WorldWideScience

Sample records for tissues biological collision

  1. Tracing molecular dephasing in biological tissue

    Science.gov (United States)

    Mokim, M.; Carruba, C.; Ganikhanov, F.

    2017-10-01

    We demonstrate the quantitative spectroscopic characterization and imaging of biological tissue using coherent time-domain microscopy with a femtosecond resolution. We identify tissue constituents and perform dephasing time (T2) measurements of characteristic Raman active vibrations. This was shown in subcutaneous mouse fat embedded within collagen rich areas of the dermis and the muscle connective tissue. The demonstrated equivalent spectral resolution (methods for characterization of biological media. This provides with the important dimensions and parameters in biological media characterization and can become an effective tool in detecting minute changes in the bio-molecular composition and environment that is critical for molecular level diagnosis.

  2. Nonlinear spectral imaging of biological tissues

    NARCIS (Netherlands)

    Palero, J.A.

    2007-01-01

    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal.

  3. Nonlinear spectral imaging of biological tissues

    Science.gov (United States)

    Palero, J. A.

    2007-07-01

    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal. Because biological intrinsic emission is generally very weak and extends from the ultraviolet to the visible spectral range, a broad-spectral range and high sensitivity 3D spectral imaging system is developed. Imaging the spectral characteristics of the biological intrinsic emission reveals the structure and biochemistry of the cells and extra-cellular components. By using different methods in visualizing the spectral images, discrimination between different tissue structures is achieved without the use of any stain or fluorescent label. For instance, RGB real color spectral images of the intrinsic emission of mouse skin tissues show blue cells, green hair follicles, and purple collagen fibers. The color signature of each tissue component is directly related to its characteristic emission spectrum. The results of this study show that skin tissue nonlinear intrinsic emission is mainly due to the autofluorescence of reduced nicotinamide adenine dinucleotide (phosphate), flavins, keratin, melanin, phospholipids, elastin and collagen and nonlinear Raman scattering and second-harmonic generation in Type I collagen. In vivo time-lapse spectral imaging is implemented to study metabolic changes in epidermal cells in tissues. Optical scattering in tissues, a key factor in determining the maximum achievable imaging depth, is also investigated in this work.

  4. Desiccation tolerance in biological tissue

    International Nuclear Information System (INIS)

    Lenne, T.; Bryant, G.

    2003-01-01

    Full text: Severe dehydration is lethal for most biological species. However, there are a number of organisms or organelles which have evolved mechanisms to avoid damage during dehydration. One of these mechanisms is the accumulation of small solutes (such as sugars), which has been shown to preserve membranes by inhibiting deleterious phase changes at low hydration. The aim of this project is to use small angle x-ray scattering (SAXS) to investigate the effects of small solutes on the phase behaviour and packing parameters of multilamellar membranes as a function of hydration. In the experiment a synthetic phospholipid 1,2-dipalmitoyl-sn-glycero-3- phosphatidylcholine (DPPC) will be used as a model system, as it is the most well characterized phospholipid. Hence the repeat spacings (distance between consecutive bilayers ∼50 Angstroms) and the intra-lipid spacing (distance between a lipid and its neighbor ∼5 Angstroms) are well documented. An appropriate solute, and solute concentration range will be chosen, and its effect on the freezing temperature of DPPC will be observed. To determine the effectiveness of the added solute the repeat spacings need to be measured. Experiments will be conducted at a number of hydrations to accurately model the phase behavior for DPPC over the entire range of hydrations and solute concentrations. Experiments using an alternate configuration of the SAXS may be attempted if time permits to measure the interlipid spacing to obtain more information regarding the phase transition. Although SAXS has been performed extensively on DPPC, experiments with solutes over a range of hydrations, particularly very low hydrations, have not been attempted

  5. Multiscale mechanical modeling of soft biological tissues

    Science.gov (United States)

    Stylianopoulos, Triantafyllos

    2008-10-01

    Soft biological tissues include both native and artificial tissues. In the human body, tissues like the articular cartilage, arterial wall, and heart valve leaflets are examples of structures composed of an underlying network of collagen fibers, cells, proteins and molecules. Artificial tissues are less complex than native tissues and mainly consist of a fiber polymer network with the intent of replacing lost or damaged tissue. Understanding of the mechanical function of these materials is essential for many clinical treatments (e.g. arterial clamping, angioplasty), diseases (e.g. arteriosclerosis) and tissue engineering applications (e.g. engineered blood vessels or heart valves). This thesis presents the derivation and application of a multiscale methodology to describe the macroscopic mechanical function of soft biological tissues incorporating directly their structural architecture. The model, which is based on volume averaging theory, accounts for structural parameters such as the network volume fraction and orientation, the realignment of the fibers in response to strain, the interactions among the fibers and the interactions between the fibers and the interstitial fluid in order to predict the overall tissue behavior. Therefore, instead of using a constitutive equation to relate strain to stress, the tissue microstructure is modeled within a representative volume element (RVE) and the macroscopic response at any point in the tissue is determined by solving a micromechanics problem in the RVE. The model was applied successfully to acellular collagen gels, native blood vessels, and electrospun polyurethane scaffolds and provided accurate predictions for permeability calculations in isotropic and oriented fiber networks. The agreement of model predictions with experimentally determined mechanical properties provided insights into the mechanics of tissues and tissue constructs, while discrepancies revealed limitations of the model framework.

  6. Adipose Tissue Biology: An Update Review

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2009-12-01

    Full Text Available BACKGROUND: Obesity is a major health problem in most countries in the world today. It increases the risk of diabetes, heart disease, fatty liver and some form of cancer. Adipose tissue biology is currently one of the “hot” areas of biomedical science, as fundamental for the development of novel therapeutics for obesity and its related disorders.CONTENT: Adipose tissue consist predominantly of adipocytes, adipose-derived stromal cells (ASCs, vascular endothelial cells, pericytes, fibroblast, macrophages, and extracellular matrix. Adipose tissue metabolism is extremely dynamic, and the supply of and removal of substrates in the blood is acutely regulated according to the nutritional state. Adipose tissue possesses the ability to a very large extent to modulate its own metabolic activities including differentiation of new adipocytes and production of blood vessels as necessary to accommodate increasing fat stores. At the same time, adipocytes signal to other tissue to regulate their energy metabolism in accordance with the body's nutritional state. Ultimately adipocyte fat stores have to match the body's overall surplus or deficit of energy. Obesity causes adipose tissue dysfunction and results in obesity-related disorders. SUMMARY: It is now clear that adipose tissue is a complex and highly active metabolic and endocrine organ. Undestanding the molecular mechanisms underlying obesity and its associated disease cluster is also of great significance as the need for new and more effective therapeutic strategies is more urgent than ever.  KEYWORDS: obesity, adipocyte, adipose, tissue, adipogenesis, angiogenesis, lipid droplet, lipolysis, plasticity, dysfunction.

  7. Processing laboratory of radio sterilized biological tissues

    International Nuclear Information System (INIS)

    Aguirre H, Paulina; Zarate S, Herman; Silva R, Samy; Hitschfeld, Mario

    2005-01-01

    The nuclear development applications have also reached those areas related to health. The risk of getting contagious illnesses through applying biological tissues has been one of the paramount worries to be solved since infectious illnesses might be provoked by virus, fungis or bacterias coming from donors or whether they have been introduced by means of intermediate stages before the use of these tissues. Therefore it has been concluded that the tissue allografts must be sterilized. The sterilization of medical products has been one of the main applications of the ionizing radiations and that it is why the International Organization of Atomic Energy began in the 70s promoting works related to the biological tissue sterilization and pharmaceutical products. The development of different tissue preservation methods has made possible the creation of tissue banks in different countries, to deal with long-term preservation. In our country, a project was launched in 1998, 'Establishment of a Tissue Bank in Latino america', this project was supported by the OIEA through the project INT/ 6/ 049, and was the starting of the actual Processing Laboratory of Radioesterilized Biological Tissues (LPTR), leaded by the Chilean Nuclear Energy Commission (CCHEN). This first organization is part of a number of entities compounding the Tissue Bank in Chile, organizations such as the Transplantation Promotion Corporation hospitals and the LPTR. The working system is carried out by means of the interaction between the hospitals and the laboratory. The medical professionals perform the procuring of tissues in the hospitals, then send them to the LPTR where they are processed and sterilized with ionizing radiation. The cycle ends up with the tissues return released to the hospitals, where they are used, and then the result information is sent to the LPTR as a form of feedback. Up to now, human skin has been processed (64 donors), amniotic membranes (35 donors) and pig skin (175 portions

  8. Sterilization of biological tissues with ionizing radiation

    International Nuclear Information System (INIS)

    Reyes F, M.L.; Martinez P, M.E.; Luna Z, D.

    1997-01-01

    On June 1994, the National Institute of Nuclear Research (ININ) and the South Central Hospital for High Specialty of PEMEX (HCSAE) began a joint work with the finality to obtain radio sterilized amniotic membranes for to be used as cover (biological bandage) in burnt patients. Subsequently the Chemistry Faculty of UNAM and the National Institute of Cardiology began to collaborate this last with interest on cardiac valves for graft. Starting from 1997, the International Atomic Energy Agency (IAEA) supports this project (MEX/7/008) whose main objective is to set up the basis to establish in Mexico a Radio sterilized Tissue Bank (amniotic membranes, skin, bones, tendons, cardiac valves, etc.) to be used with therapeutic purposes (grafts). The IAEA support has consisted in the equipment acquisition which is fundamental for the Tissue Bank performance such as an experimental irradiator, laminar flow bell, lyophilizer, vacuum sealer and special knives for tissues. Also visits to Mexico of experts have been authorized with the aim of advising to the personnel which participate in the project and scientific visits of this personnel to another tissue banks (Sri Lanka and Argentine). The establishment in Mexico of a Tissue bank will be a great benefit because it will have availability of distinct tissues for grafts and it will reduce the synthetic materials importation which is very expensive. (Author)

  9. Carotenoids in Adipose Tissue Biology and Obesity.

    Science.gov (United States)

    Bonet, M Luisa; Canas, Jose A; Ribot, Joan; Palou, Andreu

    2016-01-01

    Cell, animal and human studies dealing with carotenoids and carotenoid derivatives as nutritional regulators of adipose tissue biology with implications for the etiology and management of obesity and obesity-related metabolic diseases are reviewed. Most studied carotenoids in this context are β-carotene, cryptoxanthin, astaxanthin and fucoxanthin, together with β-carotene-derived retinoids and some other apocarotenoids. Studies indicate an impact of these compounds on essential aspects of adipose tissue biology including the control of adipocyte differentiation (adipogenesis), adipocyte metabolism, oxidative stress and the production of adipose tissue-derived regulatory signals and inflammatory mediators. Specific carotenoids and carotenoid derivatives restrain adipogenesis and adipocyte hypertrophy while enhancing fat oxidation and energy dissipation in brown and white adipocytes, and counteract obesity in animal models. Intake, blood levels and adipocyte content of carotenoids are reduced in human obesity. Specifically designed human intervention studies in the field, though still sparse, indicate a beneficial effect of carotenoid supplementation in the accrual of abdominal adiposity. In summary, studies support a role of specific carotenoids and carotenoid derivatives in the prevention of excess adiposity, and suggest that carotenoid requirements may be dependent on body composition.

  10. Nonlinear Rheology in a Model Biological Tissue.

    Science.gov (United States)

    Matoz-Fernandez, D A; Agoritsas, Elisabeth; Barrat, Jean-Louis; Bertin, Eric; Martens, Kirsten

    2017-04-14

    The rheological response of dense active matter is a topic of fundamental importance for many processes in nature such as the mechanics of biological tissues. One prominent way to probe mechanical properties of tissues is to study their response to externally applied forces. Using a particle-based model featuring random apoptosis and environment-dependent division rates, we evidence a crossover from linear flow to a shear-thinning regime with an increasing shear rate. To rationalize this nonlinear flow we derive a theoretical mean-field scenario that accounts for the interplay of mechanical and active noise in local stresses. These noises are, respectively, generated by the elastic response of the cell matrix to cell rearrangements and by the internal activity.

  11. The sensitivity of biological tissue to ultrasound.

    Science.gov (United States)

    Barnett, S B; Rott, H D; ter Haar, G R; Ziskin, M C; Maeda, K

    1997-01-01

    Mammalian tissues have differing sensitivities to damage by physical agents such as ultrasound. This article evaluates the scientific data in terms of known physical mechanisms of interaction and the impact on pre- and postnatal tissues. Actively dividing cells of the embryonic and fetal central nervous system are most readily disturbed. As a diagnostic ultrasound beam envelopes a small volume of tissue, it is possible that the effects of mild disturbance may not be detected unless major neural pathways are involved. There is evidence that ultrasound can be detected by the central nervous system; however, this does not necessarily imply that the bioeffect is hazardous to the fetus. Biologically significant temperature increases can occur at or near to bone in the fetus from the second trimester, if the beam is held stationary for more than 30 s in some pulsed Doppler applications. In this way, sensory organs that are encased in bone may be susceptible to heating by conduction. Reports in animals and humans of retarded growth and development following frequent exposures to diagnostic ultrasound, in the absence of significant heating, are difficult to explain from the current knowledge of ultrasound mechanisms. There is no evidence of cavitation effects occurring in the soft tissues of the fetus when exposed to diagnostic ultrasound; however, the possibility exists that such effects may be enhanced by the introduction of echo-contrast agents.

  12. Engineering Biology by Controlling Tissue Folding.

    Science.gov (United States)

    Hookway, Tracy A

    2018-04-01

    Achieving complex self-organization in vitro has remained a fundamental challenge in tissue engineering. A recent study in Developmental Cell by Hughes and colleagues uses computational and experimental approaches to understand and control the morphogenic process of tissue folding. These approaches provide an engineering framework to reproducibly control tissue shape. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Depth-resolved fluorescence of biological tissue

    Science.gov (United States)

    Wu, Yicong; Xi, Peng; Cheung, Tak-Hong; Yim, So Fan; Yu, Mei-Yung; Qu, Jianan Y.

    2005-06-01

    The depth-resolved autofluorescence ofrabbit oral tissue, normal and dysplastic human ectocervical tissue within l20μm depth were investigated utilizing a confocal fluorescence spectroscopy with the excitations at 355nm and 457nm. From the topmost keratinizing layer of oral and ectocervical tissue, strong keratin fluorescence with the spectral characteristics similar to collagen was observed. The fluorescence signal from epithelial tissue between the keratinizing layer and stroma can be well resolved. Furthermore, NADH and FADfluorescence measured from the underlying non-keratinizing epithelial layer were strongly correlated to the tissue pathology. This study demonstrates that the depth-resolved fluorescence spectroscopy can reveal fine structural information on epithelial tissue and potentially provide more accurate diagnostic information for determining tissue pathology.

  14. Tissue Engineering Organs for Space Biology Research

    Science.gov (United States)

    Vandenburgh, H. H.; Shansky, J.; DelTatto, M.; Lee, P.; Meir, J.

    1999-01-01

    Long-term manned space flight requires a better understanding of skeletal muscle atrophy resulting from microgravity. Atrophy most likely results from changes at both the systemic level (e.g. decreased circulating growth hormone, increased circulating glucocorticoids) and locally (e.g. decreased myofiber resting tension). Differentiated skeletal myofibers in tissue culture have provided a model system over the last decade for gaining a better understanding of the interactions of exogenous growth factors, endogenous growth factors, and muscle fiber tension in regulating protein turnover rates and muscle cell growth. Tissue engineering these cells into three dimensional bioartificial muscle (BAM) constructs has allowed us to extend their use to Space flight studies for the potential future development of countermeasures.

  15. Radiation processing of biological tissues for nuclear disaster management

    International Nuclear Information System (INIS)

    Singh, Rita

    2012-01-01

    A number of surgical procedures require tissue substitutes to repair or replace damaged or diseased tissues. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Allograft tissues provide an excellent alternative to autografts. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. However, the risk of infectious disease transmission via tissue allografts is a major concern. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Radiation processing has well appreciated technological advantages and is the most suitable method for sterilization of biological tissues. Radiation processed biological tissues can be provided by the tissue banks for the management of injuries due to a nuclear disaster. A nuclear detonation will result in a large number of casualties due to the heat, blast and radiation effects of the weapon. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone grafts can be employed for repairing fracture defects, filling in destroyed regions of bone, management of open fractures and joint injuries. Radiation processed tissues have the potential to repair or reconstruct damaged tissues and can be of great assistance in the treatment of injuries due to the nuclear weapon. (author)

  16. Urine: Waste product or biologically active tissue?

    Science.gov (United States)

    2018-03-01

    Historically, urine has been viewed primarily as a waste product with little biological role in the overall health of an individual. Increasingly, data suggest that urine plays a role in human health beyond waste excretion. For example, urine might act as an irritant and contribute to symptoms through interaction with-and potential compromise of-the urothelium. To explore the concept that urine may be a vehicle for agents with potential or occult bioactivity and to discuss existing evidence and novel research questions that may yield insight into such a role, the National Institute of Diabetes and Digestive and Kidney Disease invited experts in the fields of comparative evolutionary physiology, basic science, nephrology, urology, pediatrics, metabolomics, and proteomics (among others) to a Urinology Think Tank meeting on February 9, 2015. This report reflects ideas that evolved from this meeting and current literature, including the concept of urine quality, the biological, chemical, and physical characteristics of urine, including the microbiota, cells, exosomes, pH, metabolites, proteins, and specific gravity (among others). Additionally, the manuscript presents speculative, and hopefully testable, ideas about the functional roles of urine constituents in health and disease. Moving forward, there are several questions that need further understanding and pursuit. There were suggestions to consider actively using various animal models and their biological specimens to elaborate on basic mechanistic information regarding human bladder dysfunction. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  17. Plasma tissue inhibitor of metalloproteinases-1 as a biological marker?

    DEFF Research Database (Denmark)

    Lomholt, Anne F.; Frederiksen, Camilla B.; Christensen, Ib J.

    2007-01-01

    Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) may be a valuable biological marker in Colorectal Cancer (CRC). However, prospective validation of TIMP-1 as a biological marker should include a series of pre-analytical considerations. TIMP-1 is stored in platelets, which may degranulate during...

  18. Fabrication and characterization of biological tissue phantoms with embedded nanoparticles

    Science.gov (United States)

    Skaptsov, A. A.; Ustalkov, S. O.; Mohammed, A. H. M.; Savenko, O. A.; Novikova, A. S.; Kozlova, E. A.; Kochubey, V. I.

    2017-11-01

    Phantoms are imitations of biological tissue, which are used for modelling of the light propagation in biological tissues. Carrying out any biophysical experiments requires an indispensable constancy of the initial experiment conditions. The use of solid undegradable phantoms is the basis to obtain reliable reproducible experimental results. The fabrication of biological tissues phantoms containing high absorbance or fluorescence nanoparticles and corresponding to specific mechanical, optical properties is an actual task. This work describes development, fabrication and characterization of such solid tissue phantoms with embedded CdSe/ZnS quantum dots, gold and upconversion nanoparticles. Luminescence of samples with CdSe/ZnS quantum dots and upconversion nanoparticles were recorded. A sample of gold nanorods was analyzed using thermal gravimetric analysis. It can be concluded that the samples are well suited for experiments on laser thermolysis.

  19. An Error Analysis of Structured Light Scanning of Biological Tissue

    DEFF Research Database (Denmark)

    Jensen, Sebastian Hoppe Nesgaard; Wilm, Jakob; Aanæs, Henrik

    2017-01-01

    This paper presents an error analysis and correction model for four structured light methods applied to three common types of biological tissue; skin, fat and muscle. Despite its many advantages, structured light is based on the assumption of direct reflection at the object surface only....... This assumption is violated by most biological material e.g. human skin, which exhibits subsurface scattering. In this study, we find that in general, structured light scans of biological tissue deviate significantly from the ground truth. We show that a large portion of this error can be predicted with a simple......, statistical linear model based on the scan geometry. As such, scans can be corrected without introducing any specially designed pattern strategy or hardware. We can effectively reduce the error in a structured light scanner applied to biological tissue by as much as factor of two or three....

  20. Biologically inspired collision avoidance system for unmanned vehicles

    Science.gov (United States)

    Ortiz, Fernando E.; Graham, Brett; Spagnoli, Kyle; Kelmelis, Eric J.

    2009-05-01

    In this project, we collaborate with researchers in the neuroscience department at the University of Delaware to develop an Field Programmable Gate Array (FPGA)-based embedded computer, inspired by the brains of small vertebrates (fish). The mechanisms of object detection and avoidance in fish have been extensively studied by our Delaware collaborators. The midbrain optic tectum is a biological multimodal navigation controller capable of processing input from all senses that convey spatial information, including vision, audition, touch, and lateral-line (water current sensing in fish). Unfortunately, computational complexity makes these models too slow for use in real-time applications. These simulations are run offline on state-of-the-art desktop computers, presenting a gap between the application and the target platform: a low-power embedded device. EM Photonics has expertise in developing of high-performance computers based on commodity platforms such as graphic cards (GPUs) and FPGAs. FPGAs offer (1) high computational power, low power consumption and small footprint (in line with typical autonomous vehicle constraints), and (2) the ability to implement massively-parallel computational architectures, which can be leveraged to closely emulate biological systems. Combining UD's brain modeling algorithms and the power of FPGAs, this computer enables autonomous navigation in complex environments, and further types of onboard neural processing in future applications.

  1. Applying elastic fibre biology in vascular tissue engineering

    OpenAIRE

    Kielty, Cay M; Stephan, Simon; Sherratt, Michael J; Williamson, Matthew; Shuttleworth, C. Adrian

    2007-01-01

    For the treatment of vascular disease, the major cause of death in Western society, there is an urgent need for tissue-engineered, biocompatible, small calibre artery substitutes that restore biological function. Vascular tissue engineering of such grafts involves the development of compliant synthetic or biomaterial scaffolds that incorporate vascular cells and extracellular matrix. Elastic fibres are major structural elements of arterial walls that can enhance vascular graft design and pate...

  2. Application of Biological Tissue Grafts for Burns in Zambia

    International Nuclear Information System (INIS)

    Chishimba, Gershom

    2001-01-01

    The author discusses the advances made in the use of Biological Tissue Grafts for the treatment of burns.The paper outlines research activities and clinical trials done in the use of gamma radiation sterilised Amnion membranes and Pig skin grafts in the zambian Heath Care System for treatment of Burns.Ethical issues of Tissue Banking are also discussed in relation to religious and cultural beliefs and Good Manufacturing Practices

  3. Quantitative imaging of single upconversion nanoparticles in biological tissue.

    Directory of Open Access Journals (Sweden)

    Annemarie Nadort

    Full Text Available The unique luminescent properties of new-generation synthetic nanomaterials, upconversion nanoparticles (UCNPs, enabled high-contrast optical biomedical imaging by suppressing the crowded background of biological tissue autofluorescence and evading high tissue absorption. This raised high expectations on the UCNP utilities for intracellular and deep tissue imaging, such as whole animal imaging. At the same time, the critical nonlinear dependence of the UCNP luminescence on the excitation intensity results in dramatic signal reduction at (∼1 cm depth in biological tissue. Here, we report on the experimental and theoretical investigation of this trade-off aiming at the identification of optimal application niches of UCNPs e.g. biological liquids and subsurface tissue layers. As an example of such applications, we report on single UCNP imaging through a layer of hemolyzed blood. To extend this result towards in vivo applications, we quantified the optical properties of single UCNPs and theoretically analyzed the prospects of single-particle detectability in live scattering and absorbing bio-tissue using a human skin model. The model predicts that a single 70-nm UCNP would be detectable at skin depths up to 400 µm, unlike a hardly detectable single fluorescent (fluorescein dye molecule. UCNP-assisted imaging in the ballistic regime thus allows for excellent applications niches, where high sensitivity is the key requirement.

  4. Biological augmentation and tissue engineering approaches in meniscus surgery.

    Science.gov (United States)

    Moran, Cathal J; Busilacchi, Alberto; Lee, Cassandra A; Athanasiou, Kyriacos A; Verdonk, Peter C

    2015-05-01

    The purpose of this review was to evaluate the role of biological augmentation and tissue engineering strategies in meniscus surgery. Although clinical (human), preclinical (animal), and in vitro tissue engineering studies are included here, we have placed additional focus on addressing preclinical and clinical studies reported during the 5-year period used in this review in a systematic fashion while also providing a summary review of some important in vitro tissue engineering findings in the field over the past decade. A search was performed on PubMed for original works published from 2009 to March 31, 2014 using the term "meniscus" with all the following terms: "scaffolds," "constructs," "cells," "growth factors," "implant," "tissue engineering," and "regenerative medicine." Inclusion criteria were the following: English-language articles and original clinical, preclinical (in vivo), and in vitro studies of tissue engineering and regenerative medicine application in knee meniscus lesions published from 2009 to March 31, 2014. Three clinical studies and 18 preclinical studies were identified along with 68 tissue engineering in vitro studies. These reports show the increasing promise of biological augmentation and tissue engineering strategies in meniscus surgery. The role of stem cell and growth factor therapy appears to be particularly useful. A review of in vitro tissue engineering studies found a large number of scaffold types to be of promise for meniscus replacement. Limitations include a relatively low number of clinical or preclinical in vivo studies, in addition to the fact there is as yet no report in the literature of a tissue-engineered meniscus construct used clinically. Neither does the literature provide clarity on the optimal meniscus scaffold type or biological augmentation with which meniscus repair or replacement would be best addressed in the future. There is increasing focus on the role of mechanobiology and biomechanical and

  5. Nondestructive mechanical characterization of developing biological tissues using inflation testing.

    Science.gov (United States)

    Oomen, P J A; van Kelle, M A J; Oomens, C W J; Bouten, C V C; Loerakker, S

    2017-10-01

    One of the hallmarks of biological soft tissues is their capacity to grow and remodel in response to changes in their environment. Although it is well-accepted that these processes occur at least partly to maintain a mechanical homeostasis, it remains unclear which mechanical constituent(s) determine(s) mechanical homeostasis. In the current study a nondestructive mechanical test and a two-step inverse analysis method were developed and validated to nondestructively estimate the mechanical properties of biological tissue during tissue culture. Nondestructive mechanical testing was achieved by performing an inflation test on tissues that were cultured inside a bioreactor, while the tissue displacement and thickness were nondestructively measured using ultrasound. The material parameters were estimated by an inverse finite element scheme, which was preceded by an analytical estimation step to rapidly obtain an initial estimate that already approximated the final solution. The efficiency and accuracy of the two-step inverse method was demonstrated on virtual experiments of several material types with known parameters. PDMS samples were used to demonstrate the method's feasibility, where it was shown that the proposed method yielded similar results to tensile testing. Finally, the method was applied to estimate the material properties of tissue-engineered constructs. Via this method, the evolution of mechanical properties during tissue growth and remodeling can now be monitored in a well-controlled system. The outcomes can be used to determine various mechanical constituents and to assess their contribution to mechanical homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. A theoretical framework for jamming in confluent biological tissues

    Science.gov (United States)

    Manning, M. Lisa

    2015-03-01

    For important biological functions such as wound healing, embryonic development, and cancer tumorogenesis, cells must initially rearrange and move over relatively large distances, like a liquid. Subsequently, these same tissues must undergo buckling and support shear stresses, like a solid. Our work suggests that biological tissues can accommodate these disparate requirements because the tissues are close to glass or jamming transition. While recent self propelled particle models generically predict a glass/jamming transition that is driven by packing density φ and happens at some critical φc less than unity, many biological tissues that are confluent with no gaps between cells appear to undergo a jamming transition at a constant density (φ = 1). I will discuss a new theoretical framework for predicting energy barriers and rates of cell migration in 2D tissue monolayers, and show that this model predicts a novel type of rigidity transition, which takes place at constant φ = 1 and depends only on single cell properties such as cell-cell adhesion, cortical tension and cell elasticity. This model additionally predicts that an experimentally observable parameter, the ratio between a cell's perimeter and the square root of its cross-sectional area, attains a specific, critical value at the jamming transition. We show that this prediction is precisely realized in primary epithelial cultures from human patients, with implications for asthma pathology.

  7. The model of drugs distribution dynamics in biological tissue

    Science.gov (United States)

    Ginevskij, D. A.; Izhevskij, P. V.; Sheino, I. N.

    2017-09-01

    The dose distribution by Neutron Capture Therapy follows the distribution of 10B in the tissue. The modern models of pharmacokinetics of drugs describe the processes occurring in conditioned "chambers" (blood-organ-tumor), but fail to describe the spatial distribution of the drug in the tumor and in normal tissue. The mathematical model of the spatial distribution dynamics of drugs in the tissue, depending on the concentration of the drug in the blood, was developed. The modeling method is the representation of the biological structure in the form of a randomly inhomogeneous medium in which the 10B distribution occurs. The parameters of the model, which cannot be determined rigorously in the experiment, are taken as the quantities subject to the laws of the unconnected random processes. The estimates of 10B distribution preparations in the tumor and healthy tissue, inside/outside the cells, are obtained.

  8. Laser Ablation of Biological Tissue Using Pulsed CO2 Laser

    International Nuclear Information System (INIS)

    Hashishin, Yuichi; Sano, Shu; Nakayama, Takeyoshi

    2010-01-01

    Laser scalpels are currently used as a form of laser treatment. However, their ablation mechanism has not been clarified because laser excision of biological tissue occurs over a short time scale. Biological tissue ablation generates sound (laser-induced sound). This study seeks to clarify the ablation mechanism. The state of the gelatin ablation was determined using a high-speed video camera and the power reduction of a He-Ne laser beam. The aim of this study was to clarify the laser ablation mechanism by observing laser excision using the high-speed video camera and monitoring the power reduction of the He-Ne laser beam. We simulated laser excision of a biological tissue by irradiating gelatin (10 wt%) with radiation from a pulsed CO 2 laser (wavelength: 10.6 μm; pulse width: 80 ns). In addition, a microphone was used to measure the laser-induced sound. The first pulse caused ablation particles to be emitted in all directions; these particles were subsequently damped so that they formed a mushroom cloud. Furthermore, water was initially evaporated by laser irradiation and then tissue was ejected.

  9. Comparison of ballistic impact effects between biological tissue and gelatin.

    Science.gov (United States)

    Jin, Yongxi; Mai, Ruimin; Wu, Cheng; Han, Ruiguo; Li, Bingcang

    2018-02-01

    Gelatin is commonly used in ballistic testing as substitute for biological tissue. Comparison of ballistic impact effects produced in the gelatin and living tissue is lacking. The work in this paper was aimed to compare the typical ballistic impact effects (penetration trajectory, energy transfer, temporary cavity) caused by 4.8mm steel ball penetrating the 60kg porcine hind limbs and 10wt% gelatin. The impact event in the biological tissue was recorded by high speed flash X-ray machine at different delay time, while the event in the gelatin continuously recorded by high speed video was compared to that in the biological tissue. The collected results clearly displayed that the ballistic impact effects in the muscle and gelatin were similar for the steel ball test; as for instance, the projectile trajectory in the two targets was basically similar, the process of energy transfer was highly coincident, and the expansion of temporary cavity followed the same pattern. This study fully demonstrated that choosing gelatin as muscle simulant was reasonable. However, the maximum temporary cavity diameter in the gelatin was a little larger than that in the muscle, and the expansion period of temporary cavity was longer in the gelatin. Additionally, the temporary cavity collapse process in the two targets followed different patterns, and the collapse period in the gelatin was two times as long as that in the muscle. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The development and application of an injury prediction model for noncontact, soft-tissue injuries in elite collision sport athletes.

    Science.gov (United States)

    Gabbett, Tim J

    2010-10-01

    Limited information exists on the training dose-response relationship in elite collision sport athletes. In addition, no study has developed an injury prediction model for collision sport athletes. The purpose of this study was to develop an injury prediction model for noncontact, soft-tissue injuries in elite collision sport athletes. Ninety-one professional rugby league players participated in this 4-year prospective study. This study was conducted in 2 phases. Firstly, training load and injury data were prospectively recorded over 2 competitive seasons in elite collision sport athletes. Training load and injury data were modeled using a logistic regression model with a binomial distribution (injury vs. no injury) and logit link function. Secondly, training load and injury data were prospectively recorded over a further 2 competitive seasons in the same cohort of elite collision sport athletes. An injury prediction model based on planned and actual training loads was developed and implemented to determine if noncontact, soft-tissue injuries could be predicted and therefore prevented in elite collision sport athletes. Players were 50-80% likely to sustain a preseason injury within the training load range of 3,000-5,000 units. These training load 'thresholds' were considerably reduced (1,700-3,000 units) in the late-competition phase of the season. A total of 159 noncontact, soft-tissue injuries were sustained over the latter 2 seasons. The percentage of true positive predictions was 62.3% (n = 121), whereas the total number of false positive and false negative predictions was 20 and 18, respectively. Players that exceeded the training load threshold were 70 times more likely to test positive for noncontact, soft-tissue injury, whereas players that did not exceed the training load threshold were injured 1/10 as often. These findings provide information on the training dose-response relationship and a scientific method of monitoring and regulating training load in

  11. Applying elastic fibre biology in vascular tissue engineering.

    Science.gov (United States)

    Kielty, Cay M; Stephan, Simon; Sherratt, Michael J; Williamson, Matthew; Shuttleworth, C Adrian

    2007-08-29

    For the treatment of vascular disease, the major cause of death in Western society, there is an urgent need for tissue-engineered, biocompatible, small calibre artery substitutes that restore biological function. Vascular tissue engineering of such grafts involves the development of compliant synthetic or biomaterial scaffolds that incorporate vascular cells and extracellular matrix. Elastic fibres are major structural elements of arterial walls that can enhance vascular graft design and patency. In blood vessels, they endow vessels with the critical property of elastic recoil. They also influence vascular cell behaviour through direct interactions and by regulating growth factor activation. This review addresses physiological elastic fibre assembly and contributions to vessel structure and function, and how elastic fibre biology is now being exploited in small diameter vascular graft design.

  12. Investigation of anisotropic scattering for optical tomography in biological tissues

    International Nuclear Information System (INIS)

    Mercimek, M.; Yildirim, H.; Geckinli, M.; Aydin, M.; Aydin, E. D.

    2009-01-01

    Photons with wavelengths in near infrared region are used in optical tomography. Radiation transport theory should be preferred instead of diffusion theory for numerical modelling of photon migration in biological tissues, where diffusion theory is invalid. For example, diffusion theory is not sufficient in the regions of close to boundaries, sources or sinks and highly absorbing or void-like media. Also anisotropic scattering must be considered in the numerical models since scattering is generally highly anisotropic in biological tissues. In addition to the absorption and scattering coefficients, a suitable phase function must be known in anisotropic scattering study. Here we have compared scattering phase functions for anisotropy. Then we have calculated Legendre moments which are necessary for the implementation of anisotropy factors into the transport code, PARTISN. Discrete ordinates method (SN) has been used in the transport calculations. We have obtained solutions first a homogeneous and then heterogeneous medium.

  13. A measurement of biomechanical properties of soft biological tissues

    Science.gov (United States)

    Sauer, Piotr; Kozłowski, Krzysztof; Majchrzak, Jarosław; Waliszewski, Wojciech

    2007-12-01

    We present a method to determine the mechanical behaviour of soft biological tissues. This work presents ex vivo force response between laparoscopic tool and the pig liver. We used measurement system which is based on Staubli robot RX60 and a force sensor mounted at its end. Results of measurement will be used in surgery telerobotic system to create the force feedback to secure additionally the surgery.

  14. Universal strain stiffening in biological gels and tissues

    Science.gov (United States)

    Storm, Cornelis; Pastore, Jennifer; Mackintosh, Fred; Lubensky, Tom; Janmey, Paul

    2003-03-01

    Unlike most synthetic materials, many biological materials get stiffer as they are deformed. This nonlinear elastic response, critical for physiologic function of tissues such as the blood vessel wall, has been documented since at least the 19th century but the molecular structure and the design principles responsible for it are unknown. In various systems, different hypotheses ranging from complex multiphase structures to tensegrity models have been proposed to explain strain-stiffening in biological gels and tissues, and in these cases the specific viscoelastic properties depend critically on the detailed assembly and geometry of the highly ordered material. In this presentation we show that a much simpler molecular theory accounts for the most dramatic forms of strain stiffening found in a wide range of molecularly distinct biopolymer gels ranging from purified cytoskeletal and extracellular matrix gels to intact tissues such as the mesentery. The theory shows that the physics of semi flexible chains arranged in an open crosslinked meshwork invariably stiffen at low strains independent of the need for a specific architecture or multiple elements with different intrinsic stiffness. These findings explain why stiff polymers are chosen over more flexibler ones in tissues where only a limited range of deformation is appropriate.

  15. Motility-driven glass and jamming transitions in biological tissues

    Science.gov (United States)

    Bi, Dapeng; Yang, Xingbo; Marchetti, M. Cristina; Manning, M. Lisa

    2017-01-01

    Cell motion inside dense tissues governs many biological processes, including embryonic development and cancer metastasis, and recent experiments suggest that these tissues exhibit collective glassy behavior. To make quantitative predictions about glass transitions in tissues, we study a self-propelled Voronoi (SPV) model that simultaneously captures polarized cell motility and multi-body cell-cell interactions in a confluent tissue, where there are no gaps between cells. We demonstrate that the model exhibits a jamming transition from a solid-like state to a fluid-like state that is controlled by three parameters: the single-cell motile speed, the persistence time of single-cell tracks, and a target shape index that characterizes the competition between cell-cell adhesion and cortical tension. In contrast to traditional particulate glasses, we are able to identify an experimentally accessible structural order parameter that specifies the entire jamming surface as a function of model parameters. We demonstrate that a continuum Soft Glassy Rheology model precisely captures this transition in the limit of small persistence times, and explain how it fails in the limit of large persistence times. These results provide a framework for understanding the collective solid-to-liquid transitions that have been observed in embryonic development and cancer progression, which may be associated with Epithelial-to-Mesenchymal transition in these tissues. PMID:28966874

  16. Development of an algorithm for quantifying extremity biological tissue

    International Nuclear Information System (INIS)

    Pavan, Ana L.M.; Miranda, Jose R.A.; Pina, Diana R. de

    2013-01-01

    The computerized radiology (CR) has become the most widely used device for image acquisition and production, since its introduction in the 80s. The detection and early diagnosis, obtained via CR, are important for the successful treatment of diseases such as arthritis, metabolic bone diseases, tumors, infections and fractures. However, the standards used for optimization of these images are based on international protocols. Therefore, it is necessary to compose radiographic techniques for CR system that provides a secure medical diagnosis, with doses as low as reasonably achievable. To this end, the aim of this work is to develop a quantifier algorithm of tissue, allowing the construction of a homogeneous end used phantom to compose such techniques. It was developed a database of computed tomography images of hand and wrist of adult patients. Using the Matlab ® software, was developed a computational algorithm able to quantify the average thickness of soft tissue and bones present in the anatomical region under study, as well as the corresponding thickness in simulators materials (aluminium and lucite). This was possible through the application of mask and Gaussian removal technique of histograms. As a result, was obtained an average thickness of soft tissue of 18,97 mm and bone tissue of 6,15 mm, and their equivalents in materials simulators of 23,87 mm of acrylic and 1,07mm of aluminum. The results obtained agreed with the medium thickness of biological tissues of a patient's hand pattern, enabling the construction of an homogeneous phantom

  17. Low Level Laser Therapy: laser radiation absorption in biological tissues

    Science.gov (United States)

    Di Giacomo, Paola; Orlando, Stefano; Dell'Ariccia, Marco; Brandimarte, Bruno

    2013-07-01

    In this paper we report the results of an experimental study in which we have measured the transmitted laser radiation through dead biological tissues of various animals (chicken, adult and young bovine, pig) in order to evaluate the maximum thickness through which the power density could still produce a reparative cellular effect. In our experiments we have utilized a pulsed laser IRL1 ISO model (based on an infrared diode GaAs, λ=904 nm) produced by BIOMEDICA s.r.l. commonly used in Low Level Laser Therapy. Some of the laser characteristics have been accurately studied and reported in this paper. The transmission results suggest that even with tissue thicknesses of several centimeters the power density is still sufficient to produce a cell reparative effect.

  18. Tissue Engineering a Biological Repair Strategy for Lumbar Disc Herniation

    Science.gov (United States)

    O'Connell, Grace D.; Leach, J. Kent; Klineberg, Eric O.

    2015-01-01

    Abstract The intervertebral disc is a critical part of the intersegmental soft tissue of the spinal column, providing flexibility and mobility, while absorbing large complex loads. Spinal disease, including disc herniation and degeneration, may be a significant contributor to low back pain. Clinically, disc herniations are treated with both nonoperative and operative methods. Operative treatment for disc herniation includes removal of the herniated material when neural compression occurs. While this strategy may have short-term advantages over nonoperative methods, the remaining disc material is not addressed and surgery for mild degeneration may have limited long-term advantage over nonoperative methods. Furthermore, disc herniation and surgery significantly alter the mechanical function of the disc joint, which may contribute to progression of degeneration in surrounding tissues. We reviewed recent advances in tissue engineering and regenerative medicine strategies that may have a significant impact on disc herniation repair. Our review on tissue engineering strategies focuses on cell-based and inductive methods, each commonly combined with material-based approaches. An ideal clinically relevant biological repair strategy will significantly reduce pain and repair and restore flexibility and motion of the spine. PMID:26634189

  19. Temperature dependence of thermal conductivity of biological tissues.

    Science.gov (United States)

    Bhattacharya, A; Mahajan, R L

    2003-08-01

    In this paper, we present our experimental results on the determination of the thermal conductivity of biological tissues using a transient technique based on the principles of the cylindrical hot-wire method. A novel, 1.45 mm diameter, 50 mm long hot-wire probe was deployed. Initial measurements were made on sponge, gelatin and Styrofoam insulation to test the accuracy of the probe. Subsequent experiments conducted on sheep collagen in the range of 25 degrees C thermal conductivity to be a linear function of temperature. Further, these changes in the thermal conductivity were found to be reversible. However, when the tissue was heated beyond 55 degrees C, irreversible changes in thermal conductivity were observed. Similar experiments were also conducted for determining the thermal conductivity of cow liver. In this case, the irreversible effects were found to set in much later at around 90 degrees C. Below this temperature, in the range of 25 degrees C thermal conductivity, as for sheep collagen, varied linearly with temperature. In the second part of our study, in vivo measurements were taken on the different organs of a living pig. Comparison with reported values for dead tissues shows the thermal conductivities of living organs to be higher, indicating thereby the dominant role played by blood perfusion in enhancing the net heat transfer in living tissues. The degree of enhancement is different in different organs and shows a direct dependence on the blood flow rate.

  20. Modeling biological tissue growth: discrete to continuum representations.

    Science.gov (United States)

    Hywood, Jack D; Hackett-Jones, Emily J; Landman, Kerry A

    2013-09-01

    There is much interest in building deterministic continuum models from discrete agent-based models governed by local stochastic rules where an agent represents a biological cell. In developmental biology, cells are able to move and undergo cell division on and within growing tissues. A growing tissue is itself made up of cells which undergo cell division, thereby providing a significant transport mechanism for other cells within it. We develop a discrete agent-based model where domain agents represent tissue cells. Each agent has the ability to undergo a proliferation event whereby an additional domain agent is incorporated into the lattice. If a probability distribution describes the waiting times between proliferation events for an individual agent, then the total length of the domain is a random variable. The average behavior of these stochastically proliferating agents defining the growing lattice is determined in terms of a Fokker-Planck equation, with an advection and diffusion term. The diffusion term differs from the one obtained Landman and Binder [J. Theor. Biol. 259, 541 (2009)] when the rate of growth of the domain is specified, but the choice of agents is random. This discrepancy is reconciled by determining a discrete-time master equation for this process and an associated asymmetric nonexclusion random walk, together with consideration of synchronous and asynchronous updating schemes. All theoretical results are confirmed with numerical simulations. This study furthers our understanding of the relationship between agent-based rules, their implementation, and their associated partial differential equations. Since tissue growth is a significant cellular transport mechanism during embryonic growth, it is important to use the correct partial differential equation description when combining with other cellular functions.

  1. Estimation of anisotropy factor spectrum for determination of optical properties in biological tissues

    Science.gov (United States)

    Iwamoto, Misako; Honda, Norihiro; Ishii, Katsunori; Awazu, Kunio

    2017-07-01

    Spectroscopic setup for measuring anisotropy factor g spectrum of biological tissues was constructed. g of chicken liver tissue was lower than chicken breast tissue. High absorption of hemoglobin can have an influence on g spectrum.

  2. Fundamental Mechanisms of Pulsed Laser Ablation of Biological Tissue

    Science.gov (United States)

    Albagli, Douglas

    The ability to cut and remove biological tissue with short pulsed laser light, a process called laser ablation, has the potential to revolutionize many surgical procedures. Ablation procedures using short pulsed lasers are currently being developed or used in many fields of medicine, including cardiology, ophthalmology, dermatology, dentistry, orthopedics, and urology. Despite this, the underlying physics of the ablation process is not well understood. In fact, there is wide disagreement over whether the fundamental mechanism is primarily photothermal, photomechanical, or photochemical. In this thesis, both experimental and theoretical techniques are developed to explore this issue. The photothermal model postulates that ablation proceeds through vaporization of the target material. The photomechanical model asserts that ablation is initiated when the laser-induced tensile stress exceeds the ultimate tensile strength of the target. I have developed a three dimensional model of the thermoelastic response of tissue to short pulsed laser irradiation which allows the time dependent stress distribution to be calculated given the optical, thermal and mechanical properties of the target. A complimentary experimental technique has been developed to verify this model, measure the needed physical properties of the tissue, and record the thermoelastic response of the tissue at the onset of ablation. The results of this work have been widely disseminated to the international research community and have led to significant findings which support the photomechanical model of ablation of tissue. First, the energy deposited in tissue is an order of magnitude less than that required for vaporization. Second, unlike the one-dimensional thermoelastic model of laser-induced stress generation that has appeared in the literature, the full three-dimensional model predicts the development of significant tensile stresses on the surface of the target, precisely where ablation is observed to

  3. A model of engineering materials inspired by biological tissues

    Directory of Open Access Journals (Sweden)

    Holeček M.

    2009-12-01

    Full Text Available The perfect ability of living tissues to control and adapt their mechanical properties to varying external conditions may be an inspiration for designing engineering materials. An interesting example is the smooth muscle tissue since this "material" is able to change its global mechanical properties considerably by a subtle mechanism within individual muscle cells. Multi-scale continuum models may be useful in designing essentially simpler engineering materials having similar properties. As an illustration we present the model of an incompressible material whose microscopic structure is formed by flexible, soft but incompressible balls connected mutually by linear springs. This simple model, however, shows a nontrivial nonlinear behavior caused by the incompressibility of balls and is very sensitive on some microscopic parameters. It may elucidate the way by which "small" changes in biopolymer networks within individual muscular cells may control the stiffness of the biological tissue, which outlines a way of designing similar engineering materials. The 'balls and springs' material presents also prestress-induced stiffening and allows elucidating a contribution of extracellular fluids into the tissue’s viscous properties.

  4. Scattered and Fluorescent Photon Track Reconstruction in a Biological Tissue

    Directory of Open Access Journals (Sweden)

    Maria N. Kholodtsova

    2014-01-01

    Full Text Available Appropriate analysis of biological tissue deep regions is important for tumor targeting. This paper is concentrated on photons’ paths analysis in such biotissue as brain, because optical probing depth of fluorescent and excitation radiation differs. A method for photon track reconstruction was developed. Images were captured focusing on the transparent wall close and parallel to the source fibres, placed in brain tissue phantoms. The images were processed to reconstruct the photons most probable paths between two fibres. Results were compared with Monte Carlo simulations and diffusion approximation of the radiative transfer equation. It was shown that the excitation radiation optical probing depth is twice more than for the fluorescent photons. The way of fluorescent radiation spreading was discussed. Because of fluorescent and excitation radiation spreads in different ways, and the effective anisotropy factor, geff, was proposed for fluorescent radiation. For the brain tissue phantoms it were found to be 0.62±0.05 and 0.66±0.05 for the irradiation wavelengths 532 nm and 632.8 nm, respectively. These calculations give more accurate information about the tumor location in biotissue. Reconstruction of photon paths allows fluorescent and excitation probing depths determination. The geff can be used as simplified parameter for calculations of fluorescence probing depth.

  5. Biologically active and biomimetic dual gelatin scaffolds for tissue engineering.

    Science.gov (United States)

    Sánchez, P; Pedraz, J L; Orive, G

    2017-05-01

    We have designed, developed and optimized Genipin cross-linked 3D gelatin scaffolds that were biologically active and biomimetic, show a dual activity both for growth factor and cell delivery. Type B gelatin powder was dissolved in DI water. 100mg of genipin was dissolved in 10ml of DI water. Three genipin concentrations were prepared: 0.1%, 0.2% and 0.3% (w/v). Solutions were mixed at 40°C and under stirring and then left crosslinking for 72h. Scaffolds were obtained by punching 8 mm-cylinders into ethanol 70% solution for 10min and then freeze-drying. Scaffolds were biologically, biomechanically and morphologically evaluated. Cell adhesion and morphology of D1-Mesenchymal stem cells (MSCs) and L-929 fibroblast was studied. Vascular endothelial grwoth factor (VEGF) and Sonic hedgehog (SHH) were used as model proteins. Swelling ratio increased and younǵs module decreased along with the concentration of genipin. All scaffolds were biocompatible according to the toxicity test. MSC and L-929 cell adhesion improved in 0.2% of genipin, obtaining better results with MSCs. VEGF and SHH were released from the gels. This preliminary study suggest that the biologically active and dual gelatin scaffolds may be used for tissue engineering approaches like bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Computation of forces from deformed visco-elastic biological tissues

    Science.gov (United States)

    Muñoz, José J.; Amat, David; Conte, Vito

    2018-04-01

    We present a least-squares based inverse analysis of visco-elastic biological tissues. The proposed method computes the set of contractile forces (dipoles) at the cell boundaries that induce the observed and quantified deformations. We show that the computation of these forces requires the regularisation of the problem functional for some load configurations that we study here. The functional measures the error of the dynamic problem being discretised in time with a second-order implicit time-stepping and in space with standard finite elements. We analyse the uniqueness of the inverse problem and estimate the regularisation parameter by means of an L-curved criterion. We apply the methodology to a simple toy problem and to an in vivo set of morphogenetic deformations of the Drosophila embryo.

  7. BIOLOGICAL EFFECTS OF MICROWAVE RADIATION ON BRAIN TISSUE IN RATS

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2003-04-01

    Full Text Available Exposure to microwave radiation induces multiple organ dysfunctions, especially in CNS.The aim of this work was investigation of biological effects of microwave radiation on rats' brain and determination of increased oxidative stress as a possible pathogenetic's mechanism.Wis tar rats 3 months old were divided in experimental (4 female and 4 male animal and control group (5 female and 4 male. This experimental group was constantly exposed to a magnetic field of 5 mG. We simulated using of mobile phones 30 min every day. The source of NIR emitted MF that was similar to mobile phones at 900 MHz. The rats were killed after 2 months. Biological effects were determined by observation of individual and collective behavior and body mass changes. Lipid per oxidation was determined by measuring quantity of malondialdehyde (MDA in brain homogenate.The animals in experimental group exposed to EMF showed les weight gain. The most important observations were changing of basic behavior models and expression of aggressive or panic behavior. The content of MDA in brain tissue is singificantly higher (1.42 times in rats exposed to electromagnetic fields (3,82±0.65 vs. control 2.69±0.42 nmol/mg proteins, p<0.01.Increased oxidative stress and lipid peroxidation after exposition in EM fields induced disorders of function and structure of brain.

  8. Xenografted tissue models for the study of human endometrial biology.

    Science.gov (United States)

    Kuokkanen, Satu; Zhu, Liyin; Pollard, Jeffrey W

    The human endometrium undergoes extensive morphological, biochemical and molecular changes under the influence of female sex steroid hormones. Besides the fact that estrogen stimulates endometrial cell proliferation and progesterone inhibits this proliferation and induces differentiation, there is limited knowledge about precise molecular mechanisms underlying human endometrial biology. The importance of paracrine signaling in endometrial physiology explains why in vitro culture of endometrial cells has been challenging. Researchers, therefore, have developed alternative experimental in vivo models for the study of endometrial biology. The objective of this review is to summarize the recent developments and work on these in vivo endometrial research models. The in vivo recombinant tissue models in which wild-type endometrial cells are combined with endometrial cells from a gene-targeted mouse strain followed by xenografting to host mice have been critical in confirming the significance of paracrine signaling between the epithelium and stroma in the growth regulation of the endometrium. Additionally, these studies have uncovered differences between the mouse and human, emphasizing the need for the development of experimental models specifically of the human endometrium. Recently, xenotransplants of human endometrial fragments into the subcutaneous space of host mice and endometrial xenografts of dissociated and recombined epithelial and stromal cells beneath the kidney capsule of immunodeficient host mice have proven to be highly promising tools for in vivo research of endometrial functions. For the first time, the latter approach provides an immense opportunity for the application of genome engineering, such as targeted ablation of endometrial genes for example by using CRISPR/CAS9 system. This research will begin to elucidate the functional role of specific genes in this complex tissue. Another advantage of xenotransplantation and xenograft models of the human

  9. Pressure and temperature distribution in biological tissues by focused ultrasound

    Science.gov (United States)

    Mal, Ajit K.; Feng, Feng; Kabo, Michael; Wang, Jeffrey; Bar-Cohen, Yoseph

    2003-07-01

    The interaction between ultrasound and biological tissues has been the subject of a number of investigators for nearly half a century and the number of applications of high intensity, focused ultrasound for therapeutic purposes continues to grow. This paper is motivated by possible medical applications of focused ultrasound in minimally invasive treatment of a variety of musculoskeletal disorders that are responsive to thermal treatment. The mechanical and thermal effects in a subject"s body induced by high-frequency ultrasound are simulated using PZFlex, a finite element based program. The FEM model described in this report is of a transverse section of the body at the level of the second lumbar vertebra (L2) extracted from a CT image. In order to protect the nerves inside the spinal canal as well as to obtain an effective heating result at the focal region within the intervertebral disk, a suitable orientation of axis of the focused ultrasound lens have to be determined in advance. The pressure, energy loss distribution and temperature distribution are investigated in this paper with the different orientations of the axis and different transverse diameter of the spherical ultrasound lens. Since nonlinear effects are expected to be important in the therapeutic application in some literatures, this paper also demonstrates the effects of nonlinearities on the pressure and temperature distribution induced by focused ultrasound in a two dimensional model. Finally, a comparison of the results between linear and nonlinear cases is reported.

  10. Low angle X-ray scattering in biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Carla; Braz, Delson; Pinto, Nivia G.V.; Lima, Joao C.; Castro, Carlos R.F.; Filgueiras, R.A.; Mendonca, Leonardo; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mail: delson@lin.ufrj.br; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: cely@uerj.br

    2007-07-01

    Low-angle x-ray scatter (LAXS) for tissue characterization is based on the differences which result from the interference of photons coherently scattered from molecules of each sample. Biological samples (bone, blood and blood components) have been studied in recent years in our laboratory using powder diffractometer. The scattering information was obtained using a Shimadzu DRX 6000 diffractometer at the Nuclear Instrumentation Laboratory, Rio de Janeiro, Brazil. Unpolarized monoenergetic K{alpha} radiation from Cu provided 8.04 keV photons. The measurements were made in reflection mode ({theta}-2{theta} geometry), with the sample stationary on a goniometer which rotates the sample and detector about an axis lying in the plane of the top of the sample holder. LAXS profiles from whole blood, plasma and formed elements were measured to investigate the nature of scattering from such lyophilized samples. The statistical analysis shows that the variation found for the characterization parameters is significant for whole blood considering the age. Gender was positively associated with the variation of the second peak position for the profiles obtained for formed elements. The correlation of the measured relative coherent intensity with the mineral content in the bone samples was investigated. These results suggest that the measurement of bone mineral content within trabecular bone can be performed by using quantitative coherent scattering information. (author)

  11. THz near-field imaging of biological tissues employing synchrotronradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Ulrich; Holldack, Karsten; Martin, Michael C.; Fried,Daniel

    2004-12-23

    Terahertz scanning near-field infrared microscopy (SNIM) below 1 THz is demonstrated. The near-field technique benefits from the broadband and highly brilliant coherent synchrotron radiation (CSR) from an electron storage ring and from a detection method based on locking onto the intrinsic time structure of the synchrotron radiation. The scanning microscope utilizes conical wave guides as near-field probes with apertures smaller than the wavelength. Different cone approaches have been investigated to obtain maximum transmittance. Together with a Martin-Puplett spectrometer the set-up enables spectroscopic mapping of the transmittance of samples well below the diffraction limit. Spatial resolution down to about lambda/40 at 2 wavenumbers (0.06 THz) is derived from the transmittance spectra of the near-field probes. The potential of the technique is exemplified by imaging biological samples. Strongly absorbing living leaves have been imaged in transmittance with a spatial resolution of 130 mu-m at about 12 wave numbers (0.36 THz). The THz near-field images reveal distinct structural differences of leaves from different plants investigated. The technique presented also allows spectral imaging of bulky organic tissues. Human teeth samples of various thicknesses have been imaged between 2 and 20 wavenumbers (between 0.06and 0.6 THz). Regions of enamel and dentin within tooth samples are spatially and spectrally resolved, and buried caries lesions are imaged through both the outer enamel and into the underlying dentin.

  12. Tissue invasion and metastasis: Molecular, biological and clinical perspectives.

    Science.gov (United States)

    Jiang, W G; Sanders, A J; Katoh, M; Ungefroren, H; Gieseler, F; Prince, M; Thompson, S K; Zollo, M; Spano, D; Dhawan, P; Sliva, D; Subbarayan, P R; Sarkar, M; Honoki, K; Fujii, H; Georgakilas, A G; Amedei, A; Niccolai, E; Amin, A; Ashraf, S S; Ye, L; Helferich, W G; Yang, X; Boosani, C S; Guha, G; Ciriolo, M R; Aquilano, K; Chen, S; Azmi, A S; Keith, W N; Bilsland, A; Bhakta, D; Halicka, D; Nowsheen, S; Pantano, F; Santini, D

    2015-12-01

    Cancer is a key health issue across the world, causing substantial patient morbidity and mortality. Patient prognosis is tightly linked with metastatic dissemination of the disease to distant sites, with metastatic diseases accounting for a vast percentage of cancer patient mortality. While advances in this area have been made, the process of cancer metastasis and the factors governing cancer spread and establishment at secondary locations is still poorly understood. The current article summarizes recent progress in this area of research, both in the understanding of the underlying biological processes and in the therapeutic strategies for the management of metastasis. This review lists the disruption of E-cadherin and tight junctions, key signaling pathways, including urokinase type plasminogen activator (uPA), phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene (PI3K/AKT), focal adhesion kinase (FAK), β-catenin/zinc finger E-box binding homeobox 1 (ZEB-1) and transforming growth factor beta (TGF-β), together with inactivation of activator protein-1 (AP-1) and suppression of matrix metalloproteinase-9 (MMP-9) activity as key targets and the use of phytochemicals, or natural products, such as those from Agaricus blazei, Albatrellus confluens, Cordyceps militaris, Ganoderma lucidum, Poria cocos and Silybum marianum, together with diet derived fatty acids gamma linolenic acid (GLA) and eicosapentanoic acid (EPA) and inhibitory compounds as useful approaches to target tissue invasion and metastasis as well as other hallmark areas of cancer. Together, these strategies could represent new, inexpensive, low toxicity strategies to aid in the management of cancer metastasis as well as having holistic effects against other cancer hallmarks. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 2nd International Symposium "Atomic Cluster Collisions : Structure and Dynamics from the Nuclear to the Biological Scale"

    CERN Document Server

    Solov'yov, Andrey; ISACC 2007; Latest advances in atomic cluster collisions

    2008-01-01

    This book presents a 'snapshot' of the most recent and significant advances in the field of cluster physics. It is a comprehensive review based on contributions by the participants of the 2nd International Symposium on Atomic Cluster Collisions (ISACC 2007) held in July 19-23, 2007 at GSI, Darmstadt, Germany. The purpose of the Symposium is to promote the growth and exchange of scientific information on the structure and properties of nuclear, atomic, molecular, biological and complex cluster systems studied by means of photonic, electronic, heavy particle and atomic collisions. Particular attention is devoted to dynamic phenomena, many-body effects taking place in cluster systems of a different nature - these include problems of fusion and fission, fragmentation, collective electron excitations, phase transitions, etc.Both the experimental and theoretical aspects of cluster physics, uniquely placed between nuclear physics on the one hand and atomic, molecular and solid state physics on the other, are discuss...

  14. Corrections for inhomogeneities in biological tissue caused by blood vessels

    NARCIS (Netherlands)

    Talsma, A; Chance, B; Graaff, R

    In tissue optics, the assumption that blood is homogeneously distributed in tissue can give rise to miscalculations because blood is found only in blood vessels. In our paper randomly oriented blood vessels are treated as particles for which we obtained apparent absorption and scattering

  15. Exercise and Regulation of Bone and Collagen Tissue Biology

    DEFF Research Database (Denmark)

    Kjær, Michael; Jørgensen, Niklas Rye; Heinemeier, Katja Maria

    2015-01-01

    The musculoskeletal system and its connective tissue include the intramuscular connective tissue, the myotendinous junction, the tendon, the joints with their cartilage and ligaments, and the bone; they all together play a crucial role in maintaining the architecture of the skeletal muscle...

  16. Biological aspects of application of nanomaterials in tissue engineering

    Directory of Open Access Journals (Sweden)

    Markovic Dejan

    2016-01-01

    Full Text Available Millions of patients worldwide need surgery to repair or replace tissue that has been damaged through trauma or disease. To solve the problem of lost tissue, a major emphasis of tissue engineering (TE is on tissue regeneration. Stem cells and highly porous biomaterials used as cell carriers (scaffolds have an essential role in the production of new tissue by TE. Cellular component is important for the generation and establishment of the extracellular matrix, while a scaffold is necessary to determine the shape of the newly formed tissue and facilitate migration of cells into the desired location, as well as their growth and differentiation. This review describes the types, characteristics and classification of stem cells. Furthermore, it includes functional features of cell carriers - biocompatibility, biodegradability and mechanical properties of biomaterials used in developing state-of-the-art scaffolds for TE applications, as well as suitability for different tissues. Moreover, it explains the importance of nanotechnology and defines the challenges and the purpose of future research in this rapidly advancing field. [Projekat Ministarstva nauke Republike Srbije, br. 41030 i br. 172026

  17. Biological tissue magnetism in the frame of iron overload diseases

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, Francisco J. [Departamento de Ciencia y Tecnologia de Materiales y Fluidos, Universidad de Zaragoza, Zaragoza 50018 (Spain) and Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Zaragoza 50009 (Spain)]. E-mail: osoro@unizar.es; Gutierrez, Lucia [Departamento de Ciencia y Tecnologia de Materiales y Fluidos, Universidad de Zaragoza, Zaragoza 50018 (Spain); Abadia, Ana R. [Departamento de Farmacologia y Fisiologia, Universidad de Zaragoza, Zaragoza 50013 (Spain); Romero, Maria S. [Departamento de Medicina y Psiquiatria, Universidad de Zaragoza, Zaragoza 50009 (Spain); Lopez, A. [CNAM-Salesianos Zaragoza, Zaragoza 50009 (Spain)

    2007-09-15

    The conspicuous magnetic properties of iron, paradoxically, rarely participate in the methods routinely employed in the clinical environment to detect iron containing species in tissues. In the organism iron is just a trace metal and it mostly occurs as part of haemoproteins or ferritin, which show paramagnetic, diamagnetic or antiferromagnetic behaviour, hence resulting in a very low contribution to the tissue susceptibility. Detailed magnetic measurements make it nowadays possible to identify such species in tissues that correspond to individuals with iron overload pathologies. Since, as alternatives to the conventional biopsy, magnetism-based noninvasive techniques to diagnose and manage such diseases are recently under development, the deep knowledge of the magnetic properties of the different forms of iron in tissues is of high applied interest.

  18. Biological tissue magnetism in the frame of iron overload diseases

    Science.gov (United States)

    Lázaro, Francisco J.; Gutiérrez, Lucía; Abadía, Ana R.; Romero, María S.; López, A.

    2007-09-01

    The conspicuous magnetic properties of iron, paradoxically, rarely participate in the methods routinely employed in the clinical environment to detect iron containing species in tissues. In the organism iron is just a trace metal and it mostly occurs as part of haemoproteins or ferritin, which show paramagnetic, diamagnetic or antiferromagnetic behaviour, hence resulting in a very low contribution to the tissue susceptibility. Detailed magnetic measurements make it nowadays possible to identify such species in tissues that correspond to individuals with iron overload pathologies. Since, as alternatives to the conventional biopsy, magnetism-based noninvasive techniques to diagnose and manage such diseases are recently under development, the deep knowledge of the magnetic properties of the different forms of iron in tissues is of high applied interest.

