WorldWideScience

Sample records for biological tissue based

  1. Quantum cascade laser-based hyperspectral imaging of biological tissue.

    Science.gov (United States)

    Kröger, Niels; Egl, Alexander; Engel, Maria; Gretz, Norbert; Haase, Katharina; Herpich, Iris; Kränzlin, Bettina; Neudecker, Sabine; Pucci, Annemarie; Schönhals, Arthur; Vogt, Jochen; Petrich, Wolfgang

    2014-01-01

    The spectroscopy of analyte-specific molecular vibrations in tissue thin sections has opened up a path toward histopathology without the need for tissue staining. However, biomedical vibrational imaging has not yet advanced from academic research to routine histopathology due to long acquisition times for the microscopic hyperspectral images and/or cost and availability of the necessary equipment. Here we show that the combination of a fast-tuning quantum cascade laser with a microbolometer array detector allows for a rapid image acquisition and bares the potential for substantial cost reduction. A 3.1 x 2.8 mm2 unstained thin section of mouse jejunum has been imaged in the 9.2 to 9.7 μm wavelength range (spectral resolution ~1 cm(-1)) within 5 min with diffraction limited spatial resolution. The comparison of this hyperspectral imaging approach with standard Fourier transform infrared imaging or mapping of the identical sample shows a reduction in acquisition time per wavenumber interval and image area by more than one or three orders of magnitude, respectively. PMID:24967840

  2. Logarithmic rate based elasto-viscoplastic cyclic constitutive model for soft biological tissues.

    Science.gov (United States)

    Zhu, Yilin; Kang, Guozheng; Yu, Chao; Poh, Leong Hien

    2016-08-01

    Based on the logarithmic rate and piecewise linearization theory, a thermodynamically consistent elasto-viscoplastic constitutive model is developed in the framework of finite deformations to describe the nonlinear time-dependent biomechanical performances of soft biological tissues, such as nonlinear anisotropic monotonic stress-strain responses, stress relaxation, creep and ratchetting. In the proposed model, the soft biological tissue is assumed as a typical composites consisting of an isotropic matrix and anisotropic fiber aggregation. Accordingly, the free energy function and stress tensor are divided into two parts related to the matrix and fiber aggregation, respectively. The nonlinear biomechanical responses of the tissues are described by the piecewise linearization theory with hypo-elastic relations of fiber aggregation. The evolution equations of viscoplasticity are formulated from the dissipation inequalities by the co-directionality hypotheses. The anisotropy is considered in the hypo-elastic relations and viscoplastic flow rules by introducing some material parameters dependent on the loading direction. Then the capability of the proposed model to describe the nonlinear time-dependent deformation of soft biological tissues is verified by comparing the predictions with the corresponding experimental results of three tissues. It is seen that the predicted monotonic stress-strain responses, stress relaxation, creep and ratchetting of soft biological tissues are in good agreement with the corresponding experimental ones. PMID:27108349

  3. Macroscopic characterization of cell electroporation in biological tissue based on electrical measurements

    Science.gov (United States)

    Cima, Lionel F.; Mir, Lluis M.

    2004-11-01

    A method is described to experimentally determine the temporal evolution of state variables involved in the electroporation of biological tissue, i.e., the transmembrane voltage and the macroscopic current flowing in the electropores. Indeed, the electrical parameters of the extracellular, intracellular, and unaltered membrane contributions as well as the electropores electrical characteristics can be deduced from the measurement of the tissue bioimpedance and from the variations of both the macroscopic voltage applied to the tissue and the delivered current.

  4. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Abou Neel, Ensanya Ali, E-mail: eabouneel@kau.edu.sa [Division of Biomaterials, Conservative Dental Sciences Department, King Abdulaziz University, Jeddah (Saudi Arabia); Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta (Egypt); Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Chrzanowski, Wojciech [The University of Sydney, Faculty of Pharmacy, Pharmacy and Bank Building, NSW2006 (Australia); Department of Nanobiomedical Science and BK21 Plus NBM Global Reserch Center for Regenerative Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Knowles, Jonathan Campbell, E-mail: j.knowles@ucl.ac.uk [Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, 256 Gray' s Inn Road, London WC1X 8LD (United Kingdom); Department of Nanobiomedical Science and BK21 Plus NBM Global Reserch Center for Regenerative Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of)

    2014-02-01

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS cells cultured on the surface of glass discs. Cell proliferation was also studied in the presence of the glass extract. Cell differentiation, through osteoblast phenotype genes, alkaline phosphatase (ALP) activity and osteocalcin production, was carried out using normal or osteogenic media. Both Thermanox® and titania free glass were used as controls. The data demonstrated that titania inclusion provides desired cytocompatible surface that supported initial cell attachment, sustained viability, and increased cell proliferation similar or significantly higher than Thermanox®. The modified glasses regulated osteoblastic cell differentiation as detected by osteoblast phenotype gene transcription and upregulated ALP and osteocalcin expression. Using osteogenic media had no significant effect on ALP activity and osteocalcin expression. Therefore, titania modified phosphate glasses may have future use as bone tissue engineering scaffolds. - Highlights: • This study investigated the role of titania on the biological response of phosphate glasses. • Incorporation of titania improved HOS cell attachment, viability and proliferation. • Titania modified glasses regulated osteoblastic cell differentiation. • Using osteogenic media had no significant effect on cell differentiation. • Titania modified glasses may have future use as bone tissue engineering scaffolds.

  5. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications

    International Nuclear Information System (INIS)

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS cells cultured on the surface of glass discs. Cell proliferation was also studied in the presence of the glass extract. Cell differentiation, through osteoblast phenotype genes, alkaline phosphatase (ALP) activity and osteocalcin production, was carried out using normal or osteogenic media. Both Thermanox® and titania free glass were used as controls. The data demonstrated that titania inclusion provides desired cytocompatible surface that supported initial cell attachment, sustained viability, and increased cell proliferation similar or significantly higher than Thermanox®. The modified glasses regulated osteoblastic cell differentiation as detected by osteoblast phenotype gene transcription and upregulated ALP and osteocalcin expression. Using osteogenic media had no significant effect on ALP activity and osteocalcin expression. Therefore, titania modified phosphate glasses may have future use as bone tissue engineering scaffolds. - Highlights: • This study investigated the role of titania on the biological response of phosphate glasses. • Incorporation of titania improved HOS cell attachment, viability and proliferation. • Titania modified glasses regulated osteoblastic cell differentiation. • Using osteogenic media had no significant effect on cell differentiation. • Titania modified glasses may have future use as bone tissue engineering scaffolds

  6. Evaluation of finite-element-based simulation model of photoacoustics in biological tissues

    Science.gov (United States)

    Wang, Zhaohui; Ha, Seunghan; Kim, Kang

    2012-03-01

    A finite element (FE)-based simulation model for photoacoustic (PA) has been developed incorporating light propagation, PA signal generation, and sound wave propagation in soft tissues using a commercial FE simulation package, COMSOL Multiphysics. The developed simulation model is evaluated by comparing with other known simulation models such as Monte Carlo method and heat-pressure model. In this in silico simulation, FE model is composed of three parts of 1) homogeneous background soft tissues submerged in water, 2) target tissue inclusion (or PA contrast agents), and 3) short pulsed laser source (pulse length of 5-10 ns). The laser point source is placed right above the tissues submerged in water. This laser source light propagation through the multi-layer tissues using the diffusion equation is compared with Monte Carlo solution. Photoacoustic signal generation by the target tissue inclusion is simulated using bioheat equation for temperature change, and resultant stress and strain. With stress-strain model, the process of the PA signal generation can be simulated further in details step by step to understand and analyze the photothermal properties of the target tissues or PA contrast agents. The created wide-band acoustic pressure (band width > 150 MHz) propagates through the background tissues to the ultrasound detector located at the tissue surface, governed by sound wave equation. Acoustic scattering and absorption in soft tissues also have been considered. Accuracy and computational time of the developed FE-based simulation model of photoacoustics have been quantitatively analyzed.

  7. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications.

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Knowles, Jonathan Campbell

    2014-02-01

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS cells cultured on the surface of glass discs. Cell proliferation was also studied in the presence of the glass extract. Cell differentiation, through osteoblast phenotype genes, alkaline phosphatase (ALP) activity and osteocalcin production, was carried out using normal or osteogenic media. Both Thermanox® and titania free glass were used as controls. The data demonstrated that titania inclusion provides desired cytocompatible surface that supported initial cell attachment, sustained viability, and increased cell proliferation similar or significantly higher than Thermanox®. The modified glasses regulated osteoblastic cell differentiation as detected by osteoblast phenotype gene transcription and upregulated ALP and osteocalcin expression. Using osteogenic media had no significant effect on ALP activity and osteocalcin expression. Therefore, titania modified phosphate glasses may have future use as bone tissue engineering scaffolds. PMID:24411382

  8. Poro_Thermoelastic Duality and FE-based strategies for the analysis of biological tissues

    OpenAIRE

    Capone, Claudia Cristiana Chiara

    2010-01-01

    Many analytical and numerical approaches have been proposed in order to solve poroelastic problems describing the behavior of biological tissues. The main difficulty associated to numerical strategies concerns the solution of the coupled poroelastic equations for determining the solid response in terms of deformation and filtration. The proposal of this work is to find a strategy to numerically solve poroelastic problems employing the Finite Element Method (FEM). In particular, the strategy p...

  9. Photoacoustic tomography of water in biological tissue

    Science.gov (United States)

    Xu, Zhun; Li, Changhui; Wang, Lihong V.

    2011-03-01

    As an emerging imaging technique that combines high optical contrast and ultrasonic detection, photoacoustic tomography (PAT) has been widely used to image optically absorptive objects in both human and animal tissues. PAT overcomes the depth limitation of other high-resolution optical imaging methods, and it is also free from speckle artifacts. To our knowledge, water has never been imaged by PAT in biological tissue. Here, for the first time, we experimentally imaged water in both tissue phantoms and biological tissues using a near infrared (NIR) light source. The differences among photoacoustic images of water with different concentrations indicate that laser-based PAT can usefully detect and image water content in tissue.

  10. Hydrogel-based encapsulation of biological, functional tissue: fundamentals, technologies and applications

    Science.gov (United States)

    Zimmermann, H.; Ehrhart, F.; Zimmermann, D.; Müller, K.; Katsen-Globa, A.; Behringer, M.; Feilen, P. J.; Gessner, P.; Zimmermann, G.; Shirley, S. G.; Weber, M. M.; Metze, J.; Zimmermann, U.

    2007-12-01

    Replacing dysfunctional endocrine cells or tissues (e.g. islets, parathyroid tissue) by functional, foreign material without using immunosuppressives could soon become reality. Immunological reactions are avoided by encapsulating cells/tissues in hydrogel (e.g. alginate) microcapsules, preventing interaction of the enclosed material with the host’s immune system while permitting the unhindered passage of nutrients, oxygen and secreted therapeutic factors. Detailed investigations of the physical, physico-chemical and immunological parameters of alginate-based microcapsules have led recently to the development of a novel class of cell-entrapping microcapsules that meet the demands of biocompatibility, long-term integrity and function. This together with the development of ‘good medical practice’ microfluidic chip technology and of advanced cryopreservation technology for generation and storage of immunoisolated transplants will bring cell-based therapy to clinics and the market.

  11. Optical imaging of biological tissues

    Science.gov (United States)

    Bouza Dominguez, Jorge

    In this thesis, a new time-dependent model for describing light propagation in biological media is proposed. The model is based on the simplified spherical harmonics approximation and is represented by a set of coupled parabolic partial differential equations (TD-pSPN equations). In addition, the model is extended for modeling the time-dependent response of fluorescent agents in biological tissues and the ensuing time-domain propagation of light therein. In a comparison with Monte Carlo simulations, it is shown that the TD-pSPN equations present unique features in its derivation that makes it a more accurate alternative to the diffusion equation (DE). The TD-pSPN model (for orders N > 1) outperforms the DE in the description of the propagation of light in near-nondiffusive media and in all the physical situations where DE fails. Often, only small orders of the SP N approximation are needed to obtain accurate results. A diffuse optical tomography (DOT) algorithm is also implemented based on the TD-pSPN equations as the forward model using constrained optimization methods. The algorithm uses time-dependent (TD) data directly. Such an approach is benefited from both the accuracy of the SPN models and the richness of TD data. In the calculation of the gradient of the objective function, a time-dependent adjoint differentiation method is introduced that reduces computation time. Several numerical experiments are performed for small geometry media with embedded inclusions that mimic small animal imaging. In these experiments, the values of the optical coefficients are varied within realistic bounds that are representative of those found in the range of the near-infrared spectrum, including high absorption values. Single and multi-parameter reconstructions (absorption and diffusion coefficients) are performed. The reconstructed images based on the TD-pSPN equations (N > 1) give better estimates of the optical properties of the media than the DE. On the other hand

  12. Biological performance of titania containing phosphate-based glasses for bone tissue engineering applications

    OpenAIRE

    Abou Neel, E. A.; W. Chrzanowski; Knowles, J. C.

    2014-01-01

    The interplay between glass chemistry, structure, degradation kinetics, and biological activity provides flexibility for the development of scaffolds with highly specific cellular response. The aim of this study was therefore to investigate the role of titania inclusion into the phosphate-based glass on its ability to stimulate osteoblast-like human osteosarcoma (HOS) cells to adhere, proliferate and differentiate. In depth morphological and biochemical characterisation was performed on HOS c...

  13. Modeling the Heating of Biological Tissue based on the Hyperbolic Heat Transfer Equation

    CERN Document Server

    Tung, M M; Molina, J A Lopez; Rivera, M J; Berjano, E J

    2008-01-01

    In modern surgery, a multitude of minimally intrusive operational techniques are used which are based on the punctual heating of target zones of human tissue via laser or radio-frequency currents. Traditionally, these processes are modeled by the bioheat equation introduced by Pennes, who considers Fourier's theory of heat conduction. We present an alternative and more realistic model established by the hyperbolic equation of heat transfer. To demonstrate some features and advantages of our proposed method, we apply the obtained results to different types of tissue heating with high energy fluxes, in particular radiofrequency heating and pulsed laser treatment of the cornea to correct refractive errors. Hopefully, the results of our approach help to refine surgical interventions in this novel field of medical treatment.

  14. Crosslinked hydrogels based on biological macromolecules with potential use in skin tissue engineering.

    Science.gov (United States)

    Vulpe, Raluca; Popa, Marcel; Picton, Luc; Balan, Vera; Dulong, Virginie; Butnaru, Maria; Verestiuc, Liliana

    2016-03-01

    Zero-length crosslinked hydrogels have been synthesized by covalent linking of three natural polymers (collagen, hyaluronic acid and sericin), in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. The hydrogels have been investigated by FT-IR spectroscopy, microcalorimetry, in vitro swelling, enzymatic degradation, and in vitro cell viability studies. The obtained crosslinked hydrogels showed a macroporous structure, high swelling degree and in vitro enzymatic resistance compared to uncrosslinked collagen. The in vitro cell viability studies performed on normal human dermal fibroblasts assessed the sericin proliferation properties indicating a potential use of the hydrogels based on collagen, hyaluronic acid and sericin in skin tissue engineering. PMID:26704998

  15. 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.

  16. 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. PMID:26897376

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

    Science.gov (United States)

    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

    2008-02-01

    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. PMID:18199908

  18. Radiation sterilization of biological tissues

    International Nuclear Information System (INIS)

    After years of neglect, the value of sterile non-viable (allograft) tissue grafts in transplant surgery is now being recognised. Sterilization using γ-radiation is now becoming the method of choice for a wide range of tissues in a spectrum of Human Tissues banks throughout the world. The radiation treatment can initiate physical and chemical damage in the tissues. Where necessary methods of protection have been developed. Examples are given of the successful utilization of radiation for tissue sterilization and use. (author)

  19. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using harmonic motion imaging (HMI).

    Science.gov (United States)

    Vappou, Jonathan; Hou, Gary Y; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E

    2015-04-01

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young's modulus and the HMI modulus in the numerical study (r(2) > 0.99, relative error <10%) and on polyacrylamide gels (r(2) = 0.95, relative error <24%). The average HMI modulus on five liver samples was found to EHMI = 2.62  ±  0.41 kPa, compared to EMechTesting = 4.2  ±  2.58 kPa measured by rheometry. This study has demonstrated for the first time the initial feasibility of a non-invasive, model-independent method to estimate local elastic properties of biological tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens. PMID:25776065

  20. Interaction of electromagnetic fields and biological tissues

    Science.gov (United States)

    Darshan Shrivastava, Bhakt; Barde, Ravindra; Mishra, Ashutosh; Phadke, S.

    2014-09-01

    This paper deals with the electromagnetic field interact in biological tissues. It is actually one of the important challenges for the electromagnetic field for the recent years. The experimental techniques are use in Broad-band Dielectric Measurement (BDM) with LCR meters. The authors used Bones and scales of Fish taken from Narmada River (Rajghat Dist. Barwani) as biological tissues. Experimental work carried out done in inter-university consortium (IUC) Indore. The major difficulties that appear are related to the material properties, to the effect of the electromagnetic problem and to the thermal model of the biological tissues.

  1. 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.

  2. Thermal property of biological tissues characterized by piezoelectric photoacoustic technique

    Institute of Scientific and Technical Information of China (English)

    GAO Chunming; ZHANG Shuyi; CHEN Yan; SHUI Xiuji; YANG Yuetao

    2004-01-01

    A photoacoustic piezoelectric method based on a simplified thermoelastic theory is employed to determine thermal diffusivities of biological tissues. The thermal diffusivities of porcine tissues with different preparation conditions, including fresh, dry and specially prepared conditions, are characterized. Comparing the experimental evaluated diffusivities of the tissues in three conditions with each other, it can be seen that the diffusivities of the fresh tissues are the biggest and the diffusivities of the specially prepared tissues are bigger than that of the dry ones generally. The results show that the piezoelectric photoacoustic method is especially effective for determining macro-effective (average) thermal diffusivities of biological materials with micro- inhomogeneity and easy to be performed, which can provide useful information for researching thermal characters of biological tissues.

  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)

    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. Role of sensitivity of zinc oxide nanorods (ZnO-NRs) based photosensitizers in hepatocellular site of biological tissue

    Science.gov (United States)

    Atif, M.; Fakhar-E-Alam, M.; Alsalhi, M. S.

    2011-11-01

    Zinc oxide nanorods (ZnO-NRs) with high surface to volume ratio and bio compatibility are used as an efficient photosensitizer carrier system for achievement of Hepatocellular cancer cell (HepG2) necrosis within few minutes. Present study highlights the role of effectiveness of ZnO-NRs in photodynamic therapy (PDT). We have grown the ZnO-NRs on the tip of borosilicate glass capillaries (0.5 μm diameter). The grown ZnO-NRs were conjugated using Photofrin® and ALA for the efficient intracellular drug delivery, which produces reactive oxygen species (ROS) via photochemical reactions leading to cell death within few minutes after exposing UV light (240 nm). Viability of controlled and treated HepG2 cells with optimum dose of light (UV-visible) has been assessed by neutral red assay (NRA). The results were verified by staining of mitochondria using Mitotracker® red as an efficient dye as well as ROS detection. ZnO-NRs based Phogem® (PG) treated normal liver tissues of Sprague-Dawley rats were used as comparative experimental model. Morphological apoptotic changes in liver tissue of Sprague-Dawley rats before and after ZnO-NRs conjugated with photosensitizer (PS)-mediated PDT were investigated by microscopic examination.

  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. Preparation, characterization and biological test of 3D-scaffolds based on chitosan, fibroin and hydroxyapatite for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Paulo Autran Leite; Resende, Cristiane Xavier [Departamento de Ciências de Materiais, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n. Jardim Rosa Elze, São Cristóvão, Sergipe CEP 49000-100 (Brazil); Dulce de Almeida Soares, Glória [Departamento de Ciências de Materiais, Universidade Federal do Rio de Janeiro, Av. Brigadeiro Trompowisk, s/n. Ilha do Fundão, Rio de Janeiro, Rio de Janeiro CEP 21900-000 (Brazil); Anselme, Karine [Institut de Science des Matériaux de Mulhouse (IS2M), CNRS LRC7228, 15, Jean Starcky Street, BP 2488, 68054 Mulhouse cedex (France); Almeida, Luís Eduardo, E-mail: lealmeida2009@gmail.com [Departamento de Ciências de Materiais, Universidade Federal de Sergipe, Av. Marechal Rondon, s/n. Jardim Rosa Elze, São Cristóvão, Sergipe CEP 49000-100 (Brazil)

    2013-08-01

    This work describes the preparation and characterization of porous 3D-scaffolds based on chitosan (CHI), chitosan/silk fibroin (CHI/SF) and chitosan/silk fibroin/hydroxyapatite (CHI/SF/HA) by freeze drying. The biomaterials were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, studies of porosity, pore size, contact angle and biological response of SaOs-2osteoblastic cells were performed. The CHI scaffolds have a porosity of 94.2 ± 0.9%, which is statistically higher than the one presented by CHI/SF/HA scaffolds, 89.7 ± 2.6%. Although all scaffolds were able to promote adhesion, growth and maintenance of osteogenic differentiation of SaOs-2 cells, the new 3D-scaffold based on CHI/SF/HA showed a significantly higher cell growth at 7 days and 21 days and the level of alkaline phosphatase at 14 and 21 days was statistically superior compared to other tested materials. - Highlights: • Preparation of 3D-scaffolds based on CHI, with or without addition of SF and HA. • Scaffolds exhibited interconnected porous structure (pore size superior to 50 μm). • The tripolyphosphate did not induce any significant cytotoxic response. • The CHI/SF/HA composite showed a higher cell growth and ALP activity.

  8. Preparation, characterization and biological test of 3D-scaffolds based on chitosan, fibroin and hydroxyapatite for bone tissue engineering

    International Nuclear Information System (INIS)

    This work describes the preparation and characterization of porous 3D-scaffolds based on chitosan (CHI), chitosan/silk fibroin (CHI/SF) and chitosan/silk fibroin/hydroxyapatite (CHI/SF/HA) by freeze drying. The biomaterials were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, studies of porosity, pore size, contact angle and biological response of SaOs-2osteoblastic cells were performed. The CHI scaffolds have a porosity of 94.2 ± 0.9%, which is statistically higher than the one presented by CHI/SF/HA scaffolds, 89.7 ± 2.6%. Although all scaffolds were able to promote adhesion, growth and maintenance of osteogenic differentiation of SaOs-2 cells, the new 3D-scaffold based on CHI/SF/HA showed a significantly higher cell growth at 7 days and 21 days and the level of alkaline phosphatase at 14 and 21 days was statistically superior compared to other tested materials. - Highlights: • Preparation of 3D-scaffolds based on CHI, with or without addition of SF and HA. • Scaffolds exhibited interconnected porous structure (pore size superior to 50 μm). • The tripolyphosphate did not induce any significant cytotoxic response. • The CHI/SF/HA composite showed a higher cell growth and ALP activity

  9. Computational Laser Spectroscopy in a Biological Tissue

    Directory of Open Access Journals (Sweden)

    R. Ben Salah

    2010-01-01

    Full Text Available We present a numerical spectroscopic study of visible and infrared laser radiation in a biological tissue. We derive a solution of a general two-dimensional time dependent radiative transfer equation in a tissue-like medium. The used model is suitable for many situations especially when the external source is time-dependent or continuous. We use a control volume-discrete ordinate method associated with an implicit three-level second-order time differencing scheme. We consider a very thin rectangular biological-tissue-like medium submitted to a visible or a near infrared light sources. The RTE is solved for a set of different wavelength source. All sources are assumed to be monochromatic and collimated. The energetic fluence rate is computed at a set of detector points on the boundaries. According to the source type, we investigate either the steady-state or transient response of the medium. The used model is validated in the case of a heterogeneous tissue-like medium using referencing experimental results from the literature. Also, the developed model is used to study changes on transmitted light in a rat-liver tissue-like medium. Optical properties depend on the source wavelength and they are taken from the literature. In particular, light-transmission in the medium is studied for continuous wave and for short pulse.

  10. Sterilization of biological tissues with ionizing radiation

    International Nuclear Information System (INIS)

    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)

  11. 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)

    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.

  12. The Optical Properties of Biological Tissue.

    Science.gov (United States)

    Bews, Jeffrey Alan

    The ability of light to propagate through biological tissue has found much application in medicine (ie. Photodynamic therapy and Diaphanography). However, a poor understanding of this transport phenomenon has served to limit the effectiveness of those modalities employing it in their operation. This thesis is a study of light propagation through biological tissue, its goal being to improve on the lack of knowledge that presently exists. A spectrophotometer type instrument (DICOM-8) was developed to measure the diffuse spectra extinction of biological tissue. Results were obtained for both normal and diseased breast tissue. Extinction curves for the two tissues exhibited a similar shape (extinction monotonically decreasing with increasing wavelength) but differed in magnitude below 700 nm with carcinoma possessing a higher extinction than normal. Data obtained from these tissue measurements served as the basis for developing a homogeneous liquid (TEM) for simulating the optical properties of tissue over the range 550 to 900 nm. Bench-top Diaphanography studies carried out on a breast phantom constructed of TEM demonstrated the improved tumor visualization attainable with short wavelength light. TEM also functioned as a test medium in which light distributions resulting from highly controlled irradiation geometries (isotropic point and planar sources) were measured and compared with those predicted by Linear Transport (LT) theory. The mean free path (MFP) of TEM ranged from 0.206 mm at 550 nm to 0.495 mm at 900 nm and was found to be directly proportional to the square of the wavelength. The scatter/absorption coefficient (c) was 0.9986459 at 550 nm and 0.9997315 at 850 nm. Agreement between experimental and theoretical distributions was found to be extremely good. Theoretical distributions generated with LT theory revealed the fact that small changes in MFP will have little effect on light transport. Similar changes in c, meanwhile, will drastically alter the

  13. 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. PMID:27485231

  14. Dissipative particle dynamics simulations for biological tissues: rheology and competition

    International Nuclear Information System (INIS)

    In this work, we model biological tissues using a simple, mechanistic simulation based on dissipative particle dynamics. We investigate the continuum behavior of the simulated tissue and determine its dependence on the properties of the individual cell. Cells in our simulation adhere to each other, expand in volume, divide after reaching a specific size checkpoint and undergo apoptosis at a constant rate, leading to a steady-state homeostatic pressure in the tissue. We measure the dependence of the homeostatic state on the microscopic parameters of our model and show that homeostatic pressure, rather than the unconfined rate of cell division, determines the outcome of tissue competitions. Simulated cell aggregates are cohesive and round up due to the effect of tissue surface tension, which we measure for different tissues. Furthermore, mixtures of different cells unmix according to their adhesive properties. Using a variety of shear and creep simulations, we study tissue rheology by measuring yield stresses, shear viscosities, complex viscosities as well as the loss tangents as a function of model parameters. We find that cell division and apoptosis lead to a vanishing yield stress and fluid-like tissues. The effects of different adhesion strengths and levels of noise on the rheology of the tissue are also measured. In addition, we find that the level of cell division and apoptosis drives the diffusion of cells in the tissue. Finally, we present a method for measuring the compressibility of the tissue and its response to external stress via cell division and apoptosis

  15. Neutron interactions with biological tissue. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-17

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of neutrons with tissue through the ejected secondary charged particles. The authors used theoretical calculations whose input includes neutron cross section data; range, stopping power, ion yield, and straggling information; and geometrical properties. Outputs are initial and slowing-down spectra of charged particles, kerma factors, average values of quality factors, microdosimetric spectra, and integral microdosimetric parameters such as {bar y}{sub F}, {bar y}{sub D}, y{sup *}. Since it has become apparent that nanometer site sizes are also relevant to radiobiological effects, the calculations of event size spectra and their parameters were extended to these smaller diameters. This information is basic to radiological physics, radiation biology, radiation protection of workers, and standards for neutron dose measurement.

  16. Neutron interactions with biological tissue. Final report

    International Nuclear Information System (INIS)

    This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of neutrons with tissue through the ejected secondary charged particles. The authors used theoretical calculations whose input includes neutron cross section data; range, stopping power, ion yield, and straggling information; and geometrical properties. Outputs are initial and slowing-down spectra of charged particles, kerma factors, average values of quality factors, microdosimetric spectra, and integral microdosimetric parameters such as bar yF, bar yD, y*. Since it has become apparent that nanometer site sizes are also relevant to radiobiological effects, the calculations of event size spectra and their parameters were extended to these smaller diameters. This information is basic to radiological physics, radiation biology, radiation protection of workers, and standards for neutron dose measurement

  17. Photoacoustic tomography imaging of biological tissues

    Science.gov (United States)

    Su, Yixiong; Wang, Ruikang K.; Xu, Kexin; Zhang, Fan; Yao, Jianquan

    2005-01-01

    Non-invasive laser-induced photoacoustic tomography is attracting more and more attentions in the biomedical optical imaging field. This imaging modality takes the advantages in that the tomography image has the optical contrast similar to the optical techniques while enjoying the high spatial resolution comparable to the ultrasound. Currently, its biomedical applications are mainly focused on breast cancer diagnosis and small animal imaging. In this paper, we report in detail a photoacoustic tomography experiment system constructed in our laboratory. In our system, a Q-switched ND:YAG pulse laser operated at 532nm with a 10ns pulse width is employed to generate photoacoustic signal. A tissue-mimicking phantom was built to test the system. When imaged, the phantom and detectors were immersed in a water tank to facilitate the acoustic detection. Based on filtered back-projection process of photoacoustic imaging, the two-dimension distribution of optical absorption in tissue phantom was reconstructed.

  18. Optical properties of biological tissues: a review

    International Nuclear Information System (INIS)

    A review of reported tissue optical properties summarizes the wavelength-dependent behavior of scattering and absorption. Formulae are presented for generating the optical properties of a generic tissue with variable amounts of absorbing chromophores (blood, water, melanin, fat, yellow pigments) and a variable balance between small-scale scatterers and large-scale scatterers in the ultrastructures of cells and tissues. (topical review)

  19. Changes of color coordinates of biological tissue with superficial skin damage due to mechanical trauma

    Science.gov (United States)

    Pteruk, Vail; Mokanyuk, Olexander; Kvaternuk, Olena; Yakenina, Lesya; Kotyra, Andrzej; Romaniuk, Ryszard S.; Dussembayeva, Shynar

    2015-12-01

    Change of color coordinates of normal and pathological biological tissues is based on calculated spectral diffuse reflection. The proposed color coordinates of normal and pathological biological tissues of skin provided using standard light sources, allowing accurately diagnose skin damage due to mechanical trauma with a blunt object for forensic problems.

  20. Confocal Imaging of Biological Tissues Using Second Harmonic Generation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B-M.; Stoller, P.; Reiser, K.; Eichler, J.; Yan, M.; Rubenchik, A.; Da Silva, L.

    2000-03-06

    A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

  1. Confocal Imaging of Biological Tissues Using Second Harmonic Generation

    International Nuclear Information System (INIS)

    A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing

  2. Development of an algorithm for quantifying extremity biological tissue

    International Nuclear Information System (INIS)

    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

  3. Photon-tissue interaction model for quantitative assessment of biological tissues

    Science.gov (United States)

    Lee, Seung Yup; Lloyd, William R.; Wilson, Robert H.; Chandra, Malavika; McKenna, Barbara; Simeone, Diane; Scheiman, James; Mycek, Mary-Ann

    2014-02-01

    In this study, we describe a direct fit photon-tissue interaction model to quantitatively analyze reflectance spectra of biological tissue samples. The model rapidly extracts biologically-relevant parameters associated with tissue optical scattering and absorption. This model was employed to analyze reflectance spectra acquired from freshly excised human pancreatic pre-cancerous tissues (intraductal papillary mucinous neoplasm (IPMN), a common precursor lesion to pancreatic cancer). Compared to previously reported models, the direct fit model improved fit accuracy and speed. Thus, these results suggest that such models could serve as real-time, quantitative tools to characterize biological tissues assessed with reflectance spectroscopy.

  4. 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.

  5. Orthopaedic Interface Tissue Engineering for the Biological Fixation of Soft Tissue Grafts

    OpenAIRE

    Moffat, Kristen L.; Wang, I-Ning Elaine; Rodeo, Scott A.; Lu, Helen H.

    2009-01-01

    Interface tissue engineering is a promising new strategy aimed at the regeneration of tissue interfaces and ultimately enabling the biological fixation of soft tissue grafts utilized in orthopaedic repair and sports medicine. Many ligaments and tendons with direct insertions into subchondral bone exhibit a complex enthesis consisting of several distinct yet continuous regions of soft tissue, noncalcified fibrocartilage, calcified fibrocartilage and bone. Regeneration of this multi-tissue inte...

  6. Quantitative fluorescence microscopy of macromolecules in gel and biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Tatarkova, Svetlana A [Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom); School of Pharmacy, University of Manchester, Manchester M13 9PL (United Kingdom); Verma, Anita Kamra [School of Pharmacy, University of Manchester, Manchester M13 9PL (United Kingdom); Department of Zoology, K M College, University of Delhi, Delhi-110 007 (India); Berk, David A [School of Pharmacy, University of Manchester, Manchester M13 9PL (United Kingdom); Lloyd, Christopher J [School of Pharmacy, University of Manchester, Manchester M13 9PL (United Kingdom)

    2005-12-07

    Quantitative fluorescence microscopy provides valuable insight into drug delivery and pharmacokinetics. The technique is based on analysis of statistical fluctuations in fluorescence that arises as fluorophores pass through a small volume illuminated by a focused laser beam, and has been applied to measure particle motion and binding interactions in solutions, on surfaces and inside the cells. We examined the use of fluorescence correlation spectroscopy combined with a microscope (FCSM) to assess the transport of fluorescent beads and macromolecules in aqueous solutions, gels and living biological tissue. Obstructed diffusion of fluorescent beads in gels of various densities was tested to get a sensible estimate of diffusion in the interstitial tissue matrix consistent with previous reports. Fluorescently labelled liposomes as an artificial drug or gene carrying vehicles were used for pharmacokinetic tests of drug delivery in living tissue. The results indicate that FCS is an accurate and valuable tool for measuring the physical properties of gene vectors in vitro and for characterizing interactions with tissue in vivo.

  7. Biological tissues analysis by XRF microtomography.

    Science.gov (United States)

    Pereira, G R; Rocha, H S; Calza, C; Anjos, M J; Pérez, C A; Lopes, R T

    2010-01-01

    The main of this work is to determine the elemental distribution in breast and prostate tissue samples in order to verify the concentration of some elements correlated with characteristics and pathology of each tissue observed by the X-ray transmission microtomography (microCT). The experiments were performed at the X-ray fluorescence beamline of the Brazilian Synchrotron Light Laboratory. The microCT images were reconstructed using a filtered-back-projection algorithm and the XRF microtomographies were reconstructed using a filtered-back-projection algorithm with absorption corrections. PMID:20122839

  8. Biological tissues analysis by XRF microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, G.R.; Rocha, H.S.; Calza, C. [Nuclear Instrumentation Laboratory (LIN), COPPE, UFRJ, P.O. Box 68509, 21941-972 Rio de Janeiro (Brazil); Anjos, M.J. [Physics Institute-UERJ (Brazil); Perez, C.A. [Brazilian Synchrotron Light Laboratory (Brazil); Lopes, R.T. [Nuclear Instrumentation Laboratory (LIN), COPPE, UFRJ, P.O. Box 68509, 21941-972 Rio de Janeiro (Brazil)], E-mail: Ricardo@lin.ufrj.br

    2010-04-15

    The main of this work is to determine the elemental distribution in breast and prostate tissue samples in order to verify the concentration of some elements correlated with characteristics and pathology of each tissue observed by the X-ray transmission microtomography ({mu}CT). The experiments were performed at the X-ray fluorescence beamline of the Brazilian Synchrotron Light Laboratory. The {mu}CT images were reconstructed using a filtered-back-projection algorithm and the XRF microtomographies were reconstructed using a filtered-back-projection algorithm with absorption corrections.

  9. Adipose tissue and fat cell biology

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Jan

    New York: Springer International Publishing, 2015 - (Pappas, A.), s. 201-224 ISBN 978-3-319-09942-2 R&D Projects: GA MŠk(CZ) 7E12073; GA ČR(CZ) GA13-00871S Institutional support: RVO:67985823 Keywords : adipose tissue * endocrine function * lipid mediators Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  10. Radiation processing of biological tissues for nuclear disaster management

    International Nuclear Information System (INIS)

    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)

  11. LASER BIOLOGY: Visualisation of the distributions of melanin and indocyanine green in biological tissues

    Science.gov (United States)

    Genina, E. A.; Fedosov, I. V.; Bashkatov, A. N.; Zimnyakov, D. A.; Altshuler, G. B.; Tuchin, V. V.

    2008-03-01

    A double-wavelength laser scanning microphotometer with the high spectral and spatial resolutions is developed for studying the distribution of endogenic and exogenic dyes in biological tissues. Samples of hair and skin biopsy with hair follicles stained with indocyanine green are studied. The spatial distribution of indocyanine green and melanin in the biological tissue is determined from the measured optical transmittance.

  12. Thermal effects of laser radiation in biological tissue.

    OpenAIRE

    Cummins, L; Nauenberg, M.

    1983-01-01

    A theoretical model is presented that simulates the thermal effects of laser radiation incident on biological tissue. The multiple scattering and absorption of the laser beam and the thermal diffusion process in the tissue are evaluated by a numerical technique that is well suited for microcomputers. Results are compared with recent empirical observations.

  13. A phase-field model for fracture in biological tissues.

    Science.gov (United States)

    Raina, Arun; Miehe, Christian

    2016-06-01

    This work presents a recently developed phase-field model of fracture equipped with anisotropic crack driving force to model failure phenomena in soft biological tissues at finite deformations. The phase-field models present a promising and innovative approach to thermodynamically consistent modeling of fracture, applicable to both rate-dependent or rate-independent brittle and ductile failure modes. One key advantage of diffusive crack modeling lies in predicting the complex crack topologies where methods with sharp crack discontinuities are known to suffer. The starting point is the derivation of a regularized crack surface functional that [Formula: see text]-converges to a sharp crack topology for vanishing length-scale parameter. A constitutive balance equation of this functional governs the crack phase-field evolution in a modular format in terms of a crack driving state function. This allows flexibility to introduce alternative stress-based failure criteria, e.g., isotropic or anisotropic, whose maximum value from the deformation history drives the irreversible crack phase field. The resulting multi-field problem is solved by a robust operator split scheme that successively updates a history field, the crack phase field and finally the displacement field in a typical time step. For the representative numerical simulations, a hyperelastic anisotropic free energy, typical to incompressible soft biological tissues, is used which degrades with evolving phase field as a result of coupled constitutive setup. A quantitative comparison with experimental data is provided for verification of the proposed methodology. PMID:26165516

  14. Depth Determination of an Abnormal Heat Source in Biological Tissues

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Hua; LI Zhen-Hua; LAI Jian-Cheng; HE An-Zhi

    2011-01-01

    We deduce the surface temperature distribution generated by the inner point heat source in biological tissues and propose a graphic method to retrieve the depth of the point heat source. The practical surface temperature distribution can be regarded as the convolution of the temperature distribution of the inner point heat source with the heat source shape function. The depth of an abnormal heat source in biological tissues can be retrieved by using the graphic method combined with the blind deconvolution scheme.%We deduce the surface temperature distribution generated by the inner point heat source in biological tissues and propose a graphic method to retrieve the depth of the point heat source.The practical surface temperature distribution can be regarded as the convolution of the temperature distribution of the inner point heat source with the heat source shape function.The depth of an abnormal heat source in biological tissues can be retrieved by using the graphic method combined with the blind deconvolution scheme.Surface temperature distribution of the biological tissues is closely related to the neighboring metabolic heat production,blood circulation in an organism and environmental temperature.[1] The abnormal metabolic performances of a local region in biological tissue imply malignant changes occurring,which can be distinguished from the variance of surface temperature.Modern development of thermal infrared (TIR) imaging has made the surface temperature measurement of biological tissue easier.Nowadays,several types of tumors,e.g.skin or breast can be recognized with TIR imaging.[2] The diagnostics with TIR imaging require more experienced operators and can not accurately ascertain the site of pathological changes,which limits the value of this technology.Therefore ascertaining the depth of inner heat source in biological body has the extremely important clinical value.

  15. Inverse Parameter Fitting of Biological Tissues: A Response Surface Approach

    Energy Technology Data Exchange (ETDEWEB)

    Einstein, Daniel R.; Freed, Alan D.; Stander, Nielen; Fata, Bahar; Vesely, Ivan

    2005-12-01

    In this paper, we present the application of a semi-global inverse method for determining material parameters of biological tissues. The approach is based on the successive response surface method, and is illustrated by fitting constitutive parameters to two nonlinear anisotropic constitutive equations, one for aortic sinus and aortic wall, the other for aortic valve tissue. Material test data for the aortic sinus consisted of two independent orthogonal uniaxial tests. Material test data for the aortic valve was obtained from a dynamic inflation test. In each case, a numerical simulation of the experiment was performed and predictions were compared to the real data. For the uniaxial test simulation, the experimental targets were force at a measured displacement. For the inflation test, the experimental targets were the three-dimensional coordinates of material markers at a given pressure. For both sets of tissues, predictions with converged parameters showed excellent agreement with the data, and we found that the method was able to consistently identify model parameters. We believe the method will find wide application in biomedical material characterization and in diagnostic imaging.

  16. Clearing and Labeling Techniques for Large-Scale Biological Tissues.

    Science.gov (United States)

    Seo, Jinyoung; Choe, Minjin; Kim, Sung-Yon

    2016-06-30

    Clearing and labeling techniques for large-scale biological tissues enable simultaneous extraction of molecular and structural information with minimal disassembly of the sample, facilitating the integration of molecular, cellular and systems biology across different scales. Recent years have witnessed an explosive increase in the number of such methods and their applications, reflecting heightened interest in organ-wide clearing and labeling across many fields of biology and medicine. In this review, we provide an overview and comparison of existing clearing and labeling techniques and discuss challenges and opportunities in the investigations of large-scale biological systems. PMID:27239813

  17. Irradiation of advanced health care products – Tissues and biologics

    International Nuclear Information System (INIS)

    Radiation sterilization of tissues and biologics has become more common in recent years. As a result it has become critical to understand how to adapt the typical test methods and validation approaches to a tissue or biological product scenario. Also data evaluation sometimes becomes more critical than with traditional medical devices because for many tissues and biologics a low radiation dose is required. It is the intent behind this paper to provide information on adapting bioburden tests used in radiation validations such that the data can be most effectively used on tissues and biologics. In addition challenges with data evaluation are discussed, particularly the use of less-than values for bioburden results in radiation validation studies. - Highlights: • MPN testing can provide good bioburden results for tissue/biologics. • There are appropriate situations to pool products for bioburden testing. • Options on dealing with bioburden results of “less-than” the limit of detection. • Underestimation and overestimation of bioburden and the dangers of both

  18. Quantifying the refractive index dispersion of a pigmented biological tissue using Jamin-Lebedeff interference microscopy

    NARCIS (Netherlands)

    Stavenga, Doekele G.; Leertouwer, Hein L.; Wilts, Bodo D.

    2013-01-01

    Jamin-Lebedeff polarizing interference microscopy is a classical method for determining the refractive index and thickness of transparent tissues. Here, we extend the application of this method to pigmented, absorbing biological tissues, based on a theoretical derivation using Jones calculus. This n

  19. Geant4-based comprehensive study of the absorbed fraction for electrons and gamma-photons using various geometrical models and biological tissues

    OpenAIRE

    Rahman Ziaur; Rehman Shakeel Ur.; Mirza Sikander M.; Arshed Waheed; Mirza Nasir M.

    2013-01-01

    The Geant4-based comprehensive model has been developed to predict absorbed fraction values for both electrons and gamma photons in spherical, ellipsoidal, and cylindrical geometries. Simulations have been carried out for water, ICRP soft-, brain-, lung-, and ICRU bone tissue for electrons in 0.1 MeV-4 MeV and g-photons in the 0.02 MeV-2.75 MeV energy range. Consistent with experimental observations, the Geant4-simulated values of absorbed fractions show a ...

  20. Morpho-chemistry and functionality of diseased biological tissues

    Science.gov (United States)

    Lange, Marta; Cicchi, Riccardo; Pavone, Francesco

    2014-09-01

    Heart and cardiovascular diseases are one of the most common in the world, in particular - arthrosclerosis. The aim of the research is to distinguish pathological and healthy tissue regions in biological samples, in this case - to distinguish collagen and lipid rich regions within the arterial wall. In the work a specific combination of such methods are used: FLIM and SHG in order to evaluate the biological tissue morphology and functionality, so that this research could give a contribution for creating a new biological tissue imaging standard in the closest future. During the study the most appropriate parameter for fluorescence lifetime decay was chosen in order to evaluate lifetime decay parameters and the isotropy of the arterial wall and deposition, using statistical methods FFT and GLCM. The research gives a contribution or the future investigations for evaluating lipid properties when it can de-attach from the arterial wall and cause clotting in the blood vessel or even a stroke.

  1. Title: The validation of Cryogenic Laser Ablation ICP-MS (CLA-ICP-MS) methods by comparison to laser ablation (LA)-ICP-MS and solution based ICP-MS methods, for the analysis of metals in biological tissues

    Science.gov (United States)

    Hannigan, R.; Darrah, T. H.; Horton, M.

    2009-12-01

    ICP-MS and laser ablation ICP-MS (LA-ICP-MS) are well established techniques for the analysis of metals in geological and environmental samples. LA-ICP-MS is commonly used in geological applications to determine the spatial distribution of metal concentrations at small sampling intervals (as low as 10 microns). However, measurement of metals in water-rich, soft biological tissues typically requires samples to be digested into solutions, obfuscating spatial variations in metal concentrations. The cryogenic cell solidifies (by freezing) soft tissue, allowing these tissues to be analyzed by laser ablation for spatial variations in metal concentration. The cell is temperature programmable and capable of maintaining a sample at any temperature between -35C and 25C throughout prolonged analysis. We validate the cryogenic laser ablation ICP-MS (CLA-ICP-MS) method using NIST Glass SRM 612. We also compare metal concentration data analyzed by cryogenic laser ablation ICP-MS (CLA-ICP-MS), LA-ICP-MS, and solution based ICP-MS, for human and rodent brain samples. The cryogenic laser ablation cell will expand analytical capabilities for measuring spatial distribution and concentration of metals incorporated into biological tissues.

  2. 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 ...... collection and storage. The aim of this study was to evaluate the influence of platelet TIMP-1 contamination on plasma TIMP-1 levels in healthy volunteers.......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...

  3. Application of Biological Tissue Grafts for Burns in Zambia

    International Nuclear Information System (INIS)

    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

  4. Fibroblast Growth Factors: Biology, Function, and Application for Tissue Regeneration

    OpenAIRE

    Ye-Rang Yun; Jong Eun Won; Eunyi Jeon; Sujin Lee; Wonmo Kang; Hyejin Jo; Jun-Hyeog Jang; Ueon Sang Shin; Hae-Won Kim

    2010-01-01

    Fibroblast growth factors (FGFs) that signal through FGF receptors (FGFRs) regulate a broad spectrum of biological functions, including cellular proliferation, survival, migration, and differentiation. The FGF signal pathways are the RAS/MAP kinase pathway, PI3 kinase/AKT pathway, and PLCγ pathway, among which the RAS/MAP kinase pathway is known to be predominant. Several studies have recently implicated the in vitro biological functions of FGFs for tissue regeneration. However, to obtain opt...

  5. A density-independent glass transition in biological tissues

    CERN Document Server

    Bi, Dapeng; Schwarz, J M; Manning, M Lisa

    2014-01-01

    Cells must move through tissues in many important biological processes, including embryonic development, cancer metastasis, and wound healing. In these tissues, a cell's motion is often strongly constrained by its neighbors, leading to glassy dynamics. Recent work has demonstrated the existence of a non-equilibrium glass transition in self-propelled particle models for active matter, where the transition is driven by changes in density. However, this may not explain liquid-to-solid transitions in confluent tissues, where there are no gaps between cells and the packing fraction remains fixed and equal to unity. Here we demonstrate the existence of a different type of glass transition that occurs in the well-studied vertex model for confluent tissue monolayers. In this model, the onset of rigidity is governed by changes to single-cell properties such as cell-cell adhesion, cortical tension, and volume compressibility, providing an explanation for a liquid-to-solid transitions in confluent tissues.

