Citations

Analysis of the induced stress on undoped and boron-doped diamond (BDD) thin films by confocal Raman microscopy is performed in this study to investigate its correlation with sample chemical composition and the substrate used during fabrication. Knowledge of this nature is very important to the issue of long-term stability of BDD coated neurosurgical electrodes that will be used in fast-scan cyclic voltammetry, as potential occurrence of film delaminations and dislocations during their surgical implantation can have unwanted consequences for the reliability of BDD-based biosensing electrodes. To achieve a more uniform deposition of the films on cylindrically-shaped tungsten rods, substrate rotation was employed in a custom-built chemical vapor deposition reactor. In addition to visibly preferential boron incorporation into the diamond lattice and columnar growth, the results also reveal a direct correlation between regions of pure diamond and enhanced stress. Definite stress release throughout entire film thicknesses was found in the current Raman mapping images for higher amounts of boron addition. There is also a possible contribution to the high values of compressive stress from sp2 type carbon impurities, besides that of the expected lattice mismatch between film and substrate.

In patients with aortic stenosis (AS) and eccentric transaortic flow, greater pressure loss occurs as the jet collides with the aortic wall together with delayed and diminished pressure recovery. This leads to the elevated transaortic valve pressure gradients noted on both Doppler and cardiac catheterization. Such situations may present a diagnostic dilemma where traditional measures of stenosis severity indicate severe AS, while imaging modalities of the aortic valve geometric aortic valve area (GOA) suggest less than severe stenosis. In this study, we present a series of cases exemplifying this clinical dilemma and demonstrate how color M‐mode, 2D and 3D transthoracic (TTE) and transesophageal (TEE) echocardiography, cardiac computed tomography angiography (CTA), and magnetic resonance imaging (MRI), may be used to resolve such discrepancies.

ObjectivesThe clinical severity of aortic stenosis (AS) is based largely on symptoms. However, AS severity is primarily determined by estimating the aortic valve area (AVA) and pressure gradients (ΔP). Conditions may arise in which there is a mismatch in severity between AVA and ΔP determinations secondary to errors in measurement and/or assumption, alterations of flow, or variations in the magnitude of pressure recovery. The cause of discrepancy between area and gradient determinations must be deciphered so as to best counsel patients on the most ideal treatment strategy. (J Interven Cardiol 2013;26:183–194)

AbstractAimCurrent recommendations regarding the triage of patients with acute diverticulitis for inpatient or outpatient treatment are vague. We hypothesized that a significant number of patients treated as an inpatient could be managed as an outpatient.MethodA retrospective cohort study was carried out of 639 patients admitted for a first episode of diverticulitis. The diagnosis of acute diverticulitis was confirmed by computed tomography (CT). The endpoints included length of stay, need for surgery, percutaneous drainage and mortality. Patients were considered to have had a minimal hospitalization, defined as survival to discharge without needing a procedure, hospitalization of ≤ 3 days and no readmission for diverticulitis within 30 days after discharge.ResultsOf 639 patients, 368 (57.6%) had a minimal hospitalization. Female gender and CT scan findings of free air/fluid were negatively associated with the likelihood of minimal hospitalization. The presence of an abscess < 3 cm and stranding on CT did not predict the need for a higher level of care. Despite the statistical significance of several patient‐level predictors, the model did not identify patients likely to need only minimal hospitalization.ConclusionMost patients admitted with acute diverticulitis are discharged after minimal hospitalization. Free air/liquid in a patient admitted for acute diverticulitis indicates a more severe clinical course.