Randomized trial of conventional transseptal needle versus radiofrequency energy needle puncture for left atrial access (the TRAVERSE-LA study).

BackgroundTransseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access.Methods and resultsIn this prospective, single-blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK-1) transseptal needle. In an intention-to-treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P = 0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P < 0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P < 0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]).ConclusionsUse of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings

Posttraumatic Stress Disorder Among Domestic Violence Survivors

Graduate Theoretical Proposa

“A Debt of Honor”: The Hegemonic Benevolence of Richmond’s Female Elites at the “Last Confederate Christmas” of 1864

In poignant remembrance of the last Christmas in the Confederate White House, Varina Davis, First Lady of the Confederacy, reflected upon that special event in an extended article for the New York Sunday World, some thirty-two years after the Confederacy’s final Christmas. Davis recounted the event fondly and praised the transformation of her female peers into perfect models of Confederate endurance under the extreme duress of civil war. In re-creating the dramaturgy of the three-part event, which was organized and hosted in large part by the Confederacy’s First Lady, Davis opened a critical window into southern sensibilities and the cultural rituals which helped to sustain the Confederacy through four long years of civil war. Though Davis’s article was clearly a reflective and nostalgic piece concerning an event which occurred thirtytwo years prior, it was not written merely as a glorification of southern society, but rather to demonstrate the perpetuation of cherished southern ideals and rituals during the closing months of the war. [excerpt

Fracture initiation in multi-phase materials: a systematic three-dimensional approach using a FFT-based solver

This paper studies a two-phase material with a microstructure composed of a hard brittle reinforcement phase embedded in a soft ductile matrix. It addresses the full three-dimensional nature of the microstructure and macroscopic deformation. A large ensemble of periodic microstructures is used, whereby the individual grains of the two phases are modeled using equi-sized cubes. A particular solution strategy relying on the Fast Fourier Transform is adopted, which has a high computational efficiency both in terms of speed and memory footprint, thus enabling a statistically meaningful analysis. This solution method naturally accompanies the regular microstructural model, as the Fast Fourier Transform relies on a regular grid. Using the many considered microstructures as an ensemble, the average arrangement of phases around fracture initiation sites is objectively identified by the correlation between microstructure and fracture initiation -- in three dimensions. The results show that fracture initiates where regions of the hard phase are interrupted by bands of the soft phase that are aligned with the direction of maximum shear. In such regions, the hard phase is arranged such that the area of the phase boundary perpendicular to the principal strain direction is maximum, leading to high hydrostatic tensile stresses, while not interrupting the shear bands that form in the soft phase. The local incompatibility that is present around the shear bands is responsible for a high plastic strain. By comparing the response to a two-dimensional microstructure it is observed that the response is qualitatively similar (both macroscopically and microscopically). One important difference is that the local strain partitioning between the two phases is over-predicted by the two-dimensional microstructure, leading to an overestimation of damage

The experiences of and changes in talking about school bullying by the victims upon the implementation of KiVa anti-bullying program

Uurimistöö eesmärgiks oli kaardistada Eesti KiVa kiusamisvastase programmi rakendavate koolide 1.-6. klassi kiusamise ohvriks langenud õpilaste kogemused seoses koolikiusamisest rääkimisega ja muutustega selles. Analüüsiks kasutati 2016. ja 2017. aasta kevadel iga-aastase küsitluse käigus kogutud andmeid: baastaseme mõõtmisel osales 1626 õpilast kaheksast 2016. aastal programmiga alustanud koolist (49,7% poisse), post-taseme mõõtmisel 1784 õpilast (50,1% poisse). Leiti, et nooremate ja vanemate õpilaste kiusamisest rääkimise vaheline erinevus oli statistiliselt oluline post-tasemel. Enne ja pärast KiVa rakendamist ei esinenud kiusamisest rääkimisel erinevate kuulajate arvus statistiliselt olulist erinevust. Klassi ja perele kiusamisest rääkimise vaheline statistiliselt oluline seos ilmnes teisel mõõtmiskorral. Õpilase sugu ja kooliaste ennustasid teatud määral seda, kas ta räägib kellelegi kiusamisest või mitte. Uurimistöös arutleti andmete analüüsimisel leitud tulemuste ning võimalike tulevikuperspektiivide üle

Controlled crack growth specimen for brittle systems

A pure Mode 1 fracture specimen and test procedure has been developed which provides extended, stable, through-thickness crack growth in ceramics and other brittle, nonmetallic materials. Fixed displacement loading, applied at the crack mouth, promotes stable crack extension by reducing the stored elastic strain energy. Extremely fine control of applied displacements is achieved by utilizing the Poisson's expansion of a compressively loaded cylindrical pin. Stable cracks were successfully grown in soda-lime glass and monolithic Al2O3 for lengths in excess of 20 mm without uncontrollable catastrophic failure