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Sample records for tissue damaging threshold

  1. Infrared laser damage thresholds in corneal tissue phantoms using femtosecond laser pulses

    Science.gov (United States)

    Boretsky, Adam R.; Clary, Joseph E.; Noojin, Gary D.; Rockwell, Benjamin A.

    2018-02-01

    Ultrafast lasers have become a fixture in many biomedical, industrial, telecommunications, and defense applications in recent years. These sources are capable of generating extremely high peak power that can cause laser-induced tissue breakdown through the formation of a plasma upon exposure. Despite the increasing prevalence of such lasers, current safety standards (ANSI Z136.1-2014) do not include maximum permissible exposure (MPE) values for the cornea with pulse durations less than one nanosecond. This study was designed to measure damage thresholds in corneal tissue phantoms in the near-infrared and mid-infrared to identify the wavelength dependence of laser damage thresholds from 1200-2500 nm. A high-energy regenerative amplifier and optical parametric amplifier outputting 100 femtosecond pulses with pulse energies up to 2 mJ were used to perform exposures and determine damage thresholds in transparent collagen gel tissue phantoms. Three-dimensional imaging, primarily optical coherence tomography, was used to evaluate tissue phantoms following exposure to determine ablation characteristics at the surface and within the bulk material. The determination of laser damage thresholds in the near-IR and mid-IR for ultrafast lasers will help to guide safety standards and establish the appropriate MPE levels for exposure sensitive ocular tissue such as the cornea. These data will help promote the safe use of ultrafast lasers for a wide range of applications.

  2. Stochastic Threshold Exponential (TE) Model for Hematopoietic Tissue Reconstitution Deficit after Radiation Damage.

    Science.gov (United States)

    Scott, B R; Potter, C A

    2014-07-01

    Whole-body exposure to large radiation doses can cause severe loss of hematopoietic tissue cells and threaten life if the lost cells are not replaced in a timely manner through natural repopulation (a homeostatic mechanism). Repopulation to the baseline level N 0 is called reconstitution and a reconstitution deficit (repopulation shortfall) can occur in a dose-related and organ-specific manner. Scott et al. (2013) previously introduced a deterministic version of a threshold exponential (TE) model of tissue-reconstitution deficit at a given follow-up time that was applied to bone marrow and spleen cellularity (number of constituent cells) data obtained 6 weeks after whole-body gamma-ray exposure of female C.B-17 mice. In this paper a more realistic, stochastic version of the TE model is provided that allows radiation response to vary between different individuals. The Stochastic TE model is applied to post gamma-ray-exposure cellularity data previously reported and also to more limited X-ray cellularity data for whole-body irradiated female C.B-17 mice. Results indicate that the population average threshold for a tissue reconstitution deficit appears to be similar for bone marrow and spleen and for 320-kV-spectrum X-rays and Cs-137 gamma rays. This means that 320-kV spectrum X-rays could successfully be used in conducting such studies.

  3. Acoustic emission sensor radiation damage threshold experiment

    International Nuclear Information System (INIS)

    Beeson, K.M.; Pepper, C.E.

    1994-01-01

    Determination of the threshold for damage to acoustic emission sensors exposed to radiation is important in their application to leak detection in radioactive waste transport and storage. Proper response to system leaks is necessary to ensure the safe operation of these systems. A radiation impaired sensor could provide ''false negative or false positive'' indication of acoustic signals from leaks within the system. Research was carried out in the Radiochemical Technology Division at Oak Ridge National Laboratory to determine the beta/gamma radiation damage threshold for acoustic emission sensor systems. The individual system consisted of an acoustic sensor mounted with a two part epoxy onto a stainless steel waveguide. The systems were placed in an irradiation fixture and exposed to a Cobalt-60 source. After each irradiation, the sensors were recalibrated by Physical Acoustics Corporation. The results were compared to the initial calibrations performed prior to irradiation and a control group, not exposed to radiation, was used to validate the results. This experiment determines the radiation damage threshold of each acoustic sensor system and verifies its life expectancy, usefulness and reliability for many applications in radioactive environments

  4. Periodontal tissue damage in smokers

    Directory of Open Access Journals (Sweden)

    Hutojo Djajakusuma

    2006-09-01

    Full Text Available Dental plaque is the primary etiological factor in periodontal diseases. However, there are many factors that can modify how an individual periodontal tissue will respond to the accumulation of dental plaque. Among such risk factors, there is increasing evidence that smoking tobacco products alters the expression and rate of progression of periodontal diseases. The aim of this study was to find out the loss of periodontal tissue adhesion in smokers by measuring pocket depth using probe, and by measuring alveolar bone damage using Bone Loss Score (BLS radiographic methods on teeth 12, 11, 21, 22, 32, 31, 41, 42. Based on T Test statistical analysis, there were significant differences in pocket depth damage of alveolar bone in smokers and non smokers. In conclusion there were increasing pocket depth and alveolar bone damage in smokers.

  5. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    Xu Feng; Wen Ting; Lu Tianjian; Seffen Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great problem for burn patients. Thus, it is of great importance to quantify the thermal damage in skin tissue. In this paper, the available models and experimental methods for quantification of thermal damage in skin tissue are discussed.

  6. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    徐峰; 文婷; 卢天健; Seffen; Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great...

  7. Influence of microstructure on laser damage threshold of IBS coatings

    International Nuclear Information System (INIS)

    Stolz, C.J.; Genin, F.Y.; Kozlowski, M.R.; Long, D.; Lalazari, R.; Wu, Z.L.; Kuo, P.K.

    1996-01-01

    Ion-beam sputtering (IBS) coatings were developed for the laser gyro industry to meet significantly different requirements than those of fusion lasers. Laser gyro mirrors are small ( 26 J/cm 2 at 1,064 nm with 3-ns pulses). As part of the National Ignition Facility (NIF) coating development effort, IBS coatings are being studied to explore the possible benefits of this technology to NIF optics. As an initial step to achieving the NIF size and damage threshold requirements, the coating process is being scaled to uniformly coat a 20 x 40 cm 2 area with reduced spectral, reflected wavefront, and laser damage threshold requirements. Here, multilayer coatings deposited by ion-beam sputtering with amorphous layers were found to have lower damage thresholds at 1,064 nm than similar coatings with crystalline layers. Interestingly, at higher fluences the damage was less severe for the amorphous coatings. The magnitude of the difference in damage thresholds between the two different microstructures was strongly influenced by the size of the tested area. To better understand the microstructure effects, single layers of HfO 2 with different microstructures were studied using transmission electron microscopy, ellipsometry, and a photothermal deflection technique. Since the laser damage initiated at defects, the influence of thermal diffusivity on thermal gradients in nodular defects is also presented

  8. High-Damage-Threshold Pinhole for Glass Fusion Laser Applications

    International Nuclear Information System (INIS)

    Kumit, N.A.; Letzring, S.A.; Johnson, R.P.

    1998-01-01

    We are investigating methods to fabricate high-damage-threshold spatial-filter pinholes that might not be susceptible to plasma closure for relatively high energies and long pulses. These are based on the observation that grazing-incidence reflection from glass can withstand in excess of 5 kJ/cm 2 (normal to the beam) without plasma formation. The high damage threshold results from both the cos q spreading of the energy across the surface and the reflection of a large fraction of the energy from the surface, thereby greatly reducing the field strength within the medium

  9. Damage Models for Soft Tissues: A Survey.

    Science.gov (United States)

    Li, Wenguang

    Damage to soft tissues in the human body has been investigated for applications in healthcare, sports, and biomedical engineering. This paper reviews and classifies damage models for soft tissues to summarize achievements, identify new directions, and facilitate finite element analysis. The main ideas of damage modeling methods are illustrated and interpreted. A few key issues related to damage models, such as experimental data curve-fitting, computational effort, connection between damage and fractures/cracks, damage model applications, and fracture/crack extension simulation, are discussed. Several new challenges in the field are identified and outlined. This review can be useful for developing more advanced damage models and extending damage modeling methods to a variety of soft tissues.

  10. Intraoperative transfusion threshold and tissue oxygenation

    DEFF Research Database (Denmark)

    Nielsen, K; Dahl, B; Johansson, P I

    2012-01-01

    Transfusion with allogeneic red blood cells (RBCs) may be needed to maintain oxygen delivery during major surgery, but the appropriate haemoglobin (Hb) concentration threshold has not been well established. We hypothesised that a higher level of Hb would be associated with improved subcutaneous...... oxygen tension during major spinal surgery....

  11. Multiple pulse nanosecond laser induced damage threshold on hybrid mirrors

    Science.gov (United States)

    Vanda, Jan; Muresan, Mihai-George; Bilek, Vojtech; Sebek, Matej; Hanus, Martin; Lucianetti, Antonio; Rostohar, Danijela; Mocek, Tomas; Škoda, Václav

    2017-11-01

    So-called hybrid mirrors, consisting of broadband metallic surface coated with dielectric reflector designed for specific wavelength, becoming more important with progressing development of broadband mid-IR sources realized using parametric down conversion system. Multiple pulse nanosecond laser induced damage on such mirrors was tested by method s-on-1, where s stands for various numbers of pulses. We show difference in damage threshold between common protected silver mirrors and hybrid silver mirrors prepared by PVD technique and their variants prepared by IAD. Keywords: LIDT,

  12. Database of average-power damage thresholds at 1064 nm

    International Nuclear Information System (INIS)

    Rainer, F.; Hildum, E.A.; Milam, D.

    1987-01-01

    We have completed a database of average-power, laser-induced, damage thresholds at 1064 nm on a variety of materials. Measurements were made with a newly constructed laser to provide design input for moderate and high average-power laser projects. The measurements were conducted with 16-ns pulses at pulse-repetition frequencies ranging from 6 to 120 Hz. Samples were typically irradiated for time ranging from a fraction of a second up to 5 minutes (36,000 shots). We tested seven categories of samples which included antireflective coatings, high reflectors, polarizers, single and multiple layers of the same material, bare and overcoated metal surfaces, bare polished surfaces, and bulk materials. The measured damage threshold ranged from 2 for some metals to > 46 J/cm 2 for a bare polished glass substrate. 4 refs., 7 figs., 1 tab

  13. Large-aperture, high-damage-threshold optics for beamlet

    International Nuclear Information System (INIS)

    Campbell, J.H.; Atherton, L.J.; DeYoreo, J.J.; Kozlowski, M.R.; Maney, R.T.; Montesanti, R.C.; Sheehan, L.M.; Barker, C.E.

    1995-01-01

    Beamlet serves as a test bed for the proposed NIF laser design and components. Therefore, its optics are similar in size and quality to those proposed for the NIF. In general, the optics in the main laser cavity and transport section of Beamlet are larger and have higher damage thresholds than the optics manufactured for any of our previous laser systems. In addition, the quality of the Beamlet optical materials is higher, leading to better wavefront quality, higher optical transmission, and lower-intensity modulation of the output laser beam than, for example, that typically achieved on Nova. In this article, we discuss the properties and characteristics of the large-aperture optics used on Beamlet

  14. Porcine skin damage thresholds for pulsed nanosecond-scale laser exposure at 1064-nm

    Science.gov (United States)

    DeLisi, Michael P.; Peterson, Amanda M.; Noojin, Gary D.; Shingledecker, Aurora D.; Tijerina, Amanda J.; Boretsky, Adam R.; Schmidt, Morgan S.; Kumru, Semih S.; Thomas, Robert J.

    2018-02-01

    Pulsed high-energy lasers operating in the near-infrared (NIR) band are increasingly being used in medical, industrial, and military applications, but there are little available experimental data to characterize their hazardous effects on skin tissue. The current American National Standard for the Safe Use of Lasers (ANSI Z136.1-2014) defines the maximum permissible exposure (MPE) on the skin as either a single-pulse or total exposure time limit. This study determined the minimum visible lesion (MVL) damage thresholds in Yucatan miniature pig skin for the single-pulse case and several multiple-pulse cases over a wide range of pulse repetition frequencies (PRFs) (10, 125, 2,000, and 10,000 Hz) utilizing nanosecond-scale pulses (10 or 60 ns). The thresholds are expressed in terms of the median effective dose (ED50) based on varying individual pulse energy with other laser parameters held constant. The results confirm a decrease in MVL threshold as PRF increases for exposures with a constant number of pulses, while also noting a PRF-dependent change in the threshold as a function of the number of pulses. Furthermore, this study highlights a change in damage mechanism to the skin from melanin-mediated photomechanical events at high irradiance levels and few numbers of pulses to bulk tissue photothermal additivity at lower irradiance levels and greater numbers of pulses. The observed trends exceeded the existing exposure limits by an average factor of 9.1 in the photothermally-damaged cases and 3.6 in the photomechanicallydamaged cases.

  15. Femtosecond laser damage threshold and nonlinear characterization in bulk transparent SiC materials

    International Nuclear Information System (INIS)

    DesAutels, G. Logan; Finet, Marc; Ristich, Scott; Whitaker, Matt; Brewer, Chris; Juhl, Shane; Walker, Mark; Powers, Peter

    2008-01-01

    Semi-insulating and conducting SiC crystalline transparent substrates were studied after being processed by femtosecond (fs) laser radiation (780 nm at 160 fs). Z-scan and damage threshold experiments were performed on both SiC bulk materials to determine each sample's nonlinear and threshold parameters. 'Damage' in this text refers to an index of refraction modification as observed visually under an optical microscope. In addition, a study was performed to understand the damage threshold as a function of numerical aperture. Presented here for the first time, to the best of our knowledge, are the damage threshold, nonlinear index of refraction, and nonlinear absorption measured values

  16. Damage threshold in adult rabbit eyes after scleral cross-linking by riboflavin/blue light application.

    Science.gov (United States)

    Iseli, Hans Peter; Körber, Nicole; Karl, Anett; Koch, Christian; Schuldt, Carsten; Penk, Anja; Liu, Qing; Huster, Daniel; Käs, Josef; Reichenbach, Andreas; Wiedemann, Peter; Francke, Mike

    2015-10-01

    Several scleral cross-linking (SXL) methods were suggested to increase the biomechanical stiffness of scleral tissue and therefore, to inhibit axial eye elongation in progressive myopia. In addition to scleral cross-linking and biomechanical effects caused by riboflavin and light irradiation such a treatment might induce tissue damage, dependent on the light intensity used. Therefore, we characterized the damage threshold and mechanical stiffening effect in rabbit eyes after application of riboflavin combined with various blue light intensities. Adult pigmented and albino rabbits were treated with riboflavin (0.5 %) and varying blue light (450 ± 50 nm) dosages from 18 to 780 J/cm(2) (15 to 650 mW/cm(2) for 20 min). Scleral, choroidal and retinal tissue alterations were detected by means of light microscopy, electron microscopy and immunohistochemistry. Biomechanical changes were measured by shear rheology. Blue light dosages of 480 J/cm(2) (400 mW/cm(2)) and beyond induced pathological changes in ocular tissues; the damage threshold was defined by the light intensities which induced cellular degeneration and/or massive collagen structure changes. At such high dosages, we observed alterations of the collagen structure in scleral tissue, as well as pigment aggregation, internal hemorrhages, and collapsed blood vessels. Additionally, photoreceptor degenerations associated with microglia activation and macroglia cell reactivity in the retina were detected. These pathological alterations were locally restricted to the treated areas. Pigmentation of rabbit eyes did not change the damage threshold after a treatment with riboflavin and blue light but seems to influence the vulnerability for blue light irradiations. Increased biomechanical stiffness of scleral tissue could be achieved with blue light intensities below the characterized damage threshold. We conclude that riboflavin and blue light application increased the biomechanical stiffness of scleral tissue at

  17. Robust optimization of the laser induced damage threshold of dielectric mirrors for high power lasers.

    Science.gov (United States)

    Chorel, Marine; Lanternier, Thomas; Lavastre, Éric; Bonod, Nicolas; Bousquet, Bruno; Néauport, Jérôme

    2018-04-30

    We report on a numerical optimization of the laser induced damage threshold of multi-dielectric high reflection mirrors in the sub-picosecond regime. We highlight the interplay between the electric field distribution, refractive index and intrinsic laser induced damage threshold of the materials on the overall laser induced damage threshold (LIDT) of the multilayer. We describe an optimization method of the multilayer that minimizes the field enhancement in high refractive index materials while preserving a near perfect reflectivity. This method yields a significant improvement of the damage resistance since a maximum increase of 40% can be achieved on the overall LIDT of the multilayer.

  18. Laser induced damage threshold on metallic surfaces during laser cleaning

    CSIR Research Space (South Africa)

    Labuschagne, K

    2005-07-01

    Full Text Available laser paint removal. Laser induced damage on 316L stainless steel was studied, with the target subjected to single and multiple pulse irradiations using a Q-switched Nd:YAG, with fluences between 0.15 and 11.8 J/cm2. Several different damage morphologies...

  19. Reduction of damage threshold in dielectric materials induced by negatively chirped laser pulses

    International Nuclear Information System (INIS)

    Louzon, E.; Henis, Z.; Pecker, S.; Ehrlich, Y.; Fisher, D.; Fraenkel, M.; Zigler, A.

    2005-01-01

    The threshold fluence for laser induced damage in wide band gap dielectric materials, fused silica and MgF 2 , is observed to be lower by up to 20% for negatively (down) chirped pulses than for positively (up) chirped, at pulse durations ranging from 60 fs to 1 ps. This behavior of the threshold fluence for damage on the chirp direction was not observed in semiconductors (silicon and GaAs). Based on a model including electron generation in the conduction band and Joule heating, it is suggested that the decrease in the damage threshold for negatively chirped pulse is related to the dominant role of multiphoton ionization in wide gap materials

  20. Laser-induced damage thresholds of gold, silver and their alloys in air and water

    Energy Technology Data Exchange (ETDEWEB)

    Starinskiy, Sergey V.; Shukhov, Yuri G.; Bulgakov, Alexander V., E-mail: bulgakov@itp.nsc.ru

    2017-02-28

    Highlights: • Laser damage thresholds of Ag, Au and Ag-Au alloys in air and water are measured. • Alloy thresholds are lower than those of Ag and Au due to low thermal conductivity. • Laser damage thresholds in water are ∼1.5 times higher than those in air. • Light scattering mechanisms responsible for high thresholds in water are suggested. • Light scattering mechanisms are supported by optical reflectance measurements. - Abstract: The nanosecond-laser-induced damage thresholds of gold, silver and gold-silver alloys of various compositions in air and water have been measured for single-shot irradiation conditions. The experimental results are analyzed theoretically by solving the heat flow equation for the samples irradiated in air and in water taking into account vapor nucleation at the solid-water interface. The damage thresholds of Au-Ag alloys are systematically lower than those for pure metals, both in air and water that is explained by lower thermal conductivities of the alloys. The thresholds measured in air agree well with the calculated melting thresholds for all samples. The damage thresholds in water are found to be considerably higher, by a factor of ∼1.5, than the corresponding thresholds in air. This cannot be explained, in the framework of the used model, neither by the conductive heat transfer to water nor by the vapor pressure effect. Possible reasons for the high damage thresholds in water such as scattering of the incident laser light by the vapor-liquid interface and the critical opalescence in the superheated water are suggested. Optical pump-probe measurements have been performed to study the reflectance dynamics of the surface irradiated in air and water. Comparison of the transient reflectance signal with the calculated nucleation dynamics provides evidence that the both suggested scattering mechanisms are likely to occur during metal ablation in water.

  1. Electrocautery causes more ischemic peritoneal tissue damage than ultrasonic dissection.

    NARCIS (Netherlands)

    Broek, R.P.G ten; Wilbers, J.; Goor, H. van

    2011-01-01

    BACKGROUND: Minimizing peritoneal tissue injury during abdominal surgery has the benefit of reducing postoperative inflammatory response, pain, and adhesion formation. Ultrasonic dissection seems to reduce tissue damage. This study aimed to compare electrocautery and ultrasonic dissection in terms

  2. Laser-induced damage thresholds of gold, silver and their alloys in air and water

    Science.gov (United States)

    Starinskiy, Sergey V.; Shukhov, Yuri G.; Bulgakov, Alexander V.

    2017-02-01

    The nanosecond-laser-induced damage thresholds of gold, silver and gold-silver alloys of various compositions in air and water have been measured for single-shot irradiation conditions. The experimental results are analyzed theoretically by solving the heat flow equation for the samples irradiated in air and in water taking into account vapor nucleation at the solid-water interface. The damage thresholds of Au-Ag alloys are systematically lower than those for pure metals, both in air and water that is explained by lower thermal conductivities of the alloys. The thresholds measured in air agree well with the calculated melting thresholds for all samples. The damage thresholds in water are found to be considerably higher, by a factor of ∼1.5, than the corresponding thresholds in air. This cannot be explained, in the framework of the used model, neither by the conductive heat transfer to water nor by the vapor pressure effect. Possible reasons for the high damage thresholds in water such as scattering of the incident laser light by the vapor-liquid interface and the critical opalescence in the superheated water are suggested. Optical pump-probe measurements have been performed to study the reflectance dynamics of the surface irradiated in air and water. Comparison of the transient reflectance signal with the calculated nucleation dynamics provides evidence that the both suggested scattering mechanisms are likely to occur during metal ablation in water.

  3. Computer simulation of threshold radiation damage in rutile, TiO2

    International Nuclear Information System (INIS)

    Richardson, D.D.

    1983-01-01

    Computer simulation methods have been used to study threshold radiation damage structures in rutile. It was found Ti ions have threshold energies much larger than O ions. Basal plane displacements for oxygen were shown to be complex, and focuson behaviour was only found at energies several times the threshold energy. Oxygen ions do not have simple interstitials or vacancies, but rather a three-ion crowdion and divacancy-interstitial combination were found, respectively. Threshold energies were found to be highly dependent on crystallographic direction, being as low as 10 eV in one instance, but often much higher. Oxygen ions were seen to defocus along the c-axis. (author)

  4. Damage thresholds of thin film materials and high reflectors at 248 nm

    International Nuclear Information System (INIS)

    Rainer, F.; Lowdermilk, W.H.; Milam, D.; Carniglia, C.K.; Hart, T.T.; Lichtenstein, T.L.

    1982-01-01

    Twenty-ns, 248-nm KrF laser pulses were used to measure laser damage thresholds for halfwave-thick layers of 15 oxide and fluoride coating materials, and for high reflectance coatings made with 13 combinations of these materials. The damage thresholds of the reflectors and single-layer films were compared to measurements of several properties of the halfwave-thick films to determine whether measurements of these properties of single-layer films to determine whether measurements of these properties of single-layer films were useful for identifying materials for fabrication of damage resistant coatings

  5. Experimental Determination of Damage Threshold Characteristics of IR Compatible Optical Materials

    International Nuclear Information System (INIS)

    Soong, Ken

    2011-01-01

    The accelerating gradient in a laser-driven dielectric accelerating structure is often limited by the laser damage threshold of the structure. For a given laser-driven dielectric accelerator design, we can maximize the accelerating gradient by choosing the best combination of the accelerator's constituent material and operating wavelength. We present here a model of the damage mechanism from ultrafast infrared pulses and compare that model with experimental measurements of the damage threshold of bulk silicon. Additionally, we present experimental measurements of a variety of candidate materials, thin films, and nanofabricated accelerating structures.

  6. Radiation damages in solids and tissues

    International Nuclear Information System (INIS)

    Cevc, P.; Kogovsek, F.; Kanduser, A.; Peternelj, M.; Skaleric, U.; Funduk, N.

    1977-01-01

    In submitted research work we have studied radiation damages in ferroelectric crystals and application of ferroelectric crystals. Studying the radiation damages we have introduced new technique of EPR measurements under high hydrostatic pressure, that will enable us to obtain additional data on crystal lattice dynamics. A change of piroelectric coefficient with high radiation doses in dopped TGS has been measured also

  7. Laser-damage thresholds of thin-film optical coatings at 248 nm

    International Nuclear Information System (INIS)

    Milam, D.; Rainer, F.; Lowdermilk, W.H.

    1981-01-01

    We have measured the laser-induced damage thresholds for 248 nm wavelength light of over 100 optical coatings from commercial vendors and research institutions. All samples were irradiated once per damage site with temporally multi-lobed, 20-ns pulses generated by a KrF laser. The survey included high, partial, and dichroic reflectors, anti-reflective coatings, and single layer films. The samples were supplied by ten vendors. The majority of samples tested were high reflectors and antireflective coatings. The highest damage thresholds were 8.5 to 9.4 J/cm 2 , respectively. Although these represent extremes of what has been tested so far, several vendors have produced coatings of both types with thresholds which consistently exceed 6 J/cm 2 . Repeated irradiations of some sites were made on a few samples. These yielded no degradation in threshold, but in fact some improvement in damage resistance. These same samples also exhibited no change in threshold after being retested seven months later

  8. DNA damage in plant herbarium tissue.

    Science.gov (United States)

    Staats, Martijn; Cuenca, Argelia; Richardson, James E; Vrielink-van Ginkel, Ria; Petersen, Gitte; Seberg, Ole; Bakker, Freek T

    2011-01-01

    Dried plant herbarium specimens are potentially a valuable source of DNA. Efforts to obtain genetic information from this source are often hindered by an inability to obtain amplifiable DNA as herbarium DNA is typically highly degraded. DNA post-mortem damage may not only reduce the number of amplifiable template molecules, but may also lead to the generation of erroneous sequence information. A qualitative and quantitative assessment of DNA post-mortem damage is essential to determine the accuracy of molecular data from herbarium specimens. In this study we present an assessment of DNA damage as miscoding lesions in herbarium specimens using 454-sequencing of amplicons derived from plastid, mitochondrial, and nuclear DNA. In addition, we assess DNA degradation as a result of strand breaks and other types of polymerase non-bypassable damage by quantitative real-time PCR. Comparing four pairs of fresh and herbarium specimens of the same individuals we quantitatively assess post-mortem DNA damage, directly after specimen preparation, as well as after long-term herbarium storage. After specimen preparation we estimate the proportion of gene copy numbers of plastid, mitochondrial, and nuclear DNA to be 2.4-3.8% of fresh control DNA and 1.0-1.3% after long-term herbarium storage, indicating that nearly all DNA damage occurs on specimen preparation. In addition, there is no evidence of preferential degradation of organelle versus nuclear genomes. Increased levels of C→T/G→A transitions were observed in old herbarium plastid DNA, representing 21.8% of observed miscoding lesions. We interpret this type of post-mortem DNA damage-derived modification to have arisen from the hydrolytic deamination of cytosine during long-term herbarium storage. Our results suggest that reliable sequence data can be obtained from herbarium specimens.

  9. Development of high damage threshold optics for petawatt-class short-pulse lasers

    International Nuclear Information System (INIS)

    Stuart, B.C.; Perry, M.D.; Boyd, R.D.

    1995-01-01

    The authors report laser-induced damage threshold measurements on pure and multilayer dielectrics and gold-coated optics at 1053 and 526 nm for pulse durations, τ, ranging from 140 fs to 1 ns. Damage thresholds of gold coatings are limited to 500 mJ/cm 2 in the subpicosecond range for 1053-nm pulses. In dielectrics, qualitative differences in the morphology of damage and a departure from the diffusion-dominated τ1/2 scaling indicate that damage results from plasma formation and ablation for τ≤10 ps and from conventional melting and boiling for τ>50 ps. A theoretical model based on electron production via multiphoton ionization, Joule heating, and collisional (avalanche) ionization is in quantitative agreement with both the pulsewidth and wavelength scaling of experimental results

  10. Cleaning Process Versus Laser-Damage Threshold of Coated Optical Components

    International Nuclear Information System (INIS)

    Rigatti, A.L.

    2005-01-01

    The cleaning of optical surfaces is important in the manufacture of high-laser-damage-threshold coatings, which are a key component on peak-power laser systems such as OMEGA located at the Laboratory for Laser Energetics (LLE). Since cleaning adds time, labor, and ultimately cost to the final coated component, this experiment was designed to determine the impact of different cleaning protocols on the measured laser-damage performance

  11. DNA damage in plant herbarium tissue.

    NARCIS (Netherlands)

    Staats, M.; Cuenca, A.; Richardson, J.E.; Ginkel, R.V.; Petersen, G.; Seberg, O.; Bakker, F.T.

    2011-01-01

    Dried plant herbarium specimens are potentially a valuable source of DNA. Efforts to obtain genetic information from this source are often hindered by an inability to obtain amplifiable DNA as herbarium DNA is typically highly degraded. DNA post-mortem damage may not only reduce the number of

  12. Continuum theory of fibrous tissue damage mechanics using bond kinetics: application to cartilage tissue engineering.

    Science.gov (United States)

    Nims, Robert J; Durney, Krista M; Cigan, Alexander D; Dusséaux, Antoine; Hung, Clark T; Ateshian, Gerard A

    2016-02-06

    This study presents a damage mechanics framework that employs observable state variables to describe damage in isotropic or anisotropic fibrous tissues. In this mixture theory framework, damage is tracked by the mass fraction of bonds that have broken. Anisotropic damage is subsumed in the assumption that multiple bond species may coexist in a material, each having its own damage behaviour. This approach recovers the classical damage mechanics formulation for isotropic materials, but does not appeal to a tensorial damage measure for anisotropic materials. In contrast with the classical approach, the use of observable state variables for damage allows direct comparison of model predictions to experimental damage measures, such as biochemical assays or Raman spectroscopy. Investigations of damage in discrete fibre distributions demonstrate that the resilience to damage increases with the number of fibre bundles; idealizing fibrous tissues using continuous fibre distribution models precludes the modelling of damage. This damage framework was used to test and validate the hypothesis that growth of cartilage constructs can lead to damage of the synthesized collagen matrix due to excessive swelling caused by synthesized glycosaminoglycans. Therefore, alternative strategies must be implemented in tissue engineering studies to prevent collagen damage during the growth process.

  13. Modeling of damage generation mechanisms in silicon at energies below the displacement threshold

    International Nuclear Information System (INIS)

    Santos, Ivan; Marques, Luis A.; Pelaz, Lourdes

    2006-01-01

    We have used molecular dynamics simulation techniques to study the generation of damage in Si within the low-energy deposition regime. We have demonstrated that energy transfers below the displacement threshold can produce a significant amount of damage, usually neglected in traditional radiation damage calculations. The formation of amorphous pockets agrees with the thermal spike concept of local melting. However, we have found that the order-disorder transition is not instantaneous, but it requires some time to reach the appropriate kinetic-potential energy redistribution for melting. The competition between the rate of this energy redistribution and the energy diffusion to the surrounding atoms determines the amount of damage generated by a given deposited energy. Our findings explain the diverse damage morphology produced by ions of different masses

  14. Calculation of femtosecond pulse laser induced damage threshold for broadband antireflective microstructure arrays.

    Science.gov (United States)

    Jing, Xufeng; Shao, Jianda; Zhang, Junchao; Jin, Yunxia; He, Hongbo; Fan, Zhengxiu

    2009-12-21

    In order to more exactly predict femtosecond pulse laser induced damage threshold, an accurate theoretical model taking into account photoionization, avalanche ionization and decay of electrons is proposed by comparing respectively several combined ionization models with the published experimental measurements. In addition, the transmittance property and the near-field distribution of the 'moth eye' broadband antireflective microstructure directly patterned into the substrate material as a function of the surface structure period and groove depth are performed by a rigorous Fourier model method. It is found that the near-field distribution is strongly dependent on the periodicity of surface structure for TE polarization, but for TM wave it is insensitive to the period. What's more, the femtosecond pulse laser damage threshold of the surface microstructure on the pulse duration taking into account the local maximum electric field enhancement was calculated using the proposed relatively accurate theoretical ionization model. For the longer incident wavelength of 1064 nm, the weak linear damage threshold on the pulse duration is shown, but there is a surprising oscillation peak of breakdown threshold as a function of the pulse duration for the shorter incident wavelength of 532 nm.

  15. Radiobiology in clinical radiation therapy - Part III: Normal tissue damage

    International Nuclear Information System (INIS)

    Travis, Elizabeth L.

    1996-01-01

    Objective: This is the third part of a course designed for residents in radiation oncology preparing for their boards. This part of the course will focus on the mechanisms underlying damage in normal tissues. Although conventional wisdom long held that killing and depletion of a critical cell(s) in a tissue was responsible for the later expression of damage, histopathologic changes in normal tissue can now be explained and better understood in terms of the new molecular biology. The concept that depletion of a single cell type is responsible for the observed histopathologic changes in normal tissues has been replaced by the hypothesis that damage results from the interaction of many different cell systems, including epithelial, endothelial, macrophages and fibroblasts, via the production of specific autocrine, paracrine and endocrine growth factors. A portion of this course will discuss the clinical and experimental data on the production and interaction of those cytokines and cell systems considered to be critical to tissue damage. It had long been suggested that interindividual differences in radiation-induced normal tissue damage was genetically regulated, at least in part. Both clinical and experimental data supported this hypothesis but it is the recent advances in human and mouse molecular genetics which have provided the tools to dissect out the genetic component of normal tissue damage. These data will be presented and related to the potential to develop genetic markers to identify sensitive individuals. The impact on clinical outcome of the ability to identify prospectively sensitive patients will be discussed. Clinically it is well-accepted that the volume of tissue irradiated is a critical factor in determining tissue damage. A profusion of mathematical models for estimating dose-volume relationships in a number of organs have been published recently despite the fact that little data are available to support these models. This course will review the

  16. Infrared skin damage thresholds from 1319-nm continuous-wave laser exposures

    Science.gov (United States)

    Oliver, Jeffrey W.; Vincelette, Rebecca; Noojin, Gary D.; Clark, Clifton D.; Harbert, Corey A.; Schuster, Kurt J.; Shingledecker, Aurora D.; Kumru, Semih S.; Maughan, Justin; Kitzis, Naomi; Buffington, Gavin D.; Stolarski, David J.; Thomas, Robert J.

    2013-12-01

    A series of experiments were conducted in vivo using Yucatan miniature pigs (Sus scrofa domestica) to determine thermal damage thresholds to the skin from 1319-nm continuous-wave Nd:YAG laser irradiation. Experiments employed exposure durations of 0.25, 1.0, 2.5, and 10 s and beam diameters of ˜0.6 and 1 cm. Thermal imagery data provided a time-dependent surface temperature response from the laser. A damage endpoint of fifty percent probability of a minimally visible effect was used to determine threshold for damage at 1 and 24 h postexposure. Predicted thermal response and damage thresholds are compared with a numerical model of optical-thermal interaction. Resultant trends with respect to exposure duration and beam diameter are compared with current standardized exposure limits for laser safety. Mathematical modeling agreed well with experimental data, predicting that though laser safety standards are sufficient for exposures <10 s, they may become less safe for very long exposures.

  17. Damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses: theoretical and experimental study

    International Nuclear Information System (INIS)

    Meng, Qinglong; Zhang, Bin; Zhong, Sencheng; Zhu, Liguo

    2016-01-01

    The damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses has been studied theoretically and experimentally. Firstly, the model for the damage threshold prediction of crystal materials based on the improved rate equation has been proposed. Then, the experimental measure method of the damage threshold of crystal materials has been given in detail. On the basis, the variation of the damage threshold of lithium niobate crystal with the pulse duration has also been analyzed quantitatively. Finally, the damage threshold of lithium niobate crystal under multiple laser pulses has been measured and compared to the theoretical results. The results show that the transmittance of lithium niobate crystal is almost a constant when the laser pulse fluence is relative low, whereas it decreases linearly with the increase in the laser pulse fluence below the damage threshold. The damage threshold of lithium niobate crystal increases with the increase in the duration of the femtosecond laser pulse. And the damage threshold of lithium niobate crystal under multiple laser pulses is obviously lower than that irradiated by a single laser pulse. The theoretical data fall in good agreement with the experimental results. (orig.)

  18. Tornado risk analysis at Savannah River Plant using windspeed damage thresholds and single building strike frequencies

    International Nuclear Information System (INIS)

    Taylor, D.H.; McDonald, J.R.; Twisdale, L.A.

    1985-01-01

    Tornado risk analysis at the Savannah River Plant has taken a two pronged approach: (1) developing a catalogue of damage thresholds as a function of windspeed for processing buildings and other representative site structures; (2) developing a method of estimating, for each building, the probability of a tornado exceeding each damage threshold. Wind resistance of building construction at SRP varies widely depending on the function of the structure. It was recognized that all tornadoes do not necessarily seriously damage buildings, but the damage thresholds were unknown. In order to evaluate the safety of existing structures and properly design new structures, an analysis of tornado resistance was conducted by J.R. McDonald on each process building at SRP and other buildings by type. Damage estimates were catalogued for each Fujita class windspeed interval and windspeeds were catalogued as a function of increased levels of damage. Tornado single point and structure specific strike probabilities for the SRP site were determined by L.A. Twisdale using the TORRISK computer code. To calculate the structure specific strike probability, a correction factor is determined from a set of curves using building area and aspect ratio (length/width relative to north) as parameters. The structure specific probability is then the product of the correction factor and the point probability. The correction factor increases as a function of building size and windspeed. For large buildings (10 5 ft 2 ) and very intense storms (250 mph), the correction factor is equal to or greater than 4. The cumulative probability of a tornado striking any building type (process, personnel, etc.) was also calculated

  19. Improvement of the damage threshold of high reflectivity multidielectric coatings 1.06 μM

    International Nuclear Information System (INIS)

    Geenen, B.; Malherbes, A.; Guerain, J.; Boisgard, D.

    1985-01-01

    Development of new high power laser for laser-matter interaction in C.E.A. Limeil requires the realization of H.R. coatings with damage thresholds above 8 J/cm/sup 2/. MATRA's laboratory ''couches minces optiques'' (thin optical layers) production commercial mirrors was around 3.5 J/cm/sup 2/ in 1982. In order to obtain better results the authors decided to improve the control of evaporation parameters such as: vacuum and regulation of oxygen pressure by means of a mass spectrometer; better measurements of evaporation temperature and regulation of evaporation rate; measurement and control of substrate temperature by pyrometric observation; and to automatize the process. These different measurements and controls enable them to establish new processing operations giving better evaporation conditions. The result was an increase of damage threshold from 3.5 J/cm/sup 2/ to 8 J/cm/sup 2/

  20. High-damage-threshold static laser beam shaping using optically patterned liquid-crystal devices.

    Science.gov (United States)

    Dorrer, C; Wei, S K-H; Leung, P; Vargas, M; Wegman, K; Boulé, J; Zhao, Z; Marshall, K L; Chen, S H

    2011-10-15

    Beam shaping of coherent laser beams is demonstrated using liquid crystal (LC) cells with optically patterned pixels. The twist angle of a nematic LC is locally set to either 0 or 90° by an alignment layer prepared via exposure to polarized UV light. The two distinct pixel types induce either no polarization rotation or a 90° polarization rotation, respectively, on a linearly polarized optical field. An LC device placed between polarizers functions as a binary transmission beam shaper with a highly improved damage threshold compared to metal beam shapers. Using a coumarin-based photoalignment layer, various devices have been fabricated and tested, with a measured single-shot nanosecond damage threshold higher than 30 J/cm2.

  1. Long-range pulselength scaling of 351nm laser damage thresholds

    Science.gov (United States)

    Foltyn, S. R.; Jolin, L. J.

    1986-12-01

    In a series of experiments incorporating 351nm pulselength of 9, 26, 54, and 625ns, it was found that laser damage thresholds increased as (pulselength)/sup x/, and that the exponent averaged 0.36 and ranged, for different samples, from 0.23 to 0.48. Similar results were obtained when only catastrophic damage was considered. Samples included Al2O3/SiO2 in both AR and HR multilayers, HR's of Sc2O3/SiO2 and HfO2/SiO2, and Al-on-pyrex mirror; 9ns thresholds were between 0.2 to 5.6 J/sq cm. When these data were compared with a wide range of other results - for wavelengths from 0.25 to 10.6 microns and pulselengths down to 4ps - a remarkably consistent picture emerged. Damage thresholds, on average, increase approximately as the cube-root of pulselength from picoseconds to nearly a microsecond, and do so regardless of wavelength or material under test.

  2. [Scanning electron microscopy of heat-damaged bone tissue].

    Science.gov (United States)

    Harsanyl, L

    1977-02-01

    Parts of diaphyses of bones were exposed to high temperature of 200-1300 degrees C. Damage to the bone tissue caused by the heat was investigated. The scanning electron microscopic picture seems to be characteristic of the temperature applied. When the bones heated to the high temperature of 700 degrees C characteristic changes appear on the periostal surface, higher temperatura on the other hand causes damage to the compact bone tissue and can be observed on the fracture-surface. Author stresses the importance of this technique in the legal medicine and anthropology.

  3. DNA-repair, cell killing and normal tissue damage

    International Nuclear Information System (INIS)

    Dahm-Daphi, J.; Dikomey, E.; Brammer, I.

    1998-01-01

    Background: Side effects of radiotherapy in normal tissue is determined by a variety of factors of which cellular and genetic contributions are described here. Material and methods: Review. Results: Normal tissue damage after irradiation is largely due to loss of cellular proliferative capacity. This can be due to mitotic cell death, apoptosis, or terminal differentiation. Dead or differentiated cells release cytokines which additionally modulate the tissue response. DNA damage, in particular non-reparable or misrepaired double-strand breaks are considered the basic lesion leading to G1-arrest and ultimately to cell inactivation. Conclusion: Evidence for genetic bases of normal tissue response, cell killing and DNA-repair capacity is presented. However, a direct link of all 3 endpoints has not yet been proved directly. (orig.) [de

  4. Wavelength dependence of femtosecond laser-induced damage threshold of optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Gallais, L., E-mail: laurent.gallais@fresnel.fr; Douti, D.-B.; Commandré, M. [Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR 7249, 13013 Marseille (France); Batavičiūtė, G.; Pupka, E.; Ščiuka, M.; Smalakys, L.; Sirutkaitis, V.; Melninkaitis, A. [Laser Research Center, Vilnius University, Saulétekio aléja 10, LT-10223 Vilnius (Lithuania)

    2015-06-14

    An experimental and numerical study of the laser-induced damage of the surface of optical material in the femtosecond regime is presented. The objective of this work is to investigate the different processes involved as a function of the ratio of photon to bandgap energies and compare the results to models based on nonlinear ionization processes. Experimentally, the laser-induced damage threshold of optical materials has been studied in a range of wavelengths from 1030 nm (1.2 eV) to 310 nm (4 eV) with pulse durations of 100 fs with the use of an optical parametric amplifier system. Semi-conductors and dielectrics materials, in bulk or thin film forms, in a range of bandgap from 1 to 10 eV have been tested in order to investigate the scaling of the femtosecond laser damage threshold with the bandgap and photon energy. A model based on the Keldysh photo-ionization theory and the description of impact ionization by a multiple-rate-equation system is used to explain the dependence of laser-breakdown with the photon energy. The calculated damage fluence threshold is found to be consistent with experimental results. From these results, the relative importance of the ionization processes can be derived depending on material properties and irradiation conditions. Moreover, the observed damage morphologies can be described within the framework of the model by taking into account the dynamics of energy deposition with one dimensional propagation simulations in the excited material and thermodynamical considerations.

  5. Effects of ultrasound frequency and tissue stiffness on the histotripsy intrinsic threshold for cavitation.

    Science.gov (United States)

    Vlaisavljevich, Eli; Lin, Kuang-Wei; Maxwell, Adam; Warnez, Matthew T; Mancia, Lauren; Singh, Rahul; Putnam, Andrew J; Fowlkes, Brian; Johnsen, Eric; Cain, Charles; Xu, Zhen

    2015-06-01

    Histotripsy is an ultrasound ablation method that depends on the initiation of a cavitation bubble cloud to fractionate soft tissue. Previous work has indicated that a cavitation cloud can be formed by a single pulse with one high-amplitude negative cycle, when the negative pressure amplitude directly exceeds a pressure threshold intrinsic to the medium. We hypothesize that the intrinsic threshold in water-based tissues is determined by the properties of the water inside the tissue, and changes in tissue stiffness or ultrasound frequency will have a minimal impact on the histotripsy intrinsic threshold. To test this hypothesis, the histotripsy intrinsic threshold was investigated both experimentally and theoretically. The probability of cavitation was measured by subjecting tissue phantoms with adjustable mechanical properties and ex vivo tissues to a histotripsy pulse of 1-2 cycles produced by 345-kHz, 500-kHz, 1.5-MHz and 3-MHz histotripsy transducers. Cavitation was detected and characterized by passive cavitation detection and high-speed photography, from which the probability of cavitation was measured versus pressure amplitude. The results revealed that the intrinsic threshold (the negative pressure at which probability = 0.5) is independent of stiffness for Young's moduli (E) ultrasound frequency in the hundreds of kilohertz to megahertz range. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  6. Non-damaging laser therapy of the macula: Titration algorithm and tissue response

    Science.gov (United States)

    Palanker, Daniel; Lavinsky, Daniel; Dalal, Roopa; Huie, Philip

    2014-02-01

    Retinal photocoagulation typically results in permanent scarring and scotomata, which limit its applicability to the macula, preclude treatments in the fovea, and restrict the retreatments. Non-damaging approaches to laser therapy have been tested in the past, but the lack of reliable titration and slow treatment paradigms limited their clinical use. We developed and tested a titration algorithm for sub-visible and non-damaging treatments of the retina with pulses sufficiently short to be used with pattern laser scanning. The algorithm based on Arrhenius model of tissue damage optimizes the power and duration for every energy level, relative to the threshold of lesion visibility established during titration (and defined as 100%). Experiments with pigmented rabbits established that lesions in the 50-75% energy range were invisible ophthalmoscopically, but detectable with Fluorescein Angiography and OCT, while at 30% energy there was only very minor damage to the RPE, which recovered within a few days. Patients with Diabetic Macular Edema (DME) and Central Serous Retinopathy (CSR) have been treated over the edematous areas at 30% energy, using 200μm spots with 0.25 diameter spacing. No signs of laser damage have been detected with any imaging modality. In CSR patients, subretinal fluid resolved within 45 days. In DME patients the edema decreased by approximately 150μm over 60 days. After 3-4 months some patients presented with recurrence of edema, and they responded well to retreatment with the same parameters, without any clinically visible damage. This pilot data indicates a possibility of effective and repeatable macular laser therapy below the tissue damage threshold.

  7. Radiation-induced normal tissue damage: implications for radiotherapy

    International Nuclear Information System (INIS)

    Prasanna, Pataje G.

    2014-01-01

    Radiotherapy is an important treatment modality for many malignancies, either alone or as a part of combined modality treatment. However, despite technological advances in physical treatment delivery, patients suffer adverse effects from radiation therapy due to normal tissue damage. These side effects may be acute, occurring during or within weeks after therapy, or intermediate to late, occurring months to years after therapy. Minimizing normal tissue damage from radiotherapy will allow enhancement of tumor killing and improve tumor control and patients quality of life. Understanding mechanisms through which radiation toxicity develops in normal tissue will facilitate the development of next generation radiation effect modulators. Translation of these agents to the clinic will also require an understanding of the impact of these protectors and mitigators on tumor radiation response. In addition, normal tissues vary in radiobiologically important ways, including organ sensitivity to radiation, cellular turnover rate, and differences in mechanisms of injury manifestation and damage response. Therefore, successful development of radiation modulators may require multiple approaches to address organ/site-specific needs. These may include treatments that modify cellular damage and death processes, inflammation, alteration of normal flora, wound healing, tissue regeneration and others, specifically to counter cancer site-specific adverse effects. Further, an understanding of mechanisms of normal tissue damage will allow development of predictive biomarkers; however harmonization of such assays is critical. This is a necessary step towards patient-specific treatment customization. Examples of important adverse effects of radiotherapy either alone or in conjunction with chemotherapy, and important limitations in the current approaches of using radioprotectors for improving therapeutic outcome will be highlighted. (author)

  8. Effects of tissue mechanical properties on susceptibility to histotripsy-induced tissue damage

    Science.gov (United States)

    Vlaisavljevich, Eli; Kim, Yohan; Owens, Gabe; Roberts, William; Cain, Charles; Xu, Zhen

    2014-01-01

    Histotripsy is a non-invasive tissue ablation method capable of fractionating tissue by controlling acoustic cavitation. To determine the fractionation susceptibility of various tissues, we investigated histotripsy-induced damage on tissue phantoms and ex vivo tissues with different mechanical strengths. A histotripsy bubble cloud was formed at tissue phantom surfaces using 5-cycle long ultrasound pulses with peak negative pressure of 18 MPa and PRFs of 10, 100, and 1000 Hz. Results showed significantly smaller lesions were generated in tissue phantoms of higher mechanical strength. Histotripsy was also applied to 43 different ex vivo porcine tissues with a wide range of mechanical properties. Gross morphology demonstrated stronger tissues with higher ultimate stress, higher density, and lower water content were more resistant to histotripsy damage in comparison to weaker tissues. Based on these results, a self-limiting vessel-sparing treatment strategy was developed in an attempt to preserve major vessels while fractionating the surrounding target tissue. This strategy was tested in porcine liver in vivo. After treatment, major hepatic blood vessels and bile ducts remained intact within a completely fractionated liver volume. These results identify varying susceptibilities of tissues to histotripsy therapy and provide a rational basis to optimize histotripsy parameters for treatment of specific tissues.

  9. Damage threshold from large retinal spot size repetitive-pulse laser exposures.

    Science.gov (United States)

    Lund, Brian J; Lund, David J; Edsall, Peter R

    2014-10-01

    The retinal damage thresholds for large spot size, multiple-pulse exposures to a Q-switched, frequency doubled Nd:YAG laser (532 nm wavelength, 7 ns pulses) have been measured for 100 μm and 500 μm retinal irradiance diameters. The ED50, expressed as energy per pulse, varies only weakly with the number of pulses, n, for these extended spot sizes. The previously reported threshold for a multiple-pulse exposure for a 900 μm retinal spot size also shows the same weak dependence on the number of pulses. The multiple-pulse ED50 for an extended spot-size exposure does not follow the n dependence exhibited by small spot size exposures produced by a collimated beam. Curves derived by using probability-summation models provide a better fit to the data.

  10. On the threshold of damage formation in aluminum oxide via electronic excitations

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A., E-mail: skuratov@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); O’Connell, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Kirilkin, N.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Neethling, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2014-05-01

    This work is aimed to determine the threshold of dense ionization induced damage formation and their morphology in sapphire single crystals irradiated with 1.2 MeV/amu Xe ions. Cross-sectional TEM examination of r-oriented Al{sub 2}O{sub 3} specimens irradiated to fluences of 2 × 10{sup 12} and 2 × 10{sup 13} cm{sup −2} has revealed discontinuous ion tracks visible from the irradiated surface up to a depth of 7.6 ± 0.1 μm. According to the SRIM code calculation, the threshold electronic stopping power for track formation in Al{sub 2}O{sub 3} is within the range 9.8 ÷ 10.5 keV/nm. This value agrees with those predicted by both inelastic and analytical thermal spike models.

  11. On the threshold of damage formation in aluminum oxide via electronic excitations

    International Nuclear Information System (INIS)

    Skuratov, V.A.; O’Connell, J.; Kirilkin, N.S.; Neethling, J.

    2014-01-01

    This work is aimed to determine the threshold of dense ionization induced damage formation and their morphology in sapphire single crystals irradiated with 1.2 MeV/amu Xe ions. Cross-sectional TEM examination of r-oriented Al 2 O 3 specimens irradiated to fluences of 2 × 10 12 and 2 × 10 13 cm −2 has revealed discontinuous ion tracks visible from the irradiated surface up to a depth of 7.6 ± 0.1 μm. According to the SRIM code calculation, the threshold electronic stopping power for track formation in Al 2 O 3 is within the range 9.8 ÷ 10.5 keV/nm. This value agrees with those predicted by both inelastic and analytical thermal spike models

  12. Review of ultraviolet damage threshold measurements at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lowdermilk, W.H.; Milam, D.

    1984-01-01

    The results of damage threshold measurements made at LLNL using ultraviolet wavelength laser pulses are reviewed. Measurements were made with pulses from a krypton fluoride laser with wavelength of 248 nm and pulse duration of 20 ns and with Nd-glass laser pulses converted to the third harmonic wavelength of 355 nm with duration of 0.6 ns. Measurements are presented for transparent window materials, crystals and harmonic generation, single layer dielectric films of oxide and fluoride materials and multilayer high reflectivity and antireflective coatings.

  13. Review of ultraviolet damage threshold measurements at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.; Milam, D.

    1984-01-01

    The results of damage threshold measurements made at LLNL using ultraviolet wavelength laser pulses are reviewed. Measurements were made with pulses from a krypton fluoride laser with wavelength of 248 nm and pulse duration of 20 ns and with Nd-glass laser pulses converted to the third harmonic wavelength of 355 nm with duration of 0.6 ns. Measurements are presented for transparent window materials, crystals and harmonic generation, single layer dielectric films of oxide and fluoride materials and multilayer high reflectivity and antireflective coatings

  14. Design and fabrication of a high-damage threshold infrared Smattt interferometer

    International Nuclear Information System (INIS)

    Hammond, R.B.; Gibbs, A.J.

    1981-01-01

    It has been shown that a Smartt interferometer may be used as a very precise alignment tool for infrared lasers. This interferometer may also be used effectively to investigate the phase front of a laser pulse. To use this tool for applications to high-power, fast-pulse laser systems such as Helios and Antares; however, it has been necessary to fabricate a structure with the unique optical characteristics of the Smartt interferometer combined with a very high optical-damage threshold. We have been successful in this effort by utilizing the high technology, process control, and unique properties of semiconductor-grade, single-crystal Si

  15. Disease related tissue damage and subsequent changes in fillet structure

    DEFF Research Database (Denmark)

    of the fish and subsequent a reduction in price. Despite this, the impact of infectious diseases on the meat quality and the mechanisms behind are poorly investigated. Wound repair is a dynamic, interactive response to tissue injury that involves a complex interaction and cross talk of various cell types......, extracellular matrix molecules, soluble mediators and cytokines. In order to describe the molecular mechanisms and processes of wound repair, a panel of genes covering immunological factors and tissue regeneration were used to measure changes at the mRNA level following mechanical tissue damage in rainbow trout...... (Oncorhynchus mykiss). Needle disrupted muscle tissue was sampled at different time points and subject to real-time RT-PCR for measuring the expression of the genes IL-1β, IL-8, IL-10, TGF-β, Myostatin-1ab, MMP-2, CTGF, Collagen-1α, VEGF, iNOS, Arg-2 and FGF. The results showed an initial phase with up...

  16. Local stem cell depletion model for normal tissue damage

    International Nuclear Information System (INIS)

    Yaes, R.J.; Keland, A.

    1987-01-01

    The hypothesis that radiation causes normal tissue damage by completely depleting local regions of tissue of viable stem cells leads to a simple mathematical model for such damage. In organs like skin and spinal cord where destruction of a small volume of tissue leads to a clinically apparent complication, the complication probability is expressed as a function of dose, volume and stem cell number by a simple triple negative exponential function analogous to the double exponential function of Munro and Gilbert for tumor control. The steep dose response curves for radiation myelitis that are obtained with our model are compared with the experimental data for radiation myelitis in laboratory rats. The model can be generalized to include other types or organs, high LET radiation, fractionated courses of radiation, and cases where an organ with a heterogeneous stem cell population receives an inhomogeneous dose of radiation. In principle it would thus be possible to determine the probability of tumor control and of damage to any organ within the radiation field if the dose distribution in three dimensional space within a patient is known

  17. Protective Effect of HSP25 on Radiation Induced Tissue Damage

    International Nuclear Information System (INIS)

    Lee, Hae-June; Lee, Yoon-Jin; Kwon, Hee-Choong; Bae, Sang-Woo; Lee, Yun-Sil; Kim, Sung Ho

    2007-01-01

    Control of cancer by irradiation therapy alone or in conjunction with combination chemotherapy is often limited by organ specific toxicity. Ionizing irradiation toxicity is initiated by damage to normal tissue near the tumor target and within the transit volume of radiotherapy beams. Irradiation-induced cellular, tissue, and organ damage is mediated by acute effects, which can be dose limiting. A latent period follows recovery from the acute reaction, then chronic irradiation fibrosis (late effects) pose a second cause of organ failure. HSP25/27 has been suggested to protect cells against apoptotic cell death triggered by hyperthermia, ionizing radiation, oxidative stress, Fas ligand, and cytotoxic drugs. And several mechanisms have been proposed to account for HSP27-mediated apoptotic protection. However radioprotective effect of HSP25/27 in vivo system has not yet been evaluated. The aim of this study was to evaluate the potential of exogenous HSP25 expression, as delivered by adenoviral vectors, to protect animal from radiation induced tissue damage

  18. Tissue Damage Characterization Using Non-invasive Optical Modalities

    Science.gov (United States)

    Diaz, David

    The ability to determine the degree of cutaneous and subcutaneous tissue damage is essential for proper wound assessment and a significant factor for determining patient treatment and morbidity. Accurate characterization of tissue damage is critical for a number of medical applications including surgical removal of nonviable tissue, severity assessment of subcutaneous ulcers, and depth assessment of visually open wounds. The main objective of this research was to develop a non-invasive method for identifying the extent of tissue damage underneath intact skin that is not apparent upon visual examination. This work investigated the relationship between tissue optical properties, blood flow, and tissue viability by testing the hypotheses that (a) changes in tissue oxygenation and/or microcirculatory blood flow measurable by Diffuse Near Infrared Spectroscopy (DNIRS) and Diffuse Correlation Spectroscopy (DCS) differ between healthy and damaged tissue and (b) the magnitude of those changes differs for different degrees of tissue damage. This was accomplished by developing and validating a procedure for measuring microcirculatory blood flow and tissue oxygenation dynamics at multiple depths (up to 1 centimeter) using non-invasive DCS and DNIRS technologies. Due to the lack of pressure ulcer animal models that are compatible with our optical systems, a proof of concept was conducted in a porcine burn model prior to conducting clinical trials in order to assess the efficacy of the system in-vivo. A reduction in total hemoglobin was observed for superficial (5%) and deep burns (35%) along with a statistically significant difference between the optical properties of superficial and deep burns (p differences detected in optical properties and hemoglobin content by optical measurements correlated with the extent of tissue injury observed in histological stains. After proof of concept in animals, a human study was conducted and optical data was collected from 20 healthy

  19. Role of endothelium in radiation-induced normal tissue damages

    International Nuclear Information System (INIS)

    Milliat, F.

    2007-05-01

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  20. Neodymium: YAG laser damage threshold. A comparison of injection-molded and lathe-cut polymethylmethacrylate intraocular lenses.

    Science.gov (United States)

    Wilson, S E; Brubaker, R F

    1987-01-01

    The possibility that injection-molded intraocular lenses (IOLs) with imperfections called iridescent clefts could have a decreased threshold to neodymium: YAG (Nd:YAG) laser-induced damage was investigated. Thresholds for Nd:YAG laser-induced damage were determined for injection-molded and lathe-cut polymethylmethacrylate lenses. When aimed at a membrane in contact with a posterior convex surface, the average thresholds were 0.96 +/- 0.18 mJ (Standard deviation [SD]) and 1.80 +/- 0.55 mJ, respectively. The difference was significant at P = 0.001. When injection-molding polymethylmethacrylate was used to make lathe-cut IOLs, very few iridescent clefts were present, and the threshold to Nd:YAG laser-induced damage was 0.94 +/- 0.25 mJ. Iridescent clefts are therefore produced during the injection-molding process but they do not lower the threshold to Nd:YAG laser-induced damage. Rather, the reduced threshold in injection-molded lenses is most probably a result of the polymethylmethacrylate used in their manufacture. Clinically, iridescent clefts in a lens suggest that it has been manufactured by an injection-molding process and that Nd:YAG laser posterior capsulotomy must be performed at the lowest possible energy level to avoid damage.

  1. Enhancement of laser induced damage threshold of fused silica by acid etching combined with UV laser conditioning

    International Nuclear Information System (INIS)

    Chen Meng; Xiang Xia; Jiang Yong; Zu Xiaotao; Yuan Xiaodong; Zheng Wanguo; Wang Haijun; Li Xibin; Lu Haibing; Jiang Xiaodong; Wang Chengcheng

    2010-01-01

    Acid etching combined with UV laser conditioning is developed to enhance the laser induced damage threshold (LIDT) of fused silica. Firstly, the fused silica is etched for 1 ∼ 100 min with a buffered 1% HF solution. After acid etching, its transmittance, surface roughness and LIDT are measured. The results reveal that the fused silica has the highest LIDT and transmittance after etching for 10 min. Then UV laser (355 nm) conditioning is adopted to process the 10-min-etched fused silica. When the laser fluence is below 60% of fused silica's zero probability damage threshold, the LIDT increases gradually with the increase of laser conditioning fluence. However, the LIDT rapidly decreases to be lower than the threshold of the 10-min-etched fused silica when the conditioning fluence is up to 80% of the threshold. Proper acid etching and laser conditioning parameters will effectively enhance the laser damage resistance of fused silica. (authors)

  2. Program requirements to determine and relate fuel damage and failure thresholds to anticipated conditions in pressurized water reactors

    International Nuclear Information System (INIS)

    Loyd, R.F.; Croucher, D.W.

    1980-03-01

    Anticipated transients, licensing criteria, and damage mechanisms for PWR fuel rods are reviewed. Potential mechanistic fuel rod damage limits for PWRs are discussed. An expermental program to be conducted out-of-pile and in the Engineering Test Reactor (ETR) to generate a safety data base to define mechanistic fuel damage and failure thresholds and to relate these thresholds to the thermal-hydraulic and power conditions in a PWR is proposed. The requirements for performing the tests are outlined. Analytical support requirements are defined

  3. Renal tissue damage induced by focused shock waves

    Science.gov (United States)

    Ioritani, N.; Kuwahara, M.; Kambe, K.; Taguchi, K.; Saitoh, T.; Shirai, S.; Orikasa, S.; Takayama, K.; Lush, P. A.

    1990-07-01

    Biological evidence of renal arterial wall damage induced by the microjet due to shock wave-cavitation bubble interaction was demonstrated in living dog kidneys. We also intended to clarify the mechanism of renal tissue damage and the effects of different conditions of shock wave exposure (peak pressure of focused area, number of shots, exposure rate) on the renal tissue damage in comparison to stone disintegration. Disruption of arterial wall was the most remarkable histological change in the focused area of the kidneys. This lesion appeared as if the wall had been punctured by a needle. Large hematoma formation in the renal parenchym, and interstitial hemorrhage seemed to be the results of the arterial lesion. This arterial disorder also led to ischemic necrosis of the tubules surrounding the hematoma. Micro-angiographic examination of extracted kidneys also proved such arterial puncture lesions and ischemic lesions. The number of shots required for model stone disintegration was not inversely proportional to peak pressure. It decreased markedly when peak pressure was above 700 bar. Similarly thenumber of shots for hematoma formation was not inversely proportional to peak pressure, however, this decreased markedly above 500 bar. These results suggested that a hematoma could be formed under a lower peak pressure than that required for stone disintegration.

  4. Threshold-dependent sample sizes for selenium assessment with stream fish tissue

    Science.gov (United States)

    Hitt, Nathaniel P.; Smith, David R.

    2015-01-01

    Natural resource managers are developing assessments of selenium (Se) contamination in freshwater ecosystems based on fish tissue concentrations. We evaluated the effects of sample size (i.e., number of fish per site) on the probability of correctly detecting mean whole-body Se values above a range of potential management thresholds. We modeled Se concentrations as gamma distributions with shape and scale parameters fitting an empirical mean-to-variance relationship in data from southwestern West Virginia, USA (63 collections, 382 individuals). We used parametric bootstrapping techniques to calculate statistical power as the probability of detecting true mean concentrations up to 3 mg Se/kg above management thresholds ranging from 4 to 8 mg Se/kg. Sample sizes required to achieve 80% power varied as a function of management thresholds and Type I error tolerance (α). Higher thresholds required more samples than lower thresholds because populations were more heterogeneous at higher mean Se levels. For instance, to assess a management threshold of 4 mg Se/kg, a sample of eight fish could detect an increase of approximately 1 mg Se/kg with 80% power (given α = 0.05), but this sample size would be unable to detect such an increase from a management threshold of 8 mg Se/kg with more than a coin-flip probability. Increasing α decreased sample size requirements to detect above-threshold mean Se concentrations with 80% power. For instance, at an α-level of 0.05, an 8-fish sample could detect an increase of approximately 2 units above a threshold of 8 mg Se/kg with 80% power, but when α was relaxed to 0.2, this sample size was more sensitive to increasing mean Se concentrations, allowing detection of an increase of approximately 1.2 units with equivalent power. Combining individuals into 2- and 4-fish composite samples for laboratory analysis did not decrease power because the reduced number of laboratory samples was compensated for by increased

  5. Comparison of retina damage thresholds simulating the femtosecond-laser in situ keratomileusis (fs-LASIK) process with two laser systems in the CW- and fs-regime

    Science.gov (United States)

    Sander, M.; Minet, O.; Zabarylo, U.; Müller, M.; Tetz, M. R.

    2012-04-01

    The femtosecond-laser in situ keratomileusis procedure affords the opportunity to correct ametropia by cutting transparent corneal tissue with ultra-short laser pulses. Thereby the tissue cut is generated by a laser-induced optical breakdown in the cornea with ultra-short laser pulses in the near-infrared range. Compared to standard procedures such as photorefractive keratectomy and laser in-situ keratomileusis with the excimer laser, where the risk potential for the eye is low due to the complete absorption of ultraviolet irradiation from corneal tissue, only a certain amount of the pulse energy is deposited in the cornea during the fs-LASIK process. The remaining energy propagates through the eye and interacts with the retina and the strong absorbing tissue layers behind. The objective of the presented study was to determine and compare the retina damage thresholds during the fs-LASIK process simulated with two various laser systems in the CW- and fs-regime.

  6. A historical perspective on fifteen years of laser damage thresholds at LLNL

    International Nuclear Information System (INIS)

    Rainer, F.; De Marco, F.P.; Staggs, M.C.; Kozlowski, M.R.; Atherton, L.J.; Sheehan, L.M.

    1993-01-01

    We have completed a fifteen year, referenced and documented compilation of more than 15,000 measurements of laser-induced damage thresholds (LIDT) conducted at the Lawrence Livermore National Laboratory (LLNL). These measurements cover the spectrum from 248 to 1064 nm with pulse durations ranging from < 1 ns to 65 ns and at pulse-repetition frequencies (PRF) from single shots to 6.3 kHz. We emphasize the changes in LIDTs during the past two years since we last summarized our database. We relate these results to earlier data concentrating on improvements in processing methods, materials, and conditioning techniques. In particular, we highlight the current status of anti-reflective (AR) coatings, high reflectors (HR), polarizers, and frequency-conversion crystals used primarily at 355 nm and 1064 nm

  7. High-threshold motor unit firing reflects force recovery following a bout of damaging eccentric exercise.

    Science.gov (United States)

    Macgregor, Lewis J; Hunter, Angus M

    2018-01-01

    Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p exercise. Mean motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; pexercise. The firing rate of high-threshold motor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures.

  8. Zicam-induced damage to mouse and human nasal tissue.

    Directory of Open Access Journals (Sweden)

    Jae H Lim

    Full Text Available Intranasal medications are used to treat various nasal disorders. However, their effects on olfaction remain unknown. Zicam (zinc gluconate; Matrixx Initiatives, Inc, a homeopathic substance marketed to alleviate cold symptoms, has been implicated in olfactory dysfunction. Here, we investigated Zicam and several common intranasal agents for their effects on olfactory function. Zicam was the only substance that showed significant cytotoxicity in both mouse and human nasal tissue. Specifically, Zicam-treated mice had disrupted sensitivity of olfactory sensory neurons to odorant stimulation and were unable to detect novel odorants in behavioral testing. These findings were long-term as no recovery of function was observed after two months. Finally, human nasal explants treated with Zicam displayed significantly elevated extracellular lactate dehydrogenase levels compared to saline-treated controls, suggesting severe necrosis that was confirmed on histology. Our results demonstrate that Zicam use could irreversibly damage mouse and human nasal tissue and may lead to significant smell dysfunction.

  9. Correlating optical damage threshold with intrinsic defect populations in fused silica as a function of heat treatment temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shen, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Matthews, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Elhadj, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Miller, P. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nelson, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hamilton, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-04-03

    Here, chemical vapor deposition (CVD) is used for the production of fused silica optics in high-power laser applications. However, relatively little is known about the ultraviolet laser damage threshold of CVD films and how they relate to intrinsic defects produced during deposition. We present here a study relating structural and electronic defects in CVD films to 355 nm pulsed-laser damage threshold as a function of post-deposition annealing temperature (THT). Plasma-enhanced CVD based on SiH4/N2O under oxygen-rich conditions was used to deposit 1.5, 3.1 and 6.4 µm thick films on etched SiO2 substrates. Rapid annealing was performed using a scanned CO2 laser beam up to THT ~ 2100 K. The films were then characterized using x-ray photoemission spectroscopy, Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy. A gradual transition in the damage threshold of annealed films was observed for THT values up to 1600 K, correlating with a decrease in non-bridging silanol and oxygen deficient centres. An additional sharp transition in damage threshold also occurs at ~1850 K indicating substrate annealing. Based on our results, a mechanism for damage-related defect annealing is proposed, and the potential of using high-THT CVD SiO2 to mitigate optical damage is also discussed.

