This PDF file contains the front matter associated with SPIE Proceedings Volume 6791, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

In this article, we report on studies aimed at sensing of the stiffness of membranes, particularly in the case of vesicles. A local approach could be done with AFM techniques but the local information is not pertinent for non homogeneous membranes. To solve this problem, we have developed and checked a specific sensor based on a vibrating sphere. The near-field acoustic wave enables to characterize biological particles which change the apparent viscosity and density of the surrounding fluid. The microsphere is well suited for very small volumes of liquid (typically about one microliter). Globally, the microsensor is based on a silicon cantilever which is glued on a piezoelectric transducer at its clamped end. The sphere is connected to the cantilever with a small glass rod (the core of an optical fiber). When operating, the sphere is immersed inside the investigated liquid and the piezoelectric actuator is excited with a low frequency generator. The vibration of the cantilever is sensed with a heterodyne laser probe. The plot of the response of the sensor (Bode plot) allows computing the properties of the liquid. When biological cells or vesicles are in the fluid, the effect of the biological elements is detectable and can be discriminated. We will present the microsensor and the optical probe which have allowed doing the described measurements. The theoretical study will show the influence of the different parameters and the crucial role of the optical probe to detect the low amplitude vibrations of the cantilever. The experimental results demonstrate the high sensitivity of the sensor to small variation of the composition of the fluid (water), particularly in the case of small vesicles of different kinds. Practically, this is a simulation of cells sensing.

In this paper International Research-Educational Center of Optical Technologies for Industry and Medicine "Photonics" at Saratov State University founded in 2007 in the framework of National Russian Federation Program "Innovative Universities" is presented. Some facilities in the field of optical and biomedical optics education, research, and commercialization are discussed.

White-light endoscopy is well-established and wide used modality. However, despite the many technological advances that have been occurred, conventional endoscopy is suboptimal and usually detects advanced stage lesions. The limitations of standard endoscopy initiate development of spectroscopic techniques, additional to standard endoscopic equipment. One of the most sensitive approaches is fluorescence spectroscopy of gastrointestinal mucosa for neoplasia detection. In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. Excitation source has max of emission at 405 nm and light is delivered by the standard light guide of the endoscopic equipment. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to reabsorption of blood. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of 5-ALA/PpIX only in abnormal sites Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

In the recent years, there has been growing interest in the common use of laser-induced autofluorescence (LIAF) and reflectance spectroscopy (RS) to differentiate disease from normal surrounding tissue - so called optical biopsy method. Painless, instant diagnoses from optical biopsies will soon be a reality. These forms of optical diagnoses are preferable to the removal of several square millimeters of tissue surface - common in traditional biopsies - followed by delays while samples are sent for clinical analysis. The goal of this work was investigation of cutaneous benign and malignant lesions by the methods of LIAFS and RS. A nitrogen laser at 337 nm was applied for the needs of autofluorescence excitation. Broad-spectrum halogen lamp (from 400 to 900 nm) was applied for diffuse reflectance measurements. An associated microspectrometer detected in vivo the fluorescence and reflectance signals from human skin. The main spectral features of benign lesions - compound nevus, dysplastic nevi, heamangioma and basal cell papilloma and malignant lesions - pigmented, amelanotic and secondary malignant melanoma, as well as basal cell carcinoma are discussed and their possible origins are indicated. Spectra from healthy skin areas near to the lesion were detected to be used posteriori to reveal changes between healthy and lesion skin spectra. Influence of the main skin pigments on the spectra detected is discussed and evaluation of possibilities for differentiation between malignant and benign lesions is made based on their spectral properties. This research shows that non-invasive and high-sensitive in vivo detection by means of appropriate light sources and detectors should be possible, related to real-time determination of existing pathological conditions.

Two compact systems for cross-polarization optical coherence tomography (CP-OCT) were developed using polarization-maintaining (PM) and single mode fibers. The systems allow simultaneous investigation of birefringence and depolarization properties of biological samples. Birefringence and degree of depolarization of some selected biological test specimens were studied in experiment.

