Coherent and noncoherent light transport in living tissues impregnated by endogenous or exogenous fluids and gels

1998 ◽  
Author(s):  
Valery V. Tuchin
Keyword(s):  
Light Transport ◽  
Living Tissues ◽  
Noncoherent Light

Low-voltage field-emission SEM of polymeric membranes for glucose biosensors

1990 ◽  
Vol 48 (3) ◽  
pp. 860-861
Author(s):  
Lorna K. Mayo ◽  
Kenneth C. Moore ◽  
Mark A. Arnold
Keyword(s):  
Glucose Sensor ◽  
Low Voltage ◽  
Glucose Sensors ◽  
Polymeric Membranes ◽  
Artificial Endocrine Pancreas ◽  
Self Monitoring ◽  
Conducting Materials ◽  
Insulin Dependent ◽  
Living Tissues ◽  
Voltage Scanning

An implantable artificial endocrine pancreas consisting of a glucose sensor and a closed-loop insulin delivery system could potentially replace the need for glucose self-monitoring and regulation among insulin dependent diabetics. Achieving such a break through largely depends on the development of an appropriate, biocompatible membrane for the sensor. Biocompatibility is crucial since changes in the glucose sensors membrane resulting from attack by orinter action with living tissues can interfere with sensor reliability and accuracy. If such interactions can be understood, however, compensations can be made for their effects. Current polymer technology offers several possible membranes that meet the unique chemical dynamics required of a glucose sensor. Two of the most promising polymer membranes are polytetrafluoroethylene (PTFE) and silicone (Si). Low-voltage scanning electron microscopy, which is an excellent technique for characterizing a variety of polymeric and non-conducting materials, 27 was applied to the examination of experimental sensor membranes.

Skin Chromophore Estimation from Mobile Selfie Images using Constrained Independent Component Analysis

2020 ◽  
Vol 2020 (14) ◽  
pp. 357-1-357-6
Author(s):  
Luisa F. Polanía ◽  
Raja Bala ◽  
Ankur Purwar ◽  
Paul Matts ◽  
Martin Maltz
Keyword(s):  
Independent Component Analysis ◽  
Spectral Reflectance ◽  
Source Separation ◽  
Principal Component ◽  
Component Analysis ◽  
Previous Method ◽  
Independent Component ◽  
Light Transport ◽  
Camera Model ◽  
Constrained Independent Component Analysis

Human skin is made up of two primary chromophores: melanin, the pigment in the epidermis giving skin its color; and hemoglobin, the pigment in the red blood cells of the vascular network within the dermis. The relative concentrations of these chromophores provide a vital indicator for skin health and appearance. We present a technique to automatically estimate chromophore maps from RGB images of human faces captured with mobile devices such as smartphones. The ultimate goal is to provide a diagnostic aid for individuals to monitor and improve the quality of their facial skin. A previous method approaches the problem as one of blind source separation, and applies Independent Component Analysis (ICA) in camera RGB space to estimate the chromophores. We extend this technique in two important ways. First we observe that models for light transport in skin call for source separation to be performed in log spectral reflectance coordinates rather than in RGB. Thus we transform camera RGB to a spectral reflectance space prior to applying ICA. This process involves the use of a linear camera model and Principal Component Analysis to represent skin spectral reflectance as a lowdimensional manifold. The camera model requires knowledge of the incident illuminant, which we obtain via a novel technique that uses the human lip as a calibration object. Second, we address an inherent limitation with ICA that the ordering of the separated signals is random and ambiguous. We incorporate a domain-specific prior model for human chromophore spectra as a constraint in solving ICA. Results on a dataset of mobile camera images show high quality and unambiguous recovery of chromophores.

Matrix metalloproteinases in stroke

2017 ◽  
pp. 110-117
Author(s):  
А.А. Пальцын
Keyword(s):  
Matrix Metalloproteinases ◽  
Enzyme System ◽  
Enzyme Complex ◽  
Pathogenic Factors ◽  
Pathogenic Action ◽  
Activity Of Enzymes ◽  
Living Tissues ◽  
Current Reconstruction ◽  
Metalloproteinase Activity

Матриксные металлопротеиназы - ферментный комплекс, необходимый для сохранения гомеостаза. Он участник нормальной, постоянно текущей реконструкции всех живых тканей. Действие патогенных факторов нарушает слаженную работу этого комплекса. Часто нарушение выражается излишней активностью ферментов, усиливающей патогенное действие. Однако и заживление, форсированное новообразование тканевых элементов, может происходить только при повышенной, в сравнении с нормой, активности металлопротеиназ. Такая ситуация требует от медицины умения разумно вмешиваться в работу ферментной системы. В статье представлены некоторые результаты этих вмешательств. Matrix metalloproteinases - enzyme complex necessary for maintenance of the homeostasis. He is a participant of normal, constantly current reconstruction of all living tissues. Action of pathogenic factors breaks harmonious work of this complex. Often violation is expressed by the excessive activity of enzymes amplifying pathogenic action. However and healing, which is accelerated new growth of tissue elements, can happen only at raised, compared with norm, metalloproteinase activity. Such situation demands from medicine of ability participate reasonably in work of enzyme system. The article presents some of the results of these actions.