  10. High-threshold motor unit firing reflects force recovery following a bout of damaging eccentric exercise

    Science.gov (United States)

    Macgregor, Lewis J.

    2018-01-01

    Exercise-induced muscle damage (EIMD) is associated with impaired muscle function and reduced neuromuscular recruitment. However, motor unit firing behaviour throughout the recovery period is unclear. EIMD impairment of maximal voluntary force (MVC) will, in part, be caused by reduced high-threshold motor unit firing, which will subsequently increase to recover MVC. Fourteen healthy active males completed a bout of eccentric exercise on the knee extensors, with measurements of MVC, rate of torque development and surface electromyography performed pre-exercise and 2, 3, 7 and 14 days post-exercise, on both damaged and control limb. EIMD was associated with decreased MVC (235.2 ± 49.3 Nm vs. 161.3 ± 52.5 Nm; p motor unit firing rate was reduced (16.4 ± 2.2 Hz vs. 12.6 ± 1.7 Hz; p motor units only, 48h post-exercise, and common drive was elevated (0.36 ± 0.027 vs. 0.56 ± 0.032; pmotor units was reduced in parallel with impaired muscle function, whilst early recruited motor units remained unaltered. Common drive of motor units increased in offset to the firing rate impairment. These alterations correlated with the recovery of force decrement, but not of pain elevation. This study provides fresh insight into the central mechanisms associated with EIMD recovery, relative to muscle function. These findings may in turn lead to development of novel management and preventative procedures. PMID:29630622

  11. Downregulation of Wip1 phosphatase modulates the cellular threshold of DNA damage signaling in mitosis

    Science.gov (United States)

    Macurek, Libor; Benada, Jan; Müllers, Erik; Halim, Vincentius A.; Krejčíková, Kateřina; Burdová, Kamila; Pecháčková, Sona; Hodný, Zdeněk; Lindqvist, Arne; Medema, René H.; Bartek, Jiri

    2013-01-01

    Cells are constantly challenged by DNA damage and protect their genome integrity by activation of an evolutionary conserved DNA damage response pathway (DDR). A central core of DDR is composed of a spatiotemporally ordered net of post-translational modifications, among which protein phosphorylation plays a major role. Activation of checkpoint kinases ATM/ATR and Chk1/2 leads to a temporal arrest in cell cycle progression (checkpoint) and allows time for DNA repair. Following DNA repair, cells re-enter the cell cycle by checkpoint recovery. Wip1 phosphatase (also called PPM1D) dephosphorylates multiple proteins involved in DDR and is essential for timely termination of the DDR. Here we have investigated how Wip1 is regulated in the context of the cell cycle. We found that Wip1 activity is downregulated by several mechanisms during mitosis. Wip1 protein abundance increases from G1 phase to G2 and declines in mitosis. Decreased abundance of Wip1 during mitosis is caused by proteasomal degradation. In addition, Wip1 is phosphorylated at multiple residues during mitosis, and this leads to inhibition of its enzymatic activity. Importantly, ectopic expression of Wip1 reduced γH2AX staining in mitotic cells and decreased the number of 53BP1 nuclear bodies in G1 cells. We propose that the combined decrease and inhibition of Wip1 in mitosis decreases the threshold necessary for DDR activation and enables cells to react adequately even to modest levels of DNA damage encountered during unperturbed mitotic progression. PMID:23255129

  12. Development and validation of rheumatoid arthritis magnetic resonance imaging inflammation thresholds associated with lack of damage progression

    DEFF Research Database (Denmark)

    Baker, Joshua F.; Østergaard, Mikkel; Emery, Paul

    2017-01-01

    Objective To determine thresholds for rheumatoid arthritis (RA) magnetic resonance imaging scores (RAMRIS) associated with a low risk of structural damage progression. Methods MRI of the dominant hand was performed and RAMRIS scores determined at weeks 0, 24, and 52. X-rays were performed and van...

  13. Modelling single shot damage thresholds of multilayer optics for high-intensity short-wavelength radiation sources

    NARCIS (Netherlands)

    Loch, R.A.; Sobierajski, R.; Louis, Eric; Bosgra, J.; Bosgra, J.; Bijkerk, Frederik

    2012-01-01

    The single shot damage thresholds of multilayer optics for highintensity short-wavelength radiation sources are theoretically investigated, using a model developed on the basis of experimental data obtained at the FLASH and LCLS free electron lasers. We compare the radiation hardness of commonly

  14. Design of a high pulse repitition frequency carbon dioxide laser for processing high damage threshold materials

    Science.gov (United States)

    Chatwin, Christopher R.; McDonald, Donald W.; Scott, Brian F.

    1989-07-01

    The absence of an applications led design philosophy has compromised both the development of laser source technology and its effective implementation into manufacturing technology in particular. For example, CO2 lasers are still incapable of processing classes of refractory and non-ferrous metals. Whilst the scope of this paper is restricted to high power CO2 lasers; the design methodology reported herein is applicable to source technology in general, which when exploited, will effect an expansion of applications. The CO2 laser operational envelope should not only be expanded to incorporate high damage threshold materials but also offer a greater degree of controllability. By a combination of modelling and experimentation the requisite beam characteristics, at the workpiece, were determined then utilised to design the Laser Manufacturing System. The design of sub-system elements was achieved by a combination of experimentation and simulation which benefited from a comprehensive set of software tools. By linking these tools the physical processes in the laser - electron processes in the plasma, the history of photons in the resonator, etc. - can be related, in a detailed model, to the heating mechanisms in the workpiece.

  15. The Laser Damage Threshold for Materials and the Relation Between Solid-Melt and Melt-Vapor Interface Velocities

    International Nuclear Information System (INIS)

    Khalil, Osama Mostafa

    2010-01-01

    Numerous experiments have demonstrated and analytic theories have predicted that there is a threshold for pulsed laser ablation of a wide range of materials. Optical surface damage threshold is a very complex and important application of high-power lasers. Optical damage may also be considered to be the initial phase of laser ablation. In this work it was determined the time required and the threshold energy of a layer of thickness to heat up. We used the Finite Difference method to simulate the process of laser-target interaction in three cases. Namely, the case before melting begins using a continuous wave (c.w) laser source and a pulsed laser source, the case after the first change of state (from solid to melt), and the case after the second change of state (from melt to vapor). And also study the relation between the solid-melt and melt-vapor interface velocities to have a commonsense of the laser ablation process.

  16. On the threshold conditions for electron beam damage of asbestos amosite fibers in the transmission electron microscope (TEM).

    Science.gov (United States)

    Martin, Joannie; Beauparlant, Martin; Sauvé, Sébastien; L'Espérance, Gilles

    2016-12-01

    Asbestos amosite fibers were investigated to evaluate the damage caused by a transmission electron microscope (TEM) electron beam. Since elemental x-ray intensity ratios obtained by energy dispersive x-ray spectroscopy (EDS) are commonly used for asbestos identification, the impact of beam damage on these ratios was evaluated. It was determined that the magnesium/silicon ratio best represented the damage caused to the fiber. Various tests showed that most fibers have a current density threshold above which the chemical composition of the fiber is modified. The value of this threshold current density varied depending on the fiber, regardless of fiber diameter, and in some cases could not be determined. The existence of a threshold electron dose was also demonstrated. This value was dependent on the current density used and can be increased by providing a recovery period between exposures to the electron beam. This study also established that the electron beam current is directly related to the damage rate above a current density of 165 A/cm 2 . The large number of different results obtained suggest, that in order to ensure that the amosite fibers are not damaged, analysis should be conducted below a current density of 100 A/cm 2 .

  17. Investigation of damage threshold to TiO2 coatings at different laser wavelength and pulse duration

    International Nuclear Information System (INIS)

    Yao Jianke; Fan Zhengxiu; Jin Yunxia; Zhao Yuanan; He Hongbo; Shao Jianda

    2008-01-01

    Laser-induced damages to TiO 2 single layers and TiO 2 /SiO 2 high reflectors at laser wavelength of 1064 nm, 800 nm, 532 nm, and pulse width of 12 ns, 220 ps, 50 fs, 8 ns are investigated. All films are prepared by electron beam evaporation. The relations among microstructure, chemical composition, optical properties and laser-induced damage threshold (LIDT), have been researched. The dependence of damage mechanism on laser wavelength and pulse width is discussed. It is found that from 1064 nm to 532 nm, LIDT is mainly absorption related, which is determined by film's extinction coefficient and stoichiometric defects. The rapid decrease of LIDT at 800 nm is due to the pulse width factor. TiO 2 coatings are mainly thermally by damaged at long pulse (τ ≥ 220 ps). The damage shows ablation feature at 50 fs

  18. Eccentric muscle damage has variable effects on motor unit recruitment thresholds and discharge patterns in elbow flexor muscles.

    Science.gov (United States)

    Dartnall, Tamara J; Rogasch, Nigel C; Nordstrom, Michael A; Semmler, John G

    2009-07-01

    The purpose of this study was to determine the effect of eccentric muscle damage on recruitment threshold force and repetitive discharge properties of low-threshold motor units. Ten subjects performed four tasks involving isometric contraction of elbow flexors while electromyographic (EMG) data were recorded from human biceps brachii and brachialis muscles. Tasks were 1) maximum voluntary contraction (MVC); 2) constant-force contraction at various submaximal targets; 3) motor unit recruitment threshold task; and 4) minimum motor unit discharge rate task. These tasks were performed on three separate days before, immediately after, and 24 h after eccentric exercise of elbow flexor muscles. MVC force declined (42%) immediately after exercise and remained depressed (29%) 24 h later, indicative of muscle damage. Mean motor unit recruitment threshold for biceps brachii was 8.4+/-4.2% MVC, (n=34) before eccentric exercise, and was reduced by 41% (5.0+/-3.0% MVC, n=34) immediately after and by 39% (5.2+/-2.5% MVC, n=34) 24 h after exercise. No significant changes in motor unit recruitment threshold were observed in the brachialis muscle. However, for the minimum tonic discharge rate task, motor units in both muscles discharged 11% faster (10.8+/-2.0 vs. 9.7+/-1.7 Hz) immediately after (n=29) exercise compared with that before (n=32). The minimum discharge rate variability was greater in brachialis muscle immediately after exercise (13.8+/-3.1%) compared with that before (11.9+/-3.1%) and 24 h after exercise (11.7+/-2.4%). No significant changes in minimum discharge rate variability were observed in the biceps brachii motor units after exercise. These results indicate that muscle damage from eccentric exercise alters motor unit recruitment thresholds for >or=24 h, but the effect is not the same in the different elbow flexor muscles.

  19. Anisotropy of hardness and laser damage threshold of unidirectional organic NLO crystal in relation to the internal structure

    International Nuclear Information System (INIS)

    Natarajan, V.; Arivanandhan, M.; Sankaranarayanan, K.; Hayakawa, Y.

    2011-01-01

    Highlights: · Growth rate of the unidirectional organic crystals were measured and the variation in the growth rate was explained based on the attachment energy model. · Anisotropic behaviors of hardness and laser damage threshold of the unidirectional materials were analyzed. · The obtained results were explained based on the crystal structure of the material. - Abstract: Unidirectional benzophenone crystals were grown along , and directions by uniaxially solution crystallization method at ambient temperature. The growth rate of the grown crystals was varied with orientation. The optical absorption coefficients of benzophenone were measured as a function of wavelength. The optical absorption study reveals that the benzophenone crystal has very low absorption in the wavelength range of interest. Moreover, the laser damage threshold and micro hardness for , and oriented unidirectional benzophenone crystals were measured using a Q-switched Nd:YAG laser operating at 1064 nm radiation and Vicker's micro hardness tester, respectively. The laser damage threshold is larger for the and oriented crystals compared to oriented crystal at 1064 nm wavelength. The result is consistent with the hardness variation observed for the three different crystallographic directions of benzophenone crystal. The relation between the laser damage profile and mechanical hardness anisotropy is discussed based on the crystal structure of benzophenone.

  20. Thermal damage produced by high-irradiance continuous wave CO2 laser cutting of tissue.

    Science.gov (United States)

    Schomacker, K T; Walsh, J T; Flotte, T J; Deutsch, T F

    1990-01-01

    Thermal damage produced by continuous wave (cw) CO2 laser ablation of tissue in vitro was measured for irradiances ranging from 360 W/cm2 to 740 kW/cm2 in order to investigate the extent to which ablative cooling can limit tissue damage. Damage zones thinner than 100 microns were readily produced using single pulses to cut guinea pig skin as well as bovine cornea, aorta, and myocardium. Multiple pulses can lead to increased damage. However, a systematic decrease in damage with irradiance, predicted theoretically by an evaporation model of ablation, was not observed. The damage-zone thickness was approximately constant around the periphery of the cut, consistent with the existence of a liquid layer which stores heat and leads to tissue damage, and with a model of damage and ablation recently proposed by Zweig et al.

  1. An experimental study on tissue damage following subcutaneous injection of water soluble contrast media

    International Nuclear Information System (INIS)

    Kim, Seung Hyup; Park, Jae Hyung; Kang, Heung Sik; Kim, Chu Wan; Han, Man Chung; Kim, Yong Il

    1989-01-01

    The water soluble contrast media cause tissue necrosis infrequently by extravasation during intravenous injection in various radiological examinations. However, it has not been well documented that what kind and what concentration of contrast media can cause tissue necrosis. And also, the mechanism of tissue necrosis by extravasated contrast media has not been well known. The purpose of this experimental study was to evaluate the frequency and severity of tissue damage following subcutaneous injection of various water soluble contrast media to investigate the characteristics of the contrast media acting on the tissue damage, and to provide the basic data for the clinical application. Meglumine ioxithalamate,sodium and meglumine ioxithalamate, iopromide, iopamidol, ioxaglate,meglumine diatrizoate and sodium diatrizoate of various iodine content and osmolality were injected into subcutaneous tissue of the dorsum of 970 feet of 485 rats. The tissue reaction of injection sites were grossly examined with period from 1 day to 8 weeks after the injection. Representative gross changes were correlated with histologic findings. The results were as follows; 1. The basic tissue damage by extravasated contrast media was acute and chronic inflammatory reaction of the soft tissue with subsequent progress into the hemorrhagic and necrotizing lesion. 2. Lager volume of contrast media caused more severe tissue damage. 3. Contrast media of higher osmolality caused more severe tissue damage. 4. At same osmolality, contrast media of higher iodine content caused more severe tissue damage

  2. Nd : YAG surgical laser effects in canine prostate tissue: temperature and damage distribution

    NARCIS (Netherlands)

    van Nimwegen, S. A.; L'Eplattenier, H. F.; Rem, A. I.; van der Lugt, J. J.; Kirpensteijn, J.

    2009-01-01

    An in vitro model was used to predict short-term, laser-induced, thermal damage in canine prostate tissue. Canine prostate tissue samples were equipped with thermocouple probes to measure tissue temperature at 3, 6, 9 and 12 mm depths. The tissue surface was irradiated with a Nd:YAG laser in contact

  3. Damage Mechanisms In Polymers Upon NIR Femtosecond Pulse Laser Irradiation: Sub-Threshold Processes And Their Implications For Laser Safety Applications

    International Nuclear Information System (INIS)

    Bonse, Joern; Krueger, Joerg; Solis, Javier; Spielmann, Christian; Lippert, Thomas

    2010-01-01

    This contribution investigates laser-induced damage of thin film and bulk polymer samples, with the focus on physical processes occurring close to the damage threshold. In-situ real-time reflectivity (RTR) measurements with picosecond (ps) and nanosecond (ns) temporal resolution were performed on thin polymer films on a timescale up to a few microseconds (μs). A model for polymer thin film damage is presented, indicating that irreversible chemical modification processes take place already below the fluence threshold for macroscopic damage. On dye-doped bulk polymer filters (as used for laser goggles), transmission studies using fs-and ps-laser pulses reveal the optical saturation behavior of the material and its relation to the threshold of permanent damage. Implications of the sub-threshold processes for laser safety applications will be discussed for thin film and bulk polymer damage.

  4. Measurements of the dependence of damage thresholds on laser wavelength, pulse duration and film thickness

    International Nuclear Information System (INIS)

    Rainer, F.; Vercimak, C.L.; Carniglia, C.K.; Milam, D.; Hart, T.T.

    1985-01-01

    Results of three experiments are described. The authors used 351-nm and 355-nm pulses with durations of 0.6, 1, 5 and 9 ns to measure thresholds for a variety of antireflectance and high reflectance coatings. The functional form t/sup m/, with t the pulse duration, was used to scale fluence thresholds measured at 0.6 ns to those measured at 9.0 ns. Values of the coefficient m ranged from 0.10 to 0.51. The average value was 0.30. In the second experiment, they measured thresholds at 1064 nm, 527 nm and 355 nm for single-frequency high reflectance ZrO/sub 2//SiO/sub 2/ coatings. Coatings for all three frequencies were deposited simultaneously by use of masks in the coating chamber. Thresholds varied from 2-4 J/cm/sup 2/ at 355 nm to 7-10 J/cm/sup 2/ at 1064 nm. The third experiment measured thresholds at 355 nm for antireflection coatings made with layer thicknesses varying from greater than one wavelength to less than a quarterwavelength. A significant variation of threshold with coating thickness was not observed, but the median thresholds increased slightly as coating thickness increased

  5. Determination of ultra-short laser induced damage threshold of KH2PO4 crystal: Numerical calculation and experimental verification

    Directory of Open Access Journals (Sweden)

    Jian Cheng

    2016-03-01

    Full Text Available Rapid growth and ultra-precision machining of large-size KDP (KH2PO4 crystals with high laser damage resistance are tough challenges in the development of large laser systems. It is of high interest and practical significance to have theoretical models for scientists and manufacturers to determine the laser-induced damage threshold (LIDT of actually prepared KDP optics. Here, we numerically and experimentally investigate the laser-induced damage on KDP crystals in ultra-short pulse laser regime. On basis of the rate equation for free electron generation, a model dedicated to predicting the LIDT is developed by considering the synergistic effect of photoionization, impact ionization and decay of electrons. Laser damage tests are performed to measure the single-pulse LIDT with several testing protocols. The testing results combined with previously reported experimental data agree well with those calculated by the model. By taking the light intensification into consideration, the model is successfully applied to quantitatively evaluate the effect of surface flaws inevitably introduced in the preparation processes on the laser damage resistance of KDP crystals. This work can not only contribute to further understanding of the laser damage mechanisms of optical materials, but also provide available models for evaluating the laser damage resistance of exquisitely prepared optical components used in high power laser systems.

  6. Damage Threshold of In Vivo Rabbit Cornea by 2 micron Laser Irradiation

    National Research Council Canada - National Science Library

    Chen, Bo; Oliver, Jeffery; Dutta, Soumak; Rylander, III, Grady H; Thomsen, Sharon L; Welch, Ashley J

    2007-01-01

    To support refinement of the Maximum Permissible Exposure (MPE) safety limits, a series of experiments were conducted in vivo on Dutch Belted rabbit corneas to determine corneal minimum visible lesion thresholds...

  7. Regulation of annexins following infection like tissue damage – investigated by 2-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Wulff, Tune; Nielsen, Michael Engelbrecht

    are regulated after tissue damaged on the protein level. These proteins have been assign to functions like regulation of coagulation, apoptosis, and exocytosis, indicating their importance following infection and subsequent repair in fish. In addition the regulation observed in this study are supported...... an established model. In the model infection is mimicked by a well-defined tissue damage allowing each fish to be equally affected. Samples were taken 7 days after tissue damage and included samples from the damaged tissue, internal control and an external control. Changes in protein expression between the wound...... by previous findings on the mRNA level, where both proteins are regulated following infection. In conclusion this study show regulation on the protein level of two members of the annexin protein family after infection like tissue damage....

  8. Non-Fourier based thermal-mechanical tissue damage prediction for thermal ablation.

    Science.gov (United States)

    Li, Xin; Zhong, Yongmin; Smith, Julian; Gu, Chengfan

    2017-01-02

    Prediction of tissue damage under thermal loads plays important role for thermal ablation planning. A new methodology is presented in this paper by combing non-Fourier bio-heat transfer, constitutive elastic mechanics as well as non-rigid motion of dynamics to predict and analyze thermal distribution, thermal-induced mechanical deformation and thermal-mechanical damage of soft tissues under thermal loads. Simulations and comparison analysis demonstrate that the proposed methodology based on the non-Fourier bio-heat transfer can account for the thermal-induced mechanical behaviors of soft tissues and predict tissue thermal damage more accurately than classical Fourier bio-heat transfer based model.

  9. Quantification of change in vocal fold tissue stiffness relative to depth of artificial damage.

    Science.gov (United States)

    Rohlfs, Anna-Katharina; Schmolke, Sebastian; Clauditz, Till; Hess, Markus; Müller, Frank; Püschel, Klaus; Roemer, Frank W; Schumacher, Udo; Goodyer, Eric

    2017-10-01

    To quantify changes in the biomechanical properties of human excised vocal folds with defined artificial damage. The linear skin rheometer (LSR) was used to obtain a series of rheological measurements of shear modulus from the surface of 30 human cadaver vocal folds. The tissue samples were initially measured in a native condition and then following varying intensities of thermal damage. Histological examination of each vocal fold was used to determine the depth of artificial alteration. The measured changes in stiffness were correlated with the depth of cell damage. For vocal folds in a pre-damage state the shear modulus values ranged from 537 Pa to 1,651 Pa (female) and from 583 Pa to 1,193 Pa (male). With increasing depth of damage from the intermediate layer of the lamina propria (LP), tissue stiffness increased consistently (compared with native values) following application of thermal damage to the vocal folds. The measurement showed an increase of tissue stiffness when the depth of tissue damage was extending from the intermediate LP layer downwards. Changes in the elastic characteristics of human vocal fold tissue following damage at defined depths were demonstrated in an in vitro experiment. In future, reproducible in vivo measurements of elastic vocal fold tissue alterations may enable phonosurgeons to infer the extent of subepithelial damage from changes in surface elasticity.

  10. Thermal damage control of dye-assisted laser tissue welding: effect of dye concentration

    Science.gov (United States)

    Xie, Hua; Buckley, Lisa A.; Prahl, Scott A.; Shaffer, Brian S.; Gregory, Kenton W.

    2001-05-01

    Successful laser-assisted tissue welding was implemented to provide proper weld strength with minimized tissue thermal injury. We investigated and compared the weld strengths and morphologic changes in porcine small intestinal submucose (SIS) and porcine ureteral tissues with various concentration of indocyanine green (ICG) and with a solid albumin sheet. The study showed that the tissues were welded at lower ICG concentration (0.05 mM) with minimized tissue thermal damage using an 800-nm wavelength diode laser.

  11. Influence of post-deposition treatment by UV light and oxygen (ozone) on 350 nm damage thresholds of SiO2 films deposited from sols

    International Nuclear Information System (INIS)

    Thomas, I.; Wilder, J.; Lee, A.; George, D.

    1988-01-01

    Certain multilayer porous silica AR coatings on fused silica substrates prepared by the sol-gel process have been found to have a much lower laser damage threshold than single layer coatings prepared by the same method. Treatment with UV light in the presence of oxygen (which gives ozone) at low temperature was found to restore damage thresholds to the levels found in single layers. Damage thresholds were measured at 350 nm with a 25 ns pulse for 1000 shots at 25 Hz. The effect of exposure time and other factors such as replacement of oxygen with nitrogen and vacuum are described

  12. White Light Generation and Anisotropic Damage in Gold Films near Percolation Threshold

    DEFF Research Database (Denmark)

    Novikov, Sergey M.; Frydendahl, Christian; Beermann, Jonas

    2017-01-01

    in vanishingly small gaps between gold islands in thin films near the electrically determined percolation threshold. Optical explorations using two-photon luminescence (TPL) and near-field microscopies reveals supercubic TPL power dependencies with white-light spectra, establishing unequivocally...... that the strongest TPL signals are generated close to the percolation threshold films, and occurrence of extremely confined (similar to 30 nm) and strongly enhanced (similar to 100 times) fields at the illumination wavelength. For linearly polarized and sufficiently powerful light, we observe pronounced optical...

  13. Cellular proliferation and regeneration following tissue damage. Progress report. [Eyes

    Energy Technology Data Exchange (ETDEWEB)

    Harding, C.V.

    1976-10-01

    Results are reported from a study of wound healing in tissues of the eye, particularly lens, cornea, and surrounding tissues. The reactions of these tissues to mechanical injuries, as well as injuries induced by chemotoxic agents were studied. It is postulated that a better understanding of the basic reactions of the eye to injurious agents may be of importance in the evaluation of potential environmental hazards.

  14. Efficient Phase Locking of Fiber Amplifiers Using a Low-Cost and High-Damage-Threshold Phase Control System

    International Nuclear Information System (INIS)

    Pu, Zhou; Yan-Xing, Ma; Xiao-Lin, Wang; Hao-Tong, Ma; Xiao-Jun, Xu; Ze-Jin, Liu

    2010-01-01

    We propose a low-cost and high-damage-threshold phase control system that employs a piezoelectric ceramic transducer modulator controlled by a stochastic parallel gradient descent algorithm. Efficient phase locking of two fiber amplifiers is demonstrated. Experimental results show that energy encircled in the target pinhole is increased by a factor of 1.76 and the visibility of the fringe pattern is as high as 90% when the system is in close-loop. The phase control system has potential in phase locking of large-number and high-power fiber laser endeavors. (fundamental areas of phenomenology (including applications))

  15. Effects of deposition rates on laser damage threshold of TiO2/SiO2 high reflectors

    International Nuclear Information System (INIS)

    Yao Jianke; Xu Cheng; Ma Jianyong; Fang Ming; Fan Zhengxiu; Jin Yunxia; Zhao Yuanan; He Hongbo; Shao Jianda

    2009-01-01

    TiO 2 single layers and TiO 2 /SiO 2 high reflectors (HR) are prepared by electron beam evaporation at different TiO 2 deposition rates. It is found that the changes of properties of TiO 2 films with the increase of rate, such as the increase of refractive index and extinction coefficient and the decrease of physical thickness, lead to the spectrum shift and reflectivity bandwidth broadening of HR together with the increase of absorption and decrease of laser-induced damage threshold. The damages are found of different morphologies: a shallow pit to a seriously delaminated and deep crater, and the different amorphous-to-anatase-to-rutile phase transition processes detected by Raman study. The frequency shift of Raman vibration mode correlates with the strain in film. Energy dispersive X-ray analysis reveals that impurities and non-stoichiometric defects are two absorption initiations resulting to the laser-induced transformation.

  16. Influence of Different Substrates on Laser Induced Damage Thresholds at 1064 nm of Ta2O5 Films

    International Nuclear Information System (INIS)

    Cheng, Xu; Jian-Yong, Ma; Yun-Xia, Jin; Hong-Bo, He; Jian-Da, Shao; Zheng-Xiu, Fan

    2008-01-01

    Ta 2 O 5 films are prepared on Si, BK7, fused silica, antireflection (AR) and high reflector (HR) substrates by electron beam evaporation method, respectively. Both the optical property and laser induced damage thresholds (LIDTs) at 1064 nm of Ta 2 O 5 films on different substrates are investigated before and after annealing at 673K for 12 h. It is shown that annealing increases the refractive index and decreases the extinction index, and improves the O/Ta ratio of the Ta 2 O 5 films from 2.42 to 2.50. Moreover, the results show that the LIDTs of the Ta 2 O 5 films are mainly correlated with three parameters: substrate property, substoichiometry defect in the films and impurity defect at the interface between the substrate and the films. Details of the laser induced damage models in different cases are discussed

  17. Increasing the laser-induced damage threshold of single-crystal ZnGeP{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zawilski, Kevin T; Setzler, Scott D; Schunemann, Peter G; Pollak, Thomas M [BAE Systems, Advanced Systems and Technology, P.O. Box 868, MER15-1813, Nashua, New Hampshire 03061-0868 (United States)

    2006-11-15

    The laser-induced damage threshold (LIDT) of single-crystal zinc germanium phosphide (ZGP), ZnGeP{sub 2}, was increased to 2 J/cm{sup 2} at 2.05 {mu}m and a 10 kHz pulse rate frequency (double the previously measured value of 1 J/cm{sup 2}). This increased LIDT was achieved by improving the polishing of ZGP optical parametric oscillator crystals. Two different polishing techniques were evaluated. Surfaces were characterized using scanning white-light interferometry to determine rms surface roughness and sample flatness. The photon backscatter technique was used to determine the degree of surface and subsurface damage in the sample induced through the fabrication process. The effect of subsurface damage in the samples was studied by removing different amounts of material during polishing for otherwise identical samples. Statistical LIDT was measured using a high-average-power, repetitively Q-switched Tm,Ho:YLF 2.05 {mu}m pump laser. On average, lower surface roughness and photon backscatter measurements were a good indicator of ZGP samples exhibiting higher LIDT. The removal of more material during polishing significantly improved the LIDT of otherwise identical samples, indicating the importance of subsurface damage defects in the LIDT of ZGP.

  18. An Alternative Method of Evaluating 1540NM Exposure Laser Damage using an Optical Tissue Phantom

    National Research Council Canada - National Science Library

    Jindra, Nichole M; Figueroa, Manuel A; Rockwell, Benjamin A; Chavey, Lucas J; Zohner, Justin J

    2006-01-01

    An optical phantom was designed to physically and optically resemble human tissue, in an effort to provide an alternative for detecting visual damage resulting from inadvertent exposure to infrared lasers...

  19. Acrolein: An Effective Biomarker for Tissue Damage Produced from Polyamines.

    Science.gov (United States)

    Igarashi, Kazuei; Uemura, Takeshi; Kashiwagi, Keiko

    2018-01-01

    It is thought that the major factor responsible for cell damage is reactive oxygen species (ROS), but our recent studies have shown that acrolein (CH 2 =CH-CHO) produced from spermine and spermidine is more toxic than ROS. Thus, (1) the mechanism of acrolein production during brain stroke, (2) one of the mechanisms of acrolein toxicity, and (3) the role of glutathione in acrolein detoxification are described in this chapter.

  20. A decreased subchondral trabecular bone tissue elastic modulus is associated with pre-arthritic cartilage damage

    DEFF Research Database (Denmark)

    Day, J; Ding, Ming; van der Linden, JC

    2001-01-01

    determined using a combination of finite element models and mechanical testing. The bone tissue modulus was reduced by 60% in the medial condyle of the cases with cartilage damage compared to the control specimens. Neither the presence of cartilage damage nor the anatomic site (medial vs. lateral) affected...

  1. Using electrolyte leakage tests to determine lifting windows and detect tissue damage

    Science.gov (United States)

    Richard W. Tinus

    2002-01-01

    Physiological testing is rapidly coming into use as a means to determine the condition of nursery stock and predict how it will respond to treatment or use. One such test, the electrolyte leakage test, can be used to measure cold hardiness and detect tissue damage. The principle of this test is that when cell membranes are damaged, electrolytes leak out into the water...

  2. Probing multi-scale mechanical damage in connective tissues using X-ray diffraction.

    Science.gov (United States)

    Bianchi, Fabio; Hofmann, Felix; Smith, Andrew J; Thompson, Mark S

    2016-11-01

    The accumulation of microstructural collagen damage following repetitive loading is linked to painful and debilitating tendon injuries. As a hierarchical, semi-crystalline material, collagen mechanics can be studied using X-ray diffraction. The aim of the study was to describe multi-structural changes in tendon collagen following controlled plastic damage (5% permanent strain). We used small angle X-ray scattering (SAXS) to interrogate the spacing of collagen molecules within a fibril, and wide angle X-ray scattering (WAXS) to measure molecular strains under macroscopic loading. Simultaneous recordings of SAXS and WAXS patterns, together with whole-tissue strain in physiologically hydrated rat-tail tendons were made during increments of in situ tensile loading. Results showed that while tissue level modulus was unchanged, fibril modulus decreased significantly, and molecular modulus significantly increased. Further, analysis of higher order SAXS peaks suggested structural changes in the gap and overlap regions, possibly localising the damage to molecular cross-links. Our results provide new insight into the fundamental damage processes at work in collagenous tissues and point to new directions for their mitigation and repair. This article reports the first in situ loading synchrotron studies on mechanical damage in collagenous tissues. We provide new insight into the nano- and micro-structural mechanisms of damage processes. Pre-damaged tendons showed differential alteration of moduli at macro, micro and nano-scales as measured using X-ray scattering techniques. Detailed analysis of higher order diffraction peaks suggested damage is localised to molecular cross-links. The results are consistent with previous X-ray scattering studies of tendons and also with recent thermal stability studies on damaged material. Detailed understanding of damage mechanisms is essential in the development of new therapies promoting tissue repair. Copyright © 2016 Acta Materialia Inc

  3. Downregulation of Wip1 phosphatase modulates the cellular threshold of DNA damage signaling in mitosis

    Czech Academy of Sciences Publication Activity Database

    Macůrek, Libor; Benada, Jan; Müllers, E.; Halim, V.A.; Krejčíková, Kateřina; Burdová, Kamila; Pecháčková, Soňa; Hodný, Zdeněk; Lindqvist, A.; Medema, R.H.; Bartek, Jiří

    2013-01-01

    Roč. 12, č. 2 (2013), s. 251-262 ISSN 1538-4101 R&D Projects: GA ČR GPP305/10/P420; GA ČR GAP301/10/1525 Grant - others:Netherlands Genomic Initiative of NWO(NL) CGC; EK(XE) 259893 Institutional support: RVO:68378050 Keywords : DNA damage response * Wip1 phosphatase * cell cycle * mitotic progression * γH2AX Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.006, year: 2013

  4. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Science.gov (United States)

    Calvo, Jennifer A; Moroski-Erkul, Catherine A; Lake, Annabelle; Eichinger, Lindsey W; Shah, Dharini; Jhun, Iny; Limsirichai, Prajit; Bronson, Roderick T; Christiani, David C; Meira, Lisiane B; Samson, Leona D

    2013-04-01

    Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER) is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG) mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  5. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Directory of Open Access Journals (Sweden)

    Jennifer A Calvo

    2013-04-01

    Full Text Available Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  6. Effect of mechanical tissue properties on thermal damage in skin after IR-laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Frenz, M.; Romano, V.; Forrer, M.; Weber, H.P. (Inst. of Applied Physics, Bern Univ. (Switzerland)); Mischler, C.; Mueller, O.M. (Anatomical Inst., Bern Univ. (Switzerland))

    1991-04-01

    The damage created instantaneously in dorsal skin and in the subjacent skeletal muscle layer after CO{sub 2} and Er{sup 3+} laser incisions is histologically and ultrastructurally investigated. Light microscopical examinations show an up to three times larger damage zone in the subcutaneous layer of skeletal muscle than in the connective tissue above. The extent of thermally altered muscle tissue is classified by different zones and characterized by comparison to long time heating injuries. The unexpectedly large damage is a result of the change of elastic properties occurring abruptly at the transition between different materials. This leads to a discontinuity of the cutting dynamics that reduces the ejection of tissue material. We show that the degree of thermal damage originates from the amount of hot material that is not ejected out of the crater acting as a secondary heat source. (orig.).

  7. Oxidative DNA damage in lung tissue from patients with COPD is clustered in functionally significant sequences

    Directory of Open Access Journals (Sweden)

    Viktor M Pastukh

    2011-03-01

    Full Text Available Viktor M Pastukh1, Li Zhang2, Mykhaylo V Ruchko1, Olena Gorodnya1, Gina C Bardwell1, Rubin M Tuder2, Mark N Gillespie11Department of Pharmacology and Center for Lung Biology, University of South Alabama College of Medicine, Mobile, AL, USA; 2Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado at Denver, Aurora, CO, USAAbstract: Lung tissue from COPD patients displays oxidative DNA damage. The present study determined whether oxidative DNA damage was randomly distributed or whether it was localized in specific sequences in either the nuclear or mitochondrial genomes. The DNA damage-specific histone, gamma-H2AX, was detected immunohistochemically in alveolar wall cells in lung tissue from COPD patients but not control subjects. A PCR-based method was used to search for oxidized purine base products in selected 200 bp sequences in promoters and coding regions of the VEGF, TGF-β1, HO-1, Egr1, and β-actin genes while quantitative Southern blot analysis was used to detect oxidative damage to the mitochondrial genome in lung tissue from control subjects and COPD patients. Among the nuclear genes examined, oxidative damage was detected in only 1 sequence in lung tissue from COPD patients: the hypoxic response element (HRE of the VEGF promoter. The content of VEGF mRNA also was reduced in COPD lung tissue. Mitochondrial DNA content was unaltered in COPD lung tissue, but there was a substantial increase in mitochondrial DNA strand breaks and/or abasic sites. These findings show that oxidative DNA damage in COPD lungs is prominent in the HRE of the VEGF promoter and in the mitochondrial genome and raise the intriguing possibility that genome and sequence-specific oxidative DNA damage could contribute to transcriptional dysregulation and cell fate decisions in COPD.Keywords: DNA damage, VEGF hypoxic response element, mtDNA, COPD

  8. Level of damages and economical threshold, decisive aspects in the integrated management of plagues.

    Directory of Open Access Journals (Sweden)

    Rafael Meneses

    2011-03-01

    Full Text Available The establishment and application of economical levels demand a procedure to find with precision the insects population in a given moment. In the integrated management of plagues is not allowed the idea that any insect which is feeding from a part of plants requires a control action, that is why it is very important to determine the real effect that this insect population causes to the cultivation. Any decrease in the crop, constitutes a real waste of time; but when the economical level is defined, it is included an additional factor which is the measure cost of the plagues control. The determination of damages of levels is very important for economists, farming experts and specialists; while for producers is very significant its implementation with the objective to count with a sustainable and beneficial agriculture.

  9. Very high laser-damage threshold of polymer-derived Si(B)CN-carbon nanotube composite coatings.

    Science.gov (United States)

    Bhandavat, R; Feldman, A; Cromer, C; Lehman, J; Singh, G

    2013-04-10

    We study the laser irradiance behavior and resulting structural evolution of polymer-derived silicon-boron-carbonitride (Si(B)CN) functionalized multiwall carbon nanotube (MWCNT) composite spray coatings on copper substrate. We report a damage threshold value of 15 kWcm(-2) and an optical absorbance of 0.97 after irradiation. This is an order of magnitude improvement over MWCNT (1.4 kWcm(-2), 0.76), SWCNT (0.8 kWcm(-2), 0.65) and carbon paint (0.1 kWcm(-2), 0.87) coatings previously tested at 10.6 μm (2.5 kW CO2 laser) exposure. Electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy suggests partial oxidation of Si(B)CN forming a stable protective SiO2 phase upon irradiation.

  10. A 3D intestinal tissue model supports Clostridioides difficile germination, colonization, toxin production and epithelial damage.

    Science.gov (United States)

    Shaban, Lamyaa; Chen, Ying; Fasciano, Alyssa C; Lin, Yinan; Kaplan, David L; Kumamoto, Carol A; Mecsas, Joan

    2018-04-01

    Endospore-forming Clostridioides difficile is a causative agent of antibiotic-induced diarrhea, a major nosocomial infection. Studies of its interactions with mammalian tissues have been hampered by the fact that C. difficile requires anaerobic conditions to survive after spore germination. We recently developed a bioengineered 3D human intestinal tissue model and found that low O 2 conditions are produced in the lumen of these tissues. Here, we compared the ability of C. difficile spores to germinate, produce toxin and cause tissue damage in our bioengineered 3D tissue model versus in a 2D transwell model in which human cells form a polarized monolayer. 3D tissue models or 2D polarized monolayers on transwell filters were challenged with the non-toxin producing C. difficile CCUG 37787 serotype X (ATCC 43603) and the toxin producing UK1 C. difficile spores in the presence of the germinant, taurocholate. Spores germinated in both the 3D tissue model as well as the 2D transwell system, however toxin activity was significantly higher in the 3D tissue models compared to the 2D transwells. Moreover, the epithelium damage in the 3D tissue model was significantly more severe than in 2D transwells and damage correlated significantly with the level of toxin activity detected but not with the amount of germinated spores. Combined, these results show that the bioengineered 3D tissue model provides a powerful system with which to study early events leading to toxin production and tissue damage of C. difficile with mammalian cells under anaerobic conditions. Furthermore, these systems may be useful for examining the effects of microbiota, novel drugs and other potential therapeutics directed towards C. difficile infections. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Fractional sunburn threshold UVR doses generate equivalent vitamin D and DNA damage in skin types I-VI, but with epidermal DNA damage gradient correlated to skin darkness.

    Science.gov (United States)

    Shih, Barbara B; Farrar, Mark D; Cooke, Marcus S; Osman, Joanne; Langton, Abigail K; Kift, Richard; Webb, Ann R; Berry, Jacqueline L; Watson, Rachel E B; Vail, Andy; de Gruijl, Frank R; Rhodes, Lesley E

    2018-05-03

    Public health guidance recommends limiting sun-exposure to sub-sunburn levels, but it's unknown whether these can gain vitamin D (for musculoskeletal health) whilst avoiding epidermal DNA damage (initiates skin cancer). Well-characterised healthy humans of all skin types (I-VI; lightest to darkest skin) were exposed to a low dose-series of solar simulated UVR of 20-80% their individual sunburn threshold dose (minimal erythemal dose, MED). Significant UVR dose-responses were seen for serum 25(OH)D and whole epidermal CPD, with as little as 0.2 MED concurrently producing 25(OH)D and CPD. Notably, fractional MEDs generated equivalent levels of whole epidermal CPD and 25(OH)D across all skin types. Crucially, we demonstrated an epidermal gradient of CPD formation strongly correlated with skin darkness (r=0.74; Pskin types, ranging from darkest skin, where high CPD levels occurred superficially with none in the germinative basal layer, through to lightest skin where CPD were induced evenly across the epidermal depth. Darker skin people can be encouraged to utilise sub-sunburn UVR-exposure to enhance their vitamin D. In lighter skin people, basal cell damage occurs concurrent with vitamin D synthesis at exquisitely low UVR levels, providing an explanation for their high skin cancer incidence; greater caution is required. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Borate protection of softwood from Coptotermes acinaciformis (Isoptera: Rhinotermitidae) damage: variation in protection thresholds explained.

    Science.gov (United States)

    Peters, Brenton C; Fitzgerald, Christopher J

    2006-10-01

    Laboratory and field data reported in the literature are confusing with regard to "adequate" protection thresholds for borate timber preservatives. The confusion is compounded by differences in termite species, timber species and test methodology. Laboratory data indicate a borate retention of 0.5% mass/mass (m/m) boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 0.5% m/m BAE are required. We report two field experiments with varying amounts of untreated feeder material in which Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) responses to borate-treated radiata (Monterey) pine, Pinus radiata D. Don, were measured. The apparently conflicting results between laboratory and field data are explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, wood containing 0.5% BAE provided adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions were required. Furthermore, the retentions required increased with increased amounts of susceptible material present. Some termites, Nasutitermes sp. and Mastotermes darwiniensis Froggatt, for example, are borate-tolerant and borate timber preservatives are not a viable management option with these species. The lack of uniform standards for termite test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of timber preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed.

  13. Role of a critical visceral adipose tissue threshold (CVATT) in metabolic syndrome: implications for controlling dietary carbohydrates: a review

    OpenAIRE

    Freedland Eric S

    2004-01-01

    Abstract There are likely many scenarios and pathways that can lead to metabolic syndrome. This paper reviews mechanisms by which the accumulation of visceral adipose tissue (VAT) may contribute to the metabolic syndrome, and explores the paradigm of a critical VAT threshold (CVATT). Exceeding the CVATT may result in a number of metabolic disturbances such as insulin resistance to glucose uptake by cells. Metabolic profiles of patients with visceral obesity may substantially improve after onl...

  14. Strain-time cell death threshold for skeletal muscle in a tissue-engineered model system for deep tissue injury

    NARCIS (Netherlands)

    Gefen, A.; Nierop, van B.J.; Bader, D.L.; Oomens, C.W.J.

    2008-01-01

    Deep tissue injury (DTI) is a severe pressure ulcer that results from sustained deformation of muscle tissue overlying bony prominences. In order to understand the etiology of DTI, it is essential to determine the tolerance of muscle cells to large mechanical strains. In this study, a new

  15. Effect of temperature on surface error and laser damage threshold for self-healing BK7 glass.

    Science.gov (United States)

    Wang, Chu; Wang, Hongxiang; Shen, Lu; Hou, Jing; Xu, Qiao; Wang, Jian; Chen, Xianhua; Liu, Zhichao

    2018-03-20

    Cracks caused during the lapping and polishing process can decrease the laser-induced damage threshold (LIDT) of the BK7 glass optical elements, which would shorten the lifetime and limit the output power of the high-energy laser system. When BK7 glass is heated under appropriate conditions, the surface cracks can exhibit a self-healing phenomenon. In this paper, based on thermodynamics and viscous fluid mechanics theory, the mechanisms of crack self-healing are explained. The heat-healing experiment was carried out, and the effect of water was analyzed. The multi-spatial-frequency analysis was used to investigate the effect of temperature on surface error for self-healing BK7 glass, and the lapped BK7 glass specimens before and after heat healing were detected by an interferometer and atomic force microscopy. The low-spatial-frequency error was analyzed by peak to valley and root mean square, the mid-spatial-frequency error was analyzed by power spectral density, and the high-spatial-frequency error was analyzed by surface roughness. The results showed that the optimal heating temperature for BK7 was 450°C, and when the heating temperature was higher than the glass transition temperature (555°C), the surface quality decreased a lot. The laser damage test was performed, and the specimen heated at 450°C showed an improvement in LIDT.

  16. A tissue phantom for visualization and measurement of ultrasound-induced cavitation damage.

    Science.gov (United States)

    Maxwell, Adam D; Wang, Tzu-Yin; Yuan, Lingqian; Duryea, Alexander P; Xu, Zhen; Cain, Charles A

    2010-12-01

    Many ultrasound studies involve the use of tissue-mimicking materials to research phenomena in vitro and predict in vivo bioeffects. We have developed a tissue phantom to study cavitation-induced damage to tissue. The phantom consists of red blood cells suspended in an agarose hydrogel. The acoustic and mechanical properties of the gel phantom were found to be similar to soft tissue properties. The phantom's response to cavitation was evaluated using histotripsy. Histotripsy causes breakdown of tissue structures by the generation of controlled cavitation using short, focused, high-intensity ultrasound pulses. Histotripsy lesions were generated in the phantom and kidney tissue using a spherically focused 1-MHz transducer generating 15 cycle pulses, at a pulse repetition frequency of 100 Hz with a peak negative pressure of 14 MPa. Damage appeared clearly as increased optical transparency of the phantom due to rupture of individual red blood cells. The morphology of lesions generated in the phantom was very similar to that generated in kidney tissue at both macroscopic and cellular levels. Additionally, lesions in the phantom could be visualized as hypoechoic regions on a B-mode ultrasound image, similar to histotripsy lesions in tissue. High-speed imaging of the optically transparent phantom was used to show that damage coincides with the presence of cavitation. These results indicate that the phantom can accurately mimic the response of soft tissue to cavitation and provide a useful tool for studying damage induced by acoustic cavitation. Copyright © 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  17. Selenium and other trace metals in fish inhabiting a fly ash stream: Implications for regulatory tissue thresholds

    International Nuclear Information System (INIS)

    Reash, Robin J.; Lohner, Timothy W.; Wood, Kenneth V.

    2006-01-01

    Bluegill sunfish (Lepomis macrochirus) and caddis flies (Trichoptera: Hydropsychidae) were collected from a stream receiving fly ash discharge and nearby reference streams to determine tissue levels of selenium (Se) and other metals, and compare these levels to published 'no effect' thresholds. Stingy Run samples contained elevated levels of several metals. Mean Se concentrations in bullhead minnow whole body, bluegill whole body, bluegill ovary, and testes tissues were 44.6, 17.3, 32.5, and 37.1 μg/g (dry wt), respectively. These levels were 2-3 times higher than proposed toxic thresholds for fish whole body (7.9 μg/g) and ovary (17 μg/g). Although monitoring indicated a persistent bluegill population, some reproductive impairment may have occurred. Tissue residue data should be treated with caution because feral fish may accumulate several metals. In Stingy Run, persistence of a bluegill population may be explained by antagonistic interactions with other metals that were also elevated in the fish. - Bluegill sunfish inhabiting a coal fly ash receiving stream had elevated selenium levels in whole body and gonad tissue (9-10 times higher than reference fish), and antagonistic metal interactions may be one of several mechanisms allowing long-term persistence of the population

  18. Effect of laminaria japonica polysaccharides (LJP) on radiation damage of testis tissue in male rats

    International Nuclear Information System (INIS)

    Ren Shicheng; Luo Qiong; Yang Mingliang; Yang Jiajuan; Yan Jun; Li Zhuoneng; Wang Lihong; Cui Xiaoyan

    2007-01-01

    Objective: To observe the effect of laminaria japonica polysaccharides (LJP) on local radiation damage of testis tissue in male rats. Methods: The Wistar rats were randomly divided into 4 groups: the normal group, the model group, positive control group and LJP treatment group (50 mg·kg -1 ·d -1 ). LJP was applied to the treatment group for 10 d before local irradiation with γ-ray (6.0 Gy). The morphological change of the testis, organ index of testis and epididymides, sperm count, motility rate, superoxide dismutase (SOD) activity and malonic aldehyde (MDA) contents were measured. Results: LJP could make the damaged testis recover to near normal, elevate the organ index of testis and epididymides, promote the sperm count and motility rate, increase the activity of SOD and decrease the contents of MDA in testis tissue. Conclusions: LJP could inhibit testis tissue damage induced by local radiation, hence enhance the significant radioprotective effect to testis tissue. LJP has the conspicuous protective effect on radiation damage of testis tissue. (authors)

  19. Radiotherapy- and chemotherapy-induced normal tissue damage. The role of cytokines and adhesion molecules

    International Nuclear Information System (INIS)

    Plevova, P.

    2002-01-01

    Background. Ionising radiation and cytostatic agents used in cancer therapy exert damaging effects on normal tissues and induce a complex response at the cellular and molecular levels. Cytokines and adhesion molecules are involved in this response. Methods. Published data on the given topic have been reviewed. Results and conclusions. Various cytokines and adhesion molecules, including tumor necrosis factor α, interleukins- 1,-2,-4, and -6, interferon γ, granulocyte macrophage- and macrophage- colony stimulating factors, transforming growth factor β, platelet-derived growth factor, insulin-like growth factor I, fibroblast and epidermal growth factors, platelet-activating factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E- and P-selectins are involved in the response of normal tissues to ionizing radiation- and chemotherapy- induced normal tissues damage and are co-responsible for some side effects of these treatment modalities, including fever, anorexia and fatigue, suppression of hematopoiesis, both acute and late local tissue response. (author)

  20. Tissue repair in myxobacteria: A cooperative strategy to heal cellular damage.

    Science.gov (United States)

    Vassallo, Christopher N; Wall, Daniel

    2016-04-01

    Damage repair is a fundamental requirement of all life as organisms find themselves in challenging and fluctuating environments. In particular, damage to the barrier between an organism and its environment (e.g. skin, plasma membrane, bacterial cell envelope) is frequent because these organs/organelles directly interact with the external world. Here, we discuss the general strategies that bacteria use to cope with damage to their cell envelope and their repair limits. We then describe a novel damage-coping mechanism used by multicellular myxobacteria. We propose that cell-cell transfer of membrane material within a population serves as a wound-healing strategy and provide evidence for its utility. We suggest that--similar to how tissues in eukaryotes have evolved cooperative methods of damage repair--so too have some bacteria that live a multicellular lifestyle. © 2016 WILEY Periodicals, Inc.

  1. Effects of high repetition rate and beam size on hard tissue damage due to subpicosecond laser pulses

    International Nuclear Information System (INIS)

    Kim, Beop-Min; Feit, Michael D.; Rubenchik, Alexander M.; Joslin, Elizabeth J.; Eichler, Juergen; Stoller, Patrick C.; Da Silva, Luiz B.

    2000-01-01

    We report the effects of the repetition rate and the beam size on the threshold for ultrashort laser pulse induced damage in dentin. The observed results are explained as cumulative thermal effects. Our model is consistent with the experimental results and explains the dependence of the threshold on repetition rate, beam size, and exposure time. (c) 2000 American Institute of Physics

  2. Laser-induced damage threshold tests of ultrafast multilayer dielectric coatings in various environmental conditions relevant for operation of ELI beamlines laser systems

    Science.gov (United States)

    Ďurák, Michal; Velpula, Praveen Kumar; Kramer, Daniel; Cupal, Josef; Medřík, Tomáš; Hřebíček, Jan; Golasowski, Jiří; Peceli, Davorin; Kozlová, Michaela; Rus, Bedřich

    2017-01-01

    Increasing the laser-induced damage resistance of optical components is one of the major challenges in the development of Peta-watt (PW) class laser systems. The extreme light infrastructure (ELI) beamlines project will provide ultrafast laser systems with peak powers up to 10 PW available every minute and PW class beams at 10 Hz complemented by a 5-TW, 1-kHz beamline. Sustainable performance of PW class laser systems relies on the durability of the employed optical components. As part of an effort to evaluate the damage resistance of components utilized in ELI beamlines systems, damage thresholds of several optical multilayer dielectric coatings were measured with different laser parameters and in different environments. Three coatings were tested with 10 Hz and 1 kHz pulse repetition rates, and the effect of a cleaning treatment on their damage resistance was examined. To explore the damage threshold behavior at different vacuum levels, one coating was subject to tests at various residual gas pressures. No change of damage threshold in a high vacuum with respect to ambient pressure was recorded. The effect of the cleaning treatment was found to be inconsistent, suggesting that development of the optimal cleaning treatment for a given coating requires consideration of its specific properties.

  3. Comparison of tissue damage caused by various laser systems with tissue tolerable plasma by light and laser scan microscopy

    International Nuclear Information System (INIS)

    Vandersee, Staffan; Lademann, Jürgen; Richter, Heike; Patzelt, Alexa; Lange-Asschenfeldt, Bernhard

    2013-01-01

    Tissue tolerable plasma (TTP) represents a novel therapeutic method with promising capabilities in the field of dermatological interventions, in particular disinfection but also wound antisepsis and regeneration. The energy transfer by plasma into living tissue is not easily educible, as a variety of features such as the medium’s actual molecule-stream, the ions, electrons and free radicals involved, as well as the emission of ultraviolet, visible and infrared light contribute to its increasingly well characterized effects. Thus, relating possible adversary effects, especially of prolonged exposure to a single component of the plasma’s mode of action, is difficult. Until now, severe adverse events connected to plasma exposure have not been reported when conducted according to existing therapeutic protocols. In this study, we have compared the tissue damage-potential of CO 2 and dye lasers with TTP in a porcine model. After exposure of pig ear skin to the three treatment modalities, all specimens were examined histologically and by means of laser scan microscopy (LSM). Light microscopical tissue damage could only be shown in the case of the CO 2 laser, whereas dye laser and plasma treatment resulted in no detectable impairment of the specimens. In the case of TTP, LSM examination revealed only an impairment of the uppermost corneal layers of the skin, thus stressing its safety when used in vivo. (letter)

  4. The Sensitization Model to Explain How Chronic Pain Exists Without Tissue Damage

    NARCIS (Netherlands)

    van Wilgen, C. Paul; Keizer, Doeke

    The interaction of nurses with chronic pain patients is often difficult. One of the reasons is that chronic pain is difficult to explain, because no obvious anatomic defect or tissue damage is present. There is now enough evidence available indicating that chronic pain syndromes such as low back

  5. Stem Cell Therapy to Reduce Radiation-Induced Normal Tissue Damage

    NARCIS (Netherlands)

    Coppes, Rob P.; van der Goot, Annemieke; Lombaert, Isabelle M. A.

    Normal tissue damage after radiotherapy is still a major problem in cancer treatment. Stem cell therapy may provide a means to reduce radiation-induced side effects and improve the quality of life of patients. This review discusses the current status in stem cell research with respect to their

  6. Stem cell therapy for the treatment of radiation-induced normal tissue damage

    International Nuclear Information System (INIS)

    Chapel, A.; Benderitter, M.; Gourmelon, P.; Lataillade, J.J.; Gorin, N.C.

    2013-01-01

    Radiotherapy may induce irreversible damage on healthy tissues surrounding the tumour. In Europe, per year, 1.5 million patients undergo external radiotherapy. Acute adverse effect concern 80% of patients. The late adverse effect of radiotherapy concern 5 to 10% of them, which could be life threatening. Eradication of these manifestations is crucial. The French Institute of Radioprotection and Nuclear Safety (IRSN) contribute to understand effect of radiation on healthy tissue. IRSN is strongly implicated in the field of regeneration of healthy tissue after radiotherapy or radiological accident and in the clinical use of cell therapy in the treatment of irradiated patients. Our first success in cell therapy was the correction of deficient hematopoiesis in two patients. The intravenous injection of Mesenchymal Stem Cells (MSC) has restored bone marrow micro-environment after total body irradiation necessary to sustain hematopoiesis. Cutaneous radiation reactions play an important role in radiation accidents, but also as a limitation in radiotherapy and radio-oncology. We have evidenced for the first time, the efficiency of MSC therapy in the context of acute cutaneous and muscle damage following irradiation in five patients. Concerning the medical management of gastrointestinal disorder after irradiation, we have demonstrated the promising approach of the MSC treatment. We have shown that MSC migrate to damaged tissues and restore gut functions after radiation damage. The evaluation of stem cell therapy combining different sources of adult stem cells is under investigation

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

    DEFF Research Database (Denmark)

    Lewin, Peter A.; Jensen, Leif Bjørnø

    1981-01-01

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

  8. Synthesis, growth and characterization of o-phenylinediaminium benzilate: An SHG material with high laser damage threshold for NLO applications

    Science.gov (United States)

    Rajkumar, M.; Chandramohan, A.

    2017-02-01

    An organic molecular charge transfer complex salt, o-phenylenediaminium benzilate was synthesized and single crystals grown by slow solvent evaporation solution growth technique in methanol at ambient temperature. The grown crystal was subjected to Single crystal XRD analysis to establish the molecular structure. The molecular structure was further confirmed by 1H and 13C NMR spectral studies. The formation of the charge transfer complex salt was confirmed by UV-VIS spectroscopic technique. To identify the optical transmittance window and lower wavelength cut-off, the crystal was subjected to UV-Vis-NIR transmission spectral studies. The presence of various functional groups in the salt crystal was confirmed by FT-IR spectroscopic technique. Photoluminescence study was carried out to explore its efficiency towards device fabrications. The TG and DTA thermal analyses were simultaneously carried out to establish the thermal stability of the crystal. The dielectric studies of the grown crystal were executed at different temperatures as a function of frequency to investigate its electrical properties. The SHG efficiency of the crystal was determined using the modified Kurtz and Perry powder technique and its value was found to be 1.98 times that of the KDP crystal. Laser damage threshold value was measured using Nd:YAG laser. The mechanical stability of the title crystal was established employing Vickers micro hardness tester.

  9. Preparation of high laser-induced damage threshold Ta{sub 2}O{sub 5} films

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Cheng, E-mail: xucheng@cumt.edu.cn [School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Yi, Peng; Fan, Heliang; Qi, Jianwei; Yang, Shuai; Qiang, Yinghuai; Liu, Jiongtian [School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Li, Dawei [Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2014-08-01

    High laser-induced damage threshold (LIDT) Ta{sub 2}O{sub 5} films were prepared by the sol–gel method using TaCl{sub 5} as a new precursor. The optical properties, surface morphologies, chemical composition, absorption and LIDT of the films were investigated. The results showed that the transparent and homogenous Ta{sub 2}O{sub 5} films had small surface roughness, low absorption and high LIDT even with large number of layers. The maximum LIDT at 1064 nm and 12 ns of the films was 24.8 J/cm{sup 2}. The ion chromatograph and Fourier transform infrared spectrum were used to reveal the functions of the addition of H{sub 2}O{sub 2} in the sol formation. It was shown that H{sub 2}O{sub 2} had two important functions, which were the decrease of Cl element content and the rapid generation of tantalum oxide. The high LIDT achieved was mainly due to the nearly free of defects in the films.

  10. Improved laser damage threshold performance of calcium fluoride optical surfaces via Accelerated Neutral Atom Beam (ANAB) processing

    Science.gov (United States)

    Kirkpatrick, S.; Walsh, M.; Svrluga, R.; Thomas, M.

    2015-11-01

    Optics are not keeping up with the pace of laser advancements. The laser industry is rapidly increasing its power capabilities and reducing wavelengths which have exposed the optics as a weak link in lifetime failures for these advanced systems. Nanometer sized surface defects (scratches, pits, bumps and residual particles) on the surface of optics are a significant limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, magnesium fluoride, zinc sulfide, LBO and others presents a unique challenge for traditional polishing techniques. Exogenesis Corporation, using its new and proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and particle contamination leaving many material surfaces with roughness typically around one Angstrom. This surface defect mitigation via ANAB processing can be shown to increase performance properties of high intensity optical materials. This paper describes the ANAB technology and summarizes smoothing results for calcium fluoride laser windows. It further correlates laser damage threshold improvements with the smoothing produced by ANAB surface treatment. All ANAB processing was performed at Exogenesis Corporation using an nAccel100TM Accelerated Particle Beam processing tool. All surface measurement data for the paper was produced via AFM analysis on a Park Model XE70 AFM, and all laser damage testing was performed at Spica Technologies, Inc. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply mechanical forces associated with traditional polishing techniques. ANAB efficiently removes surface

  11. The role of tissue damage in whiplash associated disorders: Discussion paper 1

    Science.gov (United States)

    Bogduk, Nikolai; Ivancic, Paul C.; McLean, Samuel A.; Siegmund, Gunter P.; Winkelstein, Beth

    2011-01-01

    STUDY DESIGN Non-systematic review of cervical spine lesions in whiplash-associated disorders (WAD). OBJECTIVE To describe whiplash injury models in terms of basic and clinical science, to summarize what can and cannot be explained by injury models, and to highlight future research areas to better understand the role of tissue damage in WAD. SUMMARY OF BACKGROUND DATA The frequent lack of detectable tissue damage has raised questions about whether tissue damage is necessary for WAD and what role it plays in the clinical context of WAD. METHODS Non-systematic review. RESULTS Lesions of various tissues have been documented by numerous investigations conducted in animals, cadavers, healthy volunteers and patients. Most lesions are undetected by imaging techniques. For zygapophysial (facet) joints, lesions have been predicted by bioengineering studies and validated through animal studies; for zygapophysial joint pain, a valid diagnostic test and a proven treatment are available. Lesions of dorsal root ganglia, discs, ligaments, muscles and vertebral artery have been documented in biomechanical and autopsy studies, but no valid diagnostic test is available to assess their clinical relevance. The proportion of WAD patients in whom a persistent lesion is the major determinant of ongoing symptoms is unknown. Psychosocial factors, stress reactions and generalized hyperalgesia have also been shown to predict WAD outcomes. CONCLUSION There is evidence supporting a lesion-based model in WAD. Lack of macroscopically identifiable tissue damage does not rule out the presence of painful lesions. The best available evidence concerns zygapophysial joint pain. The clinical relevance of other lesions needs to be addressed by future research. PMID:22020601

  12. Laser treatment of female stress urinary incontinence: optical, thermal, and tissue damage simulations

    Science.gov (United States)

    Hardy, Luke A.; Chang, Chun-Hung; Myers, Erinn M.; Kennelly, Michael J.; Fried, Nathaniel M.

    2016-02-01

    Treatment of female stress urinary incontinence (SUI) by laser thermal remodeling of subsurface tissues is studied. Light transport, heat transfer, and thermal damage simulations were performed for transvaginal and transurethral methods. Monte Carlo (MC) provided absorbed photon distributions in tissue layers (vaginal wall, endopelvic fascia, urethral wall). Optical properties (n,μa,μs,g) were assigned to each tissue at λ=1064 nm. A 5-mm-diameter laser beam and power of 5 W for 15 s was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for ANSYS finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact cooling probe set at 0 °C. Thermal properties (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (Ea,A) were used to compute Arrhenius sums. For the transvaginal approach, 37% of energy was absorbed in endopelvic fascia layer with 0.8% deposited beyond it. Peak temperature was 71°C, treatment zone was 0.8-mm-diameter, and almost all of 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond it. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and only 0.6 mm of 2.4-mm-thick urethral wall was preserved. A transvaginal approach is more feasible than transurethral approach for laser treatment of SUI.

  13. Linking ontogeny and tissue regeneration: a study on tissue damage and wound healing in carp in connection to the developmental stage

    DEFF Research Database (Denmark)

    Nielsen, Michael Engelbrecht; Schmidt, Jacob; Ingerslev, Hans-Christian

    regeneration since its genome is well-described and it is easy visually to follow the wound healing. In this study, carps were physically damaged in the musculature using sterile needles at day 10, 16, 24, 47 and 94 post hatch. Muscle tissue samples were subsequently taken at day 1, 3 and 7 post damage...... healing and tissue regeneration, the developmental stage of the individual may influence the immune reaction initiated following damage and thus the proliferative responses, which usually cross-talk with the immune system. Common carp (Cyprinus carpio) is an excellent fish specie to study tissue...

  14. Contribution Of Brain Tissue Oxidative Damage In Hypothyroidism-associated Learning and Memory Impairments

    Directory of Open Access Journals (Sweden)

    Yousef Baghcheghi

    2017-01-01

    Full Text Available The brain is a critical target organ for thyroid hormones, and modifications in memory and cognition happen with thyroid dysfunction. The exact mechanisms underlying learning and memory impairments due to hypothyroidism have not been understood yet. Therefore, this review was aimed to compress the results of previous studies which have examined the contribution of brain tissues oxidative damage in hypothyroidism-associated learning and memory impairments.

  15. The influence of parotid gland sparing on radiation damages of dental hard tissues.

    Science.gov (United States)

    Hey, Jeremias; Seidel, Johannes; Schweyen, Ramona; Paelecke-Habermann, Yvonne; Vordermark, Dirk; Gernhardt, Christian; Kuhnt, Thomas

    2013-07-01

    The aim of the present study was to evaluate whether radiation damage on dental hard tissue depends on the mean irradiation dose the spared parotid gland is subjected to or on stimulated whole salivary flow rate. Between June 2002 and October 2008, 70 patients with neck and cancer curatively irradiated were included in this study. All patients underwent dental treatment referring to the guidelines and recommendations of the German Society of Dental, Oral and Craniomandibular Sciences prior, during, and after radiotherapy (RT). During the follow-up period of 24 months, damages on dental hard tissues were classified according to the RTOG/EORTC guidelines. The mean doses (D(mean)) during spared parotid gland RT were determined. Stimulated whole saliva secretion flow rates (SFR) were measured before RT and 1, 6, 12, 24 months after RT. Thirty patients showed no carious lesions (group A), 18 patients developed sporadic carious lesions (group B), and 22 patients developed general carious lesions (group C). Group A patients received a D mean of 21.2 ± 11.04 Gy. Group B patients received a D(mean) of 26.5 ± 11.59 Gy and group C patients received a D(mean) of 33.9 ± 9.93 Gy, respectively. The D(mean) of group A was significantly lower than the D(mean) of group C (p dental hard tissue correlates with increased mean irradiation doses as well as decreased salivary flow rates. Parotid gland sparing resulting in a dose below 20 Gy reduces radiation damage on dental hard tissues, and therefore, the dose may act as a predictor for the damage to be expected.

  16. Piezosurgery prevents brain tissue damage: an experimental study on a new rat model

    Czech Academy of Sciences Publication Activity Database

    Pavlíková, G.; Foltán, R.; Burian, M.; Horká, E.; Adámek, S.; Hejčl, Aleš; Hanzelka, T.; Šedý, Jiří

    2011-01-01

    Roč. 40, č. 8 (2011), s. 840-844 ISSN 0901-5027 R&D Projects: GA MŠk(CZ) LC554; GA ČR GAP304/10/0320 Grant - others:GA MŠk(CZ) 1M0538 Program:1M Institutional research plan: CEZ:AV0Z50390703 Keywords : piezosurgery * brain * tissue damage Subject RIV: FJ - Surgery incl. Transplants; FH - Neurology (UEM-P) Impact factor: 1.506, year: 2011

  17. Comparison of renal artery, soft tissue, and nerve damage after irrigated versus nonirrigated radiofrequency ablation.

    Science.gov (United States)

    Sakakura, Kenichi; Ladich, Elena; Fuimaono, Kristine; Grunewald, Debby; O'Fallon, Patrick; Spognardi, Anna-Maria; Markham, Peter; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Shen, Kai; Kolodgie, Frank D; Joner, Michael; Virmani, Renu

    2015-01-01

    The long-term efficacy of radiofrequency ablation of renal autonomic nerves has been proven in nonrandomized studies. However, long-term safety of the renal artery (RA) is of concern. The aim of our study was to determine if cooling during radiofrequency ablation preserved the RA while allowing equivalent nerve damage. A total of 9 swine (18 RAs) were included, and allocated to irrigated radiofrequency (n=6 RAs, temperature setting: 50°C), conventional radiofrequency (n=6 RAs, nonirrigated, temperature setting: 65°C), and high-temperature radiofrequency (n=6 RAs, nonirrigated, temperature setting: 90°C) groups. RAs were harvested at 10 days, serially sectioned from proximal to distal including perirenal tissues and examined after paraffin embedding, and staining with hematoxylin-eosin and Movat pentachrome. RAs and periarterial tissue including nerves were semiquantitatively assessed and scored. A total of 660 histological sections from 18 RAs were histologically examined by light microscopy. Arterial medial injury was significantly less in the irrigated radiofrequency group (depth of medial injury, circumferential involvement, and thinning) than that in the conventional radiofrequency group (Pradiofrequency group (Pradiofrequency group and conventional radiofrequency group (P=0.36), there was a trend toward less nerve damage in the irrigated compared with conventional. Compared to conventional radiofrequency, circumferential medial damage in highest-temperature nonirrigated radiofrequency group was significantly greater (Pradiofrequency ablation, and there is a trend toward less nerve damage. © 2014 American Heart Association, Inc.

