283 research outputs found
New material of Chirostenotes pergracilis (Theropoda, Oviraptorosauria) from the Campanian Dinosaur Park Formation of Alberta, Canada
Performance, Carcass Characteristics, and Life Cycle Assessment of Cattle Grown Utilizing Different Combinations of Growth Promoting Technologies
The objective of this study was to determine the impact of different combinations of growth promoting technologies on live animal performance, carcass characteristics, and environmental outcomes
Atomic-scale confinement of optical fields
In the presence of matter there is no fundamental limit preventing
confinement of visible light even down to atomic scales. Achieving such
confinement and the corresponding intensity enhancement inevitably requires
simultaneous control over atomic-scale details of material structures and over
the optical modes that such structures support. By means of self-assembly we
have obtained side-by-side aligned gold nanorod dimers with robust
atomically-defined gaps reaching below 0.5 nm. The existence of
atomically-confined light fields in these gaps is demonstrated by observing
extreme Coulomb splitting of corresponding symmetric and anti-symmetric dimer
eigenmodes of more than 800 meV in white-light scattering experiments. Our
results open new perspectives for atomically-resolved spectroscopic imaging,
deeply nonlinear optics, ultra-sensing, cavity optomechanics as well as for the
realization of novel quantum-optical devices
Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials
We review the basic physics behind light interaction with plasmonic
nanoparticles. The theoretical foundations of light scattering on one metallic
particle (a plasmonic monomer) and two interacting particles (a plasmonic
dimer) are systematically investigated. Expressions for effective particle
susceptibility (polarizability) are derived, and applications of these results
to plasmonic nanoantennas are outlined. In the long-wavelength limit, the
effective macroscopic parameters of an array of plasmonic dimers are
calculated. These parameters are attributable to an effective medium
corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial
where plasmonic monomers or dimers have the function of "meta-atoms". It is
shown that planar dimers consisting of rod-like particles generally possess
elliptical dichroism and function as atoms for planar chiral metamaterials. The
fabricational simplicity of the proposed rod-dimer geometry can be used in the
design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.
Mode imaging and selection in strongly coupled nanoantennas
The number of eigenmodes in plasmonic nanostructures increases with
complexity due to mode hybridization, raising the need for efficient mode
characterization and selection. Here we experimentally demonstrate direct
imaging and selective excitation of the bonding and antibonding plasmon mode in
symmetric dipole nanoantennas using confocal two-photon photoluminescence
mapping. Excitation of a high-quality-factor antibonding resonance manifests
itself as a two-lobed pattern instead of the single spot observed for the broad
bonding resonance, in accordance with numerical simulations. The two-lobed
pattern is observed due to the fact that excitation of the antibonding mode is
forbidden for symmetric excitation at the feedgap, while concomitantly the mode
energy splitting is large enough to suppress excitation of the bonding mode.
The controlled excitation of modes in strongly coupled plasmonic nanostructures
is mandatory for efficient sensors, in coherent control as well as for
implementing well-defined functionalities in complex plasmonic devices.Comment: 11 pages, 5 figures, 1 supplementary informatio
Love in a Time of Colic:Mobilizing Professional Love in Relationships with Children and Young People to Promote Their Resilience and Wellbeing
Synthesis, structural studies and photochemistry of cobalt(III) complexes of anthracenylcyclam macrocycles
This work reports the syntheses, structures and some photochemistry in DMF of the cobalt complexes trans-[CoIII( 2)Cl2]Cl·0.5CH3OH and trans-[CoIII( 3)Cl2]Cl·4H2O, where 2 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione and 3 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane. In the preparation of the macrocyclic ligand, 3, the formation of a polycyclic bis(aminal) intermediate and its subsequent acid hydrolysis to 3 is a cleaner route than the traditional procedure in which the analogous dioxocyclam 2 is reduced with borane reagents. The crystal structure of trans-[CoIII( 3)Cl2]Cl·4H2O shows that the macrocycle adopts the trans-III conformation, in which the anthracene moiety is extended away from the cobalt ion and the anthracene to Co separation is 7.22 . For the related complex trans-[CoIII( 2)Cl2]Cl·0.5CH3OH, however, the anthracene is bent over the highly conjugated tetracycle and significant interactions between the anthracene and the complex occur. A novel new complex, trans-[Co( 12)Cl2](where 12 is 5,7-hydroxy-6-oxo-1,4,8,11-tetraazacyclotetradecane-4,7-diene) which is a degradation product of the complex trans-[CoIII( 2)Cl2]Cl is also reported
Multihospital Outbreak of Clostridium difficile Ribotype 027 Infection: Epidemiology and Analysis of Control Measures
Objective. To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak. Design. Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland. Interventions. Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene. Results. A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, —0.054; lag time, 4 months; P = .003). Conclusion. These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillanc
Comparison of IRES and F2A-Based Locus-Specific Multicistronic Expression in Stable Mouse Lines
Efficient and stoichiometric expression of genes concatenated by bi- or multi-cistronic vectors has become an invaluable tool not only in basic biology to track and visualize proteins in vivo, but also for vaccine development and in the clinics for gene therapy. To adequately compare, in vivo, the effectiveness of two of the currently popular co-expression strategies - the internal ribosome entry site (IRES) derived from the picornavirus and the 2A peptide from the foot-and-mouth disease virus (FDMV) (F2A), we analyzed two locus-specific knock-in mouse lines co-expressing SRY-box containing gene 9 (Sox9) and enhanced green fluorescent protein (EGFP) linked by the IRES (Sox9IRES-EGFP) or the F2A (Sox9F2A-EGFP) sequence. Both the constructs expressed Sox9 and EGFP proteins in the appropriate Sox9 expression domains, with the IRES construct expressing reduced levels of EGFP compared to that of the F2A. The latter, on the other hand, produced about 42.2% Sox9-EGFP fusion protein, reflecting an inefficient ribosome ‘skipping’ mechanism. To investigate if the discrepancy in the ‘skipping’ process was locus-dependent, we further analyzed the FLAG3-Bapx1F2A-EGFP mouse line and found similar levels of fusion protein being produced. To assess if EGFP was hindering the ‘skipping’ mechanism, we examined another mouse line co-expressing Bagpipe homeobox gene 1 homolog (Bapx1), Cre recombinase and EGFP (Bapx1F2A-Cre-F2A-EGFP). While the ‘skipping’ was highly efficient between Bapx1 and Cre, the ‘skipping’ between Cre and EGFP was highly inefficient. We have thus demonstrated in our comparison study that the efficient and close to equivalent expression of genes linked by F2A is achievable in stable mouse lines, but the EGFP reporter may cause undesirable inhibition of the ‘skipping’ at the F2A sequence. Hence, the use of other reporter genes should be explored when utilizing F2A peptides
Single Nanoparticle-Based Heteronanojunction as a Plasmon Ruler for Measuring Dielectric Thin Films
- …