  6. Developmental biology of Cystoisospora (Apicomplexa: Sarcocystidae) monozoic tissue cysts.

    Science.gov (United States)

    Lindsay, David S; Houk, Alice E; Mitchell, Sheila M; Dubey, J P

    2014-08-01

    Tissue cyst stages are an intriguing aspect of the developmental cycle and transmission of species of Sarcocystidae. Tissue-cyst stages of Toxoplasma, Hammondia, Neospora, Besnoitia, and Sarcocystis contain many infectious stages (bradyzoites). The tissue cyst stage of Cystoisospora (syn. Isospora) possesses only 1 infectious stage (zoite), and is therefore referred to as a monozoic tissue cyst (MZTC). No tissue cyst stages are presently known for members of Nephroisospora. The present report examines the developmental biology of MZTC stages of Cystoisospora Frenkel, 1977 . These parasites cause intestinal coccidiosis in cats, dogs, pigs, and humans. The MZTC stages of C. belli are believed to be associated with reoccurrence of clinical disease in humans. PMID:24841928

  7. LASER BIOLOGY: Optomechanical tests of hydrated biological tissues subjected to laser shaping

    Science.gov (United States)

    Omel'chenko, A. I.; Sobol', E. N.

    2008-03-01

    The mechanical properties of a matrix are studied upon changing the size and shape of biological tissues during dehydration caused by weak laser-induced heating. The cartilage deformation, dehydration dynamics, and hydraulic conductivity are measured upon laser heating. The hydrated state and the shape of samples of separated fascias and cartilaginous tissues were controlled by using computer-aided processing of tissue images in polarised light.

  8. Geant4-based comprehensive study of the absorbed fraction for electrons and gamma-photons using various geometrical models and biological tissues

    Directory of Open Access Journals (Sweden)

    Rahman Ziaur

    2013-01-01

    Full Text Available The Geant4-based comprehensive model has been developed to predict absorbed fraction values for both electrons and gamma photons in spherical, ellipsoidal, and cylindrical geometries. Simulations have been carried out for water, ICRP soft-, brain-, lung-, and ICRU bone tissue for electrons in 0.1 MeV-4 MeV and g-photons in the 0.02 MeV-2.75 MeV energy range. Consistent with experimental observations, the Geant4-simulated values of absorbed fractions show a decreasing trend with an increase in radiation energy. Compared with NIST XCOM and ICRU data, the Geant4-based simulated values of the absorbed fraction remain within a 4.2% and 1.6% deviation, respectively. For electrons and g-photons, the relative difference between the Geant4-based comprehensive model predictions and those of Stabin and Konijnenberg's re-evaluation remains within a 6.8% and 7.4% range, respectively. Ellipsoidal and cylindrical models show 4.9% and 10.1% higher respective values of absorbed dose fractions relative to the spherical model. Target volume dependence of the absorbed fraction values has been found to follow a logical behavior for electrons and Belehradek's equation for g-photons. Gamma-ray absorbed fraction values have been found to be sensitive to the material composition of targets, especially at low energies, while for elections, they remain insensitive to them.

  9. 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.

  10. Interstitial growth and remodeling of biological tissues: tissue composition as state variables.

    Science.gov (United States)

    Myers, Kristin; Ateshian, Gerard A

    2014-01-01

    Growth and remodeling of biological tissues involves mass exchanges between soluble building blocks in the tissue's interstitial fluid and the various constituents of cells and the extracellular matrix. As the content of these various constituents evolves with growth, associated material properties, such as the elastic modulus of the extracellular matrix, may similarly evolve. Therefore, growth theories may be formulated by accounting for the evolution of tissue composition over time in response to various biological and mechanical triggers. This approach has been the foundation of classical bone remodeling theories that successfully describe Wolff's law by establishing a dependence between Young's modulus and bone apparent density and by formulating a constitutive relation between bone mass supply and the state of strain. The goal of this study is to demonstrate that adding tissue composition as state variables in the constitutive relations governing the stress-strain response and the mass supply represents a very general and straightforward method to model interstitial growth and remodeling in a wide variety of biological tissues. The foundation for this approach is rooted in the framework of mixture theory, which models the tissue as a mixture of multiple solid and fluid constituents. A further generalization is to allow each solid constituent in a constrained solid mixture to have its own reference (stress-free) configuration. Several illustrations are provided, ranging from bone remodeling to cartilage tissue engineering and cervical remodeling during pregnancy. PMID:23562499

  11. A density-independent rigidity transition in biological tissues

    Science.gov (United States)

    Bi, Dapeng; Lopez, J. H.; Schwarz, J. M.; Manning, M. Lisa

    2015-12-01

    Cell migration is important in many biological processes, including embryonic development, cancer metastasis and wound healing. In these tissues, a cell’s motion is often strongly constrained by its neighbours, leading to glassy dynamics. Although self-propelled particle models exhibit a density-driven glass transition, this does not explain liquid-to-solid transitions in confluent tissues, where there are no gaps between cells and therefore the density is constant. Here we demonstrate the existence of a new type of rigidity transition that occurs in the well-studied vertex model for confluent tissue monolayers at constant density. We find that the onset of rigidity is governed by a model parameter that encodes single-cell properties such as cell-cell adhesion and cortical tension, providing an explanation for liquid-to-solid transitions in confluent tissues and making testable predictions about how these transitions differ from those in particulate matter.

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

    CERN Document Server

    Bi, Dapeng; Marchetti, M Cristina; Manning, M Lisa

    2015-01-01

    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 demonstrat...

  13. Tissue-based map of the human proteome

    DEFF Research Database (Denmark)

    Uhlén, Mathias; Fagerberg, Linn; Hallström, Björn M.; Lindskog, Cecilia; Oksvold, Per; Mardinoglu, Adil; Sivertsson, Åsa; Kampf, Caroline; Sjöstedt, Evelina; Asplund, Anna; Olsson, IngMarie; Edlund, Karolina; Lundberg, Emma; Navani, Sanjay; Szigyarto, Cristina Al-Khalili; Odeberg, Jacob; Djureinovic, Dijana; Takanen, Jenny Ottosson; Hober, Sophia; Alm, Tove; Edqvist, Per-Henrik; Berling, Holger; Tegel, Hanna; Mulder, Jan; Rockberg, Johan; Nilsson, Peter; Schwenk, Jochen M.; Hamsten, Marica; von Feilitzen, Kalle; Forsberg, Mattias; Persson, Lukas; Johansson, Fredric; Zwahlen, Martin; von Heijne, Gunnar; Nielsen, Jens; Pontén, Fredrik

    2015-01-01

    Resolving the molecular details of proteome variation in the different tissues and organs of the human body will greatly increase our knowledge of human biology and disease. Here, we present a map of the human tissue proteome based on an integrated omics approach that involves quantitative...

  14. 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.

  15. The interaction between Terahertz radiation and biological tissue

    International Nuclear Information System (INIS)

    Terahertz (THz) radiation occupies that region of the electromagnetic (EM) spectrum between approximately 0.3 and 20 THz. Recent advances in methods of producing THz radiation have stimulated interest in studying the interaction between radiation and biological molecules and tissue. Given that the photon energies associated with this region of the spectrum are 2.0x10-22 to 1.3x10-20 J, an analysis of the interactions requires an understanding of the permittivity and conductivity of the medium (which describe the bulk motions of the molecules) and the possible transitions between the molecular energy levels. This paper reviews current understanding of the interactions between THz radiation and biological molecules, cells and tissues. At frequencies below approximately 6 THz, the interaction may be understood as a classical EM wave interaction (using the parameters of permittivity and conductivity), whereas at higher frequencies, transitions between different molecular vibrational and rotational energy levels become increasingly important and are more readily understood using a quantum-mechanical framework. The latter is of particular interest in using THz to probe transitions between different vibrational modes of deoxyribonucleic acid. Much additional experimental work is required in order to fully understand the interactions between THz radiation and biological molecules and tissue. (author)

  16. TissueCypher™: A systems biology approach to anatomic pathology

    Directory of Open Access Journals (Sweden)

    Jeffrey W Prichard

    2015-01-01

    Full Text Available Background: Current histologic methods for diagnosis are limited by intra- and inter-observer variability. Immunohistochemistry (IHC methods are frequently used to assess biomarkers to aid diagnoses, however, IHC staining is variable and nonlinear and the manual interpretation is subjective. Furthermore, the biomarkers assessed clinically are typically biomarkers of epithelial cell processes. Tumors and premalignant tissues are not composed only of epithelial cells but are interacting systems of multiple cell types, including various stromal cell types that are involved in cancer development. The complex network of the tissue system highlights the need for a systems biology approach to anatomic pathology, in which quantification of system processes is combined with informatics tools to produce actionable scores to aid clinical decision-making. Aims: Here, we describe a quantitative, multiplexed biomarker imaging approach termed TissueCypher™ that applies systems biology to anatomic pathology. Applications of TissueCypher™ in understanding the tissue system of Barrett's esophagus (BE and the potential use as an adjunctive tool in the diagnosis of BE are described. Patients and Methods: The TissueCypher™ Image Analysis Platform was used to assess 14 epithelial and stromal biomarkers with known diagnostic significance in BE in a set of BE biopsies with nondysplastic BE with reactive atypia (RA, n = 22 and Barrett's with high-grade dysplasia (HGD, n = 17. Biomarker and morphology features were extracted and evaluated in the confirmed BE HGD cases versus the nondysplastic BE cases with RA. Results: Multiple image analysis features derived from epithelial and stromal biomarkers, including immune biomarkers and morphology, showed significant differences between HGD and RA. Conclusions: The assessment of epithelial cell abnormalities combined with an assessment of cellular changes in the lamina propria may serve as an adjunct to conventional

  17. Quantifying the refractive index dispersion of a pigmented biological tissue using Jamin-Lebedeff interference microscopy

    OpenAIRE

    Stavenga, Doekele G; Leertouwer, Hein L.; WILTS, Bodo D.

    2013-01-01

    Jamin-Lebedeff polarizing interference microscopy is a classical method for determining the refractive index and thickness of transparent tissues. Here, we extend the application of this method to pigmented, absorbing biological tissues, based on a theoretical derivation using Jones calculus. This novel method is applied to the wings of the American Rubyspot damselfly, Hetaerina americana. The membranes in the red-colored parts of the damselfly's wings, with a thickness of similar to 2.5 mu m...

  18. Volumetric imaging of fast biological dynamics in deep tissue via wavefront engineering

    Science.gov (United States)

    Kong, Lingjie; Tang, Jianyong; Cui, Meng

    2016-03-01

    To reveal fast biological dynamics in deep tissue, we combine two wavefront engineering methods that were developed in our laboratory, namely optical phase-locked ultrasound lens (OPLUL) based volumetric imaging and iterative multiphoton adaptive compensation technique (IMPACT). OPLUL is used to generate oscillating defocusing wavefront for fast axial scanning, and IMPACT is used to compensate the wavefront distortions for deep tissue imaging. We show its promising applications in neuroscience and immunology.

  19. Motility-Driven Glass and Jamming Transitions in Biological Tissues

    Science.gov (United States)

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

    2016-04-01

    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 model that simultaneously captures polarized cell motility and multibody 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 solidlike state to a fluidlike 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.

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

    International Nuclear Information System (INIS)

    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 (Dint) 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)

  1. Hydration Sensing in Biological Tissues with the Terahertz Band

    Science.gov (United States)

    Bennett, David Bart

    This work evaluates the utility of terahertz (THz) sensing technologies to applications in medicine and then develops, characterizes, and demonstrates applications in skin and cornea sensing ex vivo and in vivo. Hie application of THz sensing to biological tissues is motivated by recent research which has confirmed THz retlectometry's unique ability to detect small changes in the water content of phantom materials, with the achievement of sensitivities on the order of one part water in a thousand by mass reported in the literature. Non-invasive methods to accurately measure and map tissue hydration are needed for a variety of medical applications. This work will examine diagnostic applications for conditions of the skin and cornea. These will include diagnostic imaging of thermal and chemical burns in the skin as well as structural and inflammation-causing conditions in the cornea including Fuchs Dystrophy, Keratoconus, and corneal graft rejection. Medical sensing using electromagnetic (EM) radiation with a focus on the specific benefits and considerations of the THz region will be discussed, followed by the presentation of THz-matter phenomenology and simulation tools which will allow the interaction between THz waves and biological tissues to be better understood. THz sensing will be demonstrated in experiments on skin and corneal tissues. Fast-imaging capability will be used to obtain time-resolved images of hydration in biological tissues including ex vivo skin affected by chemical burns. Next the systems and techniques needed for the realization of corneal imaging will be described. These will be evaluated by examining first phantom materials followed by ex vivo porcine corneas. The design trade-offs that govern the design of THz hydration sensing systems for the cornea will be examined from the vantage point of these empirical measurements. The first examination of corneal tissue hydration in vivo will be reported. The strengths and challenges of this

  2. Confocal microscopy, a tool for biological dosimetry in tissues

    International Nuclear Information System (INIS)

    Because standard histological methods and related observation are very time consuming, only a few studies have concerned biological dosimetry in tissues. This experimental approach is however the only one that could characterize a heterogeneous irradiation such as that induced after internal contamination with α and/or β emitters. The aim advantage of CM is to observe thin optical sections (50μm) which allows observation of many cells and to score events even those occurring at a low frequency if an appropriate staining has been performed. Two rat tissues have been studies, cerebellum during its histogenesis which was irradiated from bone after 90Sr contamination, and lungs from adults after radon daughter inhalation. In conclusion, our results demonstrate that CM might be an appropriate method to characterize the heterogeneous distribution of doses after internal contamination. (authors)

  3. Ionizing radiation for sterilization of medical products and biological tissues

    International Nuclear Information System (INIS)

    The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products. (S.K.K.)

  4. Infrared light scattering in biological tissues and fluids

    Science.gov (United States)

    Thomas, Gordon A.; Koo, Tae-Woong; Dasari, Ramachandra R.; Feld, Michael S.

    2001-03-01

    We have studied the elastic and Raman scattering from whole blood, blood serum and related biological fluids and tissues. The motivation of this work is to determine the composition and elastic scattering properties with a non-invasive, optical method. An example of the possible applications is the determination of the glucose concentration and its variations in a way that would be clinically effective for patients with diabetes. We have imaged the elastically scattered light and determined the scattering parameters in order to assess appropriate geometries for efficient collection of the Raman scattering. Using the Raman apectra we have determined the concentration of glucose and the other analytes under laboratory conditions.

  5. An electrical model of biological tissues undergoing hyperaemia

    Science.gov (United States)

    Olmi, R.; Andreoli, S.; Bini, M.; Feroldi, P.; Spiazzi, L.

    1998-11-01

    Tissue hyperaemia is a physiological consequence of the temperature increase that follows, for example, the absorption of electromagnetic or ultrasound power in clinical diathermy. Diathermy, as well as other physical therapies (for example massotherapy), affects the local blood content of tissues through various mechanisms (vasoconstriction/dilatation, opening/closing of precapillary sphincters). A method for evaluating hyperaemia in superficial and medium-depth tissues has been recently proposed, which is based on four-electrode impedance measurements. A microcirculation model has also been developed to describe the hyperaemic effects of local diathermic therapy. This paper describes an electrical model of the tissues in hyperaemic conditions which allows us to correlate electrical impedance measurements to microcirculation modifications.

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

    International Nuclear Information System (INIS)

    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

  7. 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.

  8. 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

  9. New derivation method and simulation of skin effect in biological tissue.

    Science.gov (United States)

    Fan, Xiaoli; Zhou, Qianxiang; Liu, Zhongqi; Xie, Fang

    2015-01-01

    Based on the electrical properties of biological tissues, bioimpedance measurement technology can be employed to collect physiologic and pathologic information by measuring changes in human bioimpedance. When an alternating current (AC) is applied as a detection signal to a tissue, the current field distribution, which is affected by skin effect, is related to both the bioimpedance of the tissue and the AC frequency. These relations would possibly reduce the accuracy and reliability of the measurement. In this study, an electromagnetic theory-based method, in which cylindrical conductor were divided into layers, was used to obtain current field distribution models of human limbs. Model simulations were conducted in MATLAB. The skin effect phenomenon and its characteristics in human tissues at different frequencies were observed, thus providing essential data on skin effect, which are useful in the development of bioimpedance measurement technology. PMID:26406033

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

    Science.gov (United States)

    Boppart, Stephen A.

    2015-03-01

    High-resolution real-time tomography of biological tissues is important for many areas of biological investigations and medical applications. Cellular level optical tomography, however, has been challenging because of the compromise between transverse imaging resolution and depth-of-field, the system and sample aberrations that may be present, and the low imaging sensitivity deep in scattering tissues. The use of computed optical imaging techniques has the potential to address several of these long-standing limitations and challenges. Two related techniques are interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO). Through three-dimensional Fourierdomain resampling, in combination with high-speed OCT, ISAM can be used to achieve high-resolution in vivo tomography with enhanced depth sensitivity over a depth-of-field extended by more than an order-of-magnitude, in realtime. Subsequently, aberration correction with CAO can be performed in a tomogram, rather than to the optical beam of a broadband optical interferometry system. Based on principles of Fourier optics, aberration correction with CAO is performed on a virtual pupil using Zernike polynomials, offering the potential to augment or even replace the more complicated and expensive adaptive optics hardware with algorithms implemented on a standard desktop computer. Interferometric tomographic reconstructions are characterized with tissue phantoms containing sub-resolution scattering particles, and in both ex vivo and in vivo biological tissue. This review will collectively establish the foundation for high-speed volumetric cellular-level optical interferometric tomography in living tissues.

  11. Spectroscopy of Multilayered Biological Tissues for Diabetes Care

    Science.gov (United States)

    Yudovsky, Dmitry

    Neurological and vascular complications of diabetes mellitus are known to cause foot ulceration in diabetic patients. Present clinical screening techniques enable the diabetes care provider to triage treatment by identifying diabetic patients at risk of foot ulceration. However, these techniques cannot effectively identify specific areas of the foot at risk of ulceration. This study aims to develop non-invasive optical techniques for accurate assessment of tissue health and viability with spatial resolution on the order of 1 mm². The thesis can be divided into three parts: (1) the use of hyperspectral tissue oximetry to detect microcirculatory changes prior to ulcer formation, (2) development of a two-layer tissue spectroscopy algorithm and its application to detection of callus formation or epidermal degradation prior to ulceration, and (3) multi-layered tissue fluorescence modeling for identification of bacterial growth in existing diabetic foot wounds. The first part of the dissertation describes a clinical study in which hyperspectral tissue oximetry was performed on multiple diabetic subjects at risk of ulceration. Tissue oxyhemoglobin and deoxyhemoglobin concentrations were estimated using the Modified Beer-Lambert law. Then, an ulcer prediction algorithm was developed based on retrospective analysis of oxyhemoglobin and deoxyhemoglobin concentrations in sites that were known to ulcerate. The ulcer prediction algorithm exhibited a large sensitivity but low specificity of 95 and 80%, respectively. The second part of the dissertation revisited the hyperspectral data presented in part one with a new and novel two-layer tissue spectroscopy algorithm. This algorithm was able to detect not only oxyhemoglobin and deoxyhemoglobin concentrations, but also the thickness of the epidermis, and the tissue's scattering coefficient. Specifically, change in epidermal thickness provided insight into the formation of diabetic foot ulcers over time. Indeed, callus formation or

  12. Transillumination imaging through biological tissue by single-pixel detection

    Science.gov (United States)

    Durán, Vicente; Soldevila, Fernando; Irles, Esther; Clemente, Pere; Tajahuerce, Enrique; Andrés, Pedro; Lancis, Jesús

    2015-07-01

    One challenge that has long held the attention of scientists is that of clearly seeing objects hidden by turbid media, as smoke, fog or biological tissue, which has major implications in fields such as remote sensing or early diagnosis of diseases. Here, we combine structured incoherent illumination and bucket detection for imaging an absorbing object completely embedded in a scattering medium. A sequence of low-intensity microstructured light patterns is launched onto the object, whose image is accurately reconstructed through the light fluctuations measured by a single-pixel detector. Our technique is noninvasive, does not require coherent sources, raster scanning nor time-gated detection and benefits from the compressive sensing strategy. As a proof of concept, we experimentally retrieve the image of a transilluminated target both sandwiched between two holographic diffusers and embedded in a 6mm-thick sample of chicken breast.

  13. Photoacoustic imaging in both soft and hard biological tissue

    International Nuclear Information System (INIS)

    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.

  14. Photoacoustic imaging in both soft and hard biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Li, T; Dewhurst, R J, E-mail: richard.dewhurst@manchester.ac.u [Photon Science Institute, University of Manchester, Alan Turing Building, Oxford road, Manchester, M13 9PL (United Kingdom)

    2010-03-01

    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.

  15. Cellular burdens and biological effects on tissue level caused by inhaled radon progenies

    CERN Document Server

    Madas, Balázs G; Farkas, Árpád; Szőke, István

    2014-01-01

    In the case of radon exposure, the spatial distribution of deposited radioactive particles is highly inhomogeneous in the central airways. The objective of this research is to investigate the consequences of this heterogeneity regarding cellular burdens in the bronchial epithelium and to study the possible biological effects on tissue level. Applying a computational fluid dynamics program, the deposition distribution of inhaled radon daughters has been determined in a bronchial airway model for 23 minutes of work in the New Mexico uranium mine corresponding to 0.0129 WLM exposure. A numerical epithelium model based on experimental data has been utilized in order to quantify cellular hits and doses. Finally, a carcinogenesis model considering cell death induced cell cycle shortening has been applied to assess the biological responses. Computations present, that cellular dose may reach 1.5 Gy, which is several orders of magnitude higher than tissue dose. The results are in agreement with the histological findin...

  16. Theoretical and experimental study of the intensity distribution in biological tissues

    Institute of Scientific and Technical Information of China (English)

    Xu Tang; Zhang Chun-Ping; Chen Gui-Ying; Tian Jian-Guo; Zhang Guang-Yin; Zhao Cheng-Mei

    2005-01-01

    Based on the diffusion approximate theory (DA ), a theoretical model about the distribution of the intensity of a narrow collimation beam illuminating on a semi-infinite biological tissue is developed. In order to verify the correctness of the model, a novel method of measuring the distributions of the intensity of light in Intralipid-10% suspension at 650 nm is presented and measurements of the distributions of the distance-dependent intensity of scattering light in different directions are made. The investigations show that the results from our diffusion model are in good agreement with the experimental results beyond and in the areas around the light source, and the distance-dependent intensity in the incident direction attenuates approximately in the exponential form. Furthermore, our theoretic results indicate the anisotropic characteristics of the intensity in different directions of scattering light inside the biological tissue.

  17. 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.

  18. Laser-Induced Biological-Tissues Photothermal Effect Based on RC Circuit Model%基于RC电路模型的激光诱导生物组织光热效应

    Institute of Scientific and Technical Information of China (English)

    李小霞; 何俊; 韩雪梅

    2013-01-01

    针对激光诱导生物组织温升预测问题提出了一种新的RC电路理论模型.根据基尔霍夫电压定律(KVL)推导了RC电路的系统函数和单位冲激响应,根据单位冲激响应和矩形输入信号的卷积得到RC电路的零状态响应模型,由激光照射下生物组织温度实验结果确定模型中的两个固定参数,提出了两种模型参数计算方法并进行模拟计算.理论计算与实验结果显示温度响应曲线一致,肝脏和肌肉组织峰值温度相对误差范围分别为-0.0557℃~-0.0025℃和0.0139℃~0.0641℃,温度曲线平均相对误差范围分别为0.55%~2.39%和0.38%~0.99%,这种方法较经典的Pennes生物热传输方程模型所需参数少,精度更高,为激光与生物组织光热效应研究提供了一种新方法.%A new theoretical model of an RC circuit is proposed for prediction problem of laser induced biological tissue temperature rise. The RC circuit system function and unit impulse response are deduced based on Kirchhoff's voltage law (KVL). Then RC circuit zero state response model is deduced from the convolution of unit impulse response and rectangle input signal. The two model constant parameters are calculated from experimental results of the laser irradiated bio-tissues temperature. Two model parameter calculation methods are proposed and simulated. Theoretical calculation and experimental results show that the temperature response curves are consistent. Relative error ranges of liver and muscle tissue peak temperature are -0.0557 ℃~-0.0025 ℃ and 0.0139 ℃ -0.0641℃ respectively, and average relative error ranges of the temperature curve are 0. 55% ~2. 39% and 0. 38% ~0. 99% respectively. This method needs less parameters and is more precise than classical Pennes bio-heat transfer equation model, which provides a new method for laser and bio-tissues photothermal effect research.

  19. Exercise and Regulation of Bone and Collagen Tissue Biology

    DEFF Research Database (Denmark)

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

    2015-01-01

    molecular and cellular signaling pathways and their adaptation to exercise is available. In contrast to tissue responses with exercise, lack of mechanical tissue loading through inactivity or immobilization of the human body will result in a dramatic loss of connective tissue content, structure, and...

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Soldatov, A. N.; Vasilieva, A. V.

    2015-11-01

    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.

  2. 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.

  3. The Biological Bases of Conformity

    Directory of Open Access Journals (Sweden)

    ThomasJoshau HenryMorgan

    2012-06-01

    Full Text Available Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favour adaptive learning strategies that facilitate effective use of social information in decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behaviour in nonhuman animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history and ontogeny of conformity and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behaviour conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subject’s behaviour is the result of both social and asocial influences, the resultant behaviour may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for

  4. Grating-based tomography of human tissues

    Science.gov (United States)

    Müller, Bert; Schulz, Georg; Mehlin, Andrea; Herzen, Julia; Lang, Sabrina; Holme, Margaret; Zanette, Irene; Hieber, Simone; Deyhle, Hans; Beckmann, Felix; Pfeiffer, Franz; Weitkamp, Timm

    2012-07-01

    The development of therapies to improve our health requires a detailed knowledge on the anatomy of soft tissues from the human body down to the cellular level. Grating-based phase contrast micro computed tomography using synchrotron radiation provides a sensitivity, which allows visualizing micrometer size anatomical features in soft tissue without applying any contrast agent. We show phase contrast tomography data of human brain, tumor vessels and constricted arteries from the beamline ID 19 (ESRF) and urethral tissue from the beamline W2 (HASYLAB/DESY) with micrometer resolution. Here, we demonstrate that anatomical features can be identified within brain tissue as well known from histology. Using human urethral tissue, the application of two photon energies is compared. Tumor vessels thicker than 20 μm can be perfectly segmented. The morphology of coronary arteries can be better extracted in formalin than after paraffin embedding.

  5. Evaluation of impedance on biological Tissues using automatic control measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Kil, Sang Hyeong; Shin, Dong Hoon; Lee, Seong Mo [Pusan National University, Yangsan (Korea, Republic of); Lee, Moo Seok; Kim, Sang Sik [Pusan National University, Busan (Korea, Republic of); Kim, Gun FDo; Lee, Jong Kyu [Pukyung National University, Busan (Korea, Republic of)

    2015-08-15

    Each biological tissue has endemic electrical characteristics owing to various differences such as those in cellular arrangement or organization form. The endemic electrical characteristics change when any biological change occurs. This work is a preliminary study surveying the changes in the electrical characteristics of biological tissue caused by radiation exposure. For protection against radiation hazards, therefore the electrical characteristics of living tissue were evaluated after development of the automatic control measurement system using LabVIEW. No alteration of biological tissues was observed before and after measurement of the electrical characteristics, and the biological tissues exhibited similar patterns. Through repeated measurements using the impedance/gain-phase analyzer, the coefficient of variation was determined as within 10%. The reproducibility impedance phase difference in electrical characteristics of the biological tissue did not change, and the tissue had resistance. The absolute value of impedance decreased constantly in proportion to the frequency. It has become possible to understand the electrical characteristics of biological tissues through the measurements made possible by the use of the developed.

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

    International Nuclear Information System (INIS)

    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. The physiology and molecular biology of sponge tissues.

    Science.gov (United States)

    Leys, Sally P; Hill, April

    2012-01-01

    Sponges have become the focus of studies on molecular evolution and the evolution of animal body plans due to their ancient branching point in the metazoan lineage. Whereas our former understanding of sponge function was largely based on a morphological perspective, the recent availability of the first full genome of a sponge (Amphimedon queenslandica), and of the transcriptomes of other sponges, provides a new way of understanding sponges by their molecular components. This wealth of genetic information not only confirms some long-held ideas about sponge form and function but also poses new puzzles. For example, the Amphimedon sponge genome tells us that sponges possess a repertoire of genes involved in control of cell proliferation and in regulation of development. In vitro expression studies with genes involved in stem cell maintenance confirm that archaeocytes are the main stem cell population and are able to differentiate into many cell types in the sponge including pinacocytes and choanocytes. Therefore, the diverse roles of archaeocytes imply differential gene expression within a single cell ontogenetically, and gene expression is likely also different in different species; but what triggers cells to enter one pathway and not another and how each archaeocyte cell type can be identified based on this gene knowledge are new challenges. Whereas molecular data provide a powerful new tool for interpreting sponge form and function, because sponges are suspension feeders, their body plan and physiology are very much dependent on their physical environment, and in particular on flow. Therefore, in order to integrate new knowledge of molecular data into a better understanding the sponge body plan, it is important to use an organismal approach. In this chapter, we give an account of sponge body organization as it relates to the physiology of the sponge in light of new molecular data. We focus, in particular, on the structure of sponge tissues and review descriptive as

  8. 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...

  9. Gelatin-Based Materials in Ocular Tissue Engineering

    Directory of Open Access Journals (Sweden)

    James B. Rose

    2014-04-01

    Full Text Available Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology.

  10. The tensile strength characteristics study of the laser welds of biological tissue using the nanocomposite solder

    Science.gov (United States)

    Rimshan, I. B.; Ryabkin, D. I.; Savelyev, M. S.; Zhurbina, N. N.; Pyanov, I. V.; Eganova, E. M.; Pavlov, A. A.; Podgaetsky, V. M.; Ichkitidze, L. P.; Selishchev, S. V.; Gerasimenko, A. Y.

    2016-04-01

    Laser welding device for biological tissue has been developed. The main device parts are the radiation system and adaptive thermal stabilization system of welding area. Adaptive thermal stabilization system provided the relation between the laser radiation intensity and the weld temperature. Using atomic force microscopy the structure of composite which is formed by the radiation of laser solder based on aqua- albuminous dispersion of multi-walled carbon nanotubes was investigated. AFM topograms nanocomposite solder are mainly defined by the presence of pores in the samples. In generally, the surface structure of composite is influenced by the time, laser radiation power and MWCNT concentration. Average size of backbone nanoelements not exceeded 500 nm. Bulk density of nanoelements was in the range 106-108 sm-3. The data of welding temperature maintained during the laser welding process and the corresponding tensile strength values were obtained. Maximum tensile strength of the suture was reached in the range 50-55°C. This temperature and the pointwise laser welding technology (point area ~ 2.5mm) allows avoiding thermal necrosis of healthy section of biological tissue and provided reliable bonding construction of weld join. In despite of the fact that tensile strength values of the samples are in the range of 15% in comparison with unbroken strips of pigskin leather. This situation corresponds to the initial stage of the dissected tissue connection with a view to further increasing of the joint strength of tissues with the recovery of tissue structure; thereby achieved ratio is enough for a medical practice in certain cases.

  11. LASER METHODS IN BIOLOGY: Optical anisotropy of fibrous biological tissues: analysis of the influence of structural properties

    Science.gov (United States)

    Zimnyakov, D. A.; Sinichkin, Yu P.; Ushakova, O. V.

    2007-08-01

    The results of theoretical analysis of the optical anisotropy of multiply scattering fibrillar biological tissues based on the model of an effective anisotropic medium are compared with the experimental in vivo birefringence data for the rat derma obtained earlier in spectral polarisation measurements of rat skin samples in the visible region. The disordered system of parallel dielectric cylinders embedded into an isotropic dielectric medium was considered as a model medium. Simulations were performed taking into account the influence of a partial mutual disordering of the bundles of collagen and elastin fibres in derma on birefringence in samples. The theoretical optical anisotropy averaged over the spectral interval 550-650 nm for the model medium with parameters corresponding to the structural parameters of derma is in good agreement with the results of spectral polarisation measurements of skin samples in the corresponding wavelength range.

  12. Methods in Enzymology (MIE): Methods of Adipose Tissue Biology-: Chapter 7: Imaging of Adipose Tissue

    OpenAIRE

    Berry, Ryan; Church, Christopher; Gericke, Martin T; Jeffery, Elise; Colman, Laura; Rodeheffer, Matthew S.

    2014-01-01

    Adipose tissue is an endocrine organ that specializes in lipid metabolism and is distributed throughout the body in distinct white adipose tissue (WAT) and brown adipose tissue (BAT) depots. These tissues have opposing roles in lipid metabolism with WAT storing excessive caloric intake in the form of lipid, and BAT burning lipid through non-shivering thermogenesis. As accumulation of lipid in mature adipocytes of WAT leads to obesity and increased risk of comorbidity (Pi-Sunyer et al., 1998),...

  13. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  14. High-Speed Coherent Raman Fingerprint Imaging of Biological Tissues

    CERN Document Server

    Camp, Charles H; Heddleston, John M; Hartshorn, Christopher M; Walker, Angela R Hight; Rich, Jeremy N; Lathia, Justin D; Cicerone, Marcus T

    2014-01-01

    We have developed a coherent Raman imaging platform using broadband coherent anti-Stokes Raman scattering (BCARS) that provides an unprecedented combination of speed, sensitivity, and spectral breadth. The system utilizes a unique configuration of laser sources that probes the Raman spectrum over 3,000 cm$^{-1}$ and generates an especially strong response in the typically weak Raman "fingerprint" region through heterodyne amplification of the anti-Stokes photons with a large nonresonant background (NRB) while maintaining high spectral resolution of $<$ 13 cm$^{-1}$. For histology and pathology, this system shows promise in highlighting major tissue components in a non-destructive, label-free manner. We demonstrate high-speed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues and interfaces between xenograft brain tumors and the surrounding healthy brain matter.

  15. TissueCypher™: A systems biology approach to anatomic pathology

    OpenAIRE

    Prichard, Jeffrey W.; Davison, Jon M.; Campbell, Bruce B.; Repa, Kathleen A.; Lia M Reese; Xuan M Nguyen; Jinhong Li; Tyler Foxwell; Lansing D Taylor; Critchley-Thorne, Rebecca J.

    2015-01-01

    Background: Current histologic methods for diagnosis are limited by intra- and inter-observer variability. Immunohistochemistry (IHC) methods are frequently used to assess biomarkers to aid diagnoses, however, IHC staining is variable and nonlinear and the manual interpretation is subjective. Furthermore, the biomarkers assessed clinically are typically biomarkers of epithelial cell processes. Tumors and premalignant tissues are not composed only of epithelial cells but are interacting system...

  16. Development of technique for laser welding of biological tissues using laser welding device and nanocomposite solder.

    Science.gov (United States)

    Gerasimenko, A; Ichcitidze, L; Podgaetsky, V; Ryabkin, D; Pyankov, E; Saveliev, M; Selishchev, S

    2015-08-01

    The laser device for welding of biological tissues has been developed involving quality control and temperature stabilization of weld seam. Laser nanocomposite solder applied onto a wound to be weld has been used. Physicochemical properties of the nanocomposite solder have been elucidated. The nature of the tissue-organizing nanoscaffold has been analyzed at the site of biotissue welding. PMID:26738200

  17. Can OCT be sensitive to nanoscale structural alterations in biological tissue?

    OpenAIRE

    Yi, Ji; Radosevich, Andrew J.; Rogers, Jeremy D.; Norris, Sam C.P.; Çapoğlu, İlker R.; Taflove, Allen; Backman, Vadim

    2013-01-01

    Exploration of nanoscale tissue structures is crucial in understanding biological processes. Although novel optical microscopy methods have been developed to probe cellular features beyond the diffraction limit, nanometer-scale quantification remains still inaccessible for in situ tissue. Here we demonstrate that, without actually resolving specific geometrical feature, OCT can be sensitive to tissue structural properties at the nanometer length scale. The statistical mass-density distributio...

  18. Physical characterization of ultrashort laser pulse drilling of biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Feit, M.D.; Rubenchik, A.M.; Kim, B.M.; Da Silva, L.D.; Stuart, B.C.; Perry, M.D.

    1997-07-21

    Ultrashort laser pulse ablation removes material with low energy fluence required and minimal collateral damage. The ultimate usefulness of this technology for biomedical applications depends, in part, on characterization of the physical conditions attained and determination of the zone of shockwave and heat affected material in particular tissues. Detailed numerical modeling of the relevant physics (deposition, plasma formation, shockwave generation and propagation, thermal conduction) are providing this information. A wide range of time scales is involved, ranging from picosecond for energy deposition and peak pressure and temperature, to nanosecond for development of shockwave, to microsecond for macroscopic thermophysical response.

  19. Is Biology based on Physics?

    Science.gov (United States)

    Goradia, Shantilal

    2015-04-01

    The equation on Boltsmann's tomb is S = K log W, giving 137 = 10E60 where 10E60 closely stands for the age of the universe in Plank times. We wish we could add ``137 = 10E60'' on his tomb as a contribution leading physics towards information in biology as explained in our book ``Quantum Consciousness - the Road to Reality.'' (1) We draft our speculation that such a step may explain the underlying physical cause for mutations. Tiny immeasurable and slow changes well beyond the tenth digit of fine structure constant may suffice to change the information system in constituent particles of nucleotides with their external effects forcing changes in the genetic code with successful changes resulting into mutations. (2) Our quantum mechanical published derivation of the strong coupling implies gravity as a cumulative effect of quantum mechanical particles further implying that the universal constant of gravity (G) can not be constant everywhere. (1) and (2) put together should remove Darwin's confusion about the constancy of gravity. Moving planets and Sunstorms should also cause changes in G on earth unnoticeable to mankind, but large enough to have an impact on the internal particles of nucleotides which should implicitly have an external effect on the genetic code per our theory.

  20. Neutron interactions with biological tissue. Progress report, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The first area of research focuses on track structure effects in neutron microdosimetry and nanodosimetry. This is an investigation of the effect of proton energy-loss straggling and the associated transport of energy by secondary electrons on neutron event-size distributions in small sites. Secondly, energy deposition spectra and their moments for fast neutrons are investigated. Using calculated charged particle initial spectra and slowing-down spectra the authors can calculate the energy deposition in spherical cavities. Lastly, an attempt was made to study the relation of neutron energy deposition calculations to biology and biophysical models.

  1. Radiochemical separation and determination of europium by Ge(Li) detector in biological tissues

    International Nuclear Information System (INIS)

    A simple neutron activation method has been developed for the determination of europium in biological tissues and applied in the analysis of marine organism samples at the nanogram level. The method is based on the separation, by ion-exchange, of the rare earth group from dry or ashed irradiated tissues and subsequent determination of sup(152m)Eu, by γ-spectrometry using a lithium drifted germanium detector. sup(152m)Eu, separated almost completely from other than rare earth elements, with better than 98% chemical yield, is counted on the 121.8 keV photopeak which than is practically free from any other γ-ray energy interfering in this counting. The determination of europium was tested in ten dry tissue samples of a marine organism for precision. The relative standard deviation found, 9%, is good enough compared with the 50% precision of the results given in the literature. The accuracy of the method is not tested, since the results for Eu in BOWEN's kale are dispersed. (T.G.)

  2. Relationship between the temperature and the acoustic nonlinearity parameter in biological tissues

    Institute of Scientific and Technical Information of China (English)

    LU Ying; LIU Xiaozhou; GONG Xiufen; ZHANG Dong

    2004-01-01

    Recently with the rapid development of the high-intensity focused ultrasound (HIFU) in biomedical ultrasound, much attention has been paid to the noninvasive temperature estimation in biological tissue in order to determine the region and degree of the ultrasound-induced lesions. In ultrasound hyperthermal therapy it is highly desirable to study the real-time noninvasive monitoring of temperature distribution in biological tissue. In this paper, the relationship between the nonlinearity parameter B/A and the temperature in biological tissue is studied and compared with the theoretical model as well as the experimental results from the thermocouple. Results indicated that B/A could be used as an effective tool to monitor the temperature distribution in biological media.

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

    International Nuclear Information System (INIS)

    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)

  4. 3-Dimensional quantitative detection of nanoparticle content in biological tissue samples after local cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rahn, Helene, E-mail: helene.rahn@gmail.com [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Technische Universitaet Dresden, Dresden 01069 (Germany); Alexiou, Christoph [ENT-Department, Section for Experimental Oncology and Nanomedicine (Else Kröner-Fresenius-Stiftungsprofessur), University Hospital Erlangen, Waldstraße 1, Erlangen 91054 (Germany); Trahms, Lutz [Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, Berlin 10587 (Germany); Odenbach, Stefan [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Technische Universitaet Dresden, Dresden 01069 (Germany)

    2014-06-01

    X-ray computed tomography is nowadays used for a wide range of applications in medicine, science and technology. X-ray microcomputed tomography (XµCT) follows the same principles used for conventional medical CT scanners, but improves the spatial resolution to a few micrometers. We present an example of an application of X-ray microtomography, a study of 3-dimensional biodistribution, as along with the quantification of nanoparticle content in tumoral tissue after minimally invasive cancer therapy. One of these minimal invasive cancer treatments is magnetic drug targeting, where the magnetic nanoparticles are used as controllable drug carriers. The quantification is based on a calibration of the XµCT-equipment. The developed calibration procedure of the X-ray-µCT-equipment is based on a phantom system which allows the discrimination between the various gray values of the data set. These phantoms consist of a biological tissue substitute and magnetic nanoparticles. The phantoms have been studied with XµCT and have been examined magnetically. The obtained gray values and nanoparticle concentration lead to a calibration curve. This curve can be applied to tomographic data sets. Accordingly, this calibration enables a voxel-wise assignment of gray values in the digital tomographic data set to nanoparticle content. Thus, the calibration procedure enables a 3-dimensional study of nanoparticle distribution as well as concentration. - Highlights: • Local cancer treatments are promising in reducing negative side effects occurring during conventional chemotherapy. • The nanoparticles play an important role in delivering drugs to the designated area during local cancer treatments as magnetic drug targeting. • We study the nanoparticles distribution in tumor tissue after magnetic drug targeting with X-ray computed tomography. • We achieved a 3-dimensional quantification of the nanoparticles content in tumor tissue out of digital tomographic data.

  5. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    CERN Document Server

    Smith, Donald F; Leach, Franklin E; Robinson, Errol W; Paša-Tolić, Ljiljana; Heeren, Ron 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 performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for elemental formula assignment based on exact mass measurement. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissu...

  6. Pomraning-Eddington calculation for the biological tissues

    International Nuclear Information System (INIS)

    Two flux model approximation has been derived for source-free radiation transfer equation for anisotropic scattering in turbid media by the Pomraning-Eddington method (Asymptotic like approximation). Relations have derived between the Kubelka-Munk coefficients and the transport parameters σa σs and g = . The calculations of the Kubelka-Munk coefficients for isotropic and anisotropic scattering and then the reflectivity and transmissivity are carried out for some tissues of different optical properties. The mathematical approach of the calculation for a single layer could be extended to a multi-layers medium. The results are compared with the published data and show good agreement. (author). 20 refs, 5 tabs

  7. Biomimetic approaches in bone tissue engineering: Integrating biological and physicomechanical strategies.

    Science.gov (United States)

    Fernandez-Yague, Marc A; Abbah, Sunny Akogwu; McNamara, Laoise; Zeugolis, Dimitrios I; Pandit, Abhay; Biggs, Manus J

    2015-04-01

    The development of responsive biomaterials capable of demonstrating modulated function in response to dynamic physiological and mechanical changes in vivo remains an important challenge in bone tissue engineering. To achieve long-term repair and good clinical outcomes, biologically responsive approaches that focus on repair and reconstitution of tissue structure and function through drug release, receptor recognition, environmental responsiveness and tuned biodegradability are required. Traditional orthopedic materials lack biomimicry, and mismatches in tissue morphology, or chemical and mechanical properties ultimately accelerate device failure. Multiple stimuli have been proposed as principal contributors or mediators of cell activity and bone tissue formation, including physical (substrate topography, stiffness, shear stress and electrical forces) and biochemical factors (growth factors, genes or proteins). However, optimal solutions to bone regeneration remain elusive. This review will focus on biological and physicomechanical considerations currently being explored in bone tissue engineering. PMID:25236302

  8. Biologically improved nanofibrous scaffolds for cardiac tissue engineering

    International Nuclear Information System (INIS)

    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

  9. 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

  10. Histological image classification using biologically interpretable shape-based features

    International Nuclear Information System (INIS)

    Automatic cancer diagnostic systems based on histological image classification are important for improving therapeutic decisions. Previous studies propose textural and morphological features for such systems. These features capture patterns in histological images that are useful for both cancer grading and subtyping. However, because many of these features lack a clear biological interpretation, pathologists may be reluctant to adopt these features for clinical diagnosis. We examine the utility of biologically interpretable shape-based features for classification of histological renal tumor images. Using Fourier shape descriptors, we extract shape-based features that capture the distribution of stain-enhanced cellular and tissue structures in each image and evaluate these features using a multi-class prediction model. We compare the predictive performance of the shape-based diagnostic model to that of traditional models, i.e., using textural, morphological and topological features. The shape-based model, with an average accuracy of 77%, outperforms or complements traditional models. We identify the most informative shapes for each renal tumor subtype from the top-selected features. Results suggest that these shapes are not only accurate diagnostic features, but also correlate with known biological characteristics of renal tumors. Shape-based analysis of histological renal tumor images accurately classifies disease subtypes and reveals biologically insightful discriminatory features. This method for shape-based analysis can be extended to other histological datasets to aid pathologists in diagnostic and therapeutic decisions

  11. Ultrasonic array of thick film transducers for biological tissue characterization.

    Science.gov (United States)

    Gwirc, Sergio N; Negreira, Carlos A; Marino, Nestor R

    2010-01-01

    The initial motivation for this work was to accomplish an easy way to manufacture different geometries of ultrasonic transducers and arrays using a PZT powder, combined with a standard process to have repetitive series of them. The piezoelectric thick film was obtained using a PZT paste and applying it by screen printing on an alumina substrate. Then, the film was drying and sintered with a temperature-time profile determined by the paste characteristics. Each transducer is composed by three layers, one by PZT and two acting as electrodes. The active element of the paste is a PZT powder which is dispersed in a commercial vehicle to obtain rheological properties suitable for use the screen printing process. The connection between PZT particles is improved by adding a lead borosilicate frit glass that also helps to attach the film to the substrate due to the relatively low temperature of sintered that has been used in this process. The PZT film has low density that is generated by internal porosity, so its acoustic impedance is lower than for a bulk ceramic transducer and so is well adapted to testing human tissues. At the same time the thick film technology is well suited to make medium size transducers and also arrays performed with tiny ultrasonic transducers. PMID:21097177

  12. Injectable 3-D Fabrication of Medical Electronics at the Target Biological Tissues

    Science.gov (United States)

    Jin, Chao; Zhang, Jie; Li, Xiaokang; Yang, Xueyao; Li, Jingjing; Liu, Jing

    2013-12-01

    Conventional transplantable biomedical devices generally request sophisticated surgery which however often causes big trauma and serious pain to the patients. Here, we show an alternative way of directly making three-dimensional (3-D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and liquid metal ink. As the most typical electronics, a variety of medical electrodes with different embedded structures were demonstrated to be easily formed at the target tissues. Conceptual in vitro experiments provide strong evidences for the excellent performances of the injectable electrodes. Further in vivo animal experiments disclosed that the formed electrode could serve as both highly efficient ECG (Electrocardiograph) electrode and stimulator electrode. These findings clarified the unique features and practicability of the liquid metal based injectable 3-D fabrication of medical electronics. The present strategy opens the way for directly manufacturing electrophysiological sensors or therapeutic devices in situ via a truly minimally invasive approach.

  13. 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.

  14. Biological Based Risk Assessment for Space Exploration

    Science.gov (United States)

    Cucinotta, Francis A.

    2011-01-01

    Exposures from galactic cosmic rays (GCR) - made up of high-energy protons and high-energy and charge (HZE) nuclei, and solar particle events (SPEs) - comprised largely of low- to medium-energy protons are the primary health concern for astronauts for long-term space missions. Experimental studies have shown that HZE nuclei produce both qualitative and quantitative differences in biological effects compared to terrestrial radiation, making risk assessments for cancer and degenerative risks, such as central nervous system effects and heart disease, highly uncertain. The goal for space radiation protection at NASA is to be able to reduce the uncertainties in risk assessments for Mars exploration to be small enough to ensure acceptable levels of risks are not exceeded and to adequately assess the efficacy of mitigation measures such as shielding or biological countermeasures. We review the recent BEIR VII and UNSCEAR-2006 models of cancer risks and their uncertainties. These models are shown to have an inherent 2-fold uncertainty as defined by ratio of the 95% percent confidence level to the mean projection, even before radiation quality is considered. In order to overcome the uncertainties in these models, new approaches to risk assessment are warranted. We consider new computational biology approaches to modeling cancer risks. A basic program of research that includes stochastic descriptions of the physics and chemistry of radiation tracks and biochemistry of metabolic pathways, to emerging biological understanding of cellular and tissue modifications leading to cancer is described.