  18. The Cell Nucleus Serves as a Mechanotransducer of Tissue Damage-Induced Inflammation.

    Science.gov (United States)

    Enyedi, Balázs; Jelcic, Mark; Niethammer, Philipp

    2016-05-19

    Tissue damage activates cytosolic phospholipase A2 (cPLA2), releasing arachidonic acid (AA), which is oxidized to proinflammatory eicosanoids by 5-lipoxygenase (5-LOX) on the nuclear envelope. How tissue damage is sensed to activate cPLA2 is unknown. We investigated this by live imaging in wounded zebrafish larvae, where damage of the fin tissue causes osmotic cell swelling at the wound margin and the generation of a chemotactic eicosanoid signal. Osmotic swelling of cells and their nuclei activates cPla2 by translocating it from the nucleoplasm to the nuclear envelope. Elevated cytosolic Ca(2+) was necessary but not sufficient for cPla2 translocation, and nuclear swelling was required in parallel. cPla2 translocation upon nuclear swelling was reconstituted in isolated nuclei and appears to be a simple physical process mediated by tension in the nuclear envelope. Our data suggest that the nucleus plays a mechanosensory role in inflammation by transducing cell swelling and lysis into proinflammatory eicosanoid signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Oxidative damage induced by cigarette smoke exposure in mice: impact on lung tissue and diaphragm muscle,

    Directory of Open Access Journals (Sweden)

    Samanta Portão de Carlos

    2014-08-01

    Full Text Available OBJECTIVE: To evaluate oxidative damage (lipid oxidation, protein oxidation, thiobarbituric acid-reactive substances [TBARS], and carbonylation and inflammation (expression of phosphorylated AMP-activated protein kinase and mammalian target of rapamycin [p-AMPK and p-mTOR, respectively] in the lung parenchyma and diaphragm muscles of male C57BL-6 mice exposed to cigarette smoke (CS for 7, 15, 30, 45, or 60 days. METHODS: Thirty-six male C57BL-6 mice were divided into six groups (n = 6/group: a control group; and five groups exposed to CS for 7, 15, 30, 45, and 60 days, respectively. RESULTS: Compared with control mice, CS-exposed mice presented lower body weights at 30 days. In CS-exposed mice (compared with control mice, the greatest differences (increases in TBARS levels were observed on day 7 in diaphragm-muscle, compared with day 45 in lung tissue; the greatest differences (increases in carbonyl levels were observed on day 7 in both tissue types; and sulfhydryl levels were lower, in both tissue types, at all time points. In lung tissue and diaphragm muscle, p-AMPK expression exhibited behavior similar to that of TBARS. Expression of p-mTOR was higher than the control value on days 7 and 15 in lung tissue, as it was on day 45 in diaphragm muscle. CONCLUSION: Our data demonstrate that CS exposure produces oxidative damage, not only in lung tissue but also (primarily in muscle tissue, having an additional effect on respiratory muscle, as is frequently observed in smokers with COPD.

  20. High and Low LET Radiation Differentially Induce Normal Tissue Damage Signals

    International Nuclear Information System (INIS)

    Niemantsverdriet, Maarten; Goethem, Marc-Jan van; Bron, Reinier; Hogewerf, Wytse; Brandenburg, Sytze; Langendijk, Johannes A.; Luijk, Peter van; Coppes, Robert P.

    2012-01-01

    Purpose: Radiotherapy using high linear energy transfer (LET) radiation is aimed at efficiently killing tumor cells while minimizing dose (biological effective) to normal tissues to prevent toxicity. It is well established that high LET radiation results in lower cell survival per absorbed dose than low LET radiation. However, whether various mechanisms involved in the development of normal tissue damage may be regulated differentially is not known. Therefore the aim of this study was to investigate whether two actions related to normal tissue toxicity, p53-induced apoptosis and expression of the profibrotic gene PAI-1 (plasminogen activator inhibitor 1), are differentially induced by high and low LET radiation. Methods and Materials: Cells were irradiated with high LET carbon ions or low LET photons. Cell survival assays were performed, profibrotic PAI-1 expression was monitored by quantitative polymerase chain reaction, and apoptosis was assayed by annexin V staining. Activation of p53 by phosphorylation at serine 315 and serine 37 was monitored by Western blotting. Transfections of plasmids expressing p53 mutated at serines 315 and 37 were used to test the requirement of these residues for apoptosis and expression of PAI-1. Results: As expected, cell survival was lower and induction of apoptosis was higher in high -LET irradiated cells. Interestingly, induction of the profibrotic PAI-1 gene was similar with high and low LET radiation. In agreement with this finding, phosphorylation of p53 at serine 315 involved in PAI-1 expression was similar with high and low LET radiation, whereas phosphorylation of p53 at serine 37, involved in apoptosis induction, was much higher after high LET irradiation. Conclusions: Our results indicate that diverse mechanisms involved in the development of normal tissue damage may be differentially affected by high and low LET radiation. This may have consequences for the development and manifestation of normal tissue damage.

  1. Cell kinetical aspect of normal tissue damages in relation to radiosensitivity of cells, especially from the points of LQ model

    International Nuclear Information System (INIS)

    Tsubouchi, Susumu; Oohara, Hiroshi.

    1989-01-01

    Several points on the early and late radiation induced-normal tissue damages in terms of LQ model in multifractionation experiments of isoeffect were discussed from two fractors, (1) dose-responses of cell survivals or of tissue damages and (2) principles of the model. Application of the model to the both early and late tissue damages was fairly difficult in several tissues and several experimental conditions. In early damages, cell survival curve of single irradiation did not always fit to LQ model and further more incomlete repair as well as repopulation in multifractionation experiment contradicted the model especially in low dose fractionation. In late damages, the damages themselves did not express directly cell survival but probably indicate the degree of functional cell damage at the level of 10 -1 . As most isoeffects in early damages were taken at the level of 10 -3 , the comparison of two results from early and late tissue damages indicated the lack of coordinations both conceptionally and experimentally. (author)

  2. LYCOPENE EFFICIENCY IN THE MODULATION OF OXIDATIVE DAMAGE IN DIFFERENT TISSUES OF GAMMA IRRADIATED RATS

    International Nuclear Information System (INIS)

    EL-TAHAWY, N.A.; NADA, A.S.; REZK, R.G.

    2008-01-01

    Exposure to ionizing radiation induces oxidative stress that has been recognized as an important etiological factor in the causation of several chronic diseases. Lycopene, a carotenoid almost exclusively present in tomatoes and tomatoes products, is a lipid soluble antioxidant claimed to possess cardio protective and anticancer properties. The present study was designed to determine the possible modulator effects of lycopene on radiation-induced oxidative damage to liver, spleen and lung tissues. Animals were supplemented with lycopene (5 mg/kg body weight/ day) by gavages for two weeks before whole body exposure to gamma rays and within the period of irradiation (3 successive doses, each of 3 Gy at 72 hours intervals). Animals were sacrificed on the 3 r d day post the last irradiation session.The results obtained in the present study showed that whole body gamma irradiation produced oxidative stress manifested by significant elevation in lipid peroxides levels measured as thiobarbituric acid reactive substances (TBARS) associated with significant decrease of nitric oxide (NO) content. Non-significant change in total cupper (Cu) in the three tissues was recorded while significant increase of total iron (Fe) was observed in liver and spleen tissues only. Liver tissue of irradiated rats showed significant decrease in the activities of the antioxidant enzymes as superoxide dismutase (SOD) and catalase (CAT). In spleen tissues, there was a significant increase of SOD and significant decrease of CAT activities while in lung tissues, both SOD and CAT activities showed significant increase.Histological observations of photomicrograph of liver sections showed that radiation-induced sever damage obvious by dilated portal vein, ruptured hepatocytes, necrotic, pyknotic, karyolitic nuclei and vacuolated cytoplasm. In spleen tissue, radiation was induced degeneration of lymphatic nodules, dilation follicular artery and marked hemorrhage. In lung tissue, radiation- induces ill

  3. Protective Effect of Pyruvate Against Radiation-Induced Damage in Collagenized Tissues

    Science.gov (United States)

    Griko, Y. V.; Yan, Xiaoli

    2016-01-01

    Exposure to high doses of ionizing radiation produces both acute and late effects on the collagenized tissues and have profound effects on wound healing. Because of the crucial practical importance for new radioprotective agents, our study has been focused on evaluation of the efficacy of non-toxic naturally occurring compounds to protect tissue integrity against high-dose gamma radiation. Here, we demonstrate that molecular integrity of collagen may serve as a sensitive biological marker for quantitative evaluation of molecular damage to collagenized tissue and efficacy of radioprotective agents. Increasing doses of gamma radiation (0-50kGy) result in progressive destruction of the native collagen fibrils, which provide a structural framework, strength, and proper milieu for the regenerating tissue. The strategy used in this study involved the thermodynamic specification of all structural changes in collagenized matrix of skin, aortic heart valve, and bone tissue induced by different doses and conditions of g-irradiation. This study describes a simple biophysical approach utilizing the Differential Scanning Calorimetry (DSC) to characterize the structural resistance of the aortic valve matrix exposed to different doses of g-irradiation. It allows us to identify the specific response of each constituent as well as to determine the influence of the different treatments on the characteristic parameters of protein structure. We found that pyruvate, a substance that naturally occurs in the body, provide significant protection (up to 80%) from biochemical and biomechanical damage to the collagenized tissue through the effective targeting of reactive oxygen species. The recently discovered role of pyruvate in the cell antioxidant defense to O2 oxidation, and its essential constituency in the daily human diet, indicate that the administration of pyruvate-based radioprotective formulations may provide safe and effective protection from deleterious effects of ionizing

  4. Hypersensitivity to DNA-damaging agents in primary degenerations of excitable tissue

    International Nuclear Information System (INIS)

    Robbins, J.H.

    1983-01-01

    Defects in DNA-repair mechanisms render xeroderma pigmentosum cells hypersensitive to killing by the uv-type of DNA-damaging agent. Some xeroderma pigmentosum patients develop a primary neuronal degeneration, and cell lines from patients with the earliest onset of neurodegeneration are the most sensitive to killing by uv radiation. These findings led to the neuronal DNA integrity theory which holds that when the integrity of neuronal DNA is destroyed by the accumulation of unrepaired DNA damaged spontaneously or by endogenous metabolites, the neurons will undergo a primary degeneration. Cells from patients with Cockayne syndrome, a demyelinating disorder with a primary retinal degeneration, are also hypersensitive to the uv-type of DNA-damaging agent. Cells from patients with the primary neuronal degeneration of ataxia telangiectasia are hypersensitive to the x-ray-type of DNA-damaging agent. Cells from other patients with primary degeneration of excitable tissue also have hypersensitivity to the x-ray-type of DNA-damaging agent. These disorders include (1) primary neuronal degenerations which are either genetic (e.g., Huntington disease, familial dysautonomia, Friedreich ataxia) or sporadic (e.g., Alzheimer disease, Parkinson disease), (2) primary muscle degenerations (e.g., Duchenne muscular dystrophy), and (3) a primary retinal degeneration (Usher syndrome). Death of excitable tissue in vivo in these radiosensitive diseases may result from unrepaired DNA. This hypersensitivity provides the basis for developing suitable presymptomatic and prenatal tests for these diseases, for elucidating their pathogenesis, and for developing future therapies. 119 references, 3 figures, 3 tables

  5. Relative binding affinity of carboxylate-, phosphonate-, and bisphosphonate-functionalized gold nanoparticles targeted to damaged bone tissue

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Ryan D. [Rush University Medical Center, Department of Anatomy and Cell Biology (United States); Cole, Lisa E.; Roeder, Ryan K., E-mail: rroeder@nd.edu [University of Notre Dame, Department of Aerospace and Mechanical Engineering Bioengineering Graduate Program (United States)

    2012-10-15

    Functionalized Au NPs have received considerable recent interest for targeting and labeling cells and tissues. Damaged bone tissue can be targeted by functionalizing Au NPs with molecules exhibiting affinity for calcium. Therefore, the relative binding affinity of Au NPs surface functionalized with either carboxylate (l-glutamic acid), phosphonate (2-aminoethylphosphonic acid), or bisphosphonate (alendronate) was investigated for targeted labeling of damaged bone tissue in vitro. Targeted labeling of damaged bone tissue was qualitatively verified by visual observation and backscattered electron microscopy, and quantitatively measured by the surface density of Au NPs using field-emission scanning electron microscopy. The surface density of functionalized Au NPs was significantly greater within damaged tissue compared to undamaged tissue for each functional group. Bisphosphonate-functionalized Au NPs exhibited a greater surface density labeling damaged tissue compared to glutamic acid- and phosphonic acid-functionalized Au NPs, which was consistent with the results of previous work comparing the binding affinity of the same functionalized Au NPs to synthetic hydroxyapatite crystals. Targeted labeling was enabled not only by the functional groups but also by the colloidal stability in solution. Functionalized Au NPs were stabilized by the presence of the functional groups, and were shown to remain well dispersed in ionic (phosphate buffered saline) and serum (fetal bovine serum) solutions for up to 1 week. Therefore, the results of this study suggest that bisphosphonate-functionalized Au NPs have potential for targeted delivery to damaged bone tissue in vitro and provide motivation for in vivo investigation.

  6. Determination of ultra-short laser induced damage threshold of KH{sub 2}PO{sub 4} crystal: Numerical calculation and experimental verification

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jian [Center for Precision Engineering, School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210 (United States); Chen, Mingjun, E-mail: chenmj@hit.edu.cn, E-mail: chowdhury.24@osu.edu; Wang, Jinghe; Xiao, Yong [Center for Precision Engineering, School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Kafka, Kyle; Austin, Drake; Chowdhury, Enam, E-mail: chenmj@hit.edu.cn, E-mail: chowdhury.24@osu.edu [Department of Physics, The Ohio State University, 191 W. Woodruff Ave, Columbus, OH 43210 (United States)

    2016-03-15

    Rapid growth and ultra-precision machining of large-size KDP (KH{sub 2}PO{sub 4}) crystals with high laser damage resistance are tough challenges in the development of large laser systems. It is of high interest and practical significance to have theoretical models for scientists and manufacturers to determine the laser-induced damage threshold (LIDT) of actually prepared KDP optics. Here, we numerically and experimentally investigate the laser-induced damage on KDP crystals in ultra-short pulse laser regime. On basis of the rate equation for free electron generation, a model dedicated to predicting the LIDT is developed by considering the synergistic effect of photoionization, impact ionization and decay of electrons. Laser damage tests are performed to measure the single-pulse LIDT with several testing protocols. The testing results combined with previously reported experimental data agree well with those calculated by the model. By taking the light intensification into consideration, the model is successfully applied to quantitatively evaluate the effect of surface flaws inevitably introduced in the preparation processes on the laser damage resistance of KDP crystals. This work can not only contribute to further understanding of the laser damage mechanisms of optical materials, but also provide available models for evaluating the laser damage resistance of exquisitely prepared optical components used in high power laser systems.

  7. Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

    International Nuclear Information System (INIS)

    Xi Xiao-Wen; Chai Chang-Chun; Liu Yang; Yang Yin-Tang; Fan Qing-Yang; Shi Chun-Lei

    2016-01-01

    An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. (paper)

  8. Gastric Tissue Damage Analysis Generated by Ischemia: Bioimpedance, Confocal Endomicroscopy, and Light Microscopy

    Directory of Open Access Journals (Sweden)

    Nohra E. Beltran

    2013-01-01

    Full Text Available The gastric mucosa ischemic tissular damage plays an important role in critical care patients’ outcome, because it is the first damaged tissue by compensatory mechanism during shock. The aim of the study is to relate bioimpedance changes with tissular damage level generated by ischemia by means of confocal endomicroscopy and light microscopy. Bioimpedance of the gastric mucosa and confocal images were obtained from Wistar male rats during basal and ischemia conditions. They were anesthetized, and stain was applied (fluorescein and/or acriflavine. The impedance spectroscopy catheter was inserted and then confocal endomicroscopy probe. After basal measurements and biopsy, hepatic and gastric arteries clamping induced ischemia. Finally, pyloric antrum tissue was preserved in buffered formaldehyde (10% for histology processing using light microscopy. Confocal images were equalized, binarized, and boundary defined, and infiltrations were quantified. Impedance and infiltrations increased with ischemia showing significant changes between basal and ischemia conditions (. Light microscopy analysis allows detection of general alterations in cellular and tissular integrity, confirming gastric reactance and confocal images quantification increments obtained during ischemia.

  9. Effect of propolis feeding on rat tissues damaged by X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Hoon; Seo, Eul Won [Andong National Univ., Andong (Korea, Republic of); Ji, Tae Jeong [Kaya Univ., Goryeong (Korea, Republic of)

    2007-06-15

    Present study aimed to investigate the radioprotective effects of propolis feeding on rat tissues damaged by X-ray irradiation. It was shown that the number of white blood cell in X-ray irradiated group supplemented with propolis increased as much to those of the control group and also the GOT activities among the blood components were decreased after propolis feeding. The mineral contents such as Mg, Fe, Ca, Mn, Cu, Mo, Ni, As in liver were increased as compared with those of the control group but maintained lower level than those of only irradiated groups, implying that the propolis feeding elevated the recovery capability of white blood cell effectively and propolis have a potential resistance to cell damage by X-ray. According to histological observations of the testis, intestine and liver tissues which are irradiated after feeding propolis, the numbers of damaged undifferentiated cells were decreased in testis and the shape of the goblet cells and inner and outer muscular layers in intestine were restored to the original state and the hepatocytes and interlobular veins were shown intact in liver, suggesting that propolis has a potential capacity to restore cell shapes or resist deformation of cell.

  10. Genipin crosslinker releasing sutures for improving the mechanical/repair strength of damaged connective tissue.

    Science.gov (United States)

    Sundararaj, Sharath; Slusarewicz, Paul; Brown, Matt; Hedman, Thomas

    2017-11-01

    The most common mode of surgical repair of ruptured tendons and ligaments involves the use of sutures for reattachment. However, there is a high incidence of rerupture and repair failure due to pulling out of the suture material from the damaged connective tissue. The main goal of this research was to achieve a localized delivery of crosslinking agent genipin (GP) from rapid-release biodegradable coatings on sutures, for strengthening the repair of ruptured connective tissue. Our hypothesis is that GP released from the suture coating will lead to exogenous crosslinking of native connective tissue resulting in beneficial effects on clinically relevant mechanical parameters such as tear resistance, tissue strength, and energy required to rupture the tissue (toughness). Sutures were successfully coated with a biodegradable polymer layer loaded with the crosslinking agent genipin, without compromising the mechanical properties of the suture. The rapid-release of genipin was achieved under both in vitro and ex vivo conditions. Exogenous crosslinking using these genipin releasing sutures was demonstrated using equine tendons. The tendons treated with genipin releasing sutures showed significant improvement in failure load, energy required for pull-out failure, and stiffness. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2199-2205, 2017. © 2016 Wiley Periodicals, Inc.

  11. The number of bleaching sessions influences pulp tissue damage in rat teeth.

    Science.gov (United States)

    Cintra, Luciano Tavares Angelo; Benetti, Francine; da Silva Facundo, Aguinaldo Cândido; Ferreira, Luciana Louzada; Gomes-Filho, João Eduardo; Ervolino, Edilson; Rahal, Vanessa; Briso, André Luiz Fraga

    2013-12-01

    Hydrogen peroxide tooth bleaching is claimed to cause alterations in dental tissue structures. This study investigated the influence of the number of bleaching sessions on pulp tissue in rats. Male Wistar rats were studied in 5 groups (groups 1S-5S) of 10 each, which differed by the number (1-5) of bleaching sessions. In each session, the animals were anesthetized, and 35% hydrogen peroxide gel was applied to 3 upper right molars. Two days after the experimental period, the animals were killed, and their jaws were processed for light microscope evaluation. Pulp tissue reactions were scored as follows: 1, no or few inflammatory cells and no reaction; 2, session, necrotic tissue in the pulp horns and underlying inflammatory changes were observed. The extent and intensity of these changes increased with the number of bleaching sessions. After 5 sessions, the changes included necrotic areas in the pulp tissue involving the second third of the radicular pulp and intense inflammation in the apical third. The number of bleaching sessions directly influenced the extent of pulp damage. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Bisphenol A induces oxidative stress and DNA damage in hepatic tissue of female rat offspring

    Directory of Open Access Journals (Sweden)

    Jehane I. Eid

    2015-08-01

    Full Text Available Bisphenol A (BPA is an endocrine disrupting compound widely spread in our living environment. It is a contaminant with increasing exposure to it and exerts both toxic and estrogenic effects on mammalian cells. Due to the limited information concerning the effect of BPA on the liver, the present study was designed to assess hepatic tissue injury induced by early life exposure to BPA in female rat offspring. Rat dams (n = 9 were gavaged with 0.5 and 50 mg of BPA/kg b.w./day throughout lactation until weaning. The sham group received olive oil for the same duration while the control group did not receive any injection. The liver tissue was collected from female pups at different pubertal periods (PND50, 90 and 110 to evaluate oxidative stress biomarkers, extent of DNA damage and histopathological changes. Our results indicated that early life exposure to BPA significantly increased oxidative/nitrosative stress, decreased antioxidant enzyme activities, induced DNA damage and chronic severe inflammation in the hepatic tissue in a time dependent manner. These data suggested that BPA causes long-term adverse effects on the liver, which leads to deleterious effects in the liver of female rat offspring.

  13. DNA damage in preserved specimens and tissue samples: a molecular assessment

    Directory of Open Access Journals (Sweden)

    Cantin Elizabeth

    2008-10-01

    Full Text Available Abstract The extraction of genetic information from preserved tissue samples or museum specimens is a fundamental component of many fields of research, including the Barcode of Life initiative, forensic investigations, biological studies using scat sample analysis, and cancer research utilizing formaldehyde-fixed, paraffin-embedded tissue. Efforts to obtain genetic information from these sources are often hampered by an inability to amplify the desired DNA as a consequence of DNA damage. Previous studies have described techniques for improved DNA extraction from such samples or focused on the effect of damaging agents – such as light, oxygen or formaldehyde – on free nucleotides. We present ongoing work to characterize lesions in DNA samples extracted from preserved specimens. The extracted DNA is digested to single nucleosides with a combination of DNase I, Snake Venom Phosphodiesterase, and Antarctic Phosphatase and then analyzed by HPLC-ESI-TOF-MS. We present data for moth specimens that were preserved dried and pinned with no additional preservative and for frog tissue samples that were preserved in either ethanol, or formaldehyde, or fixed in formaldehyde and then preserved in ethanol. These preservation methods represent the most common methods of preserving animal specimens in museum collections. We observe changes in the nucleoside content of these samples over time, especially a loss of deoxyguanosine. We characterize the fragmentation state of the DNA and aim to identify abundant nucleoside lesions. Finally, simple models are introduced to describe the DNA fragmentation based on nicks and double-strand breaks.

  14. Effects of heavy ions on rabbit tissues: damage to the forebrain

    International Nuclear Information System (INIS)

    Cox, A.B.; Keng, P.C.; Lee, A.C.; Lett, J.T.

    1982-01-01

    As part of a study of progressive radiation effects in normal tissues, the forebrains of New Zealand white rabbits (Oryctolagus cuniculus) (about 6 weeks old) were irradiated locally with single acute doses of 60 Co γ-photons (LETsub(infinity)=0.3 keV/μm), Ne ions (LETsub(infinity)=35+-3 keV/μm) or Ar ions (LETsub(infinity)=90+-5 keV/μm). Other rabbits received fractionated doses of 60 Co γ-photons according to a standard radiotherapeutic protocol. Irradiated rabbits and appropriately aged controls were sacrificed at selected intervals, and whole sagittal sections of their brains were examined for pathological changes. Forebrain damage was scored with subjective indices based on histological differences between the anterior (irradiated) and posterior (unirradiated) regions of the brain. Those indices ranged from zero (no apparent damage) to five (severe infarctions, etc.). At intermediate levels of forebrain damage, the relative biological effectiveness (r.b.e.) of each heavy ion was similar to that found for alopecia and cataractogenesis, and the early expression of the damage was also accelerated as the LETsub(infinity) increased. Late deterioration of the forebrain appeared also to be accelerated by increasing LETsub(infinity), although its accurate quantification was not possible because other priorities in the overall experimental design limited systematic sacrifice of the animals. (author)

  15. Leaf hairs of Olea europaea protect underlying tissues against ultraviolet-B radiation damage

    International Nuclear Information System (INIS)

    Karabourniotis, G.; Kyparissis, A.; Manetas, Y.

    1993-01-01

    The photochemical efficiency of photosystem II, as measured by chlorophyll fluorescence induction, was not affected in de-haired olive leaves kept in the dark or intact leaves irradiated with a moderate (3.75 W m-2) ultraviolet-B (UV-B) intensity. In de-haired, UV-B-irradiated leaves, however, the ratio of variable to maximum (F(v)/F(m)) chlorophyll fluorescence declined significantly and irreversibly. Reduction in F(v)/V(m) was associated with an increase in instantaneous and a decrease in maximum (F(m)) fluorescence, indicating perturbation by the UV-B exposure of more than one photosynthetic site. Extensive epidermal browning in de-haired, UV-B irradiated leaves was also observed, indicating possible damage to cell membranes. The results strengthen the hypothesis that leaf hairs protect the underlying tissues against UV-B radiation damage

  16. SU-E-T-168: Evaluation of Normal Tissue Damage in Head and Neck Cancer Treatments

    International Nuclear Information System (INIS)

    Ai, H; Zhang, H

    2014-01-01

    Purpose: To evaluate normal tissue toxicity in patients with head and neck cancer by calculating average survival fraction (SF) and equivalent uniform dose (EUD) for normal tissue cells. Methods: 20 patients with head and neck cancer were included in this study. IMRT plans were generated using EclipseTM treatment planning system by dosimetrist following clinical radiotherapy treatment guidelines. The average SF for three different normal tissue cells of each concerned structure can be calculated from dose spectrum acquired from differential dose volume histogram (DVH) using linear quadratic model. The three types of normal tissues include radiosensitive, moderately radiosensitive and radio-resistant that represents 70%, 50% and 30% survival fractions, respectively, for a 2-Gy open field. Finally, EUDs for three types of normal tissue of each structure were calculated from average SF. Results: The EUDs of the brainstem, spinal cord, parotid glands, brachial plexus and etc were calculated. Our analysis indicated that the brainstem can absorb as much as 14.3% of prescription dose to the tumor if the cell line is radiosensitive. In addition, as much as 16.1% and 18.3% of prescription dose were absorbed by the brainstem for moderately radiosensitive and radio-resistant cells, respectively. For the spinal cord, the EUDs reached up to 27.6%, 35.0% and 42.9% of prescribed dose for the three types of radiosensitivities respectively. Three types of normal cells for parotid glands can get up to 65.6%, 71.2% and 78.4% of prescription dose, respectively. The maximum EUDs of brachial plexsus were calculated as 75.4%, 76.4% and 76.7% of prescription for three types of normal cell lines. Conclusion: The results indicated that EUD can be used to quantify and evaluate the radiation damage to surrounding normal tissues. Large variation of normal tissue EUDs may come from variation of target volumes and radiation beam orientations among the patients

  17. Pain and Tissue Damage in Response to Orthodontic Tooth Movement: Are They Correlated?

    Science.gov (United States)

    Cuoghi, Osmar A; Topolski, Francielle; de Faria, Lorraine P; de Mendonça, Marcos R

    2016-09-01

    To evaluate the correlation between pain and tissue damage in response to orthodontic tooth movement (OTM), such as hyalinization and external apical root resorption (EARR). The literature review was used as a methodological strategy, following the knowledge development process - constructivist (ProKnow-C). Study axes were defined and keywords that best represented each axis were selected. The terms were submitted to an adherence test and validation, resulting in 12 keyword combinations. Searches were carried out in the most representative databases for the selected terms, without restriction as for language or publication dates. Retrieved studies were filtered using the EndNote X6 program and classified according to analysis of title, abstract, and keywords. The final portfolio of articles was submitted to bibliometric and systematic analysis. A total of 1,091 studies were retrieved, out of which 719 were repeated and 335 were removed in the classification stage. A total of 37 articles remained in the final portfolio. Only one article was in line with the purpose of this study, indicating absence of correlation between pain and EARR in response to OTM. Further studies are necessary to confirm whether orthodontic pain might serve as a criterion for the use of appropriate mechanical forces, contributing to minimize tissue damage following OTM. This article presents a systematic literature review, in which scientific evidence of the correlation between pain and tissue damage during orthodontic movement was studied, providing a scientific answer for the following question: Is pain reported by patients associated with application of inappropriate orthodontic force? Thus, it aims at aiding the orthodontist in the definition of clinical parameters for the use of optimal orthodontic force.

  18. Effect of dexmedetomidine combined with propofol on brain tissue damage in brain glioma resection

    Institute of Scientific and Technical Information of China (English)

    2017-01-01

    Objective:To study the effect of dexmedetomidine combined with propofol on brain tissue damage in brain glioma resection.Methods: A total of 74 patients who received brain glioma resection in our hospital between May 2014 and December 2016 were selected and randomly divided into Dex group and control group who received dexmedetomidine intervention and saline intervention before induction respectively. Serum brain tissue damage marker, PI3K/AKT/iNOS and oxidation reaction molecule contents as well as cerebral oxygen metabolism index levels were determined before anesthesia (T0), at dura mater incision (T1), immediately after recovery (T2) and 24 h after operation (T3).Results: Serum NSE, S100B, MBP, GFAP, PI3K, AKT, iNOS and MDA contents as well as AVDO2 and CERO2 levels of both groups at T2 and T3 were significantly higher than those at T0 and T1 while serum SOD and CAT contents as well as SjvO2levels were significantly lower than those at T0 and T1, and serum NSE, S100B, MBP, GFAP, PI3K, AKT, iNOS and MDA contents as well as AVDO2 and CERO2 levels of Dex group at T2 and T3 were significantly lower than those of control group while serum SOD and CAT contents as well as SjvO2 levels were significantly higher than those of control group.Conclusions: Dexmedetomidine combined with propofol can reduce the brain tissue damage in brain glioma resection.

  19. Broccoli (Brassica oleracea) Reduces Oxidative Damage to Pancreatic Tissue and Combats Hyperglycaemia in Diabetic Rats.

    Science.gov (United States)

    Suresh, Sithara; Waly, Mostafa Ibrahim; Rahman, Mohammad Shafiur; Guizani, Nejib; Al-Kindi, Mohamed Abdullah Badar; Al-Issaei, Halima Khalfan Ahmed; Al-Maskari, Sultan Nasser Mohd; Al-Ruqaishi, Bader Rashid Said; Al-Salami, Ahmed

    2017-12-01

    Oxidative stress plays a pivotal role in the development of diabetes and hyperglycaemia. The protective effects of natural extracts against diabetes are mainly dependent on their antioxidant and hypoglycaemic properties. Broccoli ( Brassica oleracea ) exerts beneficial health effects in several diseases including diabetes; however, the mechanism has not been elucidated yet. The present study was carried out to evaluate the potential hypoglycaemic and antioxidant properties of aqueous broccoli extracts (BEs) in diabetic rats. Streptozotocin (STZ) drug was used as a diabetogenic agent in a single intraperitoneal injection dose of 50 mg/kg body weight. The blood glucose level for each rat was measured twice a week. After 8 weeks, all animals were fasted overnight and sacrificed; pancreatic tissues were homogenized and used for measuring oxidative DNA damage, biochemical assessment of glutathione (GSH), and total antioxidant capacity (TAC) as well as histopathological examination for pancreatic tissues was examined. Diabetic rats showed significantly higher levels of DNA damage, GSH depletion, and impaired TAC levels in comparison to non-diabetics ( P <0.05). The treatment of diabetic rats with BE significantly reduced DNA damage and conserved GSH and TAC values ( P <0.01). BE attenuated pancreatic histopathological changes in diabetic rats. The results of this study indicated that BE reduced the STZ mediated hyperglycaemia and the STZ-induced oxidative injury to pancreas tissue. The used in vivo model confirmed the efficacy of BE as an anti-diabetic herbal medicine and provided insights into the capacity of BE to be used for phytoremediation purposes for human type 2 diabetes.

  20. Evaluation of DNA damage induced by gamma radiation in gill and muscle tissues of Cyprinus carpio and their relative sensitivity.

    Science.gov (United States)

    M K, Praveen Kumar; Shyama, Soorambail K; D'Costa, Avelyno; Kadam, Samit B; Sonaye, Bhagatsingh Harisingh; Chaubey, Ramesh Chandra

    2017-10-01

    The effect of radiation on the aquatic environment is of major concern in recent years. Limited data is available on the genotoxicity of gamma radiation on different tissues of aquatic organisms. Hence, the present investigation was carried out to study the DNA damage induced by gamma radiation in the gill and muscle tissues and their relative sensitivity using the comet assay in the freshwater teleost fish, common carp (Cyprinus carpio). The comet assay was optimized and validated in common carp using cyclophosphamide (CP), a reference genotoxic agent. The fish were exposed (acute) to various doses of gamma radiation (2, 4, 6, 8 and 10Gy) and samplings (gill and muscle tissue) were done at regular intervals (24, 48 and 72h) to assess the DNA damage. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA for all doses of gamma radiation in both tissues. We also observed a dose-related increase and a time-dependent decrease of DNA damage. In comparison, DNA damage showed different sensitivity among the tissues at different doses. This shows that a particular dose may have different effects on different tissues which could be due to physiological factors of the particular tissue. Our study also suggests that the gills and muscle of fish are sensitive and reliable tissues for evaluating the genotoxic effects of reference and environmental agents, using the comet assay. Copyright © 2017. Published by Elsevier Inc.

  1. Fibrosis of the pancreas: the initial tissue damage and the resulting pattern.

    Science.gov (United States)

    Klöppel, Günter; Detlefsen, Sönke; Feyerabend, Bernd

    2004-07-01

    Fibrosis in the pancreas is caused by such processes as necrosis/apoptosis, inflammation or duct obstruction. The initial event that induces fibrogenesis in the pancreas is an injury that may involve the interstitial mesenchymal cells, the duct cells and/or the acinar cells. Damage to any one of these tissue compartments of the pancreas is associated with cytokine-triggered transformation of resident fibroblasts/pancreatic stellate cells into myofibroblasts and the subsequent production and deposition of extracellular matrix. Depending on the site of injury in the pancreas and the involved tissue compartment, predominantly inter(peri)lobular fibrosis (as in alcoholic chronic pancreatitis), periductal fibrosis (as in hereditary pancreatitis), periductal and interlobular fibrosis (as in autoimmune pancreatitis) or diffuse inter- and intralobular fibrosis (as in obstructive chronic pancreatitis) develops.

  2. Fracture mechanics model of stone comminution in ESWL and implications for tissue damage

    Science.gov (United States)

    Lokhandwalla, Murtuza; Sturtevant, Bradford

    2000-07-01

    Focused shock waves administered during extracorporeal shock-wave lithotripsy (ESWL) cause stone fragmentation. The process of stone fragmentation is described in terms of a dynamic fracture process. As is characteristic of all brittle materials, fragmentation requires nucleation, growth and coalescence of flaws, caused by a tensile or shear stress. The mechanisms, operative in the stone, inducing these stresses have been identified as spall and compression-induced tensile microcracks, nucleating at pre-existing flaws. These mechanisms are driven by the lithotripter-generated shock wave and possibly also by cavitation effects in the surrounding fluid. In this paper, the spall mechanism has been analysed, using a cohesive-zone model for the material. The influence of shock wave parameters, and physical properties of stone, on stone comminution is described. The analysis suggests a potential means to exploit the difference between the stone and tissue physical properties, so as to make stone comminution more effective, without increasing tissue damage.

  3. Lovastatin attenuates ionizing radiation-induced normal tissue damage in vivo

    International Nuclear Information System (INIS)

    Ostrau, Christian; Huelsenbeck, Johannes; Herzog, Melanie; Schad, Arno; Torzewski, Michael; Lackner, Karl J.; Fritz, Gerhard

    2009-01-01

    Background and purpose: HMG-CoA-reductase inhibitors (statins) are widely used lipid-lowering drugs. Moreover, they have pleiotropic effects on cellular stress responses, proliferation and apoptosis in vitro. Here, we investigated whether lovastatin attenuates acute and subchronic ionizing radiation-induced normal tissue toxicity in vivo. Materials and methods: Four hours to 24 h after total body irradiation (6 Gy) of Balb/c mice, acute pro-inflammatory and pro-fibrotic responses were analyzed. To comprise subchronic radiation toxicity, mice were irradiated twice with 2.5 Gy and analyses were performed 3 weeks after the first radiation treatment. Molecular markers of inflammation and fibrosis as well as organ toxicities were measured. Results: Lovastatin attenuated IR-induced activation of NF-κB, mRNA expression of cell adhesion molecules and mRNA expression of pro-inflammatory and pro-fibrotic marker genes (i.e. TNFα, IL-6, TGFβ, CTGF, and type I and type III collagen) in a tissue- and time-dependent manner. γH2AX phosphorylation stimulated by IR was not affected by lovastatin, indicating that the statin has no major impact on the induction of DNA damage in vivo. Radiation-induced thrombopenia was significantly alleviated by lovastatin. Conclusions: Lovastatin inhibits both acute and subchronic IR-induced pro-inflammatory and pro-fibrotic responses and cell death in normal tissue in vivo. Therefore, lovastatin might be useful for selectively attenuating acute and subchronic normal tissue damage caused by radiotherapy.

  4. Using autopsy brain tissue to study alcohol-related brain damage in the genomic age.

    Science.gov (United States)

    Sutherland, Greg T; Sheedy, Donna; Kril, Jillian J

    2014-01-01

    The New South Wales Tissue Resource Centre at the University of Sydney, Australia, is one of the few human brain banks dedicated to the study of the effects of chronic alcoholism. The bank was affiliated in 1994 as a member of the National Network of Brain Banks and also focuses on schizophrenia and healthy control tissue. Alcohol abuse is a major problem worldwide, manifesting in such conditions as fetal alcohol syndrome, adolescent binge drinking, alcohol dependency, and alcoholic neurodegeneration. The latter is also referred to as alcohol-related brain damage (ARBD). The study of postmortem brain tissue is ideally suited to determining the effects of long-term alcohol abuse, but it also makes an important contribution to understanding pathogenesis across the spectrum of alcohol misuse disorders and potentially other neurodegenerative diseases. Tissue from the bank has contributed to 330 peer-reviewed journal articles including 120 related to alcohol research. Using the results of these articles, this review chronicles advances in alcohol-related brain research since 2003, the so-called genomic age. In particular, it concentrates on transcriptomic approaches to the pathogenesis of ARBD and builds on earlier reviews of structural changes (Harper et al. Prog Neuropsychopharmacol Biol Psychiatry 2003;27:951) and proteomics (Matsumoto et al. Expert Rev Proteomics 2007;4:539). Copyright © 2013 by the Research Society on Alcoholism.

  5. Role of the immune system in cardiac tissue damage and repair following myocardial infarction.

    Science.gov (United States)

    Saparov, Arman; Ogay, Vyacheslav; Nurgozhin, Talgat; Chen, William C W; Mansurov, Nurlan; Issabekova, Assel; Zhakupova, Jamilya

    2017-09-01

    The immune system plays a crucial role in the initiation, development, and resolution of inflammation following myocardial infarction (MI). The lack of oxygen and nutrients causes the death of cardiomyocytes and leads to the exposure of danger-associated molecular patterns that are recognized by the immune system to initiate inflammation. At the initial stage of post-MI inflammation, the immune system further damages cardiac tissue to clear cell debris. The excessive production of reactive oxygen species (ROS) by immune cells and the inability of the anti-oxidant system to neutralize ROS cause oxidative stress that further aggravates inflammation. On the other hand, the cells of both innate and adaptive immune system and their secreted factors are critically instrumental in the very dynamic and complex processes of regulating inflammation and mediating cardiac repair. It is important to decipher the balance between detrimental and beneficial effects of the immune system in MI. This enables us to identify better therapeutic targets for reducing the infarct size, sustaining the cardiac function, and minimizing the likelihood of heart failure. This review discusses the role of both innate and adaptive immune systems in cardiac tissue damage and repair in experimental models of MI.

  6. Identification of molecular mechanisms of radiation-induced vascular damage in normal tissues using microarray analyses

    International Nuclear Information System (INIS)

    Kruse, J.J.C.M.; Te Poele, J.A.M.; Russell, N.S.; Boersma, L.J.; Stewart, F.A.

    2003-01-01

    Radiation-induced telangiectasia, characterized by thin-walled dilated blood vessels, can be a serious late complication in patients that have been previously treated for cancer. It might cause cosmetic problems when occurring in the skin, and excessive bleeding requiring surgery when occurring in rectal mucosa. The mechanisms underlying the development of radiation-induced telangiectasia are unclear. The aim of the present study is to determine whether microarrays are useful for studying mechanisms of radiation-induced telangiectasia. The second aim is to test the hypotheses that telangiectasia is characterized by a final common pathway in different tissues. Microarray experiments were performed using amplified RNA from (sham)irradiated mouse tissues (kidney, rectum) at different intervals (1-30 weeks) after irradiation. After normalization procedures, the differentially expressed genes were identified. Control/repeat experiments were done to confirm that the observations were not artifacts of the array procedure. The mouse kidney experiments showed significant upregulation of 31 and 42 genes and downregulation of 9 and 4 genes at 10 and 20 weeks after irradiation, respectively. Irradiated mouse rectum has 278 upregulated and 537 downregulated genes at 10 weeks and 86 upregulated and 29 downregulated genes at 20 weeks. During the development of telangiectasia, 19 upregulated genes and 5 downregulated genes were common to both tissues. Upregulation of Jagged-1, known to play a role in angiogenesis, is particularly interesting in the context of radiation-induced telangiectasia. Microarrays are affective discovery tools to identify novel genes of interest, which may be involved in radiation-induced normal tissue injury. Using information from control arrays (particularly straight color, color reverse and self-self experiments) allowed for a more accurate and reproducible identification of differentially expressed genes than the selection of an arbitrary 2-fold change

  7. Damage to apparel layers and underlying tissue due to hand-gun bullets.

    Science.gov (United States)

    Carr, Debra; Kieser, Jules; Mabbott, Alexander; Mott, Charlotte; Champion, Stephen; Girvan, Elizabeth

    2014-01-01

    Ballistic damage to the clothing of victims of gunshot wounds to the chest can provide useful forensic evidence. Anyone shot in the torso will usually be wearing clothing which will be damaged by the penetrating impact event and can reportedly be the source of some of the debris in the wound. Minimal research has previously been reported regarding the effect of bullets on apparel fabrics and underlying tissue. This paper examines the effect of ammunition (9 mm full metal jacket [FMJ] DM11 A1B2, 8.0 g; and soft point flat nose Remington R357M3, 10.2 g) on clothing layers that cover the torso (T-shirt, T-shirt plus hoodie, T-shirt plus denim jacket) and underlying structures represented by porcine thoracic wall (skin, underlying tissue, ribs). Impacts were recorded using a Phantom V12 high speed camera. Ejected bone debris was collected before wound tracts were dissected and measured; any debris found was recovered for further analysis. Size and mass of bony debris was recorded; fibre debris recovered from the wound and impact damage to fabrics were imaged using scanning electron microscopy (SEM). Remington R357M3 ammunition was characteristically associated with stellate fabric damage; individual fibres were less likely to show mushrooming. In contrast, 9 mm FMJ ammunition resulted in punch-out damage to fabric layers, with mushrooming of individual fibres being more common. Entry wound sizes were similar for both types of ammunition and smaller than the diameter of the bullet that caused them. In this work, the Remington R357M3 ammunition resulted in larger exit wounds due to the bullet construction which mushroomed. That fabric coverings did not affect the amount of bony debris produced is interesting, particularly given there was some evidence that apparel layers affected the size of the wound. Recent work has suggested that denim (representative of jeans) can exacerbate wounding caused by high-velocity bullet impacts to the thigh when the bullet does not

  8. On radiation damage to normal tissues and its treatment. Pt. 2

    International Nuclear Information System (INIS)

    Michalowski, A.S.

    1994-01-01

    In addition to transiently inhibiting cell cycle progression and sterilizing those cells capable of proliferation, irradiation disturbs the homeostasis effected by endogenous mediators of intercellular communication (humoral component of tissue response to radiation). Changes in the mediator levels may modulate radiation effects either by a assisting a return to normality (e.g., through a rise in H-type cell lineage-specific growth factors) or by aggravating the damage. The latter mode is illustrated with reports on changes in eicosanoid levels after irradiation and on results of empirical treatment of radiation injuries with anti-inflammatory drugs. Prodromal, acute and chronic effects of radiation are accompanied by excessive production of eicosanoids (prostaglandins, prostacyclin, thromboxanes and leukotrienes). These endogenous mediators of inflammatory reactions may be responsible for the vasodilatation, vasoconstriction, increased microvascular permeability, thrombosis and chemotaxis observed after radiation exposure. Glucocorticoids inhibit eicosanoid synthesis primarily by interfering with phospholipase A 2 whilst non-steroidal anti-inflammatory drugs prevent prostaglandin/thromboxane synthesis by inhibiting cycloxygenase. When administered after irradiation on empirical grounds, drugs belonging to both groups tend to attenuate a range of prodomal, acute and chronic effects of radiation in man and animals. Taken together, these two sets of observations are highly suggestive of a contribution of humoral factors to the adverse responses of normal tissues and organs to radiation. A full account of radiation damage should therefore consist of complementary descriptions of cellular and humoral events. Further studies on anti-inflammatory drug treatment of radiation damage to normal organs are justified and desirable. (orig.)

  9. MRI in diagnostic of soft tissue damages by fractures of lateral tibial plate

    International Nuclear Information System (INIS)

    Dimitrova, D.; Proichev, V.; Popov, I.

    2015-01-01

    Full text: The knee is one of the most often injured joint. Fractures of tibial condyles are the most common articular damages. Koton and Berg call them „bumper“ fractures the tibia plateau is vulnerable to both high- and low-energy injury mechanisms due to its vulnerable position in the lower extremity. It must bear significant weight and sustain significant impact and deceleration forces with little skeletal constraint, and has scant surrounding soft tissue and a tethered medial and lateral integument. Furthermore, the tibial plateau has relatively forgiving ligamentous attachments that must allow for a large range of motion in a single plane. Not surprisingly, given the diversity of injury, management of these fractures has come to include a wide variety of treatment strategies. traditionally, ligament injury associated with plateau fractures has been diagnosed indirectly with stress radiographs and physical examination. With increasing use of more sensitive MRI and arthroscopy, associated ligament and meniscus injuries have been found in significant percentages of plateau fractures. these soft tissue injuries consist primarily of MCL lesions, meniscal injuries, and ACL disruptions. However, studies addressing associated soft tissue injuries all agree that neither the type of plateau fracture nor the presence or absence of ligament injury correlates with the incidence of meniscal tears

  10. Effect of Li and NH4 doping on the crystal perfection, second harmonic generation efficiency and laser damage threshold of potassium pentaborate crystals

    Science.gov (United States)

    Vigneshwaran, A. N.; Kalainathan, S.; Raja, C. Ramachandra

    2018-03-01

    Potassium pentaborate (KB5) is an excellent nonlinear optical material especially in the UV region. In this work, Li and NH4 doped KB5 crystals were grown using slow evaporation solution growth method. The incorporation of dopant has been confirmed and analysed by Energy dispersive X-ray analysis (EDAX), Inductively coupled plasma (ICP) analysis and Raman spectroscopy. The crystalline perfection of pure and doped KB5 crystals was studied by High resolution X-ray diffraction (HRXRD) analysis. Structural grain boundaries were observed in doped crystals. Second harmonic generation was confirmed for pure and doped crystals and output values revealed the enhancement of SHG efficiency in doped crystals. Resistance against laser damage was carried out using 1064 nm Nd-YAG laser of pulse width 10 ns. The laser damage threshold value is increased in Li doped crystal and decreased in NH4 doped crystal when compared to pure KB5 crystal.

  11. Contribution to the microchemistry of smoke damage by fluoride. The migration of fluorides in plant tissue. 2. The visible damage

    Energy Technology Data Exchange (ETDEWEB)

    Reckendorfer, P

    1953-01-01

    In continuation of former investigations, a theory of damage caused by fluorine compounds on green plants was developed. It is possible to differentiate between acute and chronic damages by use of microanalytical estimation of total fluorine and inorganic and organic fluorine compounds in the plants.

  12. Modulation of radiation induced DNA damage by natural products in hemopoietic tissue of mice

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2014-01-01

    Ionizing radiation is known to induce oxidative stress through generation of ROS leading to a variety of DNA lesions. However, the most dangerous DNA lesions which are responsible for the origin of lethal effects, mutagenesis, genomic instability and carcinogenesis are the DSBs. During recent years efforts are being made to identify phytochemicals, antioxidants or neutraxeuticals which can reduce harmful effect of radiation during accidental exposure or prevent normal tissue injury during radiotherapy. In the present study, we have investigated the radioprotective role of curcumin, a dietary antioxidant, taurine, malabaricone-C, and umbelliferone, for their radioprotective properties in hemopoietic cells of mice. Groups of mice-were fed 1% of curcumin in diet for three weeks. Similarly other groups of mice were injected i.p. with 50 mg/kg body weight of taurine for five consecutive days. After the completion of the treatment mice pre-treated with curcumin and taurine were exposed to 3 Gy of gamma rays. Malabaricone-C was tested for its radiomodulation potential in vitro, in spleenocytes of mouse. Spleenocytes were isolated and treated with different concentrations (0.5-25 ìM) of malabaricone-C. Immediately after irradiation, alkaline comet assay were performed using standard procedures. Twenty four post radiation exposure mice were sacrificed for micronucleus test. Results of these studies showed significant reduction in DNA damage by curcumin. The micronucleus data showed marginal increase in the frequency of micronucleated erythrocytes in curcumin fed group as compared to the controls. Mice receiving curcumin for 3 weeks in diet followed by gamma radiation (3 Gy), showed approximately 50% reduction in the frequency of micro nucleated polychromatic erythrocytes. Pre-treatment of mice with taurine significantly (p < 0.01) reduced the frequency of gamma rays induced mn-PCEs in bone marrow tissue. Malabaricone-C at 1.5 ìM concentration showed very good protection

  13. Relaxed damage threshold intensity conditions and nonlinear increase in the conversion efficiency of an optical parametric oscillator using a bi-directional pump geometry.

    Science.gov (United States)

    Norris, G; McConnell, G

    2010-03-01

    A novel bi-directional pump geometry that nonlinearly increases the nonlinear optical conversion efficiency of a synchronously pumped optical parametric oscillator (OPO) is reported. This bi-directional pumping method synchronizes the circulating signal pulse with two counter-propagating pump pulses within a linear OPO resonator. Through this pump scheme, an increase in nonlinear optical conversion efficiency of 22% was achieved at the signal wavelength, corresponding to a 95% overall increase in average power. Given an almost unchanged measured pulse duration of 260 fs under optimal performance conditions, this related to a signal wavelength peak power output of 18.8 kW, compared with 10 kW using the traditional single-pass geometry. In this study, a total effective peak intensity pump-field of 7.11 GW/cm(2) (corresponding to 3.55 GW/cm(2) from each pump beam) was applied to a 3 mm long periodically poled lithium niobate crystal, which had a damage threshold intensity of 4 GW/cm(2), without impairing crystal integrity. We therefore prove the application of this novel pump geometry provides opportunities for power-scaling of synchronously pumped OPO systems together with enhanced nonlinear conversion efficiency through relaxed damage threshold intensity conditions.

  14. Effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage

    Institute of Scientific and Technical Information of China (English)

    Nan-Lin Meng

    2017-01-01

    Objective:To study the effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage.Methods: Patients with pulpal and periapical diseases who received root canal therapy in our hospital between May 2013 and October 2016 were retrospectively analyzed, and according to the different root canal filling materials they used, they were divided into epoxy group and bioceramic group who used epoxy paste and bioceramic paste as root canal filling materials respectively. Before and after treatment, gingival crevicular fluid was collected respectively to determine the levels of inflammatory factors, oxidative stress products, cell apoptosis molecules and protease-related molecules.Results: 2 weeks after treatment, IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid of epoxy group were not significantly different from those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1 and MMP-2 levels in gingival crevicular fluid of bioceramic group were significantly higher than those before treatment while Bcl-2, TIMP-1 and TIMP-2 levels were significantly lower than those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid were significantly different between two groups of patients after treatment.Conclusion:Epoxy paste for dental restoration causes less damage to periodontal tissue than bioceramic paste.

  15. Effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage

    Directory of Open Access Journals (Sweden)

    Nan-Lin Meng

    2017-05-01

    Full Text Available Objective: To study the effect of dental restoration with epoxy and bioceramic paste on periodontal tissue damage. Methods: Patients with pulpal and periapical diseases who received root canal therapy in our hospital between May 2013 and October 2016 were retrospectively analyzed, and according to the different root canal filling materials they used, they were divided into epoxy group and bioceramic group who used epoxy paste and bioceramic paste as root canal filling materials respectively. Before and after treatment, gingival crevicular fluid was collected respectively to determine the levels of inflammatory factors, oxidative stress products, cell apoptosis molecules and protease-related molecules. Results: 2 weeks after treatment, IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid of epoxy group were not significantly different from those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1 and MMP-2 levels in gingival crevicular fluid of bioceramic group were significantly higher than those before treatment while Bcl-2, TIMP-1 and TIMP-2 levels were significantly lower than those before treatment; IL-1β, IL-6, CRP, ROS, MDA, AOPP, Bcl-2, Bax, Cyt-C, caspase-3, Smac, EMMPRIN, MMP-1, MMP-2, TIMP-1 and TIMP-2 levels in gingival crevicular fluid were significantly different between two groups of patients after treatment. Conclusion: Epoxy paste for dental restoration causes less damage to periodontal tissue than bioceramic paste.

  16. Ultrasonic energy vs monopolar electrosurgery in laparoscopic cholecystectomy: a comparison of tissue damage

    Directory of Open Access Journals (Sweden)

    Mehdi Asgari

    2016-04-01

    Full Text Available Background: Laparoscopic cholecystectomy is a minimally invasive procedure whereby the gallbladder is removed using laparoscopic techniques. Monopolar electerosurgical energy is the method of dissection of gallbladder from liver bed. Ultrasonic energy causes less thermal damage and suggests an alternative to monopolar elevterocautery. Leptin is a tissue factor and C-reactive protein (CRP is an acute phase protein that builds up in surgical damages. In laparoscopy, pneumoperitoneum and thermal damage cause this increase. In this study, after completion of surgery with both methods, plasma leptin and CPR were measured. Next, the complications and benefits of the two methods were compared. Methods: This single blind randomized clinical trial was conducted on 78 patients who were candidate for laparoscopic cholecystectomy in surgery clinic of Razi Teaching Hospital in Ahvaz Jundishapur University of Medical Sciences from March 2013 to March 2015. Patients were divided randomly into two groups of ultrasonic and electerocautery. Then, leptin’s level and CRP’s level were measured at completion of surgery, 30 minutes after completion, 6 and 24 hours after completion of surgery in the two groups. Results: This study shows that the average rate of leptin at completion of surgery, 30 minutes after completion, 6 and 24 hours after completion of surgery in ultrasonic group had less increase than electerocautery group and the difference was statistically significant (P= 0.0001. The average rate of CRP at completion of surgery, 30 minutes after completion, 6 and 24 hours after completion of surgery in ultrasonic group had less increase than electerocautery group and the difference was statistically significant (P= 0.0001. Conclusion: The level of leptin and CRP shows that surgery with ultrasonic method will provoke the immune system less than electerocautery method.

  17. Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold

    Czech Academy of Sciences Publication Activity Database

    Makhotkin, I.; Sobierajski, R.; Chalupský, Jaromír; Tiedtke, K.; de Vries, G.; Stoermer, M.; Scholze, F.; Siewert, F.; van de Kruijs, R.W.E.; Milov, I.; Louis, E.; Jacyna, I.; Jurek, M.; Klinger, D.; Nittler, L.; Syryanyy, Y.; Juha, Libor; Hájková, Věra; Vozda, Vojtěch; Burian, Tomáš; Saksl, Karel; Faatz, B.; Keitel, B.; Ploenjes, E.; Schreiber, S.; Toleikis, S.; Loch, R.A.; Hermann, M.; Strobel, S.; Nienhuys, H.-K.; Gwalt, G.; Mey, T.; Enkisch, H.

    2018-01-01

    Roč. 25, č. 1 (2018), s. 77-84 ISSN 1600-5775. [Workshop on FEL Photon Diagnostics, Instrumentation and Beamline Design (PhotonDiag2017). Stanford, 01.05.2017-03.05.2017] R&D Projects: GA MŠk LG15013; GA ČR(CZ) GA17-05167s; GA ČR(CZ) GA14-29772S Institutional support: RVO:68378271 Keywords : free-electron laser induced damage * EUV optics * thin films * FELs Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.011, year: 2016

  18. Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold

    Czech Academy of Sciences Publication Activity Database

    Makhotkin, I.A.; Sobierajski, R.; Chalupský, J.; Tiedtke, K.; de Vries, G.; Stoermer, M.; Scholze, F.; Siewert, F.; van de Kruijs, R.W.E.; Louis, E.; Jacyna, I.; Jurek, M.; Klinger, D.; Nittler, L.; Syryanyy, Y.; Juha, Libor; Hájková, V.; Vozda, V.; Burian, Tomáš; Saksl, K.; Faatz, B.; Keitel, B.; Ploenjes, E.; Schreiber, S.; Toleikis, S.; Loch, R.; Hermann, M.; Strobel, S.; Nienhuys, H.-K.; Gwalt, G.; Mey, T.; Enkisch, H.

    2018-01-01

    Roč. 25, č. 1 (2018), s. 77-84 ISSN 0909-0495. [Workshop on FEL Photon Diagnostics, Instrumentation and Beamline Design (PhotonDiag2017). Stanford, 01.05.2017-03.05.2017] R&D Projects: GA ČR(CZ) GA14-29772S; GA MŠk LG15013 Institutional support: RVO:61389021 Keywords : free-electron laser induced damage * EUV optics * thin films * FELs Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics)

  19. Multiphoton Absorption is Probably Not the Primary Threshold Damage Mechanism for Femtosecond Laser Pulse Exposures in the Retinal Pigment Epithelium

    Science.gov (United States)

    2004-01-01

    Tromberg, and E. Gratton, "Two-photon excited lifetime imaging of autofluorescence in cells during UTVA and NIR photostress", J. Micros. 183, pp. 197-204...1996. 4. K. Konig, Y. Liu, G. J. Sonek, M. W. Berns, and B. J. Tromberg, " Autofluorescence spectroscopy of optically trapped cells", Photochem...34, Photochem. Photobiol. 70, pp. 146-151, 1999. 10. R. D. Glickman, "Phototoxicity to the retina : Mechanisms of damage", International Journal of

  20. Tissue-selective effects of nucleolar stress and rDNA damage in developmental disorders.

    Science.gov (United States)

    Calo, Eliezer; Gu, Bo; Bowen, Margot E; Aryan, Fardin; Zalc, Antoine; Liang, Jialiang; Flynn, Ryan A; Swigut, Tomek; Chang, Howard Y; Attardi, Laura D; Wysocka, Joanna

    2018-02-01

    Many craniofacial disorders are caused by heterozygous mutations in general regulators of housekeeping cellular functions such as transcription or ribosome biogenesis. Although it is understood that many of these malformations are a consequence of defects in cranial neural crest cells, a cell type that gives rise to most of the facial structures during embryogenesis, the mechanism underlying cell-type selectivity of these defects remains largely unknown. By exploring molecular functions of DDX21, a DEAD-box RNA helicase involved in control of both RNA polymerase (Pol) I- and II-dependent transcriptional arms of ribosome biogenesis, we uncovered a previously unappreciated mechanism linking nucleolar dysfunction, ribosomal DNA (rDNA) damage, and craniofacial malformations. Here we demonstrate that genetic perturbations associated with Treacher Collins syndrome, a craniofacial disorder caused by heterozygous mutations in components of the Pol I transcriptional machinery or its cofactor TCOF1 (ref. 1), lead to relocalization of DDX21 from the nucleolus to the nucleoplasm, its loss from the chromatin targets, as well as inhibition of rRNA processing and downregulation of ribosomal protein gene transcription. These effects are cell-type-selective, cell-autonomous, and involve activation of p53 tumour-suppressor protein. We further show that cranial neural crest cells are sensitized to p53-mediated apoptosis, but blocking DDX21 loss from the nucleolus and chromatin rescues both the susceptibility to apoptosis and the craniofacial phenotypes associated with Treacher Collins syndrome. This mechanism is not restricted to cranial neural crest cells, as blood formation is also hypersensitive to loss of DDX21 functions. Accordingly, ribosomal gene perturbations associated with Diamond-Blackfan anaemia disrupt DDX21 localization. At the molecular level, we demonstrate that impaired rRNA synthesis elicits a DNA damage response, and that rDNA damage results in tissue-selective and

  1. Synchrotron X-ray CT of rose peduncles. Evaluation of tissue damage by radiation

    International Nuclear Information System (INIS)

    Herppich, Werner B.; Zabler, Simon; Dawson, Martin; Choinka, Gerard; Manke, Ingo

    2015-01-01

    ''Bent-neck'' syndrome, an important postharvest problem of cut roses, is probably caused by water supply limitations and/or the structural weakness of vascular bundles of the peduncle tissue. For this reason, advanced knowledge about the microstructures of rose peduncles and their cultivar specific variations may lead to a better understanding of the underlying mechanisms. Synchrotron X-ray computed tomography (SXCT), especially phase-based CT, is a highly suitable technique to nondestructively investigate plants' micro anatomy. SXCT with monochromatic X-ray beams of 30, 40 and 50 keV photon energy was used to evaluate the three-dimensional inner structures of the peduncles of 3 rose cultivars that differ greatly in their bent-neck susceptibility. Results indicated that this technique achieves sufficiently high spatial resolution to investigate complex tissues. However, further investigations with chlorophyll fluorescence analysis (CFA) and optical microscope imagery reveal different kinds of heavy damage of the irradiated regions induced by synchrotron X-rays; in a cultivar-specific manner, partial destruction of cell walls occurred a few hours after X-ray irradiation. Furthermore, a delayed inhibition of photosynthesis accompanied by the degradation of chlorophyll was obvious from CFA within hours and days after the end of CT measurements. Although SXCT is certainly well suited for three-dimensional anatomical analysis of rose peduncles, the applied technique is not nondestructive.

  2. Synchrotron X-ray CT of rose peduncles. Evaluation of tissue damage by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Herppich, Werner B. [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V., Potsdam (Germany). Abt. Technik im Gartenbau; Matsushima, Uzuki [Iwate Univ., Morioka (Japan). Faculty of Agriculture; Graf, Wolfgang [Association for Technology and Structures in Agriculture (KTBL), Darmstadt (Germany); Zabler, Simon [Fraunhofer-Institut fuer Integrierte Schaltungen (IIS), Wuerzburg (Germany). Project group NanoCT Systems (NCTS); Dawson, Martin [Salford Univ., Greater Manchester (United Kingdom); Choinka, Gerard; Manke, Ingo [Helmholtz Center Berlin for Materials and Energy (HZB), Berlin (Germany)

    2015-02-01

    ''Bent-neck'' syndrome, an important postharvest problem of cut roses, is probably caused by water supply limitations and/or the structural weakness of vascular bundles of the peduncle tissue. For this reason, advanced knowledge about the microstructures of rose peduncles and their cultivar specific variations may lead to a better understanding of the underlying mechanisms. Synchrotron X-ray computed tomography (SXCT), especially phase-based CT, is a highly suitable technique to nondestructively investigate plants' micro anatomy. SXCT with monochromatic X-ray beams of 30, 40 and 50 keV photon energy was used to evaluate the three-dimensional inner structures of the peduncles of 3 rose cultivars that differ greatly in their bent-neck susceptibility. Results indicated that this technique achieves sufficiently high spatial resolution to investigate complex tissues. However, further investigations with chlorophyll fluorescence analysis (CFA) and optical microscope imagery reveal different kinds of heavy damage of the irradiated regions induced by synchrotron X-rays; in a cultivar-specific manner, partial destruction of cell walls occurred a few hours after X-ray irradiation. Furthermore, a delayed inhibition of photosynthesis accompanied by the degradation of chlorophyll was obvious from CFA within hours and days after the end of CT measurements. Although SXCT is certainly well suited for three-dimensional anatomical analysis of rose peduncles, the applied technique is not nondestructive.

  3. Does hearing in response to soft-tissue stimulation involve skull vibrations? A within-subject comparison between skull vibration magnitudes and hearing thresholds.

    Science.gov (United States)

    Chordekar, Shai; Perez, Ronen; Adelman, Cahtia; Sohmer, Haim; Kishon-Rabin, Liat

    2018-04-03

    Hearing can be elicited in response to bone as well as soft-tissue stimulation. However, the underlying mechanism of soft-tissue stimulation is under debate. It has been hypothesized that if skull vibrations were the underlying mechanism of hearing in response to soft-tissue stimulation, then skull vibrations would be associated with hearing thresholds. However, if skull vibrations were not associated with hearing thresholds, an alternative mechanism is involved. In the present study, both skull vibrations and hearing thresholds were assessed in the same participants in response to bone (mastoid) and soft-tissue (neck) stimulation. The experimental group included five hearing-impaired adults in whom a bone-anchored hearing aid was implanted due to conductive or mixed hearing loss. Because the implant is exposed above the skin and has become an integral part of the temporal bone, vibration of the implant represented skull vibrations. To ensure that middle-ear pathologies of the experimental group did not affect overall results, hearing thresholds were also obtained in 10 participants with normal hearing in response to stimulation at the same sites. We found that the magnitude of the bone vibrations initiated by the stimulation at the two sites (neck and mastoid) detected by the laser Doppler vibrometer on the bone-anchored implant were linearly related to stimulus intensity. It was therefore possible to extrapolate the vibration magnitudes at low-intensity stimulation, where poor signal-to-noise ratio limited actual recordings. It was found that the vibration magnitude differences (between soft-tissue and bone stimulation) were not different than the hearing threshold differences at the tested frequencies. Results of the present study suggest that bone vibration magnitude differences can adequately explain hearing threshold differences and are likely to be responsible for the hearing sensation. Thus, the present results support the idea that bone and soft-tissue

  4. Oxidative damage in synovial tissue is associated with in vivo hypoxic status in the arthritic joint.

    LENUS (Irish Health Repository)

    Biniecka, Monika

    2012-02-01

    OBJECTIVES: To assess levels of oxidative DNA damage (8-oxo-7,8-dihydro-2\\'-deoxyguanine; 8-oxo-dG) and lipid peroxidation (4-hydroxy-2-nonenal; 4-HNE) in serum, synovial fluid and tissue of patients with inflammatory arthritis in relation to in vivo hypoxia levels, disease activity and angiogenic markers. METHODS: Oxygen levels in synovial tissue were assessed using an oxygen\\/temperature probe. Nuclear and cytoplasmic 8-oxo-dG and 4-HNE levels were assessed in synovial tissue from 23 patients by immunohistochemistry. 8-Oxo-dG and 4-HNE levels in serum and synovial fluid were determined using 8-oxo-dG and hexanoyl-Lys (HEL) adduct ELISAs, respectively. Serum vascular endothelial growth factor (VEGF) and angiopoietin 2 (Ang2) levels were also measured by ELISA. RESULTS: The median oxygen tension in synovial tissue was profoundly hypoxic at 19.35 mm Hg (2.5%). Nuclear 8-oxo-dG levels were significantly higher than nuclear 4-HNE levels in the lining and sublining layers (all p<0.001). In contrast, cytoplasmic 4-HNE levels were higher than cytoplasmic 8-oxo-dG levels in both cell layers (all p<0.001). Reduced in vivo oxygen tension correlated with high lipid peroxidation in synovial fluid (p=0.027; r=0.54) and tissue (p=0.004; r=0.58). Serum VEGF levels were positively correlated with cytoplasmic 4-HNE expression (p=0.05; r=0.43) and intensity (p=0.006; r=0.59) in the lining layer. Serum Ang2 levels were positively correlated with nuclear 4-HNE expression and intensity in both cell layers (all p < or = 0.05). DAS28-C-reactive protein was correlated with nuclear 4-HNE expression in the sublining layer (p=0.02; r=0.48) and DAS28-erythrocyte sedimentation rate was correlated with nuclear 4-HNE expression in both cell layers (p < or = 0.03). CONCLUSIONS: Lipid peroxidation is associated with low oxygen tension in vivo, disease activity and angiogenic marker expression in inflammatory arthritis.