  19. Beyond Turing: mechanochemical pattern formation in biological tissues.

    Science.gov (United States)

    Mercker, Moritz; Brinkmann, Felix; Marciniak-Czochra, Anna; Richter, Thomas

    2016-05-04

    During embryogenesis, chemical (morphogen) and mechanical patterns develop within tissues in a self-organized way. More than 60 years ago, Turing proposed his famous reaction-diffusion model for such processes, assuming chemical interactions as the main driving force in tissue patterning. However, experimental identification of corresponding molecular candidates is still incomplete. Recent results suggest that beside morphogens, also tissue mechanics play a significant role in these patterning processes. Combining continuous finite strain with discrete cellular tissue models, we present and numerically investigate mechanochemical processes, in which morphogen dynamics and tissue mechanics are coupled by feedback loops. We consider three different mechanical cues involved in such feedbacks: strain, stress, and compression. Based on experimental results, for each case, we present a feedback loop spontaneously creating robust mechanochemical patterns. In contrast to Turing-type models, simple mechanochemical interaction terms are sufficient to create de novo patterns. Our results emphasize mechanochemical processes as possible candidates controlling different steps of embryogenesis. To motivate further experimental research discovering related mechanisms in living tissues, we also present predictive in silicio experiments. Reviewer 1 - Marek Kimmel; Reviewer 2 - Konstantin Doubrovinski (nominated by Ned Wingreen); Reviewer 3 - Jun Allard (nominated by William Hlavacek).

  20. On the steady state temperature profiles of biological tissues during ...

    African Journals Online (AJOL)

    The Maxwell equations are solved together with the Pennes Bio-heat equation analytically. The procedure of solution is provoked by the solution to the Maxwell equation. The result revealed the effect of the model parameters such as: the thermal conductivity, blood perfusion coefficient, and the thickness of the tissues and ...

  1. Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues

    Science.gov (United States)

    Bhatt, Manish; Ayyalasomayajula, Kalyan R.; Yalavarthy, Phaneendra K.

    2016-07-01

    The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer-Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer-Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.

  2. Framework of collagen type I - vasoactive vessels structuring invariant geometric attractor in cancer tissues: insight into biological magnetic field.

    Directory of Open Access Journals (Sweden)

    Jairo A Díaz

    Full Text Available In a previous research, we have described and documented self-assembly of geometric triangular chiral hexagon crystal-like complex organizations (GTCHC in human pathological tissues. This article documents and gathers insights into the magnetic field in cancer tissues and also how it generates an invariant functional geometric attractor constituted for collider partners in their entangled environment. The need to identify this hierarquic attractor was born out of the concern to understand how the vascular net of these complexes are organized, and to determine if the spiral vascular subpatterns observed adjacent to GTCHC complexes and their assembly are interrelational. The study focuses on cancer tissues and all the macroscopic and microscopic material in which GTCHC complexes are identified, which have been overlooked so far, and are rigorously revised. This revision follows the same parameters that were established in the initial phase of the investigation, but with a new item: the visualization and documentation of external dorsal serous vascular bed areas in spatial correlation with the localization of GTCHC complexes inside the tumors. Following the standard of the electro-optical collision model, we were able to reproduce and replicate collider patterns, that is, pairs of left and right hand spin-spiraled subpatterns, associated with the orientation of the spinning process that can be an expansion or contraction disposition of light particles. Agreement between this model and tumor data is surprisingly close; electromagnetic spiral patterns generated were identical at the spiral vascular arrangement in connection with GTCHC complexes in malignant tumors. These findings suggest that the framework of collagen type 1 - vasoactive vessels that structure geometric attractors in cancer tissues with invariant morphology sets generate collider partners in their magnetic domain with opposite biological behavior. If these principles are incorporated

  3. Extraction and Simultaneous Quantification of Endocannabinoids and Endocannabinoid-Like Lipids in Biological Tissues.

    Science.gov (United States)

    Bindila, Laura; Lutz, Beat

    2016-01-01

    Extraction and quantification of endocannabinoids (eCBs) from biological tissues are essential to unravel their changes in physiological and pathophysiological conditions. We describe here an analytical protocol for extraction of endocannabinoids, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), endocannabinoid-like lipids such as palmitoyl ethanolamide (PEA) and oleoyl ethanolamide (OEA), as well as arachidonic acid (AA) from biological tissues using liquid-liquid extraction method and simultaneous quantification by liquid chromatography multiple reaction monitoring (LC/MRM).

  4. Photoacoustic imaging in both soft and hard biological tissue

    International Nuclear Information System (INIS)

    Li, T; Dewhurst, R J

    2010-01-01

    To date, most Photoacoustic (PA) imaging results have been from soft biotissues. In this study, a PA imaging system with a near-infrared pulsed laser source has been applied to obtain 2-D and 3-D images from both soft tissue and post-mortem dental samples. Imaging results showed that the PA technique has the potential to image human oral disease, such as early-stage teeth decay. For non-invasive photoacoustic imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. Several simulations based on the thermoelastic effect have been applied to predict initial temperature and pressure fields within a tooth sample. Predicted initial temperature and pressure rises are below corresponding safety limits.

  5. Biological Properties and Therapeutic Value of Cryopreserved Fat Tissue.

    Science.gov (United States)

    Mashiko, Takanobu; Wu, Szu-Hsien; Kanayama, Koji; Asahi, Rintaro; Shirado, Takako; Mori, Masanori; Sunaga, Ataru; Sarukawa, Shunji; Uda, Hirokazu; Yoshimura, Kotaro

    2018-01-01

    Fat grafting frequently requires multiple treatments and thus repeated liposuction to achieve treatment goals. The purpose of this study was to evaluate whether cryopreservation of adipose tissue may facilitate future fat grafting. Lipoaspirates were harvested from six women and preserved using two cryopreservation methods: (1) simple cooling to -80°C (cryo-1); or (2) programmed cooling to -196°C (cryo-2). Fresh fat, cryo-1 fat, and cryo-2 fat were analyzed both in vitro and in vivo. Immunohistochemistry of both types of cryopreserved adipose tissue revealed that most adipocytes were necrotic. The cell number and viability of stromal vascular fraction cells were significantly decreased in cryo-1 fat (1.7 × 10 cells, 42.6 percent viable) and cryo-2 fat (2.0 × 10 cells, 55.4 percent viable), compared with fresh fat (3.9 × 10 cells, 90.6 percent viable). Although adipose-derived stem cells were cultured successfully from all fats, functional adipose-derived stem cells from cryopreserved fats were much fewer, with comparable multilineage differentiating capacity. In vivo studies using human fat grafted into immunocompromised mice revealed that, 3 months after transplantation, all of the cryopreserved fats maintained their volume to some extent; however, the cryopreserved fats were mostly filled with dead tissue and produced significantly lower engraftment scores than fresh fat. Most adipocytes were killed in the process of cryopreservation and thawing. Adipose-derived stem cells were isolated from cryopreserved fat, but the number of functional adipose-derived stem cells was very limited in both cryopreservation methods. After grafting, cryopreserved fat was retained as dead and fibrous tissue, suggesting a risk of clinical complications such as oil cysts.

  6. Hydraulic fracturing in cells and tissues: fracking meets cell biology.

    Science.gov (United States)

    Arroyo, Marino; Trepat, Xavier

    2017-02-01

    The animal body is largely made of water. A small fraction of body water is freely flowing in blood and lymph, but most of it is trapped in hydrogels such as the extracellular matrix (ECM), the cytoskeleton, and chromatin. Besides providing a medium for biological molecules to diffuse, water trapped in hydrogels plays a fundamental mechanical role. This role is well captured by the theory of poroelasticity, which explains how any deformation applied to a hydrogel causes pressure gradients and water flows, much like compressing a sponge squeezes water out of it. Here we review recent evidence that poroelastic pressures and flows can fracture essential biological barriers such as the nuclear envelope, the cellular cortex, and epithelial layers. This type of fracture is known in engineering literature as hydraulic fracturing or 'fracking'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Cannabinoid Markers in Biological Fluids and Tissues: Revealing Intake.

    Science.gov (United States)

    Huestis, Marilyn A; Smith, Michael L

    2018-02-01

    Understanding cannabis and synthetic cannabinoid intake history is vital for treating drug dependence, investigating cannabinoid effects, and providing information to healthcare personnel, medical examiners, and public health officials; this is particularly relevant today with cannabis medicalization and legalization. Required information includes identifying exposure, time of use, frequency of use, relapse, withdrawal, and predicting cannabinoid effects. Recent controlled cannabinoid administration studies enable the development of models and markers to better identify patterns of intake and exposure. Future challenges include developing behavioral markers of cannabis impairment, bringing to market breathalyzers for cannabinoid detection, and identifying markers of recent cannabis intake in diverse biological matrices. We posit that biological monitoring of cannabinoids and metabolites will improve the characterization of cannabis and synthetic cannabinoid intake history. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Reverse engineering development: Crosstalk opportunities between developmental biology and tissue engineering.

    Science.gov (United States)

    Marcucio, Ralph S; Qin, Ling; Alsberg, Eben; Boerckel, Joel D

    2017-11-01

    The fields of developmental biology and tissue engineering have been revolutionized in recent years by technological advancements, expanded understanding, and biomaterials design, leading to the emerging paradigm of "developmental" or "biomimetic" tissue engineering. While developmental biology and tissue engineering have long overlapping histories, the fields have largely diverged in recent years at the same time that crosstalk opportunities for mutual benefit are more salient than ever. In this perspective article, we will use musculoskeletal development and tissue engineering as a platform on which to discuss these emerging crosstalk opportunities and will present our opinions on the bright future of these overlapping spheres of influence. The multicellular programs that control musculoskeletal development are rapidly becoming clarified, represented by shifting paradigms in our understanding of cellular function, identity, and lineage specification during development. Simultaneously, advancements in bioartificial matrices that replicate the biochemical, microstructural, and mechanical properties of developing tissues present new tools and approaches for recapitulating development in tissue engineering. Here, we introduce concepts and experimental approaches in musculoskeletal developmental biology and biomaterials design and discuss applications in tissue engineering as well as opportunities for tissue engineering approaches to inform our understanding of fundamental biology. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2356-2368, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Plasma tissue inhibitor of metalloproteinases-1 as a biological marker? Pre-analytical considerations

    DEFF Research Database (Denmark)

    Lomholt, Anne Fog; Frederiksen, Camilla; Christensen, Ib Jarle

    2007-01-01

    Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) may be a valuable biological marker in Colorectal Cancer (CRC). However, prospective validation of TIMP-1 as a biological marker should include a series of pre-analytical considerations. TIMP-1 is stored in platelets, which may degranulate during...

  10. Effects of microwave heating on the thermal states of biological tissues

    African Journals Online (AJOL)

    Admin

    calculated by using finite difference method to predict the effects of thermal physical properties on the transient temperature of biological tissues. This prediction of the temperature evolution in biological bodies can be used as an effective tool for thermal diagnostics in medical practices. Key words: Microwave heating, ...

  11. A mechano-biological model of multi-tissue evolution in bone

    Science.gov (United States)

    Frame, Jamie; Rohan, Pierre-Yves; Corté, Laurent; Allena, Rachele

    2017-12-01

    Successfully simulating tissue evolution in bone is of significant importance in predicting various biological processes such as bone remodeling, fracture healing and osseointegration of implants. Each of these processes involves in different ways the permanent or transient formation of different tissue types, namely bone, cartilage and fibrous tissues. The tissue evolution in specific circumstances such as bone remodeling and fracturing healing is currently able to be modeled. Nevertheless, it remains challenging to predict which tissue types and organization can develop without any a priori assumptions. In particular, the role of mechano-biological coupling in this selective tissue evolution has not been clearly elucidated. In this work, a multi-tissue model has been created which simultaneously describes the evolution of bone, cartilage and fibrous tissues. The coupling of the biological and mechanical factors involved in tissue formation has been modeled by defining two different tissue states: an immature state corresponding to the early stages of tissue growth and representing cell clusters in a weakly neo-formed Extra Cellular Matrix (ECM), and a mature state corresponding to well-formed connective tissues. This has allowed for the cellular processes of migration, proliferation and apoptosis to be described simultaneously with the changing ECM properties through strain driven diffusion, growth, maturation and resorption terms. A series of finite element simulations were carried out on idealized cantilever bending geometries. Starting from a tissue composition replicating a mid-diaphysis section of a long bone, a steady-state tissue formation was reached over a statically loaded period of 10,000 h (60 weeks). The results demonstrated that bone formation occurred in regions which are optimally physiologically strained. In two additional 1000 h bending simulations both cartilaginous and fibrous tissues were shown to form under specific geometrical and loading

  12. Ablation of biological tissues by radiation of strontium vapor laser

    Energy Technology Data Exchange (ETDEWEB)

    Soldatov, A. N., E-mail: general@tic.tsu.ru; Vasilieva, A. V., E-mail: anita-tomsk@mail.ru [National Research Tomsk State University, Lenin ave., 36, 634050, Tomsk (Russian Federation)

    2015-11-17

    A two-stage laser system consisting of a master oscillator and a power amplifier based on sources of self- contained transitions in pairs SrI and SrII has been developed. The radiation spectrum contains 8 laser lines generating in the range of 1 – 6.45 μm, with a generation pulse length of 50 – 150 ns, and pulse energy of ∼ 2.5 mJ. The divergence of the output beam was close to the diffraction and did not exceed 0.5 mrad. The control range of the laser pulse repetition rate varied from 10 to 15 000 Hz. The given laser system has allowed to perform ablation of bone tissue samples without visible thermal damage.

  13. Effective Permittivity of Biological Tissue: Comparison of Theoretical Model and Experiment

    Directory of Open Access Journals (Sweden)

    Li Gun

    2017-01-01

    Full Text Available Permittivity of biological tissue is a critical issue for studying the biological effects of electromagnetic fields. Many theories and experiments were performed to measure or explain the permittivity characteristics in biological tissue. In this paper, we investigate the permittivity parameter in biological tissues via theoretical and experimental analysis. Firstly, we analyze the permittivity characteristic in tissue by using theories on composite material. Secondly, typical biological tissues, such as blood, fat, liver, and brain, are measured by HP4275A Multi-Frequency LCR Meter within 10 kHz to 10 MHz. Thirdly, experimental results are compared with the Bottcher-Bordewijk model, the Skipetrov equation, and the Maxwell-Gannett theory. From the theoretical perspective, blood and fat are regarded as the composition of liver and brain because of the high permittivity in blood and the opposite in fat. Volume fraction of blood in liver and brain is analyzed theoretically, and the applicability and the limitation of the models are also discussed. These results benefit further study on local biological effects of electromagnetic fields.

  14. Observation of dehydration dynamics in biological tissues with terahertz digital holography [Invited].

    Science.gov (United States)

    Guo, Lihan; Wang, Xinke; Han, Peng; Sun, Wenfeng; Feng, Shengfei; Ye, Jiasheng; Zhang, Yan

    2017-05-01

    A terahertz (THz) digital holographic imaging system is utilized to investigate natural dehydration processes in three types of biological tissues, including cattle, mutton, and pork. An image reconstruction algorithm is applied to remove the diffraction influence of THz waves and further improve clarity of THz images. From THz images of different biological specimens, distinctive water content as well as dehydration features of adipose and muscle tissues are precisely distinguished. By analyzing THz absorption spectra of these samples, temporal evolution characteristics of the absorbances for adipose and muscle tissues are described and compared in detail. Discrepancies between water retention ability of different animal tissues are also discussed. The imaging technique provides a valuable measurement platform for biological sensing.

  15. A system for the obtention and analysis of diffuse reflection spectra from biological tissue

    International Nuclear Information System (INIS)

    La Cadena, A. de; La Rosa, J. de; Stolik, S.

    2012-01-01

    The diffuse reflection spectroscopy is a technique with is possible to study biological tissue. In the field of the biomedical applications is useful for diagnostic purposes, since is possible to analyze biological tissue in a non invasive way. also, can be used with therapeutical purposes, for example in photodynamic therapy or laser surgery because with this technique it can be determined the biological effects produced by these treatments. In this paper is shown the development of a system to obtain and analyze diffuse reflection spectra of biological tissues, using a LED as a light source, that emits light between 400-700nm. The system has an interface for the regulation of the emittance of the LED. For diffuse reflectance spectra analysis, we use an HR4000CG-UV-NIR spectrometer. (Author)

  16. Heart Valves from Polyester Fibers vs. Biological Tissue: Comparative Study In Vitro.

    Science.gov (United States)

    Yousefi, Atieh; Vaesken, Antoine; Amri, Amna; Dasi, Lakshmi Prasad; Heim, Frederic

    2017-02-01

    Transcatheter aortic valve implantation (TAVI) has become a popular alternative technique to surgical valve replacement for critical patients. Biological valve tissue has been used in TAVI procedures for over a decade, with over 100,000 implantations to date. However, with only 6 years follow up, little is known about the long-term durability of biological tissue. Moreover, the high cost of tissue harvesting and chemical treatment procedures favor the development of alternative synthetic valve leaflet materials. Textile polyester is one such material which provides outstanding folding and strength properties combined with proven biocompatibility, and could therefore be considered as a candidate to replace the biological valve leaflets in TAVI procedures. For that purpose, in addition to the mechanical properties, the hemodynamic properties of the synthetic material should be comparable to the properties of biological tissue. An ideal replacement heart valve would provide low static and dynamic regurgitation, ensure laminar flow across the valve, and limit the turbidity of flow downstream of the valve. The purpose of the present work is to compare in vitro the mechanical and hemodynamic performances of textile woven polyester valves with biological ones. Testing results indicate that textile valves trade elasticity for superior mechanical strength, relative to biological tissue. Despite this, the dynamic flexibility of textile valve leaflets strongly resembled what was seen with biological leaflets. Regurgitation, as well as slightly modified turbulent patterns, in textile valves was higher than biological valves due to the increased porosity, but, rapid tissue ingrowth post-implantation would likely mitigate this effect. Together these findings provide additional evidence favoring the use of textile polyester as a synthetic heart valve leaflet material.

  17. Biologically improved nanofibrous scaffolds for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Bhaarathy, V. [Centre for Nanofibers and Nanotechnology, NUSNNI, Faculty of Engineering, National University of Singapore, 117576 (Singapore); Department of Nanoscience and Technology, School of Physical Sciences, Bharathiar University, Coimbatore 641046 (India); Lee Kong Chian School of Medicine, Nanyang Technological University, 138673 (Singapore); Venugopal, J., E-mail: nnijrv@nus.edu.sg [Centre for Nanofibers and Nanotechnology, NUSNNI, Faculty of Engineering, National University of Singapore, 117576 (Singapore); Gandhimathi, C. [Centre for Nanofibers and Nanotechnology, NUSNNI, Faculty of Engineering, National University of Singapore, 117576 (Singapore); Ponpandian, N.; Mangalaraj, D. [Department of Nanoscience and Technology, School of Physical Sciences, Bharathiar University, Coimbatore 641046 (India); Ramakrishna, S. [Centre for Nanofibers and Nanotechnology, NUSNNI, Faculty of Engineering, National University of Singapore, 117576 (Singapore)

    2014-11-01

    Nanofibrous structure developed by electrospinning technology provides attractive extracellular matrix conditions for the anchorage, migration and differentiation of stem cells, including those responsible for regenerative medicine. Recently, biocomposite nanofibers consisting of two or more polymeric blends are electrospun more tidily in order to obtain scaffolds with desired functional and mechanical properties depending on their applications. The study focuses on one such an attempt of using copolymer Poly(L-lactic acid)-co-poly (ε-caprolactone) (PLACL), silk fibroin (SF) and Aloe Vera (AV) for fabricating biocomposite nanofibrous scaffolds for cardiac tissue engineering. SEM micrographs of fabricated electrospun PLACL, PLACL/SF and PLACL/SF/AV nanofibrous scaffolds are porous, beadless, uniform nanofibers with interconnected pores and obtained fibre diameter in the range of 459 ± 22 nm, 202 ± 12 nm and 188 ± 16 nm respectively. PLACL, PLACL/SF and PLACL/SF/AV electrospun mats obtained at room temperature with an elastic modulus of 14.1 ± 0.7, 9.96 ± 2.5 and 7.0 ± 0.9 MPa respectively. PLACL/SF/AV nanofibers have more desirable properties to act as flexible cell supporting scaffolds compared to PLACL for the repair of myocardial infarction (MI). The PLACL/SF and PLACL/SF/AV nanofibers had a contact angle of 51 ± 12° compared to that of 133 ± 15° of PLACL alone. Cardiac cell proliferation was increased by 21% in PLACL/SF/AV nanofibers compared to PLACL by day 6 and further increased to 42% by day 9. Confocal analysis for cardiac expression proteins myosin and connexin 43 was observed better by day 9 compared to all other nanofibrous scaffolds. The results proved that the fabricated PLACL/SF/AV nanofibrous scaffolds have good potentiality for the regeneration of infarcted myocardium in cardiac tissue engineering. - Highlights: • Fabricated nanofibrous scaffolds are porous, beadless and uniform structures. • PLACL/SF/AV nanofibers improve the

  18. Biologically improved nanofibrous scaffolds for cardiac tissue engineering

    International Nuclear Information System (INIS)

    Bhaarathy, V.; Venugopal, J.; Gandhimathi, C.; Ponpandian, N.; Mangalaraj, D.; Ramakrishna, S.

    2014-01-01

    Nanofibrous structure developed by electrospinning technology provides attractive extracellular matrix conditions for the anchorage, migration and differentiation of stem cells, including those responsible for regenerative medicine. Recently, biocomposite nanofibers consisting of two or more polymeric blends are electrospun more tidily in order to obtain scaffolds with desired functional and mechanical properties depending on their applications. The study focuses on one such an attempt of using copolymer Poly(L-lactic acid)-co-poly (ε-caprolactone) (PLACL), silk fibroin (SF) and Aloe Vera (AV) for fabricating biocomposite nanofibrous scaffolds for cardiac tissue engineering. SEM micrographs of fabricated electrospun PLACL, PLACL/SF and PLACL/SF/AV nanofibrous scaffolds are porous, beadless, uniform nanofibers with interconnected pores and obtained fibre diameter in the range of 459 ± 22 nm, 202 ± 12 nm and 188 ± 16 nm respectively. PLACL, PLACL/SF and PLACL/SF/AV electrospun mats obtained at room temperature with an elastic modulus of 14.1 ± 0.7, 9.96 ± 2.5 and 7.0 ± 0.9 MPa respectively. PLACL/SF/AV nanofibers have more desirable properties to act as flexible cell supporting scaffolds compared to PLACL for the repair of myocardial infarction (MI). The PLACL/SF and PLACL/SF/AV nanofibers had a contact angle of 51 ± 12° compared to that of 133 ± 15° of PLACL alone. Cardiac cell proliferation was increased by 21% in PLACL/SF/AV nanofibers compared to PLACL by day 6 and further increased to 42% by day 9. Confocal analysis for cardiac expression proteins myosin and connexin 43 was observed better by day 9 compared to all other nanofibrous scaffolds. The results proved that the fabricated PLACL/SF/AV nanofibrous scaffolds have good potentiality for the regeneration of infarcted myocardium in cardiac tissue engineering. - Highlights: • Fabricated nanofibrous scaffolds are porous, beadless and uniform structures. • PLACL/SF/AV nanofibers improve the

  19. Methods in elastic tissue biology: elastin isolation and purification.

    Science.gov (United States)

    Mecham, Robert P

    2008-05-01

    Elastin provides recoil to tissues subjected to repeated stretch, such as blood vessels and the lung. It is encoded by a single gene in mammals and is secreted as a 60-70 kDa monomer called tropoelastin. The functional form of the protein is that of a large, highly crosslinked polymer that organizes as sheets or fibers in the extracellular matrix. Purification of mature, crosslinked elastin is problematic because its insolubility precludes its isolation using standard wet-chemistry techniques. Instead, relatively harsh experimental approaches designed to remove non-elastin 'contaminates' are employed to generate an insoluble product that has the amino acid composition expected of elastin. Although soluble, tropoelastin also presents problems for isolation and purification. The protein's extreme stickiness and susceptibility to proteolysis requires careful attention during purification and in tropoelastin-based assays. This article describes the most common approaches for purification of insoluble elastin and tropoelastin. It also addresses key aspects of studying tropoelastin production in cultured cells, where elastin expression is highly dependent upon cell type, culture conditions, and passage number.

  20. Brown adipose tissue: Updates in cellular and molecular biology.

    Science.gov (United States)

    Bargut, Thereza Cristina Lonzetti; Aguila, Marcia Barbosa; Mandarim-de-Lacerda, Carlos Alberto

    2016-10-01

    Brown adipose tissue (BAT) is mainly composed of adipocytes, it is highly vascularized and innervated, and can be activated in adult humans. Brown adipocytes are responsible for performing non-shivering thermogenesis, which is exclusively mediated by uncoupling protein (UCP) -1 (a protein found in the inner mitochondrial membrane), the hallmark of BAT, responsible for the uncoupling of the proton leakage from the ATP production, therefore, generating heat (i.e. thermogenesis). Besides UCP1, other compounds are essential not only to thermogenesis, but also to the proliferation and differentiation of BAT, including peroxisome proliferator-activated receptor (PPAR) family, PPARgamma coactivator 1 (PGC1)-alpha, and PRD1-BF-1-RIZ1 homologous domain protein containing protein (PRDM) -16. The sympathetic nervous system centrally regulates thermogenesis through norepinephrine, which acts on the adrenergic receptors of BAT. This bound leads to the initialization of the many pathways that may activate thermogenesis in acute and/or chronic ways. In summary, this mini-review aims to demonstrate the latest advances in the knowledge of BAT. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Simulation on scattering features of biological tissue based on generated refractive-index model

    International Nuclear Information System (INIS)

    Wang Baoyong; Ding Zhihua

    2011-01-01

    Important information on morphology of biological tissue can be deduced from elastic scattering spectra, and their analyses are based on the known refractive-index model of tissue. In this paper, a new numerical refractive-index model is put forward, and its scattering properties are intensively studied. Spectral decomposition [1] is a widely used method to generate random medium in geology, but it is never used in biology. Biological tissue is different from geology in the sense of random medium. Autocorrelation function describe almost all of features in geology, but biological tissue is not as random as geology, its structure is regular in the sense of fractal geometry [2] , and fractal dimension can be used to describe its regularity under random. Firstly scattering theories of this fractal media are reviewed. Secondly the detailed generation process of refractive-index is presented. Finally the scattering features are simulated in FDTD (Finite Difference Time Domain) Solutions software. From the simulation results, we find that autocorrelation length and fractal dimension controls scattering feature of biological tissue.

  2. Simulation on scattering features of biological tissue based on generated refractive-index model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Baoyong; Ding Zhihua, E-mail: zh_ding@zju.edu.cn [State Key Lab of Modern Optical Instrumentation, Zhejiang University 38 Zheda Rd., Hangzhou 310027 (China)

    2011-01-01

    Important information on morphology of biological tissue can be deduced from elastic scattering spectra, and their analyses are based on the known refractive-index model of tissue. In this paper, a new numerical refractive-index model is put forward, and its scattering properties are intensively studied. Spectral decomposition{sup [1]} is a widely used method to generate random medium in geology, but it is never used in biology. Biological tissue is different from geology in the sense of random medium. Autocorrelation function describe almost all of features in geology, but biological tissue is not as random as geology, its structure is regular in the sense of fractal geometry{sup [2]}, and fractal dimension can be used to describe its regularity under random. Firstly scattering theories of this fractal media are reviewed. Secondly the detailed generation process of refractive-index is presented. Finally the scattering features are simulated in FDTD (Finite Difference Time Domain) Solutions software. From the simulation results, we find that autocorrelation length and fractal dimension controls scattering feature of biological tissue.

  3. Changes in diffusion properties of biological tissues associated with mechanical strain

    International Nuclear Information System (INIS)

    Tanaka, Kenichiro; Imae, T.; Mima, Kazuo; Sekino, Masaki; Ohsaki, Hiroyuki; Ueno, Shogo

    2007-01-01

    Mechanical strain in biological tissues causes a change in the diffusion properties of water molecules. This paper proposes a method of estimating mechanical strain in biological tissues using diffusion magnetic resonance imaging (MRI). Measurements were carried out on uncompressed and compressed chicken skeletal muscles. A theoretical model of the diffusion of water molecules in muscle fibers was derived based on Tanner's equation. Diameter of the muscle fibers was estimated by fitting the model equation to the measured signals. Changes in the mean diffusivity (MD), the fractional anisotropy (FA), and diameter of the muscle fiber did not have any statistical significance. The intracellular diffusion coefficient (D int ) was changed by mechanical strain (p<.05). This method has potential applications in the quantitative evaluation of strain in biological tissues, a though it poses several technical challenges. (author)

  4. Backward Multiscattering and Transport of Photons in Biological Tissue: Experiment and Simulation

    Directory of Open Access Journals (Sweden)

    Hamed Mohamed Abubaker

    2012-01-01

    Full Text Available Optical polarimetry is a mighty tool for study of transparent and translucent inorganic and organic materials. Growing interest in better health and also the quality of the food pointed the investigation of physical properties of biological turbid tissues. Due to the fact that biological tissue is complex random material showing inhomogeneity, anisotropy and nonlinearity in the structure, its rigorous characterization is almost impossible. This complexity also involves an important amount of information. Therefore, the research of polarization states of scattered light is one of emerging novel techniques in biomedical science. The paper deals with the experimental study of degree of polarization and also with simulation of the biological tissue by Monte Carlo method.

  5. Thermo-electrical equivalents for simulating the electro-mechanical behavior of biological tissue.

    Science.gov (United States)

    Cinelli, I; Duffy, M; McHugh, P E

    2015-01-01

    Equivalence is one of most popular techniques to simulate the behavior of systems governed by the same type of differential equation. In this case, a thermo-electrical equivalence is considered as a method for modelling the inter-dependence of electrical and mechanical phenomena in biological tissue. We seek to assess this approach for multi-scale models (from micro-structure to tissue scale) of biological media, such as nerve cells and cardiac tissue, in which the electrical charge distribution is modelled as a heat distribution in an equivalent thermal system. This procedure allows for the reduction in problem complexity and it facilitates the coupling of electrical and mechanical phenomena in an efficient and practical way. Although the findings of this analysis are mainly addressed towards the electro-mechanics of tissue within the biomedical domain, the same approach could be used in other studies in which a coupled finite element analysis is required.

  6. Characterization of the angular memory effect of scattered light in biological tissues.

    Science.gov (United States)

    Schott, Sam; Bertolotti, Jacopo; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain

    2015-05-18

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues and therefore grants access to superficial brain layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations ('angular memory effect') are of a very short range and should theoretically be only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range and thus the possible field-of-view by more than an order of magnitude compared to isotropic scattering for ∼1 mm thick tissue layers.

  7. Marine-derived biological macromolecule-based biomaterials for wound healing and skin tissue regeneration.

    Science.gov (United States)

    Chandika, Pathum; Ko, Seok-Chun; Jung, Won-Kyo

    2015-01-01

    Wound healing is a complex biological process that depends on the wound condition, the patient's health, and the physicochemical support given through external materials. The development of bioactive molecules and engineered tissue substitutes to provide physiochemical support to enhance the wound healing process plays a key role in advancing wound-care management. Thus, identification of ideal molecules in wound treatment is still in progress. The discovery of natural products that contain ideal molecules for skin tissue regeneration has been greatly advanced by exploration of the marine bioenvironment. Consequently, tremendously diverse marine organisms have become a great source of numerous biological macromolecules that can be used to develop tissue-engineered substitutes with wound healing properties. This review summarizes the wound healing process, the properties of macromolecules from marine organisms, and the involvement of these molecules in skin tissue regeneration applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Numerical study of water diffusion in biological tissues using an improved finite difference method

    International Nuclear Information System (INIS)

    Xu Junzhong; Does, Mark D; Gore, John C

    2007-01-01

    An improved finite difference (FD) method has been developed in order to calculate the behaviour of the nuclear magnetic resonance signal variations caused by water diffusion in biological tissues more accurately and efficiently. The algorithm converts the conventional image-based finite difference method into a convenient matrix-based approach and includes a revised periodic boundary condition which eliminates the edge effects caused by artificial boundaries in conventional FD methods. Simulated results for some modelled tissues are consistent with analytical solutions for commonly used diffusion-weighted pulse sequences, whereas the improved FD method shows improved efficiency and accuracy. A tightly coupled parallel computing approach was also developed to implement the FD methods to enable large-scale simulations of realistic biological tissues. The potential applications of the improved FD method for understanding diffusion in tissues are also discussed. (note)

  9. Heterogeneity, Cell Biology and Tissue Mechanics of Pseudostratified Epithelia: Coordination of Cell Divisions and Growth in Tightly Packed Tissues.

    Science.gov (United States)

    Strzyz, P J; Matejcic, M; Norden, C

    2016-01-01

    Pseudostratified epithelia (PSE) are tightly packed proliferative tissues that are important precursors of the development of diverse organs in a plethora of species, invertebrate and vertebrate. PSE consist of elongated epithelial cells that are attached to the apical and basal side of the tissue. The nuclei of these cells undergo interkinetic nuclear migration (IKNM) which leads to all mitotic events taking place at the apical surface of the epithelium. In this review, we discuss the intricacies of proliferation in PSE, considering cell biological, as well as the physical aspects. First, we summarize the principles governing the invariability of apical nuclear migration and apical cell division as well as the importance of apical mitoses for tissue proliferation. Then, we focus on the mechanical and structural features of these tissues. Here, we discuss how the overall architecture of pseudostratified tissues changes with increased cell packing. Lastly, we consider possible mechanical cues resulting from these changes and their potential influence on cell proliferation. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Detection of Taurine in Biological Tissues by 33S NMR Spectroscopy

    Science.gov (United States)

    Musio, Roberta; Sciacovelli, Oronzo

    2001-12-01

    The potential of 33S NMR spectroscopy for biochemical investigations on taurine (2-aminoethanesulfonic acid) is explored. It is demonstrated that 33S NMR spectroscopy allows the selective and unequivocal identification of taurine in biological samples. 33S NMR spectra of homogenated and intact tissues are reported for the first time, together with the spectrum of a living mollusc. Emphasis is placed on the importance of choosing appropriate signal processing methods to improve the quality of the 33S NMR spectra of biological tissues.

  11. Acoustic pressure amplitude thresholds for rectified diffusion in gaseous microbubbles in biological tissue

    DEFF Research Database (Denmark)

    Lewin, Peter A.; Jensen, Leif Bjørnø

    1981-01-01

    One of the mechanisms often suggested for the biological action of ultrasonic beams irradiating human tissues is concerned with the presence in the tissues of minute gaseous bubbles which may, under the influence of the ultrasonic field be stimulated to grow to a size at which resonance or collap...... of calculations for typical (transient) exposure conditions from pulse-echo equipment are presented, indicating that rectified diffusion and stable cavitation are improbable phenomena in these circumstances....

  12. Three-dimensional micro-scale strain mapping in living biological soft tissues.

    Science.gov (United States)

    Moo, Eng Kuan; Sibole, Scott C; Han, Sang Kuy; Herzog, Walter

    2018-04-01

    Non-invasive characterization of the mechanical micro-environment surrounding cells in biological tissues at multiple length scales is important for the understanding of the role of mechanics in regulating the biosynthesis and phenotype of cells. However, there is a lack of imaging methods that allow for characterization of the cell micro-environment in three-dimensional (3D) space. The aims of this study were (i) to develop a multi-photon laser microscopy protocol capable of imprinting 3D grid lines onto living tissue at a high spatial resolution, and (ii) to develop image processing software capable of analyzing the resulting microscopic images and performing high resolution 3D strain analyses. Using articular cartilage as the biological tissue of interest, we present a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning length scales from the tissue to the cell level. Using custom image processing software, we provide accurate and robust 3D micro-strain analysis that allows for detailed qualitative and quantitative assessment of the 3D tissue kinematics. This novel technique preserves tissue structural integrity post-scanning, therefore allowing for multiple strain measurements at different time points in the same specimen. The proposed technique is versatile and opens doors for experimental and theoretical investigations on the relationship between tissue deformation and cell biosynthesis. Studies of this nature may enhance our understanding of the mechanisms underlying cell mechano-transduction, and thus, adaptation and degeneration of soft connective tissues. We presented a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning from tissue length scale to cellular length scale. Using a custom image processing software (lsmgridtrack), we provide accurate and robust micro

  13. Spatial transcriptomics: paving the way for tissue-level systems biology.

    Science.gov (United States)

    Moor, Andreas E; Itzkovitz, Shalev

    2017-08-01

    The tissues in our bodies are complex systems composed of diverse cell types that often interact in highly structured repeating anatomical units. External gradients of morphogens, directional blood flow, as well as the secretion and absorption of materials by cells generate distinct microenvironments at different tissue coordinates. Such spatial heterogeneity enables optimized function through division of labor among cells. Unraveling the design principles that govern this spatial division of labor requires techniques to quantify the entire transcriptomes of cells while accounting for their spatial coordinates. In this review we describe how recent advances in spatial transcriptomics open the way for tissue-level systems biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Concise Review: Quiescence in Adult Stem Cells: Biological Significance and Relevance to Tissue Regeneration.

    Science.gov (United States)

    Rumman, Mohammad; Dhawan, Jyotsna; Kassem, Moustapha

    2015-10-01

    Adult stem cells (ASCs) are tissue resident stem cells responsible for tissue homeostasis and regeneration following injury. In uninjured tissues, ASCs exist in a nonproliferating, reversibly cell cycle-arrested state known as quiescence or G0. A key function of the quiescent state is to preserve stemness in ASCs by preventing precocious differentiation, and thus maintaining a pool of undifferentiated ASCs. Recent evidences suggest that quiescence is an actively maintained state and that excessive or defective quiescence may lead to compromised tissue regeneration or tumorigenesis. The aim of this review is to provide an update regarding the biological mechanisms of ASC quiescence and their role in tissue regeneration. © 2015 AlphaMed Press.

  15. Combining multiset resolution and segmentation for hyperspectral image analysis of biological tissues.

    Science.gov (United States)

    Piqueras, S; Krafft, C; Beleites, C; Egodage, K; von Eggeling, F; Guntinas-Lichius, O; Popp, J; Tauler, R; de Juan, A

    2015-06-30

    Hyperspectral images can provide useful biochemical information about tissue samples. Often, Fourier transform infrared (FTIR) images have been used to distinguish different tissue elements and changes caused by pathological causes. The spectral variation between tissue types and pathological states is very small and multivariate analysis methods are required to describe adequately these subtle changes. In this work, a strategy combining multivariate curve resolution-alternating least squares (MCR-ALS), a resolution (unmixing) method, which recovers distribution maps and pure spectra of image constituents, and K-means clustering, a segmentation method, which identifies groups of similar pixels in an image, is used to provide efficient information on tissue samples. First, multiset MCR-ALS analysis is performed on the set of images related to a particular pathology status to provide basic spectral signatures and distribution maps of the biological contributions needed to describe the tissues. Later on, multiset segmentation analysis is applied to the obtained MCR scores (concentration profiles), used as compressed initial information for segmentation purposes. The multiset idea is transferred to perform image segmentation of different tissue samples. Doing so, a difference can be made between clusters associated with relevant biological parts common to all images, linked to general trends of the type of samples analyzed, and sample-specific clusters, that reflect the natural biological sample-to-sample variability. The last step consists of performing separate multiset MCR-ALS analyses on the pixels of each of the relevant segmentation clusters for the pathology studied to obtain a finer description of the related tissue parts. The potential of the strategy combining multiset resolution on complete images, multiset segmentation and multiset local resolution analysis will be shown on a study focused on FTIR images of tissue sections recorded on inflamed and non

  16. A stress driven growth model for soft tissue considering biological availability

    International Nuclear Information System (INIS)

    Oller, S; Bellomo, F J; Nallim, L G; Armero, F

    2010-01-01

    Some of the key factors that regulate growth and remodeling of tissues are fundamentally mechanical. However, it is important to take into account the role of bioavailability together with the stresses and strains in the processes of normal or pathological growth. In this sense, the model presented in this work is oriented to describe the growth of soft biological tissue under 'stress driven growth' and depending on the biological availability of the organism. The general theoretical framework is given by a kinematic formulation in large strain combined with the thermodynamic basis of open systems. The formulation uses a multiplicative decomposition of deformation gradient, splitting it in a growth part and visco-elastic part. The strains due to growth are incompatible and are controlled by an unbalanced stresses related to a homeostatic state. Growth implies a volume change with an increase of mass maintaining constant the density. One of the most interesting features of the proposed model is the generation of new tissue taking into account the contribution of mass to the system controlled through biological availability. Because soft biological tissues in general have a hierarchical structure with several components (usually a soft matrix reinforced with collagen fibers), the developed growth model is suitable for the characterization of the growth of each component. This allows considering a different behavior for each of them in the context of a generalized theory of mixtures. Finally, we illustrate the response of the model in case of growth and atrophy with an application example.

  17. Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces

    NARCIS (Netherlands)

    Abayazid, Momen; Moreira, Pedro; Shahriari, Navid; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

    In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is

  18. Effects of microwave heating on the thermal states of biological tissues

    African Journals Online (AJOL)

    Effects of microwave heating on the thermal states of biological tissues. Nabil TM El-dabe, Mona AA Mohamed, Asma F El-Sayed. Abstract. A mathematical analysis of microwave heating equations in one-dimensional multi-layer model has been discussed. Maxwell's equations and transient bioheat transfer equation were ...

  19. A model for Monte Carlo simulation of low angle photon scattering in biological tissues

    CERN Document Server

    Tartari, A; Bonifazzi, C

    2001-01-01

    In order to include the molecular interference effect, a simple procedure is proposed and demonstrated to be able to update the usual cross section database for photon coherent scattering modelling in Monte Carlo codes. This effect was evaluated by measurement of coherent scattering distributions and by means of a model based on four basic materials composing biological tissues.

  20. Polarization-sensitive optical coherence tomography for imaging of biological tissues

    Science.gov (United States)

    Chen, Xiaodong; Wang, Yi; Li, Wanhui; Yu, Daoyin

    2006-09-01

    Polarization sensitive optical coherence tomography (PS-OCT) is a new non-contact and non-invasive method for measuring the change of birefringence in biological tissues caused by pathological changes of body. It has great potential in imaging the structural properties of turbid biological media because the polarization state of light backscattered from biological tissues is influenced by the birefringence of fibrous structures. The arrangement is based on a Michelson interferometer with use of quarter-wave plates and polarimeter. Through the detection of light backscattered from biological tissues and reflected from a reference mirror, the optical phase delay between orthogonal polarization compositions propagating in the birefringence media can be measured. PS-OCT is a powerful tool for research of tendon, dentin, lesions, which have strong polarization effective. We in this paper describe the experimental scheme and its mathematical representation, along with the theory of PS-OCT imaging. Besides, we introduce a fiber-based PS-OCT system for measuring the tissue birefringence.

  1. Biological Effects of Laser Radiation. Volume IV. Optical Second Harmonic Generation in Biological Tissues.

    Science.gov (United States)

    1978-10-17

    harmonic generation in ocular tissue may be of significance to vision (Fine and Hansen, 1971). Although second-harmonic radiation was observed from...efficiency of CC1 4 . The parameter values used in this computacion are listed below. -30 9/2 -1/2a) 8-6.24 x 10 cm erg for f - 1, and assuming imaginary...sise Lt La a moorfeW, coLlsmme Usmwu ad, La imma, sight be sopmed to 1ase wediaeto. tou~saie ~ the eve am bo -~atm tow Visions (YOLIM60 eg at, * .5

  2. Polymer-Based Microfluidic Devices for Pharmacy, Biology and Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Kerstin Ramser

    2012-07-01

    Full Text Available This paper reviews microfluidic technologies with emphasis on applications in the fields of pharmacy, biology, and tissue engineering. Design and fabrication of microfluidic systems are discussed with respect to specific biological concerns, such as biocompatibility and cell viability. Recent applications and developments on genetic analysis, cell culture, cell manipulation, biosensors, pathogen detection systems, diagnostic devices, high-throughput screening and biomaterial synthesis for tissue engineering are presented. The pros and cons of materials like polydimethylsiloxane (PDMS, polymethylmethacrylate (PMMA, polystyrene (PS, polycarbonate (PC, cyclic olefin copolymer (COC, glass, and silicon are discussed in terms of biocompatibility and fabrication aspects. Microfluidic devices are widely used in life sciences. Here, commercialization and research trends of microfluidics as new, easy to use, and cost-effective measurement tools at the cell/tissue level are critically reviewed.

  3. 3D printing method for freeform fabrication of optical phantoms simulating heterogeneous biological tissue

    Science.gov (United States)

    Wang, Minjie; Shen, Shuwei; Yang, Jie; Dong, Erbao; Xu, Ronald

    2014-03-01

    The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is designed to mix base, scattering, and absorption materials at different ratios. 3D tissue structures are fabricated through layer-by-layer printing with selective deposition of phantom materials of different ingredients. Different mixed ratios of base, scattering and absorption materials have been tested in order to optimize the printing outcome. A spectrometer and a tissue spectrophotometer are used for characterizing phantom absorption and scattering properties. The goal of this project is to fabricate skin tissue simulating phantoms as a traceable standard for the calibration of biomedical optical spectral devices.

  4. A multiscale analysis of nutrient transport and biological tissue growth in vitro

    KAUST Repository

    O'Dea, R. D.

    2014-10-15

    © The authors 2014. In this paper, we consider the derivation of macroscopic equations appropriate to describe the growth of biological tissue, employing a multiple-scale homogenization method to accommodate explicitly the influence of the underlying microscale structure of the material, and its evolution, on the macroscale dynamics. Such methods have been widely used to study porous and poroelastic materials; however, a distinguishing feature of biological tissue is its ability to remodel continuously in response to local environmental cues. Here, we present the derivation of a model broadly applicable to tissue engineering applications, characterized by cell proliferation and extracellular matrix deposition in porous scaffolds used within tissue culture systems, which we use to study coupling between fluid flow, nutrient transport, and microscale tissue growth. Attention is restricted to surface accretion within a rigid porous medium saturated with a Newtonian fluid; coupling between the various dynamics is achieved by specifying the rate of microscale growth to be dependent upon the uptake of a generic diffusible nutrient. The resulting macroscale model comprises a Darcy-type equation governing fluid flow, with flow characteristics dictated by the assumed periodic microstructure and surface growth rate of the porous medium, coupled to an advection-reaction equation specifying the nutrient concentration. Illustrative numerical simulations are presented to indicate the influence of microscale growth on macroscale dynamics, and to highlight the importance of including experimentally relevant microstructural information to correctly determine flow dynamics and nutrient delivery in tissue engineering applications.

  5. Electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter system*

    Science.gov (United States)

    Zan, Peng; Yang, Bang-hua; Shao, Yong; Yan, Guo-zheng; Liu, Hua

    2010-01-01

    This paper reports on the electromagnetic effects on the biological tissue surrounding a transcutaneous transformer for an artificial anal sphincter. The coupling coils and human tissues, including the skin, fat, muscle, liver, and blood, were considered. Specific absorption rate (SAR) and current density were analyzed by a finite-length solenoid model. First, SAR and current density as a function of frequency (10–107 Hz) for an emission current of 1.5 A were calculated under different tissue thickness. Then relations between SAR, current density, and five types of tissues under each frequency were deduced. As a result, both the SAR and current density were below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The results show that the analysis of these data is very important for developing the artificial anal sphincter system. PMID:21121071

  6. Dental pulp stem cells. Biology and use for periodontal tissue engineering.

    Science.gov (United States)

    Ashri, Nahid Y; Ajlan, Sumaiah A; Aldahmash, Abdullah M

    2015-12-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors.

  7. Dental pulp stem cells. Biology and use for periodontal tissue engineering

    Directory of Open Access Journals (Sweden)

    Nahid Y. Ashri

    2015-12-01

    Full Text Available Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors.

  8. Simultaneous measurement of anisotropic solute diffusivity and binding reaction rates in biological tissues by FRAP.

    Science.gov (United States)

    Travascio, Francesco; Gu, Wei Yong

    2011-01-01

    Several solutes (e.g., growth factors, cationic solutes, etc.) can reversibly bind to the extracellular matrix (ECM) of biological tissues. Binding interactions have significant implications on transport of such solutes through the ECM. In order to fully delineate transport phenomena in biological tissues, knowledge of binding kinetics is crucial. In this study, a new method for the simultaneous determination of solute anisotropic diffusivity and binding reaction rates was presented. The new technique was solely based on Fourier analysis of fluorescence recovery after photobleaching (FRAP) images. Computer-simulated FRAP tests were used to assess the sensitivity and the robustness of the method to experimental parameters, such as anisotropic solute diffusivity and rates of binding reaction. The new method was applied to the determination of diffusivity and binding rates of 5-dodecanoylaminofluorescein (DAF) in bovine coccygeal annulus fibrosus (AF). Our findings indicate that DAF reversibly binds to the ECM of AF. In addition, it was found that DAF diffusion in AF is anisotropic. The results were in agreement with those reported in previous studies. This study provides a new tool for the simultaneous determination of solute anisotropic diffusion tensor and rates of binding reaction that can be used to investigate diffusive-reactive transport in biological tissues and tissue engineered constructs.

  9. Biological Activity Alterations of Human Amniotic Membrane Pre and Post Irradiation Tissue Banking.

    Science.gov (United States)

    Nemr, Waleed; Bashandy, A S; Araby, Eman; Khamiss, O

    Innate immunity of Human Amniotic Membrane (HAM) and its highly active secretome that rich with various types of growth factors and anti-inflammatory substances proposed it as a promising material for many medical studies and applications. This study evaluate the biological activity of cultivated HAM pre and post tissue banking process in which freeze-dried HAM was sterilized by 25 KGray (kGy) dose of γ radiation. The HAM's antimicrobial activity, viability, growth of isolated human amniotic epithelial cells (HAECs), hematopoietic stimulation of co-cultivated murine bone marrow cells (mammalian model), scaffold efficiency for fish brain building up (non-mammalian model) and self re-epithelialization after trypsin denuding treatment were examined as supposed biological activity features. Native HAM revealed viability indications and was active to kill all tested microorganisms; 6 bacterial species (3 Gram-positive and 3 Gram-negative) and Candida albicans as a pathogenic fungus. Also, HAM activity promoted colony formation of murine hematopoietic cells, Tilapia nilotica brain fragment building-up and self re-epithelialization after trypsin treatment. In contrary, radiation-based tissue banking of HAM caused HAM cellular death and consequently lacked almost all of examined biological activity features. Viable HAM was featured with biological activity than fixed HAM prepared by irradiation tissue banking.

  10. Statistical Modeling of Radiative Transfer and Transient Characteristics for Multilayer Biological Tissue

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2014-01-01

    Full Text Available The Monte-Carlo method [1] already long ago proved itself as a powerful and universal tool for mathematical modelling in various areas of science and engineering. Researchers often choose this method when it is difficult to find a solution by other ways (or impossible at all, e.g. because of sophisticated analytical dependences, area of modelling or boundary conditions. Certainly, this necessarily statistical and flexible method requires significant computation time, but a continuously increasing computation capability makes it more and more attractive for a choice in specific situation.One of the promising areas to use the method of statistical modelling is description of light propagation in the turbid (scattering media. A high motivation for development of this approach is widely used lasers in biomedicine [3]. Besides, owing to its flexibility, the Monte-Carlo method is also of importance in theoretical researches, in particular, to estimate a degree of adequacy of the offered approximation methods for solving a radiative transfer equation [4].It is known that key parameters of turbid media are an absorption coefficient (characterizes absorption probability of a photon per unit of path length and a scattering coefficient (characterizes scattering probability of a photon per unit of path length. The ratio of each of the coefficients to their sum (extinction defines a probability of "death" or "survival" of a photon, respectively, in interaction with lenses. Generally, in the scattering medium there is a non-coherent radiation component, which in turbid media such as biological tissues, already at the insignificant depth becomes prevailing over the coherent one (residual of the incident laser beam [5].The author used the Monte-Carlo method to simulate optical radiation propagation in the multilayer biological tissues with their optical characteristics corresponding to the skin and subcutaneous tissues. Such a biological tissue is the absorbing

  11. Use of Mesothelial Cells and Biological Matrices for Tissue Engineering of Simple Epithelium Surrogates

    Directory of Open Access Journals (Sweden)

    Christian Claude Lachaud

    2015-08-01

    Full Text Available Tissue engineering technologies have progressed rapidly through last decades resulting in the manufacture of quite complex bioartificial tissues with potential use for human organ and tissue regeneration. The manufacture of avascular monolayered tissues such as simple squamous epithelia was initiated a few decades ago and is attracting increasing interest. Their relative morphostructural simplicity makes of their biomimetization a goal, which is currently accessible. The mesothelium is a simple squamous epithelium in nature and is the monolayered tissue lining the walls of large coelomic cavities (peritoneal, pericardial and pleural and internal organs housed inside. Interestedly, mesothelial cells can be harvested in clinically relevant numbers from several anatomical sources and not less important, they also display high transdifferentiation capacities and are low immunogenic, characteristics, which endow these cells with therapeutic interest. Their combination with a suitable scaffold (biocompatible, degradable and non-immunogenic may allow the manufacture of tailored serosal membranes biomimetics with potential spanning a wide range of therapeutic applications, principally for the regeneration of simple squamous-like epithelia such as the visceral and parietal mesothelium vascular endothelium and corneal endothelium among others. Herein, we review recent research progresses in mesothelial cells biology and their clinical sources. We make a particular emphasis on reviewing the different types of biological scaffolds suitable for the manufacture of serosal mesothelial membranes biomimetics. Finally, we also review progresses made in mesothelial cells-based therapeutic applications and propose some possible future directions.

  12. Tissue lead distribution and hematologic effects in American kestrels (Falco sparverius) fed biologically incorporated lead

    Science.gov (United States)

    Custer, T.W.; Franson, J.C.; Pattee, O.H.

    1984-01-01

    American kestrels were fed a diet containing 0.5, 120, 212, and 448 ppm (dry wt) biologically incorporated lead (Pb) for 60 days. The diet consisted of homogenized 4-wk-old cockerels raised on feed mixed with and without lead. No kestrels died and weights did not differ among treatment groups. The control group (0.5 ppm Pb) had the lowest mean concentration of lead and the high dietary group had the highest for the following tissues: Kidney, liver, femur, brain, and blood. Concentrations of lead were significantly correlated among tissues. There were no differences among treatment groups for packed cell volume, hemoglobin concentration, or erythrocyte count.

  13. Bird-Window Collisions at a West-Coast Urban Park Museum: Analyses of Bird Biology and Window Attributes from Golden Gate Park, San Francisco.

    Science.gov (United States)

    Kahle, Logan Q; Flannery, Maureen E; Dumbacher, John P

    2016-01-01

    Bird-window collisions are a major and poorly-understood generator of bird mortality. In North America, studies of this topic tend to be focused east of the Mississippi River, resulting in a paucity of data from the Western flyways. Additionally, few available data can critically evaluate factors such as time of day, sex and age bias, and effect of window pane size on collisions. We collected and analyzed 5 years of window strike data from a 3-story building in a large urban park in San Francisco, California. To evaluate our window collision data in context, we collected weekly data on local bird abundance in the adjacent parkland. Our study asks two overarching questions: first-what aspects of a bird's biology might make them more likely to fatally strike windows; and second, what characteristics of a building's design contribute to bird-window collisions. We used a dataset of 308 fatal bird strikes to examine the relationships of strikes relative to age, sex, time of day, time of year, and a variety of other factors, including mitigation efforts. We found that actively migrating birds may not be major contributors to collisions as has been found elsewhere. We found that males and young birds were both significantly overrepresented relative to their abundance in the habitat surrounding the building. We also analyzed the effect of external window shades as mitigation, finding that an overall reduction in large panes, whether covered or in some way broken up with mullions, effectively reduced window collisions. We conclude that effective mitigation or design will be required in all seasons, but that breeding seasons and migratory seasons are most critical, especially for low-rise buildings and other sites away from urban migrant traps. Finally, strikes occur throughout the day, but mitigation may be most effective in the morning and midday.

  14. Jones-matrix tomography of biological tissues phase anisotropy in the diagnosis of uterus wall prolapse

    Science.gov (United States)

    Trifonyuk, L.; Baranovsky, V.; Dubolazov, O. V.; Ushenko, V. O.; Ushenko, O. G.; Zhytaryuk, V. G.; Prydiy, O. G.; Vanchulyak, O.

    2018-01-01

    The work consists of two parts. In the first part - we mapped a distribution of optical activity and birefringence in polycrystalline networks of biological tissues. The Jones-matrix formalism is used for accessible quantitative description of these types of optical anisotropy. We demonstrate that differentiation of polycrystalline networks of biological tissues can be performed based on the statistical analysis of distribution of rotation angles and phase shifts associated with the optical activity and birefringence, respectively. In the second part we defined - practical operational characteristics, such as sensitivity, specificity and accuracy of Jones-matrix reconstruction of optical anisotropy were identified with the special emphasis on biomedical application, specifically for differentiation of two types of pathology: prolapse and albuminuria.

  15. Generalized Fokker-Planck theory for electron and photon transport in biological tissues: application to radiotherapy.

    Science.gov (United States)

    Olbrant, Edgar; Frank, Martin

    2010-12-01

    In this paper, we study a deterministic method for particle transport in biological tissues. The method is specifically developed for dose calculations in cancer therapy and for radiological imaging. Generalized Fokker-Planck (GFP) theory [Leakeas and Larsen, Nucl. Sci. Eng. 137 (2001), pp. 236-250] has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where there is a sufficient amount of large-angle scattering. We compare grid-based numerical solutions to FP and GFP in realistic medical applications. First, electron dose calculations in heterogeneous parts of the human body are performed. Therefore, accurate electron scattering cross sections are included and their incorporation into our model is extensively described. Second, we solve GFP approximations of the radiative transport equation to investigate reflectance and transmittance of light in biological tissues. All results are compared with either Monte Carlo or discrete-ordinates transport solutions.

  16. M2 macrophages participate in the biological tissue healing reaction to mineral trioxide aggregate.

    Science.gov (United States)

    Ito, Takafumi; Kaneko, Tomoatsu; Yamanaka, Yusuke; Shigetani, Yoshimi; Yoshiba, Kunihiko; Okiji, Takashi

    2014-03-01

    This study examined the protein and messenger RNA (mRNA) expression of molecules associated with M2 (wound healing) macrophages in mineral trioxide aggregate (MTA)-implanted rat subcutaneous tissue to elucidate the involvement of M2 macrophages in the connective tissue response to MTA. Silicone tubes containing freshly mixed MTA or a calcium hydroxide cement (Life; Kerr, Romulus, MI) were subcutaneously implanted into the backs of Wistar rats. Solid silicone rods implanted in different animals served as controls. The specimens were then double immunostained for ED1 (CD68, a general macrophage marker) and ED2 (CD163, an M2 macrophage marker). Immunostaining for CD34 (a marker for vascularization and wound healing) was also performed. Expression levels of CD34, CD163, and mannose receptor c type 1 (an M2 macrophage marker) mRNAs were determined with real-time polymerase chain reaction. MTA-implanted subcutaneous tissues showed significant increases in the density of ED1+ED2+ macrophages beneath the implantation site and expression levels of CD163 and MMR mRNAs compared with Life-implanted and control tissues. MTA-implanted subcutaneous tissues also showed a significant increase of CD34-immunostained areas and up-regulation of CD34 mRNAs compared with Life-implanted and control tissues. MTA implantation induced the accumulation of M2 macrophage marker (ED2)-expressing macrophages and enhanced the expression of M2 macrophage marker genes. MTA implantation also enhanced the expression of CD34, suggesting acceleration of the healing/tissue repair process. Taken together, biological connective tissue response to MTA may involve wound healing/tissue repair processes involving M2 macrophages. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Electrical circuit modeling and analysis of microwave acoustic interaction with biological tissues.

    Science.gov (United States)

    Gao, Fei; Zheng, Qian; Zheng, Yuanjin

    2014-05-01

    Numerical study of microwave imaging and microwave-induced thermoacoustic imaging utilizes finite difference time domain (FDTD) analysis for simulation of microwave and acoustic interaction with biological tissues, which is time consuming due to complex grid-segmentation and numerous calculations, not straightforward due to no analytical solution and physical explanation, and incompatible with hardware development requiring circuit simulator such as SPICE. In this paper, instead of conventional FDTD numerical simulation, an equivalent electrical circuit model is proposed to model the microwave acoustic interaction with biological tissues for fast simulation and quantitative analysis in both one and two dimensions (2D). The equivalent circuit of ideal point-like tissue for microwave-acoustic interaction is proposed including transmission line, voltage-controlled current source, envelop detector, and resistor-inductor-capacitor (RLC) network, to model the microwave scattering, thermal expansion, and acoustic generation. Based on which, two-port network of the point-like tissue is built and characterized using pseudo S-parameters and transducer gain. Two dimensional circuit network including acoustic scatterer and acoustic channel is also constructed to model the 2D spatial information and acoustic scattering effect in heterogeneous medium. Both FDTD simulation, circuit simulation, and experimental measurement are performed to compare the results in terms of time domain, frequency domain, and pseudo S-parameters characterization. 2D circuit network simulation is also performed under different scenarios including different sizes of tumors and the effect of acoustic scatterer. The proposed circuit model of microwave acoustic interaction with biological tissue could give good agreement with FDTD simulated and experimental measured results. The pseudo S-parameters and characteristic gain could globally evaluate the performance of tumor detection. The 2D circuit network

  18. Sterilization of biological tissues with ionizing radiation; Esterilizacion de tejidos biologicos con radiacion ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Reyes F, M.L.; Martinez P, M.E.; Luna Z, D. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    On June 1994, the National Institute of Nuclear Research (ININ) and the South Central Hospital for High Specialty of PEMEX (HCSAE) began a joint work with the finality to obtain radio sterilized amniotic membranes for to be used as cover (biological bandage) in burnt patients. Subsequently the Chemistry Faculty of UNAM and the National Institute of Cardiology began to collaborate this last with interest on cardiac valves for graft. Starting from 1997, the International Atomic Energy Agency (IAEA) supports this project (MEX/7/008) whose main objective is to set up the basis to establish in Mexico a Radio sterilized Tissue Bank (amniotic membranes, skin, bones, tendons, cardiac valves, etc.) to be used with therapeutic purposes (grafts). The IAEA support has consisted in the equipment acquisition which is fundamental for the Tissue Bank performance such as an experimental irradiator, laminar flow bell, lyophilizer, vacuum sealer and special knives for tissues. Also visits to Mexico of experts have been authorized with the aim of advising to the personnel which participate in the project and scientific visits of this personnel to another tissue banks (Sri Lanka and Argentine). The establishment in Mexico of a Tissue bank will be a great benefit because it will have availability of distinct tissues for grafts and it will reduce the synthetic materials importation which is very expensive. (Author)

  19. A strain-hardening bi-power law for the nonlinear behaviour of biological soft tissues.

    Science.gov (United States)

    Nicolle, S; Vezin, P; Palierne, J-F

    2010-03-22

    Biological soft tissues exhibit a strongly nonlinear viscoelastic behaviour. Among parenchymous tissues, kidney and liver remain less studied than brain, and a first goal of this study is to report additional material properties of kidney and liver tissues in oscillatory shear and constant shear rate tests. Results show that the liver tissue is more compliant but more strain hardening than kidney. A wealth of multi-parameter mathematical models has been proposed for describing the mechanical behaviour of soft tissues. A second purpose of this work is to develop a new constitutive law capable of predicting our experimental data in the both linear and nonlinear viscoelastic regime with as few parameters as possible. We propose a nonlinear strain-hardening fractional derivative model in which six parameters allow fitting the viscoelastic behaviour of kidney and liver tissues for strains ranging from 0.01 to 1 and strain rates from 0.0151 s(-1) to 0.7s(-1). Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  20. Three-Dimensional Microstructure of Biological Tissues during Freezing and Thawing

    Science.gov (United States)

    Ishiguro, Hiroshi; Horimizu, Takashi; Kataori, Akinobu; Kajigaya, Hiroshi

    Three-dimensional behavior of ice crystals and cells during the freezing and thawing of biological tissues was investigated microscopically in real time by using a confocal laser scanning microscope(CLSM) and a fluorescent dye, acridine orange (AO). Fresh tender meat (2nd pectoral muscles) of chicken was stained with the AO in physiological saline to distinguish ice crystals and cells by their different colors, and then frozen and thawed under two different thermal protocols: a) slow-cooling and rapid-warming and b) rapid-cooling and rapid-warming. The CLSM noninvasively produced optical tomograms of the tissues to clarify the pattern of freezing, morphology of ice crystals in the tissues, and the interaction between ice crystals and cells. Also, the tissues were morphologically investigated by pathological means after the freezing and thawing. Typical freezing pattern during the slow-cooling was extracellular-freezing, and those during the rapid-cooling were extracellular-freezing and intracellular freezing with a lot of fine ice crystals in the cells. Cracks caused by the extracellular and intracellular ice crystals remained in the muscle tissues after the thawing. The results obtained by using the CLSM/dye method were consistent with pathologically morphological changes in the tissues through freezing and thawing.

