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Sample records for tissue absorption modest

  1. Profile modification and hot electron temperature from resonant absorption at modest intensity

    International Nuclear Information System (INIS)

    Albritton, J.R.; Langdon, A.B.

    1980-01-01

    Resonant absorption is investigated in expanding plasmas. The momentum deposition associated with the ejection of hot electrons toward low density via wavebreaking readily exceeds that of the incident laser radiation and results in significant modification of the density profile at critical. New scaling of hot electron temperature with laser and plasma parameters is presented

  2. Chloride absorption by root, leaf and floral tissues of Petunia

    International Nuclear Information System (INIS)

    Jooste, J.H.

    1980-01-01

    Chloride absorption by root, leaf and floral tissues of Petunia was compared at two temperatures (30 and 2 degrees Celcius), employing different absorption periods, and in the presence and absence of a desorption treatment. All treatments revealed highest absorption by floral tissue. This was further confirmed by the absorption of chloride by the various tissues from solutions in the low (0-1 mM) and high (1-50 mM) concentration ranges. The results offer a possible explanation for the observed effects of organic and inorganic solutes on the longevity of cut flowers [af

  3. Infrared absorption of human breast tissues in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Liu Chenglin [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Zhang Yuan [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Yan Xiaohui [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China); Zhang Xinyi [Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433 (China) and Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)]. E-mail: xy-zhang@fudan.edu.cn; Li Chengxiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Yang Wentao [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China); Shi Daren [Cancer Hospital, Medical Center, Fudan University, Shanghai 200032 (China)

    2006-07-15

    The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared (SR-FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR) source, higher resolving power is achieved in SR-FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some specific absorption peaks were found in breast cancer tissues by SR-FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer.

  4. The Roles of Adipokines, Proinflammatory Cytokines, and Adipose Tissue Macrophages in Obesity-Associated Insulin Resistance in Modest Obesity and Early Metabolic Dysfunction.

    Directory of Open Access Journals (Sweden)

    Yea Eun Kang

    Full Text Available The roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in obesity-associated insulin resistance have been explored in both animal and human studies. However, our current understanding of obesity-associated insulin resistance relies on studies of artificial metabolic extremes. The purpose of this study was to explore the roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in human patients with modest obesity and early metabolic dysfunction. We obtained omental adipose tissue and fasting blood samples from 51 females undergoing gynecologic surgery. We investigated serum concentrations of proinflammatory cytokines and adipokines as well as the mRNA expression of proinflammatory and macrophage phenotype markers in visceral adipose tissue using ELISA and quantitative RT-PCR. We measured adipose tissue inflammation and macrophage infiltration using immunohistochemical analysis. Serum levels of adiponectin and leptin were significantly correlated with HOMA-IR and body mass index. The levels of expression of MCP-1 and TNF-α in visceral adipose tissue were also higher in the obese group (body mass index ≥ 25. The expression of mRNA MCP-1 in visceral adipose tissue was positively correlated with body mass index (r = 0.428, p = 0.037 but not with HOMA-IR, whereas TNF-α in visceral adipose tissue was correlated with HOMA-IR (r = 0.462, p = 0.035 but not with body mass index. There was no obvious change in macrophage phenotype or macrophage infiltration in patients with modest obesity or early metabolic dysfunction. Expression of mRNA CD163/CD68 was significantly related to mitochondrial-associated genes and serum inflammatory cytokine levels of resistin and leptin. These results suggest that changes in the production of inflammatory biomolecules precede increased immune cell infiltration and induction of a macrophage phenotype switch in visceral adipose tissue. Furthermore, serum resistin and

  5. NMR imaging of cell phone radiation absorption in brain tissue

    Science.gov (United States)

    Gultekin, David H.; Moeller, Lothar

    2013-01-01

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry. PMID:23248293

  6. Absorption spectra of adenocarcinoma and squamous cell carcinoma cervical tissues

    Science.gov (United States)

    Ivashko, Pavlo; Peresunko, Olexander; Zelinska, Natalia; Alonova, Marina

    2014-08-01

    We studied a methods of assessment of a connective tissue of cervix in terms of specific volume of fibrous component and an optical density of staining of connective tissue fibers in the stroma of squamous cancer and cervix adenocarcinoma. An absorption spectra of blood plasma of the patients suffering from squamous cancer and cervix adenocarcinoma both before the surgery and in postsurgical periods were obtained. Linear dichroism measurements transmittance in polarized light at different orientations of the polarization plane relative to the direction of the dominant orientation in the structure of the sample of biotissues of stroma of squamous cancer and cervix adenocarcinoma were carried. Results of the investigation of the tumor tissues showed that the magnitude of the linear dichroism Δ is insignificant in the researched spectral range λ=280-840 nm and specific regularities in its change observed short-wave ranges.

  7. Optical absorption and scattering spectra of pathological stomach tissues

    Science.gov (United States)

    Giraev, K. M.; Ashurbekov, N. A.; Lakhina, M. A.

    2011-03-01

    Diffuse reflection spectra of biotissues in vivo and transmission and reflection coefficients for biotissues in vitro are measured over 300-800 nm. These data are used to determine the spectral absorption and scattering indices and the scattering anisotropy factor for stomach mucous membranes under normal and various pathological conditions (chronic atrophic and ulcerous defects, malignant neoplasms). The most importan tphysiological (hemodynamic and oxygenation levels) and structural-morphological (scatterer size and density) parameters are also determined. The results of a morphofunctional study correlate well with the optical properties and are consistent with data from a histomorphological analysis of the corresponding tissues.

  8. Modeling microwave electromagnetic field absorption in muscle tissues

    Science.gov (United States)

    Felbacq, D.; Clerjon, S.; Damez, J. L.; Zolla, F.

    2002-07-01

    Absorption of electromagnetic energy in human tissues is an important issue with respect to the safety of low-level exposure. Simulation is a way to a better understanding of electromagnetic dosimetry. This letter presents a comparison between results obtained from a numerical simulation and experimental data of absorbed energy by a muscle. Simulation was done using a bidimensional double-scale homogenization scheme leading to the effective permittivity tensor. Experimental measurements were performed at 10 GHz on bovine muscle, 30 hours after slaughter, thanks to the open-ended rectangular waveguide method. Results show a good agreement between measurements and simulated data.

  9. Modeling of light absorption in tissue during infrared neural stimulation

    Science.gov (United States)

    Thompson, Alexander C.; Wade, Scott A.; Brown, William G. A.; Stoddart, Paul R.

    2012-07-01

    A Monte Carlo model has been developed to simulate light transport and absorption in neural tissue during infrared neural stimulation (INS). A range of fiber core sizes and numerical apertures are compared illustrating the advantages of using simulations when designing a light delivery system. A range of wavelengths, commonly used for INS, are also compared for stimulation of nerves in the cochlea, in terms of both the energy absorbed and the change in temperature due to a laser pulse. Modeling suggests that a fiber with core diameter of 200 μm and NA=0.22 is optimal for optical stimulation in the geometry used and that temperature rises in the spiral ganglion neurons are as low as 0.1°C. The results show a need for more careful experimentation to allow different proposed mechanisms of INS to be distinguished.

  10. Microwave reflection, transmission, and absorption by human brain tissue

    Science.gov (United States)

    Ansari, M. A.; Akhlaghipour, N.; Zarei, M.; Niknam, A. R.

    2018-04-01

    These days, the biological effects of electromagnetic (EM) radiations on the brain, especially in the frequency range of mobile communications, have caught the attention of many scientists. Therefore, in this paper, the propagation of mobile phone electromagnetic waves in the brain tissues is investigated analytically and numerically. The brain is modeled by three layers consisting of skull, grey and white matter. First, we have analytically calculated the microwave reflection, transmission, and absorption coefficients using signal flow graph technique. The effect of microwave frequency and variations in the thickness of layers on the propagation of microwave through brain are studied. Then, the penetration of microwave in the layers is numerically investigated by Monte Carlo method. It is shown that the analytical results are in good agreement with those obtained by Monte Carlo method. Our results indicate the absorbed microwave energy depends on microwave frequency and thickness of brain layers, and the absorption coefficient is optimized at a number of frequencies. These findings can be used for comparing the microwave absorbed energy in a child's and adult's brain.

  11. A Modest Minimalism?

    Directory of Open Access Journals (Sweden)

    Jaan Kangilaski

    2008-12-01

    Full Text Available My aim in this paper is to present and evaluate one version of the deflationary attitude to truth, namely the Modest Account, propounded by Wolfgang Künne in his Conceptions of Truth (OUP 2003. I introduce the deflationary theories of truth in the first part of my paper and present briefly the views of a more familiar deflationist, Paul Horwich, as a "stepping-stone" to Künne’s account. In the second part of the paper I give an overview of Künne's theory and in the final part I present a dilemma that his account faces: either it is not modest after all or it is incomprehensible.

  12. Absorption, tissue distribution, excretion, and metabolism of clothianidin in rats.

    Science.gov (United States)

    Yokota, Tokunori; Mikata, Kazuki; Nagasaki, Hiromi; Ohta, Kazunari

    2003-11-19

    Absorption, distribution, excretion, and metabolism of clothianidin [(E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine] were investigated after a single oral administration of [nitroimino-(14)C]- or [thiazolyl-2-(14)C]clothianidin to male and female rats at a dose of 5 mg/kg of body weight (bw) (low dose) or 250 mg/kg of bw (high dose). The maximum concentration of carbon-14 in blood occurred 2 h after administration of the low oral dose for both labeled clothianidins, and then the concentration of carbon-14 in blood decreased with a half-life of 2.9-4.0 h. The orally administered carbon-14 was rapidly and extensively distributed to all tissues and organs within 2 h after administration, especially to the kidney and liver, but was rapidly and almost completely eliminated from all tissues and organs with no evidence of accumulation. The orally administered carbon-14 was almost completely excreted into urine and feces within 2 days after administration, and approximately 90% of the administered dose was excreted via urine. The major compound in excreta was clothianidin, accounting for >60% of the administered dose. The major metabolic reactions of clothianidin in rats were oxidative demethylation to form N-(2-chlorothiazol-5-ylmethyl)-N'-nitroguanidine and the cleavage of the carbon-nitrogen bond between the thiazolylmethyl moiety and the nitroguanidine moiety. The part of the molecule containing the nitroguanidine moiety was transformed mainly to N-methyl-N'-nitroguanidine, whereas the thiazol moiety was further metabolized to 2-(methylthio)thiazole-5-carboxylic acid. With the exception of the transiently delayed excretion of carbon-14 at the high-dose level, the rates of biokinetics, excretion, distribution, and metabolism of clothianidin were not markedly influenced by dose level and sex.

  13. DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

    Science.gov (United States)

    A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

  14. The absorption, tissue distribution and excretion of di-n-octyltin dichloride in rats

    NARCIS (Netherlands)

    Penninks, A.H.; Hilgers, L.; Seinen, W.

    In this study the absorption, tissue distribution and excretion of 14C-labeled di-n-octyltin dichloride ([14C]DOTC) in rats were investigated after oral and intravenous (i.v.) administration. Although after i.v. administration with 1.2 mg [14C]DOTC/kg body weight the tissue radioactivity was about

  15. Energy-Looping Nanoparticles: Harnessing Excited-State Absorption for Deep-Tissue Imaging.

    Science.gov (United States)

    Levy, Elizabeth S; Tajon, Cheryl A; Bischof, Thomas S; Iafrati, Jillian; Fernandez-Bravo, Angel; Garfield, David J; Chamanzar, Maysamreza; Maharbiz, Michel M; Sohal, Vikaas S; Schuck, P James; Cohen, Bruce E; Chan, Emory M

    2016-09-27

    Near infrared (NIR) microscopy enables noninvasive imaging in tissue, particularly in the NIR-II spectral range (1000-1400 nm) where attenuation due to tissue scattering and absorption is minimized. Lanthanide-doped upconverting nanocrystals are promising deep-tissue imaging probes due to their photostable emission in the visible and NIR, but these materials are not efficiently excited at NIR-II wavelengths due to the dearth of lanthanide ground-state absorption transitions in this window. Here, we develop a class of lanthanide-doped imaging probes that harness an energy-looping mechanism that facilitates excitation at NIR-II wavelengths, such as 1064 nm, that are resonant with excited-state absorption transitions but not ground-state absorption. Using computational methods and combinatorial screening, we have identified Tm(3+)-doped NaYF4 nanoparticles as efficient looping systems that emit at 800 nm under continuous-wave excitation at 1064 nm. Using this benign excitation with standard confocal microscopy, energy-looping nanoparticles (ELNPs) are imaged in cultured mammalian cells and through brain tissue without autofluorescence. The 1 mm imaging depths and 2 μm feature sizes are comparable to those demonstrated by state-of-the-art multiphoton techniques, illustrating that ELNPs are a promising class of NIR probes for high-fidelity visualization in cells and tissue.

  16. Effects of dehydration on corneal tissue absorption of topical azithromycin in rabbits.

    Science.gov (United States)

    Tabbara, Khalid F; Kotb, Amgad A; Hammouda, Ehab F; Elkum, Naser

    2005-10-01

    To assess the corneal tissue absorption of azithromycin in desiccated and normal eyes of rabbits. A total of 25 New Zealand Albino rabbits weighing 2-3 kg each were included. One eye of each rabbit was desiccated. The other eye was left as control. Azithromycin 1.5% topical eyedrops were instilled in both eyes. Five rabbits were sacrificed at each of the following time points: 30 min, 3 hr, 6 hr, and 12 hr. Corneal tissues specimens were subjected to high-performance liquid chromatography mass spectrometry. A paired t test was used to evaluate the statistical difference in corneal tissue absorptions of azithromycin at each time point. The mean corneal tissue levels of azithromycin in dry eyes were 66.3 microg/ml, 92.6 microg/ml, 117.5 microg/ml, and 179.9 microg/ml, and the mean corneal tissue levels of azithromycin in normal eyes were 42.0 microg/ml, 43.4 microg/ml, 43.3 microg/ml, and 80.0 microg/ml at 30 min, 3 hr, 6 hr, and 12 hr respectively. Both groups showed increase in corneal tissue absorption overtime (p < 0.0001). Significantly higher levels of azithromycin were noted in dry eyes at each time point except at the 30-min time point. This study demonstrated that corneas exposed to desiccation showed statistically significant increase in azithromycin level compared to normal eyes.

  17. A new approach to predict human intestinal absorption using porcine intestinal tissue and biorelevant matrices

    NARCIS (Netherlands)

    Westerhout, J.; Steeg, E. van de; Grossouw, D.; Zeijdner, E.E.; Krul, C.A.M.; Verwei, M.; Wortelboer, H.M.

    2014-01-01

    A reliable prediction of the oral bioavailability in humans is crucial and of high interest for pharmaceutical and food industry. The predictive value of currently used in silico methods, in vitro cell lines, ex vivo intestinal tissue and/or in vivo animal studies for human intestinal absorption,

  18. Tissue expansion and fluid absorption by skin tissue following intradermal injections through hollow microneedles

    Science.gov (United States)

    Shrestha, Pranav; Stoeber, Boris

    2017-11-01

    Hollow microneedles provide a promising alternative to conventional drug delivery techniques due to improved patient compliance and the dose sparing effect. The dynamics of fluid injected through hollow microneedles into skin, which is a heterogeneous and deformable porous medium, have not been investigated extensively in the past. We have introduced the use of Optical Coherence Tomography (OCT) for real-time visualization of fluid injections into excised porcine tissue. The results from ex-vivo experiments, including cross-sectional tissue images from OCT and pressure/flow-rate measurements, show a transient mode of high flow-rate into the tissue followed by a lower steady-state infusion rate. The injected fluid expands the underlying tissue and causes the external free surface of the skin to rise, forming a characteristic intradermal wheal. We have used OCT to visualize the evolution of tissue and free surface deformation, and advancement of the boundary between regions of expanding and stationary tissue. We will show the effect of different injection parameters such as fluid pressure, viscosity and microneedle retraction on the injected volume. This work has been supported through funding from the Collaborative Health Research Program by the Natural Science and Engineering Research Council of Canada and the Canadian Health Research Institute, and through the Canada Research Chairs program.

  19. Oral absorption and tissue distribution of a new squalenoyl anticancer nanomedicine

    Energy Technology Data Exchange (ETDEWEB)

    Harivardhan Reddy, L.; Ferreira, Humberto; Dubernet, Catherine [Univ. Paris-Sud XI, Faculte de Pharmacie, UMR CNRS 8612, IFR 141 (France); Mouelhi, Sinda Lepetre; Desmaele, Didier [Universite Paris XI, Faculte de Pharmacie, UMR CNRS 8076 Biocis (France); Rousseau, Bernard [CEA, Bio Organic Chemistry and Labeled Compounds Division (France); Couvreur, Patrick [Univ. Paris-Sud XI, Faculte de Pharmacie, UMR CNRS 8612, IFR 141 (France)], E-mail: patrick.couvreur@u-psud.fr

    2008-05-15

    Recently, we had discovered that the linkage of nucleoside analogues to squalene, a precursor in the sterol biosynthesis, led to amphiphilic molecules, which self-organized in water as nanoassemblies of 100-300 nm in diameter, irrespective of the nucleoside analogue used. Thus, it was observed that the 4-(N)-trisnorsqualenoylgemcitabine (SQdFdC), the squalenoyl prodrug of the anticancer nucleoside analogue gemcitabine, was impressively more active than its parent compound gemcitabine, both in vitro and in vivo on experimental leukaemia. Since squalene, which is a natural constituent of shark liver and olive oil, is known to be absorbed orally, we investigated in this short note the absorption and tissue distribution of {sup 3}H-radiolabelled SQdFdC nanoassemblies comparatively to {sup 3}H-gemcitabine after oral administration to mice. Whereas gemcitabine was found to be rapidly absorbed (t{sub max} = 1 h), this compound underwent a rapid clearance from the plasma. Conversely, the SQdFdC nanoassemblies displayed slower absorption followed by the progressive tissue accumulation, and they exhibited a lower clearance rate. The accumulation of the SQdFdC nanoassemblies in tissues such as pancreas, thymus, lung, liver and spleen (except at 1 h post-administration) was similar to that of the gemcitabine, yet exhibited significantly greater penetration and retention into the stomach and intestinal tissues comparatively to gemcitabine. Thus, the SQdFdC nanoassemblies could be of potential interest in the treatment of gastrointestinal tumours by oral route.

  20. Comparison of absorption spectra of adenocarcinoma and squamous cell carcinoma cervical tissue

    Science.gov (United States)

    Peresunko, O. P.; Zelinska, N. V.; Prydij, O. G.; Zymnyakov, D. A.; Ushakova, O. V.

    2013-12-01

    We studied a methods of assessment of a connective tissue of cervix in terms of specific volume of fibrous component and an optical density of staining of connective tissue fibers in the stroma of squamous cancer and cervix adenocarcinoma. An absorption spectra of blood plasma of the patients suffering from squamous cancer and cervix adenocarcinoma both before the surgery and in postsurgical periods were obtained. Linear dichroism measurements transmittance in polarized light at different orientations of the polarization plane relative to the direction of the dominant orientation in the structure of the sample of biotissues of stroma of squamous cancer and cervix adenocarcinoma were carried. Results of the investigation of the tumor tissues showed that the magnitude of the linear dichroism Δ is insignificant in the researched spectral range λ=280-840 nm and specific regularities in its change observed short-wave ranges.

  1. Gamma-ray energy absorption and exposure buildup factor studies in some human tissues with endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Dogan, Bekir [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Ingec, Metin [Faculty of Medicine, Department of Obstetrics and Gynecology, Ataturk University, 25240 Erzurum (Turkey); Ekinci, Neslihan; Ozdemir, Yueksel [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)

    2011-02-15

    Human tissues with endometriosis have been analyzed in terms of energy absorption (EABF) and exposure (EBF) buildup factors using the five-parameter geometric progression (G-P) fitting formula in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). Chemical compositions of the tissue samples were determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Possible conclusions were drawn due to significant variations in EABF and EBF for the selected tissues when photon energy, penetration depth and chemical composition changed. Buildup factors so obtained may be of use when the method of choice for treatment of endometriosis is radiotherapy.

  2. Energy absorption buildup factors of human organs and tissues at energies and penetration depths relevant for radiotherapy and diagnostics

    DEFF Research Database (Denmark)

    Manohara, S. R.; Hanagodimath, S. M.; Gerward, Leif

    2011-01-01

    Energy absorption geometric progression (GP) fitting parameters and the corresponding buildup factors have been computed for human organs and tissues, such as adipose tissue, blood (whole), cortical bone, brain (grey/white matter), breast tissue, eye lens, lung tissue, skeletal muscle, ovary......, testis, soft tissue, and soft tissue (4-component), for the photon energy range 0.015-15 MeV and for penetration depths up to 40 mfp (mean free path). The chemical composition of human organs and tissues is seen to influence the energy absorption buildup factors. It is also found that the buildup factor...... of human organs and tissues changes significantly with the change of incident photon energy and effective atomic number, Zeff. These changes are due to the dominance of different photon interaction processes in different energy regions and different chemical compositions of human organs and tissues...

  3. Characteristics of nasal-associated lymphoid tissue (NALT) and nasal absorption capacity in chicken.

    Science.gov (United States)

    Kang, Haihong; Yan, Mengfei; Yu, Qinghua; Yang, Qian

    2013-01-01

    As the main mucosal immune inductive site of nasal cavity, nasal-associated lymphoid tissue (NALT) plays an important role in both antigen recognition and immune activation after intranasal immunization. However, the efficiency of intranasal vaccines is commonly restricted by the insufficient intake of antigen by the nasal mucosa, resulting from the nasal mucosal barrier and the nasal mucociliary clearance. The distribution of NALT and the characteristic of nasal cavity have already been described in humans and many laboratory rodents, while data about poultry are scarce. For this purpose, histological sections of the chicken nasal cavities were used to examine the anatomical structure and histological characteristics of nasal cavity. Besides, the absorptive capacity of chicken nasal mucosa was also studied using the materials with different particle size. Results showed that the NALT of chicken was located on the bottom of nasal septum and both sides of choanal cleft, which mainly consisted of second lymphoid follicle. A large number of lymphocytes were distributed under the mucosal epithelium of inferior nasal meatus. In addition, there were also diffuse lymphoid tissues located under the epithelium of the concha nasalis media and the walls of nasal cavity. The results of absorption experiment showed that the chicken nasal mucosa was capable to absorb trypan blue, OVA, and fluorescent latex particles. Inactivated avian influenza virus (IAIV) could be taken up by chicken nasal mucosa except for the stratified squamous epithelium sites located on the forepart of nasal cavity. The intake of IAIV by NALT was greater than that of the nasal mucosa covering on non-lymphoid tissue, which could be further enhanced after intranasal inoculation combined with sodium cholate or CpG DNA. The study on NALT and nasal absorptive capacity will be benefit for further understanding of immune mechanisms after nasal vaccination and development of nasal vaccines for poultry.

  4. Absorption and scattering coefficient dependence of laser-Doppler flowmetry models for large tissue volumes

    International Nuclear Information System (INIS)

    Binzoni, T; Leung, T S; Ruefenacht, D; Delpy, D T

    2006-01-01

    Based on quasi-elastic scattering theory (and random walk on a lattice approach), a model of laser-Doppler flowmetry (LDF) has been derived which can be applied to measurements in large tissue volumes (e.g. when the interoptode distance is >30 mm). The model holds for a semi-infinite medium and takes into account the transport-corrected scattering coefficient and the absorption coefficient of the tissue, and the scattering coefficient of the red blood cells. The model holds for anisotropic scattering and for multiple scattering of the photons by the moving scatterers of finite size. In particular, it has also been possible to take into account the simultaneous presence of both Brownian and pure translational movements. An analytical and simplified version of the model has also been derived and its validity investigated, for the case of measurements in human skeletal muscle tissue. It is shown that at large optode spacing it is possible to use the simplified model, taking into account only a 'mean' light pathlength, to predict the blood flow related parameters. It is also demonstrated that the 'classical' blood volume parameter, derived from LDF instruments, may not represent the actual blood volume variations when the investigated tissue volume is large. The simplified model does not need knowledge of the tissue optical parameters and thus should allow the development of very simple and cost-effective LDF hardware

  5. Solid tissue simulating phantoms having absorption at 970 nm for diffuse optics

    Science.gov (United States)

    Kennedy, Gordon T.; Lentsch, Griffin R.; Trieu, Brandon; Ponticorvo, Adrien; Saager, Rolf B.; Durkin, Anthony J.

    2017-07-01

    Tissue simulating phantoms can provide a valuable platform for quantitative evaluation of the performance of diffuse optical devices. While solid phantoms have been developed for applications related to characterizing exogenous fluorescence and intrinsic chromophores such as hemoglobin and melanin, we report the development of a poly(dimethylsiloxane) (PDMS) tissue phantom that mimics the spectral characteristics of tissue water. We have developed these phantoms to mimic different water fractions in tissue, with the purpose of testing new devices within the context of clinical applications such as burn wound triage. Compared to liquid phantoms, cured PDMS phantoms are easier to transport and use and have a longer usable life than gelatin-based phantoms. As silicone is hydrophobic, 9606 dye was used to mimic the optical absorption feature of water in the vicinity of 970 nm. Scattering properties are determined by adding titanium dioxide, which yields a wavelength-dependent scattering coefficient similar to that observed in tissue in the near-infrared. Phantom properties were characterized and validated using the techniques of inverse adding-doubling and spatial frequency domain imaging. Results presented here demonstrate that we can fabricate solid phantoms that can be used to simulate different water fractions.