  5. Improvement of oxygen supply by an artificial carrier in combination with normobaric oxygenation decreases the volume of tissue hypoxia and tissue damage from transient focal cerebral ischemia

    NARCIS (Netherlands)

    Seiffge, David J.; Lapina, Natalia E.; Tsagogiorgas, Charalambos; Theisinger, Bastian; Henning, Robert H.; Schilling, Lothar

    Tissue hypoxia may play an important role in the development of ischemic brain damage. In the present study we investigated in a rat model of transient focal brain ischemia the neuroprotective effects of increasing the blood oxygen transport capacity by applying a semifluorinated alkane

  6. The role of zinc supplementation in the inhibition of tissue damage caused by exposure to electromagnetic field in rat lung and liver tissues.

    Science.gov (United States)

    Baltaci, A K; Mogulkoc, R; Salbacak, A; Celik, I; Sivrikaya, A

    2012-01-01

    The objective of the present study was to examine the effects of zinc supplementation on the oxidant damage in lung and liver tissues in rats exposed to a 50-Hz frequency magnetic field for 5 minutes every other day over a period of 6 months. The study included 24 adult male Sprague-Dawley rats, which were divided into the three groups in equal numbers: Group 1, the control group (G1); Group 2, the group exposed to an electromagnetic field (G2); and Group 3, the group, which was exposed to an EMF and supplemented with zinc (G3). At the end of the 6-month procedures, the animals were decapitated to collect lung and liver tissue samples, in which MDA was analyzed using the "TBARS method (nmol/g/protein)", GSH by the "biuret method (mg/g/protein)" and zinc levels by atomic emission (µg/dl). MDA levels in lung and liver tissues in G2 were higher than those in G1 and G3, and the levels in G3 were higher than those in G1 (pelectromagnetic field caused cellular damage in lung and liver tissues and zinc supplementation inhibited the inflicted cellular damage. Another important result of this study that needs emphasis was that exposure to an electromagnetic field led to a significant decrease in zinc levels in lung and liver tissues (Tab. 3, Ref. 23).

  7. Microbeam Radiation-Induced Tissue Damage Depends on the Stage of Vascular Maturation

    International Nuclear Information System (INIS)

    Sabatasso, Sara; Laissue, Jean Albert; Hlushchuk, Ruslan; Graber, Werner; Bravin, Alberto; Braeuer-Krisch, Elke; Corde, Stephanie; Blattmann, Hans; Gruber, Guenther; Djonov, Valentin

    2011-01-01

    Purpose: To explore the effects of microbeam radiation (MR) on vascular biology, we used the chick chorioallantoic membrane (CAM) model of an almost pure vascular system with immature vessels (lacking periendothelial coverage) at Day 8 and mature vessels (with coverage) at Day 12 of development. Methods and Materials: CAMs were irradiated with microplanar beams (width, ∼25 μm; interbeam spacing, ∼200 μm) at entrance doses of 200 or 300 Gy and, for comparison, with a broad beam (seamless radiation [SLR]), with entrance doses of 5 to 40 Gy. Results: In vivo monitoring of Day-8 CAM vasculature 6 h after 200 Gy MR revealed a near total destruction of the immature capillary plexus. Conversely, 200 Gy MR barely affected Day-12 CAM mature microvasculature. Morphological evaluation of Day-12 CAMs after the dose was increased to 300 Gy revealed opened interendothelial junctions, which could explain the transient mesenchymal edema immediately after irradiation. Electron micrographs revealed cytoplasmic vacuolization of endothelial cells in the beam path, with disrupted luminal surfaces; often the lumen was engorged with erythrocytes and leukocytes. After 30 min, the capillary plexus adopted a striated metronomic pattern, with alternating destroyed and intact zones, corresponding to the beam and the interbeam paths within the array. SLR at a dose of 10 Gy caused growth retardation, resulting in a remarkable reduction in the vascular endpoint density 24 h postirradiation. A dose of 40 Gy damaged the entire CAM vasculature. Conclusions: The effects of MR are mediated by capillary damage, with tissue injury caused by insufficient blood supply. Vascular toxicity and physiological effects of MR depend on the stage of capillary maturation and appear in the first 15 to 60 min after irradiation. Conversely, the effects of SLR, due to the arrest of cell proliferation, persist for a longer time.

  8. Evaluation of radio-protective effect of melatonin on whole body irradiation induced liver tissue damage.

    Science.gov (United States)

    Shirazi, Alireza; Mihandoost, Ehsan; Ghobadi, Ghazale; Mohseni, Mehran; Ghazi-Khansari, Mahmoud

    2013-01-01

    Ionizing radiation interacts with biological systems to induce excessive fluxes of free radicals that attack various cellular components. Melatonin has been shown to be a direct free radical scavenger and indirect antioxidant via its stimulatory actions on the antioxidant system.The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced oxidative injury to the rat liver after whole body irradiation. In this experimental study,thirty-two rats were divided into four groups. Group 1 was the control group, group 2 only received melatonin (30 mg/kg on the first day and 30 mg/kg on the following days), group 3 only received whole body gamma irradiation of 10 Gy, and group 4 received 30 mg/kg melatonin 30 minutes prior to radiation plus whole body irradiation of 10 Gy plus 30 mg/kg melatonin daily through intraperitoneal (IP) injection for three days after irradiation. Three days after irradiation, all rats were sacrificed and their livers were excised to measure the biochemical parameters malondialdehyde (MDA) and glutathione (GSH). Each data point represents mean ± standard error on the mean (SEM) of at least eight animals per group. A one-way analysis of variance (ANOVA) was performed to compare different groups, followed by Tukey's multiple comparison tests (p<0.05). The results demonstrated that whole body irradiation induced liver tissue damage by increasing MDA levels and decreasing GSH levels. Hepatic MDA levels in irradiated rats that were treated with melatonin (30 mg/kg) were significantly decreased, while GSH levels were significantly increased, when compared to either of the control groups or the melatonin only group. The data suggest that administration of melatonin before and after irradiation may reduce liver damage caused by gamma irradiation.

  9. Semiparametric profile likelihood estimation for continuous outcomes with excess zeros in a random-threshold damage-resistance model.

    Science.gov (United States)

    Rice, John D; Tsodikov, Alex

    2017-05-30

    Continuous outcome data with a proportion of observations equal to zero (often referred to as semicontinuous data) arise frequently in biomedical studies. Typical approaches involve two-part models, with one part a logistic model for the probability of observing a zero and some parametric continuous distribution for modeling the positive part of the data. We propose a semiparametric model based on a biological system with competing damage manifestation and resistance processes. This allows us to derive a closed-form profile likelihood based on the retro-hazard function, leading to a flexible procedure for modeling continuous data with a point mass at zero. A simulation study is presented to examine the properties of the method in finite samples. We apply the method to a data set consisting of pulmonary capillary hemorrhage area in lab rats subjected to diagnostic ultrasound. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Growth, structural, optical, thermal and laser damage threshold studies of an organic single crystal: 1,3,5 – triphenylbenzene (TPB)

    International Nuclear Information System (INIS)

    Raja, R. Subramaniyan; Babu, G. Anandha; Ramasamy, P.

    2016-01-01

    Good quality single crystals of pure hydrocarbon 1,3,5-Triphenylbenzene (TPB) have been successfully grown using toluene as a solvent using controlled slow cooling solution growth technique. TPB crystallizes in orthorhombic structure with the space group Pna2 1 . The structural perfection of the grown crystal has been analysed by high resolution X-ray diffraction measurements. The range and percentage of the optical transmission are ascertained by recording the UV-vis spectrum. Thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study its thermal properties. Powder second harmonic generation studies were carried out to explore its NLO properties. Laser damage threshold value has been determined using Nd:YAG laser operating at 1064 nm.

  11. Chemical Etching, AFM, Laser Damage Threshold, and Nonlinear Optical Studies of Potential Nonlinear Optical Crystal: Bis (L-Glutamine Potassium Nitrate

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    Redrothu Hanumantharao

    2013-01-01

    Full Text Available A novel semiorganic nonlinear optical crystal bis (L-glutamine potassium nitrate (BGPN grown by slow evaporation technique at ambient temperature. The grown crystal surface has been analyzed by chemical etching and atomic force microscopy (AFM studies. Amplitude parameters like area roughness, roughness average, valley height, valley depth, peak height, and peak valley height were measured successfully from AFM studies. Etching studies were carried out by various solvents like water, methanol and ethanol. The etching study indicates the occurrence of different types of etch pit patterns like striations and steplike pattern. The laser damage threshold energy has been measured by irradiating laser beam using a Q-switched Nd: YAG laser (1064 nm. Second harmonic generation (SHG studies have been performed by famous Kurtz powder technique with reference to standard potassium dihydrogen phosphate single crystals (KDP. It is found from this technique that SHG efficiency of BGPN is in comparison to that of standard KDP crystals.

  12. Outstanding laser damage threshold in Li2MnGeS4 and tunable optical nonlinearity in diamond-like semiconductors.

    Science.gov (United States)

    Brant, Jacilynn A; Clark, Daniel J; Kim, Yong Soo; Jang, Joon I; Weiland, Ashley; Aitken, Jennifer A

    2015-03-16

    The new Li2MnGeS4 and Li2CoSnS4 compounds result from employing a rational and simple design strategy that guides the discovery of diamond-like semiconductors (DLSs) with wide regions of optical transparency, high laser damage threshold, and efficient second-order optical nonlinearity. Single-crystal X-ray diffraction was used to solve and refine the crystal structures of Li2MnGeS4 and Li2CoSnS4, which crystallize in the noncentrosymmetric space groups Pna21 and Pn, respectively. Synchrotron X-ray powder diffraction (SXRPD) was used to assess the phase purity, and diffuse reflectance UV-vis-NIR spectroscopy was used to estimate the bandgaps of Li2MnGeS4 (Eg = 3.069(3) eV) and Li2CoSnS4 (Eg = 2.421(3) eV). In comparison with Li2FeGeS4, Li2FeSnS4, and Li2CoSnS4 DLSs, Li2MnGeS4 exhibits the widest region of optical transparency (0.60-25 μm) and phase matchability (≥1.6 μm). All four of the DLSs exhibit second-harmonic generation and are compared with the benchmark NLO material, AgGaSe2. Most remarkably, Li2MnGeS4 does not undergo two- or three-photon absorption upon exposure to a fundamental Nd:YAG beam (λ = 1.064 μm) and exhibits a laser damage threshold > 16 GW/cm(2).

  13. Telomere elongation protects heart and lung tissue cells from fatal damage in rats exposed to severe hypoxia.

    Science.gov (United States)

    Wang, Yaping; Zhao, Zhen; Zhu, Zhiyong; Li, Pingying; Li, Xiaolin; Xue, Xiaohong; Duo, Jie; Ma, Yingcai

    2018-02-17

    The effects of acute hypoxia at high altitude on the telomere length of the cells in the heart and lung tissues remain unclear. This study aimed to investigate the change in telomere length of rat heart and lung tissue cells in response to acute exposure to severe hypoxia and its role in hypoxia-induced damage to heart and lung tissues. Forty male Wistar rats (6-week old) were randomized into control group (n = 10) and hypoxia group (n = 30). Rats in control group were kept at an altitude of 1500 m, while rats in hypoxia group were exposed to simulated hypoxia with an altitude of 5000 m in a low-pressure oxygen chamber for 1, 3, and 7 days (n = 10). The left ventricular and right middle lobe tissues of each rat were collected for measurement of telomere length and reactive oxygen species (ROS) content, and the mRNA and protein levels of telomerase reverse transcriptase (TERT), hypoxia-inducible factor1α (HIF-1α), and hypoxia-inducible factor1α (HIF-2α). Increased exposure to hypoxia damaged rat heart and lung tissue cells and increased ROS production and telomere length. The mRNA and protein levels of TERT and HIF-1α were significantly higher in rats exposed to hypoxia and increased with prolonged exposure; mRNA and protein levels of HIF-2α increased only in rats exposed to hypoxia for 7 days. TERT was positively correlated with telomere length and the levels of HIF-1α but not HIF-2α. Acute exposure to severe hypoxia causes damage to heart and lung tissues due to the production of ROS but promotes telomere length and adaptive response by upregulating TERT and HIF-1α, which protect heart and lung tissue cells from fatal damage.

  14. Mechanistic simulation of normal-tissue damage in radiotherapy-implications for dose-volume analyses

    International Nuclear Information System (INIS)

    Rutkowska, Eva; Baker, Colin; Nahum, Alan

    2010-01-01

    A radiobiologically based 3D model of normal tissue has been developed in which complications are generated when 'irradiated'. The aim is to provide insight into the connection between dose-distribution characteristics, different organ architectures and complication rates beyond that obtainable with simple DVH-based analytical NTCP models. In this model the organ consists of a large number of functional subunits (FSUs), populated by stem cells which are killed according to the LQ model. A complication is triggered if the density of FSUs in any 'critical functioning volume' (CFV) falls below some threshold. The (fractional) CFV determines the organ architecture and can be varied continuously from small (series-like behaviour) to large (parallel-like). A key feature of the model is its ability to account for the spatial dependence of dose distributions. Simulations were carried out to investigate correlations between dose-volume parameters and the incidence of 'complications' using different pseudo-clinical dose distributions. Correlations between dose-volume parameters and outcome depended on characteristics of the dose distributions and on organ architecture. As anticipated, the mean dose and V 20 correlated most strongly with outcome for a parallel organ, and the maximum dose for a serial organ. Interestingly better correlation was obtained between the 3D computer model and the LKB model with dose distributions typical for serial organs than with those typical for parallel organs. This work links the results of dose-volume analyses to dataset characteristics typical for serial and parallel organs and it may help investigators interpret the results from clinical studies.

  15. Adult Bone Marrow Mesenchymal Stem Cells Primed for fhe Repair of Damaged Cardiac Tissue After Myocardial Infarction

    Science.gov (United States)

    Marks, Edward D.

    The burden of cardiovascular disease around the world is growing, despite improvements in hospital care and time to treatment. As more people survive an initial myocardial infarction (MI), the decompensated heart tissue is strained, leading to heart failure (HF) and an increased risk for a second MI. While extensive progress has been made in treating the symptoms after MI, including HF and angina, little success has come from repairing the damaged heart tissue to alleviate the progression to these end- stage symptoms. One promising area of regenerative research has been the use of adult stem cells, particularly from the bone marrow (BMSCs). These cells can differentiate towards the cardiac cell lineage in vitro while producing trophic factors that can repair damaged tissue. When placed in the heart after MI though, BMSCs have mixed results, producing profound changes in some patients but zero or even negative effects in others. In this report, we used BMSCs as a stem cell base for a regenerative medicine system for the repair of damaged cardiac tissue. These cells are seeded on a polycaprolactone nanoscaffolding support system, which provides a growth substrate for in vitro work, as well as a housing system for protected in vivo delivery. When the nanoscaffold is pre-coated with a novel combination of a cardiac protein, thymosin beta4 (Tbeta4), and a small molecule effector of the WNT protein pathway, IWP-2, BMSCs differentiated towards the cardiac lineage in as little as 24hours. When injected into rat hearts that have been given an ischemic MI, the nanoscaffolding system slowly dissolves, leaving the cells in place of the damaged cardiac tissue. After two weeks of monitoring, BMSCs are present within the damaged hearts, as evidenced by immunofluorescence and nanoparticle tracking. Injections of the nanoscaffolding/cell system led to robust healing of the rat hearts that had been given small- and medium- damage heart attacks, outperforming PBS sham and cell

  16. ALK1 heterozygosity delays development of late normal tissue damage in the irradiated mouse kidney

    International Nuclear Information System (INIS)

    Scharpfenecker, Marion; Floot, Ben; Korlaar, Regina; Russell, Nicola S.; Stewart, Fiona A.

    2011-01-01

    Background and Purpose: Activin receptor-like kinase 1 (ALK1) is a transforming growth factor β (TGF-β) receptor, which is mainly expressed in endothelial cells regulating proliferation and migration in vitro and angiogenesis in vivo. Endothelial cells also express the co-receptor endoglin, which modulates ALK1 effects on endothelial cells. Our previous studies showed that mice with reduced endoglin levels develop less irradiation-induced vascular damage and fibrosis, caused by an impaired inflammatory response. This study was aimed at investigating the role of ALK1 in late radiation toxicity. Material and Methods: Kidneys of ALK +/+ and ALK1 +/- mice were irradiated with 14 Gy. Mice were sacrificed at 10, 20, and 30 weeks after irradiation and gene expression and protein levels were analyzed. Results: Compared to wild type littermates, ALK1 +/- mice developed less inflammation and fibrosis at 20 weeks after irradiation, but displayed an increase in pro-inflammatory and pro-fibrotic gene expression at 30 weeks. In addition, ALK1 +/- mice showed superior vascular integrity at 10 and 20 weeks after irradiation which deteriorated at 30 weeks coinciding with changes in the VEGF pathway. Conclusions: ALK1 +/- mice develop a delayed normal tissue response by modulating the inflammatory response and growth factor expression after irradiation.

  17. Relationship between X-ray irradiation and chromosomal damage in bone marrow tissue of mice

    International Nuclear Information System (INIS)

    Chaubey, R.C.; George, K.P.; Sundaram, K.

    1976-01-01

    X-ray induced chromosomal damage in bone-marrow tissue of male mice was studied using micronucleus technique. Dose response relationship was evaluated. Male Swiss mice received whole body x-ray irradiation at different doses from 25-1000 rads. Animals were sacrificed at the end of 24 hours, bone-marrow smears were made and stained in May-Grunwald-Giemsa. The preparatians were scored for the following types of aberrations: micronuclei in young erythocytes-polychromatic cells and in the mature erythrocytes-normechromatic cells. A dose dependent increase in the frequency of micronuclei in polychromatic cells up to a dose of 100 rads was observed. In addition the effect of post-irradiation duration on the frequency of micronuclei in polychromatic and normochromatic cells were studied. Male Swiss mice were exposed to 200 rads x-rays and were then sacrificed at different time intervals after irradiation and bone-marrow preparations were made and scored. Maximum polychromatic cells with micronuclei were observed in 24 hours post-irradiated animals, thereafter a decrease in the frequency of polychromatic cells with micronuclei was observed in 40 hours post irradiated animals. (author

  18. Space Radiation Effects on Human Cells: Modeling DNA Breakage, DNA Damage Foci Distribution, Chromosomal Aberrations and Tissue Effects

    Science.gov (United States)

    Ponomarev, A. L.; Huff, J. L.; Cucinotta, F. A.

    2011-01-01

    Future long-tem space travel will face challenges from radiation concerns as the space environment poses health risk to humans in space from radiations with high biological efficiency and adverse post-flight long-term effects. Solar particles events may dramatically affect the crew performance, while Galactic Cosmic Rays will induce a chronic exposure to high-linear-energy-transfer (LET) particles. These types of radiation, not present on the ground level, can increase the probability of a fatal cancer later in astronaut life. No feasible shielding is possible from radiation in space, especially for the heavy ion component, as suggested solutions will require a dramatic increase in the mass of the mission. Our research group focuses on fundamental research and strategic analysis leading to better shielding design and to better understanding of the biological mechanisms of radiation damage. We present our recent effort to model DNA damage and tissue damage using computational models based on the physics of heavy ion radiation, DNA structure and DNA damage and repair in human cells. Our particular area of expertise include the clustered DNA damage from high-LET radiation, the visualization of DSBs (DNA double strand breaks) via DNA damage foci, image analysis and the statistics of the foci for different experimental situations, chromosomal aberration formation through DSB misrepair, the kinetics of DSB repair leading to a model-derived spectrum of chromosomal aberrations, and, finally, the simulation of human tissue and the pattern of apoptotic cell damage. This compendium of theoretical and experimental data sheds light on the complex nature of radiation interacting with human DNA, cells and tissues, which can lead to mutagenesis and carcinogenesis later in human life after the space mission.

  19. Honey can repairing damage of liver tissue due to protein energy malnutrition through induction of endogenous stem cells

    Directory of Open Access Journals (Sweden)

    R. Heru Prasetyo

    2017-06-01

    Full Text Available Aim: This study was to evaluate effect of honey in repairing damage of liver tissue due to energy protein malnutrition and in mobilization of endogenous stem cells. Materials and Methods: Male mice model of degenerative liver was obtained through food fasting but still have drinking water for 5 days. It caused energy protein malnutrition and damage of liver tissue. The administration of 50% (v/v honey was performed for 10 consecutive days, while the positive control group was fasted and not given honey and the negative control not fasted and without honey. Observations of regeneration the liver tissue based on histologically examination, observation of Hsp70 expression, and homing signal based on vascular endothelial growth factor-1 (VEGF-1 expression using immunohistochemistry technique. Observation on expression of CD34 and CD45 as the marker of auto mobilization of hematopoietic stem cells using flow cytometry technique. Results: There is regeneration of the liver tissue due to protein energy malnutrition, decrease of Hsp70 expression, increase of VEGF-1 expression, and high expression of CD34 and CD45. Conclusion: Honey can improve the liver tissue based on: (1 Mobilization of endogenous stem cells (CD34 and CD45; (2 Hsp70 and VEGF-1 expressions as regeneration marker of improvement, and (3 regeneration histologically of liver tissue.

  20. Honey can repairing damage of liver tissue due to protein energy malnutrition through induction of endogenous stem cells.

    Science.gov (United States)

    Prasetyo, R Heru; Hestianah, Eka Pramyrtha

    2017-06-01

    This study was to evaluate effect of honey in repairing damage of liver tissue due to energy protein malnutrition and in mobilization of endogenous stem cells. Male mice model of degenerative liver was obtained through food fasting but still have drinking water for 5 days. It caused energy protein malnutrition and damage of liver tissue. The administration of 50% (v/v) honey was performed for 10 consecutive days, while the positive control group was fasted and not given honey and the negative control not fasted and without honey. Observations of regeneration the liver tissue based on histologically examination, observation of Hsp70 expression, and homing signal based on vascular endothelial growth factor-1 (VEGF-1) expression using immunohistochemistry technique. Observation on expression of CD34 and CD45 as the marker of auto mobilization of hematopoietic stem cells using flow cytometry technique. There is regeneration of the liver tissue due to protein energy malnutrition, decrease of Hsp70 expression, increase of VEGF-1 expression, and high expression of CD34 and CD45. Honey can improve the liver tissue based on: (1) Mobilization of endogenous stem cells (CD34 and CD45); (2) Hsp70 and VEGF-1 expressions as regeneration marker of improvement, and (3) regeneration histologically of liver tissue.

  1. Damage of rat liver tissue caused by repeated and sustained +Gz exposure and the mechanism thereof

    Directory of Open Access Journals (Sweden)

    Wen-bing LI

    2014-03-01

    Full Text Available Objective  To explore the mechanisms of positive acceleration (+Gz on the damage of rat liver tissue and the effect of +Gz on the expression of JNK/c-Jun in liver cells. Methods  Twenty four male Wistar rats were randomly divided into 4 groups (n=6: control, +2Gz, +6Gz and +10Gz group. With prone position, the rats in control group were fixed to the turning arm of centrifuge with head towards the axis for 5 minutes. The fixation method in +2Gz, +6Gz and +10Gz group was the same as in the control group. The increase rate of acceleration was 1G/s with a peak-time of 3 minutes, and each +Gz exposure repeated 5 times with an interval of 30 minutes. HE staining was used to observe the morphological changes of liver tissue, fluorescence real-time quantitative PCR to detect the expression of hepatic c-Jun mRNA, and Western blotting to detect the hepatic protein expression of p-c-Jun, c-Jun, p-JNK and JNK. Plasma aspartate aminotransferase (AST and alanine aminotransferase (ALT were determined. Results  The levels of serum ALT and AST increased significantly in +6Gz and, especially, the +10Gz group than in control group and +2Gz group (P<0.05. The same situation also existed in the increase of c-Jun mRNA expression (P<0.05. Hepatic c-jun and p-c-Jun (c-Jun activated form protein expression increased with the increase of G value. Compared with control group, no change was found in JNK protein expression in the other three groups, but the expression of p-JNK (activated form of JNK increased in +6Gz and +10Gz groups (P<0.05. HE staining showed the disorganized liver cells with irregular shapes, the unclear cell gap and the vacuolar changes in +6Gz and +10Gz groups. Conclusions  Repeated and sustained +Gz may cause enhanced expression of c-Jun/ p-c-Jun and p-JNK in hepatic cells. JNK/c-Jun signaling pathway may play an important role in the process of hepatic stress injury. DOI: 10.11855/j.issn.0577-7402.2014.03.15

  2. In vitro prediction of in vivo skin damage associated with the wiping of dry tissue against skin.

    Science.gov (United States)

    Koenig, David W; Dvoracek, Barb; Vongsa, Rebecca

    2013-02-01

    The ideal gentle cleansing product is one that effectively removes soils while minimizing damage to the skin. Thus, measuring physical abrasion caused by cleansing tissues is critical to the continued development of gentle cleansing products. Current analysis of cleansing materials for skin gentleness is time consuming and requires expensive human subject testing. This report describes the development of a rapid and inexpensive bench assay for the assessment of skin abrasion caused by wiping. Coefficient of friction (COF) evaluations using bench methods were compared with results from clinical studies of repeated wiping and with confocal visualizations of excised skin. A Monitor/Slip and Friction instrument (model 32-06; TMI, Amityville, NY, USA) was used to measure tissue friction on simulated skin (Vitro-Skin, N19-5X; IMS, Milford, CT, USA). Clinical data from a 4-day repetitive forearm wiping study measuring transepidermal water loss (TEWL) in 30 subjects was compared with results from the bench top assay. In addition, excised skin samples were also treated using the COF bench assay and examined using confocal microscopy to visualize stratum corneum damage caused by wiping. Using the bench COF assay, we were able to distinguish between bath tissue codes by comparing average static friction value (ASFV) for the test codes, where lower ASFV indicated less abrasive tissue. The ASFV followed the same gentleness trend observed in the clinical study. Confocal microscopy of excised skin wiped with the same materials indicated stratum corneum damage consistent with the bench COF and clinical TEWL observations. We observed significant correlation between bench and clinical methods for measuring skin damage caused by wiping of skin with tissue. The bench method will facilitate rapid and inexpensive skin gentleness assessment of cleansing materials. © 2012 John Wiley & Sons A/S.

  3. The Addition of Manganese Porphyrins during Radiation Inhibits Prostate Cancer Growth and Simultaneously Protects Normal Prostate Tissue from Radiation Damage

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    Arpita Chatterjee

    2018-01-01

    Full Text Available Radiation therapy is commonly used for prostate cancer treatment; however, normal tissues can be damaged from the reactive oxygen species (ROS produced by radiation. In separate reports, we and others have shown that manganese porphyrins (MnPs, ROS scavengers, protect normal cells from radiation-induced damage but inhibit prostate cancer cell growth. However, there have been no studies demonstrating that MnPs protect normal tissues, while inhibiting tumor growth in the same model. LNCaP or PC3 cells were orthotopically implanted into athymic mice and treated with radiation (2 Gy, for 5 consecutive days in the presence or absence of MnPs. With radiation, MnPs enhanced overall life expectancy and significantly decreased the average tumor volume, as compared to the radiated alone group. MnPs enhanced lipid oxidation in tumor cells but reduced oxidative damage to normal prostate tissue adjacent to the prostate tumor in combination with radiation. Mechanistically, MnPs behave as pro-oxidants or antioxidants depending on the level of oxidative stress inside the treated cell. We found that MnPs act as pro-oxidants in prostate cancer cells, while in normal cells and tissues the MnPs act as antioxidants. For the first time, in the same in vivo model, this study reveals that MnPs enhance the tumoricidal effect of radiation and reduce oxidative damage to normal prostate tissue adjacent to the prostate tumor in the presence of radiation. This study suggests that MnPs are effective radio-protectors for radiation-mediated prostate cancer treatment.

  4. Can cell survival parameters be deduced from non-clonogenic assays of radiation damage to normal tissue

    International Nuclear Information System (INIS)

    Michalowski, A.; Wheldon, T.E.; Kirk, J.

    1984-01-01

    The relationship between dose-response curves for large scale radiation injury to tissues and survival curves for clonogenic cells is not necessarily simple. Sterilization of clonogenic cells occurs near-instantaneously compared with the protracted lag period for gross injury to tissues. Moreover, with some types of macroscopic damage, the shapes of the dose-response curves may depend on time of assay. Changes in the area or volume of irradiated tissue may also influence the shapes of these curves. The temporal pattern of expression of large scale injury also varies between tissues, and two distinct groups can be recognized. In rapidly proliferating tissues, lag period is almost independent of dose, whilst in slowly proliferating tissues, it is inversely proportional to dose. This might be explained by invoking differences in corresponding proliferative structures of the tissues. (Three compartmental Type H versus one compartmental Type F proliferative organization). For the second group of tissues particularly, mathematical modelling suggests a systematic dissociation of the dose-response curves for clonogenic cell survival and large scale injury. In particular, it may be difficult to disentangle the contributions made to inter-fraction sparing by cellular repair processes and by proliferation-related factors. (U.K.)

  5. Radiation-induced DNA damage in tumors and normal tissues. II. Influence of dose, residual DNA damage and physiological factors in oxygenated cells

    International Nuclear Information System (INIS)

    Zhang, H.; Wheeler, K.T.

    1994-01-01

    Detection and quantification of hypoxic cells in solid tumors is important for many experimental and clinical situations. Several laboratories, including ours, have suggested that assays which measure radiation-induced DNA strand breaks and DNA-protein crosslinks (DPCs) might be used to detect or quantify hypoxic cells in tumors and normal tissues. Recently, we demonstrated the feasibility of using an alkaline elution assay that measures strand breaks and DPCs to detect and/or quantify hypoxic cells in tissues. For this approach to be valid, DPCs must not be formed to any great extent in irradiated oxygenated cells, and the formation and repair of strand breaks and DPCs in oxygenated cells must not be modified appreciably by physiological factors (e.g., temperature, pH and nutrient depletion) that are often found in solid tumors. To address these issues, two sets of experiments were performed. In one set of experiments, oxygenated 9L cells in tissue culture, subcutaneous 9L tumors and rat cerebella were irradiated with doses of 15 or 50 Gy and allowed to repair until the residual strand break damage was low enough to detect DPCs. In another set of experiments, oxygenated exponentially growing or plateau-phase 9L cells in tissue culture were irradiated with a dose of 15 Gy at 37 or 20 degrees C, while the cells were maintained at a pH of either 6.6 or 7.3. DNA-protein crosslinks were formed in oxygenated cells about 100 times less efficiently than in hypoxic cells. In addition, temperature, pH, nutrient depletion and growth phase did not appreciably alter the formation and repair of strand breaks or the formation of DPCs in oxygenated 9L cells. These results support the use of this DNA damage assay for the detection and quantification of hypoxic cells in solid tumors. 27 refs., 5 tabs

  6. Tissue Damage, Temperature, and pH Induced by Different Electrode Arrays on Potato Pieces (Solanum tuberosum L.

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    Maraelys Morales González

    2018-04-01

    Full Text Available One of the most challenging problems of electrochemical therapy is the design and selection of suitable electrode array for cancer. The aim is to determine how two-dimensional spatial patterns of tissue damage, temperature, and pH induced in pieces of potato (Solanum tuberosum L., var. Mondial depend on electrode array with circular, elliptical, parabolic, and hyperbolic shape. The results show the similarity between the shapes of spatial patterns of tissue damage and electric field intensity, which, like temperature and pH take the same shape of electrode array. The adequate selection of suitable electrodes array requires an integrated analysis that involves, in a unified way, relevant information about the electrochemical process, which is essential to perform more efficiently way the therapeutic planning and the personalized therapy for patients with a cancerous tumor.

  7. Muscle Tissue Damage Induced by the Venom of Bothrops asper: Identification of Early and Late Pathological Events through Proteomic Analysis.

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    Cristina Herrera

    2016-04-01

    Full Text Available The time-course of the pathological effects induced by the venom of the snake Bothrops asper in muscle tissue was investigated by a combination of histology, proteomic analysis of exudates collected in the vicinity of damaged muscle, and immunodetection of extracellular matrix proteins in exudates. Proteomic assay of exudates has become an excellent new methodological tool to detect key biomarkers of tissue alterations for a more integrative perspective of snake venom-induced pathology. The time-course analysis of the intracellular proteins showed an early presence of cytosolic and mitochondrial proteins in exudates, while cytoskeletal proteins increased later on. This underscores the rapid cytotoxic effect of venom, especially in muscle fibers, due to the action of myotoxic phospholipases A2, followed by the action of proteinases in the cytoskeleton of damaged muscle fibers. Similarly, the early presence of basement membrane (BM and other extracellular matrix (ECM proteins in exudates reflects the rapid microvascular damage and hemorrhage induced by snake venom metalloproteinases. The presence of fragments of type IV collagen and perlecan one hour after envenoming suggests that hydrolysis of these mechanically/structurally-relevant BM components plays a key role in the genesis of hemorrhage. On the other hand, the increment of some ECM proteins in the exudate at later time intervals is likely a consequence of the action of endogenous matrix metalloproteinases (MMPs or of de novo synthesis of ECM proteins during tissue remodeling as part of the inflammatory reaction. Our results offer relevant insights for a more integrative and systematic understanding of the time-course dynamics of muscle tissue damage induced by B. asper venom and possibly other viperid venoms.

  8. Oxidative damage parameters in renal tissues of aged and young rats based on gender

    Directory of Open Access Journals (Sweden)

    Uzun D

    2013-06-01

    young control group for both genders. Conclusion: With respect to PCO and AOPP, impaired redox homeostasis is substantially more prominent in males than females. The decrease of G-SH levels in male groups could be attributed to stabilizing the redox status of protein thiol groups by the depletion of the GSH groups. Considering the results, the renal tissue proteins and lipids in different genders may have different susceptibilities to oxidative damage. Keywords: lipid peroxidation, protein oxidation, radicals, renal aging

  9. Mesenchymal Stem Cells From Bone Marrow, Adipose Tissue, and Lung Tissue Differentially Mitigate Lung and Distal Organ Damage in Experimental Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Silva, Johnatas D; Lopes-Pacheco, Miquéias; Paz, Ana H R; Cruz, Fernanda F; Melo, Elga B; de Oliveira, Milena V; Xisto, Débora G; Capelozzi, Vera L; Morales, Marcelo M; Pelosi, Paolo; Cirne-Lima, Elizabeth; Rocco, Patricia R M

    2018-02-01

    Mesenchymal stem cells-based therapies have shown promising effects in experimental acute respiratory distress syndrome. Different mesenchymal stem cells sources may result in diverse effects in respiratory diseases; however, there is no information regarding the best source of mesenchymal stem cells to treat pulmonary acute respiratory distress syndrome. We tested the hypothesis that mesenchymal stem cells derived from bone marrow, adipose tissue, and lung tissue would lead to different beneficial effects on lung and distal organ damage in experimental pulmonary acute respiratory distress syndrome. Animal study and primary cell culture. Laboratory investigation. Seventy-five Wistar rats. Wistar rats received saline (control) or Escherichia coli lipopolysaccharide (acute respiratory distress syndrome) intratracheally. On day 2, acute respiratory distress syndrome animals were further randomized to receive saline or bone marrow, adipose tissue, or lung tissue mesenchymal stem cells (1 × 10 cells) IV. Lung mechanics, histology, and protein levels of inflammatory mediators and growth factors were analyzed 5 days after mesenchymal stem cells administration. RAW 264.7 cells (a macrophage cell line) were incubated with lipopolysaccharide followed by coculture or not with bone marrow, adipose tissue, and lung tissue mesenchymal stem cells (10 cells/mL medium). Regardless of mesenchymal stem cells source, cells administration improved lung function and reduced alveolar collapse, tissue cellularity, collagen, and elastic fiber content in lung tissue, as well as decreased apoptotic cell counts in liver. Bone marrow and adipose tissue mesenchymal stem cells administration also reduced levels of tumor necrosis factor-α, interleukin-1β, keratinocyte-derived chemokine, transforming growth factor-β, and vascular endothelial growth factor, as well as apoptotic cell counts in lung and kidney, while increasing expression of keratinocyte growth factor in lung tissue

  10. Laser-induced damage thresholds of bulk and coating optical materials at 1030  nm, 500  fs.

    Science.gov (United States)

    Gallais, Laurent; Commandré, Mireille

    2014-02-01

    We report on extensive femtosecond laser damage threshold measurements of optical materials in both bulk and thin-film form. This study, which is based on published and new data, involved simple oxide and fluoride films, composite films made from a mixture of two dielectric materials, metallic films, and the surfaces of various bulk materials: oxides, fluorides, semiconductors, and ionic crystals. The samples were tested in comparable conditions at 1030 nm, 375 to 600 fs, under single-pulse irradiation. A large number of different samples prepared by different deposition techniques have been tested, involving classical materials used in the fabrication of optical thin film components (Ag, AlF3, Al2O3, HfO2, MgF2, Nb2O5, Pt, Sc2O3, SiO2, Ta2O5, Y2O3, and ZrO2) and their combination with codeposition processes. Their behaviors are compared with the surfaces of bulk materials (Al2O3, BaF2, CaF2, Ge, KBr, LiF, MgF2, NaCl, Quartz, Si, ZnS, ZnSe, and different silica glasses). Tabulated values of results are presented and discussed.

  11. Synthesis and physicochemical properties of bis(L-asparaginato) zinc(II): A promising new semiorganic crystal with high laser damage threshold for shorter wavelength generation

    Science.gov (United States)

    Subhashini, R.; Arjunan, S.

    2018-05-01

    An exceedingly apparent nonlinear semiorganic optical crystals of bis(L-asparaginato)zinc(II) [BLAZ], was synthesized by a traditional slow evaporation solution growth technique. The cell parameters were estimated from single crystal X-ray diffraction analysis. Spectroscopic study substantiates the presence of functional groups. The UV spectrum shows the sustenance of wide transparency window and several optical constants, such as extinction coefficient (K), refractive index, optical conductivity and electric susceptibility with real and imaginary parts of dielectric constant were calculated using the transmittance data. The fluorescence emission spectrum of the crystal pronounces red emission. The laser induced surface damage threshold of the crystal was measured using Nd:YAG laser. The output intensity of second harmonic generation was estimated using the Kurtz and Perry powder method. The hardness stability was investigated by Vickers microhardness test. The decomposition and thermal stability of the compound were scrutinized by TGA-DSC studies. Dielectric studies were carried out to anatomize the electrical properties of the crystal. SEM analysis reveals the existence of minute crystallites on the growth surface.

  12. Quantitatively characterizing microstructural variations of skin tissues during ultraviolet radiation damaging process based on Mueller matrix polarimetry

    Science.gov (United States)

    Sheng, Wei; He, Honghui; Dong, Yang; Ma, Hui

    2018-02-01

    As one of the most fundamental features of light, polarization can be used to develop imaging techniques which can provide insight into the optical and structural properties of tissues. Especially, the Mueller matrix polarimetry is suitable to detect the changes in collagen and elastic fibres, which are the main compositions of skin tissue. Here we demonstrate a novel quantitative, non-contact and in situ technique to monitor the microstructural variations of skin tissue during ultraviolet radiation (UVR) induced photoaging based on Mueller matrix polarimetry. Specifically, we measure the twodimensional (2D) backscattering Mueller matrices of nude mouse skin samples, then calculate and analyze the Mueller matrix derived parameters during the skin photoaging and self-repairing processes. To induce three-day skin photoaging, the back skin of each mouse is irradiated with UVR (0.05J/cm2) for five minutes per day. After UVR, the microstructures of the nude mouse skin are damaged. During the process of UV damage, we measure the backscattering Mueller matrices of the mouse skin samples and examine the relationship between the Mueller matrix parameters and the microstructural variations of skin tissue quantitatively. The comparisons between the UVR damaged groups with and without sunscreens show that the Mueller matrix derived parameters are potential indicators for fibrous microstructure variation in skin tissue. The pathological examinations and Monte Carlo simulations confirm the relationship between the values of Mueller matrix parameters and the changes of fibrous structures. Combined with smart phones or wearable devices, this technique may have a good application prospect in the fields of cosmetics and dermatological health.

  13. Normal tissue damage in radiotherapy development of a clinical audit tool

    International Nuclear Information System (INIS)

    Barrett, A.

    2001-01-01

    Radiotherapy treatments are evaluated by two main outcomes, rates of cure or local tumour control and normal tissue complication rates. Many excellent schemes have been devised for recording the late effects of radiotherapy treatments including the RTOG and LENT SOMA Scales. These have proved invaluable in documenting the outcome of clinical trials, but have proved too complex and time consuming for routine daily use in busy departments. A group in Eindhoven led by Professor Lybeert undertook a pilot study of a potential way of auditing late radiation complications. Using a simplified form derived from the LENT SOMA scales, they collected data on grade 3 and 4 complications in a total of 675 patients and were able to correlate a number of particular complications with specific protocols, ICD codes and physician practice. Further review of the case records made it possible to identify specific factors which may have led to toxicity and could be taken into account to modify treatment protocols. From September 1999 clinicians in participating centres undertaking normal follow-up procedures were asked to identify patients who showed evidence of grade 3 or 4 toxicity as defined in the pro-forma. Date of radiotherapy was recorded so that a temporal correlation of complication with treatment could be made, but this study did not attempt to assess the incidence of complications, but to provide a cross-sectional study of prevalence. Centres participating in the study have been Eindhoven, Koeln, Gent, Brussels, Glasgow, Mount Vernon, Madrid, Geneva and Lyon. In Eindhoven 651 reports were collected between January 1995 and December 1999. 89 reports had to be discarded because complications were not validated by the reviewing radiotherapists. Dr Lybeert noticed that individual radiotherapists appeared to have different thresholds for reporting specific complications. 13 patients deaths appeared to be related to radiation problems. An overall level of detection of morbidity was

  14. Extensive tissue damage of bovine ovaries after bipolar ovarian drilling compared to monopolar electrocoagulation or carbon dioxide laser.

    Science.gov (United States)

    Hendriks, Marja-Liisa; van der Valk, Paul; Lambalk, Cornelis B; Broeckaert, Mark A M; Homburg, Roy; Hompes, Peter G A

    2010-02-01

    To evaluate the size of ovarian damage caused by ovarian drilling in polycystic ovary syndrome, the amount of inflicted damage was assessed for the most frequently used ovarian drilling techniques. Experimental prospective design. University clinic. Six fresh bovine ovaries per technique. Carbon dioxide (CO(2)) laser, monopolar electrocoagulation, and bipolar electrocoagulation were used for in vitro ovarian drilling. Amount of inflicted ovarian damage per procedure. Bipolar electrocoagulation resulted in significantly more destruction per burn than the CO(2) laser and monopolar electrocoagulation (287.6 versus 24.0 and 70.0 mm(3), respectively). The damage found per lesion was multiplied by the regularly applied number of punctures per procedure in daily practice (based on the literature). Again, the bipolar electrocoagulation resulted in significantly more tissue damage than the CO(2) laser and monopolar coagulation (2,876 versus 599 and 700 mm(3), respectively). Ovarian drilling, especially bipolar electrocoagulation, causes extensive destruction of the ovary. Given the same clinical effectiveness of the various procedures, it is essential to use the lowest possible dose that works; thus, the first choice should be CO(2) laser or monopolar electrocoagulation. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. High throughput DNA damage quantification of human tissue with home-based collection device

    Energy Technology Data Exchange (ETDEWEB)

    Costes, Sylvain V.; Tang, Jonathan; Yannone, Steven M.

    2018-04-03

    Kits, methods and systems for providing a service to provide a subject with information regarding the state of a subject's DNA damage. Collection, processing and analysis of samples are also described.

  16. High throughput DNA damage quantification of human tissue with home-based collection device

    Science.gov (United States)

    Costes, Sylvain V.; Tang, Jonathan; Yannone, Steven M.

    2018-04-03

    Kits, methods and systems for providing a service to provide a subject with information regarding the state of a subject's DNA damage. Collection, processing and analysis of samples are also described.

  17. Synthesis and stabilization of oxide-based colloidal suspensions in organic media: application in the preparation of hybrids organic-inorganic materials for very high laser damage threshold coatings

    International Nuclear Information System (INIS)

    Marchet, N.

    2008-02-01

    Multilayer coatings are widely used in optic and particular in the field of high power laser on the components of laser chains. The development of a highly reflective coating with a laser damage resistance requires the fine-tuning of a multilayer stack constituted by a succession alternated by materials with low and high refractive index. In order to limit the number of layers in the stack, refractive indexes must be optimized. To do it, an original approach consists in synthesizing new organic-inorganic hybrid materials satisfying the criteria of laser damage resistance and optimized refractive index. These hybrid materials are constituted by nano-particles of metal oxides synthesized by sol-gel process and dispersed in an organic polymer with high laser damage threshold. Nevertheless, this composite system requires returning both compatible phases between them by chemical grafting of alc-oxy-silanes or carboxylic acids. We showed that it was so possible to disperse in a homogeneous way these functionalized nano-particles in non-polar, aprotic solvent containing solubilized organic polymers, to obtain time-stable nano-composite solutions. From these organic-inorganic hybrid solutions, thin films with optical quality and high laser damage threshold were obtained. These promising results have permitted to realize highly reflective stacks, constituted by 7 pairs with optical properties in agreement with the theoretical models and high laser damage threshold. (author)

  18. Modification by cystamine of radiation-induced free radical damages to biomolecules in tissues of mouse organs

    International Nuclear Information System (INIS)

    Svistunenko, D.A.; Gudtsova, K.V.

    1989-01-01

    The method of low-temperature ESR-spectroscopy was used to study a modifying effect of cystamine on the yield of radiation-induced free radicals in different biomolecules of liver and spleen tissues of mice. Intraperitoneal administration of cystamine (150 mg/kg) 15 min before isolation and freezing of the tissues was shown to reduce by 11 per cent the yield of radicals of H-adducts of thymine DNA bases, to decrease by 23 per cent the yield of radicals of triacyglycerol and phospholipid radiolysis, and to increase by 24 per cent the yield of radicals of lipid fatty acid residues in splenic tissues. According to the criterion used, cystamine has no modyfying action on the yield of free-radical damages to liver biomolecules

  19. 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

  20. Radioprotection by WR-151327 against the late normal tissue damage in mouse hind legs from gamma ray radiation

    International Nuclear Information System (INIS)

    Matsushita, Satoru; Ando, Koichi; Koike, Sachiko

    1994-01-01

    To evaluate the protective effect of WR-151327 on late radiation-induced damaged to normal tissues in mice, the right hind legs of mice with or without WR-151327 administration (400 mg/kg) were irradiated with 137 Cs gamma rays. Leg contracture and skin shrinkage assays were performed at 380 days after irradiation. The mice were killed on day 400 postirradiation and histological sections of the legs were made. The thickness of the dermis, epidermis, and skin (dermis plus epidermis) was measured. The muscular area of the legs and the posterior knee angle between the femur and tibia were also measured. The left hind legs were similarly assessed as nonirradiated controls. Group means and standard deviations were calculated and dose-response curves were drawn for every endpoint. Then, the dose modifying factor (DMF) for each endpoint and the correlations among endpoints were determined. Latae damage assayed by leg contracture and skin shrinkage progressed with increasing radiation dose. However, it was reduced by drug treatment. The significant effect was indicated for skin shrinkage by a DMF of 1.8 at 35%. The DMF for leg contracture was 1.3 at 6 mm. In the irradiated legs, epidermal hyperplasia and dermal fibrosis in the skin, muscular atrophy, and extension disturbance of the knee joint were observed. These changes progressed with increasing radiation dose. Skin damage assayed by the present endpoints was also reduced by drug treatment by DMFs of 1.4 to 1.7. However, DMFs for damage to the muscle and knee were not determined because no isoeffect was observed. There were good correlations between leg contracture or skin shrinkage and the other endpoints in both untreated and drug-treated mice. WR-151327 has the potential to protect against radiation-induced late normal tissue damage. 17 refs., 6 figs., 2 tabs

  1. A theoretical analysis of damage evolution in skeletal muscle tissue with reference to pressure ulcer development

    NARCIS (Netherlands)

    Breuls, R.G.M.; Bouten, C.V.C.; Oomens, C.W.J.; Bader, D.L.; Baaijens, F.P.T.

    2003-01-01

    Soft tissues are sensitive to prolonged compressive loading, eventually leading to tissue necrosis in the form of pressure ulcers [1]. Pressure ulcers can occur in situations where people are subjected to sustained mechanical loads, such as when bedridden, sitting in a wheelchair or from wearing

  2. Targeted Delivery of Neutralizing Anti-C5 Antibody to Renal Endothelium Prevents Complement-Dependent Tissue Damage

    Directory of Open Access Journals (Sweden)

    Paolo Durigutto

    2017-09-01

    Full Text Available Complement activation is largely implicated in the pathogenesis of several clinical conditions and its therapeutic neutralization has proven effective in preventing tissue and organ damage. A problem that still needs to be solved in the therapeutic control of complement-mediated diseases is how to avoid side effects associated with chronic neutralization of the complement system, in particular, the increased risk of infections. We addressed this issue developing a strategy based on the preferential delivery of a C5 complement inhibitor to the organ involved in the pathologic process. To this end, we generated Ergidina, a neutralizing recombinant anti-C5 human antibody coupled with a cyclic-RGD peptide, with a distinctive homing property for ischemic endothelial cells and effective in controlling tissue damage in a rat model of renal ischemia/reperfusion injury (IRI. As a result of its preferential localization on renal endothelium, the molecule induced complete inhibition of complement activation at tissue level, and local protection from complement-mediated tissue damage without affecting circulating C5. The ex vivo binding of Ergidina to surgically removed kidney exposed to cold ischemia supports its therapeutic use to prevent posttransplant IRI leading to delay of graft function. Moreover, the finding that the ex vivo binding of Ergidina was not restricted to the kidney, but was also seen on ischemic heart, suggests that this RGD-targeted anti-C5 antibody may represent a useful tool to treat organs prior to transplantation. Based on this evidence, we propose preliminary data showing that Ergidina is a novel targeted drug to prevent complement activation on the endothelium of ischemic kidney.

  3. Comparison of single, fractionated and hyperfractionated irradiation on the development of normal tissue damage in rat lung

    International Nuclear Information System (INIS)

    Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

    1985-01-01

    The effect of fractionated thoracic irradiation on the development of normal tissue damage in rats was compared to that produced by single doses. Animals received a single dose of 15 Gy, 30 Gy in 10 daily fractions of 3 Gy each (fractionation), or 30 Gy in 30 fractions of 1 Gy each 3 times a day (hyperfractionation). The treatments produced minimal lethality since a total of only 6 animals died between days 273 and 475 after the initiation of treatment, with no difference in survival observed between the control and any of the 3 treated groups. Despite the lack of lethality, evidence of lung damage was obtained by histological examination. Animals that had received either single doses or fractionated doses had more of the pulmonary parenchyma involved than did animals that had received hyperfractionated doses. The authors conclude that, in the rat lung model, a total radiation dose of 30 Gy fractionated over 14 days produces no more lethality nor damage to lung tissue than does 15 Gy delivered as a single dose. However, long-term effects as evidenced by deposits of collagen and development of fibrosis are significantly reduced by hyperfractionation when compared to single doses and daily fractionation

  4. Speech-in-Noise Tests and Supra-threshold Auditory Evoked Potentials as Metrics for Noise Damage and Clinical Trial Outcome Measures.

    Science.gov (United States)

    Le Prell, Colleen G; Brungart, Douglas S

    2016-09-01

    In humans, the accepted clinical standards for detecting hearing loss are the behavioral audiogram, based on the absolute detection threshold of pure-tones, and the threshold auditory brainstem response (ABR). The audiogram and the threshold ABR are reliable and sensitive measures of hearing thresholds in human listeners. However, recent results from noise-exposed animals demonstrate that noise exposure can cause substantial neurodegeneration in the peripheral auditory system without degrading pure-tone audiometric thresholds. It has been suggested that clinical measures of auditory performance conducted with stimuli presented above the detection threshold may be more sensitive than the behavioral audiogram in detecting early-stage noise-induced hearing loss in listeners with audiometric thresholds within normal limits. Supra-threshold speech-in-noise testing and supra-threshold ABR responses are reviewed here, given that they may be useful supplements to the behavioral audiogram for assessment of possible neurodegeneration in noise-exposed listeners. Supra-threshold tests may be useful for assessing the effects of noise on the human inner ear, and the effectiveness of interventions designed to prevent noise trauma. The current state of the science does not necessarily allow us to define a single set of best practice protocols. Nonetheless, we encourage investigators to incorporate these metrics into test batteries when feasible, with an effort to standardize procedures to the greatest extent possible as new reports emerge.

  5. Demonstration of a 100-mJ OPO/OPA for future lidar applications and laser-induced damage threshold testing of optical components for MERLIN

    Science.gov (United States)

    Elsen, Florian; Livrozet, Marie; Strotkamp, Michael; Wüppen, Jochen; Jungbluth, Bernd; Kasemann, Raphael; Löhring, Jens; Meissner, Ansgar; Meyer, Rudolf; Hoffmann, Hans-Dieter; Poprawe, Reinhart

    2018-02-01

    In the field of atmospheric research, lidar is a powerful technology that can measure gas or aerosol concentrations, wind speed, or temperature profiles remotely. To conduct such measurements globally, spaceborne systems are advantageous. Pulse energies in the 100-mJ range are required to achieve highly accurate, longitudinal resolved measurements. Measuring concentrations of specific gases, such as CH4 or CO2, requires output wavelengths in the IR-B, which can be addressed by optical-parametric frequency conversion. An OPO/OPA frequency conversion setup was designed and built as a demonstration module to address the 1.6-μm range. The pump laser is an Nd:YAG-MOPA system, consisting of a stable oscillator and two subsequent Innoslab-based amplifier stages that deliver up to 500 mJ of output pulse energy at 100 Hz repetition frequency. The OPO is inherited from the OPO design for the CH4 lidar instrument on the French-German climate satellite methane remote-sensing lidar mission (MERLIN). To address the 100-mJ regime, the OPO output beam is amplified in a subsequent multistage OPA. With potassium titanyl phosphate as nonlinear medium, the OPO/OPA delivered more than 100 mJ of output energy at 1645 nm from 450 mJ of the pump energy and a pump pulse duration of 30 ns. This corresponds to a quantum conversion efficiency of about 25%. In addition to demonstrating optical performance for future lidar systems, this laser will be part of a laser-induced damage thresholds test facility, which will be used to qualify optical components especially for the MERLIN.

  6. Growth, spectral, thermal, laser damage threshold, microhardness, dielectric, linear and nonlinear optical properties of an organic single crystal: L-phenylalanine DL-mandelic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jayaprakash, P. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Peer Mohamed, M. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Department of Physics, C. Abdul Hakeem College, Melvisharam 632 509, Tamil Nadu (India); Krishnan, P. [Department of Physics, St. Joseph’s College of Engineering, Chennai 600 119, Tamil Nadu (India); Nageshwari, M.; Mani, G. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Lydia Caroline, M., E-mail: lydiacaroline2006@yahoo.co.in [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India)

    2016-12-15

    Single crystals of L-phenylalanine dl-mandelic acid [C{sub 9}H{sub 11}NO{sub 2}. C{sub 8}H{sub 8}O{sub 3}], have been grown by the slow evaporation technique at room temperature using aqueous solution. The single crystal XRD study confirms monoclinic system for the grown crystal. The functional groups present in the grown crystal have been identified by FTIR and FT-Raman analyses. The optical absorption studies show that the crystal is transparent in the visible region with a lower cut-off wavelength of 257 nm and the optical band gap energy E{sub g} is determined to be 4.62 eV. The Kurtz powder second harmonic generation was confirmed using Nd:YAG laser with fundamental wavelength of 1064 nm. Further, the thermal studies confirmed no weight loss up to 150°C for the as-grown crystal. The photoluminescence spectrum exhibited three peaks (414 nm, 519 nm, 568 nm) due to the donation of protons from carboxylic acid to amino group. Laser damage threshold value was found to be 4.98 GW/cm{sup 2}. The Vickers microhardness test was carried out on the grown crystals and there by Vickers hardness number (H{sub v}), work hardening coefficient (n), yield strength (σ{sub y}), stiffness constant C{sub 11} were evaluated. The dielectric behavior of the crystal has been determined in the frequency range 50 Hz–5 MHz at various temperatures.

  7. Protective effect of hydroalcoholic extract of tribulus terrestris on cisplatin induced renal tissue damage in male mice

    Directory of Open Access Journals (Sweden)

    Amir Raoofi

    2015-01-01

    Full Text Available Background: According beneficial effects of Tribulus terrestris (TT extract on tissue damage, the present study investigated the influence of hydroalcoholic extract of TT plant on cisplatin (CIS (EBEWE Pharma, Unterach, Austria induced renal tissue damage in male mice. Methods: Thirty mice were divided into five groups (n = 6. The first group (control was treated with normal saline (0.9% NaCl and experimental groups with CIS (E1, CIS + 100 mg/kg extract of TT (E2, CIS + 300 mg/kg extract of TT (E3, CIS + 500 mg/kg extract of TT (E4 intraperitoneally. The kidneys were removed after 4 days of injections, and histological evaluations were performed. Results: The data were analyzed using one-way analysis of variance followed by Tukey′s post-hoc test, paired-sample t-test, Kruskal-Wallis and Mann-Whitney tests. In the CIS treated group, the whole kidney tissue showed an increased dilatation of Bowman′s capsule, medullar congestion, and dilatation of collecting tubules and a decreased in the body weight and kidney weight. These parameters reached to the normal range after administration of fruit extracts of TT for 4 days. Conclusions: The results suggested that the oral administration of TT fruit extract at dose 100, 300 and 500 mg/kg body weight provided protection against the CIS induced toxicity in the mice.

  8. Protective Effect of Hydroalcoholic Extract of Tribulus Terrestris on Cisplatin Induced Renal Tissue Damage in Male Mice

    Science.gov (United States)

    Raoofi, Amir; Khazaei, Mozafar; Ghanbari, Ali

    2015-01-01

    Background: According beneficial effects of Tribulus terrestris (TT) extract on tissue damage, the present study investigated the influence of hydroalcoholic extract of TT plant on cisplatin (CIS) (EBEWE Pharma, Unterach, Austria) induced renal tissue damage in male mice. Methods: Thirty mice were divided into five groups (n = 6). The first group (control) was treated with normal saline (0.9% NaCl) and experimental groups with CIS (E1), CIS + 100 mg/kg extract of TT (E2), CIS + 300 mg/kg extract of TT (E3), CIS + 500 mg/kg extract of TT (E4) intraperitoneally. The kidneys were removed after 4 days of injections, and histological evaluations were performed. Results: The data were analyzed using one-way analysis of variance followed by Tukey's post-hoc test, paired-sample t-test, Kruskal–Wallis and Mann–Whitney tests. In the CIS treated group, the whole kidney tissue showed an increased dilatation of Bowman's capsule, medullar congestion, and dilatation of collecting tubules and a decreased in the body weight and kidney weight. These parameters reached to the normal range after administration of fruit extracts of TT for 4 days. Conclusions: The results suggested that the oral administration of TT fruit extract at dose 100, 300 and 500 mg/kg body weight provided protection against the CIS induced toxicity in the mice. PMID:25789143

  9. Protective effect of hydroalcoholic extract of tribulus terrestris on Cisplatin induced renal tissue damage in male mice.

    Science.gov (United States)

    Raoofi, Amir; Khazaei, Mozafar; Ghanbari, Ali

    2015-01-01

    According beneficial effects of Tribulus terrestris (TT) extract on tissue damage, the present study investigated the influence of hydroalcoholic extract of TT plant on cisplatin (CIS) (EBEWE Pharma, Unterach, Austria) induced renal tissue damage in male mice. Thirty mice were divided into five groups (n = 6). The first group (control) was treated with normal saline (0.9% NaCl) and experimental groups with CIS (E1), CIS + 100 mg/kg extract of TT (E2), CIS + 300 mg/kg extract of TT (E3), CIS + 500 mg/kg extract of TT (E4) intraperitoneally. The kidneys were removed after 4 days of injections, and histological evaluations were performed. The data were analyzed using one-way analysis of variance followed by Tukey's post-hoc test, paired-sample t-test, Kruskal-Wallis and Mann-Whitney tests. In the CIS treated group, the whole kidney tissue showed an increased dilatation of Bowman's capsule, medullar congestion, and dilatation of collecting tubules and a decreased in the body weight and kidney weight. These parameters reached to the normal range after administration of fruit extracts of TT for 4 days. The results suggested that the oral administration of TT fruit extract at dose 100, 300 and 500 mg/kg body weight provided protection against the CIS induced toxicity in the mice.

  10. Evaluation of an In Vitro of Human Immune Activation Induced by Freeze-Thaw Tissue Damage

    National Research Council Canada - National Science Library

    DuBose, D

    2002-01-01

    In training and in combat, soldiers are under the constant threat of injury. Injury that results in tissue necrosis can activate the immune system and ultimately enhance disturbances in organ function...

  11. Pathological research on acute hepatic and renal tissue damage in Wistar rats induced by cocoa

    Directory of Open Access Journals (Sweden)

    Chiedozie Onyejiaka Ibegbulem

    2016-01-01

    Conclusions: The pattern of alanine aminotransferase activity being more active than aspartate aminotransferase one in serum appeared to correlate with the extent of disarrangement of hepatic tissue architecture. The experimental rat groups exhibited no hyperbilirubinemia. Also, diets containing processed cocoa bean and raw cocoa bean products did not substantially interfere with the capacity of the hepatocytes to biosynthesize plasma proteins and the functionality of renal tissues.

  12. Neuroprotection and enhanced neurogenesis by extract from the tropical plant Knema laurina after inflammatory damage in living brain tissue.

    Science.gov (United States)

    Häke, Ines; Schönenberger, Silvia; Neumann, Jens; Franke, Katrin; Paulsen-Merker, Katrin; Reymann, Klaus; Ismail, Ghazally; Bin Din, Laily; Said, Ikram M; Latiff, A; Wessjohann, Ludger; Zipp, Frauke; Ullrich, Oliver

    2009-01-03

    Inflammatory reactions in the CNS, resulting from a loss of control and involving a network of non-neuronal and neuronal cells, are major contributors to the onset and progress of several major neurodegenerative diseases. Therapeutic strategies should therefore keep or restore the well-controlled and finely-tuned balance of immune reactions, and protect neurons from inflammatory damage. In our study, we selected plants of the Malaysian rain forest by an ethnobotanic survey, and investigated them in cell-based-assay-systems and in living brain tissue cultures in order to identify anti-inflammatory and neuroprotective effects. We found that alcoholic extracts from the tropical plant Knema laurina (Black wild nutmeg) exhibited highly anti-inflammatory and neuroprotective effects in cell culture experiments, reduced NO- and IL-6-release from activated microglia cells dose-dependently, and protected living brain tissue from microglia-mediated inflammatory damage at a concentration of 30 microg/ml. On the intracellular level, the extract inhibited ERK-1/2-phosphorylation, IkB-phosphorylation and subsequently NF-kB-translocation in microglia cells. K. laurina belongs to the family of Myristicaceae, which have been used for centuries for treatment of digestive and inflammatory diseases and is also a major food plant of the Giant Hornbill. Moreover, extract from K. laurina promotes also neurogenesis in living brain tissue after oxygen-glucose deprivation. In conclusion, extract from K. laurina not only controls and limits inflammatory reaction after primary neuronal damage, it promotes moreover neurogenesis if given hours until days after stroke-like injury.

  13. Analysis of DNA vulnerability to damage, repair and degradation in tissues of irradiated animals

    International Nuclear Information System (INIS)

    Ryabchenko, N.I.; Ivannik, B.P.

    1982-01-01

    Single-strand and paired ruptures of DNA were found to result in appearance of locally denaturated areas in its secondary structure and to disordered protein-DNA interaction. It was shown with the use of the viscosimeter method of measuring the molecular mass of single stranded high-polymeric DNA that cells of various tissues by the intensity of DNA repair can be divided into two groups, rapid- and slow-repair ones. Tissue specificity of enzyme function of the repair systems and systems responsible for post-irradiation DNA degradation depends on the activity of endonucleases synthesized by the cells both in health and in their irradiation-induced synthesis

  14. Apoptosis modulation in the immune system reveals a role of neutrophils in tissue damage in a murine model of chlamydial genital infection.

    Science.gov (United States)

    Zortel, Tom; Schmitt-Graeff, Annette; Kirschnek, Susanne; Häcker, Georg

    2018-03-07

    Chlamydial infection frequently causes damage to the female genital tract. The precise mechanisms of chlamydial clearance and tissue damage are unknown but studies suggest immunopathology with a particular role of neutrophils. The goal of this study was to understand the contribution of the immune system, in particular neutrophils. Using Chlamydia muridarum, we infected mice with a prolonged immune response due to expression of Bcl-2 in haematopoietic cells (Bcl-2-mice), and mice where mature neutrophils are lacking due to the deletion of Mcl-1 in myeloid cells (LysM-cre-mcl-1-flox-mice; Mcl-1-mice). We monitored bacterial clearance, cellular infiltrate and long-term tissue damage. Both mutant strains showed slightly delayed clearance of the acute infection. Bcl-2-mice had a strongly increased inflammatory infiltrate concerning almost all cell lineages. The infection of Bcl-2-mice caused increased tissue damage. The loss of neutrophils in Mcl-1-mice was associated with substantial quantitative and qualitative alterations of the inflammatory infiltrate. Mcl-1-mice had higher chlamydial burden and reduced tissue damage, including lower incidence of hydrosalpinx and less uterine dilation. Inhibition of apoptosis in the haematopoietic system increases inflammation and tissue damage. Neutrophils have broad functions, including a role in chlamydial clearance and in tissue destruction.

  15. Piezosurgery prevents brain tissue damage: an experimental study on a new rat model.

    Science.gov (United States)

    Pavlíková, G; Foltán, R; Burian, M; Horká, E; Adámek, S; Hejčl, A; Hanzelka, T; Sedý, J

    2011-08-01

    Piezosurgery is a promising meticulous system for bone cutting, based on ultrasound microvibrations. It is thought that the impact of piezosurgery on the integrity of soft tissue is generally low, but it has not been examined critically. The authors undertook an experimental study to evaluate the brain tissue response to skull bone removal using piezosurgery compared with a conventional drilling method. In Wistar male rats, a circular bone window was drilled to the parietal bone using piezosurgery on one side and a conventional bone drill on the other side. The behavioural performance of animals was evaluated using the motor BBB test and sensory plantar test. The brains of animals were evaluated by magnetic resonance imaging (MRI) and histology. The results of MRI showed significantly increased depth and width of the brain lesion in the region of conventional drilling compared with the region where piezosurgery was used. Cresylviolet and NF 160 staining confirmed these findings. There was no significant difference in any of the behavioural tests between the two groups. In conclusion, piezosurgery is a safe method for the performance of osteotomy in close relation to soft tissue, including an extremely injury-sensitive tissue such as brain. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. Toe Tissue Transfer for Reconstruction of Damaged Digits due to Electrical Burns

    Directory of Open Access Journals (Sweden)

    Hyung-Do Kim

    2012-03-01

    Full Text Available Background Electrical burns are one of the most devastating types of injuries, and can becharacterized by the conduction of electric current through the deeper soft tissue such asvessels, nerves, muscles, and bones. For that reason, the extent of an electric burn is veryfrequently underestimated on initial impression.Methods From July 1999 to June 2006, we performed 15 cases of toe tissue transfer for thereconstruction of finger defects caused by electrical burns. We performed preoperative rangeof motion exercise, early excision, and coverage of the digital defect with toe tissue transfer.Results We obtained satisfactory results in both functional and aesthetic aspects in all 15cases without specific complications. Static two-point discrimination results in the transferredtoe cases ranged from 8 to 11 mm, with an average of 9.5 mm. The mean range of motionof the transferred toe was 20° to 36° in the distal interphalangeal joint, 16° to 45° in theproximal interphalangeal joint, and 15° to 35° in the metacarpophalangeal joint. All of thepatients were relatively satisfied with the function and appearance of their new digits.Conclusions The strategic management of electrical injury to the hands can be both challengingand complex. Because the optimal surgical method is free tissue transfer, maintenance ofvascular integrity among various physiological changes works as a determining factor for thepostoperative outcome following the reconstruction.

  17. Inflammatory and regenerative responses in salmonids following mechanical tissue damage and natural infection

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian; Lunder, Tor; Nielsen, Michael Engelbrecht

    2010-01-01

    are coding for immunological factors and tissue regeneration. Locale, inflammatory responses were seen as strong up-regulation of IL-1β and IL-8 in both groups of fish, but it was more pronounced in infected fish. Expression of the toll-like receptors showed induction of TLR-5m following infection, but TLR-9...

  18. C60 exposure induced tissue damage and gene expression alterations in the earthworm Lumbricus rubellus

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Handy, R.D.; Heckmann, L.H.; Hout, van der A.; Brink, van den N.W.

    2013-01-01

    Effects of C60 exposure (0, 15 or 154 mg/kg soil) on the earthworm Lumbricus rubellus were assessed at the tissue and molecular level, in two experiments. In the first experiment, earthworms were exposed for four weeks, and in the second lifelong. In both experiments, gene expression of heat shock

  19. Antibodies trap tissue migrating helminth larvae and prevent tissue damage by driving IL-4Rα-independent alternative differentiation of macrophages.