  1. Applying the Kelvin probe to biological tissues: theoretical and computational analyses.

    Science.gov (United States)

    Ahn, Andrew C; Gow, Brian J; Martinsen, Orjan G; Zhao, Min; Grodzinsky, Alan J; Baikie, Iain D

    2012-06-01

    The Kelvin probe measures surface electrical potential without making physical contact with the specimen. It relies on capacitive coupling between an oscillating metal tip that is normal to a specimen's surface. Kelvin probes have been increasingly used to study surface and electrical properties of metals and semiconductors and are capable of detecting material surface potentials with submillivolt resolution at a micrometer spatial scale. Its capability for measuring electrical potential without being confounded by electrode-specimen contact makes extending its use towards biological materials particularly appealing. However, the theoretical basis for applying the Kelvin probe to dielectric or partially conductive materials such as biological tissue has not been evaluated and remains unclear. This study develops the theoretical basis underlying Kelvin probe measurements in five theoretical materials: highly conductive, conductive dielectric with rapid charge relaxation, conductive dielectric with slow charge relaxation, perfect dielectric, and tissue with a bulk serial resistance. These theoretically derived equations are then computationally analyzed using parameters from both theoretical specimens and actual biomaterials-including wet skin, dry skin, cerebrospinal fluid, and tendon. Based on these analyses, a Kelvin probe performs in two distinct ways depending on the charge relaxation rates of the sample: The specimen is treated either as a perfect dielectric or as highly conductive material. Because of their rapid relaxation rate and increased permittivity biomaterials behave similarly to highly conductive materials, such as metal, when evaluated by the Kelvin probe. These results indicate that the Kelvin probe can be readily applied to studying the surface potential of biological tissue.

  2. Laser autofluorescence polarimetry of optically anisotropic structures of biological tissues in cancer diagnostics

    Science.gov (United States)

    Ushenko, Yu. A.

    2015-06-01

    The results of a new physical study of polarization manifestations of laser autofluorescence of optically anisotropic structures in human female reproductive tissues are presented. A Mueller-matrix model of describing the complex anisotropy (linear and circular birefringence, linear and circular dichroism) of such biological layers is proposed. Interrelations between mechanisms of optical anisotropy and polarization manifestations of laser autofluorescence of histological layers of the uterine cervix tissue in different spectral regions are determined. Magnitudes and variation ranges of statistical moments from the first to the fourth order describing the distributions of azimuthally stable elements of Mueller matrices of autofluorescence in human female reproductive tissues in different physiological states are found. The informative value of the proposed method is determined and the differentiation of histological biopsy sections of benign (dysplasia) and malignant (adenocarcinoma) uterine cervix tumors is implemented for the first time.

  3. A tensile machine with a novel optical load cell for soft biological tissues application.

    Science.gov (United States)

    Faturechi, Rahim; Hashemi, Ata; Abolfathi, Nabiollah

    2014-11-01

    The uniaxial tensile testing machine is the most common device used to measure the mechanical properties of industrial and biological materials. The need for a low-cost uniaxial tension testing device for small research centers has always been the subject of research. To address this need, a novel uniaxial tensile testing machine was designed and fabricated to measure the mechanical properties of soft biological tissues. The device is equipped with a new low-cost load cell which works based on the linear displacement/force relationship of beams. The deflection of the beam load cell is measured optically by a digital microscope with an accuracy of 1 µm. The stiffness of the designed load cell was experimentally and theoretically determined at 100 N mm(-1). The stiffness of the load cell can be easily adjusted according to the tissue's strength. The force-time behaviour of soft tissue specimens was obtained by an in-house image processing program. To demonstrate the efficiency of the fabricated device, the mechanical properties of amnion tissue was measured and compared with available data. The obtained results indicate a strong agreement with that of previous studies.

  4. Predictive analysis of thermal distribution and damage in thermotherapy on biological tissue

    Science.gov (United States)

    Fanjul-Vélez, Félix; Arce-Diego, José Luis

    2007-05-01

    The use of optical techniques is increasing the possibilities and success of medical praxis in certain cases, either in tissue characterization or treatment. Photodynamic therapy (PDT) or low intensity laser treatment (LILT) are two examples of the latter. Another very interesting implementation is thermotherapy, which consists of controlling temperature increase in a pathological biological tissue. With this method it is possible to provoke an improvement on specific diseases, but a previous analysis of treatment is needed in order for the patient not to suffer any collateral damage, an essential point due to security margins in medical procedures. In this work, a predictive analysis of thermal distribution in a biological tissue irradiated by an optical source is presented. Optical propagation is based on a RTT (Radiation Transport Theory) model solved via a numerical Monte Carlo method, in a multi-layered tissue. Data obtained are included in a bio-heat equation that models heat transference, taking into account conduction, convection, radiation, blood perfusion and vaporization depending on the specific problem. Spatial-temporal differential bio-heat equation is solved via a numerical finite difference approach. Experimental temperature distributions on animal tissue irradiated by laser radiation are shown. From thermal distribution in tissue, thermal damage is studied, based on an Arrhenius analysis, as a way of predicting harmful effects. The complete model can be used for concrete treatment proposals, as a way of predicting treatment effects and consequently decide which optical source parameters are appropriate for the specific disease, mainly wavelength and optical power, with reasonable security margins in the process.

  5. Original paper Influence of biologic therapy on growth in children with chronic inflammatory connective tissue diseases

    Directory of Open Access Journals (Sweden)

    Joanna Świdrowska

    2015-04-01

    Full Text Available Objectives: Connective tissue diseases (CTD are a heterogeneous group of chronic inflammatory conditions. One of their complications in children is the inhibition of growth velocity. Due to direct inflammation within the musculoskeletal system as well as glucocorticoid therapy, this feature is the most essential and is mainly expressed in the course of juvenile spondyloarthropathies and juvenile idiopathic arthritis (JIA. Duration of the disease, but predominantly the activity of the inflammatory process, seems to have a significant impact on the abnormal growth profile in children. Effective biological therapy leads to improvement of the patient’s clinical condition and also, through the extinction of disease activity and reduction of daily doses of glucocorticosteroids (GCS, it gradually accelerates and normalizes the growth rate in children with CTD. Our objective was to evaluate the impact of biological therapy on growth in children with chronic inflammatory CTD. Material and methods: Data from 24 patients with CTD treated with tumor necrosis factor--blockers (etanercept, adalimumab, golimumab and an interleukin-6 receptor blocker (tocilizumab were reviewed at the time of disease onset, biological treatment initiation and at least 12 up to 24 months onwards. The rate of growth was correlated with the daily doses of GCS, and the type and duration of biological therapy. Results : Patient median height, measured as the change in height standard deviation score, was 0.36 ±1.07 at disease onset and –0.13 ±1.02 at biologic therapy initiation. The growth velocity accelerated in 17 patients (70.1% during the biological treatment. Mean height-SDS improvement between biological treatment initiation up to two years was 0.51 ±0.58. In 47% of patients daily doses of GCS were reduced to 0 mg/kg/day. Conclusions : In the treatment of CTD, biological agents restore growth velocity not only by inflammation inhibition, but also through limiting GCS

  6. Analysis of photon transport in biological tissue and the subsequent heating effects

    International Nuclear Information System (INIS)

    Fadhali, M.M.A.

    2015-01-01

    Analysis of laser interaction with matter revealed the possibilities of many industrial and therapeutic applications. This research article discusses the theoretical aspects of laser beam interaction with biological tissues. It introduces the numerical analysis of photon distribution and transport in the tissue and its bio-thermal heating effects. The Monte Carlo method has been applied to simulate the variation of photon distribution and photon fluence with the radial distance from the point of interaction as well as laser powers and tissue thickness. For a specific wavelength, the variation of diffuse reflectance with the absorption coefficient was depicted for different values of the anisotropy factor. It has also been used to simulate the bio-heat transfer to obtain the temperature variation with the heating depth. On the other hand, finite difference method (FDM) has been applied to simulate the heating effect resulted from the incident laser beam on the tissue based on Penne's bio-heat equation combined with the obtained photon distribution and transport parameters from the MC method. The heating effect of the laser beam and hence the occurred thermal damage in the tissue was depicted. A linear relationship between the temperature and the rate of thermal damage has been manifested. This result can be used as a threshold reference for various medical applications of lasers. (authors)

  7. Theoretical and observational analysis of individual ionizing particle effects in biological tissue

    International Nuclear Information System (INIS)

    Nelson, A.C.

    1980-11-01

    The microstructural damage to living tissue caused by heavy ion radiation was studied. Preliminary tests on rat corneal tissue, rat cerebellar tissue grown in culture, and rat retinal tissue indicated that the best assay for heavy ion damage is the rat cornea. The corneal tissue of the living rat was exposed to beams of carbon at 474 MeV/amu, neon at 8.5 MeV/amu, argon at 8.5 MeV/amu, silicon at 530 MeV/amu, iron at 500 MeV/amu, and iron at 600 MeV/amu. X-rays were also used on corneas to compare with the heavy ion irradiated corneas. Scanning electron microscopy revealed lesions with circular symmetry on the external plasma membranes of corneal epithelium which were irradiated with heavy ions, but similar lesions were not observed on the plasma membranes of x-ray irradiated or non-irradiated control samples. These data verify the special way in which heavy ions interact with matter: each ion interacts coulombically with electrons all along its trajectory to generate a track. The dose from heavy ion radiation is not distributed homogeneously on a tissue microstructural scale but is concentrated along the individual particle track. Even along a single particle track the dose is discontinuous except at the Bragg peak when the LET is maximum. Micrographs of heavy-ion-irradiated corneas demonstrated two significant correlations with the heavy ion beam: (1) the number of plasma membrane lesions per unit area was correlated with the particle fluence, and (2) the diameter of the lesions were linearly related to the energy loss or LET of the individual particle. These observations corroborate what has already been suggested theoretically about heavy ion tracks and what has been shown experimentally. But the new data indicate that particle tracks occur in biological tissues as well, and that a single heavy ion is responsible for each membrane lesion

  8. Theoretical and observational analysis of individual ionizing particle effects in biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A.C.

    1980-11-01

    The microstructural damage to living tissue caused by heavy ion radiation was studied. Preliminary tests on rat corneal tissue, rat cerebellar tissue grown in culture, and rat retinal tissue indicated that the best assay for heavy ion damage is the rat cornea. The corneal tissue of the living rat was exposed to beams of carbon at 474 MeV/amu, neon at 8.5 MeV/amu, argon at 8.5 MeV/amu, silicon at 530 MeV/amu, iron at 500 MeV/amu, and iron at 600 MeV/amu. X-rays were also used on corneas to compare with the heavy ion irradiated corneas. Scanning electron microscopy revealed lesions with circular symmetry on the external plasma membranes of corneal epithelium which were irradiated with heavy ions, but similar lesions were not observed on the plasma membranes of x-ray irradiated or non-irradiated control samples. These data verify the special way in which heavy ions interact with matter: each ion interacts coulombically with electrons all along its trajectory to generate a track. The dose from heavy ion radiation is not distributed homogeneously on a tissue microstructural scale but is concentrated along the individual particle track. Even along a single particle track the dose is discontinuous except at the Bragg peak when the LET is maximum. Micrographs of heavy-ion-irradiated corneas demonstrated two significant correlations with the heavy ion beam: (1) the number of plasma membrane lesions per unit area was correlated with the particle fluence, and (2) the diameter of the lesions were linearly related to the energy loss or LET of the individual particle. These observations corroborate what has already been suggested theoretically about heavy ion tracks and what has been shown experimentally. But the new data indicate that particle tracks occur in biological tissues as well, and that a single heavy ion is responsible for each membrane lesion. (ERB)

  9. Dual-porosity model of solute diffusion in biological tissue modified by electroporation.

    Science.gov (United States)

    Mahnič-Kalamiza, Samo; Miklavčič, Damijan; Vorobiev, Eugène

    2014-07-01

    In many electroporation applications mass transport in biological tissue is of primary concern. This paper presents a theoretical advancement in the field and gives some examples of model use in electroporation applications. The study focuses on post-treatment solute diffusion. We use a dual-porosity approach to describe solute diffusion in electroporated biological tissue. The cellular membrane presents a hindrance to solute transport into the extracellular space and is modeled as electroporation-dependent porosity, assigned to the intracellular space (the finite rate of mass transfer within an individual cell is not accounted for, for reasons that we elaborate on). The second porosity is that of the extracellular space, through which solute vacates a block of tissue. The model can be used to study extraction out of or introduction of solutes into tissue, and we give three examples of application, a full account of model construction, validation with experiments, and a parametrical analysis. To facilitate easy implementation and experimentation by the reader, the complete derivation of the analytical solution for a simplified example is presented. Validation is done by comparing model results to experimentally-obtained data; we modeled kinetics of sucrose extraction by diffusion from sugar beet tissue in laboratory-scale experiments. The parametrical analysis demonstrates the importance of selected physicochemical and geometrical properties of the system, illustrating possible outcomes of applying the model to different electroporation applications. The proposed model is a new platform that supports rapid extension by state-of-the-art models of electroporation phenomena, developed as latest achievements in the field of electroporation. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Telomere Lengths and Telomerase Activity in Dog Tissues: A Potential Model System to Study Human Telomere and Telomerase Biology

    Directory of Open Access Journals (Sweden)

    Lubna Nasir

    2001-01-01

    Full Text Available Studies on telomere and telomerase biology are fundamental to the understanding of aging and age-related diseases such as cancer. However, human studies have been hindered by differences in telomere biology between humans and the classical murine animal model system. In this paper, we describe basic studies of telomere length and telomerase activity in canine normal and neoplastic tissues and propose the dog as an alternative model system. Briefly, telomere lengths were measured in normal canine peripheral blood mononuclear cells (PBMCs, a range of normal canine tissues, and in a panel of naturally occurring soft tissue tumours by terminal restriction fragment (TRF analysis. Further, telomerase activity was measured in canine cell lines and multiple canine tissues using a combined polymerase chain reaction/enzyme-linked immunosorbent assay method. TRF analysis in canine PBMCs and tissues demonstrated mean TRF lengths to range between 12 and 23 kbp with heterogeneity in telomere lengths being observed in a range of normal somatic tissues. In soft tissue sarcomas, two subgroups were identified with mean TRFs of 22.2 and 18.2 kbp. Telomerase activity in canine tissue was present in tumour tissue and testis with little or no activity in normal somatic tissues. These results suggest that the dog telomere biology is similar to that in humans and may represent an alternative model system for studying telomere biology and telomerase-targeted anticancer therapies.

  11. Non-integer viscoelastic constitutive law to model soft biological tissues to in-vivo indentation.

    Science.gov (United States)

    Demirci, Nagehan; Tönük, Ergin

    2014-01-01

    During the last decades, derivatives and integrals of non-integer orders are being more commonly used for the description of constitutive behavior of various viscoelastic materials including soft biological tissues. Compared to integer order constitutive relations, non-integer order viscoelastic material models of soft biological tissues are capable of capturing a wider range of viscoelastic behavior obtained from experiments. Although integer order models may yield comparably accurate results, non-integer order material models have less number of parameters to be identified in addition to description of an intermediate material that can monotonically and continuously be adjusted in between an ideal elastic solid and an ideal viscous fluid. In this work, starting with some preliminaries on non-integer (fractional) calculus, the "spring-pot", (intermediate mechanical element between a solid and a fluid), non-integer order three element (Zener) solid model, finally a user-defined large strain non-integer order viscoelastic constitutive model was constructed to be used in finite element simulations. Using the constitutive equation developed, by utilizing inverse finite element method and in vivo indentation experiments, soft tissue material identification was performed. The results indicate that material coefficients obtained from relaxation experiments, when optimized with creep experimental data could simulate relaxation, creep and cyclic loading and unloading experiments accurately. Non-integer calculus viscoelastic constitutive models, having physical interpretation and modeling experimental data accurately is a good alternative to classical phenomenological viscoelastic constitutive equations.

  12. Faecal microbiota transplantation: a sui generis biological drug, not a tissue.

    Science.gov (United States)

    Megerlin, F; Fouassier, E; Lopert, R; Bourlioux, P

    2014-07-01

    Responding to Smith et al. (Nature, 2014), this paper argues that for medical use, faecal microbiota transplantation (FMT) should be considered a sui generis biological drug, rather than a tissue. Smith and colleagues' thesis is based on possible undesirable economic consequences of this designation--not on its scientific and conceptual basis. The faecal transplant (including gut microbiota, metabolites, mucus, human cells, viruses, fungi, etc.) is not a tissue; it is of topographic--not cellular--human origin. We consider the donor a bioreactor, producing the faecal substrate of therapeutic interest. The debate is of singular importance as the FDA considers FMT a drug and released a new guidance for public consultation in February 2014, whereas to date the European Medicines Agency has not promulgated its position. The UK's National Institute for Heath and Care Excellence does not consider FMT to involve the transplantation of body tissue, and in March 2014 the French regulatory agency ANSM expressly declared it to be a drug. As FM is a complex and highly variable admixture, its components cannot be completely characterized, and to date, compositional quality cannot be assessed. We consider FMT to be a sui generis biologic drug, albeit one prepared with unconventional raw material under microbiologic control. The possibility of associating identified bacterial species with particular diseases and cultivating selected bacteria of therapeutic interest would certainly define a second generation of microbiome therapeutics, but is still speculative. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering.

    Science.gov (United States)

    Jahnavi, S; Saravanan, U; Arthi, N; Bhuvaneshwar, G S; Kumary, T V; Rajan, S; Verma, R S

    2017-04-01

    Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44 + , αSMA + , Vimentin + and CD105 - human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Hybrid printing of mechanically and biologically improved constructs for cartilage tissue engineering applications

    International Nuclear Information System (INIS)

    Xu Tao; Binder, Kyle W; Albanna, Mohammad Z; Dice, Dennis; Zhao Weixin; Yoo, James J; Atala, Anthony

    2013-01-01

    Bioprinting is an emerging technique used to fabricate viable, 3D tissue constructs through the precise deposition of cells and hydrogels in a layer-by-layer fashion. Despite the ability to mimic the native properties of tissue, printed 3D constructs that are composed of naturally-derived biomaterials still lack structural integrity and adequate mechanical properties for use in vivo, thus limiting their development for use in load-bearing tissue engineering applications, such as cartilage. Fabrication of viable constructs using a novel multi-head deposition system provides the ability to combine synthetic polymers, which have higher mechanical strength than natural materials, with the favorable environment for cell growth provided by traditional naturally-derived hydrogels. However, the complexity and high cost associated with constructing the required robotic system hamper the widespread application of this approach. Moreover, the scaffolds fabricated by these robotic systems often lack flexibility, which further restrict their applications. To address these limitations, advanced fabrication techniques are necessary to generate complex constructs with controlled architectures and adequate mechanical properties. In this study, we describe the construction of a hybrid inkjet printing/electrospinning system that can be used to fabricate viable tissues for cartilage tissue engineering applications. Electrospinning of polycaprolactone fibers was alternated with inkjet printing of rabbit elastic chondrocytes suspended in a fibrin–collagen hydrogel in order to fabricate a five-layer tissue construct of 1 mm thickness. The chondrocytes survived within the printed hybrid construct with more than 80% viability one week after printing. In addition, the cells proliferated and maintained their basic biological properties within the printed layered constructs. Furthermore, the fabricated constructs formed cartilage-like tissues both in vitro and in vivo as evidenced by the

  15. Study optical properties of biological tissue in the presence of microbubbles

    Science.gov (United States)

    Assadi, Homa; Lee, Vincent; Karshafian, Raffi; Douplik, Alexandre

    2015-03-01

    Optical contrast agents introduce distinct features to induce detectable changes in native tissue properties [1]. In ultrasound imaging, microbubbles (MBs) - a gas-core shell-encapsulated agent - are used clinically as contrast agents. The working hypothesis of this study is that microbubbles can be employed as an intravascular contrast agent in optical imaging systems. Microbubbles can produce a refractive index mismatch which makes it distinguishable from surrounding media. In this work, the interaction of collimated light and microbubbles in a [1] biological phantom solution was investigated. The biological medium was comprised of intralipid and human blood which was constructed to cover the range of soft tissue optical properties. The effect of microbubbles on the optical properties such as reduced scattering and absorption coefficients were considered. Diffuse reflectance (DR) and total transmittance (TT) of a biological phantom solution were measured using a spectroscopic integrating sphere system in the absence and presence of Definity® microbubbles. The optical properties were computed using the inverse adding doubling (IAD) software. The presence of microbubbles increased DR and decreased TT of the phantom. In the presence of MB's (2.5% volume concentration), the reflectance of the phantom increased by 25% in the optical window. There is no absorption event and only scattering happened after light-microbubbles interactions. The reduced scattering coefficient increased significantly (30%) indicating the potential use of MBs as optical contrast agents. In conclusion, reflectance of a media can be enhanced by adding microbubbles to increase scattering properties and more light was detected returning to the surface of tissue.

  16. Stochastic hyperelastic constitutive laws and identification procedure for soft biological tissues with intrinsic variability.

    Science.gov (United States)

    Staber, B; Guilleminot, J

    2017-01-01

    In this work, we address the constitutive modeling, in a probabilistic framework, of the hyperelastic response of soft biological tissues. The aim is on the one hand to mimic the mean behavior and variability that are typically encountered in the experimental characterization of such materials, and on the other hand to derive mathematical models that are almost surely consistent with the theory of nonlinear elasticity. Towards this goal, we invoke information theory and discuss a stochastic model relying on a low-dimensional parametrization. We subsequently propose a two-step methodology allowing for the calibration of the model using standard data, such as mean and standard deviation values along a given loading path. The framework is finally applied and benchmarked on three experimental databases proposed elsewhere in the literature. It is shown that the stochastic model allows experiments to be accurately reproduced, regardless of the tissue under consideration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. ELF5 in epithelial ovarian carcinoma tissues and biological behavior in ovarian carcinoma cells.

    Science.gov (United States)

    Yan, Hongchao; Qiu, Linglin; Xie, Xiaolei; Yang, He; Liu, Yongli; Lin, Xiaoman; Huang, Hongxiang

    2017-03-01

    The expression of E74-like factor 5 (ELF5) in epithelial ovarian carcinoma tissues and its effects on biological behavior in ovarian carcinoma cells were assessed in search for a new approach for gene treatment of epithelial ovarian carcinoma. RT-PCR technology was applied to detect the expression of ELF5 mRNA in epithelial ovarian carcinoma (n=49), borderline ovarian epithelial tumor (n=19), benign ovarian epithelial tumor (n=31) and normal ovarian tissues (n=40). Then, we transfected recombinant plasmid pcDNA3.1‑ELF5+EGFP into human ovarian carcinoma SKOV3 cells (recombinant plasmid group) in vitro and screened out stably transfected cells to conduct multiplication culture. Western blot analysis was performed to detect the expression of ELF5 protein in the different groups. Flow cytometry was employed to detect cell apoptosis and cycles. ELF5 mRNA in epithelial ovarian carcinoma and borderline ovarian epithelial tumor tissues were significantly lower (Povarian epithelial tumor and normal ovarian tissues. ELF5 protein expression in the cells of recombinant plasmid group was significantly higher compared with empty plasmid and blank control groups. The capacity of cell reproductive recombinant plasmid group at each time point decreased (Povarian carcinoma SKOV3 cells and promoted apoptosis of human ovarian carcinoma SKOV3 cells inhibiting their growth and invasive capacity; and thus providing a new approach to gene treatment of ovarian carcinoma.

  18. Bim: guardian of tissue homeostasis and critical regulator of the immune system, tumorigenesis and bone biology.

    Science.gov (United States)

    Akiyama, Toru; Tanaka, Sakae

    2011-08-01

    One of the most important roles of apoptosis is the maintenance of tissue homeostasis. Impairment of apoptosis leads to a number of pathological conditions. In response to apoptotic signals, various proteins are activated in a pathway and signal-specific manner. Recently, the pro-apoptotic molecule Bim has attracted increasing attention as a pivotal regulator of tissue homeostasis. The Bim expression level is strictly controlled in both transcriptional and post-transcriptional levels. This control is dependent on cell, tissue and apoptotic stimuli. The phenotype of Bim-deficient mice is a systemic lupus erythematosus-like autoimmune disease with an abnormal accumulation of hematopoietic cells. Bim is thus a critical regulator of hematopoietic cells and immune system. Further studies have revealed the critical roles of Bim in various normal and pathological conditions, including bone homeostasis and tumorigenesis. The current understanding of Bim signaling and roles in the maintenance of tissue homeostasis is reviewed in this paper, focusing on the immune system, bone biology and tumorigenesis to illustrate the diversified role of Bim.

  19. CHARACTERISTIC FEATURES OF MUELLER MATRIX PATTERNS FOR POLARIZATION SCATTERING MODEL OF BIOLOGICAL TISSUES

    Directory of Open Access Journals (Sweden)

    E DU

    2014-01-01

    Full Text Available We developed a model to describe polarized photon scattering in biological tissues. In this model, tissues are simplified to a mixture of scatterers and surrounding medium. There are two types of scatterers in the model: solid spheres and infinitely long solid cylinders. Variables related to the scatterers include: the densities and sizes of the spheres and cylinders, the orientation and angular distribution of cylinders. Variables related to the surrounding medium include: the refractive index, absorption coefficient and birefringence. In this paper, as a development we introduce an optical activity effect to the model. By comparing experiments and Monte Carlo simulations, we analyze the backscattering Mueller matrix patterns of several tissue-like media, and summarize the different effects coming from anisotropic scattering and optical properties. In addition, we propose a possible method to extract the optical activity values for tissues. Both the experimental and simulated results show that, by analyzing the Mueller matrix patterns, the microstructure and optical properties of the medium can be obtained. The characteristic features of Mueller matrix patterns are potentially powerful tools for studying the contrast mechanisms of polarization imaging for medical diagnosis.

  20. Assessment of the biological variation of plasma tissue inhibitor of metalloproteinases-1

    DEFF Research Database (Denmark)

    Frederiksen, Camilla; Lomholt, A F; Lottenburger, T

    2008-01-01

    BACKGROUND: Tissue inhibitor of metalloproteinases-1 (TIMP-1) measurements in plasma may be useful for the early detection and prognosis of colorectal cancer (CRC). Data on analytical performance and normal intra- and interindividual biological variation are required in order to interpret...... the utility of TIMP-1 in CRC. The aim of this study was to establish the biological and analytical variation of plasma TIMP-1 in volunteers. MATERIAL AND METHODS: Three separate studies were undertaken. 1: Plasma was collected from 23 volunteers 6 times within a 3-week period, first in September 2004 (round.......4%, and the intraclass correlation was 46.2%. Comparison between the 3 rounds and time of collection showed that TIMP-1 values decreased by 11% after storage for more than 16 months (p=0.0002). A systematic circadian variation in plasma TIMP-1 levels was not observed (p=0.17). No significant variation of plasma TIMP-1...

  1. A technique for measuring oxygen saturation in biological tissues based on diffuse optical spectroscopy

    Science.gov (United States)

    Kleshnin, Mikhail; Orlova, Anna; Kirillin, Mikhail; Golubiatnikov, German; Turchin, Ilya

    2017-07-01

    A new approach to optical measuring blood oxygen saturation was developed and implemented. This technique is based on an original three-stage algorithm for reconstructing the relative concentration of biological chromophores (hemoglobin, water, lipids) from the measured spectra of diffusely scattered light at different distances from the probing radiation source. The numerical experiments and approbation of the proposed technique on a biological phantom have shown the high reconstruction accuracy and the possibility of correct calculation of hemoglobin oxygenation in the presence of additive noise and calibration errors. The obtained results of animal studies have agreed with the previously published results of other research groups and demonstrated the possibility to apply the developed technique to monitor oxygen saturation in tumor tissue.

  2. Elastic cavitation, tube hollowing, and differential growth in plants and biological tissues

    KAUST Repository

    Goriely, A.

    2010-07-01

    Elastic cavitation is a well-known physical process by which elastic materials under stress can open cavities. Usually, cavitation is induced by applied loads on the elastic body. However, growing materials may generate stresses in the absence of applied loads and could induce cavity opening. Here, we demonstrate the possibility of spontaneous growth-induced cavitation in elastic materials and consider the implications of this phenomenon to biological tissues and in particular to the problem of schizogenous aerenchyma formation. Copyright © EPLA, 2010.

  3. Development of a computational system for management of risks in radiosterilization processes of biological tissues

    International Nuclear Information System (INIS)

    Montoya, Cynara Viterbo

    2009-01-01

    Risk management can be understood to be a systematic management which aims to identify record and control the risks of a process. Applying risk management becomes a complex activity, due to the variety of professionals involved. In order to execute risk management the following are requirements of paramount importance: the experience, discernment and judgment of a multidisciplinary team, guided by means of quality tools, so as to provide standardization in the process of investigating the cause and effects of risks and dynamism in obtaining the objective desired, i.e. the reduction and control of the risk. This work aims to develop a computational system of risk management (software) which makes it feasible to diagnose the risks of the processes of radiosterilization of biological tissues. The methodology adopted was action-research, according to which the researcher performs an active role in the establishment of the problems found, in the follow-up and in the evaluation of the actions taken owing to the problems. The scenario of this action-research was the Laboratory of Biological Tissues (LTB) in the Radiation Technology Center IPEN/CNEN-SP - Sao Paulo/Brazil. The software developed was executed in PHP and Flash/MySQL language, the server (hosting), the software is available on the Internet (www.vcrisk.com.br), which the user can access from anywhere by means of the login/access password previously sent by email to the team responsible for the tissue to be analyzed. The software presents friendly navigability whereby the user is directed step-by-step in the process of investigating the risk up to the means of reducing it. The software 'makes' the user comply with the term and present the effectiveness of the actions taken to reduce the risk. Applying this system provided the organization (LTB/CTR/IPEN) with dynamic communication, effective between the members of the multidisciplinary team: a) in decision-making; b) in lessons learned; c) in knowing the new risk

  4. A LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) for biological tissue impedance analysis and equivalent circuit modelling

    KAUST Repository

    Bera, Tushar Kanti

    2016-12-05

    Under an alternating electrical signal, biological tissues produce a complex electrical bioimpedance that is a function of tissue composition and applied signal frequencies. By studying the bioimpedance spectra of biological tissues over a wide range of frequencies, we can noninvasively probe the physiological properties of these tissues to detect possible pathological conditions. Electrical impedance spectroscopy (EIS) can provide the spectra that are needed to calculate impedance parameters within a wide range of frequencies. Before impedance parameters can be calculated and tissue information extracted, impedance spectra should be processed and analyzed by a dedicated software program. National Instruments (NI) Inc. offers LabVIEW, a fast, portable, robust, user-friendly platform for designing dataanalyzing software. We developed a LabVIEW-based electrical bioimpedance spectroscopic data interpreter (LEBISDI) to analyze the electrical impedance spectra for tissue characterization in medical, biomedical and biological applications. Here, we test, calibrate and evaluate the performance of LEBISDI on the impedance data obtained from simulation studies as well as the practical EIS experimentations conducted on electronic circuit element combinations and the biological tissue samples. We analyze the Nyquist plots obtained from the EIS measurements and compare the equivalent circuit parameters calculated by LEBISDI with the corresponding original circuit parameters to assess the accuracy of the program developed. Calibration studies show that LEBISDI not only interpreted the simulated and circuitelement data accurately, but also successfully interpreted tissues impedance data and estimated the capacitive and resistive components produced by the compositions biological cells. Finally, LEBISDI efficiently calculated and analyzed variation in bioimpedance parameters of different tissue compositions, health and temperatures. LEBISDI can also be used for human tissue

  5. Nanowire Nanoelectronics: Building Interfaces with Tissue and Cells at the Natural Scale of Biology

    Science.gov (United States)

    Cohen-Karni, Itzhaq Tzahi

    The interface between nanoscale electronic devices and biological systems enables interactions at length-scales natural to biology, and thus should maximize communication between these two diverse yet complementary systems. Moreover, nanostructures and nanostructured substrates show enhanced coupling to artificial membranes, cells, and tissue. Such nano-bio interfaces offer better sensitivity and spatial resolution as compared to conventional planar structures. In this work, I will report the electrical properties of silicon nanowires (SiNWs) interfaced with embryonic chicken hearts and cultured cardiomyocytes. I developed a scheme that allows us to manipulate the nanoelectronic to tissue/cell interfaces while monitoring their electrical activity. In addition, by utilizing the bottom-up approach, we extend our work to the sub-cellular regime, and interface cells with the smallest reported device ever and thus exceed the spatial and temporal resolution limits of other electrical recording techniques. The exceptional synthetic control and flexible assembly of nanowires provides powerful tools for fundamental studies and applications in life science, and opens up the potential of merging active transistors with cells such that the distinction between nonliving and living systems is blurred.

  6. Analysis of nanoparticles optical propagation influence in biological tissue simulating phantoms

    Science.gov (United States)

    Rodríguez-Colmenares, Miguel A.; Fanjul-Vélez, Félix; Arévalo-Díaz, Laura; Arce-Diego, José L.

    2017-02-01

    The applications of nanoparticles in optical techniques of diagnosis and treatment of biological tissues are increasing. Image contrast can be improved in diagnostic approaches such as fluorescence, spectroscopy or optical coherence tomography. The therapeutic effect can be increased if nanoparticles are previously incorporated in the biological tissue. This is the case in thermotherapy, or in Photodynamic Therapy. All these applications take advantage of specific properties of the nanoparticles involved, either optical up- or down-conversion, thermal confinement or the ability to act as a drug-carrier. Although many biomedical applications that involve nanoparticles are being proposed and tested, there is a need to take into account the influence of those nanoparticles on optical radiation propagation. The previously mentioned optical treatment and diagnosis techniques assume a particular optical propagation pattern, which is altered by the addition of nanoparticles. This change depends on the nanoparticle material, shape, size and concentration, among other parameters. In order to try to quantify these changes, in this work several phantoms that include different nanoparticles are analyzed, in order to estimate the influence of nanoparticles in optical propagation. A theoretical model of optical propagation, which takes into account the absorption and scattering changes in the medium, is also considered. Nanoparticles of different sizes from 40 nm to 1 μm are analyzed. Nanoparticle materials of interest in biomedical applications are employed. The results are relevant in diagnosis interpretation of images and treatment outcome evaluation when nanoparticles are present.

  7. Optical simulation of laser beam phase-shaping focusing optimization in biological tissues

    Science.gov (United States)

    Gomes, Ricardo; Vieira, Pedro; Coelho, João. M. P.

    2013-11-01

    In this paper we report the development of an optical simulator that can be used in the development of methodologies for compensate/decrease the light scattering effect of most biological tissues through phase-shaping methods. In fact, scattering has long been a major limitation for the medical applications of lasers where in-depth tissues concerns due to the turbid nature of most biological media in the human body. In developing the simulator, two different approaches were followed: one using multiple identical beams directed to the same target area and the other using a phase-shaped beam. In the multiple identical beams approach (used mainly to illustrate the limiting effect of scattering on the beam's propagation) there was no improvement in the beam focus at 1 mm compared to a single beam layout but, in phase-shaped beam approach, a 8x improvement on the radius of the beam at the same depth was achieved. The models were created using the optical design software Zemax and numerical algorithms created in Matlab programming language to shape the beam wavefront. A dedicated toolbox allowed communication between both programs. The use of the two software's proves to be a simple and powerful solution combining the best of the two and allowing a significant potential for adapting the simulations to new systems and thus allow to assess their response and define critical engineering parameters prior to laboratorial implementation.

  8. A novel 3D modelling and simulation technique in thermotherapy predictive analysis on biological tissue

    Science.gov (United States)

    Fanjul-Vélez, F.; Arce-Diego, J. L.; Romanov, Oleg G.; Tolstik, Alexei L.

    2007-07-01

    Optical techniques applied to biological tissue allow the development of new tools in medical praxis, either in tissue characterization or treatment. Examples of the latter are Photodynamic Therapy (PDT) or Low Intensity Laser Treatment (LILT), and also a promising technique called thermotherapy, that tries to control temperature increase in a pathological tissue in order to reduce or even eliminate pathological effects. The application of thermotherapy requires a previous analysis in order to avoid collateral damage to the patient, and also to choose the appropriate optical source parameters. Among different implementations of opto-thermal models, the one we use consists of a three dimensional Beer-Lambert law for the optical part, and a bio-heat equation, that models heat transference, conduction, convection, radiation, blood perfusion and vaporization, solved via a numerical spatial-temporal explicit finite difference approach, for the thermal part. The usual drawback of the numerical method of the thermal model is that convergence constraints make spatial and temporal steps very small, with the natural consequence of slow processing. In this work, a new algorithm implementation is used for the bio-heat equation solution, in such a way that the simulation time decreases considerably. Thermal damage based on the Arrhenius integral damage is also considered.

  9. Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering.

    Science.gov (United States)

    Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song

    2017-08-17

    Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

  10. Fractional Calculus-Based Modeling of Electromagnetic Field Propagation in Arbitrary Biological Tissue

    Directory of Open Access Journals (Sweden)

    Pietro Bia

    2016-01-01

    Full Text Available The interaction of electromagnetic fields and biological tissues has become a topic of increasing interest for new research activities in bioelectrics, a new interdisciplinary field combining knowledge of electromagnetic theory, modeling, and simulations, physics, material science, cell biology, and medicine. In particular, the feasibility of pulsed electromagnetic fields in RF and mm-wave frequency range has been investigated with the objective to discover new noninvasive techniques in healthcare. The aim of this contribution is to illustrate a novel Finite-Difference Time-Domain (FDTD scheme for simulating electromagnetic pulse propagation in arbitrary dispersive biological media. The proposed method is based on the fractional calculus theory and a general series expansion of the permittivity function. The spatial dispersion effects are taken into account, too. The resulting formulation is explicit, it has a second-order accuracy, and the need for additional storage variables is minimal. The comparison between simulation results and those evaluated by using an analytical method based on the Fourier transformation demonstrates the accuracy and effectiveness of the developed FDTD model. Five numerical examples showing the plane wave propagation in a variety of dispersive media are examined.

  11. A compact and versatile microfluidic probe for local processing of tissue sections and biological specimens

    Science.gov (United States)

    Cors, J. F.; Lovchik, R. D.; Delamarche, E.; Kaigala, G. V.

    2014-03-01

    The microfluidic probe (MFP) is a non-contact, scanning microfluidic technology for local (bio)chemical processing of surfaces based on hydrodynamically confining nanoliter volumes of liquids over tens of micrometers. We present here a compact MFP (cMFP) that can be used on a standard inverted microscope and assist in the local processing of tissue sections and biological specimens. The cMFP has a footprint of 175 × 100 × 140 mm3 and can scan an area of 45 × 45 mm2 on a surface with an accuracy of ±15 μm. The cMFP is compatible with standard surfaces used in life science laboratories such as microscope slides and Petri dishes. For ease of use, we developed self-aligned mounted MFP heads with standardized "chip-to-world" and "chip-to-platform" interfaces. Switching the processing liquid in the flow confinement is performed within 90 s using a selector valve with a dead-volume of approximately 5 μl. We further implemented height-compensation that allows a cMFP head to follow non-planar surfaces common in tissue and cellular ensembles. This was shown by patterning different macroscopic copper-coated topographies with height differences up to 750 μm. To illustrate the applicability to tissue processing, 5 μm thick M000921 BRAF V600E+ melanoma cell blocks were stained with hematoxylin to create contours, lines, spots, gradients of the chemicals, and multiple spots over larger areas. The local staining was performed in an interactive manner using a joystick and a scripting module. The compactness, user-friendliness, and functionality of the cMFP will enable it to be adapted as a standard tool in research, development and diagnostic laboratories, particularly for the interaction with tissues and cells.

  12. Correlation of abnormal DNMT1 and MeCP2 expression with cell biological characteristics in cervical lesion tissue

    Directory of Open Access Journals (Sweden)

    Wei Lin

    2016-10-01

    Full Text Available Objective: To study the correlation of abnormal DNMT1 and MeCP2 expression with cell biological characteristics in cervical lesion tissue. Methods: Cervical cancer tissue and paracarcinoma tissue were collected from cervical cancer patients who received surgery in our hospital from May 2012 to October 2015, and HPV types as well as the expression levels of DNMTs, MeCP2, PBK, TOPK, Snail, Slug, SALL4 and Cat L were determined. Results: Protein levels of DNMT1, DNMT2, DNMT3a, DNMT3b, DNMT3l and MeCP2 in cervical cancer tissue were significantly higher than those in para-carcinoma tissue, and the rising trend of DNMT1 expression level was the most significant; protein levels of DNMT1, DNMT2, DNMT3a, DNMT3b, DNMT3l and MeCP2 in cervical cancer tissue with high-risk HPV infection were significantly higher than those in cervical cancer tissue with normal HPV infection; in cervical cancer tissue with high expression of DNMT1 and MeCP2, PBK, TOPK, Snail, Slug, SALL4 and Cat L levels were significantly higher than those in cervical cancer tissue with low expression of DNMT1 and MeCP2. Conclusions: Abnormally high expression of DNMT1 and MeCP2 in cervical cancer tissue may up-regulate the expression of a variety of malignant biological molecules by increasing methylation level.

  13. Comparative analysis of housekeeping and tissue-selective genes in human based on network topologies and biological properties.

    Science.gov (United States)

    Yang, Lei; Wang, Shiyuan; Zhou, Meng; Chen, Xiaowen; Zuo, Yongchun; Sun, Dianjun; Lv, Yingli

    2016-06-01

    Housekeeping genes are genes that are turned on most of the time in almost every tissue to maintain cellular functions. Tissue-selective genes are predominantly expressed in one or a few biologically relevant tissue types. Benefitting from the massive gene expression microarray data obtained over the past decades, the properties of housekeeping and tissue-selective genes can now be investigated on a large-scale manner. In this study, we analyzed the topological properties of housekeeping and tissue-selective genes in the protein-protein interaction (PPI) network. Furthermore, we compared the biological properties and amino acid usage between these two gene groups. The results indicated that there were significant differences in topological properties between housekeeping and tissue-selective genes in the PPI network, and housekeeping genes had higher centrality properties and may play important roles in the complex biological network environment. We also found that there were significant differences in multiple biological properties and many amino acid compositions. The functional genes enrichment and subcellular localizations analysis was also performed to investigate the characterization of housekeeping and tissue-selective genes. The results indicated that the two gene groups showed significant different enrichment in drug targets, disease genes and toxin targets, and located in different subcellular localizations. At last, the discriminations between the properties of two gene groups were measured by the F-score, and expression stage had the most discriminative index in all properties. These findings may elucidate the biological mechanisms for understanding housekeeping and tissue-selective genes and may contribute to better annotate housekeeping and tissue-selective genes in other organisms.

  14. A Two-Layer Mathematical Modelling of Drug Delivery to Biological Tissues

    Science.gov (United States)

    Chakravarty, Koyel; Dalal, D. C.

    2016-10-01

    Local drug delivery has received much recognition in recent years, yet it is still unpredictable how drug efficacy depends on physicochemical properties and delivery kinetics. The purpose of the current study is to provide a useful mathematical model for drug release from a drug delivery device and consecutive drug transport in biological tissue, thereby aiding the development of new therapeutic drug by a systemic approach. In order to study the complete process, a two-layer spatio-temporal model depicting drug transport between the coupled media is presented. Drug release is described by considering solubilisation dynamics of drug particle, diffusion of the solubilised drug through porous matrix and also some other processes like reversible dissociation / recrystallization, drug particle-receptor binding and internalization phenomena. The model has led to a system of partial differential equations describing the important properties of drug kinetics. This model contributes towards the perception of the roles played by diffusion, mass-transfer, particle binding and internalization parameters.

  15. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  16. Development of a neutral embedding resin for optical imaging of fluorescently labeled biological tissue.

    Science.gov (United States)

    Zhou, Hongfu; Gang, Yadong; Chen, Shenghua; Wang, Yu; Xiong, Yumiao; Li, Longhui; Yin, Fangfang; Liu, Yue; Liu, Xiuli; Zeng, Shaoqun

    2017-10-01

    Plastic embedding is widely applied in light microscopy analyses. Previous studies have shown that embedding agents and related techniques can greatly affect the quality of biological tissue embedding and fluorescent imaging. Specifically, it is difficult to preserve endogenous fluorescence using currently available acidic commercial embedding resins and related embedding techniques directly. Here, we developed a neutral embedding resin that improved the green fluorescent protein (GFP), yellow fluorescent protein (YFP), and DsRed fluorescent intensity without adjusting the pH value of monomers or reactivating fluorescence in lye. The embedding resin had a high degree of polymerization, and its fluorescence preservation ratios for GFP, YFP, and DsRed were 126.5%, 155.8%, and 218.4%, respectively. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  17. On the influence of microscopic architecture elements to the global viscoelastic properties of soft biological tissue

    Science.gov (United States)

    Posnansky, Oleg P.

    2014-12-01

    In this work we introduce a 2D minimal model of random scale-invariant network structures embedded in a matrix to study the influence of microscopic architecture elements on the viscoelastic behavior of soft biological tissue. Viscoelastic properties at a microscale are modeled by a cohort of basic elements with varying complexity integrated into multi-hierarchic lattice obeying self-similar geometry. It is found that this hierarchy of structure elements yields a global nonlinear frequency dependent complex-valued shear modulus. In the dynamic range of external frequency load, the modeled shear modulus proved sensitive to the network concentration and viscoelastic characteristics of basic elements. The proposed model provides a theoretical framework for the interpretation of dynamic viscoelastic parameters in the context of microstructural variations under different conditions.

  18. Development of a neutral embedding resin for optical imaging of fluorescently labeled biological tissue

    Science.gov (United States)

    Zhou, Hongfu; Gang, Yadong; Chen, Shenghua; Wang, Yu; Xiong, Yumiao; Li, Longhui; Yin, Fangfang; Liu, Yue; Liu, Xiuli; Zeng, Shaoqun

    2017-10-01

    Plastic embedding is widely applied in light microscopy analyses. Previous studies have shown that embedding agents and related techniques can greatly affect the quality of biological tissue embedding and fluorescent imaging. Specifically, it is difficult to preserve endogenous fluorescence using currently available acidic commercial embedding resins and related embedding techniques directly. Here, we developed a neutral embedding resin that improved the green fluorescent protein (GFP), yellow fluorescent protein (YFP), and DsRed fluorescent intensity without adjusting the pH value of monomers or reactivating fluorescence in lye. The embedding resin had a high degree of polymerization, and its fluorescence preservation ratios for GFP, YFP, and DsRed were 126.5%, 155.8%, and 218.4%, respectively.

  19. Photoacoustic contrast imaging of biological tissues with nanodiamonds fabricated for high near-infrared absorbance.

    Science.gov (United States)

    Zhang, Ti; Cui, Huizhong; Fang, Chia-Yi; Su, Long-Jyun; Ren, Shenqiang; Chang, Huan-Cheng; Yang, Xinmai; Forrest, M Laird

    2013-02-01

    Radiation-damaged nanodiamonds (DNDs) are potentially ideal optical contrast agents for photoacoustic (PA) imaging in biological tissues due to their low toxicity and high optical absorbance. PA imaging contrast agents have been limited to quantum dots and gold particles, since most existing carbon-based nanoparticles, including fluorescent nanodiamonds, do not have sufficient optical absorption in the near-infrared (NIR) range. A new DND by He+ ion beam irradiation with very high NIR absorption was synthesized. These DNDs produced a 71-fold higher PA signal on a molar basis than similarly dimensioned gold nanorods, and 7.1 fmol of DNDs injected into rodents could be clearly imaged 3 mm below the skin surface with PA signal enhancement of 567% using an 820-nm laser wavelength.

  20. Pathogen and biological contamination management in plant tissue culture: phytopathogens, vitro pathogens, and vitro pests.

    Science.gov (United States)

    Cassells, Alan C

    2012-01-01

    The ability to establish and grow plant cell, organ, and tissue cultures has been widely exploited for basic and applied research, and for the commercial production of plants (micro-propagation). Regardless of whether the application is for research or commerce, it is essential that the cultures be established in vitro free of biological contamination and be maintained as aseptic cultures during manipulation, growth, and storage. The risks from microbial contamination are spurious experimental results due to the effects of latent contaminants or losses of valuable experimental or commercial cultures. Much of the emphasis in culture contamination management historically focussed on the elimination of phytopathogens and the maintenance of cultures free from laboratory contamination by environmental bacteria, fungi (collectively referred to as "vitro pathogens", i.e. pathogens or environmental micro-organisms which cause culture losses), and micro-arthropods ("vitro pests"). Microbial contamination of plant tissue cultures is due to the high nutrient availability in the almost universally used Murashige and Skoog (Physiol Plant 15:473-497, 1962) basal medium or variants of it. In recent years, it has been shown that many plants, especially perennials, are at least locally endophytically colonized intercellularly by bacteria. The latter, and intracellular pathogenic bacteria and viruses/viroids, may pass latently into culture and be spread horizontally and vertically in cultures. Growth of some potentially cultivable endophytes may be suppressed by the high salt and sugar content of the Murashige and Skoog basal medium and suboptimal temperatures for their growth in plant tissue growth rooms. The management of contamination in tissue culture involves three stages: disease screening (syn. disease indexing) of the stock plants with disease and endophyte elimination where detected; establishment and pathogen and contaminant screening of established initial cultures

  1. Soft tissue sarcomas: From a morphological to a molecular biological approach.

    Science.gov (United States)

    Oda, Yoshinao; Yamamoto, Hidetaka; Kohashi, Kenichi; Yamada, Yuichi; Iura, Kunio; Ishii, Takeaki; Maekawa, Akira; Bekki, Hirofumi

    2017-09-01

    Recently developed molecular genetic techniques have led to the elucidation of tumor-specific genomic alterations and thereby the reclassification of tumor entities of soft tissue sarcoma. A solitary fibrous tumor-mimicking tumor with the AHRR-NCOA2 gene has been isolated as angiofibroma of soft tissue. As for small round cell sarcomas, novel fusion genes such as CIC-DUX4 and BCOR-CCNB3 have been identified in these tumor groups. SMARCB1/INI1 deficient tumors with round cell morphology are also expected to be reclassified in three types, based on the combination of their morphology and genotype. The identification of the MDM2 gene amplification in pleomorphic sarcomas has extended the entity of dedifferentiated liposarcoma (DDLS). Our recent molecular investigations elucidated candidates for novel therapeutic strategies. Activation of the Akt-mTOR pathway was correlated with poor prognosis or tumor grade in spindle cell sarcomas including malignant peripheral nerve sheath tumor. In vitro and in vivo studies of transcription factor Forkhead Box M1 (FOXM1) demonstrated the close correlation between aggressive biological behavior or chemosensitivity and FOXM1 expression in synovial sarcoma, so far. Finally, in regard to the investigation of cancer-testis antigens, myxoid/round cell liposarcoma and synovial sarcoma showed frequent and high expression of PRAME and NY-ESO-1. © 2017 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

  2. Metabolism and toxicological analysis of synthetic cannabinoids in biological fluids and tissues.

    Science.gov (United States)

    Presley, B C; Gurney, S M R; Scott, K S; Kacinko, S L; Logan, B K

    2016-07-01

    Synthetic cannabinoids, which began proliferating in the United States in 2009, have gone through numerous iterations of modification to their chemical structures. More recent generations of compounds have been associated with significant adverse outcomes following use, including cognitive and psychomotor impairment, seizures, psychosis, tissue injury and death. These effects increase the urgency for forensic and public health laboratories to develop methods for the detection and identification of novel substances, and apply these to the determination of their metabolism and disposition in biological samples. This comprehensive review describes the history of the appearance of the drugs in the United States, discusses the naming conventions emerging to designate new structures, and describes the most prominent new compounds linked to the adverse effects now associated with their use. We review in depth the metabolic pathways that have been elucidated for the major members of each of the prevalent synthetic cannabinoid drug subclasses, the enzyme systems responsible for their metabolism, and the use of in silico approaches to assist in predicting and identifying the metabolites of novel compounds and drug subclasses that will continue to appear. Finally, we review and critique analytical methods applied to the detection of the drugs and their metabolites, including immunoassay screening, and liquid chromatography mass spectrometry confirmatory techniques applied to urine, serum, whole blood, oral fluid, hair, and tissues. Copyright © 2016 Central Police University.

  3. Biological evaluation of porous aliphatic polyurethane/hydroxyapatite composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Yang, Wanxun; Both, Sanne K; Zuo, Yi; Birgani, Zeinab Tahmasebi; Habibovic, Pamela; Li, Yubao; Jansen, John A; Yang, Fang

    2015-07-01

    Biomaterial scaffolds meant to function as supporting structures to osteogenic cells play a pivotal role in bone tissue engineering. Recently, we synthesized an aliphatic polyurethane (PU) scaffold via a foaming method using non-toxic components. Through this procedure a uniform interconnected porous structure was created. Furthermore, hydroxyapatite (HA) particles were introduced into this process to increase the bioactivity of the PU matrix. To evaluate the biological performances of these PU-based scaffolds, their influence on in vitro cellular behavior and in vivo bone forming capacity of the engineered cell-scaffold constructs was investigated in this study. A simulated body fluid test demonstrated that the incorporation of 40 wt % HA particles significantly promoted the biomineralization ability of the PU scaffolds. Enhanced in vitro proliferation and osteogenic differentiation of the seeded mesenchymal stem cells were also observed on the PU/HA composite. Next, the cell-scaffold constructs were implanted subcutaneously in a nude mice model. After 8 weeks, a considerable amount of vascularized bone tissue with initial marrow stroma development was generated in both PU and PU/HA40 scaffold. In conclusion, the PU/HA composite is a potential scaffold for bone regeneration applications. © 2014 Wiley Periodicals, Inc.

  4. Development and characterization of a radioimmunoassay to measure human tissue kallikrein in biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, A.F.; Whicher, J.T. (Bristol Royal Infirmary (UK)); Bhoola, K.D.; Lemon, M.J.C. (Bristol Univ. (UK). Medical School)

    1984-05-01

    A direct radioimmunoassay has been developed to measure tissue kallikrein in human biological fluids, including serum, plasma, urine, pancreatic juice and saliva. Purified kallikreins from human urine and human saliva were used to raise rabbit antibody and each labelled with Na/sup 125/I for use in the radioimmunoassay. Comparison of the different antigen-antibody systems was then made. Bound and free enzyme were separated by a double-antibody technique. The usable range of the standard curve was from 2.5 to 100 ..mu..g kallikrein/1. The intra-assay coefficient of variation was 4.7%, the interassay coefficient of variation 8.9% and the recoveries of purified kallikrein added to the samples were 99.3, 96.0, 110.8 and 81.2% for urine, saliva, serum and plasma respectively. Parallel dilution curves were obtained for serum and plasma, as well as urine, saliva and pancreatic juice. Plasma anticoagulated with EDTA or heparin gave consistently lower values than serum, when measured in the radioimmunoassay. From eight different subjects plasma (EDTA) values were on average 50% lower than those of serum, and subsequent experiments revealed that treatment of blood with some anticoagulants, in particular heparin and EDTA, resulted in a marked reduction in measurable tissue kallikrein.

  5. Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells.

    Science.gov (United States)

    Florencio-Silva, Rinaldo; Sasso, Gisela Rodrigues da Silva; Sasso-Cerri, Estela; Simões, Manuel Jesus; Cerri, Paulo Sérgio

    2015-01-01

    Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can result in bone diseases including osteoporosis. Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells. For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts. Moreover, osteocytes produce factors that influence osteoblast and osteoclast activities, whereas osteocyte apoptosis is followed by osteoclastic bone resorption. The increasing knowledge about the structure and functions of bone cells contributed to a better understanding of bone biology. It has been suggested that there is a complex communication between bone cells and other organs, indicating the dynamic nature of bone tissue. In this review, we discuss the current data about the structure and functions of bone cells and the factors that influence bone remodeling.

  6. Elemental analysis of biological tissues of animal models in muscular dystrophies investigation

    International Nuclear Information System (INIS)

    Sabrina Metairon; Zamboni, C.B.; Suzuki, M.F.; Bueno, Jr.C.R.; Sant'Anna, O.A.

    2012-01-01

    Element concentrations in biological tissues of Dmd mdx /J and C57BL/6 J mice strains were determined using the neutron activation analysis technique. Samples of whole blood, bones and organs (heart and muscle) of these strains were irradiated in the IEA-R1 nuclear reactor at IPEN-CNEN/SP (Brazil). To perform this investigation biological samples of two-month-old adult females (n = 10) and males (n = 9) for Dmd mdx /J (dystrophic mice), and males (n 12) for C57BL/6 J (control group), originally obtained from the Jackson Laboratory (Maine, USA) and further inbred at IPEN-CNEN/SP (Sao Paulo, Brazil), were used. A significant change was observed in the analysis of the heart of dystrophic mice suggesting that this dysfunction affects severely the heart muscle. These data may, in the future, contribute to the healthcare area, in veterinary medicine and in the pharmaceutical industry allowing the evaluation of the best procedures in diagnosis, treatment and investigations of neuromuscular diseases (muscular dystrophy) of patients through the use of animal models. (author)

  7. Plasmophore sensitized imaging of ammonia release from biological tissues using optodes

    International Nuclear Information System (INIS)

    Stroemberg, Niklas; Hakonen, Aron

    2011-01-01

    Highlights: → A plasmophore sensitized optode for imaging ammonia (NH 3 ) concentrations in muscle tissues was developed. → Ammonia concentrations ranging from 10 nM and upwards can be quantified reversibly with an optical resolution of 127 μm. → The general sensing scheme offers new possibilities for the development of artificial optical noses and tongues. - Abstract: A plasmophore sensitized optode was developed for imaging ammonia (NH 3 ) concentrations in muscle tissues. The developed ammonia sensor and an equivalent non plasmophore version of the sensor were tested side by side to compare their limit of detection, dynamic range, reversibility and overall imaging quality. Bio-degradation patterns of ammonia release from lean porcine skeletal muscle were studied over a period of 11 days. We demonstrate that ammonia concentrations ranging from 10 nM can be quantified reversibly with an optical resolution of 127 μm in a sample area of 25 mm x 35 mm. The plasmophore ammonia optode showed improved reversibility, less false pixels and a 2 nM ammonia detection limit compared to 200 nM for the non-plasmophore sensor. Main principles of the sensing mechanism include ammonia transfer over a gas permeable film, ammonia protonation, nonactin facilitated merocyanine-ammonium coextraction and plasmophore enhancement. The vast signal improvement is suggested to rely on solvatochroism, nanoparticle scattering and plasmonic interactions that are utilized constructively in a fluorescence ratio. In addition to fundamental medicinal and biological research applications in tissue physiology, reversible ammonia quantification will be possible for a majority of demanding imaging and non imaging applications such as monitoring of low ammonia background concentrations in air and non-invasive medicinal diagnosis through medical breath or saliva analysis. The nanoparticle doped sensor constitutes a highly competitive technique for ammonia sensing in complex matrixes and the

  8. Modeling fibrous biological tissues with a general invariant that excludes compressed fibers

    Science.gov (United States)

    Li, Kewei; Ogden, Ray W.; Holzapfel, Gerhard A.

    2018-01-01

    Dispersed collagen fibers in fibrous soft biological tissues have a significant effect on the overall mechanical behavior of the tissues. Constitutive modeling of the detailed structure obtained by using advanced imaging modalities has been investigated extensively in the last decade. In particular, our group has previously proposed a fiber dispersion model based on a generalized structure tensor. However, the fiber tension-compression switch described in that study is unable to exclude compressed fibers within a dispersion and the model requires modification so as to avoid some unphysical effects. In a recent paper we have proposed a method which avoids such problems, but in this present study we introduce an alternative approach by using a new general invariant that only depends on the fibers under tension so that compressed fibers within a dispersion do not contribute to the strain-energy function. We then provide expressions for the associated Cauchy stress and elasticity tensors in a decoupled form. We have also implemented the proposed model in a finite element analysis program and illustrated the implementation with three representative examples: simple tension and compression, simple shear, and unconfined compression on articular cartilage. We have obtained very good agreement with the analytical solutions that are available for the first two examples. The third example shows the efficacy of the fibrous tissue model in a larger scale simulation. For comparison we also provide results for the three examples with the compressed fibers included, and the results are completely different. If the distribution of collagen fibers is such that it is appropriate to exclude compressed fibers then such a model should be adopted.

  9. Tracing overlapping biological signals in mid-infrared using colonic tissues as a model system.

    Science.gov (United States)

    Sahu, Ranjit Kumar; Salman, Ahmad; Mordechai, Shaul

    2017-01-14

    To understand the interference of carbohydrates absorbance in nucleic acids signals during diagnosis of malignancy using Fourier transform infrared (FTIR) spectroscopy. We used formalin fixed paraffin embedded colonic tissues to obtain infrared (IR) spectra in the mid IR region using a bruker II IR microscope with a facility for varying the measurement area by varying the aperture available. Following this procedure we could measure different regions of the crypt circles containing different biochemicals. Crypts from 18 patients were measured. Circular crypts with a maximum diameter of 120 μm and a lumen of about 30 μm were selected for uniformity. The spectral data was analyzed using conventional and advanced computational methods. Among the various components that are observed to contribute to the diagnostic capabilities of FTIR, the carbohydrates and nucleic acids are prominent. However there are intrinsic difficulties in the diagnostic capabilities due to the overlap of major absorbance bands of nucleic acids, carbohydrates and phospholipids in the mid-IR region. The result demonstrates colonic tissues as a biological system suitable for studying interference of carbohydrates and nucleic acids under ex vivo conditions. Among the diagnostic parameters that are affected by the absorbance from nucleic acids is the RNA/DNA ratio, dependent on absorbance at 1121 cm -1 and 1020 cm -1 that is used to classify the normal and cancerous tissues especially during FTIR based diagnosis of colonic malignancies. The signals of the nucleic acids and the ratio (RNA/DNA) are likely increased due to disappearance of interfering components like carbohydrates and phosphates along with an increase in amount of RNA. The present work, proposes one mechanism for the observed changes in the nucleic acid absorbance in mid-IR during disease progression (carcinogenesis).

  10. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves.

    Science.gov (United States)

    Gallyamov, Marat O; Chaschin, Ivan S; Khokhlova, Marina A; Grigorev, Timofey E; Bakuleva, Natalia P; Lyutova, Irina G; Kondratenko, Janna E; Badun, Gennadii A; Chernysheva, Maria G; Khokhlov, Alexei R

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H2O and CO2. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16-33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Relationships of the internodal distance of biological tissue with its sound velocity and attenuation at high frequency in doublet mechanics

    Science.gov (United States)

    Cheng, Kai-Xuan; Wu, Rong-Rong; Liu, Xiao-Zhou; Liu, Jie-Hui; Gong, Xiu-Fen; Wu, Jun-Ru

    2015-04-01

    In view of the discrete characteristics of biological tissue, doublet mechanics has demonstrated its advantages in the mathematic description of tissue in terms of high frequency (> 10 MHz) ultrasound. In this paper, we take human breast biopsies as an example to study the influence of the internodal distance, a microscope parameter in biological tissue in doublet mechanics, on the sound velocity and attenuation by numerical simulation. The internodal distance causes the sound velocity and attenuation in biological tissue to change with the increase of frequency. The magnitude of such a change in pathological tissue is distinctly different from that in normal tissue, which can be used to differentiate pathological tissue from normal tissue and can depict the diseased tissue structure by obtaining the sound and attenuation distribution in the sample at high ultrasound frequency. A comparison of sensitivity between the doublet model and conventional continuum model is made, indicating that this is a new method of characterizing ultrasound tissue and diagnosing diseases. Project supported by the National Basic Research Program of China (Grant Nos. 2012CB921504 and 2011CB707902), the National Natural Science Foundation of China (Grant No. 11274166), the Fundamental Research Funds for the Central Universities, China (Grant Nos. 1113020403 and 1101020402), the State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLA201401), the China Postdoctoral Science Foundation (Grant No. 2013M531313), the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions and Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry, and the Project of Interdisciplinary Center of Nanjing University, China (Grant No. NJUDC2012004).

  12. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

    Energy Technology Data Exchange (ETDEWEB)

    Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

  13. All-optical photoacoustic microscopy (AOPAM) system for remote characterization of biological tissues

    Science.gov (United States)

    Sampathkumar, Ashwin; Chitnis, Parag V.; Silverman, Ronald H.

    2014-03-01

    Conventional photoacoustic microscopy (PAM) employs light pulses to produce a photoacoustic (PA) effect and detects the resulting acoustic waves using an ultrasound transducer acoustically coupled to the target. The resolution of conventional PAM is limited by the sensitivity and bandwidth of the ultrasound transducer. We investigated a versatile, all-optical PAM (AOPAM) system for characterizing in vivo as well as ex vivo biological specimens. The system employs non-contact interferometric detection of PA signals that overcomes limitations of conventional PAM. A 532-nm pump laser with a pulse duration of 5 ns excites the PA effect in tissue. Resulting acoustic waves produce surface displacements that are sensed using a 532-nm continuous-wave (CW) probe laser in a Michelson interferometer with a 1- GHz bandwidth. The pump and probe beams are coaxially focused using a 50X objective giving a diffraction-limited spot size of 0.48 μm. The phase-encoded probe beam is demodulated using homodyne methods. The detected timedomain signal is time reversed using k-space wave-propagation methods to produce a spatial distribution of PA sources in the target tissue. A minimum surface-displacement sensitivity of 0.19 pm was measured. PA-induced surface displacements are very small; therefore, they impose stringent detection requirements and determine the feasibility of implementing an all-optical PAM in biomedical applications. 3D PA images of ex vivo porcine retina specimens were generated successfully. We believe the AOPAM system potentially is well suited for assessing retinal diseases and other near-surface biomedical applications such as sectionless histology and evaluation of skin burns and pressure or friction ulcers.

