Compact setup for standoff laser induced breakdown spectroscopy of radioactive material

Radioactive materials present a major threat and can cause severe direct and long term injuries to humans as experienced i.e. in the Fukushima and Chernobyl nuclear plant catastrophes. Furthermore, intended use of radiological dispersal devices may spread radioactive materials over large areas. Detecting these hazards and investigating the status of contaminated areas a remote standoff determination of nuclear fission products would serve as a helpful tool for first responders and damage control teams. Laser induced breakdown spectroscopy (LIBS) offers a unique possibility for the identification of nuclear fission products and can be able to distinguish different isotopes of the same species. Within this scope and based on experiences with a high power / long distance (> 100 m) LIBS setup a compact and low power setup is presented. The compactness allows for handheld operation as well as mounted on a small robot or on an unmanned aerial vehicle (UAV) an advanced setup could be controlled remotely and would be able to safely determine radioactive materials

Rotationplasty in the Elderly

Purpose. Rotationplasty has proven its efficacy in the treatment of malignant bone tumors of the lower extremity in predominantly young patients. To our knowledge this procedure has not been reported in patients over 60 years before. Materials and Methods. 3 patients over 60 years with an A1-rotationplasty because of a sarcoma were included in this study. Complications and functional results were recorded. In one patient an electromyography was done. Results. Despite electromyography showing good adaptation of the muscles to the altered function, the functional results of these three patients were limited. two out of three patients needed a cane for walking distances over 200 meters. No secondary amputation was necessary. Discussion. Our study demonstrates that rotationplasty is an alternative to an above-knee amputation in older patients but with poorer functional results in comparison to younger patients. However, limb-salvage surgery should be preferred whenever possible

The Influence of Elementary Silver Versus Titanium on Osteoblasts Behaviour In Vitro Using Human Osteosarcoma Cell Lines

Purpose. The antimicrobial effect of a silver-coated tumor endoprosthesis has been proven in clinical and experimental trials. However, in the literature there are no reports concerning the effect of elementary silver on osteoblast behaviour. Therefore, the prosthetic stem was not silver-coated because of concerns regarding a possible inhibition of the osseointegration. The aim of the present study was to investigate the effect of 5–25 mg of elementary silver in comparison to Ti-6Al-4V on human osteosarcoma cell lines (HOS-58, SAOS). Methods. Cell viability was determined by measuring the MTT proliferation rate. Cell function was studied by measuring alkaline phosphatase (AP) activity and osteocalcine production. Results. In the HOS-58 cells, the AP activity was statistically significant (P < 0.05) higher at a supplement of 5–10 mg of silver than of Ti-6 Al-4V at the same doses. For both cell lines, a supplement above 10 mg of silver resulted in a reduced AP activity in comparision to the Ti-6 Al-4V group, but a statistically significant difference (P < 0.05) was observed at a dose of 25 mg for the SAOS cells only. At doses of 20–25 mg in the HOS-58 cells and 10–25 mg in the SAOS cells, the reduction of the proliferation rate by silver was statistically significant (P < 0.05) compared to the Ti-6 Al-4V supplement. Discussion. In conclusion, elementary silver exhibits no cytotoxicity at low concentrations. In contrast, it seems to be superior to Ti-6 Al-4V concerning the stimulation of osteogenic maturation at these concentrations, whereas at higher doses it causes the known cytotoxic properties

Compact setup for standoff Laser induced breakdown spectroscopy of radioactive materials

Radioactive materials present a major threat and can cause severe direct and long term injuries to humans as experienced i.e. in the Fukushima and Chernobyl nuclear plant catastrophes. Furthermore, intended use of radiological dispersal devices can be used to spread radioactive materials over large areas. Detecting these hazards and investigating the status of contaminated areas a remote standoff determination of nuclear fission products would serve as a helpful tool for first responders and damage control teams. Laser induced breakdown spectroscopy (LIBS) offers a unique possibility for the identification of elements as nuclear fission products and is even able to distinguish different isotopes of the same species. Within this scope and based on experiences with a high power / long distance (> 100 m) LIBS setup we present a new compact and low power setup. The compactness allows for handheld operation as well as mounted on a small robot or on an unmanned aerial vehicle (UAV) an advanced setup could be controlled remotely and would be able to safely determine radioactive materials

Morphologic characterization of osteosarcoma growth on the chick chorioallantoic membrane