The calculation of permeability coefficient of analytes could potentially be used in a variety of basic science and clinical fields, as well as advanced diagnostic imaging. Before this can occur, a more thorough understanding of the diffusion rate of analytes in biological tissues is needed. For this task, we utilized Optical Coherence Tomography for the functional imaging of glucose diffusion through rabbit sclera tissues. The permeability coefficients were calculated for different concentrations of glucose solution as they diffused through the tissue. From the experiments performed it was noticed that the concentration of the analyte was inversely proportional to the permeability coefficient calculated. The permeability coefficient of glucose solution with lower concentration was faster when compared with higher concentration. The decrease in the permeability coefficient ranged from (1.67 ± 0.17) x 10^-5 cm/sec with the 10% glucose solution to (5.08 ± 0.23) x 10^-6cm/sec of 25% glucose solution. The results of this study could expand the use of the permeability coefficient into the field of diagnostic imaging.

The uniaxial optical activity induced by constant magnetic field in hemoglobin solutions is theoretically analyzed for various hemoglobin conformations and orientations of magnetic field. A rotatory power function for the description of molecular optical activity is proposed. The rotatory power for hemoglobin is calculated as a function of frequency of incident light and its direction in relation to the molecular axes.

Experimental absorption and refraction spectra measured for different tooth structures in THz frequency range from 0.1 to 3 THz (3-100 cm^-1) are presented. Characteristic features of refraction spectrum were found for different areas of tooth enamel and dentin.

The refractive index is a basic optical property of a medium which is of great importance in physics, chemistry and most of biomedical applications. In our current study we monitor the change in refractive index for aqueous solutions of glucose, CaCl₂, MgCl₂, NaCl, KCl and urea using a phase sensitive spectral domain optical coherence tomography (ph-SOCT) system. For instance, glucose induced changes in the phase are found to be 0.079 rad/mM in 200μm thick cuvette for clear media and that is in good agreement with literature and our previous obtained data using phase sensitive low coherence optical reflectometry(PS-OLCR). The importance of this study is to demonstrate the capability of ph-SOCT to monitor ultra small changes in refractive index in clear media and the accuracy for glucose sensing is estimated to be ±2.6×10^-6.

Benefits of employing laser and optical technologies in clinical dermatology are enormous, including solving the complex of questions in diagnosis and treatments of many skin diseases; introducing new methods of diagnosis, treatment and its evaluation; advancing fundamental understanding not only of physiology of skin itself, but also of pathophysiology of different dermatological diseases and conditions. Through numerous innovations in laser and optical technologies a variety of specific and important information has become available in clinical dermatology on real-time normal and lesional skin characterization and visualization, on different type and pattern recognition, on monitoring of several dermatological conditions, on assessment of various parameters for measuring dynamics of skin lesions with further possibilities to assess severity of skin symptoms, and on evaluation of different treatment regimes and their comparisons. After a decade of experiences in inter- and multi-disciplinary research I would like to share the wisdom and pitfalls of my work how to get laser and optical technologies into clinical practice of dermatological interest, that are discussed in the paper.

Phagocytosis is a complex process involving attachment, ingestion and intracellular processing of bacteria by phagocytes. A great difficulty in the evaluation of this process is to differentiate between attachment of the particles to the cell surface and internalization of the particles by the cells. Various techniques have been used to differentiate internalized and surface-attached bacteria in cultured cells, but only a few permit differentiations between surface-bound and internalized bacteria. In this study the quenching of fluorescence by crystal violet on acridine orange stained bacterial biofilm and planktonic bacterial cells is used to differentiate between surface-bound and internalized bacteria within macrophages. Method: One week old Enterococcus faecalis biofilm was grown on perspex and glass substrates in All-Culture medium (nutrient-rich condition) and phosphate buffered saline (nutrient-deprived condition). As model systems, human monocytic (THP-1) and histiocytic (U937) cell lines were used. These cell lines were incubated with the biofilm bacteria for 4 hrs in CO₂ incubator at 37^oC. The cells and bacteria were stained with acridine orange and quenched with crystal violet to distinguish between surface-bound and internalized bacteria. Results: The presence of green-fluorescing internalized bacteria was detected within the macrophages under the planktonic, nutrient-rich and nutrient-deprived biofilm conditions. All infecting bacteria take up acridine orange and fluoresced green, crystal violet quenched the fluorescence of extra-cellular adhering bacteria so that only fluorescent intracellular bacteria would be visible under fluorescent light microscopy.