  14. Chitosan fibers with improved biological and mechanical properties for tissue engineering applications.

    Science.gov (United States)

    Albanna, Mohammad Z; Bou-Akl, Therese H; Blowytsky, Oksana; Walters, Henry L; Matthew, Howard W T

    2013-04-01

    The low mechanical properties of hydrogel materials such as chitosan hinder their broad utility for tissue engineering applications. Previous research efforts improved the mechanical properties of chitosan fiber through chemical and physical modifications; however, unfavorable toxicity effects on cells were reported. In this paper, we report the preparation of chitosan fibers with improved mechanical and biocompatibility properties. The structure-property relationships of extruded chitosan fibers were explored by varying acetic acid (AA) concentration, ammonia concentration, annealing temperature and degree of heparin crosslinking. Results showed that optimizing AA concentration to 2vol% improved fiber strength and stiffness by 2-fold. Extruding chitosan solution into 25wt% of ammonia solution reduced fiber diameters and improved fiber strength by 2-fold and stiffness by 3-fold, due to an increase in crystallinity as confirmed by XRD. Fiber annealing further reduced fiber diameter and improved fiber strength and stiffness as temperature increased. Chitosan fibers crosslinked with heparin had increased diameter but lower strength and stiffness properties and higher breaking strain values. When individual parameters were combined, further improvement in fiber mechanical properties was achieved. All mechanically improved fibers and heparin crosslinked fibers promoted valvular interstitial cells (VIC) attachment and growth over 10 day cultures. Our results demonstrate the ability to substantially improve the mechanical properties of chitosan fibers without adversely affecting their biological properties. The investigated treatments offer numerous advantages over previous physical/chemical modifications and thus are expected to expand the utility of chitosan fibers with tunable mechanical properties in various tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Computational adaptive optics for broadband optical interferometric tomography of biological tissue.

    Science.gov (United States)

    Adie, Steven G; Graf, Benedikt W; Ahmad, Adeel; Carney, P Scott; Boppart, Stephen A

    2012-05-08

    Aberrations in optical microscopy reduce image resolution and contrast, and can limit imaging depth when focusing into biological samples. Static correction of aberrations may be achieved through appropriate lens design, but this approach does not offer the flexibility of simultaneously correcting aberrations for all imaging depths, nor the adaptability to correct for sample-specific aberrations for high-quality tomographic optical imaging. Incorporation of adaptive optics (AO) methods have demonstrated considerable improvement in optical image contrast and resolution in noninterferometric microscopy techniques, as well as in optical coherence tomography. Here we present a method to correct aberrations in a tomogram rather than the beam of a broadband optical interferometry system. Based on Fourier optics principles, we correct aberrations of a virtual pupil using Zernike polynomials. When used in conjunction with the computed imaging method interferometric synthetic aperture microscopy, this computational AO enables object reconstruction (within the single scattering limit) with ideal focal-plane resolution at all depths. Tomographic reconstructions of tissue phantoms containing subresolution titanium-dioxide particles and of ex vivo rat lung tissue demonstrate aberration correction in datasets acquired with a highly astigmatic illumination beam. These results also demonstrate that imaging with an aberrated astigmatic beam provides the advantage of a more uniform depth-dependent signal compared to imaging with a standard gaussian beam. With further work, computational AO could enable the replacement of complicated and expensive optical hardware components with algorithms implemented on a standard desktop computer, making high-resolution 3D interferometric tomography accessible to a wider group of users and nonspecialists.

  16. Review of temperature dependence of thermal properties, dielectric properties, and perfusion of biological tissues at hyperthermic and ablation temperatures.

    Science.gov (United States)

    Rossmanna, Christian; Haemmerich, Dieter

    2014-01-01

    The application of supraphysiological temperatures (>40°C) to biological tissues causes changes at the molecular, cellular, and structural level, with corresponding changes in tissue function and in thermal, mechanical and dielectric tissue properties. This is particularly relevant for image-guided thermal treatments (e.g. hyperthermia and thermal ablation) delivering heat via focused ultrasound (FUS), radiofrequency (RF), microwave (MW), or laser energy; temperature induced changes in tissue properties are of relevance in relation to predicting tissue temperature profile, monitoring during treatment, and evaluation of treatment results. This paper presents a literature survey of temperature dependence of electrical (electrical conductivity, resistivity, permittivity) and thermal tissue properties (thermal conductivity, specific heat, diffusivity). Data of soft tissues (liver, prostate, muscle, kidney, uterus, collagen, myocardium and spleen) for temperatures between 5 to 90°C, and dielectric properties in the frequency range between 460 kHz and 3 GHz are reported. Furthermore, perfusion changes in tumors including carcinomas, sarcomas, rhabdomyosarcoma, adenocarcinoma and ependymoblastoma in response to hyperthmic temperatures up to 46°C are presented. Where appropriate, mathematical models to describe temperature dependence of properties are presented. The presented data is valuable for mathematical models that predict tissue temperature during thermal therapies (e.g. hyperthermia or thermal ablation), as well as for applications related to prediction and monitoring of temperature induced tissue changes.

  17. Use of charged particle beams for analysis of biological tissues and fluids

    International Nuclear Information System (INIS)

    Campbell, J.L.

    1983-01-01

    PIXE has passed through its demonstration stage and matured into a viable tool supported by a reliable physics data base; the main problem to be solved at the outset of any new project is the preparation of a representative specimen of uniform thickness (or thinness) rather than any aspect of X-ray or accelerator physics or technology. The authors repeats the caution that minimum detection limits are strongly influenced by the nuclear reaction gamma-ray background from trace elements in the specimen. Thus experiment on a new target type is preferable to use of MDL calculations based on the background due to atomic processes (bremsstrahlung) in the known matrix. One hopes to see a more adventurous mood eg a move from routine blood serum analysis towards analyses of different blood fractions that concentrate specific trace elements. PIGE, while promising, must be regarded as developmental until the data-base of elemental gamma-ray yields is extended and made more accurate; work on fluorine in teeth clearly stands to profit from this technique. Finally, RBS, although scarcely used to date in any biological context, is clearly a powerful way of measuring major elemental ratios in mineralized tissues; however, RBS lacks the resolving power of PIXE and so is not a candidate for multi-trace element analysis

  18. Biological and binding activities of ovine and porcine prolactins in porcine mammary tissue

    International Nuclear Information System (INIS)

    Jerry, D.J.

    1987-01-01

    The concentration of prolactin receptors may play a critical role in regulating growth and development of the mammary gland during gestation and tumor development; however, the discrepancy between specific binding of ovine prolactin (oPRL) and porcine prolactin (pPRL) in porcine mammary tissue was disturbing. It was possible that 125 I-oPRL may be an unsuitable ligand for the procine prolactin receptor. The validate the use of oPRL in binding assays, the biological and binding activities of oPRL and pPRL were compared. A lactogenic bioassay of pPRL was developed using porcine mammary explants cultured in Medium 199 containing insulin, cortisol, and pPRL. The potencies of oPRL and pPRL were compared using this bioassay. Oxidation of glucose and incorporation of glucose into lipids were similarly enhanced by physiological concentrations of both oPRL and pPRL. However, specific binding of 125 I-oPRL was 20%, while less than 1% of 125 I-pPRL was bound. 125 I-oPRL bound to high affinity sites

  19. Oxygen diffusivity of biologic and synthetic scaffold materials for tissue engineering.

    Science.gov (United States)

    Valentin, Jolene E; Freytes, Donald O; Grasman, Jonathan M; Pesyna, Colin; Freund, John; Gilbert, Thomas W; Badylak, Stephen F

    2009-12-15

    Scaffolds for tissue engineering and regenerative medicine applications are commonly manufactured from synthetic materials, intact or isolated components of extracellular matrix (ECM), or a combination of such materials. After surgical implantation, the metabolic requirements of cells that populate the scaffold depend upon adequate gas and nutrient exchange with the surrounding microenvironment. The present study measured the oxygen transfer through three biologic scaffold materials composed of ECM including small intestinal submucosa (SIS), urinary bladder submucosa (UBS), and urinary bladder matrix (UBM), and one synthetic biomaterial, Dacron. The oxygen diffusivity was calculated from Fick's first law of diffusion. Each material permitted measurable oxygen diffusion. The diffusivity of SIS was found to be dependent on the direction of oxygen transfer; the oxygen transfer in the abluminal-to-luminal direction was significantly greater than the luminal-to-abluminal direction. The oxygen diffusivity of UBM and UBS were similar despite the presence of an intact basement membrane on the luminal surface of UBM. Dacron showed oxygen diffusivity values seven times greater than the ECM biomaterials. The current study showed that each material has unique oxygen diffusivity values, and these values may be dependent on the scaffold's ultrastructure.

  20. Role of cell deformability in the two-dimensional melting of biological tissues

    Science.gov (United States)

    Li, Yan-Wei; Ciamarra, Massimo Pica

    2018-04-01

    The size and shape of a large variety of polymeric particles, including biological cells, star polymers, dendrimes, and microgels, depend on the applied stresses as the particles are extremely soft. In high-density suspensions these particles deform as stressed by their neighbors, which implies that the interparticle interaction becomes of many-body type. Investigating a two-dimensional model of cell tissue, where the single particle shear modulus is related to the cell adhesion strength, here we show that the particle deformability affects the melting scenario. On increasing the temperature, stiff particles undergo a first-order solid/liquid transition, while soft ones undergo a continuous solid/hexatic transition followed by a discontinuous hexatic/liquid transition. At zero temperature the melting transition driven by the decrease of the adhesion strength occurs through two continuous transitions as in the Kosterlitz, Thouless, Halperin, Nelson, and Young scenario. Thus, there is a range of adhesion strength values where the hexatic phase is stable at zero temperature, which suggests that the intermediate phase of the epithelial-to-mesenchymal transition could be hexatic type.

  1. Developing a press for static and dynamic testing of orthopedic devices and biological tissue

    Directory of Open Access Journals (Sweden)

    Arlex Leyton Virgen

    2008-09-01

    Full Text Available This paper describes designing and constructing a test machine having a 1,800 N capacity and maximum 3 Hz frequency which will be used in static and dynamic testing of biological tissues and orthopedic devices such as external fixers. It consists of an oc-tagonal base with 500 mm distance between faces and a crosshead which slides between two columns (useful 350 mm opening thus allowing changing the height (maximum 600 mm according to the size of the specimen to be tested. A ball screw actuator is mounted over the crosshead which transforms a servomotor’s rotating movement into a lineal movement (maximum 150 mm stroke. First validations indicated that the machine performed within the design parameters. This project shows that the techno-logy required for supporting research is possible in developing countries thereby avoiding dependence on foreign companies for supporting, maintaining and updating equipment. Some conditions were also produced for the evolution of mechanical engi-neering in Colombia.

  2. Monolithic Multiband CMUTs for Photoacoustic Computed Tomography With In Vivo Biological Tissue Imaging.

    Science.gov (United States)

    Pun, Sio Hang; Yu, Yuanyu; Zhang, Jian; Wang, Jiujiang; Cheng, Ching-Hsiang; Lei, Kin Fong; Yuan, Zhen; Mak, Peng Un

    2018-03-01

    Among the biomedical imaging modalities, photoacoustic computed tomography (PACT) was one of the emerging hybrid techniques in recent years. In designing the PACT imaging system, a finite-bandwidth transducer is one of the limited factors for the overall performance. As the target size is inversely proportional to the dominant frequency components of the generated photoacoustic (PA) signal, a broad bandwidth transducer is desired for different scales' imaging. In this paper, a monolithic multiband capacitive micromachined ultrasonic transducer (CMUT) array was designed and fabricated for the reception of the wideband PA signals so as to provide high-resolution images with high-frequency CMUT arrays and present the high signal-to-noise-ratio major structure with low-frequency CMUT arrays. To demonstrate its performance, a phantom experiment was conducted to show and evaluate the various qualities of multiresolution images. In addition, an in vivo mouse model experiment was also carried out for revealing the multiscale PA imaging capability with the multiband CMUTs on biological tissues. From the obtained results, the images from different CMUT arrays could show the structures of the mouse brain in different scales. In addition, the images from the high-frequency CMUT arrays were able to reveal the major blood vasculatures, whereas the images from low-frequency CMUT arrays showed the gross macroscopic anatomy of the brain with higher contrast.

  3. Characterization of Anomalous Diffusion in Porous Biological Tissues Using Fractional Order Derivatives and Entropy.

    Science.gov (United States)

    Magin, Richard L; Ingo, Carson; Colon-Perez, Luis; Triplett, William; Mareci, Thomas H

    2013-09-15

    In this high-resolution magnetic resonance imaging (MRI) study at 17.6 Tesla of a fixed rat brain, we used the continuous time random walk theory (CTRW) for Brownian motion to characterize anomalous diffusion. The complex mesoporus structure of biological tissues (membranes, organelles, and cells) perturbs the motion of the random walker (water molecules in proton MRI) introducing halts between steps (waiting times) and restrictions on step sizes (jump lengths). When such waiting times and jump lengths are scaled with probability distributions that follow simple inverse power laws ( t -(1+α) , | x | -(1+β) ) non-Gaussian motion gives rise to sub- and super- diffusion. In the CTRW approach, the Fourier transform yields a solution to the generalized diffusion equation that can be expressed by the Mittag-Leffler function (MLF), E α (- D α, β | q | β Δ α ). We interrogated both white and gray matter regions in a 1 mm slice of a fixed rat brain (190 μ m in plane resolution) with diffusion weighted MRI experiments using b -values up to 25,000 s / mm 2 , by independently varying q and Δ. When fitting these data to our model, the fractional order parameters, α and β, and the entropy measure, [Formula: see text], were found to provide excellent contrast between white and gray matter and to give results that were sensitive to the type of diffusion experiment performed.

  4. THz near-field imaging of biological tissues employing synchrotron radiation

    International Nuclear Information System (INIS)

    Schade, Ulrich; Holldack, Karsten; Martin, Michael C.; Fried, Daniel

    2004-01-01

    Terahertz scanning near-field infrared microscopy (SNIM) below 1 THz is demonstrated. The near-field technique benefits from the broadband and highly brilliant coherent synchrotron radiation (CSR) from an electron storage ring and from a detection method based on locking onto the intrinsic time structure of the synchrotron radiation. The scanning microscope utilizes conical wave guides as near-field probes with apertures smaller than the wavelength. Different cone approaches have been investigated to obtain maximum transmittance. Together with a Martin-Puplett spectrometer the set-up enables spectroscopic mapping of the transmittance of samples well below the diffraction limit. Spatial resolution down to about lambda/40 at 2 wavenumbers (0.06 THz) is derived from the transmittance spectra of the near-field probes. The potential of the technique is exemplified by imaging biological samples. Strongly absorbing living leaves have been imaged in transmittance with a spatial resolution of 130 mu-m at about 12 wave numbers (0.36 THz). The THz near-field images reveal distinct structural differences of leaves from different plants investigated. The technique presented also allows spectral imaging of bulky organic tissues. Human teeth samples of various thicknesses have been imaged between 2 and 20 wavenumbers (between 0.06and 0.6 THz). Regions of enamel and dentin within tooth samples are spatially and spectrally resolved, and buried caries lesions are imaged through both the outer enamel and into the underlying dentin

  5. Advancements in Transmitters and Sensors for Biological Tissue Imaging in Magnetic Induction Tomography

    Directory of Open Access Journals (Sweden)

    Syed Mustafa Kamal Syed Aman

    2012-05-01

    Full Text Available Magnetic Induction Tomography (MIT, which is also known as Electromagnetic Tomography (EMT or Mutual Inductance Tomography, is among the imaging modalities of interest to many researchers around the world. This noninvasive modality applies an electromagnetic field and is sensitive to all three passive electromagnetic properties of a material that are conductivity, permittivity and permeability. MIT is categorized under the passive imaging family with an electrodeless technique through the use of excitation coils to induce an electromagnetic field in the material, which is then measured at the receiving side by sensors. The aim of this review is to discuss the challenges of the MIT technique and summarize the recent advancements in the transmitters and sensors, with a focus on applications in biological tissue imaging. It is hoped that this review will provide some valuable information on the MIT for those who have interest in this modality. The need of this knowledge may speed up the process of adopted of MIT as a medical imaging technology.

  6. Elements determination of clinical relevance in biological tissues Dmdmdx/J dystrophic mice strains investigated by NAA

    International Nuclear Information System (INIS)

    Metairon, Sabrina

    2012-01-01

    In this work the determination of chemistry elements in biological tissues (whole blood, bones and organs) of dystrophic mice, used as animal model of Duchenne Muscular Dystrophy (DMD), was performed using analytical nuclear technique. The aim of this work was to determine reference values of elements of clinical (Ca, Cl, K, Mg, Na) and nutritional (Br and S) relevance in whole blood, tibia, quadriceps and hearts from Dmdmdx/J (10 males and 10 females) dystrophic mice and C57BL/6J (10 males) control group mice, using Neutron Activation Analysis technique (NAA). To show in more details the alterations that this disease may cause in these biological tissues, correlations matrixes of the DMD mdx /J mouse strain were generated and compared with C57BL/6J control group. For this study 119 samples of biological tissue were irradiated in the IEA-R1 nuclear reactor at IPEN (Sao Paulo, Brazil). The concentrations of these elements in biological tissues of Dmd mdx /J and C57B/6J mice are the first indicative interval for reference values. Moreover, the alteration in some correlation coefficients data among the elements in the health status and in the diseased status indicates a connection between these elements in whole blood, tibia, quadriceps and heart. These results may help the researchers to evaluate the efficiency of new treatments and to compare the advantages of different treatment approaches before performing tests in patients with muscular dystrophy. (author)

  7. Determination of scattering coefficient considering wavelength and absorption dependence of anisotropy factor measured by polarized beam for biological tissues

    Science.gov (United States)

    Fukutomi, D.; Ishii, K.; Awazu, K.

    2015-12-01

    Anisotropy factor g, one of the optical properties of biological tissues, is the most important parameter to accurately determine scattering coefficient μs in the inverse Monte Carlo (iMC) simulation. It has been reported that g has wavelength and absorption dependence, however, there are few attempts in order to calculate μs of biological tissue considering the wavelength and absorption dependence of g. In this study, the scattering angular distributions of biological tissue phantoms were measured in order to determine g by using goniometric measurements with three polarization conditions at strongly and weakly absorbing wavelengths of hemoglobin. Then, optical properties, especially, μs were measured by integrating sphere measurements and iMC simulation in order to confirm the influence of measured g on optical properties in comparison of with general value of g (0.9) for soft biological tissue. Consequently, it was found that μs was overestimated at strongly absorbing wavelength, however, μs was underestimated at weakly absorbing wavelength if the g was not considered its wavelength and absorption dependence.

  8. High mass accuracy and high mass resolving power FT-ICR secondary ion mass spectrometry for biological tissue imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kiss, A.; Leach, F.E.; Robinson, E.W.; Paša-Tolić, L.; Heeren, R.M.A.

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically

  9. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease

    Directory of Open Access Journals (Sweden)

    Andreas Plaitakis

    2017-02-01

    Full Text Available Glutamate dehydrogenase (GDH is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P+ to NAD(PH. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate, lipid biosynthesis (via oxidative generation of citrate, and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1 is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth

  10. Collision thrills

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel

    2016-01-01

    . The working hypothesis is that the aesthetics of action and the affinities between medias centre on collision. It will be suggested that collisions produce thrills ranging from the pleasure of destruction to the experience of spatial disorientation. Following will the aesthetics of action be coined ‘collision...

  11. Synthesis and characterization of polyglycerols dendrimers for applications in tissue engineering biological

    International Nuclear Information System (INIS)

    Passos, E.D.; Queiroz, A.A.A. de

    2014-01-01

    Full text: Introduction: Over the last twenty years is the growing development in the manufacture of synthetic scaffold in tissue engineering applications. These new materials are based on polyglycerol dendrimers (PGLD's). PGLD's are highly functional polymers with hydroxymethyl side groups, fulfill all structural prerequisites to replace poly(ethylene glycol)s in medical applications. Furthermore, since these materials are based on naturally occurring compounds that degrades over time in the body and can be safely excreted. The objective of this work was the synthesis, physicochemical, biological characterization of HPGL's with potential use as scaffolds in tissue engineering. HPGL's with oligomeric cores, of diglycerol triglycerol and tetraglycerol was used. Theoretical and Experimental Simulation Details: The synthesis of PGLD procedures involves the etherification of glycerol through anionic polymerization of glycidol. The PGLD's were characterized by chromatographic techniques (SEC and HPLC), spectroscopic (FTIR, 1H-NMR and 13C - NMR) electrochemical (zeta potential) and thermal analysis (DSC and TGA) techniques. The structure- activity relationships (SAR's) of compound prototype and its analogs were studied to determine the generation number (G) of the molecule responsible for the biological activity on the adhesion and cell proliferation process. A detailed study of the structure of PGLD's of G=0-4 was performed using the Hyperchem 7. 5 and Gromacs 4 software packages. The biocompatibility studies were studied by scanning electron microscopy (SEM) and fluorescence microscopy (EPF) technique after PGLD (G=0-4) blood contact. The overall electro-negativity/total charge density, dipole moment, frontier orbital's (HOMO - LUMO) and electrostatic potential maps (EPM) were calculated. The most stable form of the resulting compounds was determined by estimating the hydration energy and energy conformation. Results and

  12. Spatio-temporal thermal kinetics of in situ MWCNT heating in biological tissues under NIR laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Picou, Laura; McMann, Casey; Boldor, Dorin [Department of Biological and Agricultural Engineering, Louisiana State University Agricultural Center, 149 E B Doran Building, Baton Rouge, LA 70803-4505 (United States); Elzer, Philip H; Enright, Frederick M [Department of Veterinary Sciences, Louisiana State University Agricultural Center, 111 Dalrymple Building, Baton Rouge, LA 70803 (United States); Biris, Alexandru S, E-mail: DBoldor@agcenter.lsu.edu [Nanotechnology Center, University of Arkansas-Little Rock, 2801 South University Avenue, ETAS 151, Little Rock, AR 72204-1099 (United States)

    2010-10-29

    Carbon nanotubes have many potential applications in life sciences and engineering as they have very high absorbance in the near-infrared (NIR) spectrum, while biological tissues do not. The purpose of this study was to determine the effect of 1064 nm NIR laser power levels on the spatial temperature distribution and the temperature kinetics in mammalian tissue at both macroscopic and microscopic scales. The model tissue was the 'flat' of a chicken wing (the section containing the radius and ulna), which was injected under the skin in the subcutaneous layer of tissue. Specimens were exposed to laser radiation and an infrared thermography system was used to measure and record the temperature distributions in the specimens at both the macroscopic and microscopic scales. Experimental results concluded that power levels of 1536 mW easily achieved hyperthermic temperatures with localized values as high as 172.7 deg. C.

  13. Prediction equation for lower limbs lean soft tissue in circumpubertal boys using anthropometry and biological maturation.

    Directory of Open Access Journals (Sweden)

    João Valente-dos-Santos

    Full Text Available Lean soft tissue (LST, a surrogate of skeletal muscle mass, is largely limited to appendicular body regions. Simple and accurate methods to estimate lower limbs LST are often used in attempts to partition out the influence of body size on performance outputs. The aim of the current study was to develop and cross-validate a new model to predict lower limbs LST in boys aged 10-13 years, using dual-energy X-ray absorptiometry (DXA as the reference method. Total body and segmental (lower limbs composition were assessed with a Hologic Explorer-W QDR DXA scanner in a cross-sectional sample of 75 Portuguese boys (144.8±6.4 cm; 40.2±9.0 kg. Skinfolds were measured at the anterior and posterior mid-thigh, and medial calf. Circumferences were measured at the proximal, mid and distal thigh. Leg length was estimated as stature minus sitting height. Current stature expressed as a percentage of attained predicted mature stature (PMS was used as an estimate of biological maturity status. Backward proportional allometric models were used to identify the model with the best statistical fit: ln (lower limbs LST  = 0.838× ln (body mass +0.476× ln (leg length - 0.135× ln (mid-thigh circumference - 0.053× ln (anterior mid-thigh skinfold - 0.098× ln (medial calf skinfold - 2.680+0.010× (percentage of attained PMS (R = 0.95. The obtained equation was cross-validated using the predicted residuals sum of squares statistics (PRESS method (R2PRESS = 0.90. Deming repression analysis between predicted and current lower limbs LST showed a standard error of estimation of 0.52 kg (95% limits of agreement: 0.77 to -1.27 kg. The new model accurately predicts lower limbs LST in circumpubertal boys.

  14. Mass Spectrometry Imaging of Biological Tissue: An Approach for Multicenter Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rompp, Andreas; Both, Jean-Pierre; Brunelle, Alain; Heeren, Ronald M.; Laprevote, Olivier; Prideaux, Brendan; Seyer, Alexandre; Spengler, Bernhard; Stoeckli, Markus; Smith, Donald F.

    2015-03-01

    Mass spectrometry imaging has become a popular tool for probing the chemical complexity of biological surfaces. This led to the development of a wide range of instrumentation and preparation protocols. It is thus desirable to evaluate and compare the data output from different methodologies and mass spectrometers. Here, we present an approach for the comparison of mass spectrometry imaging data from different laboratories (often referred to as multicenter studies). This is exemplified by the analysis of mouse brain sections in five laboratories in Europe and the USA. The instrumentation includes matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF), MALDI-QTOF, MALDIFourier transform ion cyclotron resonance (FTICR), atmospheric-pressure (AP)-MALDI-Orbitrap, and cluster TOF-secondary ion mass spectrometry (SIMS). Experimental parameters such as measurement speed, imaging bin width, and mass spectrometric parameters are discussed. All datasets were converted to the standard data format imzML and displayed in a common open-source software with identical parameters for visualization, which facilitates direct comparison of MS images. The imzML conversion also allowed exchange of fully functional MS imaging datasets between the different laboratories. The experiments ranged from overview measurements of the full mouse brain to detailed analysis of smaller features (depending on spatial resolution settings), but common histological features such as the corpus callosum were visible in all measurements. High spatial resolution measurements of AP-MALDI-Orbitrap and TOF-SIMS showed comparable structures in the low-micrometer range. We discuss general considerations for planning and performing multicenter studies in mass spectrometry imaging. This includes details on the selection, distribution, and preparation of tissue samples as well as on data handling. Such multicenter studies in combination with ongoing activities for reporting guidelines, a common

  15. Ruminant Metabolic Systems Biology: Reconstruction and Integration of Transcriptome Dynamics Underlying Functional Responses of Tissues to Nutrition and Physiological Statea

    Science.gov (United States)

    Bionaz, Massimo; Loor, Juan J.

    2012-01-01

    High-throughput ‘omics’ data analysis via bioinformatics is one key component of the systems biology approach. The systems approach is particularly well-suited for the study of the interactions between nutrition and physiological state with tissue metabolism and functions during key life stages of organisms such as the transition from pregnancy to lactation in mammals, ie, the peripartal period. In modern dairy cows with an unprecedented genetic potential for milk synthesis, the nature of the physiologic and metabolic adaptations during the peripartal period is multifaceted and involves key tissues such as liver, adipose, and mammary. In order to understand such adaptation, we have reviewed several works performed in our and other labs. In addition, we have used a novel bioinformatics approach, Dynamic Impact Approach (DIA), in combination with partly previously published data to help interpret longitudinal biological adaptations of bovine liver, adipose, and mammary tissue to lactation using transcriptomics datasets. Use of DIA with transcriptomic data from those tissues during normal physiological adaptations and in animals fed different levels of energy prepartum allowed visualization and integration of most-impacted metabolic pathways around the time of parturition. The DIA is a suitable tool for applying the integrative systems biology approach. The ultimate goal is to visualize the complexity of the systems at study and uncover key molecular players involved in the tissue’s adaptations to physiological state or nutrition. PMID:22807626

  16. Teaching the physics of medical imaging: an active learning approach involving imaging of biological tissue

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Pihl, Michael Johannes; Lonsdale, Markus Nowak

    2008-01-01

    Introduction to medical imaging is an experimentally oriented course in the physics of medical imaging, where the students record, process and analyse 3D data of an unknown piece of formalin fixed animal tissue embedded in agar in order to estimate the tissue types present. Planar X-ray, CT, MRI......, ultrasound and SPECT/PET images are recorded, showing the tissue in very different ways. In order for the students to estimate the tissue type, they need to study the physical principles of the imaging modalities. The “true” answer is subsequently revealed by slicing the tissue....

  17. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Vavpetič, P., E-mail: primoz.vavpetic@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, K. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Jeromel, L. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potočnik, N. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); FOM-Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Pongrac, P. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Department of Plant Physiology, University of Bayreuth, Universitätstr. 30, 95447 Bayreuth (Germany); Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm{sup 2} and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  18. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    International Nuclear Information System (INIS)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-01-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm 2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation

  19. Method for estimating optimal spectral and energy parameters of laser irradiation in photodynamic therapy of biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Lisenko, S A; Kugeiko, M M [Belarusian State University, Minsk (Belarus)

    2015-04-30

    We have solved the problem of layer-by-layer laser-light dosimetry in biological tissues and of selecting an individual therapeutic dose in laser therapy. A method is proposed for real-time monitoring of the radiation density in tissue layers in vivo, concentrations of its endogenous (natural) and exogenous (specially administered) chromophores, as well as in-depth distributions of the spectrum of light action on these chromophores. As the background information use is made of the spectrum of diffuse light reflected from a patient's tissue, measured by a fibre-optic spectrophotometer. The measured spectrum is quantitatively analysed by the method of approximating functions for fluxes of light multiply scattered in tissue and by a semi-analytical method for calculating the in-depth distribution of the light flux in a multi-layered medium. We have shown the possibility of employing the developed method for monitoring photosensitizer and oxyhaemoglobin concentrations in tissue, light power absorbed by chromophores in tissue layers at different depths and laser-induced changes in the tissue morphology (vascular volume content and ratios of various forms of haemoglobin) during photodynamic therapy. (biophotonics)

  20. Experimental verification of stopping-power prediction from single- and dual-energy computed tomography in biological tissues

    Science.gov (United States)

    Möhler, Christian; Russ, Tom; Wohlfahrt, Patrick; Elter, Alina; Runz, Armin; Richter, Christian; Greilich, Steffen

    2018-01-01

    An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone). Using a standard stoichiometric calibration for single-energy CT (SECT) as well as a state-of-the-art dual-energy CT (DECT) approach, SPR was predicted for all tissues and then compared to the measured reference. With the SECT approach, the SPRs of all tissues were predicted with a mean error of (-0.84  ±  0.12)% and a mean absolute error of (1.27  ±  0.12)%. In contrast, the DECT-based SPR predictions were overall consistent with the measured reference with a mean error of (-0.02  ±  0.15)% and a mean absolute error of (0.10  ±  0.15)%. Thus, in this study, the potential of DECT to decrease range uncertainty could be confirmed in biological tissue.

  1. Biological availability of manganese sources and effects of high dietary manganese on tissue mineral composition of broiler-type chicks.

    Science.gov (United States)

    Black, J R; Ammerman, C B; Henry, P R; Miles, R D

    1984-10-01

    An experiment was conducted with male broiler-type chicks to study tissue uptake of Mn as a measure of biological availability of Mn sources. A basal corn-soybean meal diet (116 ppm Mn) was supplemented with 0, 1000, 2000, or 4000 ppm Mn as either reagent grade sulfate, carbonate, or monoxide and fed ad libitum for 26 days. No toxic effects were noted as expressed by feed intake, weight gain, feed conversion, hematocrit, hemoglobin, or mortality. Analysis of Mn in tissues revealed a highly linear relationship between liver or bone Mn concentration and dietary Mn for all three sources. Manganese concentration in all tissues increased (P less than .01) as dietary Mn increased. Liver and bone Mn accumulation appeared to be excellent indicators of relative biological availability. On the basis of tissue uptake and solubility tests, MnSO4 X H2O was the most available, followed by MnO and MnCO3, respectively. There were no effects of Mn source or level on concentration of Ca, P, Mg, Cu, Zn, or Fe in tissues studied.

  2. Development and validation of a biologically realistic tissue-mimicking material for photoacoustics and other bimodal optical-acoustic modalities

    Science.gov (United States)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, T. Joshua

    2017-03-01

    Recent years have seen rapid development of hybrid optical-acoustic imaging modalities with broad applications in research and clinical imaging, including photoacoustic tomography (PAT), photoacoustic microscopy, and ultrasound-modulated optical tomography. Tissue-mimicking phantoms are an important tool for objectively and quantitatively simulating in vivo imaging system performance. However, no standard tissue phantoms exist for such systems. One major challenge is the development of tissue-mimicking materials (TMMs) that are both highly stable and possess biologically realistic properties. To address this need, we have explored the use of various formulations of PVC plastisol (PVCP) based on varying mixtures of several liquid plasticizers. We developed a custom PVCP formulation with optical absorption and scattering coefficients, speed of sound, and acoustic attenuation that are tunable and tissue-relevant. This TMM can simulate different tissue compositions and offers greater mechanical strength than hydrogels. Optical properties of PVCP samples with varying composition were characterized using integrating sphere spectrophotometry and the inverse adding-doubling method. Acoustic properties were determined using a broadband pulse-transmission technique. To demonstrate the utility of this bimodal TMM, we constructed an image quality phantom designed to enable quantitative evaluation of PAT spatial resolution. The phantom was imaged using a custom combined PAT-ultrasound imaging system. Results indicated that this more biologically realistic TMM produced performance trends not captured in simpler liquid phantoms. In the future, this TMM may be broadly utilized for performance evaluation of optical, acoustic, and hybrid optical-acoustic imaging systems.

  3. Radiation preservation of biological tissues with special emphasis on immunological alterations. Part of a coordinated programme on radiosterilization of medical products and biological tissues

    International Nuclear Information System (INIS)

    Feher, I.

    1977-01-01

    A method suitable for clinical use and preparations of tendon and skin preserved by lyophilization and radiosterilization were investigated. The fate of the graft was detected by histological and electronmicroscopical investigations. We demonstrated that the implanted preparation was desorganized and was absorbed within six weeks. Clinical examinations were made on pig-tendon preparations. Patients recovered without difficulties in every case. Skin preparations were prepared of pig-skin. It was demonstrated by indirect haemagglutination that pig-skin antigenity was decreased by approximately two orders of magnitude during the preservation process. The clinical application of skin preparations has been used for nearly two years. It is effectively used as a biological dressing for the covering of wound surface in case of burn injuries

  4. Tissue culture on a chip: Developmental biology applications of self-organized capillary networks in microfluidic devices.

    Science.gov (United States)

    Miura, Takashi; Yokokawa, Ryuji

    2016-08-01

    Organ culture systems are used to elucidate the mechanisms of pattern formation in developmental biology. Various organ culture techniques have been used, but the lack of microcirculation in such cultures impedes the long-term maintenance of larger tissues. Recent advances in microfluidic devices now enable us to utilize self-organized perfusable capillary networks in organ cultures. In this review, we will overview past approaches to organ culture and current technical advances in microfluidic devices, and discuss possible applications of microfluidics towards the study of developmental biology. © 2016 Japanese Society of Developmental Biologists.

  5. On alterations in the refractive index and scattering properties of biological tissue caused by histological processing

    Science.gov (United States)

    Aung, Htet; DeAngelo, Bianca; Soldano, John; Kostyk, Piotr; Rodriguez, Braulio; Xu, M.

    2013-02-01

    Clinical tissue processing such as formalin fixing, paraffin-embedding and histological staining alters significantly the optical properties of the tissue. We document the alterations in the optical properties of prostate cancer tissue specimens in the 500nm to 700nm spectral range caused by histological processing with quantitative differential interference contrast (qDIC) microscopy. A simple model to explain these alterations is presented at the end.

  6. Non-Directional Radiation Spread Modeling and Non-Invasive Estimating the Radiation Scattering and Absorption Parameters in Biological Tissue

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2015-01-01

    Full Text Available The article dwells on a development of new non-invasive measurement methods of optical parameters of biological tissues, which are responsible for the scattering and absorption of monochromatic radiation. It is known from the theory of radiation transfer [1] that for strongly scattering media, to which many biological tissues pertain, such parameters are parameters of diffusion approximation, as well as a scattering coefficient and an anisotropy parameter.Based on statistical modeling the paper examines a spread of non-directional radiation from a Lambert light beam with the natural polarization that illuminates a surface of the biological tissue. Statistical modeling is based on the Monte Carlo method [2]. Thus, to have the correct energy coefficient values of Fresnel reflection and transmission in simulation of such radiation by Monte Carlo method the author uses his finding that is a function of the statistical representation for the incidence of model photons [3]. The paper describes in detail a principle of fixing the power transmitted by the non-directional radiation into biological tissue [3], and the equations of a power balance in this case.Further, the paper describes the diffusion approximation of a radiation transfer theory, often used in simulation of radiation propagation in strongly scattering media and shows its application in case of fixing the power transmitted into the tissue. Thus, to represent an uneven power distribution is used an approximating expression in conditions of fixing a total input power. The paper reveals behavior peculiarities of solution on the surface of the biological tissue inside and outside of the incident beam. It is shown that the solution in the region outside of the incident beam (especially far away from it, essentially, depends neither on the particular power distribution across the surface, being a part of the tissue, nor on the refractive index of the biological tissue. It is determined only by

  7. The delayed fluorescence kinetics as a method of biological tissue diagnostics

    Science.gov (United States)

    Letuta, Sergey N.; Maryakhina, Valeriya S.

    2011-03-01

    Delayed fluorescence kinetics of exogenous fluorophores in tumor and normal mice mammary tissue cells was researched. Delayed fluorescence kinetics of fluorophores in two types of cells was researched on in its specific features and regularities. The investigation results are discussed in the context of early fluorescent diagnostics method of tissue pathological states.

  8. Study of short-pulse laser propagation in biological tissue by means of the boundary element method.

    Science.gov (United States)

    Ansari, Mohammad Ali; Massudi, Reza

    2011-07-01

    Propagation of short pulses of light through biological tissues can be studied by numerically solving the diffusion equation. The boundary integral method was used to convert the differential equation to integral form and the result was solved using the boundary element method. The effects of different optical parameters of the tissue, i.e. scattering, absorption coefficients and anisotropic factor, on temporal evolution of the diffusely reflected pulse were studied. The results were compared with those obtained using the finite difference time domain method and the boundary integral method was found to be more precise and faster than the last method. The method can be used to investigate reflected pulses in the study of cell morphology and tumours in different types of tissue.

  9. Suppression of Botrytis cinerea on necrotic grapevine tissues by early-season applications of natural products and biological control agents.

    Science.gov (United States)

    Calvo-Garrido, Carlos; Viñas, Inmaculada; Elmer, Philip A G; Usall, Josep; Teixidó, Neus

    2014-04-01

    Necrotic tissues within grape (Vitis vinifera) bunches represent an important source of Botrytis cinerea inoculum for Botrytis bunch rot (BBR) at harvest in vineyards. This research quantified the incidence of B. cinerea on necrotic floral and fruit tissues and the efficacy of biologically based treatments for suppression of B. cinerea secondary inoculum within developing bunches. At veraison (2009 and 2010), samples of aborted flowers, aborted fruits and calyptras were collected, and the incidence and sporulation of B. cinerea were determined. Aborted fruits presented significantly higher incidence in untreated samples. Early-season applications of Candida sake plus Fungicover®, Fungicover alone or Ulocladium oudemansii significantly reduced B. cinerea incidence on aborted flowers and calyptras by 46-85%. Chitosan treatment significantly reduced B. cinerea incidence on calyptras. None of the treatments reduced B. cinerea incidence on aborted fruits. Treatments significantly reduced sporulation severity by 48% or more. Treatments were effective at reducing B. cinerea secondary inoculum on necrotic tissues, in spite of the variable control on aborted fruits. This is the first report to quantify B. cinerea on several tissues of bunch trash and to describe the effective suppression of saprophytic B. cinerea inoculum by biologically based treatments. © 2013 Society of Chemical Industry.

  10. Pluripotent stem cell-derived organoids: using principles of developmental biology to grow human tissues in a dish.

    Science.gov (United States)

    McCauley, Heather A; Wells, James M

    2017-03-15

    Pluripotent stem cell (PSC)-derived organoids are miniature, three-dimensional human tissues generated by the application of developmental biological principles to PSCs in vitro The approach to generate organoids uses a combination of directed differentiation, morphogenetic processes, and the intrinsically driven self-assembly of cells that mimics organogenesis in the developing embryo. The resulting organoids have remarkable cell type complexity, architecture and function similar to their in vivo counterparts. In the past five years, human PSC-derived organoids with components of all three germ layers have been generated, resulting in the establishment of a new human model system. Here, and in the accompanying poster, we provide an overview of how principles of developmental biology have been essential for generating human organoids in vitro , and how organoids are now being used as a primary research tool to investigate human developmental biology. © 2017. Published by The Company of Biologists Ltd.

  11. Meat Science and Muscle Biology Symposium: manipulating meat tenderness by increasing the turnover of intramuscular connective tissue.

    Science.gov (United States)

    Purslow, P P; Archile-Contreras, A C; Cha, M C

    2012-03-01

    Controlled reduction of the connective tissue contribution to cooked meat toughness is an objective that would have considerable financial impact in terms of added product value. The amount of intramuscular connective tissue in a muscle appears connected to its in vivo function, so reduction of the overall connective tissue content is not thought to be a viable target. However, manipulation of the state of maturity of the collagenous component is a biologically viable target; by increasing connective tissue turnover, less mature structures can be produced that are functional in vivo but more easily broken down on cooking at temperatures above 60°C, thus improving cooked meat tenderness. Recent work using cell culture models of fibroblasts derived from muscle and myoblasts has identified a range of factors that alter the activity of the principal enzymes responsible for connective tissue turnover, the matrix metalloproteinases (MMP). Fibroblasts cultured from 3 different skeletal muscles from the same animal show different cell proliferation and MMP activity, which may relate to the different connective tissue content and architecture in functionally different muscles. Expression of MMP by fibroblasts is increased by vitamins that can counter the negative effects of oxidative stress on new collagen synthesis. Preliminary work using in situ zymography of myotubes in culture also indicates increased MMP activity in the presence of epinephrine and reactive oxidative species. Comparison of the relative changes in MMP expression from muscle cells vs. fibroblasts shows that myoblasts are more responsive to a range of stimuli. Muscle cells are likely to produce more of the total MMP in muscle tissue as a whole, and the expression of latent forms of the enzymes (i.e., pro-MMP) may vary between oxidative and glycolytic muscle fibers within the same muscle. The implication is that the different muscle fiber composition of different muscles eaten as meat may influence the

  12. Collision tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Coward, M.P.; Ries, A.C.

    1985-01-01

    The motions of lithospheric plates have produced most existing mountain ranges, but structures produced as a result of, and following the collision of continental plates need to be distinguished from those produced before by subduction. If subduction is normally only stopped when collision occurs, then most geologically ancient fold belts must be collisional, so it is essential to recognize and understand the effects of the collision process. This book consists of papers that review collision tectonics, covering tectonics, structure, geochemistry, paleomagnetism, metamorphism, and magmatism.

  13. Resonant Mie scattering (RMieS) correction applied to FTIR images of biological tissue samples.

    Science.gov (United States)

    Bambery, Keith R; Wood, Bayden R; McNaughton, Don

    2012-01-07

    Recently a resonant Mie scattering (RMieS) correction approach has been developed and demonstrated to be effective for removing the baseline distortions that compromise the raw data in individual spectra. In this paper RMieS correction is extended to FTIR images of a tissue section from biopsy of the human cervical transformation zone and a coronal tissue section of a Wistar rat brain and compared to the uncorrected images. It is shown that applying RMieS correction to FTIR images a) removes baseline distortions from the image spectra and thus reveals previously hidden information on spatial variation of chemical contents within the tissue and b) can lead to improved automatic tissue feature classification through multivariate cluster analysis. This journal is © The Royal Society of Chemistry 2012

  14. In Vitro Biological Evaluation of Electrospun Polycaprolactone/Gelatine Nanofibrous Scaffold for Tissue Engineering

    OpenAIRE

    Lim, Mim Mim; Sun, Tao; Sultana, Naznin

    2015-01-01

    The fabrication of biocompatible and biodegradable scaffolds which mimic the native extracellular matrix of tissues to promote cell adhesion and growth is emphasized recently. Many polymers have been utilized in scaffold fabrication, but there is still a need to fabricate hydrophilic nanosized fibrous scaffolds with an appropriate degradation rate for skin tissue engineering applications. In this study, nanofibrous scaffolds of a biodegradable synthetic polymer, polycaprolactone (PCL), and bl...

  15. Influence of skin surface roughness degree on energy characteristics of light scattered by a biological tissue

    Science.gov (United States)

    Barun, V. V.; Ivanov, A. P.

    2017-05-01

    We present the results of modelling of photometric characteristics of light in soft tissues illuminated by a parallel beam along the normal to the surface, obtained with allowance for the skin roughness parameters and the angular structure of radiation approaching the surface from within the tissue. The depth structure of the fluence rate and the spectra of the diffuse reflection of light by the tissue in the interval of wavelengths 300 - 1000 nm are considered. We discuss the influence of the tilt angle variance of rough surface microelements and light refraction on the studied characteristics. It is shown that these factors lead to the reduction of the radiation flux only in the near-surface tissue layer and practically do not affect the depth of light penetration into the tissue. On the other hand, the degree of the surface roughness and the conditions of its illumination from within the tissue essentially affect the coefficient of diffuse reflection of light and lead to its considerable growth compared to the cases of a smooth interface and completely diffuse illumination, often considered to simplify the theoretical problem solution. The role of the roughness of skin surface is assessed in application to the solution of different direct and inverse problems of biomedical optics.

  16. Validity of the Cauchy-Born rule applied to discrete cellular-scale models of biological tissues

    KAUST Repository

    Davit, Y.

    2013-04-30

    The development of new models of biological tissues that consider cells in a discrete manner is becoming increasingly popular as an alternative to continuum methods based on partial differential equations, although formal relationships between the discrete and continuum frameworks remain to be established. For crystal mechanics, the discrete-to-continuum bridge is often made by assuming that local atom displacements can be mapped homogeneously from the mesoscale deformation gradient, an assumption known as the Cauchy-Born rule (CBR). Although the CBR does not hold exactly for noncrystalline materials, it may still be used as a first-order approximation for analytic calculations of effective stresses or strain energies. In this work, our goal is to investigate numerically the applicability of the CBR to two-dimensional cellular-scale models by assessing the mechanical behavior of model biological tissues, including crystalline (honeycomb) and noncrystalline reference states. The numerical procedure involves applying an affine deformation to the boundary cells and computing the quasistatic position of internal cells. The position of internal cells is then compared with the prediction of the CBR and an average deviation is calculated in the strain domain. For center-based cell models, we show that the CBR holds exactly when the deformation gradient is relatively small and the reference stress-free configuration is defined by a honeycomb lattice. We show further that the CBR may be used approximately when the reference state is perturbed from the honeycomb configuration. By contrast, for vertex-based cell models, a similar analysis reveals that the CBR does not provide a good representation of the tissue mechanics, even when the reference configuration is defined by a honeycomb lattice. The paper concludes with a discussion of the implications of these results for concurrent discrete and continuous modeling, adaptation of atom-to-continuum techniques to biological

  17. Adverse event reporting and developments in radiation biology after normal tissue injury: International Atomic Energy Agency consultation

    International Nuclear Information System (INIS)

    Chen Yuhchyau; Trotti, Andy; Coleman, C. Norman; Machtay, Mitchell; Mirimanoff, Rene O.; Hay, John; O'Brien, Peter C.; El-Gueddari, Brahim; Salvajoli, Joao V.; Jeremic, Branislav

    2006-01-01

    Purpose: Recent research has enhanced our understanding of radiation injury at the molecular-cellular and tissue levels; significant strides have occurred in standardization of adverse event reporting in clinical trials. In response, the International Atomic Energy Agency, through its Division of Human Health and its section for Applied Radiation Biology and Radiotherapy, organized a consultation meeting in Atlanta (October 2, 2004) to discuss developments in radiobiology, normal tissue reactions, and adverse event reporting. Methods and Materials: Representatives from cooperative groups of African Radiation Oncology Group, Curriculo Radioterapeutica Ibero Latino Americana, European Organization for Research and Treatment of Cancer, National Cancer Institute of Canada Clinical Trials Group, Radiation Therapy Oncology Group, and Trans-Tasman Radiation Oncology Group held the meeting discussion. Results: Representatives of major radiotherapy groups/organizations and prominent leaders in radiotherapy discussed current understanding of normal tissue radiobiologic effects, the design and implementation of future clinical and translational projects for normal tissue injury, and the standardization of adverse-event reporting worldwide. Conclusions: The consensus was to adopt NCI comprehensive adverse event reporting terminology and grading system (CTCAE v3.0) as the new standard for all cooperative group trials. Future plans included the implementation of coordinated research projects focusing on normal tissue biomarkers and data collection methods

  18. Biology and potential clinical implications of tissue inhibitor of metalloproteinases-1 in colorectal cancer treatment

    DEFF Research Database (Denmark)

    Sørensen, Nanna Møller; Sørensen, irene Vejgaard; Würtz, Sidse Ørnbjerg

    2008-01-01

    Colorectal cancer (CRC) is the second leading cause of cancer-related death in the industrialized world. About half of "curatively" resected patients develop recurrent disease within the next 3-5 years despite the lack of clinical, histological and biochemical evidence of remaining overt disease ...... knowledge of the biology of TIMP-1 as well as the potential use of TIMP-1 as a biological marker in the management of CRC patients....

  19. Periodontal materials and cell biology for guided tissue and bone regeneration.

    Science.gov (United States)

    Andrei, Mihai; Dinischiotu, Anca; Didilescu, Andreea Cristiana; Ionita, Daniela; Demetrescu, Ioana

    2018-03-01

    The present review is intended to find links between periodontal materials of the dentomaxillary apparatus and cell biology at the beginning of a century fraught with various forms of periodontal diseases and needing new treatment strategies. The manuscript has two different parts. The first describes the anatomy of tooth supporting structures, as well as related pathologies. The second part is related to cell and molecular biology in the context of periodontal regeneration. Copyright © 2017. Published by Elsevier GmbH.

  20. Sialomes and Mialomes: A Systems-Biology View of Tick Tissues and Tick-Host Interactions

    Czech Academy of Sciences Publication Activity Database

    Chmelař, J.; Kotál, Jan; Karim, S.; Kopáček, Petr; Francischetti, I.M.B.; Pedra, J. H. F.; Kotsyfakis, Michalis

    2016-01-01

    Roč. 32, č. 3 (2016), s. 242-254 ISSN 1471-4922 R&D Projects: GA ČR GAP502/12/2409; GA ČR GA13-11043S EU Projects: European Commission(XE) 268177 Institutional support: RVO:60077344 Keywords : next- gene ration sequencing * sialomes * systems biology * tick-borne pathogens Subject RIV: EB - Gene tics ; Molecular Biology Impact factor: 6.333, year: 2016

  1. Suitability of a PLCL fibrous scaffold for soft tissue engineering applications: A combined biological and mechanical characterisation.

    Science.gov (United States)

    Laurent, Cédric P; Vaquette, Cédryck; Liu, Xing; Schmitt, Jean-François; Rahouadj, Rachid

    2018-04-01

    Poly(lactide-co-ε-caprolactone) (PLCL) has been reported to be a good candidate for tissue engineering because of its good biocompatibility. Particularly, a braided PLCL scaffold (PLL/PCL ratio = 85/15) has been recently designed and partially validated for ligament tissue engineering. In the present study, we assessed the in vivo biocompatibility of acellular and cellularised scaffolds in a rat model. We then determined its in vitro biocompatibility using stem cells issued from both bone marrow and Wharton Jelly. From a biological point of view, the scaffold was shown to be suitable for tissue engineering in all these cases. Secondly, while the initial mechanical properties of this scaffold have been previously reported to be adapted to load-bearing applications, we studied the evolution in time of the mechanical properties of PLCL fibres due to hydrolytic degradation. Results for isolated PLCL fibres were extrapolated to the fibrous scaffold using a previously developed numerical model. It was shown that no accumulation of plastic strain was to be expected for a load-bearing application such as anterior cruciate ligament tissue engineering. However, PLCL fibres exhibited a non-expected brittle behaviour after two months. This may involve a potential risk of premature failure of the scaffold, unless tissue growth compensates this change in mechanical properties. This combined study emphasises the need to characterise the properties of biomaterials in a pluridisciplinary approach, since biological and mechanical characterisations led in this case to different conclusions concerning the suitability of this scaffold for load-bearing applications.

  2. Method for Separation of Blood Vessels on the Three-Color Images of Biological Tissues

    Science.gov (United States)

    Lisenko, S. A.

    2017-07-01

    A new technology was developed to improve the visibility of blood vessels on images of tissues of hollow human organs(the alimentary tract and respiratory system) based on the relation between the color components of the image, the scattering properties of the tissue, and its hemoglobin content. A statistical operator was presented to convert the three-color image of the tissue into a parametric map objectively characterizing the concentration of hemoglobin in the tissue regardless of the illumination and shooting conditions. An algorithm for obtaining conversion parameters for image systems with known spectral characteristics was presented. An image of a multilayer multiple-scattering medium modeling bronchial tissue was synthesized and was used to evaluate the efficiency of the proposed conversion system. It was shown that the conversion made it possible to increase the contrast of the blood vessels by almost two orders of magnitude, to significantly improve the clarity of the display of their borders, and to eliminate almost completely the influence of background and nonuniform illumination of the medium in comparison with the original image.

  3. Biology and function of adipose tissue macrophages, dendritic cells and B cells.

    Science.gov (United States)

    Ivanov, Stoyan; Merlin, Johanna; Lee, Man Kit Sam; Murphy, Andrew J; Guinamard, Rodolphe R

    2018-04-01

    The increasing incidence of obesity and its socio-economical impact is a global health issue due to its associated co-morbidities, namely diabetes and cardiovascular disease [1-5]. Obesity is characterized by an increase in adipose tissue, which promotes the recruitment of immune cells resulting in low-grade inflammation and dysfunctional metabolism. Macrophages are the most abundant immune cells in the adipose tissue of mice and humans. The adipose tissue also contains other myeloid cells (dendritic cells (DC) and neutrophils) and to a lesser extent lymphocyte populations, including T cells, B cells, Natural Killer (NK) and Natural Killer T (NKT) cells. While the majority of studies have linked adipose tissue macrophages (ATM) to the development of low-grade inflammation and co-morbidities associated with obesity, emerging evidence suggests for a role of other immune cells within the adipose tissue that may act in part by supporting macrophage homeostasis. In this review, we summarize the current knowledge of the functions ATMs, DCs and B cells possess during steady-state and obesity. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Adipose stem cells: biology and clinical applications for tissue repair and regeneration.

    Science.gov (United States)

    Kokai, Lauren E; Marra, Kacey; Rubin, J Peter

    2014-04-01

    There is a clear clinical need for cell therapies to repair or regenerate tissue lost to disease or trauma. Adipose tissue is a renewable source of stem cells, called adipose-derived stem cells (ASCs), that release important growth factors for wound healing, modulate the immune system, decrease inflammation, and home in on injured tissues. Therefore, ASCs may offer great clinical utility in regenerative therapies for afflictions such as Parkinson's disease and Alzheimer's disease, spinal cord injury, heart disease, and rheumatoid arthritis, or for replacing lost tissue from trauma or tumor removal. This article discusses the regenerative properties of ASCs that can be harnessed for clinical applications, and explores current and future challenges for ASC clinical use. Such challenges include knowledge-based deficiencies, hurdles for translating research to the clinic, and barriers to establishing a new paradigm of medical care. Clinical experience with ASCs, ASCs as a portion of the heterogeneous stromal cell population extracted enzymatically from adipose tissue, and stromal vascular fraction are also described. Copyright © 2014 Mosby, Inc. All rights reserved.

  5. Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) for Imaging Electrical Conductivity of Biological Tissue: A Tutorial Review

    Science.gov (United States)

    Li, Xu; Yu, Kai; He, Bin

    2016-01-01

    Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. With the existence of a static magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample’s electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in these years. First, the physical mechanisms underlying MAT-MI imaging are described including the magnetic induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with magnetic induction (MAET-MI) is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue. PMID:27542088

  6. Collision Mechanics

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Servis, D.P.; Zhang, Shengming

    1999-01-01

    The first section of the present report describes the procedures that are being programmed at DTU for evaluation of the external collision dynamics. Then follows a detailed description of a comprehensive finite element analysis of one collision scenario for MS Dextra carried out at NTUA. The last...

  7. Interaction of a pulsed alexandrite laser with hard and soft biological tissue

    Science.gov (United States)

    Paterson, Lorna M.; Dickinson, Mark R.; King, Terence A.; Watts, David C.

    1994-02-01

    An alexandrite laser has been used in the fixed-Q and Q-switched modes, at the fundamental and frequency doubled wavelengths on a selection of hard and soft tissue. In an investigation into the potential use of the laser for the removal of deep lying lesions such as cutaneous vascular lesions and tatoos, studies have been carried out to characterize the depth and extent of the laser/tissue interaction in samples of tissue which greatly absorb the 750 nm radiation. The interaction of the laser radiation with extracted teeth was investigated looking at healthy enamel and dentine, and caries. Surface profile measurements of the enamel and dentine before and after irradiation show little physical effect of the laser irradiation, whereas caries appear to be ablated.

  8. Biological characterization and clinical applications of a monoclonal antibody recognizing an antigen restricted to neuroectodermal tissues.

    Science.gov (United States)

    Allan, P M; Garson, J A; Harper, E I; Asser, U; Coakham, H B; Brownell, B; Kemshead, J T

    1983-05-15

    The monoclonal antibody UJ13A was raised following immunization of mice with human foetal brain and subsequent somatic cell hyridization of spleen cells with the mouse myeloma cell line P3-X63-AG8-653. The antibody is of the IgG1 subclass and has been shown by indirect immunofluorescence studies on normal foetal, paediatric and adult tissues to selectively bind to most tissues of neuroectodermal origin. Many tumours of neural origin also express the UJ13A antigen and the reagent can be used to distinguish primary intracranial neural tumours from secondary carcinomas and lymphomas. UJ13A is also useful as one of a panel of reagents employed for the identification of metastatic spread of neuroblastoma cells to bone marrow and cerebrospinal fluid. Knowledge of the full spectrum of normal and malignant tissues binding UJ13A suggests that the antibody may have a role in the radioimmunolocalization of neuronal tumours such as neuroblastoma.

  9. Photomechanical ablation of biological tissue induced by focused femtosecond laser and its application for acupuncture

    Science.gov (United States)

    Hosokawa, Yoichiroh; Ohta, Mika; Ito, Akihiko; Takaoka, Yutaka

    2013-03-01

    Photomechanical laser ablation due to focused femtosecond laser irradiation was induced on the hind legs of living mice, and its clinical influence on muscle cell proliferation was investigated via histological examination and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis to examine the expression of the gene encoding myostatin, which is a growth repressor in muscle satellite cells. The histological examination suggested that damage of the tissue due to the femtosecond laser irradiation was localized on epidermis and dermis and hardly induced in the muscle tissue below. On the other hand, gene expression of the myostatin of muscle tissue after laser irradiation was suppressed. The suppression of myostatin expression facilitates the proliferation of muscle cells, because myostatin is a growth repressor in muscle satellite cells. On the basis of these results, we recognize the potential of the femtosecond laser as a tool for noncontact, high-throughput acupuncture in the treatment of muscle disease.

  10. Relationship between 578-nm (copper vapor) laser beam geometry and heat distribution within biological tissues

    Science.gov (United States)

    Ilyasov, Ildar K.; Prikhodko, Constantin V.; Nevorotin, Alexey J.

    1995-01-01

    Monte Carlo (MC) simulation model and the thermoindicative tissue phantom were applied for evaluation of a depth of tissue necrosis (DTN) as a result of quasi-cw copper vapor laser (578 nm) irradiation. It has been shown that incident light focusing angle is essential for DTN. In particular, there was a significant rise in DTN parallel to elevation of this angle up to +20 degree(s)C and +5 degree(s)C for both the MC simulation and tissue phantom models, respectively, with no further increase in the necrosis depth above these angles. It is to be noted that the relationship between focusing angles and DTN values was apparently stronger for the real target compared to the MC-derived hypothetical one. To what extent these date are applicable for medical practice can be evaluated in animal models which would simulate laser-assisted therapy for PWS or related dermatologic lesions with converged 578 nm laser beams.

  11. Study about quantification and classification of biological tissues in tomographic images from histograms; Estudo sobre quantificacao e classificacao dos tecidos biologicos em imagens tomograficas a partir de histogramas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Rafael T.F.; Lemke, Ney; Hormaza, Joel Mesa; Alvarez, Matheus, E-mail: rafael@ibb.unesp.b [Universidade Estadual Paulista Julio de Mesquisa Filho (DFB/IB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Pina, Diana R.; Teixeira, Altamir S. [Universidade Estadual Paulista Julio de Mesquisa Filho (HC/FM/UNESP), Botucatu, SP (Brazil). Hospital de Clinicas. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2010-06-15

    An algorithm for determining the equivalent thickness of biological tissue by the removal of Gaussian from the histograms was proposed. This algorithm classifies the different biological tissues using histograms, constructed from CT scans in DICOM format and calculates the average thickness of these tissues. The founded results show to be coherent with literature, with discrepancies of up to 21.6% on the bone, and analyzed for the anthropomorphic phantom (RANDO). These results allow the use of this method in living tissues for the construction of chest homogeneous phantoms of newborn and suckling patients, which are subsequently used in the optimization process of pediatric radiographic images. (author)

  12. Radioenzymatic microassay for picogram quantities of serotonin or acetylserotonin in biological fluids and tissues

    International Nuclear Information System (INIS)

    Hussain, M.N.; Benedict, C.R.

    1987-01-01

    This paper describes several modifications of the original radioenzymatic assay for serotonin which increase the sensitivity of the assay 20-fold as well as enhance its reliability. Using this method serotonin concentrations can be directly measured in biological examples without precleaning the sample. When compared to currently available methods this assay is specific and sensitive to approximately 1 pg of serotonin and can be used to measure serotonin levels in individual brain nuclei or microliter quantities of biological fluids. This assay can be easily adapted for the direct measurement of N-acetylserotonin. A large number of samples can be assayed in a single working day

  13. Biological therapy of strontium-substituted bioglass for soft tissue wound-healing: responses to oxidative stress in ovariectomised rats.

    Science.gov (United States)

    Jebahi, S; Oudadesse, H; Jardak, N; Khayat, I; Keskes, H; Khabir, A; Rebai, T; El Feki, H; El Feki, A

    2013-07-01

    New synthetic biomaterials are constantly being developed for wound repair and regeneration. Bioactive glasses (BG) containing strontium have shown successful applications in tissue engineering account of their biocompatibility and the positive biological effects after implantation. This study aimed to assess whether BG-Sr was accepted by the host tissue and to characterize oxidative stress biomarker and antioxidant enzyme profiles during muscle and skin healing. Wistar rats were divided into five groups (six animals per group): the group (I) was used as negative control (T), after ovariectomy, groups II, III, IV and V were used respectively as positive control (OVX), implanted tissue with BG (OVX-BG), BG-Sr (OVX-BG-Sr) and presented empty defects (OVX-NI). Soft tissues surrounding biomaterials were used to estimate superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) concentration. Our results show that 60 days after operation, treatment of rats with BG-Sr significantly increased MDA concentration and caused an increase of SOD, CAT and GPx activities in both skin and muscular tissues. BG-Sr revealed maturation of myotubes followed a normal appearance of muscle regenerated with high density and mature capillary vessels. High wound recovery with complete re-epithelialization and regeneration of skin was observed. The results demonstrate that the protective action against reactive oxygen species (ROS) was clearly observed in soft tissue surrounding BG-Sr. Moreover, the potential use of BG-Sr rapidly restores the wound skin and muscle structural and functional properties. The BG advantages such as ion release might make BG-Sr an effective biomaterial choice for antioxidative activity. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Prediction Equation for Lower Limbs Lean Soft Tissue in Circumpubertal Boys Using Anthropometry and Biological Maturation

    NARCIS (Netherlands)

    Valente-dos-Santos, Joao; Coelho-e-Silva, Manuel J.; Machado-Rodrigues, Aristides M.; Elferink-Gemser, Marije T.; Malina, Robert M.; Petroski, Edio L.; Minderico, Claudia S.; Silva, Analiza M.; Baptista, Fatima; Sardinha, Luis B.

    2014-01-01

    Lean soft tissue (LST), a surrogate of skeletal muscle mass, is largely limited to appendicular body regions. Simple and accurate methods to estimate lower limbs LST are often used in attempts to partition out the influence of body size on performance outputs. The aim of the current study was to

  15. High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues

    Directory of Open Access Journals (Sweden)

    Boel Lene WT

    2010-03-01

    Full Text Available Abstract Background In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR method for ex vivo angiography and to compare the findings with computed tomography (CT. To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. Results The optimal solution for ex vivo MR angiography (MRA was a compound containing gelatine (0.05 g/mL, the CT contrast agent barium sulphate (0.43 mol/L and the MR contrast agent gadoteric acid (2.5 mmol/L. It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. Conclusions Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.