<p>Abstract</p> <p>Background</p> <p>The chick chorio-allantoic membrane (CAM) assay is a commonly used method for studying angiogenic or anti-angiogenic activities <it>in vivo</it>. The ease of access allows direct monitoring of tumour growth by biomicroscopy and the possibility to screen many samples in an inexpensive way. The CAM model provides a powerful tool to study effects of molecules, which interfere with physiological angiogenesis, or experimental tumours derived from cancer cell lines. We therefore screened eight osteosarcoma cell lines for their ability to form vascularized tumours on the CAM.</p> <p>Findings</p> <p>We implanted 3-5 million cells of human osteosarcoma lines (HOS, MG63, MNNG-HOS, OST, SAOS, SJSA1, U2OS, ZK58) on the CAM at day 10 of embryonic development. Tumour growth was monitored by <it>in vivo </it>biomicroscopy at different time points and tumours were fixed in paraformaldehyde seven days after cell grafting. The tissue was observed, photographed and selected cases were further analyzed using standard histology.</p> <p>From the eight cell lines the MNNG-HOS, U2OS and SAOS were able to form solid tumours when grafted on the CAM. The MNNG-HOS tumours showed the most reliable and consistent growth and were able to penetrate the chorionic epithelium, grow in the CAM stroma and induce a strong angiogenic response.</p> <p>Conclusions</p> <p>Our results show that the CAM assay is a useful tool for studying osteosarcoma growth. The model provides an excellent alternative to current rodent models and could serve as a preclinical screening assay for anticancer molecules. It might increase the speed and efficacy of the development of new drugs for the treatment of osteosarcoma.</p

Comparison of Classification Methods for Spectral Data of Laser-induced Fluorescence

Online detection of CBRNE is a research field of growing importance due to its relevance for public security and defense. The selectivity of machine learning has reached maturity in order to distinguish very similar laser-induced fluorescence (LIF) spectra of different samples - establishing the basis for an automatic classification. The work in this contribution applies the classification process of decision trees, support vector machines and artificial neural networks to LIF spectra. Two experimental setups with two excitation wavelengths each (280 and 355 nm; 266 and 355 nm) and different spectral resolutions of about 1 nm and 12 nm, respectively, have been performed. In the first setup the discrimination of seven bacteria species with an accuracy of over 90 % is demonstrated. The data of the second setup with lower spectral resolution are equally sufficient for a subsequent classification. The results are compared and represented in a low-dimensional subspace for the purpose of visualization

Standoff detection and classification of bacteria by multispectral laser-induced fluorescence

Biological hazardous substances such as certain fungi and bacteria represent a high risk for the broad public if fallen into wrong hands. Incidents based on bio-agents are commonly considered to have unpredictable and complex consequences for first responders and people. The impact of such an event can be minimized by an early and fast detection of hazards. The presented approach is based on optical standoff detection applying laser-induced fluorescence (LIF) on bacteria. The LIF bio-detector has been designed for outdoor operation at standoff distances from 20 m up to more than 100 m. The detector acquires LIF spectral data for two different excitation wavelengths (280 and 355 nm) which can be used to classify suspicious samples. A correlation analysis and spectral classification by a decision tree is used to discriminate between the measured samples. In order to demonstrate the capabilities of the system, suspensions of the low-risk and non-pathogenic bacteria Bacillus thuringiensis, Bacillus atrophaeus, Bacillus subtilis, Brevibacillus brevis, Micrococcus luteus, Oligella urethralis, Paenibacillus polymyxa and Escherichia coli (K12) have been investigated with the system, resulting in a discrimination accuracy of about 90%

Novel standoff detection system for the classification of chemical and biological hazardous substances combining temporal and spectral laser induced fluorescence techniques

In the effort to reduce the potential risk of human exposure to chemical and biological hazardous material, the demand increases for a detection system which rapidly identifies possible threats from a distance to avoid direct human contact to these materials. In this scope, we present a novel detection system which is able to simultaneously measure spectrally and temporally resolved laser induced fluorescence signals excited by two consecutive laser pulses with differ-ent central wavelengths at 266 nm and 355 nm. The setup enables fast data acqui-sition that provides a complete dataset in less than a few milliseconds at repetition rates of 100 Hz. Furthermore, with its modular design it can be transported easily for operation at different locations. First measurements indicate a high perfor-mance and a good distinguishability of bacterial specimen within a limited set of three representative bacterial species. Together with the consecutive classification procedure, the setup promises to become a valuable tool for standoff detection of bio-hazards

Online discrimination of chemical substances using standoff laser induced fluorescence signals

This article explains the data acquisition and classification procedure for laser induced fluorescence spectra of twenty chemical agents using laser pulses of two UV wavelengths. Three classification algorithms are trained which can distinguish the samples by their single spectra with an accuracy of over 95 %