Using Fluorescence Spectroscopy to Diagnose Breast Cancer

Optical spectroscopy methods have had considerable impact in the field of biomedical diagnostics, providing novel methods for the early or noninvasive diagnosis of various medical conditions. Among them, fluorescence spectroscopy has been the most widely explored mainly because fluorescence is highly sensitive to the biochemical makeup of tissues. It has been shown that tumors were easily detected on account of altered fluorescence properties with respect to fluorescence of ordinary tissue. Breast cancer is one of the most commonly diagnosed cancers among women in the world and also it is one of the leading causes of deaths from cancer for the female population. However, when detected in early stage, it is one of the most treatable forms of cancer. Therefore, fluorescence technologies could be highly beneficial in early detection and timely treatment of cancer. This chapter presents main results and conclusions that have been reported on the use of fluorescence spectroscopy for the investigation of breast cancer. It also gives an overview on the instruments and methodology of measurements, on the main endogenous fluorophores present in tissues, on the tissue fluorescence, and on the statistical methods that aid interpretations of fluorescence spectra. Finally, examples of using various fluorescence techniques, such as excitation, emission and synchronous spectroscopy, excitation-emission matrices, and lifetimes, for the breast cancer diagnosis are presented

Oxide and silicate nanophosphors: soft chemical synthesis routes and luminescence properties

Besides well-known quantum dots, lanthanide- and 3d metal-doped oxide and silicate nanocrystals form a new promising class of nanophosphors. Research is boosted by opto-electronic applications, such as lasers, displays and optical storage media, and medical diagnostic applications, such as scintillators and biological essays. This entry summarizes several soft chemical approaches for the synthesis of oxide and silicate nanophosphors with special emphases on salted sol-gel and combustion techniques. Structure and morphology of phosphor nanoparticles are highlighted as a basis for discussion of luminescence properties. Luminescence emission and lifetime data for several nanophosphors are presented. It is found that the luminescence properties of nanoparticles differ from corresponding bulk materials in several ways: (i) spectroscopic changes, as a systematic broadening of the luminescence bands, resulting from a structural disorder intrinsic to the small size, and (ii) an alternated luminescence lifetimes, due to due to the change in the refractive index and modification of energy transfers and cross relaxation processe

Optical Biopsy Method for Breast Cancer Diagnosis Based on Artificial Neural Network Classification of Fluorescence Landscape Data

Supervised self-organizing map, a type of artificial neural network, is applied for classification of human breast tissue samples utilizing data obtained from fluorescence landscape measurements. Female breast tissue samples were taken soon after the surgical resection, identified and stored at -80 degrees C until fluorescence measurements. From fluorescence landscapes obtained in UV-VIS region spectral features showing statistically significant differences between malignant and normal samples are identified and further quantified to serve as a training input to neural network. Additional set of samples was used as a test group input to trained network in order to evaluate performance of proposed optical biopsy method. Classification sensitivity of 83.9% and specificity of 88.9% are found

Classification of breast cancer luminescence data using self-organizing mapping neural network

Primenjena je samoorganizujuća neuronska mreža pri analizi podataka luminescencije raka dojke. Ulazni podaci su trodimenzionalni vektori koji predstavljaju normalno i maligno humano tkivo. Analizirana je mogućnost klasifikacije podataka u dve grupe. Mreža je zadovoljavajuće obavila klasifikaciju ulaznih podataka.Self-organizing mapping neural networks are applied in the analysis of breast cancer luminescence data. Data consist of three dimensional vectors presenting normal and malignant human tissue. The possibility of such data classification in two groups (normal and malignant tissue) is analyzed. The network performed successful classification

Classification of breast cancer luminescence data using self-organizing mapping neural network

Primenjena je samoorganizujuća neuronska mreža pri analizi podataka luminescencije raka dojke. Ulazni podaci su trodimenzionalni vektori koji predstavljaju normalno i maligno humano tkivo. Analizirana je mogućnost klasifikacije podataka u dve grupe. Mreža je zadovoljavajuće obavila klasifikaciju ulaznih podataka.Self-organizing mapping neural networks are applied in the analysis of breast cancer luminescence data. Data consist of three dimensional vectors presenting normal and malignant human tissue. The possibility of such data classification in two groups (normal and malignant tissue) is analyzed. The network performed successful classification

Estimation of Absorbed Dose During Process Interruption in Radiation Processing

The quality control system enables the standardization of product quality. Dosimetry has an important role in the quality control of radiation processing. The area of radiation processing which is governed most strictly by regulations is radiation sterilization. This process is used as the example to describe the new method for establishing the effect of process interruption on absorbed dose in the Co-60 irradiation plant at the Vinca Institute of Nuclear Sciences. Establishing the effect of process interruption is one of requirements in international regulations, but there are no recommendations for its implementation. A new method has been worked out by graphical extrapolation. The advantage of this method is the ability to carry it out during the sterilization process. The ethanol-chlorobenzene (ECB) dosimeter is used to select the suitable place where absorbed dose is expected to be the most influenced by source transit, i.e. the most close to the source. In the same time, it should be convenient and reproducible for placing dosimeters. Alanine dosimeters were irradiated on this place in time intervals: 2 min., 4 min., 6 min., 8 min., 10 min. Measurements of time starts when the button to lift source is pressed and stops by pressing the button for process interruption (to sink source down). The absorbed doses were measured by ESR spectrometer. The function of absorbed dose versus irradiation time is linear as expected. The extrapolation back to zero time gives the maximal absorbed dose that can be delivered to product during source transit. In our experiment this absorbed dose obtained by this method is 154 Gy.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Trends in luminescence thermometry