  6. A neural network based approach for determination of optical scattering and absorption coefficients of biological tissue

    International Nuclear Information System (INIS)

    Warncke, D; Lewis, E; Leahy, M; Lochmann, S

    2009-01-01

    The propagation of light in biological tissue depends on the absorption and reduced scattering coefficient. The aim of this project is the determination of these two optical properties using spatially resolved reflectance measurements. The sensor system consists of five laser sources at different wavelengths, an optical fibre probe and five photodiodes. For these kinds of measurements it has been shown that an often used solution of the diffusion equation can not be applied. Therefore a neural network is being developed to extract the needed optical properties out of the reflectance data. Data sets for the training, validation and testing process are provided by Monte Carlo Simulations.

  7. Numerical simulation of ultrasound-thermotherapy combining nonlinear wave propagation with broadband soft-tissue absorption.

    Science.gov (United States)

    Ginter, S

    2000-07-01

    Ultrasound (US) thermotherapy is used to treat tumours, located deep in human tissue, by heat. It features by the application of high intensity focused ultrasound (HIFU), high local temperatures of about 90 degrees C and short treating time of a few seconds. Dosage of the therapy remains a problem. To get it under control, one has to know the heat source, i.e. the amount of absorbed US power, which shows nonlinear influences. Therefore, accurate simulations are essential. In this paper, an improved simulation model is introduced which enables accurate investigations of US thermotherapy. It combines nonlinear US propagation effects, which lead to generation of higher harmonics, with a broadband frequency-power law absorption typical for soft tissue. Only the combination of both provides a reliable calculation of the generated heat. Simulations show the influence of nonlinearities and broadband damping for different source signals on the absorbed US power density distribution.

  8. Spectroscopic method for determination of the absorption coefficient in brain tissue

    Science.gov (United States)

    Johansson, Johannes D.

    2010-09-01

    I use Monte Carlo simulations and phantom measurements to characterize a probe with adjacent optical fibres for diffuse reflectance spectroscopy during stereotactic surgery in the brain. Simulations and measurements have been fitted to a modified Beer-Lambert model for light transport in order to be able to quantify chromophore content based on clinically measured spectra in brain tissue. It was found that it is important to take the impact of the light absorption into account when calculating the apparent optical path length, lp, for the photons in order to get good estimates of the absorption coefficient, μa. The optical path length was found to be well fitted to the equation lp=a+b ln(Is)+c ln(μa)+d ln(Is)ln(μa), where Is is the reflected light intensity for scattering alone (i.e., zero absorption). Although coefficients a-d calculated in this study are specific to the probe used here, the general form of the equation should be applicable to similar probes.

  9. Specific absorption spectra of hemoglobin at different PO2 levels: potential noninvasive method to detect PO2 in tissues.

    Science.gov (United States)

    Liu, Peipei; Zhu, Zhirong; Zeng, Changchun; Nie, Guang

    2012-12-01

    Hemoglobin (Hb), as one of main components of blood, has a unique quaternary structure. Its release of oxygen is controlled by oxygen partial pressure (PO2). We investigate the specific spectroscopic changes in Hb under different PO2 levels to optimize clinical methods of measuring tissue PO2. The transmissivity of Hb under different PO2 levels is measured with a UV/Vis fiber optic spectrometer. Its plotted absorption spectral curve shows two high absorption peaks at 540 and 576 nm and an absorption valley at 560 nm when PO2 is higher than 100 mm Hg. The two high absorption peaks decrease gradually with a decrease in PO2, whereas the absorption valley at 560 nm increases. When PO2 decreases to approximately 0 mm Hg, the two high absorption peaks disappear completely, while the absorption valley has a hypochromic shift (8 to 10 nm) and forms a specific high absorption peak at approximately 550 nm. The same phenomena can be observed in visible reflectance spectra of finger-tip microcirculation. Specific changes in extinction coefficient and absorption spectra of Hb occur along with variations in PO2, which could be used to explain pathological changes caused by tissue hypoxia and for early detection of oxygen deficiency diseases in clinical monitoring.

  10. Determination of cadmium in bovine tissue by spectrophotometry of atomic absorption

    International Nuclear Information System (INIS)

    Gonzalez Zeledon, Mauricio

    2004-01-01

    The present work utilized the suggested method by Food Safety and Inspection Service (FSIS) for the analysis of cadmium in animal tissue, it was adapted by the Toxicology's Laboratory of MAG, where the project was organized. This method consist of a burning of sample and the instrumental analysis by means of the atomic absorption's technique. In the study there were determined parameters of carrying out of the analytical methodology, it was getting the following values: linearity : 0,020 -1,0 mg/L; homogeneity of the model: homoscedastic; limit of detection (LD) : 0,0049 mg/kg (4,9 μg/Kg); limit of quantification (LC): 0,016 μg/L (16 mg/kg); sensibility of calibration: 0,243 A * L/gm; analytical sensibility: 105 L/mg; instrumental repetitively: [es

  11. Scattering and absorption measurements of cervical tissues measures using low cost multi-spectral imaging

    Science.gov (United States)

    Bernat, Amir S.; Bar-Am, Kfir; Cataldo, Leigh; Bolton, Frank J.; Kahn, Bruce S.; Levitz, David

    2018-02-01

    Cervical cancer is a leading cause of death for women in low resource settings. In order to better detect cervical dysplasia, a low cost multi-spectral colposcope was developed utilizing low costs LEDs and an area scan camera. The device is capable of both traditional colposcopic imaging and multi-spectral image capture. Following initial bench testing, the device was deployed to a gynecology clinic where it was used to image patients in a colposcopy setting. Both traditional colposcopic images and spectral data from patients were uploaded to a cloud server for remote analysis. Multi-spectral imaging ( 30 second capture) took place before any clinical procedure; the standard of care was followed thereafter. If acetic acid was used in the standard of care, a post-acetowhitening colposcopic image was also captured. In analyzing the data, normal and abnormal regions were identified in the colposcopic images by an expert clinician. Spectral data were fit to a theoretical model based on diffusion theory, yielding information on scattering and absorption parameters. Data were grouped according to clinician labeling of the tissue, as well as any additional clinical test results available (Pap, HPV, biopsy). Altogether, N=20 patients were imaged in this study, with 9 of them abnormal. In comparing normal and abnormal regions of interest from patients, substantial differences were measured in blood content, while differences in oxygen saturation parameters were more subtle. These results suggest that optical measurements made using low cost spectral imaging systems can distinguish between normal and pathological tissues.

  12. The absorption, tissue distribution and excretion of Di-n-Octylten dichloride in rats

    International Nuclear Information System (INIS)

    Penninks, A.H.; Hilgers, Luuk; Seinen, Willem

    1987-01-01

    In this study the absorption, tissue distribution and excretion of 14 C-labeled di-n-octyltin dichloride ([ 14 C] DOTC) in rats were investigated after oral and intravenous (i.v.) administration with 6.3 mg [ 14 C] DOTC/Kg body weight, the relative tissue accumulation was found to be the same after oral and i.v. dosage. The highest amount of radioactivity was found in liver and kidney, and to a lesser degree in adrenal, pituitary and thyroid glands. The lowest activity was recovered from blood and brain. No selective accumulation was observed in thymus, although it has been reported that thymus atrophy is the most sensitive parameter of DOTC toxicity in rats. For all tissues a time dependent decrease in radioactivity was found, except for kidney. The excretion of radioactivity in feces and urine was determined after a single i.v. or oral dose of l.2 and 2 mg [ 14 C] DOTC, respectively. After i.v. administration most of the radioactivity was excreted in the feces which was characterized by a biphasic excretion pattern. In orally treated rats more than 80% of the radioactivity was already excreted in the feces during the first day after administration. This indicated that only a small part of the DOTC was absorbed, which was calculated to be approximately 20% of the dose. Similar half-life values of 8.3 and 8.9 days were obtained from the fecal excretion of radioactivity after the i.v. and oral administration, respectively. The urinary excretion of radioactivity appeared to be independent of the body burden, since the daily amount of radioactivity excreted in urine was nearly the same independent of the route of administration as well as the time after administration. 26 refs. (author)

  13. Heat dissipation by blood circulation and airway tissue heat absorption in a canine model of inhalational thermal injury.

    Science.gov (United States)

    Wan, Jiangbo; Zhang, Guoan; Qiu, Yuxuan; Wen, Chunquan; Fu, Tairan

    2016-05-01

    This study aimed to further explore heat dissipation by blood circulation and airway tissue heat absorption in an inhalational thermal injury model. Twelve adult male Beagle dogs were divided into four groups to inhale heated air for 10min: the control group, group I (100.5°C), group II (161.5°C), and group III (218°C). The relative humidity and temperature of the inhaled heated air were measured in the heating tube and trachea, as were blood temperatures and flow velocities in both common jugular veins. Formulas were used to calculate the total heat quantity reduction of the heated air, heat dissipation by the blood, and airway tissue heat absorption. The blood temperatures of both the common jugular veins increased by 0.29°C±0.07°C to 2.96°C±0.24°C and the mean blood flow volume after injury induction was about 1.30-1.74 times greater than before injury induction. The proportions of heat dissipated by the blood and airway tissue heat absorption were 68.92%±14.88% and 31.13%±14.87%, respectively. The heat dissipating ability of the blood circulation was demonstrated and improved upon along with tissue heat absorption owing to increased regional blood flow. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  14. Effects of heat stress on dynamic absorption process, tissue distribution and utilization efficiency of vitamin C in broilers

    International Nuclear Information System (INIS)

    Liu Guohua; Chen Guosheng; Cai Huiyi

    1998-01-01

    The experiment was conducted to determine the effects of heat stress on ascorbic acid nutritional physiology of broilers with radioisotope technology. 3 H-Vc was fed to broilers and then the blood, liver, kidney, breast muscle, and excreta were sampled to determine the dynamic absorption process, the tissue distribution and the utilization efficiency of vitamin C. The results indicated that the absorption, metabolism and mobilization of supplemented vitamin C in broilers with heat stress was faster than that in broilers without heat stress. However, the utilization efficiency of supplemented vitamin C in broilers with heat stress was not higher than that of broilers without heat stress

  15. Determination of concentration of heavy metals (Pb, Cd, Fe) in animal tissues using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    RAZAFINTSALAMA, V.T.

    2009-01-01

    Heavy metals are classified among the inorganic compounds. The latter type of metal is found in rocks, fertilizers, urban mud but may also originate from the atmospheric pollution. A particular characteristic of heavy metals is their bioaccumulation in the food chain. Therefore, lead and cadmium, which are classified as heavy metals may be easily found in animal products and can lead to food poisoning if their concentrations are higher than the maximum permissible values as requested by international agencies such as the c odex alimentarius . The values are set down and differ according to types of food for human consuption and the trading companies take action accordingly. Therefore, it is necessary to set up a quality control system through analytical laboratory measurements and testings. This study underlies the method of determination of lead, cadmium and iron in animal tissues by atomic absorption spectrometry. The results showed that the method is sensitive and reliable. For each analyte, the Z-score lies between -2 and 2, indicating that the method is working properly. The analytical results showed that: (i) only beef and chicken meats and beef liver contain lead [0,09μg.g - 1; 0,29μg.g - 1]. The limit value of 0,1μg.g - 1 is almost reached in beef and chicken meats, (ii) as far as cadmium is concerned, the five studied samples contain this analyte [0,02μg.g - 1; 0,9μg.g - 1]. Except the chicken liver of which the concentration (0,15μg.g - 1) exceeds the maximum permissible value (0,1μg.g - 1), the others are in conformity with the standards and appropriate to be consumed,(iii) iron is higher in the liver and kidney samples: beef liver 282mg.g - 1, chicken liver 250 mg.g - 1, pork kidney 247mg.g - 1. The study also showed that the calcium concentration in animal tissues is low and they can be classified as poor-calcium food. [fr

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

    Science.gov (United States)

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

    2015-12-01

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

  17. Detection of cancerous biological tissue areas by means of infrared absorption and SERS spectroscopy of intercellular fluid

    Science.gov (United States)

    Velicka, M.; Urboniene, V.; Ceponkus, J.; Pucetaite, M.; Jankevicius, F.; Sablinskas, V.

    2015-08-01

    We present a novel approach to the detection of cancerous kidney tissue areas by measuring vibrational spectra (IR absorption or SERS) of intercellular fluid taken from the tissue. The method is based on spectral analysis of cancerous and normal tissue areas in order to find specific spectral markers. The samples were prepared by sliding the kidney tissue over a substrate - surface of diamond ATR crystal in case of IR absorption or calcium fluoride optical window in case of SERS. For producing the SERS signal the dried fluid film was covered by silver nanoparticle colloidal solution. In order to suppress fluorescence background the measurements were performed in the NIR spectral region with the excitation wavelength of 1064 nm. The most significant spectral differences - spectral markers - were found in the region between 400 and 1800 cm-1, where spectral bands related to various vibrations of fatty acids, glycolipids and carbohydrates are located. Spectral markers in the IR and SERS spectra are different and the methods can complement each other. Both of them have potential to be used directly during surgery. Additionally, IR absorption spectroscopy in ATR mode can be combined with waveguide probe what makes this method usable in vivo.

  18. Energy absorption buildup factors for thermoluminescent dosimetric materials and their tissue equivalence

    DEFF Research Database (Denmark)

    Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

    2010-01-01

    Gamma ray energy-absorption buildup factors were computed using the five-parameter geometric progression (G-P) fitting formula for seven thermoluminescent dosimetric (TLD) materials in the energy range 0.015-15 MeV, and for penetration depths up to 40 mfp (mean free path). The generated energy-absorption...

  19. Oral absorption of peptides and nanoparticles across the human intestine: Opportunities, limitations and studies in human tissues.

    Science.gov (United States)

    Lundquist, P; Artursson, P

    2016-11-15

    In this contribution, we review the molecular and physiological barriers to oral delivery of peptides and nanoparticles. We discuss the opportunities and predictivity of various in vitro systems with special emphasis on human intestine in Ussing chambers. First, the molecular constraints to peptide absorption are discussed. Then the physiological barriers to peptide delivery are examined. These include the gastric and intestinal environment, the mucus barrier, tight junctions between epithelial cells, the enterocytes of the intestinal epithelium, and the subepithelial tissue. Recent data from human proteome studies are used to provide information about the protein expression profiles of the different physiological barriers to peptide and nanoparticle absorption. Strategies that have been employed to increase peptide absorption across each of the barriers are discussed. Special consideration is given to attempts at utilizing endogenous transcytotic pathways. To reliably translate in vitro data on peptide or nanoparticle permeability to the in vivo situation in a human subject, the in vitro experimental system needs to realistically capture the central aspects of the mentioned barriers. Therefore, characteristics of common in vitro cell culture systems are discussed and compared to those of human intestinal tissues. Attempts to use the cell and tissue models for in vitro-in vivo extrapolation are reviewed. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Reference-free determination of tissue absorption coefficient by modulation transfer function characterization in spatial frequency domain.

    Science.gov (United States)

    Chen, Weiting; Zhao, Huijuan; Li, Tongxin; Yan, Panpan; Zhao, Kuanxin; Qi, Caixia; Gao, Feng

    2017-08-08

    Spatial frequency domain (SFD) measurement allows rapid and non-contact wide-field imaging of the tissue optical properties, thus has become a potential tool for assessing physiological parameters and therapeutic responses during photodynamic therapy of skin diseases. The conventional SFD measurement requires a reference measurement within the same experimental scenario as that for a test one to calibrate mismatch between the real measurements and the model predictions. Due to the individual physical and geometrical differences among different tissues, organs and patients, an ideal reference measurement might be unavailable in clinical trials. To address this problem, we present a reference-free SFD determination of absorption coefficient that is based on the modulation transfer function (MTF) characterization. Instead of the absolute amplitude that is used in the conventional SFD approaches, we herein employ the MTF to characterize the propagation of the modulated lights in tissues. With such a dimensionless relative quantity, the measurements can be naturally corresponded to the model predictions without calibrating the illumination intensity. By constructing a three-dimensional database that portrays the MTF as a function of the optical properties (both the absorption coefficient μ a and the reduced scattering coefficient [Formula: see text]) and the spatial frequency, a look-up table approach or a least-square curve-fitting method is readily applied to recover the absorption coefficient from a single frequency or multiple frequencies, respectively. Simulation studies have verified the feasibility of the proposed reference-free method and evaluated its accuracy in the absorption recovery. Experimental validations have been performed on homogeneous tissue-mimicking phantoms with μ a ranging from 0.01 to 0.07 mm -1 and [Formula: see text] = 1.0 or 2.0 mm -1 . The results have shown maximum errors of 4.86 and 7% for [Formula: see text] = 1.0 mm -1 and

  1. Lack of energy policy clouds modest gain

    International Nuclear Information System (INIS)

    Floyd, J.G.

    1991-01-01

    This paper reports that, without a national policy some form of relief for the domestic side of the petroleum and natural gas industry, only modest improvement can be expected. Gas prices are expected to improve, but significant increases will not occur until 1995. Companies will shift their budgets toward exploration in foreign regions, and the greening of corporate America will continue

  2. In situ analyses of Ag speciation in tissues of cucumber and wheat using synchrotron-based X-ray absorption spectroscopy

    Data.gov (United States)

    U.S. Environmental Protection Agency — In situ analyses of Ag speciation in tissues of cucumber and wheat using synchrotron-based X-ray absorption spectroscopy showing spectral fitting and linear...

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

    Science.gov (United States)

    Fukutomi, Daichi; Ishii, Katsunori; Awazu, Kunio

    2016-04-01

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

  4. Strontium Localization in Bone Tissue Studied by X-Ray Absorption Spectroscopy

    DEFF Research Database (Denmark)

    Frankær, Christian Grundahl; Raffalt, Anders Christer; Ståhl, Kenny

    2014-01-01

    Strontium has recently been introduced as a pharmacological agent for the treatment and prevention of osteoporosis. We determined the localization of strontium incorporated into bone matrix from dogs treated with Sr malonate by X-ray absorption spectroscopy. A new approach for analyzing the X...... highly ordered sites, and at least 30 % is located at less ordered sites where only the first solvation shell is resolved, suggesting that strontium is sur- rounded by only oxygen atoms similar to Sr2? in solution. Strontium was furthermore shown to be absorbed in collagen in which it obtains a higher...

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

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2015-01-01

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

  6. Fragment emission from modestly excited nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Y. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Souza, R.T. de [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Chen, S.L. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Cornell, E.W. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Davin, B. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Fox, D. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Hamilton, T.M. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Mcdonald, K. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Tsang, M.B. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Glasmacher, T. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Dinius, J. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Gelbke, C.K. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Handzy, D.O. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility]|[Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Hsi, W.C.

    1996-07-08

    Fragment emission patterns occurring in nuclear systems of modest excitation are studied. Exclusive measurement of fragment emission in {sup 14}N+{sup 197}Au reactions at E/A=100, 130 and 156 MeV allows selection of central collisions where a single source dominates the decay. Low threshold measurement of IMF emission for these events allows investigation of the influence of detector threshold effects. The time scale of fragment emission is deduced using fragment-fragment velocity correlations. Comparisons are made to the predictions of a statistical decay model. (orig.).

  7. MODEST: A Tool for Geodesy and Astronomy

    Science.gov (United States)

    Sovers, Ojars J.; Jacobs, Christopher S.; Lanyi, Gabor E.

    2004-01-01

    Features of the JPL VLBI modeling and estimation software "MODEST" are reviewed. Its main advantages include thoroughly documented model physics, portability, and detailed error modeling. Two unique models are included: modeling of source structure and modeling of both spatial and temporal correlations in tropospheric delay noise. History of the code parallels the development of the astrometric and geodetic VLBI technique and the software retains many of the models implemented during its advancement. The code has been traceably maintained since the early 1980s, and will continue to be updated with recent IERS standards. Scripts are being developed to facilitate user-friendly data processing in the era of e-VLBI.

  8. FDTD chiral brain tissue model for specific absorption rate determination under radiation from mobile phones at 900 and 1800 MHz

    Energy Technology Data Exchange (ETDEWEB)

    Zamorano, M; Torres-Silva, H [Departamento de Electronica, Universidad de Tarapaca, 18 de Septiembre 2222, Arica (Chile)

    2006-04-07

    A new electrodynamics model formed by chiral bioplasma, which represents the human head inner structure and makes it possible to analyse its behaviour when it is irradiated by a microwave electromagnetic field from cellular phones, is presented. The finite-difference time-domain (FDTD) numeric technique is used, which allows simulation of the electromagnetic fields, deduced with Maxwell's equations, and allows us to simulate the specific absorption rate (SAR). The results show the SAR behaviour as a function of the input power and the chirality factor. In considering the chiral brain tissue in the proposed human head model, the two more important conclusions of our work are the following: (a) the absorption of the electromagnetic fields from cellular phones is stronger, so the SAR coefficient is higher than that using the classical model, when values of the chiral factor are of order of 1; (b) 'inverse skin effect' shows up at 1800 MHz, with respect to a 900 MHz source.

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

    Science.gov (United States)

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

    2008-07-01

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

  10. Determination of absorption changes from moments of distributions of times of flight of photons: optimization of measurement conditions for a two-layered tissue model.

    Science.gov (United States)

    Liebert, Adam; Wabnitz, Heidrun; Elster, Clemens

    2012-05-01

    Time-resolved near-infrared spectroscopy allows for depth-selective determination of absorption changes in the adult human head that facilitates separation between cerebral and extra-cerebral responses to brain activation. The aim of the present work is to analyze which combinations of moments of measured distributions of times of flight (DTOF) of photons and source-detector separations are optimal for the reconstruction of absorption changes in a two-layered tissue model corresponding to extra- and intra-cerebral compartments. To this end we calculated the standard deviations of the derived absorption changes in both layers by considering photon noise and a linear relation between the absorption changes and the DTOF moments. The results show that the standard deviation of the absorption change in the deeper (superficial) layer increases (decreases) with the thickness of the superficial layer. It is confirmed that for the deeper layer the use of higher moments, in particular the variance of the DTOF, leads to an improvement. For example, when measurements at four different source-detector separations between 8 and 35 mm are available and a realistic thickness of the upper layer of 12 mm is assumed, the inclusion of the change in mean time of flight, in addition to the change in attenuation, leads to a reduction of the standard deviation of the absorption change in the deeper tissue layer by a factor of 2.5. A reduction by another 4% can be achieved by additionally including the change in variance.

  11. Solid sampling-graphite furnace atomic absorption spectrometry for the direct determination of boron in plant tissues

    International Nuclear Information System (INIS)

    Resano, M.; Briceno, J.; Aramendia, M.; Belarra, M.A.

    2007-01-01

    In this work, the potential of graphite furnace atomic absorption spectrometry for the direct determination of B in plant tissues has been investigated. Three certified reference materials (NIST SRM 1570a spinach leaves, NIST SRM 1573a tomato leaves and BCR CRM 679 white cabbage) were selected for this study, the goal always being to develop a fast procedure that could be robust enough to provide a satisfactory performance for all of them, without any modifications in the conditions applied. The use of a suitable chemical modifier was found to be essential for obtaining a reproducible and sufficiently sensitive signal for boron solutions. In this regard, the performance of the combination of citric acid plus W (added as a permanent modifier) was noteworthy, resulting in well-defined signal profiles, a remarkable analyte stabilization during the pyrolysis step (up to 2100 deg. C) and minimal memory effects. This mixture of modifiers provided a good performance for the direct analysis of solid samples as well, but only if a suitable temperature program, favoring the interaction between the analyte and the modifiers, was used. Thus, such a temperature program, with two pyrolysis steps and the addition of NH 4 NO 3 in order to carry out the in situ sample microdigestion, was optimized. Under these conditions, the peak areas obtained for both solid samples and aqueous standards were comparable. Finally, the analysis of the samples was carried out. In all cases, a good agreement with the certified values was obtained, while R.S.D. values ranged between 6 and 10%. It can be concluded that the method proposed shows significant advantages for the determination of this complicated element in solid samples such as the use of aqueous standards for calibration, a high sample throughput (20 min per sample), a suitable limit of detection (0.3 μg g -1 ) and reduced risk of analyte losses and contamination

  12. Characterization of the electromagnetic near-field absorption in layered biological tissue in the frequency range from 30 MHz to 6000 MHz

    Energy Technology Data Exchange (ETDEWEB)

    Christ, A [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland); Samaras, T [Radiocommunications Laboratory, Aristotle University of Thessaloniki, 541 24 Thessaloniki (Greece); Klingenboeck, A [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland); Kuster, N [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr 43, 8004 Zurich (Switzerland)

    2006-10-07

    Currently, standards for the compliance testing of wireless devices are being extended to cover a wider frequency band and different usage patterns of mobile phones as well as of novel body-worn and handheld devices. As a consequence, not only the head but also strongly varying tissue distributions of the body are exposed to electromagnetic radiation. Several authors have reported changes in the SAR absorption of body tissue due to the presence of a low permittivity fat layer. This paper identifies two different effects which can lead to increased SAR in layered tissue in comparison to the SAR assessed using homogeneous tissue simulating liquid: (1) for larger distances between the tissue and the antenna, standing wave effects occur depending on the frequency and fat layer thickness. (2) In the very close near-field (distances approximately {lambda}/40), reactive E-field components lead to high local absorption in the skin. The latter effect occurs at lower frequencies and depends on the antenna type. Modification of the parameters of the homogeneous liquids cannot compensate for these effects. However, a conservative exposure estimate can be obtained by applying a multiplication factor between 1 and 3 to the values assessed using current experimental dosimetric techniques.