Differential Mueller matrix of nondepolarizing anisotropic homogeneous media is derived. It has been shown that equality of refraction indexes (absorption coefficients) of anisotropic media is not sufficient condition for the absence of birefringence (dichroism). Additional conditions for the eigenpolarizations of media to be pure dichroic or birefringent has been analysed. Relation between differential Jones matrix and permittivity and conductivity tensors is derived. It has been shown that eigenpolarizations are nonorthogonal only if eigenvectors of permittivity and conductivity tensors not coincide.

The Finite-Difference Time-Domain (FDTD) modeling technique is applied to build a simple simulation equivalent of an optical phase contrast microscope. The model is validated by demonstrating the effect of optical immersion on the optical phase contrast microscope image of a simple biological cell containing a cytoplasm, a nucleus and a membrane. To the best of our knowledge, this is the first study using the FDTD approach to construct optical phase contrast microscope images. The results demonstrate the potential of the FDTD modelling approach and extend its area of applicability a new biomedical research area.

In order to find a non-invasive way to improve the efficacy of skin optical clearing with topically applied optical clearing agents (OCA), we evaluated the effect of azone ® (epsilon-Laurocapram) as a chemical penetration enhancer on optical clearing of intact skin in vitro. Fresh porcine skin with topical application of glycerol (G) mixed with water-soluble azone (A) was investigated using near-infrared spectroscopy and optical coherence tomography (OCT). Light transmittance at 1276 nm increased by 41% and diffuse reflectance at 1066 nm decreased by 29% at 60 min after treatment with 40%G5%A on a spectrophotometer with an internal integrating sphere. 40% glycerol with addition of azone was a more effective optical clearing agent than 40% and 80% glycerol. 60%G/5%A led to a 2-fold increase in achievable OCT imaging depth and a 2.2-fold increase in light intensity reflected off the underneath needle surface after 60 minutes in the OCT in-depth reflectance profiles. In conclusion, skin optical clearing with the topical application of glycerol was markedly enhanced by water-soluble azone. Skin permeation enhancing effect of azone accounts probably for the skin clearing enhancement.

Optical imaging in biomedicine is governed by the light absorption and scattering interaction on microscopic and macroscopic constituents in the medium. Therefore, light scattering characteristics of human tissue correlate with the stage of some diseases. In the near infrared range the scattering event with the coefficient approximately two orders of magnitude greater than absorption plays a dominant role. When measuring the optical parameters variations were discovered that correlate with the rheumatoid arthritis of a small joint. The potential of an experimental setup for transillumination the finger joint with a laser diode and the pattern of the stray light detection are demonstrated. The scattering caused by skin contains no useful information and it can be removed by a deconvolution technique to enhance the diagnostic value of this non-invasive optical method. Monte Carlo simulations ensure both the construction of the corresponding point spread function and both the theoretical verification of the stray light picture in rather complex geometry.

A novel method of direct control of local tissue oxygenation based on laser-induced photodissociation of oxyhemoglobin in cutaneous blood vessels is discussed. New technology in selective and local increase of the concentration of free molecular oxygen in tissue that enhances metabolism of cells is demonstrated. Direct in vivo measurements of the tissue oxygen tension are carried out on human skin. Kinetics of oxygen tension in tissue is investigated under the effect of He-Ne laser radiation at the power of 1mW relatively to initial value of tissue oxygen tension. The results of experimental study the kinetics of oxygen distribution into tissue from arterial blood is presented. Biomedical applications of proposed new technology in laser therapy of pathologies where elimination of local tissue hypoxia is critical are discussed.