  16. Mass spectrometry imaging of small molecules in biological tissues using graphene oxide as a matrix.

    Science.gov (United States)

    Zhou, Dan; Guo, Shuai; Zhang, Mo; Liu, Yujie; Chen, Tianjing; Li, Zhili

    2017-04-15

    With the development of matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI), molecular interrogation of tissue sections over a wide mass range has become feasible, but small molecule analysis is still far from being fully reached due to the limited sensitivity and matrix interference. Herein, graphene oxide (GO) is used as a MALDI matrix to image small molecules in tissues in negative ion mode. Finally, 212 of molecules including 190 of lipids and 22 of low molecular weight metabolites were detected and spatially visualized in mouse brain tissue sections without the interference of matrix ions/clusters, and the structures of 69 of the lipids were confirmed by using in situ tandem mass spectrometry. A further application of GO matrix could reveal distinct spatio-molecular signatures in viable and necrotic tumor regions derived from a mouse breast cancer tissue. In addition, GO as a MALDI matrix has exhibited a better performance in MSI of lipids relative to N-(1-naphthyl) ethylenediamine dihydrochloride and 9-aminoacridine. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Multimodal nonlinear microscopy: A powerful label-free method for supporting standard diagnostics on biological tissues

    Directory of Open Access Journals (Sweden)

    Riccardo Cicchi

    2014-09-01

    Full Text Available The large use of nonlinear laser scanning microscopy in the past decade paved the way for potential clinical application of this imaging technique. Modern nonlinear microscopy techniques offer promising label-free solutions to improve diagnostic performances on tissues. In particular, the combination of multiple nonlinear imaging techniques in the same microscope allows integrating morphological with functional information in a morpho-functional scheme. Such approach provides a high-resolution label-free alternative to both histological and immunohistochemical examination of tissues and is becoming increasingly popular among the clinical community. Nevertheless, several technical improvements, including automatic scanning and image analysis, are required before the technique represents a standard diagnostic method. In this review paper, we highlight the capabilities of multimodal nonlinear microscopy for tissue imaging, by providing various examples on colon, arterial and skin tissues. The comparison between images acquired using multimodal nonlinear microscopy and histology shows a good agreement between the two methods. The results demonstrate that multimodal nonlinear microscopy is a powerful label-free alternative to standard histopathological methods and has the potential to find a stable place in the clinical setting in the near future.

  18. Biomimeticity in tissue engineering scaffolds through synthetic peptide modifications-altering chemistry for enhanced biological response.

    Science.gov (United States)

    Sreejalekshmi, Kumaran G; Nair, Prabha D

    2011-02-01

    Biomimetic and bioactive biomaterials are desirable as tissue engineering scaffolds by virtue of their capability to mimic natural environments of the extracellular matrix. Biomimeticity has been achieved by the incorporation of synthetic short peptide sequences into suitable materials either by surface modification or by bulk incorporation. Research in this area has identified several novel synthetic peptide segments, some of them with cell-specific interactions, which may serve as potential candidates for use in explicit tissue applications. This review focuses on the developments and prospective directions of incorporating short synthetic peptide sequences onto scaffolds for tissue engineering, with emphasis on the chemistry of peptide immobilization and subsequent cell responses toward modified scaffolds. The article provides a decision-tree-type flow chart indicating the most probable cellular events on a given peptide-modified scaffold along with the consolidated list of synthetic peptide sequences, supports as well as cell types used in various tissue engineering studies, and aims to serve as a quick reference guide to peptide chemists and material scientists interested in the field. 2010 Wiley Periodicals, Inc.

  19. Biological mechanisms of normal tissue damage : Importance for the design of NTCP models

    NARCIS (Netherlands)

    Trott, Klaus-Ruediger; Doerr, Wolfgang; Facoetti, Angelica; Hopewell, John; Langendijk, Johannes; van Luijk, Peter; Ottolenghi, Andrea; Smyth, Vere

    2012-01-01

    The normal tissue complication probability (NTCP) models that are currently being proposed for estimation of risk of harm following radiotherapy are mainly based on simplified empirical models, consisting of dose,distribution parameters, possibly combined with clinical or other treatment-related

  20. Systems Biology Analysis of Sjogren's Syndrome and Mucosa-Associated Lymphoid Tissue Lymphoma in Parotid Glands

    NARCIS (Netherlands)

    Hu, Shen; Zhou, Michael; Jiang, Jiang; Wang, Jianghua; Elashoff, David; Gorr, Sven; Michie, Sara A.; Spijkervet, Fred K. L.; Bootsma, Hendrika; Kallenberg, Cees G. M.; Vissink, Arjan; Horvath, Steve; Wong, David T.

    Objective. To identify key target genes and activated signaling pathways associated with the pathogenesis of Sjogren's syndrome (SS) by conducting a systems analysis of parotid glands manifesting primary SS or primary SS/mucosa-associated lymphoid tissue (MALT) lymphoma phenotypes. Methods. A

  1. Backscatter radiation at tissue-titanium interfaces; Biological effects from diagnostic 65 kVp X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Rosengren, B. (Department of Radiation Sciences, Uppsala University (Sweden) Dept. of Oncology, University Hospital, Bergen (Norway)); Wulff, L. (Dept. of Oral and Maxillofacial Surgery, Central Hospital, Boden (Sweden)); Carlsson, E. (Department of Radiation Sciences, Uppsala University (Sweden)); Carlsson, J. (Department of Radiation Sciences, Uppsala University (Sweden)); Strid, K.G. (Dept. of Handicap Research, Goeteborg Univ. (Sweden)); Montelius, A. (Dept. of Hospital Physics, University Hospital, Uppsala (Sweden))

    1993-01-01

    The induced secondary electrons from a metal surface by diagnostic X-rays are thought to contribute to cell damage near the tissue-metal boundaries of metal implants. Titanium implants are becoming increasingly more popular for tissue reconstructions and it is rather often desirable to take radiographs of the operated area. In this study we compared the biological effects of radiation on cultured mammalian test cells grown on titanium plates with the radiation effects on cells that were grown on plastic control plates. In order to study the acute radiation effects on cell growth it was necessary to work with rather high radiation doses (0.7-5 Gy). Photon energies, suitable for diagnostic radiography in odontology, 65 kV, were applied. We found that the cells grown on titanium plates were, in terms of the applied dose in the surrounding culture medium, more sensitive to the irradiations than the cells growing on plastic plates. The survival curve for the cells on titanium had a steeper slope, showed no shoulder in the low-dose region and looked like curves normally obtained for high LET radiation. It was not possible to resolve to what degree the titanium-dependent changes were due to an increased dose near the titanium surface or to a change in the radiobiological effectiveness. Although there was a significant decrease in cellular survival near the metal, postoperative intraoral radiography after titanium implantations need not be excluded. The maximal doses given in odontological X-ray examinations are less than 1 mGy and, if the results in this study are applied, the biological effects near the titanium implant will correspond to biological effects in soft tissue of doses less than 20 mGy which is lower than the doses that give acute effects. The risk of acute healing disturbances are significant only at much higher radiation doses. (orig.).

  2. Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

    Science.gov (United States)

    Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

    2015-08-01

    Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Organochlorine compounds in streambed sediment and in biological tissue from streams and their relations to land use, central Arizona

    Science.gov (United States)

    Gebler, Joseph B.

    2000-01-01

    Streambed-sediment samples from 13 sites and biological-tissue samples from 11 sites in the Gila River Basin in central Arizona were analyzed for 32 organochlorine compounds in streambed sediment and 28 compounds in biological tissue during 1996 as part of the U.S. Geological Survey's National Water-Quality Assessment program. The objectives of the study were to determine the occurrence and distribution of organochlorine compounds and their relation to land use. Sampling sites were categorized on the basis of major land uses in the basin or the source of water in the stream. Because land uses were mixed or had changed over time, some land-use categories were combined. Sites were categorized as forest/rangeland (6), forest/urban (1), urban (4), or agricultural/urban (2). Thirteen organochlorine compounds were detected in streambed-sediment samples, and 10 were detected in tissue samples. The number of compounds found in streambed-sediment samples from individual sites ranged from 0 to 10, and the range for individual tissue samples was 0 to 7. Comparison of the number of detections in streambed-sediment samples to the number of detections in tissue samples from particular sites where both were sampled yielded five instances where more compounds were detected in streambed sediment, six instances where more compounds were detected in tissue, and five instances where the number of detections in streambed sediment and tissue were equal. The frequency of detection of particular compounds for sites where both streambed sediment and tissue were sampled resulted in five compounds being detected more frequently in streambed sediment, five more frequently in tissue, and three compounds that were equally frequent in streambed sediment and in tissue. Few contaminants were detected in samples from the forest/rangeland sites; greater numbers of compounds were detected at the urban sites and at the forest/urban site. The greatest number of compounds and the highest concentrations

  4. Novel joint TOA/RSSI-based WCE location tracking method without prior knowledge of biological human body tissues.

    Science.gov (United States)

    Ito, Takahiro; Anzai, Daisuke; Jianqing Wang

    2014-01-01

    This paper proposes a novel joint time of arrival (TOA)/received signal strength indicator (RSSI)-based wireless capsule endoscope (WCE) location tracking method without prior knowledge of biological human tissues. Generally, TOA-based localization can achieve much higher localization accuracy than other radio frequency-based localization techniques, whereas wireless signals transmitted from a WCE pass through various kinds of human body tissues, as a result, the propagation velocity inside a human body should be different from one in free space. Because the variation of propagation velocity is mainly affected by the relative permittivity of human body tissues, instead of pre-measurement for the relative permittivity in advance, we simultaneously estimate not only the WCE location but also the relative permittivity information. For this purpose, this paper first derives the relative permittivity estimation model with measured RSSI information. Then, we pay attention to a particle filter algorithm with the TOA-based localization and the RSSI-based relative permittivity estimation. Our computer simulation results demonstrates that the proposed tracking methods with the particle filter can accomplish an excellent localization accuracy of around 2 mm without prior information of the relative permittivity of the human body tissues.

  5. In vivo biocompatibility of boron nitride nanotubes: effects on stem cell biology and tissue regeneration in planarians.

    Science.gov (United States)

    Salvetti, Alessandra; Rossi, Leonardo; Iacopetti, Paola; Li, Xia; Nitti, Simone; Pellegrino, Teresa; Mattoli, Virgilio; Golberg, Dmitri; Ciofani, Gianni

    2015-07-01

    Boron nitride nanotubes (BNNTs) represent an extremely interesting class of nanomaterials, and recent findings have suggested a number of applications in the biomedical field. Anyhow, extensive biocompatibility investigations are mandatory before any further advancement toward preclinical testing. Here, we report on the effects of multiwalled BNNTs in freshwater planarians, one of the best-characterized in vivo models for developmental biology and regeneration research. Obtained results indicate that BNNTs are biocompatible in the investigated model, since they do not induce oxidative DNA damage and apoptosis, and do not show adverse effects on planarian stem cell biology and on de novo tissue regeneration. In summary, collected findings represent another important step toward BNNT realistic applications in nanomedicine.

  6. Instructive Biologic Scaffold for Functional Tissue Regeneration Following Trauma to the Extremities

    Science.gov (United States)

    2016-10-01

    was to evaluate the effectiveness of a regenerative biologic scaffold, Biodesign ® 6-layer Plastic Surgery Matrix [Cook Biotech]; Premarket...planned to be enrolled and followed for a period of 1 year (12 months). This study had the intention to evaluate the effectiveness of Biodesign ®, a 6

  7. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Chisvert, Alberto, E-mail: alberto.chisvert@uv.es [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Leon-Gonzalez, Zacarias [Unidad Analitica, Instituto de Investigacion Sanitaria Fundacion Hospital La Fe, 46009 Valencia (Spain); Tarazona, Isuha; Salvador, Amparo [Departamento de Quimica Analitica, Facultad de Quimica, Universitat de Valencia, Doctor Moliner St. 50, 46100 Burjassot, Valencia (Spain); Giokas, Dimosthenis [Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina (Greece)

    2012-11-08

    Highlights: Black-Right-Pointing-Pointer Papers describing the determination of UV filters in fluids and tissues are reviewed. Black-Right-Pointing-Pointer Matrix complexity and low amounts of analytes require effective sample treatments. Black-Right-Pointing-Pointer The published papers do not cover the study of all the substances allowed as UV filters. Black-Right-Pointing-Pointer New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of

  8. An overview of the analytical methods for the determination of organic ultraviolet filters in biological fluids and tissues

    International Nuclear Information System (INIS)

    Chisvert, Alberto; León-González, Zacarías; Tarazona, Isuha; Salvador, Amparo; Giokas, Dimosthenis

    2012-01-01

    Highlights: ► Papers describing the determination of UV filters in fluids and tissues are reviewed. ► Matrix complexity and low amounts of analytes require effective sample treatments. ► The published papers do not cover the study of all the substances allowed as UV filters. ► New analytical methods for UV filters determination in these matrices are encouraged. - Abstract: Organic UV filters are chemical compounds added to cosmetic sunscreen products in order to protect users from UV solar radiation. The need of broad-spectrum protection to avoid the deleterious effects of solar radiation has triggered a trend in the cosmetic market of including these compounds not only in those exclusively designed for sun protection but also in all types of cosmetic products. Different studies have shown that organic UV filters can be absorbed through the skin after topical application, further metabolized in the body and eventually excreted or bioaccumulated. These percutaneous absorption processes may result in various adverse health effects, such as genotoxicity caused by the generation of free radicals, which can even lead to mutagenic or carcinogenic effects, and estrogenicity, which is associated with the endocrine disruption activity caused by some of these compounds. Due to the absence of official monitoring protocols, there is a demand for analytical methods that enable the determination of UV filters in biological fluids and tissues in order to retrieve more information regarding their behavior in the human body and thus encourage the development of safer cosmetic formulations. In view of this demand, there has recently been a noticeable increase in the development of sensitive and selective analytical methods for the determination of UV filters and their metabolites in biological fluids (i.e., urine, plasma, breast milk and semen) and tissues. The complexity of the biological matrix and the low concentration levels of these compounds inevitably impose sample

  9. Advancements in mass spectrometry for biological samples: Protein chemical cross-linking and metabolite analysis of plant tissues

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Adam [Iowa State Univ., Ames, IA (United States)

    2015-01-01

    This thesis presents work on advancements and applications of methodology for the analysis of biological samples using mass spectrometry. Included in this work are improvements to chemical cross-linking mass spectrometry (CXMS) for the study of protein structures and mass spectrometry imaging and quantitative analysis to study plant metabolites. Applications include using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to further explore metabolic heterogeneity in plant tissues and chemical interactions at the interface between plants and pests. Additional work was focused on developing liquid chromatography-mass spectrometry (LC-MS) methods to investigate metabolites associated with plant-pest interactions.

  10. Thulium fiber laser for the use in low-invasive endoscopic and robotic surgery of soft biological tissues

    Science.gov (United States)

    Michalska, M.; Brojek, W.; Rybak, Z.; Sznelewski, P.; Mamajek, M.; Gogler, S.; Swiderski, J.

    2016-12-01

    An all-fiber, diode-pumped, continuous-wave Tm3+-doped fiber laser operated at a wavelength of 1.94 μm was developed. 37.4 W of output power with a slope efficiency as high as 57% with respect to absorbed pump power at 790 nm was demonstrated. The laser output beam quality factor M2 was measured to be 1.2. The output beam was very stable with power fluctuations system is to be implemented as a scalpel for surgery of soft biological tissues.

  11. Dynamic model of thermal reaction of biological tissues to laser-induced fluorescence and photodynamic therapy.

    Science.gov (United States)

    Seteikin, Alexey Yu; Krasnikov, Ilya V; Drakaki, Eleni; Makropoulou, Mersini

    2013-07-01

    The aim of this work was to evaluate the temperature fields and the dynamics of heat conduction into the skin tissue under several laser irradiation conditions with both a pulsed ultraviolet (UV) laser (λ=337  nm) and a continuous-wave (cw) visible laser beam (λ=632.8  nm) using Monte Carlo modeling. Finite-element methodology was used for heat transfer simulation. The analysis of the results showed that heat is not localized on the surface, but is collected inside the tissue in lower skin layers. The simulation was made with the pulsed UV laser beam (used as excitation source in laser-induced fluorescence) and the cw visible laser (used in photodynamic therapy treatments), in order to study the possible thermal effects.

  12. Nonlinearity parameter B/A of biological tissue ultrasound imaging in echo mode

    Energy Technology Data Exchange (ETDEWEB)

    Toulemonde, M., E-mail: matthieu.toulemonde@creatis.univ-lyon1.fr; Varray, F.; Bernard, A.; Basset, O.; Cachard, C. [Université de Lyon, CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Université Claude Bernard Lyon 1 (France)

    2015-10-28

    The nonlinearity B/A parameter influences the distortion of ultrasound waves during their propagation in tissue. Normal and pathological media have different B/A values and this parameter may be used to characterize them. In this paper the multitaper coherent plane wave compounding (MCPWC) is combined with the extended comparative method (ECM) to estimate the B/A parameter in simulation and acquisition. Using plane wave transmission and orthogonal apodization during beam forming improves the B/A estimation and delineation.

  13. Long-term luminescence of organic dyes in cells of biological tissues

    Science.gov (United States)

    Letuta, S. N.; Maryakhina, V. S.; Pashkevich, S. N.; Rakhmatullin, R. R.

    2011-01-01

    We studied the kinetics of delayed fluorescence and phosphoresce of exogenous fluorophores in cells extracted from tumorous and normal tissues of the mammary gland of mice of the BYRB strain. We revealed the specifics and determined regularities of the kinetics of long-term luminescence of fluorophores in different cells. The possibility of developing of a method for the early fluorescence diagnostics of the pathology of biotissues based on the obtained results is discussed.

  14. Tracing overlapping biological signals in mid-infrared using colonic tissues as a model system

    OpenAIRE

    Sahu, Ranjit Kumar; Salman, Ahmad; Mordechai, Shaul

    2017-01-01

    AIM To understand the interference of carbohydrates absorbance in nucleic acids signals during diagnosis of malignancy using Fourier transform infrared (FTIR) spectroscopy. METHODS We used formalin fixed paraffin embedded colonic tissues to obtain infrared (IR) spectra in the mid IR region using a bruker II IR microscope with a facility for varying the measurement area by varying the aperture available. Following this procedure we could measure different regions of the crypt circles containin...

  15. Towards biologically relevant synthetic designer matrices in 3D bioprinting for tissue engineering and regenerative medicine

    KAUST Repository

    Costa, Rúben M.

    2017-05-12

    3D bioprinting is one of the most promising technologies in tissue engineering and regenerative medicine. As new printing techniques and bioinks are getting developed, new cellular constructs with high resolution and functionality arise. Different to bioinks of animal, algal or plant origin, synthesized bioinks are proposed as superior biomaterials because their characteristics are fully under control. In this review, we will highlight the potential of synthetic biomaterials to be used as bioinks in 3D bioprinting to produce functionally enhanced matrices.

  16. Sensing Lanthanide Metal Content in Biological Tissues with Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Mark D. Pagel

    2013-10-01

    Full Text Available The development and validation of MRI contrast agents consisting of a lanthanide chelate often requires a determination of the concentration of the agent in ex vivo tissue. We have developed a protocol that uses 70% nitric acid to completely digest tissue samples that contain Gd(III, Dy(III, Tm(III, Eu(III, or Yb(III ions, or the MRI contrast agent gadodiamide. NMR spectroscopy of coaxial tubes containing a digested sample and a separate control solution of nitric acid was used to rapidly and easily measure the bulk magnetic susceptibility (BMS shift caused by each lanthanide ion and gadodiamide. Each BMS shift was shown to be linearly correlated with the concentration of each lanthanide ion and gadodiamide in the 70% nitric acid solution and in digested rat kidney and liver tissues. These concentration measurements had outstanding precision, and also had good accuracy for concentrations ³10 mM for Tm(III Eu(III, and Yb(III, and ³3 mM for Gd(III, gadodiamide, and Dy(III. Improved sample handling methods are needed to improve measurement accuracy for samples with lower concentrations.

  17. Regular character of chromatin degradation in lymphoid tissues after treatment with biological alkylating agents in vivo

    International Nuclear Information System (INIS)

    Matyasova, J.; Skalka, M.; Cejkova, M.

    1979-01-01

    The chromatin changes are reevaluated occurring in lymphoid tissues of mice treated with alkylating agents of the nitrogen-mustard type in relation to recent evidence on the nucleosomal organization of chromatin and to our new data on the regular character of chromatin degradation in lymphoid tissues of irradiated mice. DNA was isolated from nuclei at various intervals (1 to 18 h) after treatment of mice and subjected to gel electrophoresis in polyacrylamide gels. Thymus chromatin from treated mice has been shown to degrade in a regular fashion and to yield discrete DNA fragments, resembling those that originate in lymphoid tissues of irradiated mice or in thymus nuclei digested with micrococcal nuclease in vitro. With increasing interval after treatment higher amounts of smaller DNA fragments appear. Chromatin in spleen cells responds to treatment in a similar way, whilst no degradation in vivo takes place in liver chromatin. Chromatin of LS/BL lymphosarcoma cells in mice treated with alkylating agents or with irradiation suffers from a similar regular degradation. The results stress the significance of the action of liberated or activated endogenous nuclease(s) in the development of chromatin damage in lymphoid cells after treatment with alkylating agents. (author)

  18. Retention of the metabolized trace elements in biological tissues following different drying procedures. I

    International Nuclear Information System (INIS)

    Iyengar, G.V.; Kasperek, K.; Feinendegen, L.E.

    1978-01-01

    Loss of Sb, Co, I, Hg, Se and Zn during freeze-drying and oven-drying at 80, 105 and 120 0 C were studied in rat tissues that contained metabolized radioactive isotopes. No loss was observed for any of the 6 elements on freeze-drying. However, tissue-specific differences were observed in many cases for Hg, Se, I and Sb on oven-drying. A significant loss of Hg was observed in liver even at 80 0 C, and for brain at 105 0 C. Se was lost from whole blood, brain, lung and muscle at 120 0 C, Sb was lost from whole blood at 105 0 C, but from brain, kidney, lung and spleen at 120 0 C. Iodine was also lost from whole blood, kidney, blood serum, erythrocytes, brain, lung and muscle at 120 0 C. Although the losses were statistically significant, they remained in most cases between 2 and 10% with the exception of Hg at 120 0 C, where the losses in some of the tissues were unpredictable. For urine, freeze-drying and oven-drying at 80 0 C was found to be relatively safe for Hg and I. At 105 0 C and above, serious loss of Hg was observed. In this experiment, the elements Zn, Co, Sb and Se were not studied for urine. (Auth

  19. In Vitro Biological Evaluation of Electrospun Polycaprolactone/Gelatine Nanofibrous Scaffold for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Mim Mim Lim

    2015-01-01

    Full Text Available The fabrication of biocompatible and biodegradable scaffolds which mimic the native extracellular matrix of tissues to promote cell adhesion and growth is emphasized recently. Many polymers have been utilized in scaffold fabrication, but there is still a need to fabricate hydrophilic nanosized fibrous scaffolds with an appropriate degradation rate for skin tissue engineering applications. In this study, nanofibrous scaffolds of a biodegradable synthetic polymer, polycaprolactone (PCL, and blends of PCL with a natural polymer, gelatine (Ge, in three different compositions: 85 : 15, 70 : 30, and 50 : 50 were fabricated via an electrospinning technique. The nanofibrous scaffold prepared from 14% w/v PCL/Ge (70 : 30 exhibited more balanced properties of homogeneous nanofibres with an average fibre diameter of 155.60 ± 41.13 nm, 83% porosity, and surface roughness of 176.27 ± 2.53 nm. In vitro cell culture study using human skin fibroblasts (HSF demonstrated improved cell attachment with a flattened morphology on the PCL/Ge (70 : 30 nanofibrous scaffold and accelerated proliferation on day 3 compared to the PCL nanofibrous scaffold. These results show that the PCL/Ge (70 : 30 nanofibrous scaffold was more favourable and has the potential to be a promising scaffold for skin tissue engineering applications.

  20. Adaptive optics via pupil segmentation for high-resolution imaging in biological tissues.

    Science.gov (United States)

    Ji, Na; Milkie, Daniel E; Betzig, Eric

    2010-02-01

    Biological specimens are rife with optical inhomogeneities that seriously degrade imaging performance under all but the most ideal conditions. Measuring and then correcting for these inhomogeneities is the province of adaptive optics. Here we introduce an approach to adaptive optics in microscopy wherein the rear pupil of an objective lens is segmented into subregions, and light is directed individually to each subregion to measure, by image shift, the deflection faced by each group of rays as they emerge from the objective and travel through the specimen toward the focus. Applying our method to two-photon microscopy, we could recover near-diffraction-limited performance from a variety of biological and nonbiological samples exhibiting aberrations large or small and smoothly varying or abruptly changing. In particular, results from fixed mouse cortical slices illustrate our ability to improve signal and resolution to depths of 400 microm.

  1. Biological safety and tissue distribution of (16-mercaptohexadecyl) trimethylammonium bromide-modified cationic gold nanorods

    Czech Academy of Sciences Publication Activity Database

    Žárská, Monika; Šrámek, Michal; Novotný, Filip; Havel, Filip; Babelova, A.; Mrázková, Blanka; Benada, Oldřich; Reiniš, Milan; Štěpánek, Ivan; Musílek, K.; Bartek, Jiří; Ursinyova, M.; Novák, Ondřej; Dzijak, Rastislav; Kuca, K.; Proška, J.; Hodný, Zdeněk

    2018-01-01

    Roč. 154 (2018), s. 275-290 ISSN 0142-9612 R&D Projects: GA ČR GA16-13967S; GA MŠk(CZ) LO1509; GA MŠk(CZ) LM2015062; GA MŠk LO1419 Institutional support: RVO:68378050 ; RVO:61388971 ; RVO:68378041 Keywords : Genotoxicity * Autophagy * Lysosomal stress * Spleen * Thrombocytes * Plasmonic photothermal effect Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.402, year: 2016

  2. A comparison of sample preparation strategies for biological tissues and subsequent trace element analysis using LA-ICP-MS.

    Science.gov (United States)

    Bonta, Maximilian; Török, Szilvia; Hegedus, Balazs; Döme, Balazs; Limbeck, Andreas

    2017-03-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is one of the most commonly applied methods for lateral trace element distribution analysis in medical studies. Many improvements of the technique regarding quantification and achievable lateral resolution have been achieved in the last years. Nevertheless, sample preparation is also of major importance and the optimal sample preparation strategy still has not been defined. While conventional histology knows a number of sample pre-treatment strategies, little is known about the effect of these approaches on the lateral distributions of elements and/or their quantities in tissues. The technique of formalin fixation and paraffin embedding (FFPE) has emerged as the gold standard in tissue preparation. However, the potential use for elemental distribution studies is questionable due to a large number of sample preparation steps. In this work, LA-ICP-MS was used to examine the applicability of the FFPE sample preparation approach for elemental distribution studies. Qualitative elemental distributions as well as quantitative concentrations in cryo-cut tissues as well as FFPE samples were compared. Results showed that some metals (especially Na and K) are severely affected by the FFPE process, whereas others (e.g., Mn, Ni) are less influenced. Based on these results, a general recommendation can be given: FFPE samples are completely unsuitable for the analysis of alkaline metals. When analyzing transition metals, FFPE samples can give comparable results to snap-frozen tissues. Graphical abstract Sample preparation strategies for biological tissues are compared with regard to the elemental distributions and average trace element concentrations.

  3. Development of an algorithm for quantifying extremity biological tissue; Desenvolvimento de um algoritmo quantificador de tecido biologico de extremidade

    Energy Technology Data Exchange (ETDEWEB)

    Pavan, Ana L.M.; Miranda, Jose R.A., E-mail: analuiza@ibb.unesp.br, E-mail: jmiranda@ibb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (IBB/UNESP), Botucatu, SP (Brazil). Instituto de Biociencias. Dept. de Fisica e Biofisica; Pina, Diana R. de, E-mail: drpina@frnb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (FMB/UNESP), Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicas e Diagnostico por Imagem

    2013-07-01

    The computerized radiology (CR) has become the most widely used device for image acquisition and production, since its introduction in the 80s. The detection and early diagnosis, obtained via CR, are important for the successful treatment of diseases such as arthritis, metabolic bone diseases, tumors, infections and fractures. However, the standards used for optimization of these images are based on international protocols. Therefore, it is necessary to compose radiographic techniques for CR system that provides a secure medical diagnosis, with doses as low as reasonably achievable. To this end, the aim of this work is to develop a quantifier algorithm of tissue, allowing the construction of a homogeneous end used phantom to compose such techniques. It was developed a database of computed tomography images of hand and wrist of adult patients. Using the Matlab Registered-Sign software, was developed a computational algorithm able to quantify the average thickness of soft tissue and bones present in the anatomical region under study, as well as the corresponding thickness in simulators materials (aluminium and lucite). This was possible through the application of mask and Gaussian removal technique of histograms. As a result, was obtained an average thickness of soft tissue of 18,97 mm and bone tissue of 6,15 mm, and their equivalents in materials simulators of 23,87 mm of acrylic and 1,07mm of aluminum. The results obtained agreed with the medium thickness of biological tissues of a patient's hand pattern, enabling the construction of an homogeneous phantom.

  4. Determination of the scattering coefficient of biological tissue considering the wavelength and absorption dependence of the anisotropy factor

    Science.gov (United States)

    Fukutomi, Daichi; Ishii, Katsunori; Awazu, Kunio

    2016-04-01

    The anisotropy factor g, one of the optical properties of biological tissues, has a strong influence on the calculation of the scattering coefficient μ s in inverse Monte Carlo (iMC) simulations. It has been reported that g has the wavelength and absorption dependence; however, few attempts have been made to calculate μ s using g values by taking the wavelength and absorption dependence into account. In this study, the angular distributions of scattered light for biological tissue phantoms containing hemoglobin as a light absorber were measured by a goniometric optical setup at strongly (405 nm) and weakly (664 nm) absorbing wavelengths to obtain g. Subsequently, the optical properties were calculated with the measured values of g by integrating sphere measurements and an iMC simulation, and compared with the results obtained with a conventional g value of 0.9. The μ s values with measured g were overestimated at the strongly absorbing wavelength, but underestimated at the weakly absorbing wavelength if 0.9 was used in the iMC simulation.

  5. Reusable bi-directional 3ω sensor to measure thermal conductivity of 100-μm thick biological tissues.

    Science.gov (United States)

    Lubner, Sean D; Choi, Jeunghwan; Wehmeyer, Geoff; Waag, Bastian; Mishra, Vivek; Natesan, Harishankar; Bischof, John C; Dames, Chris

    2015-01-01

    Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method-widely used for rigid, inorganic solids-as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used "boundary mismatch approximation" of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from -69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.

  6. Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/chitosan/carboxymethyl cellulose for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Chengdong Xiong

    2009-07-01

    Full Text Available Abstract In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl cellulose, namely, n-HA/CS/CMC, which was prepared by freeze-drying method. The physico-chemical properties of n-HA/CS/CMC scaffold were tested by infrared absorption spectra (IR, transmission electron microscope(TEM, scanning electron microscope(SEM, universal material testing machine and phosphate buffer solution (PBS soaking experiment. Besides, the biological properties were evaluated by MG63 cells and Mesenchymal stem cells (MSCs culture experiment in vitro and a short period implantation study in vivo. The results show that the composite scaffold is mainly formed through the ionic crossing-linking of the two polyions between CS and CMC, and n-HA is incorporated into the polyelectrolyte matrix of CS-CMC without agglomeration, which endows the scaffold with good physico-chemical properties such as highly interconnected porous structure, high compressive strength and good structural stability and degradation. More important, the results of cells attached, proliferated on the scaffold indicate that the scaffold is non-toxic and has good cell biocompatibility, and the results of implantation experiment in vivo further confirm that the scaffold has good tissue biocompatibility. All the above results suggest that the novel degradable n-HA/CS/CMC composite scaffold has a great potential to be used as bone tissue engineering material.

  7. The Determination of Trace Metals in Saline Waters and Biological Tissues Using the Heated Graphite Atomizer

    Science.gov (United States)

    Segar, D. A.

    1971-01-01

    A selective, volatalization technique utilizing the heated graphite atomizer atomic absorption technique has been developed for the analysis of iron in sea water. A similar technique may be used to determine vanadium, copper, nickel and cobalt in saline waters when their concentrations are higher than those normally encountered'in unpolluted sea waters. A preliminary solvent extraction using ammonium pyrolidine dithiocarbamate and methyl iso-butyl ketone permits the determination of a number of elements including iron, copper, zinc, nickel, cobalt and lead in sea water. The heated graphite atomized technique has also been applied to the determination of a range of trace transition elements in marine plant and animal tissues.

  8. Accuracy of identification of tissue types in endoscopic esophageal mucosal biopsies used for molecular biology studies

    Directory of Open Access Journals (Sweden)

    Plauto Beck

    2009-02-01

    Full Text Available Plauto Beck1, George C Mayne1, David Astill2, Tanya Irvine1, David I Watson1, Willem A Dijckmeester1, Bas PL Wijnhoven1, Damian J Hussey11Department of Surgery, 2Department of Anatomical Pathology, Flinders University, Flinders Medical Centre, Bedford Park, South Australia, AustraliaObjectives: To determine if histopathologic assessment of esophageal biopsies harvested for research study is justified due to the heterogeneity of tissues in the esophagus, and the consequent histopathologic mis-matches with the clinical histopathology of biopsies taken at the same level.Methods: Since 2004, patients undergoing upper endoscopy for a variety of clinical conditions were invited to provide additional esophageal biopsies; those were collected for research purpose at the same level as biopsies collected for clinical histopathology. Research biopsies were cut in two parts: one part was submitted to research histopathology and the other stored for molecular analysis. Results of clinical histopathology for each patient were summarized per biopsy level and compared to results obtained from research biopsies at the corresponding level.Results: A total of 377 level summaries were obtained from 137 patients. Clinical histopathology summaries classified 123 levels (32.6% as squamous epithelium, 84 levels (22.3% as metaplastic columnar-lined epithelium, 135 levels (35.8% as columnar-lined epithelium with intestinal metaplasia, 30 levels (8% as dysplasia, and 5 levels (1.3% as adenocarcinoma. Research histopathology matched to clinical summaries on 120 of 123 (97.5% levels for squamous epithelium, 52 of 84 (61.9% for metaplastic columnar-lined epithelium, and 94 of 135 (69.5% for columnar-lined epithelium with intestinal metaplasia. There were no matches for dysplasia between the groups; however, they agreed on all five cases of AC. On 59 (70.2% metaplastic columnar-lined epithelium levels and on 62 (46% columnar-lined epithelium with intestinal metaplasia levels

  9. Cellular and molecular effects of n–3 polyunsaturated fatty acids on adipose tissue biology and metabolism

    Czech Academy of Sciences Publication Activity Database

    Flachs, Pavel; Rossmeisl, Martin; Bryhn, M.; Kopecký, Jan

    2009-01-01

    Roč. 116, č. 1 (2009), s. 1-16 ISSN 0143-5221 R&D Projects: GA ČR(CZ) GA303/05/2580; GA MŠk(CZ) 1M0520 Grant - others:EC(XE) LSHM-CT-2004-005272; EC(XE) FOOD-CT-2005-007036; EC(XE) COST FA0602; EC(XE) COST BM0602 Institutional research plan: CEZ:AV0Z50110509 Keywords : n-3 PUFA * DHA * adipose tissue Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.982, year: 2009

  10. COMPARATIVE ANALYSIS OF KIRLIANOGRAFIIA IMAGES GLOW OF BIOLOGICAL TISSUES WITH BIOCHEMICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    L. A. Pisotska

    2015-12-01

    the investigated samples. For kirlianograficeskih studies used an experimental device, RIVERS 1, developed by Ukrainian Scientific Research Institute of mechanical engineering technologies (Dnepropetrovsk. For mathematical processing of results using Matlab program. The growing shortage of ATP causes the breach and termination of ion exchange, increases reactive oxygen generation, lipid peroxidation destroys cell membranes. The process of self digestion (autoliza tissue tendons, as shown by the results of the experiments, had cyclical changes metabolism enzyme activity (ALT, carbohydrate (LDH, nucleotides, of total protein and micronutrients.

  11. Nanoelectronics-biology frontier: From nanoscopic probes for action potential recording in live cells to three-dimensional cyborg tissues.

    Science.gov (United States)

    Duan, Xiaojie; Fu, Tian-Ming; Liu, Jia; Lieber, Charles M

    2013-08-01

    Semiconductor nanowires configured as the active channels of field-effect transistors (FETs) have been used as detectors for high-resolution electrical recording from single live cells, cell networks, tissues and organs. Extracellular measurements with substrate supported silicon nanowire (SiNW) FETs, which have projected active areas orders of magnitude smaller than conventional microfabricated multielectrode arrays (MEAs) and planar FETs, recorded action potential and field potential signals with high signal-to-noise ratio and temporal resolution from cultured neurons, cultured cardiomyocytes, acute brain slices and whole animal hearts. Measurements made with modulation-doped nanoscale active channel SiNW FETs demonstrate that signals recorded from cardiomyocytes are highly localized and have improved time resolution compared to larger planar detectors. In addition, several novel three-dimensional (3D) transistor probes, which were realized using advanced nanowire synthesis methods, have been implemented for intracellular recording. These novel probes include (i) flexible 3D kinked nanowire FETs, (ii) branched intracellular nanotube SiNW FETs, and (iii) active silicon nanotube FETs. Following phospholipid modification of the probes to mimic the cell membrane, the kinked nanowire, branched intracellular nanotube and active silicon nanotube FET probes recorded full-amplitude intracellular action potentials from spontaneously firing cardiomyocytes. Moreover, these probes demonstrated the capability of reversible, stable, and long-term intracellular recording, thus indicating the minimal invasiveness of the new nanoscale structures and suggesting biomimetic internalization via the phospholipid modification. Simultaneous, multi-site intracellular recording from both single cells and cell networks were also readily achieved by interfacing independently addressable nanoprobe devices with cells. Finally, electronic and biological systems have been seamlessly merged in 3D

  12. A comparative examination of sample treatment procedures for ICAP-AES analysis of biological tissue

    Science.gov (United States)

    De Boer, J. L. M.; Maessen, F. J. M. J.

    The objective of this study was to contribute to the evaluation of existing sample preparation procedures for ICAP-AES analysis of biological material. Performance characteristics were established of current digestion procedures comprising extraction, solubilization, pressure digestion, and wet and dry ashing methods. Apart from accuracy and precision, a number of criteria of special interest for the analytical practice was applied. As a test sample served SRM bovine liver. In this material six elements were simultaneously determined. Results showed that every procedure has its defects and advantages. Hence, unambiguous recommendation of standard digestion procedures can be made only when taking into account the specific analytical problem.

  13. Biological effects of Naja haje crude venom on the hepatic and renal tissues of mice

    Directory of Open Access Journals (Sweden)

    Amany A. Tohamy

    2014-07-01

    Full Text Available Snake venoms are known to cause different metabolic disorders, altering cellular and enzymatic activities in animals and releasing pharmacological substances. In this study, the lethality as well as biochemical and histopathological effect of Egyptian cobra (Naja haje; N. haje crude venom at a sublethal dose have been investigated on liver and kidney of male mice. Venom injected intramuscularly in mice with 1/2 LD50 (approximately 0.0115 μg/g body weight of mice and the animals were sacrificed 6 days post injection. Results indicated that the injection of crude venom of the N. haje induced a significant disturbance in liver and kidney functions. In addition, results revealed that N. haje venom has a potent oxidative activity by increasing the level of reactive oxygen species with concomitant significant increase in hydrogen peroxide, lipid peroxidation, carbonyl protein and nitric oxide levels in hepatic and renal tissues. This activity was extended to decrease non-enzymatic and enzymatic antioxidant defense components such as glutathione, superoxide dismutase and catalase. Additionally, the biochemical alternations induced in hepatic and renal tissues were associated with significant alternations in the histological architecture of liver and kidney of injected mice. From this study, we can conclude that such injury could be considered among the factors that lead to death caused by N. haje venom.

  14. Human biological sample biobanking to support tissue biomarkers in pharmaceutical research and development.

    Science.gov (United States)

    Womack, Christopher; Mager, S Rachel

    2014-11-01

    Advances in the understanding of molecular pathology and thereby the mechanisms that could be amenable to therapeutic manipulation are the reason that pharmaceutical research and development is focused increasingly on measurement of molecular biomarkers in human biological samples. Obtaining direct or indirect access to sufficient samples that are fit for research purposes can be a major challenge. A biobanking infrastructure has a significant role in the acquisition, storage and usage of human biological samples and here we review some key requirements for establishing a biobank. These include ensuring; that appropriate governance mechanisms are in place, that samples available are appropriate and fit for the intended research purposes that the infrastructure is sustainable in the future and that use of the biobank assets meets the strategic aims of the host organisation. Finally we present a case study--the STRATUM project which has recently completed and through a collaborative approach involving six industry and public partners drawing on a network of experts, examined biobank policies, public attitudes to biobanking, donor consent, sample and data standards, technical requirements for a register and biobanking financial models, albeit from a UK perspective. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Biological N2 fixation mainly controlled by Sphagnum tissue N:P ratio in ombrotrophic bogs

    Science.gov (United States)

    Zivkovic, Tatjana; Moore, Tim R.

    2017-04-01

    Most of the 18 Pg nitrogen (N) accumulated in northern nutrient-poor and Sphagnum-dominated peatlands (bogs and fens) can be attributed to N2-fixation by diazotrophs either associated with the live Sphagnum or non-symbiotically in the deeper peat such as through methane consumption close to the water table. Where atmospheric N deposition is low (Sphagnum, suggested by the increase in tissue N:P to >16. It is unclear how Sphagnum-hosted diazotrophic activity may be affected by N deposition and thus changes in N:P ratio. First, we investigated the effects of long-term addition of different sources of nitrogen (0, 1.6, 3.2 and 6.4 g N m-2 y-1as NH4Cl and NaNO3), and phosphorus (5 g P m-2 y-1as KH2PO4) on Sphagnum nutrient status (N, P and N:P ratio), net primary productivity (NPP) and Sphagnum-associated N2fixation at Mer Bleue, a temperate ombrotrophic bog. We show that N concentration in Sphagnum tissue increased with larger rates of N addition, with a stronger effect on Sphagnum from NH4 than NO3. The addition of P created a 3.5 fold increase in Sphagnum P content compared to controls. Sphagnum NPP decreased linearly with the rise in N:P ratio, while linear growth declined exponentially with increase in Sphagnum N content. Rates of N2-fixation determined in the laboratory significantly decreased in response to even the smallest addition of both N species. In contrast, the addition of P increased N2 fixation by up to 100 times compared to N treatments and up to 5-30 times compared to controls. The change in N2-fixation was best modeled by the N:P ratio, across all experimental treatments. Secondly, to test the role of N:P ratio on N2-fixation across a range of bogs, eight study sites along the latitudinal gradient from temperate, boreal to subarctic zone in eastern Canada were selected. From each bog, two predominant microptopographies, hummocks and hollows, were tested for both N2-fixation activity in the laboratory and Sphagnum tissue concentrations of N, P and N

  16. Thermal Damage Analysis in Biological Tissues Under Optical Irradiation: Application to the Skin

    Science.gov (United States)

    Fanjul-Vélez, Félix; Ortega-Quijano, Noé; Solana-Quirós, José Ramón; Arce-Diego, José Luis

    2009-07-01

    The use of optical sources in medical praxis is increasing nowadays. In this study, different approaches using thermo-optical principles that allow us to predict thermal damage in irradiated tissues are analyzed. Optical propagation is studied by means of the radiation transport theory (RTT) equation, solved via a Monte Carlo analysis. Data obtained are included in a bio-heat equation, solved via a numerical finite difference approach. Optothermal properties are considered for the model to be accurate and reliable. Thermal distribution is calculated as a function of optical source parameters, mainly optical irradiance, wavelength and exposition time. Two thermal damage models, the cumulative equivalent minutes (CEM) 43 °C approach and the Arrhenius analysis, are used. The former is appropriate when dealing with dosimetry considerations at constant temperature. The latter is adequate to predict thermal damage with arbitrary temperature time dependence. Both models are applied and compared for the particular application of skin thermotherapy irradiation.

  17. Imaging cell size and permeability in biological tissue using the diffusion-time dependence of the apparent diffusion coefficient.

    Science.gov (United States)

    Dietrich, Olaf; Hubert, Alexander; Heiland, Sabine

    2014-06-21

    The purpose of this study was to analyze and evaluate a model of restricted water diffusion between equidistant permeable membranes for cell-size and permeability measurements in biological tissue. Based on the known probability distribution of diffusion distances after the diffusion time τ in a system of permeable membranes characterized by three parameters (membrane permeability P, membrane distance L, and free diffusivity D0), an equivalent dimensionless model was derived with a probability distribution characterized by only a single (dimensionless) tissue parameter [Formula: see text]. Evaluating this proposed model function, the dimensionless diffusion coefficient [Formula: see text] was numerically calculated for 60 values of the dimensionless diffusion time [Formula: see text] and 35 values of [Formula: see text]. Diffusion coefficients were measured in a carrot by diffusion-weighted magnetic resonance imaging (MRI) at 18 diffusion times between 9.9 and 1022.7 ms and fitted to the simulation results [Formula: see text] to determine L, P, and D0. The measured diffusivities followed the simulated dependence of [Formula: see text]. Determined cell sizes varied from 21 to 76 μm, permeabilities from 0.007 to 0.039 μm(-1), and the free diffusivities from 1354 to 1713 μm(2) s(-1). In conclusion, the proposed dimensionless tissue model can be used to determine tissue parameters (D0, L, P) based on diffusion MRI with multiple diffusion times. Measurements in a carrot showed a good agreement of the cell diameter, L, determined by diffusion MRI and by light microscopy.

  18. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil [and others

    2000-04-01

    Util now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline(triage) to be able to be treated the victims as fast as possible. We established the apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay.

  19. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    International Nuclear Information System (INIS)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil

    2000-04-01

    Util now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline(triage) to be able to be treated the victims as fast as possible. We established the apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay

  20. Modulation of tissue tropism and biological activity of exosomes and other extracellular vesicles: New nanotools for cancer treatment.

    Science.gov (United States)

    Kooijmans, Sander A A; Schiffelers, Raymond M; Zarovni, Natasa; Vago, Riccardo

    2016-09-01

    Exosomes are naturally secreted nanovesicles that have recently aroused a great interest in the scientific and clinical community for their roles in intercellular communication in almost all physiological and pathological processes. These 30-100nm sized vesicles are released from the cells into the extracellular space and ultimately into biofluids in a tightly regulated way. Their molecular composition reflects their cells of origin, may confer specific cell or tissue tropism and underlines their biological activity. Exosomes and other extracellular vesicles (EVs) carry specific sets of proteins, nucleic acids (DNA, mRNA and regulatory RNAs), lipids and metabolites that represent an appealing source of novel noninvasive markers through biofluid biopsies. Exosome-shuttled molecules maintain their biological activity and are capable of modulating and reprogramming recipient cells. This multi-faceted nature of exosomes hold great promise for improving cancer treatment featuring them as novel diagnostic sensors as well as therapeutic effectors and drug delivery vectors. Natural biological activity including the therapeutic payload and targeting behavior of EVs can be tuned via genetic and chemical engineering. In this review we describe the properties that EVs share with conventional synthetic nanoparticles, including size, liposome-like membrane bilayer with customizable surface, and multifunctional capacity. We also highlight unique characteristics of EVs, which possibly allow them to circumvent some limitations of synthetic nanoparticle systems and facilitate clinical translation. The latter are in particular correlated with their innate stability, ability to cross biological barriers, efficiently deliver bioactive cargos or evade immune recognition. Furthermore, we discuss the potential roles for EVs in diagnostics and theranostics, and highlight the challenges that still need to be overcome before EVs can be applied to routine clinical practice. Copyright © 2016

  1. Section of Atomic Collisions

    International Nuclear Information System (INIS)

    Berenyi, D.; Biri, S.; Gulyas, L.; Juhasz, Z.; Kover, A.; Orban, A.; Palinkas, J.; Papp, T.; Racz, R.; Ricz, S.

    2009-01-01

    emission from H 2 by fast ion impact; Fast electron ejection in slow and intermediate velocity ion-atom collisions: Fermi-shuttle type pingpong games in single ionization; Fragmentation of biologically relevant molecules in collisions with ions; Guiding of highly charged ions through insulating nanocapillaries; Theoretical description of the atomic collision processes. Summary: We hope that the present selection provides the reader with a flavor of the atomic collision physics research performed in our Section. It is seen that we have a strong interest in fundamental processes. It is also seen that the research work in the field is developing from the basic study of simple systems to different directions. One of them goes towards a deeper understanding of simple systems and fundamental processes. The other direction is the analysis of complex, sometimes strange phenomena, up to the study of mesoscopic effects governed by atomic collision processes. Moreover, new experimental facilities and possibilities (e.g., the availability of antiparticles) are always a challenge to start into a new direction. Finally, as our community gets better equipped for handling complex problems, we are turning to study systems, which are related to applied sciences and direct applications. We believe that these are all natural ways to find the future of the field of atomic collision physics.

  2. Generation of monoclonal antibodies and development of an immunofluorometric assay for the detection of CUZD1 in tissues and biological fluids.

    Science.gov (United States)

    Farkona, Sofia; Soosaipillai, Antoninus; Filippou, Panagiota; Korbakis, Dimitrios; Serra, Stefano; Rückert, Felix; Diamandis, Eleftherios P; Blasutig, Ivan M

    2017-12-01

    CUB and zona pellucida-like domain-containing protein 1 (CUZD1) was identified as a pancreas-specific protein and was proposed as a candidate biomarker for pancreatic related disorders. CUZD1 protein levels in tissues and biological fluids have not been extensively examined. The purpose of the present study was to generate specific antibodies targeting CUZD1 to assess CUZD1 expression within tissues and biological fluids. Mouse monoclonal antibodies against CUZD1 were generated and used to perform immunohistochemical analyses and to develop a sensitive and specific enzyme-linked immunosorbent assay (ELISA). CUZD1 protein expression was assessed in various human tissue extracts and biological fluids and in gel filtration chromatography-derived fractions of pancreatic tissue extract, pancreatic juice and recombinant protein. Immunohistochemical staining of CUZD1 in pancreatic tissue showed that the protein is localized to the acinar cells and the lumen of the acini. Western blot analysis detected the protein in pancreatic tissue extract and pancreatic juice. The newly developed ELISA measured CUZD1 in high levels in pancreas and in much lower but detectable levels in several other tissues. In the biological fluids tested, CUZD1 expression was detected exclusively in pancreatic juice. The analysis of gel filtration chromatography-derived fractions of pancreatic tissue extract, pancreatic juice and recombinant CUZD1 suggested that the protein exists in high molecular weight protein complexes. This study describes the development of tools targeting CUZD1 protein, its tissue expression pattern and levels in several biological fluids. These new tools will facilitate future investigations aiming to delineate the role of CUZD1 in physiology and pathobiology. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  3. Volatile Profiling of Aromatic Traditional Medicinal Plant, Polygonum minus in Different Tissues and Its Biological Activities

    Directory of Open Access Journals (Sweden)

    Rafidah Ahmad

    2014-11-01

    Full Text Available The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS. Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.

  4. Semi-Automated Needle Steering in Biological Tissue Using an Ultrasound-Based Deflection Predictor.

    Science.gov (United States)

    Khadem, Mohsen; Rossa, Carlos; Usmani, Nawaid; Sloboda, Ron S; Tavakoli, Mahdi

    2017-04-01

    The performance of needle-based interventions depends on the accuracy of needle tip positioning. Here, a novel needle steering strategy is proposed that enhances accuracy of needle steering. In our approach the surgeon is in charge of needle insertion to ensure the safety of operation, while the needle tip bevel location is robotically controlled to minimize the targeting error. The system has two main components: (1) a real-time predictor for estimating future needle deflection as it is steered inside soft tissue, and (2) an online motion planner that calculates control decisions and steers the needle toward the target by iterative optimization of the needle deflection predictions. The predictor uses the ultrasound-based curvature information to estimate the needle deflection. Given the specification of anatomical obstacles and a target from preoperative images, the motion planner uses the deflection predictions to estimate control actions, i.e., the depth(s) at which the needle should be rotated to reach the target. Ex-vivo needle insertions are performed with and without obstacle to validate our approach. The results demonstrate the needle steering strategy guides the needle to the targets with a maximum error of 1.22 mm.

  5. Effects of alginate hydrogel cross-linking density on mechanical and biological behaviors for tissue engineering.

    Science.gov (United States)

    Jang, Jinah; Seol, Young-Joon; Kim, Hyeon Ji; Kundu, Joydip; Kim, Sung Won; Cho, Dong-Woo

    2014-09-01

    An effective cross-linking of alginate gel was made through reaction with calcium carbonate (CaCO3). We used human chondrocytes as a model cell to study the effects of cross-linking density. Three different pore size ranges of cross-linked alginate hydrogels were fabricated. The morphological, mechanical, and rheological properties of various alginate hydrogels were characterized and responses of biosynthesis of cells encapsulated in each gel to the variation in cross-linking density were investigated. Desired outer shape of structure was maintained when the alginate solution was cross-linked with the applied method. The properties of alginate hydrogel could be tailored through applying various concentrations of CaCO3. The rate of synthesized GAGs and collagens was significantly higher in human chondrocytes encapsulated in the smaller pore structure than that in the larger pore structure. The expression of chondrogenic markers, including collagen type II and aggrecan, was enhanced in the smaller pore structure. It was found that proper structural morphology is a critical factor to enhance the performance and tissue regeneration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Volatile profiling of aromatic traditional medicinal plant, Polygonum minus in different tissues and its biological activities.

    Science.gov (United States)

    Ahmad, Rafidah; Baharum, Syarul Nataqain; Bunawan, Hamidun; Lee, Minki; Mohd Noor, Normah; Rohani, Emelda Roseleena; Ilias, Norashikin; Zin, Noraziah Mohamad

    2014-11-20

    The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots) of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME) and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol) extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane) showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus.

  7. Biology of soft tissue wound healing and regeneration--consensus report of Group 1 of the 10th European Workshop on Periodontology.

    Science.gov (United States)

    Hämmerle, Christoph H F; Giannobile, William V

    2014-04-01

    The scope of this consensus was to review the biological processes of soft tissue wound healing in the oral cavity and to histologically evaluate soft tissue healing in clinical and pre-clinical models. To review the current knowledge regarding the biological processes of soft tissue wound healing at teeth, implants and on the edentulous ridge. Furthermore, to review soft tissue wound healing at these sites, when using barrier membranes, growth and differentiation factors and soft tissue substitutes. Searches of the literature with respect to recessions at teeth and soft tissue deficiencies at implants, augmentation of the area of keratinized tissue and soft tissue volume were conducted. The available evidence was collected, categorized and summarized. Oral mucosal and skin wound healing follow a similar pattern of the four phases of haemostasis, inflammation, proliferation and maturation/matrix remodelling. The soft connective tissue determines the characteristics of the overlaying oral epithelium. Within 7-14 days, epithelial healing of surgical wounds at teeth is completed. Soft tissue healing following surgery at implants requires 6-8 weeks for maturation. The resulting tissue resembles scar tissue. Well-designed pre-clinical studies providing histological data have been reported describing soft tissue wound healing, when using barrier membranes, growth and differentiation factors and soft tissue substitutes. Few controlled clinical studies with low numbers of patients are available for some of the treatments reviewed at teeth. Whereas, histological new attachment has been demonstrated in pre-clinical studies resulting from some of the treatments reviewed, human histological data commonly report a lack of new attachment but rather long junctional epithelial attachment and connective tissue adhesion. Regarding soft tissue healing at implants human data are very scarce. Oral soft tissue healing at teeth, implants and the edentulous ridge follows the same phases

  8. Nonlinear optical methods for the analysis of protein nanocrystals and biological tissues

    Science.gov (United States)

    Dow, Ximeng You

    Structural biology underpins rational drug design and fundamental understanding of protein function. X-ray diffraction (XRD) has been the golden standard for solving for high-resolution protein structure. Second harmonic generation (SHG) microscopy has been developed by the Simpson lab as a sensitive, crystal-specific detection method for the identification of protein crystal and help optimize the crystallization condition. Protein nanocrystals has been widely used for structure determination of membrane proteins in serial femtosecond nanocrystallography. In this thesis work, novel nonlinear optical methods were developed to address the challenges associated with the detection and characterization of protein nanocrystals. SHG-correlation spectroscopy (SHG-CS) was developed to take advantage of the diffusing motion and retrieve the size distribution and crystal quality of the nanocrystals. Polarization-dependent SHG imaging technique was developed to measure the relative orientation as well as the internal structure of the sample. Two photon- excited fluorescence has been used in the Simpson lab as a complementary measurement besides the inherent SHG signal from the crystals. A novel instrumentation development was also introduced in this thesis work to greatly improve the speed of fluorescence lifetime imaging (FLIM).

  9. The Molecular Biology of Soft-Tissue Sarcomas and Current Trends in Therapy

    Directory of Open Access Journals (Sweden)

    Jorge Quesada

    2012-01-01

    Full Text Available Basic research in sarcoma models has been fundamental in the discovery of scientific milestones leading to a better understanding of the molecular biology of cancer. Yet, clinical research in sarcoma has lagged behind other cancers because of the multiple clinical and pathological entities that characterize sarcomas and their rarity. Sarcomas encompass a very heterogeneous group of tumors with diverse pathological and clinical overlapping characteristics. Molecular testing has been fundamental in the identification and better definition of more specific entities among this vast array of malignancies. A group of sarcomas are distinguished by specific molecular aberrations such as somatic mutations, intergene deletions, gene amplifications, reciprocal translocations, and complex karyotypes. These and other discoveries have led to a better understanding of the growth signals and the molecular pathways involved in the development of these tumors. These findings are leading to treatment strategies currently under intense investigation. Disruption of the growth signals is being targeted with antagonistic antibodies, tyrosine kinase inhibitors, and inhibitors of several downstream molecules in diverse molecular pathways. Preliminary clinical trials, supported by solid basic research and strong preclinical evidence, promises a new era in the clinical management of these broad spectrum of malignant tumors.

  10. High-contrast FFT acousto-optical tomography of biological tissues with a frequency-chirped modulation of the ultrasound

    Science.gov (United States)

    Forget, Benoit C.; Atlan, Michael; Selb, Juliette; Pottier, Lionel; Ramaz, Francois; Boccara, Albert C.

    2003-06-01

    Although tumors can show important contrast in their optical properties at an early stage of development, they are difficult to image optically due the diffusive nature of biological tissues. Such tumors can also be detected by "classical" ultrasound (US) imaging, but the acoustic constrast is often weak at early stages. Acousto-optical (AO) imaging combines light and ultrasound : light carries the desired information and ultrasound provides the spatial resolution. Based on a previous work made by the group of L.V. Wang, we present AO images obtained with chirped US. This modulation of the US frequency allows to encode a spatial region of the medium in the frequency spectrum of the AO signal. We can then obtain the optical contrast along the US path with improved resolution. The technique was apply to the imaging of buried objects in phantoms and to the vizualization of the "virtual source".

  11. Application of a new MR Microscope using an Independent Console System (MRMICS) for biological tissues in vitro

    International Nuclear Information System (INIS)

    Yoshioka, Hiroshi; Anno, Izumi; Itai, Yuji; Haishi, Tomoyuki; Adachi, Naotaka; Kose, Katsumi

    1999-01-01

    We studied microscopic MR images of the normal appendix in vitro using a new MR microscope system: MR Microscope using an Independent Console System (MRMICS). The MRMICS was placed in the clinical MR room, and the probe box was fixed on the bed of the 1.5 T clinical MR machine. T1-, T2-, and proton density-weighted images were obtained using spin echo sequences with an in-plane pixel size of 100 x 100 μm. Zonal structures of the appendix were clearly demonstrated with different contrast by different sequences. Therefore, the MRMICS is a useful add-on system for investigating microscopic MR images of biological tissues in vitro. (author)

  12. Biology

    Indian Academy of Sciences (India)

    I am particularly happy that the Academy is bringing out this document by Professor M S. Valiathan on Ayurvedic Biology. It is an effort to place before the scientific community, especially that of India, the unique scientific opportunities that arise out of viewing Ayurveda from the perspective of contemporary science, its tools ...

  13. Time-resolved diffuse optical tomographic imaging for the provision of both anatomical and functional information about biological tissue

    Science.gov (United States)

    Zhao, Huijuan; Gao, Feng; Tanikawa, Yukari; Homma, Kazuhiro; Yamada, Yukio

    2005-04-01

    We present in vivo images of near-infrared (NIR) diffuse optical tomography (DOT) of human lower legs and forearm to validate the dual functions of a time-resolved (TR) NIR DOT in clinical diagnosis, i.e., to provide anatomical and functional information simultaneously. The NIR DOT system is composed of time-correlated single-photon-counting channels, and the image reconstruction algorithm is based on the modified generalized pulsed spectral technique, which effectively incorporates the TR data with reasonable computation time. The reconstructed scattering images of both the lower legs and the forearm revealed their anatomies, in which the bones were clearly distinguished from the muscles. In the absorption images, some of the blood vessels were observable. In the functional imaging, a subject was requested to do handgripping exercise to stimulate physiological changes in the forearm tissue. The images of oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentration changes in the forearm were obtained from the differential images of the absorption at three wavelengths between the exercise and the rest states, which were reconstructed with a differential imaging scheme. These images showed increases in both blood volume and oxyhemoglobin concentration in the arteries and simultaneously showed hypoxia in the corresponding muscles. All the results have demonstrated the capability of TR NIR DOT by reconstruction of the absolute images of the scattering and the absorption with a high spatial resolution that finally provided both the anatomical and functional information inside bulky biological tissues.

  14. Regulatory inhibition of biological tissue mineralization by calcium phosphate through post-nucleation shielding by fetuin-A

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Joshua C., E-mail: joshchang@ucla.edu [Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA and Mathematical Biosciences Institute, The Ohio State University, Columbus, Ohio 43210 (United States); Miura, Robert M., E-mail: miura@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

    2016-04-21

    In vertebrates, insufficient availability of calcium and inorganic phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are usually present at high concentrations throughout bodily fluids—at concentrations exceeding the saturation point. This condition leads to the opposite situation where unwanted mineral sedimentation may occur. Remarkably, ectopic or out-of-place sedimentation into soft tissues is rare, in spite of the thermodynamic driving factors. This fortunate fact is due to the presence of auto-regulatory proteins that are found in abundance in bodily fluids. Yet, many important inflammatory disorders such as atherosclerosis and osteoarthritis are associated with this undesired calcification. Hence, it is important to gain an understanding of the regulatory process and the conditions under which it can go awry. In this manuscript, we extend mean-field continuum classical nucleation theory of the growth of clusters to encompass surface shielding. We use this formulation to study the regulation of sedimentation of calcium phosphate salts in biological tissues through the mechanism of post-nuclear shielding of nascent mineral particles by binding proteins. We develop a mathematical description of this phenomenon using a countable system of hyperbolic partial differential equations. A critical concentration of regulatory protein is identified as a function of the physical parameters that describe the system.

  15. Application of synchrotron x-ray microbeam spectroscopy to the determination of metal distribution and speciation in biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Punshon, T.; Jackson, B.P.; Lanzirotti, A.; Hopkins, W.A.; Bertsch, P.M.; Burger, J. [Rutgers State University, Piscataway, NJ (United States). Division of Life Science

    2005-07-01

    Resolving the distribution and speciation of metal(loid)s within biological environmental samples is essential for understanding bioavailability, trophic transfer, and environmental risk. We used synchrotron x-ray microspectroscopy to analyze a range of samples that had been exposed to metal(loid) contamination. Microprobe x-ray fluorescence elemental mapping ({mu} SXRF) of decomposing rhizosphere microcosms consisting of Ni- and U-contaminated soil planted with wheat (Triticum aestivum) showed the change in Ni and U distribution over a 27-day period, with a progressive movement of U into decaying tissue. mu SXRF maps showed the micrometer-scale distribution of Ca, Mn, Fe, Ni, and U in roots of willow (Salix nigra L.) growing on a former radiological settling pond, with U located outside of the epidermis and Ni inside the cortex. X-ray computed tomography (CMT) of woody tissue of this same affected willow showed that small points of high Ni fluorescence observed previously are actually a Ni-rich substance contained within an individual xylem vessel. {mu} SXRF and x-ray absorption near-edge spectroscopy (XANES) linked the elevated Se concentrations in sediments of a coal fly ash settling pond with oral deformities of bullfrog tadpoles (Rana catesbeiana). Se distribution was localized within the deformed mouthparts, and with an oxidation state of Se (-II) consistent with organo-Se compounds, it suggests oral deformities are caused by incorporation of Se into proteins.