    Directory of Open Access Journals (Sweden)

    Julia Esser-von Bieren

    Full Text Available Approximately one-third of the world's population suffers from chronic helminth infections with no effective vaccines currently available. Antibodies and alternatively activated macrophages (AAM form crucial components of protective immunity against challenge infections with intestinal helminths. However, the mechanisms by which antibodies target these large multi-cellular parasites remain obscure. Alternative activation of macrophages during helminth infection has been linked to signaling through the IL-4 receptor alpha chain (IL-4Rα, but the potential effects of antibodies on macrophage differentiation have not been explored. We demonstrate that helminth-specific antibodies induce the rapid trapping of tissue migrating helminth larvae and prevent tissue necrosis following challenge infection with the natural murine parasite Heligmosomoides polygyrus bakeri (Hp. Mice lacking antibodies (JH (-/- or activating Fc receptors (FcRγ(-/- harbored highly motile larvae, developed extensive tissue damage and accumulated less Arginase-1 expressing macrophages around the larvae. Moreover, Hp-specific antibodies induced FcRγ- and complement-dependent adherence of macrophages to larvae in vitro, resulting in complete larval immobilization. Antibodies together with helminth larvae reprogrammed macrophages to express wound-healing associated genes, including Arginase-1, and the Arginase-1 product L-ornithine directly impaired larval motility. Antibody-induced expression of Arginase-1 in vitro and in vivo occurred independently of IL-4Rα signaling. In summary, we present a novel IL-4Rα-independent mechanism of alternative macrophage activation that is antibody-dependent and which both mediates anti-helminth immunity and prevents tissue disruption caused by migrating larvae.

  20. Relationship between opioid therapy, tissue-damaging procedures, and brain metabolites as measured by proton MRS in asphyxiated term neonates.

    Science.gov (United States)

    Angeles, Danilyn M; Ashwal, Stephen; Wycliffe, Nathaniel D; Ebner, Charlotte; Fayard, Elba; Sowers, Lawrence; Holshouser, Barbara A

    2007-05-01

    To examine the effects of opioid and tissue-damaging procedures (TDPs) [i.e. procedures performed in the neonatal intensive care unit (NICU) known to result in pain, stress, and tissue damage] on brain metabolites, we reviewed the medical records of 28 asphyxiated term neonates (eight opioid-treated, 20 non-opioid treated) who had undergone magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) within the first month of life as well as eight newborns with no clinical findings of asphyxial injury. We found that lower creatine (Cr), myoinositol (Ins), and N-acetylaspartate (NAA)/choline (Cho) (p OGM) NAA/Cr was decreased (p = 0.03) and lactate (Lac) was present in a significantly higher amount (40%; p = 0.03) in non-opioid-treated neonates compared with opioid-treated neonates. Compared with controls, untreated neonates showed larger changes in more metabolites in basal ganglia (BG), thalami (TH), and OGM with greater significance than treated neonates. Our data suggest that TDPs affect spectral metabolites and that opioids do not cause harm in asphyxiated term neonates exposed to repetitive TDPs in the first 2-4 DOL and may provide a degree of neuroprotection.

  1. Comparison of two threshold detection criteria methodologies for determination of probe positivity for intraoperative in situ identification of presumed abnormal 18F-FDG-avid tissue sites during radioguided oncologic surgery.

    Science.gov (United States)

    Chapman, Gregg J; Povoski, Stephen P; Hall, Nathan C; Murrey, Douglas A; Lee, Robert; Martin, Edward W

    2014-09-13

    Intraoperative in situ identification of (18)F-FDG-avid tissue sites during radioguided oncologic surgery remains a significant challenge for surgeons. The purpose of our study was to evaluate the 1.5-to-1 ratiometric threshold criteria method versus the three-sigma statistical threshold criteria method for determination of gamma detection probe positivity for intraoperative in situ identification of presumed abnormal (18)F-FDG-avid tissue sites in a manner that was independent of the specific type of gamma detection probe used. From among 52 patients undergoing appropriate in situ evaluation of presumed abnormal (18)F-FDG-avid tissue sites during (18)F-FDG-directed surgery using 6 available gamma detection probe systems, a total of 401 intraoperative gamma detection probe measurement sets of in situ counts per second measurements were cumulatively taken. For the 401 intraoperative gamma detection probe measurement sets, probe positivity was successfully met by the 1.5-to-1 ratiometric threshold criteria method in 150/401 instances (37.4%) and by the three-sigma statistical threshold criteria method in 259/401 instances (64.6%) (P < 0.001). Likewise, the three-sigma statistical threshold criteria method detected true positive results at target-to-background ratios much lower than the 1.5-to-1 target-to-background ratio of the 1.5-to-1 ratiometric threshold criteria method. The three-sigma statistical threshold criteria method was significantly better than the 1.5-to-1 ratiometric threshold criteria method for determination of gamma detection probe positivity for intraoperative in situ detection of presumed abnormal (18)F-FDG-avid tissue sites during radioguided oncologic surgery. This finding may be extremely important for reshaping the ongoing and future research and development of gamma detection probe systems that are necessary for optimizing the in situ detection of radioisotopes of higher-energy gamma photon emissions used during radioguided oncologic surgery.

  2. Growth, structural, physical and computational perspectives of trans-4-hydroxy-l-proline: a promising organic nonlinear optical material with large laser-induced damage threshold

    Science.gov (United States)

    Thirumurugan, Ramaiah; Anitha, Kandasamy

    2017-05-01

    In this work, a systematic study of an organic nonlinear optical (NLO) material, trans-4-hydroxy-l-proline (THP), C5H9NO3 is reported. An optical quality single crystals of THP have been successfully grown by using slow evaporation solution growth technique (SEST). The single crystal x-ray diffraction (SXRD) analysis reveals that grown crystal belongs to the orthorhombic system with non-centrosymmetric space group (NCS), P212121. Powder x-ray diffraction (PXRD) analysis shows relatively a good crystalline nature. The molecular structure of THP was recognized by NMR (1H and 13C) studies and its vibrational modes were confirmed by FTIR and FT-Raman vibrational studies. UV-Vis-NIR spectrum of grown crystal shows high optical transparency in the visible and near-IR region with low near-UV cut-off wavelength at 218 nm. Photoluminescence study confirms ultraviolet wavelength emission of THP crystal. The second harmonic generation (SHG) efficiency of grown crystal is 1.6 times greater with respect to standard potassium dihydrogen phosphate (KDP). Nonlinear refractive index (n 2) and nonlinear absorption coefficient (β) were determined using the Z-scan technique. The title compound owns high thermal stability of 294 °C and specific heat capacity (C P) of 1.21 J g-1 K-1 at 300 K and 11.33 J g-1 K-1 at 539 K (melting point). The laser-induced damage threshold (LDT) value of grown crystal was measured as 7.25 GW cm-2. The crystal growth mechanism and defects of grown crystal were studied by chemical etching technique. Mechanical strength was extensively studied by Vickers microhardness test and crystal void percentage analysis. Moreover, density functional theory (DFT) studies were carried out to probe the Mulliken charge distribution, frontier molecular orbitals (FMOs) and first order hyperpolarizability (β) of the optimized molecular structure to get a better insight of the molecular properties. These characterization results endorse that grown THP crystal as a

  3. Crystal growth, structural, optical, thermal, mechanical, laser damage threshold and electrical properties of triphenylphosphine oxide 4-nitrophenol (TP4N) single crystals for nonlinear optical applications

    Science.gov (United States)

    Karuppasamy, P.; Senthil Pandian, Muthu; Ramasamy, P.; Verma, Sunil

    2018-05-01

    The optically good quality single crystals of triphenylphosphine oxide 4-nitrophenol (TP4N) with maximum dimension of 15 × 10 × 5 mm3 were grown by slow evaporation solution technique (SEST) at room temperature. The cell dimensions of the grown TP4N crystal were confirmed by single crystal X-ray diffraction (SXRD) and the crystalline purity was confirmed and planes were indexed by powder X-ray diffraction (PXRD) analysis. Functional groups of TP4N crystal were confirmed by Fourier transform infrared (FTIR) spectral analysis. The optical transmittance of the grown crystal was determined by the UV-Vis NIR spectral analysis and it has good optical transparency in the entire visible region. The band tail (Urbach) energy of the grown crystal was analyzed and it appears to be minimum, which indicates that the TP4N has good crystallinity. The position of valence band (Ev) and conduction band (Ec) of the TP4N have been determined from the electron affinity energy (EA) and the ionization energy (EI) of its elements and using the optical band gap. The thermal behaviour of the grown crystal was investigated by thermogravimetric and differential thermal analysis (TG-DTA). Vickers microhardness analysis was carried out to identify the mechanical stability of the grown crystal and their indentation size effect (ISE) was explained by the Meyer's law (ML), Hays-Kendall's (HK) approach, proportional specimen resistance (PSR) model, modified PSR model (MPSR), elastic/plastic deformation (EPD) model and indentation induced cracking (IIC) model. Chemical etching study was carried out to find the etch pit density (EPD) of the grown crystal. Laser damage threshold (LDT) value was measured by using Nd:YAG laser (1064 nm). The dielectric permittivity (ε՛) and dielectric loss (tan δ) as a function of frequency was measured. The electronic polarizability (α) of the TP4N crystal was calculated. It is well matched to the value which was calculated from Clausius-Mossotti relation

  4. Residual tissue post splenectomy detected by splenic scintillography with erythrocytes damaged by heat

    International Nuclear Information System (INIS)

    Rivera B, B.; Garcia C, E.S.; Garcia O, J.R.

    2005-01-01

    Feminine of 26 years old with diagnostic of purple thrombocytopenic idiopathic to those 4 years of age, tried with steroids and splenectomy at 11 years old. Pathway practically asymptomatic until 4 months ago she had presented asthenia, adynamia and general uneasiness, with platelet figures of 40,000 plat/microliter. It was carried out scintillographic study with damaged erythrocytes for post surgical remainder search. Its were took two-dimensional images and tomography by single photon emission (SPECT), being knitted splenic residual in area of anatomical projection of the spleen. (Author)

  5. Effects of cryotherapy combined with therapeutic ultrasound on oxidative stress and tissue damage after musculoskeletal contusion in rats.

    Science.gov (United States)

    Martins, C N; Moraes, M B; Hauck, M; Guerreiro, L F; Rossato, D D; Varela, A S; da Rosa, C E; Signori, L U

    2016-12-01

    To investigate the combined effects of cryotherapy and pulsed ultrasound therapy (PUT) on oxidative stress parameters, tissue damage markers and systemic inflammation after musculoskeletal injury. Experimental animal study. Research laboratory. Seventy male Wistar rats were divided into five groups: control, lesion, cryotherapy, PUT, and cryotherapy+PUT. The gastrocnemius muscle was injured by mechanical crushing. Cryotherapy was applied immediately after injury (immersion in water at 10°C for 20minutes). PUT was commenced 24hours after injury (1MHz, 0.4W/cm 2SPTA , 20% duty cycle, 5minutes). All animals were treated every 8hours for 3 days. Oxidative stress in muscle was evaluated by concentration of reactive oxygen species (ROS), lipid peroxidation (LPO), anti-oxidant capacity against peroxyl radicals (ACAP) and catalase. Plasma levels of creatine kinase (CK), lactate dehydrogenase (LDH) and C-reactive protein (CRP) were assessed. When applied individually, cryotherapy and PUT reduced CK, LDH, CRP and LPO caused by muscle damage. Cryotherapy+PUT in combination maintained the previous results, caused a reduction in ROS [P=0.005, mean difference -0.9×10 -8 relative area, 95% confidence interval (CI) -0.2 to -1.9], and increased ACAP {P=0.007, mean difference 0.34 1/[relative area with/without 2,2-azobis(2-methylpropionamidine)dihydrochloride], 95% CI 0.07 to 0.61} and catalase (P=0.002, mean difference 0.41units/mg protein, 95% CI 0.09 to 0.73) compared with the lesion group. Cryotherapy+PUT in combination reduced oxidative stress in muscle, contributing to a reduction in adjacent damage and tissue repair. Copyright © 2016 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  6. Magnetic Resonance Imaging Allows the Evaluation of Tissue Damage and Regeneration in a Mouse Model of Critical Limb Ischemia.

    Directory of Open Access Journals (Sweden)

    Germana Zaccagnini

    Full Text Available Magnetic resonance imaging (MRI provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time, diffusion-tensor imaging (Fractional Anisotropy and perfusion by Dynamic Contrast-Enhanced MRI (K-trans were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1 T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2 Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3 K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.

  7. Magnetic Resonance Imaging Allows the Evaluation of Tissue Damage and Regeneration in a Mouse Model of Critical Limb Ischemia.

    Science.gov (United States)

    Zaccagnini, Germana; Palmisano, Anna; Canu, Tamara; Maimone, Biagina; Lo Russo, Francesco M; Ambrogi, Federico; Gaetano, Carlo; De Cobelli, Francesco; Del Maschio, Alessandro; Esposito, Antonio; Martelli, Fabio

    2015-01-01

    Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.

  8. Cavitation Induced Structural and Neural Damage in Live Brain Tissue Slices: Relevance to TBI

    Science.gov (United States)

    2014-09-29

    objective of this project is to determine the conditions conducive for cavitation in cerebrospinal fluid (CSF) and corresponding tissue injury in 2-D brain...the radius of an isolated spherical bubble in an infinite, incompressible liquid is given by Where, R is the instantaneous bubble radius, which can...by the pressure transducer placed in the test chamber, and PR is the pressure in the liquid at the boundary of the bubble. The measurable bubble

  9. Voxel-by-voxel analysis of ECD-brain SPECT can separate penumbra from irreversibly damaged tissue at the acute phase of stroke

    International Nuclear Information System (INIS)

    Darcourt, J.; Migneco, O.; David, O.; Bussiere, F.; Mahagne, M.H.; Dunac, A.; Baron, J.C.

    2002-01-01

    Aim. At the acute phase of ischemic stroke, the target of treatment is still salvageable hypoperfused cerebral tissue; so called penumbra. We tested the possibility of separating on early ECD brain SPECT penumbral voxels (P) from irreversibly damaged damaged tissue (IDT). We used ECD which is not only a perfusion tracer but also a metabolic marker. Materials and methods. We prospectively studied 18 patients who underwent ECD-SPECT within the 12 hours following a first-ever acute middle cerebral artery stroke. Neurological evaluation was performed using the Orgogozo's scale at admission and 3 months later in order to calculate and evolution index (IE%) (Martinez-Vila et al.). SPECT data were obtained using a triple head camera equipped with fan beam collimators one hour after injection of 1000 MBq of 99mTc-ECD. On reconstructed images gray matter voxels were automatically segmented. Contralateral healthy hemisphere was used as reference leading to the identification of 3 cortical voxel types: normal (N-SPECT) above 80%; penumbra (P-SPECT) between 80% and 40% and IDT (IDT-SPECT) below 40%. 10 patients also underwent a T2 weighted 3D MRI study at 3 months. Cortical voxels with hypersignal served as reference for IDT (IDT-MRI) the others were considered normal (N-MRI). SPECT and MRI data were co-registered. Therefore each voxel belonged to one of 6 categories (3 SPECT x 2 MRI). Results. (1) The SPECT thresholds were validated on the MRI subgroup. 99% of the N-SPECT voxels were normal on late MRI. 84% of IDT-SPECT voxels corresponded to IDT-MRI. 89% of P-SPECT voxels were normal on late MRI and 11% corresponded to IDT on late MRI. Other categories of voxels (N-SPECT IDT-MRI and IDT-SPECT N-MRI) represented less than 5%. (2) Percentages of each voxel SPECT type was correlated with the EI% on the entire population (Spearman test). P-SPECT extent correlated with EI% improvement (p<0.001) and IDT-SPECT with EI% worsening (p<0.001). Conclusion. Analysis of ECD cortical

  10. Clinical implications of oral candidiasis: host tissue damage and disseminated bacterial disease.

    Science.gov (United States)

    Kong, Eric F; Kucharíková, Sona; Van Dijck, Patrick; Peters, Brian M; Shirtliff, Mark E; Jabra-Rizk, Mary Ann

    2015-02-01

    The clinical significance of polymicrobial interactions, particularly those between commensal species with high pathogenic potential, remains largely understudied. Although the dimorphic fungal species Candida albicans and the bacterium Staphylococcus aureus are common cocolonizers of humans, they are considered leading opportunistic pathogens. Oral candidiasis specifically, characterized by hyphal invasion of oral mucosal tissue, is the most common opportunistic infection in HIV(+) and immunocompromised individuals. In this study, building on our previous findings, a mouse model was developed to investigate whether the onset of oral candidiasis predisposes the host to secondary staphylococcal infection. The findings demonstrated that in mice with oral candidiasis, subsequent exposure to S. aureus resulted in systemic bacterial infection with high morbidity and mortality. Histopathology and scanning electron microscopy of tongue tissue from moribund animals revealed massive C. albicans hyphal invasion coupled with S. aureus deep tissue infiltration. The crucial role of hyphae in the process was demonstrated using a non-hypha-producing and a noninvasive hypha-producing mutant strains of C. albicans. Further, in contrast to previous findings, S. aureus dissemination was aided but not contingent upon the presence of the Als3p hypha-specific adhesion. Importantly, impeding development of mucosal C. albicans infection by administering antifungal fluconazole therapy protected the animals from systemic bacterial disease. The combined findings from this study demonstrate that oral candidiasis may constitute a risk factor for disseminated bacterial disease warranting awareness in terms of therapeutic management of immunocompromised individuals. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

    2015-08-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

  12. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    International Nuclear Information System (INIS)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E.

    2015-01-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm

  13. Alteration of gene expression profile in Niemann-Pick type C mice correlates with tissue damage and oxidative stress.

    Directory of Open Access Journals (Sweden)

    Mary C Vázquez

    Full Text Available BACKGROUND: Niemann-Pick type C disease (NPC is a neurovisceral lipid storage disorder mainly characterized by unesterified cholesterol accumulation in lysosomal/late endosomal compartments, although there is also an important storage for several other kind of lipids. The main tissues affected by the disease are the liver and the cerebellum. Oxidative stress has been described in various NPC cells and tissues, such as liver and cerebellum. Although considerable alterations occur in the liver, the pathological mechanisms involved in hepatocyte damage and death have not been clearly defined. Here, we assessed hepatic tissue integrity, biochemical and oxidative stress parameters of wild-type control (Npc1(+/+; WT and homozygous-mutant (Npc1(-/-; NPC mice. In addition, the mRNA abundance of genes encoding proteins associated with oxidative stress, copper metabolism, fibrosis, inflammation and cholesterol metabolism were analyzed in livers and cerebella of WT and NPC mice. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed various oxidative stress parameters in the liver and hepatic and cerebellum gene expression in 7-week-old NPC1-deficient mice compared with control animals. We found signs of inflammation and fibrosis in NPC livers upon histological examination. These signs were correlated with increased levels of carbonylated proteins, diminished total glutathione content and significantly increased total copper levels in liver tissue. Finally, we analyzed liver and cerebellum gene expression patterns by qPCR and microarray assays. We found a correlation between fibrotic tissue and differential expression of hepatic as well as cerebellar genes associated with oxidative stress, fibrosis and inflammation in NPC mice. CONCLUSIONS/SIGNIFICANCE: In NPC mice, liver disease is characterized by an increase in fibrosis and in markers associated with oxidative stress. NPC is also correlated with altered gene expression, mainly of genes involved in oxidative stress

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

    International Nuclear Information System (INIS)

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

    2000-04-01

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

  15. 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.

  16. Mechanisms of Vascular Damage by Hemorrhagic Snake Venom Metalloproteinases: Tissue Distribution and In Situ Hydrolysis

    Science.gov (United States)

    Baldo, Cristiani; Jamora, Colin; Yamanouye, Norma; Zorn, Telma M.; Moura-da-Silva, Ana M.

    2010-01-01

    Background Envenoming by viper snakes constitutes an important public health problem in Brazil and other developing countries. Local hemorrhage is an important symptom of these accidents and is correlated with the action of snake venom metalloproteinases (SVMPs). The degradation of vascular basement membrane has been proposed as a key event for the capillary vessel disruption. However, SVMPs that present similar catalytic activity towards extracellular matrix proteins differ in their hemorrhagic activity, suggesting that other mechanisms might be contributing to the accumulation of SVMPs at the snakebite area allowing capillary disruption. Methodology/Principal Findings In this work, we compared the tissue distribution and degradation of extracellular matrix proteins induced by jararhagin (highly hemorrhagic SVMP) and BnP1 (weakly hemorrhagic SVMP) using the mouse skin as experimental model. Jararhagin induced strong hemorrhage accompanied by hydrolysis of collagen fibers in the hypodermis and a marked degradation of type IV collagen at the vascular basement membrane. In contrast, BnP1 induced only a mild hemorrhage and did not disrupt collagen fibers or type IV collagen. Injection of Alexa488-labeled jararhagin revealed fluorescent staining around capillary vessels and co-localization with basement membrane type IV collagen. The same distribution pattern was detected with jararhagin-C (disintegrin-like/cysteine-rich domains of jararhagin). In opposition, BnP1 did not accumulate in the tissues. Conclusions/Significance These results show a particular tissue distribution of hemorrhagic toxins accumulating at the basement membrane. This probably occurs through binding to collagens, which are drastically hydrolyzed at the sites of hemorrhagic lesions. Toxin accumulation near blood vessels explains enhanced catalysis of basement membrane components, resulting in the strong hemorrhagic activity of SVMPs. This is a novel mechanism that underlies the difference between

  17. Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Kwangwon [Eulji Univ. Hospital, Daejeon (Korea, Republic of); Kwon, Jungkee [Chonbuk National Univ., Jeonju (Korea, Republic of); Kim, Taewoon [Jeonbuk Technopark, Jeonju (Korea, Republic of)

    2012-03-15

    This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage.

  18. Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

    International Nuclear Information System (INIS)

    Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon; Lee, Kwangwon; Kwon, Jungkee; Kim, Taewoon

    2012-01-01

    This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage

  19. Application of a handheld Pressure Application Measurement device for the characterisation of mechanical nociceptive thresholds in intact pig tails

    DEFF Research Database (Denmark)

    Di Giminiani, Pierpaolo; Sandercock, Dale A.; Malcolm, Emma M.

    2016-01-01

    The assessment of nociceptive thresholds is employed in animals and humans to evaluate changes in sensitivity potentially arising from tissue damage. Its application on the intact pig tail might represent a suitable method to assess changes in nociceptive thresholds arising from tail injury...... to the body was observed (P knowledge, no other...... nociceptive threshold in pig tails. This methodological approach is possibly suitable for assessing changes in tail stump MNTs after tail injury caused by tail docking and biting....

  20. [Interference of vitamin E on the brain tissue damage by electromagnetic radiation of cell phone in pregnant and fetal rats].

    Science.gov (United States)

    Gao, Xian; Luo, Rui; Ma, Bin; Wang, Hui; Liu, Tian; Zhang, Jing; Lian, Zhishun; Cui, Xi

    2013-07-01

    To investigate the interlerence ot vitamin E on brain tissue damage by electromagnetic radiation of cell phone in pregnant and fetal rats. 40 pregnant rats were randomly divided into five groups (positive control, negative control, low, middle and high dosage of vitamin E groups). The low, middle and high dosage of vitamin E groups were supplemented with 5, 15 and 30 mg/ml vitamin E respectively since the first day of pregnancy. And the negative control group and the positive control group were given peanut oil without vitamin E. All groups except for the negative control group were exposed to 900MHz intensity of cell phone radiation for one hour each time, three times per day for 21 days. After accouchement, the right hippocampus tissue of fetal rats in each group was taken and observed under electron microscope. The vitality of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the content of malondialdehyde (MDA) in pregnant and fetal rats' brain tissue were tested. Compared with the negative control group, the chondriosomes in neuron and neuroglia of brain tissues was swelling, mild edema was found around the capillary, chromatin was concentrated and collected, and bubbles were formed in vascular endothelial cells (VEC) in the positive fetal rat control group, whereas the above phenomenon was un-conspicuous in the middle and high dosage of vitamin E groups. We can see uniform chromatin, abundant mitochondrion, rough endoplasmic reticulum and free ribosomes in the high dosage group. The apoptosis has not fond in all groups'sections. In the antioxidase activity analysis, compared with the negative control group, the vitality of SOD and GSH-Px significantly decreased and the content of MDA significantly increased both in the pregnant and fetal rats positive control group (P electromagnetic radiation of cell phone in pregnant rats and fetal rats.

  1. Extensive scarring induced by chronic intrathecal tubing augmented cord tissue damage and worsened functional recovery after rat spinal cord injury.

    Science.gov (United States)

    Zhang, Shu-xin; Huang, Fengfa; Gates, Mary; White, Jason; Holmberg, Eric G

    2010-08-30

    Intrathecal infusion has been widely used to directly deliver drugs or neurotrophins to a lesion site following spinal cord injury. Evidence shows that intrathecal infusion is efficient for 7 days but is markedly reduced after 14 days, due to time dependent occlusion. In addition, extensive fibrotic scarring is commonly observed with intrathecal infusion. These anomalies need to be clearly elucidated in histology. In the present study, all adult Long-Evans rats received a 25 mm contusion injury on spinal cord T10 produced using the NYU impactor device. Immediately after injury, catheter tubing with an outer diameter of 0.38 mm was inserted through a small dural opening at L3 into the subdural space with the tubing tip positioned near the injury site. The tubing was connected to an Alzet mini pump, which was filled with saline solution and was placed subcutaneously. Injured rats without tubing served as control. Rats were behaviorally tested for 6 weeks using the BBB locomotor rating scale and histologically assessed for tissue scarring. Six weeks later, we found that the intrathecal tubing caused extensive scarring and inflammation, related to neutrophils, macrophages and plasma cells. The tubing's tip was occluded by scar tissue and inflammatory cells. The scar tissue surrounding the tubing consists of 20-70 layers of fibroblasts and densely compacted collagen fibers, seriously compressing and damaging the cord tissue. BBB scores of rats with intrathecal tubing were significantly lower than control rats (p<0.01) from 2 weeks after injury, implying serious impairment of functional recovery caused by the scarring. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  2. Photodynamic damage to cartilage and synovial tissue grafted on a chick's chorioallantoic membrane

    Science.gov (United States)

    Fisher, M.; Nahir, A. M.; Kimel, Sol

    1997-09-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints causing pain deformities and disability. The highly vascular inflamed synovium has aggressive and destructive characteristics, it invades, erodes and gradually destroys cartilage and underlying bone. Photodynamic therapy (PDT) was performed using the chick chorioallantoic membrane (CAM) model to investigate the vitality of synovium and cartilage implanted on the CAM. Synovium, obtained from human patients, was grafted onto the CAM; gross microscopy and histology proved its vitality 7 days post grafting. Cartilage obtained from rabbit knee joint was also maintained on the CAM for 7 days. Its vitality was demonstrated by histology and by measuring metabolic and enzymatic activity of cartilage cells (chondrocytes) as well as the collagen and proteoglycans content. Selective PDT was performed using aluminum phthalocyanine tetrasulfonate (AlPcS4), a hydrophilic compound, soluble in biological solutions, as a photosensitizer. After irradiation with a diode laser (lambda equals 670 nm, 10 mW) damage was observed in vascularized synovium grafts, whereas avascular cartilage remained intact.

  3. The influence of water/air cooling on collateral tissue damage using a diode laser with an innovative pulse design (micropulsed mode)-an in vitro study.

    Science.gov (United States)

    Beer, F; Körpert, W; Buchmair, A G; Passow, H; Meinl, A; Heimel, P; Moritz, A

    2013-05-01

    Since the diode laser is a good compromise for the daily use in dental offices, finding usage in numerous dental indications (e.g., surgery, periodontics, and endodontics), the minimization of the collateral damage in laser surgery is important to improve the therapeutical outcome. The aim of this study was to investigate the effect of water/air cooling on the collateral thermal soft tissue damage of 980-nm diode laser incisions. A total of 36 mechanically executed laser cuts in pork liver were made with a 980-nm diode laser in micropulsed mode with three different settings of water/air cooling and examined by histological assessment to determine the area and size of carbonization, necrosis, and reversible tissue damage as well as incision depth and width. In our study, clearly the incision depth increased significantly under water/air cooling (270.9 versus 502.3 μm-test group 3) without significant changes of incision width. In test group 2, the total area of damage was significantly smaller than in the control group (in this group, the incision depth increases by 65 %). In test group 3, the total area of damage was significantly higher (incision depth increased by 85 %), but the bigger part of it represented a reversible tissue alteration leaving the amount of irreversible damage almost the same as in the control group. This first pilot study clearly shows that water/air cooling in vitro has an effect on collateral tissue damage. Further studies will have to verify, if the reduced collateral damage we have proved in this study can lead to accelerated wound healing. Reduction of collateral thermal damage after diode laser incisions is clinically relevant for promoted wound healing.

  4. Mercuric dichloride induces DNA damage in human salivary gland tissue cells and lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Katharina; Kroemer, Susanne [University of Regensburg, Regensburg (Germany); Sassen, Andrea [University of Regensburg, Department of Pathology, Regensburg (Germany); Staudenmaier, Rainer [Technical University of Munich, Department of Otorhinolaryngology, Head and Neck Surgery, Munich (Germany); Reichl, Franz-Xaver [University of Munich, Institute of Pharmacology and Toxicology, Munich (Germany); Harreus, Ulrich [University of Munich, Department of Otorhinolaryngology, Head and Neck Surgery, Munich (Germany); Hagen, Rudolf; Kleinsasser, Norbert [University of Wuerzburg, Department of Otorhinolaryngology, Head and Neck Surgery, Wuerzburg (Germany)

    2007-11-15

    Amalgam is still one of the most frequently used dental filling materials. However, the possible adverse effects especially that of the mercuric component have led to continued controversy. Considering that mercury may be released from amalgam fillings into the oral cavity and also reach the circulating blood after absorption and resorption, it eventually may contribute to tumorigenesis in a variety of target cells. The present investigation focuses on genotoxic effects below a cytotoxic dose level of mercuric dichloride (HgCl{sub 2}) in human samples of salivary glands and lymphocytes to elucidate a possible role in tumor initiation. DNA migration due to single strand breaks, alkali labile sites and incomplete excision repair was quantified with the aid of the single cell microgel electrophoresis (Comet) assay. The concepts of Olive Tail Moment, percentage of DNA in the Tail and Tail Length were used as measures of DNA damage. To control for cytotoxic effects, the trypan blue exclusion test was applied. Human samples of the parotid salivary gland and lymphocytes of ten donors were exposed to HgCl{sub 2} concentrations from 1 to 50 {mu}M. N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and dimethyl sulfoxide (DMSO) served as controls. Increasing dose-dependent DNA migration could be demonstrated after exposure to HgCl{sub 2} in cells of the salivary glands and lymphocytes. In both cell types a significant increase in DNA migration could be shown starting from HgCl{sub 2} concentrations of 5 {mu}M in comparison to the negative control. The viability of the cell systems was not affected except at the highest concentration (50 {mu}M) tested. These data indicate genotoxic effects of mercuric dichloride in human salivary glands and lymphocytes at concentrations not leading to cytotoxic effects or cell death. Consequently, a contributory role in oral salivary gland tumor initiation warrants further investigation. (orig.)

  5. Protective effect of pumpkin powder (Cucurbita pepo L. on fetal testicular tissue damage in alloxan- induced diabetic rats

    Directory of Open Access Journals (Sweden)

    2014-08-01

    Full Text Available The occurrence of abnormalities in different organs of the fetus and newborn of diabetic mothers has been proven today. Considering the irreversible damages of the disease in newborns’ reproductive system any action to reduce the abnormalities has an especial importance and necessity. In this experimental study, the protective effects of pumpkin powder on reducing testicular tissue damages of rats born from diabetic mothers has been studied. The pregnant rats were divided into 4 groups of 10 rats, as follows: 1 treatment group with pumpkin powder, 2 diabetic control group, 3 treatment group (diabetic animals treated with pumpkin powder and 4 healthy control group. Experimental diabetes was induced in pregnant rats by intraperitoneal injection of 120 mg/kg b.w. alloxan monohydrate. The first and third groups received 2 g/kg b.w. pumpkin powder for 4 weeks via gavage. The histological and morphometric changes such as weight, seminiferous tubules diameter, spermatogonia, leydig and sertoli cell numbers were compared. Data was analyzed using the ANOVA and Tukey multiple comparisons test and p

  6. Innate lymphoid cells: the role in respiratory infections and lung tissue damage.

    Science.gov (United States)

    Głobińska, Anna; Kowalski, Marek L

    2017-10-01

    Innate lymphoid cells (ILCs) represent a diverse family of cells of the innate immune system, which play an important role in regulation of tissue homeostasis, immunity and inflammation. Emerging evidence has highlighted the importance of ILCs in both protective immunity to respiratory infections and their pathological roles in the lungs. Therefore, the aim of this review is to summarize the current knowledge, interpret and integrate it into broader perspective, enabling greater insight into the role of ILCs in respiratory diseases. Areas covered: In this review we highlighted the role of ILCs in the lungs, citing the most recent studies in this area. PubMed searches (2004- July 2017) were conducted using the term 'innate lymphoid cells respiratory viral infections' in combination with other relevant terms including various respiratory viruses. Expert commentary: Since studies of ILCs have opened new areas of investigation, understanding the role of ILCs in respiratory infections may help to clarify the mechanisms underlying viral-induced exacerbations of lung diseases, providing the basis for novel therapeutic strategies. Potential therapeutic targets have already been identified. So far, the most promising strategy is cytokine-targeting, although further clinical trials are needed to verify its effectiveness.

  7. Can Rotational Atherectomy Cause Thermal Tissue Damage? A Study of the Potential Heating and Thermal Tissue Effects of a Rotational Atherectomy Device

    International Nuclear Information System (INIS)

    Gehani, Abdurrazzak A.; Rees, Michael R.

    1998-01-01

    Purpose: Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device. Methods: We used a high-resolution infrared imaging system that can detect changes as small as 0.1 deg. C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy. Results: There was significant heating of the rotating cam. The mean 'peak' temperature rise was 52.8 ± 16.9 deg. C. This was related to rotational speed; thus the 'peak' temperature rise was 88.3 ± 12.6 deg. C at 80,000 rpm and 17.3 ± 3.8 deg. C at 20,000 rpm (p < 0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 ± 2.9 deg. C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of 'thermal' tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence. (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds. (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p < 0.05). (iv) None of the above changes was seen in control segments. Conclusion: RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices

  8. Global Proteomic Analysis of Brain Tissues in Transient Ischemia Brain Damage in Rats

    Directory of Open Access Journals (Sweden)

    Jiann-Hwa Chen

    2015-05-01

    Full Text Available Ischemia-reperfusion injury resulting from arterial occlusion or hypotension in patients leads to tissue hypoxia with glucose deprivation, which causes endoplasmic reticulum (ER stress and neuronal death. A proteomic approach was used to identify the differentially expressed proteins in the brain of rats following a global ischemic stroke. The mechanisms involved the action in apoptotic and ER stress pathways. Rats were treated with ischemia-reperfusion brain injuries by the bilateral occlusion of the common carotid artery. The cortical neuron proteins from the stroke animal model (SAM and the control rats were separated using two-dimensional gel electrophoresis (2-DE to purify and identify the protein profiles. Our results demonstrated that the SAM rats experienced brain cell death in the ischemic core. Fifteen proteins were expressed differentially between the SAM rats and control rats, which were assayed and validated in vivo and in vitro. Interestingly, the set of differentially expressed, down-regulated proteins included catechol O-methyltransferase (COMT and cathepsin D (CATD, which are implicated in oxidative stress, inflammatory response and apoptosis. After an ischemic stroke, one protein spot, namely the calretinin (CALB2 protein, showed increased expression. It mediated the effects of SAM administration on the apoptotic and ER stress pathways. Our results demonstrate that the ischemic injury of neuronal cells increased cell cytoxicity and apoptosis, which were accompanied by sustained activation of the IRE1-alpha/TRAF2, JNK1/2, and p38 MAPK pathways. Proteomic analysis suggested that the differential expression of CALB2 during a global ischemic stroke could be involved in the mechanisms of ER stress-induced neuronal cell apoptosis, which occurred via IRE1-alpha/TRAF2 complex formation, with activation of JNK1/2 and p38 MAPK. Based on these results, we also provide the molecular evidence supporting the ischemia

  9. The effects of different fractions of Coriandrum sativum on pentylenetetrazole-induced seizures and brain tissues oxidative damage in rats

    Directory of Open Access Journals (Sweden)

    Akbar Anaeigoudari

    2016-03-01

    Full Text Available Objective: In the present work, the effects of different fractions of Coriandrum sativum (C. sativum, on pentylenetetrazole (PTZ-induced seizures and brain tissues oxidative damage were investigated in rats. Materials and Methods: The rats were divided into the following groups: (1 vehicle, (2 PTZ (90 mg/kg, (3 water fraction (WF of C. sativum (25 and 100 mg/kg, (4 n-butanol fraction (NBF of C. sativum (25 and 100 mg/kg, and (5 ethyl acetate fraction (EAF of C. sativum (25 and 100 mg/kg. Results: The first generalized tonic-clonic seizures (GTCS latency in groups treated with 100 mg /kg of WF or EAF was significantly higher than that of PTZ group (p< 0.01. In contrast to WF, the EAF and NBF were not effective in increasing the first minimal clonic seizure (MCS latency. Malondialdehyde (MDA levels in both cortical and hippocampal tissues of PTZ group were significantly higher than those of control animals (p< 0.001. Pretreatment with WF, NBF, or EAF resulted in a significant reduction in the MDA levels of hippocampi (pConclusion: The present study showed that different fractions of C. sativum possess antioxidant activity in the brain and WF and EAF of this plant have anticonvulsant effects.

  10. ALKBH7 drives a tissue and sex-specific necrotic cell death response following alkylation-induced damage

    Science.gov (United States)

    Jordan, Jennifer J; Chhim, Sophea; Margulies, Carrie M; Allocca, Mariacarmela; Bronson, Roderick T; Klungland, Arne; Samson, Leona D; Fu, Dragony

    2017-01-01

    Regulated necrosis has emerged as a major cell death mechanism in response to different forms of physiological and pharmacological stress. The AlkB homolog 7 (ALKBH7) protein is required for regulated cellular necrosis in response to chemotherapeutic alkylating agents but its role within a whole organism is unknown. Here, we show that ALKBH7 modulates alkylation-induced cellular death through a tissue and sex-specific mechanism. At the whole-animal level, we find that ALKBH7 deficiency confers increased resistance to MMS-induced toxicity in male but not female mice. Moreover, ALKBH7-deficient mice exhibit protection against alkylation-mediated cytotoxicity in retinal photoreceptor and cerebellar granule cells, two cell types that undergo necrotic death through the initiation of the base excision repair pathway and hyperactivation of the PARP1/ARTD1 enzyme. Notably, the protection against alkylation-induced cerebellar degeneration is specific to ALKBH7-deficient male but not female mice. Our results uncover an in vivo role for ALKBH7 in mediating a sexually dimorphic tissue response to alkylation damage that could influence individual responses to chemotherapies based upon alkylating agents. PMID:28726787

  11. Safety and effectiveness of a polyvinyl alcohol barrier in reducing risks of vascular tissue damage during anterior spinal revision surgery.

    Science.gov (United States)

    Jeffords, Paul; Li, Jinsheng; Panchal, Deepal; Denoziere, Guilhem; Fetterolf, Donald

    2012-05-01

    This study was conducted as a controlled, prospective investigation to show the safety and efficacy of a polyvinyl alcohol (PVA) device in a sheep model. To evaluate the ability of a permanent PVA hydrogel barrier to reduce the risk of potential vessel damage during anterior vertebral revision surgery, to provide a nonadhesive barrier at the surgical site, and to create a surgical revision plane of dissection. The development of scar tissue and adhesions presents a significant postoperative problem in spine surgery, where adhesion involvement of overlying structures can cause pain, neurovascular complications, and present a difficult surgical environment during revisions. The devices were implanted onto the ventral surface of exposed lumbar intervertebral discs using an anterolateral approach. One disc separated from the study site was also exposed to serve as a control. Three sheep each were then evaluated with an explant procedure at 30 and 90 days. Extensive sampling was undertaken to evaluate gross anatomic, micropathologic, and biochemical environments and properties of the device. The structural properties and appearance of the device remained intact at both 30 and 90 days. The material remained flexible, hydrophilic, and soft, without visible resorption or decomposition. The material was well tolerated by the animal, with minimal histologic signs of inflammation or rejection. Tissue planes were easily able to be localized by the surgeon attempting to locate the prior surgical site at the time of resection. The PVA vessel shield effectively protected the structures overlying the sheep spine during revision, providing a clear dissection plane for resection at repeat surgery. The overlying structures separated from the previous surgical site with no adhesion, and allowed safe separation of adjacent tissues without the use of sharp dissection.

  12. Differences in supratentorial white matter diffusion after radiotherapy - New biomarker of normal brain tissue damage?

    Energy Technology Data Exchange (ETDEWEB)

    Ravn, Soeren; Jens Broendum Froekaer, Jens [Dept. of Radiology, Aalborg Univ. Hospital, Aalborg (Denmark)], e-mail: sorl@rn.dk; Holmberg, Mats [Dept. of Oncology, Aalborg Univ. Hospital, Aalborg (Denmark); Soerensen, Preben [Dept. of Neurosurgery, Aalborg Univ. Hospital, Aalborg (Denmark); Carl, Jesper [Dept. of Neurosurgery, Aalborg Univ. Hospital, Aalborg (Denmark)

    2013-10-15

    Introduction: Therapy-induced injury to normal brain tissue is a concern in the treatment of all types of brain tumours. The purpose of this study was to investigate if magnetic resonance diffusion tensor imaging (DTI) could serve as a potential biomarker for the assessment of radiation-induced long-term white matter injury. Material and methods: DTI- and T1-weighted images of the brain were obtained in 19 former radiotherapy patients [nine men and 10 women diagnosed with astrocytoma (4), pituitary adenoma (6), meningioma (8) and craniopharyngioma (1), average age 57.8 (range 35-71) years]. Average time from radiotherapy to DTI scan was 4.6 (range 2.0-7.1) years. NordicICE software (NIC) was used to calculate apparent diffusion coefficient maps (ADC-maps). The co-registration between T1 images and ADC-maps were done using the auto function in NIC. The co-registration between the T1 images and the patient dose plans were done using the auto function in the treatment planning system Eclipse from Varian. Regions of interest were drawn on the T1-weighted images in NIC based on iso curves from Eclipse. Data was analysed by t-test. Estimates are given with 95 % CI. Results: A mean ADC difference of 4.6(0.3;8.9) X 10{sup -5} mm{sup 2}/s, p = 0.03 was found between paired white matter structures with a mean dose difference of 31.4 Gy. Comparing the ADC-values of the areas with highest dose from the paired data (dose > 33 Gy) with normal white matter (dose < 5 Gy) resulted in a mean dose difference of 44.1 Gy and a mean ADC difference of 7.87(3.15;12.60) X 10{sup -5} mm{sup 2}/s, p = 0.003. Following results were obtained when looking at differences between white matter mean ADC in average dose levels from 5 to 55 Gy in steps of 10 Gy with normal white matter mean ADC: 5 Gy; 1.91(-1.76;5.58) X 10{sup -5} mm{sup 2}/s, p = 0.29; 15 Gy; 5.81(1.53;10.11) X 10{sup -5} mm{sup 2}/s, p = 0.01; 25 Gy; 5.80(2.43;9.18) X 10{sup -5} mm{sup 2}/s, p = 0.002; 35 Gy; 5.93(2.89;8.97) X 10

  13. The role of platelet factor 4 in local and remote tissue damage in a mouse model of mesenteric ischemia/reperfusion injury.

    Directory of Open Access Journals (Sweden)

    Peter H Lapchak

    Full Text Available The robust inflammatory response that occurs during ischemia reperfusion (IR injury recruits factors from both the innate and adaptive immune systems. However the contribution of platelets and their products such as Platelet Factor 4 (PF4; CXCL4, during the pathogenesis of IR injury has not been thoroughly investigated. We show that a deficiency in PF4 protects mice from local and remote tissue damage after 30 minutes of mesenteric ischemia and 3 hours of reperfusion in PF4-/- mice compared to control B6 mice. This protection was independent from Ig or complement deposition in the tissues. However, neutrophil and monocyte infiltration were decreased in the lungs of PF4-/- mice compared with B6 control mice. Platelet-depleted B6 mice transfused with platelets from PF4-/- mice displayed reduced tissue damage compared with controls. In contrast, transfusion of B6 platelets into platelet depleted PF4-/- mice reconstituted damage in both intestine and lung tissues. We also show that PF4 may modulate the release of IgA. Interestingly, we show that PF4 expression on intestinal epithelial cells is increased after IR at both the mRNA and protein levels. In conclusion, these findings demonstrate that may PF4 represent an important mediator of local and remote tissue damage.

  14. Renal deterioration caused by carcinogens as a consequence of free radical mediated tissue damage: a review of the protective action of melatonin

    Energy Technology Data Exchange (ETDEWEB)

    Gultekin, Fatih; Hicyilmaz, Hicran [Suleyman Demirel University, School of Medicine, Department of Biochemistry, Isparta (Turkey)

    2007-10-15

    This brief review summarizes some of the publications that document the preventive role of melatonin in kidney damage caused by carcinogens such as 2-nitropropane, arsenic, carbon tetrachloride, nitrilotriacetic acid and potassium bromate. Numerous chemicals generate excessive free radicals that eventually induce renal worsening. Melatonin partially or totally prevents free radical mediated tissue damages induced by many carcinogens. Protective actions of melatonin against the harmful effects of carcinogens are believed to stem from its direct free radical scavenging and indirect antioxidant activities. Dietary or pharmacologically given melatonin may attenuate the oxidative stress, thereby mitigating the subsequent renal damage. (orig.)

  15. A quantitative and non-contact technique to characterise microstructural variations of skin tissues during photo-damaging process based on Mueller matrix polarimetry.

    Science.gov (United States)

    Dong, Yang; He, Honghui; Sheng, Wei; Wu, Jian; Ma, Hui

    2017-10-31

    Skin tissue consists of collagen and elastic fibres, which are highly susceptible to damage when exposed to ultraviolet radiation (UVR), leading to skin aging and cancer. However, a lack of non-invasive detection methods makes determining the degree of UVR damage to skin in real time difficult. As one of the fundamental features of light, polarization can be used to develop imaging techniques capable of providing structural information about tissues. In particular, Mueller matrix polarimetry is suitable for detecting changes in collagen and elastic fibres. Here, we demonstrate a novel, quantitative, non-contact and in situ technique based on Mueller matrix polarimetry for monitoring the microstructural changes of skin tissues during UVR-induced photo-damaging. We measured the Mueller matrices of nude mouse skin samples, then analysed the transformed parameters to characterise microstructural changes during the skin photo-damaging and self-repairing processes. Comparisons between samples with and without the application of a sunscreen showed that the Mueller matrix-derived parameters are potential indicators for fibrous microstructure in skin tissues. Histological examination and Monte Carlo simulations confirmed the relationship between the Mueller matrix parameters and changes to fibrous structures. This technique paves the way for non-contact evaluation of skin structure in cosmetics and dermatological health.

  16. Changes in markers of oxidative stress and DNA damage in human visceral adipose tissue from subjects with obesity and type 2 diabetes.

    Science.gov (United States)

    Jones, D A; Prior, S L; Barry, J D; Caplin, S; Baxter, J N; Stephens, J W

    2014-12-01

    In the past 30 years, prevalence of obesity has almost trebled resulting in an increased incidence of type 2 diabetes mellitus and other co-morbidities. Visceral adipose tissue is believed to play a vital role, but underlying mechanisms remain unclear. Our aim was to investigate changes in markers of oxidative damage in human visceral adipose tissue to determine levels of oxidative burden that may be attributed to obesity and/or diabetes. Visceral adipose tissue samples from 61 subjects undergoing abdominal surgery grouped as lean, obese and obese with type 2 diabetes mellitus, were examined using 3 different markers of oxidative stress. Malondialdehyde (MDA) concentration was measured as a marker of lipid peroxidation, telomere length and Comet assay as markers of oxidative DNA damage. No significant difference in MDA concentration, telomere length and DNA damage was observed between groups, although longer telomere lengths were seen in the obese with diabetes group compared to the obese group (Pstress and DNA damage was observed in samples from subjects with type 2 diabetes mellitus. Further work is required to investigate this further, however this phenomenon may be due to an up regulation of antioxidant defences in adipose tissue. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Radioprotective effects of hesperidin on oxidative damages and histopathological changes induced by X-irradiation in rats heart tissue

    Directory of Open Access Journals (Sweden)

    Abolhasan Rezaeyan

    2016-01-01

    Full Text Available This study was carried out to evaluate radioprotective effects of hesperidin (HES administration before the irradiation on the cardiac oxidative stress and histopathological changes in an experimental rat model. The cardiovascular complications of radiation exposure cause morbidity and mortality in patients who received radiotherapy. HES, an antioxidant flavonoid found in citrus fruits, suggests the protection against the tissue damage. Fifty-eight rats were divided into four groups: Group 1 received phosphate buffered saline (PBS and sham radiation; Group 2, HES and sham radiation; Group 3, PBS and radiation; and Group 4, HES and radiation. The rats were exposed to single dose of 18 Gy of 6 MV X-ray. One hundred milligrams per kilogram doses of HES was administered for 7 days before irradiation. The estimation of superoxide dismutase (SOD, malondialdehyde (MDA, and histopathological analyses was performed at 24 h and 8 weeks after radiation exposure. The irradiation of chest area resulted in an elevated MDA level and decreased SOD activity. Moreover, long-term pathological lesions of radiation were inflammation, fibrosis, the increased number of mast cells and macrophages, and development of plaque, vascular leakage, myocardial degeneration, and myocyte necrosis. Although the administration of HES decreases inflammation, fibrosis, mast cell and macrophage numbers, and myocyte necrosis, it did not result in reduced thrombus, myocardium degeneration, and vascular leakage. In conclusion, these results suggest that HES can perform a radioprotection action. The protective effect of HES may be attributable to its immunomodulatory effects and free radical-scavenging properties.

  18. The effects of vitamin E on brain derived neurotrophic factor, tissues oxidative damage and learning and memory of juvenile hypothyroid rats.

    Science.gov (United States)

    Baghcheghi, Yousef; Beheshti, Farimah; Shafei, Mohammad Naser; Salmani, Hossein; Sadeghnia, Hamid Reza; Soukhtanloo, Mohammad; Anaeigoudari, Akbar; Hosseini, Mahmoud

    2018-06-01

    The effects of vitamin E (Vit E) on brain derived neurotrophic factor (BDNF) and brain tissues oxidative damage as well as on learning and memory impairments in juvenile hypothyroid rats were examined. The rats were grouped as: (1) Control; (2) Propylthiouracil (PTU); (3) PTU-Vit E and (4) Vit E. PTU was added to their drinking water (0.05%) during 6 weeks. Vit E (20 mg/kg) was daily injected (IP). Morris water maze (MWM) and passive avoidance (PA) were carried out. The animals were deeply anesthetized and the brain tissues were removed for biochemical measurements. PTU increased the escape latency and traveled path in MWM (P E (P E improved BDNF, thiol, SOD and CAT while diminished MDA. The results of the present study showed that Vit E improved BDNF and prevented from brain tissues oxidative damage as well as learning and memory impairments in juvenile hypothyroid rats.

  19. Tissue

    Directory of Open Access Journals (Sweden)

    David Morrissey

    2012-01-01

    Full Text Available Purpose. In vivo gene therapy directed at tissues of mesenchymal origin could potentially augment healing. We aimed to assess the duration and magnitude of transene expression in vivo in mice and ex vivo in human tissues. Methods. Using bioluminescence imaging, plasmid and adenoviral vector-based transgene expression in murine quadriceps in vivo was examined. Temporal control was assessed using a doxycycline-inducible system. An ex vivo model was developed and optimised using murine tissue, and applied in ex vivo human tissue. Results. In vivo plasmid-based transgene expression did not silence in murine muscle, unlike in liver. Although maximum luciferase expression was higher in muscle with adenoviral delivery compared with plasmid, expression reduced over time. The inducible promoter cassette successfully regulated gene expression with maximum levels a factor of 11 greater than baseline. Expression was re-induced to a similar level on a temporal basis. Luciferase expression was readily detected ex vivo in human muscle and tendon. Conclusions. Plasmid constructs resulted in long-term in vivo gene expression in skeletal muscle, in a controllable fashion utilising an inducible promoter in combination with oral agents. Successful plasmid gene transfection in human ex vivo mesenchymal tissue was demonstrated for the first time.

  20. Correlation of damage threshold and surface geometry of nodular defects in HR coatings as determined by in-situ atomic force microscopy

    International Nuclear Information System (INIS)

    Staggs, M.C.; Kozlowski, M.R.; Siekhaus, W.J.; Balooch, M.

    1992-10-01

    Atomic force microscopy (AFM) was used to determine in-situ the correlation between the surface dimensions of defects in dielectric multilayer optical coatings and their susceptibility to damage by pulsed laser illumination. The primary surface defects studied were μm-scale domes associated with the classic nodule defect. The optical film studied was a highly reflective dielectric multilayer consisting of pairs of alternating HfO 2 and SiO 2 layers of quarter wave thickness at 1.06 μm. Nodule defect height and width dimensions were measured prior to laser illumination on two different samples. Correlation between these dimensions supported a simple model for the defect geometry. Defects with high nodule heights (> 0.6 μm) were found to be most susceptible to laser damage over a range of fluences between 0-35 J/cm 2 (1.06 μm, 10 ns, and 1/e 2 diam. of 1.3 mm). Crater defects, formed by nodules ejected from the coating prior to illumination, were also studied. None of the crater defects damaged when illuminated over the same range of fluences that the nodule defects were subjected to

  1. [Effect of Medicated-catgut Embedding at "Changqiang" (GV 1) on Mechanical Pain Threshold and P 38 MAPK Expression in Spinal Cord Tissue in Anus Incisional Pain Rats].

    Science.gov (United States)

    Shu, Tao; Zhang, Shi-Ti; Yan, Feng; Ke, Yu-Pei; Wang, Jun

    2017-10-25

    To observe the effect of medicated-catgut embedding at "Changqiang"(GV 1) on regional pain reaction and expression of p 38 MAPK in the dorsal horn of spinal cord in anus incisional pain rats, so as to explore its analgesic mechanism. Forty male SD rats were randomly divided into control, model, GV 1-embedding and sham acupoint embedding groups ( n =10 rats in each group). The anus incisional pain model was established by making a radial incision (about 10 mm length) at the left lithotomy position of the anus with a surgical knife, and the mechanical pain threshold (PT) was measured by using a Von Frey before and 4, 8, 12, 24 h after operation. The medicated-catgut (about 12.5 mm length/kg body weight) was implanted in the subcutaneous tissue of GV 1 region. The immunoactivity of p 38 MAPK was determined by immunohistochemistry. Compared with the control group, the mechanical PTs were significantly decreased 4, 8, 12 and 24 h after operation both at the site of incision and about 15 mm proximal to the site of incision in the model group ( P <0.05), and the immunoactivity of phosphorylated (p)-p 38 MAPK in the superficial layer of dorsal horns of lumbar spinal cord was significantly increased(24 h)after operation( P <0.05). Compared with the model group, the PTs were significantly increased 8, 12 and 24 h after operation at the site of incision, and 12 h and 24 h at the site about 15 mm proximal to the incision region ( P <0.05), and the immunoactivity level of p-p 38 MAPK was significantly down-regulated in the GV 1-embedding group ( P <0.05). No significant changes were found in the PT and p-p 38 MAPK immunoactivity levels in the sham acupoint embedding group ( P <0.05). Medicated-catgut embedding at "Changqiang"(GV 1) has an analgesic effect in anus incisional pain model rats, which may be related to its effect in down-regulating the expression of p 38 MAPK in the dorsal horn of lumbar spinal cord.

  2. Epicardial Adipose Tissue (EAT Thickness Is Associated with Cardiovascular and Liver Damage in Nonalcoholic Fatty Liver Disease.

    Directory of Open Access Journals (Sweden)

    Anna Ludovica Fracanzani

    Full Text Available Epicardial adipose tissue (EAT has been proposed as a cardiometabolic and hepatic fibrosis risk factor in patients with non alcoholic fatty liver disease (NAFLD. Aim of this study was to evaluate the role of EAT in NAFLD by analyzing 1 the association between EAT, the other metabolic parameters and the severity of steatosis 2 the relationship between cardiovascular (cIMT, cplaques, E/A, liver (presence of NASH and significant fibrosis damage and metabolic risk factors including EAT 3 the relationship between EAT and genetic factors strongly influencing liver steatosis.In a cross-sectional study, we considered 512 consecutive patients with NAFLD (confirmed by biopsy in 100. EAT, severity of steatosis, carotid intima-media thickness (cIMT and plaques were evaluated by ultrasonography and results analysed by multiple linear and logistic regression models. Variables independently associated with EAT (mm were female gender (p = 0.003, age (p = 0.001, BMI (p = 0.01, diastolic blood pressure (p = 0.009, steatosis grade 2 (p = 0.01 and 3 (p = 0.04, fatty liver index (p = 0.001 and statin use (p = 0.03. Variables independently associated with carotid IMT were age (p = 0.0001, hypertension (p = 0.009, diabetes (p = 0.04, smoking habits (p = 0.04 and fatty liver index (p = 0.02, with carotid plaques age (p = 0.0001, BMI (p = 0.03, EAT (p = 0.02, and hypertension (p = 0.02, and with E/A age (p = 0.0001, diabetes (p = 0.005, hypertension (p = 0.04 and fatty liver index (p = 0.004. In the 100 patients with available liver histology non alcoholic steatohepatitis (NASH was independently associated with EAT (p = 0.04 and diabetes (p = 0.054 while significant fibrosis with EAT (p = 0.02, diabetes (p = 0.01 and waist circumference (p = 0.05. No association between EAT and PNPLA3 and TM6SF2 polymorphisms was found.In patients with NAFLD, EAT is associated with the severity of liver and vascular damage besides with the known metabolic risk factors.

  3. Testosterone depletion increases the susceptibility of brain tissue to oxidative damage in a restraint stress mouse model.

    Science.gov (United States)

    Son, Seung-Wan; Lee, Jin-Seok; Kim, Hyeong-Geug; Kim, Dong-Woon; Ahn, Yo-Chan; Son, Chang-Gue

    2016-01-01

    Among sex hormones, estrogen is particularly well known to act as neuroprotective agent. Unlike estrogen, testosterone has not been well investigated in regard to its effects on the brain, especially under psychological stress. To investigate the role of testosterone in oxidative brain injuries under psychological stress, we adapted an orchiectomy and restraint stress model. BALB/c mice were subjected to either an orchiectomy or sham operation. After allowing 15 days for recovery, mice were re-divided into four groups according to exposure of restraint stress: sham, sham plus stress, orchiectomy, and orchiectomy plus stress. Serum testosterone was undetectable in orchiectomized groups and restraint-induced stress significantly reduced testosterone levels in sham plus stress group. The serum levels of corticosterone and adrenaline were notably elevated by restraint stress, and these elevated hormones were markedly augmented by orchiectomy. Two oxidative stressors and biomarkers for lipid and protein peroxidation were significantly increased in the cerebral cortex and hippocampus by restraint stress, while the reverse pattern was observed in antioxidant enzymes. These results were supported by histopathological findings, with 4-hydroxynonenal staining for oxidative injury and Fluoro-Jade B staining showing the degenerating neurons. The aforementioned patterns of oxidative injury were accelerated by orchiectomy. These findings strongly suggest the conclusion that testosterone exerts a protective effect against oxidative brain damage, especially under stressed conditions. Unlike estrogen, the effects of testosterone on the brain have not been thoroughly investigated. In order to investigate the role of testosterone in oxidative brain injuries under psychological stress, we adapted an orchiectomy and restraint stress model. Orchiectomy markedly augmented the restraint stress-induced elevation of serum corticosterone and adrenaline levels as well as oxidative alterations

  4. Extensive tissue damage of bovine ovaries after bipolar ovarian drilling compared to monopolar electrocoagulation or carbon dioxide laser

    NARCIS (Netherlands)

    Hendriks, M.L.; van der Valk, P.; Lambalk, C.B.; Broeckaert, M.A.M.; Homburg, R.R.; Hompes, P.G.A.

    2010-01-01

    Objective: To evaluate the size of ovarian damage caused by ovarian drilling in polycystic ovary syndrome, the amount of inflicted damage was assessed for the most frequently used ovarian drilling techniques. Design: Experimental prospective design. Setting: University clinic. Patient(s): Six fresh

  5. The influence of combined treatment of Cd, and γ-irradiation on DNA damage and repair in lymphoid tissues of mice

    International Nuclear Information System (INIS)

    Privezentsev, K.V.; Sirota, N.P.; Gaziev, A.I.

    1996-01-01

    The effect of combined treatment of Cd and γ-irradiation on DNA damage and repair was studied in lymphoid tissues of mice using single-cell gel assay. Single i.p. injection of CdCl 2 (1 mg Cd/kg body wt), 2 h prior to irradiation resulted in increasing of DNA lesions in peripheral blood lymphocytes (PBL) when compared to non-injected animals. However, the same treatment, 48 h prior to irradiation is shown to decrease DNA damage in PBL and splenocytes in comparison with untreated mice. In thymocytes maximal protective effect of Cd was determined when mice were irradiated in 24 h after injection. The protective effect observed is due to decreasing of initial level of DNA damage in thymocytes as well as acceleration of DNA repair in PBL and splenocytes. 28 refs.; 2 figs

  6. Tissue Damage Caused by Myeloablative, but Not Non-Myeloablative, Conditioning before Allogeneic Stem Cell Transplantation Results in Dermal Macrophage Recruitment without Active T-Cell Interaction

    Directory of Open Access Journals (Sweden)

    Peter van Balen

    2018-02-01

    Full Text Available IntroductionConditioning regimens preceding allogeneic stem cell transplantation (alloSCT can cause tissue damage and acceleration of the development of graft-versus-host disease (GVHD. T-cell-depleted alloSCT with postponed donor lymphocyte infusion (DLI may reduce GVHD, because tissue injury can be restored at the time of DLI. In this study, we investigated the presence of tissue injury and inflammation in skin during the period of hematologic recovery and immune reconstitution after alloSCT.MethodsSkin biopsies were immunohistochemically stained for HLA class II, CD1a, CD11c, CD40, CD54, CD68, CD86, CD206, CD3, and CD8. HLA class II-expressing cells were characterized as activated T-cells, antigen-presenting cells (APCs, or tissue repairing macrophages. In sex-mismatched patient and donor couples, origin of cells was determined by multiplex analysis combining XY-FISH and fluorescent immunohistochemistry.ResultsNo inflammatory environment due to pretransplant conditioning was detected at the time of alloSCT, irrespective of the conditioning regimen. An increase in HLA class II-positive macrophages and CD3 T-cells was observed 12–24 weeks after myeloablative alloSCT, but these macrophages did not show signs of interaction with the co-localized T-cells. In contrast, during GVHD, an increase in HLA class II-expressing cells coinciding with T-cell interaction was observed, resulting in an overt inflammatory reaction with the presence of activated APC, activated donor T-cells, and localized upregulation of HLA class II expression on epidermal cells. In the absence of GVHD, patient derived macrophages were gradually replaced by donor-derived macrophages although patient-derived macrophages were detectable even 24 weeks after alloSCT.ConclusionConditioning regimens cause tissue damage in the skin, but this does not result in a local increase of activated APC. In contrast to the inflamed situation in GVHD, when interaction takes place between

  7. Role of endothelium in radiation-induced normal tissue damages; Role de l'endothelium dans les dommages radio-induits aux tissus sains

    Energy Technology Data Exchange (ETDEWEB)

    Milliat, F

    2007-05-15

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  8. Role of endothelium in radiation-induced normal tissue damages; Role de l'endothelium dans les dommages radio-induits aux tissus sains

    Energy Technology Data Exchange (ETDEWEB)

    Milliat, F

    2007-05-15

    More than half of cancers are treated with radiation therapy alone or in combination with surgery and/or chemotherapy. The goal of radiation therapy is to deliver enough ionising radiation to destroy cancer cells without exceeding the level that the surrounding healthy cells can tolerate. Unfortunately, radiation-induced normal tissue injury is still a dose limiting factor in the treatment of cancer with radiotherapy. The knowledge of normal tissue radiobiology is needed to determine molecular mechanisms involved in normal tissue pathogenic pathways in order to identify therapeutic targets and develop strategies to prevent and /or reduce side effects of radiation therapy. The endothelium is known to play a critical role in radiation-induced injury. Our work shows that endothelial cells promote vascular smooth muscle cell proliferation, migration and fibro-genic phenotype after irradiation. Moreover, we demonstrate for the first time the importance of PAI-1 in radiation-induced normal tissue damage suggesting that PAI-1 may represent a molecular target to limit injury following radiotherapy. We describe a new role for the TGF-b/Smad pathway in the pathogenesis of radiation-induced damages. TGF-b/Smad pathway is involved in the fibro-genic phenotype of VSMC induced by irradiated EC as well as in the radiation-induced PAI-1 expression in endothelial cells. (author)

  9. Benfotiamine alleviates diabetes-induced cerebral oxidative damage independent of advanced glycation end-product, tissue factor and TNF-alpha.

    Science.gov (United States)

    Wu, Shan; Ren, Jun

    2006-02-13

    Diabetes mellitus leads to thiamine deficiency and multiple organ damage including diabetic neuropathy. This study was designed to examine the effect of benfotiamine, a lipophilic derivative of thiamine, on streptozotocin (STZ)-induced cerebral oxidative stress. Adult male FVB mice were made diabetic with a single injection of STZ (200 mg/kg, i.p.). Fourteen days later, control and diabetic (fasting blood glucose >13.9 mM) mice received benfotiamine (100 mg/kg/day, i.p.) for 14 days. Oxidative stress and protein damage were evaluated by glutathione/glutathione disulfide (GSH/GSSG) assay and protein carbonyl formation, respectively. Pro-oxidative or pro-inflammatory factors including advanced glycation end-product (AGE), tissue factor and tumor necrosis factor-alpha (TNF-alpha) were evaluated by immunoblot analysis. Four weeks STZ treatment led to hyperglycemia, enhanced cerebral oxidative stress (reduced GSH/GSSG ratio), elevated TNF-alpha and AGE levels without changes in protein carbonyl or tissue factor. Benfotiamine alleviated diabetes-induced cerebral oxidative stress without affecting levels of AGE, protein carbonyl, tissue factor and TNF-alpha. Collectively, our results indicated benfotiamine may antagonize diabetes-induced cerebral oxidative stress through a mechanism unrelated to AGE, tissue factor and TNF-alpha.

  10. Subepidermal moisture (SEM) and bioimpedance: a literature review of a novel method for early detection of pressure-induced tissue damage (pressure ulcers).

    Science.gov (United States)

    Moore, Zena; Patton, Declan; Rhodes, Shannon L; O'Connor, Tom

    2017-04-01

    Current detection of pressure ulcers relies on visual and tactile changes at the skin surface, but physiological changes below the skin precede surface changes and have a significant impact on tissue health. Inflammatory and apoptotic/necrotic changes in the epidermal and dermal layers of the skin, such as changes in interstitial fluid (also known as subepidermal moisture (SEM)), may precede surface changes by 3-10 days. Those same epidermal and subepidermal changes result in changes in the electrical properties (bioimpedance) of the tissue, thereby presenting an objective, non-invasive method for assessing tissue damage. Clinical studies of bioimpedance for the detection of pressure ulcers have demonstrated that changes in bioimpedance correlate with increasing severity of pressure ulcer stages. Studies have also demonstrated that at anatomical locations with pressure ulcers, bioimpedance varies with distance from the centre of the pressure ulcers. The SEM Scanner, a handheld medical device, offers an objective and reliable method for the assessment of local bioimpedance, and therefore, assessment of tissue damage before signs become visible to the unaided eye. This literature review summarises pressure ulcer pathophysiology, principles of bioimpedance and clinical research using bioimpedance technology to assess pressure ulcers. © 2016 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  11. Pathomorphological features of the skin and muscle tissue of experimental animals in the case of lifetime and postmortem damage

    Directory of Open Access Journals (Sweden)

    A. V. Kis

    2013-04-01

    Full Text Available The problem of forensic medical diagnosis of tissue injury is currently the subject of numerous investigations. Pathomorphological changes of the skin and muscle tissue of experimental animals, resulting in the case of lifetime and postmortem traumatic injuries, depending on the time and temperature, were revealed by the author. Data obtained by the author is very necessary for improving the forensic medical diagnosis of traumatic soft tissue injuries.