  15. Simple Empirical Model for Identifying Rheological Properties of Soft Biological Tissues

    CERN Document Server

    Kobayashi, Yo; Miyashita, Tomoyuki; Fujie, Masakatsu G

    2015-01-01

    Understanding the rheological properties of soft biological tissue is a key issue for mechanical systems used in the healthcare field. We propose a simple empirical model using Fractional Dynamics and Exponential Nonlinearity (FDEN) to identify the rheological properties of soft biological tissue. The model is derived from detailed material measurements using samples isolated from porcine liver. We conducted dynamic viscoelastic and creep tests on liver samples using a rheometer. The experimental results indicated that biological tissue has specific properties: i) power law increases in storage elastic modulus and loss elastic modulus with the same slope; ii) power law gain decrease and constant phase delay in the frequency domain over two decades; iii) log-log scale linearity between time and strain relationships under constant force; and iv) linear and log scale linearity between strain and stress relationships. Our simple FDEN model uses only three dependent parameters and represents the specific propertie...

  16. Development of Spectral Domain Optical Coherence Tomography for in vivo Functional Imaging of Biological Tissues

    Science.gov (United States)

    An, Lin

    Optical coherence tomography is a rapidly developing optical imaging modality capable of noninvasively providing depth resolved information of biological tissue at micrometer scale. In this thesis, we described several OCT technologies that can be used to double the imaging depth, realize functional vasculature imaging of biological tissue and increase the imaging speed of OCT system. Aim 1: Use of a scanner to introduce spatial frequency modulation to OCT spectral interferograms for in vivo full-range Fourier-domain optical coherence tomography. A novel method was developed that could easily introduce a modulation frequency onto the X-direction (i.e., B-scan) of the FDOCT scanning system, enabling full-range Fourier-domain Optical Coherence Tomography (frFDOCT). Compared to the conventional FDOCT system, the newly developed frFDOCT system can provide increased system sensitivity and deeper imaging depth. The previous technology that can achieve frFDOCT either needed multiple steps for data capturing, which is time consuming, or required additional components which increased the system's complexity. The newly developed method generates a modulation spatial frequency in the spectral interferogram by simply offsetting the probe beam at the X-scanner. Aim 2: Using optical micro-angiography to achieve in vivo volumetric imaging of vascular perfusion within human retina and choroids. Optical Micro-Angiography (OMAG) is a functional extension of FDOCT technology. It can achieve visualization of vasculature network of biological tissue. In order to apply the OMAG method to image vasculature map of human retina and choroid, a phase compensation algorithm was developed, which could minimize the motion artifacts generated by the movements of human eye and head. Aim 3: Developing ultrahigh sensitive optical micro-angiography to achieve micro vasculature imaging of biological tissue. To improve the vasculature image quality, we developed ultrahigh sensitive OMAG (UHS

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

    CERN Document Server

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

    2015-01-01

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues. It therefore grants access to superficial 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 very short range and, in theory, 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 $\\sim$1\\,mm thick tissue layers.

  18. Mesenchymal Stem Cells Isolated from Adipose and Other Tissues: Basic Biological Properties and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Hakan Orbay

    2012-01-01

    Full Text Available Mesenchymal stem cells (MSCs are adult stem cells that were initially isolated from bone marrow. However, subsequent research has shown that other adult tissues also contain MSCs. MSCs originate from mesenchyme, which is embryonic tissue derived from the mesoderm. These cells actively proliferate, giving rise to new cells in some tissues, but remain quiescent in others. MSCs are capable of differentiating into multiple cell types including adipocytes, chondrocytes, osteocytes, and cardiomyocytes. Isolation and induction of these cells could provide a new therapeutic tool for replacing damaged or lost adult tissues. However, the biological properties and use of stem cells in a clinical setting must be well established before significant clinical benefits are obtained. This paper summarizes data on the biological properties of MSCs and discusses current and potential clinical applications.

  19. 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.

  20. Imaging of the interaction of low frequency electric fields with biological tissues by optical coherence tomography

    Science.gov (United States)

    Peña, Adrian F.; Devine, Jack; Doronin, Alexander; Meglinski, Igor

    2014-03-01

    We report the use of conventional Optical Coherence Tomography (OCT) for visualization of propagation of low frequency electric field in soft biological tissues ex vivo. To increase the overall quality of the experimental images an adaptive Wiener filtering technique has been employed. Fourier domain correlation has been subsequently applied to enhance spatial resolution of images of biological tissues influenced by low frequency electric field. Image processing has been performed on Graphics Processing Units (GPUs) utilizing Compute Unified Device Architecture (CUDA) framework in the frequencydomain. The results show that variation in voltage and frequency of the applied electric field relates exponentially to the magnitude of its influence on biological tissue. The magnitude of influence is about twice more for fresh tissue samples in comparison to non-fresh ones. The obtained results suggest that OCT can be used for observation and quantitative evaluation of the electro-kinetic changes in biological tissues under different physiological conditions, functional electrical stimulation, and potentially can be used non-invasively for food quality control.

  1. Double integrating spheres: A method for assessment of optical properties of biological tissues

    OpenAIRE

    Poppendieck, Wigand

    2004-01-01

    The determination of the optical properties of biological tissue is an important issue in laser medicine. The optical properties define the tissue´s absorption and scattering behaviour, and can be expressed by quantities such as the albedo, the optical thickness and the anisotropy coefficient. During this project, a measurement system for the determination of the optical properties was built up. The system consists of a double integrating sphere set-up to perform the necessary reflection and ...

  2. High-resolution atmospheric pressure infrared laser desorption/ionization mass spectrometry imaging of biological tissue.

    Science.gov (United States)

    Römpp, Andreas; Schäfer, Karl Christian; Guenther, Sabine; Wang, Zheng; Köstler, Martin; Leisner, Arne; Paschke, Carmen; Schramm, Thorsten; Spengler, Bernhard

    2013-09-01

    An atmospheric pressure laser desorption/ionization mass spectrometry imaging ion source has been developed that combines high spatial resolution and high mass resolution for the in situ analysis of biological tissue. The system is based on an infrared laser system working at 2.94 to 3.10 μm wavelength, employing a Nd:YAG laser-pumped optical parametrical oscillator. A Raman-shifted Nd:YAG laser system was also tested as an alternative irradiation source. A dedicated optical setup was used to focus the laser beam, coaxially with the ion optical axis and normal to the sample surface, to a spot size of 30 μm in diameter. No additional matrix was needed for laser desorption/ionization. A cooling stage was developed to reduce evaporation of physiological cell water. Ions were formed under atmospheric pressure and transferred by an extended heated capillary into the atmospheric pressure inlet of an orbital trapping mass spectrometer. Various phospholipid compounds were detected, identified, and imaged at a pixel resolution of up to 25 μm from mouse brain tissue sections. Mass accuracies of better than 2 ppm and a mass resolution of 30,000 at m/z = 400 were achieved for these measurements. PMID:23877173

  3. Biological Basis of Exercise-Based Treatments for Musculoskeletal Conditions

    Science.gov (United States)

    Ambrosio, Fabrisia; Tarabishy, Ayman; Kadic, Fawzi; Brown, Elke H.P.; Sowa, Gwendolyn

    2016-01-01

    Exercise-based therapies are the cornerstone of rehabilitation programs. While the benefits of exercise on systemic and tissue function are generally accepted, mechanisms underlying these benefits are sometimes poorly understood. An improved understanding of the effects of mechanical loading on molecular and cellular processes has the potential to lead to more disease-specific and efficacious exercise-based therapies. The purpose of this paper is to review the current literature examining the role of mechanical signaling on muscle and cartilage biology. PMID:21703582

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

    Institute of Scientific and Technical Information of China (English)

    程凯旋; 吴融融; 刘晓宙; 刘杰惠; 龚秀芬; 吴君汝

    2015-01-01

    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.

  5. Heavy metal pathways and archives in biological tissue

    International Nuclear Information System (INIS)

    Nuclear milli and microprobes at the Australian Nuclear Science and Technology Organisation (ANSTO) were used to determine lead accumulation in native Australian plants and animals. Three species of eucalypt plants (Eucalyptus camaldulensis, Eucalyptus globulus and Eucalyptus lesouefii), one species of salt bush (Atriplex burbhanyana) and one species each of acacia (Acacia saligna) and estuarine crocodiles (Crocodylus porosus) were investigated. Experimentally grown plants were subjected to a nutrient solution with a pH of 5 and spiked with a 200 μmol concentration of Pb. Lead concentrations in leaves of both E. globulus and E. camaldulensis showed an almost exponential decrease from the base of the main vein to the tip. Similarly, Pb concentrations decreased from the main vein to secondary veins. Concentrations of essential elements such as K, Fe, Zn and Br in the main and secondary veins were constant within experimental uncertainty. In contrast, the concentrations of Pb in the leaf veins of E. lesouefii were much lower and showed no systematic pattern. In stem and root samples the highest concentration of Pb was found in roots and stem of E. globulus and A. burbhanyana followed by E. camaldulensis. Some Pb was found in roots of A. saligna and only very low concentration in stem of the same plant. More detailed analysis of thin cross-sectional samples of roots and stem showed that Pb is present in much higher concentration in the growth area of the plant structure (i.e. meristemic region) and in relatively low concentration within the pith region and outer cortex. The osteoderms (dermal bones) of estuarine crocodiles, exposed to lead ammunition in food from the hunting activities of traditional Aboriginal owners, were sampled at two sites in Kakadu National Park, northern Australia. PIXE analyses showed enhanced, but relatively constant, ratios of Pb/Ca in the annual laminations. This was consistent with both their history of long term exposure to elevated

  6. Heavy metal pathways and archives in biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Orlic, I. E-mail: ivo@ansto.gov.au; Siegele, R.; Menon, D.D.; Markich, S.J.; Cohen, D.D.; Jeffree, R.A.; McPhail, D.C.; Sarbutt, A.; Stelcer, E

    2002-05-01

    Nuclear milli and microprobes at the Australian Nuclear Science and Technology Organisation (ANSTO) were used to determine lead accumulation in native Australian plants and animals. Three species of eucalypt plants (Eucalyptus camaldulensis, Eucalyptus globulus and Eucalyptus lesouefii), one species of salt bush (Atriplex burbhanyana) and one species each of acacia (Acacia saligna) and estuarine crocodiles (Crocodylus porosus) were investigated. Experimentally grown plants were subjected to a nutrient solution with a pH of 5 and spiked with a 200 {mu}mol concentration of Pb. Lead concentrations in leaves of both E. globulus and E. camaldulensis showed an almost exponential decrease from the base of the main vein to the tip. Similarly, Pb concentrations decreased from the main vein to secondary veins. Concentrations of essential elements such as K, Fe, Zn and Br in the main and secondary veins were constant within experimental uncertainty. In contrast, the concentrations of Pb in the leaf veins of E. lesouefii were much lower and showed no systematic pattern. In stem and root samples the highest concentration of Pb was found in roots and stem of E. globulus and A. burbhanyana followed by E. camaldulensis. Some Pb was found in roots of A. saligna and only very low concentration in stem of the same plant. More detailed analysis of thin cross-sectional samples of roots and stem showed that Pb is present in much higher concentration in the growth area of the plant structure (i.e. meristemic region) and in relatively low concentration within the pith region and outer cortex. The osteoderms (dermal bones) of estuarine crocodiles, exposed to lead ammunition in food from the hunting activities of traditional Aboriginal owners, were sampled at two sites in Kakadu National Park, northern Australia. PIXE analyses showed enhanced, but relatively constant, ratios of Pb/Ca in the annual laminations. This was consistent with both their history of long term exposure to elevated

  7. Heavy metal pathways and archives in biological tissue

    Science.gov (United States)

    Orlic, I.; Siegele, R.; Menon, D. D.; Markich, S. J.; Cohen, D. D.; Jeffree, R. A.; McPhail, D. C.; Sarbutt, A.; Stelcer, E.

    2002-05-01

    Nuclear milli and microprobes at the Australian Nuclear Science and Technology Organisation (ANSTO) were used to determine lead accumulation in native Australian plants and animals. Three species of eucalypt plants ( Eucalyptus camaldulensis, Eucalyptus globulus and Eucalyptus lesouefii), one species of salt bush ( Atriplex burbhanyana) and one species each of acacia ( Acacia saligna) and estuarine crocodiles ( Crocodylus porosus) were investigated. Experimentally grown plants were subjected to a nutrient solution with a pH of 5 and spiked with a 200 μmol concentration of Pb. Lead concentrations in leaves of both E. globulus and E. camaldulensis showed an almost exponential decrease from the base of the main vein to the tip. Similarly, Pb concentrations decreased from the main vein to secondary veins. Concentrations of essential elements such as K, Fe, Zn and Br in the main and secondary veins were constant within experimental uncertainty. In contrast, the concentrations of Pb in the leaf veins of E. lesouefii were much lower and showed no systematic pattern. In stem and root samples the highest concentration of Pb was found in roots and stem of E. globulus and A. burbhanyana followed by E. camaldulensis. Some Pb was found in roots of A. saligna and only very low concentration in stem of the same plant. More detailed analysis of thin cross-sectional samples of roots and stem showed that Pb is present in much higher concentration in the growth area of the plant structure (i.e. meristemic region) and in relatively low concentration within the pith region and outer cortex. The osteoderms (dermal bones) of estuarine crocodiles, exposed to lead ammunition in food from the hunting activities of traditional Aboriginal owners, were sampled at two sites in Kakadu National Park, northern Australia. PIXE analyses showed enhanced, but relatively constant, ratios of Pb/Ca in the annual laminations. This was consistent with both their history of long term exposure to elevated

  8. Extraction and analysis of silver and gold nanoparticles from biological tissues using single particle inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Gray, Evan P; Coleman, Jessica G; Bednar, Anthony J; Kennedy, Alan J; Ranville, James F; Higgins, Christopher P

    2013-12-17

    Expanded use of engineered nanoparticles (ENPs) in consumer products increases the potential for environmental release and unintended biological exposures. As a result, measurement techniques are needed to accurately quantify ENP size, mass, and particle number distributions in biological matrices. This work combines single particle inductively coupled plasma mass spectrometry (spICPMS) with tissue extraction to quantify and characterize metallic ENPs in environmentally relevant biological tissues for the first time. ENPs were extracted from tissues via alkaline digestion using tetramethylammonium hydroxide (TMAH). Method development was performed using ground beef and was verified in Daphnia magna and Lumbriculus variegatus . ENPs investigated include 100 and 60 nm Au and Ag stabilized by polyvynylpyrrolidone (PVP). Mass- and number-based recovery of spiked Au and Ag ENPs was high (83-121%) from all tissues tested. Additional experiments suggested ENP mixtures (60 and 100 nm Ag ENPs) could be extracted and quantitatively analyzed. Biological exposures were also conducted to verify the applicability of the method for aquatic organisms. Size distributions and particle number concentrations were determined for ENPs extracted from D. magna exposed to 98 μg/L 100 nm Au and 4.8 μg/L 100 nm Ag ENPs. The D. magna nanoparticulate body burden for Au ENP uptake was 613 ± 230 μg/kgww, while the measured nanoparticulate body burden for D. magna exposed to Ag ENPs was 59 ± 52 μg/kgww. Notably, the particle size distributions determined from D. magna tissues suggested minimal shifts in the size distributions of ENPs accumulated, as compared to the exposure media. PMID:24218983

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

    International Nuclear Information System (INIS)

    This investigation was conducted in an effort to gain a deeper understanding of the microstructural damage to living tissue caused by heavy ion radiation. Preliminary tests on rat corneal tissue, rat cerebellar tissue grown in culture, and rat retinal tissue indicated that of these three tissues the best assay for heavy ion damage might be the rat cornea. The anterior surface of the cornea consists of squamous epithelial cells whose plasma membrane morphology is readily characterized under high resolution scanning electron microscopy (SEM). Thus any structural changed leading to alterations in corneal morphology should be relatively easy to detect if they are within the resolution capability of the SEM. Prior to this work, biological lesions caused by ionizing radiation were almost never observed shortly after a dose was delivered even if the dose was lethal

  10. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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

  13. Computed tomography of the acoustic nonlinearity parameter B/A for biological tissues via difference frequency wave from a parametric array in reflection mode

    Institute of Scientific and Technical Information of China (English)

    WANG Huanlei; ZHU Xiaofeng; GONG Xiufen; ZHANG Dong

    2003-01-01

    Based on the finite amplitude insert-substitu- tion method, a novel technique to reconstruct the acoustic nonlinear parameter B/A tomography for biological tissues in reflection mode via the difference frequency wave generated by a parametric array is developed in this paper. An experimental system is established, and the beam pattern of the difference frequency wave is measured and compared with that excited directly from a transmitter at the same frequency. B/A tomography for several biological tissues including normal and pathological tissues, is experimentally obtained with satisfying quality. Results indicate that B/A imaging using this mode may become a novel modality in ultrasonic diagnosis.

  14. 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.

  15. New vibro-acoustic paradigms in biological tissues with application to diagnosis of pulmonary disorders

    Science.gov (United States)

    Zhang, Xiangling

    The fundamental objective of the present study is to improve our understanding of audible sound propagation in the pulmonary system and torso. A related applied objective is to assess the feasibility of using audible acoustics for diagnosis of specific pulmonary conditions, such as pneumothorax (PTX). To accomplish these objectives, this study includes theoretical, computational and experimental developments aimed at: (1) better identifying the mechanical dynamic properties of soft biological tissues found in the torso region, (2) investigating the mechanisms of sound attenuation that occur when a PTX is present using greatly simplified theoretical and computational models, and (3) exploring the feasibility and utility of more comprehensive and precise computational finite element models of audible sound propagation in the pulmonary system and torso that would aid in related diagnostic developments. Mechanical material properties of soft biological tissue are studied for the low audible frequency range. The sensitivity to shear viscoelastic material constants of theoretical solutions for radiation impedance and surface wave motion are compared. Theoretical solutions are also compared to experimental measurements and numerical results from finite element analysis. It is found that, while prior theoretical solutions for radiation impedance are accurate, use of such measurements to estimate shear viscoelastic constants is not as precise as the use of surface wave measurements. The feasibility of using audible sound for diagnosis of pneumothorax is studied. Simplified one- and two-dimensional theoretical and numerical models of sound transmission through the pulmonary system and chest region to the chest wall surface are developed to more clearly understand the mechanism of energy loss when a pneumothorax is present, relative to a baseline case. A canine study on which these models are based predicts significant decreases in acoustic transmission strength when a

  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. Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue

    Science.gov (United States)

    Horstmeyer, Roarke; Ruan, Haowen; Yang, Changhuei

    2015-09-01

    In the field of biomedical optics, optical scattering has traditionally limited the range of imaging within tissue to a depth of one millimetre. A recently developed class of wavefront-shaping techniques now aims to overcome this limit and achieve diffraction-limited control of light beyond one centimetre. By manipulating the spatial profile of an optical field before it enters a scattering medium, it is possible to create a micrometre-scale focal spot deep within tissue. To successfully operate in vivo, these wavefront-shaping techniques typically require feedback from within the biological sample. This Review summarizes recently developed 'guidestar' mechanisms that provide feedback for intra-tissue focusing. Potential applications of guidestar-assisted focusing include optogenetic control over neurons, targeted photodynamic therapy and deep tissue imaging.

  18. Optical-Based Analysis of Soft Tissue Structures.

    Science.gov (United States)

    Goth, Will; Lesicko, John; Sacks, Michael S; Tunnell, James W

    2016-07-11

    Fibrous structures are an integral and dynamic feature of soft biological tissues that are directly related to the tissues' condition and function. A greater understanding of mechanical tissue behavior can be gained through quantitative analyses of structure alone, as well as its integration into computational models of soft tissue function. Histology and other nonoptical techniques have traditionally dominated the field of tissue imaging, but they are limited by their invasiveness, inability to provide resolution on the micrometer scale, and dynamic information. Recent advances in optical modalities can provide higher resolution, less invasive imaging capabilities, and more quantitative measurements. Here we describe contemporary optical imaging techniques with respect to their suitability in the imaging of tissue structure, with a focus on characterization and implementation into subsequent modeling efforts. We outline the applications and limitations of each modality and discuss the overall shortcomings and future directions for optical imaging of soft tissue structure. PMID:27420574

  19. Solution of a Radiative Transfer Problem in a Biological Tissue. An Optical Tomography Model.

    Science.gov (United States)

    Gantri, M.; Trabelsi, H.; Bensalah, R.; Sediki, E.

    2007-09-01

    In this work, we present a solution of the radiative transfer equation in a biological tissue like-medium. This solution is obtained using a finite volume discrete ordinate method. In medical imaging, this could be an optical tomography forward model. We consider a very thin rectangular biological-tissue-like medium submitted to a visible or an infrared light source. The source is assumed to be monochromatic, isotropic and time-independent. Transmitted fluences, in the detector points, are calculated. The model is validated in the case of a homogeneous tissue-like medium. The proposed model is also used to study changes on the transmitted light in multilayer media. We simulate skin, fat and muscle. Next, we study the effect of the wavelength light source on the distribution of the transmitted luminance. This is done by using biological tissue spectral properties reported in literature. This gives some validity conditions for the use of the computed optical tomography as a medical imaging technique.

  20. Recent Progress on Tissue-Resident Adult Stem Cell Biology and Their Therapeutic Implications

    OpenAIRE

    Mimeault, Murielle; Batra, Surinder K.

    2008-01-01

    Recent progress in the field of the stem cell research has given new hopes to treat and even cure diverse degenerative disorders and incurable diseases in human. Particularly, the identification of a rare population of adult stem cells in the most tissues/organs in human has emerged as an attractive source of multipotent stem/progenitor cells for cell replacement-based therapies and tissue engineering in regenerative medicine. The tissue-resident adult stem/progenitor cells offer the possibil...

  1. TEMPORAL EVOLUTION OF SKELETAL REGENERATED TISSUE : WHAT CAN MECHANICAL INVESTIGATION ADD TO BIOLOGICAL?

    OpenAIRE

    Casanova, Remy; Mokoko, Didier; Pithioux, Martine; Pailler-Mattéi, Cyril; Zahouani, Hassan; Chabrand, Patrick

    2010-01-01

    The objective here was to experimentally characterise the temporal evolution of the structural and mechanical properties of large volume immature regenerated tissues. We studied these evolving tissues from their genesis in controlled mechanical conditions. We developed an animal model based on the periosteal properties leading to unloaded regenerated skeletal tissue. To characterize the temporal evolution of mechanical properties, we carried out indentation tests coupled with macroscopic exam...

  2. Predicting tissue-specific expressions based on sequence characteristics

    KAUST Repository

    Paik, Hyojung

    2011-04-30

    In multicellular organisms, including humans, understanding expression specificity at the tissue level is essential for interpreting protein function, such as tissue differentiation. We developed a prediction approach via generated sequence features from overrepresented patterns in housekeeping (HK) and tissue-specific (TS) genes to classify TS expression in humans. Using TS domains and transcriptional factor binding sites (TFBSs), sequence characteristics were used as indices of expressed tissues in a Random Forest algorithm by scoring exclusive patterns considering the biological intuition; TFBSs regulate gene expression, and the domains reflect the functional specificity of a TS gene. Our proposed approach displayed better performance than previous attempts and was validated using computational and experimental methods.

  3. Primary and secondary damage to biological tissue induced by laser radiation

    International Nuclear Information System (INIS)

    A simply analytic model describing the evolution of the thermal injury during and after exposure of biological tissue to pulses of intense laser radiation is presented. Estimates for the upper and lower bounds of the extent of the thermal injury associated with protein and enzyme denaturization (secondary damage) relative to the extent of burned tissue (primary damage) are presented. The energy necessary for burn threshold and the energy required to induce both types of thermal injury increase with laser pulse duration. An optimal duration of laser pulse exists at which the extent of the secondary damage relative to the primary damage is the smallest

  4. Magnetoacoustic imaging of magnetic iron oxide nanoparticles embedded in biological tissues with microsecond magnetic stimulation

    Science.gov (United States)

    Hu, Gang; He, Bin

    2012-01-01

    We present an experimental study on magnetoacoustic imaging of superparamagnetic iron oxide (SPIO) nanoparticles embedded in biological tissues. In experiments, a large-current-carrying coil is used to deliver microsecond pulsed magnetic stimulation to samples. The ultrasound signals induced by magnetic forces on SPIO nanoparticles are measured by a rotating transducer. The distribution of nanoparticles is reconstructed by a back-projection imaging algorithm. The results demonstrated the feasibility to obtain cross-sectional image of magnetic nanoparticle targets with faithful dimensional and positional information, which suggests a promising tool for tomographic reconstruction of magnetic nanoparticle-labeled diseased tissues (e.g., cancerous tumor) in molecular or clinic imaging.

  5. Discrete frequency infrared imaging using quantum cascade lasers for biological tissue analysis

    Science.gov (United States)

    Yeh, Kevin; Bhargava, Rohit

    2016-03-01

    Infrared (IR) spectroscopic imaging is an emerging modality for biological tissue analysis that has traditionally employed an interferometer for spectral discrimination. Recent technology developments have made discrete frequency sources, both lasers and filters, practical for imaging. The use of quantum cascade lasers in particular, presents new opportunities as well as challenges. Here we describe results from a novel point scanning confocal IR microscope and demonstrate the performance imaging several important spectral bands of lung tissue. Results show the possibility of discrete frequency (DF) absorbance measurements with RMS noise levels down to 0.34 mAU in 0.25 ms.

  6. Laser-induced damage in biological tissue: Role of complex and dynamic optical properties of the medium

    Science.gov (United States)

    Ahmed, Elharith M.

    Since its invention in the early 1960's, the laser has been used as a tool for surgical, therapeutic, and diagnostic purposes. To achieve maximum effectiveness with the greatest margin of safety it is important to understand the mechanisms of light propagation through tissue and how that light affects living cells. Lasers with novel output characteristics for medical and military applications are too often implemented prior to proper evaluation with respect to tissue optical properties and human safety. Therefore, advances in computational models that describe light propagation and the cellular responses to laser exposure, without the use of animal models, are of considerable interest. Here, a physics-based laser-tissue interaction model was developed to predict the spatial and temporal temperature and pressure rise during laser exposure to biological tissues. Our new model also takes into account the dynamic nature of tissue optical properties and their impact on the induced temperature and pressure profiles. The laser-induced retinal damage is attributed to the formation of microbubbles formed around melanosomes in the retinal pigment epithelium (RPE) and the damage mechanism is assumed to be photo-thermal. Selective absorption by melanin creates these bubbles that expand and collapse around melanosomes, destroying cell membranes and killing cells. The Finite Element (FE) approach taken provides suitable ground for modeling localized pigment absorption which leads to a non-uniform temperature distribution within pigmented cells following laser pulse exposure. These hot-spots are sources for localized thermo-elastic stresses which lead to rapid localized expansions that manifest themselves as microbubbles and lead to microcavitations. Model predictions for the interaction of lasers at wavelengths of 193, 694, 532, 590, 1314, 1540, 2000, and 2940 nm with biological tissues were generated and comparisons were made with available experimental data for the retina

  7. A Novel Albumin-Based Tissue Scaffold for Autogenic Tissue Engineering Applications

    Science.gov (United States)

    Li, Pei-Shan; -Liang Lee, I.; Yu, Wei-Lin; Sun, Jui-Sheng; Jane, Wann-Neng; Shen, Hsin-Hsin

    2014-07-01

    Tissue scaffolds provide a framework for living tissue regeneration. However, traditional tissue scaffolds are exogenous, composed of metals, ceramics, polymers, and animal tissues, and have a defined biocompatibility and application. This study presents a new method for obtaining a tissue scaffold from blood albumin, the major protein in mammalian blood. Human, bovine, and porcine albumin was polymerised into albumin polymers by microbial transglutaminase and was then cast by freeze-drying-based moulding to form albumin tissue scaffolds. Scanning electron microscopy and material testing analyses revealed that the albumin tissue scaffold possesses an extremely porous structure, moderate mechanical strength, and resilience. Using a culture of human mesenchymal stem cells (MSCs) as a model, we showed that MSCs can be seeded and grown in the albumin tissue scaffold. Furthermore, the albumin tissue scaffold can support the long-term osteogenic differentiation of MSCs. These results show that the albumin tissue scaffold exhibits favourable material properties and good compatibility with cells. We propose that this novel tissue scaffold can satisfy essential needs in tissue engineering as a general-purpose substrate. The use of this scaffold could lead to the development of new methods of artificial fabrication of autogenic tissue substitutes.

  8. Language Based Techniques for Systems Biology

    DEFF Research Database (Denmark)

    Pilegaard, Henrik

    calculi have similarly been used for the study of bio-chemical reactive systems. In this dissertation it is argued that techniques rooted in the theory and practice of programming languages, language based techniques if you will, constitute a strong basis for the investigation of models of biological......Process calculus is the common denominator for a class of compact, idealised, domain-specific formalisms normally associated with the study of reactive concurrent systems within Computer Science. With the rise of the interactioncentred science of Systems Biology a number of bio-inspired process...... systems as formalised in a process calculus. In particular it is argued that Static Program Analysis provides a useful approach to the study of qualitative properties of such models. In support of this claim a number of static program analyses are developed for Regev’s BioAmbients – a bio-inspired variant...

  9. An Approximate Numerical Technique for Characterizing Optical Pulse Propagation in Inhomogeneous Biological Tissue

    Directory of Open Access Journals (Sweden)

    Chintha C. Handapangoda

    2008-01-01

    Full Text Available An approximate numerical technique for modeling optical pulse propagation through weakly scattering biological tissue is developed by solving the photon transport equation in biological tissue that includes varying refractive index and varying scattering/absorption coefficients. The proposed technique involves first tracing the ray paths defined by the refractive index profile of the medium by solving the eikonal equation using a Runge-Kutta integration algorithm. The photon transport equation is solved only along these ray paths, minimizing the overall computational burden of the resulting algorithm. The main advantage of the current algorithm is that it enables to discretise the pulse propagation space adaptively by taking optical depth into account. Therefore, computational efficiency can be increased without compromising the accuracy of the algorithm.

  10. Nonlinear effects of the finite amplitude ultrasound wave in biological tissues

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Nonlinear effects will occur during the transmission of the finite amplitude wave in biological tissues.The theoretical prediction and experimental demonstration of the nonlinear effects on the propagation of the finite amplitude wave at the range of biomedical ultrasound frequency and intensity are studied.Results show that the efficiency factor and effective propagation distance will decrease while the attenuation coefficient increases due to the existence of nonlinear effects.The experimental results coincided quite well with the theory.This shows that the effective propagation distance and efficiency factor can be used to describe quantitatively the influence of nonlinear effects on the propagation of the finite amplitude sound wave in biological tissues.

  11. Deposition rates in growing tissue: Implications for physiology, molecular biology, and response to environmental variation

    OpenAIRE

    Silk, Wendy K.; Bogeat-Triboulot, Marie-Béatrice

    2014-01-01

    Net rates of biosynthesis and mineral deposition are needed to understand the physiology and molecular biology of growth and plant responses to environmental variation. Many popular models ignore cell expansion and displacement. In contrast, the continuity equation, used with empirical data on growth velocity and concentration, allows computation of biosynthesis and deposition rates in growing tissue. This article describes data and methods needed to calculate deposition rates and reviews som...

  12. Preface to Special Topic: Microfluidics in cell biology and tissue engineering

    OpenAIRE

    Dokmeci, Mehmet R.; Khademhosseini, Ali

    2011-01-01

    In this special issue of Biomicrofluidics, a wide variety of applications of microfluidics to tissue engineering and cell biology are presented. The articles illustrate the benefits of using microfluidics for controlling the cellular environment in a precise yet high rate manner using minimum reagents. The topic is very timely and takes a stab at portraying a glimpse of what is to come in this exciting and emerging field of research.

  13. 'TISUCROMA': A Software for Color Processing of Biological Tissue's Images

    International Nuclear Information System (INIS)

    In this work a software intended to plot and analyze digital image RGB histograms from normal and abnormal regions of biological tissue. The obtained RGB histograms from each zone can be used to show the image in only one color or the mixture of some of them. The Software was developed in Lab View to process the images in a laptop. Some medical application examples are shown. (Author)

  14. Role of structural anisotropy of biological tissues in poroelastic wave propagation.

    Science.gov (United States)

    Cardoso, Luis; Cowin, Stephen C

    2012-01-01

    Ultrasound waves have a broad range of clinical applications as a non-destructive testing approach in imaging and in the diagnoses of medical conditions. Generally, biological tissues are modeled as an homogenized equivalent medium with an apparent density through which a single wave propagates. Only the first wave arriving at the ultrasound probe is used for the measurement of the speed of sound. However, the existence of a second wave in tissues such as cancellous bone has been reported and its existence is an unequivocal signature of Biot type poroelastic media. To account for the fact that ultrasound is sensitive to microarchitecture as well as density, a fabric-dependent anisotropic poroelastic ultrasound (PEU) propagation theory was recently developed. Key to this development was the inclusion of the fabric tensor - a quantitative stereological measure of the degree of structural anisotropy of bone - into the linear poroelasticity theory. In the present study, this framework is extended to the propagation of waves in several soft and hard tissues. It was found that collagen fibers in soft tissues and the mineralized matrix in hard tissues are responsible for the anisotropy of the solid tissue constituent through the fabric tensor in the model. PMID:22162897

  15. Can OCT be sensitive to nanoscale structural alterations in biological tissue?

    Science.gov (United States)

    Yi, Ji; Radosevich, Andrew J; Rogers, Jeremy D; Norris, Sam C P; Çapoğlu, İlker R; Taflove, Allen; Backman, Vadim

    2013-04-01

    Exploration of nanoscale tissue structures is crucial in understanding biological processes. Although novel optical microscopy methods have been developed to probe cellular features beyond the diffraction limit, nanometer-scale quantification remains still inaccessible for in situ tissue. Here we demonstrate that, without actually resolving specific geometrical feature, OCT can be sensitive to tissue structural properties at the nanometer length scale. The statistical mass-density distribution in tissue is quantified by its autocorrelation function modeled by the Whittle-Mateŕn functional family. By measuring the wavelength-dependent backscattering coefficient μb(λ) and the scattering coefficient μs, we introduce a technique called inverse spectroscopic OCT (ISOCT) to quantify the mass-density correlation function. We find that the length scale of sensitivity of ISOCT ranges from ~30 to ~450 nm. Although these sub-diffractional length scales are below the spatial resolution of OCT and therefore not resolvable, they are nonetheless detectable. The sub-diffractional sensitivity is validated by 1) numerical simulations; 2) tissue phantom studies; and 3) ex vivo colon tissue measurements cross-validated by scanning electron microscopy (SEM). Finally, the 3D imaging capability of ISOCT is demonstrated with ex vivo rat buccal and human colon samples. PMID:23571994

  16. 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)

  17. Mueller-matrix mapping of optically anisotropic fluorophores of biological tissues in the diagnosis of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ushenko, Yu A; Sidor, M I; Bodnar, G B [Yuriy Fedkovych Chernivtsi National University, Chernivtsi (Ukraine); Koval' , G D [Bukovinian State Medical University, Chernivtsi (Ukraine)

    2014-08-31

    We report the results of studying the polarisation manifestations of laser autofluorescence of optically anisotropic structures in biological tissues. A Mueller-matrix model is proposed to describe their complex anisotropy (linear and circular birefringence, linear and circular dichroism). The relationship is established between the mechanisms of optical anisotropy and polarisation manifestations of laser autofluorescence of histological sections of rectal tissue biopsy in different spectral regions. The ranges of changes in the statistical moments of the 1st-to-4th orders, which describe the distribution of the azimuth-invariant elements of Mueller matrices of rectal tissue autofluorescence, are found. Effectiveness of laser autofluorescence polarimetry is determined and the histological sections of biopsy of benign (polyp) and malignant (adenocarcinoma) tumours of the rectal wall are differentiated for the first time. (laser biophotonics)

  18. Mueller-matrix mapping of optically anisotropic fluorophores of biological tissues in the diagnosis of cancer

    Science.gov (United States)

    Ushenko, Yu A.; Sidor, M. I.; Bodnar, G. B.; Koval', G. D.

    2014-08-01

    We report the results of studying the polarisation manifestations of laser autofluorescence of optically anisotropic structures in biological tissues. A Mueller-matrix model is proposed to describe their complex anisotropy (linear and circular birefringence, linear and circular dichroism). The relationship is established between the mechanisms of optical anisotropy and polarisation manifestations of laser autofluorescence of histological sections of rectal tissue biopsy in different spectral regions. The ranges of changes in the statistical moments of the 1st-to-4th orders, which describe the distribution of the azimuth-invariant elements of Mueller matrices of rectal tissue autofluorescence, are found. Effectiveness of laser autofluorescence polarimetry is determined and the histological sections of biopsy of benign (polyp) and malignant (adenocarcinoma) tumours of the rectal wall are differentiated for the first time.

  19. 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.

  20. Mueller-matrix mapping of optically anisotropic fluorophores of biological tissues in the diagnosis of cancer

    International Nuclear Information System (INIS)

    We report the results of studying the polarisation manifestations of laser autofluorescence of optically anisotropic structures in biological tissues. A Mueller-matrix model is proposed to describe their complex anisotropy (linear and circular birefringence, linear and circular dichroism). The relationship is established between the mechanisms of optical anisotropy and polarisation manifestations of laser autofluorescence of histological sections of rectal tissue biopsy in different spectral regions. The ranges of changes in the statistical moments of the 1st-to-4th orders, which describe the distribution of the azimuth-invariant elements of Mueller matrices of rectal tissue autofluorescence, are found. Effectiveness of laser autofluorescence polarimetry is determined and the histological sections of biopsy of benign (polyp) and malignant (adenocarcinoma) tumours of the rectal wall are differentiated for the first time. (laser biophotonics)

  1. Mueller matrix polarimetry for the characterization of complex random medium like biological tissues

    Indian Academy of Sciences (India)

    Nirmalya Ghosh; Jalpa Soni; M F G Wood; M A Wallenberg; I A Vitkin

    2010-12-01

    The polarization parameters of light scattered from biological tissues contain wealth of morphological and functional information of potential biomedical importance. But, in optically thick turbid media such as tissues, numerous complexities due to multiple scattering and simultaneous occurrences of many polarization events present formidable challenges, in terms of both accurate measurement and unique interpretation of the individual polarimetry characteristics. We have developed and validated an expanded Mueller matrix decomposition approach to overcome this problem. The approach was validated theoretically with a polarization-sensitive Monte Carlo light propagation model and experimentally by recording Mueller matrices from tissue-like complex random medium. In this paper, we discuss our comprehensive turbid polarimetry platform consisting of the experimental polarimetry system, forward Monte Carlo modelling and inverse polar decomposition analysis. Initial biomedical applications of this novel general method for polarimetry analysis in random media are also presented.

  2. Random laser in biological tissues impregnated with a fluorescent anticancer drug

    Science.gov (United States)

    Lahoz, F.; Martín, I. R.; Urgellés, M.; Marrero-Alonso, J.; Marín, R.; Saavedra, C. J.; Boto, A.; Díaz, M.

    2015-04-01

    We have demonstrated that chemically modified anticancer drugs can provide random laser (RL) when infiltrated in a biological tissue. A fluorescent biomarker has been covalently bound to tamoxifen, which is one of the most frequently used drugs for breast cancer therapy. The light emitted by the drug-dye composite is scattered in tissue, which acts as a gain medium. Both non-coherent and coherent RL regimes have been observed. Moreover, the analysis of power Fourier transforms of coherent RL spectra indicates that the tissues show a dominant random laser cavity length of about 18 µm, similar to the average size of single cells. These results show that RL could be obtained from other drugs, if properly marked with a fluorescent tag, which could be appealing for new forms of combined opto-chemical therapies.

  3. Reactive DESI-MS imaging of biological tissues with dicationic ion-pairing compounds.

    Science.gov (United States)

    Lostun, Dragos; Perez, Consuelo J; Licence, Peter; Barrett, David A; Ifa, Demian R

    2015-03-17

    This work illustrates reactive desorption electrospray ionization mass spectrometry (DESI-MS) with a stable dication on biological tissues. Rat brain and zebra fish tissues were investigated with reactive DESI-MS in which the dictation forms a stable bond with biological tissue fatty acids and lipids. Tandem mass spectrometry (MS/MS) was used to characterize the dication (DC9) and to identify linked lipid-dication compounds formed. The fragment m/z 85 common to both DC9 fragmentation and DC9-lipid fragmentation was used to confirm that DC9 is indeed bonded with the lipids. Lipid signals in the range of m/z 250-350 and phosphoethanolamines (PE) m/z 700-800 observed in negative ion mode were also detected in positive ion mode with reactive DESI-MS with enhanced signal intensity. Reactive DESI-MS imaging in positive ion mode of rat brain and zebra fish tissues allowed enhanced detection of compounds commonly observed in the negative ion mode. PMID:25710577

  4. Quantification of titanium from TiO2 particles in biological tissue.

    Science.gov (United States)

    Faucher, Stéphane; Lespes, Gaëtane

    2015-10-01

    This study presents the development of a strategy for the quantification of titanium from titanium dioxide polydisperse particles (TiO2) in dry biological tissue. Calf liver was chosen as laboratory testing material. The challenge was to (i) obtain a complete mineralization of the solid material (biological tissue and TiO2) and (ii) ensure the accuracy of the determined concentrations with a sufficient sensitivity. Mineralization was performed using a mixture of concentrated nitric and hydrofluoric acids. Atomic mass spectrometry associated with light-scattering technique was used to control the physical state (dissolved and particle forms) of titanium and reliably estimate the total titanium concentration in calf liver. The monitoring of (46)Ti and (49)Ti, operating in helium collision/reaction cell mode, and using external calibration with internal standard addition, allowed the quantification of Ti while removing isobaric interferences. The limit of detection and quantification were 0.7 and 2.3μg (Ti)g(-1) (tissue) respectively. The mean analytical recovery over the whole procedure was (103±6)% in a range of concentrations from LOD to 200μg(Ti)g(-1) (tissue). PMID:26302910

  5. Mapping the functional properties of soft biological tissues under shear loading

    Science.gov (United States)

    Buckley, Mark Raymond

    The structure and composition of articular cartilage and other load-bearing biological tissues are highly complex and heterogeneous. As a result, their functional mechanical properties exhibit clear spatial variations. Unlocking the structure-function relationship in these materials is critical for devising strategies to restore tissue impaired by injury or disease and can provide a template for successful implant design. Here, we describe a tissue deformation imaging stage (TDIS) allowing for simultaneous force measurement and visualization of microscale deformation in soft biological tissues under controlled shear strain. In combination with a fast confocal microscope, the TDIS is used to test the microscale response of articular cartilage to shear loading. To obtain the location-specific shear modulus of this tissue, we employ a high-resolution technique that involves tracking the deformation of a line photobleached into a fluorescently stained sample loaded in the TDIS. We find that the quasi-static and dynamic shear moduli are lowest roughly 100 mum below the articular surface. Here, articular cartilage is highly nonlinear, stiffening under increased shear strain and becoming more compliant under increased compressive strain. Using a simple thought model, we relate these results to structural features of the collagen network in articular cartilage. Furthermore, we demonstrate that the region of maximum compliance is also the primary site of shear energy dissipation in articular cartilage. Our findings suggest that damage to or surgical removal of the surface of this tissue will increase the joint's susceptibility to shear-induced damage. Finally, similar experiments are performed on intervertebral disc and growth plate, demonstrating the versatility of our in-situ strain mapping techniques.

  6. Internal dosimetry for alpha emitters radiopharmaceuticals in biological tissue studied with the FLUKA code 10

    International Nuclear Information System (INIS)

    Clinical practices for neoplastic disease diagnose and treatment are based on the incorporation of α, β and γ radiotracers and radiopharmaceuticals, which might be associated with potential damage. Thus, being necessary accurate dosimetry strategies. In vivo absorbed dose appears as an ideal solution. However, its implementation in clinics does not attain enough reliability. On the other hand, different approaches were proposed for internal dosimetry calculations. Some special analytical methodologies were developed by the Committee on Medical Internal Radiation Dose (MIRD) to assess organ level dose values in nuclear medicine. Improvements in informatics achieve better computation performance, but Monte Carlo approaches for patient-specific dosimetry are sometimes high time-consuming l imitating its use in routine clinical practices. Analytical approaches introduce kernel convolution techniques aimed to patient spe ci dosimetry. Although scattering effects are not accurately handled, these methods are capable of fast dosimetry computation based on photon Energy Deposition Kernel (EDK and particle Dose Point Kernel (DPK) assessed for radionuclides in order to perform further dosimetry calculations. EDK and DPK are obtained according to specific source emission. It was considered a point source isotropically emitting within an homogeneous medium, so that radiation transport is accounted as uniformly distributed over concentric spherical regions by shell tally. Dedicated Monte Carlo simulations were performed by a subroutine adapted from the FLUKA co se. In water EDK were evaluated at different photon energies and some typical γ-emitters radiopharmaceuticals; whereas DPK were obtained for both α and β emitters. Additionally, EDK and DPK were calculated for several biological tissues. Obtained results agree with energy loss from stopping power calculated by Bethe-Bark as- Bloch theory in the continuous slowing down approximation

  7. Activity Based Profiling of Deubiquitylating Enzymes and Inhibitors in Animal Tissues.

    Science.gov (United States)

    McLellan, Lauren; Forder, Cassie; Cranston, Aaron; Harrigan, Jeanine; Jacq, Xavier

    2016-01-01

    The attachment of ubiquitin or ubiquitin-like modifiers to proteins is an important signal for the regulation of a variety of biological processes including the targeting of substrates for degradation, receptor internalization, regulation of gene expression, and DNA repair. Posttranslational modification of proteins by ubiquitin controls many cellular processes, and aberrant ubiquitylation can contribute to cancer, immunopathologies, and neurodegeneration. Thus, deubiquitylating enzymes (DUBs) that remove ubiquitin from proteins have become attractive therapeutic targets. Monitoring the activity of DUBs in cells or in tissues is critical for understanding the biological function of DUBs in particular pathways and is essential for determining the physiological specificity and potency of small-molecule DUB inhibitors. Here, we describe a method for the homogenization of animal tissues and incubation of tissue lysates with ubiquitin-based activity probes to monitor DUB activity in mouse tissues and target engagement following treatment of animals with small-molecule DUB inhibitors. PMID:27613053

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

    International Nuclear Information System (INIS)

    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

  9. Glycogen-based materials for tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Rabyk, Mariia; Hrubý, Martin; Vetrík, Miroslav; Kučka, Jan; Pospíšilová, Aneta; Štěpánek, Petr

    Prague : Institute of Macromolecular Chemistry AS CR, 2013. P8. ISBN 978-80-85009-76-7. [Workshop "Career in Polymers" /5./. 12.07.2013-13.07.2013, Prague] R&D Projects: GA ČR GA202/09/2078 Institutional support: RVO:61389013 Keywords : nanoparticles * tissue engineering Subject RIV: BO - Biophysics

  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. EUD-based biological optimization for carbon ion therapy

    International Nuclear Information System (INIS)

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  12. EUD-based biological optimization for carbon ion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brüningk, Sarah C., E-mail: sarah.brueningk@icr.ac.uk; Kamp, Florian; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, München 81675, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, Garching 85748 (Germany)

    2015-11-15

    Purpose: Treatment planning for carbon ion therapy requires an accurate modeling of the biological response of each tissue to estimate the clinical outcome of a treatment. The relative biological effectiveness (RBE) accounts for this biological response on a cellular level but does not refer to the actual impact on the organ as a whole. For photon therapy, the concept of equivalent uniform dose (EUD) represents a simple model to take the organ response into account, yet so far no formulation of EUD has been reported that is suitable to carbon ion therapy. The authors introduce the concept of an equivalent uniform effect (EUE) that is directly applicable to both ion and photon therapies and exemplarily implemented it as a basis for biological treatment plan optimization for carbon ion therapy. Methods: In addition to a classical EUD concept, which calculates a generalized mean over the RBE-weighted dose distribution, the authors propose the EUE to simplify the optimization process of carbon ion therapy plans. The EUE is defined as the biologically equivalent uniform effect that yields the same probability of injury as the inhomogeneous effect distribution in an organ. Its mathematical formulation is based on the generalized mean effect using an effect-volume parameter to account for different organ architectures and is thus independent of a reference radiation. For both EUD concepts, quadratic and logistic objective functions are implemented into a research treatment planning system. A flexible implementation allows choosing for each structure between biological effect constraints per voxel and EUD constraints per structure. Exemplary treatment plans are calculated for a head-and-neck patient for multiple combinations of objective functions and optimization parameters. Results: Treatment plans optimized using an EUE-based objective function were comparable to those optimized with an RBE-weighted EUD-based approach. In agreement with previous results from photon

  13. PIXE characterization of tissues surrounding metallic prostheses coated with biological glasses

    Energy Technology Data Exchange (ETDEWEB)

    Barbotteau, Y. E-mail: yves.barbotteau@qse.tohoku.ac.jp; Irigaray, J.L.; Moretto, Ph

    2004-01-01

    Biological glasses can be used as coatings for metallic prostheses in order to prevent corrosion. According to their composition, these glasses have different properties. We studied, in vivo, two glasses referred to as BVA and BVH. They are used as coatings of Ti6Al4V metallic implant. BVA glass disappears after 3 months of implantation and is replaced by bone. Prostheses initially coated by this glass have a larger osseous contact perimeter compared to the uncoated prostheses. This ensures a better anchoring of the implant and limits the micro-motions which cause wear debris. BVH glass keeps a constant composition during implantation and it is used like a layer which isolates metal implant from biological environment. In order to characterize the bony environment surrounding implants, we have used PIXE and RBS methods. This paper shows results of the behavior of bony tissue under micro-beam, the quality tests of new bone which replaces the BVA glass coating and the evaluation of corrosion effects. Titanium release in bony tissues begins when the metal surface of the prosthesis is exposed to biological fluids. After a few months of implantation, the titanium contamination is stabilized and remains localized within the first tens of micrometers of surrounding bone.