  16. FTIR microscopy of biological cells and tissue: data analysis using resonant Mie scattering (RMieS) EMSC algorithm.

    Science.gov (United States)

    Bassan, Paul; Sachdeva, Ashwin; Kohler, Achim; Hughes, Caryn; Henderson, Alex; Boyle, Jonathan; Shanks, Jonathan H; Brown, Michael; Clarke, Noel W; Gardner, Peter

    2012-03-21

    Transmission and transflection infrared microscopy of biological cells and tissue suffer from significant baseline distortions due to scattering effects, predominantly resonant Mie scattering (RMieS). This scattering can also distort peak shapes and apparent peak positions making interpretation difficult and often unreliable. A correction algorithm, the resonant Mie scattering extended multiplicative signal correction (RMieS-EMSC), has been developed that can be used to remove these distortions. The correction algorithm has two key user defined parameters that influence the accuracy of the correction. The first is the number of iterations used to obtain the best outcome. The second is the choice of the initial reference spectrum required for the fitting procedure. The choice of these parameters influences computational time. This is not a major concern when correcting individual spectra or small data sets of a few hundred spectra but becomes much more significant when correcting spectra from infrared images obtained using large focal plane array detectors which may contain tens of thousands of spectra. In this paper we show that, classification of images from tissue can be achieved easily with a few (<10) iterations but a reliable interpretation of the biochemical differences between classes could require more iterations. Regarding the choice of reference spectrum, it is apparent that the more similar it is to the pure absorption spectrum of the sample, the fewer iterations required to obtain an accurate corrected spectrum. Importantly however, we show that using three different non-ideal reference spectra, the same unique correction solution can be obtained.

  17. High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor

    Science.gov (United States)

    Liang, Xin M.; Sekar, Praveen K.; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

    2015-05-01

    An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to -40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments.

  18. High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor

    Science.gov (United States)

    Liang, Xin M.; Sekar, Praveen K.; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

    2015-01-01

    An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to –40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments. PMID:25993037

  19. Investigation of the soluble metals in tissue as biological response pattern to environmental pollutants (Gammarus fossarum example).

    Science.gov (United States)

    Filipović Marijić, Vlatka; Dragun, Zrinka; Sertić Perić, Mirela; Matoničkin Kepčija, Renata; Gulin, Vesna; Velki, Mirna; Ečimović, Sandra; Hackenberger, Branimir K; Erk, Marijana

    2016-07-01

    In the present study, Gammarus fossarum was used to investigate the bioaccumulation and toxic effects of aquatic pollutants in the real environmental conditions. The novelty of the study is the evaluation of soluble tissue metal concentrations in gammarids as indicators in early assessment of metal exposure. In the Sutla River, industrially/rurally/agriculturally influenced catchment in North-Western Croatia, physico-chemical water properties pointed to disturbed ecological status, which was reflected on population scale as more than 50 times lower gammarid density compared to the reference location, Črnomerec Stream. Significantly higher levels of soluble toxic metals (Al, As, Cd, Pb, Sb, Sn, Sr) were observed in gammarids from the Sutla River compared to the reference site and reflected the data on higher total dissolved metal levels in the river water at that site. The soluble metal estimates were supplemented with the common multibiomarker approach, which showed significant biological responses for decreased acetylcholinesterase activity and increased total soluble protein concentrations, confirming stressed environmental conditions for biota in the Sutla River. Biomarker of metal exposure, metallothionein, was not induced and therefore, toxic effect of metals was not confirmed on molecular level. Comparable between-site pattern of soluble toxic metals in gammarids and total dissolved metal levels in water suggests that prior to biomarker response and observed toxic impact, soluble metals in tissue might be used as early warning signs of metal impact in the aquatic environment and improve the assessment of water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Regulatory inhibition of biological tissue mineralization by calcium phosphate through post-nucleation shielding by fetuin-A

    Science.gov (United States)

    Chang, Joshua C.; Miura, Robert M.

    2016-04-01

    In vertebrates, insufficient availability of calcium and inorganic phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are usually present at high concentrations throughout bodily fluids—at concentrations exceeding the saturation point. This condition leads to the opposite situation where unwanted mineral sedimentation may occur. Remarkably, ectopic or out-of-place sedimentation into soft tissues is rare, in spite of the thermodynamic driving factors. This fortunate fact is due to the presence of auto-regulatory proteins that are found in abundance in bodily fluids. Yet, many important inflammatory disorders such as atherosclerosis and osteoarthritis are associated with this undesired calcification. Hence, it is important to gain an understanding of the regulatory process and the conditions under which it can go awry. In this manuscript, we extend mean-field continuum classical nucleation theory of the growth of clusters to encompass surface shielding. We use this formulation to study the regulation of sedimentation of calcium phosphate salts in biological tissues through the mechanism of post-nuclear shielding of nascent mineral particles by binding proteins. We develop a mathematical description of this phenomenon using a countable system of hyperbolic partial differential equations. A critical concentration of regulatory protein is identified as a function of the physical parameters that describe the system.

  1. High accuracy thermal conductivity measurement of aqueous cryoprotective agents and semi-rigid biological tissues using a microfabricated thermal sensor.

    Science.gov (United States)

    Liang, Xin M; Sekar, Praveen K; Zhao, Gang; Zhou, Xiaoming; Shu, Zhiquan; Huang, Zhongping; Ding, Weiping; Zhang, Qingchuan; Gao, Dayong

    2015-05-20

    An improved thermal-needle approach for accurate and fast measurement of thermal conductivity of aqueous and soft biomaterials was developed using microfabricated thermal conductivity sensors. This microscopic measuring device was comprehensively characterized at temperatures from 0 °C to 40 °C. Despite the previous belief, system calibration constant was observed to be highly temperature-dependent. Dynamic thermal conductivity response during cooling (40 °C to -40 °C) was observed using the miniaturized single tip sensor for various concentrations of CPAs, i.e., glycerol, ethylene glycol and dimethyl sulfoxide. Chicken breast, chicken skin, porcine limb, and bovine liver were assayed to investigate the effect of anatomical heterogeneity on thermal conductivity using the arrayed multi-tip sensor at 20 °C. Experimental results revealed distinctive differences in localized thermal conductivity, which suggests the use of approximated or constant property values is expected to bring about results with largely inflated uncertainties when investigating bio-heat transfer mechanisms and/or performing sophisticated thermal modeling with complex biological tissues. Overall, the presented micro thermal sensor with automated data analysis algorithm is a promising approach for direct thermal conductivity measurement of aqueous solutions and soft biomaterials and is of great value to cryopreservation of tissues, hyperthermia or cryogenic, and other thermal-based clinical diagnostics and treatments.

  2. Characterization of mechanical and biological properties of 3-D scaffolds reinforced with zinc oxide for bone tissue engineering.

    Directory of Open Access Journals (Sweden)

    Pei Feng

    Full Text Available A scaffold for bone tissue engineering should have highly interconnected porous structure, appropriate mechanical and biological properties. In this work, we fabricated well-interconnected porous β-tricalcium phosphate (β-TCP scaffolds via selective laser sintering (SLS. We found that the mechanical and biological properties of the scaffolds were improved by doping of zinc oxide (ZnO. Our data showed that the fracture toughness increased from 1.09 to 1.40 MPam(1/2, and the compressive strength increased from 3.01 to 17.89 MPa when the content of ZnO increased from 0 to 2.5 wt%. It is hypothesized that the increase of ZnO would lead to a reduction in grain size and an increase in density of the strut. However, the fracture toughness and compressive strength decreased with further increasing of ZnO content, which may be due to the sharp increase in grain size. The biocompatibility of the scaffolds was investigated by analyzing the adhesion and the morphology of human osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The scaffolds exhibited better and better ability to support cell attachment and proliferation when the content of ZnO increased from 0 to 2.5 wt%. Moreover, a bone like apatite layer formed on the surfaces of the scaffolds after incubation in simulated body fluid (SBF, indicating an ability of osteoinduction and osteoconduction. In summary, interconnected porous β-TCP scaffolds doped with ZnO were successfully fabricated and revealed good mechanical and biological properties, which may be used for bone repair and replacement potentially.

  3. DEPENDENCE OF THE SPECKLE-PATTERNS SIZE AND THEIR CONTRAST ON THE BIOPHYSICAL AND STRUCTURAL PARAMETERS OF BIOLOGICAL TISSUES

    Directory of Open Access Journals (Sweden)

    N. D. Abramovich

    2017-01-01

    Full Text Available Speckle fields are widely used in optical diagnostics of biotissues and evaluation of the functional state of bioobjects. The speckle field is formed by laser radiation scattered from the object under study. It bears information about the average dimensions of the scatterers, the degree of surface roughness makes it possible to judge the structural and biophysical characteristics of individual tissue cells (particles, on the one hand, and the integral optical characteristics of the entire biological tissue. The aim of the study was – the determination of connections between the biophysical and structural characteristics of the biotissue and the light fields inside the biotissues.The model developed of the medium gives a direct relationship between the optical and biophysical parameters of the biotissue. Calculations were carried out using known solutions of the radiation transfer equation, taking into account the multilayer structure of the tissue, multiple scattering in the medium, and multiple reflection of irradiation between the layers.With the increase wavelength, the size of speckles formed by the non-scattered component (direct light of laser radiation increases by a factor of 2 from 400 to 800 μm in the stratum corneum and 5 times from 0.6 to 3 μm for the epidermis and from 0.27 to 1.4 μm to the dermis. Typical values of sizes of speckles formed by the diffraction component of laser radiation for the stratum corneum and epidermis range from 0.02 to 0.15 μm. For the dermis typical spot sizes are up to 0.03 μm. The speckle-spot size of the diffusion component in the dermis can vary from ±10 % at 400 nm and up to ±23 % for 800 nm when the volume concentration of blood capillaries changes. Characteristic dependencies are obtained and biophysical factors associated with the volume concentration of blood and the degree of it’s oxygenation that affect the contrast of the speckle structure in the dermis are discussed.The of speckles

  4. Collision Risk and Damage after Collision

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Hansen, Peter Friis; Nielsen, Lars Peter

    1996-01-01

    The paper presents a new and complete procedure for calculation of ship-ship collision rates on specific routes and the hull damage caused by such collisions.The procedure is applied to analysis of collision risks for Ro-Ro pasenger vessels. Given a collision the spatial probability distribution...

  5. An Inverse Power-Law Distribution of Molecular Bond Lifetimes Predicts Fractional Derivative Viscoelasticity in Biological Tissue

    Science.gov (United States)

    Palmer, Bradley M.; Tanner, Bertrand C.W.; Toth, Michael J.; Miller, Mark S.

    2013-01-01

    Viscoelastic characteristics of many materials falling under the category of soft glassy substances, including biological tissue, often exhibit a mechanical complex modulus Y(ω) well described by a fractional derivative model: Y(ω) = E(iω/ϕ)k, where E = a generalized viscoelastic stiffness; i = (−1)1/2; ω = angular frequency; ϕ = scaling factor; and k = an exponent valued between 0 and 1. The term “fractional derivative” refers to the value of k: when k = 0 the viscoelastic response is purely elastic, and when k = 1 the response is purely viscous. We provide an analytical derivation of the fractional derivative complex modulus based on the hypothesis that the viscoelastic response arises from many intermittent molecular crosslinks, whose lifetimes longer than a critical threshold lifetime, tcrit, are distributed with an inverse power law proportional to t-(k+2). We demonstrate that E is proportional to the number and stiffness of crosslinks formed at any moment; the scaling factor ϕ is equivalent to reciprocal of tcrit; and the relative mean lifetime of the attached crosslinks is inversely proportional to the parameter k. To test whether electrostatic molecular bonds could be responsible for the fractional derivative viscoelasticity, we used chemically skinned human skeletal muscle as a one-dimensional model of a soft glassy substance. A reduction in ionic strength from 175 to 110 mEq resulted in a larger E with no change in k, consistent with a higher probability of interfilament molecular interactions. Thick to thin filament spacing was reduced by applying 4% w/v of the osmolyte Dextran T500, which also resulted in a larger E, indicating a greater probability of crosslink formation in proportion to proximity. A 10°C increase in temperature resulted in an increase in k, which corresponded to a decrease in cross-bridge attachment lifetime expected with higher temperatures. These theoretical and experimental results suggest that the fractional

  6. A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

    International Nuclear Information System (INIS)

    Bohndiek, Sarah E; Cook, Emily J; Arvanitis, Costas D; Olivo, Alessandro; Royle, Gary J; Clark, Andy T; Prydderch, Mark L; Turchetta, Renato; Speller, Robert D

    2008-01-01

    X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable

  7. Doped tricalcium phosphate bone tissue engineering scaffolds using sucrose as template and microwave sintering: enhancement of mechanical and biological properties.

    Science.gov (United States)

    Ke, Dongxu; Bose, Susmita

    2017-09-01

    β-tricalcium phosphate (β-TCP) is a widely used biocompatible ceramic in orthopedic and dental applications. However, its osteoinductivity and mechanical properties still require improvements. In this study, porous β-TCP and MgO/ZnO-TCP scaffolds were prepared by the thermal decomposition of sucrose. Crack-free cylindrical scaffolds could only be prepared with the addition of MgO and ZnO due to their stabilization effects. Porous MgO/ZnO-TCP scaffolds with a density of 61.39±0.66%, an estimated pore size of 200μm and a compressive strength of 24.96±3.07MPa were prepared by using 25wt% sucrose after conventional sintering at 1250°C. Microwave sintering further increased the compressive strength to 37.94±6.70MPa, but it decreased the open interconnected porosity to 8.74±1.38%. In addition, the incorporation of polycaprolactone (PCL) increased 22.36±3.22% of toughness while maintaining its compressive strength at 25.45±2.21MPa. Human osteoblast cell line was seeded on scaffolds to evaluate the effects of MgO/ZnO and PCL on the biological property of β-TCP in vitro. Both MgO/ZnO and PCL improved osteoinductivity of β-TCP. PCL also decreased osteoblastic apoptosis due to its particular surface chemistry. This novel porous MgO/ZnO-TCP scaffold with PCL shows improved mechanical and biological properties, which has great potential in bone tissue engineering applications. Copyright © 2017. Published by Elsevier B.V.

  8. Analyses of chlorogenic acids and related cinnamic acid derivatives from Nicotiana tabacum tissues with the aid of UPLC-QTOF-MS/MS based on the in-source collision-induced dissociation method.

    Science.gov (United States)

    Ncube, Efficient N; Mhlongo, Msizi I; Piater, Lizelle A; Steenkamp, Paul A; Dubery, Ian A; Madala, Ntakadzeni E

    2014-01-01

    Chlorogenic acids (CGAs) are a class of phytochemicals that are formed as esters between different derivatives of cinnamic acid and quinic acid molecules. In plants, accumulation of these compounds has been linked to several physiological responses against various stress factors; however, biochemical synthesis differs from one plant to another. Although structurally simple, the analysis of CGA molecules with modern analytical platforms poses an analytical challenge. The objective of the study was to perform a comparison of the CGA profiles and related derivatives from differentiated tobacco leaf tissues and undifferentiated cell suspension cultures. Using an UHPLC-Q-TOF-MS/MS fingerprinting method based on the in-source collision induced dissociation (ISCID) approach, a total of 19 different metabolites with a cinnamic acid core moiety were identified. These metabolites were either present in both leaf tissue and cell suspension samples or in only one of the two plant systems. Profile differences point to underlying biochemical similarities or differences thereof. Using this method, the regio- and geometric-isomer profiles of chlorogenic acids of the two tissue types of Nicotiana tabacum were achieved. The method was also shown to be applicable for the detection of other related molecules containing a cinnamic acid core.

  9. A New Sample Substrate for Imaging and Correlating Organic and Trace Metal Composition in Biological Cells and Tissues

    International Nuclear Information System (INIS)

    Miller, L.; Wang, Q.; Smith, R.; Zhong, H.; Elliott, D.; Warren, J.

    2007-01-01

    Many disease processes involve alterations in the chemical makeup of tissue. Synchrotron-based infrared (IR) and X-ray fluorescence (XRF) microscopes are becoming increasingly popular tools for imaging the organic and trace metal compositions of biological materials, respectively, without the need for extrinsic labels or stains. Fourier transform infrared microspectroscopy (FTIRM) provides chemical information on the organic components of a material at a diffraction-limited spatial resolution of 2-10 μm in the mid-infrared region. The synchrotron X-ray fluorescence (SXRF) microprobe is a complementary technique used to probe trace element content in the same systems with a similar spatial resolution. However to be most beneficial, it is important to combine the results from both imaging techniques on a single sample, which requires precise overlap of the IR and X-ray images. In this work, we have developed a sample substrate containing a gold grid pattern on its surface, which can be imaged with both the IR and X-ray microscopes. The substrate consists of a low trace element glass slide that has a gold grid patterned on its surface, where the major and minor parts of the grid contain 25 and 12 nm gold, respectively. This grid pattern can be imaged with the IR microscope because the reflectivity of gold differs as a function of thickness. The pattern can also be imaged with the SXRF microprobe because the Au fluorescence intensity changes with gold thickness. The tissue sample is placed on top of the patterned substrate. The grid pattern's IR reflectivity image and the gold SXRF image are used as fiducial markers for spatially overlapping the IR and SXRF images from the tissue. Results show that IR and X-ray images can be correlated precisely, with a spatial resolution of less than one pixel (i.e., 2-3 microns). The development of this new tool will be presented along with applications to paraffin-embedded metalloprotein crystals, Alzheimer's disease, and hair

  10. Impact of fluorescence emission from gold atoms on surrounding biological tissue-implications for nanoparticle radio-enhancement.

    Science.gov (United States)

    Byrne, H L; Gholami, Y; Kuncic, Z

    2017-04-21

    The addition of gold nanoparticles within target tissue (i.e. a tumour) to enhance the delivered radiation dose is a well studied radiotherapy treatment strategy, despite not yet having been translated into standard clinical practice. While several studies have used Monte Carlo simulations to investigate radiation dose enhancement by Auger electrons emitted from irradiated gold nanoparticles, none have yet considered the effects due to escaping fluorescence photons. Geant4 was used to simulate a water phantom containing 10 mg ml -1 uniformly dispersed gold (1% by mass) at 5 cm depth. Incident monoenergetic photons with energies either side of the gold K-edge at 73 keV and 139.5 keV were chosen to give the same attenuation contrast against water, where water is used as a surrogate for biological tissue. For 73 keV incident photons, adding 1% gold into the water phantom enhances the energy deposited in the phantom by a factor of  ≈1.9 while 139.5 keV incident photons give a lower enhancement ratio of  ≈1.5. This difference in enhancement ratio, despite the equivalent attenuation ratios, can be attributed to energy carried from the target into the surrounding volume by fluorescence photons for the higher incident photon energy. The energy de-localisation is maximal just above the K-edge with 36% of the initial energy deposit in the phantom lost to escaping fluorescence photons. Conversely we find that the absorption of more photons by gold in the phantom reduces the number of scattered photons and hence energy deposited in the surrounding volume by up to 6% for incident photons below the K-edge. For incident photons above the K-edge this is somewhat offset by fluorescence. Our results give new insight into the previously unstudied centimetre scale energy deposition outside a target, which will be valuable for the future development of treatment plans using gold nanoparticles. From these results, we can conclude that gold nanoparticles delivered

  11. POD for Real-Time Simulation of Hyperelastic Soft Biological Tissue Using the Point Collocation Method of Finite Spheres

    Directory of Open Access Journals (Sweden)

    Suleiman Banihani

    2013-01-01

    Full Text Available The point collocation method of finite spheres (PCMFS is used to model the hyperelastic response of soft biological tissue in real time within the framework of virtual surgery simulation. The proper orthogonal decomposition (POD model order reduction (MOR technique was used to achieve reduced-order model of the problem, minimizing computational cost. The PCMFS is a physics-based meshfree numerical technique for real-time simulation of surgical procedures where the approximation functions are applied directly on the strong form of the boundary value problem without the need for integration, increasing computational efficiency. Since computational speed has a significant role in simulation of surgical procedures, the proposed technique was able to model realistic nonlinear behavior of organs in real time. Numerical results are shown to demonstrate the effectiveness of the new methodology through a comparison between full and reduced analyses for several nonlinear problems. It is shown that the proposed technique was able to achieve good agreement with the full model; moreover, the computational and data storage costs were significantly reduced.

  12. Implementation and clinical application of a deformation method for fast simulation of biological tissue formed by fibers and fluid.

    Science.gov (United States)

    Sardinha, Ana Gabriella de Oliveira; Oyama, Ceres Nunes de Resende; de Mendonça Maroja, Armando; Costa, Ivan F

    2016-01-01

    The aim of this paper is to provide a general discussion, algorithm, and actual working programs of the deformation method for fast simulation of biological tissue formed by fibers and fluid. In order to demonstrate the benefit of the clinical applications software, we successfully used our computational program to deform a 3D breast image acquired from patients, using a 3D scanner, in a real hospital environment. The method implements a quasi-static solution for elastic global deformations of objects. Each pair of vertices of the surface is connected and defines an elastic fiber. The set of all the elastic fibers defines a mesh of smaller size than the volumetric meshes, allowing for simulation of complex objects with less computational effort. The behavior similar to the stress tensor is obtained by the volume conservation equation that mixes the 3D coordinates. Step by step, we show the computational implementation of this approach. As an example, a 2D rectangle formed by only 4 vertices is solved and, for this simple geometry, all intermediate results are shown. On the other hand, actual implementations of these ideas in the form of working computer routines are provided for general 3D objects, including a clinical application.

  13. Butter blend containing fish oil improves the level of n-3 fatty acids in biological tissues of hamster.

    Science.gov (United States)

    Porsgaard, Trine; Overgaard, Julie; Krogh, Anne Louise; Jensen, Mette Behrmann; Guo, Zheng; Mu, Huiling

    2007-09-05

    Many studies have shown beneficial effects of long chain n-3 polyunsaturated fatty acids (PUFA) on human health. Regardless of the positive effects of n-3 PUFA, the intake of these fatty acids remains low. An approach to increase the intake of n-3 PUFA in the population is to incorporate fish oil into food. In the present study, fish oil was incorporated into butter blends by enzymatic interesterification. The aim of the study was to investigate the effects of this butter product in comparison with a commercial butter blend and a product produced by interesterification but without fish oil. Golden Syrian hamsters received hamster feed blended with one of the three butter products. After 6 weeks of feeding, the fatty acid compositions of plasma, erythrocytes, liver, brain, and visceral fat were determined. The intake of butter product with fish oil resulted in a higher level of n-3 PUFA in plasma, erythrocytes, and liver. The incorporation of n-3 PUFA was significantly higher in phospholipids than in triacylglycerols. The results suggest that enriching butter blends with small amounts of fish oil can be used as an alternative method for improving the level of n-3 PUFA in biological tissues.

  14. Evaluating the Bone Tissue Regeneration Capability of the Chinese Herbal Decoction Danggui Buxue Tang from a Molecular Biology Perspective

    Directory of Open Access Journals (Sweden)

    Wen-Ling Wang

    2014-01-01

    Full Text Available Large bone defects are a considerable challenge to reconstructive surgeons. Numerous traditional Chinese herbal medicines have been used to repair and regenerate bone tissue. This study investigated the bone regeneration potential of Danggui Buxue Tang (DBT, a Chinese herbal decoction prepared from Radix Astragali (RA and Radix Angelicae Sinensis (RAS, from a molecular biology perspective. The optimal ratio of RA and RAS used in DBT for osteoblast culture was obtained by colorimetric and alkaline phosphatase (ALP activity assays. Moreover, the optimal concentration of DBT for bone cell culture was also determined by colorimetric, ALP activity, nodule formation, Western blotting, wound-healing, and tartrate-resistant acid phosphatase activity assays. Consequently, the most appropriate weight ratio of RA to RAS for the proliferation and differentiation of osteoblasts was 5 : 1. Moreover, the most effective concentration of DBT was 1,000 μg/mL, which significantly increased the number of osteoblasts, intracellular ALP levels, and nodule numbers, while inhibiting osteoclast activity. Additionally, 1,000 μg/mL of DBT was able to stimulate p-ERK and p-JNK signal pathway. Therefore, DBT is highly promising for use in accelerating fracture healing in the middle or late healing periods.

  15. Mechanical, Biological and Electrochemical Investigations of Advanced Micro/Nano Materials for Tissue Engineering and Energy Storage

    Science.gov (United States)

    Pu, Juan

    Various micro/nano materials have been extensively studied for applications in tissue engineering and energy storage. Tissue engineering seeks to repair or replace damaged tissue by integrating approaches from cellular/molecular biology and material chemistry/engineering. A major challenge is the consistent design of three-dimensional (3D) scaffolds that mimic the structure and biological functions of extracellular matrix (ECM), guide cell migration, provide mechanical support, and regulate cell activity. Electrospun micro/nanofibers have been investigated as promising tissue engineering scaffolds because they resemble native ECM and possess tunable surface morphologies. Supercapacitors, one of the energy storage devices, bridge the performance gap between rechargeable batteries and conventional capacitors. Active electrode materials of supercapacitors must possess high specific surface area, high conductivity, and good electrochemical properties. Carbon-based micro/nano-particles, such as graphene, activated carbon (AC), and carbon nanotubes, are commonly used as active electrode materials for storing charge in supercapacitors by the electrical double layer mechanism due to their high specific surface area and excellent conductivity. In this thesis, the mechanical properties of electrospun bilayer microfibrous membranes were investigated for potential applications in tissue engineering. Bilayer microfibrous membranes of poly(l-lactic acid) (PLLA) were fabricated by electrospinning using a parallel-disk mandrel configuration, which resulted in the sequential deposition of a layer with aligned fibers (AFL) across the two parallel disks and a layer with random fibers (RFL), both deposited by a single process step. The membrane structure and fiber alignment were characterized by scanning electron microscopy and two-dimensional fast Fourier transform. Because of the intricacies of the generated electric field, the bilayer membranes exhibited higher porosity than the

  16. In vitro study of the biological activity of RNAs after incubation of hog liver, heart and brain tissue at room temperature

    DEFF Research Database (Denmark)

    Reichert, G H; Issinger, O G

    1985-01-01

    The biological activity of RNA, isolated from tissue which was incubated for 1, 3, or 6 hours at room temperature (simulation of post-mortem conditions), was preserved. However, the different organs used differ from each other. When liver is used, qualitative differences in the in vitro translation...

  17. Two-Photon Sensing and Imaging of Endogenous Biological Cyanide in Plant Tissues Using Graphene Quantum Dot/Gold Nanoparticle Conjugate.

    Science.gov (United States)

    Wang, Lili; Zheng, Jing; Yang, Sheng; Wu, Cuichen; Liu, Changhui; Xiao, Yue; Li, Yinhui; Qing, Zhihe; Yang, Ronghua

    2015-09-02

    One main source of cyanide (CN(-)) exposure for mammals is through the plant consumption, and thus, sensitive and selective CN(-) detection in plants tissue is a significant and urgent work. Although various fluorescence probes have been reported for CN(-) in water and mammalian cells, the detection of endogenous biological CN(-) in plant tissue remains to be explored due to the high background signal and large thickness of plant tissue that hamper the effective application of traditional one-photo excitation. To address these issues, we developed a new two-photo excitation (TPE) nanosensor using graphene quantum dots (GQDs)/gold nanoparticle (AuNPs) conjugate for sensing and imaging endogenous biological CN(-). With the benefit of the high quenching efficiency of AuNPs and excellent two-photon properties of GQDs, our sensing system can achieve a low detection limit of 0.52 μM and deeper penetration depth (about 400 μm) without interference from background signals of a complex biological environment, thus realizing sensing and imaging of CN(-) in different types of plant tissues and even monitoring CN(-) removal in food processing. To the best of our knowledge, this is the first time for fluorescent sensing and imaging of CN(-) in plant tissues. Moreover, our design also provides a new model scheme for the development of two-photon fluorescent nanomaterial, which is expected to hold great potential for food processing and safety testing.

  18. [Optical properties of human normal small intestine tissue with theoretical model of optics about biological tissues at Ar+ laser and 532 nm laser and their linearly polarized laser irradiation in vitro].

    Science.gov (United States)

    Wei, Hua-jiang; Xing, Da; Wu, Guo-yong; Jin, Ying; Gu, Huai-min

    2004-05-01

    A double-integrating-spheres system, basic principle of measuring technology of ray radiation, and optical model of biological tissues were used for the study. Optical properties of human normal small intestine tissue at 476.5, 488, 496.5, 514.5 and 532 nm laser and their linearly polarized laser irradiation were studied. The results of measurement showed that the total attenuation coefficient and scattering coefficient of the tissue at these wavelengths of laser and their linearly polarized laser irradiation increased with decreasing wavelengths. And obviously there was a distinction at 514.5 to 532 nm wavelength between lasers and their linearly polarized laser irradiation. Absorption coefficient of tissue at these wavelengths of laser and their linearly polarized laser irradiation increased with decreasing wavelengths. Absorption coefficient of tissue at 514.5 to 532 nm wavelength of laser was obviously decreasing, which was independent of these wavelengths of laser or their linearly polarized laser irradiation. Mean cosine of scattering of tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with decreasing wavelengths. But penetration depth of tissue at these wavelengths of laser and their linearly polarized laser irradiation also increased with increasing of wavelengths. Refractive index of tissue between these wavelengths of laser was within 1.38 to 1.48. Absorption coefficient, scattering coefficient, total attenuation coefficient, effective attenuation coefficients of tissue in Kubelka-Munk two-flux model at the same wavelength of laser and their linearly polarized laser irradiation showed no prominent distinction (P>0.01). Absorption coefficient, scattering coefficient, total attenuation coefficient, effective attenuation coefficients of tissue in Kubelka-Munk two-flux model at different wavelength of laser and their linearly polarized laser irradiation showed obvious distinction. Optical properties of tissue

  19. Apparatus and method to control atmospheric water vapor composition and concentration during dynamic cooling of biological tissues in conjunction with laser irradiations

    Science.gov (United States)

    Nelson, J. Stuart; Anvari, Bahman; Tanenbaum, B. Samuel; Milner, Thomas E.

    1999-01-01

    Cryogen spray cooling of skin surface with millisecond cryogen spurts is an effective method for establishing a controlled temperature distribution in tissue and protecting the epidermis from nonspecific thermal injury during laser mediated dermatological procedures. Control of humidity level, spraying distance and cryogen boiling point is material to the resulting surface temperature. Decreasing the ambient humidity level results in less ice formation on the skin surface without altering the surface temperature during the cryogen spurt. For a particular delivery nozzle, increasing the spraying distance to 85 millimeters lowers the surface temperature. The methodology comprises establishing a controlled humidity level in the theater of operation of the irradiation site of the biological tissues before and/or during the cryogenic spray cooling of the biological tissue. At cold temperatures calibration was achieved by mounting a thermistor on a thermoelectric cooler. The thermal electric cooler was cooled from from 20.degree. C. to about -20.degree. C. while measuring its infrared emission.

  20. The Chernobyl Tissue Bank — A Repository for Biomaterial and Data Used in Integrative and Systems Biology Modeling the Human Response to Radiation

    Science.gov (United States)

    Thomas, Geraldine; Unger, Kristian; Krznaric, Marko; Galpine, Angela; Bethel, Jackie; Tomlinson, Christopher; Woodbridge, Mark; Butcher, Sarah

    2012-01-01

    The only unequivocal radiological effect of the Chernobyl accident on human health is the increase in thyroid cancer in those exposed in childhood or early adolescence. In response to the scientific interest in studying the molecular biology of thyroid cancer post Chernobyl, the Chernobyl Tissue Bank (CTB: www.chernobyltissuebank.com) was established in 1998. Thus far it is has collected biological samples from 3,861 individuals, and provided 27 research projects with 11,254 samples. The CTB was designed from its outset as a resource to promote the integration of research and clinical data to facilitate a systems biology approach to radiation related thyroid cancer. The project has therefore developed as a multidisciplinary collaboration between clinicians, dosimetrists, molecular biologists and bioinformaticians and serves as a paradigm for tissue banking in the omics era. PMID:24704918

  1. Non-Immunogenic Structurally and Biologically Intact Tissue Matrix Grafts for the Immediate Repair of Ballistic-Induced Vascular and Nerve Tissue Injury in Combat Casualty Care

    National Research Council Canada - National Science Library

    Bachrach, Nathaniel

    2003-01-01

    .... This past year the source of he defects was determined to be the freeze-drying process. Ongoing efforts toward process optimization and design modifications that will provide undamaged tissue grafts are presented in this report...

  2. Tissue Inhibitor of Metalloprotease-2 (TIMP-2): Bioprocess Development, Physicochemical, Biochemical, and Biological Characterization of Highly Expressed Recombinant Protein.

    Science.gov (United States)

    Chowdhury, Anandã; Brinson, Robert; Wei, Beiyang; Stetler-Stevenson, William G

    2017-12-12

    Tissue inhibitor of metalloprotease-2 (TIMP-2) is a secreted 21 kDa multifunctional protein first described as an endogenous inhibitor of matrix metalloproteinases (MMPs) that prevents breakdown of the extracellular matrix often observed in chronic diseases. TIMP-2 diminishes the level of growth factor-mediated cell proliferation in vitro, as well as neoangiogenesis and tumor growth in vivo independent of its MMP inhibitory activity. These physiological properties make TIMP-2 an excellent candidate for further preclinical development as a biologic therapy of cancer. Here we present a straightforward bioprocessing methodology that yields >35 mg/L recombinant human TIMP-2 6XHis-tagged protein (rhTIMP-2) from suspension cultures of HEK-293-F cells. Enhanced rhTIMP-2-6XHis yields were achieved by optimization of both TIMP-2 cDNA codon sequence and cell culture conditions. Using a two-step chromatographic process, we achieved >95% purity with minimal processing losses. Purified rhTIMP-2-6XHis was free of mouse antigen contamination. Circular dichroism spectroscopy indicated a well-folded rhTIMP-2-6XHis that is highly stable and refractory to pH changes. Two-dimensional heteronuclear single-quantum coherence nuclear magnetic resonance of full length rhTIMP-2-6XHis also indicated a monodisperse, well-folded protein preparation. Purified rhTIMP-2-6XHis inhibited MMP-2 enzymatic activity in a dose-dependent fashion with an IC 50 of ∼1.4 nM. Pretreatment of A549 lung cancer and JygMC(A) triple-negative breast cancer cells with rhTIMP-2-6XHis in low-nanomolar amounts inhibited EGF-induced proliferation to basal (unstimulated) levels. This study therefore not only offers a robust bioprocess methodology for rhTIMP-2 production but also characterizes critical physicochemical and biological attributes that are useful for monitoring quality control of the production process.

  3. A regenerative biology view on artificial tissue construction and 3D bioprinting: what may we learn from natural regenerative phenomena?

    DEFF Research Database (Denmark)

    Lauridsen, Henrik

    2017-01-01

    organ structures by decellularisation/recellularisation procedures and recently with three-dimensional (3D) bioprinting show promising results in obtaining anatomically accurate constructs, however, the function of these artificial tissues is still lacking compared to natural tissues. This review...

  4. Multi-scale, multi-modal analysis uncovers complex relationship at the brain tissue-implant neural interface: New Emphasis on the Biological Interface.

    Science.gov (United States)

    Michelson, Nicholas J; Vazquez, Alberto L; Eles, James R; Salatino, Joseph William; Purcell, Erin K; Williams, Jordan John; Cui, Tracy; Kozai, Takashi D Yoshida

    2017-11-28

    Implantable neural electrode devices are important tools for neuroscience research and have an increasing range of clinical applications. However, the intricacies of the biological response after implantation, and their ultimate impact on recording performance, remain challenging to elucidate. Establishing a relationship between the neurobiology and chronic recording performance is confounded by technical challenges related to traditional electrophysiological, material, and histological limitations. This can greatly impact the interpretations of results pertaining to device performance and tissue health surrounding the implant. Approach: In this work, electrophysiological activity and immunohistological analysis are compared after controlling for motion artifacts, quiescent neuronal activity, and material failure of devices in order to better understand the relationship between histology and electrophysiological outcomes. Results: Even after carefully accounting for these factors, the presence of viable neurons and lack or glial scarring does not convey single unit recording performance. Significance: To better understand the biological factors influencing neural activity, detailed cellular and molecular tissue responses were examined. Decreases in neural activity and blood oxygenation in the tissue surrounding the implant, shift in expression levels of vesicular transporter proteins and ion channels, axon and myelin injury, and interrupted blood flow in nearby capillaries can impact neural activity around implanted neural interfaces. Combined, these tissue changes highlight the need for more comprehensive, basic science research to elucidate the relationship between biology and chronic electrophysiology performance in order to advance neural technologies. © 2017 IOP Publishing Ltd.

  5. The main features of electrical stimulation of biological tissues by implant electrodes: study from engineering perspective and equipment development to produce

    International Nuclear Information System (INIS)

    Suarez Bagnasco, D.; Alvarez Alonso, J.; Suarez Antola, R.

    2004-08-01

    The main features of electrical stimulation of biological tissues by implant electrodes are studied.These electrodes are applied in neural prostheses and cardiac pacing.Threshold phenomena are stressed and some aspects related with implant electrode design are discussed. A fairly through theoretical research about the optimal pulse shape for electrical stimulation of biological tissues is done.The excitation functional is introduced as a criterium to identify threshold pulses of electric current. We obtain the optimal pulse shapes that minimize the energy dissipated in tissues, or the energy taken by the load seen by the pulse generator, amongst other criteria.We show how these pulse shapes can be determined from experimentally measured strength-duration (S-D) curves using rectangular pulses of current. The development of a prototype of a new equipment is described.The equipment may be used to measure S-D curves and with this information it is able to syntetize the abovementioned optimal pulse shapes. The top-down design process is presented, involving both hardware and software.The construction and assembling of the prototype, as well as the implementation of software are described.Some testing and measures with the prototype, including test with biological tissues are described and assessed

  6. LASER BIOLOGY AND MEDICINE: Effect of repetitive laser pulses on the electrical conductivity of intervertebral disc tissue

    Science.gov (United States)

    Omel'chenko, A. I.; Sobol', E. N.

    2009-03-01

    The thermomechanical effect of 1.56-μm fibre laser pulses on intervertebral disc cartilage has been studied using ac conductivity measurements with coaxial electrodes integrated with an optical fibre for laser radiation delivery to the tissue. The observed time dependences of tissue conductivity can be interpreted in terms of hydraulic effects and thermomechanical changes in tissue structure. The laserinduced changes in the electrical parameters of the tissue are shown to correlate with the structural changes, which were visualised using shadowgraph imaging. Local ac conductivity measurements in the bulk of tissue can be used to develop a diagnostic/monitoring system for laser regeneration of intervertebral discs.

  7. Puck collisions

    Science.gov (United States)

    Hauge, E. H.

    2012-09-01

    Collisions between two ice hockey pucks sliding on frictionless ice are studied, with both inelasticity and frictional contact between the colliding surfaces of the two pucks taken into account. The latter couples translational and rotational motion. The full solution depends on the sign and magnitude of the initial mismatch between the surface velocities at the point of contact. The initial state defines two physically distinct regimes for the friction coefficient. To illustrate the complexities, we discuss at length the typical situation (well known from curling) when puck number 1 is initially at rest, and is hit by puck number 2 with an arbitrary impact parameter, velocity and angular velocity. We find that the total outgoing angle between the pucks exceeds \\frac{1}{2}\\pi if and only if the collision leads to a net increase in the translational part of the kinetic energy. The conditions for this to happen are scrutinized, and the results are presented both analytically and numerically by a set of representative curves. This paper is written with an ambitious undergraduate, and her teacher, in mind.

  8. Biological therapeutics

    National Research Council Canada - National Science Library

    Greenstein, Ben; Brook, Daniel A

    2011-01-01

    This introductory textbook covers all the main categories of biological medicines, including vaccines, hormonal preparations, drugs for rheumatoid arthritis and other connective tissue diseases, drugs...

  9. Collision avoidance

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P.

    2008-04-01

    A suite of new collision avoidance systems (CAS 1,2,3, and 4) for heavy vehicles particularly mine haul trucks, is presented for vehicles whose structure and size necessarily impeded driver visibility. The systems use probe radar systems, continuous wave Doppler radar, ultrasonic Doppler, radio frequency tagging and laser scanning technology. The main goal of the ACARP/CSIRO funded projects is to determine the appropriate use and adaptation of commercially available technologies, and where possible, produce a low cost variant suitable for use in proximity detection on large mining industry haul trucks. CAS variants produced were subjected to a field demonstration and linked to the output from the earlier CAS 1 project. The research concentrated on large mine haul trucks operating in open cut coal mines. While the results are especially applicable to the Queensland and New South Wales coal industries, they are also applicable worldwide. 1 tab.

  10. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, Rebecca Antonia

    2014-06-03

    Treatment planning in ion beam therapy requires a reliable estimation of the relative biological effectiveness (RBE) of the irradiated tissue. For the pilot project at GSI Helmholtzzentrum fuer Schwerionenforschung GmbH and at other European ion beam therapy centers RBE prediction is based on a biophysical model, the Local Effect Model (LEM). The model version in use, LEM I, is optimized to give a reliable estimation of RBE in the target volume for carbon ion irradiation. However, systematic deviations are observed for the entrance channel of carbon ions and in general for lighter ions. Thus, the LEM has been continuously developed to improve accuracy. The recent version LEM IV has proven to better describe in-vitro cell experiments. Thus, for the clinical application of LEM IV it is of interest to analyze potential differences compared to LEM I under treatment-like conditions. The systematic analysis presented in this work is aiming at the comparison of RBE-weighted doses resulting from different approaches and model versions for protons and carbon ions. This will facilitate the assessment of consequences for clinical application and the interpretation of clinical results from different institutions. In the course of this thesis it has been shown that the RBE-weighted doses predicted on the basis of LEM IV for typical situations representing chordoma treatments differ on average by less than 10 % to those based on LEM I and thus also allow a consistent interpretation of the clinical results. At Japanese ion beam therapy centers the RBE is estimated using their clinical experience from neutron therapy in combination with in-vitro measurements for carbon ions (HIMAC approach). The methods presented in this work allow direct comparison of the HIMAC approach and the LEM and thus of the clinical results obtained at Japanese and European ion beam therapy centers. Furthermore, the sensitivity of the RBE on the model parameters was evaluated. Among all parameters the

  11. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    International Nuclear Information System (INIS)

    Gruen, Rebecca Antonia

    2014-01-01

    Treatment planning in ion beam therapy requires a reliable estimation of the relative biological effectiveness (RBE) of the irradiated tissue. For the pilot project at GSI Helmholtzzentrum fuer Schwerionenforschung GmbH and at other European ion beam therapy centers RBE prediction is based on a biophysical model, the Local Effect Model (LEM). The model version in use, LEM I, is optimized to give a reliable estimation of RBE in the target volume for carbon ion irradiation. However, systematic deviations are observed for the entrance channel of carbon ions and in general for lighter ions. Thus, the LEM has been continuously developed to improve accuracy. The recent version LEM IV has proven to better describe in-vitro cell experiments. Thus, for the clinical application of LEM IV it is of interest to analyze potential differences compared to LEM I under treatment-like conditions. The systematic analysis presented in this work is aiming at the comparison of RBE-weighted doses resulting from different approaches and model versions for protons and carbon ions. This will facilitate the assessment of consequences for clinical application and the interpretation of clinical results from different institutions. In the course of this thesis it has been shown that the RBE-weighted doses predicted on the basis of LEM IV for typical situations representing chordoma treatments differ on average by less than 10 % to those based on LEM I and thus also allow a consistent interpretation of the clinical results. At Japanese ion beam therapy centers the RBE is estimated using their clinical experience from neutron therapy in combination with in-vitro measurements for carbon ions (HIMAC approach). The methods presented in this work allow direct comparison of the HIMAC approach and the LEM and thus of the clinical results obtained at Japanese and European ion beam therapy centers. Furthermore, the sensitivity of the RBE on the model parameters was evaluated. Among all parameters the

  12. In situ biological dose mapping estimates the radiation burden delivered to 'spared' tissue between synchrotron X-ray microbeam radiotherapy tracks.

    Directory of Open Access Journals (Sweden)

    Kai Rothkamm

    Full Text Available Microbeam radiation therapy (MRT using high doses of synchrotron X-rays can destroy tumours in animal models whilst causing little damage to normal tissues. Determining the spatial distribution of radiation doses delivered during MRT at a microscopic scale is a major challenge. Film and semiconductor dosimetry as well as Monte Carlo methods struggle to provide accurate estimates of dose profiles and peak-to-valley dose ratios at the position of the targeted and traversed tissues whose biological responses determine treatment outcome. The purpose of this study was to utilise γ-H2AX immunostaining as a biodosimetric tool that enables in situ biological dose mapping within an irradiated tissue to provide direct biological evidence for the scale of the radiation burden to 'spared' tissue regions between MRT tracks. Γ-H2AX analysis allowed microbeams to be traced and DNA damage foci to be quantified in valleys between beams following MRT treatment of fibroblast cultures and murine skin where foci yields per unit dose were approximately five-fold lower than in fibroblast cultures. Foci levels in cells located in valleys were compared with calibration curves using known broadbeam synchrotron X-ray doses to generate spatial dose profiles and calculate peak-to-valley dose ratios of 30-40 for cell cultures and approximately 60 for murine skin, consistent with the range obtained with conventional dosimetry methods. This biological dose mapping approach could find several applications both in optimising MRT or other radiotherapeutic treatments and in estimating localised doses following accidental radiation exposure using skin punch biopsies.

  13. Ethical aspects of informed consent for the collection, preservation and use of cells and tissues in biological banks for research purposes.

    Science.gov (United States)

    Petrini, Carlo

    2012-01-01

    This article explores the current and proposed requirements for informed consent for research with biological samples. The establishment of biobanks and the capabilities of collecting, storing, and using cells and tissues for research purposes have noticeably grown. With new abilities come new challenges to ethical questions of consent, specifically concerning genetic information, and unanticipated usage. This paper summarizes these issues in the context of levels of informed consent, subject risk, individual vs. societal benefits, anonymity, legal consensus.

  14. The effect of Ligula intestinalis on blood sex steroid hormones, gonadal tissue and some other biological parameters changes of Chalcalburnus mossulensis in Vahdat dam of Kordestan-Iran

    OpenAIRE

    Khanghah, Ali Parsa

    2010-01-01

    Chalcalburnus mossulensis from the cyprinidae family is one of the indigenous fish in Gheshlag Lake of Kordestan-Iran. Ligula intestinalis is one of the infective parasites of this fish. In this study, the effect of this parasite on some biological aspects of this fish like weight, length, PI, CF, GSR, blood sex steroid hormones and gonadal tissue, was investigated. During one year, by seasonal sampling, 144 fish sample from mentioned species were collected using trap net. By considering the ...

  15. Comparison of digestion procedures used for the determination of boron in biological tissues by ICP-AES [inductively-coupled, plasma-atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Bauer, W.F.; Miller, D.L.; Steele, S.M.

    1988-01-01

    A study was designed to identify the most accurate and reliable procedures for the digestion of biological tissues prior to the determination of boron by inductively-coupled, plasma-atomic emission spectroscopy (ICP-AES). The four procedures used in this study were an acid bomb digestion and digestions performed in test tubes using perchloric acid and hydrogen peroxide, nitric acid and hydrogen peroxide, and nitric acid alone. Digestions using nitric acid and hydrogen peroxide and nitric acid alone were performed in a manner analogous to the perchloric acid/hydrogen peroxide procedure. The tissues used in the study were from dogs that had been administered a boron compound (Na 2 B 12 H 11 SH) and included two brain tissues, a liver and a tongue. These tissues were selected in order to eliminate results that may be due to surface spiking only. None of the test tube procedures were successful in completely dissolving the samples, as was evidenced by residual color and a coagulated precipitate. The amount of precipitate was much larger for the brain tissues in all cases. The acid bomb digestion and the perchloric acid/hydrogen peroxide procedures gave comparable boron concentrations for all of the tissues in this study. 2 refs., 1 tab

  16. Nitrated type III collagen as a biological marker of nitric oxide-mediated synovial tissue metabolism in osteoarthritis

    DEFF Research Database (Denmark)

    Richardot, P; Charni-Ben Tabassi, N; Toh, L

    2009-01-01

    OBJECTIVES: Nitric oxide (NO) is a major mediator of joint tissue inflammation and damage in osteoarthritis (OA) and mediates the nitration of tyrosine (Y*) residues in proteins. We investigated the nitration of type III collagen, a major constituent of synovial membrane, in knee OA. METHODS: A p...... investigation of oxidative-related alterations of synovial tissue metabolism in OA....

  17. The adipose tissue of origin influences the biological potential of human adipose stromal cells isolated from mediastinal and subcutaneous fat depots

    Directory of Open Access Journals (Sweden)

    Camilla Siciliano

    2016-09-01

    Full Text Available Indirect evidence suggests that adipose tissue-derived stromal cells (ASCs possess different physiological and biological variations related to the anatomical localization of the adipose depots. Accordingly, to investigate the influence of the tissue origin on the intrinsic properties of ASCs and to assess their response to specific stimuli, we compared the biological, functional and ultrastructural properties of two ASC pools derived from mediastinal and subcutaneous depots (thoracic compartment by means of supplements such as platelet lysate (PL and FBS. Subcutaneous ASCs exhibited higher proliferative and clonogenic abilities than mediastinal counterpart, as well as increased secreted levels of IL-6 combined with lower amount of VEGF-C. In contrast, mediastinal ASCs displayed enhanced pro-angiogenic and adipogenic differentiation properties, increased cell diameter and early autophagic processes, highlighted by electron microscopy. Our results further support the hypothesis that the origin of adipose tissue significantly defines the biological properties of ASCs, and that a homogeneric function for all ASCs cannot be assumed.

  18. Signaling pathways effecting crosstalk between cartilage and adjacent tissues: Seminars in cell and developmental biology: The biology and pathology of cartilage.

    Science.gov (United States)

    Maes, Christa

    2017-02-01

    Endochondral ossification, the mechanism responsible for the development of the long bones, is dependent on an extremely stringent coordination between the processes of chondrocyte maturation in the growth plate, vascular expansion in the surrounding tissues, and osteoblast differentiation and osteogenesis in the perichondrium and the developing bone center. The synchronization of these processes occurring in adjacent tissues is regulated through vigorous crosstalk between chondrocytes, endothelial cells and osteoblast lineage cells. Our knowledge about the molecular constituents of these bidirectional communications is undoubtedly incomplete, but certainly some signaling pathways effective in cartilage have been recognized to play key roles in steering vascularization and osteogenesis in the perichondrial tissues. These include hypoxia-driven signaling pathways, governed by the hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF), which are absolutely essential for the survival and functioning of chondrocytes in the avascular growth plate, at least in part by regulating the oxygenation of developing cartilage through the stimulation of angiogenesis in the surrounding tissues. A second coordinating signal emanating from cartilage and regulating developmental processes in the adjacent perichondrium is Indian Hedgehog (IHH). IHH, produced by pre-hypertrophic and early hypertrophic chondrocytes in the growth plate, induces the differentiation of adjacent perichondrial progenitor cells into osteoblasts, thereby harmonizing the site and time of bone formation with the developmental progression of chondrogenesis. Both signaling pathways represent vital mediators of the tightly organized conversion of avascular cartilage into vascularized and mineralized bone during endochondral ossification. Copyright © 2016. Published by Elsevier Ltd.

  19. Elimination and Concentration Correlations between Edible Tissues and Biological Fluids and Hair of Ractopamine in Pigs and Goats Fed with Ractopamine-Medicated Feed.

    Science.gov (United States)

    Huang, Lingli; Shi, Jingfei; Pan, Yuanhu; Wang, Liye; Chen, Dongmei; Xie, Shuyu; Liu, Zhenli; Yuan, Zonghui

    2016-03-09

    Ractopamine (RAC), a β-adrenergic leanness-enhancing agent, endangers the food safety of animal products because of overdosing and illegal use in food animals. Excretion and residue depletion of RAC in pigs and goats were investigated to determine a representative biological fluid or surface tissue for preslaughter monitoring. After a single oral gavage of RAC, 64-67% of the dose was excreted from the urine of pigs and goats within 12-24 h. RAC persisted the longest in the hair of pigs and goats but depleted rapidly in the plasma, muscle, and fat. Urine and hair were excellent for predicting RAC residues in edible tissues of pigs, whereas plasma and urine were satisfactory body fluids for the prediction of RAC concentrations in edible tissues of goats. These data provided a simple and economical preslaughter living monitoring method for the illegal use and violative residue of RAC in food animals.

  20. A chemo-mechano-biological formulation for the effects of biochemical alterations on arterial mechanics: the role of molecular transport and multiscale tissue remodelling.

    Science.gov (United States)

    Marino, Michele; Pontrelli, Giuseppe; Vairo, Giuseppe; Wriggers, Peter

    2017-11-01

    This paper presents a chemo-mechano-biological framework for arterial physiopathology. The model accounts for the fine remodelling in the multiscale hierarchical arrangement of tissue constituents and for the diffusion of molecular species involved in cell-cell signalling pathways. Effects in terms of alterations in arterial compliance are obtained. A simple instructive example is introduced. Although oversimplified with respect to realistic case studies, the proposed application mimics the biochemical activity of matrix metalloproteinases, transforming growth factors beta and interleukins on tissue remodelling. Effects of macrophage infiltration, of intimal thickening and of a healing phase are investigated, highlighting the corresponding influence on arterial compliance. The obtained results show that the present approach is able to capture changes in arterial mechanics as a consequence of the alterations in tissue biochemical environment and cellular activity, as well as to incorporate the protective role of both autoimmune responses and pharmacological treatments. © 2017 The Author(s).

  1. Coagulation and ablation of biological soft tissue by quantum cascade laser with peak wavelength of 5.7 μm

    Directory of Open Access Journals (Sweden)

    Keisuke Hashimura

    2014-05-01

    Full Text Available Molecules such as water, proteins and lipids that are contained in biological tissue absorb mid-infrared (MIR light, which allows such light to be used in laser surgical treatment. Esters, amides and water exhibit strong absorption bands in the 5–7 μm wavelength range, but at present there are no lasers in clinical use that can emit in this range. Therefore, the present study focused on the quantum cascade laser (QCL, which is a new type of semiconductor laser that can emit at MIR wavelengths and has recently achieved high output power. A high-power QCL with a peak wavelength of 5.7 μm was evaluated for use as a laser scalpel for ablating biological soft tissue. The interaction of the laser beam with chicken breast tissue was compared to a conventional CO2 laser, based on surface and cross-sectional images. The QCL was found to have sufficient power to ablate soft tissue, and its coagulation, carbonization and ablation effects were similar to those for the CO2 laser. The QCL also induced comparable photothermal effects because it acted as a pseudo-continuous wave laser due to its low peak power. A QCL can therefore be used as an effective laser scalpel, and also offers the possibility of less invasive treatment by targeting specific absorption bands in the MIR region.

  2. Expression of transcription factor Klf8 in lung cancer tissue and the biological effect of downregulation of Klf8 expression in lung cancer cell lines

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2016-01-01

    Full Text Available Objective: To study the expression of transcription factor Klf8 in lung cancer tissue and the biological effect of downregulation of Klf8 expression in lung cancer cell lines. Methods: Cancer tissue and adjacent normal lung tissue were collected and mRNA contents of Klf8 were detected; lung cancer A549 cell lines were cultured, and after transfection of Klf8 siRNA, cell cycle, cell invasion and epithelial-mesenchymal transition were detected. Results: mRNA contents of Klf8 in lung cancer tissue were higher than those in adjacent normal lung tissue; after transfection of Klf8 siRNA, Klf8 mRNA inhibition rate was 74.31%; G0/G1 phase ratio of Klf8 siRNA group was higher than that of negative control siRNA group; ratios of S-phase and G2/M phase cells, mRNA contents of Cyclin D1 and number of cells invading to the outer side of the transwell microporous membrane were lower than those of negative control siRNA group; mRNA contents of CDH1 and CK18 as well as Snail and Slug of Klf8 siRNA group were higher than those of negative control siRNA group; mRNA contents of VIM and N-cadherin were lower than those of negative control siRNA group. Conclusion: The expression of Klf8 in lung cancer tissue abnormally elevates; downregulation of Klf8 expression in lung cancer cell lines can inhibit malignant biological effect of cells, manifested as cell cycle arrest as well as the inhibition of cell invasion and epithelial-mesenchymal transition processes.

  3. Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

    Science.gov (United States)

    Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

    2013-07-01

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. 14C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. 14C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve 14C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts.

  4. Analysis of Arsenicals and Their Sulfur Analogs in Biological Samples Using HPLC with Collision Cell ICP-MS and ESI-MS/MS

    Science.gov (United States)

    Recent arsenic speciation studies have indicated that the sulfur analogs of the more common arsenic oxides are present in environmental and biological systems. This discovery was previously impeded due to the strong affinity of these arsenic-sulfides for the stationary phases typ...

  5. Numerical analysis of temperature and thermal dose response of biological tissues to thermal non-equilibrium during hyperthermia therapy.

    Science.gov (United States)

    Yuan, Ping

    2008-03-01

    The temperature and thermal dose response of tumor tissue to hyperthermia therapy under conditions of thermal non-equilibrium have been investigated. The thermal model considers the tissue with its blood vessel distribution as a porous medium and employs the convection term instead of the perfusion term in the energy conservation equations for both tissue and blood. By using a numerical method, the temperatures and thermal dose responses of tissues with different vessel diameters, blood velocities, and porosities were calculated. Through an accuracy comparison, the numerical results were used to compare this model with the results for the one-equation porous model under thermal equilibrium. The primary results indicate that the one-equation porous model is suitable for a distribution of blood vessels when the diameters are less than 30 microm and the blood velocities are lower than 0.4 cm s(-1).

  6. Evaluation of heart tissue viability under redox-magnetohydrodynamics conditions: toward fine-tuning flow in biological microfluidics applications.

    Science.gov (United States)

    Cheah, Lih Tyng; Fritsch, Ingrid; Haswell, Stephen J; Greenman, John

    2012-07-01

    A microfluidic system containing a chamber for heart tissue biopsies, perfused with Krebs-Henseleit buffer containing glucose and antibiotic (KHGB) using peristaltic pumps and continuously stimulated, was used to evaluate tissue viability under redox-magnetohydrodynamics (redox-MHD) conditions. Redox-MHD possesses unique capabilities to control fluid flow using ionic current from oxidation and reduction processes at electrodes in a magnetic field, making it attractive to fine-tune fluid flow around tissues for "tissue-on-a-chip" applications. The manuscript describes a parallel setup to study two tissue samples simultaneously, and 6-min static incubation with Triton X100. Tissue viability was subsequently determined by assaying perfusate for lactate dehydrogenase (LDH) activity, where LDH serves as an injury marker. Incubation with KHGB containing 5 mM hexaammineruthenium(III) (ruhex) redox species with and without a pair of NdFeB magnets (∼ 0.39 T, placed parallel to the chamber) exhibited no additional tissue insult. MHD fluid flow, viewed by tracking microbeads with microscopy, occurred only when the magnet was present and stimulating electrodes were activated. Pulsating MHD flow with a frequency similar to the stimulating waveform was superimposed over thermal convection (from a hotplate) for Triton-KHGB, but fluid speed was up to twice as fast for ruhex-Triton-KHGB. A large transient ionic current, achieved when switching on the stimulating electrodes, generates MHD perturbations visible over varying peristaltic flow. The well-controlled flow methodology of redox-MHD is applicable to any tissue type, being useful in various drug uptake and toxicity studies, and can be combined equally with on- or off-device analysis modalities. Copyright © 2012 Wiley Periodicals, Inc.

  7. Design, synthesis, and biological evaluation of 16-substituted 4-azasteroids as tissue-selective androgen receptor modulators (SARMs).

    Science.gov (United States)

    Mitchell, Helen J; Dankulich, William P; Hartman, George D; Prueksaritanont, Thomayant; Schmidt, Azriel; Vogel, Robert L; Bai, Chang; McElwee-Witmer, Sheila; Zhang, Hai Z; Chen, Fang; Leu, Chih-Tai; Kimmel, Donald B; Ray, William J; Nantermet, Pascale; Gentile, Michael A; Duggan, Mark E; Meissner, Robert S

    2009-08-13

    A novel series of 16-substituted-4-azasteroids has been identified as potential tissue-selective androgen receptor modulators. These ligands display potent hAR binding and agonist activity, low virilizing potential, and good pharmacokinetic profiles in dogs. On the basis of its in vitro profile, 21 was evaluated in the OVX and ORX rat models and exhibited an osteoanabolic, tissue-selective profile.

  8. Character, distribution and biological implications of ice crystallization in cryopreserved rabbit ovarian tissue revealed by cryo-scanning electron microscopy.

    Science.gov (United States)

    Gosden, Roger G; Yin, Hang; Bodine, Richard J; Morris, G John

    2010-02-01

    Ovarian tissue banking is an emerging strategy for fertility preservation which has led to several viable pregnancies after transplantation. However, the standard method of slow cooling was never rigorously optimized for human tissue nor has the extent and location of ice crystals in tissue been investigated. To address this, we used cryo-scanning electron microscopy (cryo-SEM) to study ice formation in cryopreserved ovarian tissue. Rabbit ovarian tissue slices were equilibrated in 1,2-propanediol-sucrose solution and cooled at either 0.3 degrees C/min or 3.0 degrees C/min after nucleating ice at -7 degrees C, or snap-frozen by plunging in liquid nitrogen. Frozen tissues were fractured, etched and coated with gold or prepared by freeze substitution and sectioning for cryo-SEM. The size, location and orientation of extracellular ice crystals were revealed as pits and channels that had grown radially between freeze-concentrated cellular materials. They represented 60% of the total volume in slowly cooled samples that were nucleated at -7 degrees C and the crystals, often >30 microm in length, displaced cells without piercing them. Samples cooled more rapidly were much less dehydrated, accounting for the presence of small ice crystals inside cells and possibly in organelles. Cryo-SEM revealed the internal structure of ovarian tissue in the frozen state was dominated by elongated ice crystals between islands of freeze-concentrated cellular matrix. Despite the grossly distorted anatomy, the greater degree of dehydration and absence of intracellular ice confirmed the superiority of a very slow rate of cooling for optimal cell viability. These ultrastructural methods will be useful for validating and improving new protocols for tissue cryopreservation.

  9. Evaluation of single-tooth replacement by an immediate implant covered with connective tissue graft as a biologic barrier.

    Science.gov (United States)

    Jyothi, S G; Triveni, M G; Mehta, D S; Nandakumar, K

    2013-05-01

    The aim of the present study was to evaluate the survival rate of Screw-Vent(®) immediate implants augmented with sub epithelial connective tissue graft for single-tooth replacement for 1 year. Ten patients (five men and five women), with the mean age of 25.3 years, were consecutively treated on the out-patient basis by the placement of Screw-Vent(®) dental implants in to the fresh extraction sockets in association of augmentation with sub epithelial connective tissue graft harvested from the palate, supporting single crowns. The clinical and radiographic parameters were recorded to evaluate the peri-implant soft tissue health and marginal bone loss, respectively, for each patient at baseline and at every 3 months interval for 1 year. The 1 year cumulative survival rate of Screw-Vent(®) dental implants was 100% for all 10 patients. Statistical analysis demonstrated highly significant values indicating an improvement in peri-implant soft tissue parameters in terms of peri-implant aesthetic parameters, which estimated the keratinized mucosa width. Statistically, non-significant marginal bone loss or gain indicated stable condition in hard tissue parameters. Single-tooth replacement by Screw-Vent(®) dental implants in to a fresh extraction socket, in association with guided bone regeneration using autologous connective tissue graft is a predictable treatment as demonstrated by the 100% implant survival rates and appreciable increase in the width of the keratinized mucosa at 1 year follow up.

  10. Use of high-intensity sonication for pre-treatment of biological tissues prior to multielemental analysis by total reflection X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    De La Calle, Inmaculada; Costas, Marta; Cabaleiro, Noelia; Lavilla, Isela; Bendicho, Carlos

    2012-01-01

    In this work, two ultrasound-based procedures are developed for sample preparation prior to determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se and Sr in biological tissues by total reflection X-ray fluorescence spectrometry. Ultrasound-assisted extraction by means of a cup-horn sonoreactor and ultrasonic-probe slurry sampling were compared with a well-established procedure such as magnetic agitation slurry sampling. For that purpose, seven certified reference materials and different real samples of animal tissue were used. Similar accuracy and precision is obtained with the three sample preparation approaches tried. Limits of detection were dependent on both the sample matrix and the sample pre-treatment used, best values being achieved with ultrasound-assisted extraction. Advantages of ultrasound-assisted extraction include reduced sample handling, decreased contamination risks (neither addition of surfactants nor use of foreign objects inside the extraction vial), simpler background (no solid particles onto the sample carrier) and improved recovery for some elements such as P. A mixture of 10% v/v HNO 3 + 20–40% v/v HCl was suitable for extraction from biological tissues. - Highlights: ► We implement high-intensity sonication for pre-treatment of biological tissues. ► Multielemental analysis is performed by total reflection X-ray spectrometry. ► Ultrasound-based procedures are developed and compared to conventional slurry preparation. ► Features such as background, recovery and sample handling are favored by using ultrasonic extraction.

  11. Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity

    Directory of Open Access Journals (Sweden)

    Boguslawa Żywicka

    2017-10-01

    Full Text Available Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide, (PLGA, and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate (PLGA/PHB. The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

  12. Clinical and biometrical evaluation of socket preservation using demineralized freeze-dried bone allograft with and without the palatal connective tissue as a biologic membrane.

