4,448 research outputs found
Costly choices for treating Wilson's disease
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110871/1/hep27663.pd
A Practical and Efficient Synthesis of Uniform Conjugated Rod‐Like Oligomers
Herein, a more practical and efficient synthesis protocol for the preparation of uniform rod-like oligo(1,4-phenylene ethynylene)s (OPE)s is presented. Applying an iterative reaction cycle consisting of a decarboxylative coupling reaction and a saponification of an alkynyl carboxylic ester, a uniform pentamer is obtained in ten steps with 14% overall yield. The copper-free conditions prevent homocoupling until the trimer stage, resulting in a significantly easier work-up of the products. Homocoupling is observed from the tetramer stage on, but a simple variation of the work-up procedure also yields the uniform tetramer and pentamer. A thorough comparison with the commonly used and described Sonogashira approach reveals that with the new presented strategy, OPEs can be built in similar overall yield, but easier purification and in a quarter of the time. All oligomers are fully characterized by proton and carbon nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), size-exclusion chromatography (SEC), and infrared spectroscopy (IR)
Crawling the Cosmic Network: Identifying and Quantifying Filamentary Structure
We present the Smoothed Hessian Major Axis Filament Finder (SHMAFF), an
algorithm that uses the eigenvectors of the Hessian matrix of the smoothed
galaxy distribution to identify individual filamentary structures. Filaments
are traced along the Hessian eigenvector corresponding to the largest
eigenvalue, and are stopped when the axis orientation changes more rapidly than
a preset threshold. In both N-body simulations and the Sloan Digital Sky Survey
(SDSS) main galaxy redshift survey data, the resulting filament length
distributions are approximately exponential. In the SDSS galaxy distribution,
using smoothing lengths of 10 h^{-1} Mpc and 15 h^{-1} Mpc, we find filament
lengths per unit volume of 1.9x10^{-3} h^2 Mpc^{-2} and 7.6x10^{-4} h^2
Mpc^{-2}, respectively. The filament width distributions, which are much more
sensitive to non-linear growth, are also consistent between the real and mock
galaxy distributions using a standard cosmology. In SDSS, we find mean filament
widths of 5.5 h^{-1} Mpc and 8.4 h^{-1} Mpc on 10 h^{-1} Mpc and 15 h^{-1} Mpc
smoothing scales, with standard deviations of 1.1 h^{-1} Mpc and 1.4 h^{-1}
Mpc, respectively. Finally, the spatial distribution of filamentary structure
in simulations is very similar between z=3 and z=0 on smoothing scales as large
as 15 h^{-1} Mpc, suggesting that the outline of filamentary structure is
already in place at high redshift.Comment: 10 pages, 11 figures, accepted to MNRA
Announcing the 2019 Processes Travel Awards for Post-Doctoral Fellows and Ph.D. Students
Note: In lieu of an abstract, this is an excerpt from the first page.
In order to support the development of early career researchers involved in chemical and biological process/systems engineering, Processes launched the second Travel Awards for Post-doctoral Fellows and Ph.D. Students. We received a large number of highly meritorious applications from all over the world. On behalf of the Editors of Processes, we are pleased to announce the winners of Processes Travel Awards for 2019
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Addendum: “Storage Ring Measurement of Electron Impact Ionization for Mg7+ Forming Mg8+” (2010, Apj, 712, 1166)
Experimental cross-section data are presented as online data tables for electron impact single ionization of Mg7+ forming Mg8+
965-48 Ejection Fraction and Wall Thickness Correlate with Impaired Energy Metabolism in Patients with Dilated Cardiomyopathy
Using 31P-MR spectroscopy, abnormalities of cardiac energy metabolism have been demonstrated in patients with dilated cardiomyopathy (DCM). However. a detailed analysis of the correlations among energy metabolism, cardiac hemodynamics and myocardial hypertrophy obtained from 31P-MR, right and left heart catheterization and echocardiography has not been presented, 23 patients with DCM (left ventricular (LV) EF 34±3%; NYHA class 2.7±0.1; SE) underwent right and left heart catheterization and echocardiography±3 days before/after MR spectroscopy. Coronary artery disease was ruled out by coronary angiography. ECG-triggered. localized 31 P-MR spectra from the anteroseptal myocardium were acquired at rest (prone position) during 30min on a 1.5 T Philips Gyroscan MR system using ISIS localization, adiabatic pulses. and a 15 sec repetition time. Peak areas were corrected for T1 effects and for blood contamination. and were determined with Lorentzian line fits in the time domain. Linear correlations between creatine phosphate (CP)/ATP ratios and hemodynamic parameters were calculated.LV pressures and diameters. cardiac output, stroke volume, pulmonary arterial pressures, right atrial pressure and pulmonary arterial oxygen saturation did not correlate with CP/ATP. Thus, our data demonstrate that in DCM, the extent of high-energy phosphate depletion is related to the extent of mechanical dysfunction as well as to LV wall thickness
Gene Loss and Adaptation to Hominids Underlie the Ancient Origin of HIV-1
SummaryHIV-1 resulted from cross-species transmission of SIVcpz, a simian immunodeficiency virus that naturally infects chimpanzees. SIVcpz, in turn, is a recombinant between two SIV lineages from Old World monkeys. Lentiviral interspecies transmissions are partly driven by the evolution and capacity of viral accessory genes, such as vpx, vpr, and vif, to antagonize host antiviral factors, such as SAMHD1 and the APOBEC3 proteins. We show that vpx, which in other lentiviruses antagonizes SAMHD1, was deleted during the creation of SIVcpz. This genomic deletion resulted in the reconstruction of the overlapping vif gene by “overprinting,” creating a unique vif that overlaps in its 3′ end with the vpr gene and can antagonize hominid APOBEC3s. Moreover, passage of SIVs through chimpanzees facilitated the subsequent adaptation of HIV-1 to humans. Thus, HIV-1 originated through a series of gene loss and adaptation events that generated its chimpanzee precursor and lowered the species barrier to human infection
Comparative analysis of the ability of Clostridium clariflavum strains and Clostridium thermocellumto utilize hemicellulose and unpretreated plant material
Experimental measurement of stress at a four-domain junction in lead zirconate titanate
A junction between two lamellar bands of ferroelectric domains in a lead zirconate titanate (PZT) ceramic is analysed using Kikuchi diffraction patterns in the transmission electron microscope. Indexing of the diffraction patterns allowed the determination of the 3D relative orientation of the 4 different domains at the junction and thus the characterisation of the domain boundaries. The local c/a ratio could also be determined from the misorientations at the domain boundaries. Analysis of the data showed that large stresses were concentrated at the junction, and that this is inevitable at such band junctions. Such stress concentrations could act as nuclei for cracking of the ceramic under additional loading in service, perhaps particularly as a consequence of extended electromechanical cycling. Moreover, the stresses would increase with increasing c/a making the issues all the more serious for Ti-rich compositions having larger c/a ratios
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