Abstract
The study of the optical properties of biological tissues for a wide spectral range is necessary for the development and planning of noninvasive optical methods to be used in clinical practice. In this study, we propose a new method to calculate almost all optical properties of tissues as a function of wavelength directly from spectral measurements. Using this method, and with the exception of the reduced scattering coefficient, which was obtained by traditional simulation methods, all the other optical properties were calculated in a simple and fast manner for human and pathological colorectal tissues. The obtained results are in good agreement with previous published data, both in magnitude and in wavelength dependence. Since this method is based on spectral measurements and not on discrete-wavelength experimental data, the calculated optical properties contain spectral signatures that correspond to major tissue chromophores such as DNA and hemoglobin. Analysis of the absorption bands of hemoglobin in the wavelength dependence of the absorption spectra of normal and pathological colorectal mucosa allowed to identify differentiated accumulation of a pigment in these tissues. The increased content of this pigment in the pathological mucosa may be used for the future development of noninvasive diagnostic methods for colorectal cancer detection.

Abstract
The interest of using light in clinical practice is increasing strongly and many applications work at various wavelengths from the ultraviolet to the infrared. Due to this great range of applications, the determination of the optical properties of biological tissues in a wide spectral range becomes of interest. The liver is an important organ, since it has a major role in the human body and various pathologies are known to develop within it. For these reasons, this study concerns the estimation of the optical properties of human normal and pathological (metastatic carcinoma) liver tissues between 200 and 1000 nm. The obtained optical properties present the expected wavelength dependencies for both tissues - the refractive index, the absorption and the scattering coefficients decrease with the wavelength and the anisotropy and light penetration depth increase with the wavelength. Although similar behavior was observed for the various properties between the normal and pathological tissues, evidence of smaller blood content in the pathological tissues was found. A possible explanation is that the cancer cells destroy liver's vasculature and internal architecture, providing though a reduction in the blood content. For low wavelengths, it was observed a matching between the scattering and the reduced scattering coefficients, which implies a nearly zero anisotropy in that range. The scattering coefficient decreases from nearly 140 cm(-1) (at 200 nm) to 80 cm(-1) (at 1000 nm) for the normal liver and from nearly 140 cm(-1) (at 200 nm) to 95 cm(-1) (at 1000 nm) for the pathological tissue.

Abstract
The concept of 'tissue optical windows' and method of optical clearing (OC) based on controllable and reversible modification of tissue optical properties by their soaking with a biocompatible optical clearing agent (OCA) are prsented. Fundamentals and major mechanisms of OC allowing one to enhance optical imaging facilities and laser treatment efficiency of living tissues are described. Perspectives of immersion optical clearing/contrasting technique aiming to enhance optical imaging of living tissues by using different imaging modalities working in the ultra-broad wavelength range from deep UV to terahertz waves are discussed. It demonstrated that immersion OC method can be applied to evaluate the characteristic diffusion properties of water and OCA in various tissues and even discriminate between the mobile water content in normal and pathological tissues.

Abstract
The evaluation of the optical clearing mechanisms in tissues provides information about the efficiency of the clearing treatment. One of such mechanisms is the refractive index matching, which is created by the partial replacement of tissue water by an optical clearing agent with higher refractive index, better matched to the index of tissue scatterers. With the objective of evaluating the refractive index matching mechanism for a wide spectral range and comparing its magnitude between treatments with different clearing agent osmolarities, thickness and collimated transmittance measurements were obtained from human colorectal muscle samples under treatment with 20%-, 40% and 60%-glycerol. Such measurements were used in a calculation model to obtain the refractive index kinetics for the interstitial fluid and for the whole tissue. The calculation results show that the refractive index matching has a stronger effect in the ultraviolet and that such matching is more effective for higher agent concentrations in the treating solutions.

Abstract
AbstractNowadays, the low efficiency of solar energy power plant systems brings about uneconomical performance and high-cost uncompetitive industries compared with the traditional fossil fuel ones. In order to overcome these kinds of issues, in this study, the performance of a solar tower coupled with a Rankine cycle is scrutinized using the first and second laws of thermodynamic. Moreover, a numerical code has been developed in the GNU Octave software environment to calculate the precise value for both energy and exergy losses of each component. Furthermore, the sensitivity analysis approach corresponds to the variation of several inner parameters such as direct normal irradiation (DNI), molten salt outlet temperature (MSOT), and the molten salt velocity (MSV), environmental parameters such as wind speed and ambient temperature have been performed. In addition, the overall losses are calculated by considering all possible forms of losses such as convection, conduction, reflection, and emission, and also, the portion of each source of these losses are determined. The obtained results indicate that the maximum exergy loss occurs in the central receiver system (CRS), while the major energy loss occurs in the turbine located in the power block. The sensitivity analysis shows that the rise of DNI significantly increases the exergy%energy efficiency of the cycle and also, the portion of loss related to emission heat transfer would be enhanced. Moreover, the variation of the MSV and MSOT illustrate influencing the performance of the cycle; consequently, the MSOT changes demonstrate a reverse relation with energy and direct relation with exergy efficiency. Accordingly, an optimum value of 650K is calculated for the MSOT as well as an optimum value of 2 m%s for the MSV. The environmental sensitivity analysis indicates that the enhancement of wind speed and ambient temperature has a negative impact on the net output of the cycle, which is not desirable.

Abstract
The future of healthcare systems is being shaped by incorporating emerged technological innovations to drive new models for patient care. By acquiring, integrating, analyzing, and exchanging medical data at different system levels, new practices can be introduced, offering a radical improvement to healthcare services. This article presents a novel smart and secure Healthcare system (ssHealth), which, leveraging advances in edge computing and blockchain technologies, permits epidemics discovering, remote monitoring, and fast emergency response. The proposed system also allows for secure medical data exchange among local healthcare entities, thus realizing the integration of multiple national and international entities and enabling the correlation of critical medical events for, for example, emerging epidemics management and control. In particular, we develop a blockchain-based architecture and enable a flexible configuration thereof, which optimize medical data sharing between different health entities and fulfil the diverse levels of Quality of Service (QoS) that ssHealth may require. Finally, we highlight the benefits of the proposed ssHealth system and possible directions for future research.