    Science.gov (United States)

    Moghaddas, Hamid; Amjadi, Mohammad Reza; Naghsh, Narges

    2012-11-01

    Alveolar ridge preservation following tooth extraction has the ability to maintain the ridge dimensions and allow the implant placement in an ideal position fulfilling both functional and aesthetic results. The aim of this study was to evaluate the efficacy of the palatal connective tissue as a biological membrane for socket preservation with demineralized freeze-dried bone allograft (DFDBA). Twelve extraction sites were treated with DFDBA with (case group) and without (control group) using autogenous palatal connective tissue membrane before placement of implants. Alveolar width and height, amount of keratinized tissue, and gingival level were measured at pre-determined points using a surgical stent at two times, the time of socket preservation surgery. In both groups a decrease in all socket dimensions was found. The average decrease in socket width, height, keratinized tissue, and gingival level in case group was 1.16, 0.72, 3.58, and 1.27 mm, and in control group was 2.08, 0.86, 4.52, and 1.58 mm respectively. Statistical analysis showed that decrease in socket width (P = 0.012), keratinized tissue (P ≤ 0.001), and gingival level (P = 0.031) in case group was significantly lower than that of the control group. Results showed no meaningful difference in socket height changes when compared with case and control groups (P = 0.148). Under the limits of this study, connective tissue membrane could preserve socket width, amount of keratinized tissue, and the gingival level more effectively than DFDBA alone.

  13. Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

    International Nuclear Information System (INIS)

    Chatelin, Simon; Bernal, Miguel; Deffieux, Thomas; Papadacci, Clément; Nahas, Amir; Boccara, Claude; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu; Flaud, Patrice

    2014-01-01

    Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305–11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original multimodality imaging characterization of this new transverse isotropic (TI) PVA hydrogel. Multiple properties were investigated using a large variety of techniques at different scales compared with an isotropic PVA hydrogel undergoing similar imaging and rheology protocols. The anisotropic mechanical (dynamic and static) properties were studied using supersonic shear wave imaging technique, full-field optical coherence tomography (FFOCT) strain imaging and classical linear rheometry using dynamic mechanical analysis. The anisotropic optical and ultrasonic spatial coherence properties were measured by FFOCT volumetric imaging and backscatter tensor imaging, respectively. Correlation of mechanical and optical properties demonstrates the complementarity of these techniques for the study of anisotropy on a multi-scale range as well as the potential of this TI phantom as fibrous tissue-mimicking phantom for shear wave elastographic applications. (paper)

  14. Anisotropic polyvinyl alcohol hydrogel phantom for shear wave elastography in fibrous biological soft tissue: a multimodality characterization

    Science.gov (United States)

    Chatelin, Simon; Bernal, Miguel; Deffieux, Thomas; Papadacci, Clément; Flaud, Patrice; Nahas, Amir; Boccara, Claude; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-11-01

    Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral tissues are composed of fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these tissues cannot be accurately represented by existing elastography phantoms. Recently, a novel approach for orthotropic hydrogel mimicking soft tissues has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305-11). The mechanical anisotropy is induced in a polyvinyl alcohol (PVA) cryogel by stretching the physical crosslinks of the polymeric chains while undergoing freeze/thaw cycles. In the present study we propose an original multimodality imaging characterization of this new transverse isotropic (TI) PVA hydrogel. Multiple properties were investigated using a large variety of techniques at different scales compared with an isotropic PVA hydrogel undergoing similar imaging and rheology protocols. The anisotropic mechanical (dynamic and static) properties were studied using supersonic shear wave imaging technique, full-field optical coherence tomography (FFOCT) strain imaging and classical linear rheometry using dynamic mechanical analysis. The anisotropic optical and ultrasonic spatial coherence properties were measured by FFOCT volumetric imaging and backscatter tensor imaging, respectively. Correlation of mechanical and optical properties demonstrates the complementarity of these techniques for the study of anisotropy on a multi-scale range as well as the potential of this TI phantom as fibrous tissue-mimicking phantom for shear wave elastographic applications.

  15. Biobanking human endometrial tissue and blood specimens: standard operating procedure and importance to reproductive biology research and diagnostic development.

    Science.gov (United States)

    Sheldon, Elizabeth; Vo, Kim Chi; McIntire, Ramsey A; Aghajanova, Lusine; Zelenko, Zara; Irwin, Juan C; Giudice, Linda C

    2011-05-01

    To develop a standard operating procedure (SOP) for collection, transport, storage of human endometrial tissue and blood samples, subject and specimen annotation, and establishing sample priorities. The SOP synthesizes sound scientific procedures, the literature on ischemia research, sample collection and gene expression profiling, good laboratory practices, and the authors' experience of workflow and sample quality. The National Institutes of Health, University of California, San Francisco, Human Endometrial Tissue and DNA Bank. Women undergoing endometrial biopsy or hysterectomy for nonmalignant indications. Collecting, processing, storing, distributing endometrial tissue and blood samples under approved institutional review board protocols and written informed consent from participating subjects. Standard operating procedure. The SOP addresses rigorous and consistent subject annotation, specimen processing and characterization, strict regulatory compliance, and a reference for researchers to track collection and storage times that may influence their research. The comprehensive and systematic approach to the procurement of human blood and endometrial tissue in this SOP ensures the high quality, reliability, and scientific usefulness of biospecimens made available to investigators by the National Institutes of Health, University of California, San Francisco, Human Endometrial Tissue and DNA Bank. The detail and perspective in this SOP also provides a blueprint for implementation of similar collection programs at other institutions. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  16. Analysis of classical Fourier, SPL and DPL heat transfer model in biological tissues in presence of metabolic and external heat source

    Science.gov (United States)

    Kumar, Dinesh; Singh, Surjan; Rai, K. N.

    2016-06-01

    In this paper, the temperature distribution in a finite biological tissue in presence of metabolic and external heat source when the surface subjected to different type of boundary conditions is studied. Classical Fourier, single-phase-lag (SPL) and dual-phase-lag (DPL) models were developed for bio-heat transfer in biological tissues. The analytical solution obtained for all the three models using Laplace transform technique and results are compared. The effect of the variability of different parameters such as relaxation time, metabolic heat source, spatial heat source, different type boundary conditions on temperature distribution in different type of the tissues like muscle, tumor, fat, dermis and subcutaneous based on three models are analyzed and discussed in detail. The result obtained in three models is compared with experimental observation of Stolwijk and Hardy (Pflug Arch 291:129-162, 1966). It has been observe that the DPL bio-heat transfer model provides better result in comparison of other two models. The value of metabolic and spatial heat source in boundary condition of first, second and third kind for different type of thermal therapies are evaluated.

  17. Modeling the thermo-acoustic effects of thermal-dependent speed of sound and acoustic absorption of biological tissues during focused ultrasound hyperthermia.

    Science.gov (United States)

    López-Haro, S A; Gutiérrez, M I; Vera, A; Leija, L

    2015-10-01

    To evaluate the effects of thermal dependence of speed of sound (SOS) and acoustic absorption of biological tissues during noninvasive focused ultrasound (US) hyperthermia therapy. A finite element (FE) model was used to simulate hyperthermia therapy in the liver by noninvasive focused US. The model consisted of an ultrasonic focused transducer radiating a four-layer biological medium composed of skin, fat, muscle, and liver. The acoustic field and temperature distribution along the layers were obtained after 15 s of hyperthermia therapy using the bio-heat equation. The model solution was found with and without the thermal dependence of SOS and acoustic absorption of biological tissues. The inclusion of the thermal dependence of the SOS generated an increment of 0.4 mm in the longitudinal focus axis of the acoustic field. Moreover, results indicate an increment of the hyperthermia area (zone with temperature above 43 °C), and a maximum temperature difference of almost 3.5 °C when the thermal dependence of absorption was taken into account. The increment of the achieved temperatures at the treatment zone indicated that the effects produced by the thermal dependence of SOS and absorption must be accounted for when planning hyperthermia treatment in order to avoid overheating undesired regions.

  18. Study of the conditions necessary for propane-jet freezing of fresh biological tissues without detectable ice formation.

    Science.gov (United States)

    Haggis, G H

    1986-09-01

    The performance of a commercial double-propane-jet freezer (Balzers QFD 101) has been assessed, for rapid freezing of fresh tissues in freeze-etch work. Samples of diaphragm muscle and intestinal villi were frozen between copper sheets, with a spacer to give 20-30 microns thickness of tissue. Fracture cuts were made with the Balzers BAF 400 freeze-etch microtome within 5-10 microns of a freezing face (i.e. a tissue face in contact with the copper sheets of the frozen sandwich). After some modifications to the QFD 101, replicas showing no evidence of ice were obtained of muscle cells, although for intestinal epithelial cells some evidence of ice formation was found. Infiltration with 5% glycerol or dimethylsulphoxide improves the depth of good freezing. Results and problems arising from such infiltration are briefly discussed.

  19. Synthetic fossilization of soft biological tissues and their shape-preserving transformation into silica or electron-conductive replicas.

    Science.gov (United States)

    Townson, Jason L; Lin, Yu-Shen; Chou, Stanley S; Awad, Yasmine H; Coker, Eric N; Brinker, C Jeffrey; Kaehr, Bryan

    2014-12-08

    Structural preservation of complex biological systems from the subcellular to whole organism level in robust forms, enabling dissection and imaging while preserving 3D context, represents an enduring grand challenge in biology. Here we report a simple immersion method for structurally preserving intact organisms via conformal stabilization within silica. This self-limiting process, which we refer to as silica bioreplication, occurs by condensation of water-soluble silicic acid proximally to biomolecular interfaces throughout the organism. Conformal nanoscopic silicification of all biomolecular features imparts structural rigidity enabling the preservation of shape and nano-to-macroscale dimensional features upon drying to form a biocomposite and further high temperature oxidative calcination to form silica replicas or reductive pyrolysis to form electrically conductive carbon replicas of complete organisms. The simplicity and generalizability of this approach should facilitate efforts in biological preservation and analysis and could enable the development of new classes of biomimetic composite materials.

  20. Extended automated separation techniques in destructive neutron activation analysis; application to various biological materials, including human tissues and blood

    International Nuclear Information System (INIS)

    Tjioe, P.S.; Goeij, J.J.M. de; Houtman, J.P.W.

    1976-09-01

    Neutron activation analysis may be performed as a multi-element and low-level technique for many important trace elements in biological materials, provided that post-irradiation chemical separations are applied. This paper describes a chemical separation consisting of automated procedures for destruction, distillation, and anion-chromatography. The system developed enables the determination of 14 trace elements in biological materials, viz. antimony, arsenic, bromine, cadmium, chromium, cobalt, copper, gold, iron, mercury, molybdenum, nickel, selenium, and zinc. The aspects of sample preparation, neutron irradiation, gamma-spectrum evaluation, and blank-value contribution are also discussed

  1. Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features

    Directory of Open Access Journals (Sweden)

    Schlegel Karl A

    2010-10-01

    Full Text Available Abstract Background Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL; however, osteonecrosis of the jaw (ONJ is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP-related and denosumab (anti-RANKL antibody-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL in ONJ-altered and healthy periodontal tissue. Methods Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment. Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels. Results Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p Conclusions These results explain the sclerotic and osteopetrotic changes of periodontal tissue following BP application and substantiate clinical findings of BP-related impaired remodeling specific to periodontal tissue. RANKL suppression substantiated the clinical finding of impaired bone remodelling in BP- and aRANKL-induced ONJ-affected bone structures. Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in cellular differentiation that occurred exclusively jaw remodelling. Further research on developmental biology-related unique features of jaw bone structures will help to elucidate pathologies restricted to

  2. Asymmetric PDLLA membranes containing Bioglass(R) for guided tissue regeneration: characterization and in vitro biological behavior

    NARCIS (Netherlands)

    Leal, A.I.; Caridade, S.G.; Ma, J.; Yu, N.; Gomes, M.; Reis, R.L.; Jansen, J.A.; Walboomers, X.F.; Mano, J.F.

    2013-01-01

    OBJECTIVE: In the treatment of periodontal defects, composite membranes might be applied to protect the injured area and simultaneously stimulate tissue regeneration. This work describes the development and characterization of poly(d,l-lactic acid)/Bioglass(R) (PDLLA/BG) composite membranes with

  3. Detection of cancerous biological tissue areas by means of infrared absorption and SERS spectroscopy of intercellular fluid

    Science.gov (United States)

    Velicka, M.; Urboniene, V.; Ceponkus, J.; Pucetaite, M.; Jankevicius, F.; Sablinskas, V.

    2015-08-01

    We present a novel approach to the detection of cancerous kidney tissue areas by measuring vibrational spectra (IR absorption or SERS) of intercellular fluid taken from the tissue. The method is based on spectral analysis of cancerous and normal tissue areas in order to find specific spectral markers. The samples were prepared by sliding the kidney tissue over a substrate - surface of diamond ATR crystal in case of IR absorption or calcium fluoride optical window in case of SERS. For producing the SERS signal the dried fluid film was covered by silver nanoparticle colloidal solution. In order to suppress fluorescence background the measurements were performed in the NIR spectral region with the excitation wavelength of 1064 nm. The most significant spectral differences - spectral markers - were found in the region between 400 and 1800 cm-1, where spectral bands related to various vibrations of fatty acids, glycolipids and carbohydrates are located. Spectral markers in the IR and SERS spectra are different and the methods can complement each other. Both of them have potential to be used directly during surgery. Additionally, IR absorption spectroscopy in ATR mode can be combined with waveguide probe what makes this method usable in vivo.

  4. A new composite hydrogel combining the biological properties of collagen with the mechanical properties of a supramolecular scaffold for bone tissue engineering.

    Science.gov (United States)

    Maisani, Mathieu; Ziane, Sophia; Ehret, Camille; Levesque, Lucie; Siadous, Robin; Le Meins, Jean-François; Chevallier, Pascale; Barthélémy, Philippe; De Oliveira, Hugo; Amédée, Joëlle; Mantovani, Diego; Chassande, Olivier

    2018-03-01

    Tissue engineering is a promising alternative to autografts, allografts, or biomaterials to address the treatment of severe and large bone lesions. Classically, tissue engineering products associate a scaffold and cells and are implanted or injected into the lesion. These cells must be embedded in an appropriate biocompatible scaffold, which offers a favourable environment for their survival and differentiation. Here, we designed a composite hydrogel composed of collagen I, an extracellular matrix protein widely used in several therapeutic applications, which we associated with a physical hydrogel generated from a synthetic small amphiphilic molecule. This composite showed improved mechanical and biological characteristics as compared with gels obtained from each separate compound. Incorporation of the physical hydrogel prevented shrinkage of collagen and cell diffusion out of the gel and yielded a gel with a higher elastic modulus than those of gels obtained with each component alone. The composite hydrogel allowed cell adhesion and proliferation in vitro and long-term cell survival in vivo. Moreover, it promoted the differentiation of human adipose-derived stem cells in the absence of any osteogenic factors. In vivo, cells embedded in the composite gel and injected subcutaneously in immunodeficient mice produced lamellar osteoid tissue and differentiated into osteoblasts. This study points this new composite hydrogel as a promising scaffold for bone tissue engineering applications. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Electrical impedance spectroscopy (EIS)-based evaluation of biological tissue phantoms to study multifrequency electrical impedance tomography (Mf-EIT) systems

    KAUST Repository

    Bera, Tushar Kanti

    2016-03-18

    Abstract: Electrical impedance tomography (EIT) phantoms are essential for the calibration, comparison and evaluation of the EIT systems. In EIT, the practical phantoms are typically developed based on inhomogeneities surrounded by a homogeneous background to simulate a suitable conductivity contrast. In multifrequency EIT (Mf-EIT) evaluation, the phantoms must be developed with the materials which have recognizable or distinguishable impedance variations over a wide range of frequencies. In this direction the impedance responses of the saline solution (background) and a number vegetable and fruit tissues (inhomogeneities) are studied with electrical impedance spectroscopy (EIS) and the frequency responses of bioelectrical impedance and conductivity are analyzed. A number of practical phantoms with different tissue inhomogeneities and different inhomogeneity configurations are developed and the multifrequency impedance imaging is studied with the Mf-EIT system to evaluate the phantoms. The conductivity of the vegetable inhomogeneities reconstructed from the EIT imaging is compared with the conductivity values obtained from the EIS studies. Experimental results obtained from multifrequency EIT reconstruction demonstrate that the electrical impedance of all the biological tissues inhomogenity decreases with frequency. The potato tissue phantom produces better impedance image in high frequency ranges compared to the cucumber phantom, because the cucumber impedance at high frequency becomes lesser than that of the potato at the same frequency range. Graphical Abstract: [Figure not available: see fulltext.] © 2016 The Visualization Society of Japan

  6. Neuromorphic UAS Collision Avoidance

    Data.gov (United States)

    National Aeronautics and Space Administration — Collision avoidance for unmanned aerial systems (UAS) traveling at high relative speeds is a challenging task. It requires both the detection of a possible collision...

  7. Collision Repair Campaign

    Science.gov (United States)

    The Collision Repair Campaign targets meaningful risk reduction in the Collision Repair source category to reduce air toxic emissions in their communities. The Campaign also helps shops to work towards early compliance with the Auto Body Rule.

  8. Quantitative autoradiography of radionuclides in biological tissues by high resolution nuclear analysis: application in radio-toxicology and dosimetry

    International Nuclear Information System (INIS)

    Aubineau Laniece, I.

    1997-01-01

    In the framework of radiation damage on cells in living organisms an auto-radiograph, based on the STIC method, has been developed for the particles detection. This apparatus associates a thin scintillator with a photosensitive detector (CCD). The design and the performance of this well adapted tool for low activity biological samples study, are described. (A.L.B.)

  9. Hybrid chitosan-ß-glycerol phosphate-gelatin nano-/micro fibrous scaffolds with suitable mechanical and biological properties for tissue engineering.

    Science.gov (United States)

    Lotfi, Marzieh; Bagherzadeh, Roohollah; Naderi-Meshkin, Hojjat; Mahdipour, Elahe; Mafinezhad, Asghar; Sadeghnia, Hamid Reza; Esmaily, Habibollah; Maleki, Masoud; Hasssanzadeh, Halimeh; Ghayaour-Mobarhan, Majid; Bidkhori, Hamid Reza; Bahrami, Ahmad Reza

    2016-03-01

    Scaffold-based tissue engineering is considered as a promising approach in the regenerative medicine. Graft instability of collagen, by causing poor mechanical properties and rapid degradation, and their hard handling remains major challenges to be addressed. In this research, a composite structured nano-/microfibrous scaffold, made from a mixture of chitosan-ß-glycerol phosphate-gelatin (chitosan-GP-gelatin) using a standard electrospinning set-up was developed. Gelatin-acid acetic and chitosan ß-glycerol phosphate-HCL solutions were prepared at ratios of 30/70, 50/50, 70/30 (w/w) and their mechanical and biological properties were engineered. Furthermore, the pore structure of the fabricated nanofibrous scaffolds was investigated and predicted using a theoretical model. Higher gelatin concentrations in the polymer blend resulted in significant increase in mean pore size and its distribution. Interaction between the scaffold and the contained cells was also monitored and compared in the test and control groups. Scaffolds with higher chitosan concentrations showed higher rate of cell attachment with better proliferation property, compared with gelatin-only scaffolds. The fabricated scaffolds, unlike many other natural polymers, also exhibit non-toxic and biodegradable properties in the grafted tissues. In conclusion, the data clearly showed that the fabricated biomaterial is a biologically compatible scaffold with potential to serve as a proper platform for retaining the cultured cells for further application in cell-based tissue engineering, especially in wound healing practices. These results suggested the potential of using mesoporous composite chitosan-GP-gelatin fibrous scaffolds for engineering three-dimensional tissues with different inherent cell characteristics. © 2015 Wiley Periodicals, Inc.

  10. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  11. Periradicular Tissue Responses to Biologically Active Molecules or MTA When Applied in Furcal Perforation of Dogs' Teeth

    OpenAIRE

    Zairi, Anna; Lambrianidis, Theodoros; Pantelidou, Ourania; Papadimitriou, Serafim; Tziafas, Dimitrios

    2012-01-01

    The aim of this study was the comparative evaluation of inflammatory reactions and tissue responses to four growth factors, or mineral trioxide aggregate (MTA), or a zinc-oxide-eugenol-based cement (IRM) as controls, when used for the repair of furcal perforations in dogs' teeth. Results showed significantly higher inflammatory cell response in the transforming growth factor ? 1 (TGF ? 1) and zinc-oxide-eugenol-based cement (IRM) groups and higher rates of epithelial proliferation in the TGF ...

  12. Study on lethal effect on cells by determination of 10B in biological tissues and (n, α) reaction

    International Nuclear Information System (INIS)

    Ishida, Masahiro; Tsuruta, Takao; Takagaki, Masao

    1980-01-01

    As for the macroscopic distribution in tissues and microscopic distribution in cells of 10 B administrated to patients, which are important in thermal neutron capture therapy, it is difficult to say that the method of quantitative determination has been established. The authors tried some experiments by solid state track detection for the determination. That is, the trial determinations of boron in cells by solution method (wet process), filter paper method (dry process) and the method using an electron microscope are reported. If the maximum thermal neutron fluence available is assumed to be 10 14 /cm 2 and the minimum detectable surface density of etch pits is 10 4 /cm 2 , the detection limit of 10 B concentration is estimated as about 10 -2 μg/ml either in the solution method or in the filter paper method. In the quantitative determination of boron distribution at cell level with an electron microscope, a sample of tissue was covered with a plastic thin film, etched after the irradiation with thermal neutrons, and the tissue and the thin film were simultaneously observed with the transmission electron microscope. The thin film thickness of about 0.1 μm is suitable for the sliced tissue of about 0.1 μm thick. The existence of fast neutrons at the time of thermal neutron irradiation causes the generation of etch pits by recoiled particles in celluloid, and increases background counts, while γ-dose above 10 6 rad leads to the deterioration of celluloid composition. Some automatic methods of counting etch pits under consideration are described. (Wakatsuki, Y.)

  13. Mechanical and biological evaluations of beta-tricalcium phosphate/silicone rubber composite as a novel soft-tissue implant.

    Science.gov (United States)

    Zhang, Yi-ming; Wang, Shao-liang; Lei, Ze-yuan; Fan, Dong-li

    2009-09-01

    Although silicone rubber (SR) implants are most commonly used and effective for soft-tissue augmentation, they still have been implicated in many adverse reactions. To overcome this problem, a novel composite beta-tricalcium phosphate/silicone rubber (beta-TCP/SR) was prepared by adding beta-TCP into a SR matrix. This study was to evaluate its application potential by investigating the mechanical properties and biocompatibility of beta-TCP/SR. Mechanical properties, including Shore A hardness and tensile strength, were evaluated with 3-mm-thick samples and a universal testing machine. Cytocompatibility tests were conducted in vitro using 0.2-mm-thick beta-TCP/SR samples by seeding fibroblasts onto different samples. Soft-tissue response to beta-TCP/SR and pull-out measurements were investigated 4 weeks and 24 weeks after implantation. The main mechanical properties were all significantly changed after mixing beta-TCP into the SR matrix, except for tearing strength. The cytocompatibility test showed enhanced adhesion and proliferation of fibroblasts onto beta-TCP/SR. Fibrous tissue ingrowth after resorption of beta-TCP was observed by in vivo histologic analysis. The peri-implant capsules in the beta-TCP/SR group were thinner than in the SR group 24 weeks after implantation. In a 24-week test, the maximum force required to pull out the beta-TCP/SR sheet was about six times greater than that needed for SR. Although some mechanical properties were significantly changed, the results of the cytocompatibility test and in vivo animal study still suggest that beta-TCP/SR may be more suitable as a soft-tissue implant than SR and has the potential to be used in plastic surgery.

  14. Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

    OpenAIRE

    Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

    2013-01-01

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa...

  15. Nanoelectronics-biology frontier: From nanoscopic probes for action potential recording in live cells to three-dimensional cyborg tissues

    OpenAIRE

    Duan, Xiaojie; Fu, Tian-Ming; Liu, Jia; Lieber, Charles M.

    2013-01-01

    Semiconductor nanowires configured as the active channels of field-effect transistors (FETs) have been used as detectors for high-resolution electrical recording from single live cells, cell networks, tissues and organs. Extracellular measurements with substrate supported silicon nanowire (SiNW) FETs, which have projected active areas orders of magnitude smaller than conventional microfabricated multielectrode arrays (MEAs) and planar FETs, recorded action potential and field potential signa...

  16. Regeneration of articular cartilage by adipose tissue derived mesenchymal stem cells: perspectives from stem cell biology and molecular medicine.

    Science.gov (United States)

    Wu, Ling; Cai, Xiaoxiao; Zhang, Shu; Karperien, Marcel; Lin, Yunfeng

    2013-05-01

    Adipose-derived stem cells (ASCs) have been discovered for more than a decade. Due to the large numbers of cells that can be harvested with relatively little donor morbidity, they are considered to be an attractive alternative to bone marrow derived mesenchymal stem cells. Consequently, isolation and differentiation of ASCs draw great attention in the research of tissue engineering and regenerative medicine. Cartilage defects cause big therapeutic problems because of their low self-repair capacity. Application of ASCs in cartilage regeneration gives hope to treat cartilage defects with autologous stem cells. In recent years, a lot of studies have been performed to test the possibility of using ASCs to re-construct damaged cartilage tissue. In this article, we have reviewed the most up-to-date articles utilizing ASCs for cartilage regeneration in basic and translational research. Our topic covers differentiation of adipose tissue derived mesenchymal stem cells into chondrocytes, increased cartilage formation by co-culture of ASCs with chondrocytes and enhancing chondrogenic differentiation of ASCs by gene manipulation. Copyright © 2012 Wiley Periodicals, Inc.

  17. Bimodal spectroscopy in elastic scattering and spatially resolved auto-fluorescence: instrumentation, light-tissues interaction modeling and application to ex vivo and in vivo biological tissues characterization for cancers detection

    International Nuclear Information System (INIS)

    Pery, Emilie

    2007-01-01

    This research activity aims at developing and validating a multimodal spectroscopy method in elastic scattering and auto-fluorescence to characterize biological tissues in vitro and in vivo. It is articulated in four axes. At first, instrumentation is considered with the development, the engineering and the experimental characterization of a fibers bimodal, multi-points spectrometry system allowing the acquisition of spectra in vivo (variable distances, fast acquisition). Secondly, the optical properties of tissues are modelled with the development and the experimental validation on phantoms of a photons propagation simulation algorithm in turbid media and multi-fluorescent. Thirdly, an experimental study has been conducted ex vivo on fresh and cryo-preserved arterial rings. It confirms the complementarity of spectroscopic measurements in elastic scattering and auto-fluorescence, and validates the method of multi-modality spectroscopy and the simulation of photons propagation algorithm. Results have well proved a correlation between rheological and optical properties. Finally, one second experimental study in vivo related to a pre-clinical tumoral model of bladder has been carried out. It highlights a significant difference in diffuse reflectance and/or auto-fluorescence and/or intrinsic fluorescence between healthy, inflammatory and tumoral tissues, on the basis of specific wavelength. The results of not supervised classification show that the combination of various spectroscopic approaches increases the reliability of the diagnosis. (author) [fr

  18. X-ray phase microtomography with a single grating for high-throughput investigations of biological tissue.

    Science.gov (United States)

    Zdora, Marie-Christine; Vila-Comamala, Joan; Schulz, Georg; Khimchenko, Anna; Hipp, Alexander; Cook, Andrew C; Dilg, Daniel; David, Christian; Grünzweig, Christian; Rau, Christoph; Thibault, Pierre; Zanette, Irene

    2017-02-01

    The high-throughput 3D visualisation of biological specimens is essential for studying diseases and developmental disorders. It requires imaging methods that deliver high-contrast, high-resolution volumetric information at short sample preparation and acquisition times. Here we show that X-ray phase-contrast tomography using a single grating can provide a powerful alternative to commonly employed techniques, such as high-resolution episcopic microscopy (HREM). We present the phase tomography of a mouse embryo in paraffin obtained with an X-ray single-grating interferometer at I13-2 Beamline at Diamond Light Source and discuss the results in comparison with HREM measurements. The excellent contrast and quantitative density information achieved non-destructively and without staining using a simple, robust setup make X-ray single-grating interferometry an optimum candidate for high-throughput imaging of biological specimens as an alternative for existing methods like HREM.

  19. Influence of length of interval between pulses in PDR brachytherapy (PDRBT on value of Biologically Equivalent Dose (BED in healthy tissues

    Directory of Open Access Journals (Sweden)

    Tomasz Piotrowski

    2010-07-01

    Full Text Available Purpose: Different PDR treatment schemas are used in clinical practice, however optimal length of interval between pulses still remains unclear. The aim of this work was to compare value of BED doses measured in surrounded healthy tissues according to different intervals between pulses in PDRBT. Influence of doses optimization on BED values was analyzed.Material and methods: Fifty-one patients treated in Greater Poland Cancer Centre were qualified for calculations.Calculations of doses were made in 51 patients with head and neck cancer, brain tumor, breast cancer, sarcoma, penis cancer and rectal cancer. Doses were calculated with the use of PLATO planning system in chosen critical points in surrounded healthy tissues. For all treatment plans the doses were compared using Biologically Equivalent Dose formula.Three interval lengths (1, 2 and 4 hours between pulses were chosen for calculations. For statistical analysis Friedman ANOVA test and Kendall ratio were used.Results: The median value of BED in chosen critical points in healthy tissues was statistically related to the length of interval between PDR pulses and decreased exponentially with 1 hour interval to 4 hours (Kendall = from 0.48 to 1.0; p = from 0.002 to 0.00001.Conclusions: Prolongation of intervals between pulses in PDR brachytherapy was connected with lower values of BED doses in healthy tissues. It seems that longer intervals between pulses reduced the risk of late complications, but also decreased the tumour control. Furthermore, optimization influenced the increase of doses in healthy tissues.

  20. Side-by-Side Comparison of the Biological Characteristics of Human Umbilical Cord and Adipose Tissue-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Li Hu

    2013-01-01

    Full Text Available Both human adipose tissue-derived mesenchymal stem cells (ASCs and umbilical cord-derived mesenchymal stem cells (UC-MSCs have been explored as attractive mesenchymal stem cells (MSCs sources, but very few parallel comparative studies of these two cell types have been made. We designed a side-by-side comparative study by isolating MSCs from the adipose tissue and umbilical cords from mothers delivering full-term babies and thus compared the various biological aspects of ASCs and UC-MSCs derived from the same individual, in one study. Both types of cells expressed cell surface markers characteristic of MSCs. ASCs and UC-MSCs both could be efficiently induced into adipocytes, osteoblasts, and neuronal phenotypes. While there were no significant differences in their osteogenic differentiation, the adipogenesis of ASCs was more prominent and efficient than UC-MSCs. In the meanwhile, ASCs responded better to neuronal induction methods, exhibiting the higher differentiation rate in a relatively shorter time. In addition, UC-MSCs exhibited a more prominent secretion profile of cytokines than ASCs. These results indicate that although ASCs and UC-MSCs share considerable similarities in their immunological phenotype and pluripotentiality, certain biological differences do exist, which might have different implications for future cell-based therapy.

  1. Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

    Science.gov (United States)

    Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

    2017-06-01

    In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

  2. Elemental analysis of biological tissues of Dmdmdx/J and C57BL/6J mice strains investigated by neutron activation analysis

    International Nuclear Information System (INIS)

    Sabrina Metairon; Zamboni, C.B.; Suzuki, M.F.; Bueno Junior, C.R.; Sant'Anna, O.A.

    2013-01-01

    In order to understand in more details the alterations that Duchenne muscular dystrophy disease may cause in biological tissues (blood, tibia, quadriceps and heart), correlations matrixes of the Dmd mdx /J dystrophic mice as well as C57BL/6J (control group) were generated. These mice were obtained from Jackson Laboratory (Maine, USA) and bred at IPEN (Dmd mdx /J), and at Centro de Estudos do Genoma Humano (C57BL/6J), both research centers at Sao Paulo city. Elements of clinical and nutritional relevance (Br, Ca, Cl, K, Mg, Na and S) were investigated by neutron activation analysis. These measurements were performed using the nuclear reactor IEA-R1 (3.5-4.5 MW, pool type) at IPEN. Comparisons between concentrations and correlations in these biological tissues, of these strains, showed that a Ca and Mg in blood are altered for the dystrophic mice. A significant change in the heart of dystrophic mice was also observed suggesting that a constant monitoring is required. Moreover, these results may help the researchers to evaluate the efficiency of new treatments and to compare the advantages of different treatment approaches before performing tests in patients with muscular dystrophy. (author)

  3. Biological activity of the functional epitope of ciguatoxin fragment AB on the neuroblastoma sodium channel in tissue culture.

    Science.gov (United States)

    Hokama, Y; Chun, K E; Campora, C E; Higa, N; Suma, C; Hamajima, A; Isobe, M

    2006-01-01

    It is well established that the targeted receptor for ciguatoxin (CTX) in mammalian tissues is the sodium channel, affecting the influx of sodium into cells and altering the action potential and function of the cell. Since the syntheses of fragments of CTX has become available, our focus has been on the receptor functions of the west sphere AB and east sphere JKLM fragments using the neuroblastoma cell assay, guinea pig atrium assay, and the membrane immunobead assay (MIA). The data presented here suggest that the west sphere AB of the ciguatoxin molecule is the active portion and is responsible for the activation of the sodium channels. (c) 2006 Wiley-Liss, Inc.

  4. Two-point Stokes vector parameters of object field for diagnosis and differentiation of optically anisotropic biological tissues

    Science.gov (United States)

    Dubolazov, O. V.; Trifonyuk, L.; Marchuk, Yu.; Ushenko, Yu. O.; Zhytaryuk, V. G.; Prydiy, O. G.; Kushnerik, L.; Meglinskiy, I.

    2017-08-01

    A new method of Stokes correlometry of polarization-inhomogeneous images of biological layers is presented. Analytic relations are determined for the modulus of complex parameters of the Stokes vector. A technique for measuring the coordinate distributions of the magnitude of the two-point modulus of the Stokes vector is proposed. Objective criteria for differentiating the optical anisotropy of polycrystalline urine films of healthy donors and patients with albuminuria have been found. An excellent level of balanced accuracy of differential diagnostics has been achieved.

  5. Metabolic Reconstruction of Setaria italica: A Systems Biology Approach for Integrating Tissue-Specific Omics and Pathway Analysis of Bioenergy Grasses.

    Science.gov (United States)

    de Oliveira Dal'Molin, Cristiana G; Orellana, Camila; Gebbie, Leigh; Steen, Jennifer; Hodson, Mark P; Chrysanthopoulos, Panagiotis; Plan, Manuel R; McQualter, Richard; Palfreyman, Robin W; Nielsen, Lars K

    2016-01-01

    The urgent need for major gains in industrial crops productivity and in biofuel production from bioenergy grasses have reinforced attention on understanding C4 photosynthesis. Systems biology studies of C4 model plants may reveal important features of C4 metabolism. Here we chose foxtail millet (Setaria italica), as a C4 model plant and developed protocols to perform systems biology studies. As part of the systems approach, we have developed and used a genome-scale metabolic reconstruction in combination with the use of multi-omics technologies to gain more insights into the metabolism of S. italica. mRNA, protein, and metabolite abundances, were measured in mature and immature stem/leaf phytomers, and the multi-omics data were integrated into the metabolic reconstruction framework to capture key metabolic features in different developmental stages of the plant. RNA-Seq reads were mapped to the S. italica resulting for 83% coverage of the protein coding genes of S. italica. Besides revealing similarities and differences in central metabolism of mature and immature tissues, transcriptome analysis indicates significant gene expression of two malic enzyme isoforms (NADP- ME and NAD-ME). Although much greater expression levels of NADP-ME genes are observed and confirmed by the correspondent protein abundances in the samples, the expression of multiple genes combined to the significant abundance of metabolites that participates in C4 metabolism of NAD-ME and NADP-ME subtypes suggest that S. italica may use mixed decarboxylation modes of C4 photosynthetic pathways under different plant developmental stages. The overall analysis also indicates different levels of regulation in mature and immature tissues in carbon fixation, glycolysis, TCA cycle, amino acids, fatty acids, lignin, and cellulose syntheses. Altogether, the multi-omics analysis reveals different biological entities and their interrelation and regulation over plant development. With this study, we demonstrated

  6. Metabolic reconstruction of Setaria italica: a systems biology approach for integrating tissue-specific omics and pathway analysis of bioenergy grasses

    Directory of Open Access Journals (Sweden)

    Cristiana Gomes De Oliveira Dal'molin

    2016-08-01

    Full Text Available The urgent need for major gains in industrial crops productivity and in biofuel production from bioenergy grasses have reinforced attention on understanding C4 photosynthesis. Systems biology studies of C4 model plants may reveal important features of C4 metabolism. Here we chose foxtail millet (Setaria italica, as a C4 model plant and developed protocols to perform systems biology studies. As part of the systems approach, we have developed and used a genome-scale metabolic reconstruction in combination with the use of multi-omics technologies to gain more insights into the metabolism of S.italica. mRNA, protein and metabolite abundances, were measured in mature and immature stem/leaf phytomers and the multi-omics data were integrated into the metabolic reconstruction framework to capture key metabolic features in different developmental stages of the plant. RNA-Seq reads were mapped to the S. italica resulting for 83% coverage of the protein coding genes of S. italica. Besides revealing similarities and differences in central metabolism of mature and immature tissues, transcriptome analysis indicates significant gene expression of two malic enzyme isoforms (NADP- ME and NAD-ME. Although much greater expression levels of NADP-ME genes are observed and confirmed by the correspondent protein abundances in the samples, the expression of multiple genes combined to the significant abundance of metabolites that participates in C4 metabolism of NAD-ME and NADP-ME subtypes suggest that S. italica may use mixed decarboxylation modes of C4 photosynthetic pathways under different plant developmental stages. The overall analysis also indicates different levels of regulation in mature and immature tissues in carbon fixation, glycolysis, TCA cycle, amino acids, fatty acids, lignin and cellulose syntheses. Altogether, the multi-omics analysis reveals different biological entities and their interrelation and regulation over plant development. With this study

  7. Gene expression in normal-appearing tissue adjacent to prostate cancers are predictive of clinical outcome: evidence for a biologically meaningful field effect

    Science.gov (United States)

    Magi-Galluzzi, Cristina; Maddala, Tara; Falzarano, Sara Moscovita; Cherbavaz, Diana B.; Zhang, Nan; Knezevic, Dejan; Febbo, Phillip G.; Lee, Mark; Lawrence, Hugh Jeffrey; Klein, Eric A.

    2016-01-01

    Purpose We evaluated gene expression in histologically normal-appearing tissue (NT) adjacent to prostate tumor in radical prostatectomy specimens, assessing for biological significance based on prediction of clinical recurrence (cR - metastatic disease or local recurrence). Results A total of 410 evaluable patients had paired tumor and NT. Fortysix genes, representing diverse biological pathways (androgen signaling, stromal response, stress response, cellular organization, proliferation, cell adhesion, and chromatin remodeling) were associated with cR in NT (FDR < 20%), of which 39 concordantly predicted cR in tumor (FDR < 20%). Overall GPS and its stromal response and androgen-signaling gene group components also significantly predicted time to cR in NT (RM-corrected HR/20 units = 1.25; 95% CI: 1.01-1.56; P = 0.024). Experimental Design Expression of 732 genes was measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) separately in tumor and adjacent NT specimens from 127 patients with and 374 without cR following radical prostatectomy for T1/T2 prostate cancer. A 17-gene expression signature (Genomic Prostate Score [GPS]), previously validated to predict aggressive prostate cancer when measured in tumor tissue, was also assessed using pre-specified genes and algorithms. Analysis used Cox proportional hazards models, Storey's false discovery rate (FDR) control, and regression to the mean (RM) correction. Conclusions Gene expression profiles, including GPS, from NT adjacent to tumor can predict prostate cancer outcome. These findings suggest that there is a biologically significant field effect in primary prostate cancer that is a marker for aggressive disease. PMID:27121323

  8. PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

    International Nuclear Information System (INIS)

    Sultana, Naznin; Wang Min

    2012-01-01

    Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

  9. A non-invasive diffuse reflectance calibration-free method for absolute determination of exogenous biochemicals concentration in biological tissues

    Science.gov (United States)

    Lappa, Alexander V.; Kulikovskiy, Artem N.; Busarov, Oleg G.

    2014-03-01

    The paper presents a new method for distant non-destructive determination of concentration of light absorbing admixtures in turbid media. In particular, it is intended for non-invasive in vivo control of accumulation in patient tissues of various biochemicals introduced to the patients for chemotherapy, photodynamic therapy or diagnostics. It is require that the admixture absorption spectrum should have a clearly marked peak in the wavelength region where the pure medium one varies regularly. Fluorescence of admixtures is not required. The method uses the local diffuse reflectance spectroscopy with optical fiber probe including one emitting and two reading There are several features in the method: the value to be determined is absolute concentration of admixtures; the method needs no calibration measurements on phantoms; it needs no reference measurements on sample with zero admixture concentration; it uses a two parametric kinetic light propagation model and original algorithms to resolve direct and inverse tasks of radiation transport theory. Experimental testing passed with tissue equivalent phantoms and different admixtures, including a chlorine photosensitizer, showed accuracy under 10% in all cases.

  10. Ambient Molecular Analysis of Biological Tissue Using Low-Energy, Femtosecond Laser Vaporization and Nanospray Postionization Mass Spectrometry

    Science.gov (United States)

    Shi, Fengjian; Flanigan, Paul M.; Archer, Jieutonne J.; Levis, Robert J.

    2016-03-01

    Direct analysis of plant and animal tissue samples by laser electrospray mass spectrometry (LEMS) was investigated using low-energy, femtosecond duration laser vaporization at wavelengths of 800 and 1042 nm followed by nanospray postionization. Low-energy (molecular species in fresh flower petal and leaf samples using 435 fs, 10 Hz bursts of 20 pulses from a Ytterbium-doped fiber laser and revealed comparable results to high energy (75-1120 μJ), 45 fs, 800 nm Ti:Sapphire-based LEMS (Ti:Sapphire-LEMS) measurements. Anthocyanins, sugars, and other metabolites were successfully detected and revealed the anticipated metabolite profile for the petal and leaf samples. Phospholipids, especially phosphatidylcholine, were identified from a fresh mouse brain section sample using Ti:Sapphire-LEMS without the application of matrix. These lipid features were suppressed in both the fiber-based and Ti:Sapphire-based LEMS measurements when the brain sample was prepared using the optimal cutting temperature compounds that are commonly used in animal tissue cryosections.

  11. Multi-species, multi-transcription factor binding highlights conserved control of tissue-specific biological pathways

    Science.gov (United States)

    Ballester, Benoit; Medina-Rivera, Alejandra; Schmidt, Dominic; Gonzàlez-Porta, Mar; Carlucci, Matthew; Chen, Xiaoting; Chessman, Kyle; Faure, Andre J; Funnell, Alister PW; Goncalves, Angela; Kutter, Claudia; Lukk, Margus; Menon, Suraj; McLaren, William M; Stefflova, Klara; Watt, Stephen; Weirauch, Matthew T; Crossley, Merlin; Marioni, John C; Odom, Duncan T; Flicek, Paul; Wilson, Michael D

    2014-01-01

    As exome sequencing gives way to genome sequencing, the need to interpret the function of regulatory DNA becomes increasingly important. To test whether evolutionary conservation of cis-regulatory modules (CRMs) gives insight into human gene regulation, we determined transcription factor (TF) binding locations of four liver-essential TFs in liver tissue from human, macaque, mouse, rat, and dog. Approximately, two thirds of the TF-bound regions fell into CRMs. Less than half of the human CRMs were found as a CRM in the orthologous region of a second species. Shared CRMs were associated with liver pathways and disease loci identified by genome-wide association studies. Recurrent rare human disease causing mutations at the promoters of several blood coagulation and lipid metabolism genes were also identified within CRMs shared in multiple species. This suggests that multi-species analyses of experimentally determined combinatorial TF binding will help identify genomic regions critical for tissue-specific gene control. DOI: http://dx.doi.org/10.7554/eLife.02626.001 PMID:25279814

  12. On the Rule of Mixtures for Predicting Stress-Softening and Residual Strain Effects in Biological Tissues and Biocompatible Materials

    Directory of Open Access Journals (Sweden)

    Alex Elías-Zúñiga

    2014-01-01

    Full Text Available In this work, we use the rule of mixtures to develop an equivalent material model in which the total strain energy density is split into the isotropic part related to the matrix component and the anisotropic energy contribution related to the fiber effects. For the isotropic energy part, we select the amended non-Gaussian strain energy density model, while the energy fiber effects are added by considering the equivalent anisotropic volumetric fraction contribution, as well as the isotropized representation form of the eight-chain energy model that accounts for the material anisotropic effects. Furthermore, our proposed material model uses a phenomenological non-monotonous softening function that predicts stress softening effects and has an energy term, derived from the pseudo-elasticity theory, that accounts for residual strain deformations. The model’s theoretical predictions are compared with experimental data collected from human vaginal tissues, mice skin, poly(glycolide-co-caprolactone (PGC25 3-0 and polypropylene suture materials and tracheal and brain human tissues. In all cases examined here, our equivalent material model closely follows stress-softening and residual strain effects exhibited by experimental data.

  13. Implantation of a novel biologic and hybridized tissue engineered bioimplant in large tendon defect: an in vivo investigation.

    Science.gov (United States)

    Oryan, Ahmad; Moshiri, Ali; Parizi, Abdolhamid Meimandi; Maffulli, Nicola

    2014-02-01

    Surgical reconstruction of large Achilles tendon defects is technically demanding. There is no standard method, and tissue engineering may be a valuable option. We investigated the effects of 3D collagen and collagen-polydioxanone sheath (PDS) implants on a large tendon defect model in rabbits. Ninety rabbits were divided into three groups: control, collagen, and collagen-PDS. In all groups, 2 cm of the left Achilles tendon were excised and discarded. A modified Kessler suture was applied to all injured tendons to retain the gap length. The control group received no graft, the treated groups were repaired using the collagen only or the collagen-PDS prostheses. The bioelectrical characteristics of the injured areas were measured at weekly intervals. The animals were euthanized at 60 days after the procedure. Gross, histopathological and ultrastructural morphology and biophysical characteristics of the injured and intact tendons were investigated. Another 90 pilot animals were also used to investigate the inflammatory response and mechanism of graft incorporation during tendon healing. The control tendons showed severe hyperemia and peritendinous adhesion, and the gastrocnemius muscle of the control animals showed severe atrophy and fibrosis, with a loose areolar connective tissue filling the injured area. The tendons receiving either collagen or collagen-PDS implants showed lower amounts of peritendinous adhesion, hyperemia and muscle atrophy, and a dense tendon filled the defect area. Compared to the control tendons, application of collagen and collagen-PDS implants significantly improved water uptake, water delivery, direct transitional electrical current and tissue resistance to direct transitional electrical current. Compared to the control tendons, both prostheses showed significantly increased diameter, density and alignment of the collagen fibrils and maturity of the tenoblasts at ultrastructure level. Both prostheses influenced favorably tendon healing

  14. Medical radiation dosimetry theory of charged particle collision energy loss

    CERN Document Server

    McParland, Brian J

    2014-01-01

    Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. ​ Each year, about one-third of the worl...

  15. A multifunctional 3D co-culture system for studies of mammary tissue morphogenesis and stem cell biology.

    Directory of Open Access Journals (Sweden)

    Jonathan J Campbell

    Full Text Available Studies on the stem cell niche and the efficacy of cancer therapeutics require complex multicellular structures and interactions between different cell types and extracellular matrix (ECM in three dimensional (3D space. We have engineered a 3D in vitro model of mammary gland that encompasses a defined, porous collagen/hyaluronic acid (HA scaffold forming a physiologically relevant foundation for epithelial and adipocyte co-culture. Polarized ductal and acinar structures form within this scaffold recapitulating normal tissue morphology in the absence of reconstituted basement membrane (rBM hydrogel. Furthermore, organoid developmental outcome can be controlled by the ratio of collagen to HA, with a higher HA concentration favouring acinar morphological development. Importantly, this culture system recapitulates the stem cell niche as primary mammary stem cells form complex organoids, emphasising the utility of this approach for developmental and tumorigenic studies using genetically altered animals or human biopsy material, and for screening cancer therapeutics for personalised medicine.

  16. Endogenous Generation of Singlet Oxygen and Ozone in Human and Animal Tissues: Mechanisms, Biological Significance, and Influence of Dietary Components

    Directory of Open Access Journals (Sweden)

    Arnold N. Onyango

    2016-01-01

    Full Text Available Recent studies have shown that exposing antibodies or amino acids to singlet oxygen results in the formation of ozone (or an ozone-like oxidant and hydrogen peroxide and that human neutrophils produce both singlet oxygen and ozone during bacterial killing. There is also mounting evidence that endogenous singlet oxygen production may be a common occurrence in cells through various mechanisms. Thus, the ozone-producing combination of singlet oxygen and amino acids might be a common cellular occurrence. This paper reviews the potential pathways of formation of singlet oxygen and ozone in vivo and also proposes some new pathways for singlet oxygen formation. Physiological consequences of the endogenous formation of these oxidants in human tissues are discussed, as well as examples of how dietary factors may promote or inhibit their generation and activity.

  17. Biologic role of activated leukocyte cell adhesion molecule overexpression in breast cancer cell lines and clinical tumor tissue.

    Science.gov (United States)

    Hein, Sibyll; Müller, Volkmar; Köhler, Nadine; Wikman, Harriet; Krenkel, Sylke; Streichert, Thomas; Schweizer, Michaela; Riethdorf, Sabine; Assmann, Volker; Ihnen, Maike; Beck, Katrin; Issa, Rana; Jänicke, Fritz; Pantel, Klaus; Milde-Langosch, Karin

    2011-09-01

    The activated leukocyte cell adhesion molecule (ALCAM) is overexpressed in many mammary tumors, but controversial results about its role and prognostic impact in breast cancer have been reported. Therefore, we evaluated the biologic effects of ALCAM expression in two breast cancer cell lines and a larger cohort of mammary carcinomas. By stable transfections, MCF7 cells with ALCAM overexpression and MDA-MB231 cells with reduced ALCAM levels were generated and analyzed in functional assays and cDNA microarrays. In addition, an immunohistochemical study on 347 patients with breast cancer with long-term follow-up and analysis of disseminated tumor cells (DTCs) was performed. In both cell lines, high ALCAM expression was associated with reduced cell motility. In addition, ALCAM silencing in MDA-MB231 cells resulted in lower invasive potential, whereas high ALCAM expression was associated with increased apoptosis in both cell lines. Among genes which were differentially expressed in clones with altered ALCAM expression, there was an overlap of 15 genes between both cell lines, among them cathepsin D, keratin 7, gelsolin, and ets2 whose deregulation was validated by western blot analysis. In MDA-MB231 cells, we observed a correlation with VEGF expression which was validated by enzyme-linked immuno sorbent assay (ELISA). Our IHC results on primary breast carcinomas showed that ALCAM expression was associated with an estrogen receptor-positive phenotype. In addition, strong ALCAM immunostaining correlated with nodal involvement and the presence of tumor cells in bone marrow. By Kaplan-Meier analysis, strong ALCAM expression in ductal carcinomas correlated with shorter recurrence-free intervals (P=0.048) and overall survival (OAS, P=0.003). Our results indicate that the biologic role of ALCAM in breast cancer is complex, but overexpression might be relevant for outcome in ductal carcinomas.

  18. Design and validation of a dynamic cell-culture system for bone biology research and exogenous tissue-engineering applications.

    Science.gov (United States)

    Allori, Alexander C; Davidson, Edward H; Reformat, Derek D; Sailon, Alexander M; Freeman, James; Vaughan, Adam; Wootton, David; Clark, Elizabeth; Ricci, John L; Warren, Stephen M

    2016-10-01

    Bone lacunocanalicular fluid flow ensures chemotransportation and provides a mechanical stimulus to cells. Traditional static cell-culture methods are ill-suited to study the intricacies of bone biology because they ignore the three-dimensionality of meaningful cellular networks and the lacunocanalicular system; furthermore, reliance on diffusion alone for nutrient supply and waste product removal effectively limits scaffolds to 2-3 mm thickness. In this project, a flow-perfusion system was custom-designed to overcome these limitations: eight adaptable chambers housed cylindrical cell-seeded scaffolds measuring 12 or 24 mm in diameter and 1-10 mm in thickness. The porous scaffolds were manufactured using a three-dimensional (3D) periodic microprinting process and were composed of hydroxyapatite/tricalcium phosphate with variable thicknesses, strut sizes, pore sizes and structural configurations. A multi-channel peristaltic pump drew medium from parallel reservoirs and perfused it through each scaffold at a programmable rate. Hermetically sealed valves permitted sampling or replacement of medium. A gas-permeable membrane allowed for gas exchange. Tubing was selected to withstand continuous perfusion for > 2 months without leakage. Computational modelling was performed to assess the adequacy of oxygen supply and the range of fluid shear stress in the bioreactor-scaffold system, using 12 × 6 mm scaffolds, and these models suggested scaffold design modifications that improved oxygen delivery while enhancing physiological shear stress. This system may prove useful in studying complex 3D bone biology and in developing strategies for engineering thick 3D bone constructs. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Normal tissue complication probabilities: dependence on choice of biological model and dose-volume histogram reduction scheme

    International Nuclear Information System (INIS)

    Moiseenko, Vitali; Battista, Jerry; Van Dyk, Jake

    2000-01-01

    Purpose: To evaluate the impact of dose-volume histogram (DVH) reduction schemes and models of normal tissue complication probability (NTCP) on ranking of radiation treatment plans. Methods and Materials: Data for liver complications in humans and for spinal cord in rats were used to derive input parameters of four different NTCP models. DVH reduction was performed using two schemes: 'effective volume' and 'preferred Lyman'. DVHs for competing treatment plans were derived from a sample DVH by varying dose uniformity in a high dose region so that the obtained cumulative DVHs intersected. Treatment plans were ranked according to the calculated NTCP values. Results: Whenever the preferred Lyman scheme was used to reduce the DVH, competing plans were indistinguishable as long as the mean dose was constant. The effective volume DVH reduction scheme did allow us to distinguish between these competing treatment plans. However, plan ranking depended on the radiobiological model used and its input parameters. Conclusions: Dose escalation will be a significant part of radiation treatment planning using new technologies, such as 3-D conformal radiotherapy and tomotherapy. Such dose escalation will depend on how the dose distributions in organs at risk are interpreted in terms of expected complication probabilities. The present study indicates considerable variability in predicted NTCP values because of the methods used for DVH reduction and radiobiological models and their input parameters. Animal studies and collection of standardized clinical data are needed to ascertain the effects of non-uniform dose distributions and to test the validity of the models currently in use

  20. WE-DE-206-01: MRI Signal in Biological Tissues - Proton, Spin, T1, T2, T2*

    Energy Technology Data Exchange (ETDEWEB)

    Gorny, K. [Mayo Clinic (United States)

    2016-06-15

    Magnetic resonance imaging (MRI) has become an essential part of clinical imaging due to its ability to render high soft tissue contrast. Instead of ionizing radiation, MRI use strong magnetic field, radio frequency waves and field gradients to create diagnostic useful images. It can be used to image the anatomy and also functional and physiological activities within the human body. Knowledge of the basic physical principles underlying MRI acquisition is vitally important to successful image production and proper image interpretation. This lecture will give an overview of the spin physics, imaging principle of MRI, the hardware of the MRI scanner, and various pulse sequences and their applications. It aims to provide a conceptual foundation to understand the image formation process of a clinical MRI scanner. Learning Objectives: Understand the origin of the MR signal and contrast from the spin physics level. Understand the main hardware components of a MRI scanner and their purposes Understand steps for MR image formation including spatial encoding and image reconstruction Understand the main kinds of MR pulse sequences and their characteristics.

  1. The Importance of Biological Oscillators for Hypothalamic-Pituitary-Adrenal Activity and Tissue Glucocorticoid Response: Coordinating Stress and Neurobehavioural Adaptation

    Science.gov (United States)

    Russell, G M; Kalafatakis, K; Lightman, S L

    2015-01-01

    The hypothalamic-pituitary-adrenal (HPA) axis is critical for life. It has a circadian rhythm that anticipates the metabolic, immunoregulatory and cognitive needs of the active portion of the day, and retains an ability to react rapidly to perceived stressful stimuli. The circadian variation in glucocorticoids is very ‘noisy’ because it is made up from an underlying approximately hourly ultradian rhythm of glucocorticoid pulses, which increase in amplitude at the peak of circadian secretion. We have shown that these pulses emerge as a consequence of the feedforward–feedback relationship between the actions of corticotrophin hormone (ACTH) on the adrenal cortex and of endogenous glucocorticoids on pituitary corticotrophs. The adrenal gland itself has adapted to respond preferentially to a digital signal of ACTH and has its own feedforward–feedback system that effectively amplifies the pulsatile characteristics of the incoming signal. Glucocorticoid receptor signalling in the body is also adapted to respond in a tissue-specific manner to oscillating signals of glucocorticoids, and gene transcriptional and behavioural responses depend on the pattern (i.e. constant or pulsatile) of glucocorticoid presentation. During major stressful activation of the HPA, there is a marked remodelling of the pituitary–adrenal interaction. The link between ACTH and glucocorticoid pulses is maintained, although there is a massive increase in the adrenal responsiveness to the ACTH signals. PMID:25494867

  2. Aluminium and breast cancer: Sources of exposure, tissue measurements and mechanisms of toxicological actions on breast biology.

    Science.gov (United States)

    Darbre, Philippa D; Mannello, Ferdinando; Exley, Christopher

    2013-11-01

    This review examines recent evidence linking exposure to aluminium with the aetiology of breast cancer. The human population is exposed to aluminium throughout daily life including through diet, application of antiperspirants, use of antacids and vaccination. Aluminium has now been measured in a range of human breast structures at higher levels than in blood serum and experimental evidence suggests that the tissue concentrations measured have the potential to adversely influence breast epithelial cells including generation of genomic instability, induction of anchorage-independent proliferation and interference in oestrogen action. The presence of aluminium in the human breast may also alter the breast microenvironment causing disruption to iron metabolism, oxidative damage to cellular components, inflammatory responses and alterations to the motility of cells. The main research need is now to investigate whether the concentrations of aluminium measured in the human breast can lead in vivo to any of the effects observed in cells in vitro and this would be aided by the identification of biomarkers specific for aluminium action. © 2013.

  3. Hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1981-01-01

    Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

  4. LEXUS heavy ion collisions

    CERN Document Server

    Sang Yong Jeon

    1997-01-01

    We use a Glauber-like approach to describe very energetic nucleus- nucleus collisions as a sequence of binary nucleon-nucleon collisions. No free parameters are needed: all the information comes from simple parametrizations of nucleon-nucleon collision data. Produced mesons are assumed not to interact with each other or with the original baryons. Comparisons are made to published experimental measurements of baryon rapidity and transverse momentum distributions, negative hadron rapidity and transverse momentum distributions, average multiplicities of pions, kaons, hyperons, and antihyperons, and zero degree energy distributions for sulfur-sulfur collisions at 200 GeV/c per nucleon and for lead-lead collisions at 158 GeV/c per nucleon. Good agreement is found except that the number of strange particles produced, especially antihyperons, is too small compared with experiment. We call this model LEXUS: Linear EXtrapolation of Ultrarelativistic nucleon-nucleon Scattering to heavy ion collisions. (11 refs).

  5. Condensed matter applied atomic collision physics, v.4

    CERN Document Server

    Datz, Sheldon

    1983-01-01

    Applied Atomic Collision Physics, Volume 4: Condensed Matter deals with the fundamental knowledge of collision processes in condensed media.The book focuses on the range of applications of atomic collisions in condensed matter, extending from effects on biological systems to the characterization and modification of solids. This volume begins with the description of some aspects of the physics involved in the production of ion beams. The radiation effects in biological and chemical systems, ion scattering and atomic diffraction, x-ray fluorescence analysis, and photoelectron and Auger spectrosc

  6. A high-throughput method for the simultaneous determination of multiple mycotoxins in human and laboratory animal biological fluids and tissues by PLE and HPLC-MS/MS.

    Science.gov (United States)

    Cao, Xiaoqin; Wu, Shuangchan; Yue, Yuan; Wang, Shi; Wang, Yuting; Tao, Li; Tian, Hui; Xie, Jianmei; Ding, Hong

    2013-12-30

    A high-throughput method for the determination of 28 mycotoxins involving pressurised liquid extraction (PLE) coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been optimised and validated for determination in various biological fluids and tissues of human and laboratory animals. High-throughput analysis was achieved using PLE pre-treatment and without the need for any cleanup. The extraction solvent was acetonitrile/water/acetic acid (80/19/1, v/v/v). The static extraction time was 5min. The extraction pressure and temperature were 1500psi and 140°C, respectively. The flush volume was 60%. The limits of detection, which were defined as CCα, varied from 0.01μg/kg (μg/L) to 0.69μg/kg (μg/L). The recoveries of spiked samples from 0.20μg/kg (μg/L) to 2μg/kg (μg/L) ranged from 71% to 100.5% with relative standard deviations of less than 17.5%, except FB1 and FB2 recoveries, which were lower than 60%. The method was successfully applied in real samples, and the data indicate that this technique is a useful analytical method for the determination of mycotoxins from humans and animals. To the best of our knowledge, this method is the first for the large-scale testing of multi-class mycotoxins in all types of biological fluids and tissues that uses PLE and HPLC-MS/MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Human rheumatoid arthritis tissue production of IL-17A drives matrix and cartilage degradation: synergy with tumour necrosis factor-alpha, Oncostatin M and response to biologic therapies.

    LENUS (Irish Health Repository)

    Moran, Ellen M

    2009-01-01

    INTRODUCTION: The aim of this study was to examine IL-17A in patients, following anti-TNF-alpha therapy and the effect of IL-17A on matrix turnover and cartilage degradation. METHODS: IL-17A expression was examined by ELISA and immunohistology in the rheumatoid arthritis (RA) joints. RA whole synovial tissue explant (RA ST), primary synovial fibroblasts (RASFC), human cartilage and chondrocyte cultures were stimulated with IL-17A +\\/- TNF-alpha and Oncostatin M (OSM). Matrix metalloproteinase (MMP) and tissue inhibitor (TIMP-1) were assessed by ELISA and zymography. Cartilage proteoglycan release was assessed histologically by Safranin-O staining. Clinical parameters, IL-17A, MMP\\/TIMP were assessed in patients pre\\/post biologic therapy. RESULTS: IL-17A levels were higher in RA vs osteoarthritis (OA)\\/normal joints (P < 0.05). IL-17A up-regulated MMP-1, -2, -9, and -13 in RA ST, RASFC, cartilage and chondrocyte cultures (P < 0.05). In combination with TNF-alpha and OSM, IL-17A shifted the MMP:TIMP-1 ratio in favor of matrix degradation (all P < 0.05). Cartilage proteoglycan depletion in response to IL-17A was mild; however, in combination with TNF-alpha or OSM showed almost complete proteoglycan depletion. Serum IL-17A was detected in 28% of patients commencing biologic therapy. IL-17A negative patients demonstrated reductions post therapy in serum MMP1\\/TIMP4, MMP3\\/TIMP1 and MMP3\\/TIMP4 ratios and an increase in CS846 (all P < 0.05). No significant changes were observed in IL-17A positive patients. CONCLUSIONS: IL-17A is produced locally in the inflamed RA joint. IL-17A promotes matrix turnover and cartilage destruction, especially in the presence of other cytokines, mimicking the joint environment. IL-17A levels are modulated in vivo, following anti-TNF therapy, and may reflect changes in matrix turnover.

  8. Evidence that 17alpha-estradiol is biologically active in the uterine tissue: Antiuterotonic and antiuterotrophic action

    Directory of Open Access Journals (Sweden)

    Navarrete Erika

    2005-07-01

    Full Text Available Abstract Background 17alpha-Estradiol has been considered as the hormonally inactive isomer of 17beta-estradiol. Recently, nongenomic (smooth muscle relaxation and genomic (light estrogenic activity effects of 17alpha-estradiol have been reported, but no reports have yet determined its possible antiestrogenic activity. Therefore, this study investigated: the nongenomic action of 17alpha-estradiol on uterine contractile activity and its potential agonist-antagonist activity on uterine growth. Methods Uterine rings from rats were isometrically recorded. Different concentrations (0.2–200 microM of 17alpha-estradiol were tested on spontaneous contraction and equimolarly compared with 17beta-estradiol. To examine the mechanism of 17alpha-estradiol action, its effect was studied in presence of beta2-antagonist (propranolol, antiestrogens (tamoxifen and ICI 182,780 or inhibitors of protein synthesis (cycloheximide and transcription (actinomycin D. Moreover, contractions induced by high potassium (KCl solution or calcium in depolarized tissues by KCl-calcium free solution were exposed to 17alpha-estradiol. Collaterally, we performed an uterotrophic assay in adult ovariectomized rats measuring the uterine wet weight. The administration for three days of 0.3 microM/day/Kg 17beta-estradiol was equimolarly compared with the response produced by 17alpha-estradiol. Antiuterotrophic activity was assayed by administration of 0.3 microM/day/Kg 17beta-estradiol and various doses ratios (1:1, 1:3, 1:5, and 1:100 of 17alpha-estradiol. Results The estradiol isomers elicited an immediate relaxation, concentration-dependent and reversible on spontaneous contraction. 17alpha-Estradiol presented lower potency than 17beta-estradiol although it did not antagonize 17beta-estradiol-induced relaxation. Relaxation to 17alpha-estradiol was not inhibited by propranolol, tamoxifen, ICI 182,780, cycloheximide or actinomycin D. The KCl contractions were also sensitive to 17alpha

  9. Prospective study of single-stage repair of contaminated hernias using a biologic porcine tissue matrix: the RICH Study.