We introduce the concept of tuning in the low-coherence trans-illumination interferometer to enhance its overall applicability (i.e., to enable selective diagnosis from different tissue regions). Modulation artifacts of the tuned interferometer are restricted to the reference arm. Displacements in this system, for pass-through photon-based modality, must be inverted. Tuning of specific radiation depends on modulation parameters and coherence-time gate. We propose to use Recurrence Plots and Recurrence Quantification Analysis (RQA) as a robust platform to identify different tuning states in the trans-illumination experiment. To the best of our knowledge, this is the first time that recurrence analyses are employed in trans-illumination studies. We suggest the quantitative metric of Determinism as a reference to assess the degree of tuning of the instrument. Theoretical results confirm that RQA may be useful for discriminating between different tuning states, including photon isolation for pass-through photon-based biomedical trans-illumination.

Skeletal muscle is a fibrous tissue composed by muscle fibers and interstitial fluid. Due to this constitution, the muscle presents a non uniform refractive index profile that origins strong light scattering. One way to improve tissue transmittance is to reduce this refractive index mismatch by immersing the muscle in an optical clearing agent. As a consequence of such immersion tissue also suffers dehydration. The study of the optical clearing effect created by a simple mixture composed by ethanol, glycerol and distilled water has proven its effectiveness according to the variations observed in the parameters under study. The effect was characterized in terms of its magnitude, time duration and histological variations. The applied treatment has created a small reduction of the global sample refractive index that is justified by the long time rehydration caused by water in the immersing solution. From the reduction in sample pH we could also identify the dehydration process created in the sample. The immersion treatment has originated fiber bundle contraction and a spread distribution of the muscle fiber bundles inside. New studies with the mixture used, or with other combinations of its constituents might be interesting to perform with the objective to develop new clinical procedures.

The experimental registration of RBC flow "in vitro" on the base of cross-correlation method is carried out. The range of erythrocytes concentrations in the whole blood solution flow, when the application of physical method used is possible, was revealed. The principle possibility to use the cross-correlation method to register RBC complexes, to estimate their sizes and motion velocity in the flow was shown experimentally. It is easy to see, that the registration of RBC complexes may be treated as the base of cross-correlation method application for the aims of aggregometers, medical diagnostic apparatus development, for example, the device to define the blood group type of probe automatically.

Present paper focuses on correction for effect of vertical imbalance, which can make difficulties to observing stereoscopic image in Greenough stereoscopic microscopes. In the context of geometrical optics we derive condition of vertical imbalance elimination for all points of stereoscopic image observed in Greenough stereoscopic microscope.

Traditional biological and chemical methods for pathogen identification require complicated sample preparation for reliable results. The process of identification of malignant and non-malignant growths is not easier. Optical scattering method may be useful to detect bacterial cells in suspension and to determine malignant and non-malignant growths. Orthogonal Zernike moments of different order were used to analyze speckle patterns, which are formed by irradiated object of interests. Being irradiated by light every object forms a unique speckle pattern. Due to the originality of every single speckle pattern they may be used to obtain some information about object that formed this pattern.

It is established change of character of stimulated Raman scattering spectrum of ceruloplasmin by powerful laser radiation. This change is connected with destruction peptides connections in molecule ceruloplasmin. It is shown, that dependence of integrated intensity of the first stokes line of stimulated Raman scattering spectrum of ceruloplasmin from its concentration in solutions is linear. It can be used for definition of concentration of protein in physiological solutions.

This study is focused on the determination of the extinction coefficient of oxyhemoglobin solutions at different concentrations of glucose and hemoglobin incubation with glucose from 3 days to 18 days. The extinction coefficient was determined using absorbance measurements at the wavelength range from 500 nm to 850 nm. Measurements of the absorbance spectra have been performed using fiber-optic spectrometer USB2000 (Ocean Optics, USA).