scholarly journals Coherent control of light transport in a dense and disordered atomic ensemble

2015 ◽  
Vol 91 (5) ◽  
Author(s):  
A. S. Sheremet ◽  
D. F. Kornovan ◽  
L. V. Gerasimov ◽  
B. Gouraud ◽  
J. Laurat ◽  
...  
Keyword(s):  
Coherent Control ◽  
Light Transport ◽  
Atomic Ensemble

Delayed Rejection Metropolis Light Transport

2020 ◽  
Vol 39 (3) ◽  
pp. 1-14 ◽  
Author(s):  
Damien Rioux-Lavoie ◽  
Joey Litalien ◽  
Adrien Gruson ◽  
Toshiya Hachisuka ◽  
Derek Nowrouzezahrai
Keyword(s):  
Light Transport ◽  
Delayed Rejection

scholarly journals Survival and Proliferation under Severely Hypoxic Microenvironments Using Cell-Laden Oxygenating Hydrogels

2021 ◽  
Vol 12 (2) ◽  
pp. 30
Author(s):  
Shabir Hassan ◽  
Berivan Cecen ◽  
Ramon Peña-Garcia ◽  
Fernanda Roberta Marciano ◽  
Amir K. Miri ◽  
...  
Keyword(s):  
Prolonged Release ◽  
Therapeutic Approaches ◽  
Encapsulated Cells ◽  
Hypoxic Conditions ◽  
Skeletal Myoblasts ◽  
Artificial Tissue ◽  
Delivery Platform ◽  
Living Tissues

Different strategies have been employed to provide adequate nutrients for engineered living tissues. These have mainly revolved around providing oxygen to alleviate the effects of chronic hypoxia or anoxia that result in necrosis or weak neovascularization, leading to failure of artificial tissue implants and hence poor clinical outcome. While different biomaterials have been used as oxygen generators for in vitro as well as in vivo applications, certain problems have hampered their wide application. Among these are the generation and the rate at which oxygen is produced together with the production of the reaction intermediates in the form of reactive oxygen species (ROS). Both these factors can be detrimental for cell survival and can severely affect the outcome of such studies. Here we present calcium peroxide (CPO) encapsulated in polycaprolactone as oxygen releasing microparticles (OMPs). While CPO releases oxygen upon hydrolysis, PCL encapsulation ensures that hydrolysis takes place slowly, thereby sustaining prolonged release of oxygen without the stress the bulk release can endow on the encapsulated cells. We used gelatin methacryloyl (GelMA) hydrogels containing these OMPs to stimulate survival and proliferation of encapsulated skeletal myoblasts and optimized the OMP concentration for sustained oxygen delivery over more than a week. The oxygen releasing and delivery platform described in this study opens up opportunities for cell-based therapeutic approaches to treat diseases resulting from ischemic conditions and enhance survival of implants under severe hypoxic conditions for successful clinical translation.

scholarly journals The emerging technology of biohybrid micro-robots: a review

2021 ◽  
Author(s):  
Zening Lin ◽  
Tao Jiang ◽  
Jianzhong Shang
Keyword(s):  
Self Assembly ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Living Cells ◽  
Multiple Degrees Of Freedom ◽  
The Past ◽  
Great Prevalence ◽  
Performance Decline ◽  
High Energy Efficiency ◽  
Living Tissues

Abstract In the past few decades, robotics research has witnessed an increasingly high interest in miniaturized, intelligent, and integrated robots. The imperative component of a robot is the actuator that determines its performance. Although traditional rigid drives such as motors and gas engines have shown great prevalence in most macroscale circumstances, the reduction of these drives to the millimeter or even lower scale results in a significant increase in manufacturing difficulty accompanied by a remarkable performance decline. Biohybrid robots driven by living cells can be a potential solution to overcome these drawbacks by benefiting from the intrinsic microscale self-assembly of living tissues and high energy efficiency, which, among other unprecedented properties, also feature flexibility, self-repair, and even multiple degrees of freedom. This paper systematically reviews the development of biohybrid robots. First, the development of biological flexible drivers is introduced while emphasizing on their advantages over traditional drivers. Second, up-to-date works regarding biohybrid robots are reviewed in detail from three aspects: biological driving sources, actuator materials, and structures with associated control methodologies. Finally, the potential future applications and major challenges of biohybrid robots are explored. Graphic abstract

scholarly journals Nonreciprocity and Quantum Correlations of Light Transport in Hot Atoms via Reservoir Engineering

2021 ◽  
Vol 126 (22) ◽  
Author(s):  
Xingda Lu ◽  
Wanxia Cao ◽  
Wei Yi ◽  
Heng Shen ◽  
Yanhong Xiao
Keyword(s):  
Quantum Correlations ◽  
Light Transport ◽  
Reservoir Engineering
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