  13. The in vivo pharmacokinetics, tissue distribution and excretion investigation of mesaconine in rats and its in vitro intestinal absorption study using UPLC-MS/MS.

    Science.gov (United States)

    Liu, Xiuxiu; Tang, Minghai; Liu, Taohong; Wang, Chunyan; Tang, Qiaoxin; Xiao, Yaxin; Yang, Ruixin; Chao, Ruobing

    2017-12-27

    1. Mesaconine, an ingredient from Aconitum carmichaelii Debx., has been proven to have cardiac effect. For further development and better pharmacological elucidation, the in vivo process and intestinal absorptive behavior of mesaconine should be investigated comprehensively. 2. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitation of mesaconine in rat plasma, tissue homogenates, urine and feces to investigate the in vivo pharmacokinetic profiles, tissue distribution and excretion. The intestinal absorptive behavior of mesaconine was investigated using in vitro everted rat gut sac model. 3. Mesaconine was well distributed in tissues and a mass of unchanged form was detected in feces. It was difficultly absorbed into blood circulatory system after oral administration. The insufficient oral bioavailability of mesaconine may be mainly attributed to its low intestinal permeability due to a lack of lipophilicity. The absorption of mesaconine in rat's intestine is a first-order process with the passive diffusion mechanism.

  14. Effects of Long-term Use of Polyphenols on the Absorption and Tissue Distribution of Orally Administered Metformin and Atenolol in Rats

    Directory of Open Access Journals (Sweden)

    Saad Abdulrahman Hussain

    2013-06-01

    Full Text Available Aim: To evaluate the effect of long-term use of silibinin, epigallocatechin (ECGC, quercetin and rutin on the absorption and tissue distribution of metformin and atenolol. Materials and Methods: Thirty male rats were used, allocated into 5 groups and treated as follow: 1st group treated with olive oil and served as control; the other 4 groups were treated with either silibinin, EPGC, quercetin or rutin, administered orally as oily solutions for 30 days. At day 30, a 300mg/kg metformin and 50mg/kg atenolol were administered orally; 3.0 hrs later, the animals were sacrificed and blood samples, tissues of brain, kidney and liver were obtained for evaluation of the drugs level. Results: The polyphenols increased both serum and tissue levels of metformin compared with controls. This effect was relatively varied according to the structural differences among flavonoids. Conclusion: Long-term use of supraphysiological doses of flavonoids increase absorption of Zn, Cu and Fe and their tissue availability in brain, kidney and liver; this effect seems to be different with variations in structural features. [J Intercult Ethnopharmacol 2013; 2(3.000: 147-154

  15. Effect of insulin catheter wear-time on subcutaneous adipose tissue blood flow and insulin absorption in humans

    DEFF Research Database (Denmark)

    Clausen, Trine Schnedler; Kaastrup, Peter; Stallknecht, Bente

    2009-01-01

    blood flow (ATBF) and absorption of the rapid-acting insulin analog insulin aspart over a period of 4 days. METHODS: Teflon insulin catheters (Medtronic, Minneapolis, MN) were inserted into the abdominal SAT of 10 healthy men without diabetes (mean +/- SEM age, 23.0 +/- 1.1 years; body mass index, 22...... +/- 3 min on day 0 to 45 +/- 4 min on day 4 (P = 0.019). Neither peak plasma concentration nor area under the curve of insulin aspart changed significantly. CONCLUSIONS: Insertion of a Teflon insulin catheter into the SAT results in increased ATBF and faster absorption of insulin aspart in a period of 4...

  16. In vivo monitoring of seeds and plant-tissue water absorption using optical coherence tomography and optical coherence microscopy

    Science.gov (United States)

    Sapozhnikova, Veronika V.; Kutis, Irina S.; Kutis, Sergey D.; Kuranov, Roman V.; Gelikonov, Grigory V.; Shabanov, Dmitry V.; Kamensky, Vladislav A.

    2004-07-01

    First experimental results on OCT imaging of internal structure of plant tissues and in situ OCT monitoring of plant tissue regeneration at different water supply are reported. Experiments for evaluating OCT capabilities were performed on Tradescantia. The investigation of seeds swelling was performed on wheat seeds (Triticum L.), barley seeds (Hordeum L.), long-fibred flax seeds (Linum usitatissimum L.) and cucumber seeds (Cucumis sativus L.). These OCT images correlate with standard microscopy data from the same tissue regions. Seeds were exposed to a low-intensity physical factor-the pulsed gradient magnetic field (GMF) with pulse duration 0.1 s and maximum amplitude 5 mT (4 successive pulses during 0.4 s). OCT and OCM enable effective monitoring of fast reactions in plants and seeds at different water supply.

  17. Secreted phospholipase A(2) as a new enzymatic trigger mechanism for localised liposomal drug release and absorption in diseased tissue

    DEFF Research Database (Denmark)

    Davidsen, Jesper; Jørgensen, K.; Andresen, Thomas Lars

    2003-01-01

    Polymer-coated liposomes can act as versatile drug-delivery systems due to long vascular circulation time and passive targeting by leaky blood vessels in diseased tissue. We present an experimental model system illustrating a new principle for improved and programmable drug-delivery, which takes ...

  18. 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.

  19. Exogenous mineralization of hard tissues using photo-absorptive minerals and femto-second lasers; the case of dental enamel.

    Science.gov (United States)

    Anastasiou, A D; Strafford, S; Thomson, C L; Gardy, J; Edwards, T J; Malinowski, M; Hussain, S A; Metzger, N K; Hassanpour, A; Brown, C T A; Brown, A P; Duggal, M S; Jha, A

    2018-04-15

    A radical new methodology for the exogenous mineralization of hard tissues is demonstrated in the context of laser-biomaterials interaction. The proposed approach is based on the use of femtosecond pulsed lasers (fs) and Fe 3+ -doped calcium phosphate minerals (specifically in this work fluorapatite powder containing Fe 2 O 3 nanoparticles (NP)). A layer of the synthetic powder is applied to the surface of eroded bovine enamel and is irradiated with a fs laser (1040 nm wavelength, 1 GHz repetition rate, 150 fs pulse duration and 0.4 W average power). The Fe 2 O 3 NPs absorb the light and may act as thermal antennae, dissipating energy to the vicinal mineral phase. Such a photothermal process triggers the sintering and densification of the surrounding calcium phosphate crystals thereby forming a new, dense layer of typically ∼20 μm in thickness, which is bonded to the underlying surface of the natural enamel. The dispersed iron oxide NPs, ensure the localization of temperature excursion, minimizing collateral thermal damage to the surrounding natural tissue during laser irradiation. Simulated brushing trials (pH cycle and mechanical force) on the synthetic layer show that the sintered material is more acid resistant than the natural mineral of enamel. Furthermore, nano-indentation confirms that the hardness and Young's modulus of the new layers are significantly more closely matched to enamel than current restorative materials used in clinical dentistry. Although the results presented herein are exemplified in the context of bovine enamel restoration, the methodology may be more widely applicable to human enamel and other hard-tissue regenerative engineering. In this work we provide a new methodology for the mineralisation of dental hard tissues using femtosecond lasers and iron doped biomaterials. In particular, we demonstrate selective laser sintering of an iron doped fluorapatite on the surface of eroded enamel under low average power and mid

  20. Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

    Science.gov (United States)

    Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

    2017-06-01

    In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

  1. The dielectric properties of human pineal gland tissue and RF absorption due to wireless communication devices in the frequency range 400-1850 MHz

    International Nuclear Information System (INIS)

    Schmid, Gernot; Ueberbacher, Richard; Samaras, Theodoros; Tschabitscher, Manfred; Mazal, Peter R

    2007-01-01

    In order to enable a detailed analysis of radio frequency (RF) absorption in the human pineal gland, the dielectric properties of a sample of 20 freshly removed pineal glands were measured less than 20 h after death. Furthermore, a corresponding high resolution numerical model of the brain region surrounding the pineal gland was developed, based on a real human tissue sample. After inserting this model into a commercially available numerical head model, FDTD-based computations for exposure scenarios with generic models of handheld devices operated close to the head in the frequency range 400-1850 MHz were carried out. For typical output power values of real handheld mobile communication devices, the obtained results showed only very small amounts of absorbed RF power in the pineal gland when compared to SAR limits according to international safety standards. The highest absorption was found for the 400 MHz irradiation. In this case the RF power absorbed inside the pineal gland (organ mass 96 mg) was as low as 11 μW, when considering a device of 500 mW output power operated close to the ear. For typical mobile phone frequencies (900 MHz and 1850 MHz) and output power values (250 mW and 125 mW) the corresponding values of absorbed RF power in the pineal gland were found to be lower by a factor of 4.2 and 36, respectively. These results indicate that temperature-related biologically relevant effects on the pineal gland induced by the RF emissions of typical handheld mobile communication devices are unlikely

  2. Effects of organometallic chelates and inulin in diets for laying hens on Mn and Fe absorption coefficients and their content in egg and tissue

    Directory of Open Access Journals (Sweden)

    Cornescu Gabriela Maria

    2015-01-01

    Full Text Available The aim of this study was to evaluate effects of organic sources of manganese (Mn and iron (Fe and inulin in diets for laying hens on absorption of these minerals and their deposition in egg and tissue. The study was conducted on 90 Lohmann Brown laying hens in the period from 46-52 weeks of age, assigned to 3 groups with 30 hens/group and 3 hens/cage. The hens from the control group (C received a diet based on corn, rice bran and soybean meal with 16% of crude protein, as well as 60 mg Fe/kg and 71.9 mg Mn/kg of diet in form of inorganic salts. The formulation of the experimental diets (E1 and E2 differed from C group diet by the replacement of inorganic Fe and Mn salts by organometallic chelates of these elements, at a level of 25% lower than in the premix for group C. As source of inulin, group E1 diet also included 0.5% of dry Jerusalem artichoke, while group E2 diet included 0.5% of a product based on chicory root extract. At the end of the experiment, 6 hens from each group were slaughtered and blood serum and liver samples were collected and assayed for concentration of Fe and Mn. In the final week of the experiment, 18 eggs/group were collected for determination of Fe and Mn concentration in egg yolk. Concentration of measured blood serum parameters (haemoglobin, haematocrit, Fe and Mn in experimental (E groups were lower than in group C, but no significant differences (P>0.05 were registered. Absorption coefficients of Mn had higher values in E groups than in group C, with significant increase (P0.05 between groups were observed for Mn and Fe concentration in egg yolk.

  3. Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

    Science.gov (United States)

    Baldauf, Brian; Conti, Alberto

    2016-01-01

    The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The High Definition Space Telescope (HDST) envisioned for this mission would have an aperture >10 m, which is a larger payload than what can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. Space-based telescopes with large apertures will require major changes to system architectures.The Optical Telescope Assembly (OTA) for HDST is a primary mission cost driver. Enabling and affordable solutions for this next generation of large aperture space-based telescope are needed.This paper reports on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST), which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will also facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, and a testbed for new instruments. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Other key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal

  4. Shrub expansion in SW Greenland under modest regional warming

    DEFF Research Database (Denmark)

    Jørgensen, Rasmus Halfdan; Meilby, Henrik; Kollmann, Johannes

    2013-01-01

    Shrub expansion has been observed widely in tundra areas across the Arctic. This phenomenon has been partially attributed to increasing temperatures over the past century. However, relationships among shrub expansion, grazing, and human disturbance have been studied little. SW Greenland...... is a subarctic to low-arctic region with a long and complex land-use history and only modest temperature increases over the past 50 years (0.2 °C decade-1), but changes in shrub cover have not previously been studied in this region. We compiled historical photographs of vegetation in SW Greenland (1898......–1974) and repeated the photos in 2010 and 2011. Sixty-four photo pairs were cropped into 133 smaller units and classified by aspect, substrate stability, muskoxen grazing, and human disturbance. The photo material was evaluated by 22 experts with respect to changes in shrub cover, revealing a general increase across...

  5. Polymerization of nitrogen in cesium azide under modest pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoli, E-mail: use126126@126.com, E-mail: lijianfu@lyu.edu.cn [Institute of Condensed Matter Physics, Linyi University, Linyi 276005 (China); Beijing Computational Science Research Center, Beijing 100084 (China); State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); Li, Jianfu, E-mail: use126126@126.com, E-mail: lijianfu@lyu.edu.cn [Institute of Condensed Matter Physics, Linyi University, Linyi 276005 (China); Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Zhu, Hongyang [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); Chen, Li [Institute of Condensed Matter Physics, Linyi University, Linyi 276005 (China); Lin, Haiqing [Beijing Computational Science Research Center, Beijing 100084 (China)

    2014-07-28

    Alkali metal azides can be used as starting materials in the synthesis of polymeric nitrogen, a potential high-energy-density material. The structural evolutionary behaviors of nitrogen in CsN{sub 3} have been studied up to 200 GPa using particle swarm optimization structure search combining with density functional theory. Three stable new phases with C2/m, P2{sub 1}/m, and P-1 structure at pressure of 6, 13, and 51 GPa are identified for the first time. The phase transition to chain like structure (P-1 phase) occurs at a modest pressure 51 GPa, the azide ions N{sub 3}{sup −} (linear chains of three N atoms with covalent bonds and interact weakly with each other) begin to show remarkable polymeric N properties in the CsN{sub 3} system. Throughout the stable pressure range, the structure is metallic and consists of N atoms in sp{sup 2} hybridizations. Our study completes the structural evolution of CsN{sub 3} under pressure and reveals that the introduced Cs atoms are responsible for the decreased synthesis pressure comparing to pure molecular nitrogen under compression.

  6. Modestly increased use of colonoscopy when copayments are waived.

    Science.gov (United States)

    Khatami, Shabnam; Xuan, Lei; Roman, Rolando; Zhang, Song; McConnel, Charles; Halm, Ethan A; Gupta, Samir

    2012-07-01

    Colorectal cancer (CRC) screening with colonoscopy often requires expensive copayments from patients. The 2010 Patient Protection and Affordable Care Act mandated elimination of copayments for CRC screening, including colonoscopy, but little is known about the effects of copayment elimination on use. The University of Texas employee, retiree, and dependent health plan instituted and promoted a waiver of copayments for screening colonoscopies in fiscal year (FY) 2009; we examined the effects of removing cost sharing on colonoscopy use. We conducted a retrospective cohort study of 59,855 beneficiaries of the University of Texas employee, retiree, and dependent health plan, associated with 16 University of Texas health and nonhealth campuses, ages 50-64 years at any point in FYs 2002-2009 (267,191 person-years of follow-up evaluation). The primary outcome was colonoscopy incidence among individuals with no prior colonoscopy. We compared the age- and sex-standardized incidence ratios for colonoscopy in FY 2009 (after the copayment waiver) with the expected incidence for FY 2009, based on secular trends from years before the waiver. The annual incidence of colonoscopy increased to 9.5% after the copayment was waived, compared with an expected incidence of 8.0% (standardized incidence ratio, 1.18; 95% confidence interval, 1.14-1.23; P screening results in a statistically significant, but modest (1.5%), increase in use. Additional strategies beyond removing financial disincentives are needed to increase use of CRC screening. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

  7. Transport of radiolabelled glycoprotein to cell surface and lysosome-like bodies of absorptive cells in cultured small-intestinal tissue from normal subjects and patients with a lysosomal storage disease

    International Nuclear Information System (INIS)

    Ginsel, L.A.; Onderwater, J.J.M.; Daems, W.T.

    1979-01-01

    The transport of 3 H-fucose and 3 H-glucosamine-labelled glycoproteins in the absorptive cells of cultured human small-intestinal tissue was investigated with light- and electron-microscopical autoradiography. The findings showed that these glycoproteins were completed in the Golgi apparatus and transported in small vesicular structures to the apical cytoplasm of these cells. Since this material arrived in the cell coat on the microvilli and in the lysosome-like bodies simultaneously, a crinophagic function of these organelles in the regulation of the transport or secretion of cell-coat material was supported. In the absorptive cells of patients with fucosidosis or Hunter's type of lysosomal storage disease, a similar transport of cell-coat material to the lysosome-like bodies and a congenital defect of a lysosomal hydrolase normally involved in the degradation of cell-coat material, can explain the accumulation of this material in the dense bodies. (orig.) [de

  8. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  9. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  10. A Modest Critical Pedagogy for English as a Foreign Language Education

    Science.gov (United States)

    Kim, Mi Kyong; Pollard, Vikki Ann

    2017-01-01

    This paper uses the introduction of critical pedagogy to an English as a Foreign Language class in the Republic of Korea as a case study for a "modest critical pedagogy" (Tinning 2002). Focusing on the stress and resistances experienced during the introduction, we suggest a modest critical pedagogy that 1) makes the paradigm itself an…

  11. Folate absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Folate is the generic term given to numerous compounds of pteroic acid with glutamic acid. Knowledge of absorption is limited because of the complexities introduced by the variety of compounds and because of the inadequacy of investigational methods. Two assay methods are in use, namely microbiological and radioactive. Techniques used to study absorption include measurement of urinary excretion, serum concentration, faecal excretion, intestinal perfusion, and haematological response. It is probably necessary to test absorption of both pteroylmonoglutamic acid and one or more polyglutamates, and such tests would be facilitated by availability of synthesized compounds labelled with radioactive tracers at specifically selected sites. (author)

  12. Enhancement of the cytotoxicity of radiosensitizers by modest hyperthermia: the electron-affinity relationship

    Energy Technology Data Exchange (ETDEWEB)

    Rajaratnam, S.; Adams, G.E.; Stratford, I.J.; Clarke, C.

    1982-01-01

    The cytotoxicity of 3 electron-affinic radiosensitizers has been studied in Chinese hamster V-79 cells as a function of pH and modest hyperthermia. When equitoxic concentrations were used and temperature was increased from 34 to 41/sup 0/C metronidazole, the compound with the lowest electron affinity showed the greatest enhancement of hypoxic-cell toxicity, and nitrofurantoin, the compound with the highest electron affinity, the least. The results can be explained if the mechanisms of toxicity involves a redox reaction, since it would be expected that the least toxic compound (lowest electron affinity) would have the largest activation energy and hence the greatest temperature effect. This appears to hold for these 3 compounds. Experiments also showed that nitrofurantoin which exhibits no increase in toxicity when the temperature was increased from 37 to 41/sup 0/C at pH 7.4, showed an increase in toxicity for the same temperature change at the pH of 7.0 and 6.6. Under aerobic conditions only metronidazole showed significant toxicity at 41/sup 0/C, where the differential between aerobic and hypoxic cell toxicity was minimal, both at pH 7.4, and at the low pH values of 7.0 and 6.6. In the clinical setting there is evidence that tumor cells are at a lower pH than their surrounding normal tissues. Hypoxic-cell cytotoxicity is enhanced at low pH, and even further enhanced at low pH in combination with a temperature of 41/sup 0/C. However, this finding correlates conversely with electron affinity.

  13. Marketing modest fashion or fashioning modesty? HijUp Unveiled at London Fashion Week

    OpenAIRE

    Wilson, Jonathan

    2016-01-01

    The Indonesians came, they saw and we learned more about their spicy blend of fashion and fun, in the streets of London. Here’s a slice of what’s going on in the emerging global Modest Fashion scene.

  14. Narrative absorption

    DEFF Research Database (Denmark)

    Narrative Absorption brings together research from the social sciences and Humanities to solve a number of mysteries: Most of us will have had those moments, of being totally absorbed in a book, a movie, or computer game. Typically we do not have any idea about how we ended up in such a state. No...

  15. Characteristics of water absorption of beans

    OpenAIRE

    上中, 登紀子; 森, 孝夫; 豊沢, 功; Tokiko, Uenaka; Takao, Mori; Isao, Toyosawa

    2001-01-01

    Characteristics of water absorption of soybean, azuki bean and kidney beans (cv. Toramame and Taishokintoki) were investigated. The way of water absorption of soybean was different from that of other beans, because soybeans absorbed water from whole surface of seed coat immediately after the immersion. Azuki beans absorbed extremely slowly water from only strophiole, and then the water absorption in other tissue was induced by a certain amount of water absorption playing a role of trigger. Th...

  16. Absorptive products

    International Nuclear Information System (INIS)

    Assarsson, P.G.; King, P.A.

    1976-01-01

    Applications for hydrophile gels produced by the radiation induced cross-linking in aqueous solution of polyethylene oxide and starch, as described in Norwegian patent 133501 (INIS RN 281494), such as sanitary napkins (diapers) and sanitary towels, are discussed. The process itself is also discussed and results, expressed as the percentage of insoluble gel and its absorptive capacity for saline solution as functions of the ratio of polyethylene oxide to starch and the radiation dose, are presented. (JIW)

  17. THE CONCEPTIONS OF MODESTY AND MODEST DRESS IN THE SCRIPTURES OF ABRAHAMIC RELIGIONS

    OpenAIRE

    Dr. Zohreh. Sadatmoosavi; Wan Zailan Kamaruddin Wan Ali; Mohammad Ali Shokouhi

    2017-01-01

    Over the past two decades, the issue of modesty norms and women's wearing modest dress were widely discussed in academic and media discourse. Basically, modesty does not belong to any specific culture but today it has become the subject of intense scrutiny in the Islamic context. However, all scriptures of Abrahamic religions; the Qur‘an, Old and New Testaments have emphasized on the observing modesty as a moral and social virtue for both men and women and recommended modest dress for women d...

  18. Feasibility and safety of inducing modest hypothermia in awake patients with acute stroke through surface cooling

    DEFF Research Database (Denmark)

    Kammersgaard, L P; Rasmussen, B H; Jørgensen, Henrik Stig

    2000-01-01

    Hypothermia reduces neuronal damage in animal stroke models. Whether hypothermia is neuroprotective in patients with acute stroke remains to be clarified. In this case-control study, we evaluated the feasibility and safety of inducing modest hypothermia by a surface cooling method in awake patients...

  19. Modest Labor-Management Bargains Continue in 1984 Despite the Recovery.

    Science.gov (United States)

    Ruben, George

    1985-01-01

    Major collective bargaining agreements in 1984 resulted in modest settlements, due to concern about foreign competition, domestic deregulation, and inflation. Agreements occurred in the following industries: auto, soft coal, airlines, aircraft and aerospace, construction, petroleum refining, longshore industry, railroads, trucking, steel, West…

  20. Endothelin-1 exacerbates development of hypertension and atherosclerosis in modest insulin resistant syndrome

    International Nuclear Information System (INIS)

    Lin, Yan-Jie; Juan, Chi-Chang; Kwok, Ching-Fai; Hsu, Yung-Pei; Shih, Kuang-Chung; Chen, Chin-Chang; Ho, Low-Tone

    2015-01-01

    Endothelin-1 (ET-1) is known as potent vasoconstrictor, by virtue of its mitogenic effects, and may deteriorate the process of hypertension and atherosclerosis by aggravating hyperplasia and migration in VSMCs. Our previous study demonstrated that insulin infusion caused sequential induction of hyperinsulinemia, hyperendothelinemia, insulin resistance, and then hypertension in rats. However, the underlying mechanism of ET-1 interfere insulin signaling in VSMCs remains unclear. To characterize insulin signaling during modest insulin resistant syndrome, we established and monitored rats by feeding high fructose-diet (HFD) until high blood pressure and modest insulin resistance occurred. To explore the role of ET-1/ET A R during insulin resistance, ET A R expression, ET-1 binding, and insulin signaling were investigated in the HFD-fed rats and cultured A-10 VSMCs. Results showed that high blood pressure, tunica medial wall thickening, plasma ET-1 and insulin, and accompanied with modest insulin resistance without overweight and hyperglycemia occurred in early-stage HFD-fed rats. In the endothelium-denuded aorta from HFD-fed rats, ET A R expression, but not ET B R, and ET-1 binding in aorta were increased. Moreover, decreasing of insulin-induced Akt phosphorylation and increasing of insulin-induced ERK phosphorylation were observed in aorta during modest insulin resistance. Interestingly, in ET-1 pretreated VSMCs, the increment of insulin-induced Akt phosphorylation was decreased whereas the increment of insulin-induced ERK phosphorylation was increased. In addition, insulin potentiated ET-1-induced VSMCs migration and proliferation due to increasing ET-1 binding. ETAR antagonist reversed effects of ET-1 on insulin-induced signaling and VSMCs migration and proliferation. In summary, modest insulin resistance syndrome accompanied with hyperinsulinemia leading to the potentiation on ET-1-induced actions in aortic VSMCs. ET-1 via ET A R pathway suppressed insulin

  1. MODEST: a web-based design tool for oligonucleotide-mediated genome engineering and recombineering

    DEFF Research Database (Denmark)

    Bonde, Mads; Klausen, Michael Schantz; Anderson, Mads Valdemar

    2014-01-01

    Recombineering and multiplex automated genome engineering (MAGE) offer the possibility to rapidly modify multiple genomic or plasmid sites at high efficiencies. This enables efficient creation of genetic variants including both single mutants with specifically targeted modifications as well......, which confers the corresponding genetic change, is performed manually. To address these challenges, we have developed the MAGE Oligo Design Tool (MODEST). This web-based tool allows designing of MAGE oligos for (i) tuning translation rates by modifying the ribosomal binding site, (ii) generating...