Feasibility of luminescent determination of polycyclic aromatic hydrocarbons (PAHs) on a cellulose matrix with sorbtion of analyzable substance from water-micellar solutions is investigated. As a solubilizer was used anionic surface-active agent - sodium dodecylsulphate (SDS) and cationic detergent - cetyltrimethylammonium bromide (CTAB). It is established, that the maximal signal of PAHs luminescence on a cellulose matrix is observed at the critical micellar concentration of detergent.

This paper deals with the problem of using semiconductor laser radiation (wavelength 810 nm) for healing skin and mucous cancer of small animal. Opportunities of using different types of lasers for clinical applications under oncological diseases of skin and oral mucous have been analyzed. We determined power densities and duration of laser irradiation for different types of tumors. IR thermograph was used for noninvasive temperature monitoring in the area of tumor localization. For noninvasive measuring and registration of spatial distribution of radiation temperature of investigated objects, we used IR Imager IRISYS 4010 Infrared Integrated System Ltd (UK).

Acne is a genetic, hormonal disease characterized by overproduction of oil by the sebaceous glands, plugging of the sebaceous glands to form micro- and macro- comedons and, finally, action of skin bacteria on oil trapped underneath the skin to red inflammatory cystic lesions. It was shown, that Propionibacterium acnes, the bacteria responsible for acne, was rather subjected to action of red and infrared radiation. The effect of the given radiation amplified at this bacteria by various solutions of photosensitizes.

The effects of Escherichia coli A5 and Escherichia coli B6 toxins on blood microcirculation in ventral mesentery of white rats were studied. In vivo investigation of blood microcirculation has been conducted by speckle-microscopy. The increasing of blood flow velocity in capillaries has been observed under the influence of exotoxin in the course of short intervals.

Dentinal permeation is of interest in a wide context of tooth care and treatment, in particular, tooth color improvement using combination of chemical whitening agents and light activation. A simple model of dentinal permeation accounting for the morphology of human tooth dentine and including dentinal tubules, more dense and homogeneous peritubular dentine, and less dense and less homogeneous intertubular dentin is proposed. Calculation of permeability of dentine layer is carried out for H₂O and H₂O₂ versus the tubule diameter and tubule density taken from the microphotograph analysis. This opens the possibility to calculate the distribution of permeability over the tooth surface taking into account the variations of tubule diameter and density as well as those of the diffusion coefficients and layer thickness

In this study for the first time there were registered and investigated the effects accompanying the interaction with human tooth enamel of YAG: Er laser radiation at energy density below the enamel removal threshold. A comparative research of efficiency of removal of hard tissues of human tooth by YAG: Er and YSGG: Cr, Er laser radiation was carried out. There was investigated the influence of duration and structure of the YSGG: Cr, Er laser pulse on efficiency of laser removal of human tooth enamel and dentine. The most effective for destruction of tooth hard tissues appeared the pulse with general duration of about 2 millisecond, consisting of equidistant sequence of spikes, while the duration of each spike was about 500 nanoseconds.

How to improve physicist's creativity? How one can make himself an instrument for creativity? What is the role of the humanities in initiation of intuitive moments in thinking? The problems are discussed in terms of such modern conception as Self-management, in context of the dialogue between nature and human being by Prigogine, "Farther reaches of human nature" by Maslow, and mathematical approach for modeling of mental structure elements.

An opportunity of distance education and elevation of specialist's qualification, using telemedicine technologies, has an important role in the improvement of the medical aids quality. This article reflects the formation stages of distance training system for the specialists of Archangelsk region health care. Here there are some results of this system activity in the region.

The paper presents recent examples of formal letter writing. The most recent forms of the papers such as CV, covering letter, letter of information, invoice, business plan, application to open a bank account, etc. have been considered in detail a and the requirements for their writing have also been discussed. Careful study of various genres of formal letter writing enables the young scientist both to join the scientific community and be independent.