  14. PIXE characterization of tissues surrounding metallic prostheses coated with biological glasses

    International Nuclear Information System (INIS)

    Biological glasses can be used as coatings for metallic prostheses in order to prevent corrosion. According to their composition, these glasses have different properties. We studied, in vivo, two glasses referred to as BVA and BVH. They are used as coatings of Ti6Al4V metallic implant. BVA glass disappears after 3 months of implantation and is replaced by bone. Prostheses initially coated by this glass have a larger osseous contact perimeter compared to the uncoated prostheses. This ensures a better anchoring of the implant and limits the micro-motions which cause wear debris. BVH glass keeps a constant composition during implantation and it is used like a layer which isolates metal implant from biological environment. In order to characterize the bony environment surrounding implants, we have used PIXE and RBS methods. This paper shows results of the behavior of bony tissue under micro-beam, the quality tests of new bone which replaces the BVA glass coating and the evaluation of corrosion effects. Titanium release in bony tissues begins when the metal surface of the prosthesis is exposed to biological fluids. After a few months of implantation, the titanium contamination is stabilized and remains localized within the first tens of micrometers of surrounding bone

  15. Cadmium contamination of tissues and organs of delphinids species (Stenella attenuata)--influence of biological and ecological factors

    Energy Technology Data Exchange (ETDEWEB)

    Andre, J.M.; Amiard, J.C.; Amiard-Triquet, C.; Boudou, A.; Ribeyre, F. (Universite de Bordeaux I, (France))

    1990-12-01

    Based on a sample of 27 dolphins (Stenella attenuata) captured in the Eastern tropical zone of the Pacific Ocean, this study was carried out to analyze the cadmium accumulation levels and distribution in 12 organs or tissue samples. The average cadmium concentrations were between 0.2 mg Cd.kg-1 in the brain and muscle and 48 mg Cd.kg-1 in the kidneys. For most of organs and tissues the average values were between 1 and 5 mg Cd.kg-1. Kidneys, liver, muscle, and intestine contained almost 85% of the total cadmium burden of all tissues considered in this study. Most of the biological and ecological factors taken into account (age, sex, total weight, and length of the dolphins, weight of the organs, place and date of capture) interacted with the cadmium concentrations and burdens in the collected organs or tissues. Three factors appear to be of prime importance: age, body weight, and geographical location of the area of capture.

  16. Cadmium contamination of tissues and organs of delphinids species (Stenella attenuata)--influence of biological and ecological factors.

    Science.gov (United States)

    André, J M; Amiard, J C; Amiard-Triquet, C; Boudou, A; Ribeyre, F

    1990-12-01

    Based on a sample of 27 dolphins (Stenella attenuata) captured in the Eastern tropical zone of the Pacific Ocean, this study was carried out to analyze the cadmium accumulation levels and distribution in 12 organs or tissue samples. The average cadmium concentrations were between 0.2 mg Cd.kg-1 in the brain and muscle and 48 mg Cd.kg-1 in the kidneys. For most of organs and tissues the average values were between 1 and 5 mg Cd.kg-1. Kidneys, liver, muscle, and intestine contained almost 85% of the total cadmium burden of all tissues considered in this study. Most of the biological and ecological factors taken into account (age, sex, total weight, and length of the dolphins, weight of the organs, place and date of capture) interacted with the cadmium concentrations and burdens in the collected organs or tissues. Three factors appear to be of prime importance: age, body weight, and geographical location of the area of capture. PMID:2090444

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

    Science.gov (United States)

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

    2013-03-01

    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

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

    International Nuclear Information System (INIS)

    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

  19. RELATIONSHIP AMONG COX-2 PROTEIN EXPRESSION, PGs LEVELS AND BIOLOGIC BEHAVIOR IN OVARIAN CARCINOMA TISSUES

    Institute of Scientific and Technical Information of China (English)

    王敏; 王欣彦; 唐丽霞; 高岩

    2004-01-01

    Objective: To study the relationship among cyclooxygenase-2 (COX-2) protein expression, prostaglandins levels and biologic behavior in ovarian carcinoma tissues. Methods: The expression of COX-2 protein, levels of prostaglandin (PG)E2, 6-keto-PGF1( and thromboxane (TX)B2 in 54 biopsy specimens from patients with ovarian serous tumors which included three groups: 33 samples of ovarian serous carcinoma; 10 samples of borderline ovarian serous tumors and 11 samples of benign ovarian serous tumors and 10 samples of normal ovarian tissues were detected by Western blot analysis and radioimmunoassay to investigate their clinical significance. Results: The expression of COX-2 protein (82%, 27/33) and its relative content (20.08±3.53) in ovarian serous carcinoma tissues were statistically higher than those in benign ovarian serous tumor tissues and normal ovary tissues i.e., 0 and (15.04(0.12), 0 and (15.33(0.60) (P0.05). The levels of PGE2, 6-keto-PGF1( and TXB2 showed no significant differences in ovarian carcinoma tissues with different clinical stages (I to II and III to IV), different histological grades, with or without ascites and lymph metastasis. COX-2 expression was correlated with the levels of PGE2, 6-KETO-PGF1( and TXB2 (P<0.01). Conclusion: Our data suggest that COX-2 overexpression leads to increased PGE2, 6-KETA-PGF1( and TXB2 biosynthesis, which may be mechanisms underlying the contribution of COX-2 to the development of ovarian serous carcinoma. BGF2, 6-keto-PGF1( and TXB2 may be helpful parameters of diagnosis and differentiate diagnosis in ovarian serous carcinoma.

  20. Frequency doubling and tripling of ultrashort laser pulses in biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L. B.; Eichler, J.; Joslin, E. J.; Kim, B.-M.

    1998-07-24

    Structural proteins such as collagen and elastin are known to generate second harmonic at high laser intensities. Second and third harmonic generations (SHG, THG) of 0.4 ps Ti-Sapphire laser radiation at 800 nm were observed in various biological tissues. Dependence of SHG on laser pulse energy and pulse width was investigated. Reflected second harmonic yield was measured for animal tissue in vitro and human skin in vivo. The yield varies about a factor of 20 for various areas of the skin while the scattered laser radiation (diffuse reflectance) varies only by a factor of 2. In some cases the THG efficiency was comparable to the SHG. Possible applications of higher harmonic radiation for diagnostics and microscopy are discussed.

  1. Sex differences in human adipose tissues – the biology of pear shape

    Directory of Open Access Journals (Sweden)

    Karastergiou Kalypso

    2012-05-01

    Full Text Available Abstract Women have more body fat than men, but in contrast to the deleterious metabolic consequences of the central obesity typical of men, the pear-shaped body fat distribution of many women is associated with lower cardiometabolic risk. To understand the mechanisms regulating adiposity and adipose tissue distribution in men and women, significant research attention has focused on comparing adipocyte morphological and metabolic properties, as well as the capacity of preadipocytes derived from different depots for proliferation and differentiation. Available evidence points to possible intrinsic, cell autonomous differences in preadipocytes and adipocytes, as well as modulatory roles for sex steroids, the microenvironment within each adipose tissue, and developmental factors. Gluteal-femoral adipose tissues of women may simply provide a safe lipid reservoir for excess energy, or they may directly regulate systemic metabolism via release of metabolic products or adipokines. We provide a brief overview of the relationship of fat distribution to metabolic health in men and women, and then focus on mechanisms underlying sex differences in adipose tissue biology.

  2. Analyzing Biological Performance of 3D-Printed, Cell-Impregnated Hybrid Constructs for Cartilage Tissue Engineering.

    Science.gov (United States)

    Izadifar, Zohreh; Chang, Tuanjie; Kulyk, William; Chen, Xiongbiao; Eames, B Frank

    2016-03-01

    Three-dimensional (3D) bioprinting of hybrid constructs is a promising biofabrication method for cartilage tissue engineering because a synthetic polymer framework and cell-impregnated hydrogel provide structural and biological features of cartilage, respectively. During bioprinting, impregnated cells may be subjected to high temperatures (caused by the adjacent melted polymer) and process-induced mechanical forces, potentially compromising cell function. This study addresses these biofabrication issues, evaluating the heat distribution of printed polycaprolactone (PCL) strands and the rheological property and structural stability of alginate hydrogels at various temperatures and concentrations. The biocompatibility of parameters from these studies was tested by culturing 3D hybrid constructs bioprinted with primary cells from embryonic chick cartilage. During initial two-dimensional culture expansion of these primary cells, two morphologically and molecularly distinct cell populations ("rounded" and "fibroblastic") were isolated. The biological performance of each population was evaluated in 3D hybrid constructs separately. The cell viability, proliferation, and cartilage differentiation were observed at high levels in hybrid constructs of both cell populations, confirming the validity of these 3D bioprinting parameters for effective cartilage tissue engineering. Statistically significant performance variations were observed, however, between the rounded and fibroblastic cell populations. Molecular and morphological data support the notion that such performance differences may be attributed to the relative differentiation state of rounded versus fibroblastic cells (i.e., differentiated chondrocytes vs. chondroprogenitors, respectively), which is a relevant issue for cell-based tissue engineering strategies. Taken together, our study demonstrates that bioprinting 3D hybrid constructs of PCL and cell-impregnated alginate hydrogel is a promising approach for

  3. On The Construction of Models for Electrical Conduction in Biological Tissues

    International Nuclear Information System (INIS)

    Applying RC circuit theory, a theoretical representation for the electrical conduction in a biological multilayer system was developed. In particular an equivalent circuit for the epidermis, dermis and the subcutaneous tissue was constructed. This model includes an equivalent circuit, inside the dermis, in order to model a small formation like tumor. This work shows the feasibility to apply superficial electrodes to detect subcutaneous abnormalities. The behavior of the model is shown in the form of a frequency response chart. The Bode and Nyquist plots are also obtained. This theoretical frame is proposed to be a general treatment to describe the bioelectrical transport in a three layer bioelectrical system.

  4. 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.

  5. Image standards in Tissue-Based Diagnosis (Diagnostic Surgical Pathology

    Directory of Open Access Journals (Sweden)

    Vollmer Ekkehard

    2008-04-01

    Full Text Available Abstract Background Progress in automated image analysis, virtual microscopy, hospital information systems, and interdisciplinary data exchange require image standards to be applied in tissue-based diagnosis. Aims To describe the theoretical background, practical experiences and comparable solutions in other medical fields to promote image standards applicable for diagnostic pathology. Theory and experiences Images used in tissue-based diagnosis present with pathology – specific characteristics. It seems appropriate to discuss their characteristics and potential standardization in relation to the levels of hierarchy in which they appear. All levels can be divided into legal, medical, and technological properties. Standards applied to the first level include regulations or aims to be fulfilled. In legal properties, they have to regulate features of privacy, image documentation, transmission, and presentation; in medical properties, features of disease – image combination, human – diagnostics, automated information extraction, archive retrieval and access; and in technological properties features of image acquisition, display, formats, transfer speed, safety, and system dynamics. The next lower second level has to implement the prescriptions of the upper one, i.e. describe how they are implemented. Legal aspects should demand secure encryption for privacy of all patient related data, image archives that include all images used for diagnostics for a period of 10 years at minimum, accurate annotations of dates and viewing, and precise hardware and software information. Medical aspects should demand standardized patients' files such as DICOM 3 or HL 7 including history and previous examinations, information of image display hardware and software, of image resolution and fields of view, of relation between sizes of biological objects and image sizes, and of access to archives and retrieval. Technological aspects should deal with image

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

    International Nuclear Information System (INIS)

    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

  7. Miniaturized droplets-based microarray of chemical and biological high-throughput tests

    OpenAIRE

    Neto, Ana I.; Correia, Clara R.; Custódio, Catarina A.; Mano, J.F

    2013-01-01

    Publicado em "Journal of Tissue Engineering and Regenerative Medicine, vol. 7, supp. 1 (2013) The development of high-throughput and combinatorial technologies is helping to speed up research that is applicable in many areas of chemistry, engineering and biology. We propose a simple, versatile high-efficient and new superhydrophobic platform, which permits to arrange of quasi-spherical aqueous-based droplets with the capability to support and monitor a series of chemical/biolog...

  8. Cell-Based Strategies for Meniscus Tissue Engineering

    OpenAIRE

    Wei Niu; Weimin Guo; Shufeng Han; Yun Zhu; Shuyun Liu; Quanyi Guo

    2016-01-01

    Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a ...

  9. Planar biaxial testing of soft biological tissue using rakes: A critical analysis of protocol and fitting process.

    Science.gov (United States)

    Fehervary, Heleen; Smoljkić, Marija; Vander Sloten, Jos; Famaey, Nele

    2016-08-01

    Mechanical characterization of soft biological tissue is becoming more and more prevalent. Despite the growing use of planar biaxial testing for soft tissue characterization, testing conditions and subsequent data analysis have not been standardized and vary widely. This also influences the quality of the result of the parameter fitting. Moreover, the testing conditions and data analysis are often not or incompletely reported, which impedes the proper comparison of parameters obtained from different studies. With a focus on planar biaxial tests using rakes, this paper investigates varying testing conditions and varying data analysis methods and their effect on the quality of the parameter fitting results. By means of a series of finite element simulations, aspects such as number of rakes, rakes׳ width, loading protocol, constitutive model, material stiffness and anisotropy are evaluated based on the degree of homogeneity of the stress field, and on the correlation between the experimentally obtained stress and the stress derived from the constitutive model. When calculating the aforementioned stresses, different definitions of the section width and deformation gradient are used in literature, each of which are looked into. Apart from this degree of homogeneity and correlation, also the effect on the quality of the parameter fitting result is evaluated. The results show that inhomogeneities can be reduced to a minimum for wise choices of testing conditions and analysis methods, but never completely eliminated. Therefore, a new parameter optimization procedure is proposed that corrects for the inhomogeneities in the stress field and induces significant improvements to the fitting results. Recommendations are made for best practice in rake-based planar biaxial testing of soft biological tissues and subsequent parameter fitting, and guidelines are formulated for reporting thereof in publications. PMID:26854936

  10. Analysis of biological tissues in infant chest for the development of an equivalent radiographic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Pina, D. R.; Souza, Rafael T. F.; Duarte, Sergio B.; Alvarez, Matheus; Miranda, Jose R. A. [Faculdade de Medicina de Botucatu, Departamento de Doencas Tropicais e Diagnostico por Imagem, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Centro Brasileiro de Pesquisas Fisicas-CBPF/MCT, Rio de Janeiro 22290-180 (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil); Instituto de Biociencias de Botucatu, Departamento de Fisica e Biofisica, Universidade Estadual Paulista-UNESP, Distrito de Rubiao Junior S/N, Botucatu, 18618-000 Sao Paulo (Brazil)

    2012-03-15

    Purpose: The main purpose of the present study was to determine the amounts of different tissues in the chest of the newborn patient (age {<=}1 year), with the aim of developing a homogeneous phantom chest equivalent. This type of phantom is indispensable in the development of optimization procedures for radiographic techniques, including dosimetric control, which is a crucial aspect of pediatric radiology. The authors present a systematic set of procedures, including a computational algorithm, to estimate the amounts of tissues and thicknesses of the corresponding simulator material plates used to construct the phantom. Methods: The Gaussian fit of computed tomographic (CT) analysis was applied to classify and quantify different biological tissues. The methodology is summarized with a computational algorithm, which was used to quantify tissues through automated CT analysis. The thicknesses of the equivalent homogeneous simulator material plates were determined to construct the phantom. Results: A total of 180 retrospective CT examinations with anterior-posterior diameter values ranging 8.5-13.0 cm were examined. The amounts of different tissues were evaluated. The results provided elements to construct a phantom to simulate the infant chest in the posterior-anterior or anterior-posterior (PA/AP) view. Conclusions: To our knowledge, this report represents the first demonstration of an infant chest phantom dedicated to the radiology of children younger than one year. This phantom is a key element in the development of clinical charts for optimizing radiographic technique in pediatric patients. Optimization procedures for nonstandard patients were reported previously [Pina et al., Phys. Med. Biol. 49, N215-N226 (2004) and Pina et al., Appl. Radiat. Isot. 67, 61-69 (2009)]. The constructed phantom represents a starting point to obtain radiologic protocols for the infant patient.

  11. Analysis of biological tissues in infant chest for the development of an equivalent radiographic phantom

    International Nuclear Information System (INIS)

    Purpose: The main purpose of the present study was to determine the amounts of different tissues in the chest of the newborn patient (age ≤1 year), with the aim of developing a homogeneous phantom chest equivalent. This type of phantom is indispensable in the development of optimization procedures for radiographic techniques, including dosimetric control, which is a crucial aspect of pediatric radiology. The authors present a systematic set of procedures, including a computational algorithm, to estimate the amounts of tissues and thicknesses of the corresponding simulator material plates used to construct the phantom. Methods: The Gaussian fit of computed tomographic (CT) analysis was applied to classify and quantify different biological tissues. The methodology is summarized with a computational algorithm, which was used to quantify tissues through automated CT analysis. The thicknesses of the equivalent homogeneous simulator material plates were determined to construct the phantom. Results: A total of 180 retrospective CT examinations with anterior-posterior diameter values ranging 8.5-13.0 cm were examined. The amounts of different tissues were evaluated. The results provided elements to construct a phantom to simulate the infant chest in the posterior-anterior or anterior-posterior (PA/AP) view. Conclusions: To our knowledge, this report represents the first demonstration of an infant chest phantom dedicated to the radiology of children younger than one year. This phantom is a key element in the development of clinical charts for optimizing radiographic technique in pediatric patients. Optimization procedures for nonstandard patients were reported previously [Pina et al., Phys. Med. Biol. 49, N215-N226 (2004) and Pina et al., Appl. Radiat. Isot. 67, 61-69 (2009)]. The constructed phantom represents a starting point to obtain radiologic protocols for the infant patient.

  12. Biological Tissue Imaging with a Position and Time Sensitive Pixelated Detector

    CERN Document Server

    Jungmann, Julia H; MacAleese, Luke; Klinkert, Ivo; Visser, Jan; Heeren, Ron M A

    2013-01-01

    We demonstrate the capabilities of a highly parallel, active pixel detector for large-area, mass spectrometric imaging of biological tissue sections. A bare Timepix assembly (512x512 pixels) is combined with chevron microchannel plates on an ion microscope matrix-assisted laser desorption time-of-flight mass spectrometer (MALDI TOF-MS). The detector assembly registers position- and time-resolved images of multiple m/z species in every measurement frame. We prove the applicability of the detection system to bio-molecular mass spectrometry imaging on biologically relevant samples by mass-resolved images from Timepix measurements of a peptide-grid benchmark sample and mouse testis tissue slices. Mass-spectral and localization information of analytes at physiological concentrations are measured in MALDI-TOF-MS imaging experiments. We show a high spatial resolution (pixel size down to 740x740 nm2 on the sample surface) and a spatial resolving power of 6 {\\mu}m with a microscope mode laser field of view of 100-335 ...

  13. A DIC Based Technique to Measure the Contraction of a Skeletal Muscle Engineered Tissue

    Science.gov (United States)

    Carosio, Silvia; Faraldi, Martina; Pisu, Simona; Musarò, Antonio; Del Prete, Zaccaria

    2016-01-01

    Tissue engineering is a multidisciplinary science based on the application of engineering approaches to biologic tissue formation. Engineered tissue internal organization represents a key aspect to increase biofunctionality before transplant and, as regarding skeletal muscles, the potential of generating contractile forces is dependent on the internal fiber organization and is reflected by some macroscopic parameters, such as the spontaneous contraction. Here we propose the application of digital image correlation (DIC) as an independent tool for an accurate and noninvasive measurement of engineered muscle tissue spontaneous contraction. To validate the proposed technique we referred to the X-MET, a promising 3-dimensional model of skeletal muscle. The images acquired through a high speed camera were correlated with a custom-made algorithm and the longitudinal strain predictions were employed for measuring the spontaneous contraction. The spontaneous contraction reference values were obtained by studying the force response. The relative error between the spontaneous contraction frequencies computed in both ways was always lower than 0.15%. In conclusion, the use of a DIC based system allows for an accurate and noninvasive measurement of biological tissues' spontaneous contraction, in addition to the measurement of tissue strain field on any desired region of interest during electrical stimulation. PMID:27034612

  14. 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.

  15. Powder-based 3D printing for bone tissue engineering.

    Science.gov (United States)

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed. PMID:27086202

  16. Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

    CERN Document Server

    Sultana, Naznin

    2013-01-01

    This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

  17. Adipose tissue-organotypic culture system as a promising model for studying adipose tissue biology and regeneration

    OpenAIRE

    Toda, Shuji; Uchihashi, Kazuyoshi; Aoki, Shigehisa; Sonoda, Emiko; Yamasaki, Fumio; Piao, Meihua; Ootani, Akifumi; Yonemitsu, Nobuhisa; Sugihara, Hajime

    2009-01-01

    Adipose tissue consists of mature adipocytes, preadipocytes and mesenchymal stem cells (MSCs), but a culture system for analyzing their cell types within the tissue has not been established. We have recently developed “adipose tissue-organotypic culture system” that maintains unilocular structure, proliferative ability and functions of mature adipocytes for a long term, using three-dimensional collagen gel culture of the tissue fragments. In this system, both preadipocytes and MSCs regenerate...

  18. Network-Based Models in Molecular Biology

    Science.gov (United States)

    Beyer, Andreas

    Biological systems are characterized by a large number of diverse interactions. Interaction maps have been used to abstract those interactions at all biological scales ranging from food webs at the ecosystem level down to protein interaction networks at the molecular scale.

  19. Relationship between biologic tissue heterogeneity and absorbed dose distribution in therapy of oncologic patients with cyclotron U-120 fast neutrons

    International Nuclear Information System (INIS)

    Effect of biological tissue heterogeneity on the absorbed dose distribution of U-120 cyclotron fast neutron beam was studied by estimation and experimental method. It was found that adipose and bone tissues significantly changes the pattern of neutron absorbed dose distribution in patient body. Absorbed dose in adipose layer increase by 20% as compared to the dose in soft biological tissue. Approximation method for estimation of the absorbed dose distribution of fast neutrons in heterogeneities was proposed which could be applied in the dosimetric planning of U-120 cyclotron neutron therapy of neoplasms

  20. Data analysis in Raman measurements of biological tissues using wavelet techniques

    Science.gov (United States)

    Gaeta, Giovanni M.; Zenone, Flora; Camerlingo, Carlo; Riccio, Roberto; Moro, Gianfranco; Lepore, Maria; Indovina, Pietro L.

    2005-03-01

    Raman spectroscopy of oral tissues is a promising tool for in vivo diagnosis of oral pathologies, due to the high chemical and structural information content of Raman spectra. However, measurements on biological tissues are usually hindered by low level signals and by the presence of interfering noise and background components due to light diffusion or fluorescence processes. Numerical methods can be used in data analysis, in order to overcome these problems. In this work the wavelet multicomponent decomposition approach has been tested in a series of micro-Raman measurements performed on "in vitro" animal tissue samples. The experimental set-up was mainly composed by a He-Ne laser and a monochromator equipped with a liquid nitrogen cooled CCD equipped with a grating of 1800 grooves/mm. The laser light was focused on the sample surface by means of a 50 X optical objective. The resulting spectra were analysed using a wavelet software package and the contribution of different vibration modes have been singled out. In particular, the C=C stretching mode, and the CH2 bending mode of amide I and amide III and tyrosine contributions were present. The validity of wavelet approach in the data treatment has been also successfully tested on aspirin.

  1. Effect of lipopolysaccharide on the biological characteristics of human skin fibroblasts and hypertrophic scar tissue formation.

    Science.gov (United States)

    Yang, Hongming; Hu, Chao; Li, Fengyu; Liang, Liming; Liu, Lingying

    2013-06-01

    Burn injury-mediated destruction of the skin barrier normally induces microbial invasion, in turn leading to the development of systemic infection and occasional septic shock by the release of endotoxins. The objective of this work was to study the influence of lipopolysaccharide (LPS) on the biological characteristics of normal skin fibroblasts and to elucidate the influence of LPS in the initial stage of skin wound healing. Twenty patients with hypertrophic scar in proliferative stage were selected randomly and primary cultures were established from fibroblasts derived from their hypertrophic scar tissue and normal skin. Normal skin fibroblasts of passage 3 were stimulated with different concentrations of LPS. LPS stimulated the proliferation and collagen synthesis of fibroblasts within a certain extent of concentrations (0.005-0.5 μg/mL) (P effect on normal skin fibroblasts-continuous passage of these fibroblasts resulted in ultrastructural pattern similar to fibroblasts derived from hypertrophic scar tissue, and the findings was substantiated by hematoxylin and eosin staining and immunohistochemistry detection of proliferation cell nuclear antigen, type I procollagen and α-smooth muscle actin. Our results suggest that LPS might convert normal skin fibroblasts to hypertrophic scar tissue fibroblasts and participate in the formation of hypertrophic scar; hence, appropriate concentration of LPS may have no effect or be beneficial to skin wound healing, whereas excessive concentration of LPS may delay the time of wound healing. PMID:23653386

  2. Tumour visualisation in human soft tissue using grating-based X-ray phase contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Herzen, Julia; Willner, Marian; Schleede, Simone; Bech, Martin; Tapfer, Arne; Stockmar, Marco; Achterhold, Klaus; Pfeiffer, Franz [Department of Physics (E17) and Institute of Medical Engineering (IMETUM), Technische Universitaet Muenchen (Germany)

    2011-07-01

    The grating-based phase-contrast imaging provides enhanced image structure details, which are partly complementary or even not attainable with standard X-ray absorption imaging. Especially in the case of biological soft tissue when standard x-ray radiography is often limited due to the weak absorption contrast, this method represents a real alternative. Based on X-ray optical transmission gratings this modality has transferred the phase-contrast imaging from the highly brilliant synchrotron radiation sources to conventional laboratory-based broadband x-ray tubes. Here, we present a study on human soft tissue specimens containing tumours using the grating-based phase contrast imaging at both highly brilliant synchrotron (ESRF, Grenoble), and at conventional X-ray laboratory radiation sources. Our results demonstrate a superior contrast for different kinds of soft tissue in the phase contrast and verify this imaging modality to be a promising candidate to establish phase-contrast imaging in clinical radiology.

  3. Tumour visualisation in human soft tissue using grating-based X-ray phase contrast imaging

    International Nuclear Information System (INIS)

    The grating-based phase-contrast imaging provides enhanced image structure details, which are partly complementary or even not attainable with standard X-ray absorption imaging. Especially in the case of biological soft tissue when standard x-ray radiography is often limited due to the weak absorption contrast, this method represents a real alternative. Based on X-ray optical transmission gratings this modality has transferred the phase-contrast imaging from the highly brilliant synchrotron radiation sources to conventional laboratory-based broadband x-ray tubes. Here, we present a study on human soft tissue specimens containing tumours using the grating-based phase contrast imaging at both highly brilliant synchrotron (ESRF, Grenoble), and at conventional X-ray laboratory radiation sources. Our results demonstrate a superior contrast for different kinds of soft tissue in the phase contrast and verify this imaging modality to be a promising candidate to establish phase-contrast imaging in clinical radiology.

  4. Tissue engineered heart valves based on human cells

    OpenAIRE

    Schmidt, D.; Hoerstrup, S P

    2006-01-01

    Valvular heart disease is still a significant cause of morbidity and mortality worldwide. Clinically used valve replacements including mechanical valves as well as fixed biological xeno- or homografts are associated with several major disadvantages. Alternatively, tissue engineering aims at the fabrication of autologous living cardiovascular replacements with the potential to grow and to repair, particularly for paediatric applications. Therefore, autologous cells are harvested and seeded ont...

  5. Tissue engineered heart valves based on human cells

    OpenAIRE

    Schmidt, D.; Hoerstrup, S P

    2007-01-01

    Valvular heart disease is still a significant cause of morbidity and mortality worldwide. Clinically used valve replacements including mechanical valves as well as fixed biological xeno- or homografts are associated with several major disadvantages. Alternatively, tissue engineering aims at the fabrication of autologous living cardiovascular replacements with the potential to grow and to repair, particularly for paediatric applications. Therefore, autologous cells are harvested and seeded ont...

  6. Laser-based micro/nanoengineering for biological applications

    Science.gov (United States)

    Stratakis, E.; Ranella, A.; Farsari, M.; Fotakis, C.

    2009-09-01

    Controlling the interactions of light with matter is crucial for the success and scalability for materials processing applications at micro and nano-scales. The use of ultrafast pulsed lasers (i.e. lasers emitting pulses of duration shorter than 10 -12 s) for the micro/nano engineering of biomaterials or materials relevant to biological applications opens up several exciting possibilities in this respect. These possibilities rely on several attractive features of ultrafast laser-matter interaction processes which allow nanoscale spatial resolution, non-thermal and non-destructive engineering to take place. This article presents a review of novel laser-based techniques for the printing and micro- and nano- scale surface modification of materials for biological applications. Emphasis is placed on techniques appropriate for biochip and tissue engineering applications, for which there is an increasing demand over the last years. Besides presenting recent advances achieved by these techniques, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.

  7. Computed Biological Relations among Five Select Treatment-Related Organ/Tissue Toxicities.

    Science.gov (United States)

    Sakellaropoulos, Theodore; Herod, Timothy J; Alexopoulos, Leonidas G; Bai, Jane P F

    2016-05-16

    Drug toxicity presents a major challenge in drug development and patient care. We set to build upon previous works regarding select drug-induced toxicities to find common patterns in the mode of action of the drugs associated with these toxicities. In particular, we focused on five disparate organ toxicities, peripheral neuropathy (PN), rhabdomyolysis (RM), Stevens-Johnson syndrome/toxic epidermal necrosis (SJS/TEN), lung injury (LI), and heart contraction-related cardiotoxicity (CT), and identified biological commonalities between and among the toxicities in terms of pharmacological targets and nearest neighbors (indirect effects) using the hyper-geometric test and a distance metric of Spearman correlation. There were 20 significant protein targets associated with two toxicities and 0 protein targets associated with three or more toxicities. Per Spearman distance, PN was closest to SJS/TEN compared to other pairs, whereas the pairs involving RM were more different than others excluding RM. The significant targets associated with RM outnumbered those associated with every one of the other four toxicities. Enrichment analysis of drug targets that are expressed in corresponding organ/tissues determined proteins that should be avoided in drug discovery. The identified biological patterns emerging from the mode of action of these drugs are statistically associated with these serious toxicities and could potentially be used as predictors for new drug candidates. The predictive power and usefulness of these biological patterns will increase with the database of these five toxicities. Furthermore, extension of our approach to all severe adverse reactions will produce useful biological commonalities for reference in drug discovery and development. PMID:27063352

  8. Gelatin-Methacryloyl Hydrogels: Towards Biofabrication-Based Tissue Repair.

    Science.gov (United States)

    Klotz, Barbara J; Gawlitta, Debby; Rosenberg, Antoine J W P; Malda, Jos; Melchels, Ferry P W

    2016-05-01

    Research over the past decade on the cell-biomaterial interface has shifted to the third dimension. Besides mimicking the native extracellular environment by 3D cell culture, hydrogels offer the possibility to generate well-defined 3D biofabricated tissue analogs. In this context, gelatin-methacryloyl (gelMA) hydrogels have recently gained increased attention. This interest is sparked by the combination of the inherent bioactivity of gelatin and the physicochemical tailorability of photo-crosslinkable hydrogels. GelMA is a versatile matrix that can be used to engineer tissue analogs ranging from vasculature to cartilage and bone. Convergence of biological and biofabrication approaches is necessary to progress from merely proving cell functionality or construct shape fidelity towards regenerating tissues. GelMA has a critical pioneering role in this process and could be used to accelerate the development of clinically relevant applications. PMID:26867787

  9. Protocols for the in vitro design of animal articular cartilage based on tissue engineering methods

    Directory of Open Access Journals (Sweden)

    Diego Correa

    2012-10-01

    Full Text Available The articular cartilage is the structure that covers the joint ends. It has some specific tasks crucial to the correct joint physiology. It may experience a large amount of injuries that could generate considerable disabilities. Unfortunately its selfrepair capacity is too limited; therefore, many treatments have been developed with partial success, given the suboptimal biomechanical behavior of the resultant tissue. Given that, Tissue Engineering offers an alternative, based on the design of a new tissue with biological and biomechanical features which resembles the native tissue. In this work, the authors describe the methodologies followed to accomplish that goal, studying the chondrocytes harvesting, the cellular cultures, the scaffold seeding processes, the mechanical stimulation and the structural and biomechanical evaluation. Finally, exposed some of the preliminary results, as a experimental validation of the methods proposed are.

  10. The first protocol of stable isotope ratio assessment in tumor tissues based on original research.

    Science.gov (United States)

    Taran, Katarzyna; Frączek, Toma; Kamiński, Rafal; Sitkiewicz, Anna; Kobos, Jozef; Paneth, Piotr

    2015-09-01

    Thanks to proteomics and metabolomics, for the past several years there has been a real explosion of information on the biology of cancer, which has been achieved by spectroscopic methods, including mass spectrometry. These modern techniques can provide answers to key questions about tissue structure and mechanisms of its pathological changes. However, despite the thousands of spectroscopic studies in medicine, there is no consensus on issues ranging from the choice of research tools, acquisition and preparation of test material to the interpretation and validation of the results, which greatly reduces the possibility of transforming the achieved knowledge to progress in the treatment of individual patients. The aim of this study was to verify the utility of isotope ratio mass spectrometry in the evaluation of tumor tissues. Based on experimentation on animal tissues and human neoplasms, the first protocol of stable isotope ratio assessment of carbon and nitrogen isotopes in tumor tissues was established. PMID:26619108

  11. Cell-Based Strategies for Meniscus Tissue Engineering

    Science.gov (United States)

    Niu, Wei; Guo, Weimin; Han, Shufeng; Zhu, Yun; Liu, Shuyun; Guo, Quanyi

    2016-01-01

    Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering. PMID:27274735

  12. Cell-Based Strategies for Meniscus Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Wei Niu

    2016-01-01

    Full Text Available Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering.

  13. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-07-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications.

  14. Analysis of micro-composition of biological tissue by means of induced radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, C.A.; Dunn, R.W.

    1948-05-24

    The use of radioactive isotopes as tracers promises a wealth of information regarding the biochemical role of most elements and their components. Usually a radioactive sample of the element to be studied is administered to the plant or animal in a convenient form, and its distribution and rate of exchange are determined in later assays. This technique has, however, certain limitations, two of which will be discussed here: (1) radioactive isotopes are not generally useful for measurements of the concentration of elements in the body or its parts. They can be used only to give a measure of the rate of exchange of the elements and (2) the use of radioactive isotopes for tracer experiments requires that the radiation dose delivered to the tissue should be small in order not to disturb normal biological function.

  15. A Polydisperse Sphere Model Describing the Propagation of Light in Biological Tissue

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Hua; LI Zhen-Hua; LAI Jian-Cheng; HE An-Zhi

    2007-01-01

    A polydisperse sphere model with the complex refractive index is employed to describe the propagation of light in biological tissue.The scattering coefficient,absorption coefficient and scattering phase function are calculated.At the same time,the inverse problem on retrieving the particles size distribution,imaginary part of the refractive index and number density of scatterers is investigated.The result shows that the retrieval scheme together with the Chahine algorithm is effective in dealing with such an inverse problem.IT is also clarified that a group of parameters including the scattering coefficient,absorption coefficient and phase function are associated with another group including the refractive index,particle size distribution and number density of scatterers,which is a problem described in two different ways and the anisotropy factor is not an independent variable,but is determined by the phase function.

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

    CERN Document Server

    Chakravarty, Koyel

    2016-01-01

    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...

  17. MEMS scanner enabled real-time depth sensitive hyperspectral imaging of biological tissue.

    Science.gov (United States)

    Wang, Youmin; Bish, Sheldon; Tunnell, James W; Zhang, Xiaojing

    2010-11-01

    We demonstrate a hyperspectral and depth sensitive diffuse optical imaging microsystem, where fast scanning is provided by a CMOS compatible 2-axis MEMS mirror. By using lissajous scanning patterns, large field-of-view (FOV) of 1.2 cmx1.2 cm images with lateral resolution of 100 µm can be taken at 1.3 frames-per-second (fps). Hyperspectral and depth-sensitive images were acquired on tissue simulating phantom samples containing quantum dots (QDs) patterned at various depths in Polydimethylsiloxane (PDMS). Device performance delivers 6 nm spectral resolution and 0.43 wavelengths per second acquisition speed. A sample of porcine epithelium with subcutaneously placed QDs was also imaged. Images of the biological sample were processed by spectral unmixing in order to qualitatively separate chromophores in the final images and demonstrate spectral performance of the imaging system. PMID:21164757

  18. 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.

  19. Depth-encoded synthetic aperture optical coherence tomography of biological tissues with extended focal depth.

    Science.gov (United States)

    Mo, Jianhua; de Groot, Mattijs; de Boer, Johannes F

    2015-02-23

    Optical coherence tomography (OCT) has proven to be able to provide three-dimensional (3D) volumetric images of scattering biological tissues for in vivo medical diagnostics. Unlike conventional optical microscopy, its depth-resolving ability (axial resolution) is exclusively determined by the laser source and therefore invariant over the full imaging depth. In contrast, its transverse resolution is determined by the objective's numerical aperture and the wavelength which is only approximately maintained over twice the Rayleigh range. However, the prevailing laser sources for OCT allow image depths of more than 5 mm which is considerably longer than the Rayleigh range. This limits high transverse resolution imaging with OCT. Previously, we reported a novel method to extend the depth-of-focus (DOF) of OCT imaging in Mo et al.Opt. Express 21, 10048 (2013)]. The approach is to create three different optical apertures via pupil segmentation with an annular phase plate. These three optical apertures produce three OCT images from the same sample, which are encoded to different depth positions in a single OCT B-scan. This allows for correcting the defocus-induced curvature of wave front in the pupil so as to improve the focus. As a consequence, the three images originating from those three optical apertures can be used to reconstruct a new image with an extended DOF. In this study, we successfully applied this method for the first time to both an artificial phantom and biological tissues over a four times larger depth range. The results demonstrate a significant DOF improvement, paving the way for 3D high resolution OCT imaging beyond the conventional Rayleigh range. PMID:25836528

  20. Aplicación de biomateriales de base biológica, moléculas bioactivas e ingeniería de tejidos en cirugía plástica periodontal: Una revisión Application of biological based biomaterials, bioactive molecules and tissue engineering in periodontal plastic surgery: A review

    Directory of Open Access Journals (Sweden)

    JC Durán Yaneth

    2012-12-01

    Full Text Available Objetivo: Describir, clasificar y discutir las indicaciones de los biomateriales de base biológica, moléculas bioactivas e ingeniería de tejidos que se están usando para el manejo de recesiones y aumento de encía en cirugía plástica periodontal. En esta revisión de la literatura, se utilizó una combinación de los términos de búsqueda específicos que consideraran los materiales en revisión, para el aumento de encía adherida, y el recubrimiento radicular. Materiales y Métodos: Se usaron las siguientes fuentes: Medline, Biblioteca Cochrane, y búsqueda manual de revistas específicas como el Journal of Periodontology, International Journal of Periodontics and Restorative Dentistry y Journal of Clinical Periodontology entre años 1985 y 2011. Se revisaron un total de 117 artículos y se seleccionaron 74 entre estudios clínicos controlados, estudios clínicos randomizados, reportes de casos y estudios en animales. Los artículos fueron revisados por los autores y aceptados por consenso para su discusión. Conclusiones: 1 Existe una serie de materiales que presentan gran potencial y podrían ser una alternativa viable a los injertos autógenos, pero se requiere más estudios a largo plazo. 2 Existe necesidad de estudios con la investigación de estos procedimientos en relación a resultados orientados a la estabilidad, seguridad y efectividad de los diferentes materiales existentes.Objective: To describe, classify and discuss the clinical applications of biologically based biomaterials, bioactive molecules and tissue engineering being utilized in gingival recession therapy and gingival augmentation procedures in plastic periodontal surgery. In this literature review, a combination of specific search key words were used, including materials being reviewed, indicated for gingival augmentation and root coverage procedures. Materials and Methods: The following sources were consulted: Medline, Cochrane Library and manual search of specific

  1. 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. PMID:27257717

  2. Numerical modelling of thermal effects on biological tissue during laser-material interaction

    International Nuclear Information System (INIS)

    Among numerous methods of the modelling of laser interaction with the material equivalent of biological tissue (including macroscopic and microscopic cell interaction), the case of pathogenic prostates is chosen to be studied. The principal difference between the inorganic and tissue equivalent material is the term which includes blood flow. Thermal modelling is chosen for interaction mechanisms, i.e. bio-heat equation. It was noticed that the principal problems are in selecting appropriate numerical methods, available mathematical program packages and finding all exact parameters for performing the needed calculations. As principal parameters, among them density, heat conduction, and specific heat, there are many other parameters which depend on the chosen approach (there could be up to 20 parameters, among them coefficient of time scaling, arterial blood temperature, metabolic heat source, etc). The laser type, including its wavelength which defines the quantity of absorbed energy and dynamic of irradiation, presents the term which could be modulated for the chosen problem. In this study, the program Comsol Multiphysics 3.5 is used in the simulation of prostate exposed to Nd3+:YAG laser in its fundamental mode. (paper)

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

    International Nuclear Information System (INIS)

    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 Na125I 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 μg 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. (author)

  4. Regulatory inhibition of biological tissue mineralization through post-nucleation shielding

    Science.gov (United States)

    Chang, Joshua; Miura, Robert

    In vertebrates, insufficient availability of calcium and phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are present at high concentrations throughout body 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. We adapted mean-field classical nucleation theory to the case of surface-shielding in order to study the regulation of sedimentation of calcium phosphate salts in biological tissues. Mathematical Biosciences Institute, NSF DMS-1021818, National Institutes of Health, Rehab Medicine.

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

    International Nuclear Information System (INIS)

    Element concentrations in biological tissues of Dmdmdx/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 Dmdmdx/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)

  6. 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. PMID:24582232

  7. How preconditioning affects the measurement of poro-viscoelastic mechanical properties in biological tissues.

    Science.gov (United States)

    Hosseini, Sayyed Mohsen; Wilson, Wouter; Ito, Keita; van Donkelaar, Corrinus C

    2014-06-01

    It is known that initial loading curves of soft biological tissues are substantially different from subsequent loadings. The later loading curves are generally used for assessing the mechanical properties of a tissue, and the first loading cycles, referred to as preconditioning, are omitted. However, slow viscoelastic phenomena related to fluid flow or collagen viscoelasticity are initiated during these first preconditioning loading cycles and may persist during the actual data collection. When these data are subsequently used for fitting of material properties, the viscoelastic phenomena that occurred during the initial cycles are not accounted for. The aim of the present study is to explore whether the above phenomena are significant for articular cartilage, by evaluating the effect of such time-dependent phenomena by means of computational modeling. Results show that under indentation, collagen viscoelasticity dominates the time-dependent behavior. Under UC, fluid-dependent effects are more important. Interestingly, viscoelastic and poroelastic effects may act in opposite directions and may cancel each other out in a stress-strain curve. Therefore, equilibrium may be apparent in a stress-strain relationship, even though internally the tissue is not in equilibrium. Also, the time-dependent effects of viscoelasticity and poroelasticity may reinforce each other, resulting in a sustained effect that lasts longer than suggested by their individual effects. Finally, the results illustrate that data collected from a mechanical test may depend on the preconditioning protocol. In conclusion, preconditioning influences the mechanical response of articular cartilage significantly and therefore cannot be neglected when determining the mechanical properties. To determine the full viscoelastic and poroelastic properties of articular cartilage requires fitting to both preconditioning and post-preconditioned loading cycles. PMID:23864393

  8. Controlled laser delivery into biological tissue via thin-film optical tunneling and refraction

    Science.gov (United States)

    Whiteside, Paul J. D.; Goldschmidt, Benjamin S.; Curry, Randy; Viator, John A.

    2015-02-01

    Due to the often extreme energies employed, contemporary methods of laser delivery utilized in clinical dermatology allow for a dangerous amount of high-intensity laser light to reflect off a multitude of surfaces, including the patient's own skin. Such techniques consistently represent a clear and present threat to both patients and practitioners alike. The intention of this work was therefore to develop a technique that mitigates this problem by coupling the light directly into the tissue via physical contact with an optical waveguide. In this manner, planar waveguides cladded in silver with thin-film active areas were used to illuminate agar tissue phantoms with nanosecond-pulsed laser light at 532nm. The light then either refracted or optically tunneled through the active area, photoacoustically generating ultrasonic waves within the phantom, whose peak-to-peak intensity directly correlated to the internal reflection angle of the beam. Consequently, angular spectra for energy delivery were recorded for sub-wavelength silver and titanium films of variable thickness. Optimal energy delivery was achieved for internal reflection angles ranging from 43 to 50 degrees, depending on the active area and thin film geometries, with titanium films consistently delivering more energy across the entire angular spectrum due to their relatively high refractive index. The technique demonstrated herein therefore not only represents a viable method of energy delivery for biological tissue while minimizing the possibility for stray light, but also demonstrates the possibility for utilizing thin films of high refractive index metals to redirect light out of an optical waveguide.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stroemberg, Niklas, E-mail: niklas.stromberg@sp.se [SP Technical Research Institute of Sweden, Box 857, SE-501 15 Boras (Sweden); Hakonen, Aron, E-mail: hakonen@chem.gu.se [University of Gothenburg, Kemivaegen 10, SE-412 96 Gothenburg (Sweden)

    2011-10-17

    Highlights: {yields} A plasmophore sensitized optode for imaging ammonia (NH{sub 3}) concentrations in muscle tissues was developed. {yields} Ammonia concentrations ranging from 10 nM and upwards can be quantified reversibly with an optical resolution of 127 {mu}m. {yields} 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{sub 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 {mu}m 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

  10. Hydrodynamics and convection enhanced macromolecular fluid transport in soft biological tissues: Application to solid tumor.

    Science.gov (United States)

    Dey, Bibaswan; Sekhar, G P Raja

    2016-04-21

    This work addresses a theoretical framework for transvascular exchange and extravascular transport of solute macromolecules through soft interstitial space inside a solid tumor. Most of the soft biological tissues show materialistic properties similar to deformable porous material. They exhibit mechanical behavior towards the fluid motion since the solid phase of the tumor tissue gets compressed by the drag force that is associated with the extracellular fluid flow. This paper presents a general view about the transvascular and interstitial transport of solute nutrients inside a tumor in the macroscopic level. Modified Starling׳s equation is used to describe transvascular nutrient transport. On the macroscopic level, motion of extracellular fluid within the tumor interstitium is modeled with the help of biphasic mixture theory and a spherical symmetry solution is given as a simpler case. This present model describes the average interstitial fluid pressure (IFP), extracellular fluid velocity (EFV) and flow rate of extracellular fluid, as well as the deformation of the solid phase of the tumor tissue as an immediate cause of extracellular fluid flow. When the interstitial transport is diffusion dominated, an analytical treatment of advection-diffusion-reaction equation finds the overall nutrient distribution. We propose suitable criteria for the formation of necrosis within the tumor interstitium. This study introduces some parameters that represent the nutrient supply from tumor blood vessels into the tumor extracellular space. These transport parameters compete with the reversible nutrient metabolism of the tumor cells present in the interstitium. The present study also shows that the effectiveness factor corresponding to a first order nutrient metabolism may reach beyond unity if the strength of the distributive solute source assumes positive non-zero values. PMID:26851443

  11. Review: Polymeric-Based 3D Printing for Tissue Engineering

    OpenAIRE

    Wu, Geng-Hsi; Hsu, Shan-hui

    2015-01-01

    Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue ...

