2,099 research outputs found
Indium tin oxide overlayered waveguides for sensor applications
The use of indium tin oxide (ITO) thin films as electrodes for integrated optical electrochemical sensor devices is discussed. The effect of various thicknesses of ITO overlayers exhibiting low resistivity and high transparency on potassium ion-exchanged waveguides fabricated in glass substrates is investigated over the wavelength range 500-900 nm. ITO overlayers are formed by reactive thermal evaporation in oxygen, followed by annealing in air to a maximum temperature of 320°C. With air as superstrate, losses in the waveguides were found to increase dramatically above 30nm ITO thickness for TE polarization, and above 50nm thickness for TM. Losses were increased over the whole wavelength range for a superstrate index close to that of water. A one-dimensional multilayer waveguide model is used in the interpretation of the experimental results
A minimaj-preserving crystal on ordered multiset partitions
We provide a crystal structure on the set of ordered multiset partitions,
which recently arose in the pursuit of the Delta Conjecture. This conjecture
was stated by Haglund, Remmel and Wilson as a generalization of the Shuffle
Conjecture. Various statistics on ordered multiset partitions arise in the
combinatorial analysis of the Delta Conjecture, one of them being the minimaj
statistic, which is a variant of the major index statistic on words. Our
crystal has the property that the minimaj statistic is constant on connected
components of the crystal. In particular, this yields another proof of the
Schur positivity of the graded Frobenius series of the generalization
due to Haglund, Rhoades and Shimozono of the coinvariant algebra . The
crystal structure also enables us to demonstrate the equidistributivity of the
minimaj statistic with the major index statistic on ordered multiset
partitions.Comment: 17 pages; v2 contains minor changes suggested by referee, references
update
Class I Gap-formation in Highly-viscous Glass-ionomer Restorations: Delayed vs Immediate Polishing
This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, GlasIonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000Ă magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p<0.05) in gap-incidence were observed between polishing immediately and after one-day storage. In the former case, 80â100 gaps were found. In the latter case, only 9â21 gaps were observed. For all materials, their shear-bond-strengths, flexural strength and moduli increased significantly after 24-hour storage.</p
Class I Gap-formation in Highly-viscous Glass-ionomer Restorations: Delayed vs Immediate Polishing
This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, GlasIonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000Ă magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p<0.05) in gap-incidence were observed between polishing immediately and after one-day storage. In the former case, 80â100 gaps were found. In the latter case, only 9â21 gaps were observed. For all materials, their shear-bond-strengths, flexural strength and moduli increased significantly after 24-hour storage.</p
Identification of small-molecule inhibitors of the antiapoptotic protein myeloid cell leukaemia-1 (Mcl-1)
Proteinâprotein interactions (PPIs) control many cellular processes in cancer and tumour growth. Of significant interest is the role PPIs play in regulating apoptosis. The overexpression of the antiapoptosis regulating Bcl-2 family of proteins is commonly observed in several cancers, leading to resistance towards both radiation and chemotherapies. From this family, myeloid cell leukemia-1 (Mcl-1) has proven the most difficult to target, and one of the leading causes of treatment resistance. Exploiting the selective PPI between the apoptosis-regulating protein Noxa and Mcl-1, utilising a fluorescence polarization assay, we have identified four small molecules with the ability to modulate Mcl-1. The identified compounds were computationally modelled and docked against the Mcl-1 binding interface to obtain structural information about their binding sites allowing for future analogue design. When examined for their activity towards pancreatic cell lines that overexpress Mcl-1 (MiaPaCa-2 and BxPC-3), the identified compounds demonstrated growth inhibition, suggesting effective Mcl-1 modulation
Administering asylum seekers in Hong Kong : government policies and action
published_or_final_versionPolitics and Public AdministrationMasterMaster of Public Administratio
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Deciphering the genetic basis for polyketide variation among mycobacteria producing mycolactones.
BACKGROUND: Mycolactones are immunosuppressive and cytotoxic polyketides, comprising five naturally occurring structural variants (named A/B, C, D, E and F), produced by different species of very closely related mycobacteria including the human pathogen, Mycobacterium ulcerans. In M. ulcerans strain Agy99, mycolactone A/B is produced by three highly homologous type I polyketide megasynthases (PKS), whose genes (mlsA1: 51 kb, mlsA2: 7.2 kb and mlsB: 42 kb) are found on a 174 kb plasmid, known as pMUM001. RESULTS: We report here comparative genomic analysis of pMUM001, the complete DNA sequence of a 190 kb megaplasmid (pMUM002) from Mycobacterium liflandii 128FXT and partial sequence of two additional pMUM replicons, combined with liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis. These data reveal how PKS module and domain differences affecting MlsB correlate with the production of mycolactones E and F. For mycolactone E these differences from MlsB in M. ulcerans Agy99 include replacement of the AT domain of the loading module (acetate to propionate) and the absence of an entire extension module. For mycolactone F there is also a reduction of one extension module but also a swap of ketoreductase domains that explains the characteristic stereochemistry of the two terminal side-chain hydroxyls, an arrangement unique to mycolactone F CONCLUSION: The mycolactone PKS locus on pMUM002 revealed the same large, three-gene structure and extraordinary pattern of near-identical PKS domain sequence repetition as observed in pMUM001 with greater than 98.5% nucleotide identity among domains of the same function. Intra- and inter-strain comparisons suggest that the extreme sequence homogeneity seen among the mls PKS genes is caused by frequent recombination-mediated domain replacement. This work has shed light on the evolution of mycolactone biosynthesis among an unusual group of mycobacteria and highlights the potential of the mls locus to become a toolbox for combinatorial PKS biochemistry.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Precious Metals in SDSS Quasar Spectra I: Tracking the Evolution of Strong, 1.5 < z < 4.5 CIV Absorbers with Thousands of Systems
We have vastly increased the CIV statistics at intermediate redshift by
surveying the thousands of quasars in the Sloan Digital Sky Survey Data-Release
7. We visually verified over 16,000 CIV systems with 1.46 < z < 4.55---a sample
size that renders Poisson error negligible. Detailed Monte Carlo simulations
show we are approximately 50% complete down to rest equivalent widths W_r ~ 0.6
\AA. We analyzed the sample as a whole and in ten small redshift bins with
approximately 1500 doublets each. The equivalent width frequency distributions
f(W_r) were well modeled by an exponential, with little evolution in shape. In
contrast with previous studies that modeled the frequency distribution as a
single power law, the fitted exponential gives a finite mass density for the
CIV ions. The co-moving line density dN_CIV/dX evolved smoothly with redshift,
increasing by a factor of 2.37+/-0.09 from z = 4.55 to 1.96, then plateauing at
dN_CIV/dX ~ 0.34 for z = 1.96 to 1.46. Comparing our SDSS sample with z < 1
(ultraviolet) and z > 5 (infrared) surveys, we see an approximately 10-fold
increase in dN_CIV/dX over z ~ 6 --> 0, for W_r >= 0.6 \AA. This suggests a
monotonic and significant increase in the enrichment of gas outside galaxies
over the 12 Gyr lifetime of the universe.Comment: 17 pages (emulateapj), 13 figures, 4 tables; accepted to ApJ and in
press; also see http://igmabsorbers.inf
Best practice policy statement on urodynamic antibiotic prophylaxis in the nonâindex patient
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136686/1/nau23253.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136686/2/nau23253_am.pd
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