  2. Endothelin-1 exacerbates development of hypertension and atherosclerosis in modest insulin resistant syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yan-Jie [Institute of Physiology, National Yang-Ming University, Taipei, Taiwan (China); Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan (China); Juan, Chi-Chang [Institute of Physiology, National Yang-Ming University, Taipei, Taiwan (China); Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Kwok, Ching-Fai [Division of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Hsu, Yung-Pei [Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan (China); Shih, Kuang-Chung [Division of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Chen, Chin-Chang [Institute of Physiology, National Yang-Ming University, Taipei, Taiwan (China); Ho, Low-Tone, E-mail: ltho@vghtpe.gov.tw [Institute of Physiology, National Yang-Ming University, Taipei, Taiwan (China); Division of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan (China); Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan (China)

    2015-05-08

    Endothelin-1 (ET-1) is known as potent vasoconstrictor, by virtue of its mitogenic effects, and may deteriorate the process of hypertension and atherosclerosis by aggravating hyperplasia and migration in VSMCs. Our previous study demonstrated that insulin infusion caused sequential induction of hyperinsulinemia, hyperendothelinemia, insulin resistance, and then hypertension in rats. However, the underlying mechanism of ET-1 interfere insulin signaling in VSMCs remains unclear. To characterize insulin signaling during modest insulin resistant syndrome, we established and monitored rats by feeding high fructose-diet (HFD) until high blood pressure and modest insulin resistance occurred. To explore the role of ET-1/ET{sub A}R during insulin resistance, ET{sub A}R expression, ET-1 binding, and insulin signaling were investigated in the HFD-fed rats and cultured A-10 VSMCs. Results showed that high blood pressure, tunica medial wall thickening, plasma ET-1 and insulin, and accompanied with modest insulin resistance without overweight and hyperglycemia occurred in early-stage HFD-fed rats. In the endothelium-denuded aorta from HFD-fed rats, ET{sub A}R expression, but not ET{sub B}R, and ET-1 binding in aorta were increased. Moreover, decreasing of insulin-induced Akt phosphorylation and increasing of insulin-induced ERK phosphorylation were observed in aorta during modest insulin resistance. Interestingly, in ET-1 pretreated VSMCs, the increment of insulin-induced Akt phosphorylation was decreased whereas the increment of insulin-induced ERK phosphorylation was increased. In addition, insulin potentiated ET-1-induced VSMCs migration and proliferation due to increasing ET-1 binding. ETAR antagonist reversed effects of ET-1 on insulin-induced signaling and VSMCs migration and proliferation. In summary, modest insulin resistance syndrome accompanied with hyperinsulinemia leading to the potentiation on ET-1-induced actions in aortic VSMCs. ET-1 via ET{sub A}R pathway

  3. Influence of Modest Endotoxemia on Postoperative Antithrombin Deficiency and Circulating Secretory Immunoglobulin A Levels

    Science.gov (United States)

    Fujita, Tetsuji; Imai, Takashi; Anazawa, Sadao

    2003-01-01

    Objective: To evaluate the influence of modest endotoxemia on postoperative antithrombin deficiency and cholestasis. Summary Background Data: It has not been determined whether endotoxin translocation in small amounts is a physiological phenomenon or whether it is a potential health hazard. Methods: Blood endotoxin, antithrombin III (ATIII), secretory immunoglobulin A (sIgA), which was selected as a marker of cholestasis, C-reactive protein (CRP), and α-1-antitrypsin (AAT) concentrations were measured from the 20 patients undergoing curative gastrectomy for gastric cancer preoperatively and postoperatively. Portal and systemic blood samples were taken for the analysis of endotoxin and interleukin-6 (IL-6) concentrations during surgery in these patients. Results: Although plasma endotoxin levels showed a significant increase during surgery, we did not find a correlation with ATIII, sIgA, CRP, and IL-6 levels. Systemic blood endotoxin levels during surgery correlated with a postoperative rise of serum AAT levels. Plasma ATIII levels transiently decreased on the first and third postoperative day, and sIgA levels were shown to increase on the seventh postoperative day. There was a weak relationship between the extent of postoperative endotoxemia and a reduction in ATIII concentrations. Conclusions: The influence of modest endotoxemia on postoperative antithrombin deficiency and cholestasis was limited, and increased translocational endotoxemia during abdominal surgery may be a physiological phenomenon to trigger off an acute-phase protein response. PMID:12894020

  4. A Modest Critical Pedagogy for English as a Foreign Language Education

    Directory of Open Access Journals (Sweden)

    Mi Kyong Kim

    2017-07-01

    Full Text Available This paper uses the introduction of critical pedagogy to an English as a Foreign Language class in the Republic of Korea as a case study for a “modest critical pedagogy” (Tinning 2002. Focusing on the stress and resistances experienced during the introduction, we suggest a modest critical pedagogy that 1 makes the paradigm itself an explicit part of the curriculum, 2 redefines the emancipatory aspect of critical pedagogy to focus on “what we expect students to do and what we as educators do” (Gore 1993, 154 and, 3 re-examines the facilitator role of teachers. We use the work of Michel Foucault (1983 to suggest a critical pedagogy that asks students and educators to examine previous experiences of education and the effects of these experiences upon a sense of self, that explores the limits of critical pedagogy in terms of a sense of self and that experiments with the possibility of going beyond these limits to develop a different sense of self. This shift to an examination of the effects of critical pedagogy re-defines its emancipatory potential.

  5. Absorption and Metabolism of Xanthophylls

    OpenAIRE

    Kotake-Nara, Eiichi; Nagao, Akihiko

    2011-01-01

    Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has bee...

  6. Absorption and Metabolism of Xanthophylls

    Directory of Open Access Journals (Sweden)

    Eiichi Kotake-Nara

    2011-06-01

    Full Text Available Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  7. Absorption and metabolism of xanthophylls.

    Science.gov (United States)

    Kotake-Nara, Eiichi; Nagao, Akihiko

    2011-01-01

    Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  8. Effect of a Modest Weight Loss in Normalizing Blood Pressure in Obese Subjects on Antihypertensive Drugs

    Directory of Open Access Journals (Sweden)

    Luisa Gilardini

    2016-07-01

    Full Text Available Objective: To assess the effect of a lifestyle intervention in lowering/normalizing blood pressure (BP levels in hypertensive (controlled or not obese patients. Methods: In this prospective observational study, 490 obese hypertensive patients, 389 controlled (BP Results: 18.9% of CH and 20.0% of UH were on ≥ 3 antihypertensive drugs. Weight change (average -4.9 ± 2.7% was independent of the antihypertensive drugs employed. Systolic BP (SBP decreased by 23 mm Hg and diastolic BP (DBP by 9 mm Hg, in patients with UH most of whom (89% normalized BP levels (in 49% after a weight loss Conclusion: Lifestyle interventions are useful for all obese hypertensive patients in most of whom a modest weight loss is sufficient to normalize BP levels avoiding the aggressive use of multiple antihypertensive drugs.

  9. Patients With Fibromyalgia Have Significant Autonomic Symptoms But Modest Autonomic Dysfunction.

    Science.gov (United States)

    Vincent, Ann; Whipple, Mary O; Low, Phillip A; Joyner, Michael; Hoskin, Tanya L

    2016-05-01

    Research suggests that disordered autonomic function may be one contributor to deconditioning reported in fibromyalgia; however, no study to date has assessed these variables simultaneously with comprehensive measures. To characterize physical fitness and autonomic function with the use of clinically validated measures and subjective questionnaires between patients with fibromyalgia and healthy controls. Cross-sectional, observational, controlled study. Community sample of patients with fibromyalgia and healthy controls. Thirty patients with fibromyalgia and 30 pain and fatigue-free controls. Participants completed a battery of self-report questionnaires and physiological measures, including clinically validated measures of physical fitness and autonomic function. Six-Minute Walk Test total distance, maximal oxygen consumption as assessed by cardiopulmonary exercise testing, total steps using activity monitor, Composite Autonomic Scoring Scale as assessed by Autonomic Reflex Screen, total metabolic equivalents per week using the International Physical Activity Questionnaire, and self-reported autonomic symptoms via the 31-item Composite Autonomic Symptom Score questionnaire. Autonomic function, as assessed by self-report, was significantly different between patients and controls (P physical activity was not significantly different between patients and controls (P = .99), but levels of moderate and vigorous physical activity as measured by actigraphy were significantly lower in patients (P = .012 and P = .047, respectively). Exercise capacity (6-Minute Walk) was poorer in patients (P = .0006), but there was no significant difference in maximal volume of oxygen consumption (P = .07). Patients with fibromyalgia report more severe symptoms across all domains, including physical activity and autonomic symptoms, compared with controls, but the objective assessments only showed modest differences. Our results suggest that patients with widespread subjective impairment of

  10. 51Cr-ethylenediaminetetraacetic acid absorption test

    International Nuclear Information System (INIS)

    Aabakken, L.

    1989-01-01

    The 51 Cr-ethylenediaminetetraacetic acid (EDTA) absorption test was evaluated in 83 healthy, male volunteers. Base-line 24 h excretion after peroral administration ranged from 0.88% to 7.96%, with a higher median absorption than reported by most authors (2.45%). However, the reproducibility and stability of the method and the reproducibility of the results were satisfactory. Urinary excretion after intraduodenal installation (n=18) was comparable to that seen after peroral test dose administration, indicating a limited significance of gastric 51 Cr-EDTA absorption under normal conditions. In 16 subjects a single intake of alcohol immediately before the test gave a modest and short-lasting increase in 51 Cr-EDTA absorption. No correlation was seen to body mass index, creatinine clearance, urinary volume, or small-bowel transit time, possibly reducing the number of confounding factors in the evaluation of absorption data. A small but significant negative correlation was, however, found to body surface area and age

  11. Using a higher criticism statistic to detect modest effects in a genome-wide study of rheumatoid arthritis

    Science.gov (United States)

    2009-01-01

    In high-dimensional studies such as genome-wide association studies, the correction for multiple testing in order to control total type I error results in decreased power to detect modest effects. We present a new analytical approach based on the higher criticism statistic that allows identification of the presence of modest effects. We apply our method to the genome-wide study of rheumatoid arthritis provided in the Genetic Analysis Workshop 16 Problem 1 data set. There is evidence for unknown bias in this study that could be explained by the presence of undetected modest effects. We compared the asymptotic and empirical thresholds for the higher criticism statistic. Using the asymptotic threshold we detected the presence of modest effects genome-wide. We also detected modest effects using 90th percentile of the empirical null distribution as a threshold; however, there is no such evidence when the 95th and 99th percentiles were used. While the higher criticism method suggests that there is some evidence for modest effects, interpreting individual single-nucleotide polymorphisms with significant higher criticism statistics is of undermined value. The goal of higher criticism is to alert the researcher that genetic effects remain to be discovered and to promote the use of more targeted and powerful studies to detect the remaining effects. PMID:20018032

  12. Orally administered indomethacin acutely reduces cellular prion protein in the small intestine and modestly increases survival of mice exposed to infectious prions.

    Science.gov (United States)

    Martin, Gary R; Sharkey, Keith A; Jirik, Frank R

    2015-05-01

    The oral uptake of infectious prions represents a common way to acquire a prion disease; thus, host factors, such as gut inflammation and intestinal "leakiness", have the potential to influence infectivity. For example, the ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs) is known to induce intestinal inflammation and increase intestinal permeability. Previously, we reported that normal cellular prion protein (PrP(C)) expression was increased in experimental colitis, and since the level of PrP(C) expressed is a determinant of prion disease propagation, we hypothesized that NSAID administration prior to the oral inoculation of mice with infectious prions would increase intestinal PrP(C) expression and accelerate the onset of neurological disease. In the long-term experiments, one group of mice was gavaged with indomethacin, followed by a second gavage with brain homogenate containing mouse-adapted scrapie (ME7). Control mice received ME7 brain homogenate alone. Brain and splenic tissues were harvested at several time points for immunoblotting, including at the onset of clinical signs of disease. In a second series of experiments, mice were gavaged with indomethacin to assess the acute effects of this treatment on intestinal PrP(C) expression. Acutely, NSAID treatment reduced intestinal PrP(C) expression, and chronically, there was a modest delay in the onset of neurological disease. In contrast to our hypothesis, brief exposure to an NSAID decreased intestinal PrP(C) expression and led to a modest survival advantage following oral ingestion of infectious prions.

  13. LACK OF INFLATED RADII FOR KEPLER GIANT PLANET CANDIDATES RECEIVING MODEST STELLAR IRRADIATION

    International Nuclear Information System (INIS)

    Demory, Brice-Olivier; Seager, Sara

    2011-01-01

    The most irradiated transiting hot Jupiters are characterized by anomalously inflated radii, sometimes exceeding Jupiter's size by more than 60%. While different theoretical explanations have been applied, none of them provide a universal resolution to this observation, despite significant progress in the past years. We refine the photometric transit light curve analysis of 115 Kepler giant planet candidates based on public Q0-Q2 photometry. We find that 14% of them are likely false positives, based on their secondary eclipse depth. We report on planet radii versus stellar flux. We find an increase in planet radii with increased stellar irradiation for the Kepler giant planet candidates, in good agreement with existing hot Jupiter systems. We find that in the case of modest irradiation received from the stellar host, giant planets do not have inflated radii, and appear to have radii independent of the host star incident flux. This finding suggests that the physical mechanisms inflating hot Jupiters become ineffective below a given orbit-averaged stellar irradiation level of ∼2 × 10 8 erg s –1 cm –2 .

  14. Social networking strategies that aim to reduce obesity have achieved significant although modest results.

    Science.gov (United States)

    Ashrafian, Hutan; Toma, Tania; Harling, Leanne; Kerr, Karen; Athanasiou, Thanos; Darzi, Ara

    2014-09-01

    The global epidemic of obesity continues to escalate. Obesity accounts for an increasing proportion of the international socioeconomic burden of noncommunicable disease. Online social networking services provide an effective medium through which information may be exchanged between obese and overweight patients and their health care providers, potentially contributing to superior weight-loss outcomes. We performed a systematic review and meta-analysis to assess the role of these services in modifying body mass index (BMI). Our analysis of twelve studies found that interventions using social networking services produced a modest but significant 0.64 percent reduction in BMI from baseline for the 941 people who participated in the studies' interventions. We recommend that social networking services that target obesity should be the subject of further clinical trials. Additionally, we recommend that policy makers adopt reforms that promote the use of anti-obesity social networking services, facilitate multistakeholder partnerships in such services, and create a supportive environment to confront obesity and its associated noncommunicable diseases. Project HOPE—The People-to-People Health Foundation, Inc.

  15. Effect of modest caloric restriction on oxidative stress in women, a randomized trial.

    Science.gov (United States)

    Buchowski, Maciej S; Hongu, Nobuko; Acra, Sari; Wang, Li; Warolin, Joshua; Roberts, L Jackson

    2012-01-01

    It is not established to what extent caloric intake must be reduced to lower oxidative stress in humans. The aim of this study was to determine the effect of short-term, moderate caloric restriction on markers of oxidative stress and inflammation in overweight and obese premenopausal women. Randomized trial comparison of 25% caloric restriction (CR) or control diet in 40 overweight or obese women (body mass index 32±5.8 kg/m(2)) observed for 28 days and followed for the next 90 days. Weight, anthropometry, validated markers of oxidative stress (F(2)-isoprostane) and inflammation (C-reactive protein), adipokines, hormones, lipids, interleukins, and blood pressure were assessed at baseline, during the intervention, and at follow-up. Baseline median F(2)-isoprostane concentration (57.0, IQR = 40.5-79.5) in the CR group was 1.75-fold above average range for normal weight women (32.5 pg/ml). After starting of the caloric restriction diet, F(2)-isoprostane levels fell rapidly in the CR group, reaching statistical difference from the control group by day 5 (median 33.5, IQR = 26.0-48.0, Prestriction diet. Three months after resuming a habitual diet, concentrations of F(2)-isoprostane returned to baseline elevated levels in ∼80% of the women. Oxidative stress can be rapidly reduced and sustained through a modest reduction in caloric intake suggesting potential health benefits in overweight and obese women. Clinicaltrials.gov NCT00808275.

  16. The modest environmental relief resulting from the transition to a service economy

    International Nuclear Information System (INIS)

    Henriques, Sofia Teives; Kander, Astrid

    2010-01-01

    A service transition is supposed to lead to the decline of energy intensity (energy/GDP). We argue that this interpretation is overly optimistic because the shift to a service economy is somewhat of an illusion in terms of real production. Several recent studies of structural effects on energy intensity have made the error of using sector shares in current prices, combined with GDP in constant prices, which is inconsistent and ignores the different behaviour of prices across sectors. We use the more correct method of sector shares in constant prices, and make an attempt to single out the effect from the real service transition by using two complementary methods: shift share analyses in current and constant prices, and Logarithmic Mean Divisia Index (LMDI) for 10 developed and 3 emerging economies. A service transition is rather modest in real terms. The major driver of the decline in energy intensity rests within the manufacturing sector. Meanwhile, the transition to a service sector had a small downward impact on energy intensity in 7 of the developed countries (and no impact in the others). For emerging economies like Brazil, Mexico and India, it is the residential sector that drives energy intensity down because of the declining share of this sector as the formal economy grows, and as a consequence of switching to more efficient fuels. (author)

  17. A Multi-ringed, Modestly Inclined Protoplanetary Disk around AA Tau

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, Ryan A.; Öberg, Karin I.; Andrews, Sean M.; MacGregor, Meredith A., E-mail: rloomis@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2017-05-01

    AA Tau is the archetype for a class of stars with a peculiar periodic photometric variability thought to be related to a warped inner disk structure with a nearly edge-on viewing geometry. We present high resolution (∼0.″2) ALMA observations of the 0.87 and 1.3 mm dust continuum emission from the disk around AA Tau. These data reveal an evenly spaced three-ringed emission structure, with distinct peaks at 0.″34, 0.″66, and 0.″99, all viewed at a modest inclination of 59.°1 ± 0.°3 (decidedly not edge-on). In addition to this ringed substructure, we find non-axisymmetric features, including a “bridge” of emission that connects opposite sides of the innermost ring. We speculate on the nature of this “bridge” in light of accompanying observations of HCO{sup +} and {sup 13}CO ( J = 3–2) line emission. The HCO{sup +} emission is bright interior to the innermost dust ring, with a projected velocity field that appears rotated with respect to the resolved disk geometry, indicating the presence of a warp or inward radial flow. We suggest that the continuum bridge and HCO{sup +} line kinematics could originate from gap-crossing accretion streams, which may be responsible for the long-duration dimming of optical light from AA Tau.

  18. A Multi-ringed, Modestly Inclined Protoplanetary Disk around AA Tau

    International Nuclear Information System (INIS)

    Loomis, Ryan A.; Öberg, Karin I.; Andrews, Sean M.; MacGregor, Meredith A.

    2017-01-01

    AA Tau is the archetype for a class of stars with a peculiar periodic photometric variability thought to be related to a warped inner disk structure with a nearly edge-on viewing geometry. We present high resolution (∼0.″2) ALMA observations of the 0.87 and 1.3 mm dust continuum emission from the disk around AA Tau. These data reveal an evenly spaced three-ringed emission structure, with distinct peaks at 0.″34, 0.″66, and 0.″99, all viewed at a modest inclination of 59.°1 ± 0.°3 (decidedly not edge-on). In addition to this ringed substructure, we find non-axisymmetric features, including a “bridge” of emission that connects opposite sides of the innermost ring. We speculate on the nature of this “bridge” in light of accompanying observations of HCO + and 13 CO ( J = 3–2) line emission. The HCO + emission is bright interior to the innermost dust ring, with a projected velocity field that appears rotated with respect to the resolved disk geometry, indicating the presence of a warp or inward radial flow. We suggest that the continuum bridge and HCO + line kinematics could originate from gap-crossing accretion streams, which may be responsible for the long-duration dimming of optical light from AA Tau.

  19. D-xylose absorption

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003606.htm D-xylose absorption To use the sharing features on this page, please enable JavaScript. D-xylose absorption is a laboratory test to determine ...

  20. Absorption and excretion tests

    International Nuclear Information System (INIS)

    Berberich, R.

    1988-01-01

    The absorption and excretion of radiopharmaceuticals is still of interest in diagnostic investigations of nuclear medicine. In this paper the most common methods of measuring absorption and excretion are described. The performance of the different tests and their standard values are discussed. More over the basic possibilities of measuring absorption and excretion including the needed measurement equipments are presented. (orig.) [de

  1. Effect of a Modest Weight Loss in Normalizing Blood Pressure in Obese Subjects on Antihypertensive Drugs.

    Science.gov (United States)

    Gilardini, Luisa; Redaelli, Gabriella; Croci, Marina; Conti, Antonio; Pasqualinotto, Lucia; Invitti, Cecilia

    2016-01-01

    To assess the effect of a lifestyle intervention in lowering/normalizing blood pressure (BP) levels in hypertensive (controlled or not) obese patients. In this prospective observational study, 490 obese hypertensive patients, 389 controlled (BP < 140/90 mm Hg; CH) and 101 uncontrolled (BP ≥ 140/90 mm Hg; UH) attended a 3-month lifestyle intervention. Before and after the intervention we assessed weight, waist circumference, fat mass, BP, metabolic and renal variables, and physical activity. A multivariate regression model was used to determine the predictors of BP changes. 18.9% of CH and 20.0% of UH were on ≥ 3 antihypertensive drugs. Weight change (average -4.9 ± 2.7%) was independent of the antihypertensive drugs employed. Systolic BP (SBP) decreased by 23 mm Hg and diastolic BP (DBP) by 9 mm Hg, in patients with UH most of whom (89%) normalized BP levels (in 49% after a weight loss < 5%). Age, gender, whole and central obesity, concomitance of type 2 diabetes, chronic renal disease, physical activity intensification, and pharmacological therapy did not affect BP lowering. In the regression analysis with SBP change as dependent variable, weight reduction (β = 0.523, p = 0.005) and group (UH vs. CH, β = -19.40, p = 0.0005) remained associated with SBP reduction. When DBP change was entered as dependent variable, baseline uric acid remained associated with DBP reduction (β = 0.824, p < 0.05). Lifestyle interventions are useful for all obese hypertensive patients in most of whom a modest weight loss is sufficient to normalize BP levels avoiding the aggressive use of multiple antihypertensive drugs. © 2016 The Author(s) Published by S. Karger GmbH, Freiburg.

  2. Plasma Irisin Modestly Increases during Moderate and High-Intensity Afternoon Exercise in Obese Females

    Science.gov (United States)

    Winn, Nathan C.; Grunewald, Zachary I.; Liu, Ying; Heden, Timothy D.; Nyhoff, Lauren M.; Kanaley, Jill A.

    2017-01-01

    Background and Purpose Irisin is an exercise-responsive myokine that has been proposed to exert anti-obesity benefits; yet its response during exercise in obese women is not described. This study characterized plasma irisin levels during a single bout of afternoon isocaloric-exercise of different intensities (moderate- vs high-intensity) in obese females. Methods Eleven obese females participated in 3 randomized study days beginning at 1600h: 1) no exercise (NoEx), 2) moderate exercise (ModEx; 55%VO2max) and 3) high intensity interval exercise (IntEx; 4 min (80%VO2max)/3 min (50% VO2max). Frequent blood samples were analyzed for glucose and lactate (whole-blood), and insulin, c-peptide, glucagon, and irisin (plasma) throughout 190 min of testing. Results Plasma irisin increased above baseline during ModEx and IntEx (P0.05). Peak irisin levels during ModEx and IntEx exercise were 11.9± 3.4% and 12.3 ± 4.1% relative to baseline (Pexercise intensities (P>0.05). Irisin levels remained elevated above resting for 125 minutes post-exercise during ModEx, whereas levels returned to baseline within 15 minutes post-exercise during IntEx. Similarly, no associations were found between plasma irisin levels and circulating lactate, glucose, insulin, c-peptide, or glucagon among study days (P>0.05). However, there was an inverse association between basal irisin and lean mass (r = -0.70, P = 0.01). Conclusion A single bout of moderate and high intensity afternoon exercise induces modest increases in circulating irisin concentrations during exercise; however the regulation post-exercise appears to be dimorphic between exercise intensity in obese females. Future studies are needed to compare morning and afternoon exercise on irisin secretion. PMID:28125733

  3. Calcium absorption and achlorhydria

    International Nuclear Information System (INIS)

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  4. [The percutaneous absorption of diclofenac].

    Science.gov (United States)

    Riess, W; Schmid, K; Botta, L; Kobayashi, K; Moppert, J; Schneider, W; Sioufi, A; Strusberg, A; Tomasi, M

    1986-07-01

    The percutaneous absorption of diclofenac diethylammonium 1.16% (w/w) in a combination of emulsion cream and gel (Voltaren Emulgel) and of diclofenac sodium 1% (w/w) in a cream formulation (Voltaren cream) was investigated in guinea-pig, rabbit and man. The percutaneous absorption of diclofenac sodium in guinea-pig was 3 to 6% of the dose when the cream formulation in doses of 320, 100 or 40 mg was applied on 10 cm2 of occluded skin and left in place for 6 h. The transdermal delivery of 14C-labelled diclofenac yielded plateau plasma concentrations of radiotracer from 1.5 h after application until removal of the residual cream. Subsequently the steady state drug depots in the skin and muscle tissue were depleted promptly. During daily administration the steady state levels in the muscle tissue in proximity to the application site were about 3 times higher than in distant muscle tissue. By topical application on knee joints of rabbits diclofenac penetrated into the patellar ligament, the adipose corpus and the synovial fluid. In man the percutaneous absorption was 6% of the dose when the Emulgel formulation was spread by 5 mg/cm2 and left for 12 h on non-occluded skin. The pattern of metabolites of diclofenac in human urine was the same after topical and oral administration. In man, upon daily topical administration of 3 times 2.5 g cream formulation (10 mg/cm2) the diclofenac steady state plasma levels were 20 to 40 nmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  6. Absorption heat pumps

    International Nuclear Information System (INIS)

    Formigoni, C.