  12. Nucleic Acid-Based Nanodevices in Biological Imaging.

    Science.gov (United States)

    Chakraborty, Kasturi; Veetil, Aneesh T; Jaffrey, Samie R; Krishnan, Yamuna

    2016-06-01

    The nanoscale engineering of nucleic acids has led to exciting molecular technologies for high-end biological imaging. The predictable base pairing, high programmability, and superior new chemical and biological methods used to access nucleic acids with diverse lengths and in high purity, coupled with computational tools for their design, have allowed the creation of a stunning diversity of nucleic acid-based nanodevices. Given their biological origin, such synthetic devices have a tremendous capacity to interface with the biological world, and this capacity lies at the heart of several nucleic acid-based technologies that are finding applications in biological systems. We discuss these diverse applications and emphasize the advantage, in terms of physicochemical properties, that the nucleic acid scaffold brings to these contexts. As our ability to engineer this versatile scaffold increases, its applications in structural, cellular, and organismal biology are clearly poised to massively expand. PMID:27294440

  13. Updated Lagrangian finite element formulations of various biological soft tissue non-linear material models: a comprehensive procedure and review.

    Science.gov (United States)

    Townsend, Molly T; Sarigul-Klijn, Nesrin

    2016-08-01

    Simplified material models are commonly used in computational simulation of biological soft tissue as an approximation of the complicated material response and to minimize computational resources. However, the simulation of complex loadings, such as long-duration tissue swelling, necessitates complex models that are not easy to formulate. This paper strives to offer the updated Lagrangian formulation comprehensive procedure of various non-linear material models for the application of finite element analysis of biological soft tissues including a definition of the Cauchy stress and the spatial tangential stiffness. The relationships between water content, osmotic pressure, ionic concentration and the pore pressure stress of the tissue are discussed with the merits of these models and their applications. PMID:26611112

  14. Complementary constraints from carbon (13C) and nitrogen (15N) isotopes on the glacial ocean's soft-tissue biological pump

    Science.gov (United States)

    Schmittner, A.; Somes, C. J.

    2016-06-01

    A three-dimensional, process-based model of the ocean's carbon and nitrogen cycles, including 13C and 15N isotopes, is used to explore effects of idealized changes in the soft-tissue biological pump. Results are presented from one preindustrial control run (piCtrl) and six simulations of the Last Glacial Maximum (LGM) with increasing values of the spatially constant maximum phytoplankton growth rate μmax, which accelerates biological nutrient utilization mimicking iron fertilization. The default LGM simulation, without increasing μmax and with a shallower and weaker Atlantic Meridional Overturning Circulation and increased sea ice cover, leads to 280 Pg more respired organic carbon (Corg) storage in the deep ocean with respect to piCtrl. Dissolved oxygen concentrations in the colder glacial thermocline increase, which reduces water column denitrification and, with delay, nitrogen fixation, thus increasing the ocean's fixed nitrogen inventory and decreasing δ15NNO3 almost everywhere. This simulation already fits sediment reconstructions of carbon and nitrogen isotopes relatively well, but it overestimates deep ocean δ13CDIC and underestimates δ15NNO3 at high latitudes. Increasing μmax enhances Corg and lowers deep ocean δ13CDIC, improving the agreement with sediment data. In the model's Antarctic and North Pacific Oceans modest increases in μmax result in higher δ15NNO3 due to enhanced local nutrient utilization, improving the agreement with reconstructions there. Models with moderately increased μmax fit both isotope data best, whereas large increases in nutrient utilization are inconsistent with nitrogen isotopes although they still fit the carbon isotopes reasonably well. The best fitting models reproduce major features of the glacial δ13CDIC, δ15N, and oxygen reconstructions while simulating increased Corg by 510-670 Pg compared with the preindustrial ocean. These results are consistent with the idea that the soft-tissue pump was more efficient

  15. Ultrasound-modulated optical microscopy for ex-vivo imaging of scattering biological tissue

    Science.gov (United States)

    Kothapalli, Sri-Rajasekhar; Wang, Lihong V.

    2009-02-01

    Ultrasound-modulated optical microscopy (UOM) based on a long-cavity confocal Fabry-Perot interferometer (CFPI) [J.Biomed.Opt. 13(5), 0504046, (2008)] is used for real time detection of multiply scattered light modulated by high frequency (30 MHz) ultrasound pulses propagating in an optically strongly scattering medium. In this article, we use this microscope to study the dependence of ultrasound-modulated optical signals on the optical absorption of objects embedded about 3 mm deep in tissue mimicking phantoms. These results demonstrate that the dependence is nearly linear. Most importantly, we imaged blood vasculature and melanin in highly scattering tissue samples from a mouse and a rat. Thus UOM can be used to study the morphology of blood vasculature and blood-associated functional parameters, such as oxygen saturation.

  16. 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

  17. Streamlined bioreactor-based production of human cartilage tissues.

    Science.gov (United States)

    Tonnarelli, B; Santoro, R; Adelaide Asnaghi, M; Wendt, D

    2016-01-01

    Engineered tissue grafts have been manufactured using methods based predominantly on traditional labour-intensive manual benchtop techniques. These methods impart significant regulatory and economic challenges, hindering the successful translation of engineered tissue products to the clinic. Alternatively, bioreactor-based production systems have the potential to overcome such limitations. In this work, we present an innovative manufacturing approach to engineer cartilage tissue within a single bioreactor system, starting from freshly isolated human primary chondrocytes, through the generation of cartilaginous tissue grafts. The limited number of primary chondrocytes that can be isolated from a small clinically-sized cartilage biopsy could be seeded and extensively expanded directly within a 3D scaffold in our perfusion bioreactor (5.4 ± 0.9 doublings in 2 weeks), bypassing conventional 2D expansion in flasks. Chondrocytes expanded in 3D scaffolds better maintained a chondrogenic phenotype than chondrocytes expanded on plastic flasks (collagen type II mRNA, 18-fold; Sox-9, 11-fold). After this "3D expansion" phase, bioreactor culture conditions were changed to subsequently support chondrogenic differentiation for two weeks. Engineered tissues based on 3D-expanded chondrocytes were more cartilaginous than tissues generated from chondrocytes previously expanded in flasks. We then demonstrated that this streamlined bioreactor-based process could be adapted to effectively generate up-scaled cartilage grafts in a size with clinical relevance (50 mm diameter). Streamlined and robust tissue engineering processes, as the one described here, may be key for the future manufacturing of grafts for clinical applications, as they facilitate the establishment of compact and closed bioreactor-based production systems, with minimal automation requirements, lower operating costs, and increased compliance to regulatory guidelines. PMID:27232665

  18. Comparison of Metabolic Network between Muscle and Intramuscular Adipose Tissues in Hanwoo Beef Cattle Using a Systems Biology Approach

    OpenAIRE

    Hyun-Jeong Lee; Hye-Sun Park; Woonsu Kim; Duhak Yoon; Seongwon Seo

    2014-01-01

    The interrelationship between muscle and adipose tissues plays a major role in determining the quality of carcass traits. The objective of this study was to compare metabolic differences between muscle and intramuscular adipose (IMA) tissues in the longissimus dorsi (LD) of Hanwoo (Bos taurus coreanae) using the RNA-seq technology and a systems biology approach. The LD sections between the 6th and 7th ribs were removed from nine (each of three cows, steers, and bulls) Hanwoo beef cattle (carc...

  19. Functional analysis of biological matter across dimensions by atomic force microscopy (AFM): from tissues to molecules and, ultimately, atoms

    OpenAIRE

    Stolz, Martin

    2004-01-01

    For a detailed understanding of biological tissues and proteins and their dynamical processes the 3D structures of the components involved must be known. Most of the structural data have been obtained through the combination of three major techniques: X-ray crystallography, NMR and TEM. These three methods enable the determination of the structure of biological macromolecules at near atomic resolution and each of those was developed over many years to perfection. Nevertheless each one has its...

  20. Nonresonant, femtosecond laser vaporization and electrospray post-ionization mass spectrometry as a tool for biological tissue imaging.

    Science.gov (United States)

    Shi, Fengjian; Archer, Jieutonne J; Levis, Robert J

    2016-07-15

    An ambient mass spectrometry imaging (MSI) source is demonstrated with both high spatial and mass resolution that enables measurement of the compositional heterogeneity within a biological tissue sample. The source is based on nonresonant, femtosecond laser electrospray mass spectrometry (LEMS) coupled to a quadrupole time-of-flight (QTOF) mass analyzer. No matrix deposition and minimal sample preparation is necessary for the source. The laser, translation stage, and mass spectrometer are synchronized and controlled using a customized user interface. Single or multiple laser shots may be applied to each pixel. A scanning rate of 2.0s per pixel is achieved. Measurement of a patterned ink film indicates the potential of LEMS for ambient imaging with a lateral resolution of ∼60μm. Metabolites including sugar, anthocyanins and other small metabolites were successfully mapped from plant samples without oversampling using a spot size of 60×70μm(2). Molecular identification of the detected analytes from the tissue was enabled by accurate mass measurement in conjunction with tandem mass spectrometry. Statistical analysis, non-negative matrix factorization and principle component analysis, were applied to the imaging data to extract regions with distinct and/or correlated spectral profiles. PMID:26931651

  1. A Monte-Carlo maplet for the study of the optical properties of biological tissues

    Science.gov (United States)

    Yip, Man Ho; Carvalho, M. J.

    2007-12-01

    Monte-Carlo simulations are commonly used to study complex physical processes in various fields of physics. In this paper we present a Maple program intended for Monte-Carlo simulations of photon transport in biological tissues. The program has been designed so that the input data and output display can be handled by a maplet (an easy and user-friendly graphical interface), named the MonteCarloMaplet. A thorough explanation of the programming steps and how to use the maplet is given. Results obtained with the Maple program are compared with corresponding results available in the literature. Program summaryProgram title:MonteCarloMaplet Catalogue identifier:ADZU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:3251 No. of bytes in distributed program, including test data, etc.:296 465 Distribution format: tar.gz Programming language:Maple 10 Computer: Acer Aspire 5610 (any running Maple 10) Operating system: Windows XP professional (any running Maple 10) Classification: 3.1, 5 Nature of problem: Simulate the transport of radiation in biological tissues. Solution method: The Maple program follows the steps of the C program of L. Wang et al. [L. Wang, S.L. Jacques, L. Zheng, Computer Methods and Programs in Biomedicine 47 (1995) 131-146]; The Maple library routine for random number generation is used [Maple 10 User Manual c Maplesoft, a division of Waterloo Maple Inc., 2005]. Restrictions: Running time increases rapidly with the number of photons used in the simulation. Unusual features: A maplet (graphical user interface) has been programmed for data input and output. Note that the Monte-Carlo simulation was programmed with Maple 10. If attempting to run the simulation with an earlier version of Maple

  2. Atmospheric-pressure molecular imaging of biological tissues and biofilms by LAESI mass spectrometry.

    Science.gov (United States)

    Nemes, Peter; Vertes, Akos

    2010-01-01

    Ambient ionization methods in mass spectrometry allow analytical investigations to be performed directly on a tissue or biofilm under native-like experimental conditions. Laser ablation electrospray ionization (LAESI) is one such development and is particularly well-suited for the investigation of water-containing specimens. LAESI utilizes a mid-infrared laser beam (2.94 μm wavelength) to excite the water molecules of the sample. When the ablation fluence threshold is exceeded, the sample material is expelled in the form of particulate matter and these projectiles travel to tens of millimeters above the sample surface. In LAESI, this ablation plume is intercepted by highly charged droplets to capture a fraction of the ejected sample material and convert its chemical constituents into gas-phase ions. A mass spectrometer equipped with an atmospheric-pressure ion source interface is employed to analyze and record the composition of the released ions originating from the probed area (pixel) of the sample. A systematic interrogation over an array of pixels opens a way for molecular imaging in the microprobe analysis mode. A unique aspect of LAESI mass spectrometric imaging is depth profiling that, in combination with lateral imaging, enables three-dimensional (3D) molecular imaging. With current lateral and depth resolutions of ~100 μm and ~40 μm, respectively, LAESI mass spectrometric imaging helps to explore the molecular structure of biological tissues. Herein, we review the major elements of a LAESI system and provide guidelines for a successful imaging experiment. PMID:20834223

  3. Biologically and mechanically driven design of an RGD-mimetic macroporous foam for adipose tissue engineering applications.

    Science.gov (United States)

    Rossi, Eleonora; Gerges, Irini; Tocchio, Alessandro; Tamplenizza, Margherita; Aprile, Paola; Recordati, Camilla; Martello, Federico; Martin, Ivan; Milani, Paolo; Lenardi, Cristina

    2016-10-01

    Despite clinical treatments for adipose tissue defects, in particular breast tissue reconstruction, have certain grades of efficacy, many drawbacks are still affecting the long-term survival of new formed fat tissue. To overcome this problem, in the last decades, several scaffolding materials have been investigated in the field of adipose tissue engineering. However, a strategy able to recapitulate a suitable environment for adipose tissue reconstruction and maintenance is still missing. To address this need, we adopted a biologically and mechanically driven design to fabricate an RGD-mimetic poly(amidoamine) oligomer macroporous foam (OPAAF) for adipose tissue reconstruction. The scaffold was designed to fulfil three fundamental criteria: capability to induce cell adhesion and proliferation, support of in vivo vascularization and match of native tissue mechanical properties. Poly(amidoamine) oligomers were formed into soft scaffolds with hierarchical porosity through a combined free radical polymerization and foaming reaction. OPAAF is characterized by a high water uptake capacity, progressive degradation kinetics and ideal mechanical properties for adipose tissue reconstruction. OPAAF's ability to support cell adhesion, proliferation and adipogenesis was assessed in vitro using epithelial, fibroblast and endothelial cells (MDCK, 3T3L1 and HUVEC respectively). In addition, in vivo subcutaneous implantation in murine model highlighted OPAAF potential to support both adipogenesis and vessels infiltration. Overall, the reported results support the use of OPAAF as a scaffold for engineered adipose tissue construct. PMID:27428768

  4. Analysis of current density and specific absorption rate in biological tissue surrounding transcutaneous transformer for an artificial heart.

    Science.gov (United States)

    Shiba, Kenji; Nukaya, Masayuki; Tsuji, Toshio; Koshiji, Kohji

    2008-01-01

    This paper reports on the current density and specific absorption rate (SAR) analysis of biological tissue surrounding an air-core transcutaneous transformer for an artificial heart. The electromagnetic field in the biological tissue is analyzed by the transmission line modeling method, and the current density and SAR as a function of frequency, output voltage, output power, and coil dimension are calculated. The biological tissue of the model has three layers including the skin, fat, and muscle. The results of simulation analysis show SARs to be very small at any given transmission conditions, about 2-14 mW/kg, compared to the basic restrictions of the International Commission on nonionizing radiation protection (ICNIRP; 2 W/kg), while the current density divided by the ICNIRP's basic restrictions gets smaller as the frequency rises and the output voltage falls. It is possible to transfer energy below the ICNIRP's basic restrictions when the frequency is over 250 kHz and the output voltage is under 24 V. Also, the parts of the biological tissue that maximized the current density differ by frequencies; in the low frequency is muscle and in the high frequency is skin. The boundary is in the vicinity of the frequency 600-1000 kHz. PMID:18232363

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

    International Nuclear Information System (INIS)

    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 DMDmdx/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 Dmdmdx/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)

  6. 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 performe

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

    International Nuclear Information System (INIS)

    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 125I-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 125I-oPRL was 20%, while less than 1% of 125I-pPRL was bound. 125I-oPRL bound to high affinity sites

  8. The two coupling fluids method for ultrasonic velocity measurement. Application to biological tissues

    International Nuclear Information System (INIS)

    Measuring the ultrasonic velocity in soft materials, especially in biological tissues, is never easy. One of the main issues is that the thickness of the sample under test is badly defined. From the time-of-flight measurement method, uncertainties in the thickness induce important uncertainties in experimental results. This implies that the ultrasonic velocity is often a poor criterion when it could be a good one. This paper introduces a new method to measure the ultrasonic velocity in soft materials without knowing the sample thickness The main idea of this method is to use two different coupling media to make two relative time-of-flight measurements. The comparison of these two measurements gives the ultrasonic velocity in the sample under test. Furthermore, this comparison can give the local thickness of the sample. The uncertainty calculations show that the effect on the thickness is drastically reduced by using this new ultrasound method. This method is validated on a reference sample (silicone). Before conclusion, some experimental results obtained with mouse skin samples are presented

  9. Effects of space environment on biological characters of tissue cultured rose seedlings

    Institute of Scientific and Technical Information of China (English)

    XUE Huai; LIU Min; LU Jinying; PAN Yi; ZHANG Chunhua

    2005-01-01

    Tissue cultured rose seedlings were carried into space by SHENZHOU-4 spacecraft and then used as the experimental material to investigate effects of the space environmental conditions on morphology, cytology, physiology and molecular biology of the seedlings. After loaded on the space flight, the plant's height, number of leaves, and fresh weight per seedling were all increased significantly compared to the ground controls. The content of chlorophyll was basically unchanged. In some cells, the ultrastructural changes involved twist, contraction and deformation of cell wall, curvature and loose arrangement of lamellae of some chloroplasts, and a significant increase in number of starch grains per chloroplast. In addition, the number of mitochondria increased, but some mitochondrial outer membrane broke, and some mitochondrial cristae disappeared. The activities of the defense enzymes, such as superoxide dismutase, peroxidase and catalyse, in rose leaves increased and the content of malondialdehyde decreased. In the RAPD analysis with 40 10-mer primers, 36 primers generated 148 DNA bands from both of the space flight treated seedlings and the ground controls, and five primers amplified polymorphic products. The rate of DNA variation was 6.34 %.

  10. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-01-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications. PMID:27435424

  11. Scanning-fiber-based imaging method for tissue engineering

    Science.gov (United States)

    Hofmann, Matthias C.; Whited, Bryce M.; Mitchell, Josh; Vogt, William C.; Criswell, Tracy; Rylander, Christopher; Rylander, Marissa Nichole; Soker, Shay; Wang, Ge; Xu, Yong

    2012-06-01

    A scanning-fiber-based method developed for imaging bioengineered tissue constructs such as synthetic carotid arteries is reported. Our approach is based on directly embedding one or more hollow-core silica fibers within the tissue scaffold to function as micro-imaging channels (MIC). The imaging process is carried out by translating and rotating an angle-polished fiber micro-mirror within the MIC to scan excitation light across the tissue scaffold. The locally emitted fluorescent signals are captured using an electron multiplying CCD camera and then mapped into fluorophore distributions according to fiber micro-mirror positions. Using an optical phantom composed of fluorescent microspheres, tissue scaffolds, and porcine skin, we demonstrated single-cell-level imaging resolution (20 to 30 μm) at an imaging depth that exceeds the photon transport mean free path by one order of magnitude. This result suggests that the imaging depth is no longer constrained by photon scattering, but rather by the requirement that the fluorophore signal overcomes the background ``noise'' generated by processes such as scaffold autofluorescence. Finally, we demonstrated the compatibility of our imaging method with tissue engineering by visualizing endothelial cells labeled with green fluorescent protein through a ~500 μm thick and highly scattering electrospun scaffold.

  12. MODELLING OF RING-SHAPED ULTRASONIC WAVEGUIDES FOR TESTING OF MECHANICAL PROPERTIES AND THERAPEUTIC TREATMENT OF BIOLOGICAL TISSUES

    Directory of Open Access Journals (Sweden)

    V. T. Minchenya

    2011-01-01

    Full Text Available The article presents results of modelling of ring-shaped waveguide tool for ultrasonic treatment of biological materials, particularly malignant tumours, and testing of their mechanical properties. Harmonic analysis of forced flexural vibration of the waveguide using ANSYS software and APDL programming language was implemented for determination of waveguide geometric parameters providing its resonance for the given excitation frequency. The developed finite element model accounts for interaction between the waveguide and tumour tissue as well as initial prestressing of tissue radially compressed by the waveguide. Resonant curves of the waveguide in terms of its thickness and diameter are calculated and presented. Principle of application of the developed modeling technique for extraction of diagnostic data on mechanical properties of biological tissues is described.

  13. Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics

    OpenAIRE

    Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander

    2010-01-01

    We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-...

  14. Tissue-specific laser microdissection of the Brassica napus funiculus improves gene discovery and spatial identification of biological processes

    Science.gov (United States)

    Chan, Ainsley C.; Khan, Deirdre; Girard, Ian J.; Becker, Michael G.; Millar, Jenna L.; Sytnik, David; Belmonte, Mark F.

    2016-01-01

    The three primary tissue systems of the funiculus each undergo unique developmental programs to support the growth and development of the filial seed. To understand the underlying transcriptional mechanisms that orchestrate development of the funiculus at the globular embryonic stage of seed development, we used laser microdissection coupled with RNA-sequencing to produce a high-resolution dataset of the mRNAs present in the epidermis, cortex, and vasculature of the Brassica napus (canola) funiculus. We identified 7761 additional genes in these tissues compared with the whole funiculus organ alone using this technology. Differential expression and enrichment analyses were used to identify several biological processes associated with each tissue system. Our data show that cell wall modification and lipid metabolism are prominent in the epidermis, cell growth and modification occur in the cortex, and vascular tissue proliferation and differentiation occur in the central vascular strand. We provide further evidence that each of the three tissue systems of the globular stage funiculus are involved in specific biological processes that all co-ordinate to support seed development. The identification of genes and gene regulators responsible for tissue-specific developmental processes of the canola funiculus now serves as a valuable resource for seed improvement research. PMID:27194740

  15. Periradicular Tissue Responses to Biologically Active Molecules or MTA When Applied in Furcal Perforation of Dogs' Teeth

    Directory of Open Access Journals (Sweden)

    Anna Zairi

    2012-01-01

    Full Text Available 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 factorβ1 (TGFβ1 and zinc-oxide-eugenol-based cement (IRM groups and higher rates of epithelial proliferation in the TGFβ1, basic fibroblast growth factor (bFGF, and insulin growth factor-I (IGF-I groups compared to the MTA. Significantly higher rates of bone formation were found in the control groups compared to the osteogenic protein-1 (OP-1. Significantly higher rates of cementum formation were observed in the IGF-I and bFGF groups compared to the IRM. None of the biologically active molecules can be suggested for repairing furcal perforations, despite the fact that growth factors exerted a clear stimulatory effect on cementum formation and inhibited collagen capsule formation. MTA exhibited better results than the growth factors.

  16. Microbes clearance from biological tissues by soaking in a mixture of non-ionic detergent and hydrogen peroxide

    International Nuclear Information System (INIS)

    Full text: The aim of this work is to find the good processing method to reduce the microbes contaminated biological tissues. Processing of tissues by soaking or washing in 3 % of hydrogen peroxyde (H2O2) has been done elsewhere. Processing of bone by soaking in a mixture of H2O2 and non-ionic detergent has been used to eliminate several kind of viruses from biological tissues (Pauli et al ). This work was done to see the effects of soaking in that mixture to eliminate microbes isolated from contaminated biological tissues. Bone allografts with size of 1x1x1 cm were contaminated by about 10?1?0 cells/ pieces of microbes such as E. coli, Staphylococcus sp, Pseudomanoas sp, and spores of B. pumilus E 601, and then were dried for 6 hours under laminar flow bench and follow by soaking in that mixture for 10. 20. 30 and 60 minutes. As a comparison soaking in 3% H2O2 only was also done. Results showed that E. coli, Staphylococcus sp, Pseudomanoas sp, can be eliminated after soaking for 10 minutes in that mixture, however spores of B. pumilus E 601 still exist after soaking for 60 minutes, although the number reduced significantly. (Author)

  17. 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

  18. A Gauss-Kronrod-Trapezoidal integration scheme for modeling biological tissues with continuous fiber distributions.

    Science.gov (United States)

    Hou, Chieh; Ateshian, Gerard A

    2016-06-01

    Fibrous biological tissues may be modeled using a continuous fiber distribution (CFD) to capture tension-compression nonlinearity, anisotropic fiber distributions, and load-induced anisotropy. The CFD framework requires spherical integration of weighted individual fiber responses, with fibers contributing to the stress response only when they are in tension. The common method for performing this integration employs the discretization of the unit sphere into a polyhedron with nearly uniform triangular faces (finite element integration or FEI scheme). Although FEI has proven to be more accurate and efficient than integration using spherical coordinates, it presents three major drawbacks: First, the number of elements on the unit sphere needed to achieve satisfactory accuracy becomes a significant computational cost in a finite element (FE) analysis. Second, fibers may not be in tension in some regions on the unit sphere, where the integration becomes a waste. Third, if tensed fiber bundles span a small region compared to the area of the elements on the sphere, a significant discretization error arises. This study presents an integration scheme specialized to the CFD framework, which significantly mitigates the first drawback of the FEI scheme, while eliminating the second and third completely. Here, integration is performed only over the regions of the unit sphere where fibers are in tension. Gauss-Kronrod quadrature is used across latitudes and the trapezoidal scheme across longitudes. Over a wide range of strain states, fiber material properties, and fiber angular distributions, results demonstrate that this new scheme always outperforms FEI, sometimes by orders of magnitude in the number of computational steps and relative accuracy of the stress calculation. PMID:26291492

  19. 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.

  20. CAD-based modeling of sustainable community tissue

    International Nuclear Information System (INIS)

    In global terms, communities can be open-quotes readclose quotes as tissues on the land. In both their placement and physical form, they demonstrate varying degrees of environmental fit. They can work with and support, or conquer and degrade the natural environment. Energy resources in their acquisition, delivery and conversion play an insidious but fundamental role in this linkage. CAD-based modeling offers a powerful tool for interpreting the role of energy resource in community patterning/community form -- the open-quote tissuing of the landclose quotes. When linked to database capability (e.g. GIS), the very opportunity for open-quote designing environmental impactclose quotes is possible. This paper presents CAD-based models which examine the organizational impact of energy resources and environmental forces as prime determinants in community form. Included is a discussion of global and local determinants. As a rule, the community models presented attempt to consider tissuing of the land as a transparent/interactive condition. That is, the layering of the community is structured to interpret and express opportunities for the design of earth/sky connection through, the community fabric. The plan/footprint patterning reflects consideration of orientation and encompasses reference to infrastructure options for tissue support. Extensive descriptive, and experiential, images will be provided during presentation of the paper to support the written explanation of the models examined

  1. Preface to Special Topic: Biological microfluidics in tissue engineering and regenerative medicine

    OpenAIRE

    Jayasinghe, S. N.

    2011-01-01

    In this special issue of Biomicrofluidics, many manifestations of biological microfluidics have been highlighted that have significance to regenerative biology and medicine. The collated articles demonstrate the applicability of these biological microfluidics for studying a wide range of biomedical problems most useful for understanding and shining light on basic biology to those applications relevant to clinical medicine. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3571478

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

    International Nuclear Information System (INIS)

    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 μm2 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

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

    Science.gov (United States)

    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.

    2015-04-01

    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 μm2 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.

  4. 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.

  5. Contextual Multivariate Segmentation of Pork Tissue from Grating-Based Multimodal X-Ray Tomography

    DEFF Research Database (Denmark)

    Einarsdottir, Hildur; Nielsen, Mikkel S.; Ersbøll, Bjarne Kjær;

    2013-01-01

    X-ray computed tomography is increasingly used as a nondestructive method for studying three dimensional food structures. For meat products, studies have focused mainly on fat and protein content due to limited contrast capabilities of absorption based techniques. Recent advances in X-ray imaging...... have made novel X-ray image modalities available, where the refraction and scattering of X-rays is obtained simultaneously with the absorption properties, providing enhanced contrast for soft biological tissues. This paper demonstrates how data obtained from grating-based imaging can be segmented by...... means of multivariate and contextual methods to improve the classification of soft tissues in meat products. The results show that the presented segmentation method provides improved classification over univariate segmentation....

  6. Modeling of Nonlinear Propagation in Multi-layer Biological Tissues for Strong Focused Ultrasound

    Institute of Scientific and Technical Information of China (English)

    FAN Ting-Bo; LIU Zhen-Bo; ZHANG Zhe; ZHANG DONG; GONG Xiu-Fen

    2009-01-01

    A theoretical model of the nonlinear propagation in multi-layered tissues for strong focused ultrasound is proposed. In this model, the spheroidal beam equation (SBE) is utilized to describe the nonlinear sound propagation in each layer tissue, and generalized oblique incidence theory is used to deal with the sound transmission between two layer tissues. Computer simulation is performed on a fat-muscle-liver tissue model under the irradiation of a 1 MHz focused transducer with a large aperture angle of 35°. The results demonstrate that the tissue layer would change the amplitude of sound pressure at the focal region and cause the increase of side petals.

  7. Towards a wearable near infrared spectroscopic probe for monitoring concentrations of multiple chromophores in biological tissue in vivo

    Science.gov (United States)

    Chitnis, Danial; Airantzis, Dimitrios; Highton, David; Williams, Rhys; Phan, Phong; Giagka, Vasiliki; Powell, Samuel; Cooper, Robert J.; Tachtsidis, Ilias; Smith, Martin; Elwell, Clare E.; Hebden, Jeremy C.; Everdell, Nicholas

    2016-06-01

    The first wearable multi-wavelength technology for functional near-infrared spectroscopy has been developed, based on a custom-built 8-wavelength light emitting diode (LED) source. A lightweight fibreless probe is designed to monitor changes in the concentrations of multiple absorbers (chromophores) in biological tissue, the most dominant of which at near-infrared wavelengths are oxyhemoglobin and deoxyhemoglobin. The use of multiple wavelengths enables signals due to the less dominant chromophores to be more easily distinguished from those due to hemoglobin and thus provides more complete and accurate information about tissue oxygenation, hemodynamics, and metabolism. The spectroscopic probe employs four photodiode detectors coupled to a four-channel charge-to-digital converter which includes a charge integration amplifier and an analogue-to-digital converter (ADC). Use of two parallel charge integrators per detector enables one to accumulate charge while the other is being read out by the ADC, thus facilitating continuous operation without dead time. The detector system has a dynamic range of about 80 dB. The customized source consists of eight LED dies attached to a 2 mm × 2 mm substrate and encapsulated in UV-cured epoxy resin. Switching between dies is performed every 20 ms, synchronized to the detector integration period to within 100 ns. The spectroscopic probe has been designed to be fully compatible with simultaneous electroencephalography measurements. Results are presented from measurements on a phantom and a functional brain activation study on an adult volunteer, and the performance of the spectroscopic probe is shown to be very similar to that of a benchtop broadband spectroscopy system. The multi-wavelength capabilities and portability of this spectroscopic probe will create significant opportunities for in vivo studies in a range of clinical and life science applications.

  8. Evaluation of a multi-electrode bioimpedance spectroscopy tensor probe to detect the anisotropic conductivity spectra of biological tissues

    International Nuclear Information System (INIS)

    This paper presents bioimpedance spectroscopy measurements of anisotropic tissues using a 16 electrode probe and reconstruction method of estimating the anisotropic impedance spectrum in a local region just underneath the center of the probe. This may enable in-vivo surface bioimpedance measurements with similar performance to the ex-vivo gold standard that requires excising and placing the entire tissue sample in a unit measurement cell with uniform electric field. The multiple surface electrodes enable us to create a focused current pattern so that the resulting measured voltage is more sensitive to a local region and less sensitive to other areas. This is exploited in a reconstruction method to provide improved bioimpedance and anisotropy measurements. In this paper, we describe the current pattern for localized electrical energy concentration, performance with the spring loaded pin electrodes, data calibration and experimental results on anisotropic agar phantoms and different tissue types. The anisotropic conductivity spectra are able to differentiate insulating films of different thickness and detect their orientation. Bioimpedance spectra of biological tissues are in agreement with published data and reference instruments. The anisotropy expressed as the ratio of eigenvalues and the orientation of eigenfunctions were reconstructed at 45° intervals. This information is used to predict the underlying anisotropy of the region under the probe. Tissue measurements clearly demonstrate the expected higher anisotropy of muscle tissue compared to liver tissue and spectral changes. (paper)

  9. Evaluation of a multi-electrode bioimpedance spectroscopy tensor probe to detect the anisotropic conductivity spectra of biological tissues

    Science.gov (United States)

    Karki, Bishal; Wi, Hun; McEwan, Alistair; Kwon, Hyeuknam; In Oh, Tong; Woo, Eung Je; Seo, Jin Keun

    2014-07-01

    This paper presents bioimpedance spectroscopy measurements of anisotropic tissues using a 16 electrode probe and reconstruction method of estimating the anisotropic impedance spectrum in a local region just underneath the center of the probe. This may enable in-vivo surface bioimpedance measurements with similar performance to the ex-vivo gold standard that requires excising and placing the entire tissue sample in a unit measurement cell with uniform electric field. The multiple surface electrodes enable us to create a focused current pattern so that the resulting measured voltage is more sensitive to a local region and less sensitive to other areas. This is exploited in a reconstruction method to provide improved bioimpedance and anisotropy measurements. In this paper, we describe the current pattern for localized electrical energy concentration, performance with the spring loaded pin electrodes, data calibration and experimental results on anisotropic agar phantoms and different tissue types. The anisotropic conductivity spectra are able to differentiate insulating films of different thickness and detect their orientation. Bioimpedance spectra of biological tissues are in agreement with published data and reference instruments. The anisotropy expressed as the ratio of eigenvalues and the orientation of eigenfunctions were reconstructed at 45° intervals. This information is used to predict the underlying anisotropy of the region under the probe. Tissue measurements clearly demonstrate the expected higher anisotropy of muscle tissue compared to liver tissue and spectral changes.

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

    Science.gov (United States)

    Lisenko, S. A.; Kugeiko, M. M.

    2015-04-01

    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.

  11. 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. PMID:27272910

  12. Determination of antisense phosphorothioate oligonucleotides and catabolites in biological fluids and tissue extracts using anion-exchange high-performance liquid chromatography and capillary gel electrophoresis.

    Science.gov (United States)

    Chen, S H; Qian, M; Brennan, J M; Gallo, J M

    1997-04-25

    Chemically modified phosphorothioate oligodeoxynucleotides (ODNs) have become critical tools for research in the fields of gene expression and experimental therapeutics. Bioanalytical assays were developed that utilized fast anion-exchange high-performance liquid chromatography (HPLC) and capillary gel electrophoresis (CGE) for the determination of 20-mer ODNs in biological fluids (plasma and urine) and tissues. A 20 mer ODN in the antisense orientation directed against DNA methyltransferase (denoted as MT-AS) was studied as the model ODN. The anion-exchange HPLC method employed a short column packed with non-porous polymer support and a ternary gradient elution with 2 M lithium bromide containing 30% formamide. Analysis of the MT-AS is accomplished within 5 min with a detection limit of approximately 3 ng on-column at 267 nm. For plasma and urine, samples were diluted with Nonidet P-40 in 0.9% NaCl and directly injected onto the column, resulting in 100% recovery. For tissue homogenates, a protein kinase K digestion and phenol-chloroform extraction were used, with an average recovery of about 50%. Since the HPLC assay cannot provide one-base separation, biological samples were also processed by an anion-exchange solid-phase extraction and a CGE method to characterize MT-AS and its catabolites of 15-20-mer, species most relevant to biological activity. One base separation, under an electric field of 400 V/cm at room temperature, was achieved for a mixture of 15-20-mer with about 50 pg injected. Assay validation studies revealed that the combined HPLC-CGE methods are accurate, reproducible and specific for the determination of MT-AS and its catabolites in biological fluids and tissue homogenates, and can be used for the pharmacokinetic characterization of MT-AS. PMID:9187382

  13. Semantic Search among Heterogeneous Biological Databases Based on Gene Ontology

    Institute of Scientific and Technical Information of China (English)

    Shun-Liang CAO; Lei QIN; Wei-Zhong HE; Yang ZHONG; Yang-Yong ZHU; Yi-Xue LI

    2004-01-01

    Semantic search is a key issue in integration of heterogeneous biological databases. In thispaper, we present a methodology for implementing semantic search in BioDW, an integrated biological datawarehouse. Two tables are presented: the DB2GO table to correlate Gene Ontology (GO) annotated entriesfrom BioDW data sources with GO, and the semantic similarity table to record similarity scores derived fromany pair of GO terms. Based on the two tables, multifarious ways for semantic search are provided and thecorresponding entries in heterogeneous biological databases in semantic terms can be expediently searched.

  14. Cell-based and biomaterial approaches to connective tissue repair

    Science.gov (United States)

    Stalling, Simone Suzette

    vitro as well as in a subcutaneous mouse model. Stable MA-MC hydrogels, of varying weight percentages, demonstrated tunable swelling and mechanical properties in the absence of cytotoxic degradation products. In vivo, 6wt% MA-MC hydrogels maintained their shape and mechanical integrity while eliciting a minimal inflammatory response; highly desirable properties for soft tissue reconstruction. These cellulose-based photopolymerizable hydrogels can be further optimized for drug delivery and tissue engineering applications to enhance wound repair.

  15. A radioenzymatic technique for the measurement of free and conjugated 3,4-dihydroxyphenylethyleneglycol in brain tissue and biological fluids

    International Nuclear Information System (INIS)

    A simple, sensitive and specific radioenzymatic assay for the measurement of 3,4-dihydroxyphenylethyleneglycol (DOPEG) was developed. The assay is based on the conversion of the compound to its O-methylated derivative in the presence of catechol-O-methyltransferase and [3H]S-adenosyl-methionine. The tritiated 3-methoxy-4-hydroxyphenylethyleneglycol formed is selectively extracted in organic solvents and isolated by thin layer chromatography. After oxidation to vanillin the O-methylated compound is extracted and measured by liquid scintillation spectrophotometry. This assay has been applied to the measurement of free and conjugated DOPEG is a variety of biological tissues and fluids. Both free and conjugated DOPEG were readily detected in discrete rat brain areas. Substantial amounts of free and conjugated DOPEG were also measured in ventricular perfusates from freely moving rats. Finally, the presence of DOPEG was also demonstrated in human cerebrospinal fluid, plasma and urine. Only the free form of DOPEG was found in cerebrospinal fluid, whereas both unconjugated and conjugated forms were present in plasma and urine. (Auth.)

  16. Roles of biologic breast tissue composition and quantitative image analysis of mammographic images in breast tumor characterization

    Science.gov (United States)

    Drukker, Karen; Giger, Maryellen L.; Duewer, Fred; Malkov, Serghei; Flowers, Christopher I.; Joe, Bonnie; Kerlikowske, Karla; Drukteinis, Jennifer S.; Shepherd, John

    2014-03-01

    Purpose. Investigate whether knowledge of the biologic image composition of mammographic lesions provides imagebased biomarkers above and beyond those obtainable from quantitative image analysis (QIA) of X-ray mammography. Methods. The dataset consisted of 45 in vivo breast lesions imaged with the novel 3-component breast (3CB) imaging technique based on dual-energy mammography (15 malignant, 30 benign diagnoses). The 3CB composition measures of water, lipid, and protein thicknesses were assessed and mathematical descriptors, `3CB features', were obtained for the lesions and their periphery. The raw low-energy mammographic images were analyzed with an established in-house QIA method obtaining `QIA features' describing morphology and texture. We investigated the correlation within the `3CB features', within the `QIA features', and between the two. In addition, the merit of individual features in the distinction between malignant and benign lesions was assessed. Results. Whereas many descriptors within the `3CB features' and `QIA features' were, often by design, highly correlated, correlation between descriptors of the two feature groups was much weaker (maximum absolute correlation coefficient 0.58, pappeared equally well-suited for the distinction between malignant and benign lesions, with maximum area under the ROC curve 0.71 for a protein feature (3CB) and 0.71 for a texture feature (QIA). Conclusions. In this pilot study analyzing the new 3CB imaging modality, knowledge of breast tissue composition appeared additive in combination with existing mammographic QIA methods for the distinction between benign and malignant lesions.

  17. 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)

    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

  18. The biological bases of radiation protection

    International Nuclear Information System (INIS)

    Radiation protection is based on a large number of human data collected during the past 80 years. For dose levels of a few hundred rads, risks can be evaluated very accurately. Yet it is difficult to derive from them the risks due to low doses because of the uncertainty on the dose-effect relationship. In the practice, pessimistic assumptions are used, which involves an over-estimation of risks. However, even in these unfavorable conditions, risks associated to occupational activities implying radiation exposure seem to be less important than in most industries. Radiation protection has played a historical and essential part in the quantitative assessment of risks and opened a new era of occupational medicine and environmental health investigations. Many substances, such as radiations, are mutagenic and/or carcinogenic at very low doses, and in many cases human exposure cannot be avoided. Therefore, a policy advocating refusal of any risk whatsoever and absolute safety will lure with unattainable and misleading prospects. The only method is to assess the quantitative importance of the various risks in order to decide how far a damage may be tolerable in the various cases when exposure cannot be avoided

  19. Mesenchymal Stem Cells Isolated from Adipose and Other Tissues: Basic Biological Properties and Clinical Applications

    OpenAIRE

    Hakan Orbay; Morikuni Tobita; Hiroshi Mizuno

    2012-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells that were initially isolated from bone marrow. However, subsequent research has shown that other adult tissues also contain MSCs. MSCs originate from mesenchyme, which is embryonic tissue derived from the mesoderm. These cells actively proliferate, giving rise to new cells in some tissues, but remain quiescent in others. MSCs are capable of differentiating into multiple cell types including adipocytes, chondrocytes, osteocytes, and cardiomyoc...

  20. A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study

    Science.gov (United States)

    White, Shane A.; Reniers, Brigitte; de Jong, Evelyn E. C.; Rusch, Thomas; Verhaegen, Frank

    2016-01-01

    Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB  ≈  1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Wen-Ling Wang; Shi-Yuan Sheu; Yueh-Sheng Chen; Shung-Te Kao; Yuan-Tsung Fu; Tzong-Fu Kuo; Kuo-Yu Chen; Chun-Hsu Yao

    2014-01-01

    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 a...

  3. On optimizing distance-based similarity search for biological databases.

    Science.gov (United States)

    Mao, Rui; Xu, Weijia; Ramakrishnan, Smriti; Nuckolls, Glen; Miranker, Daniel P

    2005-01-01

    Similarity search leveraging distance-based index structures is increasingly being used for both multimedia and biological database applications. We consider distance-based indexing for three important biological data types, protein k-mers with the metric PAM model, DNA k-mers with Hamming distance and peptide fragmentation spectra with a pseudo-metric derived from cosine distance. To date, the primary driver of this research has been multimedia applications, where similarity functions are often Euclidean norms on high dimensional feature vectors. We develop results showing that the character of these biological workloads is different from multimedia workloads. In particular, they are not intrinsically very high dimensional, and deserving different optimization heuristics. Based on MVP-trees, we develop a pivot selection heuristic seeking centers and show it outperforms the most widely used corner seeking heuristic. Similarly, we develop a data partitioning approach sensitive to the actual data distribution in lieu of median splits. PMID:16447992

  4. Frequency domain photoacoustic correlation (radar) imaging: a novel methodology for non-invasive imaging of biological tissues

    Science.gov (United States)

    Telenkov, Sergey A.; Alwi, Rudolf; Mandelis, Andreas; Shi, Willa; Chen, Emily; Vitkin, Alex I.

    2012-02-01

    We report the development of a novel frequency-domain biomedical photoacoustic (PA) system that utilizes a continuous-wave laser source with a custom intensity modulation pattern for spatially-resolved imaging of biological tissues. The feasibility of using relatively long duration and low optical power laser sources for spatially-resolved PA imaging is presented. We demonstrate that B-mode PA imaging can be performed using an ultrasonic phased array coupled with multi-channel correlation processing and a frequency-domain beamforming algorithm. Application of the frequency-domain PA correlation methodology is shown using tissue-like phantoms with embedded optical contrast, tissue ex-vivo samples and a small animal model in-vivo.

  5. Evaluation of a CCD-based tissue imaging system

    International Nuclear Information System (INIS)

    A digital tissue imaging system based on a cooled charge coupled device (CCD) has been developed at the Physics Department of the Institute of Cancer Research. The system images low energy X-ray emissions and β particle emissions from a variety of isotopes, with a position resolution approaching 20μm and sensitivity approaching 100%. Because of the frame-by-frame composite way in which images are constructed, the dynamic range of the system is 16 bit, limited only by the microcomputer used to acquire and store the images. Images have been obtained of isotope distributions in tissue with radioactivity levels which were too low to be detected using conventional technology. Room temperature operation of the CCD in the inverted mode has been investigated

  6. Calculation of RBE for normal tissue complications based on charged particle track structure

    International Nuclear Information System (INIS)

    A new approach for the calculation of RBE for normal tissue complications after charged particle and neutron irradiation is discussed. It is based on the extension of a model originally developed for the application to cell survival. It can be shown, that according to the model RBE values are determined largely by the α/β-ratio of the photon dose response curve, but are expected to be nearly independent of the absolute values of α and β. Thus, the model can be applied to normal tissue complications as well, where α/β-ratios can be determined by means of fractionation experiments. Agreement of model predictions and experimental results obtained in animal experiments confirm the appliability of the model even in the case of complex biological endpoints. (orig.)

  7. Photoacoustic detection and optical spectroscopy of high-intensity focused ultrasound-induced thermal lesions in biologic tissue

    International Nuclear Information System (INIS)

    0.26 (mean ± standard error of the mean). The authors’ spectroscopic investigation has shown that HIFU-treated tissues have a greater optical absorption and reduced scattering coefficients than native tissues in the wavelength range of 500–900 nm. In fact, at 720 and 845 nm, the ratio of the optical absorption coefficient of HIFU-treated tissues to that of native tissues was 1.13 and 1.17, respectively; on the other hand, the ratio of the reduced scattering coefficient of HIFU-treated tissues to that of native tissues was 13.22 and 14.67 at 720 and 845 nm, respectively. Consequently, HIFU-treated tissues have a higher effective attenuation coefficient and a lower light penetration depth than native tissues in the wavelength range 500–900 nm. Conclusions: Using a PA approach, HIFU-treated tissues interrogated at 720 and 845 nm optical wavelengths can be differentiated from untreated tissues. Based on the authors’ spectroscopic investigation, the authors conclude that the observed PA contrast between HIFU-induced thermal lesions and untreated tissue is due, in part, to the increase in the optical absorption coefficient, the reduced scattering coefficient and, therefore, the deposited laser energy fluence in HIFU-treated tissues

  8. Photoacoustic detection and optical spectroscopy of high-intensity focused ultrasound-induced thermal lesions in biologic tissue

    Energy Technology Data Exchange (ETDEWEB)

    Alhamami, Mosa; Kolios, Michael C.; Tavakkoli, Jahan, E-mail: jtavakkoli@ryerson.ca [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada)

    2014-05-15

    0.26 (mean ± standard error of the mean). The authors’ spectroscopic investigation has shown that HIFU-treated tissues have a greater optical absorption and reduced scattering coefficients than native tissues in the wavelength range of 500–900 nm. In fact, at 720 and 845 nm, the ratio of the optical absorption coefficient of HIFU-treated tissues to that of native tissues was 1.13 and 1.17, respectively; on the other hand, the ratio of the reduced scattering coefficient of HIFU-treated tissues to that of native tissues was 13.22 and 14.67 at 720 and 845 nm, respectively. Consequently, HIFU-treated tissues have a higher effective attenuation coefficient and a lower light penetration depth than native tissues in the wavelength range 500–900 nm. Conclusions: Using a PA approach, HIFU-treated tissues interrogated at 720 and 845 nm optical wavelengths can be differentiated from untreated tissues. Based on the authors’ spectroscopic investigation, the authors conclude that the observed PA contrast between HIFU-induced thermal lesions and untreated tissue is due, in part, to the increase in the optical absorption coefficient, the reduced scattering coefficient and, therefore, the deposited laser energy fluence in HIFU-treated tissues.

  9. 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.

