Thermal evaluation by infrared measurement of implant site preparation between single and gradual drilling in artificial bone blocks of different densities.

The aim of this study was to investigate the influence of bone density and drilling protocol on heat generation during implant bed preparation. Ten single and 10 gradual implant sites with diameters of 2.8, 3.

Influence of bone density and implant drill diameter on the resulting axial force and temperature development in implant burs and artificial bone: an in vitro study.

Purpose: The aim of this study was to determine how the bone density affects the temperature development in artificial bone and drill.

Methods: Ten single drills with diameters of 2.2, 2.

The dynamic role of cardiac myosin binding protein-C during ischemia.

Cardiac myosin binding protein C (cMyBP-C) is a myofibrillar protein important for normal myocardial contractility and stability. In mutated form it can cause cardiomyopathy and heart failure. cMyBP-C appears to have separate regions for different functions.

Refractive index variation in compression molding of precision glass optical components.

Compression molding of glass optical components is a high volume near net-shape precision fabrication method. In a compression molding process, a variation of the refractive index occurs along the radial direction of the glass component due to thermal treatment. The variation of refractive index is an important parameter that can affect the performance of optical lenses, especially lenses used for high precision optical systems.

Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study.

Objectives: Ejection fraction (EF) and end-systolic volume index (ESVI) are established predictors of outcomes following ST-segment elevation myocardial infarction (STEMI). We sought to assess the relative impact of infarct size, EF and ESVI on clinical outcomes and left ventricular (LV) remodelling.

Design: Prospective cohort study.

Angiographic estimates of myocardium at risk during acute myocardial infarction: validation study using cardiac magnetic resonance imaging.

Aims: Global angiographic scores have been developed to determine the extent of myocardium jeopardized by significant coronary stenosis. We adapted these scores to quantify the anatomic area at risk during acute myocardial infarction. We used contrast-enhanced magnetic resonance (CMR) infarct imaging to measure the portion of myocardium that developed necrosis within the so defined angiographic area at risk.

Development of a compression molding process for three-dimensional tailored free-form glass optics.

Because of the limitation of manufacturing capability, free-form glass optics cannot be produced in a large volume using traditional processes such as grinding, lapping, and polishing. Very recently compression molding of glass optics became a viable manufacturing process for the high-volume production of precision glass optical components. An ultraprecision diamond-turning machine retrofitted with a fast tool servo was used to fabricate a free-form optical mold on a nickel-plated surface.

Magnetic resonance approaches and recent advances in myocardial perfusion imaging.

Myocardial perfusion imaging identifies the presence of coronary artery stenoses and defines the functional significance of those lesions. Single photon emission computed tomography and positron emission tomography have established roles. Cardiac magnetic resonance is evolving as a promising new modality in the evaluation of myocardial perfusion.

Diagnostic and clinical perspectives of fusion imaging in cardiology: is the total greater than the sum of its parts?

Positron emission tomography, cardiovascular magnetic resonance and multislice computed tomography have contributed to changing our pathophysiological understanding of many conditions. Clinically, they have provided new tools for the identification of preclinical disease and a better understanding of how disease progresses. The application of these imaging modalities to preclinical disease and the use of these techniques in patients with overt cardiovascular disease are reviewed.

Myosin-binding protein C phosphorylation, myofibril structure, and contractile function during low-flow ischemia.

Background: Contractile dysfunction develops in the chronically instrumented canine myocardium after bouts of low-flow ischemia and persists after reperfusion. The objective of this study is to identify whether changes in the phosphorylation state of myosin-binding protein C (MyBP-C) are a potential cause of dysfunction.

Methods And Results: During low-flow ischemia, MyBP-C is dephosphorylated, and the number of actomyosin cross-bridges in the central core of the sarcomere decreases as thick filaments dissemble from the periphery of the myofibril.

Cardiac magnetic resonance imaging: what can it add clinically in 2004?

Although a number of applications of cardiac magnetic resonance imaging are receiving increasing attention, situations in which cardiac magnetic resonance imaging can provide clinically useful information that is not available via other imaging techniques are of particular interest. It is now appreciated that cardiac magnetic resonance imaging can provide consistently excellent assessments of ventricular function when other techniques are not optimum. This article addresses an additional recently developed capacity for direct, high-resolution imaging of infarcted myocardium.

Magnetic resonance versus radionuclide pharmacological stress perfusion imaging for flow-limiting stenoses of varying severity.

Background: Although magnetic resonance first-pass imaging (MRFP) has potential advantages in pharmacological stress perfusion imaging, direct comparisons of current MRFP and established radionuclide techniques are not available.

Methods And Results: Graded regional differences in coronary flow were produced during global coronary vasodilation in chronically instrumented dogs by partially occluding the left circumflex artery. Regional differences in full-thickness flow quantified using microspheres were compared with regional differences obtained with MRFP and radionuclide SPECT imaging (99mTc-sestamibi and 201Tl).

Infarct resorption, compensatory hypertrophy, and differing patterns of ventricular remodeling following myocardial infarctions of varying size.

Objectives: We sought to identify advantages of contrast-enhanced magnetic resonance imaging (MRI) in studying postinfarction ventricular remodeling.

Background: Although sequential measurements of ventricular volumes, internal dimensions, and total ventricular mass have provided important insights into postinfarction left ventricular remodeling, it has not been possible to define serial, directionally opposite changes in resorption of infarcted tissue and hypertrophy of viable myocardium and effects of these changes on commonly used indices of remodeling.

Methods: Using gadolinium-enhanced MRI, the time course and geometry of changes in infarcted and noninfarcted regions were assessed serially in dogs subjected to coronary occlusion for 45 min, 90 min, or permanently.

Gadolinium cardiovascular magnetic resonance predicts reversible myocardial dysfunction and remodeling in patients with heart failure undergoing beta-blocker therapy.

Background: In some patients with heart failure, beta-blockers can improve left ventricular (LV) function and reduce morbidity and mortality. We hypothesized that gadolinium-enhanced cardiovascular magnetic resonance imaging (CMR) can predict reversible myocardial dysfunction and remodeling in heart failure patients treated with beta-blockers.

Methods And Results: Forty-five patients with chronic heart failure underwent CMR.