl-X-glycerol from Actinoalloteichus sp. 2L868 and sungsanpin from Streptomyces sp. 8LB7. These results demonstrate the potential for the discovery of novel bioactive metabolites from actinomycetes isolated from Atlantic Canadian marine sediments
Discovery of Levesquamide B through Global Natural Product Social Molecular Networking
Levesquamide A is an isothiazolinone-containing anti-tubercular natural product isolated from Streptomyces sp. RKND-216. Through the use of Global Natural Product Social Molecular Networking (GNPS), additional members of the levesquamide family were identified (B-G). Levesquamide B is a glycosylated analogue, isolated and structurally elucidated via spectroscopical techniques along with the putative structures of levesquamide C and D. For masses relating to the additional three levesquamides (E-G), their complete structures remain ambiguous
The secreted metabolome of Streptomyces chartreusis and implications for bacterial chemistry
Senges CHR, Al-Dilaimi A, Marchbank DH, et al. The secreted metabolome of Streptomyces chartreusis and implications for bacterial chemistry. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. 2018;115(10):2490-2495.Actinomycetes are known for producing diverse secondary metabolites. Combining genomics with untargeted data-dependent tandem MS and molecular networking, we characterized the secreted metabolome of the tunicamycin producer Streptomyces chartreusis NRRL 3882. The genome harbors 128 predicted biosynthetic gene clusters. We detected > 1,000 distinct secreted metabolites in culture supernatants, only 22 of which were identified based on standards and public spectral libraries. S. chartreusis adapts the secreted metabolome to cultivation conditions. A number of metabolites are produced iron dependently, among them 17 desferrioxamine siderophores aiding in iron acquisition. Eight previously unknown members of this long-known compound class are described. A single desferrioxamine synthesis gene cluster was detected in the genome, yet different sets of desferrioxamines are produced in different media. Additionally, a polyether ionophore, differentially produced by the calcimycin biosynthesis cluster, was discovered. This illustrates that metabolite output of a single biosynthetic machine can be exquisitely regulated not only with regard to product quantity but also with regard to product range. Compared with chemically defined medium, in complex medium, total metabolite abundancewas higher, structural diversity greater, and the average molecular weight almost doubled. Tunicamycins, for example, were only produced in complex medium. Extrapolating from this study, we anticipate that the larger part of bacterial chemistry, including chemical structures, ecological functions, and pharmacological potential, is yet to be uncovered