  10. Optical fiber based imaging of bioengineered tissue construct

    Science.gov (United States)

    Sapoznik, Etai; Niu, Guoguang; Lu, Peng; Zhou, Yu; Xu, Yong; Soker, Shay

    2016-04-01

    Imaging cells and tissues through opaque and turbid media is challenging and presents a major barrier for monitoring maturation and remodeling of bioengineered tissues. The fiber optics based imaging system described here offers a new approach for fluorescent cell imaging. A micro imaging channel is embedded in a Polycaprolactone (PCL) electrospun scaffold designed for cell seeding, which allows us to use an optical fiber to locally deliver excitation laser close to the fluorescent cells. The emission is detected by an Electron Multiplying Charge Coupled Device (EMCCD) detector and image reconstruction of multiple excitation points is achieved with a working distance of several centimeters. The objective of this study is to assess the effects of system parameters on image reconstruction outcomes. Initial studies using fluorescent beads indicated that scaffold thickness had a small effect on image quality, whereas scaffold composition (collagen content), fluorophore spectra, and the reconstruction window size had a large effect. The results also suggest that a far-red fluorescent emission is preferential when using collagenous scaffolds with a thickness of up to 500 μm. Using these optimized parameters, we were able to image fluorescently labeled cells on a scaffold with a resolution of 15-20 μm, and have also measured muscle progenitor cell differentiation and scaffold surface coverage with endothelial cells. In the future, this imaging platform can be applied to other bioengineered tissues for non-invasive monitoring both in vitro and in vivo.

  11. Magnetic resonance brain tissue segmentation based on sparse representations

    Science.gov (United States)

    Rueda, Andrea

    2015-12-01

    Segmentation or delineation of specific organs and structures in medical images is an important task in the clinical diagnosis and treatment, since it allows to characterize pathologies through imaging measures (biomarkers). In brain imaging, segmentation of main tissues or specific structures is challenging, due to the anatomic variability and complexity, and the presence of image artifacts (noise, intensity inhomogeneities, partial volume effect). In this paper, an automatic segmentation strategy is proposed, based on sparse representations and coupled dictionaries. Image intensity patterns are singly related to tissue labels at the level of small patches, gathering this information in coupled intensity/segmentation dictionaries. This dictionaries are used within a sparse representation framework to find the projection of a new intensity image onto the intensity dictionary, and the same projection can be used with the segmentation dictionary to estimate the corresponding segmentation. Preliminary results obtained with two publicly available datasets suggest that the proposal is capable of estimating adequate segmentations for gray matter (GM) and white matter (WM) tissues, with an average overlapping of 0:79 for GM and 0:71 for WM (with respect to original segmentations).

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

    International Nuclear Information System (INIS)

    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

  13. Biological tissue adhesive for multiple use in the accident and emergency department

    OpenAIRE

    Gerrard, C.; S. Moore; Ryan, B

    2000-01-01

    Objective—To assess the strength of the glue and microbial contamination over 28 days from opening a vial of tissue adhesive in the accident and emergency setting, and to quantify cost savings of repeated use of the vials.

  14. The role of pH fronts in tissue electroporation based treatments.

    Directory of Open Access Journals (Sweden)

    Felipe Maglietti

    Full Text Available Treatments based on electroporation (EP induce the formation of pores in cell membranes due to the application of pulsed electric fields. We present experimental evidence of the existence of pH fronts emerging from both electrodes during treatments based on tissue EP, for conditions found in many studies, and that these fronts are immediate and substantial. pH fronts are indirectly measured through the evanescence time (ET, defined as the time required for the tissue buffer to neutralize them. The ET was measured through a pH indicator imaged at a series of time intervals using a four-cluster hard fuzzy-c-means algorithm to segment pixels corresponding to the pH indicator at every frame. The ET was calculated as the time during which the number of pixels was 10% of those in the initial frame. While in EP-based treatments such as reversible (ECT and irreversible electroporation (IRE the ET is very short (though enough to cause minor injuries due to electric pulse characteristics and biological buffers present in the tissue, in gene electrotransfer (GET, ET is much longer, enough to denaturate plasmids and produce cell damage. When any of the electric pulse parameters is doubled or tripled the ET grows and, remarkably, when any of the pulse parameters in GET is halved, the ET drops significantly. Reducing pH fronts has relevant implications for GET treatment efficiency, due to a substantial reduction of plasmid damage and cell loss.

  15. Bioreactor Conditioning for Accelerated Remodeling of Fibrin-Based Tissue Engineered Heart Valves

    Science.gov (United States)

    Schmidt, Jillian Beth

    Fibrin is a promising scaffold material for tissue engineered heart valves, as it is completely biological, allows for engineered matrix alignment, and is able to be degraded and replaced with collagen by entrapped cells. However, the initial fibrin matrix is mechanically weak, and extensive in vitro culture is required to create valves with sufficient mechanical strength and stiffness for in vivo function. Culture in bioreactor systems, which provide cyclic stretching and enhance nutrient transport, has been shown to increase collagen production by cells entrapped in a fibrin scaffold, accelerating strengthening of the tissue and reducing the required culture time. In the present work, steps were taken to improve bioreactor culture conditions with the goal of accelerating collagen production in fibrin-based tissue engineered heart valves using two approaches: (i) optimizing the cyclic stretching protocol and (ii) developing a novel bioreactor system that permits transmural and lumenal flow of culture medium for improved nutrient transport. The results indicated that incrementally increasing strain amplitude cyclic stretching with small, frequent increments in strain amplitude was optimal for collagen production in our system. In addition, proof of concept studies were performed in the novel bioreactor system and increased cellularity and collagen deposition near the lumenal surface of the tissue were observed.

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

    OpenAIRE

    Mim Mim Lim; Tao Sun; Naznin Sultana

    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...

  17. Constitutive gene expression and specification of tissue identity in adult planarian biology

    OpenAIRE

    Reddien, Peter W.

    2011-01-01

    Planarians are flatworms that constitutively maintain adult tissues through cell turnover and can regenerate entire organisms from tiny body fragments. In addition to requiring new cells (from neoblasts), these feats require mechanisms that specify tissue identity in the adult. Critical roles for Wnt and BMP signaling in regeneration and maintenance of the body axes have been uncovered, among other regulatory factors. Available data indicate that genes involved in positional identity regulati...

  18. Thermal distribution in biological tissue at laser induced fluorescence and photodynamic therapy

    Science.gov (United States)

    Krasnikov, I. V.; Seteikin, A. Yu.; Drakaki, E.; Makropoulou, M.

    2012-03-01

    Laser induced fluorescence spectroscopy and photodynamic therapy (PDT) are techniques currently introduced in clinical applications for visualization and local destruction of malignant tumours as well as premalignant lesions. During the laser irradiation of tissues for the diagnostic and therapeutic purposes, the absorbed optical energy generates heat, although the power density of the treatment light for surface illumination is normally low enough not to cause any significantly increased tissue temperature. In this work we tried to evaluate the utility of Monte Carlo modeling for simulating the temperature fields and the dynamics of heat conduction into the skin tissue under several laser irradiation conditions with both a pulsed UV laser and a continuous wave visible laser beam. The analysis of the results showed that heat is not localized on the surface, but it is collected inside the tissue. By varying the boundary conditions on the surface and the type of the laser radiation (continuous or pulsed) we can reach higher than normal temperature inside the tissue without simultaneous formation of thermally damaged tissue (e.g. coagulation or necrosis zone).

  19. Red laser attenuation in biological tissues: study of the inflammatory process and pigmentation influence

    Science.gov (United States)

    Sabino, Caetano P.; Meneguzzo, Daiane T.; Benetti, Endi; Kato, Ilka T.; Prates, Renato A.; Ribeiro, Martha S.

    2012-03-01

    Several studies indicate that low level laser therapy (LLLT) accelerates the healing process, however, for a determined pathology, dosimetry remains difficult to be established. To understand the tissue optical properties under different conditions is extremely relevant since the dose delivered to the target tissue is known to be critical. The skin pigmentation influence on the laser attenuation is not yet well established on different mice lineages or human ethnical groups, making the dose problematic. Along the same line, inflammatory processes may cause similar problems since the tissues in this condition change their optical properties due to inflammatory cell accumulation. This work evaluated the attenuation pattern of a HeNe laser (λ=632.8 nm) using ex vivo skin samples from Balb/C and C57BL/6 mice under inflammatory stages induced in their paw by local carrageenan inoculation. The samples were placed between two microscope slides, and a CCD camera was placed orthogonal to the beam path. The intensity distribution of the scattered light was photographed in grayscale and analyzed by ImageJ software. Our findings suggest that even slight differences of the epithelial pigmentation could result in a relevant dose loss delivered to the deeper tissues. The increase of the inflammatory cell density in the connective tissue indicated a highly scattering area also resulting in a dose loss for the deeper tissues when compared to control group.

  20. 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. PMID:26566174

  1. Biological Impact of Music and Software-Based Auditory Training

    Science.gov (United States)

    Kraus, Nina

    2012-01-01

    Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals--both young and old--encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in…

  2. A Project-Based Biologically-Inspired Robotics Module

    Science.gov (United States)

    Crowder, R. M.; Zauner, K.-P.

    2013-01-01

    The design of any robotic system requires input from engineers from a variety of technical fields. This paper describes a project-based module, "Biologically-Inspired Robotics," that is offered to Electronics and Computer Science students at the University of Southampton, U.K. The overall objective of the module is for student groups to…

  3. Visualization of Nanofibrillar Cellulose in Biological Tissues Using a Biotinylated Carbohydrate Binding Module of β-1,4-Glycanase.

    Science.gov (United States)

    Knudsen, Kristina Bram; Kofoed, Christian; Espersen, Roall; Højgaard, Casper; Winther, Jakob Rahr; Willemoës, Martin; Wedin, Irene; Nuopponen, Markus; Vilske, Sara; Aimonen, Kukka; Weydahl, Ingrid Elise Konow; Alenius, Harri; Norppa, Hannu; Wolff, Henrik; Wallin, Håkan; Vogel, Ulla

    2015-08-17

    Nanofibrillar cellulose is a very promising innovation with diverse potential applications including high quality paper, coatings, and drug delivery carriers. The production of nanofibrillar cellulose on an industrial scale may lead to increased exposure to nanofibrillar cellulose both in the working environment and the general environment. Assessment of the potential health effects following exposure to nanofibrillar cellulose is therefore required. However, as nanofibrillar cellulose primarily consists of glucose moieties, detection of nanofibrillar cellulose in biological tissues is difficult. We have developed a simple and robust method for specific and sensitive detection of cellulose fibers, including nanofibrillar cellulose, in biological tissue, using a biotinylated carbohydrate binding module (CBM) of β-1,4-glycanase (EXG:CBM) from the bacterium Cellulomonas fimi. EXG:CBM was expressed in Eschericia coli, purified, and biotinylated. EXG:CBM was shown to bind quantitatively to five different cellulose fibers including four different nanofibrillar celluloses. Biotinylated EXG:CBM was used to visualize cellulose fibers by either fluorescence- or horse radish peroxidase (HRP)-tagged avidin labeling. The HRP-EXG:CBM complex was used to visualize cellulose fibers in both cryopreserved and paraffin embedded lung tissue from mice dosed by pharyngeal aspiration with 10-200 μg/mouse. Detection was shown to be highly specific, and the assay appeared very robust. The present method represents a novel concept for the design of simple, robust, and highly specific detection methods for the detection of nanomaterials, which are otherwise difficult to visualize. PMID:26208679

  4. 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)

  5. Biological impact of music and software-based auditory training

    OpenAIRE

    Kraus, Nina

    2012-01-01

    Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals – both young and old – encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in noisy environments and reading, pointing to an intersection between hearing and cognition. Musical experience, amplification, and software-based ...

  6. Synthetic biology for microbial production of lipid-based biofuels.

    Science.gov (United States)

    d'Espaux, Leo; Mendez-Perez, Daniel; Li, Rachel; Keasling, Jay D

    2015-12-01

    The risks of maintaining current CO2 emission trends have led to interest in producing biofuels using engineered microbes. Microbial biofuels reduce emissions because CO2 produced by fuel combustion is offset by CO2 captured by growing biomass, which is later used as feedstock for biofuel fermentation. Hydrocarbons found in petroleum fuels share striking similarity with biological lipids. Here we review synthetic metabolic pathways based on fatty acid and isoprenoid metabolism to produce alkanes and other molecules suitable as biofuels. We further discuss engineering strategies to optimize engineered biosynthetic routes, as well as the potential of synthetic biology for sustainable manufacturing. PMID:26479184

  7. 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.

  8. 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

  9. The potential of standards-based agriculture biology as an alternative to traditional biology in California

    Science.gov (United States)

    Sellu, George Sahr

    schools. Thoron & Meyer (2011) suggested that research into the contribution of integrated science courses toward higher test scores yielded mixed results. This finding may have been due in part to the fact that integrated science courses only incorporate select topics into agriculture education courses. In California, however, agriculture educators have developed standards-based courses such as Agriculture Biology (AgBio) that cover the same content standards as core traditional courses such as traditional biology. Students in both AgBio and traditional biology take the same standardized biology test. This is the first time there has been an opportunity for a fair comparison and a uniform metric for an agriscience course such as AgBio to be directly compared to traditional biology. This study will examine whether there are differences between AgBio and traditional biology with regard to standardized test scores in biology. Furthermore, the study examines differences in perception between teachers and students regarding teaching and learning activities associated with higher achievement in science. The findings of the study could provide a basis for presenting AgBio as a potential alternative to traditional biology. The findings of this study suggest that there are no differences between AgBio and traditional biology students with regard to standardized biology test scores. Additionally, the findings indicate that co-curricular activities in AgBio could contribute higher student achievement in biology. However, further research is required to identify specific activities in AgBio that contribute to higher achievement in science.

  10. 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.).

  11. 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. PMID:25910818

  12. A new era in brown adipose tissue biology: molecular control of brown fat development and energy homeostasis.

    Science.gov (United States)

    Kajimura, Shingo; Saito, Masayuki

    2014-01-01

    Brown adipose tissue (BAT) is specialized to dissipate chemical energy in the form of heat as a defense against cold and excessive feeding. Interest in the field of BAT biology has exploded in the past few years because of the therapeutic potential of BAT to counteract obesity and obesity-related diseases, including insulin resistance. Much progress has been made, particularly in the areas of BAT physiology in adult humans, developmental lineages of brown adipose cell fate, and hormonal control of BAT thermogenesis. As we enter into a new era of brown fat biology, the next challenge will be to develop strategies for activating BAT thermogenesis in adult humans to increase whole-body energy expenditure. This article reviews the recent major advances in this field and discusses emerging questions. PMID:24188710

  13. 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

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    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...

  16. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  17. 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.

  18. Mesenchymal stromal cells derived from various tissues: Biological, clinical and cryopreservation aspects.

    Science.gov (United States)

    Marquez-Curtis, Leah A; Janowska-Wieczorek, Anna; McGann, Locksley E; Elliott, Janet A W

    2015-10-01

    Originally isolated from bone marrow, mesenchymal stromal cells (MSCs) have since been obtained from various fetal and post-natal tissues and are the focus of an increasing number of clinical trials. Because of their tremendous potential for cellular therapy, regenerative medicine and tissue engineering, it is desirable to cryopreserve and bank MSCs to increase their access and availability. A remarkable amount of research and resources have been expended towards optimizing the protocols, freezing media composition, cooling devices and storage containers, as well as developing good manufacturing practices in order to ensure that MSCs retain their therapeutic characteristics following cryopreservation and that they are safe for clinical use. Here, we first present an overview of the identification of MSCs, their tissue sources and the properties that render them suitable as a cellular therapeutic. Next, we discuss the responses of cells during freezing and focus on the traditional and novel approaches used to cryopreserve MSCs. We conclude that viable MSCs from diverse tissues can be recovered after cryopreservation using a variety of freezing protocols, cryoprotectants, storage periods and temperatures. However, alterations in certain functions of MSCs following cryopreservation warrant future investigations on the recovery of cells post-thaw followed by expansion of functional cells in order to achieve their full therapeutic potential. PMID:26186998

  19. Gene expression in midgut tissues of Diaphorina citri: Application to biology and vector control

    Science.gov (United States)

    We produced a gene expression dataset from the midgut tissues of the Asian citrus psyllid (AsCP), Diaphorina citri (Hemiptera: Psyllidae). The AsCP is the primary vector associated with the spread of a devastating citrus trees disease, huanglongbing (HLB). The occurrence and spread of the AsCP and H...

  20. 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.

  1. 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

    2013-07-16

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) 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 (14)C 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. (14)C 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. (14)C 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 (14)C 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. PMID:23818577

  2. Cancer tissue engineering - new perspectives in understanding the biology of solid tumours - a critical review

    NARCIS (Netherlands)

    Ricci, C.; Moroni, L.; Danti, S.

    2013-01-01

    Understanding cancer biology is a major challenge of this century. The recent insight about carcinogenesis mechanisms, including the role exerted by the tumour microenvironment and cancer stem cells in chemoresistance, relapse and metastases, has made it self-evident that only new cancer models, wit

  3. Advancing cardiovascular tissue engineering

    Science.gov (United States)

    Truskey, George A.

    2016-01-01

    Cardiovascular tissue engineering offers the promise of biologically based repair of injured and damaged blood vessels, valves, and cardiac tissue. Major advances in cardiovascular tissue engineering over the past few years involve improved methods to promote the establishment and differentiation of induced pluripotent stem cells (iPSCs), scaffolds from decellularized tissue that may produce more highly differentiated tissues and advance clinical translation, improved methods to promote vascularization, and novel in vitro microphysiological systems to model normal and diseased tissue function. iPSC technology holds great promise, but robust methods are needed to further promote differentiation. Differentiation can be further enhanced with chemical, electrical, or mechanical stimuli. PMID:27303643

  4. High concentrations of drug in target tissues following local controlled release are utilized for both drug distribution and biologic effect: An example with epicardial inotropic drug delivery

    OpenAIRE

    Maslov, Mikhail Y.; Edelman, Elazer R.; Wei, Abraham E.; Pezone, Matthew J.; Lovich, Mark A.

    2013-01-01

    Local drug delivery preferentially loads target tissues with a concentration gradient from the surface or point of release that tapers down to more distant sites. Drug that diffuses down this gradient must be in unbound form, but such drug can only elicit a biologic effect through receptor interactions. Drug excess loads tissues, increasing gradients and driving penetration, but with limited added biological response. We examined the hypothesis that local application reduces dramatically syst...

  5. A novel Tissue-Equivalent Proportional Counter based on a Gas Electron Multiplier

    OpenAIRE

    M. Farahmand

    2004-01-01

    Ionising radiation causes a wide variety of effects in biological targets. In experimental microdosimetry these effects are studied by investigating the statistical distribution of energy deposition events at the microscopic level employing a Tissue-Equivalent Proportional Counter (TEPC). A TEPC is usually designed with a cavity of a few centimetres in diameter containing a central anode wire and operated with a tissue-equivalent wall and counting gas at low pressure to simulate tissue volume...

  6. 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.

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

    International Nuclear Information System (INIS)

    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

  8. Sex differences in human adipose tissues – the biology of pear shape

    OpenAIRE

    Karastergiou Kalypso; Smith Steven R; Greenberg Andrew S; Fried Susan K

    2012-01-01

    Abstract Women have more body fat than men, but in contrast to the deleterious metabolic consequences of the central obesity typical of men, the pear-shaped body fat distribution of many women is associated with lower cardiometabolic risk. To understand the mechanisms regulating adiposity and adipose tissue distribution in men and women, significant research attention has focused on comparing adipocyte morphological and metabolic properties, as well as the capacity of preadipocytes derived fr...

  9. Biologic function and clinical potential of telomerase and associated proteins in cardiovascular tissue repair and regeneration

    OpenAIRE

    Madonna, Rosalinda; De Caterina, Raffaele; Willerson, James T.; Geng, Yong-Jian

    2010-01-01

    Telomeres comprise long tracts of double-stranded TTAGGG repeats that extend for 9–15 kb in humans. Telomere length is maintained by telomerase, a specialized ribonucleoprotein that prevents the natural ends of linear chromosomes from undergoing inappropriate repair, which could otherwise lead to deleterious chromosomal fusions. During the development of cardiovascular tissues, telomerase activity is strong but diminishes with age in adult hearts. Dysfunction of telomerase is associated with ...

  10. Resonant second-harmonic-generation circular-dichroism microscopy reveals molecular chirality in native biological tissues

    CERN Document Server

    Chen, Mei-Yu; Kan, Che-Wei; Lin, Yen-Yin; Ye, Cin-Wei; Wu, Meng-Jer; Liu, Hsiang-Lin; Chu, Shi-Wei

    2016-01-01

    Conventional linear optical activity effects are widely used for studying chiral materials. However, poor contrast and artifacts due to sample anisotropy limit the applicability of these methods. Here we demonstrate that nonlinear second-harmonic-generation circular dichroism spectral microscopy can overcome these limits. In intact collagenous tissues, clear spectral resonance is observed with sub-micrometer spatial resolution. By performing gradual protein denaturation studies, we show that the resonant responses are dominantly due to the molecular chirality.

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

    OpenAIRE

    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 res...

  12. Atmospheric-pressure Molecular Imaging of Biological Tissues and Biofilms by LAESI Mass Spectrometry

    OpenAIRE

    Nemes, Peter; Vertes, Akos

    2010-01-01

    Ambient ionization methods in mass spectrometry allow analytical investigations to be performed directly on a tissue or biofilm under native-like experimental conditions. Laser ablation electrospray ionization (LAESI) is one such development and is particularly well-suited for the investigation of water-containing specimens. LAESI utilizes a mid-infrared laser beam (2.94 μm wavelength) to excite the water molecules of the sample. When the ablation fluence threshold is exceeded, the sample mat...

  13. Biological and engineering design considerations for vascular tissue engineered blood vessels (TEBVs)

    OpenAIRE

    Fernandez, Cristina E.; Achneck, Hardean E.; Reichert, William M.; Truskey, George A.

    2014-01-01

    Considerable advances have occurred in the development of tissue-engineered blood vessels (TEBVs) to repair or replace injured blood vessels, or as in vitro systems for drug toxicity testing. Here we summarize approaches to produce TEBVs and review current efforts to (1) identify suitable cell sources for the endothelium and vascular smooth muscle cells, (2) design the scaffold to mimic the arterial mechanical properties and (3) regulate the functional state of the cells of the vessel wall. I...

  14. Identifying discriminative classification-based motifs in biological sequences

    OpenAIRE

    Vens, Celine; Rosso, Marie-Noëlle; Danchin, Etienne

    2011-01-01

    Motivation: Identification of conserved motifs in biological sequences is crucial to unveil common shared functions. Many tools exist for motif identification, including some that allow degenerate positions with multiple possible nucleotides or amino acids. Most efficient methods available today search conserved motifs in a set of sequences, but do not check for their specificity regarding to a set of negative sequences. Results: We present a tool to identify degenerate motifs, based on a giv...

  15. Applications of Case-Based Reasoning in Molecular Biology

    OpenAIRE

    Jurisica, Igor; Glasgow, Janice

    2004-01-01

    Case-based reasoning (CBR) is a computational reasoning paradigm that involves the storage and retrieval of past experiences to solve novel problems. It is an approach that is particularly relevant in scientific domains, where there is a wealth of data but often a lack of theories or general principles. This article describes several CBR systems that have been developed to carry out planning, analysis, and prediction in the domain of molecular biology.

  16. Sleep and Multisystem Biological Risk: A Population-Based Study

    OpenAIRE

    Carroll, Judith E.; Irwin, Michael R.; Merkin, Sharon Stein; Seeman, Teresa E

    2015-01-01

    Background Short sleep and poor sleep quality are associated with risk of cardiovascular disease, diabetes, cancer, and mortality. This study examines the contribution of sleep duration and sleep quality on a multisystem biological risk index that is known to be associated with morbidity and mortality. Methods Analyses include a population-based sample from the Midlife Development in the United States survey recruited to the Biomarker substudy. A total of 1,023 participants aged 54.5 years (S...

  17. Biologically-inspired Microfluidic Platforms and Aptamer-based Nanobiosensors

    OpenAIRE

    Cho, Hansang

    2010-01-01

    Recent advances in micro/nano- technologies have shown high potentials in the field of quantitative biology, biomedical science, and analytical chemistry. However, micro/nano fluidics still requires multi-layered structures, complex plumbing/tubing, and external equipments for large-scale applications and nanotechnology-based sensors demand high cost. Interestingly, nature has much simpler and more effective solutions. The goal of this dissertation is to develop novel microfluidic platforms a...

  18. Mass spectrometry-based proteomics in cell biology

    OpenAIRE

    Walther, T. C.; Mann, M

    2010-01-01

    The global analysis of protein composition, modifications, and dynamics are important goals in cell biology. Mass spectrometry (MS)–based proteomics has matured into an attractive technology for this purpose. Particularly, high resolution MS methods have been extremely successful for quantitative analysis of cellular and organellar proteomes. Rapid advances in all areas of the proteomic workflow, including sample preparation, MS, and computational analysis, should make the technology more eas...

  19. What is infidelity? Perceptions based on biological sex and personality

    OpenAIRE

    Thornton V; Nagurney AJ

    2011-01-01

    Victoria Thornton, Alexander NagurneyTexas State University – San Marcos, San Marcos, Texas, USAAbstract: The study examines perceptions of infidelity, paying particular attention to how these perceptions differ based on biological sex and personality traits, specifically agency and communion and their unmitigated counterparts. The study utilizes a sample of 125 male and 233 female college students. In addition to the personality measures, participants completed a 19-item checklist ...

  20. Bioinformatics glossary based Database of Biological Databases: DBD

    OpenAIRE

    Siva Kiran RR; Setty MVN; Hanumatha Rao G

    2009-01-01

    Database of Biological/Bioinformatics Databases (DBD) is a collection of 1669 databases and online resources collected from NAR Database Summary Papers (http://www.oxfordjournals.org/nar/database/a/) & Internet search engines. The database has been developed based on 437 keywords (Glossary) available in http://falcon.roswellpark.org/labweb/glossary.html. Keywords with their relevant databases are arranged in alphabetic order which enables quick accession of databases by researchers. Dat...

  1. Competency-based reforms of the undergraduate biology curriculum: integrating the physical and biological sciences.

    Science.gov (United States)

    Thompson, Katerina V; Chmielewski, Jean; Gaines, Michael S; Hrycyna, Christine A; LaCourse, William R

    2013-06-01

    The National Experiment in Undergraduate Science Education project funded by the Howard Hughes Medical Institute is a direct response to the Scientific Foundations for Future Physicians report, which urged a shift in premedical student preparation from a narrow list of specific course work to a more flexible curriculum that helps students develop broad scientific competencies. A consortium of four universities is working to create, pilot, and assess modular, competency-based curricular units that require students to use higher-order cognitive skills and reason across traditional disciplinary boundaries. Purdue University; the University of Maryland, Baltimore County; and the University of Miami are each developing modules and case studies that integrate the biological, chemical, physical, and mathematical sciences. The University of Maryland, College Park, is leading the effort to create an introductory physics for life sciences course that is reformed in both content and pedagogy. This course has prerequisites of biology, chemistry, and calculus, allowing students to apply strategies from the physical sciences to solving authentic biological problems. A comprehensive assessment plan is examining students' conceptual knowledge of physics, their attitudes toward interdisciplinary approaches, and the development of specific scientific competencies. Teaching modules developed during this initial phase will be tested on multiple partner campuses in preparation for eventual broad dissemination. PMID:23737624

  2. 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.

  3. Impact of tissue specific parameters on the predition of the biological effectiveness for treatment planning in ion beam therapy

    International Nuclear Information System (INIS)

    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

  4. A Biologically Based Chemo-Sensing UAV for Humanitarian Demining

    Directory of Open Access Journals (Sweden)

    Paul F.M.J. Verschure

    2008-11-01

    Full Text Available Antipersonnel mines, weapons of cheap manufacture but lethal effect, have a high impact on the population even decades after the conflicts have finished. Here we investigate the use of a chemo-sensing Unmanned Aerial Vehicle (cUAV for demining tasks. We developed a blimp based UAV that is equipped with a broadly tuned metal-thin oxide chemo-sensor. A number of chemical mapping strategies were investigated including two biologically based localization strategies derived from the moth chemical search that can optimize the efficiency of the detection and localization of explosives and therefore be used in the demining process. Additionally, we developed a control layer that allows for both fully autonomous and manual controlled flight, as well as for the scheduling of a fleet of cUAVs. Our results confirm the feasibility of this technology for demining in real-world scenarios and give further support to a biologically based approach where the understanding of biological systems is used to solve difficult engineering problems.

  5. Which, when and why? Rational use of tissue-based molecular testing in localized prostate cancer.

    Science.gov (United States)

    Ross, A E; D'Amico, A V; Freedland, S J

    2016-03-01

    An increased molecular understanding of localized prostate cancer and the improved ability for molecular testing of pathologic tissue has led to the development of multiple clinical assays. Here we review the relevant molecular biology of localized prostate cancer, currently available tissue-based tests and describe which is best supported for use in various clinical scenarios. Literature regarding testing of human prostate cancer tissue with Ki-67, PTEN (by immunohistochemistry (IHC) or fluroescence in situ hybridization (FISH)), ProMark, Prolaris, OncotypeDX Prostate and Decipher was reviewed to allow for generation of expert opinions. At diagnosis, evaluation of PTEN status, use of ProMark or OncotypeDX Prostate in men with Gleason 6 or 3+4=7 disease may help guide the use of active surveillance. For men with Gleason 7 or above disease considering watchful waiting, Ki-67 and Prolaris add independent prognostic information. For those men who have undergone prostatectomy and have adverse pathology, Decipher testing may aid in the decision to undergo adjuvant radiation. Newly available molecular tests bring opportunities to improve decision making for men with localized prostate cancer. A review of the currently available data suggests clinical scenarios for which each of these tests may have the greatest utility. PMID:26123120

  6. Energy transmission transformer for a wireless capsule endoscope: analysis of specific absorption rate and current density in biological tissue.

    Science.gov (United States)

    Shiba, Kenji; Nagato, Tomohiro; Tsuji, Toshio; Koshiji, Kohji

    2008-07-01

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype energy transmission system for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current. PMID:18595805

  7. 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.

  8. Study of the temperature rise induced by a focusing transducer with a wide aperture angle on biological tissue containing ribs

    Science.gov (United States)

    Xin, Wang; Jiexing, Lin; Xiaozhou, Liu; Jiehui, Liu; Xiufen, Gong

    2016-04-01

    We used the spheroidal beam equation to calculate the sound field created by focusing a transducer with a wide aperture angle to obtain the heat deposition, and then we used the Pennes bioheat equation to calculate the temperature field in biological tissue with ribs and to ascertain the effects of rib parameters on the temperature field. The results show that the location and the gap width between the ribs have a great influence on the axial and radial temperature rise of multilayer biological tissue. With a decreasing gap width, the location of the maximum temperature rise moves forward; as the ribs are closer to the transducer surface, the sound energy that passes through the gap between the ribs at the focus decreases, the maximum temperature rise decreases, and the location of the maximum temperature rise moves forward with the ribs. 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 No. 020414380001), the Fund from State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLA201401), China Postdoctoral Science Foundation (Grant No. 2013M531313), and the Priority Academic Program Development of Jiangsu Higher Education Institutions and SRF for ROCS, SEM.

  9. Cardiovascular tissue engineering and regeneration based on adipose tissue-derived stem/stromal cells

    OpenAIRE

    Parvizi, Mojtaba

    2016-01-01

    Currently, the pre-clinical field is rapidly progressing in search of new therapeutic modalities that replace or complement current medication to treat cardiovascular disease. Among these are the single or combined use of stem cells, biomaterials and instructive factors, which together form the triad of tissue engineering and regenerative medicine. Stem cell therapy is a promising approach for repair, remodeling and even regenerate tissue of otherwise irreparable damage, such as after myocard...

  10. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    Science.gov (United States)

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  11. Magnetic Thermal Ablation Using Ferrofluids: Influence of Administration Mode on Biological Effect in Different Porcine Tissues

    International Nuclear Information System (INIS)

    The purpose of this study was to compare the effects of magnetic thermal ablation in different porcine tissues using either a singular injection or a continuous infusion of superparamagnetic iron oxide nanoparticles. In the first setting samples of three ferrofluids containing different amounts of iron (1:171, 2:192, and 3:214 mg/ml) were singularly interstitially injected into specimens of porcine liver, kidney, and muscle (n = 5). Then the specimens were exposed to an alternating magnetic field (2.86 kA/m, 190 kHz) generated by a circular coil for 5 min. In the second experimental setup ferrofluid samples were continuously interstitially infused into the tissue specimens during the exposure to the magnetic field. To measure the temperature increase two fiber-optic temperature probes with a fixed distance of 0.5 cm were inserted into the specimens along the puncture tract of the injection needle and the temperature was measured every 15 s. Finally, the specimens were dissected, the diameters of the created thermal lesions were measured, and the volumes were calculated and compared. Compared to continuous infusion, a single injection of ferrofluids resulted in smaller coagulation volumes in all tissues. Significant differences regarding coagulation volume were found in kidney and muscle specimens. The continuous infusion technique led to more elliptically shaped coagulation volumes due to larger diameters along the puncture tract. Our data show the feasibility of magnetic thermal ablation using either a single interstitial injection or continuous infusion for therapy of lesions in muscle, kidney, and liver. Continuous infusion of ferrofluids results in larger zones of necrosis compared to a single injection technique.

  12. FTIR spectroscopic imaging and mapping with correcting lenses for studies of biological cells and tissues.

    Science.gov (United States)

    Kimber, James A; Foreman, Liberty; Turner, Benjamin; Rich, Peter; Kazarian, Sergei G

    2016-06-23

    Histopathology of tissue samples is used to determine the progression of cancer usually by staining and visual analysis. It is recognised that disease progression from healthy tissue to cancerous is accompanied by spectral signature changes in the mid-infrared range. In this work, FTIR spectroscopic imaging in transmission mode using a focal plane array (96 × 96 pixels) has been applied to the characterisation of Barrett's oesophageal adenocarcinoma. To correct optical aberrations, infrared transparent lenses were used of the same material (CaF2) as the slide on which biopsies were fixed. The lenses acted as an immersion objective, reducing scattering and improving spatial resolution. A novel mapping approach using a sliding lens is presented where spectral images obtained with added lenses are stitched together such that the dataset contained a representative section of the oesophageal tissue. Images were also acquired in transmission mode using high-magnification optics for enhanced spatial resolution, as well as with a germanium micro-ATR objective. The reduction of scattering was assessed using k-means clustering. The same tissue section map, which contained a region of high grade dysplasia, was analysed using hierarchical clustering analysis. A reduction of the trough at 1077 cm(-1) in the second derivative spectra was identified as an indicator of high grade dysplasia. In addition, the spatial resolution obtained with the lens using high-magnification optics was assessed by measurements of a sharp interface of polymer laminate, which was also compared with that achieved with micro ATR-FTIR imaging. In transmission mode using the lens, it was determined to be 8.5 μm and using micro-ATR imaging, the resolution was 3 μm for the band at a wavelength of ca. 3 μm. The spatial resolution was also assessed with and without the added lens, in normal and high-magnification modes using a USAF target. Spectroscopic images of cells in transmission mode using two

  13. 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

    would be appropriate for further calculations. The thresholds calculated range below the peak pressure amplitudes used in continuous wave diagnostic instruments, indicating the need for a more careful investigation both of this damage mechanism and of the exposures used in routine diagnosis. The results...... occurs with severe associated shear stresses. The evidence for the existence of microbubbles in tissues is reviewed. The results of calculations, using two existing theoretical models, of the peak pressure threshold as a function of frequency are presented. The frequency is normalized with the resonant...

  14. 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 ostatní: 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

  15. Quantitative autoradiography of radionuclides in biological tissues by high resolution nuclear analysis: application in radio-toxicology and dosimetry

    International Nuclear Information System (INIS)

    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.)

  16. Laser method of biological activity stimulation of cryoconserved hemopoietic tissue transplant

    Science.gov (United States)

    Khyznyak, Anatoly I.; Lesnik, Svetlana A.; Kogut, Georgy I.; Glukhenkaya, Galina T.

    1994-02-01

    The biological activity of cryoconserved fetal liver cells of mice (FLM) having undergone the He-Ne laser action has been estimated by the efficiency of their transplantation to mice- recipients exposed to lethal x-ray dose. The survival rate 30 days after x-ray exposure for those mice was 75% in comparison with 70% for mice with cryoconserved nonirradiated graft. The trial animals' peripheral blood investigations have been made. The obtained results indicate that the laser method of cryoconserved cells stimulation can help to increase the therapeutic efficiency of mielotransplantation.

  17. Web-based software tool for constraint-based design specification of synthetic biological systems.

    Science.gov (United States)

    Oberortner, Ernst; Densmore, Douglas

    2015-06-19

    miniEugene provides computational support for solving combinatorial design problems, enabling users to specify and enumerate designs for novel biological systems based on sets of biological constraints. This technical note presents a brief tutorial for biologists and software engineers in the field of synthetic biology on how to use miniEugene. After reading this technical note, users should know which biological constraints are available in miniEugene, understand the syntax and semantics of these constraints, and be able to follow a step-by-step guide to specify the design of a classical synthetic biological system-the genetic toggle switch.1 We also provide links and references to more information on the miniEugene web application and the integration of the miniEugene software library into sophisticated Computer-Aided Design (CAD) tools for synthetic biology ( www.eugenecad.org ). PMID:25426642

  18. Network-based analysis of affected biological processes in type 2 diabetes models.

    Directory of Open Access Journals (Sweden)

    Manway Liu

    2007-06-01

    Full Text Available Type 2 diabetes mellitus is a complex disorder associated with multiple genetic, epigenetic, developmental, and environmental factors. Animal models of type 2 diabetes differ based on diet, drug treatment, and gene knockouts, and yet all display the clinical hallmarks of hyperglycemia and insulin resistance in peripheral tissue. The recent advances in gene-expression microarray technologies present an unprecedented opportunity to study type 2 diabetes mellitus at a genome-wide scale and across different models. To date, a key challenge has been to identify the biological processes or signaling pathways that play significant roles in the disorder. Here, using a network-based analysis methodology, we identified two sets of genes, associated with insulin signaling and a network of nuclear receptors, which are recurrent in a statistically significant number of diabetes and insulin resistance models and transcriptionally altered across diverse tissue types. We additionally identified a network of protein-protein interactions between members from the two gene sets that may facilitate signaling between them. Taken together, the results illustrate the benefits of integrating high-throughput microarray studies, together with protein-protein interaction networks, in elucidating the underlying biological processes associated with a complex disorder.

  19. Investigation of the Impact of Desorption Electrospray Ionization Sprayer Geometry on Its Performance in Imaging of Biological Tissue.

    Science.gov (United States)

    Tillner, Jocelyn; McKenzie, James S; Jones, Emrys A; Speller, Abigail V M; Walsh, James L; Veselkov, Kirill A; Bunch, Josephine; Takats, Zoltan; Gilmore, Ian S

    2016-05-01

    In this study, the impact of sprayer design and geometry on performance in desorption electrospray ionization mass spectrometry (DESI-MS) is assessed, as the sprayer is thought to be a major source of variability. Absolute intensity repeatability, spectral composition, and classification accuracy for biological tissues are considered. Marked differences in tissue analysis performance are seen between the commercially available and a lab-built sprayer. These are thought to be associated with the geometry of the solvent capillary and the resulting shape of the primary electrospray. Experiments with a sprayer with a fixed solvent capillary position show that capillary orientation has a crucial impact on tissue complex lipid signal and can lead to an almost complete loss of signal. Absolute intensity repeatability is compared for five lab-built sprayers using pork liver sections. Repeatability ranges from 1 to 224% for individual sprayers and peaks of different spectral abundance. Between sprayers, repeatability is 16%, 9%, 23%, and 34% for high, medium, low, and very low abundance peaks, respectively. To assess the impact of sprayer variability on tissue classification using multivariate statistical tools, nine human colorectal adenocarcinoma sections are analyzed with three lab-built sprayers, and classification accuracy for adenocarcinoma versus the surrounding stroma is assessed. It ranges from 80.7 to 94.5% between the three sprayers and is 86.5% overall. The presented results confirm that the sprayer setup needs to be closely controlled to obtain reliable data, and a new sprayer setup with a fixed solvent capillary geometry should be developed. PMID:27014929

  20. Performance-based assessment of biology teachers: Promises and pitfalls

    Science.gov (United States)

    Collins, Angelo

    BioTAP, the biology component of the Teacher Assessment Project, explored three modes of performance-based teacher assessment: portfolios, simulations, and portfolio-based simulations. Assessments were designed by a team of university-based researchers and classroom teachers. Assessments were completed by 15 high school biology teachers from a variety of teaching contexts. Portfolios are defined as collections of evidence gathered on site, such as videotapes of instruction. The portfolios had four sections: planning, instruction, assessment, and professional development. Simulation exercises are replications of critical tasks of teaching in a standardized setting, for example, an interview about adapting a textbook. Portfolio-based simulations take advantage of the contextual aspects of portfolios and the standardization of simulations, for example, an interview on student misconceptions about the laboratory experience that was presented in the portfolio. Using a holistic process, teachers were rated in categories derived from the five core propositions of teacher knowledge and skill proposed by the National Board for Professional Teaching Standards. Teachers reported that the assessments had a high degree of fidelity to teaching and provided stimuli to improving teaching. The description presented in this article provides a foundation for those who wish to advance the research in science teacher assessment.

  1. Biocompatibility of a Novel Cyanoacrylate Based Tissue Adhesive: Cytotoxicity and Biochemical Property Evaluation

    OpenAIRE

    Lee, Young Ju; Jung, Gyeong Bok; Choi, Samjin; Lee, Gihyun; Kim, Ji Hye; Son, Ho Sung; Bae, Hyunsu; Park, Hun-Kuk

    2013-01-01

    Cyanoacrylate (CA) is most widely used as a medical and commercial tissue adhesive because of easier wound closure, good cosmetic results and little discomfort. But, CA-based tissue adhesives have some limitations including the release of cytotoxic chemicals during biodegradation. In previous study, we made prepolymerized allyl 2-CA (PACA) based tissue adhesive, resulting in longer chain structure. In this study, we investigated a biocompatibility of PACA as alternative tissue adhesive for me...

  2. A radioimmunological analytical system for thyroid peroxidase determination in biological tissue extracts

    International Nuclear Information System (INIS)

    An analytical system for radioimmunological determination of human thyroid peroxidase (TPO) has been developed for the first time. This system includes lyophilised preparations of human autoantibodies to TPO, radioiodinated TPO, standards prepared with the use of pure TPO and immobilized protein A as a solid phase precipitating agent. The specific binding of [125I] TPO in the system accounts for 35-40%, the non-specific binding of the radioactive label do not exceed 5%. TPO is accurately determined in a concentration range 8 to 1000 microgram/l, and the total analysis takes 3 h. The procedure and reagents developed can be applied in a technology of TPO isolation and purification from thyroid tissue extracts, that is intended for immuno analytical kits production

  3. Content Based Mammogram Retrieval based on Breast Tissue Characterization using Statistical Features

    Directory of Open Access Journals (Sweden)

    K. Vaidehi

    2014-08-01

    Full Text Available The aim of the study is to retrieve the similar mammographic images based on the type of breast tissue density of the given query image. Statistical descriptors were extracted from the candidate blocks of the breast parenchyma. The mean of extracted features are fed into the SVM classifier for classification of the tissue density into any of the three classes namely dense, glandular and fatty and the classification accuracy obtained is 91.54%. After classification the mammogram images along with its feature vector are stored into three separate databases based on tissue type. Then K-means clustering algorithm is used to divide each database into 2 clusters. For content based retrieval of the mammograms based on the given query image, first the query image is classified into any of the three tissue class. Then the feature vector of the query image is compared with the two cluster centroids of the corresponding class, so as to confine the search within the closest cluster. Top 5 similar images are retrieved from its corresponding class database. Euclidean distance based k-NN is used for mammogram retrieval and this study obtained the highest precision rate ranging between 98 and 99%.

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

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. Deep in vivo photoacoustic imaging of mammalian tissues using a tyrosinase-based genetic reporter

    Science.gov (United States)

    Jathoul, Amit P.; Laufer, Jan; Ogunlade, Olumide; Treeby, Bradley; Cox, Ben; Zhang, Edward; Johnson, Peter; Pizzey, Arnold R.; Philip, Brian; Marafioti, Teresa; Lythgoe, Mark F.; Pedley, R. Barbara; Pule, Martin A.; Beard, Paul

    2015-04-01

    Photoacoustic imaging allows absorption-based high-resolution spectroscopic in vivo imaging at a depth beyond that of optical microscopy. Until recently, photoacoustic imaging has largely been restricted to visualizing the vasculature through endogenous haemoglobin contrast, with most non-vascularized tissues remaining invisible unless exogenous contrast agents are administered. Genetically encodable photoacoustic contrast is attractive as it allows selective labelling of cells, permitting studies of, for example, specific genetic expression, cell growth or more complex biological behaviours in vivo. In this study we report a novel photoacoustic imaging scanner and a tyrosinase-based reporter system that causes human cell lines to synthesize the absorbing pigment eumelanin, thus providing strong photoacoustic contrast. Detailed three-dimensional images of xenografts formed of tyrosinase-expressing cells implanted in mice are obtained in vivo to depths approaching 10 mm with a spatial resolution below 100 μm. This scheme is a powerful tool for studying cellular and genetic processes in deep mammalian tissues.

  7. Dental hard tissue characterization using laser-based ultrasonics

    Science.gov (United States)

    Blodgett, David W.; Massey, Ward L.

    2003-07-01

    Dental health care and research workers require a means of imaging the structures within teeth in vivo. One critical need is the detection of tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated to help re-mineralize the tooth. Currently employed x-ray imaging is limited in its ability to visualize interfaces and incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration. To this end, non-destructive and non-contact in vitro measurements on extracted human molars using laser-based ultrasonics are presented. Broadband ultrasonic waves are excited in the extracted sections by using a pulsed carbon-dioxide (CO2) laser operating in a region of high optical absorption in the dental hard tissues. Optical interferometric detection of the ultrasonic wave surface displacements in accomplished with a path-stabilized Michelson-type interferometer. Results for bulk and surface in-vitro characterization of caries are presented on extracted molars with pre-existing caries.

  8. Image-based surface matching algorithm oriented to structural biology.

    Science.gov (United States)

    Merelli, Ivan; Cozzi, Paolo; D'Agostino, Daniele; Clematis, Andrea; Milanesi, Luciano

    2011-01-01

    Emerging technologies for structure matching based on surface descriptions have demonstrated their effectiveness in many research fields. In particular, they can be successfully applied to in silico studies of structural biology. Protein activities, in fact, are related to the external characteristics of these macromolecules and the ability to match surfaces can be important to infer information about their possible functions and interactions. In this work, we present a surface-matching algorithm, based on encoding the outer morphology of proteins in images of local description, which allows us to establish point-to-point correlations among macromolecular surfaces using image-processing functions. Discarding methods relying on biological analysis of atomic structures and expensive computational approaches based on energetic studies, this algorithm can successfully be used for macromolecular recognition by employing local surface features. Results demonstrate that the proposed algorithm can be employed both to identify surface similarities in context of macromolecular functional analysis and to screen possible protein interactions to predict pairing capability. PMID:21566253

  9. Photonic applications based on biological/inorganic nano hybrids

    Science.gov (United States)

    Zhang, Xin; Wu, Pengfei; Yelleswarapu, Chandra

    2016-02-01

    Biological Retinal is an effective and efficient photochromic compounds and one of the best candidates for photon conversion, transmission and storage, from the view of bionics and natural selection. We observed large optical nonlinearity by using new fabricated films of photoactive Retinol hybrid materials. Based on reversible photoinduced anisotropy and transient optical characteristics, the Retinol hybrids can be used to design novel photonic devices, such as holographic elements, all-optical switch and spatial light modulator. Also, the study is important for further understanding the photochemical mechanism of vision process.

  10. Learning Cell Biology as a Team: A Project-Based Approach to Upper-Division Cell Biology

    Science.gov (United States)

    Wright, Robin; Boggs, James

    2002-01-01

    To help students develop successful strategies for learning how to learn and communicate complex information in cell biology, we developed a quarter-long cell biology class based on team projects. Each team researches a particular human disease and presents information about the cellular structure or process affected by the disease, the cellular…

  11. Strontium and bromide as tracers in X-ray microanalysis of biological tissue

    International Nuclear Information System (INIS)

    Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br

  12. 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

    2014-01-01

    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. PMID:25420073

  13. Biological effect of radiation-degraded alginate on flower plants in tissue culture.

    Science.gov (United States)

    Le, Q Luan; Nguyen, Q Hien; Nagasawa, Naotsugu; Kume, Tamikazu; Yoshii, Fumio; Nakanishi, Tomoko M

    2003-12-01

    Alginate with a weight-average molecular mass (Mw) of approx. 9.04 x 10(5) Da was irradiated at 10-200 kGy in 4% (w/v) aqueous solution. The degraded alginate product was used to study its effectiveness as a growth promoter for plants in tissue culture. Alginate irradiated at 75 kGy with an Mw of approx. 1.43 x 10(4) Da had the highest positive effect in the growth of flower plants, namely limonium, lisianthus and chrysanthemum. Treatment of plants with irradiated alginate at concentrations of 30-200 mg/l increased the shoot multiplication rate from 17.5 to 40.5% compared with control. In plantlet culture, 100 mg/l irradiated alginate supplementation enhanced shoot height (9.7-23.2%), root length (9.7-39.4%) and fresh biomass (8.1-19.4%) of chrysanthemum, lisianthus and limonium compared with that of the untreated control. The survival ratios of the transferred flower plantlets treated with irradiated alginate were almost the same as the control value under greenhouse conditions. However, better growth was attained for the treated plantlets. PMID:12901723

  14. 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.