  12. Effect of sucralfate and its components on taurocholate-induced damage to rat gastric mucosal cells in tissue culture

    Energy Technology Data Exchange (ETDEWEB)

    Romano, M.; Razandi, M.; Ivey, K.J. (Long Beach VA Medical Center, CA (USA))

    1990-04-01

    The present study evaluated the effect of sucralfate and its components, sucrose octasulfate and aluminum hydroxide, on: (1) damage to rat cultured gastric mucosal cells induced by sodium taurocholate in a neutral environment and in conditions independent of systemic factors, (2) prostaglandin E2 and on 6-keto prostaglandin F1 alpha release by cultured cells, and (3) sulfhydryl content of cultured cells. Cell damage was quantitated by chromium-51 release assay. Prostaglandin E2 and 6-keto prostaglandin F1 alpha were measured by radioimmunoassay. Total sulfhydryl content of cultured cells was determined calorimetrically. Microscopically, sucralfate was found to adhere tightly to epithelial cell surfaces despite frequent washings. Sucralfate 2 mg/ml and 5 mg/ml significantly decreased taurocholate-induced damage, reducing taurocholate-induced specific 51Cr release by 11.8 points (equal to 29% decrease in cell damage, P less than 0.01) and 22.9 points (equal to 56% decrease in cell damage, P less than 0.001), respectively. Sucrose octasulfate and aluminum hydroxide did not exert significant protection against damage induced by sodium taurocholate. The protective effect of sucralfate was not prevented by indomethacin, nor was it counteracted by the sulfhydryl blocker, iodoacetamide. Sucralfate, but not its components, significantly and dose-dependently stimulated prostaglandin E2 (r = 0.94, P less than 0.05) and 6-keto prostaglandin F1 alpha (r = 0.89, P less than 0.05) production by cultured cells. Neither sucralfate nor its components affected sulfhydryl content of cultured cells. In conclusion, sucralfate, but not its components, (1) protects rat gastric mucosal cells against taurocholate-induced damage in conditions independent of systemic factors and in a neutral environment and (2) significantly stimulates prostaglandin production by cultured cells.

  13. Effect of sucralfate and its components on taurocholate-induced damage to rat gastric mucosal cells in tissue culture

    International Nuclear Information System (INIS)

    Romano, M.; Razandi, M.; Ivey, K.J.

    1990-01-01

    The present study evaluated the effect of sucralfate and its components, sucrose octasulfate and aluminum hydroxide, on: (1) damage to rat cultured gastric mucosal cells induced by sodium taurocholate in a neutral environment and in conditions independent of systemic factors, (2) prostaglandin E2 and on 6-keto prostaglandin F1 alpha release by cultured cells, and (3) sulfhydryl content of cultured cells. Cell damage was quantitated by chromium-51 release assay. Prostaglandin E2 and 6-keto prostaglandin F1 alpha were measured by radioimmunoassay. Total sulfhydryl content of cultured cells was determined calorimetrically. Microscopically, sucralfate was found to adhere tightly to epithelial cell surfaces despite frequent washings. Sucralfate 2 mg/ml and 5 mg/ml significantly decreased taurocholate-induced damage, reducing taurocholate-induced specific 51Cr release by 11.8 points (equal to 29% decrease in cell damage, P less than 0.01) and 22.9 points (equal to 56% decrease in cell damage, P less than 0.001), respectively. Sucrose octasulfate and aluminum hydroxide did not exert significant protection against damage induced by sodium taurocholate. The protective effect of sucralfate was not prevented by indomethacin, nor was it counteracted by the sulfhydryl blocker, iodoacetamide. Sucralfate, but not its components, significantly and dose-dependently stimulated prostaglandin E2 (r = 0.94, P less than 0.05) and 6-keto prostaglandin F1 alpha (r = 0.89, P less than 0.05) production by cultured cells. Neither sucralfate nor its components affected sulfhydryl content of cultured cells. In conclusion, sucralfate, but not its components, (1) protects rat gastric mucosal cells against taurocholate-induced damage in conditions independent of systemic factors and in a neutral environment and (2) significantly stimulates prostaglandin production by cultured cells

  14. Gefarnate stimulates mucin-like glycoprotein secretion in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models

    Directory of Open Access Journals (Sweden)

    Dota A

    2013-01-01

    Full Text Available Atsuyoshi Dota, Yuko Takaoka-Shichijo, Masatsugu NakamuraOphthalmic Research and Development Center, Santen Pharmaceutical Co, Ltd, Ikoma-shi, Nara, JapanPurpose: The aim of this study was to evaluate the effect of gefarnate on mucin-like glycoprotein secretion in isolated rabbit conjunctival tissue, and on corneal epithelial damage in rabbit and cat dry-eye models.Methods: Conjunctival tissue isolated from rabbits was treated with gefarnate. Mucin-like glycoprotein was detected in the culture supernatant by an enzyme-linked lectin assay. Gefarnate ointment was topically applied to eyes once daily for 7 days in the rabbit dry-eye model, in which the lacrimal glands, Harderian gland, and nictitating membrane were removed, or for 4 weeks in the cat dry-eye model, in which the lacrimal gland and nictitating membrane were removed. Corneal epithelial damage was evaluated by measurement of corneal permeability by rose bengal in the rabbit model or by fluorescein staining in the cat model.Results: Gefarnate stimulated mucin-like glycoprotein secretion in conjunctival tissue in a dose-dependent manner. In the rabbit dry-eye model, application of gefarnate ointment to the eyes resulted in a dose-dependent decrease in rose bengal permeability in the cornea, with the effect being significant at concentrations of ≥0.3%. In the cat dry-eye model, application of gefarnate ointment resulted in a significant decrease in the corneal fluorescein staining score.Conclusion: These results suggest that gefarnate stimulates in vitro secretion of mucin-like glycoprotein in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models. Gefarnate may therefore be effective for treating dry eye.Keywords: gefarnate, fluorescein staining, rose bengal permeability, rabbit, cat, dry eye

  15. Hair cell counts in a rat model of sound damage: Effects of tissue preparation & identification of regions of hair cell loss.

    Science.gov (United States)

    Neal, Christopher; Kennon-McGill, Stefanie; Freemyer, Andrea; Shum, Axel; Staecker, Hinrich; Durham, Dianne

    2015-10-01

    Exposure to intense sound can damage or kill cochlear hair cells (HC). This loss of input typically manifests as noise induced hearing loss, but it can also be involved in the initiation of other auditory disorders such as tinnitus or hyperacusis. In this study we quantify changes in HC number following exposure to one of four sound damage paradigms. We exposed adult, anesthetized Long-Evans rats to a unilateral 16 kHz pure tone that varied in intensity (114 dB or 118 dB) and duration (1, 2, or 4 h) and sacrificed animals 2-4 weeks later. We compared two different methods of tissue preparation, plastic embedding/sectioning and whole mount dissection, for quantifying hair cell loss as a function of frequency. We found that the two methods of tissue preparation produced largely comparable cochleograms, with whole mount dissections allowing a more rapid evaluation of hair cell number. Both inner and outer hair cell loss was observed throughout the length of the cochlea irrespective of sound damage paradigm. Inner HC loss was either equal to or greater than outer HC loss. Increasing the duration of sound exposures resulted in more severe HC loss, which included all HC lesions observed in an analogous shorter duration exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The involvement of oxidative stress in the mechanisms of damaging cadmium action in bone tissue: A study in a rat model of moderate and relatively high human exposure

    International Nuclear Information System (INIS)

    Brzoska, Malgorzata M.; Rogalska, Joanna; Kupraszewicz, Elzbieta

    2011-01-01

    It was investigated whether cadmium (Cd) may induce oxidative stress in the bone tissue in vivo and in this way contribute to skeleton damage. Total antioxidative status (TAS), antioxidative enzymes (glutathione peroxidase, superoxide dismutase, catalase), total oxidative status (TOS), hydrogen peroxide (H 2 O 2 ), lipid peroxides (LPO), total thiol groups (TSH) and protein carbonyl groups (PC) as well as Cd in the bone tissue at the distal femoral epiphysis and femoral diaphysis of the male rats that received drinking water containing 0, 5, or 50 mg Cd/l for 6 months were measured. Cd, depending on the level of exposure and bone location, decreased the bone antioxidative capacity and enhanced its oxidative status resulting in oxidative stress and oxidative protein and/or lipid modification. The treatment with 5 and 50 mg Cd/l decreased TAS and activities of antioxidative enzymes as well as increased TOS and concentrations of H 2 O 2 and PC at the distal femur. Moreover, at the higher exposure, the concentration of LPO increased and that of TSH decreased. The Cd-induced changes in the oxidative/antioxidative balance of the femoral diaphysis, abundant in cortical bone, were less advanced than at the distal femur, where trabecular bone predominates. The results provide evidence that, even moderate, exposure to Cd induces oxidative stress and oxidative modifications in the bone tissue. Numerous correlations noted between the indices of oxidative/antioxidative bone status, and Cd accumulation in the bone tissue as well as indices of bone turnover and bone mineral status, recently reported by us (Toxicology 2007, 237, 89-103) in these rats, allow for the hypothesis that oxidative stress is involved in the mechanisms of damaging Cd action in the skeleton. The paper is the first report from an in vivo study indicating that Cd may affect bone tissue through disorders in its oxidative/antioxidative balance resulting in oxidative stress.

  17. Chilling-related cell damage of apple (Malus × domestica Borkh.) fruit cortical tissue impacts antioxidant, lipid and phenolic metabolism.

    Science.gov (United States)

    Leisso, Rachel S; Buchanan, David A; Lee, Jinwook; Mattheis, James P; Sater, Chris; Hanrahan, Ines; Watkins, Christopher B; Gapper, Nigel; Johnston, Jason W; Schaffer, Robert J; Hertog, Maarten L A T M; Nicolaï, Bart M; Rudell, David R

    2015-02-01

    'Soggy breakdown' (SB) is an internal flesh disorder of 'Honeycrisp' apple (Malus × domestica Borkh.) fruit that occurs during low temperature storage. The disorder is a chilling injury (CI) in which visible symptoms typically appear after several weeks of storage, but information about the underlying metabolism associated with its induction and development is lacking. The metabolic profile of flesh tissue from wholly healthy fruit and brown and healthy tissues from fruit with SB was characterized using gas chromatography-mass spectrometry (GC-MS) and liquid chromatograph-mass spectrometry (LC-MS). Partial least squares discriminant analysis (PLS-DA) and correlation networks revealed correlation among ester volatile compounds by composition and differences in phytosterol, phenolic and putative triacylglycerides (TAGs) metabolism among the tissues. anova-simultaneous component analysis (ASCA) was used to test the significance of metabolic changes linked with tissue health status. ASCA-significant components included antioxidant compounds, TAGs, and phytosterol conjugates. Relative to entirely healthy tissues, elevated metabolite levels in symptomatic tissue included γ-amino butyric acid, glycerol, sitosteryl (6'-O-palmitoyl) β-d-glucoside and sitosteryl (6'-O-stearate) β-d-glucoside, and TAGs containing combinations of 16:0, 18:3, 18:2 and 18:1 fatty acids. Reduced metabolite levels in SB tissue included 5-caffeoyl quinate, β-carotene, catechin, epicatechin, α-tocopherol, violaxanthin and sitosteryl β-d glucoside. Pathway analysis indicated aspects of primary metabolism differed according to tissue condition, although differences in metabolites involved were more subtle than those of some secondary metabolites. The results implicate oxidative stress and membrane disruption processes in SB development and constitute a diagnostic metabolic profile for the disorder. © 2014 Scandinavian Plant Physiology Society.

  18. Investigation of the Relationship of Some Antihypertensive Drugs with Oxidant/Antioxidant Parameters and DNA Damage on Rat Uterus Tissue

    OpenAIRE

    Mustafa Talip Sener; Hamit Hakan Alp; Beyzagul Polat; Bunyamin Borekci; Yakup Kumtepe; Nesrin Gursan; Serkan Kumbasar; Suleyman Salman; Halis Suleyman

    2011-01-01

    Background In this study, we investigated the effects of treatment with chronic antihypertensive drugs (clonidine, methyldopa, amlodipine, ramipril and rilmenidine) on oxidant-antioxidant parameters and toxic effects on DNA in rat uterus tissue. In addition, uterus tissues were examined histopathologically. Materials and Methods A total of 36 albino Wistar rats were divided into the following six groups: 0.075 mg/kg clonidine group; 100 mg/kg methyldopa group; 2 mg/kg amlodipine group; 2.5 mg...

  19. Nuclear medicine in the detection of radiation associated normal tissue damage of kidney, brain and salivary glands

    International Nuclear Information System (INIS)

    Liu Xiaomei; Li Dongxue; Pan Liping

    2005-01-01

    The radiation induced damage of kidney, brain and salivary glands is an important complicating disease after limit radiotherapy. The routine technology of nuclear medicine, such as tracing and imaging technique conduce to dose-effect calculations used in the planning of modern radiotherapy to three major organ systems and early detection of irradiation induced organ dysfunctions, as well as increased availability of radiotherapy. (authors)

  20. In-vivo optical imaging of hsp70 expression to assess collateral tissue damage associated with infrared laser ablation of skin

    Science.gov (United States)

    Wilmink, Gerald J.; Opalenik, Susan R.; Beckham, Joshua T.; Mackanos, Mark A.; Nanney, Lillian B.; Contag, Christopher H.; Davidson, Jeffrey M.; Jansen, E. Duco

    2013-01-01

    Laser surgical ablation is achieved by selecting laser parameters that remove confined volumes of target tissue and cause minimal collateral damage. Previous studies have measured the effects of wavelength on ablation, but neglected to measure the cellular impact of ablation on cells outside the lethal zone. In this study, we use optical imaging in addition to conventional assessment techniques to evaluate lethal and sublethal collateral damage after ablative surgery with a free-electron laser (FEL). Heat shock protein (HSP) expression is used as a sensitive quantitative marker of sublethal damage in a transgenic mouse strain, with the hsp70 promoter driving luciferase and green fluorescent protein (GFP) expression (hsp70A1-L2G). To examine the wavelength dependence in the mid-IR, laser surgery is conducted on the hsp70A1-L2G mouse using wavelengths targeting water (OH stretch mode, 2.94 μm), protein (amide-II band, 6.45 μm), and both water and protein (amide-I band, 6.10 μm). For all wavelengths tested, the magnitude of hsp70 expression is dose-dependent and maximal 5 to 12 h after surgery. Tissues treated at 6.45 μm have approximately 4× higher hsp70 expression than 6.10 μm. Histology shows that under comparable fluences, tissue injury at the 2.94-μm wavelength was 2× and 3× deeper than 6.45 and 6.10 μm, respectively. The 6.10-μm wavelength generates the least amount of epidermal hyperplasia. Taken together, this data suggests that the 6.10-μm wavelength is a superior wavelength for laser ablation of skin. PMID:19021444

  1. Disruption of the ECM33 Gene in Candida albicans Prevents Biofilm Formation, Engineered Human Oral Mucosa Tissue Damage and Gingival Cell Necrosis/Apoptosis

    Directory of Open Access Journals (Sweden)

    Mahmoud Rouabhia

    2012-01-01

    Full Text Available In this study we demonstrated that ΔCaecm33 double mutant showed reduced biofilm formation and causes less damage to gingival mucosa tissues. This was confirmed by the reduced level of necrotic cells and Bax/Bcl2 gene expression as apoptotic markers. In contrast, parental and Caecm33 mutant strains decreased basement membrane protein production (laminin 5 and type IV collagen. We thus propose that ECM33 gene/protein represents a novel target for the prevention and treatment of infections caused by Candida.

  2. Brain Tissues Oxidative Damage as a Possible Mechanism of Deleterious Effects of Propylthiouracil- Induced Hypothyroidism on Learning and Memory in Neonatal and Juvenile Growth in Rats

    Directory of Open Access Journals (Sweden)

    Esmeil Farrokhi

    2014-11-01

    randomly selected and tested in the Morris water maze (MWM. Then, samples of blood were collected to measure thyroxine. Finally, the brains were removed and total thiol groups and molondialdehyde (MDA concentrations were determined. Results: Compared to the control group’s offspring, serum thyroxine levels in the PTU group’s off spring were significantly low (P<0.001. In MWM, the escape latency and traveled path in the PTU group were significantly higher than that in the control group (P<0.01- P<0.001. In PTU group, the total thiol concentrations in both cortical and hippocampal tissues were significantly lower and MDA concentrations were higher than control group (P<0.001. Discussion: It seems that deleterious effect of hypothyroidism during neonatal and juvenile growth on learning and memory is at least in part due to brain tissues oxidative damage.

  3. Aluminium and Gamma Irradiation Induced Oxidative Damage in Brain Tissue of Male Rats - Protective Role of Ferulic Acid

    International Nuclear Information System (INIS)

    Mansour, S.Z.; Hanafi, N.; Noaman, E.

    2011-01-01

    The current study was carried out to investigate the potential role of ferulic acid (FA) against Aluminium chloride (AlCl 3 ), γ- radiation either alone or combination induced oxidative stress in brain tissue of Wistar rats. The period of the experiment was eight weeks. Animals were administrated by aluminium chloride at a dose of 8.5 mg/kg/day and exposed to a single dose (4 Gy) of γ-radiation. FA was administered orally (50 mg/Kg body weight)/day. Histopathological observations and myeloid protein distribution were recorded in brain tissue. Induction of oxidative stress was recorded after all exposures. Brain tissue of AlCl 3 and γ- irradiation treatments either alone or combined revealed many altered changes and myeloid protein distribution. Also a decrease in serotonin concentration was recorded. An increase in Malonaldialdahyde (MDA) and acetylcholinesterase activity and percentage of saturated fatty acids in plasma and brain tissue was recorded. Reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) in blood and brain showed a significant decrease. Treatment of AlCl 3 loaded animals by FA showed simple atrophy as shrunken morphology saw in amyotrophic lateral sclerosis and a decrease in myeloid protein deposition. FA treatment of AlCl 3 loaded or irradiated animals represented a significant increase in serotonin concentration and ameliorated affects on oxidative stress markers, acetylcholinesterase activity and percentage of saturated fatty acids in plasma and brain tissue. In conclusion FA has a role in reducing the oxidative stress of AlCl 3 and γ- irradiation on brain tissue of rats

  4. Accumulation of DNA damage-induced chromatin alterations in tissue-specific stem cells: the driving force of aging?

    Directory of Open Access Journals (Sweden)

    Nadine Schuler

    Full Text Available Accumulation of DNA damage leading to stem cell exhaustion has been proposed to be a principal mechanism of aging. Using 53BP1-foci as a marker for DNA double-strand breaks (DSBs, hair follicle stem cells (HFSCs in mouse epidermis were analyzed for age-related DNA damage response (DDR. We observed increasing amounts of 53BP1-foci during the natural aging process independent of telomere shortening and after protracted low-dose radiation, suggesting substantial accumulation of DSBs in HFSCs. Electron microscopy combined with immunogold-labeling showed multiple small 53BP1 clusters diffusely distributed throughout the highly compacted heterochromatin of aged HFSCs, but single large 53BP1 clusters in irradiated HFSCs. These remaining 53BP1 clusters did not colocalize with core components of non-homologous end-joining, but with heterochromatic histone modifications. Based on these results we hypothesize that these lesions were not persistently unrepaired DSBs, but may reflect chromatin rearrangements caused by the repair or misrepair of DSBs. Flow cytometry showed increased activation of repair proteins and damage-induced chromatin modifications, triggering apoptosis and cellular senescence in irradiated, but not in aged HFSCs. These results suggest that accumulation of DNA damage-induced chromatin alterations, whose structural dimensions reflect the complexity of the initial genotoxic insult, may lead to different DDR events, ultimately determining the biological outcome of HFSCs. Collectively, our findings support the hypothesis that aging might be largely the remit of structural changes to chromatin potentially leading to epigenetically induced transcriptional deregulation.

  5. Application of TMA (Tissue micro-array) in the observation of apoptotic cascade in postradiation damage in avian medicine

    International Nuclear Information System (INIS)

    Fridman, E.; Skarda, J.; Skardova, I.

    2006-01-01

    The study of apoptotic cascade by the use of relatively new technique in avian medicine: TMA may help in early detection and prevention of acquired immunodeficiency caused by the influence of a variety of pathogenic and non-pathogenic environmental factors, which may result in severe economical losses in conditions of intensive poultry farming. There has not been any report of applying this method in veterinary medicine. Tissue micro-array (TMA) technology allows rapid visualization of molecular targets in thousands of tissue specimens at a time, either at the DNA, RNA or protein level. The technique facilitates rapid translation of molecular discoveries to clinical applications. This technology has a number of advantages compared with conventional techniques: speed and high throughput, standardization and experimental uniformity, ease of use, all histochemical and molecular detection techniques can be used, decreased assay volume, preservation of original block, and conservation of valuable tissue etc. The aim of the present work were the study of immunosuppression and apoptotic cascade and possibilities of application of tissue micro-array in chicken in experimental condition and diagnostics in avian medicine in general. The selection of samples from avian primary immune organs: thymus and Bursa Fabric was done after gamma irradiation and infectious bursal virus infection (IBDV). (authors)

  6. 4-Aminobiphenyl (4-ABP) - DNA Damage in Breast Tissue and Relationship to p53 Mutations and Polymorphisms of Metabolizing Genes

    National Research Council Canada - National Science Library

    Niguidula, Nancy

    2000-01-01

    .... The analysis of the CYP1A2 gene is currently in progress. Due to the difficulty in obtaining large fragments of DNA from the tumor tissue sections required for PCR-RFLP, a new method is under development for genotyping NAT2...

  7. Radiation damage

    CERN Document Server

    Heijne, Erik H M; CERN. Geneva

    1998-01-01

    a) Radiation damage in organic materials. This series of lectures will give an overview of radiation effects on materials and components frequently used in accelerator engineering and experiments. Basic degradation phenomena will be presented for organic materials with comprehensive damage threshold doses for commonly used rubbers, thermoplastics, thermosets and composite materials. Some indications will be given for glass, scintillators and optical fibres. b) Radiation effects in semiconductor materials and devices. The major part of the time will be devoted to treat radiation effects in semiconductor sensors and the associated electronics, in particular displacement damage, interface and single event phenomena. Evaluation methods and practical aspects will be shown. Strategies will be developed for the survival of the materials under the expected environmental conditions of the LHC machine and detectors. I will describe profound revolution in our understanding of black holes and their relation to quantum me...

  8. Treatment with metallothionein prevents demyelination and axonal damage and increases oligodendrocyte precursors and tissue repair during experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Penkowa, Milena; Hidalgo, Juan

    2003-01-01

    Experimental autoimmune encephalomyelitis (EAE) is an animal model for the human demyelinating disease multiple sclerosis (MS). EAE and MS are characterized by significant inflammation, demyelination, neuroglial damage, and cell death. Metallothionein-I and -II (MT-I + II) are antiinflammatory an......)beta, neurotrophin-3 (NT-3), NT-4/5, and nerve growth factor (NGF). These beneficial effects of Zn-MT-II treatment could not be attributable to its zinc content per se. The present results support further the use of Zn-MT-II as a safe and successful therapy for multiple sclerosis....

  9. Extracellular histones are essential effectors of C5aR- and C5L2-mediated tissue damage and inflammation in acute lung injury.

    Science.gov (United States)

    Bosmann, Markus; Grailer, Jamison J; Ruemmler, Robert; Russkamp, Norman F; Zetoune, Firas S; Sarma, J Vidya; Standiford, Theodore J; Ward, Peter A

    2013-12-01

    We investigated how complement activation promotes tissue injury and organ dysfunction during acute inflammation. Three models of acute lung injury (ALI) induced by LPS, IgG immune complexes, or C5a were used in C57BL/6 mice, all models requiring availability of both C5a receptors (C5aR and C5L2) for full development of ALI. Ligation of C5aR and C5L2 with C5a triggered the appearance of histones (H3 and H4) in bronchoalveolar lavage fluid (BALF). BALF from humans with ALI contained H4 histone. Histones were absent in control BALF from healthy volunteers. In mice with ALI, in vivo neutralization of H4 with IgG antibody reduced the intensity of ALI. Neutrophil depletion in mice with ALI markedly reduced H4 presence in BALF and was highly protective. The direct lung damaging effects of extracellular histones were demonstrated by airway administration of histones into mice and rats (Sprague-Dawley), which resulted in ALI that was C5a receptor-independent, and associated with intense inflammation, PMN accumulation, damage/destruction of alveolar epithelial cells, together with release into lung of cytokines/chemokines. High-resolution magnetic resonance imaging demonstrated lung damage, edema and consolidation in histone-injured lungs. These studies confirm the destructive C5a-dependent effects in lung linked to appearance of extracellular histones.

  10. Systems Biology Model of Interactions between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFβ and ATM Signaling

    International Nuclear Information System (INIS)

    Cucinotta, Francis A

    2016-01-01

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently, the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses, and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low-dose responses and cross-talk between the ATM and TGFβ pathways initiated by low- and high-LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to crosstalk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  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. Systems Biology Model of Interactions between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFβ and ATM Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Cucinotta, Francis A [Univ. of Nevada, Las Vegas, NV (United States)

    2016-09-01

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently, the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses, and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low-dose responses and cross-talk between the ATM and TGFβ pathways initiated by low- and high-LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to crosstalk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  13. Decay-Accelerating Factor Mitigates Controlled Hemorrhage-Instigated Intestinal and Lung Tissue Damage and Hyperkalemia in Swine

    Science.gov (United States)

    2011-07-01

    glucose , hematocrit (Hct), hemoglobin (Hb), sodium (Na+), potassium (K+), and ionized calcium (iCa2+) using i-STAT cartridges ( Abbott Laboratories...animals were observed for 200 minutes. Blood chemistry and physiological parameters were recorded. Tissue samples from lung and small intestine were...seemingly acceptable medical therapy and surgical intervention.4 The first physiologic response to severe blood loss is activation of the neuroendocrine

  14. Effects of grape seed polyphenols on oxidative damage in liver tissue of acutely and chronically exercised rats.

    Science.gov (United States)

    Belviranlı, Muaz; Gökbel, Hakkı; Okudan, Nilsel; Büyükbaş, Sadık

    2013-05-01

    The objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE-supplemented Control (GC), GSE-supplemented Chronic Exercise(GCE) and GSE-supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six-week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg(-1) .day(-1) ) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non-supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise-induced oxidative stress in liver tissue.

  15. Nicotine-induced damages in testicular tissue of rats; evidences for bcl-2, p53 and caspase-3 expression

    Directory of Open Access Journals (Sweden)

    Maryam Mosadegh

    2017-02-01

    Full Text Available Objective(s: Present study was performed in order to uncover new aspects for nicotine-induced damages on spermatogenesis cell lineage. Materials and Methods: For this purpose, 36 mature male Wistar rats were divided into three groups as; control-sham (0.2 ml, saline normal, IP, low dose (0.2 mg/kg BW-1, IP nicotine-received and high dose (0.4 mg/kg BW-1, IP nicotine-received groups. Following 7 weeks, the expression of bcl-2, p53 and caspase-3 at mRNA and protein levels were investigated by using reverse-transcriptase PCR (RT-PCR and immunohistochemical (IHC analyses, respectively. Moreover, the serum level of FSH, LH and testosterone were evaluated. Finally, the mRNA damage was analyzed by using special fluorescent staining. Results: Nicotine, at both dose levels, decreased tubular differentiation, spermiogenesis and repopulation indices and enhanced cellular depletion. Animals in nicotine-received groups exhibited a significant (P

  16. Systemic transplantation of human adipose tissue-derived mesenchymal stem cells for the regeneration of irradiation-induced salivary gland damage.

    Directory of Open Access Journals (Sweden)

    Jae-Yol Lim

    Full Text Available OBJECTIVES: Cell-based therapy has been reported to repair or restore damaged salivary gland (SG tissue after irradiation. This study was aimed at determining whether systemic administration of human adipose-derived mesenchymal stem cells (hAdMSCs can ameliorate radiation-induced SG damage. METHODS: hAdMSCs (1 × 10(6 were administered through a tail vein of C3H mice immediately after local irradiation, and then this infusion was repeated once a week for 3 consecutive weeks. At 12 weeks after irradiation, functional evaluations were conducted by measuring salivary flow rates (SFRs and salivation lag times, and histopathologic and immunofluorescence histochemistry studies were performed to assay microstructural changes, apoptosis, and proliferation indices. The engraftment and in vivo differentiation of infused hAdMSCs were also investigated, and the transdifferentiation of hAdMSCs into amylase-producing SG epithelial cells (SGCs was observed in vitro using a co-culture system. RESULTS: The systemic administration of hAdMSCs exhibited improved SFRs at 12 weeks after irradiation. hAdMSC-transplanted SGs showed fewer damaged and atrophied acinar cells and higher mucin and amylase production levels than untreated irradiated SGs. Immunofluorescence TUNEL assays revealed fewer apoptotic cells in the hAdMSC group than in the untreated group. Infused hAdMSCs were detected in transplanted SGs at 4 weeks after irradiation and some cells were found to have differentiated into SGCs. In vitro, a low number of co-cultured hAdMSCs (13%-18% were observed to transdifferentiate into SGCs. CONCLUSION: The findings of this study indicate that hAdMSCs have the potential to protect against irradiation-induced cell loss and to transdifferentiate into SGCs, and suggest that hAdMSC administration should be viewed as a candidate therapy for the treatment of radiation-induced SG damage.

  17. DNA damage in the kidney tissue cells of the fish Rhamdia quelen after trophic contamination with aluminum sulfate

    Directory of Open Access Journals (Sweden)

    Tatiane Klingelfus

    2015-01-01

    Full Text Available Abstract Even though aluminum is the third most common element present in the earth's crust, information regarding its toxicity remains scarce. It is known that in certain cases, aluminum is neurotoxic, but its effect in other tissues is unknown. The aim of this work was to analyze the genotoxic potential of aluminum sulfate in kidney tissue of the fish Rhamdia quelen after trophic contamination for 60 days. Sixty four fish were subdivided into the following groups: negative control, 5 mg, 50 mg and 500 mg of aluminum sulfate per kg of fish. Samples of the posterior kidney were taken and prepared to obtain mitotic metaphase, as well as the comet assay. The three types of chromosomal abnormalities (CA found were categorized as chromatid breaks, decondensation of telomeric region, and early separation of sister chromatids. The tests for CA showed that the 5 mg/kg and 50 mg/kg doses of aluminum sulfate had genotoxic potential. Under these treatments, early separation of the sister chromatids was observed more frequently and decondensation of the telomeric region tended to increase in frequency. We suggest that structural changes in the proteins involved in DNA compaction may have led to the decondensation of the telomeric region, making the DNA susceptible to breaks. Moreover, early separation of the sister chromatids may have occurred due to changes in the mobility of chromosomes or proteins that keep the sister chromatids together. The comet assay confirmed the genotoxicity of aluminum sulfate in the kidney tissue of Rhamdia quelen at the three doses of exposure.

  18. High-grain diet feeding altered the composition and functions of the rumen bacterial community and caused the damage to the laminar tissues of goats.

    Science.gov (United States)

    Zhang, R Y; Jin, W; Feng, P F; Liu, J H; Mao, S Y

    2018-03-19

    In the current intensive production system, ruminants are often fed high-grain (HG) diets. However, this feeding pattern often causes rumen metabolic disorders and may further trigger laminitis, the exact mechanism is not clear. This study investigated the effect of HG diet feeding on fermentative and microbial changes in the rumen and on the expression of pro-inflammatory cytokines and matrix metalloproteinases (MMPs) in the lamellar tissue. In all, 12 male goats were fed a hay diet (0% grain; n=6) or an HG diet (56.5% grain; n=6). On day 50 of treatment, samples of blood, rumen content, and lamellar tissue of hooves of goats were collected. The data showed that compared with the hay group, HG-fed goats had lower (Pdiet feeding altered the composition of rumen bacterial community, and correspondingly, the results suggested that their functions in the HG group were also altered. HG diet feeding increased (Pbacterial community, and lead to higher levels of LPS in the peripheral blood, and further activated the inflammatory response in lamellar tissues, which may progress to the level of laminar damage.

  19. Increased abundance of ADAM9 transcripts in the blood is associated with tissue damage [version 2; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Darawan Rinchai

    2016-10-01

    Full Text Available Background: Members of the ADAM (a disintegrin and metalloprotease domain family have emerged as critical regulators of cell-cell signaling during development and homeostasis. ADAM9 is consistently overexpressed in various human cancers, and has been shown to play an important role in tumorigenesis. However, little is known about the involvement of ADAM9 during immune-mediated processes. Results: Mining of an extensive compendium of transcriptomic datasets identified important gaps in knowledge regarding the possible role of ADAM9 in immunological homeostasis and inflammation: 1 The abundance of ADAM9 transcripts in the blood was increased in patients with acute infection but, 2 changed very little after in vitro exposure to a wide range of pathogen-associated molecular patterns (PAMPs. 3 Furthermore it was found to increase significantly in subjects as a result of tissue injury or tissue remodeling, in absence of infectious processes. Conclusions: Our findings indicate that ADAM9 may constitute a valuable biomarker for the assessment of tissue damage, especially in clinical situations where other inflammatory markers are confounded by infectious processes.

  20. Case report: transpalatal arch resulting in soft tissue damage of the tongue 3 years post-orthodontic treatment.

    Science.gov (United States)

    Noar, Joe; Woods, Eva; Hodgson, Tim

    2015-03-01

    Whilst transient effects of orthodontic appliances on the oral mucosa are well recognized, chronic lesions, persisting post therapy are unusual. We describe a persistent lingual mucosal defect related to a transpalatal arch (TPA) in a healthy 19-year-old female. The asymptomatic lesion is presently being monitored, however, surgical revision in the future may be requested by the patient if the area fails to remodel. Clinical Relevance: Soft tissue trauma to the tongue by anchorage reinforcing appliances may result in long-term effects that could require surgical management.

  1. The role of pyrimidine and water as underlying molecular constituents for describing radiation damage in living tissue: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Fuss, M. C.; Ellis-Gibbings, L. [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 113-bis, 28006 Madrid (Spain); Jones, D. B. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Brunger, M. J. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Blanco, F. [Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid (Spain); Muñoz, A. [Centro de Investigaciones Energéticas Medioambientales y Tecnológicas, Avenida Complutense 22, 28040 Madrid (Spain); Limão-Vieira, P. [School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); García, G., E-mail: g.garcia@csic.es [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 113-bis, 28006 Madrid (Spain); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2015-06-07

    Water is often used as the medium for characterizing the effects of radiation on living tissue. However, in this study, charged-particle track simulations are employed to quantify the induced physicochemical and potential biological implications when a primary ionising particle with energy 10 keV strikes a medium made up entirely of water or pyrimidine. Note that pyrimidine was chosen as the DNA/RNA bases cytosine, thymine, and uracil can be considered pyrimidine derivatives. This study aims to assess the influence of the choice of medium on the charged-particle transport, and identify how appropriate it is to use water as the default medium to describe the effects of ionising radiation on living tissue. Based on the respective electron interaction cross sections, we provide a model, which allows the study of radiation effects not only in terms of energy deposition (absorbed dose and stopping power) but also in terms of the number of induced molecular processes. Results of these parameters for water and pyrimidine are presented and compared.

  2. Investigation of the Relationship of Some Antihypertensive Drugs with Oxidant/Antioxidant Parameters and DNA Damage on Rat Uterus Tissue

    Directory of Open Access Journals (Sweden)

    Mustafa Talip Sener

    2011-01-01

    Full Text Available Background: In this study, we investigated the effects of treatment with chronic antihypertensivedrugs (clonidine, methyldopa, amlodipine, ramipril and rilmenidine on oxidant-antioxidantparameters and toxic effects on DNA in rat uterus tissue. In addition, uterus tissues were examinedhistopathologically.Materials and Methods: A total of 36 albino Wistar rats were divided into the following six groups:0.075 mg/kg clonidine group; 100 mg/kg methyldopa group; 2 mg/kg amlodipine group; 2.5 mg/kgramipril group; 0.5 mg/kg rilmenidine group; and the healthy group. Rats underwent chronic drugadministration for 30 days and at the end, biochemical and histopathological examinations wereperformed. All data were subjected to one-way ANOVA test.Results: We divided these drugs into the following three groups according to their effects on ratuteri: (I mild negative effects (clonidine, (II moderate negative effects (rilmenidine, methyldopaand (III drugs which had severe negative effects (amlodipine, ramipril.Conclusion: These data may help with selection of antihypertensive drugs, in order to determinewhich drugs have the lowest toxicity in pregnant and non-pregnant (pre-pregnancy women.

  3. Effect of Kombucha, a fermented black tea in attenuating oxidative stress mediated tissue damage in alloxan induced diabetic rats.

    Science.gov (United States)

    Bhattacharya, Semantee; Gachhui, Ratan; Sil, Parames C

    2013-10-01

    Diabetic complications associated with increased oxidative stress can be suppressed by antioxidants. In the present study we investigated the antidiabetic and antioxidant effects of Kombucha (KT), a fermented black tea, in comparison to that of unfermented black tea (BT), in ALX-induced diabetic rats. ALX exposure lowered the body weight and plasma insulin by about 28.12% and 61.34% respectively and elevated blood glucose level and glycated Hb by about 3.79 and 3.73 folds respectively. The oxidative stress related parameters like lipid peroxidation end products (increased by 3.38, 1.7, 1.65, 1.94 folds respectively), protein carbonyl content (increased by 2.5, 2.35, 1.8, 3.26 folds respectively), glutathione content (decreased by 59.8%, 47.27%, 53.69%, 74.03% respectively), antioxidant enzyme activities were also altered in the pancreatic, hepatic, renal and cardiac tissues of diabetic animals. Results showed significant antidiabetic potential of the fermented beverage (150 mg lyophilized extract/kg bw for 14 days) as it effectively restored ALX-induced pathophysiological changes. Moreover, it could ameliorate DNA fragmentation and caspase-3 activation in the pancreatic tissue of diabetic rats. Although unfermented black tea is effective in the above pathophysiology, KT was found to be more efficient. This might be due to the formation of some antioxidant molecules during fermentation period. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Accumulation of free oligosaccharides and tissue damage in cytosolic α-mannosidase (Man2c1)-deficient mice.

    Science.gov (United States)

    Paciotti, Silvia; Persichetti, Emanuele; Klein, Katharina; Tasegian, Anna; Duvet, Sandrine; Hartmann, Dieter; Gieselmann, Volkmar; Beccari, Tommaso

    2014-04-04

    Free Man(7-9)GlcNAc2 is released during the biosynthesis pathway of N-linked glycans or from misfolded glycoproteins during the endoplasmic reticulum-associated degradation process and are reduced to Man5GlcNAc in the cytosol. In this form, free oligosaccharides can be transferred into the lysosomes to be degraded completely. α-Mannosidase (MAN2C1) is the enzyme responsible for the partial demannosylation occurring in the cytosol. It has been demonstrated that the inhibition of MAN2C1 expression induces accumulation of Man(8-9)GlcNAc oligosaccharides and apoptosis in vitro. We investigated the consequences caused by the lack of cytosolic α-mannosidase activity in vivo by the generation of Man2c1-deficient mice. Increased amounts of Man(8-9)GlcNAc oligosaccharides were recognized in all analyzed KO tissues. Histological analysis of the CNS revealed neuronal and glial degeneration with formation of multiple vacuoles in deep neocortical layers and major telencephalic white matter tracts. Enterocytes of the small intestine accumulate mannose-containing saccharides and glycogen particles in their apical cytoplasm as well as large clear vacuoles in retronuclear position. Liver tissue is characterized by groups of hepatocytes with increased content of mannosyl compounds and glycogen, some of them undergoing degeneration by hydropic swelling. In addition, lectin screening showed the presence of mannose-containing saccharides in the epithelium of proximal kidney tubules, whereas scattered glomeruli appeared collapsed or featured signs of fibrosis along Bowman's capsule. Except for a moderate enrichment of mannosyl compounds and glycogen, heterozygous mice were normal, arguing against possible toxic effects of truncated Man2c1. These findings confirm the key role played by Man2c1 in the catabolism of free oligosaccharides.

  5. Purified rutin and rutin-rich asparagus attenuates disease severity and tissue damage following dextran sodium sulfate-induced colitis.

    Science.gov (United States)

    Power, Krista A; Lu, Jenifer T; Monk, Jennifer M; Lepp, Dion; Wu, Wenqing; Zhang, Claire; Liu, Ronghua; Tsao, Rong; Robinson, Lindsay E; Wood, Geoffrey A; Wolyn, David J

    2016-11-01

    This study investigated the effects of cooked whole asparagus (ASP) versus its equivalent level of purified flavonoid glycoside, rutin (RUT), on dextran sodium sulfate (DSS)-induced colitis and subsequent colitis recovery in mice. C57BL/6 male mice were fed an AIN-93G basal diet (BD), or BD supplemented with 2% cooked ASP or 0.025% RUT for 2 wks prior to and during colitis induction with 2% DSS in water for 7 days, followed by 5 days colitis recovery. In colitic mice, both ASP and RUT upregulated mediators of improved barrier integrity and enhanced mucosal injury repair (e.g. Muc1, IL-22, Rho-A, Rac1, and Reg3γ), increased the proportion of mouse survival, and improved disease activity index. RUT had the greatest effect in attenuating DSS-induced colonic damage indicated by increased crypt and goblet cell restitution, reduced colonic myeloperoxidase, as well as attenuated DSS-induced microbial dysbiosis (reduced Enterobacteriaceae and Bacteroides, and increased unassigned Clostridales, Oscillospira, Lactobacillus, and Bifidobacterium). These findings demonstrate that dietary cooked ASP and its flavonoid glycoside, RUT, may be useful in attenuating colitis severity by modulating the colonic microenvironment resulting in reduced colonic inflammation, promotion of colonic mucosal injury repair, and attenuation of colitis-associated microbial dysbiosis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A Mechanobiological model for damage-induced growth in arterial tissue with application to in-stent restenosis

    Science.gov (United States)

    Fereidoonnezhad, B.; Naghdabadi, R.; Sohrabpour, S.; Holzapfel, G. A.

    In-stent restenosis (ISR) is one of the main drawbacks of stent implementation which limits the long-term success of the procedure. Morphological changes occurring within the arterial wall due to stent-induced mechanical injury are a major cause for activation of vascular smooth muscle cells (VSMCs), and the subsequent development of ISR. Considering the theory of volumetric mass growth and adopting a multiplicative decomposition of the deformation gradient into an elastic part and a growth part, we present a mechanobiological model for ISR. An evolution equation is developed for mass growth of the neointima, in which the activation of VSMCs due to stent-induced damage (injury) and the proliferation rate of the activated cells are considered. By introducing the mass evolution into the mass balance equation, we obtain the evolution of the growth tensor over time. The model is implemented in a finite element code and the procedure of angioplasty is simulated, whereby the features of the proposed growth model are illustrated.

  7. [Effect of oxidative stress-associated damage to the lung tissue caused by different body mass index in the rat models].

    Science.gov (United States)

    Li, X Y; Zhang, X J; Zhao, J H; Xu, J Y

    2016-12-12

    Objective: To investigate the influence of different diets on serum protein expression levels of 4-hydroxynonenal (4-HNE), thioredoxin (Trx), thioredoxin reductase (TrxR) and the activities of Trx and TrxR, and to explore the effect of damage to the lung tissue and the underlying mechanisms of different body mass index caused by different diets in the rat models . Method: Healthy clean male SD rats were randomly divided into normal group, emaciation group and fat group, which were raised by different diets for 6 months.Then the rats were sacrificed and the serum and lung tissue were prepared. The levels of 4-HNE, Trx and TrxR in peripheral blood were quantitatively analyzed by enzyme-linked immunosorbent assay(ELISA), and the activities of Trx and TrxR were measured by chemical methods. Results: Compared with the normal group, the lung tissue had more apparent emphysema in the emaciation and the fat groups under light microscope, and more inflammatory cell infiltration in alveolar septum was observed in the fat group.The levels of 4-HNE in the fat group[(24.7±8.7)mg/L]was significantly higher than that in the normal group[(15.4±4.7)mg/L, P 0.05)in the levels of 4-HNE between the emaciation and the normal groups. The levels of TrxR in the emaciation group[(7.7±1.4)μg/ml]was significantly higher than that in the normal and the fat groups[(6.2±1.1), (4.9±1.4)μg/ml, all P 0.05). The activity of Trx in the emaciation group[(32.4±8.5)×10 -3 A ·min -1 ·mg -1 ]was significantly higher than that in the normal group[(19.6±3.3)×10 -3 A ·min -1 ·mg -1 ]and the fat group[(11.3±7.5)×10 -3 A ·min -1 ·mg -1 , all P 0.05). Conclusion: Both high BMI and low BMI can affect the oxidative stress of the body, resulting in increased oxidants and decreased antioxidants, and can cause damage to the lung tissue in the rat models.

  8. Protective effect of Urtica dioica L against nicotine-induced damage on sperm parameters, testosterone and testis tissue in mice.

    Science.gov (United States)

    Jalili, Cyrus; Salahshoor, Mohammad Reza; Naseri, Ali

    2014-06-01

    Nicotine consumption can decrease fertility drive in males by inducing oxidative stress and DNA damage. Urtica dioica L (U.dioica) is a multipurpose herb in traditional medicine for which some anti-oxidative and anti-inflammatory properties have been identified. The main goal is to investigate whether the U.dioica could inhibit nicotine adverse effects on sperm cells viability, count, motility, and testis histology and testosterone hormone. In this study, hydro-alcoholic extract of U.dioica was prepared and various doses of U.dioica (0, 10, 20, and 50 mg/kg) and U.dioica plus nicotine (0, 10, 20, and 50 mg/kg) were administered intraperitoneally to 56 male mice for 28 consequent days. These mice were randomly assigned to 8 groups (n=7) and sperm parameters (sperm cells viability, count, motility, and morphology), testis and prostate weight, testis histology and testosterone hormone were analyzed and compared. The results indicated that nicotine administration (0.5 mg/kg) significantly decreased testosterone level, count and motility of sperm cells, and testis weight compared to control group (p=0.00). However, increasing the dose of U.dioica significantly boosted motility, count, normal morphology of sperm cells, seminiferous tubules diameter, and testosterone in all groups compared to control (p=0.00) and testis weight in 20 and 50 mg/kg doses in comparison with control group (p=0.00). It seems that U.dioica hydro-alcoholic extract administration could increase the quality of spermatozoa and inhibits nicotine-induced adverse effects on sperm parameters.

  9. A Method to Correlate mRNA Expression Datasets Obtained from Fresh Frozen and Formalin-Fixed, Paraffin-Embedded Tissue Samples: A Matter of Thresholds.

    Directory of Open Access Journals (Sweden)

    Dana A M Mustafa

    Full Text Available Gene expression profiling of tumors is a successful tool for the discovery of new cancer biomarkers and potential targets for the development of new therapeutic strategies. Reliable profiling is preferably performed on fresh frozen (FF tissues in which the quality of nucleic acids is better preserved than in formalin-fixed paraffin-embedded (FFPE material. However, since snap-freezing of biopsy materials is often not part of daily routine in pathology laboratories, one may have to rely on archival FFPE material. Procedures to retrieve the RNAs from FFPE materials have been developed and therefore, datasets obtained from FFPE and FF materials need to be made compatible to ensure reliable comparisons are possible.To develop an efficient method to compare gene expression profiles obtained from FFPE and FF samples using the same platform.Twenty-six FFPE-FF sample pairs of the same tumors representing various cancer types, and two FFPE-FF sample pairs of breast cancer cell lines, were included. Total RNA was extracted and gene expression profiling was carried out using Illumina's Whole-Genome cDNA-mediated Annealing, Selection, extension and Ligation (WG-DASL V3 arrays, enabling the simultaneous detection of 24,526 mRNA transcripts. A sample exclusion criterion was created based on the expression of 11 stably expressed reference genes. Pearson correlation at the probe level was calculated for paired FFPE-FF, and three cut-off values were chosen. Spearman correlation coefficients between the matched FFPE and FF samples were calculated for three probe lists with varying levels of significance and compared to the correlation based on all measured probes. Unsupervised hierarchical cluster analysis was performed to verify performance of the included probe lists to compare matched FPPE-FF samples.Twenty-seven FFPE-FF pairs passed the sample exclusion criterion. From the profiles of 27 FFPE and FF matched samples, the best correlating probes were identified

  10. Radiation-induced brain damage in children; Histological analysis of sequential tissue changes in 34 autopsy cases

    Energy Technology Data Exchange (ETDEWEB)

    Oi, Shizuo; Kokunai, Takashi; Ijichi, Akihiro; Matsumoto, Satoshi [Kobe Univ. (Japan). School of Medicine; Raimondi, A J

    1990-01-01

    The nature and sequence of the radiation-induced changes in the brain were studied postmortem in 34 children with glioma, 22 of whom underwent central nervous system radiation therapy. Twenty received whole-brain or whole-neuroaxis radiation at a total mean dosage of 4063 cGy. Brain tissue alternations were analyzed histologically by means of various staining methods, including immunohistochemical techniques. The histological features of irradiated brains were compared with those of non-irradiated brains. Microscopic findings included demyelination (seven cases), focal necrosis (six cases), cortical atrophy (four cases), endothelial proliferation (four cases), and telangiectatic vascular proliferation with vascular thickening and oozing of a thick fluid (one case). Such findings were rare in non-irradiated patients. Demyelination was observed earliest in a patient who died 5 months after radiation therapy and was more common after 9 months. Focal necrosis was first observed 9 months post-irradiation but was more advanced and extensive after 1 year. Calcified foci were found only after 60 months. Various vascular changes such as vascular thickening and thrombosis suggested ischemic insult to the brain as a late effect of radiation injury. The results of this study suggest that the immature brain may be more sensitive to radiation than is the adult brain, and that the manifestations of radiation-induced injury depend on the time elapsed after irradiation. (author).

  11. Ultrastructural and cellular damage to rat lung with x-rays: a search for target cell in lung tissue

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, I

    1975-03-01

    Radiation effects on the peripheral alveoli of conventional rats were examined by means of electron microscopy. The right hemithorax alone was exposed to various single doses of x rays. The initial cellular lesions selectively involved the cytoplasms of alveolar capillary endothelial (Ed) and type 1 epithelial (Ep 1) cells in a dose-dependent fashion, where the major alterations were multifocal vacuolations and swellings. These lesions became visible as early as 1 hr after 1000 R (the assumed mean lethal dose for Ed cells) and more. However, progenitor Ep 2 cells exhibited no obvious cytoplasmic lesions by the doses below 2000 R, indicating that Ep 2 cells are more resistant to x rays. With time following 1000 R, the capillary Ed blebbing abruptly developed in various forms from the sites presumably other than the Ed junctions. The Ed blebs and interstitial edema progressed until about 2 weeks without recovery, while some signs of cellular recovery were recognized in Ep 1 cells during this period. The observations after a long period of 6 months following 1000 R showed that the typical pulmonary fibrotic changes were initiated in the interstitium perhaps around unrepaired capillaries. Further, inflammatory reaction characterized by massive cellular infiltations was superimposed on developing pulmonary fibrosis. Considering the current knowledge about the cell sensitivity and renewal in stable tissues, the present results imply that capillary Ed cell is the primary target for the radiation lesion leading to the secondary pulmonary alterations.

  12. Spinal cord injury after blunt cervical spine trauma: correlation of soft-tissue damage and extension of lesion.

    Science.gov (United States)

    Martínez-Pérez, R; Paredes, I; Cepeda, S; Ramos, A; Castaño-León, A M; García-Fuentes, C; Lobato, R D; Gómez, P A; Lagares, A

    2014-05-01

    In patients with spinal cord injury after blunt trauma, several studies have observed a correlation between neurologic impairment and radiologic findings. Few studies have been performed to correlate spinal cord injury with ligamentous injury. The purpose of this study was to retrospectively evaluate whether ligamentous injury or disk disruption after spinal cord injury correlates with lesion length. We retrospectively reviewed 108 patients diagnosed with traumatic spinal cord injury after cervical trauma between 1990-2011. Plain films, CT, and MR imaging were performed on patients and then reviewed for this study. MR imaging was performed within 96 hours after cervical trauma for all patients. Data regarding ligamentous injury, disk injury, and the extent of the spinal cord injury were collected from an adequate number of MR images. We evaluated anterior longitudinal ligaments, posterior longitudinal ligaments, and the ligamentum flavum. Length of lesion, disk disruption, and ligamentous injury association, as well as the extent of the spinal cord injury were statistically assessed by means of univariate analysis, with the use of nonparametric tests and multivariate analysis along with linear regression. There were significant differences in lesion length on T2-weighted images for anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum in the univariate analysis; however, when this was adjusted by age, level of injury, sex, and disruption of the soft tissue evaluated (disk, anterior longitudinal ligaments, posterior longitudinal ligaments, and ligamentum flavum) in a multivariable analysis, only ligamentum flavum showed a statistically significant association with lesion length. Furthermore, the number of ligaments affected had a positive correlation with the extension of the lesion. In cervical spine trauma, a specific pattern of ligamentous injury correlates with the length of the spinal cord lesion in MR imaging studies

  13. Brain tissue oxidative damage as a possible mechanism for the deleterious effect of a chronic high dose of estradiol on learning and memory in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Fatimeh Khodabandehloo

    2013-05-01

    Full Text Available In addition to antioxidative effects, estrogens also exert pro-oxidative actions. The effect of chronic administration of a high dose of estradiol valerate on Morris water maze tasks and brain tissues oxidative damage was investigated. The Sham-Est and OVX-Est groups were treated with estradiol valerate (4 mg/kg for 12 weeks. Escape latency and traveled path in the Sham-Est and OVX-Est groups were significantly higher than in the Sham and OVX groups (p≪0.01 and p≪0.001. In the probe trial, the animals of the Sham-Est and OVX-Est groups spent lower time in Q1 compared to Sham and OVX groups (p≪0.05 and p≪0.001. In Sham-Est and OVX-Est groups, the brain tissue total thiol concentration was significantly lower, and malondialdehyde (MDA concentrations were higher than in the Sham and OVX groups (p≪0.05 and p≪0.001. It is concluded that administration of high exogenous levels of estradiol impairs performance and enhances oxidative stress.

  14. Pretreatment with AQP4 and NKCC1 Inhibitors Concurrently Attenuated Spinal Cord Edema and Tissue Damage after Spinal Cord Injury in Rats.

    Science.gov (United States)

    Yan, Xiaodong; Liu, Juanfang; Wang, Xiji; Li, Wenhao; Chen, Jingyuan; Sun, Honghui

    2018-01-01

    Spinal cord injury (SCI) affects more than 2.5 million people worldwide. Spinal cord edema plays critical roles in the pathological progression of SCI. This study aimed to delineate the roles of aquaporin 4 (AQP4) and Na + -K + -Cl - cotransporter 1 (NKCC1) in acute phase edema and tissue destruction after SCI and to explore whether inhibiting both AQP4 and NKCC1 could improve SCI-induced spinal edema and damage. Rat SCI model was established by modified Allen's method. Spinal cord water content, cerebrospinal fluid lactose dehydrogenase (LDH) activity, AQP4 and NKCC1 expression, and spinal cord pathology from 30 min to 7 days after SCI were monitored. Additionally, aforementioned parameters in rats treated with AQP4 and/or NKCC1 inhibitors were assessed 2 days after SCI. Spinal cord water content was significantly increased 1 h after SCI while AQP4 and NKCC1 expression and spinal fluid LDH activity elevated 6 h after SCI. Spinal cord edema and spinal cord destruction peaked around 24 h after SCI and maintained at high levels thereafter. Treating rats with AQP4 inhibitor TGN-020 and NKCC1 antagonist bumetanide significantly reduced spinal cord edema, tissue destruction, and AQP4 and NKCC1 expression after SCI in an additive manner. These results demonstrated the benefits of simultaneously inhibiting both AQP4 and NKCC1 after SCI.

  15. Doubler system quench detection threshold

    International Nuclear Information System (INIS)

    Kuepke, K.; Kuchnir, M.; Martin, P.

    1983-01-01

    The experimental study leading to the determination of the sensitivity needed for protecting the Fermilab Doubler from damage during quenches is presented. The quench voltage thresholds involved were obtained from measurements made on Doubler cable of resistance x temperature and voltage x time during quenches under several currents and from data collected during operation of the Doubler Quench Protection System as implemented in the B-12 string of 20 magnets. At 4kA, a quench voltage threshold in excess of 5.OV will limit the peak Doubler cable temperature to 452K for quenches originating in the magnet coils whereas a threshold of 0.5V is required for quenches originating outside of coils

  16. The metabolism of 32P-CP-PLLA seed implanted in the liver and its damage to the normal liver tissue: a study in the experimental dogs

    International Nuclear Information System (INIS)

    Tan Zhongbao; Liu Lu; Guo Jinhe; Zhu Guangyu; Wang Fuan; Nie Qi; Gao Hailin; Teng Gaojun

    2010-01-01

    Objective: To investigate the effects of intratumoral implantation of 32 P -CP-PLLA seeds on the normal canine liver tissue and to explore the metabolism of 32 P-CP-PLLA seeds implanted in the liver of experimental dogs. Methods: Twelve beagles were enrolled in this study. The dogs were randomly and equally divided into four groups: group A (185 MBq), group B (370 MBq), group C (740 MBq) and group D (0 MBq). By using laparotomy procedure 32 P-CP-PLLA seeds were implanted into dog's liver. CT scan was performed before operation as well as before the dog was sacrificed. All dogs were sacrificed three months after the implantation. Before the procedure and 1, 2, 4, 8 and 12 weeks after the procedure the blood tests and serum biochemical tests were conducted. One dog from group B and group C was selected respectively and was fed in a metabolic cage. Within one month after the procedure the cpm in feces and in urine was determined every 24 hours. One dog was picked out from each of the three groups and was punctured to get its liver tissue for pathologic exam each time at 1, 2, 4, 8 and 12 weeks after the implantation, and SPECT imaging was also performed at the same time. Pathologic study, both macroscopic and microscopic (including optical and electronic microscopy) was made to observe the liver damage after the dog was sacrificed. The statistical analysis was processed by using SPSS 13.0 software and the measuring data were expressed with mean ± standard deviation (x ± s). Results: Two months after the procedure, serological examination found that the serum alkaline phosphatase (BKP) in both group B and group C was significantly higher than that in other groups, the difference was statistically significant (P 32 P-CP-PLLA seeds was manifested as a spherical lesion which was encysted by a layer of fibrous tissue with an edematous zone peripherally. Conclusion: The implantation of 32 P-CP-PLLA seeds in dog's liver causes only localized hepatic damage with no general

  17. Growth, spectral, optical, laser damage threshold and DFT investigations on 2-amino 4-methyl pyridinium 4-methoxy benzoate (2A4MP4MB): A potential organic third order nonlinear optical material for optoelectronic applications

    Science.gov (United States)

    Krishnakumar, M.; Karthick, S.; Thirupugalmani, K.; Babu, B.; Vinitha, G.

    2018-05-01

    In present investigation, single crystals of organic charge transfer complex, 2-amino-4-methyl pyridinium-4-methoxy benzoate (2A4MP4MB) was grown by controlled slow evaporation solution growth technique using methanol as a solvent at room temperature. Single crystal XRD analysis confirmed the crystal system and lattice parameters of 2A4MP4MB. The crystalline nature, presence of various vibrational modes and other chemical bonds in the compound have been recognized and confirmed by powder X-ray diffraction, FT-IR and FT-Raman spectroscopic techniques respectively. The presence of various proton and carbon positions in title compound was confirmed using 1H NMR and 13C NMR spectral studies. The wide optical operating window and cut-off wavelength were identified and band gap value of the title compound was calculated using UV-vis-NIR study. The specific heat capacity (cp) values of the title compound, 1.712 J g-1·K-1 at 300 K and 13.6 J g-1 K-1 at 433 K (melting point) were measured using Modulated Differential Scanning Calorimetric studies (MDSC). From Z-scan study, nonlinear refractive index (n2), nonlinear absorption (β) and third order nonlinear susceptibility (χ(3)) values were determined. The self-defocusing effect and saturable absorption behavior of the material were utilized to exhibit the optical limiting action at λ = 532 nm by employing the same continuous wave (cw) Nd: YAG laser source. The laser damage threshold (LDT) study of title compound was carried out using Nd: YAG laser of 532 nm wavelength. The Vickers' micro hardness test was carried out at room temperature and obtained results were investigated using classical Meyer's law. In addition, DFT calculations were carried out for the first time for this compound. These characterization studies performed on the title compound planned to probe the valuable and safe region of optical, thermal and mechanical properties to improve efficacy of 2A4MP4MB single crystals in optoelectronic device

  18. DNA damage induced in mouse tissues by organic wood preserving waste extracts as assayed by {sup 32}P-postlabeling

    Energy Technology Data Exchange (ETDEWEB)

    Randerath, E. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States); Zhou, G.D. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States); Donnelly, K.C. [Department of Veterinary Anatomy and Public Health, Texas A and M University, College Station, TX (United States); Safe, S.H. [Department of Veterinary Physiology/Pharmacology, Texas A and M University, College Station, TX (United States); Randerath, K. [Division of Toxicology, Department of Pharmacology, Baylor College of Medicine, Houston, TX (United States)

    1996-09-01

    In the present study, a mouse bioassay was used in combination with {sup 32}P-postlabeling to determine DNA adduct formation induced by hexane/acetone extracts of two samples from a WPW site. Female ICR mice were treated dermally with extract corresponding to 3 mg residue or vehicle control once per day for 2 days and killed 24 h later. Skin, lung, liver, kidney, and heart DNA preparations were assayed by nuclease P1-enhanced postlabeling. Adduct profiles were tissue-specific and displayed a multitude of non-polar DNA adducts with levels amounting to one adduct in 1.6 x 10{sup 6} DNA nucleotides in skin (both extracts) and one adduct in 3.2 x 10{sup 7} or 1.2 x 10{sup 7} DNA nucleotides in liver (extract 1 or extract 2). Based on their chromatographic properties, these adducts appeared largely derived from polycyclic aromatic hydrocarbons (PAHs) present in the extracts. One of the major adducts was identified as the {sup 32}P-labeled derivative of the reaction product of 7{beta}, 8{alpha}-dihydroxy-9{alpha}, 10{alpha}-epoxy-7, 8, 9, 10-tetrahydrobenzo[a]pyrene (BPDE I) with N{sup 2} of deoxyguanosine. Total non-polar DNA adduct levels were highest in skin and lung, amounting to 17.4 and 24.0% of the skin values for extracts 1 and 2, respectively, in lung while the corresponding levels in liver were 5.0 and 12.6%. These results were in accord with the carcinogenic potencies of PAHs in these organs. Extract 2 induced higher adduct levels in internal organs, although its PAH concentrations were lower than those of extract 1, i.e. lung, liver, kidney, and heart had 1.4, 2.5, 1.9, and 1.7 times higher total adduct levels and 1.6, 3.3, 1.6, and 1.9 times higher benzo[a]pyrene adduct levels. With the exception of total adducts in lung, the differences between the two extracts were all significant, suggestive of compound interactions. (orig.) (orig.). With 5 figs., 6 tabs.

  19. DNA damage induced in mouse tissues by organic wood preserving waste extracts as assayed by 32P-postlabeling

    International Nuclear Information System (INIS)

    Randerath, E.; Zhou, G.D.; Donnelly, K.C.; Safe, S.H.; Randerath, K.

    1996-01-01

    In the present study, a mouse bioassay was used in combination with 32 P-postlabeling to determine DNA adduct formation induced by hexane/acetone extracts of two samples from a WPW site. Female ICR mice were treated dermally with extract corresponding to 3 mg residue or vehicle control once per day for 2 days and killed 24 h later. Skin, lung, liver, kidney, and heart DNA preparations were assayed by nuclease P1-enhanced postlabeling. Adduct profiles were tissue-specific and displayed a multitude of non-polar DNA adducts with levels amounting to one adduct in 1.6 x 10 6 DNA nucleotides in skin (both extracts) and one adduct in 3.2 x 10 7 or 1.2 x 10 7 DNA nucleotides in liver (extract 1 or extract 2). Based on their chromatographic properties, these adducts appeared largely derived from polycyclic aromatic hydrocarbons (PAHs) present in the extracts. One of the major adducts was identified as the 32 P-labeled derivative of the reaction product of 7β, 8α-dihydroxy-9α, 10α-epoxy-7, 8, 9, 10-tetrahydrobenzo[a]pyrene (BPDE I) with N 2 of deoxyguanosine. Total non-polar DNA adduct levels were highest in skin and lung, amounting to 17.4 and 24.0% of the skin values for extracts 1 and 2, respectively, in lung while the corresponding levels in liver were 5.0 and 12.6%. These results were in accord with the carcinogenic potencies of PAHs in these organs. Extract 2 induced higher adduct levels in internal organs, although its PAH concentrations were lower than those of extract 1, i.e. lung, liver, kidney, and heart had 1.4, 2.5, 1.9, and 1.7 times higher total adduct levels and 1.6, 3.3, 1.6, and 1.9 times higher benzo[a]pyrene adduct levels. With the exception of total adducts in lung, the differences between the two extracts were all significant, suggestive of compound interactions. (orig.) (orig.). With 5 figs., 6 tabs

  20. The effect of the Z mutation on the ability of alpha 1-antitrypsin to prevent neutrophil mediated tissue damage.

    Science.gov (United States)

    Llewellyn-Jones, C G; Lomas, D A; Carrell, R W; Stockley, R A

    1994-11-29

    Recent studies have shown that alpha 1-antitrypsin (alpha 1-AT) from Z antitrypsin deficiency subjects has a slightly lower association rate constant with neutrophil elastase (NE) than alpha 1-AT from normal subjects, although it is unknown whether this is of clinical importance. We have purified alpha 1-AT from a normal (M alpha 1-AT) and from a deficient (Z alpha 1-AT) subject and have confirmed that the association rate constants for NE are different (5.28; S.E. 0.06.10(7) M-1 s-1 and 1.2; S.E. 0.2.10(7) M-1 s-1, respectively). We have assessed the ability of both of these proteins to inhibit neutrophil mediated fibronectin (FN) degradation in vitro. Both proteins inhibited FN degradation in a dose dependant manner although Z alpha 1-AT was less effective than M alpha 1-AT at equivalent concentrations of active inhibitor (P < 0.05). Inhibition by M alpha 1-AT was 28.5% S.E. 3.9 at 0.01 microM; 35.5% S.E. 7.3 at 0.1 microM and 37% S.E. 8.4 at 0.5 microM, whereas inhibition by Z alpha 1-AT was 9.25% S.E. 3.9; 19.25% S.E. 7.7 and 21.2% S.E. 9.7, respectively. When the time course of inhibition of FN degradation was studied the difference (although less at 1.0 microM) became greater over the 3 h period of the assay. These results suggest that Z alpha 1-AT is less able than the M phenotype to inhibit connective tissue degradation by neutrophils at equivalent concentrations. This is probably due to the lower association rate constant although the reduced stability of the Z molecule may play a role. The differences, together with the reduced plasma concentration, may accentuate the susceptibility of deficient subjects to the development of emphysema.

  1. High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

    OpenAIRE

    Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

    2011-01-01

    CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at ...

  2. Checking the foundation: recent radiobiology and the linear no-threshold theory.

    Science.gov (United States)

    Ulsh, Brant A

    2010-12-01

    The linear no-threshold (LNT) theory has been adopted as the foundation of radiation protection standards and risk estimation for several decades. The "microdosimetric argument" has been offered in support of the LNT theory. This argument postulates that energy is deposited in critical cellular targets by radiation in a linear fashion across all doses down to zero, and that this in turn implies a linear relationship between dose and biological effect across all doses. This paper examines whether the microdosimetric argument holds at the lowest levels of biological organization following low dose, low dose-rate exposures to ionizing radiation. The assumptions of the microdosimetric argument are evaluated in light of recent radiobiological studies on radiation damage in biological molecules and cellular and tissue level responses to radiation damage. There is strong evidence that radiation initially deposits energy in biological molecules (e.g., DNA) in a linear fashion, and that this energy deposition results in various forms of prompt DNA damage that may be produced in a pattern that is distinct from endogenous (e.g., oxidative) damage. However, a large and rapidly growing body of radiobiological evidence indicates that cell and tissue level responses to this damage, particularly at low doses and/or dose-rates, are nonlinear and may exhibit thresholds. To the extent that responses observed at lower levels of biological organization in vitro are predictive of carcinogenesis observed in vivo, this evidence directly contradicts the assumptions upon which the microdosimetric argument is based.

  3. CARA Risk Assessment Thresholds

    Science.gov (United States)

    Hejduk, M. D.

    2016-01-01

    Warning remediation threshold (Red threshold): Pc level at which warnings are issued, and active remediation considered and usually executed. Analysis threshold (Green to Yellow threshold): Pc level at which analysis of event is indicated, including seeking additional information if warranted. Post-remediation threshold: Pc level to which remediation maneuvers are sized in order to achieve event remediation and obviate any need for immediate follow-up maneuvers. Maneuver screening threshold: Pc compliance level for routine maneuver screenings (more demanding than regular Red threshold due to additional maneuver uncertainty).

  4. Ligamentous Injuries and the Risk of Associated Tissue Damage in Acute Ankle Sprains in Athletes: A Cross-sectional MRI Study.