    1998-01-01

    A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

  7. Special Issue: The 7th International Conference on Modification, Degradation and Stabilisation of polymers (MoDeSt)

    Czech Academy of Sciences Publication Activity Database

    Al-Malaika, S. (ed.); George, G. (ed.); Pilař, Jan (ed.)

    2013-01-01

    Roč. 98, č. 12 (2013) ISSN 0141-3910. [MoDeSt Conference /7./. Prague, 02.09.2012-06.09.2012] Institutional support: RVO:61389013 Keywords : stabilization of polymer systems * polymer nanoparticles * fire retardant polymers Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.633, year: 2013

  8. Research Managers at Jamaica's National University Are Strategically Deploying a Modest Research Development Fund in Support of Impactful Research

    Science.gov (United States)

    Ivey, Paul W.; Henry, Martin

    2016-01-01

    The purpose of this paper is to highlight, using examples, how the University of Technology, Jamaica (UTech, Jamaica) is strategically using a modest internal research development fund, which is managed by the research managers in its research and innovation management office, to support impactful research projects. Critical reflection and the…

  9. Insulin analogues with improved absorption characteristics.

    Science.gov (United States)

    Brange, J; Hansen, J F; Langkjaer, L; Markussen, J; Ribel, U; Sørensen, A R

    1992-01-01

    The insulin preparations available today are not ideal for therapy as s.c. injection does not provide a physiological insulin profile. With the aim to improve the absorption properties recombinant DNA technology has been utilized to design novel insulin molecules with changed physico-chemical characteristics and hence altered subcutaneous absorption kinetics. Soluble, long-acting human insulin analogues in which the isoelectric point has been increased from 5.4 to approx. 7 are absorbed very slowly, providing a more constant basal insulin delivery with lower day-to-day variation than present protracted preparations. In addition they have better storage stability. Rapid-acting human insulin analogues with largely reduced self-association are absorbed substantially faster from subcutaneous tissue than current regular insulin and thus are better suited for bolus injection. The absorption kinetics of these analogues have been able to explain the mechanism behind the dose effect on insulin absorption rate.

  10. Solar absorption surface panel

    Science.gov (United States)

    Santala, Teuvo J.

    1978-01-01

    A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

  11. Nutrition and magnesium absorption

    NARCIS (Netherlands)

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true

  12. Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Loos-Vollebregt, M.T.C. de.

    1980-01-01

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  13. Self-Esteem, Modest Responding, Sandbagging, Fear of Negative Evaluation, and Self-Concept Clarity in Japan

    OpenAIRE

    Brown, R. A.

    2006-01-01

    Japanese people typically score low on explicit measures of self-esteem, such as the Rosenberg selfesteem scale. Modest self-presentation has been offered as a possible explanation. The present research provides evidence that modesty is indeed implicated, but is not solely responsible for low Japanese self-esteem scores. Samples of 449 and 122 Japanese college students participated. Results indicate that modesty is a highly valued characteristic, while immodesty is disdained and that modesty,...

  14. Quasar Absorption Studies

    Science.gov (United States)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  15. Uranium absorption study pile

    International Nuclear Information System (INIS)

    Raievski, V.; Sautiez, B.

    1959-01-01

    The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF 3 counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10 -6 boron per gr. of uranium) or better. (author) [fr

  16. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-06-01

    The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented

  17. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  18. Zeeman atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Hadeishi, T.; McLaughlin, R.

    1978-08-01

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given

  19. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  20. Comment on resonant absorption

    International Nuclear Information System (INIS)

    Hammerling, P.

    1977-01-01

    An average over angles of incidence of the usual resonant absorption function is presented. This form is appropriate under experimental conditions where the angles of incidence vary greatly and in an unknown manner. For comparison a lens-ellipsoidal mirror illumination system with a known longitudinal aberration is considered. In the latter example the angles of incidence are readily obtained and the resulting resonance absorption function evaluated. The associated fields are calculated in a similar fashion. (author)

  1. Optical absorption measurement system

    International Nuclear Information System (INIS)

    Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

    1989-01-01

    This patent describes a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature

  2. Exercise, Insulin Absorption Rates, and Artificial Pancreas Control

    Science.gov (United States)

    Frank, Spencer; Hinshaw, Ling; Basu, Rita; Basu, Ananda; Szeri, Andrew J.

    2016-11-01

    Type 1 Diabetes is characterized by an inability of a person to endogenously produce the hormone insulin. Because of this, insulin must be injected - usually subcutaneously. The size of the injected dose and the rate at which the dose reaches the circulatory system have a profound effect on the ability to control glucose excursions, and therefore control of diabetes. However, insulin absorption rates via subcutaneous injection are variable and depend on a number of factors including tissue perfusion, physical activity (vasodilation, increased capillary throughput), and other tissue geometric and physical properties. Exercise may also have a sizeable effect on the rate of insulin absorption, which can potentially lead to dangerous glucose levels. Insulin-dosing algorithms, as implemented in an artificial pancreas controller, should account accurately for absorption rate variability and exercise effects on insulin absorption. The aforementioned factors affecting insulin absorption will be discussed within the context of both fluid mechanics and data driven modeling approaches.

  3. Morphology of urethral tissues

    Science.gov (United States)

    Müller, Bert; Schulz, Georg; Herzen, Julia; Mushkolaj, Shpend; Bormann, Therese; Beckmann, Felix; Püschel, Klaus

    2010-09-01

    Micro computed tomography has been developed to a powerful technique for the characterization of hard and soft human and animal tissues. Soft tissues including the urethra, however, are difficult to be analyzed, since the microstructures of interest exhibit X-ray absorption values very similar to the surroundings. Selective staining using highly absorbing species is a widely used approach, but associated with significant tissue modification. Alternatively, one can suitably embed the soft tissue, which requires the exchange of water. Therefore, the more recently developed phase contrast modes providing much better contrast of low X-ray absorbing species are especially accommodating in soft tissue characterization. The present communication deals with the morphological characterization of sheep, pig and human urethras on the micrometer scale taking advantage of micro computed tomography in absorption and phase contrast modes. The performance of grating-based tomography is demonstrated for freshly explanted male and female urethras in saline solution. The micro-morphology of the urethra is important to understand how the muscles close the urethra to reach continence. As the number of incontinent patients is steadily increasing, the function under static and, more important, under stress conditions has to be uncovered for the realization of artificial urinary sphincters, which needs sophisticated, biologically inspired concepts to become nature analogue.

  4. Systemic injection of AAV9-GDNF provides modest functional improvements in the SOD1G93A ALS rat but has adverse side effects.

    Science.gov (United States)

    Thomsen, G M; Alkaslasi, M; Vit, J-P; Lawless, G; Godoy, M; Gowing, G; Shelest, O; Svendsen, C N

    2017-04-01

    Injecting proteins into the central nervous system that stimulate neuronal growth can lead to beneficial effects in animal models of disease. In particular, glial cell line-derived neurotrophic factor (GDNF) has shown promise in animal and cell models of Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis (ALS). Here, systemic AAV9-GDNF was delivered via tail vein injections to young rats to determine whether this could be a safe and functional strategy to treat the SOD1 G93A rat model of ALS and, therefore, translated to a therapy for ALS patients. We found that GDNF administration in this manner resulted in modest functional improvement, whereby grip strength was maintained for longer and the onset of forelimb paralysis was delayed compared to non-treated rats. This did not, however, translate into an extension in survival. In addition, ALS rats receiving GDNF exhibited slower weight gain, reduced activity levels and decreased working memory. Collectively, these results confirm that caution should be applied when applying growth factors such as GDNF systemically to multiple tissues.

  5. Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model

    Science.gov (United States)

    Chatterjee, Aparajita; Ratner, Daniel M.; Ryan, Christopher M.; Johnson, Patricia J.; O’Keefe, Barry R.; Secor, W. Evan; Anderson, Deborah J.; Robbins, Phillips W.; Samuelson, John

    2015-01-01

    Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans), like those of HIV, bind the mannose-binding lectin (MBL) that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin) and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas. PMID:26252012

  6. Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model.

    Directory of Open Access Journals (Sweden)

    Aparajita Chatterjee

    Full Text Available Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans, like those of HIV, bind the mannose-binding lectin (MBL that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas.

  7. Percutaneous absorption and disposition of Tinopal EMS

    International Nuclear Information System (INIS)

    Black, T.G.; Moule, R.C.; Philp, J.

    1977-01-01

    A cotton-substantive, anionic, fluorescent whitening agent manufactured by several suppliers under various trade names e.g. Tinopal EMS, has been synthesized in radioactive form. Intubation of detergent or aqueous solution into rats resulted in little absorption from the intestinal tract as evidenced by low radioactivity in the urine and tissues. Most of the dose was excreted rapidly in the faeces. After parenteral administration to rats, the radioactivity was rapidly excreted in the faeces with small amounts remaining in tissues and organs. There was slight evidence of retention of radioactivity in the kidneys. Very small amounts of Tinopal EMS in detergent were absorbed through rat skin, but only when concentrations greater than those normally used by the consumer, together with occlusion of the skin were employed. Small amounts were absorbed through skin when applied in ethanol. It is concluded that the possibility of systemic toxic effects in man as a result of percutaneous absorption is remote

  8. Institute a modest carbon tax to reduce carbon emissions, finance clean energy technology development, cut taxes, and reduce the deficit

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Mark; Rothwell, Jonathan

    2012-11-15

    The nation should institute a modest carbon tax in order to help clean up the economy and stabilize the nation’s finances. Specifically, Congress and the president should implement a $20 per ton, steadily increasing carbon excise fee that would discourage carbon dioxide emissions while shifting taxation onto pollution, financing energy efficiency (EE) and clean technology development, and providing opportunities to cut taxes or reduce the deficit. The net effect of these policies would be to curb harmful carbon emissions, improve the nation’s balance sheet, and stimulate job-creation and economic renewal.

  9. Vitamin A absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Investigation of the absorption of vitamin A and related substances is complicated by the multiplicity of forms in which they occur in the diet and by the possibility that they may be subject to different mechanisms of absorption. Present knowledge of these mechanisms is inadequate, especially in the case of carotenoids. Numerous tests of absorption have been developed. The most common has been the biochemical measurement of the rise in plasma vitamin A after an oral dose of retinol or retinyl ester, but standardization is inadequate. Radioisotope tests based upon assay of serum or faecal activity following oral administration of tritiated vitamin A derivaties hold considerable promise, but again standardization is inadequate. From investigations hitherto performed it is known that absorption of vitamin A is influenced by several diseases, although as yet the consistency of results and the correlation with other tests of intestinal function have often been poor. However, the test of vitamin A absorption is nevertheless of clinical importance as a specialized measure of intestinal function. (author)

  10. Neutron resonance absorption theory

    International Nuclear Information System (INIS)

    Reuss, P.

    1991-11-01

    After some recalls on the physics of neutron resonance absorption during their slowing down, this paper presents the main features of the theoretical developments performed by the french school of reactor physics: the effective reaction rate method so called Livolant-Jeanpierre theory, the generalizations carried out by the author, and the probability table method [fr

  11. Noble gas absorption process

    International Nuclear Information System (INIS)

    Thomas, J.W.

    1975-01-01

    A method of removing a noble gas from air comprising the use of activated carbon filters in stages in which absorption and desorption steps in succession are conducted in order to increase the capacity of the filters is described. (U.S.)

  12. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-01-01

    Experimental methods using real photon beams for measurements of total photonuclear absorption cross section σ(Tot : E/sub γ/) are recalled. Most recent σ(Tot : E/sub γ/)results for complex nuclei and in the nucleon resonance region are presented

  13. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  14. Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene

    Directory of Open Access Journals (Sweden)

    De Deyn PP

    2006-08-01

    Full Text Available Summary Background Arylsulfatase A (ASA-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT. This deficiency is known to lead to a decreased synthesis of galactosylceramide and sulfatide, which should reduce sulfatide storage and improve pathology in ASA-deficient mice. Results ASA-/- CGT+/- mice, however, showed no detectable decrease in sulfatide storage. Neuronal degeneration of cells in the spiral ganglion of the inner ear, however, was decreased. Behavioural tests showed small but clear improvements of the phenotype in ASA-/- CGT+/- mice. Conclusion Thus the reduction of galactosylceramide and sulfatide biosynthesis by genetic means overall causes modest improvements of pathology.

  15. Ineffectiveness of commercial weight-loss programs for achieving modest but meaningful weight loss: Systematic review and meta-analysis.

    Science.gov (United States)

    McEvedy, Samantha M; Sullivan-Mort, Gillian; McLean, Siân A; Pascoe, Michaela C; Paxton, Susan J

    2017-10-01

    This study collates existing evidence regarding weight loss among overweight but otherwise healthy adults who use commercial weight-loss programs. Systematic search of 3 databases identified 11 randomized controlled trials and 14 observational studies of commercial meal-replacement, calorie-counting, or pre-packaged meal programs which met inclusion criteria. In meta-analysis using intention-to-treat data, 57 percent of individuals who commenced a commercial weight program lost less than 5 percent of their initial body weight. One in two (49%) studies reported attrition ≥30 percent. A second meta-analysis found that 37 percent of program completers lost less than 5 percent of initial body weight. We conclude that commercial weight-loss programs frequently fail to produce modest but clinically meaningful weight loss with high rates of attrition suggesting that many consumers find dietary changes required by these programs unsustainable.

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

    Science.gov (United States)

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

    2017-07-01

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

  17. Reduction in the absorption and retention of strontium in rats

    Energy Technology Data Exchange (ETDEWEB)

    Slat, B; Kostial, K; Harrison, G E

    1971-12-01

    Rats were fed a stock diet supplemented with calcium phosphate and sodium alginate, both separately and simultaneously, over a period of 4-5 months. Observations were made at intervals on the growth rate and on visual and histological abnormalities in some body tissues. No toxic effects were observed. The absorption and skeletal retention of calcium for rats on the combined supplements remained almost unchanged but the absorption and retention of strontium was reduced 7-fold.

  18. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe3O4 composite

    International Nuclear Information System (INIS)

    Min, Dandan; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-01-01

    Highlights: • Flake carbonyl iron/Fe 3 O 4 composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe 3 O 4 composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe 3 O 4 (FCI/Fe 3 O 4 ) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe 3 O 4 composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe 3 O 4 composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe 3 O 4 composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  19. Linear absorptive dielectrics

    Science.gov (United States)

    Tip, A.

    1998-06-01

    Starting from Maxwell's equations for a linear, nonconducting, absorptive, and dispersive medium, characterized by the constitutive equations D(x,t)=ɛ1(x)E(x,t)+∫t-∞dsχ(x,t-s)E(x,s) and H(x,t)=B(x,t), a unitary time evolution and canonical formalism is obtained. Given the complex, coordinate, and frequency-dependent, electric permeability ɛ(x,ω), no further assumptions are made. The procedure leads to a proper definition of band gaps in the periodic case and a new continuity equation for energy flow. An S-matrix formalism for scattering from lossy objects is presented in full detail. A quantized version of the formalism is derived and applied to the generation of Čerenkov and transition radiation as well as atomic decay. The last case suggests a useful generalization of the density of states to the absorptive situation.

  20. Iron absorption studies

    International Nuclear Information System (INIS)

    Ekenved, G.

    1976-01-01

    The main objective of the present work was to study iron absorption from different iron preparations in different types of subjects and under varying therapeutic conditions. The studies were performed with different radioiron isotope techniques and with a serum iron technique. The preparations used were solutions of ferrous sulphate and rapidly-disintegrating tablets containing ferrous sulphate, ferrous fumarate and ferrous carbonate and a slow-release ferrous sulphate tablet of an insoluble matrix type (Duroferon Durules). The serum iron method was evaluated and good correlation was found between the serum iron response and the total amount of iron absorbed after an oral dose of iron given in solution or in tablet form. New technique for studying the in-vivo release properties of tablets was presented. Iron tablets labelled with a radio-isotope were given to healthy subjects. The decline of the radioactivity in the tablets was followed by a profile scanning technique applied to different types of iron tablets. The release of iron from the two types of tablets was shown to be slower in vivo than in vitro. It was found that co-administration of antacids and iron tablets led to a marked reduction in the iron absorption and that these drugs should not be administered sumultaneously. A standardized meal markedly decreased the absorbability of iron from iron tablets. The influence of the meal was more marked with rapidly-disintegrating than with slow-release ferrous sulphate tablets. The absorption from rapidly-disintegrating and slow-release ferrous sulphate tablets was compared under practical clinical conditions during an extended treatment period. The studies were performed in healthy subjects, blood donors and patients with iron deficiency anaemia and it was found that the absorption of iron from the slow-release tablets was significantly better than from the rapidly-disintegrating tablets in all three groups of subjects. (author)

  1. Gamma absorption meter

    International Nuclear Information System (INIS)

    Dincklage, R.D. von.

    1984-01-01

    The absorption meter consists of a radiation source, a trough for the absorbing liquid and a detector. It is characterized by the fact that there is a foil between the detector and the trough, made of a material whose binding energy of the K electrons is a little greater than the energy of the photons emitted by the radiation source. The source of radiation and foil are replaceable. (orig./HP) [de

  2. Total Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Rubio, B.; Gelletly, W.

    2007-01-01

    The problem of determining the distribution of beta decay strength (B(GT)) as a function of excitation energy in the daughter nucleus is discussed. Total Absorption Spectroscopy is shown to provide a way of determining the B(GT) precisely. A brief history of such measurements and a discussion of the advantages and disadvantages of this technique, is followed by examples of two recent studies using the technique. (authors)

  3. Determination of optical absorption coefficient with focusing photoacoustic imaging.

    Science.gov (United States)

    Li, Zhifang; Li, Hui; Zeng, Zhiping; Xie, Wenming; Chen, Wei R

    2012-06-01

    Absorption coefficient of biological tissue is an important factor for photothermal therapy and photoacoustic imaging. However, its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique to quantify the target optical absorption coefficient. It utilizes the ratio of the amplitude of the peak signal from the top boundary of the target to that from the bottom boundary based on wavelet transform. This method is self-calibrating. Factors, such as absolute optical fluence, ultrasound parameters, and Grüneisen parameter, can be canceled by dividing the amplitudes of the two peaks. To demonstrate this method, we quantified the optical absorption coefficient of a target with various concentrations of an absorbing dye. This method is particularly useful to provide accurate absorption coefficient for predicting the outcomes of photothermal interaction for cancer treatment with absorption enhancement.

  4. Tissue engineering

    CERN Document Server

    Fisher, John P; Bronzino, Joseph D

    2007-01-01

    Increasingly viewed as the future of medicine, the field of tissue engineering is still in its infancy. As evidenced in both the scientific and popular press, there exists considerable excitement surrounding the strategy of regenerative medicine. To achieve its highest potential, a series of technological advances must be made. Putting the numerous breakthroughs made in this field into a broad context, Tissue Engineering disseminates current thinking on the development of engineered tissues. Divided into three sections, the book covers the fundamentals of tissue engineering, enabling technologies, and tissue engineering applications. It examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue engineered devices. Contributions focus on those strategies typically incorporated into tissue engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene t...

  5. Effect of UV laser irradiation on tissue

    International Nuclear Information System (INIS)

    Nakayama, Takeyoshi; Kubo, Uichi

    1992-01-01

    Laser-tissue interactions have been investigated through Electron Probe Micro Analysis (EPMA), UV-visible optical absorption and Fourier Transform Infrared Spectroscopy (FTIR). Three excimer lasers, ArF, KrF and XeCl, were used to irradiate tissue; cow thighbone and gelatin thin film. Features of UV laser irradiation are described. (author)

  6. Modest alcohol consumption decreases the risk of fatty liver disease or nonalcoholic fatty liver disease: a Meta-analysis

    Directory of Open Access Journals (Sweden)

    Guo-li CAO

    2016-08-01

    Full Text Available Objective  To evaluate the association between modest alcohol consumption and the risk of fatty liver disease (FLD or nonalcoholic fatty liver disease (NAFLD. Methods  PubMed, EMBASE, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI, Wanfang Digital Journal Full-text Database, and database for Chinese Technical Periodicals (VIP till Nov. 2015 were searched for the studies in evaluating the effect of alcohol consumption on FLD or NAFLD. The quality assessment of included studies was performed according to the combined evaluation for cross-sectional studies and Newcastle-Ottawa scale (NOS for cohort studies. A meta-analysis was performed using Stata12.0 software. Results  A total of 16 studies including 13 cross-sectional studies, 2 cross-sectional following longitudinal studies, and 1 cohort study with 76 967 participants were selected finally. The results of Meta-analysis were as follows. Minimal and light alcohol consumptions reduced the risk for FLD or NAFLD by 17% and 27%, respectively, and moderate alcohol consumption was marginally associated with decreased risk for FLD or NAFLD. The results of subgroup analysis by gender showed that (1 Minimal and light alcohol consumptions reduced the risk of FLD or NAFLD by 29% and 33%, respectively, but moderate alcohol consumption was not statistically significant in reducing the risk of FLD or NAFLD in females compared with controls; (2 Light alcohol consumption reduced the risk of FLD or NAFLD by 23%, but minimal and moderate alcohol consumptions were not statistically significant in reducing the risk of FLD or NAFLD in male compared with controls; (3 Light and moderate alcohol consumptions in Asian males reduced the risk of FLD or NAFLD by 29.7% and 30.3%, respectively. Conclusions  Modest alcohol consumptions may not increase the risk of FLD or NAFLD. Inversely, minimal and light alcohol consumptions in female reduce the risk of FLD or NAFLD remarkably

  7. Evaluation of the potential of Pontederia parviflora Alexander in the absorption of copper (Cu and its effects on tissues = Avaliação do potencial de pontederia parviflora Alexander na absorção de cobre (Cu e efeitos nos tecidos

    Directory of Open Access Journals (Sweden)

    Graziela Custodio Balassa

    2010-07-01

    Full Text Available The study sought to evaluate the potential of the aquatic macrophytePontederia parviflora Alexander in the absorption of copper (Cu and possible variations in its tissues after 21 days of exposure to this metal. The concentration of Cu was analyzed in the solution and in the vegetal tissues (stem, root and leaves. The experiment was set up in triplicates with weekly measurements of pH, temperature and DO. The results indicated that P. parviflora reduced 96% of Cu in the solution and the root was the vegetal tissue, which accumulated more Cu. Values of pH, DO and temperature were in accordance with the metabolic activities of the plants. In the anatomic analyses, dark spots were identified in the vascular bundles and in the epidermis of the aerial parts, highlighting the variation resulting from the presence of this substance. However, these variations were not sufficient to damage the development of the individuals. P. parviflora showed high capacity of extraction and storage of the metal, being a good alternative to aquatic environments with high concentrations of Cu. O estudo avaliou o potencial da macrófita aquática Pontederia parviflora Alexander na absorção de cobre (Cu e possíveis alterações nos tecidos, após 21 dias de exposição. O teor do metal foi analisado na solução e nos tecidos vegetais (caule, raiz e folhas. O experimento foi montado em triplicatas com medidas semanais dopH, temperatura e OD. Os resultados mostraram que P. parviflora reduziu 96% do Cu na solução e a porção vegetal que acumulou mais o metal foi a radicular. O pH, OD e temperatura apresentaram valores condizentes com as atividades metabólicas das plantas. Nas análises anatômicas, foram identificadas manchas escuras nos feixes vasculares e na epiderme das partes aéreas, evidenciando a alteração provocada pela presença da substância. No entanto essas alterações não foram suficientes para prejudicar o desenvolvimento dos indivíduos. P

  8. Optical absorption in dendrimers

    International Nuclear Information System (INIS)

    Supritz, C.; Engelmann, A.; Reineker, P.

    2004-01-01

    Dendrimers are highly branched molecules, which are expected to be useful, for example, as efficient artificial light harvesting systems in nano-technological applications. There are two different classes of dendrimers: compact dendrimers with constant distance between neighboring branching points throughout the macromolecule and extended dendrimers, where this distance increases from the system periphery to the center. We investigate the linear absorption spectra of these dendrimer types using the Frenkel exciton concept. The electron-phonon interaction is taken into account by introducing a heat bath that interacts with the exciton in a stochastic manner

  9. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  10. Geospatial Absorption and Regional Effects

    Directory of Open Access Journals (Sweden)

    IOAN MAC

    2009-01-01

    Full Text Available The geospatial absorptions are characterized by a specific complexity both in content and in their phenomenological and spatial manifestation fields. Such processes are differentiated according to their specificity to pre-absorption, absorption or post-absorption. The mechanisms that contribute to absorption are extremely numerous: aggregation, extension, diffusion, substitution, resistivity (resilience, stratification, borrowings, etc. Between these mechanisms frequent relations are established determining an amplification of the process and of its regional effects. The installation of the geographic osmosis phenomenon in a given territory (a place for example leads to a homogenization of the geospatial state and to the installation of the regional homogeneity.

