3,028 research outputs found
Recommended from our members
Prospective Evaluation of Cardiopulmonary Resuscitation Performed in Dogs and Cats According to the RECOVER Guidelines. Part 1: Prognostic Factors According to Utstein-Style Reporting.
Factors associated with positive cardiopulmonary resuscitation (CPR) outcomes defined according to the veterinary Utstein-style CPR reporting guidelines have not been described since implementation of the Reassessment Campaign on Veterinary Resuscitation (RECOVER) CPR clinical guidelines in 2012. The aims of this study were to assess factors associated with positive CPR outcomes at a U.S. veterinary teaching hospital, to re-evaluate these factors since implementation of the RECOVER guidelines compared to reported factors prior to their publication, and to identify potential additional factors since guideline publication. One-hundred and seventy-two dogs and 47 cats that experienced cardiopulmonary arrest (CPA) and had CPR performed were prospectively included in this observational study. Supervising clinicians were asked to complete a data form on CPR events immediately following completion of CPR efforts. Multivariable logistic regression was used to evaluate the effect of twenty hospital, animal, and arrest variables on the three patient outcomes "any return of spontaneous circulation (ROSC)," "sustained ROSC," and survival to hospital discharge. Cats had significantly higher odds to achieve any ROSC [OR (95%CI) 2.72 (1.12-6.61), p = 0.028] and survive to hospital discharge than dogs [OR (95%CI) 4.87 (1.52-15.58), p = 0.008]. Patients had significantly lower odds of achieving any ROSC if CPA occurred during nighttime hours [OR (95%CI) nighttime = 0.52 (0.27-0.98), p = 0.043], and higher odds if CPA was witnessed [OR (95%CI) 3.45 (1.57-7.55), p = 0.002], if less people were involved in CPR efforts [OR (95%CI) 0.8 (0.66-0.96), p = 0.016], if pulses were palpable during CPR [OR (95%CI) 9.27 (4.16-20.63), p < 0.0005], and if an IV catheter was already in place at the time of CPA [OR (95%CI) 5.07 (2.12-12.07), p = 0.0003]. Odds for survival to hospital discharge were significantly higher if less people were involved in CPR efforts [OR (95%CI) 0.65 (0.46-0.91), p = 0.013] and for patients of the anesthesia service [OR (95%CI) 14.82 (3.91-56.17), p = 0.00007]. Overall, factors associated with improved CPR outcomes have remained similar since incorporation of RECOVER guidelines into daily practice. Witnessed CPA events and high-quality CPR interventions were associated with positive patient outcomes, emphasizing the importance of timely recognition and initiation of CPR efforts. An optimal CPR team size has yet to be determined
Creep fatigue of low-cobalt superalloys: Waspalloy, PM U 700 and wrought U 700
The influence of cobalt content on the high temperature creep fatigue crack initiation resistance of three primary alloys was evaluated. These were Waspalloy, Powder U 700, and Cast U 700, with cobalt contents ranging from 0 up to 17 percent. Waspalloy was studied at 538 C whereas the U 700 was studied at 760 C. Constraints of the program required investigation at a single strain range using diametral strain control. The approach was phenomenological, using standard low cycle fatigue tests involving continuous cycling tension hold cycling, compression hold cycling, and symmetric hold cycling. Cycling in the absence of or between holds was done at 0.5 Hz, whereas holds when introduced lasted 1 minute. The plan was to allocate two specimens to the continuous cycling, and one specimen to each of the hold time conditions. Data was taken to document the nature of the cracking process, the deformation response, and the resistance to cyclic loading to the formation of small cracks and to specimen separation. The influence of cobalt content on creep fatigue resistance was not judged to be very significant based on the results generated. Specific conclusions were that the hold time history dependence of the resistance is as significant as the influence of cobalt content and increased cobalt content does not produce increased creep fatigue resistance on a one to one basis
Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred Racehorse
Abstract
Objectives: The exact aetiopathogenesis of microdamage induced long bone fractures remains unknown. These fractures are likely the result of inadequate bone remodeling in response to damage. This study aims to identifiesy an association of osteocyte apoptosis, the presence of osteocytic osteolysis and any alterations in sclerostin expression with fracture of the third metacarpal bone of (Mc-III) thoroughbred (TB) racehorses.