    Science.gov (United States)

    Roemer, Frank W; Jomaah, Nabil; Niu, Jingbo; Almusa, Emad; Roger, Bernard; D'Hooghe, Pieter; Geertsema, Celeste; Tol, Johannes L; Khan, Karim; Guermazi, Ali

    2014-07-01

    Ankle joint injuries are extremely common sports injuries, with the anterior talofibular ligament involved in the majority of ankle sprains. There have been only a few large magnetic resonance imaging (MRI) studies on associated structural injuries after ankle sprains. To describe the injury pattern in athletes who were referred to MRI for the assessment of an acute ankle sprain and to assess the risk of associated traumatic tissue damage including lateral and syndesmotic ligament involvement. Cross-sectional study; Level of evidence, 3. A total of 261 ankle MRI scans of athletes with acute ankle sprains were evaluated for: lateral and syndesmotic ligament injury; concomitant injuries to the deltoid and spring ligaments and sinus tarsi; peroneal, flexor, and extensor retinacula and tendons; traumatic and nontraumatic osteochondral and osseous changes; and joint effusion. Patients were on average 22.5 years old, and the average time from injury to MRI was 5.7 days. Six exclusive injury patterns were defined based on lateral and syndesmotic ligament involvement. The risk for associated injuries was assessed by logistic regression using ankles with no or only low-grade lateral ligament injuries and no syndesmotic ligament damage as the reference. With regard to the injury pattern, there were 103 ankles (39.5%) with complete anterior talofibular ligament disruption and no syndesmotic injury, and 53 ankles (20.3%) had a syndesmotic injury with or without lateral ligament damage. Acute osteochondral lesions of the lateral talar dome were seen in 20 ankles (7.7%). The percentage of chronic lateral osteochondral lesions was 1.1%. The risk for talar bone contusions increased more than 3-fold for ankles with complete lateral ligament ruptures (adjusted odds ratio [aOR], 3.43; 95% CI, 1.72-6.85) but not for ankles with syndesmotic involvement. The risk for associated deltoid ligament injuries increased for ankles with complete lateral ligament injuries (aOR, 4.04; 95% CI, 1

  5. High-speed scanning ablation of dental hard tissues with a λ=9.3-μm CO2 laser: heat accumulation and peripheral thermal damage

    Science.gov (United States)

    Nguyen, Daniel; Staninec, Michal; Lee, Chulsung; Fried, Daniel

    2010-02-01

    A mechanically scanned CO2 laser operated at high laser pulse repetition rates can be used to rapidly and precisely remove dental decay. This study aims to determine whether these laser systems can safely ablate enamel and dentin without excessive heat accumulation and peripheral thermal damage. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. Samples were derived from noncarious extracted molars. Pulpal temperatures were recorded using microthermocouples situated at the pulp chamber roof of samples (n=12), which were occlusally ablated using a rapid-scanning, water-cooled 300 Hz CO2 laser over a two minute time course. The mechanical strength of facially ablated dentin (n=10) was determined via four-point bend test and compared to control samples (n=10) prepared with 320 grit wet sand paper to simulate conventional preparations. Composite-to-enamel bond strength was measured via single-plane shear test for ablated/non-etched (n=10) and ablated/acid-etched (n=8) samples and compared to control samples (n=9) prepared by 320 grit wet sanding. Thermocouple measurements indicated that the temperature remained below ambient temperature at 19.0°C (s.d.=0.9) if water-cooling was used. There was no discoloration of either dentin and enamel, the treated surfaces were uniformly ablated and there were no cracks observable on the laser treated surfaces. Fourpoint bend tests yielded mean mechanical strengths of 18.2 N (s.d.=4.6) for ablated dentin and 18.1 N (s.d.=2.7) for control (p>0.05). Shear tests yielded mean bond strengths of 31.2 MPa (s.d.=2.5, penamel without excessive heat accumulation and with minimal thermal damage. It is not clear whether the small (16%) but statistically significant reduction in the shear bond strength to enamel is clinically significant since the mean shear bond strength exceeded 30 MPa.

  6. Protective effect of hydroferrate fluid, MRN-100, against lethality and hematopoietic tissue damage in γ-radiated Nile tilapia, Oreochromis niloticus

    International Nuclear Information System (INIS)

    Ghoneum, Mamdooh; Elbaghdady, Heba Allah M.; El-Shebly, Abdallah A.; Pan, Deyu; Assanah, Edward; Lawson, Greg

    2013-01-01

    Hydroferrate fluid, MRN-100, an iron-based compound derived from bivalent and trivalent ferrates, is a potent antioxidant compound. Therefore, we examined the protective effect of MRN-100 against γ-radiation-induced lethality and damage to hematopoietic tissues in fish. A total of 216 Nile tilapia fish (Oreochromis niloticus) were randomly divided into four groups. Group 1 served as a control that was administered no radiation and no MRN-100 treatment. Group 2 was exposed only to γ-radiation (15 Gy). Groups 3 and 4 were pre-treated with MRN-100 at doses of either 1 ml/l or 3 ml/l in water for 1 week, and subsequently exposed to radiation while continuing to receive MRN-100 for 27 days. The survival rate was measured, and biochemical and histopathological analyses of hematopoietic tissues were performed for the different treatment groups at 1 and 4 weeks post-radiation. Exposure to radiation reduced the survival rate to 27.7%, while treatment with MRN-100 maintained the survival rate at 87.2%. In addition, fish exposed to γ-radiation for 1 week showed a significant decrease in the total number of white blood cells (WBCs) and red blood cells (RBCs) series. However, treatment with MRN-100 protected the total WBC count and the RBCs series when compared with irradiated fish. Furthermore, significant histological lesions were observed in the hepatopancreas, spleen and gills of irradiated fish. However, treatment with MRN-100 protected the histopathology of various organs. We conclude that MRN-100 is a radioprotective agent in fish and may be useful as an adjuvant treatment to counteract the adverse side effects associated with radiation exposure. (author)

  7. Adipose Tissue-Derived Mesenchymal Stromal Cells Protect Mice Infected with Trypanosoma cruzi from Cardiac Damage through Modulation of Anti-parasite Immunity.

    Science.gov (United States)

    Mello, Debora B; Ramos, Isalira P; Mesquita, Fernanda C P; Brasil, Guilherme V; Rocha, Nazareth N; Takiya, Christina M; Lima, Ana Paula C A; Campos de Carvalho, Antonio C; Goldenberg, Regina S; Carvalho, Adriana B

    2015-01-01

    Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is a complex disease endemic in Central and South America. It has been gathering interest due to increases in non-vectorial forms of transmission, especially in developed countries. The objective of this work was to investigate if adipose tissue-derived mesenchymal stromal cells (ASC) can alter the course of the disease and attenuate pathology in a mouse model of chagasic cardiomyopathy. ASC were injected intraperitoneally at 3 days post-infection (dpi). Tracking by bioluminescence showed that cells remained in the abdominal cavity for up to 9 days after injection and most of them migrated to the abdominal or subcutaneous fat, an early parasite reservoir. ASC injection resulted in a significant reduction in blood parasitemia, which was followed by a decrease in cardiac tissue inflammation, parasitism and fibrosis at 30 dpi. At the same time point, analyses of cytokine release in cells isolated from the heart and exposed to T. cruzi antigens indicated an anti-inflammatory response in ASC-treated animals. In parallel, splenocytes exposed to the same antigens produced a pro-inflammatory response, which is important for the control of parasite replication, in placebo and ASC-treated groups. However, splenocytes from the ASC group released higher levels of IL-10. At 60 dpi, magnetic resonance imaging revealed that right ventricular (RV) dilation was prevented in ASC-treated mice. In conclusion, the injection of ASC early after T. cruzi infection prevents RV remodeling through the modulation of immune responses. Lymphoid organ response to the parasite promoted the control of parasite burden, while the heart, a target organ of Chagas disease, was protected from damage due to an improved control of inflammation in ASC-treated mice.

  8. Adipose Tissue-Derived Mesenchymal Stromal Cells Protect Mice Infected with Trypanosoma cruzi from Cardiac Damage through Modulation of Anti-parasite Immunity.

    Directory of Open Access Journals (Sweden)

    Debora B Mello

    Full Text Available Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi, is a complex disease endemic in Central and South America. It has been gathering interest due to increases in non-vectorial forms of transmission, especially in developed countries. The objective of this work was to investigate if adipose tissue-derived mesenchymal stromal cells (ASC can alter the course of the disease and attenuate pathology in a mouse model of chagasic cardiomyopathy.ASC were injected intraperitoneally at 3 days post-infection (dpi. Tracking by bioluminescence showed that cells remained in the abdominal cavity for up to 9 days after injection and most of them migrated to the abdominal or subcutaneous fat, an early parasite reservoir. ASC injection resulted in a significant reduction in blood parasitemia, which was followed by a decrease in cardiac tissue inflammation, parasitism and fibrosis at 30 dpi. At the same time point, analyses of cytokine release in cells isolated from the heart and exposed to T. cruzi antigens indicated an anti-inflammatory response in ASC-treated animals. In parallel, splenocytes exposed to the same antigens produced a pro-inflammatory response, which is important for the control of parasite replication, in placebo and ASC-treated groups. However, splenocytes from the ASC group released higher levels of IL-10. At 60 dpi, magnetic resonance imaging revealed that right ventricular (RV dilation was prevented in ASC-treated mice.In conclusion, the injection of ASC early after T. cruzi infection prevents RV remodeling through the modulation of immune responses. Lymphoid organ response to the parasite promoted the control of parasite burden, while the heart, a target organ of Chagas disease, was protected from damage due to an improved control of inflammation in ASC-treated mice.

  9. Re-examination of the threshold energy surface in copper

    International Nuclear Information System (INIS)

    King, W.E.; Benedek, R.; Merkle, K.L.; Meshii, M.

    1981-01-01

    Radiation-induced defect production in copper has been studied using in-situ electrical resistivity damage-rate measurements in the HVEM and molecular dynamics simulations. Analysis of the results yields a threshold energy surface characterized by two isolated pockets of low threshold energy centered at and surrounded by regions of much higher threshold energy; the corresponding damage function exhibits a plateau at 0.65 Frenkel pairs. A Frenkel pair resistivity of (2.75/sub -0.2/ + 0 6 ) x 10 - 4 Ω-cm is proposed. A model damage function is constructed and compared to results from ion irradiation damage-rate measurements. 7 figures

  10. Effect of time intervals between irradiation and chemotherapeutic agents on the normal tissue damage. Comparison between in vivo and in vitro experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hisao; Nakayama, Toshitake; Hashimoto, Shozo (Keio Univ., Tokyo (Japan). School of Medicine)

    1989-05-01

    Experiments have been carried out to determine the effect on the cell survivals at different time intervals between irradiation and chemotherapeutic agents (BLM, cisDDP, ADM and ACNU) in either the in vivo or the in vitro system. The intestinal epithelial assay was applied on the in vivo system. The clonogenic cell survivals of V/sub 79/ cells, both in the proliferative and the plateau phases, were determined in the in vitro system. The V/sub 79/ cells in the plateau phase were more sensitive to BLM, cisDDP and ACNU than those in the proliferative phase, however, the result was reverse with ADM. When BLM, cisDDP or ACNU was combined with irradiation at different time intervals, the response of the plateau phase V/sub 79/ cells to combination therapies were very similar to those of the intestinal epithelial cells. On the other hand, V/sub 79/ cells in the proliferative phase, which were treated with ADM and irradiation, showed the similar response as the intestinal cells. These results suggest that studies of chemo-radiotherapy with cultured cells which are sensitive to chemotherapeutic agents might be suitable to expect the in vivo damage of the normal tissue. (author).

  11. Increments in cytokines and matrix metalloproteinases in skeletal muscle after injection of tissue-damaging toxins from the venom of the snake Bothrops asper

    Directory of Open Access Journals (Sweden)

    Alexandra Rucavado

    2002-01-01

    Full Text Available Envenomations by the snake Bothrops asper are characterized by prominent local tissue damage (i.e. myonecrosis, blistering, hemorrhage and edema. Various phospholipases A2 and metalloproteinases that induce local pathological alterations have been purified from this venom. Since these toxins induce a conspicuous inflammatory response, it has been hypothesized that inflammatory mediators may contribute to the local pathological alterations described. This study evaluated the local production of cytokines and matrix metalloproteinases (MMPs as a consequence of intramuscular injections of an Asp-49 myotoxic phospholipase A2 (myotoxin III (MT-III and a P-I type hemorrhagic metalloproteinase (BaP1 isolated from B. asper venom. Both enzymes induced prominent tissue alterations and conspicuous increments in interleukin (IL-1β, IL-6 and a number of MMPs, especially gelatinase MMP-9, rapidly after injection. In contrast, no increments in tumor necrosis factor-α (TNF-α and interferon-γ were detected. In agreement, MT-III and BaP1 did not induce the synthesis of TNF-α by resident peritoneal macrophages in vitro. Despite the conspicuous expression of latent forms of MMPs in muscle, evidenced by zymography, there were no increments in activated MMP-2 and only a small increase in activated MMP-9, as detected by a functional enzymatic assay. This suggests that MMP activity was regulated by a highly controlled activation of latent forms and, probably, by a concomitant synthesis of MMP inhibitors. Since no hemorrhage nor dermonecrosis were observed after injection of MT-III, despite a prominent increase in MMP expression, and since inflammatory exudate did not enhance hemorrhage induced by BaP1, it is suggested that endogenous MMPs released in the tissue are not responsible for the dermonecrosis and hemorrhage characteristic of B. asper envenomation. Moreover, pretreatment of mice with the peptidomimetic MMP inhibitor batimastat did not reduce myotoxic nor

  12. Threshold quantum cryptography

    International Nuclear Information System (INIS)

    Tokunaga, Yuuki; Okamoto, Tatsuaki; Imoto, Nobuyuki

    2005-01-01

    We present the concept of threshold collaborative unitary transformation or threshold quantum cryptography, which is a kind of quantum version of threshold cryptography. Threshold quantum cryptography states that classical shared secrets are distributed to several parties and a subset of them, whose number is greater than a threshold, collaborates to compute a quantum cryptographic function, while keeping each share secretly inside each party. The shared secrets are reusable if no cheating is detected. As a concrete example of this concept, we show a distributed protocol (with threshold) of conjugate coding

  13. Investigation of retinal damage during refractive eye surgery

    Science.gov (United States)

    Schumacher, S.; Sander, M.; Dopke, C.; Grone, A.; Ertmer, W.; Lubatschowski, H.

    2005-04-01

    Ultrashort laser pulses are increasingly used in refractive eye surgery to cut inside transparent corneal tissue. This is exploited by the fs-LASIK procedure which affords the opportunity to correct ametropia without any mechanical effects. The cutting process is caused by the optical breakdown occurring in the laser focus. During this process only a certain amount of the pulse energy is deposited into the tissue. The remaining pulse energy propagates further through the eye and interacts with the retina and the strong absorbing tissue layers behind. Therefore this investigation shall clarify if the intensity of the remaining laser pulse and the resulting temperature field can damage the retina and the surrounding tissue. Threshold values of the retinal tissue and theoretical calculations of the temperature field will be presented.

  14. Theory of threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2002-01-01

    Theory of Threshold Phenomena in Quantum Scattering is developed in terms of Reduced Scattering Matrix. Relationships of different types of threshold anomalies both to nuclear reaction mechanisms and to nuclear reaction models are established. Magnitude of threshold effect is related to spectroscopic factor of zero-energy neutron state. The Theory of Threshold Phenomena, based on Reduced Scattering Matrix, does establish relationships between different types of threshold effects and nuclear reaction mechanisms: the cusp and non-resonant potential scattering, s-wave threshold anomaly and compound nucleus resonant scattering, p-wave anomaly and quasi-resonant scattering. A threshold anomaly related to resonant or quasi resonant scattering is enhanced provided the neutron threshold state has large spectroscopic amplitude. The Theory contains, as limit cases, Cusp Theories and also results of different nuclear reactions models as Charge Exchange, Weak Coupling, Bohr and Hauser-Feshbach models. (author)

  15. Role of Omega 3 fatty acids on radiation-induced oxidative and structural damage in different tissues of male albino rats

    International Nuclear Information System (INIS)

    Rezk, R.G.; Abou Zaid, N.M.; Ahmed, A. G.

    2011-01-01

    Omega-3 fatty acids play a critical role in the development and function of the reproductive and central nervous systems. The aim of this study is to evaluate the effect of omega-3 fatty acids supplementation on lipid peroxidation and antioxidant enzyme levels associated with histopathologic changes induced by gamma irradiation in the testis and brain of male albino rats. Rats were whole body exposed to radiation at a single dose of 3 Gy. Omega-3 fatty acids (0.4 gm/kg b wt/day) were given to rats, by gavages, for 15 consecutive days before irradiation and for 15 days after irradiation. Rats were sacrificed one and 15 days post irradiation .Biochemical analysis of testis and cerebral cortex samples showed that irradiation induced a significant increase in xanthine oxidase (XO) activity and lipid peroxidation end product malondialdehyde (MDA) and a decrease in the content of reduced glutathione (GSH) and activity of antioxidant enzymes; glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT).Histological examination of testis and cerebral cortex tissues showed spermatogonia degeneration, apoptosis and necrosis in the testis and neurons cell bodies with ill defined and even ruptured cell membrane and damaged blood capillaries in the cerebral cortex. Omega-3 administration has attenuated the toxic effects of radiation by decreasing the levels of MDA, and XO, and increasing the activity of endogenous antioxidant enzymes, which was associated with amelioration of the histological injury markers in both testis and cerebral cortex. It could be postulated that omega-3 fatty acids as a multi-functional dietary supplement could exert a modulatory role in radiation- induced testis and cerebral cortex biochemical and histological changes through its antioxidant properties.

  16. Corneal Damage from Infrared Radiation

    National Research Council Canada - National Science Library

    McCally, Russell

    2000-01-01

    ...) laser radiation at 10.6 (micrometer) and Tm: YAG laser radiation at 2.02 (micrometer). Retinal damage from sources with rectangular irradiance distributions was also modeled. Thresholds for CO(2...

  17. Early intervention with human albumin to reduce the tissue plasminogen activator-mediated blood-brain barrier permeability damaged by delayed reperfusion: an experimental study in rats

    International Nuclear Information System (INIS)

    Lu Haitao; Zhao Jungong; Li Minghua; Li Yongdong; Zhang Peilei

    2011-01-01

    Objective: To clarify whether early use of high-dose human albumin can reduce the permeability of blood-brain barrier (BBB) damaged by delayed thrombolysis or not, and, in tun, reduce the vasogenic brain edema. Methods: A total of 138 male SD rats weighing 320-380 grams were randomly divided into 4 groups: sham operation group (n=3), control group (n=45), albumin group (n=45) and albumin+rt-PA group (n=45). According to the reperfusion time after the onset of middle cerebral artery occlusion (MCAO), each group, except sham operation group, was divided into three subgroups of 2 h, 3 h and 4 h with 15 rats in each subgroup. Rats in albumin group and albumin+rt-PA group received an intravenous infusion of 20% human albumin (2.5 g/kg) 2 hours after the onset of MCAO, and rats in albumin+rt-PA group received an intravenous infusion of rt-PA (10 mg/kg) at all points of reperfusion time via the rat's femoral vein immediately after the reperfusion. All rats were sacrificed 24 hours after MCAO, the infarct volume of the brain was determined with TTC dye method, the leakage extent of BBB was quantitatively estimated by using Evans blue method, and the matrix metalloproteinase-9 (MMP-9) expression was assessed with immunohistochemistry technique. Results: Early intervention with the use of high-dose human albumin could significantly improve the neurological score at 24 h. In MCAO 3 h albumin group, MCAO 4 h albumin group and MCAO 3 h albumin+rt-PA group, neurological score was significantly better than that in the control group (P 0.05). The volume of the infarct tissue was also significantly smaller in all the treated groups with high-dose human albumin groups (P<0.05) when compared with the control group. The infarct volume of the MCAO 4 h in albumin group and albumin+rt-PA group was reduced by 23% and by 17.3%, respectively. Cerebral hemorrhage transformation occurred in two rats of MCAO 4 h control group, in one rat of MCAO 4 h albumin group and in one rat of MCAO 4 h

  18. Tissue responses to low protracted doses of high LET radiations or photons: Early and late damage relevant to radio-protective countermeasures

    Science.gov (United States)

    Ainsworth, E. J.; Afzal, S. M. J.; Crouse, D. A.; Hanson, W. R.; Fry, R. J. M.

    Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Low dose rates per fraction were used in some neutron experiments. Split-dose lethality studies (LD 50/30) with fission neutrons indicated greater accumulation of injury during a 9 fraction course (over 17 days) than was the case for γ-radiation. When total doses of 96 or 247 cGy of neutrons or γ rays were given as a single dose or in 9 fractions, a significant sparing effect on femur CFU-S depression was observed for both radiation qualities during the first 11 days, but there was not an earlier return to normal with dose fractionation. During the 9 fraction sequence, a significant sparing effect of low dose rate on CFU-S depression was observed in both neutron and γ-irradiated mice. CFU-S content at the end of the fractionation sequence did not correlate with measured LD 50/30. Sustained depression of femur and spleen CFU-S and a significant thrombocytopenia were observed when a total neutron dose of 240 cGy was given in 72 fractions over 24 weeks at low dose rates. The temporal aspects of CFU-S repopulation were different after a single versus fractionated neutron doses. The sustained reduction in the size of the CFU-S population was accompanied by an increase in the fraction in DNA synthesis. The proliferation characteristics and effects of age were different for radial CFU-S population closely associated with bone, compared with the axial population that can be readily aspirated from the femur. In aged irradiated animals, the CFU-S proliferation/redistribution response to typhoid vaccine showed both an age and radiation effect. After high single doses of neutrons or γ rays, a significant age- and radiation-related deficiency

  19. Tissue responses to low protracted doses of high let radiations or photons: Early and late damage relevant to radio-protective countermeasures

    International Nuclear Information System (INIS)

    Ainsworth, E.J.; Afzal, S.M.J.; Crouse, D.A.; Hanson, W.R.; Fry, R.J.M.

    1988-01-01

    Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Low dose rates per fraction were used in some neutron experiments. Split-dose lethality studies (LD 50/30) with fission neutrons indicated greater accumulation of injury during a 9 fraction course (over 17 days) than was the case for γ-radiation. When total doses of 96 or 247 cGy of neutrons or γ rays were given as a single dose or in 9 fractions, a significant sparing effect on femur CFU-S depression was observed for both radiation qualities during the first 11 days, but there was not an earlier return to normal with dose fractionation. During the 9 fraction sequence, a significant sparing effect of low dose rate on CFU-S depression was observed in both neutron and γ-irradiated mice. CFU-S content at the end of the fractionation sequence did not correlate with measured LD 50/30. Sustained depression of femur and spleen CFU-S and a significant thrombocytopenia were observed when a total neutron dose of 240 cGy was given in 72 fractions over 24 weeks at low dose rates. The temporal aspects of CFU-S repopulation were different after a single versus fractionated neutron doses. The sustained reduction in the size of the CFU-S population was accompanied by an increase in the fraction in DNA synthesis. The proliferation characteristics and effects of age were different for radial CFU-S population closely associated with bone, compared with the axial population that can be readily aspirated from the femur. In aged irradiated animals, the CFU-S proliferation/redistribution response to typhoid vaccine showed both an age and radiation effect. 63 refs., 6 figs., 7 tabs

  20. Threshold Signature Schemes Application

    Directory of Open Access Journals (Sweden)

    Anastasiya Victorovna Beresneva

    2015-10-01

    Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

  1. Particles near threshold

    International Nuclear Information System (INIS)

    Bhattacharya, T.; Willenbrock, S.

    1993-01-01

    We propose returning to the definition of the width of a particle in terms of the pole in the particle's propagator. Away from thresholds, this definition of width is equivalent to the standard perturbative definition, up to next-to-leading order; however, near a threshold, the two definitions differ significantly. The width as defined by the pole position provides more information in the threshold region than the standard perturbative definition and, in contrast with the perturbative definition, does not vanish when a two-particle s-wave threshold is approached from below

  2. Some considerations regarding the creep crack growth threshold

    International Nuclear Information System (INIS)

    Thouless, M.D.; Evans, A.G.

    1984-01-01

    The preceding analysis reveals that the existence of a threshold determined by the sintering stress does not influence the post threshold crack velocity. Considerations of the sintering stress can thus be conveniently excluded from analysis of the post threshold crack velocity. The presence of a crack growth threshold has been predicted, based on the existence of cavity nucleation controlled crack growth. A preliminary analysis of cavity nucleation rates within the damage zone reveals that this threshold is relatively abrupt, in accord with experimental observations. Consequently, at stress intensities below K /SUB th/ growth becomes nucleation limited and crack blunting occurs in preference to crack growth

  3. Thresholding magnetic resonance images of human brain

    Institute of Scientific and Technical Information of China (English)

    Qing-mao HU; Wieslaw L NOWINSKI

    2005-01-01

    In this paper, methods are proposed and validated to determine low and high thresholds to segment out gray matter and white matter for MR images of different pulse sequences of human brain. First, a two-dimensional reference image is determined to represent the intensity characteristics of the original three-dimensional data. Then a region of interest of the reference image is determined where brain tissues are present. The non-supervised fuzzy c-means clustering is employed to determine: the threshold for obtaining head mask, the low threshold for T2-weighted and PD-weighted images, and the high threshold for T1-weighted, SPGR and FLAIR images. Supervised range-constrained thresholding is employed to determine the low threshold for T1-weighted, SPGR and FLAIR images. Thresholding based on pairs of boundary pixels is proposed to determine the high threshold for T2- and PD-weighted images. Quantification against public data sets with various noise and inhomogeneity levels shows that the proposed methods can yield segmentation robust to noise and intensity inhomogeneity. Qualitatively the proposed methods work well with real clinical data.

  4. Double Photoionization Near Threshold

    Science.gov (United States)

    Wehlitz, Ralf

    2007-01-01

    The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We have investigated that cross section for lithium and beryllium and have analyzed our data with respect to the latest results in the Coulomb-dipole theory. We find that our data support the idea of a Coulomb-dipole interaction.

  5. Thresholds in radiobiology

    International Nuclear Information System (INIS)

    Katz, R.; Hofmann, W.

    1982-01-01

    Interpretations of biological radiation effects frequently use the word 'threshold'. The meaning of this word is explored together with its relationship to the fundamental character of radiation effects and to the question of perception. It is emphasised that although the existence of either a dose or an LET threshold can never be settled by experimental radiobiological investigations, it may be argued on fundamental statistical grounds that for all statistical processes, and especially where the number of observed events is small, the concept of a threshold is logically invalid. (U.K.)

  6. Clinical light damage to the eye

    International Nuclear Information System (INIS)

    Miller, D.

    1987-01-01

    This book contains four sections: The Nature of Light and of Light Damage to Biological Tissues; Light Damage to the Eye; Protecting the Eye from Light Damage; and Overview of Light Damage to the Eye. Some of the paper titles are: Ultraviolet-Absorbing Intraocular Lens Implants; Phototoxic Changes in the Retina; Light Damage to the Lens; and Radiation, Light, and Sight

  7. Hydrometeorological threshold conditions for debris flow initiation in Norway

    Directory of Open Access Journals (Sweden)

    N. K. Meyer

    2012-10-01

    Full Text Available Debris flows, triggered by extreme precipitation events and rapid snow melt, cause considerable damage to the Norwegian infrastructure every year. To define intensity-duration (ID thresholds for debris flow initiation critical water supply conditions arising from intensive rainfall or snow melt were assessed on the basis of daily hydro-meteorological information for 502 documented debris flow events. Two threshold types were computed: one based on absolute ID relationships and one using ID relationships normalized by the local precipitation day normal (PDN. For each threshold type, minimum, medium and maximum threshold values were defined by fitting power law curves along the 10th, 50th and 90th percentiles of the data population. Depending on the duration of the event, the absolute threshold intensities needed for debris flow initiation vary between 15 and 107 mm day−1. Since the PDN changes locally, the normalized thresholds show spatial variations. Depending on location, duration and threshold level, the normalized threshold intensities vary between 6 and 250 mm day−1. The thresholds obtained were used for a frequency analysis of over-threshold events giving an estimation of the exceedance probability and thus potential for debris flow events in different parts of Norway. The absolute thresholds are most often exceeded along the west coast, while the normalized thresholds are most frequently exceeded on the west-facing slopes of the Norwegian mountain ranges. The minimum thresholds derived in this study are in the range of other thresholds obtained for regions with a climate comparable to Norway. Statistics reveal that the normalized threshold is more reliable than the absolute threshold as the former shows no spatial clustering of debris flows related to water supply events captured by the threshold.

  8. Regional Seismic Threshold Monitoring

    National Research Council Canada - National Science Library

    Kvaerna, Tormod

    2006-01-01

    ... model to be used for predicting the travel times of regional phases. We have applied these attenuation relations to develop and assess a regional threshold monitoring scheme for selected subregions of the European Arctic...

  9. Raman spectral markers of collagen denaturation and hydration in human cortical bone tissue are affected by radiation sterilization and high cycle fatigue damage.

    Science.gov (United States)

    Flanagan, Christopher D; Unal, Mustafa; Akkus, Ozan; Rimnac, Clare M

    2017-11-01

    Thermal denaturation and monotonic mechanical damage alter the organic and water-related compartments of cortical bone. These changes can be detected using Raman spectroscopy. However, less is known regarding Raman sensitivity to detect the effects of cyclic fatigue damage and allograft sterilization doses of gamma radiation. To determine if Raman spectroscopic biomarkers of collagen denaturation and hydration are sensitive to the effects of (a) high cycle fatigue damage and (b) 25kGy irradiation. Unirradiated and gamma-radiation sterilized human cortical bone specimens previously tested in vitro under high-cycle (> 100,000 cycles) fatigue conditions at 15MPa, 25MPa, 35MPa, 45MPa, and 55MPa cyclic stress levels were studied. Cortical bone Raman spectral profiles from wavenumber ranges of 800-1750cm -1 and 2700-3800cm -1 were obtained and compared from: a) non-fatigue vs fatigue fracture sites and b) radiated vs. unirradiated states. Raman biomarker ratios 1670/1640 and 3220/2949, which reflect collagen denaturation and organic matrix (mainly collagen)-bound water, respectively, were assessed. One- and two-way ANOVA analyses were utilized to identify differences between groups along with interaction effects between cyclic fatigue and radiation-induced damage. Cyclic fatigue damage resulted in increases in collagen denaturation (1670/1640: 1.517 ± 0.043 vs 1.579 ± 0.021, p Raman spectroscopy can detect the effects of cyclic fatigue damage and 25kGy irradiation via increases in organic matrix (mainly collagen)-bound water. A Raman measure of collagen denaturation was sensitive to cyclic fatigue damage but not 25kGy irradiation. Collagen denaturation was correlated with organic matrix-bound water, suggesting that denaturation of collagen to gelatinous form may expose more binding sites to water by unwinding the triple alpha chains. This research may eventually be useful to help identify allograft quality and more appropriately match donors to recipients. Copyright

  10. Supra-threshold epidermis injury from near-infrared laser radiation prior to ablation onset

    Science.gov (United States)

    DeLisi, Michael P.; Peterson, Amanda M.; Lile, Lily A.; Noojin, Gary D.; Shingledecker, Aurora D.; Stolarski, David J.; Zohner, Justin J.; Kumru, Semih S.; Thomas, Robert J.

    2017-02-01

    With continued advancement of solid-state laser technology, high-energy lasers operating in the near-infrared (NIR) band are being applied in an increasing number of manufacturing techniques and medical treatments. Safety-related investigations of potentially harmful laser interaction with skin are commonplace, consisting of establishing the maximum permissible exposure (MPE) thresholds under various conditions, often utilizing the minimally-visible lesion (MVL) metric as an indication of damage. Likewise, characterization of ablation onset and velocity is of interest for therapeutic and surgical use, and concerns exceptionally high irradiance levels. However, skin injury response between these two exposure ranges is not well understood. This study utilized a 1070-nm Yb-doped, diode-pumped fiber laser to explore the response of excised porcine skin tissue to high-energy exposures within the supra-threshold injury region without inducing ablation. Concurrent high-speed videography was employed to assess the effect on the epidermis, with a dichotomous response determination given for three progressive damage event categories: observable permanent distortion on the surface, formation of an epidermal bubble due to bounded intra-cutaneous water vaporization, and rupture of said bubble during laser exposure. ED50 values were calculated for these categories under various pulse configurations and beam diameters, and logistic regression models predicted injury events with approximately 90% accuracy. The distinction of skin response into categories of increasing degrees of damage expands the current understanding of high-energy laser safety while also underlining the unique biophysical effects during induced water phase change in tissue. These observations could prove useful in augmenting biothermomechanical models of laser exposure in the supra-threshold region.

  11. Threshold Assessment of Gear Diagnostic Tools on Flight and Test Rig Data

    Science.gov (United States)

    Dempsey, Paula J.; Mosher, Marianne; Huff, Edward M.

    2003-01-01

    A method for defining thresholds for vibration-based algorithms that provides the minimum number of false alarms while maintaining sensitivity to gear damage was developed. This analysis focused on two vibration based gear damage detection algorithms, FM4 and MSA. This method was developed using vibration data collected during surface fatigue tests performed in a spur gearbox rig. The thresholds were defined based on damage progression during tests with damage. The thresholds false alarm rates were then evaluated on spur gear tests without damage. Next, the same thresholds were applied to flight data from an OH-58 helicopter transmission. Results showed that thresholds defined in test rigs can be used to define thresholds in flight to correctly classify the transmission operation as normal.

  12. Health effects of radiation damage

    International Nuclear Information System (INIS)

    Gasimova, K; Azizova, F; Mehdieva, K.

    2012-01-01

    Full text : A summary of the nature of radiactive contamination would be incomplete without some mention of the human health effects relatied to radioactivity and radioactive materials. Several excellent reviews at the variety of levels of detail have been written and should be consulted by the reader. Internal exposures of alpha and beta particles are important for ingested and inhaled radionuclides. Dosimetry models are used to estimate the dose from internally deposited radioactive particles. As mentioned above weighting parameters that take into account the radiation type, the biological half-life and the tissue or organ at risk are used to convert the physically absorbed dose in units of gray (or red) to the biologically significant committed equivalent dose and effective dose, measured in units of Sv (or rem). There is considerable controversy over the shape of the dose-response curve at the chronic low dose levels important for enviromental contamination. Proposed models include linear models, non-linear models and threshold models. Because risks at low dose must be extrapolated from available date at high doses, the shape of the dose-response curve has important implications for the environmental regulations used to protect the general public. The health effect of radiation damage depends on a combination of events of on the cellular, tissue and systemic levels. These lead to mutations and cellular of the irradiated parent cell. The dose level at which significant damage occurs depends on the cell type. Cells that reproduce rapidily, such as those found in bone marrow or the gastrointestinal tract, will be more sensitive to radiation than those that are longer lived, such as striated muscle or nerve cells. The effects of high radiation doses on an organ depends on the various cell types it contains

  13. Large area damage testing of optics

    International Nuclear Information System (INIS)

    Sheehan, L.; Kozlowski, M.; Stolz, C.

    1996-01-01

    The damage threshold specifications for the National Ignition Facility will include a mixture of standard small-area tests and new large-area tests. During our studies of laser damage and conditioning processes of various materials we have found that some damage morphologies are fairly small and this damage does not grow with further illumination. This type of damage might not be detrimental to the laser performance. We should therefore assume that some damage can be allowed on the optics, but decide on a maximum damage allowance of damage. A new specification of damage threshold termed open-quotes functional damage thresholdclose quotes was derived. Further correlation of damage size and type to system performance must be determined in order to use this measurement, but it is clear that it will be a large factor in the optics performance specifications. Large-area tests have verified that small-area testing is not always sufficient when the optic in question has defect-initiated damage. This was evident for example on sputtered polarizer and mirror coatings where the defect density was low enough that the features could be missed by standard small- area testing. For some materials, the scale-length at which damage non-uniformities occur will effect the comparison of small-area and large-area tests. An example of this was the sub-aperture tests on KD*P crystals on the Beamlet test station. The tests verified the large-area damage threshold to be similar to that found when testing a small-area. Implying that for this KD*P material, the dominate damage mechanism is of sufficiently small scale-length that small-area testing is capable of determining the threshold. The Beamlet test station experiments also demonstrated the use of on-line laser conditioning to increase the crystals damage threshold

  14. Carotid Catheterization and Automated Blood Sampling Induce Systemic IL-6 Secretion and Local Tissue Damage and Inflammation in the Heart, Kidneys, Liver and Salivary Glands in NMRI Mice

    DEFF Research Database (Denmark)

    Teilmann, Anne Charlotte; Rozell, Björn; Kalliokoski, Otto

    2016-01-01

    Automated blood sampling through a vascular catheter is a frequently utilized technique in laboratory mice. The potential immunological and physiological implications associated with this technique have, however, not been investigated in detail. The present study compared plasma levels of the cyt...... and embolized to distant sites. Thus, catheterization and subsequent automated blood sampling may have physiological impact. Possible confounding effects of visceral damage should be assessed and considered, when using catheterized mouse models....

  15. Identification of the IGF-1 processing product human Ec/rodent Eb peptide in various tissues: Evidence for its differential regulation after exercise-induced muscle damage in humans.

    Science.gov (United States)

    Vassilakos, George; Philippou, Anastassios; Koutsilieris, Michael

    2017-02-01

    Insulin-like growth factor-1 (IGF-1) is a pleiotropic factor expressed in various tissues and plays a critical role in skeletal muscle physiology. Alternative splicing of the IGF-1 gene gives rise to different precursor polypeptides (isoforms) which could undergo post-translational cleavage, generating the common mature IGF-1 peptide and different carboxyl terminal extension (E-) peptides, with the fate of the latter being, so far, unknown. The objective if this study was to identify the IGF-1Ec forms or processing product(s), other than mature IGF-1, generated in different human and rodent tissues and particularly in human skeletal muscle after exercise-induced damage. Protein lysates from a wide range of human and rodent tissues were immunoblotted with a rabbit anti-human Ec polyclonal antibody raised against the last 24 amino acids of the C-terminal of the Ec peptide. This antibody can recognize the Ec peptide, both as part of IGF-1Ec and alone, and also the corresponding rodent forms, due to the high homology that the human Ec shares with the rodent Eb. We were able to confirm, for the first time, that the human Ec peptide and its rodent homologous Eb peptide are produced simultaneously with their precursor protein (pro-IGF-1Ec/Eb) in vivo, in a wide range of tissues (e.g. muscle, liver, heart). Proprotein convertase furin digestion of human muscle and liver protein lysates confirmed that the higher molecular form, pro-IGF-1Ec, can be cleaved to produce the free Ec peptide. Furthermore, initial evidence is provided that Ec peptide is differentially regulated during the process of muscle regeneration after exercise-induced damage in humans. The findings of this study possibly imply that the post-translational modification of the IGF-1Ec pro-peptide may regulate the bioavailability and activity of the processing product(s). Copyright © 2016. Published by Elsevier Ltd.

  16. Lactation Affects Isolated Mitochondria and Its Fatty Acid Composition but Has No Effect on Tissue Protein Oxidation, Lipid Peroxidation or DNA-Damage in Laboratory Mice

    Directory of Open Access Journals (Sweden)

    Teresa G. Valencak

    2016-01-01

    Full Text Available Linking peak energy metabolism to lifespan and aging remains a major question especially when focusing on lactation in females. We studied, if and how lactation affects in vitro mitochondrial oxygen consumption and mitochondrial fatty acid composition. In addition, we assessed DNA damage, lipid peroxidation and protein carbonyls to extrapolate on oxidative stress in mothers. As model system we used C57BL/6NCrl mice and exposed lactating females to two ambient temperatures (15 °C and 22 °C while they nursed their offspring until weaning. We found that state II and state IV respiration rates of liver mitochondria were significantly higher in the lactating animals than in non-lactating mice. Fatty acid composition of isolated liver and heart mitochondria differed between lactating and non-lactating mice with higher n-6, and lower n-3 polyunsaturated fatty acids in the lactating females. Surprisingly, lactation did not affect protein carbonyls, lipid peroxidation and DNA damage, nor did moderate cold exposure of 15 °C. We conclude that lactation increases rates of mitochondrial uncoupling and alters mitochondrial fatty acid composition thus supporting the “uncoupling to survive” hypothesis. Regarding oxidative stress, we found no impact of lactation and lower ambient temperature and contribute to growing evidence that there is no linear relationship between oxidative damage and lactation.

  17. Threshold guidance update

    International Nuclear Information System (INIS)

    Wickham, L.E.

    1986-01-01

    The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Last years' activities (1984) included the development of a threshold guidance dose, the development of threshold concentrations corresponding to the guidance dose, the development of supporting documentation, review by a technical peer review committee, and review by the DOE community. As a result of the comments, areas have been identified for more extensive analysis, including an alternative basis for selection of the guidance dose and the development of quality assurance guidelines. Development of quality assurance guidelines will provide a reasonable basis for determining that a given waste stream qualifies as a threshold waste stream and can then be the basis for a more extensive cost-benefit analysis. The threshold guidance and supporting documentation will be revised, based on the comments received. The revised documents will be provided to DOE by early November. DOE-HQ has indicated that the revised documents will be available for review by DOE field offices and their contractors

  18. Staining Against Phospho-H2AX (gamma-H2AX) as a Marker for DNA Damage and Genomic Instability in Cancer Tissues and Cells

    NARCIS (Netherlands)

    Nagelkerke, A.P.; Span, P.N.

    2016-01-01

    Phospho-H2AX or gamma-H2AX- is a marker of DNA double-stranded breaks and can therefore be used to monitor DNA repair after, for example, irradiation. In addition, positive staining for phospho-H2AX may indicate genomic instability and telomere dysfunction in tumour cells and tissues. Here, we

  19. Near threshold fatigue testing

    Science.gov (United States)

    Freeman, D. C.; Strum, M. J.

    1993-01-01

    Measurement of the near-threshold fatigue crack growth rate (FCGR) behavior provides a basis for the design and evaluation of components subjected to high cycle fatigue. Typically, the near-threshold fatigue regime describes crack growth rates below approximately 10(exp -5) mm/cycle (4 x 10(exp -7) inch/cycle). One such evaluation was recently performed for the binary alloy U-6Nb. The procedures developed for this evaluation are described in detail to provide a general test method for near-threshold FCGR testing. In particular, techniques for high-resolution measurements of crack length performed in-situ through a direct current, potential drop (DCPD) apparatus, and a method which eliminates crack closure effects through the use of loading cycles with constant maximum stress intensity are described.

  20. Lowered threshold energy for femtosecond laser induced optical breakdown in a water based eye model by aberration correction with adaptive optics.

    Science.gov (United States)

    Hansen, Anja; Géneaux, Romain; Günther, Axel; Krüger, Alexander; Ripken, Tammo

    2013-06-01

    In femtosecond laser ophthalmic surgery tissue dissection is achieved by photodisruption based on laser induced optical breakdown. In order to minimize collateral damage to the eye laser surgery systems should be optimized towards the lowest possible energy threshold for photodisruption. However, optical aberrations of the eye and the laser system distort the irradiance distribution from an ideal profile which causes a rise in breakdown threshold energy even if great care is taken to minimize the aberrations of the system during design and alignment. In this study we used a water chamber with an achromatic focusing lens and a scattering sample as eye model and determined breakdown threshold in single pulse plasma transmission loss measurements. Due to aberrations, the precise lower limit for breakdown threshold irradiance in water is still unknown. Here we show that the threshold energy can be substantially reduced when using adaptive optics to improve the irradiance distribution by spatial beam shaping. We found that for initial aberrations with a root-mean-square wave front error of only one third of the wavelength the threshold energy can still be reduced by a factor of three if the aberrations are corrected to the diffraction limit by adaptive optics. The transmitted pulse energy is reduced by 17% at twice the threshold. Furthermore, the gas bubble motions after breakdown for pulse trains at 5 kilohertz repetition rate show a more transverse direction in the corrected case compared to the more spherical distribution without correction. Our results demonstrate how both applied and transmitted pulse energy could be reduced during ophthalmic surgery when correcting for aberrations. As a consequence, the risk of retinal damage by transmitted energy and the extent of collateral damage to the focal volume could be minimized accordingly when using adaptive optics in fs-laser surgery.

  1. Residual tissue post splenectomy detected by splenic scintillography with erythrocytes damaged by heat; Tejido residual postesplenectomia detectado por centellografia esplenica con eritrocitos danados por calor

    Energy Technology Data Exchange (ETDEWEB)

    Rivera B, B; Garcia C, E S; Garcia O, J R [Centro Medico ABC, Departamento de Medicina Nuclear, Mexico, D.F. (Mexico)

    2005-07-01

    Feminine of 26 years old with diagnostic of purple thrombocytopenic idiopathic to those 4 years of age, tried with steroids and splenectomy at 11 years old. Pathway practically asymptomatic until 4 months ago she had presented asthenia, adynamia and general uneasiness, with platelet figures of 40,000 plat/microliter. It was carried out scintillographic study with damaged erythrocytes for post surgical remainder search. Its were took two-dimensional images and tomography by single photon emission (SPECT), being knitted splenic residual in area of anatomical projection of the spleen. (Author)

  2. Comparison of the predictions of the LQ and CRE models for normal tissue damage due to biologically targeted radiotherapy with exponentially decaying dose rates

    International Nuclear Information System (INIS)

    O'Donoghue, J.A.; West of Schotland Health Boards, Glasgow

    1989-01-01

    For biologically targeted radiotherapy organ dose rates may be complex functions of time, related to the biodistribution kinetics of the delivery vehicle and radiolabel. The simples situation is where dose rates are exponentially decaying functions of time. Two normal tissue isoeffect models enable the effects of exponentially decaying dose rates to be addressed. These are the extension of the linear-quadratic model and the cumulative radiation effect model. This communication will compare the predictions of these models. (author). 14 refs.; 1 fig

  3. Threshold factorization redux

    Science.gov (United States)

    Chay, Junegone; Kim, Chul

    2018-05-01

    We reanalyze the factorization theorems for the Drell-Yan process and for deep inelastic scattering near threshold, as constructed in the framework of the soft-collinear effective theory (SCET), from a new, consistent perspective. In order to formulate the factorization near threshold in SCET, we should include an additional degree of freedom with small energy, collinear to the beam direction. The corresponding collinear-soft mode is included to describe the parton distribution function (PDF) near threshold. The soft function is modified by subtracting the contribution of the collinear-soft modes in order to avoid double counting on the overlap region. As a result, the proper soft function becomes infrared finite, and all the factorized parts are free of rapidity divergence. Furthermore, the separation of the relevant scales in each factorized part becomes manifest. We apply the same idea to the dihadron production in e+e- annihilation near threshold, and show that the resultant soft function is also free of infrared and rapidity divergences.

  4. Elaborating on Threshold Concepts

    Science.gov (United States)

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-01-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account…

  5. The effects of deformation, ischemia, and reperfusion on the development of muscle damage during prolonged loading.

    Science.gov (United States)

    Loerakker, S; Manders, E; Strijkers, G J; Nicolay, K; Baaijens, F P T; Bader, D L; Oomens, C W J

    2011-10-01

    Deep tissue injury (DTI) is a severe form of pressure ulcer where tissue damage starts in deep tissues underneath intact skin. In the present study, the contributions of deformation, ischemia, and reperfusion to skeletal muscle damage development were examined in a rat model during a 6-h period. Magnetic resonance imaging (MRI) was used to study perfusion (contrast-enhanced MRI) and tissue integrity (T2-weighted MRI). The levels of tissue deformation were estimated using finite element models. Complete ischemia caused a gradual homogeneous increase in T2 (∼20% during the 6-h period). The effect of reperfusion on T2 was highly variable, depending on the anatomical location. In experiments involving deformation, inevitably associated with partial ischemia, a variable T2 increase (17-66% during the 6-h period) was observed reflecting the significant variation in deformation (with two-dimensional strain energies of 0.60-1.51 J/mm) and ischemia (50.8-99.8% of the leg) between experiments. These results imply that deformation, ischemia, and reperfusion all contribute to the damage process during prolonged loading, although their importance varies with time. The critical deformation threshold and period of ischemia that cause muscle damage will certainly vary between individuals. These variations are related to intrinsic factors, such as pathological state, which partly explain the individual susceptibility to the development of DTI and highlight the need for regular assessments of individual subjects.

  6. Hyperglycemia in Streptozotocin-Induced Diabetes Leads to Persistent Inflammation and Tissue Damage Following Uveitis Due to Reduced Levels of Ciliary Body Heme Oxygenase-1

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available This study investigated the heme oxygenase-1 (HO-1 and the endotoxin-induced uveitis (EIU in diabetic streptozotocin (STZ-hyperglycemic rats. STZ-hyperglycemic rats had impaired levels of the enzyme HO-1 within the ciliary bodies if compared with the nondiabetic rats. STZ-hyperglycemic rats also predisposed the eye to produce high levels of both the cytokines IL-1 β and CXCL8. Subsequent EIU further and significantly P<.01 increased the cytokines production, an effect partly prevented by hemin treatment. Most importantly, hemin, an inducer of heme oxygenase expression and activity, recovered the huge number of infiltrated polymorphonuclear leukocytes PMN within the ciliary bodies associated with STZ-hyperglycemic state and EIU damage. Impairment of the stress-sensitive enzyme HO-1 in STZ-hyperglycemic rats increases and prolongs the inflammatory response to EIU.

  7. Hadron production near threshold

    Indian Academy of Sciences (India)

    Abstract. Final state interaction effects in pp → pΛK+ and pd → 3He η reactions are explored near threshold to study the sensitivity of the cross-sections to the pΛ potential and the ηN scattering matrix. The final state scattering wave functions between Λ and p and η and 3He are described rigorously. The Λ production is ...

  8. Casualties and threshold effects

    International Nuclear Information System (INIS)

    Mays, C.W.; National Cancer Inst., Bethesda

    1988-01-01

    Radiation effects like cancer are denoted as casualties. Other radiation effects occur almost in everyone when the radiation dose is sufficiently high. One then speaks of radiation effects with a threshold dose. In this article the author puts his doubt about this classification of radiation effects. He argues that some effects of exposure to radiation do not fit in this classification. (H.W.). 19 refs.; 2 figs.; 1 tab

  9. Resonance phenomena near thresholds

    International Nuclear Information System (INIS)

    Persson, E.; Mueller, M.; Rotter, I.; Technische Univ. Dresden

    1995-12-01

    The trapping effect is investigated close to the elastic threshold. The nucleus is described as an open quantum mechanical many-body system embedded in the continuum of decay channels. An ensemble of compound nucleus states with both discrete and resonance states is investigated in an energy-dependent formalism. It is shown that the discrete states can trap the resonance ones and also that the discrete states can directly influence the scattering cross section. (orig.)

  10. Relationship between in vitro chromosomal radiosensitivity of peripheral blood lymphocytes and the expression of normal tissue damage following radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Barber, J.B.P.; Burrill, W.; Spreadborough, A.R.; Levine, E.; Warren, C.; Scott, D.; Kiltie, A.E.; Roberts, S.A.

    2000-01-01

    There is a need for rapid and reliable tests for the prediction of normal tissue responses to radiotherapy, as this could lead to individualization of patient radiotherapy schedules and thus improvements in the therapeutic ratio. Because the use of cultured fibroblasts is too slow to be practicable in a clinical setting, we evaluated the predictive role of assays of lymphocyte chromosomal radiosensitivity in patients having radiotherapy for breast cancer. Radiosensitivity was assessed using a macronucleus (MN) assay at high dose rate (HDR) and low dose rate (LDR) on lymphocytes irradiated in the G 0 phase of the cell cycle (Scott D, Barber JB, Levine EL, Burril W, Roberts SA. Radiation-induced micronucleus induction in lymphocytes identifies a frequency of radiosensitive cases among breast cancer patients: a test for predisposition? Br. J. Cancer 1998;77;614-620) and an assay of G 2 phase chromatid radiosensitivity ('G 2 assay') (Scott D, Spreadborough A, Levine E, Roberts SA. Genetic predisposition in breast cancer. Lancet 1994; 344: 1444). In a study of acute reactions, blood samples were taken from breast cancer patients before the start of radiotherapy, and the skin reaction documented. 116 patients were tested with the HDR MN assay, 73 with the LDR MN assay and 123 with the G 2 assay. In a study of late reactions, samples were taken from a series of breast cancer patients 8-14 years after radiotherapy and the patients assessed for the severity of late effects according to the 'LENT SOMA' scales. 47 were tested with the HDR assay, 26 with the LDR assay and 19 with the G 2 assay. For each clinical endpoint, patients were classified as being normal reactors or 'highly radiosensitive patients' (HR patients (Burnet NG. Johansen J, Turesson I, Nyman J. Describing patients' normal tissue reactions: Concerning the possibility of individualising radiotherapy dose prescriptions based on potential predictive assays of normal tissue radiosensitivity. Int. J. Cancer 1998

  11. Selenium nanoparticles prevents lead acetate-induced hypothyroidism and oxidative damage of thyroid tissues in male rats through modulation of selenoenzymes and suppression of miR-224.

    Science.gov (United States)

    Atteia, Hebatallah Husseini; Arafa, Manar Hamed; Prabahar, Kousalya

    2018-03-01

    Selenium nanoparticles (Se-NPs) are customizable drug delivery vehicles that show good bioavailability, higher efficacy and lower toxicity than ordinary Se. Pre-treatment of male rats with these NPs has been recently shown to exert a protective effect against chromium-induced thyroid dysfunction. This study, therefore, aimed to investigate and characterize the potential protective mechanism of Se-NPs against lead (Pb) acetate-induced thyrotoxicity. We found that prophylactic and concurrent treatment of Pb acetate-exposed rats with Nano-Se (0.5 mg/kg, i.p) for 15 wk significantly alleviated the decrease in free triiodothyronine (fT3) and free thyroxine (fT4) levels as well as fT3/fT4 ratio% and the increase in thyroid stimulating hormone (TSH) levels to approach control values. This was accompanied by a reduction in the accumulation of Pb in serum and thyroid tissues as well as maintenance of thyroidal pro-oxidant/antioxidant balance and iodothyronine deiodinase type 1 (ID1), an essential enzyme for metabolizing of T4 into active T3, gene expression. Surprisingly, miR-224, a direct complementary target of ID1 mRNA, expression in the thyroid tissues was significantly down-regulated in Nano-Se-pre- and co-treated Pb acetate intoxicated animals. Such changes in miR-224 expression were negatively correlated with the changes in ID1 gene expression and serum fT3 level. These results suggest that Se-NPs can rescue from Pb-induced impairment of thyroid function through the maintenance of selenoproteins and down-regulation of miR-224. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  12. Nuclear survivin and its relationship to DNA damage repair genes in non-small cell lung cancer investigated using tissue array.

    Directory of Open Access Journals (Sweden)

    Songliu Hu

    Full Text Available To investigate the predictive role and association of nuclear survivin and the DNA double-strand breaks repair genes in non-small cell lung cancer (NSCLC: DNA-dependent protein kinase catalytic subunit (DNA-PKcs, Ku heterodimeric regulatory complex 70-KD subunit (Ku70 and ataxia-telangiectasia mutated (ATM.The protein expression of nuclear survivin, DNA-PKcs, Ku70 and ATM were investigated using immunohistochemistry in tumors from 256 patients with surgically resected NSCLC. Furthermore, we analyzed the correlation between the expression of nuclear survivin, DNA-PKcs, Ku70 and ATM. Univariate and multivariate analyses were performed to determine the prognostic factors that inuenced the overall survival and disease-free survival of NSCLC.The expression of nuclear survivin, DNA-PKcs, Ku70 and ATM was significantly higher in tumor tissues than in normal tissues. By dichotomizing the specimens as expressing low or high levels of nuclear survivin, nuclear survivin correlated significantly with the pathologic stage (P = 0.009 and lymph node status (P = 0.004. The nuclear survivin levels were an independent prognostic factor for both the overall survival and the disease-free survival in univariate and multivariate analyses. Patients with low Ku70 and DNA-PKcs expression had a greater benefit from radiotherapy than patients with high expression of Ku70 (P = 0.012 and DNA-PKcs (P = 0.02. Nuclear survivin expression positively correlated with DNA-PKcs (P<0.001 and Ku70 expression (P<0.001.Nuclear survivin may be a prognostic factor for overall survival in patients with resected stage I-IIIA NSCLC. DNA-PKcs and Ku70 could predict the effect of radiotherapy in patients with NSCLC. Nuclear survivin may also stimulates DNA double-strand breaks repair by its interaction with DNA-PKcs and Ku70.

  13. Towards a "free radical theory of graying": melanocyte apoptosis in the aging human hair follicle is an indicator of oxidative stress induced tissue damage.

    Science.gov (United States)

    Arck, Petra Clara; Overall, Rupert; Spatz, Katharina; Liezman, Christiane; Handjiski, Bori; Klapp, Burghard F; Birch-Machin, Mark A; Peters, Eva Milena Johanne

    2006-07-01

    Oxidative stress is generated by a multitude of environmental and endogenous challenges such as radiation, inflammation, or psychoemotional stress. It also speeds the aging process. Graying is a prominent but little understood feature of aging. Intriguingly, the continuous melanin synthesis in the growing (anagen) hair follicle generates high oxidative stress. We therefore hypothesize that hair bulb melanocytes are especially susceptible to free radical-induced aging. To test this hypothesis, we subjected human scalp skin anagen hair follicles from graying individuals to macroscopic and immunohistomorphometric analysis and organ culture. We found evidence of melanocyte apoptosis and increased oxidative stress in the pigmentary unit of graying hair follicles. The "common" deletion, a marker mitochondrial DNA-deletion for accumulating oxidative stress damage, occurred most prominently in graying hair follicles. Cultured unpigmented hair follicles grew better than pigmented follicles of the same donors. Finally, cultured pigmented hair follicles exposed to exogenous oxidative stress (hydroquinone) showed increased melanocyte apoptosis in the hair bulb. We conclude that oxidative stress is high in hair follicle melanocytes and leads to their selective premature aging and apoptosis. The graying hair follicle, therefore, offers a unique model system to study oxidative stress and aging and to test antiaging therapeutics in their ability to slow down or even stop this process.

  14. Three-Dimensional Normal Human Neural Progenitor Tissue-Like Assemblies: A Model for Persistent Varicell-Zoster Virus Infection and Platform to Study Viral Infectivity and Oxidative Stress and Damage

    Science.gov (United States)

    Goodwin, T. J.; McCarthy, M.; Osterrieder, N.; Cohrs, R. J.; Kaufer, B. B.

    2014-01-01

    The environment of space results in a multitude of challenges to the human physiology that present barriers to extended habitation and exploration. Over 40 years of investigation to define countermeasures to address space flight adaptation has left gaps in our knowledge regarding mitigation strategies partly due to the lack of investigative tools, monitoring strategies, and real time diagnostics to understand the central causative agent(s) responsible for physiologic adaptation and maintaining homeostasis. Spaceflight-adaptation syndrome is the combination of space environmental conditions and the synergistic reaction of the human physiology. Our work addresses the role of oxidative stress and damage (OSaD) as a negative and contributing Risk Factor (RF) in the following areas of combined spaceflight related dysregulation: i) radiation induced cellular damage [1], [2] ii) immune impacts and the inflammatory response [3], [4] and iii) varicella zoster virus (VZV) reactivation [5]. Varicella-zoster (VZV)/Chicken Pox virus is a neurotropic human alphaherpesvirus resulting in varicella upon primary infection, suppressed by the immune system becomes latent in ganglionic neurons, and reactivates under stress events to re-express in zoster and possibly shingles. Our laboratory has developed a complex threedimensional (3D) normal human neural tissue model that emulates several characteristics of the human trigeminal ganglia (TG) and allows the study of combinatorial experimentation which addresses, simultaneously, OSaD associated with Spaceflight adaptation and habitation [6].

  15. Threshold values characterizing iodine-induced SCC of zircaloys

    International Nuclear Information System (INIS)

    Une, K.

    1984-01-01

    Threshold values of stress, stress intensity factor, strain, strain rate and iodine concentration for SCC of unirradiated and irradiated Zircaloys are reviewed. The ratio of σsub(th)/σsub(y) adequately represents the effects of cold work and irradiation damage on the SCC susceptibility, where threshold stress σsub(th) is defined as the minimum stress to cause SCC to failure after -6 and 10 -3 min -1 . A comparison of SCC data between constant strain rate and constant stress tests is presented in order to examine the validity of a cumulative-damage concept under SCC conditions. (author)

  16. DNA damage in nasal and brain tissues of canines exposed to air pollutants is associated with evidence of chronic brain inflammation and neurodegeneration.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Maronpot, Robert R; Torres-Jardon, Ricardo; Henríquez-Roldán, Carlos; Schoonhoven, Robert; Acuña-Ayala, Hilda; Villarreal-Calderón, Anna; Nakamura, Jun; Fernando, Reshan; Reed, William; Azzarelli, Biagio; Swenberg, James A

    2003-01-01

    Acute, subchronic, or chronic exposures to particulate matter (PM) and pollutant gases affect people in urban areas and those exposed to fires, disasters, and wars. Respiratory tract inflammation, production of mediators of inflammation capable of reaching the brain, systemic circulation of PM, and disruption of the nasal respiratory and olfactory barriers are likely in these populations. DNA damage is crucial in aging and in age-associated diseases such as Alzheimer's disease. We evaluated apurinic/apyrimidinic (AP) sites in nasal and brain genomic DNA, and explored by immunohistochemistry the expression of nuclear factor NFkappaB p65, inducible nitric oxide synthase (iNOS), cyclo-oxygenase 2 (COX2), metallothionein I and II, apolipoprotein E, amyloid precursor protein (APP), and beta-amyloid(1-42) in healthy dogs naturally exposed to urban pollution in Mexico City. Nickel (Ni) and vanadium (V) were measured by inductively coupled plasma mass spectrometry (ICP-MS). Forty mongrel dogs, ages 7 days-10 years were studied (14 controls from Tlaxcala and 26 exposed to urban pollution in South West Metropolitan Mexico City (SWMMC)). Nasal respiratory and olfactory epithelium were found to be early pollutant targets. Olfactory bulb and hippocampal AP sites were significantly higher in exposed than in control age matched animals. Ni and V were present in a gradient from olfactory mucosa > olfactory bulb > frontal cortex. Exposed dogs had (a) nuclear neuronal NFkappaB p65, (b) endothelial, glial and neuronal iNOS, (c) endothelial and glial COX2, (d) ApoE in neuronal, glial and vascular cells, and (e) APP and beta amyloid(1-42) in neurons, diffuse plaques (the earliest at age 11 months), and in subarachnoid blood vessels. Increased AP sites and the inflammatory and stress protein brain responses were early and significant in dogs exposed to urban pollution. Oil combustion PM-associated metals Ni and V were detected in the brain. There was an acceleration of Alzheimer

  17. Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B{sub 1}

    Energy Technology Data Exchange (ETDEWEB)

    Techapiesancharoenkij, Nirachara [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Fiala, Jeannette L.A. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Navasumrit, Panida [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Croy, Robert G.; Wogan, Gerald N. [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Groopman, John D. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Ruchirawat, Mathuros [Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210 (Thailand); Essigmann, John M., E-mail: jessig@mit.edu [Department of Biological Engineering and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2015-01-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB{sub 1}-DNA adducts in AFB{sub 1}-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB{sub 1} and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4 h after AFB{sub 1} administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB{sub 1}-induced hepatotoxicity. At 24 h after AFB{sub 1} administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB{sub 1}-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB{sub 1} hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. - Highlights: • This study revealed sulforaphane (SF)-deregulated gene sets in aflatoxin B{sub 1} (AFB{sub 1})-treated rat livers. • SF redirects biochemical networks toward lipid biosynthesis in AFB{sub 1}-dosed rats. • SF enhanced gene sets that would be expected to favor cell repair and regeneration.

  18. Radiation-induced DNA damage in tumors and normal tissues. III. Oxygen dependence of the formation of strand breaks and DNA-protein crosslinks

    International Nuclear Information System (INIS)

    Zhang, H.; Wallen, C.A.; Wheeler, K.T.; Joch, C.J.

    1995-01-01

    Results from several laboratories, including ours, have suggested that measurements of radiation-induced DNA strand breaks and DNA-protein crosslinks (DPCs) may be used to estimate the hypoxic fraction or fractional hypoxic volume of tumors and normal tissues. This suggestion has been predicated on both published and nonpublished information that (1) the oxygen dependence of the formation of strand breaks in irradiated mammalian cells is similar to the oxygen dependence of radiation-produced cell killing, and (2) the oxygen dependence of the formation of DPCs in irradiated mammalian cells is the mirror image of the oxygen dependence of radiation-induced cell killing. However, the published studies that attempted to determine the relationship between the oxygen dependence of the formation of strand breaks and the radiation sensitivity of mammalian cells were not performed at 37 degrees C, the exact oxygen concentrations were not always known, and the results were conflicting. In addition, most of the data on the oxygen dependence of the formation of DPCs are unpublished. Consequently, we have undertaken a comprehensive investigation of one cell line, 9L/Ro rat brain tumor cells, to determine if the shape of the oxygen dependence curve and the K m value for radiation-induced strand breaks and DPCs were similar when 9L cells were irradiated under both ideal gas-liquid equilibrium conditions at 4 degrees C and nonideal gas-liquid equilibrium conditions at 37 degrees C. At 4 degrees C under ideal gas-liquid equilibrium conditions, the K m for the formation of strand breaks was approximately 0.0045 mM, and Km for radiation sensitivity was approximately 0.005mM. A similar comparison for the formation of DPCs at 4 degrees C could not be made, because the efficiency of the formation of DPC was much lower at 4 degrees C than at 37 degrees C. 30 refs., 3 figs

  19. Study of damages induced by fungicide propiconazole on testicular tissue and process of spermatogenesis and protective effects of selenium in male Sprague Dawley rat

    Directory of Open Access Journals (Sweden)

    H Mohsenikouchesfehani

    2015-04-01

    Full Text Available Background & aim: Propiconazole is an herbal fungicide which is used as a tropical and systematic drug for fungal infection and also as an agricultural chemical for protection and preservation of fruits, vegetables and grains. The aim of this study was to assess the efficacy of fungicides propiconazol and possible protective effects of selenium on testes tissue. Methods: The present expremental trail study was conducted on forty rats which were divided into ten groups of four including control , sham (solvent of propiconazole, distilled water, solvent of selenium (normal saline and seven experimental groups : group 1 received 0.5 mg/kg/day of selenium, groups 2,3,4 received three doses of 10,50,75 mg/kg/day of Propiconazole, and groups 5,6,7 received three doses of 10, 50, 75 mg/kg/day of propiconazole with 0.5 mg/kg/day of selenium toevaluate. The administration was done intrapritoneal for two weeks in an alternatively fashion. After determining the level of LH, FSH, Testosterone, sperm was counted by hemocitometer. Data were analyzed by the SPSS software using ANOVA test. Results: No significant differences was observed in the level of hormones in the experimental groups2-7 compared with the control group, but the number of sertoli cells, spermatogonia , primary spermatocyte , spermatid and sperm decreased significantly in comparison with the control group (p<0.05. Conclusion: The decrease in numbers of counted sperm indicates that propiconazole has disrupted the production process of these cells and selenium was unable to improve that.

  20. Intermediate structure and threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2004-01-01

    The Intermediate Structure, evidenced through microstructures of the neutron strength function, is reflected in open reaction channels as fluctuations in excitation function of nuclear threshold effects. The intermediate state supporting both neutron strength function and nuclear threshold effect is a micro-giant neutron threshold state. (author)

  1. Coloring geographical threshold graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Percus, Allon [Los Alamos National Laboratory; Muller, Tobias [EINDHOVEN UNIV. OF TECH

    2008-01-01

    We propose a coloring algorithm for sparse random graphs generated by the geographical threshold graph (GTG) model, a generalization of random geometric graphs (RGG). In a GTG, nodes are distributed in a Euclidean space, and edges are assigned according to a threshold function involving the distance between nodes as well as randomly chosen node weights. The motivation for analyzing this model is that many real networks (e.g., wireless networks, the Internet, etc.) need to be studied by using a 'richer' stochastic model (which in this case includes both a distance between nodes and weights on the nodes). Here, we analyze the GTG coloring algorithm together with the graph's clique number, showing formally that in spite of the differences in structure between GTG and RGG, the asymptotic behavior of the chromatic number is identical: {chi}1n 1n n / 1n n (1 + {omicron}(1)). Finally, we consider the leading corrections to this expression, again using the coloring algorithm and clique number to provide bounds on the chromatic number. We show that the gap between the lower and upper bound is within C 1n n / (1n 1n n){sup 2}, and specify the constant C.

  2. Crossing the Petawatt threshold

    International Nuclear Information System (INIS)

    Perry, M.

