Response of portable gamma monitors for dose rate measurements under various radiation conditions

Journal of Radioanalytical and Nuclear Chemistry - Responses of the hand-held gamma monitors available for the ambient dose equivalent rate measurements in the Federation of Bosnia and Herzegovina...     

Synthesis and Rearrangement of P‐Nitroxyl‐Substituted PIII and PV Phosphanes: A Combined Experimental and Theoretical Case Study

Low‐temperature generation of P‐nitroxyl phosphane 2 (Ph₂POTEMP), which was obtained by the reaction of Ph₂PH ( 1 ) with two equivalents of TEMPO, is presented. Upon warming, phosphane 2 decomposed to give P‐nitroxyl phosphane P‐oxide 3 (Ph₂P(O)OTEMP) as one of the final products. This facile synthetic protocol also enabled access to P‐sulfide and P‐borane derivatives 7 and 13 , respectively, by using Ph₂P(S)H ( 6 ) or Ph₂P(BH₃)H ( 11 ) and TEMPO. Phosphane sulfide 7 revealed a rearrangement to phosphane oxide 8 (Ph₂P(O)STEMP) in CDCl₃ at ambient temperature, whereas in THF, thermal decomposition of sulfide 7 yielded salt 10 ([TEMP‐H₂][Ph₂P(S)O]). As well as EPR and detailed NMR kinetic studies, indepth theoretical studies provided an insight into the reaction pathways and spin‐density distributions of the reactive intermediates.     

Measurement of natural environmental radioactivity and estimation of population exposure in Bihac,Bosnia and Herzegovina

Journal of Radioanalytical and Nuclear Chemistry - This work presents measurements of activity concentrations and estimation of population exposure from the naturally occurring radionuclides 238U,...     

Implementation of a novel low‐noise InGaAs detector enabling rapid near‐infrared multichannel Raman spectroscopy of pigmented biological samples

Pigmented tissues are inaccessible to Raman spectroscopy using visible laser light because of the high level of laser‐induced tissue fluorescence. The fluorescence contribution to the acquired Raman signal can be reduced by using an excitation wavelength in the near infrared range around 1000 nm. This will shift the Raman spectrum above 1100 nm, which is the principal upper detection limit for silicon‐based CCD detectors. For wavelengths above 1100 nm indium gallium arsenide detectors can be used. However, InGaAs detectors have not yet demonstrated satisfactory noise level characteristics for demanding Raman applications. We have tested and implemented for the first time a novel sensitive InGaAs imaging camera with extremely low readout noise for multichannel Raman spectroscopy in the short‐wave infrared (SWIR) region. The effective readout noise of two electrons is comparable to that of high quality CCDs and two orders of magnitude lower than that of other commercially available InGaAs detector arrays. With an in‐house built Raman system we demonstrate detection of shot‐noise limited high quality Raman spectra of pigmented samples in the high wavenumber region, whereas a more traditional excitation laser wavelength (671 nm) could not generate a useful Raman signal because of high fluorescence. Our Raman instrument makes it possible to substantially decrease fluorescence background and to obtain high quality Raman spectra from pigmented biological samples in integration times well below 20 s. Copyright © 2015 John Wiley & Sons, Ltd.     

Fluorescence-based Western blotting for quantitation of protein biomarkers in clinical samples

Since most high throughput techniques used in biomarker discovery are very time and cost intensive, highly specific and quantitative analytical alternative application methods are needed for the routine analysis. Conventional Western blotting allows detection of specific proteins to the level of single isotypes while its quantitative accuracy is rather limited. We report a novel and improved quantitative Western blotting method. The use of fluorescently labelled secondary antibodies strongly extends the dynamic range of the quantitation and improves the correlation with the protein amount (r=0.997). By an additional fluorescent staining of all proteins immediately after their transfer to the blot membrane, it is possible to visualise simultaneously the antibody binding and the total protein profile. This allows for an accurate correction for protein load. Applying this normalisation it could be demonstrated that fluorescence-based Western blotting is able to reproduce a quantitative analysis of two specific proteins in blood platelet samples from 44 subjects with different diseases as initially conducted by 2D-DIGE. These results show that the proposed fluorescence-based Western blotting is an adequate application technique for biomarker quantitation and suggest possibilities of employment that go far beyond.     

Assessment of the indoor-to-outdoor ratio of dose rates in and around the historic objects in Bosnia and Herzegovina

Journal of Radioanalytical and Nuclear Chemistry - This paper deals with the first study of the indoor to outdoor ambient dose equivalent rates ratio measured in and around the historic objects at...     

Method development: Raman spectroscopy‐based histopathology of oral mucosa

An earlier and more accurate detection of (small) cancerous and precancerous lesions in the oral cavity is essential to improve the prognosis of oral squamous cell carcinomas. Raman spectroscopy is being pursued as a potential method to realize this improvement, since the technique provides objective information on a biochemical level and can be used for real‐time guidance of the diagnostic procedure. Since oral mucosal tissue is inhomogeneous and comprises different layers and histological structures, a good understanding of the signal contributions of the individual layers and structures is required for an accurate interpretation of in vivo tissue spectra measurement volumes. The aim of this study was to create a standardized method to collect and analyse the spectral contributions of individual histopathological structures in oral mucosa. The method is based on Raman microspectroscopic mapping of unstained frozen tissue sections and subsequent histopathological annotation of the features in the resulting Raman images. The obtained annotated reference spectra were used as input in an unsupervised hierarchical cluster analysis in order to determine the spectral characteristics and variance within one histo(patho)logical structure. The described method resulted in an annotated database of Raman spectral characteristics of individual histopathological structures encountered in oral tissue. This database can be used as input for the development of classification and quantification algorithms, in order to achieve a high specificity and sensitivity for clinical diagnostic instruments. Additionally, this database can be used to optimize the exact location and measurement volume of in vivo measurements. Copyright © 2013 John Wiley & Sons, Ltd.