Methods: 30 Mc-III bones were obtained; 10 from bones fractured during racing, 10 from the contralateral limb and 10 from control horses. Each Mc- III bone was divided into fracture site, condyle, condylar groove and sagittal ridge. Microcracks and diffuse microdamage were quantified. Apoptotic osteocytes were measured using TUNEL staining. Cathepsin K, matrix metalloproteinase -13 (MMP-13), HtrA1 and sclerostin expression was analysed.
of apoptotic cells between contralateral limb and unraced control, however, there were significantly less apoptotic cells in fractured samples (p<0.02). Immunohistochemistry showed that in the deep zones of the fractured samples sclerostin expression was significantly higher (p<0.03) of the total number of osteocytes. No increase in cathepsin K, MMP-13 or HtrA1 was present
Spin-Dependent Quantum Emission in Hexagonal Boron Nitride at Room Temperature
Optically addressable spins associated with defects in wide-bandgap
semiconductors are versatile platforms for quantum information processing and
nanoscale sensing, where spin-dependent inter-system crossing (ISC) transitions
facilitate optical spin initialization and readout. Recently, the van der Waals
material hexagonal boron nitride (h-BN) has emerged as a robust host for
quantum emitters (QEs), but spin-related effects have yet to be observed. Here,
we report room-temperature observations of strongly anisotropic
photoluminescence (PL) patterns as a function of applied magnetic field for
select QEs in h-BN. Field-dependent variations in the steady-state PL and
photon emission statistics are consistent with an electronic model featuring a
spin-dependent ISC between triplet and singlet manifolds, indicating that
optically-addressable spin defects are present in h-BN a versatile
two-dimensional material promising efficient photon extraction, atom-scale
engineering, and the realization of spin-based quantum technologies using van
der Waals heterostructures.Comment: 38 pages, 34 figure
Phase Change Material (PCM) thermal stores
The application of inorganic Phase Change Material thermal stores in sustainable building design in Europe – an on-going research project
On the Gold Standard for Security of Universal Steganography
While symmetric-key steganography is quite well understood both in the
information-theoretic and in the computational setting, many fundamental
questions about its public-key counterpart resist persistent attempts to solve
them. The computational model for public-key steganography was proposed by von
Ahn and Hopper in EUROCRYPT 2004. At TCC 2005, Backes and Cachin gave the first
universal public-key stegosystem - i.e. one that works on all channels -
achieving security against replayable chosen-covertext attacks (SS-RCCA) and
asked whether security against non-replayable chosen-covertext attacks (SS-CCA)
is achievable. Later, Hopper (ICALP 2005) provided such a stegosystem for every
efficiently sampleable channel, but did not achieve universality. He posed the
question whether universality and SS-CCA-security can be achieved
simultaneously. No progress on this question has been achieved since more than
a decade. In our work we solve Hopper's problem in a somehow complete manner:
As our main positive result we design an SS-CCA-secure stegosystem that works
for every memoryless channel. On the other hand, we prove that this result is
the best possible in the context of universal steganography. We provide a
family of 0-memoryless channels - where the already sent documents have only
marginal influence on the current distribution - and prove that no
SS-CCA-secure steganography for this family exists in the standard
non-look-ahead model.Comment: EUROCRYPT 2018, llncs styl
Extremely asymmetrical scattering in gratings with varying mean structural parameters
Extremely asymmetrical scattering (EAS) is an unusual type of Bragg
scattering in slanted periodic gratings with the scattered wave (the +1
diffracted order) propagating parallel to the grating boundaries. Here, a
unique and strong sensitivity of EAS to small stepwise variations of mean
structural parameters at the grating boundaries is predicted theoretically (by
means of approximate and rigorous analyses) for bulk TE electromagnetic waves
and slab optical modes of arbitrary polarization in holographic (for bulk
waves) and corrugation (for slab modes) gratings. The predicted effects are
explained using one of the main physical reasons for EAS--the diffractional
divergence of the scattered wave (similar to divergence of a laser beam). The
approximate method of analysis is based on this understanding of the role of
the divergence of the scattered wave, while the rigorous analysis uses the
enhanced T-matrix algorithm. The effect of small and large stepwise variations
of the mean permittivity at the grating boundaries is analysed. Two distinctly
different and unusual patterns of EAS are predicted in the cases of wide and
narrow (compared to a critical width) gratings. Comparison between the
approximate and rigorous theories is carried out.Comment: 16 pages, 5 figure
- …