Initial results of in vivo non-invasive cancer imaging in the human breast using near-infrared photoacoustics

Near-infrared photoacoustic images of regions-of-interest in 4 of the 5 cases of patients with symptomatic breasts reveal higher intensity regions which we attribute to vascular distribution associated with cancer. Of the 2 cases presented here, one is especially significant where benign indicators dominate in conventional radiological images, while photoacoustic images reveal vascular features suggestive of malignancy, which is corroborated by histopathology. The results show that photoacoustic imaging may have potential in visualizing certain breast cancers based on intrinsic optical absorption contrast. A future role for the approach could be in supplementing conventional breast imaging to assist detection and/or diagnosis.\ud \u

Rolling/Slipping Motion of Euler's Disk

We present an experimental study of the motion of a circular disk spun onto a table. With the help of a high speed video system, the temporal evolutions of (i) the inclination angle $\alpha$, (ii) the angular velocity $\omega$ and (iii) the precession rate $\Omega$ are studied. The influence of the mass of the disk and the friction between the disk and the supporting surface are considered. %The motions of disks with different masses and over different surfaces are studied. The inclination angle $\alpha$ and the angular velocity are observed to decrease according to a power law. We also show that the precession rate $\Omega$ diverges as the disk stops. Exponents are measured very near the collapse as well as on long range times. Collapsing times have been also measured. The results are compared with previous theoretical and experimental works. The major source of energy dissipation is found to be the slipping of the disk on the plane.Comment: Submitted for publication (2003) - 6page

Increased mortality in schizophrenia due to cardiovascular disease - a non-systematic review of epidemiology, possible causes and interventions

Background: Schizophrenia is among the major causes of disability worldwide and the mortality from cardiovascular disease (CVD) is significantly elevated. There is a growing concern that this health challenge is not fully understood and efficiently addressed. Methods: Non-systematic review using searches in PubMed on relevant topics as well as selection of references based on the authors’ experience from clinical work and research in the field. Results: In most countries, the standardized mortality rate in schizophrenia is about 2.5, leading to a reduction in life expectancy between 15 and 20 years. A major contributor of the increased mortality is due to CVD, with CVD mortality ranging from 40 to 50% in most studies. Important causal factors are related to lifestyle, including poor diet, lack of physical activity, smoking, and substance abuse. Recent findings suggest that there are overlapping pathophysiology and genetics between schizophrenia and CVD-risk factors, further increasing the liability to CVD in schizophrenia. Many pharmacological agents used for treating psychotic disorders have side effects augmenting CVD risk. Although several CVD-risk factors can be effectively prevented and treated, the provision of somatic health services to people with schizophrenia seems inadequate. Further, there is a sparseness of studies investigating the effects of lifestyle interventions in schizophrenia, and there is little knowledge about effective programs targeting physical health in this population. Discussion: The risk for CVD and CVD-related deaths in people with schizophrenia is increased, but the underlying mechanisms are not fully known. Coordinated interventions in different health care settings could probably reduce the risk. There is an urgent need to develop and implement effective programs to increase life expectancy in schizophrenia, and we argue that mental health workers should be more involved in this important task

CRANKITE: a fast polypeptide backbone conformation sampler

Background: CRANKITE is a suite of programs for simulating backbone conformations of polypeptides and proteins. The core of the suite is an efficient Metropolis Monte Carlo sampler of backbone conformations in continuous three-dimensional space in atomic details. Methods: In contrast to other programs relying on local Metropolis moves in the space of dihedral angles, our sampler utilizes local crankshaft rotations of rigid peptide bonds in Cartesian space. Results: The sampler allows fast simulation and analysis of secondary structure formation and conformational changes for proteins of average length

Theoretical analysis of the role of chromatin interactions in long-range action of enhancers and insulators

Long-distance regulatory interactions between enhancers and their target genes are commonplace in higher eukaryotes. Interposed boundaries or insulators are able to block these long distance regulatory interactions. The mechanistic basis for insulator activity and how it relates to enhancer action-at-a-distance remains unclear. Here we explore the idea that topological loops could simultaneously account for regulatory interactions of distal enhancers and the insulating activity of boundary elements. We show that while loop formation is not in itself sufficient to explain action at a distance, incorporating transient non-specific and moderate attractive interactions between the chromatin fibers strongly enhances long-distance regulatory interactions and is sufficient to generate a euchromatin-like state. Under these same conditions, the subdivision of the loop into two topologically independent loops by insulators inhibits inter-domain interactions. The underlying cause of this effect is a suppression of crossings in the contact map at intermediate distances. Thus our model simultaneously accounts for regulatory interactions at a distance and the insulator activity of boundary elements. This unified model of the regulatory roles of chromatin loops makes several testable predictions that could be confronted with \emph{in vitro} experiments, as well as genomic chromatin conformation capture and fluorescent microscopic approaches.Comment: 10 pages, originally submitted to an (undisclosed) journal in May 201

A proximal femoral implant preserves physiological bone deformation: a biomechanical investigation in cadaveric bones

The aim of this study was to compare the perturbances in bone deformation patterns of the proximal femur due to a conventional cemented femoral stem and a novel uncemented implant designed on the principles of osseointegration. Five matched pairs of fresh frozen human femora were mechanically tested. Bone deformation patterns, measured with a video digitizing system under 1.5 kN joint force, showed that the cemented Spectron femoral implant caused significant alterations to the proximal femoral deformation pattern, whereas the Gothenburg osseointegrated titanium femoral implant did not significantly alter the bone behaviour (p < 0.05). Vertical micromotions measured under 1 kN after 1000 cycles were within the threshold of movement tolerable for bone ingrowth (21 microm for the Gothenburg system and 26 microm for the cemented implant).Published versio