  11. Irradiation induced modest changes in murine cardiac function despite progressive structural damage to the myocardium and microvasculature

    International Nuclear Information System (INIS)

    Seemann, Ingar; Gabriels, Karen; Visser, Nils L.; Hoving, Saske; Poele, Johannes A. te; Pol, Jeffrey F.; Gijbels, Marion J.; Janssen, Ben J.; Leeuwen, Fijs W. van; Daemen, Mat J.; Heeneman, Sylvia; Stewart, Fiona A.

    2012-01-01

    Background: Radiotherapy of thoracic and chest wall tumors increases the long-term risk of cardiotoxicity, but the underlying mechanisms are unclear. Methods: Single doses of 2, 8, or 16 Gy were delivered to the hearts of mice and damage was evaluated at 20, 40, and 60 weeks, relative to age matched controls. Single photon emission computed tomography (SPECT/CT) and ultrasound were used to measure cardiac geometry and function, which was related to histo-morphology and microvascular damage. Results: Gated SPECT/CT and ultrasound demonstrated decreases in end diastolic and systolic volumes, while the ejection fraction was increased at 20 and 40 weeks after 2, 8, and 16 Gy. Cardiac blood volume was decreased at 20 and 60 weeks after irradiation. Histological examination revealed inflammatory changes at 20 and 40 weeks after 8 and 16 Gy. Microvascular density in the left ventricle was decreased at 40 and 60 weeks after 8 and 16 Gy, with functional damage to remaining microvasculature manifest as decreased alkaline phosphatase (2, 8, and 16 Gy), increased von Willebrand Factor and albumin leakage from vessels (8 and 16 Gy), and amyloidosis (16 Gy). 16 Gy lead to sudden death between 30 and 40 weeks in 38% of mice. Conclusions: Irradiation with 2 and 8 Gy induced modest changes in murine cardiac function within 20 weeks but this did not deteriorate further, despite progressive structural and microvascular damage. This indicates that heart function can compensate for significant structural damage, although higher doses, eventually lead to sudden death.

  12. SPARTA+: a modest improvement in empirical NMR chemical shift prediction by means of an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Shen Yang; Bax, Ad, E-mail: bax@nih.go [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2010-09-15

    NMR chemical shifts provide important local structural information for proteins and are key in recently described protein structure generation protocols. We describe a new chemical shift prediction program, SPARTA+, which is based on artificial neural networking. The neural network is trained on a large carefully pruned database, containing 580 proteins for which high-resolution X-ray structures and nearly complete backbone and {sup 13}C{sup {beta}} chemical shifts are available. The neural network is trained to establish quantitative relations between chemical shifts and protein structures, including backbone and side-chain conformation, H-bonding, electric fields and ring-current effects. The trained neural network yields rapid chemical shift prediction for backbone and {sup 13}C{sup {beta}} atoms, with standard deviations of 2.45, 1.09, 0.94, 1.14, 0.25 and 0.49 ppm for {delta}{sup 15}N, {delta}{sup 13}C', {delta}{sup 13}C{sup {alpha}}, {delta}{sup 13}C{sup {beta}}, {delta}{sup 1}H{sup {alpha}} and {delta}{sup 1}H{sup N}, respectively, between the SPARTA+ predicted and experimental shifts for a set of eleven validation proteins. These results represent a modest but consistent improvement (2-10%) over the best programs available to date, and appear to be approaching the limit at which empirical approaches can predict chemical shifts.

  13. SPARTA+: a modest improvement in empirical NMR chemical shift prediction by means of an artificial neural network

    International Nuclear Information System (INIS)

    Shen Yang; Bax, Ad

    2010-01-01

    NMR chemical shifts provide important local structural information for proteins and are key in recently described protein structure generation protocols. We describe a new chemical shift prediction program, SPARTA+, which is based on artificial neural networking. The neural network is trained on a large carefully pruned database, containing 580 proteins for which high-resolution X-ray structures and nearly complete backbone and 13 C β chemical shifts are available. The neural network is trained to establish quantitative relations between chemical shifts and protein structures, including backbone and side-chain conformation, H-bonding, electric fields and ring-current effects. The trained neural network yields rapid chemical shift prediction for backbone and 13 C β atoms, with standard deviations of 2.45, 1.09, 0.94, 1.14, 0.25 and 0.49 ppm for δ 15 N, δ 13 C', δ 13 C α , δ 13 C β , δ 1 H α and δ 1 H N , respectively, between the SPARTA+ predicted and experimental shifts for a set of eleven validation proteins. These results represent a modest but consistent improvement (2-10%) over the best programs available to date, and appear to be approaching the limit at which empirical approaches can predict chemical shifts.

  14. Tissue types (image)

    Science.gov (United States)

    ... are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue. Connective tissue supports ... binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the ...

  15. MCSLTT, Monte Carlo Simulation of Light Transport in Tissue

    International Nuclear Information System (INIS)

    2008-01-01

    Description of program or function: Understanding light-tissue interaction is fundamental in the field of Biomedical Optics. It has important implications for both therapeutic and diagnostic technologies. In this program, light transport in scattering tissue is modeled by absorption and scattering events as each photon travels through the tissue. The path of each photon is determined statistically by calculating probabilities of scattering and absorption. Other measured quantities are total reflected light, total transmitted light, and total heat absorbed

  16. No effect of modest selenium supplementation on insulin resistance in UK pregnant women, as assessed by plasma adiponectin concentration.

    Science.gov (United States)

    Mao, Jinyuan; Bath, Sarah C; Vanderlelie, Jessica J; Perkins, Anthony V; Redman, Christopher W G; Rayman, Margaret P

    2016-01-14

    Concern has been expressed recently that Se may increase the risk of type 2 diabetes, but this has not been tested in a randomised-controlled trial (RCT) in pregnant women. We took advantage of having stored plasma samples from the Se in Pregnancy Intervention (SPRINT) RCT of Se supplementation in pregnancy to test the effect of Se supplementation on a marker of insulin resistance in UK pregnant women. Because our blood samples were not fasted, we measured plasma adiponectin concentration, a recognised marker of insulin resistance that gives valid measurements in non-fasted samples, as diurnal variability is minor and there is no noticeable effect of food intake. In SPRINT, 230 primiparous UK women were randomised to treatment with Se (60 μg/d) or placebo from 12 weeks of gestation until delivery. We hypothesised that supplementation with Se at a nutritional level would not exacerbate the fall in adiponectin concentration that occurs in normal pregnancy, indicating the lack of an adverse effect on insulin resistance. Indeed, there was no significant difference between the two groups in the change in adiponectin from 12 to 35 weeks (P=0·938), nor when the analysis was restricted to the bottom or top quartiles of baseline whole-blood Se (P=0·515 and 0·858, respectively). Cross-sectionally, adiponectin concentration was not associated with any parameter of Se status, either at 12 or 35 weeks. It is reassuring that a nutritional dose of Se had no adverse effect on the concentration of adiponectin, a biomarker of insulin resistance, in pregnant women of modest Se status.

  17. Ultrasonic vocalizations in golden hamsters (Mesocricetus auratus) reveal modest sex differences and nonlinear signals of sexual motivation.

    Science.gov (United States)

    Fernández-Vargas, Marcela; Johnston, Robert E

    2015-01-01

    Vocal signaling is one of many behaviors that animals perform during social interactions. Vocalizations produced by both sexes before mating can communicate sex, identity and condition of the caller. Adult golden hamsters produce ultrasonic vocalizations (USV) after intersexual contact. To determine whether these vocalizations are sexually dimorphic, we analyzed the vocal repertoire for sex differences in: 1) calling rates, 2) composition (structural complexity, call types and nonlinear phenomena) and 3) acoustic structure. In addition, we examined it for individual variation in the calls. The vocal repertoire was mainly composed of 1-note simple calls and at least half of them presented some degree of deterministic chaos. The prevalence of this nonlinear phenomenon was confirmed by low values of harmonic-to-noise ratio for most calls. We found modest sexual differences between repertoires. Males were more likely than females to produce tonal and less chaotic calls, as well as call types with frequency jumps. Multivariate analysis of the acoustic features of 1-note simple calls revealed significant sex differences in the second axis represented mostly by entropy and bandwidth parameters. Male calls showed lower entropy and inter-quartile bandwidth than female calls. Because the variation of acoustic structure within individuals was higher than among individuals, USV could not be reliably assigned to the correct individual. Interestingly, however, this high variability, augmented by the prevalence of chaos and frequency jumps, could be the result of increased vocal effort. Hamsters motivated to produce high calling rates also produced longer calls of broader bandwidth. Thus, the sex differences found could be the result of different sex preferences but also of a sex difference in calling motivation or condition. We suggest that variable and complex USV may have been selected to increase responsiveness of a potential mate by communicating sexual arousal and

  18. Ultrasonic vocalizations in golden hamsters (Mesocricetus auratus reveal modest sex differences and nonlinear signals of sexual motivation.

    Directory of Open Access Journals (Sweden)

    Marcela Fernández-Vargas

    Full Text Available Vocal signaling is one of many behaviors that animals perform during social interactions. Vocalizations produced by both sexes before mating can communicate sex, identity and condition of the caller. Adult golden hamsters produce ultrasonic vocalizations (USV after intersexual contact. To determine whether these vocalizations are sexually dimorphic, we analyzed the vocal repertoire for sex differences in: 1 calling rates, 2 composition (structural complexity, call types and nonlinear phenomena and 3 acoustic structure. In addition, we examined it for individual variation in the calls. The vocal repertoire was mainly composed of 1-note simple calls and at least half of them presented some degree of deterministic chaos. The prevalence of this nonlinear phenomenon was confirmed by low values of harmonic-to-noise ratio for most calls. We found modest sexual differences between repertoires. Males were more likely than females to produce tonal and less chaotic calls, as well as call types with frequency jumps. Multivariate analysis of the acoustic features of 1-note simple calls revealed significant sex differences in the second axis represented mostly by entropy and bandwidth parameters. Male calls showed lower entropy and inter-quartile bandwidth than female calls. Because the variation of acoustic structure within individuals was higher than among individuals, USV could not be reliably assigned to the correct individual. Interestingly, however, this high variability, augmented by the prevalence of chaos and frequency jumps, could be the result of increased vocal effort. Hamsters motivated to produce high calling rates also produced longer calls of broader bandwidth. Thus, the sex differences found could be the result of different sex preferences but also of a sex difference in calling motivation or condition. We suggest that variable and complex USV may have been selected to increase responsiveness of a potential mate by communicating sexual

  19. Humanlike substitutions to Ω-loop D of yeast iso-1-cytochrome c only modestly affect dynamics and peroxidase activity.

    Science.gov (United States)

    Lei, Haotian; Bowler, Bruce E

    2018-06-01

    Structural studies of yeast iso-1-cytochrome c (L.J. McClelland, T.-C. Mou, M.E. Jeakins-Cooley, S.R. Sprang, B.E. Bowler, Proc. Natl. Acad. Sci. U.S.A. 111 (2014) 6648-6653) show that modest movement of Ω-loop D (residues 70-85, average RMSD versus the native structure: 0.81 Å) permits loss of Met80-heme ligation creating an available coordination site to catalyze the peroxidase activity mediated by cytochrome c early in apoptosis. However, Ala81 and Gly83 move significantly (RMSDs of 2.18 and 1.26 Å, respectively). Ala81 and Gly83 evolve to Ile and Val, respectively, in human cytochrome c and peroxidase activity decreases 25-fold relative to the yeast protein at pH 7. To test the hypothesis that these residues evolved to restrict the peroxidase activity of cytochrome c, A81I and G83V variants of yeast iso-1-cytochrome c were prepared. For both variants, the apparent pK a of the alkaline transition increases by 0.2 to 0.3 relative to the wild type (WT) protein and the rate of opening the heme crevice is slowed. The cooperativity of acid unfolding is decreased for the G83V variant. At pH 7 and 8, the catalytic rate constant, k cat , for the peroxidase activity of both variants decreases relative to WT, consistent with the effects on alkaline isomerization. Below pH 7, the loss in the cooperativity of acid unfolding causes k cat for peroxidase activity to increase for the G83V variant relative to WT. Neither variant decreases k cat to the level of the human protein, indicating that other residues also contribute to the low peroxidase activity of human cytochrome c. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Acute Zika Virus Infection in an Endemic Area Shows Modest Proinflammatory Systemic Immunoactivation and Cytokine-Symptom Associations

    Directory of Open Access Journals (Sweden)

    Jéssica Barletto de Sousa Barros

    2018-05-01

    Full Text Available An early immune response to Zika virus (ZIKV infection may determine its clinical manifestation and outcome, including neurological effects. However, low-grade and transient viremia limits the prompt diagnosis of acute ZIKV infection. We have investigated the plasma cytokine, chemokine, and growth factor profiles of 36 individuals from an endemic area displaying different symptoms such as exanthema, headache, myalgia, arthralgia, fever, hyperemia, swelling, itching, and nausea during early-phase infection. These profiles were then associated with symptoms, revealing important aspects of the immunopathophysiology of ZIKV infection. The levels of some cytokines/chemokines were significantly higher in acute ZIKV-infected individuals compared to healthy donors, including interferon (IFN gamma-induced protein 10 (IP-10, regulated on activation, normal T cell expressed and secreted (RANTES, IFN-γ, interleukin (IL-9, IL-7, IL-5, and IL-1ra, including some with predominantly immunoregulatory activity. Of note, we found that higher levels of IP-10 and IL-5 in ZIKV-infected individuals were strongly associated with exanthema and headache, respectively. Also, higher levels of IL-1ra were associated with subjects with arthralgia, whereas those with fever showed lower levels of granulocyte-colony stimulating factor (G-CSF. No correlation was observed between the number of symptoms and ZIKV viral load. Interestingly, only IP-10 showed significantly decreased levels in the recovery phase. In conclusion, our results indicate that acute ZIKV infection in a larger cohort resident to an endemic area displays a modest systemic immune activation profile, involving both proinflammatory and immunoregulatory cytokines and chemokines that could participate of virus control. In addition, we showed that differential cytokine/chemokine levels are related to specific clinical symptoms, suggesting their participation in underlying mechanisms.

  1. Using data sources beyond PubMed has a modest impact on the results of systematic reviews of therapeutic interventions.

    Science.gov (United States)

    Halladay, Christopher W; Trikalinos, Thomas A; Schmid, Ian T; Schmid, Christopher H; Dahabreh, Issa J

    2015-09-01

    Searching multiple sources when conducting systematic reviews is considered good practice. We aimed to investigate the impact of using sources beyond PubMed in systematic reviews of therapeutic interventions. We randomly selected 50 Cochrane reviews that searched the PubMed (or MEDLINE) and EMBASE databases and included a meta-analysis of ≥10 studies. We checked whether each eligible record in each review (n = 2,700) was retrievable in PubMed and EMBASE. For the first-listed meta-analysis of ≥10 studies in each review, we examined whether excluding studies not found in PubMed affected results. A median of one record per review was indexed in EMBASE but not in PubMed; a median of four records per review was not indexed in PubMed or EMBASE. Meta-analyses included a median of 13.5 studies; a median of zero studies per meta-analysis was indexed in EMBASE but not in PubMed; a median of one study per meta-analysis was not indexed in PubMed or EMBASE. Meta-analysis using only PubMed-indexed vs. all available studies led to a different conclusion in a single case (on the basis of conventional criteria for statistical significance). In meta-regression analyses, effects in PubMed- vs. non-PubMed-indexed studies were statistically significantly different in a single data set. For systematic reviews of the effects of therapeutic interventions, gains from searching sources beyond PubMed, and from searching EMBASE in particular are modest. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Haswell, S.J.

    1991-01-01

    Atomic absorption spectroscopy is now well established and widely used technique for the determination of trace and major elements in a wide range analyte types. There have been many advances in the atomic spectroscopy over the last decade and for this reason and to meet the demand, it was felt that there was a need for an updated book. Whilst interest in instrumental design has tended to dominate the minds of the spectrocopist, the analyst concerned with obtaining reliable and representative data, in diverse areas of application, has been diligently modifying and developing sample treatment and instrumental introduction techniques. Such methodology is de fundamental part of analysis and form the basis of the fourteen application chapters of this book. The text focuses in the main on AAS; however, the sample handling techniques described are in many cases equally applicable to ICP-OES and ICP-MS analysis. (author). refs.; figs.; tabs

  3. Atomic absorption spectrophotometer

    International Nuclear Information System (INIS)

    Stockdale, T. J.

    1985-01-01

    In atomic absorption spectrophotometer, a reference path may be provided for radiation which excludes the flame. This radiation provides a signal from a detector which varies only with the instrumental drift produced by variations in the radiation source brightness and by variations in detector gain. The signal can be used to compensate for drift in other signals received through a sample path including the flame. In the present invention, radiation passes through the sample path continuously during measurement, and only through the reference path between sample measurements. Movable mirrors shift the radiation between the paths upon externally applied commands. Conveniently, the reference path measurement is made while the flame is stabilized during the change between samples. The reference path measurements are stored and used to correct for drift

  4. Analyzing Water's Optical Absorption

    Science.gov (United States)

    2002-01-01

    A cooperative agreement between World Precision Instruments (WPI), Inc., and Stennis Space Center has led the UltraPath(TM) device, which provides a more efficient method for analyzing the optical absorption of water samples at sea. UltraPath is a unique, high-performance absorbance spectrophotometer with user-selectable light path lengths. It is an ideal tool for any study requiring precise and highly sensitive spectroscopic determination of analytes, either in the laboratory or the field. As a low-cost, rugged, and portable system capable of high- sensitivity measurements in widely divergent waters, UltraPath will help scientists examine the role that coastal ocean environments play in the global carbon cycle. UltraPath(TM) is a trademark of World Precision Instruments, Inc. LWCC(TM) is a trademark of World Precision Instruments, Inc.

  5. Rôle modeste du citrate comme transporteur d'acétyl-CoA chez l'animal vivant.

    Science.gov (United States)

    Rous, S

    1971-02-09

    2,4-(14) C-Citrate incorporated to a far greater extent than 1,5-(14) C-citrate into liver, carcass or adipose tissue fatty acids of living mice. This finding excludes the possibility that the acetyl units emerge from the mitochondria in the form of citrate.

  6. Atomic absorption spectrophotometry in perspective

    International Nuclear Information System (INIS)

    Soffiantini, V.

    1981-01-01

    Atomic absorption spectrophotometry is essentially an analytical technique used for quantitative trace metal analysis in a variety of materials. The speed and specificity of the technique is its greatest advantage over other analytical techniques. What atomic absorption spectrophotometry can and cannot do and its advantages and disadvantages are discussed, a summary of operating instructions are given, as well as a summary of analytical interferences. The applications of atomic absorption spectrophotometry are also shortly discussed

  7. Nonlinear effects in collective absorption

    International Nuclear Information System (INIS)

    Uenoyama, Takeshi; Mima, Kunioki; Watanabe, Tsuguhiro.

    1981-01-01

    The collective absorption of high intensity laser radiation is analyzed numerically. Density profile modification due to the ponderomotive force associating laser radiation and the excited electron plasma waves is self-consistently taken into account, and the intensity dependences of the absorption efficiency are obtained. In the high intensity regime, the absorption efficiency is found to be strongly enhanced in the plasma without flow, but reduced with supersonic flow. (author)

  8. Tissue Classification

    DEFF Research Database (Denmark)

    Van Leemput, Koen; Puonti, Oula

    2015-01-01

    Computational methods for automatically segmenting magnetic resonance images of the brain have seen tremendous advances in recent years. So-called tissue classification techniques, aimed at extracting the three main brain tissue classes (white matter, gray matter, and cerebrospinal fluid), are now...... well established. In their simplest form, these methods classify voxels independently based on their intensity alone, although much more sophisticated models are typically used in practice. This article aims to give an overview of often-used computational techniques for brain tissue classification...

  9. Paracellular absorption: a bat breaks the mammal paradigm.

    Directory of Open Access Journals (Sweden)

    Enrique Caviedes-Vidal

    Full Text Available Bats tend to have less intestinal tissue than comparably sized nonflying mammals. The corresponding reduction in intestinal volume and hence mass of digesta carried is advantageous because the costs of flight increase with load carried and because take-off and maneuverability are diminished at heavier masses. Water soluble compounds, such as glucose and amino acids, are absorbed in the small intestine mainly via two pathways, the transporter-mediated transcellular and the passive, paracellular pathways. Using the microchiropteran bat Artibeus literatus (mean mass 80.6+/-3.7 g, we tested the predictions that absorption of water-soluble compounds that are not actively transported would be extensive as a compensatory mechanism for relatively less intestinal tissue, and would decline with increasing molecular mass in accord with sieve-like paracellular absorption. Using a standard pharmacokinetic technique, we fed, or injected intraperitoneally the metabolically inert carbohydrates L-rhamnose (molecular mass = 164 Da and cellobiose (molecular mass = 342 Da which are absorbed only by paracellular transport, and 3-O-methyl-D-glucose (3OMD-glucose which is absorbed via both mediated (active and paracellular transport. As predicted, the bioavailability of paracellular probes declined with increasing molecular mass (rhamnose, 90+/-11%; cellobiose, 10+/-3%, n = 8 and was significantly higher in bats than has been reported for laboratory rats and other mammals. In addition, absorption of 3OMD-glucose was high (96+/-11%. We estimated that the bats rely on passive, paracellular absorption for more than 70% of their total glucose absorption, much more than in non-flying mammals. Although possibly compensating for less intestinal tissue, a high intestinal permeability that permits passive absorption might be less selective than a carrier-mediated system for nutrient absorption and might permit toxins to be absorbed from plant and animal material in the

  10. Neuropeptide Y Y1 receptor hippocampal overexpression via viral vectors is associated with modest anxiolytic-like and proconvulsant effects in mice

    DEFF Research Database (Denmark)

    Olesen, Mikkel V; Christiansen, Søren Hofman Oliveira; Gøtzsche, Casper René

    2012-01-01

    overexpression was found to be associated with modest anxiolytic-like effect in the open field and elevated plus maze tests, but no effect was seen on depression-like behavior using the tail suspension and forced swim tests. However, the rAAV-Y1 vector modestly aggravated kainate-induced seizures. These data...... in the hippocampus of adult mice and tested the animals in anxiety- and depression-like behavior. Hippocampal Y1 receptors have been suggested to mediate seizure-promoting effect, so the effects of rAAV-induced Y1 receptor overexpression were also tested in kainate-induced seizures. Y1 receptor transgene...

  11. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  12. Gas in scattering media absorption spectroscopy - GASMAS

    Science.gov (United States)

    Svanberg, Sune

    2008-09-01

    An overview of the new field of Gas in Scattering Media Absorption Spectroscopy (GASMAS) is presented. GASMAS combines narrow-band diode-laser spectroscopy with diffuse media optical propagation. While solids and liquids have broad absorption features, free gas in pores and cavities in the material is characterized by sharp spectral signatures, typically 10,000 times sharper than those of the host material. Many applications in materials science, food packaging, pharmaceutics and medicine have been demonstrated. So far molecular oxygen and water vapour have been studied around 760 and 935 nm, respectively. Liquid water, an important constituent in many natural materials, such as tissue, has a low absorption at such wavelengths, allowing propagation. Polystyrene foam, wood, fruits, food-stuffs, pharmaceutical tablets, and human sinus cavities have been studied. Transport of gas in porous media can readily be studied by first immersing the material in, e.g., pure nitrogen, and then observing the rate at which normal air, containing oxygen, reinvades the material. The conductance of the sinus connective passages can be measured in this way by flushing the nasal cavity with nitrogen. Also other dynamic processes such as drying of materials can be studied. The techniques have also been extended to remote-sensing applications (LIDAR-GASMAS).

  13. Electromagnetic-radiation absorption by water

    Science.gov (United States)

    Lunkenheimer, P.; Emmert, S.; Gulich, R.; Köhler, M.; Wolf, M.; Schwab, M.; Loidl, A.

    2017-12-01

    Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

  14. Electromagnetic-radiation absorption by water.

    Science.gov (United States)

    Lunkenheimer, P; Emmert, S; Gulich, R; Köhler, M; Wolf, M; Schwab, M; Loidl, A

    2017-12-01

    Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

  15. Satisfactory surgical option for cartilage graft absorption in microtia reconstruction.

    Science.gov (United States)

    Han, So-Eun; Oh, Kap Sung

    2016-04-01

    We routinely perform auricular elevation at least 6 months after implantation of framework in microtia reconstruction using costal cartilage. However, in a few cases, cartilage graft absorption has occurred, which has led to contour irregularity with unfavorable long-term results. In the present study, we recount the details of using additional rib cartilage augmentation to achieve an accentuated contour in cartilage graft absorption cases. The cartilage graft absorption was defined as contour irregularity or cartilage graft deformation as evaluated by the surgeon and patient. Depending on the extent of cartilage graft absorption, another rib cartilage framework was added to the previously implanted framework, targeting the absorption area. We used banked cartilage or harvested new cartilage based on three-dimensional rib computed tomography. Additional recontouring of framework was conducted in eight patients who were examined for cartilage graft absorption from 1.5 to 5 years after implantation of the framework. Four patients received additional rib cartilage augmentation and tissue expander insertion simultaneously prior to auricular elevation. Two patients underwent auricular elevation simultaneously. In another two patients, additional rib cartilage augmentation was performed before auricular elevation. The mean follow-up period was 18 months, and in all cases reconstructive results were acceptable. Although further follow-up evaluation is required, additional rib cartilage augmentation is an attractive surgical option for cartilage graft absorption cases. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  16. Galactic absorption line coronae

    International Nuclear Information System (INIS)

    Bregman, J.N.

