Ex-vivo porcine organs with a circulation pump are effective for teaching hemostatic skills

Surgical residents have insufficient opportunites to learn basic hemostatic skills from clinical experience alone. We designed an ex-vivo training system using porcine organs and a circulation pump to teach hemostatic skills. Residents were surveyed before and after the training and showed significant improvement in their self-confidence (1.83 ± 1.05 vs 3.33 ± 0.87, P < 0.01) on a 5 point Likert scale. This training may be effective to educate residents in basic hemostatic skills

An Iterative Reconstruction Algorithm for Faraday Tomography

Faraday tomography offers crucial information on the magnetized astronomical objects, such as quasars, galaxies, or galaxy clusters, by observing its magnetoionic media. The observed linear polarization spectrum is inverse Fourier transformed to obtain the Faraday dispersion function (FDF), providing us a tomographic distribution of the magnetoionic media along the line of sight. However, this transform gives a poor reconstruction of the FDF because of the instrument's limited wavelength coverage. The current Faraday tomography techniques' inability to reliably solve the above inverse problem has noticeably plagued cosmic magnetism studies. We propose a new algorithm inspired by the well-studied area of signal restoration, called the Constraining and Restoring iterative Algorithm for Faraday Tomography (CRAFT). This iterative model-independent algorithm is computationally inexpensive and only requires weak physically-motivated assumptions to produce high fidelity FDF reconstructions. We demonstrate an application for a realistic synthetic model FDF of the Milky Way, where CRAFT shows greater potential over other popular model-independent techniques. The dependence of observational frequency coverage on the various techniques' reconstruction performance is also demonstrated for a simpler FDF. CRAFT exhibits improvements even over model-dependent techniques (i.e., QU-fitting) by capturing complex multi-scale features of the FDF amplitude and polarization angle variations within a source. The proposed approach will be of utmost importance for future cosmic magnetism studies, especially with broadband polarization data from the Square Kilometre Array and its precursors. We make the CRAFT code publicly available.Comment: Accepted for publication in MNRAS. 13 pages and 12 figure

P-wave tomography of the mantle beneath the South Pacific Superswell revealed by joint ocean floor and islands broadband seismic experiments

International audienceThree-dimensional P-wave velocity structure of the mantle beneath the South Pacific Superswell is determined through passive broadband seismic experiments on the ocean floor and islands between 2003 and 2005. We collected approximately 1500 relative times of long-period teleseismic P-waves by using a waveform cross-correlation. We analyzed this data set with relative time tomography to depths of 2000 km. The resultant structure shows lateral heterogeneity of approximately +/- 2%, in which a distinct low velocity region is found beneath the center of the Superswell at a depth of 1600 km. At 1200km depth, an elongated low velocity region is found beneath the Society to Pitcairn hotspots. At 800 km depth, two linear low velocity regions are located beneath Tuamotu and Austral islands. Isolated low velocity regions are identified beneath the Society, Marquesas, and Macdonald hotspots at 400 km depth. Our new tomographic images reveal that the large low velocity region rooted in the deep lower mantle is split into two sheets at 1200 km depth and these terminate at approximately 800 km depth. This feature appears to be consistent with the characteristics of a thermo-chemical pile or dome

Effect of atmospheric control during MA-HIP process on mechanical properties of oxide dispersion-strengthened Cu alloy

In this study, mechanical properties of Dispersion Strengthened (DS)-Cu-Al (aluminum) and Zr (zirconium) alloys, which were fabricated by an MA-HIP method, were investigated for application to the heat sink materials of fusion reactors. The effect of air exposure before the HIP process was studied using a NIFS-Sealing Device. Cu–Al specimen with air exposure before HIP was broken during wire-electrical discharge formation. Cu–Al specimen without air exposure exhibited high fracture strength, but without yielding. Cu–Zr specimen, both with and without the exposure, yielded and exhibits elongation. An increase in yield and tensile strength by approximately 61% and 45%, respectively, were obtained for Cu–Zr specimen by avoiding air exposure. The results showed that Cu–Zr specimen is less susceptible to the atmosphere of the MA-HIP process than Cu–Al

Physicochemical Properties of Low Transition Temperature Mixtures in Water

A new generation of designer solvents, low transition temperature mixtures (LTTMs) could be the ideal solvent for the separation of the main biopolymers in lignocellulosic biomass such as lignin, cellulose and hemicellulose. The separated biopolymers have prospective to be converted into high valuable products. LTTMs can be synthesized from two natural high melting point materials through hydrogen bonding interactions. The objective of this research was to study the effects of water in the physicochemical properties of LTTMs such as hydrogen bonding, thermal stability and lignin solubility. LTTMs were prepared in the presence and absence of distilled water with malic acid as the hydrogen bond donor (HBD) and sucrose as hydrogen bond acceptor (HBA). The molar ratio of malic acid to sucrose was fixed at 1:1. Based on the fourier transform infrared spectroscopy (FTIR) analysis, the FT-IR spectra of all the LTTMs shown representative peak of carboxylic acid group of malic acid turned broader at 1,710 cm-1 for the C=O group. Nevertheless, the peaks involved in the H-bonding due to the formation of LTTMs shifted and became broader within 2,500 - 3,600 cm-1 for the OH groups of carboxylic acid and alcohols in the presence of water. The degradation temperature of LTTM was not affected by the addition of water which remained at 400 K. In addition, the LTTM with water had increased the lignin solubility from 6.22 to 6.38 wt% without affecting the thermal behaviour of LTTMs