  15. MathBench Biology Modules: Web-Based Math for All Biology Undergraduates

    Science.gov (United States)

    Nelson, Karen C.; Marbach-Ad, Gili; Schneider, Katie; Thompson, Katerina V.; Shields, Patricia A.; Fagan, William F.

    2009-01-01

    Historically, biology has not been a heavily quantitative science, but this is changing rapidly (Ewing 2002; Gross 2000; Hastings and palmer 2003; Jungck 2005; Steen 2005). Quantitative approaches now constitute a key tool for modern biologists, yet undergraduate biology courses remain largely qualitative and descriptive. Although biology majors…

  16. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  17. 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.

  18. OCT-based in vivo tissue injury mapping

    Science.gov (United States)

    Baran, Utku; Li, Yuandong; Wang, Ruikang K.

    2016-03-01

    Tissue injury mapping (TIM) is developed by using a non-invasive in vivo optical coherence tomography to generate optical attenuation coefficient and microvascular map of the injured tissue. Using TIM, the infarct region development in mouse cerebral cortex during stroke is visualized. Moreover, we demonstrate the in vivo human facial skin structure and microvasculature during an acne lesion development. The results indicate that TIM may help in the study and the treatment of various diseases by providing high resolution images of tissue structural and microvascular changes.

  19. A glycosaminoglycan based, modular tissue scaffold system for rapid assembly of perfusable, high cell density, engineered tissues.

    Directory of Open Access Journals (Sweden)

    Ramkumar Tiruvannamalai-Annamalai

    Full Text Available The limited ability to vascularize and perfuse thick, cell-laden tissue constructs has hindered efforts to engineer complex tissues and organs, including liver, heart and kidney. The emerging field of modular tissue engineering aims to address this limitation by fabricating constructs from the bottom up, with the objective of recreating native tissue architecture and promoting extensive vascularization. In this paper, we report the elements of a simple yet efficient method for fabricating vascularized tissue constructs by fusing biodegradable microcapsules with tunable interior environments. Parenchymal cells of various types, (i.e. trophoblasts, vascular smooth muscle cells, hepatocytes were suspended in glycosaminoglycan (GAG solutions (4%/1.5% chondroitin sulfate/carboxymethyl cellulose, or 1.5 wt% hyaluronan and encapsulated by forming chitosan-GAG polyelectrolyte complex membranes around droplets of the cell suspension. The interior capsule environment could be further tuned by blending collagen with or suspending microcarriers in the GAG solution These capsule modules were seeded externally with vascular endothelial cells (VEC, and subsequently fused into tissue constructs possessing VEC-lined, inter-capsule channels. The microcapsules supported high density growth achieving clinically significant cell densities. Fusion of the endothelialized, capsules generated three dimensional constructs with an embedded network of interconnected channels that enabled long-term perfusion culture of the construct. A prototype, engineered liver tissue, formed by fusion of hepatocyte-containing capsules exhibited urea synthesis rates and albumin synthesis rates comparable to standard collagen sandwich hepatocyte cultures. The capsule based, modular approach described here has the potential to allow rapid assembly of tissue constructs with clinically significant cell densities, uniform cell distribution, and endothelialized, perfusable channels.

  20. Biomaterial based cardiac tissue engineering and its applications.

    Science.gov (United States)

    Huyer, Locke Davenport; Montgomery, Miles; Zhao, Yimu; Xiao, Yun; Conant, Genevieve; Korolj, Anastasia; Radisic, Milica

    2015-06-01

    Cardiovascular disease is a leading cause of death worldwide, necessitating the development of effective treatment strategies. A myocardial infarction involves the blockage of a coronary artery leading to depletion of nutrient and oxygen supply to cardiomyocytes and massive cell death in a region of the myocardium. Cardiac tissue engineering is the growth of functional cardiac tissue in vitro on biomaterial scaffolds for regenerative medicine application. This strategy relies on the optimization of the complex relationship between cell networks and biomaterial properties. In this review, we discuss important biomaterial properties for cardiac tissue engineering applications, such as elasticity, degradation, and induced host response, and their relationship to engineered cardiac cell environments. With these properties in mind, we also emphasize in vitro use of cardiac tissues for high-throughput drug screening and disease modelling. PMID:25989939

  1. Biochemical And Biological Effects Of GAMMA Irradiation On Certain Mineral Contents In The Almond Moth Tissues, EPHESTIA CAUTELLA (WALKER)

    International Nuclear Information System (INIS)

    In the present study, the biochemical and biological effects of two sub-sterilizing doses of gamma radiation (100 and 200 Gray) were studied on F1 adult male and female almond moths, Ephestia cautella (Walker) (Pyralidae: Lepidoptera) descendant of irradiated parental male pupae. The insects were maintained continuously on peanuts and hazelnuts diets. Oviposition, average of adult longevity per days, the emerged adult weight, the percentage loss in diet weight and the percentage free fatty acid and peroxide values of infested peanuts and hazelnuts were determined. The effect of gamma irradiation on the relative percentage of metal contents was detected in the whole body tissues of males and females descendant of irradiated parental male pupae. The obtained results indicated that the total concentrations of the light metals (Mg, Al, Si, P, S, Cl, K and Fe) of F1 male and female tissues at 100 and 200 Gy and reared on peanuts and hazelnuts diets were very higher than those of the heavy metals (Cu and Zn) at all treatments.

  2. Estimation of regional hemoglobin concentration in biological tissues using diffuse reflectance spectroscopy with a novel spectral interpretation algorithm

    International Nuclear Information System (INIS)

    Both in medical research and clinical settings, regional hemoglobin concentrations ([Hb]) in the microcirculation of biological tissues are highly sought. Diffuse reflectance spectroscopy has been proven to be a favorable method by which to detect regional [Hb]. This paper introduces a new algorithm to retrieve [Hb] information from diffuse reflectance spectra. The proposed algorithm utilizes the natural logarithmic operation and the differential wavelet transform to effectively quench the scattering effects, and then employs the concept of isosbestic wavelength in the transformed spectra to reduce the effects of hemoglobin oxygenation. As a result, the intensity at the defined isosbestic wavelength of the transformed spectra is a good indicator of [Hb] estimation. The algorithm was derived and validated using theoretical spectra produced by Monte Carlo simulation of photon migration. Its accuracy was further evaluated using liquid tissue phantoms, and its clinical utility with an in vivo clinical study of brain tumors. The results demonstrate the applicability of the algorithm for real-time [Hb] estimations from diffuse reflectance spectra, acquired by means of a fiber-optic spectroscopy system.

  3. 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

    2016-04-21

    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 nucleationtheory 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. PMID:27389239

  4. 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.

  5. 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. PMID:27060638

  6. Pattern secretion of matrix Metalloproteinases and their biological tissue inhibitors by human glomerular mesangial cells in culture

    Directory of Open Access Journals (Sweden)

    "Hosseini R

    2001-08-01

    Full Text Available The glomerular mesangial cells (GMC play a central role in the synthesis and turnover of the glomerular mesangial matrix. The breakdown of the matrix likely depends on the balance between of a variety of proteinases including matrix metalloproteinases and their biological inhibitors secreted by the GMC, and any disturbance in the balance may result in appearance of various pathological states such as glomerulosclerosis. We therefore studied pattern secretion of matrix metalloproteinases (MMPs, MMP-1, MMP-2, MMP-3, MMP-9 and their biological tissue inhibitor of matrix metalloproteinases (TIMPs, TIMP-1 and TIMP-2 by cultured human GMC. We also measured MMP-1/TIMP-1 complex level in the cell culture supernatants. For this purpose, the GMC were incubated under serum-free conditions with medium (RPMI-1640 alone or in combination with TNF-α (30 ng/ml or phorbol myristate acetate (PMA (50 ng/ml for exactly 24, 48 and 72 hours. The above parameters were assayed by established ELISA techniques. Our results showed that the lowest and largest secretions were related to MMP-9 and MMP-2, respectively. The results indicated that the MMPs and TIMPs secretion were increased by TNF-α (MMP-1, MMP-2, TIMP-1 and TIMP-2 and PMA (MMP-2, TIMP-1 and TIMP-2, significantly (P<0.05. These results suggest that the GMC can synthesis and release various MMPs and their inhibitors (TIMPs that, in part, control turnover of extracellular matrix proteins.

  7. Design Strategies of Fluorescent Biosensors Based on Biological Macromolecular Receptors

    Directory of Open Access Journals (Sweden)

    Takashi Morii

    2010-02-01

    Full Text Available Fluorescent biosensors to detect the bona fide events of biologically important molecules in living cells are increasingly demanded in the field of molecular cell biology. Recent advances in the development of fluorescent biosensors have made an outstanding contribution to elucidating not only the roles of individual biomolecules, but also the dynamic intracellular relationships between these molecules. However, rational design strategies of fluorescent biosensors are not as mature as they look. An insatiable request for the establishment of a more universal and versatile strategy continues to provide an attractive alternative, so-called modular strategy, which permits facile preparation of biosensors with tailored characteristics by a simple combination of a receptor and a signal transducer. This review describes an overview of the progress in design strategies of fluorescent biosensors, such as auto-fluorescent protein-based biosensors, protein-based biosensors covalently modified with synthetic fluorophores, and signaling aptamers, and highlights the insight into how a given receptor is converted to a fluorescent biosensor. Furthermore, we will demonstrate a significance of the modular strategy for the sensor design.

  8. Mathematical simulation of microwave scattering in the medium with characteristic features of biological tissues and prospectives of microwave tomography

    OpenAIRE

    Sukharevsky, Oleg I.; Lesovoy, V. N.; Zamiatin, V. L.; Gorelyshev, S. A.; Podorozhnyak, A. A.

    1995-01-01

    Computer aided tomography is used today in many areas of science and technology, such as biology, medicine, geophysics, plasma physics, non-destructive introscopy and state control of heat-radiation elements at nuclear power plants, cartography, etc. Microwave imaging is one of the prospective methods of tomography. It is based on the retrieval of dielectric properties of a solid body irradiated by an electromagnetic wave of microwave band. Scanning the scientific and technical literature, in...

  9. The Mechanical and Biological Properties of Chitosan Scaffolds for Tissue Regeneration Templates Are Significantly Enhanced by Chitosan from Gongronella butleri

    Directory of Open Access Journals (Sweden)

    Hiroshi Tamura

    2009-04-01

    Full Text Available Chitosan with a molecular weight (MW of 104 Da and 13% degree of acetylation (DA was extracted from the mycelia of the fungus Gongronella butleri USDB 0201 grown in solid substrate fermentation and used to prepare scaffolds by the freeze-drying method. The mechanical and biological properties of the fungal chitosan scaffolds were evaluated and compared with those of scaffolds prepared using chitosans obtained from shrimp and crab shells and squid bone plates (MW 105-106 Da and DA 10-20%. Under scanning electron microscopy, it was observed that all scaffolds had average pore sizes of approximately 60-90 mm in diameter. Elongated pores were observed in shrimp chitosan scaffolds and polygonal pores were found in crab, squid and fungal chitosan scaffolds. The physico-chemical properties of the chitosans had an effect on the formation of pores in the scaffolds, that consequently influenced the mechanical and biological properties of the scaffolds. Fungal chitosan scaffolds showed excellent mechanical, water absorption and lysozyme degradation properties, whereas shrimp chitosan scaffolds (MW 106Da and DA 12% exhibited the lowest water absorption properties and lysozyme degradation rate. In the evaluation of biocompatibility of chitosan scaffolds, the ability of fibroblast NIH/3T3 cells to attach on all chitosan scaffolds was similar, but the proliferation of cells with polygonal morphology was faster on crab, squid and fungal chitosan scaffolds than on shrimp chitosan scaffolds. Therefore fungal chitosan scaffold, which has excellent mechanical and biological properties, is the most suitable scaffold to use as a template for tissue regeneration.

  10. Possible Patient Early Diagnosis by Ultrasonic Noninvasive Estimation of Thermal Gradients into Tissues Based on Spectral Changes Modeling

    Directory of Open Access Journals (Sweden)

    I. Bazan

    2012-01-01

    Full Text Available To achieve a precise noninvasive temperature estimation, inside patient tissues, would open promising research fields, because its clinic results would provide early-diagnosis tools. In fact, detecting changes of thermal origin in ultrasonic echo spectra could be useful as an early complementary indicator of infections, inflammations, or cancer. But the effective clinic applications to diagnosis of thermometry ultrasonic techniques, proposed previously, require additional research. Before their implementations with ultrasonic probes and real-time electronic and processing systems, rigorous analyses must be still made over transient echotraces acquired from well-controlled biological and computational phantoms, to improve resolutions and evaluate clinic limitations. It must be based on computing improved signal-processing algorithms emulating tissues responses. Some related parameters in echo-traces reflected by semiregular scattering tissues must be carefully quantified to get a precise processing protocols definition. In this paper, approaches for non-invasive spectral ultrasonic detection are analyzed. Extensions of author's innovations for ultrasonic thermometry are shown and applied to computationally modeled echotraces from scattered biological phantoms, attaining high resolution (better than 0.1°C. Computer methods are provided for viability evaluation of thermal estimation from echoes with distinct noise levels, difficult to be interpreted, and its effectiveness is evaluated as possible diagnosis tool in scattered tissues like liver.

  11. Direct online HPLC-CV-AFS method for traces of methylmercury without derivatisation: a matrix-independent method for urine, sediment and biological tissue samples.

    Science.gov (United States)

    Brombach, Christoph-Cornelius; Gajdosechova, Zuzana; Chen, Bin; Brownlow, Andrew; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2015-01-01

    Mercury (Hg) is a global pollutant which occurs in different species, with methylmercury (MeHg) being the critical compound due to its neurotoxicity and bioaccumulation through the food chain. Methods for trace speciation of MeHg are therefore needed for a vast range of sample matrices, such as biological tissues, fluids, soils or sediments. We have previously developed an ultra-trace speciation method for methylmercury in water, based on a preconcentration HPLC cold vapour atomic fluorescence spectrometry (HPLC-CV-AFS) method. The focus of this work is mercury speciation in a variety of sample matrices to assess the versatility of the method. Certified reference materials were used where possible, and samples were spiked where reference materials were not available, e.g. human urine. Solid samples were submitted for commonly used digestion or extraction processes to obtain a liquid sample for injection into the analytical system. For MeHg in sediment samples, an extraction procedure was adapted to accommodate MeHg separation from high amounts of Hg(2+) to avoid an overload of the column. The recovery for MeHg determination was found to be in the range of 88-104% in fish reference materials (DOLT-2, DOLT-4, DORM-3), lobster (TORT-2), seaweed (IAEA-140/TM), sediments (ERM(®)-CC580) and spiked urine and has been proven to be robust, reliable, virtually matrix-independent and relatively cost-effective. Applications in the ultra-trace concentration range are possible using the preconcentration up to 200 mL, while for higher MeHg-containing samples, lower volumes can be applied. A comparison was carried out between species-specific isotope dilution gas chromatography inductively coupled plasma mass spectrometry (SSID-GC-ICP-MS) as the gold standard and HPLC-CV-AFS for biological tissues (liver, kidney and muscle of pilot whales), showing a slope of 1.008 and R (2) = 0.97, which indicates that the HPLC-CV-AFS method achieves well-correlated results for MeHg in

  12. Biologically engineered protein-graft-poly(ethylene glycol) hydrogels: A cell-adhesive and plasmin-degradable biosynthetic material for tissue repair

    Science.gov (United States)

    Halstenberg, Sven

    2002-01-01

    The goal of the research presented in this dissertation was to create a biomimetic artificial material that exhibits functions of extracellular matrix relevant for improved nerve regeneration. Neural adhesion peptides were photoimmobilized on highly crosslinked poly(ethylene glycol)-based substrates that were otherwise non-adhesive. Neurons adhered in two-dimensional patterns for eleven hours, but no neurites extended. To enable neurite extension and nerve regeneration in three dimensions, and to address the need for specifically cell adhesive and cell degradable materials for clinical applications in tissue repair in general, an artificial protein was recombinantly expressed and purified that consisted of a repeating amino acid sequence based on fibrinogen and anti-thrombin III. The recombinant protein contained integrin-binding RGD sites, plasmin degradation sites, heparin binding sites, and six thiol-containing cysteine residues as grafting sites for poly(ethylene glycol) diacrylate via Michael-type conjugate addition. The resulting protein-graft-poly(ethylene glycol)acrylates were crosslinked by photopolymerization to form hydrogels. Although three-dimensional, RGD mediated and serine protease-dependent ingrowth of human fibroblasts into protein-graft-poly(ethylene glycol) hydrogels occurred, only surface neurite outgrowth was observed from chick dorsal root ganglia. Axonal outgrowth depended on the concentration of matrix-bound heparin, suggesting that improved mechanical strength of the hydrogels and possible immobilization of neuroactive factors due to the presence of heparin promoted neurite outgrowth. Together, the above results show that specific biological functions can be harnessed by protein-graft-poly(ethylene glycol) hydrogels to serve as matrices for tissue repair and regeneration. In particular, the two design objectives, specific cell adhesion and degradability by cell-associated proteases, were fulfilled by the material. In the future, this and

  13. Mesenchymal stromal cells from human perinatal tissues: From biology to cell therapy

    OpenAIRE

    Bieback, Karen; Brinkmann, Irena

    2010-01-01

    Cell-based regenerative medicine is of growing interest in biomedical research. The role of stem cells in this context is under intense scrutiny and may help to define principles of organ regeneration and develop innovative therapeutics for organ failure. Utilizing stem and progenitor cells for organ replacement has been conducted for many years when performing hematopoietic stem cell transplantation. Since the first successful transplantation of umbilical cord blood to treat hematological ma...

  14. The estimation of biological tissues trauma under their perforation by one-dimensional implants

    Science.gov (United States)

    Shil'ko, S.; Chernous, D.; Panin, S.

    2015-11-01

    The subject of paper is a base stage of positioning of one-dimensional implants (fixing, diagnostic) element, stretching through an aperture in a biotissue. Corresponding mechanical and mathematical model describes implant interaction with biotissues in the conditions of sticking and sliding of contacting surfaces. Theoretical dependences for implant elongation and the maximum value of stress tensor intensity in interfacing volumes of the material are presented, allowing one to calculate the frictional and mechanical characteristics of one-dimensional implant and to estimate the injuring action from biomechanics point of view.

  15. A Transient 3D-CFD Model Incorporating Biological Processes for Use in Tissue Engineering

    DEFF Research Database (Denmark)

    Krühne, Ulrich; Wendt, D.; Martin, I.;

    2010-01-01

    In this article a mathematical model is presented in which the fluid dynamic interaction between the liquid flow in a scaffold and growing cells is simulated. The model is based on a computational fluid dynamic (CFD) model for the representation of the fluid dynamic conditions in the scaffold. It...... after 2, 8 and 13 days. The development of the cells is compared to the simulated growth of cells and it is attempted to draw a conclusion about the impact of the shear stress on the cell growth. Keyword: Computational fluid dynamics (CFD),Micro pores,Scaffold,Bioreactor,Fluid structure interaction...

  16. Micro Soft Tissues Visualization Based on X-Ray Phase-Contrast Imaging

    OpenAIRE

    Zhang, Lu; Luo, Shuqian

    2011-01-01

    The current imaging methods have a limited ability to visualize microstructures of biological soft tissues. Small lesions cannot be detected at the early stage of the disease. Phase contrast imaging (PCI) is a novel non-invasive imaging technique that can provide high contrast images of soft tissues by the use of X-ray phase shift. It is a new choice in terms of non-invasively revealing soft tissue details. In this study, the lung and hepatic fibrosis models of mice and rats were used to inve...

  17. Biomaterials-based strategies for salivary gland tissue regeneration.

    Science.gov (United States)

    Ozdemir, Tugba; Fowler, Eric W; Hao, Ying; Ravikrishnan, Anitha; Harrington, Daniel A; Witt, Robert L; Farach-Carson, Mary C; Pradhan-Bhatt, Swati; Jia, Xinqiao

    2016-04-22

    The salivary gland is a complex, secretory tissue that produces saliva and maintains oral homeostasis. Radiation induced salivary gland atrophy, manifested as "dry mouth" or xerostomia, poses a significant clinical challenge. Tissue engineering recently has emerged as an alternative, long-term treatment strategy for xerostomia. In this review, we summarize recent efforts towards the development of functional and implantable salivary glands utilizing designed polymeric substrates or synthetic matrices/scaffolds. Although the in vitro engineering of a complex implantable salivary gland is technically challenging, opportunities exist for multidisciplinary teams to assemble implantable and secretory tissue modules by combining stem/progenitor cells found in the adult glands with biomimetic and cell-instructive materials. PMID:26878077

  18. Post Processing and Biological Evaluation of the Titanium Scaffolds for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Bartłomiej Wysocki

    2016-03-01

    Full Text Available Nowadays, post-surgical or post-accidental bone loss can be substituted by custom-made scaffolds fabricated by additive manufacturing (AM methods from metallic powders. However, the partially melted powder particles must be removed in a post-process chemical treatment. The aim of this study was to investigate the effect of the chemical polishing with various acid baths on novel scaffolds’ morphology, porosity and mechanical properties. In the first stage, Magics software (Materialise NV, Leuven, Belgium was used to design a porous scaffolds with pore size equal to (A 200 µm, (B 500 µm and (C 200 + 500 µm, and diamond cell structure. The scaffolds were fabricated from commercially pure titanium powder (CP Ti using a SLM50 3D printing machine (Realizer GmbH, Borchen, Germany. The selective laser melting (SLM process was optimized and the laser beam energy density in range of 91–151 J/mm3 was applied to receive 3D structures with fully dense struts. To remove not fully melted titanium particles the scaffolds were chemically polished using various HF and HF-HNO3 acid solutions. Based on scaffolds mass loss and scanning electron (SEM observations, baths which provided most uniform surface cleaning were proposed for each porosity. The pore and strut size after chemical treatments was calculated based on the micro-computed tomography (µ-CT and SEM images. The mechanical tests showed that the treated scaffolds had Young’s modulus close to that of compact bone. Additionally, the effect of pore size of chemically polished scaffolds on cell retention, proliferation and differentiation was studied using human mesenchymal stem cells. Small pores yielded higher cell retention within the scaffolds, which then affected their growth. This shows that in vitro cell performance can be controlled to certain extent by varying pore sizes.

  19. Theory of sampling and its application in tissue based diagnosis

    Directory of Open Access Journals (Sweden)

    Kayser Gian

    2009-02-01

    Full Text Available Abstract Background A general theory of sampling and its application in tissue based diagnosis is presented. Sampling is defined as extraction of information from certain limited spaces and its transformation into a statement or measure that is valid for the entire (reference space. The procedure should be reproducible in time and space, i.e. give the same results when applied under similar circumstances. Sampling includes two different aspects, the procedure of sample selection and the efficiency of its performance. The practical performance of sample selection focuses on search for localization of specific compartments within the basic space, and search for presence of specific compartments. Methods When a sampling procedure is applied in diagnostic processes two different procedures can be distinguished: I the evaluation of a diagnostic significance of a certain object, which is the probability that the object can be grouped into a certain diagnosis, and II the probability to detect these basic units. Sampling can be performed without or with external knowledge, such as size of searched objects, neighbourhood conditions, spatial distribution of objects, etc. If the sample size is much larger than the object size, the application of a translation invariant transformation results in Kriege's formula, which is widely used in search for ores. Usually, sampling is performed in a series of area (space selections of identical size. The size can be defined in relation to the reference space or according to interspatial relationship. The first method is called random sampling, the second stratified sampling. Results Random sampling does not require knowledge about the reference space, and is used to estimate the number and size of objects. Estimated features include area (volume fraction, numerical, boundary and surface densities. Stratified sampling requires the knowledge of objects (and their features and evaluates spatial features in relation to

  20. Modeling to Improve Vegetation-Based Wetland Biological Assessment

    OpenAIRE

    Jones, Robin C

    2014-01-01

    To meet the requirements of the Clean Water Act (1972), natural resource managers need to be able to detect biological degradation in wetland ecosystems. Biological indices are commonly used by managers to assess wetland biological condition. The accuracy and precision of wetland condition assessments are directly related to the performance of these indices, and biological index performance is thought to be related to how well an index controls for the effects of environmental attributes on b...

  1. Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

    International Nuclear Information System (INIS)

    Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation

  2. Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Bindu P., E-mail: bindumelekkuttu@gmail.com; Gangadharan, Dhanya; Mohan, Neethu; Sumathi, Babitha; Nair, Prabha D., E-mail: pdnair49@gmail.com

    2015-07-01

    Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation.

  3. Spectral pre and post processing for infrared and Raman spectroscopy of biological tissues and cells.

    Science.gov (United States)

    Byrne, Hugh J; Knief, Peter; Keating, Mark E; Bonnier, Franck

    2016-04-01

    Vibrational spectroscopy, both infrared absorption and Raman spectroscopy, have attracted increasing attention for biomedical applications, from in vivo and ex vivo disease diagnostics and screening, to in vitro screening of therapeutics. There remain, however, many challenges related to the accuracy of analysis of physically and chemically inhomogeneous samples, across heterogeneous sample sets. Data preprocessing is required to deal with variations in instrumental responses and intrinsic spectral backgrounds and distortions in order to extract reliable spectral data. Data postprocessing is required to extract the most reliable information from the sample sets, based on often very subtle changes in spectra associated with the targeted pathology or biochemical process. This review presents the current understanding of the factors influencing the quality of spectra recorded and the pre-processing steps commonly employed to improve on spectral quality. It further explores some of the most common techniques which have emerged for classification and analysis of the spectral data for biomedical applications. The importance of sample presentation and measurement conditions to yield the highest quality spectra in the first place is emphasised, as is the potential of model simulated datasets to validate both pre- and post-processing protocols. PMID:26463830

  4. Force-based assessment of tissue handling skills

    NARCIS (Netherlands)

    Horeman, T.

    2014-01-01

    In laparoscopic surgery, special instruments with long and slender shafts are inserted through small incisions in the abdominal wall. A laparoscope is used for a clear vision inside the inflated abdominal cavity while laparoscopic graspers and cutters are used for manipulation of tissue. The use of

  5. Tissue Engineering of Cartilage on Ground-Based Facilities

    DEFF Research Database (Denmark)

    Aleshcheva, Ganna; Bauer, Johann; Hemmersbach, Ruth;

    2016-01-01

    Investigations under simulated microgravity offer the opportunity for a better understanding of the influence of altered gravity on cells and the scaffold-free threedimensional (3D) tissue formation. To investigate the shortterm influence, human chondrocytes were cultivated for 2h, 4 h, 16 h, and...

  6. RegenBase: a knowledge base of spinal cord injury biology for translational research.

    Science.gov (United States)

    Callahan, Alison; Abeyruwan, Saminda W; Al-Ali, Hassan; Sakurai, Kunie; Ferguson, Adam R; Popovich, Phillip G; Shah, Nigam H; Visser, Ubbo; Bixby, John L; Lemmon, Vance P

    2016-01-01

    Spinal cord injury (SCI) research is a data-rich field that aims to identify the biological mechanisms resulting in loss of function and mobility after SCI, as well as develop therapies that promote recovery after injury. SCI experimental methods, data and domain knowledge are locked in the largely unstructured text of scientific publications, making large scale integration with existing bioinformatics resources and subsequent analysis infeasible. The lack of standard reporting for experiment variables and results also makes experiment replicability a significant challenge. To address these challenges, we have developed RegenBase, a knowledge base of SCI biology. RegenBase integrates curated literature-sourced facts and experimental details, raw assay data profiling the effect of compounds on enzyme activity and cell growth, and structured SCI domain knowledge in the form of the first ontology for SCI, using Semantic Web representation languages and frameworks. RegenBase uses consistent identifier schemes and data representations that enable automated linking among RegenBase statements and also to other biological databases and electronic resources. By querying RegenBase, we have identified novel biological hypotheses linking the effects of perturbagens to observed behavioral outcomes after SCI. RegenBase is publicly available for browsing, querying and download.Database URL:http://regenbase.org. PMID:27055827

  7. Methemoglobin-Based Biological Dose Assessment for Human Blood.

    Science.gov (United States)

    Zhang, Xiao-Hong; Hu, Xiao-Dan; Zhao, Su-Ying; Xie, Li-Hua; Miao, Yu-Ji; Li, Qun; Min, Rui; Liu, Pei-Dang; Zhang, Hai-Qian

    2016-07-01

    Methemoglobin is an oxidative form of hemoglobin in erythrocytes. The authors' aim was to develop a new biological dosimeter based on a methemoglobin assay. Methemoglobin in peripheral blood (of females or males) that was exposed to a Co source (0.20 Gy min) was quantified using an enzyme-linked immunosorbent assay. The dose range was 0.5-8.0 Gy. In a time-course experiment, the time points 0, 0.02, 1, 2, 3, 7, 15, 21, and 30 d after 4-Gy irradiation of heparinized peripheral blood were used. Methemoglobin levels in a lysed erythrocyte pellet from the irradiated blood of females and males increased with the increasing dose. Methemoglobin levels in female blood irradiated with γ-doses more than 4 Gy were significantly higher than those in male samples at the same doses. Two dose-response relations were fitted to the straight line: one is with the correlation coefficient of 0.98 for females, and the other is with the correlation coefficient of 0.99 for males. The lower limit of dose assessment based on methemoglobin is about 1 Gy. Methemoglobin levels in blood as a result of auto-oxidation increase after 7-d storage at -20 °C. The upregulation of methemoglobin induced by γ-radiation persists for ∼3 d. The absorbed doses that were estimated using the two dose-response relations were close to the actual doses. The results suggest that methemoglobin can be used as a rapid and accurate biological dosimeter for early assessment of absorbed γ-dose in human blood. PMID:27218292

  8. A pressure cooking-based DNA extraction from archival formalin fixed, paraffin embedded tissue

    OpenAIRE

    Chung, Joon-Yong; Yi, Joo Mi; Xie, Ran; Brown, Victoria; Lee, Olivia; Ahuja, Nita; Braunschweig, Till; Hewitt, Stephen M.

    2012-01-01

    As emerging novel DNA-based methodologies are adopted, nucleic acid-based assays depend critically on the quality and quantity of extracted DNA. Formalin fixed, paraffin embedded (FFPE) tissue samples provide an invaluable resource for subsequent molecular studies of clinical phenotypes, but high quality DNA extraction from archival FFPE tissue specimen remains complex and time consuming. To address this challenge, we have developed a reliable rapid DNA extraction method for FFPE tissue speci...

  9. Target Image Classification through Encryption Algorithm Based on the Biological Features

    OpenAIRE

    Zhiwu Chen; Qing E. Wu; Weidong Yang

    2014-01-01

    In order to effectively make biological image classification and identification, this paper studies the biological owned characteristics, gives an encryption algorithm, and presents a biological classification algorithm based on the encryption process. Through studying the composition characteristics of palm, this paper uses the biological classification algorithm to carry out the classification or recognition of palm, improves the accuracy and efficiency of the existing biological classifica...

  10. Highly sensitive detection of the soft tissues based on refraction contrast by in-plane diffraction-enhanced imaging CT

    Energy Technology Data Exchange (ETDEWEB)

    Yuasa, Tetsuya [Department of Bio-system Engineering, Faculty of Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan)], E-mail: yuasa@yz.yamagata-u.ac.jp; Hashimoto, Eiko [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Maksimenko, Anton [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Sugiyama, Hiroshi [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Arai, Yoshinori [Matsumoto Dental University, 1980 Hirooka, Shiojiri, Nagano (Japan); Shimao, Daisuke [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Inashiki, Ibaraki 300-0394 (Japan); Ichihara, Shu [Department of Pathology, Nagoya Medical Center, 4-1-1 Sannomaru, Naka-ku, Nagoya 460-0001 (Japan); Ando, Masami [DDS Center, Research Institute for Science and Technology, Tokyo University of Science, Yamasaki 2641, Noda, Chiba 278-8510 (Japan)

    2008-07-01

    We discuss the recently proposed computed tomography (CT) technique based on refractive effects for biomedical use, which reconstructs the in-plane refractive-index gradient vector field in a cross-sectional plane of interest by detecting the angular deviation of the beam, refracted by a sample, from the incident beam, using the diffraction-enhanced imaging (DEI) method. The CT has advantages for delineating biological weakly absorbing soft tissues over the conventional absorption-contrast CT because of the use of phase sensitive detection. The paper aims to define the imaging scheme rigidly and to demonstrate its efficacy for non-destructive measurement of biomedical soft-tissue samples without imaging agent. We first describe the imaging principle of in-plane DEI-CT from the physico-mathematical viewpoints in detail, and investigate what physical quantities are extracted from the reconstructed images. Then, we introduce the imaging system using the synchrotron radiation as a light source, constructed at beamline BL-14B in KEK, Japan. Finally, we demonstrate the advantage of the refraction-based image for non-destructive analysis of biological sample by investigating the image of human breast cancer tumors obtained using the imaging system. Here, the refraction- and the apparent absorption-based images obtained simultaneously by the in-plane DEI-CT are compared. Also, the conventional absorption-based image obtained using micro-computed tomography ({mu}CT) imaging system is compared with them. Thereby, it is shown that the refraction contrast much more sensitively delineates the soft tissues than the absorption contrast. In addition, the radiologic-histologic correlation study not only validates the efficacy for imaging soft tissues, but also produces the potential that the pathological inspection for the breast cancer tumors may be feasible non-destructively.

  11. Exploring the cellular and tissue uptake of nanomaterials in a range of biological samples using multimodal nonlinear optical microscopy

    Science.gov (United States)

    Johnston, Helinor J.; Mouras, Rabah; Brown, David M.; Elfick, Alistair; Stone, Vicki

    2015-12-01

    The uptake of nanomaterials (NMs) by cells is critical in determining their potential biological impact, whether beneficial or detrimental. Thus, investigation of NM internalization by cells is a common consideration in hazard and efficacy studies. There are currently a number of approaches that are routinely used to investigate NM-cell interactions, each of which have their own advantages and limitations. Ideally, imaging modalities used to investigate NM uptake by cells should not require the NM to be labelled (e.g. with fluorophores) to facilitate its detection. We present a multimodal imaging approach employing a combination of label-free microscopies that can be used to investigate NM-cell interactions. Coherent anti-Stokes Raman scattering microscopy was used in combination with either two-photon photoluminescence or four-wave mixing (FWM) to visualize the uptake of gold or titanium dioxide NMs respectively. Live and fixed cell imaging revealed that NMs were internalized by J774 macrophage and C3A hepatocyte cell lines (15-31 μg ml-1). Sprague Dawley rats were exposed to NMs (intratracheal instillation, 62 μg) and NMs were detected in blood and lung leucocytes, lung and liver tissue, demonstrating that NMs could translocate from the exposure site. Obtained data illustrate that multimodal nonlinear optical microscopy may help overcome current challenges in the assessment of NM cellular uptake and biodistribution. It is therefore a powerful tool that can be used to investigate unlabelled NM cellular and tissue uptake in three dimensions, requires minimal sample preparation, and is applicable to live and fixed cells.

  12. Hyaluronic acid based hydrogel system for soft tissue regeneration and drug delivery

    Science.gov (United States)

    Jha, Amit Kumar

    the gels. Human MSCs were undifferentiated during the early time points of culture, however differentiated into osteoblast phenotype after 28 days of culture. In summary, the HA-based hydrogel matrices are hierarchically structured, mechanically robust and enzymatically stable, capable of mediating cellular functions through the spatial and temporal presentation of defined biological cues. These hydrogel systems are promising candidates for soft tissue regeneration.

  13. Poly(caprolactone) based magnetic scaffolds for bone tissue engineering

    Science.gov (United States)

    Bañobre-López, M.; Piñeiro-Redondo, Y.; De Santis, R.; Gloria, A.; Ambrosio, L.; Tampieri, A.; Dediu, V.; Rivas, J.

    2011-04-01

    Synthetic scaffolds for tissue engineering coupled to stem cells represent a promising approach aiming to promote the regeneration of large defects of damaged tissues or organs. Magnetic nanocomposites formed by a biodegradable poly(caprolactone) (PCL) matrix and superparamagnetic iron doped hydroxyapatite (FeHA) nanoparticles at different PCL/FeHA compositions have been successfully prototyped, layer on layer, through 3D bioplotting. Magnetic measurements, mechanical testing, and imaging were carried out to calibrate both model and technological processing in the magnetized scaffold prototyping. An amount of 10% w/w of magnetic FeHA nanoparticles represents a reinforcement for PCL matrix, however, a reduction of strain at failure is also observed. Energy loss (absorption) measurements under a radio-frequency applied magnetic field were performed in the resulting magnetic scaffolds and very promising heating properties were observed, making them very useful for potential biomedical applications.

  14. 激光照射下生物组织内部温度分布的数值模拟%Numerical sinulation of the internal temperature distribution in biological tissues under laser irradiation

    Institute of Scientific and Technical Information of China (English)

    宋伟宏; 熊国欣; 李立本

    2011-01-01

    基于生物热传导理论和有限元算法,采用Matlab软件中的偏微分方程工具箱,模拟激光照射下生物组织的温度分布,并用三维图展现生物组织的温度随时间、空间的变化规律.对激光临床应用有理论指导意义.%Based on the bio - heal transfer theory, numerical simulation results for temperature distribution in biological tissue under irradiation of laser are presented by using Partial Differential Equation Toolbox of Matlab. 3 - dimensional graphs showing the temperature of biological tissue with time and space variation is derived. This study is beneficial for the clinical practices of laser surgery on human body.

  15. Hyaluronic acid-based scaffold for central neural tissue engineering

    OpenAIRE

    Wang, Xiumei; He, Jin; Wang, Ying; CUI, FU-ZHAI

    2012-01-01

    Central nervous system (CNS) regeneration with central neuronal connections and restoration of synaptic connections has been a long-standing worldwide problem and, to date, no effective clinical therapies are widely accepted for CNS injuries. The limited regenerative capacity of the CNS results from the growth-inhibitory environment that impedes the regrowth of axons. Central neural tissue engineering has attracted extensive attention from multi-disciplinary scientists in recent years, and ma...

  16. A highly elastic tissue sealant based on photopolymerised gelatin.

    Science.gov (United States)

    Elvin, Christopher M; Vuocolo, Tony; Brownlee, Alan G; Sando, Lillian; Huson, Mickey G; Liyou, Nancy E; Stockwell, Peter R; Lyons, Russell E; Kim, Misook; Edwards, Glenn A; Johnson, Graham; McFarland, Gail A; Ramshaw, John A M; Werkmeister, Jerome A

    2010-11-01

    Gelatin is widely used as a medical biomaterial because it is readily available, cheap, biodegradable and demonstrates favourable biocompatibility. Many applications require stabilisation of the biomaterial by chemical crosslinking, and this often involves derivatisation of the protein or treatment with cytotoxic crosslinking agents. We have previously shown that a facile photochemical method, using blue light, a ruthenium catalyst and a persulphate oxidant, produces covalent di-tyrosine crosslinks in resilin and fibrinogen to form stable hydrogel biomaterials. Here we show that various gelatins can also be rapidly crosslinked to form highly elastic (extension to break >650%) and adhesive (stress at break >100 kPa) biomaterials. Although the method does not require derivatisation of the protein, we show that when the phenolic (tyrosine-like) content of gelatin is increased, the crosslinked material becomes resistant to swelling, yet retains considerable elasticity and high adhesive strength. The reagents are not cytotoxic at the concentration used in the photopolymerisation reaction. When tested in vivo in sheep lung, the photopolymerised gelatin effectively sealed a wound in lung tissue from blood and air leakage, was not cytotoxic and did not produce an inflammatory response. The elastic properties, thermal stability, speed of curing and high tissue adhesive strength of this photopolymerised gelatin, offer considerable improvement over current surgical tissue sealants. PMID:20674967

  17. Scaffold- and Cell System-Based Bone Grafts in Tissue Engineering (Review

    Directory of Open Access Journals (Sweden)

    Kuznetsova D.S.

    2014-12-01

    Full Text Available The review considers the current trends in tissue engineering including maxillofacial surgery based on the use of scaffolds, autologous stem cells and bioactive substances. The authors have shown the advantages and disadvantages of basic materials used for scaffold synthesis — three-dimensional porous or fiber matrices serving as a mechanical frame for cells; among such materials there are natural polymers (collagen, cellulose, fibronectin, chitosan, alginate and agarose, fibroin, synthetic polymers (polylactide, polyglycolide, polycaprolactone, polyvinyl alcohol and bioceramics (hydroxyapatite, tricalcium phosphate and bioactive glasses. There have been demonstrated the matrix techniques, special attention being paid to innovative technologies of rapid prototyping — the process of 3D-imaging according to a digital model. The most applicable of these techniques for biopolymers are laser stereolithography, selective laser sintering, fused deposition modeling, and 3D-printing. Great emphasis has been put on the use of bioactive substances in the process of obtaining scaffold-based bioengineered constructions — setting of stem cells on matrices before their transplantation to the defect area. Special attention has been given to a current trend of cellular biology — the application of multipotent mesenchymal stromal cells (most common marrow cells used in bone tissue regeneration, in particular, the available sources of their isolation and the variants of directed osteogenic differentiation have been presented. The review covers the characteristics and aims of bioactive substance inclusion in scaffold structure — not only to induce osteogenic differentiation, but also to attract new stem cells of a carrier, as well as promote angiogenesis.

  18. 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...

  19. 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.

  20. 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

    2015-09-01

    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. PMID:26264405

  1. Quantification of collagen fiber organization in biological tissues at cellular and molecular scales using second-harmonic generation imaging

    Science.gov (United States)

    Ambekar Ramachandra Rao, Raghu

    Collagen is the most abundant structural protein found in the human body, and is responsible for providing structure and function to tissues. Collagen molecules organize naturally into structures called fibers on the scale of the wavelength of light and lack inversion symmetry, thus allowing for the process of second harmonic generation (SHG) when exposed to intense incident light. We have developed two quantitative techniques: Fourier transform-second-harmonic generation (FT-SHG) imaging and generalized chi2 second-harmonic generation (chi2-SHG) imaging. In order to show that FT-SHG imaging can be used as a valuable diagnostic tool for real-world biological problems, we first investigate collagenase-induced injury in horse tendons. Clear differences in collagen fiber organization between normal and injured tendon are quantified. In particular, we observe that the regularly oriented organization of collagen fibers in normal tendons is disrupted in injured tendons leading to a more random organization. We also observe that FT-SHG microscopy is more sensitive in assessing tendon injury compared to the conventional polarized light microscopy. The second study includes quantifying collagen fibers in cortical bone using FT-SHG imaging and comparing it with scanning electron microscopy (SEM). Further, as an example study, we show how FT-SHG imaging could be used to quantify changes in bone structure as a function of age. Some initial work and future directions for extending FT-SHG to 3D are also discussed. The second technique, chi2-SHG imaging, takes advantage of the coherent nature of SHG and utilizes polarization to extract the second-order susceptibility (d elements) which provides information on molecular organization, i.e., it provides access to sub-diffractional changes "optically". We use chi2-SHG in combination with FT-SHG imaging to investigate a couple of biological problems. First, we quantify differences in collagen fiber organization between cornea and

  2. SYNTHESIS OF SULFONAMIDE BASED SCHIFF’S BASES AND THEIR BIOLOGICAL EVALUATION TOWARDS COLLETOTRICHUM GLOEOSPORIOIDES

    OpenAIRE

    Siliveru Swamy; Parthasarathy, T.

    2012-01-01

    The purpose of research was to synthesize the better antifungal compounds, different substituted aromatic aldehydes are chosen as the starting materials for the synthesis of Schiff’s bases with sulfonamides in presence of alcohol and acidic reagent. The structures of synthesized compounds were confirmed by HRMS spectral analysis data. The derivatives were subjected to Colletotrichum gloeosporioides spore germination to evaluate their biological activity.

  3. STS-based education in non-majors college biology

    Science.gov (United States)

    Henderson, Phyllis Lee

    The study explored the effect of the science-technology-society (STS) and traditional teaching methods in non-majors biology classes at a community college. It investigated the efficacy of the two methods in developing cognitive abilities at Bloom's first three levels of learning. It compared retention rates in classes taught in the two methods. Changes in student attitude relating to anxiety, fear, and interest in biology were explored. The effect of each method on grade attainment among men and women was investigated. The effect of each method on grade attainment among older and younger students was examined. Results of the study indicated that no significant differences, relating to retention or student attitude, existed in classes taught in the two methods. The study found no significant cognitive gains at Bloom's first three levels in classes taught in the traditional format. In the STS classes no significant gains were uncovered at Bloom's first level of cognition. Statistically significant gains were found in the STS classes at Bloom's second and third levels of cognition. In the classes taught in the traditional format no difference was identified in grade attainment between males and females. In the STS-based classes a small correlational difference between males and females was found with males receiving lower grades than expected. No difference in grade attainment was found between older and younger students taught in the traditional format. In the STS-based classes a small statistically significant difference in grade attainment was uncovered between older and younger students with older students receiving more A's and fewer C's than expected. This study found no difference in the grades of older, female students as compared to all other students in the traditionally taught classes. A weak statistically significant difference was discovered between grade attainment of older, female students and all other students in the STS classes with older, female

  4. Organization of a radioisotope based molecular biology laboratory

    International Nuclear Information System (INIS)

    Polymerase chain reaction (PCR) has revolutionized the application of molecular techniques to medicine. Together with other molecular biology techniques it is being increasingly applied to human health for identifying prognostic markers and drug resistant profiles, developing diagnostic tests and genotyping systems and for treatment follow-up of certain diseases in developed countries. Developing Member States have expressed their need to also benefit from the dissemination of molecular advances. The use of radioisotopes, as a step in the detection process or for increased sensitivity and specificity is well established, making it ideally suitable for technology transfer. Many molecular based projects using isotopes for detecting and studying micro organisms, hereditary and neoplastic diseases are received for approval every year. In keeping with the IAEA's programme, several training activities and seminars have been organized to enhance the capabilities of developing Member States to employ in vitro nuclear medicine technologies for managing their important health problems and for undertaking related basic and clinical research. The background material for this publication was collected at training activities and from feedback received from participants at research and coordination meetings. In addition, a consultants' meeting was held in June 2004 to compile the first draft of this report. Previous IAEA TECDOCS, namely IAEA-TECDOC-748 and IAEA-TECDOC-1001, focused on molecular techniques and their application to medicine while the present publication provides information on organization of the laboratory, quality assurance and radio-safety. The technology has specific requirements of the way the laboratory is organized (e.g. for avoiding contamination and false positives in PCR) and of quality assurance in order to provide accurate information to decision makers. In addition while users of the technology accept the scientific rationale of using radio

  5. A Hyaluronan-Based Scaffold for the in Vitro Construction of Dental Pulp-Like Tissue

    OpenAIRE

    Letizia Ferroni; Chiara Gardin; Stefano Sivolella; Giulia Brunello; Mario Berengo; Adriano Piattelli; Eriberto Bressan; Barbara Zavan

    2015-01-01

    Dental pulp tissue supports the vitality of the tooth, but it is particularly vulnerable to external insults, such as mechanical trauma, chemical irritation or microbial invasion, which can lead to tissue necrosis. In the present work, we present an endodontic regeneration method based on the use of a tridimensional (3D) hyaluronan scaffold and human dental pulp stem cells (DPSCs) to produce a functional dental pulp-like tissue in vitro. An enriched population of DPSCs was seeded onto hyalur...