    1996-01-01

    A revolutionary new laser called the Petawatt, developed by Lawrence Livermore researchers after an intensive three-year development effort, has produced more than 1,000 trillion (open-quotes petaclose quotes) watts of power, a world record. By crossing the petawatt threshold, the extraordinarily powerful laser heralds a new age in laser research. Lasers that provide a petawatt of power or more in a picosecond may make it possible to achieve fusion using significantly less energy than currently envisioned, through a novel Livermore concept called open-quotes fast ignition.close quotes The petawatt laser will also enable researchers to study the fundamental properties of matter, thereby aiding the Department of Energy's Stockpile Stewardship efforts and opening entirely new physical regimes to study. The technology developed for the Petawatt has also provided several spinoff technologies, including a new approach to laser material processing

  3. In-vivo singlet oxygen threshold doses for PDT.

    Science.gov (United States)

    Zhu, Timothy C; Kim, Michele M; Liang, Xing; Finlay, Jarod C; Busch, Theresa M

    2015-02-01

    Dosimetry of singlet oxygen ( 1 O 2 ) is of particular interest because it is the major cytotoxic agent causing biological effects for type-II photosensitizers during photodynamic therapy (PDT). An in-vivo model to determine the singlet oxygen threshold dose, [ 1 O 2 ] rx,sh , for PDT was developed. An in-vivo radiation-induced fibrosarcoma (RIF) tumor mouse model was used to correlate the radius of necrosis to the calculation based on explicit PDT dosimetry of light fluence distribution, tissue optical properties, and photosensitizer concentrations. Inputs to the model include five photosensitizer-specific photochemical parameters along with [ 1 O 2 ] rx,sh . Photosensitizer-specific model parameters were determined for benzoporphyrin derivative monoacid ring A (BPD) and compared with two other type-II photosensitizers, Photofrin ® and m-tetrahydroxyphenylchlorin (mTHPC) from the literature. The mean values (standard deviation) of the in-vivo [ 1 O 2 ] rx,sh are approximately 0.56 (0.26) and 0.72 (0.21) mM (or 3.6×10 7 and 4.6×10 7 singlet oxygen per cell to reduce the cell survival to 1/e) for Photofrin ® and BPD, respectively, assuming that the fraction of generated singlet oxygen that interacts with the cell is 1. While the values for the photochemical parameters (ξ, σ, g , β) used for BPD were preliminary and may need further refinement, there is reasonable confidence for the values of the singlet oxygen threshold doses. In comparison, the [ 1 O 2 ] rx,sh value derived from in-vivo mouse study was reported to be 0.4 mM for mTHPC-PDT. However, the singlet oxygen required per cell is reported to be 9×10 8 per cell per 1/ e fractional kill in an in-vitro mTHPC-PDT study on a rat prostate cancer cell line (MLL cells) and is reported to be 7.9 mM for a multicell in-vitro EMT6/Ro spheroid model for mTHPC-PDT. A theoretical analysis is provided to relate the number of in-vitro singlet oxygen required per cell to reach cell killing of 1/ e to in-vivo singlet

  4. Pulsed laser damage to optical fibers

    International Nuclear Information System (INIS)

    Allison, S.W.; Gillies, G.T.; Magnuson, D.W.; Pagano, T.S.

    1985-01-01

    This paper describes some observations of pulsed laser damage to optical fibers with emphasis on a damage mode characterized as a linear fracture along the outer core of a fiber. Damage threshold data are presented which illustrate the effects of the focusing lens, end-surface preparation, and type of fiber. An explanation based on fiber-beam misalignment is given and is illustrated by a simple experiment and ray trace

  5. Adaptive optics for reduced threshold energy in femtosecond laser induced optical breakdown in water based eye model

    Science.gov (United States)

    Hansen, Anja; Krueger, Alexander; Ripken, Tammo

    2013-03-01

    In ophthalmic microsurgery tissue dissection is achieved using femtosecond laser pulses to create an optical breakdown. For vitreo-retinal applications the irradiance distribution in the focal volume is distorted by the anterior components of the eye causing a raised threshold energy for breakdown. In this work, an adaptive optics system enables spatial beam shaping for compensation of aberrations and investigation of wave front influence on optical breakdown. An eye model was designed to allow for aberration correction as well as detection of optical breakdown. The eye model consists of an achromatic lens for modeling the eye's refractive power, a water chamber for modeling the tissue properties, and a PTFE sample for modeling the retina's scattering properties. Aberration correction was performed using a deformable mirror in combination with a Hartmann-Shack-sensor. The influence of an adaptive optics aberration correction on the pulse energy required for photodisruption was investigated using transmission measurements for determination of the breakdown threshold and video imaging of the focal region for study of the gas bubble dynamics. The threshold energy is considerably reduced when correcting for the aberrations of the system and the model eye. Also, a raise in irradiance at constant pulse energy was shown for the aberration corrected case. The reduced pulse energy lowers the potential risk of collateral damage which is especially important for retinal safety. This offers new possibilities for vitreo-retinal surgery using femtosecond laser pulses.

  6. Three-Dimensional Normal Human Neutral Progenitor Tissue-Like Assemblies: A Model for Persistent Varicella-Zoster Virus Infection and Platform to Study Oxidate Stress and Damage in Multiple Hit Scenarios

    Science.gov (United States)

    Goodwin, Thomas J.; McCarthy, M.; Osterrieder, N.; Cohrs, R. J.; Kaufer, B. B.

    2014-01-01

    The environment of space results in a multitude of challenges to the human physiology that present barriers to extended habitation and exploration. Over 40 years of investigation to define countermeasures to address space flight adaptation has left gaps in our knowledge regarding mitigation strategies partly due to the lack of investigative tools, monitoring strategies, and real time diagnostics to understand the central causative agent(s) responsible for physiologic adaptation and maintaining homeostasis. Spaceflight-adaptation syndrome is the combination of space environmental conditions and the synergistic reaction of the human physiology. Our work addresses the role of oxidative stress and damage (OSaD) as a negative and contributing Risk Factor (RF) in the following areas of combined spaceflight related dysregulation: i) radiation induced cellular damage [1], [2] ii) immune impacts and the inflammatory response [3], [4] and iii) varicella zoster virus (VZV) reactivation [5]. Varicella-zoster (VZV)/Chicken Pox virus is a neurotropic human alphaherpes virus resulting in varicella upon primary infection, suppressed by the immune system becomes latent in ganglionic neurons, and reactivates under stress events to re-express in zoster and possibly shingles. Our laboratory has developed a complex three-dimensional (3D) normal human neural tissue model that emulates several characteristics of the human trigeminal ganglia (TG) and allows the study of combinatorial experimentation which addresses, simultaneously, OSaD associated with Spaceflight adaptation and habitation [6]. By combining the RFs of microgravity, radiation, and viral infection we will demonstrate that living in the space environment leads to significant physiological consequences for the peripheral and subsequently the central nervous system (PNS, CNS) associated with OSaD generation and consequentially endangers long-duration and exploration-class missions.

  7. High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

    Science.gov (United States)

    Nguyen, Daniel; Chang, Kwang; Hedayatollahnajafi, Saba; Staninec, Michal; Chan, Kenneth; Lee, Robert; Fried, Daniel

    2011-07-01

    CO2 lasers can be operated at high laser pulse repetition rates for the rapid and precise removal of dental decay. Excessive heat accumulation and peripheral thermal damage is a concern when using high pulse repetition rates. Peripheral thermal damage can adversely impact the mechanical strength of the irradiated tissue, particularly for dentin, and reduce the adhesion characteristics of the modified surfaces. The interpulpal temperature rise was recorded using microthermocouples situated at the roof of the pulp chamber on teeth that were occlusally ablated using a rapidly-scanned CO2 laser operating at 9.3 μm with a pulse duration of 10 to 15 μs and repetition rate of 300 Hz over a 2 min time course. The adhesion strength of laser treated enamel and dentin surfaces was measured for various laser scanning parameters with and without post-ablation acid etching using the single-plane shear test. The mechanical strength of laser-ablated dentin surfaces were determined via the four-point bend test and compared to control samples prepared with 320 grit wet sand paper to simulate conventional preparations. Thermocouple measurements indicated that the temperature remained below ambient temperature if water-cooling was used. There was no discoloration of either dentin or enamel laser treated surfaces, the surfaces were uniformly ablated, and there were no cracks visible. Four-point bend tests yielded mean mechanical strengths of 18.2 N (s.d. = 4.6) for ablated dentin and 18.1 N (s.d. = 2.7) for control (p > 0.05). Shear tests yielded mean bond strengths approaching 30 MPa for both enamel and dentin under certain irradiation conditions. These values were slightly lower than nonirradiated acid-etched control samples. Additional studies are needed to determine if the slightly lower bond strength than the acid-etched control samples is clinically significant. These measurements demonstrate that enamel and dentin surfaces can be rapidly ablated by CO2 lasers with minimal

  8. Investigation of damage in KDP using scattering techniques

    International Nuclear Information System (INIS)

    Woods, B.; Runkel, M.; Yan, M.; Staggs, M.; Zaitseva, N.; Kozlowski, M.; De Yoreo, J.

    1997-01-01

    Interest in producing high damage threshold KH 2 PO 4 (KDP) and (D x H 1-x ) 2 PO 4 (DKDP)(also called KD*P) for frequency conversion and optical switching applications is driven by the requirements of the National Ignition Facility (NIF). Presently only the best crystals meet the NIF system requirements at the third harmonic (351 nm) and only after a laser conditioning process. Neither the mechanism for damage in bulk KDP nor the mechanism for conditioning is understood. As part of a development effort to increase the damage thresholds of KDP and DKDP, we have been developing techniques to pinpoint the locations where damage will initiate in the bulk material. After we find these locations we will use other measurement techniques to determine how these locations differ from the other surrounding material and why they cause damage. This will allow crystal growers to focus their efforts to improve damage thresholds. Historically damage thresholds have increased it is believed as a consequence of increased purity of the growth solution and through the use of constant filtration during the growth process. As a result we believe that damage is caused by defects in the crystals and have conducted a series of experiments using light scatter to locate these defects and to determine when and where damage occurs. In this paper we present results which show a low correlation between light scatter from bulk defects in KDP and the initiation sites for damage. We have also studied the effects of thermal conditioning on light scatter, strain induced birefringence and damage threshold. We have seen evidence that regions of high strain also exhibit lower damage threshold than the surrounding lower strain material. When thermally conditioned, these crystals show a decrease in some of the strong linear scattering features and a decrease in the strain birefringence while the damage threshold in these regions increased to that of the surrounding bulk material

  9. Crossing the threshold

    Science.gov (United States)

    Bush, John; Tambasco, Lucas

    2017-11-01

    First, we summarize the circumstances in which chaotic pilot-wave dynamics gives rise to quantum-like statistical behavior. For ``closed'' systems, in which the droplet is confined to a finite domain either by boundaries or applied forces, quantum-like features arise when the persistence time of the waves exceeds the time required for the droplet to cross its domain. Second, motivated by the similarities between this hydrodynamic system and stochastic electrodynamics, we examine the behavior of a bouncing droplet above the Faraday threshold, where a stochastic element is introduced into the drop dynamics by virtue of its interaction with a background Faraday wave field. With a view to extending the dynamical range of pilot-wave systems to capture more quantum-like features, we consider a generalized theoretical framework for stochastic pilot-wave dynamics in which the relative magnitudes of the drop-generated pilot-wave field and a stochastic background field may be varied continuously. We gratefully acknowledge the financial support of the NSF through their CMMI and DMS divisions.

  10. Albania - Thresholds I and II

    Data.gov (United States)

    Millennium Challenge Corporation — From 2006 to 2011, the government of Albania (GOA) received two Millennium Challenge Corporation (MCC) Threshold Programs totaling $29.6 million. Albania received...

  11. Applicability of the tissue stem cell turnover concept on the validity of cumulative dose based radiation risk evaluation

    International Nuclear Information System (INIS)

    Otsuka, Kensuke; Hamada, Nobuyuki; Iwasaki, Toshiyasu; Yoshida, Kazuo

    2011-01-01

    The radiation protection system adopts the linear no-threshold model to achieve proper radiation protection for considering cancer risks resulting from radiation exposure. This model uses cumulative dose to a tissue for risk evaluation in which cumulative dose is related to the amount of DNA damage and consequential induction of gene mutation. In this concept, gene mutation accumulates in tissue stem cells, the putative target of carcinogenesis, with total dose given to the tissue. Unlike high-dose-rate exposure, epidemiological studies in high radiation background areas, such as Kerala in India, revealed that cancer risks is not elevated by the dose to the inhabitants, suggesting that there exists some mechanisms to eliminate the damage/mutation in the exposed tissue under extremely low-dose-rate exposure situations. In this report, the dynamics of tissue stem cell turnover is evaluated as a possible mechanism under extremely low-dose-rate exposure situations. To this end, we reviewed recent literatures studying tissue stem cell turnover, and found that great advances in stem cell research have made it possible to trace a fate of stem cells in tissues. Furthermore, turnover of tissue stem cells is found to occur after irradiation, due to competition of stem cells within tissues. This raises a possibility that radiation effects may not accumulate in a tissue depending on the dose-rate and duration of exposure period. (author)

  12. Laser-induced damage to thin film dielectric coatings

    International Nuclear Information System (INIS)

    Walker, T.W.

    1980-01-01

    The laser-induced damage thresholds of dielectric thin film coatings have been found to be more than an order of magnitude lower than the bulk material damage thresholds. Prior damage studies have been inconclusive in determining the damage mechanism which is operative in thin films. A program was conducted in which thin film damage thresholds were measured as a function of laser wavelength (1.06 μm, 0.53 μm, 0.35 μm and 0.26 μm), laser pulse length (5 and 15 nanoseconds), film materials and film thickness. The large matrix of data was compared to predictions given by avalanche ionization, multiphoton ionization and impurity theories of laser damage. When Mie absorption cross-sections and the exact thermal equations were included into the impurity theory excellent agreement with the data was found. The avalanche and multiphoton damage theories could not account for most parametric variations in the data. For example, the damage thresholds for most films increased as the film thickness decreased and only the impurity theory could account for this behavior. Other observed changes in damage threshold with changes in laser wavelength, pulse length and film material could only be adequately explained by the impurity theory. The conclusion which results from this study is that laser damage in thin film coatings results from absorbing impurities included during the deposition process

  13. Threshold Concepts and Information Literacy

    Science.gov (United States)

    Townsend, Lori; Brunetti, Korey; Hofer, Amy R.

    2011-01-01

    What do we teach when we teach information literacy in higher education? This paper describes a pedagogical approach to information literacy that helps instructors focus content around transformative learning thresholds. The threshold concept framework holds promise for librarians because it grounds the instructor in the big ideas and underlying…

  14. Precipitation Thresholds for Triggering Floods in the Corgo Basin, Portugal

    Directory of Open Access Journals (Sweden)

    Mónica Santos

    2016-08-01

    Full Text Available Thresholds based on critical combinations of amount/duration of precipitation and flood events were estimated for the Corgo hydrographic basin, in northern Portugal. Thirty-one flood events in the Corgo basin were identified between 1865 and 2011 from a database of hydrometeorological disasters in Portugal. The minimum, maximum, and pre-warning thresholds that define the boundaries for flood occurrence were determined. The results show that the ratio between the total number of floods and precipitation events exceeding the minimum threshold denotes a relatively low probability of successful forecasting. This result may be due to the reduced number of flooding events in the floods database, which only include floods that caused damage as reported by the media. The estimated maximum threshold is not adequate for use in floods, since the majority of true positives are below this limit. However, and more interestingly, the retrospective verification of the estimated thresholds suggests that the minimum and pre-warning thresholds are well adjusted. Therefore, the application of these precipitation thresholds may contribute to minimize possible situations of pre-crisis or immediate crisis by reducing the flood consequences and the resources involved in emergency response to flood events.

  15. Neutron RBE for normal tissues

    International Nuclear Information System (INIS)

    Field, S.B.; Hornsey, S.

    1979-01-01

    RBE for various normal tissues is considered as a function of neutron dose per fraction. Results from a variety of centres are reviewed. It is shown that RBE is dependent on neutron energy and is tissue dependent, but is not specially high for the more critical tissues or for damage occurring late after irradiation. (author)

  16. 75 FR 75911 - Adjustment of Monetary Threshold for Reporting Rail Equipment Accidents/Incidents for Calendar...

    Science.gov (United States)

    2010-12-07

    ..., Notice No. 3] RIN 2130-ZA04 Adjustment of Monetary Threshold for Reporting Rail Equipment Accidents... (DOT). ACTION: Final rule. SUMMARY: This rule increases the rail equipment accident/incident reporting threshold from $9,200 to $9,400 for certain railroad accidents/incidents involving property damage that...

  17. Microgel Technology to Advance Modular Tissue Engineering

    NARCIS (Netherlands)

    Kamperman, Tom

    2018-01-01

    The field of tissue engineering aims to restore the function of damaged or missing tissues by combining cells and/or a supportive biomaterial scaffold into an engineered tissue construct. The construct’s design requirements are typically set by native tissues – the gold standard for tissue

  18. Comparison on taste threshold between adult male white cigarette and clove cigarette smokers using Murphy clinical test method

    OpenAIRE

    Ronald Reyses Tapilatu; Edeh Rolleta Haroen; Rosiliwati Wihardja

    2008-01-01

    The habit of smoking white cigarettes and clove cigarettes may affect the gustatory function, that is, it will cause damage to taste buds, resulting in an increase in gustatory threshold. This research used the descriptive comparative method and had the purpose of obtaining an illustration of gustatory threshold and compare gustatory threshold in white cigarette smokers and clove cigarette smokers in young, male adults. For gustatory threshold evaluation, the Murphy method was used to obtain ...

  19. Tort Damages

    NARCIS (Netherlands)

    L.T. Visscher (Louis)

    2008-01-01

    textabstractAbstract: In this Chapter, I provide an overview of Law and Economics literature regarding tort damages. Where necessary, attention is also spent to rules of tort liability. Both types of rules provide behavioral incentives to both injurers and victims, with respect to their level of

  20. Music effect on pain threshold evaluated with current perception threshold

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: Music relieves anxiety and psychotic tension. This effect of music is applied to surgical operation in the hospital and dental office. It is still unclear whether this music effect is only limited to the psychological aspect but not to the physical aspect or whether its music effect is influenced by the mood or emotion of audience. To elucidate these issues, we evaluated the music effect on pain threshold by current perception threshold (CPT) and profile of mood states (POMC) test. METHODS: Healthy 30 subjects (12 men, 18 women, 25-49 years old, mean age 34.9) were tested. (1)After POMC test, all subjects were evaluated pain threshold with CPT by Neurometer (Radionics, USA) under 6 conditions, silence, listening to the slow tempo classic music, nursery music, hard rock music, classic paino music and relaxation music with 30 seconds interval. (2)After Stroop color word test as the stresser, pain threshold was evaluated with CPT under 2 conditions, silence and listening to the slow tempo classic music. RESULTS: Under litening to the music, CPT sores increased, especially 2 000 Hz level related with compression, warm and pain sensation. Type of music, preference of music and stress also affected CPT score. CONCLUSION: The present study demonstrated that the concentration on the music raise the pain threshold and that stress and mood influence the music effect on pain threshold.

  1. Parton distributions with threshold resummation

    CERN Document Server

    Bonvini, Marco; Rojo, Juan; Rottoli, Luca; Ubiali, Maria; Ball, Richard D.; Bertone, Valerio; Carrazza, Stefano; Hartland, Nathan P.

    2015-01-01

    We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction with any QCD calculation in which threshold resummation is included at the level of partonic cross sections. These resummed PDF sets, based on the NNPDF3.0 analysis, are extracted from deep-inelastic scattering, Drell-Yan, and top quark pair production data, for which resummed calculations can be consistently used. We find that, close to threshold, the inclusion of resummed PDFs can partially compensate the enhancement in resummed matrix elements, leading to resummed hadronic cross-sections closer to the fixed-order calculation. On the other hand, far from threshold, resummed PDFs reduce to their fixed-order counterparts. Our results demonstrate the need for a consistent use of resummed PDFs in resummed calculations.

  2. Status of SiO2/TiO2 HR coating damage

    International Nuclear Information System (INIS)

    Lowermilk, W.H.

    1979-01-01

    The data, observations, and conclusions from a number of experiments on high-reflector (HR) coating damage which were done in FY 1979 are summarized. Damage threshold measurements for the experiments described are presented

  3. Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

    Science.gov (United States)

    Piascik, Robert S.; Newman, John A.

    2002-01-01

    Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

  4. Conceptions of nuclear threshold status

    International Nuclear Information System (INIS)

    Quester, G.H.

    1991-01-01

    This paper reviews some alternative definitions of nuclear threshold status. Each of them is important, and major analytical confusions would result if one sense of the term is mistaken for another. The motives for nations entering into such threshold status are a blend of civilian and military gains, and of national interests versus parochial or bureaucratic interests. A portion of the rationale for threshold status emerges inevitably from the pursuit of economic goals, and another portion is made more attraction by the derives of the domestic political process. Yet the impact on international security cannot be dismissed, especially where conflicts among the states remain real. Among the military or national security motives are basic deterrence, psychological warfare, war-fighting and, more generally, national prestige. In the end, as the threshold phenomenon is assayed for lessons concerning the role of nuclear weapons more generally in international relations and security, one might conclude that threshold status and outright proliferation coverage to a degree in the motives for all of the states involved and in the advantages attained. As this paper has illustrated, nuclear threshold status is more subtle and more ambiguous than outright proliferation, and it takes considerable time to sort out the complexities. Yet the world has now had a substantial amount of time to deal with this ambiguous status, and this may tempt more states to exploit it

  5. Theoretical research of multi-pulses laser induced damage in dielectrics

    International Nuclear Information System (INIS)

    Luo Jin; Liu Zhichao; Chen Songlin; Ma Ping

    2013-01-01

    The pulse width is different, the mechanism of the laser-matter interaction is different. Damage results from plasma formation and ablation forτ≤10 ps and from heat depositing and conventional melting for τ>100 ps. Two theoretical models of transparent dielectrics irradiated by multi-pulses laser are respectively developed based on the above-mentioned different mechanism. One is the dielectric breakdown model based on electron density evolution equation for femtosecond multi-pluses laser, the other is the dielectric heat-damage model based on Fourier's heat exchange equation for nanosecond multi-pluses laser. Using these models, the effects of laser parameters and material parameters on the laser-induced damage threshold of dielectrics are analyzed. The analysis results show that different parameters have different influence on the damage threshold. The effect of parameters on the multi -pulses damage threshold is not entirely the same to the single-pulse damage threshold. The multi-pulses damage mechanism of dielectrics is discussed in detail, considering the effect of different parameters. The discussion provides more information for understanding its damage process and more knowledge to improve its damage thresholds. And the relationship between damage threshold and pulse number is illustrated, it is in good agreement with experimental results. The illustration can help us to predict the multi-pulses damage threshold and the lifetime of optical components. (authors)

  6. Cranial nerve threshold for thermal injury induced by MRI-guided high-intensity focused ultrasound (MRgHIFU): preliminary results on an optic nerve model.

    Science.gov (United States)

    Harnof, Sagi; Zibly, Zion; Cohen, Zvi; Shaw, Andrew; Schlaff, Cody; Kassel, Neal F

    2013-04-01

    Future clinical applications of magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) are moving toward the management of different intracranial pathologies. We sought to validate the production, safety, and efficacy of thermal injury to cranial nerves generated by MRgHIFU. In this study, five female domestic pigs underwent a standard bifrontal craniectomy under general anesthesia. Treatment was then given using an MRgHIFU system to induce hyperthermic ablative sonication (6 to 10 s; 50 to 2000 J.) Histological analyses were done to confirm nerve damage; temperature measured on the optic nerve was approximately 53.4°C (range: 39°C to 70°C.) Histology demonstrated a clear definition between a necrotic, transitional zone, and normal tissue. MRgHIFU induces targeted thermal injury to nervous tissue within a specific threshold of 50°C to 60°C with the tissue near the sonication center yielding the greatest effect; adjacent tissue showed minimal changes. Additional studies utilizing this technology are required to further establish accurate threshold parameters for optic nerve thermo-ablation.

  7. DNA from keratinous tissue

    DEFF Research Database (Denmark)

    Bengtsson, Camilla F.; Olsen, Maja E.; Brandt, Luise Ørsted

    2011-01-01

    Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle – although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

  8. Biomaterials for tissue engineering applications.

    Science.gov (United States)

    Keane, Timothy J; Badylak, Stephen F

    2014-06-01

    With advancements in biological and engineering sciences, the definition of an ideal biomaterial has evolved over the past 50 years from a substance that is inert to one that has select bioinductive properties and integrates well with adjacent host tissue. Biomaterials are a fundamental component of tissue engineering, which aims to replace diseased, damaged, or missing tissue with reconstructed functional tissue. Most biomaterials are less than satisfactory for pediatric patients because the scaffold must adapt to the growth and development of the surrounding tissues and organs over time. The pediatric community, therefore, provides a distinct challenge for the tissue engineering community. Copyright © 2014. Published by Elsevier Inc.

  9. Fluence thresholds for grazing incidence hard x-ray mirrors

    Czech Academy of Sciences Publication Activity Database

    Aquila, A.; Sobierajski, R.; Ozkan, C.; Hájková, Věra; Burian, Tomáš; Chalupský, Jaromír; Juha, Libor; Störmer, M.; Bajt, S.; Klepka, M.T.; Dlužewski, P.; Morawiec, K.; Ohashi, H.; Koyama, T.; Tono, K.; Inubushi, Y.; Yabashi, M.; Sinn, H.; Tschentscher, T.; Mancuso, A.P.; Gaudin, J.

    2015-01-01

    Roč. 106, č. 24 (2015), "241905-1"-"241905-5" ISSN 0003-6951 R&D Projects: GA ČR(CZ) GA14-29772S Grant - others:AVČR(CZ) M100101221 Institutional support: RVO:68378271 Keywords : XFEL * Free Electron Laser * damage threshold * X-ray optics Subject RIV: BH - Optics , Masers, Lasers Impact factor: 3.142, year: 2015

  10. Thermotactile perception thresholds measurement conditions.

    Science.gov (United States)

    Maeda, Setsuo; Sakakibara, Hisataka

    2002-10-01

    The purpose of this paper is to investigate the effects of posture, push force and rate of temperature change on thermotactile thresholds and to clarify suitable measuring conditions for Japanese people. Thermotactile (warm and cold) thresholds on the right middle finger were measured with an HVLab thermal aesthesiometer. Subjects were eight healthy male Japanese students. The effects of posture in measurement were examined in the posture of a straight hand and forearm placed on a support, the same posture without a support, and the fingers and hand flexed at the wrist with the elbow placed on a desk. The finger push force applied to the applicator of the thermal aesthesiometer was controlled at a 0.5, 1.0, 2.0 and 3.0 N. The applicator temperature was changed to 0.5, 1.0, 1.5, 2.0 and 2.5 degrees C/s. After each measurement, subjects were asked about comfort under the measuring conditions. Three series of experiments were conducted on different days to evaluate repeatability. Repeated measures ANOVA showed that warm thresholds were affected by the push force and the rate of temperature change and that cold thresholds were influenced by posture and push force. The comfort assessment indicated that the measurement posture of a straight hand and forearm laid on a support was the most comfortable for the subjects. Relatively high repeatability was obtained under measurement conditions of a 1 degrees C/s temperature change rate and a 0.5 N push force. Measurement posture, push force and rate of temperature change can affect the thermal threshold. Judging from the repeatability, a push force of 0.5 N and a temperature change of 1.0 degrees C/s in the posture with the straight hand and forearm laid on a support are recommended for warm and cold threshold measurements.

  11. DOE approach to threshold quantities

    International Nuclear Information System (INIS)

    Wickham, L.E.; Kluk, A.F.; Department of Energy, Washington, DC)

    1985-01-01

    The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Ideally, the threshold must be set high enough to significantly reduce the amount of waste requiring special handling. It must also be low enough so that waste at the threshold quantity poses a very small health risk and multiple exposures to such waste would still constitute a small health risk. It should also be practical to segregate waste above or below the threshold quantity using available instrumentation. Guidance is being prepared to aid DOE sites in establishing threshold quantity values based on pathways analysis using site-specific parameters (waste stream characteristics, maximum exposed individual, population considerations, and site specific parameters such as rainfall, etc.). A guidance dose of between 0.001 to 1.0 mSv/y (0.1 to 100 mrem/y) was recommended with 0.3 mSv/y (30 mrem/y) selected as the guidance dose upon which to base calculations. Several tasks were identified, beginning with the selection of a suitable pathway model for relating dose to the concentration of radioactivity in the waste. Threshold concentrations corresponding to the guidance dose were determined for waste disposal sites at a selected humid and arid site. Finally, cost-benefit considerations at the example sites were addressed. The results of the various tasks are summarized and the relationship of this effort with related developments at other agencies discussed

  12. Modeling laser damage to the retina

    Science.gov (United States)

    Clark, Clifton D.

    This dissertation presents recent progress in several areas related to modeling laser damage to the retina. In Chapter 3, we consider the consequences of using the Arrhenius damage model to predict the damage thresholds of multiple pulse, or repetitive pulse, exposures. We have identified a few fundamental trends associated with the multiple pulse damage predictions made by the Arrhenius model. These trends differ from what would be expected by non-thermal mechanisms, and could prove useful in differentiating thermal and non-thermal damage. Chapter 4 presents a new rate equation damage model hypothesized to describe photochemical damage. The model adds a temperature dependent term to the simple rate equation implied by the principle of reciprocity that is characteristic of photochemical damage thresholds. A recent damage threshold study, conducted in-vitro, has revealed a very sharp transition between thermal and photochemical damage threshold trends. For the wavelength used in the experiment (413 nm), thermal damage thresholds were observed at exposure levels that were twice the expected photochemical damage threshold, based on the traditional understanding of photochemical damage. Our model accounts for this observed trend by introducing a temperature dependent quenching, or repair, rate to the photochemical damage rate. For long exposures that give a very small temperature rise, the model reduces to the principle of reciprocity. Near the transition region between thermal and photochemical damage, the model allows the damage threshold to be set by thermal mechanisms, even at exposure above the reciprocity exposure. In Chapter 5, we describe a retina damage model that includes thermal lensing in the eye by coupling beam propagation and heat transfer models together. Thermal lensing has recently been suggested as a contributing factor to the large increase in measured retinal damage thresholds in the near infrared. The transmission of the vitreous decreases

  13. A threshold for dissipative fission

    International Nuclear Information System (INIS)

    Thoennessen, M.; Bertsch, G.F.

    1993-01-01

    The empirical domain of validity of statistical theory is examined as applied to fission data on pre-fission data on pre-fission neutron, charged particle, and γ-ray multiplicities. Systematics are found of the threshold excitation energy for the appearance of nonstatistical fission. From the data on systems with not too high fissility, the relevant phenomenological parameter is the ratio of the threshold temperature T thresh to the (temperature-dependent) fission barrier height E Bar (T). The statistical model reproduces the data for T thresh /E Bar (T) thresh /E Bar (T) independent of mass and fissility of the systems

  14. Thresholds in chemical respiratory sensitisation.

    Science.gov (United States)

    Cochrane, Stella A; Arts, Josje H E; Ehnes, Colin; Hindle, Stuart; Hollnagel, Heli M; Poole, Alan; Suto, Hidenori; Kimber, Ian

    2015-07-03

    There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the

  15. Optimization Problems on Threshold Graphs

    Directory of Open Access Journals (Sweden)

    Elena Nechita

    2010-06-01

    Full Text Available During the last three decades, different types of decompositions have been processed in the field of graph theory. Among these we mention: decompositions based on the additivity of some characteristics of the graph, decompositions where the adjacency law between the subsets of the partition is known, decompositions where the subgraph induced by every subset of the partition must have predeterminate properties, as well as combinations of such decompositions. In this paper we characterize threshold graphs using the weakly decomposition, determine: density and stability number, Wiener index and Wiener polynomial for threshold graphs.

  16. Threshold current for fireball generation

    Science.gov (United States)

    Dijkhuis, Geert C.

    1982-05-01

    Fireball generation from a high-intensity circuit breaker arc is interpreted here as a quantum-mechanical phenomenon caused by severe cooling of electrode material evaporating from contact surfaces. According to the proposed mechanism, quantum effects appear in the arc plasma when the radius of one magnetic flux quantum inside solid electrode material has shrunk to one London penetration length. A formula derived for the threshold discharge current preceding fireball generation is found compatible with data reported by Silberg. This formula predicts linear scaling of the threshold current with the circuit breaker's electrode radius and concentration of conduction electrons.

  17. Nuclear threshold effects and neutron strength function

    International Nuclear Information System (INIS)

    Hategan, Cornel; Comisel, Horia

    2003-01-01

    One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

  18. Membrane supported scaffold architectures for tissue engineering

    NARCIS (Netherlands)

    Bettahalli Narasimha, M.S.

    2011-01-01

    Tissue engineering aims at restoring or regenerating a damaged tissue. Often the tissue recreation occurs by combining cells, derived from a patient biopsy, onto a 3D porous matrix, functioning as a scaffold. One of the current limitations of tissue engineering is the inability to provide sufficient

  19. Rainfall thresholds for the triggering of landslides in Slovenia

    Science.gov (United States)

    Peternel, Tina; Jemec Auflič, Mateja; Rosi, Ascanio; Segoni, Samuele; Komac, Marko; Casagli, Nicola

    2017-04-01

    Both at the worldwide level and in Slovenia, precipitation and related phenomena represent one of the most important triggering factors for the occurrence of slope mass movements. In the past decade, extreme rainfall events with a very high amount of precipitation occurs in a relatively short rainfall period have become increasingly important and more frequent, that causing numerous undesirable consequences. Intense rainstorms cause flash floods and mostly trigger shallow landslides and soil slips. On the other hand, the damage of long lasting rainstorms depends on the region's adaptation and its capacity to store or infiltrate excessive water from the rain. The amount and, consequently, the intensity of daily precipitation that can cause floods in the eastern part of Slovenia is a rather common event for the north-western part of the country. Likewise, the effect of rainfall is very dependent on the prior soil moisture, periods of full soil saturation and the creation of drifts in groundwater levels due to the slow melting of snow, growing period, etc. Landslides could be identified and to some extent also prevent with better knowledge of the relation between landslides and rainfall. In this paper the definition of rainfall thresholds for rainfall-induced landslides in Slovenia is presented. The thresholds have been calculated by collecting approximately 900 landslide data and the relative rainfall amounts, which have been collected from 41 rain gauges all over the country. The thresholds have been defined by the (1) use of an existing procedure, characterized by a high degree of objectiveness and (2) software that was developed for a test site with very different geological and climatic characteristics (Tuscany, central Italy). Firstly, a single national threshold has been defined, later the country was divided into four zones, on the basis of major the river basins and a single threshold has been calculated for each of them. Validation of the calculated

  20. Colour thresholding and objective quantification in bioimaging

    Science.gov (United States)

    Fermin, C. D.; Gerber, M. A.; Torre-Bueno, J. R.

    1992-01-01

    Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples.

  1. Low doses of ionizing radiation: Relationship between biological benefit and damage induction. A synopsis

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

    Absorption of ionizing radiation in biological tissue stochastically interacts with constituent atoms and molecules and always generates energy deposition (track) events accompanied by bursts of reactive oxygen species (ROS). These ROS are quite similar to those ROS that arise abundantly and constantly by normal oxidative metabolism. ROS effects from either source need attention when assessing radiation-induced alterations in biological structure and function. Endogenous ROS alone induce about 10 6 DNA oxyadducts per cell per day compared to about 5x10 -3 total DNA damage per average cell per day from background radiation exposure (1 mGy per year). At this background level, the corresponding ratio of probabilities of endogenous versus radiogenic DNA double strand breaks (DSBs) per cell per day is about 103 with some 25-40 % of low-LET caused radiogenic DNA-DSBs being of the multi-damage-site type. Radiogenic DNA damage increases in proportion to absorbed dose over a certain dose range. By evolution, tissues possess physiological mechanisms of protection against an array of potentially toxic agents, externally from the environment and endogenously from metabolism, mainly against the abundantly and constantly produced ROS. Ad hoc protection operates at a level that is genetically determined. Following small to moderate perturbation of cell-tissue homeostasis by a toxic impact, adaptive responses develop with a delay and may last from hours to weeks, even months, and aim at protecting the system against renewed insults. Protective responses encompass defense by scavenging mechanisms, DNA repair, damage removal largely by apoptosis and immune responses, as well as changes in cell proliferation. Acute low-dose irradiation below about 0.2 Gy can not only disturb cell-tissue homeostasis but also initiate adaptived protection that appears with a delay of hours and may last from less than a day to months. The balance between damage production and adaptive protection favors

  2. [Connective tissue and inflammation].

    Science.gov (United States)

    Jakab, Lajos

    2014-03-23

    The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue.

  3. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  4. Irradiation damage

    International Nuclear Information System (INIS)

    Howe, L.M.

    2000-01-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization

  5. Percolation Threshold Parameters of Fluids

    Czech Academy of Sciences Publication Activity Database

    Škvor, J.; Nezbeda, Ivo

    2009-01-01

    Roč. 79, č. 4 (2009), 041141-041147 ISSN 1539-3755 Institutional research plan: CEZ:AV0Z40720504 Keywords : percolation threshold * universality * infinite cluster Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.400, year: 2009

  6. Threshold analyses and Lorentz violation

    International Nuclear Information System (INIS)

    Lehnert, Ralf

    2003-01-01

    In the context of threshold investigations of Lorentz violation, we discuss the fundamental principle of coordinate independence, the role of an effective dynamical framework, and the conditions of positivity and causality. Our analysis excludes a variety of previously considered Lorentz-breaking parameters and opens an avenue for viable dispersion-relation investigations of Lorentz violation

  7. Threshold enhancement of diphoton resonances

    Directory of Open Access Journals (Sweden)

    Aoife Bharucha

    2016-10-01

    Full Text Available We revisit a mechanism to enhance the decay width of (pseudo-scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 12MA threshold and a small decay width, <1 MeV. The implications of such a threshold enhancement are discussed in two explicit scenarios: i the Minimal Supersymmetric Standard Model in which the A state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through loops of charginos with masses close to 12MA and ii a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.

  8. Oxidative damage and aging: spotlight on mitochondria.

    Science.gov (United States)

    Linford, Nancy J; Schriner, Samuel E; Rabinovitch, Peter S

    2006-03-01

    Whereas free radical damage has been proposed as a key component in the tissue degeneration associated with aging, there has been little evidence that free radical damage limits life span in mammals. The current research shows that overexpression of the antioxidant enzyme catalase in mitochondria can extend mouse life span. These results highlight the importance of mitochondrial damage in aging and suggest that when targeted appropriately, boosting antioxidant defenses can increase mammalian life span.

  9. Genotoxic thresholds, DNA repair, and susceptibility in human populations

    International Nuclear Information System (INIS)

    Jenkins, Gareth J.S.; Zair, Zoulikha; Johnson, George E.; Doak, Shareen H.

    2010-01-01

    It has been long assumed that DNA damage is induced in a linear manner with respect to the dose of a direct acting genotoxin. Thus, it is implied that direct acting genotoxic agents induce DNA damage at even the lowest of concentrations and that no 'safe' dose range exists. The linear (non-threshold) paradigm has led to the one-hit model being developed. This 'one hit' scenario can be interpreted such that a single DNA damaging event in a cell has the capability to induce a single point mutation in that cell which could (if positioned in a key growth controlling gene) lead to increased proliferation, leading ultimately to the formation of a tumour. There are many groups (including our own) who, for a decade or more, have argued, that low dose exposures to direct acting genotoxins may be tolerated by cells through homeostatic mechanisms such as DNA repair. This argument stems from the existence of evolutionary adaptive mechanisms that allow organisms to adapt to low levels of exogenous sources of genotoxins. We have been particularly interested in the genotoxic effects of known mutagens at low dose exposures in human cells and have identified for the first time, in vitro genotoxic thresholds for several mutagenic alkylating agents (Doak et al., 2007). Our working hypothesis is that DNA repair is primarily responsible for these thresholded effects at low doses by removing low levels of DNA damage but becoming saturated at higher doses. We are currently assessing the roles of base excision repair (BER) and methylguanine-DNA methyltransferase (MGMT) for roles in the identified thresholds (Doak et al., 2008). This research area is currently important as it assesses whether 'safe' exposure levels to mutagenic chemicals can exist and allows risk assessment using appropriate safety factors to define such exposure levels. Given human variation, the mechanistic basis for genotoxic thresholds (e.g. DNA repair) has to be well defined in order that susceptible individuals are

  10. DNA damage in neurodegenerative diseases

    Energy Technology Data Exchange (ETDEWEB)

    Coppedè, Fabio, E-mail: fabio.coppede@med.unipi.it; Migliore, Lucia, E-mail: lucia.migliore@med.unipi.it

    2015-06-15

    Highlights: • Oxidative DNA damage is one of the earliest detectable events in the neurodegenerative process. • The mitochondrial DNA is more vulnerable to oxidative attack than the nuclear DNA. • Cytogenetic damage has been largely documented in Alzheimer's disease patients. • The question of whether DNA damage is cause or consequence of neurodegeneration is still open. • Increasing evidence links DNA damage and repair with epigenetic phenomena. - Abstract: Following the observation of increased oxidative DNA damage in nuclear and mitochondrial DNA extracted from post-mortem brain regions of patients affected by neurodegenerative diseases, the last years of the previous century and the first decade of the present one have been largely dedicated to the search of markers of DNA damage in neuronal samples and peripheral tissues of patients in early, intermediate or late stages of neurodegeneration. Those studies allowed to demonstrate that oxidative DNA damage is one of the earliest detectable events in neurodegeneration, but also revealed cytogenetic damage in neurodegenerative conditions, such as for example a tendency towards chromosome 21 malsegregation in Alzheimer's disease. As it happens for many neurodegenerative risk factors the question of whether DNA damage is cause or consequence of the neurodegenerative process is still open, and probably both is true. The research interest in markers of oxidative stress was shifted, in recent years, towards the search of epigenetic biomarkers of neurodegenerative disorders, following the accumulating evidence of a substantial contribution of epigenetic mechanisms to learning, memory processes, behavioural disorders and neurodegeneration. Increasing evidence is however linking DNA damage and repair with epigenetic phenomena, thereby opening the way to a very attractive and timely research topic in neurodegenerative diseases. We will address those issues in the context of Alzheimer's disease

  11. DNA damage in neurodegenerative diseases

    International Nuclear Information System (INIS)

    Coppedè, Fabio; Migliore, Lucia

    2015-01-01

    Highlights: • Oxidative DNA damage is one of the earliest detectable events in the neurodegenerative process. • The mitochondrial DNA is more vulnerable to oxidative attack than the nuclear DNA. • Cytogenetic damage has been largely documented in Alzheimer's disease patients. • The question of whether DNA damage is cause or consequence of neurodegeneration is still open. • Increasing evidence links DNA damage and repair with epigenetic phenomena. - Abstract: Following the observation of increased oxidative DNA damage in nuclear and mitochondrial DNA extracted from post-mortem brain regions of patients affected by neurodegenerative diseases, the last years of the previous century and the first decade of the present one have been largely dedicated to the search of markers of DNA damage in neuronal samples and peripheral tissues of patients in early, intermediate or late stages of neurodegeneration. Those studies allowed to demonstrate that oxidative DNA damage is one of the earliest detectable events in neurodegeneration, but also revealed cytogenetic damage in neurodegenerative conditions, such as for example a tendency towards chromosome 21 malsegregation in Alzheimer's disease. As it happens for many neurodegenerative risk factors the question of whether DNA damage is cause or consequence of the neurodegenerative process is still open, and probably both is true. The research interest in markers of oxidative stress was shifted, in recent years, towards the search of epigenetic biomarkers of neurodegenerative disorders, following the accumulating evidence of a substantial contribution of epigenetic mechanisms to learning, memory processes, behavioural disorders and neurodegeneration. Increasing evidence is however linking DNA damage and repair with epigenetic phenomena, thereby opening the way to a very attractive and timely research topic in neurodegenerative diseases. We will address those issues in the context of Alzheimer's disease

  12. Rainfall thresholds for the possible occurrence of landslides in Italy

    Directory of Open Access Journals (Sweden)

    M. T. Brunetti

    2010-03-01

    Full Text Available In Italy, rainfall is the primary trigger of landslides that frequently cause fatalities and large economic damage. Using a variety of information sources, we have compiled a catalogue listing 753 rainfall events that have resulted in landslides in Italy. For each event in the catalogue, the exact or approximate location of the landslide and the time or period of initiation of the slope failure is known, together with information on the rainfall duration D, and the rainfall mean intensity I, that have resulted in the slope failure. The catalogue represents the single largest collection of information on rainfall-induced landslides in Italy, and was exploited to determine the minimum rainfall conditions necessary for landslide occurrence in Italy, and in the Abruzzo Region, central Italy. For the purpose, new national rainfall thresholds for Italy and new regional rainfall thresholds for the Abruzzo Region were established, using two independent statistical methods, including a Bayesian inference method and a new Frequentist approach. The two methods proved complementary, with the Bayesian method more suited to analyze small data sets, and the Frequentist method performing better when applied to large data sets. The new regional thresholds for the Abruzzo Region are lower than the new national thresholds for Italy, and lower than the regional thresholds proposed in the literature for the Piedmont and Lombardy Regions in northern Italy, and for the Campania Region in southern Italy. This is important, because it shows that landslides in Italy can be triggered by less severe rainfall conditions than previously recognized. The Frequentist method experimented in this work allows for the definition of multiple minimum rainfall thresholds, each based on a different exceedance probability level. This makes the thresholds suited for the design of probabilistic schemes for the prediction of rainfall-induced landslides. A scheme based on four

  13. Soft tissue conduction as a possible contributor to the limited attenuation provided by hearing protection devices

    Directory of Open Access Journals (Sweden)

    Shai Chordekar

    2016-01-01

    Full Text Available Context: Damage to the auditory system by loud sounds can be avoided by hearing protection devices (HPDs such as earmuffs, earplugs, or both for maximum attenuation. However, the attenuation can be limited by air conduction (AC leakage around the earplugs and earmuffs by the occlusion effect (OE and by skull vibrations initiating bone conduction (BC. Aims: To assess maximum attenuation by HPDs and possible flanking pathways to the inner ear. Subjects and Methods: AC attenuation and resulting thresholds were assessed using the real ear attenuation at threshold (REAT procedure on 15 normal-hearing participants in four free-field conditions: (a unprotected ears, (b ears covered with earmuffs, (c ears blocked with deeply inserted customized earplugs, and (d ears blocked with both earplugs and earmuffs. BC thresholds were assessed with and without earplugs to assess the OE. Results: Addition of earmuffs to earplugs did not cause significantly greater attenuation than earplugs alone, confirming minimal AC leakage through the external meatus and the absence of the OE. Maximum REATs ranged between 40 and 46 dB, leading to thresholds of 46–54 dB HL. Furthermore, calculation of the acoustic impedance mismatch between air and bone predicted at least 60 dB attenuation of BC. Conclusion: Results do not support the notion that skull vibrations (BC contributed to the limited attenuation provided by traditional HPDs. An alternative explanation, supported by experimental evidence, suggests transmission of sound to inner ear via non-osseous pathways such as skin, soft tissues, and fluid. Because the acoustic impedance mismatch between air and soft tissues is smaller than that between air and bone, air-borne sounds would be transmitted to soft tissues more effectively than to bone, and therefore less attenuation is expected through soft tissue sound conduction. This can contribute to the limited attenuation provided by traditional HPDs. The present study

  14. Analysis of Ricefield Land Damage in Denpasar City, Bali, Indonesia

    Science.gov (United States)

    Suyarto, R.; Wiyanti; Dibia, I. N.

    2018-02-01

    Soil as a natural resource, living area, environmental media, and factors of production including biomass production that supports human life and other living beings must be preserved, on the other hand, uncontrolled biomass production activities can cause soil damage, ultimately can threaten the survival of humans and other living things. Therefore, in order to control soil damage, first must inventories the soil condition data and its damage which then visualised in soil damage potential and soil damage status. The activities of the study are the preparation of a map of the initial soil conditions and the delineation of potentially land degradation distribution. Mapping results are used as work maps for verification on the field to take soil samples and create soil damage status. In general, Denpasar City have soil damage potential at very low, low until medium rate. Soil damage status in Denpasar City generally is low damage of bulk volume, total porosity, soil permeability and electrolyte conductivity which beyond limitation thresholds.

  15. Damaged Skylab

    Science.gov (United States)

    1973-01-01

    The Saturn V vehicle, carrying the unmarned orbital workshop for the Skylab-1 mission, lifted off successfully and all systems performed normally. Sixty-three seconds into the flight, engineers in the operation support and control center saw an unexpected telemetry indication that signalled that damages occurred on one solar array and the micrometeoroid shield during the launch. The micrometeoroid shield, a thin protective cylinder surrounding the workshop protecting it from tiny space particles and the sun's scorching heat, ripped loose from its position around the workshop. This caused the loss of one solar wing and jammed the other. Still unoccupied, the Skylab was stricken with the loss of the heat shield and sunlight beat mercilessly on the lab's sensitive skin. Internal temperatures soared, rendering the station uninhabitable, threatening foods, medicines, films, and experiments. This image, taken during a fly-around inspection by the Skylab-2 crew, shows a crippled Skylab in orbit. The crew found their home in space to be in serious shape; the heat shield gone, one solar wing gone, and the other jammed. The Marshall Space Flight Center (MSFC) developed, tested, rehearsed, and approved three repair options. These options included a parasol sunshade and a twin-pole sunshade to restore the temperature inside the workshop, and a set of metal cutting tools to free the jammed solar panel.

  16. Structural damage

    International Nuclear Information System (INIS)

    Gray, R.E.; Bruhn, R.W.

    1992-01-01

    Virtually all structures show some signs of distress due to deterioration of the building components, to changed loads, or to changed support conditions. Changed support conditions result from ground movements. In mining regions many cases of structural distress are attributed to mining without considering alternative causes. This is particularly true of coal mining since it occurs under extensive areas. Coal mining is estimated to have already undermined more than eight million acres and may eventually undermine 40 million acres in the United States. Other nonmetal and metal underground mines impact much smaller areas. Although it is sometimes difficult, even with careful study, to identify the actual cause of damage, persons responsible for underground coal mining should at least be aware of possible causes of building stress other than mine subsidence. This paper presents information on distress to structures and briefly reviews a number of causes of ground movements other than subsidence: Mass movements, dissolution, erosion, frost action, shrinking and swelling, yield into excavations and compressibility

  17. Radiation damage prediction system using damage function

    International Nuclear Information System (INIS)

    Tanaka, Yoshihisa; Mori, Seiji

    1979-01-01

    The irradiation damage analysis system using a damage function was investigated. This irradiation damage analysis system consists of the following three processes, the unfolding of a damage function, the calculation of the neutron flux spectrum of the object of damage analysis and the estimation of irradiation effect of the object of damage analysis. The damage function is calculated by applying the SAND-2 code. The ANISN and DOT3, 5 codes are used to calculate neutron flux. The neutron radiation and the allowable time of reactor operation can be estimated based on these calculations of the damage function and neutron flux. The flow diagram of the process of analyzing irradiation damage by a damage function and the flow diagram of SAND-2 code are presented, and the analytical code for estimating damage, which is determined with a damage function and a neutron spectrum, is explained. The application of the irradiation damage analysis system using a damage function was carried out to the core support structure of a fast breeder reactor for the damage estimation and the uncertainty evaluation. The fundamental analytical conditions and the analytical model for this work are presented, then the irradiation data for SUS304, the initial estimated values of a damage function, the error analysis for a damage function and the analytical results are explained concerning the computation of a damage function for 10% total elongation. Concerning the damage estimation of FBR core support structure, the standard and lower limiting values of damage, the permissible neutron flux and the allowable years of reactor operation are presented and were evaluated. (Nakai, Y.)

  18. Thresholds for Coral Bleaching: Are Synergistic Factors and Shifting Thresholds Changing the Landscape for Management? (Invited)

    Science.gov (United States)

    Eakin, C.; Donner, S. D.; Logan, C. A.; Gledhill, D. K.; Liu, G.; Heron, S. F.; Christensen, T.; Rauenzahn, J.; Morgan, J.; Parker, B. A.; Hoegh-Guldberg, O.; Skirving, W. J.; Strong, A. E.

    2010-12-01

    As carbon dioxide rises in the atmosphere, climate change and ocean acidification are modifying important physical and chemical parameters in the oceans with resulting impacts on coral reef ecosystems. Rising CO2 is warming the world’s oceans and causing corals to bleach, with both alarming frequency and severity. The frequent return of stressful temperatures has already resulted in major damage to many of the world’s coral reefs and is expected to continue in the foreseeable future. Warmer oceans also have contributed to a rise in coral infectious diseases. Both bleaching and infectious disease can result in coral mortality and threaten one of the most diverse ecosystems on Earth and the important ecosystem services they provide. Additionally, ocean acidification from rising CO2 is reducing the availability of carbonate ions needed by corals to build their skeletons and perhaps depressing the threshold for bleaching. While thresholds vary among species and locations, it is clear that corals around the world are already experiencing anomalous temperatures that are too high, too often, and that warming is exceeding the rate at which corals can adapt. This is despite a complex adaptive capacity that involves both the coral host and the zooxanthellae, including changes in the relative abundance of the latter in their coral hosts. The safe upper limit for atmospheric CO2 is probably somewhere below 350ppm, a level we passed decades ago, and for temperature is a sustained global temperature increase of less than 1.5°C above pre-industrial levels. How much can corals acclimate and/or adapt to the unprecedented fast changing environmental conditions? Any change in the threshold for coral bleaching as the result of acclimation and/or adaption may help corals to survive in the future but adaptation to one stress may be maladaptive to another. There also is evidence that ocean acidification and nutrient enrichment modify this threshold. What do shifting thresholds mean

  19. Pulsed total dose damage effect experimental study on EPROM

    International Nuclear Information System (INIS)

    Luo Yinhong; Yao Zhibin; Zhang Fengqi; Guo Hongxia; Zhang Keying; Wang Yuanming; He Baoping

    2011-01-01

    Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

  20. The issue of threshold states

    International Nuclear Information System (INIS)

    Luck, L.

    1994-01-01

    The states which have not joined the Non-proliferation Treaty nor have undertaken any other internationally binding commitment not to develop or otherwise acquire nuclear weapons are considered a threshold states. Their nuclear status is rendered opaque as a conscious policy. Nuclear threshold status remains a key disarmament issue. For those few states, as India, Pakistan, Israel, who have put themselves in this position, the security returns have been transitory and largely illusory. The cost to them, and to the international community committed to the norm of non-proliferation, has been huge. The decisions which could lead to recovery from the situation in which they find themselves are essentially at their own hands. Whatever assistance the rest of international community is able to extend, it will need to be accompanied by a vital political signal

  1. Multiscalar production amplitudes beyond threshold

    CERN Document Server

    Argyres, E N; Kleiss, R H

    1993-01-01

    We present exact tree-order amplitudes for $H^* \\to n~H$, for final states containing one or two particles with non-zero three-momentum, for various interaction potentials. We show that there are potentials leading to tree amplitudes that satisfy unitarity, not only at threshold but also in the above kinematical configurations and probably beyond. As a by-product, we also calculate $2\\to n$ tree amplitudes at threshold and show that for the unbroken $\\phi^4$ theory they vanish for $n>4~$, for the Standard Model Higgs they vanish for $n\\ge 3~$ and for a model potential, respecting tree-order unitarity, for $n$ even and $n>4~$. Finally, we calculate the imaginary part of the one-loop $1\\to n$ amplitude in both symmetric and spontaneously broken $\\phi^4$ theory.

  2. Realistic Realizations Of Threshold Circuits

    Science.gov (United States)

    Razavi, Hassan M.

    1987-08-01

    Threshold logic, in which each input is weighted, has many theoretical advantages over the standard gate realization, such as reducing the number of gates, interconnections, and power dissipation. However, because of the difficult synthesis procedure and complicated circuit implementation, their use in the design of digital systems is almost nonexistant. In this study, three methods of NMOS realizations are discussed, and their advantages and shortcomings are explored. Also, the possibility of using the methods to realize multi-valued logic is examined.

  3. Root finding with threshold circuits

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil

    2012-01-01

    Roč. 462, Nov 30 (2012), s. 59-69 ISSN 0304-3975 R&D Projects: GA AV ČR IAA100190902; GA MŠk(CZ) 1M0545 Institutional support: RVO:67985840 Keywords : root finding * threshold circuit * power series Subject RIV: BA - General Mathematics Impact factor: 0.489, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304397512008006#

  4. Design proposal for door thresholds

    Directory of Open Access Journals (Sweden)

    Smolka Radim

    2017-01-01

    Full Text Available Panels for openings in structures have always been an essential and integral part of buildings. Their importance in terms of a building´s functionality was not recognised. However, the general view on this issue has changed from focusing on big planar segments and critical details to sub-elements of these structures. This does not only focus on the forms of connecting joints but also on the supporting systems that keep the panels in the right position and ensure they function properly. One of the most strained segments is the threshold structure, especially the entrance door threshold structure. It is the part where substantial defects in construction occur in terms of waterproofing, as well as in the static, thermal and technical functions thereof. In conventional buildings, this problem is solved by pulling the floor structure under the entrance door structure and subsequently covering it with waterproofing material. This system cannot work effectively over the long term so local defects occur. A proposal is put forward to solve this problem by installing a sub-threshold door coupler made of composite materials. The coupler is designed so that its variability complies with the required parameters for most door structures on the European market.

  5. Picosecond laser damage of fused silica at 355 nm

    International Nuclear Information System (INIS)

    Meng Xiangjie; Liu Hongjie; Wang Fang; Zhang Zhen; An Xinyou; Huang Jin; Jiang Xiaodong; Wu Weidong; Ren Weiyi

    2013-01-01

    This paper studies the initiated damage threshold, the damage morphology and the subsequent damage growth on fused silica's input-surface and exit-surface under picosecond laser irradiation at 355 nm. Defects induced fluorescence on surface of the optical component is observed. The results demonstrate a significant dependence of the initiated damage on pulse duration and surface defects, and that of the damage growth on self-focusing, sub-surface defects. The damage-threshold is 3.98 J/cm 2 of input surface and 2.91 J/cm 2 of exit surface. The damage morphologies are quite different between input surface and exit surface. Slow growth behavior appears for the diameter of exit-surface and linear growth one for the depth of exit-surface in the lateral side of damage site with the increase of shot number. Defects have changed obviously compared with nanosecond laser damage in the damage area. Several main reasons such as electric intensification and self-focusing for the observed initiated damage and damage growth behavior are discussed. (authors)

  6. Measurement of radiation damage on an optical reflector

    International Nuclear Information System (INIS)

    Peng, K.C.; Sahu, S.K.; Huang, H.C.; Ueno, K.; Chang, Y.H.; Wang, C.H.; Hou, W.S.

    1997-01-01

    We measured the radiation damage on an optical white fluorocarbon reflector called Goretex, which is to be used for aerogel threshold counters and crystal calorimeters of the BELLE detector of the KEK B-factory. Reflectance of the Goretex surface was monitored to see any effect of the radiation damage. Maximum equivalent dose was 8.6 Mrad. No radiation damage is observed within measurement errors. (orig.)

  7. Comparison on taste threshold between adult male white cigarette and clove cigarette smokers using Murphy clinical test method

    Directory of Open Access Journals (Sweden)

    Ronald Reyses Tapilatu

    2008-03-01

    Full Text Available The habit of smoking white cigarettes and clove cigarettes may affect the gustatory function, that is, it will cause damage to taste buds, resulting in an increase in gustatory threshold. This research used the descriptive comparative method and had the purpose of obtaining an illustration of gustatory threshold and compare gustatory threshold in white cigarette smokers and clove cigarette smokers in young, male adults. For gustatory threshold evaluation, the Murphy method was used to obtain a value for perception threshold and taste identification threshold using sucrose solution of 0.0006 M-0.06 M concentration. Research results indicate that the perception threshold and identification threshold of young, male adult smokers are 0.0119 M and 0.0292 M. Young, male adult clove cigarette smokers have a perception threshold and identification threshold of 0.0151 M and 0.0348 M. The conclusion of this research is that the perception threshold of young, male adult white cigarette smokers and clove cigarette smokers are the same, whereas the identification threshold of young, male adult white cigarette smokers and clove cigarette smokers are different, that is, the identification threshold of clove cigarette smokers is higher than that of white cigarette smokers.

  8. Color difference thresholds in dentistry.

    Science.gov (United States)

    Paravina, Rade D; Ghinea, Razvan; Herrera, Luis J; Bona, Alvaro D; Igiel, Christopher; Linninger, Mercedes; Sakai, Maiko; Takahashi, Hidekazu; Tashkandi, Esam; Perez, Maria del Mar

    2015-01-01

    The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold (PT) and 50:50% acceptability threshold (AT) of dental ceramic under simulated clinical settings. The spectral radiance of 63 monochromatic ceramic specimens was determined using a non-contact spectroradiometer. A total of 60 specimen pairs, divided into 3 sets of 20 specimen pairs (medium to light shades, medium to dark shades, and dark shades), were selected for psychophysical experiment. The coordinating center and seven research sites obtained the Institutional Review Board (IRB) approvals prior the beginning of the experiment. Each research site had 25 observers, divided into five groups of five observers: dentists-D, dental students-S, dental auxiliaries-A, dental technicians-T, and lay persons-L. There were 35 observers per group (five observers per group at each site ×7 sites), for a total of 175 observers. Visual color comparisons were performed using a viewing booth. Takagi-Sugeno-Kang (TSK) fuzzy approximation was used for fitting the data points. The 50:50% PT and 50:50% AT were determined in CIELAB and CIEDE2000. The t-test was used to evaluate the statistical significance in thresholds differences. The CIELAB 50:50% PT was ΔEab  = 1.2, whereas 50:50% AT was ΔEab  = 2.7. Corresponding CIEDE2000 (ΔE00 ) values were 0.8 and 1.8, respectively. 50:50% PT by the observer group revealed differences among groups D, A, T, and L as compared with 50:50% PT for all observers. The 50:50% AT for all observers was statistically different than 50:50% AT in groups T and L. A 50:50% perceptibility and ATs were significantly different. The same is true for differences between two color difference formulas ΔE00 /ΔEab . Observer groups and sites showed high level of statistical difference in all thresholds. Visual color difference thresholds can serve as a quality control tool to guide the selection of esthetic dental materials, evaluate clinical performance, and

  9. Bedding material affects mechanical thresholds, heat thresholds and texture preference

    Science.gov (United States)

    Moehring, Francie; O’Hara, Crystal L.; Stucky, Cheryl L.

    2015-01-01

    It has long been known that the bedding type animals are housed on can affect breeding behavior and cage environment. Yet little is known about its effects on evoked behavior responses or non-reflexive behaviors. C57BL/6 mice were housed for two weeks on one of five bedding types: Aspen Sani Chips® (standard bedding for our institute), ALPHA-Dri®, Cellu-Dri™, Pure-o’Cel™ or TEK-Fresh. Mice housed on Aspen exhibited the lowest (most sensitive) mechanical thresholds while those on TEK-Fresh exhibited 3-fold higher thresholds. While bedding type had no effect on responses to punctate or dynamic light touch stimuli, TEK-Fresh housed animals exhibited greater responsiveness in a noxious needle assay, than those housed on the other bedding types. Heat sensitivity was also affected by bedding as animals housed on Aspen exhibited the shortest (most sensitive) latencies to withdrawal whereas those housed on TEK-Fresh had the longest (least sensitive) latencies to response. Slight differences between bedding types were also seen in a moderate cold temperature preference assay. A modified tactile conditioned place preference chamber assay revealed that animals preferred TEK-Fresh to Aspen bedding. Bedding type had no effect in a non-reflexive wheel running assay. In both acute (two day) and chronic (5 week) inflammation induced by injection of Complete Freund’s Adjuvant in the hindpaw, mechanical thresholds were reduced in all groups regardless of bedding type, but TEK-Fresh and Pure-o’Cel™ groups exhibited a greater dynamic range between controls and inflamed cohorts than Aspen housed mice. PMID:26456764

  10. Freezing cytorrhysis and critical temperature thresholds for photosystem II in the peat moss Sphagnum capillifolium.

    Science.gov (United States)

    Buchner, Othmar; Neuner, Gilbert

    2010-07-01

    Leaflets of Sphagnum capillifolium were exposed to temperatures from -5 degrees C to +60 degrees C under controlled conditions while mounted on a microscope stage. The resultant cytological response to these temperature treatments was successfully monitored using a light and fluorescence microscope. In addition to the observable cytological changes during freezing cytorrhysis and heat exposure on the leaflets, the concomitant critical temperature thresholds for inactivation of photosystem II (PS II) were studied using a micro fibre optic and a chlorophyll fluorometer mounted to the microscope stage. Chlorophyllous cells of S. capillifolium showed extended freezing cytorrhysis immediately after ice nucleation at -1.1 degrees C in the water in which the leaflets were submersed during the measurement. The occurrence of freezing cytorrhysis, which was visually manifested by cell shrinkage, was highly dynamic and was completed within 2 s. A total reduction of the mean projected diameter of the chloroplast containing area during freezing cytorrhysis from 8.9 to 3.8 microm indicates a cell volume reduction of approximately -82%. Simultaneous measurement of chlorophyll fluorescence of PS II was possible even through the frozen water in which the leaf samples were submersed. Freezing cytorrhysis was accompanied by a sudden rise of basic chlorophyll fluorescence. The critical freezing temperature threshold of PS II was identical to the ice nucleation temperature (-1.1 degrees C). This is significantly above the temperature threshold at which frost damage to S. capillifolium leaflets occurs (-16.1 degrees C; LT(50)) which is higher than observed in most higher plants from the European Alps during summer. High temperature thresholds of PS II were 44.5 degrees C which is significantly below the heat tolerance of chlorophyllous cells (49.9 degrees C; LT(50)). It is demonstrated that light and fluorescence microscopic techniques combined with simultaneous chlorophyll fluorescence

  11. DNA damage and repair in plants

    International Nuclear Information System (INIS)

    Britt, A.B.

    1996-01-01

    The biological impact of any DNA damaging agent is a combined function of the chemical nature of the induced lesions and the efficiency and accuracy of their repair. Although much has been learned frommicrobes and mammals about both the repair of DNA damage and the biological effects of the persistence of these lesions, much remains to be learned about the mechanism and tissue-specificity of repair in plants. This review focuses on recent work on the induction and repair of DNA damage in higher plants, with special emphasis on UV-induced DNA damage products. (author)

  12. Prediction of temperature and damage in an irradiated human eye-Utilization of a detailed computer model which includes a vectorial blood stream in the choroid.

    Science.gov (United States)

    Heussner, Nico; Holl, Lukas; Nowak, Timo; Beuth, Thorsten; Spitzer, Martin S; Stork, Wilhelm

    2014-08-01

    The work presented here describes the development and use of a three-dimensional thermo-dynamic model of the human eye for the prediction of temperatures and damage thresholds under irradiation. This model takes into account the blood flow by the implementation of a vectorial blood stream in the choroid and also uses the actual physiological extensions and tissue parameters of the eye. Furthermore it considers evaporation, radiation and convection at the cornea as well as the eye lid. The predicted temperatures were successfully validated against existing eye models in terms of corneal and global thermal behaviour. The model׳s predictions were additionally checked for consistency with in-vivo temperature measurements of the cornea, the irradiated retina and its damage thresholds. These thresholds were calculated from the retinal temperatures using the Arrhenius integral. Hence the model can be used to predict the temperature increase and irradiation hazard within the human eye as long as the absorption values and the Arrhenius coefficients are known and the damage mechanism is in the thermal regime. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Bulk and surface laser damage of silica by picosecond and nanosecond pulses at 1064 nm

    International Nuclear Information System (INIS)

    Smith, Arlee V.; Do, Binh T.

    2008-01-01

    We measured bulk and surface dielectric breakdown thresholds of pure silica for 14 ps and 8 ns pulses of 1064 nm light. The thresholds are sharp and reproducible. For the 8 ns pulses the bulk threshold irradiance is 4.75 ± 0.25 kW/μm 2 . The threshold is approximately three times higher for 14 ps pulses. For 8 ns pulses the input surface damage threshold can be made equal to the bulk threshold by applying an alumina or silica surface polish

  14. Optimizing Systems of Threshold Detection Sensors

    National Research Council Canada - National Science Library

    Banschbach, David C

    2008-01-01

    .... Below the threshold all signals are ignored. We develop a mathematical model for setting individual sensor thresholds to obtain optimal probability of detecting a significant event, given a limit on the total number of false positives allowed...

  15. 11 CFR 9036.1 - Threshold submission.

    Science.gov (United States)

    2010-01-01

    ... credit or debit card, including one made over the Internet, the candidate shall provide sufficient... section shall not count toward the threshold amount. (c) Threshold certification by Commission. (1) After...

  16. Tissue Engineering of the Penis

    Directory of Open Access Journals (Sweden)

    Manish N. Patel

    2011-01-01

    Full Text Available Congenital disorders, cancer, trauma, or other conditions of the genitourinary tract can lead to significant organ damage or loss of function, necessitating eventual reconstruction or replacement of the damaged structures. However, current reconstructive techniques are limited by issues of tissue availability and compatibility. Physicians and scientists have begun to explore tissue engineering and regenerative medicine strategies for repair and reconstruction of the genitourinary tract. Tissue engineering allows the development of biological substitutes which could potentially restore normal function. Tissue engineering efforts designed to treat or replace most organs are currently being undertaken. Most of these efforts have occurred within the past decade. However, before these engineering techniques can be applied to humans, further studies are needed to ensure the safety and efficacy of these new materials. Recent progress suggests that engineered urologic tissues and cell therapy may soon have clinical applicability.

  17. Nuclear thermodynamics below particle threshold

    International Nuclear Information System (INIS)

    Schiller, A.; Agvaanluvsan, U.; Algin, E.; Bag