6 research outputs found
How can the company Eurekadoc Publishing expand beyond publishing books to better fulfil the career development needs of medical professionals?
No full textImperial Users onl
Electromagnetic ice absorption rate at Dome C, Antarctica
No full textRadio-echo sounding (RES) is a radar technique widely employed in Antarctica and
Greenland to define bedrock topography but, over the last decade, it has also played an important role
in subglacial lake exploration and hydrogeological studies at the bedrock/ice interface. In recent
studies, bedrock characterization has been improved through analysis of radar power echoes to evaluate
the electromagnetic (EM) properties of the interface and allow the distinction between wet and dry
interfaces. The RES received signal power depends on ice absorption and bedrock reflectivity, which is
closely linked to the specific physical condition of the bedrock. In this paper, an evaluation of EM ice
absorption was conducted starting from RES measurements collected over subglacial lakes in
Antarctica. The idea was to calculate ice absorption starting from the radar equation in the case of
subglacial lakes, where the EM reflectivity value is considered a known constant. These values were
compared with those obtained from analysis of ice-core dielectric profiles from EPICA ice-core drilling
data. Our analysis reveals that the ice absorption rate calculated from RES measurements has an average
value of 7.2 dBkm–1, and it appears constant, independent of the subglacial lake depth in different zones
of the Dome C area.Published849-8547A. Geofisica di esplorazioneJCR Journalrestricte
A Virtual Reality System to Train Image Guided Placement of Kirschner-Wires for Distal Radius Fractures
No full textFemoral fracture type can be predicted from femoral structure: a finite element study validated by digital volume correlation experiments
No full textProximal femoral fractures can be categorized into two main types: Neck and intertrochanteric fractures accounting for 53% and 43% of all proximal femoral fractures, respectively. The possibility to predict the type of fracture a specific patient is predisposed to would allow drug and exercise therapies, hip protector design, and prophylactic surgery to be better targeted for this patient rendering fracture preventing strategies more effective. This study hypothesized that the type of fracture is closely related to the patient-specific femoral structure and predictable by finite element (FE) methods. Fourteen femora were DXA scanned, CT scanned, and mechanically tested to fracture. FE-predicted fracture patterns were compared to experimentally observed fracture patterns. Measurements of strain patterns to explain neck and intertrochanteric fracture patterns were performed using a digital volume correlation (DVC) technique and compared to FE-predicted strains and experimentally observed fracture patterns. Although loaded identically, the femora exhibited different fracture types (six neck and eight intertrochanteric fractures). CT-based FE models matched the experimental observations well (86%) demonstrating that the fracture type can be predicted. DVC-measured and FE-predicted strains showed obvious consistency. Neither DXA-based BMD nor any morphologic characteristics such as neck diameter, femoral neck length, or neck shaft angle were associated with fracture type. In conclusion, patient-specific femoral structure correlates with fracture type and FE analyses were able to predict these fracture types. Also, the demonstration of FE and DVC as metrics of the strains in bones may be of substantial clinical value, informing treatment strategies and device selection and design