  6. Cardiac tissue engineering and regeneration using cell-based therapy

    Directory of Open Access Journals (Sweden)

    Alrefai MT

    2015-05-01

    Full Text Available Mohammad T Alrefai,1–3 Divya Murali,4 Arghya Paul,4 Khalid M Ridwan,1,2 John M Connell,1,2 Dominique Shum-Tim1,2 1Division of Cardiac Surgery, 2Division of Surgical Research, McGill University Health Center, Montreal, QC, Canada; 3King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia; 4Department of Chemical and Petroleum Engineering, School of Engineering, University of Kansas, Lawrence, KS, USA Abstract: Stem cell therapy and tissue engineering represent a forefront of current research in the treatment of heart disease. With these technologies, advancements are being made into therapies for acute ischemic myocardial injury and chronic, otherwise nonreversible, myocardial failure. The current clinical management of cardiac ischemia deals with reestablishing perfusion to the heart but not dealing with the irreversible damage caused by the occlusion or stenosis of the supplying vessels. The applications of these new technologies are not yet fully established as part of the management of cardiac diseases but will become so in the near future. The discussion presented here reviews some of the pioneering works at this new frontier. Key results of allogeneic and autologous stem cell trials are presented, including the use of embryonic, bone marrow-derived, adipose-derived, and resident cardiac stem cells. Keywords: stem cells, cardiomyocytes, cardiac surgery, heart failure, myocardial ischemia, heart, scaffolds, organoids, cell sheet and tissue engineering

  7. Microablation of collagen-based substrates for soft tissue engineering

    International Nuclear Information System (INIS)

    Noting the abundance and importance of collagen as a biomaterial, we have developed a facile method for the production of a dense fibrillar extracellular matrix mimicking collagen–elastin hybrids with tunable mechanical properties. Through the use of excimer-laser technology, we have optimized conditions for the ablation of collagen lamellae without denaturation of protein, maintenance of fibrillar ultrastructure and preservation of native D-periodicity. Strengths of collagen–elastin hybrids ranged from 0.6 to 13 MPa, elongation at break from 9 to 70% and stiffness from 2.9 to 94 MPa, allowing for the design of a wide variety of tissue specific scaffolds. Further, large (centimeter scale) lamellae can be fabricated and embedded with recombinant elastin to generate collagen–elastin hybrids. Exposed collagen in hybrids act as cell adhesive sites for rat mesenchymal stem cells that conform to ablate waveforms. The ability to modulate these features allows for the generation of a class of biopolymers that can architecturally and physiologically replicate native tissue. (communication)

  8. High concentrations of drug in target tissues following local controlled release are utilized for both drug distribution and biologic effect: an example with epicardial inotropic drug delivery.

    Science.gov (United States)

    Maslov, Mikhail Y; Edelman, Elazer R; Wei, Abraham E; Pezone, Matthew J; Lovich, Mark A

    2013-10-28

    Local drug delivery preferentially loads target tissues with a concentration gradient from the surface or point of release that tapers down to more distant sites. Drug that diffuses down this gradient must be in unbound form, but such drug can only elicit a biologic effect through receptor interactions. Drug excess loads tissues, increasing gradients and driving penetration, but with limited added biological response. We examined the hypothesis that local application reduces dramatically systemic circulating drug levels but leads to significantly higher tissue drug concentration than might be needed with systemic infusion in a rat model of local epicardial inotropic therapy. Epinephrine was infused systemically or released locally to the anterior wall of the heart using a novel polymeric platform that provides steady, sustained release over a range of precise doses. Epinephrine tissue concentration, upregulation of cAMP, and global left ventricular response were measured at equivalent doses and at doses equally effective in raising indices of contractility. The contractile stimulation by epinephrine was linked to drug tissue levels and commensurate cAMP upregulation for IV systemic infusion, but not with local epicardial delivery. Though cAMP was a powerful predictor of contractility with local application, tissue epinephrine levels were high and variable--only a small fraction of the deposited epinephrine was utilized in second messenger signaling and biologic effect. The remainder of deposited drug was likely used in diffusive transport and distribution. Systemic side effects were far more profound with IV infusion which, though it increased contractility, also induced tachycardia and loss of systemic vascular resistance, which were not seen with local application. Local epicardial inotropic delivery illustrates then a paradigm of how target tissues differentially handle and utilize drug compared to systemic infusion. PMID:23872515

  9. Indoor biology pollution control based on system-based humidity priority control strategy

    Institute of Scientific and Technical Information of China (English)

    刘亚昱; 谢慧; 石博强

    2009-01-01

    Indoor biological contamination and HVAC system secondary contamination problems caused wide public concerns. Biological contamination control will be the next step to achieve better IAQ. The most efficient and safe way to control biological contamination was to limit relative humidity in HVAC system and conditioned environment in the range that is more unsuitable for microorganism to survive. In this paper,by referring to bio-clean project experiences,a system-based humidity priority control manner came into being by lowering outdoor air humidity ratio to eliminate all indoor latent load and using self recirculation units to bear indoor sensible load. Based on the whole-course residue humidity contaminant control concept,dynamic step models for coil and conditioned zone were developed to describe mass and energy conservation and transformation processes. Then,HVAC system and conditioned zone dynamic models were established on LabVIEW+Matlab platform to investigate optimized regulation types,input signatures and control logics. Decoupling between cooling and dehumidification processes can be achieved and a more simplified and stable control system can be acquired by the system-based humidity priority control strategy. Therefore,it was a promising way for controlling biological pollution in buildings in order to achieve better IAQ.

  10. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    Science.gov (United States)

    Skopinska-Wisniewska, J.; Sionkowska, A.; Kaminska, A.; Kaznica, A.; Jachimiak, R.; Drewa, T.

    2009-07-01

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in biomaterial

  11. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    International Nuclear Information System (INIS)

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in biomaterial

  12. Hydrogel-Based Platforms for the Regeneration of Osteochondral Tissue and Intervertebral Disc

    Directory of Open Access Journals (Sweden)

    Luigi Ambrosio

    2012-09-01

    Full Text Available Hydrogels currently represent a powerful solution to promote the regeneration of soft and hard tissues. Primarily, they assure efficient bio-molecular interactions with cells, also regulating their basic functions, guiding the spatially and temporally complex multi-cellular processes of tissue formation, and ultimately facilitating the restoration of structure and function of damaged or dysfunctional tissues. In order to overcome basic drawbacks of traditional synthesized hydrogels, many recent strategies have been implemented to realize multi-component hydrogels based on natural and/or synthetic materials with tailored chemistries and different degradation kinetics. Here, a critical review of main strategies has been proposed based on the use of hydrogels-based devices for the regeneration of complex tissues, i.e., osteo-chondral tissues and intervertebral disc.

  13. Challenges and Opportunities for Learning Biology in Distance-Based Settings

    Science.gov (United States)

    Hallyburton, Chad L.; Lunsford, Eddie

    2013-01-01

    The history of learning biology through distance education is documented. A review of terminology and unique problems associated with biology instruction is presented. Using published research and their own teaching experience, the authors present recommendations and best practices for managing biology in distance-based formats. They offer ideas…

  14. Engineering spinal fusion: evaluating ceramic materials for cell based tissue engineered approaches

    NARCIS (Netherlands)

    Wilson, C.E.

    2011-01-01

    The principal aim of this thesis was to advance the development of tissue engineered posterolateral spinal fusion by investigating the potential of calcium phosphate ceramic materials to support cell based tissue engineered bone formation. This was accomplished by developing several novel model syst

  15. Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics

    Science.gov (United States)

    Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander

    2010-01-01

    We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to…

  16. Identification of co-expression gene networks, regulatory genes and pathways for obesity based on adipose tissue RNA Sequencing in a porcine model

    DEFF Research Database (Denmark)

    Kogelman, Lisette; Cirera Salicio, Susanna; Zhernakova, Daria V.;

    2014-01-01

    interactions. Identification of co-expressed and regulatory genes in RNA extracted from relevant tissues representing lean and obese individuals provides an entry point for the identification of genes and pathways of importance to the development of obesity. The pig, an omnivorous animal, is an excellent model...... for human obesity, offering the possibility to study in-depth organ-level transcriptomic regulations of obesity, unfeasible in humans. Our aim was to reveal adipose tissue co-expression networks, pathways and transcriptional regulations of obesity using RNA Sequencing based systems biology approaches...... associated with obesity in humans and rodents, e.g. CSF1R and MARC2. Conclusions To our knowledge, this is the first study to apply systems biology approaches using porcine adipose tissue RNA-Sequencing data in a genetically characterized porcine model for obesity. We revealed complex networks, pathways...

  17. 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)

    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

  18. CCQM-K86/P113.1: Relative quantification of genomic DNA fragments extracted from a biological tissue

    Science.gov (United States)

    Corbisier, P.; Vincent, S.; Schimmel, H.; Kortekaas, A.-M.; Trapmann, S.; Burns, M.; Bushell, C.; Akgoz, M.; Akyürek, S.; Dong, L.; Fu, B.; Zhang, L.; Wang, J.; Pérez Urquiza, M.; Bautista, J. L.; Garibay, A.; Fuller, B.; Baoutina, A.; Partis, L.; Emslie, K.; Holden, M.; Chum, W. Y.; Kim, H.-H.; Phunbua, N.; Milavec, M.; Zel, J.; Vonsky, M.; Konopelko, L. A.; Lau, T. L. T.; Yang, B.; Hui, M. H. K.; Yu, A. C. H.; Viroonudomphol, D.; Prawettongsopon, C.; Wiangnon, K.; Takabatake, R.; Kitta, K.; Kawaharasaki, M.; Parkes, H.

    2012-01-01

    Key comparison CCQM-K86 was performed to demonstrate and document the capacity of interested national metrology institutes (NMIs) and designated institutes (DIs) in the determination of the relative quantity of two specific genomic DNA fragments present in a biological tissue. The study provides the support for the following measurement claim: "Quantification of the ratio of the number of copies of specified intact sequence fragments of a length in the range of 70 to 100 nucleotides in a single genomic DNA extract from ground maize seed materials". The study was carried out under the auspices of the Bioanalysis Working Group (BAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) and was piloted by the Institute for Reference Materials and Methods (IRMM) in Geel (Belgium). The following laboratories (in alphabetical order) participated in this key comparison: AIST (Japan), CENAM (Mexico), DMSc (Thailand), GLHK (Hong Kong), IRMM (European Union), KRISS (Republic of Korea), LGC (United Kingdom), MIRS/NIB (Slovenia), NIM (PR China), NIST (USA), NMIA (Australia), TÜBITAK UME (Turkey) and VNIIM (Russian Federation). The following laboratories (in alphabetical order) participated in a pilot study that was organized in parallel: LGC (United Kingdom), PKU (PR China), NFRI (Japan) and NIMT (Thailand). Good agreement was observed between the reported results of eleven participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  19. Mass Spectrometry-based Proteomics and Peptidomics for Systems Biology and Biomarker Discovery

    OpenAIRE

    Cunningham, Robert; Ma, Di; Li, Lingjun

    2012-01-01

    The scientific community has shown great interest in the field of mass spectrometry-based proteomics and peptidomics for its applications in biology. Proteomics technologies have evolved to produce large datasets of proteins or peptides involved in various biological and disease progression processes producing testable hypothesis for complex biological questions. This review provides an introduction and insight to relevant topics in proteomics and peptidomics including biological material sel...

  20. Degradation of zinc containing phosphate-based glass as a material for orthopedic tissue engineering.

    Science.gov (United States)

    Qaysi, Mustafa Al; Petrie, Aviva; Shah, Rishma; Knowles, Jonathan C

    2016-10-01

    Phosphate-based glasses have been examined in many studies as a potential biomaterial for bone repair because of its degradation properties, which can be controlled and allow the release of various elements to promote osteogenic tissue growth. However most of these experiments studied either tertiary or quaternary glass systems. This study investigated a qinternary system that included titanium dioxide for degradation rate control and zinc that is considered to have a role in bone formation. Zinc and titanium phosphate glass discs of different compositions were melt synthesized and samples of each composition was tested for different physical, chemical and biological characteristics via density measurement, X-ray diffraction, differential thermal analysis, mass loss, ion release, scanning electron microscopy, biocompatibility studies via live/dead assays at three time points (day 1, 4, and 7). The results showed that the glass was amorphous and that the all thermal variables decreased as zinc oxide amount raised, mass loss as well as ion release increased as zinc oxide increased, and the maximum rise was with ZnO15. The cellular studies showed that all the formulation showed similar cytocompatibility properties with MG63 except ZnO15, which displayed cytotoxic properties and this was confirmed also by the scanning electron microscope images. In conclusion, replacing calcium oxide with zinc oxide in proportion less than 10 % can have a positive effect on bone forming cells. PMID:27620740

  1. Drug delivery, cell-based therapies, and tissue engineering approaches for spinal cord injury.

    Science.gov (United States)

    Kabu, Shushi; Gao, Yue; Kwon, Brian K; Labhasetwar, Vinod

    2015-12-10

    Spinal cord injury (SCI) results in devastating neurological and pathological consequences, causing major dysfunction to the motor, sensory, and autonomic systems. The primary traumatic injury to the spinal cord triggers a cascade of acute and chronic degenerative events, leading to further secondary injury. Many therapeutic strategies have been developed to potentially intervene in these progressive neurodegenerative events and minimize secondary damage to the spinal cord. Additionally, significant efforts have been directed toward regenerative therapies that may facilitate neuronal repair and establish connectivity across the injury site. Despite the promise that these approaches have shown in preclinical animal models of SCI, challenges with respect to successful clinical translation still remain. The factors that could have contributed to failure include important biologic and physiologic differences between the preclinical models and the human condition, study designs that do not mirror clinical reality, discrepancies in dosing and the timing of therapeutic interventions, and dose-limiting toxicity. With a better understanding of the pathobiology of events following acute SCI, developing integrated approaches aimed at preventing secondary damage and also facilitating neuroregenerative recovery is possible and hopefully will lead to effective treatments for this devastating injury. The focus of this review is to highlight the progress that has been made in drug therapies and delivery systems, and also cell-based and tissue engineering approaches for SCI. PMID:26343846

  2. Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

    Science.gov (United States)

    DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

    2016-03-01

    Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

  3. Aquaporin-4 autoantibodies in neuromyelitis optica spectrum disorders: comparison between tissue-based and cell-based indirect immunofluorescence assays

    Directory of Open Access Journals (Sweden)

    Chan Koon H

    2010-09-01

    Full Text Available Abstract Background Neuromyelitis optica spectrum disorders (NMOSD are severe central nervous system inflammatory demyelinating disorders (CNS IDD characterized by monophasic or relapsing, longitudinally extensive transverse myelitis (LETM and/or optic neuritis (ON. A significant proportion of NMOSD patients are seropositive for aquaporin-4 (AQP4 autoantibodies. We compared the AQP4 autoantibody detection rates of tissue-based indirect immunofluorescence assay (IIFA and cell-based IIFA. Methods Serum of Chinese CNS IDD patients were assayed for AQP4 autoantibodies by tissue-based IIFA using monkey cerebellum and cell-based IIFA using transfected HEK293 cells which express human AQP4 on their cell membranes. Results In total, 128 CNS IDD patients were studied. We found that 78% of NMO patients were seropositive for AQP4 autoantibodies by cell-based IIFA versus 61% by tissue-based IFA (p = 0.250, 75% of patients having relapsing myelitis (RM with LETM were seropositive by cell-based IIFA versus 50% by tissue-based IIFA (p = 0.250, and 33% of relapsing ON patients were seropositive by cell-based IIFA versus 22% by tissue-based IIFA (p = 1.000; however the differences were not statistically significant. All patients seropositive by tissue-based IIFA were also seropositive for AQP4 autoantibodies by cell-based IIFA. Among 29 NMOSD patients seropositive for AQP4 autoantibodies by cell-based IIFA, 20 (69% were seropositive by tissue-based IIFA. The 9 patients seropositive by cell-based IIFA while seronegative by tissue-based IIFA had NMO (3, RM with LETM (3, a single attack of LETM (1, relapsing ON (1 and a single ON attack (1. Among 23 NMO or RM patients seropositive for AQP4 autoantibodies by cell-based IIFA, comparison between those seropositive (n = 17 and seronegative (n = 6 by tissue-based IIFA revealed no differences in clinical and neuroradiological characteristics between the two groups. Conclusion Cell-based IIFA is slightly more sensitive

  4. 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.

  5. A Novel Method for Single Sample Multi-Axial Nanoindentation of Hydrated Heterogeneous Tissues Based on Testing Great White Shark Jaws

    OpenAIRE

    Ferrara, Toni L.; Philip Boughton; Eve Slavich; Stephen Wroe

    2013-01-01

    Nanomechanical testing methods that are suitable for a range of hydrated tissues are crucial for understanding biological systems. Nanoindentation of tissues can provide valuable insights into biology, tissue engineering and biomimetic design. However, testing hydrated biological samples still remains a significant challenge. Shark jaw cartilage is an ideal substrate for developing a method to test hydrated tissues because it is a unique heterogeneous composite of both mineralized (hard) and ...

  6. Molecular biology-based diagnosis and therapy for pancreatic cancer

    International Nuclear Information System (INIS)

    Mainly described are author's investigations of the title subject through clinical and basic diagnosis/therapeutic approach. Based on their consideration of carcinogenesis and pathological features of pancreatic cancer (PC), analysis of expression of cancer-related genes in clinically available samples like pancreatic juice and cells biopsied can result in attaining their purposes. Desmoplasia, a pathological feature of PC, possibly induces resistance to therapy and one of strategies is probably its suppression. Targeting stem cells of the mesenchyma as well as those of PC is also a strategy in future. Authors' studies have revealed that quantitation of hTERT (coding teromerase) mRNA levels in PC cells micro-dissected from cytological specimens is an accurate molecular biological diagnostic method applicable clinically. Other cancer-related genes are also useful for the diagnosis and mucin (MUC) family genes are shown to be typical ones for differentiating the precancerous PC, PC and chronic pancreatisis. Efficacy of standard gemcitabine chemotherapy can be individualized with molecular markers concerned to metabolism of the drug like dCK. Radiotherapy/radio-chemotherapy are not so satisfactory for PC treatment now. Authors have found elevated MMP-2 expression and HGF/c-Met signal activation in irradiated PC cells, which can increase the invasive capability; and stimulation of phosphorylation and activation of c-Met/MARK in co-culture of irradiated PC cells with messenchymal cells from PC, which possibly leads to progression of malignancy of PC through their interaction, of which suppression, therefore, can be a new approach to increase the efficacy of radiotherapy. Authors are making effort to introducing adenovirus therapy in clinic; exempli gratia (e.g.), the virus carrying wild type p53, a cancer-suppressive gene, induces apoptosis of PC cells often having its mutated gene. (T.T.)

  7. NMR-based metabolomics of mammalian cell and tissue cultures

    International Nuclear Information System (INIS)

    NMR spectroscopy was used to evaluate growth media and the cellular metabolome in two systems of interest to biomedical research. The first of these was a Chinese hamster ovary cell line engineered to express a recombinant protein. Here, NMR spectroscopy and a quantum mechanical total line shape analysis were utilized to quantify 30 metabolites such as amino acids, Krebs cycle intermediates, activated sugars, cofactors, and others in both media and cell extracts. The impact of bioreactor scale and addition of anti-apoptotic agents to the media on the extracellular and intracellular metabolome indicated changes in metabolic pathways of energy utilization. These results shed light into culture parameters that can be manipulated to optimize growth and protein production. Second, metabolomic analysis was performed on the superfusion media in a common model used for drug metabolism and toxicology studies, in vitro liver slices. In this study, it is demonstrated that two of the 48 standard media components, choline and histidine are depleted at a faster rate than many other nutrients. Augmenting the starting media with extra choline and histidine improves the long-term liver slice viability as measured by higher tissues levels of lactate dehydrogenase (LDH), glutathione and ATP, as well as lower LDH levels in the media at time points out to 94 h after initiation of incubation. In both models, media components and cellular metabolites are measured over time and correlated with currently accepted endpoint measures.

  8. Impact of Detergent-Based Decellularization Methods on Porcine Tissues for Heart Valve Engineering.

    Science.gov (United States)

    Roosens, Annelies; Somers, Pamela; De Somer, Filip; Carriel, Victor; Van Nooten, Guido; Cornelissen, Ria

    2016-09-01

    To date an optimal decellularization protocol of heart valve leaflets (HVL) and pericardia (PER) with an adequate preservation of the extracellular matrix (ECM) is still lacking. This study compares a 4 day Triton X-100-based protocol with faster SDC-based protocols for the decellularization of cardiac tissues. Decellularized and non-treated HVL and PER were processed for histological, biochemical and mechanical analysis to determine the effect of these agents on the structure, ECM components, and biomechanical properties. Tissues treated with SDC-based protocols still showed nuclear material, whereas tissues treated with Triton X-100 1% + ENZ ± TRYP were completely cell free. For both decellularized tissues, an almost complete washout of glycosaminoglycans, a reduction of soluble collagen and an alteration of the surface ultrastructure was observed. Interestingly, only the elastic fibers of pericardial tissue were affected and this tissue had a decreased maximum load. This study showed that both detergents had a similar impact on the ECM. However, Triton X-100 1% +DNase/RNase (ENZ) ± Trypsin (TRYP) is the only protocol that generated completely cell free bioscaffolds. Also, our study clearly demonstrated that the decellularization agents have more impact on pericardial tissues than on heart valve leaflets. Thus, for the purpose of tissue engineering of heart valves, it is advisable to use valvular rather than pericardial matrices. PMID:26842626

  9. Development of new chitosan based biodegradable blends for bone and cartilage tissue engineering

    OpenAIRE

    Silva, Vitor Manuel Correlo da

    2009-01-01

    Tese de Doutoramento em Ciência e Tecnologia de Materiais - Engenharia de Tecidos - Materiais Híbridos A number of natural origin polymers are being employed in tissue engineering strategies. Natural origin polymers offer the advantage of being similar to macromolecular substances, which the biological environment is prepared to recognize and to deal with metabolically. Another attractive characteristic of natural polymers is their ability to be degraded by naturally occurring enz...

  10. Tissue Reinforcement in Implant-based Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Michael Scheflan, MD

    2014-08-01

    Conclusions: ADM-assisted implant-based breast reconstruction may improve aesthetic outcomes. However, appropriate patient selection, surgical technique, and postoperative management are critical for its success, including minimizing the risk of complications.

  11. 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

  12. Content-based image retrieval applied to BI-RADS tissue classification in screening mammography

    OpenAIRE

    2011-01-01

    AIM: To present a content-based image retrieval (CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classification.

  13. Bridging cancer biology and the patients' needs with nanotechnology-based approaches.

    Science.gov (United States)

    Fonseca, Nuno A; Gregório, Ana C; Valério-Fernandes, Angela; Simões, Sérgio; Moreira, João N

    2014-06-01

    Cancer remains as stressful condition and a leading cause of death in the western world. Actual cornerstone treatments of cancer disease rest as an elusive alternative, offering limited efficacy with extensive secondary effects as a result of severe cytotoxic effects in healthy tissues. The advent of nanotechnology brought the promise to revolutionize many fields including oncology, proposing advanced systems for cancer treatment. Drug delivery systems rest among the most successful examples of nanotechnology. Throughout time they have been able to evolve as a function of an increased understanding from cancer biology and the tumor microenvironment. Marketing of Doxil® unleashed a remarkable impulse in the development of drug delivery systems. Since then, several nanocarriers have been introduced, with aspirations to overrule previous technologies, demonstrating increased therapeutic efficacy besides decreased toxicity. Spatial and temporal targeting to cancer cells has been explored, as well as the use of drug combinations co-encapsulated in the same particle as a mean to take advantage of synergistic interactions in vivo. Importantly, targeted delivery of siRNA for gene silencing therapy has made its way to the clinic for a "first in man" trial using lipid-polymeric-based particles. Focusing in state-of-the-art technology, this review will provide an insightful vision on nanotechnology-based strategies for cancer treatment, approaching them from a tumor biology-driven perspective, since their early EPR-based dawn to the ones that have truly the potential to address unmet medical needs in the field of oncology, upon targeting key cell subpopulations from the tumor microenvironment. PMID:24613464

  14. Multilayered Scaffolds for Osteochondral Tissue Engineering Based on Bioactive Glass and Biodegradable Polymers

    OpenAIRE

    Nooeaid, Patcharakamon

    2014-01-01

    Injuries of the articular cartilage may penetrate to the underlying subchondral bone, forming osteochondral defects which have a limited capacity of self-regeneration. Accompanied with limited surgical treatments and the fact that the causes are not understood well, an approach based in tissue engineering becomes a promising strategy for osteochondral repair. Such tissue engineering approaches are based on the combination of synthetic scaffolds, suitable cell sources and active molecules or g...

  15. Improved circuit model of open-ended coaxial probe for measurement of the biological tissue dielectric properties between megahertz and gigahertz

    International Nuclear Information System (INIS)

    This note describes an improved equivalent circuit analysis model for open-ended coaxial probes for measurement of the dielectric properties of biological tissues below the gigahertz level. Some parameters in the conventional model that influence the measurement results were found to be still relative to the dielectric properties of the test sample and the terminal admittance of the probe was found to be dependent on the frequency. This was not found to be the case with the conventional model. According to the simulation results in frequency range from 30 MHz to 1 GHz, a polynomial expression was found to fit the frequency–admittance curve for terminal admittance and the equivalent circuit expression of probe terminal admittance was finally modified. The simulated annealing algorithm was used to calculate the dielectric properties of the new expression. The accuracy of the improved model was validated through a simulation test and experiment based on a series of solutions over 30 MHz–1 GHz. The new model was compared to the conventional model and was found to provide more accurate permittivity estimation over a wider frequency range than the conventional model if said range was between megahertz and gigahertz. (note)

  16. Biological and ecological responses to carbon-based nanomaterials

    Science.gov (United States)

    Ratnikova, Tatsiana A.

    This dissertation examines the biological and ecological responses to carbon nanoparticles, a major class of nanomaterials which have been mass produced and extensively studied for their rich physical properties and commercial values. Chapter I of this dissertation offers a comprehensive review on the structures, properties, applications, and implications of carbon nanomaterials, especially related to the perspectives of biological and ecosystems. Given that there are many types of carbon nanomaterials available, this chapter is focused on three major types of carbon-based nanomaterials only, namely, fullerenes, single walled and multi-walled carbon nanotubes. On the whole organism level, specifically, Chapter II presents a first study on the fate of fullerenes and multiwalled carbon nanotubes in rice plants, which was facilitated by the self assembly of these nanomaterials with NOM. The aspects of fullerene uptake, translocation, biodistribution, and generational transfer in the plants were examined and quantified using bright field and electron microscopy, FT-Raman, and FTIR spectroscopy. The uptake and transport of fullerene in the plant vascular system were attributed to water transpiration, convection, capillary force, and the fullerene concentration gradient from the roots to the leaves of the plants. On the cellular level, Chapter III documents the differential uptake of hydrophilic C60(OH)20 vs. amphiphilic C70-NOM complex in Allium cepa plant cells and HT-29 colon carcinoma cells. This study was conducted using a plant cell viability assay, and complemented by bright field, fluorescence and electron microscopy imaging. In particular, C60(OH)20 and C70-NOM showed contrasting uptake in both the plant and mammalian cells, due to their significant differences in physicochemistry and the presence of an extra hydrophobic plant cell wall in the plant cells. Consequently, C60(OH)20 was found to induce toxicity in Allium cepa cells but not in HT-29 cells, while C70

  17. Usefulness and limits of biological dosimetry based on cytogenetic methods

    International Nuclear Information System (INIS)

    Damage from occupational or accidental exposure to ionising radiation is often assessed by monitoring chromosome aberrations in peripheral blood lymphocytes, and these procedures have, in several cases, assisted physicians in the management of irradiated persons. Thereby, circulating lymphocytes, which are in the G0 stage of the cell cycle are stimulated with a mitogenic agent, usually phytohaemagglutinin, to replicate in vitro their DNA and enter cell division, and are then observed for abnormalities. Comparison with dose response relationships obtained in vitro allows an estimate of exposure based on scoring: - Unstable aberrations by the conventional, well-established analysis of metaphases for chromosome abnormalities or for micronuclei; - So-called stable aberrations by the classical G-banding (Giemsa-Stain-banding) technique or by the more recently developed fluorescent in situ hybridisation (FISH) method using fluorescent-labelled probes for centromeres and chromosomes. Three factors need to be considered in applying such biological dosimetry: (1) Radiation doses in the body are often inhomogeneous. A comparison of the distribution of the observed aberrations among with that expected from a normal poisson distribution can allow conclusions to be made with regard to the inhomogeneity of exposure by means of the so-called contaminated poisson distribution method; however, its application requires a sufficiently large number of aberrations, i.e. an exposure to a rather large dose at a high dose rate. (2) Exposure can occur at a low dose rate (e.g. from spread or lost radioactive sources) rendering a comparison with in vitro exposure hazardous. Dose-effect relationships of most aberrations that were scored, such as translocations, follow a square law. Repair intervening during exposure reduces the quadratic component with decreasing dose rate as exposure is spread over a longer period of time. No valid solution for this problem has yet been developed, although

  18. Usefulness and limits of biological dosimetry based on cytogenetic methods.

    Science.gov (United States)

    Léonard, A; Rueff, J; Gerber, G B; Léonard, E D

    2005-01-01

    Damage from occupational or accidental exposure to ionising radiation is often assessed by monitoring chromosome aberrations in peripheral blood lymphocytes, and these procedures have, in several cases, assisted physicians in the management of irradiated persons. Thereby, circulating lymphocytes, which are in the G0 stage of the cell cycle are stimulated with a mitogenic agent, usually phytohaemagglutinin, to replicate in vitro their DNA and enter cell division, and are then observed for abnormalities. Comparison with dose-response relationships obtained in vitro allows an estimate of exposure based on scoring: Unstable aberrations by the conventional, well-established analysis of metaphases for chromosome abnormalities or for micronuclei; So-called stable aberrations by the classical G-banding (Giemsa-Stain-banding) technique or by the more recently developed fluorescent in situ hybridisation (FISH) method using fluorescent-labelled probes for centromeres and chromosomes. Three factors need to be considered in applying such biological dosimetry: (1) Radiation doses in the body are often inhomogeneous. A comparison of the distribution of the observed aberrations among cells with that expected from a normal poisson distribution can allow conclusions to be made with regard to the inhomogeneity of exposure by means of the so-called contaminated poisson distribution method; however, its application requires a sufficiently large number of aberrations, i.e. an exposure to a rather large dose at a high dose rate. (2) Exposure can occur at a low dose rate (e.g. from spread or lost radioactive sources) rendering a comparison with in vitro exposure hazardous. Dose-effect relationships of most aberrations that were scored, such as translocations, follow a square law. Repair intervening during exposure reduces the quadratic component with decreasing dose rate as exposure is spread over a longer period of time. No valid solution for this problem has yet been developed, although

  19. SYNTHESIS OF SULFONAMIDE BASED SCHIFF’S BASES AND THEIR BIOLOGICAL EVALUATION TOWARDS COLLETOTRICHUM GLOEOSPORIOIDES

    Directory of Open Access Journals (Sweden)

    Siliveru Swamy

    2012-11-01

    Full Text Available The purpose of research was to synthesize the better antifungal compounds, different substituted aromatic aldehydes are chosen as the starting materials for the synthesis of Schiff’s bases with sulfonamides in presence of alcohol and acidic reagent. The structures of synthesized compounds were confirmed by HRMS spectral analysis data. The derivatives were subjected to Colletotrichum gloeosporioides spore germination to evaluate their biological activity.

  20. Simulation studies of statistical distributions of cell membrane capacities and an ellipse model to assess the frequency behaviour of biological tissues

    International Nuclear Information System (INIS)

    The frequency behaviour of biological tissues is commonly described by a Cole model reflecting a single-cell bio-impedance model extended with an exponent α. However, for this parameter α there is no physical or biological substrate, which impedes an interpretation. The present study confirms by computer simulations of tissue models that the factual frequency behaviour can be explained by assuming a distribution of the electrical impedance properties of cells and of the capacitive coupling between cells. This behaviour is modelled mathematically by an ellipse. A mathematical procedure is presented to estimate this ellipse from experimental data by a least square method. A model parameter β is introduced, representing the ratio of the axes of the ellipse. A higher value of β means a larger variation in cell properties, which makes a patho-physiological interpretation of changes possible.

  1. Biofilms of chitosan-gold nanorods as a novel composite for the laser welding of biological tissue

    Science.gov (United States)

    Matteini, P.; Ratto, F.; Rossi, F.; Pini, R.

    2010-02-01

    Gold nanorods (GNRs) exhibit intense localized plasmon resonances at optical frequencies in the near infrared (NIR), which is the window where the penetration of light into the body is maximal. Upon excitation with a NIR laser, a strong photothermal effect is produced, which can be exploited to develop minimally invasive therapies. Here we prove the use of chitosan-GNRs films as a novel NIR sensitive nanocomposite for the photothermal conversion of NIR laser light during surgical interventions of tissue welding. Chitosan is an attractive biomaterial due to its biodegradability, biocompatibility, hemostatic, antimicrobial and wound healing-promoting activity. Colloidal GNRs were embedded in chitosan based, highly stabilized, flexible and easy-to-handle films, which were stored in water until the time of surgery. The chitosan-GNRs films were first positioned on freshly explanted rabbit tendon samples. Then, by administration of single pulses ranging from 80 to 140 ms duration and 0.5 to 1.5 W power delivered by a 300-μm optic fiber coupled with a 810 nm diode laser, spots of local thermally-induced adhesion characterized by a tensile strength of ~ 10 kPa were obtained. The present results are encouraging toward the development of a novel minimally-invasive technology based on the application of bioderived nanoplasmonic materials to biomedical optics.

  2. Expression of Hepatocyte Growth Factor-Like Protein in Human Wound Tissue and Its Biological Functionality in Human Keratinocytes

    OpenAIRE

    James C. Glasbey; Sanders, Andrew J.; David C. Bosanquet; Fiona Ruge; HARDING, KEITH G.; Jiang, Wen G

    2015-01-01

    Hepatocyte growth factor-like protein (HGFl) and its receptor, Recepteur d'Origine Nantais (RON), have been implicated in the development of wound chronicity. HGFl and RON expression was detected in acute wound tissue, chronic wound tissue and in normal skin using quantitative polymerase chain reaction (Q-PCR). HGFl and RON expression was also assessed in chronic healing and chronic non-healing wound tissues using Q-PCR and immunohistochemical staining. Expression was similarly detected in th...

  3. A quantitative and qualitative comparative analysis of collagen fibers to determine the role of connective tissue stroma on biological behavior of odontogenic cysts: A histochemical study

    OpenAIRE

    Singh, Harkanwal Preet; Shetty, Devi Charan; Wadhwan, Vijay; Aggarwal, Palak

    2012-01-01

    Background: Intricate relationship between epithelium and connective tissue is believed to play a significant role in pathogenesis of odontogenic lesions. Role of epithelium in its pathogenesis is well established and at the same time role of mesenchyme cannot be underestimated. Aim: To investigate, compare and correlate different types and pattern of collagen fibers in odontogenic cysts using picrosiriusred stain under polarizing microscopy in order to delineate its exact role in biological ...

  4. 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. PMID:23115828

  5. Clinical and biometrical evaluation of socket preservation using demineralized freeze-dried bone allograft with and without the palatal connective tissue as a biologic membrane

    OpenAIRE

    Hamid Moghaddas; Mohammad Reza Amjadi; Narges Naghsh

    2012-01-01

    Background: 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). Materials and Methods: Twelve extraction sites were treated with DFDBA with (case gro...

  6. Tissue engineered periodontal products.

    Science.gov (United States)

    Bartold, P M; Gronthos, S; Ivanovski, S; Fisher, A; Hutmacher, D W

    2016-02-01

    Attainment of periodontal regeneration is a significant clinical goal in the management of advanced periodontal defects arising from periodontitis. Over the past 30 years numerous techniques and materials have been introduced and evaluated clinically and have included guided tissue regeneration, bone grafting materials, growth and other biological factors and gene therapy. With the exception of gene therapy, all have undergone evaluation in humans. All of the products have shown efficacy in promoting periodontal regeneration in animal models but the results in humans remain variable and equivocal concerning attaining complete biological regeneration of damaged periodontal structures. In the early 2000s, the concept of tissue engineering was proposed as a new paradigm for periodontal regeneration based on molecular and cell biology. At this time, tissue engineering was a new and emerging field. Now, 14 years later we revisit the concept of tissue engineering for the periodontium and assess how far we have come, where we are currently situated and what needs to be done in the future to make this concept a reality. In this review, we cover some of the precursor products, which led to our current position in periodontal tissue engineering. The basic concepts of tissue engineering with special emphasis on periodontal tissue engineering products is discussed including the use of mesenchymal stem cells in bioscaffolds and the emerging field of cell sheet technology. Finally, we look into the future to consider what CAD/CAM technology and nanotechnology will have to offer. PMID:25900048

  7. The chemical fate of the Cd/Se/Te-based quantum dot 705 in the biological system: toxicity implications

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C-H; Chang, Louis W; Lai, W-H; Chang, W-H; Lin Pinpin [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Chang Han [Department of Pathology, Chung Shan Medical University, Taichung, Taiwan (China); Yang, M-H [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan (China); Yang, C-S [Center for Nanomedicine Research, National Health Research Institutes, Zhunan, Taiwan (China)], E-mail: pplin@nhri.org.tw

    2009-05-27

    QD705 is a cadmium/selenium/tellurium (Cd/Se/Te)-based quantum dot with good potential for biomedical applications. Although the biological fate of QD705 is established, its chemical fate in the biological system is still unknown. Since the chemical nature of Cd in QD705 (either stays as bounded Cd or becomes free Cd) is closely related to the toxicity of this nanocrystal, information on its chemical fate is critically needed. In this study we investigated the chemical fate of QD705 in the kidneys of mice. We used the molar ratio of Cd and Te (increased Cd/Te ratio signifies increased Cd release from QD705) and the induction of tissue metallothionein (MT) as markers for elevated free Cd in tissues. Our study indicated that 100% of QD705 (measured as Cd) was still retained in the body 16 weeks after exposure, with significant time redistribution to the kidneys. Furthermore, there were an elevation in both the molar Cd/Te ratio and MT-1 expression in the kidneys, suggesting that free Cd was released from QD705. Thus QD705 is not as stable or biologically inert as many may have once believed. Our study demonstrated that free Cd indeed can be released from QD705 in the kidneys and increases the risk of renal toxicity.

  8. The chemical fate of the Cd/Se/Te-based quantum dot 705 in the biological system: toxicity implications

    International Nuclear Information System (INIS)

    QD705 is a cadmium/selenium/tellurium (Cd/Se/Te)-based quantum dot with good potential for biomedical applications. Although the biological fate of QD705 is established, its chemical fate in the biological system is still unknown. Since the chemical nature of Cd in QD705 (either stays as bounded Cd or becomes free Cd) is closely related to the toxicity of this nanocrystal, information on its chemical fate is critically needed. In this study we investigated the chemical fate of QD705 in the kidneys of mice. We used the molar ratio of Cd and Te (increased Cd/Te ratio signifies increased Cd release from QD705) and the induction of tissue metallothionein (MT) as markers for elevated free Cd in tissues. Our study indicated that 100% of QD705 (measured as Cd) was still retained in the body 16 weeks after exposure, with significant time redistribution to the kidneys. Furthermore, there were an elevation in both the molar Cd/Te ratio and MT-1 expression in the kidneys, suggesting that free Cd was released from QD705. Thus QD705 is not as stable or biologically inert as many may have once believed. Our study demonstrated that free Cd indeed can be released from QD705 in the kidneys and increases the risk of renal toxicity.

  9. Opto-acoustic diagnostics of the thermal action of high-intensity focused ultrasound on biological tissues: the possibility of its applications and model experiments

    International Nuclear Information System (INIS)

    The possibility of using the opto-acoustic (OA) method for monitoring high-intensity ultrasonic therapy is studied. The optical properties of raw and boiled liver samples used as the undamaged model tissue and tissue destroyed by ultrasound, respectively, are measured. Experiments are performed with samples consisting of several alternating layers of raw and boiled liver of different thickness. The position and transverse size of the thermal lesion were determined from the temporal shape of the OA signals. The results of measurements are compared with the real size and position of the thermal lesion determined from the subsequent cuts of the sample. It is shown that the OA method permits the diagnostics of variations in biological tissues upon ultrasonic therapy. (special issue devoted to multiple radiation scattering in random media)

  10. 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

    2016-03-01

    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. PMID:26883087

  11. 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 (optimal cutting temperature compounds that are commonly used in animal tissue cryosections.

  12. Expression of transcription factor Klf8 in lung cancer tissue and the biological effect of downregulation of Klf8 expression in lung cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Xuan-Hong Yi; Jing Wang

    2016-01-01

    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.

  13. Physical and Biological Modification of Polycaprolactone Electrospun Nanofiber by Panax Ginseng Extract for Bone Tissue Engineering Application.

    Science.gov (United States)

    Pajoumshariati, Seyedramin; Yavari, Seyedeh Kimia; Shokrgozar, Mohammad Ali

    2016-05-01

    Medicinal plants as a therapeutic agent with osteogenic properties can enhance fracture-healing process. In this study, the osteo-inductive potential of Asian Panax Ginseng root extract within electrospun polycaprolactone (PCL) based nanofibers has been investigated. Scanning electron microscopy images revealed that all nanofibers were highly porous and beadles with average diameter ranging from 250 to 650 nm. The incorporation of ginseng extract improved the physical characteristics (i.e., hydrophilicity) of PCL nanofibers, as well as the mechanical properties. Although ginseng extract increased the degradation rate of pure PCL nanofibers, the porous structure and morphology of fibers did not change significantly after 42 days. It was found that nanofibrous scaffolds containing ginseng extract had higher proliferation (up to ~1.5 fold) compared to the pristine PCL. The qRT-PCR analysis demonstrated the addition of ginseng extract into PCL nanofibers induced significant expression of osteogenic genes (Osteocalcin, Runx-2 and Col-1) in MSCs in a concentration dependent manner. Moreover, higher calcium content, alkaline phosphatase activity and higher mineralization of MSCs were observed compared to the pristine PCL fibers. Our results indicated the promising potential of ginseng extract as an additive to enhance osteo-inductivity, mechanical and physical properties of PCL nanofibers for bone tissue engineering application. PMID:26429789

  14. SPECTRA: An Integrated Knowledge Base for Comparing Tissue and Tumor-Specific PPI Networks in Human.

    Science.gov (United States)

    Micale, Giovanni; Ferro, Alfredo; Pulvirenti, Alfredo; Giugno, Rosalba

    2015-01-01

    Protein-protein interaction (PPI) networks available in public repositories usually represent relationships between proteins within the cell. They ignore the specific set of tissues or tumors where the interactions take place. Indeed, proteins can form tissue-selective complexes, while they remain inactive in other tissues. For these reasons, a great attention has been recently paid to tissue-specific PPI networks, in which nodes are proteins of the global PPI network whose corresponding genes are preferentially expressed in specific tissues. In this paper, we present SPECTRA, a knowledge base to build and compare tissue or tumor-specific PPI networks. SPECTRA integrates gene expression and protein interaction data from the most authoritative online repositories. We also provide tools for visualizing and comparing such networks, in order to identify the expression and interaction changes of proteins across tissues, or between the normal and pathological states of the same tissue. SPECTRA is available as a web server at http://alpha.dmi.unict.it/spectra. PMID:26005672

  15. Correlating optical coherence elastography based strain measurements with collagen content of the human ovarian tissue.

    Science.gov (United States)

    Nandy, Sreyankar; Salehi, Hassan S; Wang, Tianheng; Wang, Xiaohong; Sanders, Melinda; Kueck, Angela; Brewer, Molly; Zhu, Quing

    2015-10-01

    In this manuscript, the initial feasibility of a catheter based phase stabilized swept source optical coherence tomography (OCT) system was studied for characterization of the strain inside different human ovarian tissue groups. The ovarian tissue samples were periodically compressed with 500 Hz square wave signal along the axial direction between the surface of an unfocused transducer and a glass cover slide. The displacement and corresponding strain were calculated during loading from different locations for each tissue sample. A total of 27 ex vivo ovaries from 16 patients were investigated. Statistically significant difference (p Sirius Red stained histological sections. The average collagen area fraction (CAF) obtained from the tissue groups were found to have a strong negative correlation (R = -0.75, p < 0.0001) with the amount of strain inside the tissue. This indicates much softer and degenerated tissue structure for the malignant ovaries as compared to the dense, collagen rich structure of the normal ovarian tissue. The initial results indicate that the swept source OCT system can be useful for estimating the elasticity of the human ovarian tissue. PMID:26504631

  16. Detection of liver cancer tissue using silver nanoparticles-based surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Lin, Juqiang; Liao, Fadian; Ruan, Qiuyong; Zeng, Yongyi; Li, Ling; Huang, Zufang; Lu, Peng; Chen, Rong

    2014-11-01

    Early detection of hepatocellular carcinoma is difficult due to the absence of recognizable physical symptoms. In this study, Raman spectra of liver normal tissues and hepatocellular carcinoma tissues were measured by using silver nanoparticles based surface enhanced Raman spectroscopy (SERS), respectively. The mean Raman spectra of two groups are roughly similar. But the peaks intensity of hepatocellular carcinoma tissues at 722 cm-1 and 1049 cm-1 are obviously higher than those of normal tissues. Some peaks of hepatocellular carcinoma tissues have shifted by different degree. Besides, Raman peaks at 1004cm-1 had disappeared in normal tissue. The result suggested that SERS spectra can feature liver normal tissue and hepatocellular carcinoma tissue. Principal component analysis (PCA) coupled with linear discriminant analysis (LDA) was performed on the measured spectra. There were three most diagnostically significant PCs (PC3, PC9, and PC15, p<0.05) for discriminating these two groups. The diagnostic sensitivity and specificity both were 84.6%. The whole analysis of each sample needs less time-consumed and cost than other traditional methods in detecting and diagnosing HCC. The preliminary result suggests that SERS spectra can be a potential medical technology to detect and diagnose HCC.

  17. Stem cell-based biological tooth repair and regeneration

    OpenAIRE

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T.

    2010-01-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regene...

  18. Advantages and Pitfalls of Mass Spectrometry Based Metabolome Profiling in Systems Biology

    Science.gov (United States)

    Aretz, Ina; Meierhofer, David

    2016-01-01

    Mass spectrometry-based metabolome profiling became the method of choice in systems biology approaches and aims to enhance biological understanding of complex biological systems. Genomics, transcriptomics, and proteomics are well established technologies and are commonly used by many scientists. In comparison, metabolomics is an emerging field and has not reached such high-throughput, routine and coverage than other omics technologies. Nevertheless, substantial improvements were achieved during the last years. Integrated data derived from multi-omics approaches will provide a deeper understanding of entire biological systems. Metabolome profiling is mainly hampered by its diversity, variation of metabolite concentration by several orders of magnitude and biological data interpretation. Thus, multiple approaches are required to cover most of the metabolites. No software tool is capable of comprehensively translating all the data into a biologically meaningful context yet. In this review, we discuss the advantages of metabolome profiling and main obstacles limiting progress in systems biology. PMID:27128910

  19. Advantages and Pitfalls of Mass Spectrometry Based Metabolome Profiling in Systems Biology

    Directory of Open Access Journals (Sweden)

    Ina Aretz

    2016-04-01

    Full Text Available Mass spectrometry-based metabolome profiling became the method of choice in systems biology approaches and aims to enhance biological understanding of complex biological systems. Genomics, transcriptomics, and proteomics are well established technologies and are commonly used by many scientists. In comparison, metabolomics is an emerging field and has not reached such high-throughput, routine and coverage than other omics technologies. Nevertheless, substantial improvements were achieved during the last years. Integrated data derived from multi-omics approaches will provide a deeper understanding of entire biological systems. Metabolome profiling is mainly hampered by its diversity, variation of metabolite concentration by several orders of magnitude and biological data interpretation. Thus, multiple approaches are required to cover most of the metabolites. No software tool is capable of comprehensively translating all the data into a biologically meaningful context yet. In this review, we discuss the advantages of metabolome profiling and main obstacles limiting progress in systems biology.

  20. Advantages and Pitfalls of Mass Spectrometry Based Metabolome Profiling in Systems Biology.

    Science.gov (United States)

    Aretz, Ina; Meierhofer, David

    2016-01-01

    Mass spectrometry-based metabolome profiling became the method of choice in systems biology approaches and aims to enhance biological understanding of complex biological systems. Genomics, transcriptomics, and proteomics are well established technologies and are commonly used by many scientists. In comparison, metabolomics is an emerging field and has not reached such high-throughput, routine and coverage than other omics technologies. Nevertheless, substantial improvements were achieved during the last years. Integrated data derived from multi-omics approaches will provide a deeper understanding of entire biological systems. Metabolome profiling is mainly hampered by its diversity, variation of metabolite concentration by several orders of magnitude and biological data interpretation. Thus, multiple approaches are required to cover most of the metabolites. No software tool is capable of comprehensively translating all the data into a biologically meaningful context yet. In this review, we discuss the advantages of metabolome profiling and main obstacles limiting progress in systems biology. PMID:27128910