    Science.gov (United States)

    Itani, Kamal M F; Rosen, Michael; Vargo, Daniel; Awad, Samir S; Denoto, George; Butler, Charles E

    2012-09-01

    In the presence of contamination, the repair of a ventral incisional hernia (VIH) is challenging. The presence of comorbidities poses an additional risk for postoperative wound events and hernia recurrence. To date, very few studies describe the outcomes of VIH repair in this high-risk population. A prospective, multicenter, single-arm, the Repair of Infected or Contaminated Hernias study was performed to study the clinical outcomes of open VIH repair of contaminated abdominal defects with a non-cross-linked, porcine, acellular dermal matrix, Strattice. Of 85 patients who consented to participate, 80 underwent open VIH repair with Strattice. Hernia defects were 'clean-contaminated' (n = 39), 'contaminated' (n = 39), or 'dirty' (n = 2), and the defects were classified as grade 3 (n = 60) or grade 4 (n = 20). The midline was restored, and primary closure was achieved in 64 patients; the defect was bridged in 16 patients. At 24 months, 53 patients (66%) experienced 95 wound events. There were 28 unique, infection-related events in 24 patients. Twenty-two patients experienced seromas, all but 5 of which were transient and required no intervention. No unanticipated adverse events occurred, and no tissue matrix required complete excision. There were 22 hernia (28%) recurrences by month 24. There was no correlation between infection-related events and hernia recurrence. The use of the intact, non-cross-linked, porcine, acellular dermal matrix, Strattice, in the repair of contaminated VIH in high-risk patients allowed for successful, single-stage reconstruction in >70% of patients followed for 24 months after repair. Published by Mosby, Inc.

  10. Autopsy tissues as biological monitors of human exposure to environmental pollutants. A case study: Concentrations of metals and PCDD/Fs in subjects living near a hazardous waste incinerator.

    Science.gov (United States)

    Domingo, José L; García, Francisco; Nadal, Martí; Schuhmacher, Marta

    2017-04-01

    Human biomonitoring is of tremendous importance to prevent potential adverse effects derived from human exposure to chemicals. Blood and urine are among the biological monitors more frequently used. However, biological matrices such as breast milk, hair, nails, saliva, feces, teeth, and expired air are also often used. In addition, and focused mainly on long-term exposure, adipose tissue and other human tissues like bone, liver, brain or kidney, are also used as biological monitors of certain substances, especially for long-term biomonitoring. However, for this kind of tissues sampling is always a limiting factor. In this paper, we have examined the role of autopsy tissues as biological monitors of human exposure to environmental pollutants. For it, we have used a case study conducted near a hazardous waste incinerator (HWI) in Catalonia (Spain), in which the concentrations of metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), have been periodically determined in autopsy tissues of subjects living in the area under potential influence of the facility. This case study does not show advantages -in comparison to other appropriate biomonitors such as blood- in using autopsy tissues in the monitoring of long-term exposure to metals and PCDD/Fs. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Proteome analysis of mouse model systems: A tool to model human disease and for the investigation of tissue-specific biology.

    Science.gov (United States)

    Kislinger, Thomas; Gramolini, Anthony O

    2010-10-10

    The molecular dissections of the mechanistic pathways involved in human disease have always relied on the use of model organisms. Among the higher mammalian organisms, the laboratory mouse (Mus musculus) is the most widely used model. A large number of commercially-available, inbred strains are available to the community, including an ever growing collection of transgenic, knock-out, and disease models. Coupled to availability is the fact that animal colonies can be kept under standardized housing condition at most major universities and research institutes, with relative ease and cost efficiency (compared to larger vertebrates). As such, mouse models to study human biology and disease remains extremely attractive. In the current review we will provide an historic overview of the use of mouse models in proteome research with a focus on general tissue and organelle biology, comparative proteomics of human and mouse and the use of mouse models to study cardiac disease. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  12. Impacts of maternal selenium supply and nutritional plane on visceral tissues and intestinal biology in 180-day-old offspring in sheep.

    Science.gov (United States)

    Yunusova, R D; Neville, T L; Vonnahme, K A; Hammer, C J; Reed, J J; Taylor, J B; Redmer, D A; Reynolds, L P; Caton, J S

    2013-05-01

    Objectives were to investigate the effects of maternal Se supply and nutritional plane during gestation on offspring visceral tissues and indices of intestinal growth, vascularity, and function at 180 d of age. Rambouillet ewe lambs (n = 82, approximately 240 d of age; 52 ± 0.8 kg BW at breeding) were allocated to a 2 × 3 factorial arrangement of treatments. Treatments included dietary Se [adequate Se (ASe, 9.5 µg/kg BW) or high Se (HSe, 81.8 µg/kg BW)] initiated at breeding and nutritional plane [60% (restricted, RES), 100% (control, CON), and 140% (high, HI) of requirements] initiated at d 50 of gestation. Ewes were fed pelleted diets and housed individually indoors. At parturition, lambs were immediately removed and fed artificial colostrum for the first 20 h followed by ad libitum access to milk replacer. At 180 ± 2 d of age, lambs were euthanized and tissues were harvested. Birth weight was affected by nutritional treatments (P lambs from CON being greater than RES. Expression of most mRNA for measured angiogenic factors and receptors was not altered (P ≤ 0.13) by maternal treatments; however, expression of glucagon-like peptide-2 (GLP-2) was decreased (P = 0.07) in offspring from RES compared with CON ewes. Offspring from ewes fed HI diets had increased (P = 0.08) jejunal mucosal maltase activity. In conclusion, maternal Se supply and nutritional plane during gestation resulted in measurable changes in offspring visceral tissues and intestinal biology, including perirenal fat, blood volume, intestinal mass, total jejunal crypt cell proliferation, area per capillary in jejunal villi, GLP-2 mRNA expression, and maltase activity at 180 d. Additional work is needed to determine impacts on intestinal function and nutrient uptake.

  13. Ball Collision Experiments

    Science.gov (United States)

    Cross, R.

    2015-01-01

    Experiments are described on collisions between two billiard balls and between a bat and a ball. The experiments are designed to extend a student's understanding of collision events and could be used either as a classroom demonstration or for a student project.

  14. Effect of sample preparation techniques on the concentrations and distributions of elements in biological tissues using µSRXRF: a comparative study

    International Nuclear Information System (INIS)

    Al-Ebraheem, A; Dao, E; Desouza, E; McNeill, F E; Farquharson, M J; Li, C; Wainman, B C

    2015-01-01

    Routine tissue sample preparation using chemical fixatives is known to preserve the morphology of the tissue being studied. A competitive method, cryofixation followed by freeze drying, involves no chemical agents and maintains the biological function of the tissue. The possible effects of both sample preparation techniques in terms of the distribution of bio-metals (calcium (Ca), copper (Cu) zinc (Zn), and iron (Fe) specifically) in human skin tissue samples was investigated. Micro synchrotron radiation x-ray fluorescence (μSRXRF) was used to map bio-metal distribution in epidermal and dermal layers of human skin samples from various locations of the body that have been prepared using both techniques. For Ca, Cu and Zn, there were statistically significant differences between the epidermis and dermis using the freeze drying technique (p = 0.02, p < 0.01, and p < 0.01, respectively). Also using the formalin fixed, paraffin embedded technique the levels of Ca, Cu and Zn, were significantly different between the epidermis and dermis layers (p = 0.03, p < 0.01, and p < 0.01, respectively). However, the difference in levels of Fe between the epidermis and dermis was unclear and further analysis was required. The epidermis was further divided into two sub-layers, one mainly composed of the stratum corneum and the other deeper layer, the stratum basale. It was found that the difference between the distribution of Fe in the two epidermal layers using the freeze drying technique resulted in a statistically significant difference (p = 0.012). This same region also showed a difference in Fe using the formalin fixed, paraffin embedded technique (p < 0.01). The formalin fixed, paraffin embedded technique also showed a difference between the deeper epidermal layer and the dermis (p < 0.01). It can be concluded that studies involving Ca, Cu and Zn might show similar results using both sample preparation techniques, however studies involving Fe would need more

  15. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    International Nuclear Information System (INIS)

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-01-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

  16. Systems Biology Model of Interactions Between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFbeta and ATM Signaling

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Peter [University of Oxford; Anderson, Jennifer [University of Oxford

    2014-10-02

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low dose responses and cross-talk between the ATM and TGFβ pathways initiated by low and high LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to cross- talk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  17. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Pon-On, Weeraphat, E-mail: fsciwpp@ku.ac.th [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip [Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University (Thailand); Department of Physiology, Faculty of Science, Mahidol University (Thailand); Tang, I-Ming [ThEP Center, Commission of Higher Education, 328 Si Ayutthaya Rd. (Thailand); Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand)

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze–thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. - Graphical abstract: Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)–bioglass/chitosan–collagen composite scaffolds: A bone tissue engineering applications. - Highlights: • Preparation of PVABG:ChiCol hybrid composites and their bioactivities • Mechanical

  18. Systems Biology Model of Interactions between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFβ and ATM Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Cucinotta, Francis A [Univ. of Nevada, Las Vegas, NV (United States)

    2016-09-01

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently, the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses, and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low-dose responses and cross-talk between the ATM and TGFβ pathways initiated by low- and high-LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to crosstalk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  19. Systems Biology Model of Interactions between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFβ and ATM Signaling

    International Nuclear Information System (INIS)

    Cucinotta, Francis A

    2016-01-01

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently, the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses, and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low-dose responses and cross-talk between the ATM and TGFβ pathways initiated by low- and high-LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to crosstalk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  20. Potential characteristics of stem cells from human exfoliated deciduous teeth compared with bone marrow-derived mesenchymal stem cells for mineralized tissue-forming cell biology.

    Science.gov (United States)

    Hara, Kenji; Yamada, Yoichi; Nakamura, Sayaka; Umemura, Eri; Ito, Kenji; Ueda, Minoru

    2011-12-01

    Tissue engineering and regenerative medicine using stem cell biology has been a promising field for treatment of local and systemic intractable diseases. Recently, stem cells from human exfoliated deciduous teeth (SHED) have been identified as a novel population of stem cells. This study focused on the characterization of SHED as compared with bone marrow-derived mesenchymal stem cells (BMMSCs). We investigated potential characteristics of SHED by using DNA microarray, real-time reverse transcriptase polymerase chain reaction, and immunofluorescence analysis. Multiple gene expression profiles indicated that the expression of 2753 genes in SHED had changed by ≥2.0-fold as compared with that in BMMSCs. One of the most significant pathways that accelerated in SHED was that of bone morphogenetic protein (BMP) receptor signaling, which contains several cascades such as PKA, JNK, and ASK1. When the BMP signaling pathway was stimulated by BMP-2, the expression of BMP-2, BMP-4, Runx2, and DSPP was up-regulated significantly in SHED than that in BMMSCs. Furthermore, the BMP-4 protein was expressed much higher in SHED but not in BMMSCs, as confirmed by immunofluorescence. By using the gene expression profiles, this study indicates that SHED is involved in the BMP signaling pathway and suggests that BMP-4 might play a crucial role in this. These results might be useful for effective cell-based tissue regeneration, including that of bone, pulp, and dentin, by applying the characteristics of SHED. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. Development and validation of a liquid chromatography-MS/MS method for simultaneous quantification of tenofovir and efavirenz in biological tissues and fluids.

    Science.gov (United States)

    Barreiros, Luisa; Cunha-Reis, Cassilda; Silva, Eduarda M P; Carvalho, Joana R B; das Neves, José; Sarmento, Bruno; Segundo, Marcela A

    2017-03-20

    Millions of people worldwide live with human immunodeficiency virus (HIV) infection thus justifying the continuous search for new prevention and treatment strategies, including topical microbicide products combining antiretroviral drugs (ARVs) such as tenofovir (TFV) and efavirenz (EFV). Therefore, the aim of this work was to develop and validate a high performance liquid chromatography method coupled to triple quadrupole-tandem mass spectrometry (HPLC-MS/MS) for the quantification of TFV and EFV in biological matrices (mouse vaginal tissue, vaginal lavage and blood plasma). Chromatographic separation was achieved using a reversed phase C18 column (3μm, 100×2.1mm) at 45°C and elution in gradient mode using a combination of 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile at 0.35mLmin -1 . Total run time was 9min, with retention time of 2.8 and 4.1min for TFV and EFV, respectively. The MS was operated in positive ionization mode (ESI+) for TFV and in negative ionization mode (ESI-) for EFV detection. Data were acquired in selected reaction monitoring (SRM) mode and deuterated ARVs were employed as internal standards. Calibration curves were linear for ARV concentrations ranging from 4 to 500ngmL -1 with LOD and LOQ for both analytes ≤0.4 and ≤0.7ngmL -1 in sample extracts, respectively. The method was found to be specific, accurate (96.0-106.0% of nominal values) and precise (RSDfluids were ≥88.4%. Matrix effects were observed for EFV determination in tissue and plasma extracts but compensated by the use of deuterated internal standards. The proposed methodology was successfully applied to a pharmacokinetic study following intravaginal administration of both ARVs. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Distribution of Podoplanin in Synovial Tissues in Rheumatoid Arthritis Patients Using Biologic or Conventional Disease-Modifying Anti-Rheumatic Drugs.

    Science.gov (United States)

    Takakubo, Yuya; Oki, Hiroharu; Naganuma, Yasushi; Saski, Kan; Sasaki, Akiko; Tamaki, Yasunobu; Suran, Yang; Konta, Tsuneo; Takagi, Michiaki

    2017-01-01

    Podoplanin (PDPN) mediates tumor cell migration and invasion, which phenomena might also play a role in severe rheumatoid arthritis (RA). Therefore, the precise cellular distribution of PDPN and it's relationships with inflammation was studied in RA treated with biologic disease-modifying anti-rheumatic drugs (DMARD) or conventional DMARDs (cDMARD). PDPN+ cells were immunostained by NZ-1 mAb, and scored (3+; >50%/ area, 2+; 20%- 50%, 1+; 5%-20%, 0: <5%) in synovial tissues from RA treated with biologic DMARDs (BIO, n=20) or cDMARD (n=20) for comparison with osteoarthritis (OA, n=5), followed by cell grading of inflammation and cell-typing. Inflammatory synovitis score was 1.4 in both BIO and cDMARD, compared to only 0.2 in OA. PDPN+ cells were found in the lining layer (BIO 1.6, cDMARD 1.3, OA 0.2) and lymphoid aggregates (BIO 0.6, cDMRD 0.7, OA 0.2), and correlated with RA-inflammation in BIO- and cDMARD-groups in both area (r=0.7/0.9, r=0.6/0.7, respectively p<0.05). PDPN was expressed in CD68+ type A macrophage-like and 5B5+ type B fibroblast-like cells in the lining layer, and in IL- 17+ cells in lymphoid aggregates in RA. PDPN was markedly increased in the immunologically inflamed RA synovitis, which was surgically treated due to BIO- and cDMARD-resistant RA. PDPN may have potential of a new marker of residual arthritis in local joints for inflammation-associated severe RA. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Optical tissue clearing improves usability of optical coherence tomography (OCT) for high-throughput analysis of the internal structure and 3D morphology of small biological objects such as vertebrate embryos

    Science.gov (United States)

    Thrane, Lars; Jørgensen, Thomas M.; Männer, Jörg

    2014-03-01

    Developmental biology studies frequently require rapid analysis of the morphology of a large number of embryos (highthroughput analysis). Conventional microscopic analysis is time-consuming and, therefore, is not well suited for highthroughput analysis. OCT facilitates rapid generation of optical sections through small biological objects at high resolutions. However, due to light scattering within biological tissues, the quality of OCT images drops significantly with increasing penetration depth of the light beam. We show that optical clearing of fixed embryonic organs with methyl benzoate can significantly reduce the light scattering and, thereby, improves the usability of OCT for high-throughput analysis of embryonic morphology.

  4. Optical tissue clearing improves usability of optical coherence tomography (OCT) for high-throughput analysis of the internal structure and 3D morphology of small biological objects such as vertebrate embryos

    DEFF Research Database (Denmark)

    Thrane, Lars; Jørgensen, Thomas Martini; Männer, Jörg

    2014-01-01

    Developmental biology studies frequently require rapid analysis of the morphology of a large number of embryos (highthroughput analysis). Conventional microscopic analysis is time-consuming and, therefore, is not well suited for highthroughput analysis. OCT facilitates rapid generation of optical...... sections through small biological objects at high resolutions. However, due to light scattering within biological tissues, the quality of OCT images drops significantly with increasing penetration depth of the light beam. We show that optical clearing of fixed embryonic organs with methyl benzoate can...

  5. Evidence of early alterations in adipose tissue biology and function and its association with obesity-related inflammation and insulin resistance in children.

    Science.gov (United States)

    Landgraf, Kathrin; Rockstroh, Denise; Wagner, Isabel V; Weise, Sebastian; Tauscher, Roy; Schwartze, Julian T; Löffler, Dennis; Bühligen, Ulf; Wojan, Magdalena; Till, Holger; Kratzsch, Jürgen; Kiess, Wieland; Blüher, Matthias; Körner, Antje

    2015-04-01

    Accumulation of fat mass in obesity may result from hypertrophy and/or hyperplasia and is frequently associated with adipose tissue (AT) dysfunction in adults. Here we assessed early alterations in AT biology and function by comprehensive experimental and clinical characterization of 171 AT samples from lean and obese children aged 0 to 18 years. We show an increase in adipocyte size and number in obese compared with lean children beginning in early childhood. These alterations in AT composition in obese children were accompanied by decreased basal lipolytic activity and significantly enhanced stromal vascular cell proliferation in vitro, potentially underlying the hypertrophy and hyperplasia seen in obese children, respectively. Furthermore, macrophage infiltration, including the formation of crown-like structures, was increased in AT of obese children from 6 years on and was associated with higher hs-CRP serum levels. Clinically, adipocyte hypertrophy was not only associated with leptin serum levels but was highly and independently correlated with HOMA-IR as a marker of insulin resistance in children. In summary, we show that adipocyte hypertrophy is linked to increased inflammation in AT in obese children, thereby providing evidence that obesity-associated AT dysfunction develops in early childhood and is related to insulin resistance. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  6. Elements determination of clinical relevance in biological tissues Dmd{sup mdx}/J dystrophic mice strains investigated by NAA; Determinacao de elementos de relevancia clinica em tecidos biologicos de camundongos distroficos Dmd{sup mdx}/J por AAN

    Energy Technology Data Exchange (ETDEWEB)

    Metairon, Sabrina

    2012-07-01

    In this work the determination of chemistry elements in biological tissues (whole blood, bones and organs) of dystrophic mice, used as animal model of Duchenne Muscular Dystrophy (DMD), was performed using analytical nuclear technique. The aim of this work was to determine reference values of elements of clinical (Ca, Cl, K, Mg, Na) and nutritional (Br and S) relevance in whole blood, tibia, quadriceps and hearts from Dmdmdx/J (10 males and 10 females) dystrophic mice and C57BL/6J (10 males) control group mice, using Neutron Activation Analysis technique (NAA). To show in more details the alterations that this disease may cause in these biological tissues, correlations matrixes of the DMD{sup mdx}/J mouse strain were generated and compared with C57BL/6J control group. For this study 119 samples of biological tissue were irradiated in the IEA-R1 nuclear reactor at IPEN (Sao Paulo, Brazil). The concentrations of these elements in biological tissues of Dmd{sup mdx}/J and C57B/6J mice are the first indicative interval for reference values. Moreover, the alteration in some correlation coefficients data among the elements in the health status and in the diseased status indicates a connection between these elements in whole blood, tibia, quadriceps and heart. These results may help the researchers to evaluate the efficiency of new treatments and to compare the advantages of different treatment approaches before performing tests in patients with muscular dystrophy. (author)

  7. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  8. Mechanics of train collision

    Science.gov (United States)

    1976-04-30

    A simple and a more detailed mathematical model for the simulation of train collisions are presented. The study presents considerable insight as to the causes and consequences of train motions on impact. Comparison of model predictions with two full ...

  9. Photon-photon collisions

    International Nuclear Information System (INIS)

    Haissinski, J.

    1986-06-01

    The discussions presented in this paper deal with the following points: distinctive features of gamma-gamma collisions; related processes; photon-photon elastic scattering in the continuum and γγ →gg; total cross section; γγ → V 1 V 2 (V=vector meson); radiative width measurements and light meson spectroscopy; exclusive channels at large /t/; jets and inclusive particle distribution in γγ collisions; and, the photon structure function F γ 2

  10. Photon-photon collisions

    International Nuclear Information System (INIS)

    Burke, D.L.

    1982-10-01

    Studies of photon-photon collisions are reviewed with particular emphasis on new results reported to this conference. These include results on light meson spectroscopy and deep inelastic e#betta# scattering. Considerable work has now been accumulated on resonance production by #betta##betta# collisions. Preliminary high statistics studies of the photon structure function F 2 /sup #betta#/(x,Q 2 ) are given and comments are made on the problems that remain to be solved

  11. Collision risk analysis based train collision early warning strategy.

    Science.gov (United States)

    Li, Si-Hui; Cai, Bai-Gen; Liu, Jiang; Wang, Jian

    2018-03-01

    A Train Collision Early Warning System (TCEWS) has been developed for collision avoidance. However, there are few studies regarding how to evaluate the collision risk and provide an early warning concerning a preceding train on the railway. In this paper, we have found that the time for collision avoidance is constrained by the timing of events, such as wireless communication latency, driver reaction, safety protection distance and deceleration rate. Considering these timing components, the time to avoid a collision is calculated accurately. To evaluate the potential collision severity when the following train approaches, the collision risk is defined based on the time to avoid a collision. The train collision early warning signal is divided into a four-tier color-coded system based on the collision risk, with red representing the most severe collision risk, followed by orange, yellow and blue. A field test of the train collision early warning strategy on the Hankou-Yichang Railway is analysed. It is demonstrated that the strategy has sufficient capability to indicate a potential collision and warn the following train. Copyright © 2017. Published by Elsevier Ltd.

  12. The role of SDF-1-CXCR4/CXCR7 axis in biological behaviors of adipose tissue-derived mesenchymal stem cells in vitro

    International Nuclear Information System (INIS)

    Li, Qiang; Zhang, Aijun; Tao, Changbo; Li, Xueyang; Jin, Peisheng

    2013-01-01

    Highlights: •SDF-1 pretreating increased the levels of CXCR4, CXCR7 in ADSCs. •SDF-1 improved cells paracrine migration and proliferation abilities. •CXCR4 and CXCR7 could function in ADSCs paracrine, migration and proliferation. -- Abstract: Numerous studies have reported that CXCR4 and CXCR7 play an essential, but differential role in stromal cell-derived factor-1 (SDF-1)-inducing cell chemotaxis, viability and paracrine actions of BMSCs. Adipose tissue-derived mesenchymal stem cells (ADSCs) have been suggested to be potential seed cells for clinical application instead of bone marrow derived stroma cell (BMSCs). However, the function of SDF-1/CXCR4 and SDF-1/CXCR7 in ADSCs is not well understood. This study was designed to analyze the effect of SDF-1/CXCR4 and SDF-1/CXCR7 axis on ADSCs biological behaviors in vitro. Using Flow cytometry and Western blot methods, we found for the first time that CXCR4/CXCR7 expression was increased after treatment with SDF-1 in ADSCs. SDF-1 promoted ADSCs paracrine, proliferation and migration abilities. CXCR4 or CXCR7 antibody suppressed ADSCs paracrine action induced by SDF-1. The migration of ADSCs can be abolished by CXCR4 antibody, while the proliferation of ADSCs was only downregulated by CXCR7 antibody. Our study indicated that the angiogenesis of ADSCs is, at least partly, mediated by SDF-1/CXCR4 and SDF-1/CXCR7 axis. However, only binding of SDF-1/CXCR7 was required for proliferation of ADSCs, and CXCR7 was required for migration of ADSCs induced by SDF-1. Our studies provide evidence that the activation of either axis may be helpful to improve the effectiveness of ADSCs-based stem cell therapy

  13. The role of SDF-1-CXCR4/CXCR7 axis in biological behaviors of adipose tissue-derived mesenchymal stem cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qiang; Zhang, Aijun; Tao, Changbo; Li, Xueyang; Jin, Peisheng, E-mail: jinps2006@163.com

    2013-11-22

    Highlights: •SDF-1 pretreating increased the levels of CXCR4, CXCR7 in ADSCs. •SDF-1 improved cells paracrine migration and proliferation abilities. •CXCR4 and CXCR7 could function in ADSCs paracrine, migration and proliferation. -- Abstract: Numerous studies have reported that CXCR4 and CXCR7 play an essential, but differential role in stromal cell-derived factor-1 (SDF-1)-inducing cell chemotaxis, viability and paracrine actions of BMSCs. Adipose tissue-derived mesenchymal stem cells (ADSCs) have been suggested to be potential seed cells for clinical application instead of bone marrow derived stroma cell (BMSCs). However, the function of SDF-1/CXCR4 and SDF-1/CXCR7 in ADSCs is not well understood. This study was designed to analyze the effect of SDF-1/CXCR4 and SDF-1/CXCR7 axis on ADSCs biological behaviors in vitro. Using Flow cytometry and Western blot methods, we found for the first time that CXCR4/CXCR7 expression was increased after treatment with SDF-1 in ADSCs. SDF-1 promoted ADSCs paracrine, proliferation and migration abilities. CXCR4 or CXCR7 antibody suppressed ADSCs paracrine action induced by SDF-1. The migration of ADSCs can be abolished by CXCR4 antibody, while the proliferation of ADSCs was only downregulated by CXCR7 antibody. Our study indicated that the angiogenesis of ADSCs is, at least partly, mediated by SDF-1/CXCR4 and SDF-1/CXCR7 axis. However, only binding of SDF-1/CXCR7 was required for proliferation of ADSCs, and CXCR7 was required for migration of ADSCs induced by SDF-1. Our studies provide evidence that the activation of either axis may be helpful to improve the effectiveness of ADSCs-based stem cell therapy.

  14. Mechanical properties, biological activity and protein controlled release by poly(vinyl alcohol)-bioglass/chitosan-collagen composite scaffolds: a bone tissue engineering applications.

    Science.gov (United States)

    Pon-On, Weeraphat; Charoenphandhu, Narattaphol; Teerapornpuntakit, Jarinthorn; Thongbunchoo, Jirawan; Krishnamra, Nateetip; Tang, I-Ming

    2014-05-01

    In the present study, composite scaffolds made with different weight ratios (0.5:1, 1:1 and 2:1) of bioactive glass (15Ca:80Si:5P) (BG)/polyvinyl alcohol (PVA) (PVABG) and chitosan (Chi)/collagen (Col) (ChiCol) were prepared by three mechanical freeze-thaw followed by freeze-drying to obtain the porous scaffolds. The mechanical properties and the in vitro biocompatibility of the composite scaffolds to simulated body fluid (SBF) and to rat osteoblast-like UMR-106 cells were investigated. The results from the studies indicated that the porosity and compressive strength were controlled by the weight ratio of PVABG:ChiCol. The highest compressive modulus of the composites made was 214.64 MPa which was for the 1:1 weight ratio PVABG:ChiCol. Mineralization study in SBF showed the formation of apatite crystals on the PVABG:ChiCol surface after 7 days of incubation. In vitro cell availability and proliferation tests confirmed the osteoblast attachment and growth on the PVABG:ChiCol surface. MTT and ALP tests on the 1:1 weight ratio PVABG:ChiCol composite indicated that the UMR-106 cells were viable. Alkaline phosphatase activity was found to increase with increasing culturing time. In addition, we showed the potential of PVABG:ChiCol drug delivery through PBS solution studies. 81.14% of BSA loading had been achieved and controlled release for over four weeks was observed. Our results indicated that the PVABG:ChiCol composites, especially the 1:1 weight ratio composite exhibited significantly improved mechanical, mineral deposition, biological properties and controlled release. This made them potential candidates for bone tissue engineering applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Collision tumor: serous cystadenocarcinoma and dermoid cyst in the same ovary

    DEFF Research Database (Denmark)

    Bige, Ozgur; Demir, Ahmet; Koyuncuoglu, Meral

    2008-01-01

    INTRODUCTION: Collision tumor means the coexistence of two adjacent, but histologically distinct tumors without histologic admixture in the same tissue or organ. Collision tumors involving ovaries are extremely rare. CASE: We present a case of 45-year-old parous woman with a left dermoid cyst......, with unusual imaging findings, massive ascites and peritoneal carcinomatosis. The patient underwent cytoreductive surgery. The histopathology revealed a collision tumor consisting of an invasive serous cystadenocarcinoma and a dermoid cyst....

  16. About the Collision Repair Campaign

    Science.gov (United States)

    EPA developed the Collision Repair Campaign to focus on meaningful risk reduction in the Collision Repair source sector to complement ongoing community air toxics work and attain reductions at a faster rate.

  17. Consumers’ Collision Insurance Decisions

    DEFF Research Database (Denmark)

    Austin, Laurel; Fischhoff, Baruch

    Using interviews with 74 drivers, we elicit and analyse how people think about collision coverage and, more generally, about insurance decisions. We compare the judgments and behaviours of these decision makers to the predictions of a range of theoretical models: (a) A model developed by Lee (2007...... a cognitive model based on budgeting. Our findings emphasize the importance of budget constraints, which lead consumers to budget their income across consumption categories. We find also that a simple heuristic accounts for many collision coverage decisions: purchase coverage for cars worth more than some...

  18. Vocal Fold Collision Modeling

    DEFF Research Database (Denmark)

    Granados, Alba; Brunskog, Jonas; Misztal, M. K.

    2015-01-01

    When vocal folds vibrate at normal speaking frequencies, collisions occurs. The numerics and formulations behind a position-based continuum model of contact is an active field of research in the contact mechanics community. In this paper, a frictionless three-dimensional finite element model...... of the vocal fold collision is proposed, which incorporates different procedures used in contact mechanics and mathematical optimization theories. The penalty approach and the Lagrange multiplier method are investigated. The contact force solution obtained by the penalty formulation is highly dependent...

  19. Ice particle collisions

    Science.gov (United States)

    Sampara, Naresh; Turnbull, Barbara; Hill, Richard; Swift, Michael

    2017-04-01

    Granular interactions of ice occur in a range of geophysical, astrophysical and industrial applications. For example, Saturn's Rings are composed of icy particles from micrometers to kilometres in size - inertial and yet too small to interact gravitationally. In clouds, ice crystals are smashed to pieces before they re-aggregate to for snow floccules in a process that is very much open to interpretation. In a granular flow of ice particles, the energy spent in collisions can lead to localized surface changes and wetting, which in turn can promote aggregation. To understand the induced wetting and its effects, we present two novel experimental methods which provide snippets of insight into the collisional behaviour of macroscopic ice particles. Experiment 1: Microgravity experiments provide minute details of the contact between the ice particles during the collision. A diamagnetic levitation technique, as alternative to the parabolic flight or falling tower experiments, was used to understand the collisional behaviour of individual macroscopic icy bodies. A refrigerated cylinder, that can control ambient conditions, was inserted into the bore of an 18 Tesla superconducting magnet and cooled to -10°C. Initial binary collisions were created, where one 4 mm ice particle was levitated in the magnet bore whilst another particle was dropped vertically from the top of the bore. The trajectories of both particles were captured by high speed video to provide the three-dimensional particle velocities and track the collision outcome. Introducing complexity, multiple particles were levitated in the bore and an azimuthal turbulent air flow introduced, allowing the particles to collide with other particles within a coherent fluid structure (mimicking Saturn's rings, or an eddy in a cloud). In these experiments, a sequence of collisions occur, each one different to the previous one due to the changes in surface characteristics created by the collisions themselves. Aggregation

  20. Utility of imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) on an ion trap mass spectrometer in the analysis of drugs and metabolites in biological tissues.

    Science.gov (United States)

    Drexler, Dieter M; Garrett, Timothy J; Cantone, Joseph L; Diters, Richard W; Mitroka, James G; Prieto Conaway, Maria C; Adams, Stephen P; Yost, Richard A; Sanders, Mark

    2007-01-01

    The properties and potential liabilities of drug candidate are investigated in detailed ADME assays and in toxicity studies, where findings are placed in context of exposure to dosed drug and metabolites. The complex nature of biological samples may necessitate work-up procedures prior to high performance liquid chromatography-mass spectrometric (HPLC-MS) analysis of endogenous or xenobiotic compounds. This concept can readily be applied to biological fluids such as blood or urine, but in localized samples such as organs and tissues potentially important spatial, thus anatomical, information is lost during sample preparation as the result of homogenization and extraction procedures. However, the localization of test article or spatial identification of metabolites may be critical to the understanding of the mechanism of target-organ toxicity and its relevance to clinical safety. Tissue imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) and ion trap mass spectrometry (MS) with higher order mass spectrometric scanning functions was utilized for localization of dosed drug or metabolite in tissue. Laser capture microscopy (LCM) was used to obtain related samples from tissue for analyses by standard MALDI-MS and HPLC-MS. In a toxicology study, rats were administered with a high dosage of a prodrug for 2 weeks. Birefringent microcrystalline material (10-25 microm) was observed in histopathologic formalin-fixed tissue samples. Direct analysis by IMS provided the identity of material in the microcrystals as circulating active drug while maintaining spatial orientation. Complementary data from visual cross-polarized light microscopy as well as standard MALDI-MS and HPLC-MS experiments on LCM samples validated the qualitative results obtained by IMS. Furthermore, the HPLC-MS analysis on the LCM samples afforded a semi-quantitative assessment of the crystalline material in the tissue samples. IMS by MALDI ion trap MS proved sensitive

  1. Processes and procedures for a worldwide biological samples distribution; product assurance and logistic activities to support the mice drawer system tissue sharing event

    Science.gov (United States)

    Benassai, Mario; Cotronei, Vittorio

    The Mice Drawer System (MDS) is a scientific payload developed by the Italian Space Agency (ASI), it hosted 6 mice on the International Space Station (ISS) and re-entered on ground on November 28, 2009 with the STS 129 at KSC. Linked to the MDS experiment, a Tissue Sharing Program (TSP), was developed in order to make available to 16 Payload Investigators (PI) (located in USA, Canada, EU -Italy, Belgium and Germany -and Japan) the biological samples coming from the mice. ALTEC SpA (a PPP owned by ASI, TAS-I and local institutions) was responsible to support the logistics aspects of the MDS samples for the first MDS mission, in the frame of Italian Space Agency (ASI) OSMA program (OSteoporosis and Muscle Atrophy). The TSP resulted in a complex scenario, as ASI, progressively, extended the original OSMA Team also to researchers from other ASI programs and from other Agencies (ESA, NASA, JAXA). The science coordination was performed by the University of Genova (UNIGE). ALTEC has managed all the logistic process with the support of a specialized freight forwarder agent during the whole shipping operation phases. ALTEC formalized all the steps from the handover of samples by the dissection Team to the packaging and shipping process in a dedicated procedure. ALTEC approached all the work in a structured way, performing: A study of the aspects connected to international shipments of biological samples. A coopera-tive work with UNIGE/ASI /PIs to identify all the needs of the various researchers and their compatibility. A complete revision and integration of shipment requirements (addresses, tem-peratures, samples, materials and so on). A complete definition of the final shipment scenario in terms of boxes, content, refrigerant and requirements. A formal approach to identification and selection of the most suited and specialized Freight Forwarder. A clear identification of all the processes from sample dissection by PI Team, sample processing, freezing, tube preparation

  2. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  3. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1988-07-01

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  4. Protons in collision

    International Nuclear Information System (INIS)

    Albrow, M.

    1983-01-01

    The article is concerned with the Intersecting Storage Rings (ISR), sited at CERN, which produces the world's highest energy collisions between protons, but is due to be dismantled soon. The ISR has contributed to major advances in physics, during the past 13 years, particularly in quantum chromodynamics. (U.K.)

  5. Collision Probability Analysis

    DEFF Research Database (Denmark)

    Hansen, Peter Friis; Pedersen, Preben Terndrup

    1998-01-01

    It is the purpose of this report to apply a rational model for prediction of ship-ship collision probabilities as function of the ship and the crew characteristics and the navigational environment for MS Dextra sailing on a route between Cadiz and the Canary Islands.The most important ship and crew...

  6. High energy nuclear collisions

    Indian Academy of Sciences (India)

    We review some basic concepts of relativistic heavy-ion physics and discuss our understanding of some key results from the experimental program at the relativistic heavy-ion collider (RHIC). We focus in particular on the early time dynamics of nuclear collisions, some result from lattice QCD, hard probes and photons.

  7. CMS SEES FIRST COLLISIONS

    CERN Multimedia

      A very special moment.  On 23rd November, 19:40 we recorded our first collisions with 450GeV beams well centred in CMS.   If you have any comments / suggestions please contact Karl Aaron GILL (Editor)

  8. Collisions in soccer kicking

    DEFF Research Database (Denmark)

    Andersen, Thomas Bull; Dörge, Henrik C.; Thomsen, Franz Ib

    1999-01-01

    An equation to describe the velocity of the soccer ball after the collision with a foot was derived. On the basis of experimental results it was possible to exclude certain factors and only describe the angular momentum of the system, consisting of the shank, the foot and the ball, leading...

  9. Ultrarelativistic oscillon collisions

    NARCIS (Netherlands)

    Amin, M.A.; Banik, I.; Negreanu, C.; Yang, I.S.

    2014-01-01

    In this short paper we investigate the ultrarelativistic collisions of small amplitude oscillons in 1+1 dimensions. Using the amplitude of the oscillons and the inverse relativistic boost factor γ−1 as the perturbation variables, we analytically calculate the leading order spatial and temporal phase

  10. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    “Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  11. Theoretical variance analysis of single- and dual-energy computed tomography methods for calculating proton stopping power ratios of biological tissues

    International Nuclear Information System (INIS)

    Yang, M; Zhu, X R; Mohan, R; Dong, L; Virshup, G; Clayton, J

    2010-01-01

    We discovered an empirical relationship between the logarithm of mean excitation energy (ln I m ) and the effective atomic number (EAN) of human tissues, which allows for computing patient-specific proton stopping power ratios (SPRs) using dual-energy CT (DECT) imaging. The accuracy of the DECT method was evaluated for 'standard' human tissues as well as their variance. The DECT method was compared to the existing standard clinical practice-a procedure introduced by Schneider et al at the Paul Scherrer Institute (the stoichiometric calibration method). In this simulation study, SPRs were derived from calculated CT numbers of known material compositions, rather than from measurement. For standard human tissues, both methods achieved good accuracy with the root-mean-square (RMS) error well below 1%. For human tissues with small perturbations from standard human tissue compositions, the DECT method was shown to be less sensitive than the stoichiometric calibration method. The RMS error remained below 1% for most cases using the DECT method, which implies that the DECT method might be more suitable for measuring patient-specific tissue compositions to improve the accuracy of treatment planning for charged particle therapy. In this study, the effects of CT imaging artifacts due to the beam hardening effect, scatter, noise, patient movement, etc were not analyzed. The true potential of the DECT method achieved in theoretical conditions may not be fully achievable in clinical settings. Further research and development may be needed to take advantage of the DECT method to characterize individual human tissues.

  12. Tissue bionics: examples in biomimetic tissue engineering

    International Nuclear Information System (INIS)

    Green, David W

    2008-01-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

  13. Tissue bionics: examples in biomimetic tissue engineering.

    Science.gov (United States)

    Green, David W

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  14. Tissue bionics: examples in biomimetic tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  15. Semianalytical Solution for the Deformation of an Elastic Layer under an Axisymmetrically Distributed Power-Form Load: Application to Fluid-Jet-Induced Indentation of Biological Soft Tissues

    Directory of Open Access Journals (Sweden)

    Minhua Lu

    2017-01-01

    Full Text Available Fluid-jet-based indentation is used as a noncontact excitation technique by systems measuring the mechanical properties of soft tissues. However, the application of these devices has been hindered by the lack of theoretical solutions. This study developed a mathematical model for testing the indentation induced by a fluid jet and determined a semianalytical solution. The soft tissue was modeled as an elastic layer bonded to a rigid base. The pressure of the fluid jet impinging on the soft tissue was assumed to have a power-form function. The semianalytical solution was verified in detail using finite-element modeling, with excellent agreement being achieved. The effects of several parameters on the solution behaviors are reported, and a method for applying the solution to determine the mechanical properties of soft tissues is suggested.

  16. Reactive Collision Avoidance Algorithm

    Science.gov (United States)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  17. GC-MS Metabolomic Analysis to Reveal the Metabolites and Biological Pathways Involved in the Developmental Stages and Tissue Response of Panax ginseng

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2017-03-01

    Full Text Available Ginsenosides, the major compounds present in ginseng, are known to have numerous physiological and pharmacological effects. The physiological processes, enzymes and genes involved in ginsenoside synthesis in P. ginseng have been well characterized. However, relatively little information is known about the dynamic metabolic changes that occur during ginsenoside accumulation in ginseng. To explore this topic, we isolated metabolites from different tissues at different growth stages, and identified and characterized them by using gas chromatography coupled with mass spectrometry (GC-MS. The results showed that a total of 30, 16, 20, 36 and 31 metabolites were identified and involved in different developmental stages in leaf, stem, petiole, lateral root and main root, respectively. To investigate the contribution of tissue to the biosynthesis of ginsenosides, we examined the metabolic changes of leaf, stem, petiole, lateral root and main root during five development stages: 1-, 2-, 3-, 4- and 5-years. The score plots of partial least squares-discriminate analysis (PLS-DA showed clear discrimination between growth stages and tissue samples. Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis in the same tissue at different growth stages indicated profound biochemical changes in several pathways, including carbohydrate metabolism and pentose phosphate metabolism, in addition, the tissues displayed significant variations in amino acid metabolism, sugar metabolism and energy metabolism. These results should facilitate further dissection of the metabolic flux regulation of ginsenoside accumulation in different developmental stages or different tissues of ginseng.

  18. Collision physics going west

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The centroid of proton-antiproton physics is moving west across the Atlantic concluded Luigi Di Leila of CERN in his summary talk at the Topical Workshop on Proton-Antiproton Collider Physics, held at Fermilab in June. Previous meetings in this series had been dominated by results from CERN's big proton-antiproton collider, dating back to 1981. However last year saw the first physics run at Fermilab's collider, and although the number of collisions in the big CDF detector was only about one thirtieth of the score so far at CERN, the increased collision energy at Fermilab of 1.8 TeV (1800 GeV, compared to the routine 630 GeV at CERN) is already paying dividends

  19. Biologic Scaffolds.

    Science.gov (United States)

    Costa, Alessandra; Naranjo, Juan Diego; Londono, Ricardo; Badylak, Stephen F

    2017-09-01

    Biologic scaffold materials composed of allogeneic or xenogeneic extracellular matrix are commonly used for the repair and functional reconstruction of injured and missing tissues. These naturally occurring bioscaffolds are manufactured by the removal of the cellular content from source tissues while preserving the structural and functional molecular units of the remaining extracellular matrix (ECM). The mechanisms by which these bioscaffolds facilitate constructive remodeling and favorable clinical outcomes include release or creation of effector molecules that recruit endogenous stem/progenitor cells to the site of scaffold placement and modulation of the innate immune response, specifically the activation of an anti-inflammatory macrophage phenotype. The methods by which ECM biologic scaffolds are prepared, the current understanding of in vivo scaffold remodeling, and the associated clinical outcomes are discussed in this article. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  20. Collective flow in relativistic heavy-ion collisions

    Indian Academy of Sciences (India)

    journal of. November 2003 physics pp. 1021–1025. Collective flow in relativistic heavy-ion collisions. R S BHALERAO. Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road,. Mumbai 400 .... Wherever statistical analyses are done, whether in physics, biology or psychology, corre-.

  1. Characterization of the electromagnetic near-field absorption in layered biological tissue in the frequency range from 30 MHz to 6000 MHz

    Energy Technology Data Exchange (ETDEWEB)

    Christ, A [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland); Samaras, T [Radiocommunications Laboratory, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece); Klingenboeck, A [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland); Kuster, N [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland)

    2006-10-07

    Currently, standards for the compliance testing of wireless devices are being extended to cover a wider frequency band and different usage patterns of mobile phones as well as of novel body-worn and handheld devices. As a consequence, not only the head but also strongly varying tissue distributions of the body are exposed to electromagnetic radiation. Several authors have reported changes in the SAR absorption of body tissue due to the presence of a low permittivity fat layer. This paper identifies two different effects which can lead to increased SAR in layered tissue in comparison to the SAR assessed using homogeneous tissue simulating liquid: (1) for larger distances between the tissue and the antenna, standing wave effects occur depending on the frequency and fat layer thickness. (2) In the very close near-field (distances approximately {lambda}/40), reactive E-field components lead to high local absorption in the skin. The latter effect occurs at lower frequencies and depends on the antenna type. Modification of the parameters of the homogeneous liquids cannot compensate for these effects. However, a conservative exposure estimate can be obtained by applying a multiplication factor between 1 and 3 to the values assessed using current experimental dosimetric techniques.

  2. Tissue engineered aortic valve

    OpenAIRE

    Dohmen, P M

    2012-01-01

    Several prostheses are available to replace degenerative diseased aortic valves with unique advantages and disadvantages. Bioprotheses show excellent hemodynamic behavior and low risk of thromboembolic complications, but are limited by tissue deterioration. Mechanical heart valves have extended durability, but permanent anticoagulation is mandatory. Tissue engineering created a new generation heart valve, which overcome limitations of biological and mechanical heart valves due to remodelling,...

  3. Analyses of chlorogenic acids and related cinnamic acid derivatives from Nicotiana tabacum tissues with the aid of UPLC-QTOF-MS/MS based on the in-source collision-induced dissociation method

    CSIR Research Space (South Africa)

    Ncube, EN

    2014-11-01

    Full Text Available ) produces frag- mentation similarly to 5-CQA (Figure 8). Interestingly, the CQA glycosides were only present in leaf tissue samples. Also, a previous report showed the accumula- tion of similar glycosides in Moringa leaves [32] and re- cently in Lonicera... (Aquifoliaceae) leaves by liquid chromatography tandem mass spectrometry. Phytochemistry 2014, 106:141–155. 32. Kashiwada Y, Ahmed FA, Kurimoto S, Kim SY, Shibata H, Fujikota T, Takaishi Y: New alpha-glucosides of caffeoyl quinic acid from the leaves of Moringa...

  4. A unique tripartite collision tumor of the esophagus

    Science.gov (United States)

    Schizas, Dimitrios; Michalinos, Adamantios; Alexandrou, Paraskevi; Moris, Demetrios; Baliou, Evangelia; Tsilimigras, Diamantis; Throupis, Theodore; Liakakos, Theodore

    2017-01-01

    Abstract Rationale: We report a unique case of a tripartite esophageal collision tumor consisting of three separate histologic types. Patients concerns: Therapeutic dilemmas on the proper treatment of those rare neoplasms remain unanswered considering both proper surgical therapy and adjuvant therapy. Diagnose: In this paper, we report a unique case of a patient with a tripartite esophageal collision tumor consisting of a small cell carcinoma, an adenocarcinoma of medium differentiation and a signet ring cell carcinoma. Diagnosis is difficult as clinical presentation of the patient was undistinguishable from other, commoner tumor types. Interventions: The patient's diagnostic and therapeutic course along with available data on the collisions tumor's biological behavior and treatment are briefly discussed. Outcomes: Esophagectomy is the best treatment options for these patients. Unique nature of this tumor demands aggresive oncologic treatment. Lessons: Collision tumors are rare neoplasms consisting of distinct cell populations developing in juxtaposition to one another without any areas of intermingling. Various cell types can be found. However, collision neoplasms of the esophagus combining adenomatous and neuroendocrine components are exceedingly rare, with only 5 cases described to date in the literature. Given their rarity, limited information is available on their tumorigenesis, biological behavior and clinical course. In general, these tumors are aggressive neoplasms and significantly affect patient treatment and prognosis. PMID:29245236

  5. Ship Collision and Grounding Analysis

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    2010-01-01

    It is the purpose of the paper to present a review of prediction and analysis tools for collision and grounding analyses and to outline a probabilistic procedure whereby these tools can be used by the maritime industry to develop performance based rules to reduce the risk associated with human......, environmental and economic costs of collision and grounding events. The main goal of collision and grounding research should be to identify the most economic risk control options associated with prevention and mitigation of collision and grounding events...

  6. Road rage and collision involvement.

    Science.gov (United States)

    Mann, Robert E; Zhao, Jinhui; Stoduto, Gina; Adlaf, Edward M; Smart, Reginald G; Donovan, John E

    2007-01-01

    To assess the contribution of road rage victimization and perpetration to collision involvement. The relationship between self-reported collision involvement and road rage victimization and perpetration was examined, based on telephone interviews with a representative sample of 4897 Ontario adult drivers interviewed between 2002 and 2004. Perpetrators and victims of both any road rage and serious road rage had a significantly higher risk of collision involvement than did those without road rage experience. This study provides epidemiological evidence that both victims and perpetrators of road rage experience increased collision risk. More detailed studies of the contribution of road rage to traffic crashes are needed.

  7. Topics in atomic collision theory

    CERN Document Server

    Geltman, Sydney; Brueckner, Keith A

    1969-01-01

    Topics in Atomic Collision Theory originated in a course of graduate lectures given at the University of Colorado and at University College in London. It is recommended for students in physics and related fields who are interested in the application of quantum scattering theory to low-energy atomic collision phenomena. No attention is given to the electromagnetic, nuclear, or elementary particle domains. The book is organized into three parts: static field scattering, electron-atom collisions, and atom-atom collisions. These are in the order of increasing physical complexity and hence necessar

  8. Analysis of Phospholipid Mixtures from Biological Tissues by Matrix-Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS): A Laboratory Experiment

    Science.gov (United States)

    Eibisch, Mandy; Fuchs, Beate; Schiller, Jurgen; Sub, Rosmarie; Teuber, Kristin

    2011-01-01

    Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is increasingly used to investigate the phospholipid (PL) compositions of tissues and body fluids, often without previous separation of the total mixture into the individual PL classes. Therefore, the questions of whether all PL classes are detectable…

  9. A glovebox with three levels of containment and clean room facilities for growing and handling biological material at physiologically correct gas compositions and with optimal quality assessment for tissue-engineering, ex vivo expansion, manipulation and gene therapy.

    Science.gov (United States)

    Villadsen, J A; Voeten, R G H M; Mosborg Peterson, P

    2002-07-01

    Traditional two levels of containment provide enclosure and underpressure in order to avoid hazardous material to flow towards e.g. a crewmember and thereby cause severe harm. The present-day demands for laboratory safety have revealed a paradox: In the laboratory overpressure is needed to prevent contamination of biological material and under pressure is needed to prevent the pollution of the environment. A new type of combined workbench/incubator has been constructed to meet future regulatory demands for handling and growing human biological cellular material at safe constant physiological conditions: A so-called three levels of containment glovebox/workbench. This new invention avoids the hazards of prior technology. It sets new standards for proper handling of biological materials and will meet the coming safety demands from the growing field of tissue engineering and ex vivo biotechnology. The invention is computer controlled, has a build in cleaning facility for assuring a particle free and aseptic working facility. We now have invented a solution to the above paradox concerning laboratory safety that seems to fulfil the need for safe biological experiments in microgravity. This concept has already been applied into ground-based research and is expected in a few years also to be applied similarly in the ISS environment. Furthermore, handling biological material mimicking in vivo conditions ex vivo requires precise and stabile monitoring and regulation of the isotherm and isobar conditions. Handling stem cells requires in addition low to very low oxygen tension to mimic the stem cells natural habitats. Besides that, the ex vivo gaseous atmosphere and temperature surrounding the cells has to be of same correct composition and temperature as found in the body in order to mimic in vivo situations in such way, that scientifically correct, reproducible and comparable results can be achieved. This fact is strengthened by forthcoming regulations as being prepared by

  10. Ship collision with iceberg database

    Energy Technology Data Exchange (ETDEWEB)

    Hill, B.T. [National Research Council of Canada, St. John' s, NL (Canada). Inst. for Ocean Technology

    2006-11-15

    Approximately 20 per cent of collisions between icebergs, steam ships and motor vessels since 1850 have resulted in sinkings. The available data indicates that most sinkings were due to some kind of indirect impact rather than a head on collision. This paper presented the newly augmented Microsoft Access Database of Ship Collisions with Icebergs that includes more than 670 events over 200 years, most of which occurred on the Grand Banks. Other collisions occurred further afield in the Arctic, off Greenland and in the fjords of Alaska. The operation, search categories and data fields of the database were described along with various trends of collisions, scope of damage and environmental factors involved. Based on an estimate of the number of voyages over the Grand Banks, a probability of collision was derived from the number of cargo ship collisions over the past several years. The Microsoft Access template was provided by the Canadian Hydraulic Centre which had been developed by them for their Ice Regime Database to describe sea ice and ship interactions. This template was adapted and modified for iceberg collisions. Where possible, the data base was augmented to include information about the nature of the damage, the weather and sea state, the ice conditions, iceberg size, the vessel route and location at the time of collision, and vessel characteristics. The purpose of the database is to provide operators and regulators with an assessment of the frequency of collisions and environmental factors that played a role at the time of the collision. The database provides a basis to undertake risk analysis for vessels entering a given area and provides a better understanding of conditions under which collisions are likely to occur. It was concluded that although the trend of collisions has improved over the years with better observation and detection techniques, collisions still occur. Reduced visibility by fog, precipitation or low light conditions were found to be

  11. Electron collisions with biomolecules

    International Nuclear Information System (INIS)

    McKoy, V; Winstead, C

    2008-01-01

    We report on results of recent studies of collisions of low-energy electrons with nucleobases and other DNA constituents. A particular focus of these studies has been the identification and characterization of resonances that play a role in electron attachment leading to strand breaks in DNA. Comparison of the calculated resonance positions with results of electron transmission measurements is quite encouraging. However, the higher-lying π* resonances of the nucleobases appear to be of mixed elastic and core-excited character. Such resonant channel coupling raises the interesting possibility that the higher π*resonances in the nucleobases may promote dissociation of DNA by providing doorway states to triplet excited states.

  12. Molecular collision theory

    CERN Document Server

    Child, M S

    2010-01-01

    This high-level monograph offers an excellent introduction to the theory required for interpretation of an increasingly sophisticated range of molecular scattering experiments. There are five helpful appendixes dealing with continuum wavefunctions, Green's functions, semi-classical connection formulae, curve-crossing in the momentum representation, and elements of classical mechanics.The contents of this volume have been chosen to emphasize the quantum mechanical and semi-classical nature of collision events, with little attention given to purely classical behavior. The treatment is essentiall

  13. On a Three Dimensional Vision Based Collision Avoidance Model

    Science.gov (United States)

    Parzani, Céline; Filbet, Francis

    2017-08-01

    This paper presents a three dimensional collision avoidance approach for aerial vehicles inspired by coordinated behaviors in biological groups. The proposed strategy aims to enable a group of vehicles to converge to a common destination point avoiding collisions with each other and with moving obstacles in their environment. The interaction rules lead the agents to adapt their velocity vectors through a modification of the relative bearing angle and the relative elevation. Moreover the model satisfies the limited field of view constraints resulting from individual perception sensitivity. From the proposed individual based model, a mean-field kinetic model is derived. Simulations are performed to show the effectiveness of the proposed model.

  14. The effects of grafted mesenchymal stem cells labeled with iron oxide or cobalt-zinc-iron nanoparticles on the biological macromolecules of rat brain tissue extracts

    Czech Academy of Sciences Publication Activity Database

    Novotná, Božena; Herynek, V.; Rössner ml., Pavel; Turnovcová, Karolína; Jendelová, Pavla

    2017-01-01

    Roč. 12, č. 2017 (2017), s. 4519-4526 E-ISSN 1178-2013 R&D Projects: GA MŠk(CZ) LO1309; GA MŠk(CZ) LO1508; GA MŠk(CZ) 7F14057 Institutional support: RVO:68378041 Keywords : MRI * comet assay * genotoxicity Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Human genetics Impact factor: 4.300, year: 2016

  15. SEM examination of human erythrocytes in uncoated bloodstains on stone: use of conventional as environmental-like SEM in a soft biological tissue (and hard inorganic material).

    Science.gov (United States)

    Hortolà, P

    2005-05-01

    Although nowadays the so-called environmental scanning electron microscopes (ESEMs) allow the observation of the samples without metal or carbon coating, many conventional scanning electron microscopes (SEMs) are still in use. On the other hand, the presence of erythrocytes (red blood cells, RBCs) in a smear is considered a blood confirmation. Such a presence has been previously reported even in Lower Stone Age implements. In previous works, I have reported several studies dealing with cytomorphology of RBCs in bloodstains using scanning electron microscopy with standard specimen preparation procedures, i.e. via coating the samples before SEM analysis. In order to explore the potential of conventional SEM as environmental-like SEM in haemotaphonomical studies, two alkaline (limestone) and two acid (flint) rock fragments were smeared with human blood from a male and a female. The bloodstains obtained in this way were then air dried indoors and stored into a non-hermetic plastic box. Afterwards, the smears and their rock substrates were examined directly without coating, via secondary electrons, using a JEOL JSM-6400 scanning electron microscope. Satisfactory results reveal the capability of a conventional SEM to work in secondary-electron mode as an environmental-like SEM on these kinds of biological and inorganic materials, and probably in many other biological and non-biological samples.

  16. CONFERENCE: Photon-photon collisions

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Despite being difficult to observe, photon-photon collisions have opened up a range of physics difficult, or even impossible, to access by other methods. The progress which has been made in this field was evident at the fifth international workshop on photon-photon collisions, held in Aachen from 13-16 April and attended by some 120 physicists

  17. Outer Dynamics of Ship Collisions

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    The purpose is to present analysis procedures for the motion of ships during ship-ship collisions and for ship collisions with offshore structures. The aim is to estimate that part of the lost kinetic energy which will have to be absorbed by rupture and plastic damage of the colliding structures....

  18. Photon-photon collisions

    International Nuclear Information System (INIS)

    Field, J.H.

    1984-01-01

    The current status, both theoretical and experimental, of two photon collision physics is reviewed with special emphasis on recent experimental results from e + e - storage rings. After a complete presentation of the helicity amplitude formalism for the general process e + e - → Xe + e - , various approximations (transverse photon, Weisaecker Williams) are discussed. Beam polarisation effects and radiative corrections are also briefly considered. A number of specific processes, for which experimental results are now available, are then described. In each case existing theoretical prediction are confronted with experimental results. The processes described include single resonance production, lepton and hadron pair production, the structure functions of the photon, the production of high Psub(T) jets and the total photon photon cross section. In the last part of the review the current status of the subject is summarised and some comments are made on future prospects. These include both extrapolations of current research to higher energy machines (LEP, HERA) as well as a brief mention of both the technical realisation and the physics interest of the real γγ and eγ collisions which may be possible using linear electron colliders in the 1 TeV energy range

  19. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  20. Photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of α/sub s/ and Λ/sup ms/ from the γ*γ → π 0 form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from γγ → H anti H, reconstruction of sigma/sub γγ/ from exclusive channels at low W/sub γγ/, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z 0 and W +- beams from e → eZ 0 and e → nu W will become important. 44 references

  1. Collision in space

    Science.gov (United States)

    Ellis, S. R.

    2000-01-01

    On June 25, 1997, the Russian supply spacecraft Progress 234 collided with the Mir space station, rupturing Mir's pressure hull, throwing it into an uncontrolled attitude drift, and nearly forcing evacuation of the station. Like many high-profile accidents, this collision was the consequence of a chain of events leading to the final piloting errors that were its immediate cause. The discussion in this article does not resolve the relative contributions of the actions and decisions in this chain. Neither does it suggest corrective measures, many of which are straightforward and have already been implemented by the National Aeronautics and Space Administration (NASA) and the Russian Space Agency. Rather, its purpose is to identify the human factors that played a pervasive role in the incident. Workplace stress, fatigue, and sleep deprivation were identified by NASA as contributory factors in the Mir-Progress collision (Culbertson, 1997; NASA, forthcoming), but other contributing factors, such as requiring crew to perform difficult tasks for which their training is not current, could potentially become important factors in future situations.

  2. Collisions between Globular Clusters

    Science.gov (United States)

    Belloni, D. T.; Rocha-Pinto, H. J.

    2014-10-01

    The study of globular clusters (GC) plays an important role in our understanding of the Universe since these systems are true laboratories for theories of stellar dynamics and evolution. We are interested in studying a globular cluster formed by a collision between two different GC with NBODY6 (Aarseth, 2003). Firstly, in order to understand this code, we analyse how tidal streams form from a globular cluster in a circular orbit (on the disk) around the center of the Milky Way. In the next stage of this work we will study that collision. The stellar escape or capture from globular cluster can be understood with the Restricted Three Body Problem. These stars escape in a chaotic orbit, and in some cases may return (again in a chaotic orbit) to the cluster due to the Galactic potential. In most cases, such stars quickly alter their escape chaotic orbits to orbits that are similar to the parent cluster's orbit. Our results show an agglomeration of stars in a normal direction related to the direction towards the center of the Milky Way, forming thus a stream. We can explain this considering that a circular orbit around the dominant potential is the most likely orbit, since it requires minimum energy. In this coordinate systems, the tidal tails (or streams) rotates around the cluster center with the same mean motion associated to cluster around the Milky Way center.

  3. A Changing Wind Collision

    Science.gov (United States)

    Nazé, Yaël; Koenigsberger, Gloria; Pittard, Julian M.; Parkin, Elliot Ross; Rauw, Gregor; Corcoran, Michael F.; Hillier, D. John

    2018-02-01

    We report on the first detection of a global change in the X-ray emitting properties of a wind–wind collision, thanks to XMM-Newton observations of the massive Small Magellenic Cloud (SMC) system HD 5980. While its light curve had remained unchanged between 2000 and 2005, the X-ray flux has now increased by a factor of ∼2.5, and slightly hardened. The new observations also extend the observational coverage over the entire orbit, pinpointing the light-curve shape. It has not varied much despite the large overall brightening, and a tight correlation of fluxes with orbital separation is found without any hysteresis effect. Moreover, the absence of eclipses and of absorption effects related to orientation suggests a large size for the X-ray emitting region. Simple analytical models of the wind–wind collision, considering the varying wind properties of the eruptive component in HD 5980, are able to reproduce the recent hardening and the flux-separation relationship, at least qualitatively, but they predict a hardening at apastron and little change in mean flux, contrary to observations. The brightness change could then possibly be related to a recently theorized phenomenon linked to the varying strength of thin-shell instabilities in shocked wind regions. Based on XMM-Newton and Chandra data.

  4. The QUASIMENE Inter-laboratory Performance Study: trace metals in sediments and biological tissues; Partecipazione della sezione AMB-TEIN-CHIM a programmi di intercalibrazione in ambito nazionale ed europeo

    Energy Technology Data Exchange (ETDEWEB)

    Cremisini, C.; Galletti, M.; Gragnani, R. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1998-12-01

    Between 1993 and 1996 the European Union supported the development of a Quality Assurance programme of Information in Marine Environmental Monitoring in Europe (QUASIMEME). The aim of the programme was to improve and control the quality of marine environmental information through inter-laboratory studies on nutrients in sea water, chloro biphenyls and trace metals in sediments and biological tissue. This paper describes the participation of ENEA laboratory (AMB/TEIN/CHIM) to QUASIMEME-Programme for trace metals in sediments and biological tissues. [Italiano] Nel triennio 1993-1996 la Comunita` Europea ha supportato lo sviluppo del Programma QUASIMEME (Quality Assurance of Information in Marine Environmental Monitoring in Europe). L`obiettivo prioritario e` stato il controllo e il miglioramento della qualita` delle informazioni relative all`ambiente marino. Cio` e` stato realizzato mediante una serie di esercizi d`intercalibrazione tra circa 80 laboratori, sparsi in tutta Europa, relativamente a: nutrienti nell`acqua di mare, policlorobifenili e metalli nei sedimenti e nei tessuti biologici. In questo lavoro viene descritta la partecipazione del laboratorio ENEA (AMB/TEIN/CHIM) a tale Programma per la parte relativa alla determinazione dei metalli in traccia nei sedimenti e nei tessuti biologici.

  5. TU-FG-201-07: Development of SRS Conical Collimator Collision Prediction Software for Radiation Treatment Safety

    International Nuclear Information System (INIS)

    Gutti, V; Morrow, A; Kim, S; Patel, M

    2016-01-01

    Purpose: Stereotactic radiosurgery (SRS) treatments using conical collimators can potentially result in gantry collision with treatment table due to limited collision-clear spaces. An in-house software was developed to help the SRS treatment planner mitigate potential SRS conical collimator (Varian Medical System, Palo Alto, CA) collisions with the treatment table. This software was designed to remove treatment re-planning secondary to unexpected collisions. Methods: A BrainLAB SRS ICT Frameless Extension used for SRS treatments in our clinic was mathematically modelled using surface points registered to the 3D co-ordinate space of the couch extension. The surface points are transformed based on the treatment isocenter point and potential collisions ar