118 research outputs found
The complete mitochondrial genome of the vulnerable Australian crest-tailed mulgara (Dasycercus cristicauda)
In this announcement, we report the complete mitogenome of the vulnerable Crest-tailed Mulgara (Dasycercus cristicauda) (Krefft, 1867). The mitogenome was 17,085âbp in length and contained 13 protein-coding genes, two rRNA genes, 22 tRNAs and a 1583âbp variable control region (D-loop). The features of the D. cristicauda mitogenome are consistent with other vertebrate mitogenomes but, in contrast to other marsupials, appears to contain a functional tRNA-Lysine with a UUU anticodon. Phylogenetic analysis of available entire mitogenomes reveals it forms a cluster with other marsupials in the Dasyuromorphia order within the Australidelphian clade, being most closely related to the Northern Quoll and the Tasmanian Devil
A Model of Habitability Within the Milky Way Galaxy
We present a model of the Galactic Habitable Zone (GHZ), described in terms
of the spatial and temporal dimensions of the Galaxy that may favour the
development of complex life. The Milky Way galaxy is modelled using a
computational approach by populating stars and their planetary systems on an
individual basis using Monte-Carlo methods. We begin with well-established
properties of the disk of the Milky Way, such as the stellar number density
distribution, the initial mass function, the star formation history, and the
metallicity gradient as a function of radial position and time. We vary some of
these properties, creating four models to test the sensitivity of our
assumptions. To assess habitability on the Galactic scale, we model supernova
rates, planet formation, and the time required for complex life to evolve. Our
study improves on other literature on the GHZ by populating stars on an
individual basis and by modelling SNII and SNIa sterilizations by selecting
their progenitors from within this preexisting stellar population. Furthermore,
we consider habitability on tidally locked and non-tidally locked planets
separately, and study habitability as a function of height above and below the
Galactic midplane. In the model that most accurately reproduces the properties
of the Galaxy, the results indicate that an individual SNIa is ~5.6 \times more
lethal than an individual SNII on average. In addition, we predict that ~1.2%
of all stars host a planet that may have been capable of supporting complex
life at some point in the history of the Galaxy. Of those stars with a
habitable planet, ~75% of planets are predicted to be in a tidally locked
configuration with their host star. The majority of these planets that may
support complex life are found towards the inner Galaxy, distributed within,
and significantly above and below, the Galactic midplane.Comment: Accepted for publication in Astrobiology. 40 pages, 12 figures, 3
table
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Design and preparation of a novel colon-targeted tablet of hydrocortisone
ABSTRACT The objective of this research was to design a new colon-targeted drug delivery system based on chitosan. The properties of the films were studied to obtain useful information about the possible applications of composite films. The composite films were used in a bilayer system to investigate their feasibility as coating materials. Tensile strength, swelling degree, solubility, biodegradation degree, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) investigations showed that the composite film was formed when chitosan and gelatin were reacted jointly. The results showed that a 6:4 blend ratio was the optimal chitosan/gelatin blend ratio. In vitro drug release results indicated that the Eudragit- and chitosan/gelatin-bilayer coating system prevented drug release in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). However, the drug release from a bilayer-coated tablet in SCF increased over time, and the drug was almost completely released after 24h. Overall, colon-targeted drug delivery was achieved by using a chitosan/gelatin complex film and a multilayer coating system
Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer.
BACKGROUND: The randomized, double-blind OlympiA trial compared one year of the oral poly(adenosine diphosphate-ribose) polymerase) inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2 (HER2)-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive-disease-free survival (IDFS) and distant-disease-free survival (DDFS). The olaparib-group had fewer deaths than the placebo-group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety. PATIENTS AND METHODS: 1,836 patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy (N)ACT, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone-receptor-positive-cancers. Statistical significance for OS at this IA required P<0.015. RESULTS: With median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib-group relative to the placebo-group (HR, 0.68; 98.5% CI 0.47 to 0.97; P=0.009). Four-year OS was 89.8% in the olaparib-group and 86.4% in the placebo-group (Î 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for olaparib-group versus placebo-group was 82.7% versus 75.4% (Î 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Î 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myelogenous leukemia or myelodysplastic syndrome (AML/MDS). CONCLUSION: With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals
Opposing reactions in coenzyme A metabolism sensitize Mycobacterium tuberculosis to enzyme inhibition
Mycobacterium tuberculosis (Mtb) is the leading infectious cause of death in humans. Synthesis of lipids critical for Mtbâs cell wall and virulence depends on phosphopantetheinyl transferase (PptT), an enzyme that transfers 4âČ-phosphopantetheine (Ppt) from coenzyme A (CoA) to diverse acyl carrier proteins. We identified a compound that kills Mtb by binding and partially inhibiting PptT. Killing of Mtb by the compound is potentiated by another enzyme encoded in the same operon, Ppt hydrolase (PptH), that undoes the PptT reaction. Thus, loss-of-function mutants of PptH displayed antimicrobial resistance. Our PptT-inhibitor cocrystal structure may aid further development of antimycobacterial agents against this long-sought target. The opposing reactions of PptT and PptH uncover a regulatory pathway in CoA physiology
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