    1981-01-01

    We have investigated whether gaseous coronae around galaxies rise to the absorption systems seen in quasar spectra. In our model, gas originally located in the disk is heated to the million degree range and rises to surround the galaxy; the gas remains bound to the galaxy. Optically thin radiative cooling drives a thermal instability in the hot gas which causes cool clouds (T 4 K) to condense out of the corona. These clouds, which follow ballistic trajectories back to the disk, are the absorption sites. A two-dimensional hydrodynamic code with radiative cooling was used to study the dynamics and thermodynamics of the corona as well as the position rate at which clouds form. Coupled to the code is a galaxy with two mass components, a disk (approx.10 11 M/sub sun/) and a dark halo (approx.10 12 M/sub sun/). In a model where the temperature at the base of the corona (in the disk) is 3 x 10 6 K, absorbing gas of column density NL> or approx. =10 18 cm 2 extends radially to 100 kpc (face-on orientation) and vertically to 60 Kpc (edge-on orientation). The total mass of gas required here (coronal plus cloud gas) is 1.4 x 10 10 M/sub sun/, while the minimum supernova heating rate is one supernova per 27 years. In two other models (base coronal temperatures of 0.50 x 10 6 K and 1 x 10 6 K), coronal gas rises from an extended gaseous disk (in the previous model, the gas comes from a typical gaseous disk approximately 15 kpc in extent). Here, column densities of 10 19 cm -2 out to a radius of 70 kpc (face-on orientation) are achieved with a total gas mass of 1.7 x 10 9 M/sub direct-product/ and 2.0 x 10 9 M/sub sun/ and minimum heating rates of approximately one supernova per 170 years and one supernova per 60 years

  17. Modest elevation in BNP in asymptomatic hypertensive patients reflects sub-clinical cardiac remodeling, inflammation and extracellular matrix changes.

    LENUS (Irish Health Repository)

    Phelan, Dermot

    2012-11-01

    In asymptomatic subjects B-type natriuretic peptide (BNP) is associated with adverse cardiovascular outcomes even at levels well below contemporary thresholds used for the diagnosis of heart failure. The mechanisms behind these observations are unclear. We examined the hypothesis that in an asymptomatic hypertensive population BNP would be associated with sub-clinical evidence of cardiac remodeling, inflammation and extracellular matrix (ECM) alterations. We performed transthoracic echocardiography and sampled coronary sinus (CS) and peripheral serum from patients with low (n = 14) and high BNP (n = 27). Peripheral BNP was closely associated with CS levels (r = 0.92, p<0.001). CS BNP correlated significantly with CS levels of markers of collagen type I and III turnover including: PINP (r = 0.44, p = 0.008), CITP (r = 0.35, p = 0.03) and PIIINP (r = 0.35, p = 0.001), and with CS levels of inflammatory cytokines including: TNF-α (r = 0.49, p = 0.002), IL-6 (r = 0.35, p = 0.04), and IL-8 (r = 0.54, p<0.001). The high BNP group had greater CS expression of fibro-inflammatory biomarkers including: CITP (3.8±0.7 versus 5.1±1.9, p = 0.007), TNF-α (3.2±0.5 versus 3.7±1.1, p = 003), IL-6 (1.9±1.3 versus 3.4±2.7, p = 0.02) and hsCRP (1.2±1.1 versus 2.4±1.1, p = 0.04), and greater left ventricular mass index (97±20 versus 118±26 g\\/m(2), p = 0.03) and left atrial volume index (18±2 versus 21±4, p = 0.008). Our data provide insight into the mechanisms behind the observed negative prognostic impact of modest elevations in BNP and suggest that in an asymptomatic hypertensive cohort a peripheral BNP measurement may be a useful marker of an early, sub-clinical pathological process characterized by cardiac remodeling, inflammation and ECM alterations.

  18. Modest elevation in BNP in asymptomatic hypertensive patients reflects sub-clinical cardiac remodeling, inflammation and extracellular matrix changes.

    Directory of Open Access Journals (Sweden)

    Dermot Phelan

    Full Text Available In asymptomatic subjects B-type natriuretic peptide (BNP is associated with adverse cardiovascular outcomes even at levels well below contemporary thresholds used for the diagnosis of heart failure. The mechanisms behind these observations are unclear. We examined the hypothesis that in an asymptomatic hypertensive population BNP would be associated with sub-clinical evidence of cardiac remodeling, inflammation and extracellular matrix (ECM alterations. We performed transthoracic echocardiography and sampled coronary sinus (CS and peripheral serum from patients with low (n = 14 and high BNP (n = 27. Peripheral BNP was closely associated with CS levels (r = 0.92, p<0.001. CS BNP correlated significantly with CS levels of markers of collagen type I and III turnover including: PINP (r = 0.44, p = 0.008, CITP (r = 0.35, p = 0.03 and PIIINP (r = 0.35, p = 0.001, and with CS levels of inflammatory cytokines including: TNF-α (r = 0.49, p = 0.002, IL-6 (r = 0.35, p = 0.04, and IL-8 (r = 0.54, p<0.001. The high BNP group had greater CS expression of fibro-inflammatory biomarkers including: CITP (3.8±0.7 versus 5.1±1.9, p = 0.007, TNF-α (3.2±0.5 versus 3.7±1.1, p = 003, IL-6 (1.9±1.3 versus 3.4±2.7, p = 0.02 and hsCRP (1.2±1.1 versus 2.4±1.1, p = 0.04, and greater left ventricular mass index (97±20 versus 118±26 g/m(2, p = 0.03 and left atrial volume index (18±2 versus 21±4, p = 0.008. Our data provide insight into the mechanisms behind the observed negative prognostic impact of modest elevations in BNP and suggest that in an asymptomatic hypertensive cohort a peripheral BNP measurement may be a useful marker of an early, sub-clinical pathological process characterized by cardiac remodeling, inflammation and ECM alterations.

  19. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Takeshi, E-mail: thashimo@fc.ritsumei.ac.jp [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Yokokawa, Takumi; Endo, Yuriko [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Iwanaka, Nobumasa [Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Higashida, Kazuhiko [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Faculty of Sport Science, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192 (Japan); Taguchi, Sadayoshi [Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan)

    2013-10-11

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O{sub 2} for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  20. Modest hypoxia significantly reduces triglyceride content and lipid droplet size in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Hashimoto, Takeshi; Yokokawa, Takumi; Endo, Yuriko; Iwanaka, Nobumasa; Higashida, Kazuhiko; Taguchi, Sadayoshi

    2013-01-01

    Highlights: •Long-term hypoxia decreased the size of LDs and lipid storage in 3T3-L1 adipocytes. •Long-term hypoxia increased basal lipolysis in 3T3-L1 adipocytes. •Hypoxia decreased lipid-associated proteins in 3T3-L1 adipocytes. •Hypoxia decreased basal glucose uptake and lipogenic proteins in 3T3-L1 adipocytes. •Hypoxia-mediated lipogenesis may be an attractive therapeutic target against obesity. -- Abstract: Background: A previous study has demonstrated that endurance training under hypoxia results in a greater reduction in body fat mass compared to exercise under normoxia. However, the cellular and molecular mechanisms that underlie this hypoxia-mediated reduction in fat mass remain uncertain. Here, we examine the effects of modest hypoxia on adipocyte function. Methods: Differentiated 3T3-L1 adipocytes were incubated at 5% O 2 for 1 week (long-term hypoxia, HL) or one day (short-term hypoxia, HS) and compared with a normoxia control (NC). Results: HL, but not HS, resulted in a significant reduction in lipid droplet size and triglyceride content (by 50%) compared to NC (p < 0.01). As estimated by glycerol release, isoproterenol-induced lipolysis was significantly lowered by hypoxia, whereas the release of free fatty acids under the basal condition was prominently enhanced with HL compared to NC or HS (p < 0.01). Lipolysis-associated proteins, such as perilipin 1 and hormone-sensitive lipase, were unchanged, whereas adipose triglyceride lipase and its activator protein CGI-58 were decreased with HL in comparison to NC. Interestingly, such lipogenic proteins as fatty acid synthase, lipin-1, and peroxisome proliferator-activated receptor gamma were decreased. Furthermore, the uptake of glucose, the major precursor of 3-glycerol phosphate for triglyceride synthesis, was significantly reduced in HL compared to NC or HS (p < 0.01). Conclusion: We conclude that hypoxia has a direct impact on reducing the triglyceride content and lipid droplet size via

  1. Indirect measurement of lymphatic absorption in CAPD patients is not influenced by trapping

    NARCIS (Netherlands)

    Struijk, D. G.; Koomen, G. C.; Krediet, R. T.; Arisz, L.

    1992-01-01

    The disappearance rate of intraperitoneally administered macromolecules is often used to calculate lymphatic absorption during CAPD. The possible contribution of local accumulation (trapping) of such solutes in the tissues surrounding the peritoneal cavity, leading to overestimation of lymphatic

  2. Wave energy absorption by ducks

    OpenAIRE

    Kurniawan, Adi

    2017-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle.

  3. Wave energy absorption by ducks

    DEFF Research Database (Denmark)

    Kurniawan, Adi

    2018-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle....

  4. Atomic absorption instrument functional description

    International Nuclear Information System (INIS)

    Bystroff, R.I.; Boyle, W.G. Jr.; Barton, G.W. Jr.

    1976-01-01

    This report describes a proposed system for automating atomic absorption analysis. The system consists of two atomic absorption instruments and an automatic sampler that can be attached to either instrument. A computer program controls the sampling and gathers data. The program then uses the data to perform bookkeeping, data processing, and report writing

  5. Sublinear absorption in OCS gas

    International Nuclear Information System (INIS)

    Bogani, F.; Querzoli, R.; Ernst, K.

    1988-01-01

    Sublinear absorption in OCS gas has been experimentally studied in detail by means of an optoacustic technique and transmission measurements. The best fit of the results is obtained by a phenomenological model, that considers the process as the sum of one-and two-photon absorptions

  6. Optical absorption of irradiated carbohydrates

    International Nuclear Information System (INIS)

    Supe, A.A.; Tiliks, Yu.E.

    1994-01-01

    The optical absorption spectra of γ-irradiated carbohydrates (glucose, lactose, sucrose, maltose, and starch) and their aqueous solutions were studied. The comparison of the data obtained with the determination of the concentrations of molecular and radical products of radiolysis allows the absorption bands with maxima at 250 and 310 nm to be assigned to the radicals trapped in the irradiated carbohydrates

  7. Water absorption in brick masonry

    NARCIS (Netherlands)

    Brocken, H.J.P.; Smolders, H.R.

    1996-01-01

    The water absorption in brick, mortar that was cured separately, and masonry samples was studied using NMR. Models of the moisture transport are usually formulated on the basis of a diffusion equation. In the case of water absorption in separate brick and mortar samples, the moisture diffusivity in

  8. Subgap absorption in conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  9. Multifunctional hybrids for electromagnetic absorption

    International Nuclear Information System (INIS)

    Huynen, I.; Quievy, N.; Bailly, C.; Bollen, P.; Detrembleur, C.; Eggermont, S.; Molenberg, I.; Thomassin, J.M.; Urbanczyk, L.

    2011-01-01

    Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

  10. Broadband enhancement of infrared absorption in microbolometers using Ag nanocrystals

    International Nuclear Information System (INIS)

    Hyun, Jerome K.; Ahn, Chi Won; Kim, Woo Choong; Kim, Tae Hyun; Hyun, Moon Seop; Kim, Hee Yeoun; Park, Jae Hong; Lee, Won-Oh

    2015-01-01

    High performance microbolometers are widely sought for thermal imaging applications. In order to increase the performance limits of microbolometers, the responsivity of the device to broadband infrared (IR) radiation needs to be improved. In this work, we report a simple, quick, and cost-effective approach to modestly enhance the broadband IR response of the device by evaporating Ag nanocrystals onto the light entrance surface of the device. When irradiated with IR light, strong fields are built up within the gaps between adjacent Ag nanocrystals. These fields resistively generate heat in the nanocrystals and underlying substrate, which is transduced into an electrical signal via a resistive sensing element in the device. Through this method, we are able to enhance the IR absorption over a broadband spectrum and improve the responsivity of the device by ∼11%

  11. Radioisotope studies for quantitative measurement of manganese absorption

    International Nuclear Information System (INIS)

    Helbig, U.

    1981-01-01

    Purpose of the present study was to quantitatively determine the manganese absorption in growing rats by means of radioisotopes. First of all the following factors had to be investigated, which are significant for this determination: Measurability of stable and radioactive Mn in rat tissues; labelling of stable Mn and distribution of stable and radioactive Mn in the organism; verification of the isotope dilution method and of the comparative balance method with regard to its applicability for the determination of the true Mn absorption. We useed male and female Sprague-Dawley rats. The most important results are summarized in the following: in some separate tissues measurement of stable Mn was accompanied by difficulties. The measurement of radioactive Mn however, could be performed without any problems. 10 d after i.m. injection of 54 Mn only 17% of the administered Mn was still detectable in the organism. However, there was no uniform tissue labelling found. Therefore it is possible to an only restricted extent to draw quantitative conclusions on the content of stable Mn. A high percentage of stable and radioactive Mn was found above all in the liver. The isotope dilution method permits by feces analysis to differentiate between unabsorbed Mn coming from the food and endogenic Mn coming from the organism itself. The effective Mn absorption was also determined by means of the comparative balance method. By means of the isotope dilution method we determined the quantitative Mn-absorption with staged Mn administration and the contribution of absorption and excretion to the homeostatic regulation mechanisms of Mn. We found that absorption and excretion help the organism to keep an almost constant Mn concentration even with a differing Mn supply. (orig./MG) [de

  12. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  13. Importance of the green color, absorption gradient, and spectral absorption of chloroplasts for the radiative energy balance of leaves.

    Science.gov (United States)

    Kume, Atsushi

    2017-05-01

    Terrestrial green plants absorb photosynthetically active radiation (PAR; 400-700 nm) but do not absorb photons evenly across the PAR waveband. The spectral absorbance of photosystems and chloroplasts is lowest for green light, which occurs within the highest irradiance waveband of direct solar radiation. We demonstrate a close relationship between this phenomenon and the safe and efficient utilization of direct solar radiation in simple biophysiological models. The effects of spectral absorptance on the photon and irradiance absorption processes are evaluated using the spectra of direct and diffuse solar radiation. The radiation absorption of a leaf arises as a consequence of the absorption of chloroplasts. The photon absorption of chloroplasts is strongly dependent on the distribution of pigment concentrations and their absorbance spectra. While chloroplast movements in response to light are important mechanisms controlling PAR absorption, they are not effective for green light because chloroplasts have the lowest spectral absorptance in the waveband. With the development of palisade tissue, the incident photons per total palisade cell surface area and the absorbed photons per chloroplast decrease. The spectral absorbance of carotenoids is effective in eliminating shortwave PAR (solar radiation. However, most of the near infrared radiation is unabsorbed and heat stress is greatly reduced. The incident solar radiation is too strong to be utilized for photosynthesis under the current CO 2 concentration in the terrestrial environment. Therefore, the photon absorption of a whole leaf is efficiently regulated by photosynthetic pigments with low spectral absorptance in the highest irradiance waveband and through a combination of pigment density distribution and leaf anatomical structures.

  14. Sabine absorption coefficients to random incidence absorption coefficients

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2014-01-01

    into random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...

  15. Absorption factor for cylindrical samples

    International Nuclear Information System (INIS)

    Sears, V.F.

    1984-01-01

    The absorption factor for the scattering of X-rays or neutrons in cylindrical samples is calculated by numerical integration for the case in which the absorption coefficients of the incident and scattered beams are not equal. An extensive table of values having an absolute accuracy of 10 -4 is given in a companion report [Sears (1983). Atomic Energy of Canada Limited, Report No. AECL-8176]. In the present paper an asymptotic expression is derived for the absorption factor which can be used with an error of less than 10 -3 for most cases of interest in both neutron inelastic scattering and neutron diffraction in crystals. (Auth.)

  16. Modest effect on plaque progression and vasodilatory function in atherosclerosis-prone mice exposed to nanosized TiO2

    DEFF Research Database (Denmark)

    Mikkelsen, Lone; Sheykhzade, Majid; Jensen, Keld A

    2011-01-01

    of atherosclerotic plaques in aorta was assessed in mice exposed to nanosized TiO2 (0.5 mg/kg bodyweight) once a week for 4 weeks. We measured mRNA levels of Mcp-1, Mip-2, Vcam-1, Icam-1 and Vegf in lung tissue to assess pulmonary inflammation and vascular function. TiO2-induced alterations in nitric oxide (NO...... were intratracheally instilled (0.5 mg/kg bodyweight) with rutile fine TiO2 (fTiO2, 288 nm), photocatalytic 92/8 anatase/rutile TiO2 (pTiO2, 12 nm), or rutile nano TiO2 (nTiO2, 21.6 nm) at 26 and 2 hours before measurement of vasodilatory function in aorta segments mounted in myographs. The progression...

  17. Lymphatic Vascular Regeneration : The Next Step in Tissue Engineering

    NARCIS (Netherlands)

    Huethorst, Eline; Krebber, Merle M; Fledderus, Joost O; Gremmels, Hendrik; Xu, Yan Juan; Pei, Jiayi; Verhaar, Marianne C; Cheng, Caroline

    2016-01-01

    The lymphatic system plays a crucial role in interstitial fluid drainage, lipid absorption, and immunological defense. Lymphatic dysfunction results in lymphedema, fluid accumulation, and swelling of soft tissues, as well as a potentially impaired immune response. Lymphedema significantly reduces

  18. Human tissue optical properties measurements and light propagation modelling

    CSIR Research Space (South Africa)

    Dam, JS

    2006-07-01

    Full Text Available Biomedical Optics is the study of the optical properties of living biological material, especially its scattering and absorption characteristics, and their significance to light propagation within the material. Determination of tissue optical...

  19. OZONE ABSORPTION IN RAW WATERS

    Directory of Open Access Journals (Sweden)

    LJILJANA TAKIĆ

    2008-03-01

    Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

  20. Microwaves absorption in superconducting materials

    International Nuclear Information System (INIS)

    Biasi, R.S. de; Fernandes, A.A.R.; Pereira, R.F.R.

    1989-01-01

    Microwaves absorption measures in two superconductors ceramics systems, Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O are compared with similars datas obtained in the same band of temperature by a conventional method, mutual inductance. The results suggest that the microwaves absorption can be used as single and non-destructive method for investigating the properties of ceramics superconductors. (C.G.C.) [pt

  1. Ultrasonic absorption in solid specimens

    International Nuclear Information System (INIS)

    Siwabessy, P.J. W.; Stewart, G.A.

    1996-01-01

    As part of a project to measure the absorption of high frequency (50 - 500 kHz) sonar signals in warm sea-water, a laboratory apparatus has been constructed and tested against room temperature distilled water and various solutions of MgSO 4 (chemical relaxation of MgSO 4 is the major contribution to absorption below 200 kHz). The technique involves monitoring the decay of an acoustic signal for different sizes of vessels of water suspended in an evacuated chamber. So far, all containing vessels used have been spherical in shape. Extrapolation of the results to infinite volume yields the absorption due to the water alone. In order to accommodate variations in temperature and pressure, and to make the system more robust (e.g. for ship deck usage), it is desirable to employ stainless steel vessels. However, it was found that the quality of the data was greatly improved when pyrex glass spheres were used. The stainless steel spheres were manufactured by welding together mechanically spun hemispheres. The linear frequency dependence characteristic of acoustic absorption in solids was observed (in contrast to the quadratic frequency dependence of acoustic absorption in water), and the acoustic absorption was found to depend strongly on the thermal history of the steel

  2. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe{sub 3}O{sub 4} composite

    Energy Technology Data Exchange (ETDEWEB)

    Min, Dandan, E-mail: mdd4776@126.com; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-08-01

    Highlights: • Flake carbonyl iron/Fe{sub 3}O{sub 4} composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe{sub 3}O{sub 4} (FCI/Fe{sub 3}O{sub 4}) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe{sub 3}O{sub 4} composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe{sub 3}O{sub 4} composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe{sub 3}O{sub 4} composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  3. Reducing microwave absorption with fast frequency modulation.

    Science.gov (United States)

    Qin, Juehang; Hubler, A

    2017-05-01

    We study the response of a two-level quantum system to a chirp signal, using both numerical and analytical methods. The numerical method is based on numerical solutions of the Schrödinger solution of the two-level system, while the analytical method is based on an approximate solution of the same equations. We find that when two-level systems are perturbed by a chirp signal, the peak population of the initially unpopulated state exhibits a high sensitivity to frequency modulation rate. We also find that the aforementioned sensitivity depends on the strength of the forcing, and weaker forcings result in a higher sensitivity, where the frequency modulation rate required to produce the same reduction in peak population would be lower. We discuss potential applications of this result in the field of microwave power transmission, as it shows applying fast frequency modulation to transmitted microwaves used for power transmission could decrease unintended absorption of microwaves by organic tissue.

  4. Nonfreezing Tissue Injuries

    Science.gov (United States)

    ... Early Breast Cancer to Avoid Chemo Could a Blood Test Spot Lung Cancer Early? Experimental Drug Shows 'Modest' Benefit ... the foot Elevating the foot Keeping the foot dry and ... impairs blood flow, avoiding smoking and using nicotine products may ...

  5. Noninvasive photoacoustic measurement of absorption coefficient using internal light irradiation of cylindrical diffusing fiber

    Science.gov (United States)

    Peng, Dong-qing; Zhu, Li-li; Li, Zhi-fang; Li, Hui

    2017-09-01

    Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and internal light irradiation of cylindrical diffusing fiber (CDF) to quantify the target optical absorption coefficient. Absorption coefficients for ink absorbers are firstly determined through photoacoustic and spectrophotometric measurements at the same excitation, which demonstrates the feasibility of this method. Also, the optical absorption coefficients of ink absorbers with several concentrations are measured. Finally, the two-dimensional scanning photoacoustic image is obtained. Optical absorption coefficient measurement and simultaneous photoacoustic imaging of absorber non-invasively are the typical characteristics of the method. This method can play a significant role for non-invasive determination of blood oxygen saturation, the absorption-based imaging and therapy.

  6. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    International Nuclear Information System (INIS)

    Asimov, M.; Asimov, R.; Gisbrecht, A.

    1999-01-01

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO 2 ) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO 2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO 2 and Hb

  7. Behavioral and Biological Effects of Resonant Electromagnetic Absorption in Rats.

    Science.gov (United States)

    1976-11-01

    for 23-550 MHz, biological phantom materials to simulate tissue properties, monopole -above-ground radiation chamber, design of a waveguide slot array...Resonant Electromagnetic Power Absorption in Rats" L T OF FTCTIF S A,’L i .LIS SFigure Pa 1 A photograiph of the monopole -above-gruund radiation...and mice without ground effects (L/2b = 3.25 where 21Tb is the "average" circumference of the animals) ........ .................... ... 20 8

  8. Tissue irradiator

    International Nuclear Information System (INIS)

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-01-01

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in-vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood-carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170

  9. Absorption properties of identical atoms

    International Nuclear Information System (INIS)

    Sancho, Pedro

    2013-01-01

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions

  10. Transdermic absorption of Melagenina II

    International Nuclear Information System (INIS)

    Hernandez Gonzalez, I.; Martinez Lopez, B.; Ruiz Pena, M.; Caso Pena, R.

    1997-01-01

    The transdermic absorption of Melagenina II (MII) was evaluated. MII was a labelled with 125I by the yodogen method and purified by column chromatography with Sephadex LH-20 in ethanol: water (7:3). In vitro absorption of ( 125I ) - MII thought human skin was carried out in Keshary-Chien modified diffusion cells. Tape stripping method was applied after 24 hours to evaluate the accumulated activity in dermis and epidermis. In vivo assays were performed in Sprague Dawley rats to analyze absorption of MII until 24 hours after a single application and for five days a low penetrability of the drug while in vivo there were not found blood levels significantly greater than zero , nevertheless and important amount of radioactivity was found in feces and urine. The activity was concentrated mainly in the application site in both models

  11. Architecture for Absorption Based Heaters

    Science.gov (United States)

    Moghaddam, Saeed; Chugh, Devesh

    2018-04-24

    An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. The absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.

  12. Mercury absorption in aqueous hypochlorite

    International Nuclear Information System (INIS)

    Zhao, L.L.; Rochelle, G.T.

    1999-01-01

    The absorption of elemental Hg vapor into aqueous hypochlorite was measured in a stirred tank reactor at 25 and 55C. NaOCl strongly absorbs Hg even at high pH. Low pH, high Cl - and high-temperature favor mercury absorption. Aqueous free Cl 2 was the active species that reacted with mercury. However, chlorine desorption was evident at high Cl - and pH 15 M -1 s -1 at 25C and 1.4x10 17 M -1 s -1 at 55C. Gas-phase reaction was observed between Hg and Cl 2 on apparatus surfaces. Strong mercury absorption in water was also detected with Cl 2 present. Results indicate that the chlorine concentration, moisture, and surface area contribute positively to mercury removal. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  13. Phytases for improved iron absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    Phytase enzymes present an alternative to iron supplements, because they have been shown to improve iron absorption by means of catalysing the degradation of a potent iron absorption inhibitor: phytic acid. Phytic acid is a hexaphosphate of inositol and is particularly prevalent in cereal grains......, where it serves as a storage molecule for phosphorous. Phytic acid is also associated with minerals. The minerals are bound by chelation to the negatively charged phosphate groups in phytic acid. Phytases catalyse the dephosphorylation of phytic acid, thus releasing bound minerals to make them available...... for absorption. This article presents research on phytase catalysis in gastric conditions and considers potential benefits and drawbacks for using phytases as a food supplement....

