Patient-specific 3D printed model of biliary ducts with congenital cyst

Background: 3D printing has shown great promise in medical applications, with increasing reports in liver diseases. However, research on 3D printing in biliary disease is limited with lack of studies on validation of model accuracy. In this study, we presented our experience of creating a realistic 3D printed model of biliary ducts with congenital cyst. Measurements of anatomical landmarks were compared at different stages of model generation to determine dimensional accuracy. Methods: Contrast-enhanced computed tomography (CT) images of a patient diagnosed with congenital cyst in the common bile duct with dilated hepatic ducts were used to create the 3D printed model. The 3D printed model was scanned on a 64-slice CT scanner using the similar abdominal CT protocol. Measurements of anatomical structures including common hepatic duct (CHD), right hepatic duct (RHD), left hepatic duct (LHD) and the cyst at left to right and anterior to posterior dimensions were performed and compared between original CT images, the standard tessellation language (STL) image and CT images of the 3D model. Results: The 3D printing model was successfully generated with replication of biliary ducts and cyst. Significant differences in measurements of these landmarks were found between the STL and the original CT images, and the CT images of the 3D printed model and the original CT images (

Observing the temperature dependent transition of the GP2 peptide using terahertz spectroscopy

The GP2 peptide is derived from the Human Epidermal growth factor Receptor 2 (HER2/nue), a marker protein for breast cancer present in saliva. In this paper we study the temperature dependent behavior of hydrated GP2 at terahertz frequencies and find that the peptide undergoes a dynamic transition between 200 and 220 K. By fitting suitable molecular models to the frequency response we determine the molecular processes involved above and below the transition temperature (TD). In particular, we show that below TD the dynamic transition is dominated by a simple harmonic vibration with a slow and temperature dependent relaxation time constant and that above TD, the dynamic behavior is governed by two oscillators, one of which has a fast and temperature independent relaxation time constant and the other of which is a heavily damped oscillator with a slow and temperature dependent time constant. Furthermore a red shifting of the characteristic frequency of the damped oscillator was observed, confirming the presence of a non-harmonic vibration potential. Our measurements and modeling of GP2 highlight the unique capabilities of THz spectroscopy for protein characterization.Yiwen Sun, Zexuan Zhu, Siping Chen, Jega Balakrishnan, Derek Abbott, Anil T. Ahuja and Emma Pickwell-MacPherso

Information empowers but who is empowered?

Communication & MedicineThis article presents part of the findings of a study that examined an information pamphlet written by nurses and given to relatives of patients in a Critical Care Unit (CCU) in an Australian acute care hospital. The pamphlet, Information for Relatives, was analyzed using Systemic Functional Linguistics (SFL) and examines how a relatives' information pamphlet written by nurses constructs the reader-relatives' view of a Critical Care Unit. The results revealed how the language chosen by the nurse-writers of this pamphlet acts to restrict and constrain the reader-relatives while constructing the staff as ethical experts. Furthermore, it questions the notion that all information empowers healthcare clients and demonstrates how this information pamphlet is not value free but has embedded in it social values of the culture from which it emanates. The pamphlet empowers the writers and staff, not the relatives.Jill Kealley, Colleen Smith and Bill Winse

Neutron characterisation of hydroxyapatite bioceramics

This paper reports neutron diffraction data and its analysis that characterise a biocompatible hydroxyapatite composite material. The neutron data has elucidated the crystal structure, and enabled the positions of the hydrogen atoms to be determined. The data also shows the improvement of crystallinity during the heat treatment process. An extension of the work involved looking at a hydroxyapatite - carbon nanotube composite material, and neutron diffraction has shown that the retention of the carbon nanotubes in the composite material has been successful. The nanotubes have had no affect on the hydroxyapatite structure

Development of carbon nanotube-reinforced hydroxyapatite bioceramics

This paper reports development of a production method to create a composite material that is biocompatible, which will have high mechanical strength and resilience, and be able to withstand exposure to the physiological environment. The chemical precipitation conditions necessary for the production of single-phase synthetic hydroxyapatite (HAp) and a HAp and carbon nanotube (CNT)composite material have been optimised. Neutron diffraction patterns collected before and after sintering show that the nanotubes have remained intact within the structure, while most of the remaining soot has burnt off. Small-angle neutron scattering, in conjunction with scanning electron microscopy (SEM), also shows preservation of the CNTs. Hot isostatically pressed samples showed excellent densification. Neutron diffraction data has enabled the positions of the hydroxide bonds to be determined, and shown that the addition of the CNTs has had no effect on the structural parameters of the HAp phase, with the exception of a slight reduction in the unit cell parameter a

Neutron diffraction comparison of bone derived and synthetic hydroxyapatite

This paper reports neutron diffraction data and its analysis of bone derived hydroxyapatite and synthetic hydroxyapatite (HAp). FTIR spectroscopy showed a number of changes in the bone derived hydroxyapatite as a function of temperature, and that firing at 600°C provides an increased crystallinity without decomposition of the HAp. The neutron diffraction data has elucidated the crystal structure of both materials, and enabled the positions of the hydrogen atoms to be accurately determined, and the lattice parameters to be compared. The only noticeable difference was a slight reduction in the lattice parameter a, and an increase in c in the bone derived HAp material. This can be attributed to the residual carbonate phase. The data also shows the improvement of crystallinity of the bovine bone during the heat treatment process

Hydration induced structural changes in native, denatured and protected soy glycinin (11s).

Proteins and other biomolecules undergo a dynamic transition to a glass-like solid state with small atomic fluctuations. This dynamic transition can inhibit biological function and alter their material properties.Institute of Food Technologists; Illinois Department of Agricultur