Following astonishing growth in the last decade, the field of luminescence thermometry has reached the stage of becoming a mature technology. To achieve that goal, further developments should resolve inherent problems and methodological faults to facilitate its widespread use. This perspective presents recent findings in luminescence thermometry, with the aim of providing a guide for the reader to the paths in which this field is currently directed. Besides the well-known temperature read-out techniques, which are outlined and compared in terms of performance, some recently introduced read-out methods have been discussed in more detail. These include intensity ratio measurements that exploit emissions from excited lanthanide levels with large energy differences, dual-excited and time-resolved single-band ratiometric methods, and phase-angle temperature readouts. The necessity for the extension of theoretical models and a careful re-examination of those currently in use are emphasized. Regarding materials, the focus of this perspective is on dual-activated probes for the luminescence intensity ratio (LIR) and transition-metal-ion-activated phosphors for both lifetime and LIR thermometry. Several particularly important applications of luminescence thermometry are presented. These include temperature measurement in catalysis, in situ temperature mapping for microfluidics, thermal history measurement, thermometry at extremely high temperatures, fast temperature transient measurement, low-pressure measurement via upconversion nanoparticle emission intensity ratios, evaluation of the photothermal chirality of noble metal clusters, and luminescence thermometry using mobile devices. Routes for the development of primary luminescence thermometry are discussed in view of the recent redefinition of the kelvin

Sensing temperature via downshifting emissions of lanthanide-doped metal oxides and salts. A review

Temperature is important because it has an effect on even the tiniest elements of daily life and is involved in a broad spectrum of human activities. That is why it is the most commonly measured physical quantity. Traditional temperature measurements encounter difficulties when used in some emerging technologies and environments, such as nanotechnology and biomedicine. The problem may be alleviated using optical techniques, one of which is luminescence thermometry. This paper reviews the state of luminescence thermometry and presents different temperature read-out schemes with an emphasis on those utilizing the downshifting emission of lanthanide-doped metal oxides and salts. The read-out schemes for temperature include those based on measurements of spectral characteristics of luminescence (band positions and shapes, emission intensity and ratio of emission intensities), and those based on measurements of the temporal behavior of luminescence (lifetimes and rise times). This review (with 140 references) gives the basics of the fundamental principles and theory that underlie the methods presented, and describes the methodology for the estimation of their performance. The major part of the text is devoted to those lanthanide-doped metal oxides and salts that are used as temperature probes, and to the comparison of their performance and characteristics

Luminescence Thermometry with Nanoparticles: A Review

Luminescence thermometry has emerged as a very versatile optical technique for remote temperature measurements, exhibiting a wide range of applicability spanning from cryogenic temperatures to 2000 K. This technology has found extensive utilization across many disciplines. In the last thirty years, there has been significant growth in the field of luminous thermometry. This growth has been accompanied by the development of temperature read-out procedures, the creation of luminescent materials for very sensitive temperature probes, and advancements in theoretical understanding. This review article primarily centers on luminescent nanoparticles employed in the field of luminescence thermometry. In this paper, we provide a comprehensive survey of the recent literature pertaining to the utilization of lanthanide and transition metal nanophosphors, semiconductor quantum dots, polymer nanoparticles, carbon dots, and nanodiamonds for luminescence thermometry. In addition, we engage in a discussion regarding the benefits and limitations of nanoparticles in comparison with conventional, microsized probes for their application in luminescent thermometry

Influence of activated flux on the penetration depth in non-consumable electrode welding of strainless steel in inert gas shielding

U disertaciji je prikazan odabir rastvarača, veličine, vrste i udela čestica za aktivni premaz namenjen postizanju povećane dubine uvara na austenitnom nerđajućem čeliku pri zavarivanju netopljivom elektrodom u zaštiti inertnog gasa. Pored sastava aktivnog premaza, u disertaciji je izvršena optimizacija: geometrije elektrode, jačine struje i brzine zavarivanja. Nakon odabira perspektivnih tipova sastava premaza i parametara zavarivanja, na zavarenim uzorcima izvršena je karakterizacija mehaničkih osobina, hemijskog sastava i mikrostrukture.In this doctoral thesis, the selection of solvent, size, type and the content of oxide particles in activated flux aimed at increasing the penetration on austenitic stainless steel in gas tungsten arc welding is presented. Besides activated flux composition, the optimization of welding parameters such as electrode geometry, welding current and welding speed was done. After the selection of successful activated flux formulations and welding parameters, the characterization of mechanical properties, chemical composition and microstructure was determined