  14. Absorption-heat-pump system

    Science.gov (United States)

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  15. Absorption Efficiency of Receiving Antennas

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...... patterns. It can approach 100% as closely as desired, although in practice this may not be an attractive solution. An example with a small endfire array of dipoles shows an efficiency of 93%. Several examples of small conical horn antennas are also given, and they all have absorption efficiencies less than...

  16. Aerosol Absorption Measurements in MILAGRO.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  17. Absorption of plant-incorporated nuclear fuel cycle elements from the gastro-intestinal tract

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Garland, T.R.; Cataldo, D.A.; Schreckhise, R.G.

    1979-01-01

    Soybean plants (Glycine max cv Williams) grown hydroponically on solutions containing ammonium pertechnetate ( 95 Tcsup(m)O - 4 ) were fed to rats (omnivores) and guinea pigs (herbivores). Absorption of plant-incorporated technetium was compared with absorption of inorganic 95 Tcsup(m) from a gavaged solution or with absorption of 95 Tcsup(m) added to non-radioactive soybean tissues. In a second study absorption of plutonium from alfalfa (Medicago sativa cv Ladak) grown on soil amended with either 238 Pu nitrate or 238 Pu-DTPA was compared with absorption of gavaged 238 Pu solutions and 238 Pu mixed with non-radioactive alfalfa. Incorporation of 95 Tcsup(m) into soybean tissues resulted in decreased absorption by both animal species. In contrast, incorporation of 238 Pu in alfalfa resulted in an increased absorption when compared with controls that were administered inorganic 238 Pu. These results suggest that organic binding may alter, in either direction, absorption of nuclear fuel cycle elements. (author)

  18. Relativistic effects in resonance absorption

    International Nuclear Information System (INIS)

    Drake, J.F.; Lee, Y.C.

    1976-01-01

    The role of the relativistic-electron-mass variation in the generation of plasma waves by the linear mode conversion of intense electromagnetic waves is investigated. The increase in the electron mass in high intensity regions of the mode-converted wave reduces the local plasma frequency and thereby strongly modifies the plasma-driver resonance. A spatial discontinuity in the structure of the mode-converted wave results and causes the wave to break. Under rather modest restrictions, the wave breaking resulting from these effects occurs before the wave amplitude is limited either by thermal convection or by breaking caused by previously investigated nonrelativistic effects. Consequently, the amplitude of the mode-converted plasma wave should saturate at a much lower level than previously predicted. For simplicity, the analysis is limited to the initial stages of mode conversion where the ion dynamics can be neglected. The validity of this approximation is discussed

  19. Konference Distillation and Absorption 2010

    Czech Academy of Sciences Publication Activity Database

    Bendová, Magdalena

    2009-01-01

    Roč. 103, č. 10 (2009), s. 862 ISSN 0009-2770 R&D Projects: GA MŠk LA320 Institutional research plan: CEZ:AV0Z40720504 Keywords : conference * announcement * distillation and absorption Subject RIV: CF - Physical ; Theoretical Chemistry

  20. Gamm-ray absorption techniques

    International Nuclear Information System (INIS)

    Charlton, J.S.

    1986-01-01

    In this chapter the principles of gamma-ray absorption are described and important applications in plant and process techniques such as measurement of thickness of deposits on pipes, checking for voids in concrete, metal corrosion, measurement of the density of materials inside vessels in industrial radiography are discussed. (U.K.)

  1. Emission and absorption of radiation

    International Nuclear Information System (INIS)

    Fetter, S.

    1992-01-01

    A full understanding of fissile-material detection requires a solid knowledge of nuclear physics, especially the emission and absorption of radiation. The purpose of this paper is therefore to give a brief explanation of these processes so that the reader can better understand the assumptions leading to the results in the main text

  2. Absorptive capacity and smart companies

    Directory of Open Access Journals (Sweden)

    Patricia Moro González

    2014-12-01

    Full Text Available Purpose: The current competitive environment is substantially modifying the organizations’ learning processes due to a global increase of available information allowing this to be transformed into knowledge. This opportunity has been exploited since the nineties by the tools of “Business Analytics” and “Business Intelligence” but, nevertheless, being integrated in the study of new organizational capacities engaged in the process of creating intelligence inside organizations is still an outstanding task. The review of the concept of absorptive capacity and a detailed study from the perspective of this new reality will be the main objective of study of this paper.Design/methodology/approach: By comparing classical absorptive capacity and absorptive capacity from the point of view of information management tools in each one of the three stages of the organizational learning cycle, some gaps of the former are overcome/fulfilled. The academic/bibliographical references provided in this paper have been obtained from ISI web of knowledge, Scopus and Dialnet data bases, supporting the state of affairs on absorptive capacity and thereafter filtering by "Business Intelligence" and "Business Analytics". Specialized websites and Business Schools` Publications there have also been included, crowning the content on information management tools used that are currently used in the strategic consulting.Findings: Our contribution to the literature is the development of "smart absorptive capacity". This is a new capacity emerging from the reformulation of the classical concept of absorptive capacity wherein some aspects of its definition that might have been omitted are emphasized. The result of this new approach is the creation of a new Theoretical Model of Organizational Intelligence, which aims to explain, within the framework of the Resources and Capabilities Theory, the competitive advantage achieved by the so-called smart companies

  3. Fat digestion and absorption in spice-pretreated rats.

    Science.gov (United States)

    Prakash, Usha N S; Srinivasan, Krishnapura

    2012-02-01

    A few common spices are known to stimulate secretion of bile with higher amount of bile acids which play a major role in digestion and absorption of dietary lipids. It would be appropriate to verify if these spices enable efficient digestion and absorption during high-fat intake. In this context, dietary ginger (0.05%), piperine (0.02%), capsaicin (0.015%), and curcumin (0.5%) were examined for their influence on bile secretion, digestive enzymes of pancreas and absorption of dietary fat in high-fat (30%) fed Wistar rats for 8 weeks. These spices enhanced the activity of pancreatic lipase, amylase, trypsin and chymotrypsin by 22-57%, 32-51%, 63-81% and 12-38%, respectively. Dietary intake of spices along with high-fat enhanced fat absorption. These dietary spices increased bile secretion with higher bile acid content. Stimulation of lipid mobilisation from adipose tissue was suggested by the decrease in perirenal adipose tissue weight by dietary capsaicin and piperine. This was also accompanied by prevention of the accumulation of triglyceride in liver and serum in high-fat fed rats. Activities of key lipogenic enzymes in liver were reduced which was accompanied by an increased activity of hormone-sensitive lipase. Thus, dietary ginger and other spice compounds enhance fat digestion and absorption in high-fat fed situation through enhanced secretion of bile salts and a stimulation of the activity pancreatic lipase. At the same time, the energy expenditure is facilitated by these spices to prevent the accumulation of absorbed fat. Copyright © 2011 Society of Chemical Industry.

  4. Converting Sabine absorption coefficients to random incidence absorption coefficients

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2013-01-01

    are suggested: An optimization method for the surface impedances for locally reacting absorbers, the flow resistivity for extendedly reacting absorbers, and the flow resistance for fabrics. With four porous type absorbers, the conversion methods are validated. For absorbers backed by a rigid wall, the surface...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...... impedance optimization produces the best results, while the flow resistivity optimization also yields reasonable results. The flow resistivity and flow resistance optimization for extendedly reacting absorbers are also found to be successful. However, the theoretical conversion factors based on Miki's model...

  5. Mice expressing a “hyper-sensitive” form of the CB1 cannabinoid receptor (CB1) show modestly enhanced alcohol preference and consumption

    Science.gov (United States)

    Gonek, Maciej; Zee, Michael L.; Farnsworth, Jill C.; Amin, Randa A.; Andrews, Mary-Jeanette; Davis, Brian J.; Mackie, Ken; Morgan, Daniel J.

    2017-01-01

    We recently characterized S426A/S430A mutant mice expressing a desensitization-resistant form of the CB1 receptor. These mice display an enhanced response to endocannabinoids and ∆9-THC. In this study, S426A/S430A mutants were used as a novel model to test whether ethanol consumption, morphine dependence, and reward for these drugs are potentiated in mice with a “hyper-sensitive” form of CB1. Using an unlimited-access, two-bottle choice, voluntary drinking paradigm, S426A/S430A mutants exhibit modestly increased intake and preference for low (6%) but not higher concentrations of ethanol. S426A/S430A mutants and wild-type mice show similar taste preference for sucrose and quinine, exhibit normal sensitivity to the hypothermic and ataxic effects of ethanol, and have normal blood ethanol concentrations following administration of ethanol. S426A/S430A mutants develop robust conditioned place preference for ethanol (2 g/kg), morphine (10 mg/kg), and cocaine (10 mg/kg), demonstrating that drug reward is not changed in S426A/S430A mutants. Precipitated morphine withdrawal is also unchanged in opioid-dependent S426A/S430A mutant mice. Although ethanol consumption is modestly changed by enhanced CB1 signaling, reward, tolerance, and acute sensitivity to ethanol and morphine are normal in this model. PMID:28426670

  6. Mice expressing a "hyper-sensitive" form of the CB1 cannabinoid receptor (CB1 show modestly enhanced alcohol preference and consumption.

    Directory of Open Access Journals (Sweden)

    David J Marcus

    Full Text Available We recently characterized S426A/S430A mutant mice expressing a desensitization-resistant form of the CB1 receptor. These mice display an enhanced response to endocannabinoids and ∆9-THC. In this study, S426A/S430A mutants were used as a novel model to test whether ethanol consumption, morphine dependence, and reward for these drugs are potentiated in mice with a "hyper-sensitive" form of CB1. Using an unlimited-access, two-bottle choice, voluntary drinking paradigm, S426A/S430A mutants exhibit modestly increased intake and preference for low (6% but not higher concentrations of ethanol. S426A/S430A mutants and wild-type mice show similar taste preference for sucrose and quinine, exhibit normal sensitivity to the hypothermic and ataxic effects of ethanol, and have normal blood ethanol concentrations following administration of ethanol. S426A/S430A mutants develop robust conditioned place preference for ethanol (2 g/kg, morphine (10 mg/kg, and cocaine (10 mg/kg, demonstrating that drug reward is not changed in S426A/S430A mutants. Precipitated morphine withdrawal is also unchanged in opioid-dependent S426A/S430A mutant mice. Although ethanol consumption is modestly changed by enhanced CB1 signaling, reward, tolerance, and acute sensitivity to ethanol and morphine are normal in this model.

  7. Modest Amounts of Voluntary Exercise Reduce Pain- and Stress-Related Outcomes in a Rat Model of Persistent Hind Limb Inflammation.

    Science.gov (United States)

    Pitcher, Mark H; Tarum, Farid; Rauf, Imran Z; Low, Lucie A; Bushnell, Catherine

    2017-06-01

    Aerobic exercise improves outcomes in a variety of chronic health conditions, yet the support for exercise-induced effects on chronic pain in humans is mixed. Although many rodent studies have examined the effects of exercise on persistent hypersensitivity, the most used forced exercise paradigms that are known to be highly stressful. Because stress can also produce analgesic effects, we studied how voluntary exercise, known to reduce stress in healthy subjects, alters hypersensitivity, stress, and swelling in a rat model of persistent hind paw inflammation. Our data indicate that voluntary exercise rapidly and effectively reduces hypersensitivity as well as stress-related outcomes without altering swelling. Moreover, the level of exercise is unrelated to the analgesic and stress-reducing effects, suggesting that even modest amounts of exercise may impart significant benefit in persistent inflammatory pain states. Modest levels of voluntary exercise reduce pain- and stress-related outcomes in a rat model of persistent inflammatory pain, independently of the amount of exercise. As such, consistent, self-regulated activity levels may be more relevant to health improvement in persistent pain states than standardized exercise goals. Published by Elsevier Inc.

  8. Terahertz pulsed imaging of freshly excised human colonic tissues

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Caroline B; Gibson, Adam P [Department of Medical Physics and Bioengineering, University College London, London, WC1E 6BT (United Kingdom); Fitzgerald, Anthony; Wallace, Vincent P [School of Physics, University of Western Australia, Crawley 6009 (Australia); Reese, George; Tekkis, Paris [Division of Surgery, Chelsea and Westminster Campus, Imperial College London, London (United Kingdom); Goldin, Robert [Centre for Pathology, Imperial College London, St Mary' s Campus, London (United Kingdom); O' Kelly, P S [TeraView Ltd, Platinum Building, St John' s Innovation Park, Cowley Road, Cambridge, CB4 0WS (United Kingdom); Pickwell-MacPherson, Emma, E-mail: c.reid@medphys.ucl.ac.uk [Department of Electronic Engineering, Chinese University of Hong Kong, Shatin, NT (Hong Kong)

    2011-07-21

    We present the results from a feasibility study which measures properties in the terahertz frequency range of excised cancerous, dysplastic and healthy colonic tissues from 30 patients. We compare their absorption and refractive index spectra to identify trends which may enable different tissue types to be distinguished. In addition, we present statistical models based on variations between up to 17 parameters calculated from the reflected time and frequency domain signals of all the measured tissues. These models produce a sensitivity of 82% and a specificity of 77% in distinguishing between healthy and all diseased tissues and a sensitivity of 89% and a specificity of 71% in distinguishing between dysplastic and healthy tissues. The contrast between the tissue types was supported by histological staining studies which showed an increased vascularity in regions of increased terahertz absorption.

  9. Terahertz pulsed imaging of freshly excised human colonic tissues

    International Nuclear Information System (INIS)

    Reid, Caroline B; Gibson, Adam P; Fitzgerald, Anthony; Wallace, Vincent P; Reese, George; Tekkis, Paris; Goldin, Robert; O'Kelly, P S; Pickwell-MacPherson, Emma

    2011-01-01

    We present the results from a feasibility study which measures properties in the terahertz frequency range of excised cancerous, dysplastic and healthy colonic tissues from 30 patients. We compare their absorption and refractive index spectra to identify trends which may enable different tissue types to be distinguished. In addition, we present statistical models based on variations between up to 17 parameters calculated from the reflected time and frequency domain signals of all the measured tissues. These models produce a sensitivity of 82% and a specificity of 77% in distinguishing between healthy and all diseased tissues and a sensitivity of 89% and a specificity of 71% in distinguishing between dysplastic and healthy tissues. The contrast between the tissue types was supported by histological staining studies which showed an increased vascularity in regions of increased terahertz absorption.

  10. Influence of circulating epinephrine on absorption of subcutaneously injected insulin

    International Nuclear Information System (INIS)

    Fernqvist, E.; Gunnarsson, R.; Linde, B.

    1988-01-01

    Effects of epinephrine (Epi) infusion on the absorption of subcutaneously injected 125I-labeled soluble human insulin (10 U) from the thigh or the abdomen were studied in 16 healthy subjects and from the thigh in 10 insulin-dependent diabetic (IDDM) patients. Epi was infused at 0.3 (high dose) or 0.1 (low dose; healthy subjects) nmol.kg-1.min-1 i.v., resulting in arterial plasma Epi levels of approximately 6 and 2 nM, respectively. Saline was infused on a control day. Insulin absorption was measured as disappearance of radioactivity from the injection site and as appearance of plasma immunoreactive insulin (IRI). Adipose tissue blood flow was measured with the 133Xe clearance technique. First-order disappearance rate constants of 125I from the thigh depot decreased approximately 40-50% during the high dose of Epi compared with control (P less than .001). The corresponding decrease from the abdominal depot was approximately 40% (P less than .001), whereas no significant change was found during the low Epi dose. IRI fell compared with control in all groups at the high Epi dose. The Epi-induced depression of insulin absorption occurred despite unaltered or even slightly increased subcutaneous blood flow. The results indicate that circulating Epi at levels seen during moderate physical stress depresses the absorption of soluble insulin from subcutaneous injection sites to an extent that might be important for glycemic control in IDDM patients. Furthermore, dissociation is found between changes in insulin absorption and subcutaneous blood flow during Epi infusion, suggesting that factors other than blood flow may also influence the absorption of subcutaneously injected insulin

  11. Absorption/desorption in sprays

    International Nuclear Information System (INIS)

    Naimpally, A.

    1987-01-01

    This survey paper shall seek to present the present state of knowledge concerning absorption and desorption in spray chambers. The first part of the paper presents the theories and formulas for the atomization and break-up of sprays in nozzles. Formulas for the average (sauter-mean) diameters are then presented. For the case of absorption processes, the formulas for the dimensionless mass transfer coefficients is in drops. The total; mass transfer is the total of the transfer in individual drops. For the case of desorption of sparingly soluble gases from liquids in a spray chamber, the mass transfer occurs in the spray just at the point of break-up of the jet. Formulas for the desorption of gases are presented

  12. Bent Electro-Absorption Modulator

    DEFF Research Database (Denmark)

    2002-01-01

    by applying a variable electric or electronmagnetic field. The modulation of the complex refractive index results in a modulation of the refractive index contrast and the absorption coefficient for the waveguide at the frequency of the light. By carefully adjusting the composition of the semiconducting...... components and the applied electric field in relation to the frequency of the modulated radiation, the bending losses (and possibly coupling losses) will provide extinction of light guided by the bent waveguide section. The refractive index contract may be modulated while keeping the absorption coefficient......The present invention relates to a method and a device for modulating optical signals based on modulating bending losses in bend, quantum well semiconductor waveguide sections. The complex refractive index of the optical active semiconducting components of the waveguide section is modulated...

  13. Absorption of human skin and its detecting platform in the process of laser cosmetology

    Science.gov (United States)

    Zhang, Yong-Lin; Ouyang, Li; Wang, Yang

    2000-10-01

    Because of the melanin, hemoglobin and water molecules, etc. contained, light absorption of human skin tissue changes with wavelength of light. This is the principle used in laser cosmetology for treating pigment diseases and vascular lesion diseases as well as skin decoration such as body tattooing, eyebrow tattooing, etc. The parameters of treatment used in laser cosmetology principally come from the research of the skin tissue optical characteristics of whites, and it is not suitable for the Oriental. The absorption spectrum of yellow race alive skin has been researched. The detecting platform for use in the measuring of vivi-tissue absorption spectrum has been developed which using opto-electronic nondestructive testing and virtual instrument techniques. The degree of pathological changes of skin can be detected by this platform also, thus the shortcoming of dosage selection in laser clinical treatments which have been decided only by naked eye observation and past experience of doctors can be solved.

  14. Geometrical interpretation of optical absorption

    Energy Technology Data Exchange (ETDEWEB)

    Monzon, J. J.; Barriuso, A. G.; Sanchez-Soto, L. L. [Departamento de Optica, Facultad de Fisica, Universidad Complutense, E-28040 Madrid (Spain); Montesinos-Amilibia, J. M. [Departamento de Geometria y Topologia, Facultad de Matematicas, Universidad Complutense, E-28040 Madrid (Spain)

    2011-08-15

    We reinterpret the transfer matrix for an absorbing system in very simple geometrical terms. In appropriate variables, the system appears as performing a Lorentz transformation in a (1 + 3)-dimensional space. Using homogeneous coordinates, we map that action on the unit sphere, which is at the realm of the Klein model of hyperbolic geometry. The effects of absorption appear then as a loxodromic transformation, that is, a rhumb line crossing all the meridians at the same angle.

  15. Modernization of Atomic Absorption Spectrophotometer

    International Nuclear Information System (INIS)

    Tasic, Visa; Milivojevic, Dragan; Karabasevic, Dejan

    2003-01-01

    In Copper Institute in Bor, connection has been made between absorption spectrophotometer and standard PC with the aim to make its operation more reliable and comfortable. Applied solution includes both software and hardware components. An I/O interface module has been installed in PC [1]. Software component consists of programs for measuring and interpretation of results. Paper presents details of this job realization.(Author)

  16. Turbulent effective absorptivity and refractivity

    International Nuclear Information System (INIS)

    Rax, J.M.

    1984-09-01

    The problem of wave propagation in a turbulent magnetized plasma is investigated. Considering small scale, low frequency density fluctuations we solve the Maxwell equations and show that the eikonal approximation remains valid with an effective refractivity and an effective absorptivity taking into account the energy diffusion due to the turbulent motion. Then the result is applied to the problem of lower hybrid waves scattering by drift waves density fluctuations in tokamaks

  17. Slowing down with resonance absorption

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The presence of heavy nuclei in nuclear reactors, in significant concentrations, facilitates the appearance of absorption resonances. For the moderation in the presence of absorbers an exact solution of the integral equations is possible by numerical methods. Approximated solutions for separated resonances in function of the practical width, (NR and NRIM approximations) are discussed in this paper. The method is generalized, presenting the solution by an intermediate approximation, in the definition of the resonance integral. (Author) [pt

  18. Organizational forms and knowledge absorption

    Directory of Open Access Journals (Sweden)

    Radovanović Nikola

    2016-01-01

    Full Text Available Managing the entire portion of knowledge in an organization is a challenging task. At the organizational level, there can be enormous quantities of unknown, poorly valued or inefficiently applied knowledge. This is normally followed with the underdeveloped potential or inability of organizations to absorb knowledge from external sources. Facilitation of the efficient internal flow of knowledge within the established communication network may positively affect organizational capacity to absorb or identify, share and subsequently apply knowledge to commercial ends. Based on the evidences that the adoption of different organizational forms affects knowledge flows within an organization, this research analyzed the relationship between common organizational forms and absorptive capacity of organizations. In this paper, we test the hypothesis stating that the organizational structure affects knowledge absorption and exploitation in the organization. The methodology included quantitative and qualitative research method based on a questionnaire, while the data has been statistically analyzed and the hypothesis has been tested with the use of cross-tabulation and chi-square tests. The findings suggest that the type of organizational form affects knowledge absorption capacity and that having a less formalized and more flexible structure in an organization increases absorbing and exploiting opportunities of potentially valuable knowledge.

  19. Peculiarities of determination of coefficient of radionuclide absorption in alimentary canal of ruminants

    International Nuclear Information System (INIS)

    Korneev, N.A.; Sirotkin, A.N.; Rasin, I.M.; Sarapul'tsev, I.A.; Abramova, T.N.

    1986-01-01

    Sheep taken as example, the new method for calculation of the coefficient of radionuclide ( 65 Zn) absorption in gastrointestinal tract (GIT) is suggested. It is shown that the radionuclide absorption process of sheep lasted 35 h. In case of parenteral intake radionuclide excretion from tissues and organs and its inclusion in structural parts of blood occurs. In animals to which 65 Zn is injected orally, the same processes at 65 Zn simultaneous absorption in GIT during 35 h take place. In 35 hours after radio nuclide injection its absorption coefficient in the GIT of sheep constituted 10.1+-0.05%. Using traditional calculation methods the 65 Zn absorption coefficient for the first 24 h constituted 6.6%

  20. Tissue dose in thorotrast patients

    International Nuclear Information System (INIS)

    Kaul, A.; Noffz, W.

    1978-01-01

    Absorbed doses to the liver, spleen, red marrow, lungs, kidneys, and to various parts of bone tissue were calculated for long-term burdens of intravascularly injected Thorotrast. The estimates were performed for typical injection levels of 10, 30, 50 and 100 ml, based upon best estimates of 232 Th tissue distribution, and steady state activity ratios between the subsequent daughters. Correcting for the α-particle self absorption within Thorotrast aggregates, the mean α-dose to a standard 70-kg man at 30 yr after the injection 0f 25 ml of Thorotrast is 750 rad to the liver, 2100 rad to the spleen, 270 rad to the red marrow, 60-620 rad in various parts of the lung, and 13 rad to the kidneys. Dose rates to various parts of bone tissue (bone surface, compact, and cancellous bone) were estimated by applying the ICRP model on alkaline earth metabolism to the continuous translocation of thorium daughters to bone and to the formation of thorium daughters by decay within bone tissue. The average dose to calcified bone from translocated 224 Ra with its daughters is 18 rad at 30 yr after the injection of 25 ml of Thorotrast. Considering the Spiess-Mays risk coefficient of 0.9-1.7% bone sarcoma/ 100 rad of average skeletal dose from 224 Ra and its daughters, the induction of 1.6-3.1 bone sarcomas per 1000 Thorotrast patients is predicted. (author)

  1. Near infrared laser penetration and absorption in human skin

    Science.gov (United States)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  2. Enriching Absorptive Capacity through Social Interaction

    NARCIS (Netherlands)

    Hotho, Jasper J.; Becker-Ritterspach, Florian; Saka-Helmhout, Ayse

    Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within multinational enterprises. But how individual behaviour translates into absorptive capacity at the subsidiary level, and how this is contingent on subsidiaries' social context, remains under-addressed.

  3. Hopping absorption edge in silicon inversion layers

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.

    1983-09-01

    The low frequency gap observed in the absorption spectrum of silicon inversion layers is related to the AC variable range hopping. The frequency dependence of the absorption coefficient is calculated. (author)

  4. Plant root absorption and metabolic fate of technetium in plants

    International Nuclear Information System (INIS)

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.

    1984-10-01

    Root absorption characteristics for the pertechnetate ion (TcO 4 - ) were determined using hydroponically grown soybean seedlings (Glycine max, cv. Williams). Absorption of TcO 4 - was found to be linear with time, sensitive to metabolic inhibitors, and exhibit multiple absorption isotherms over the concentration range 0.02 to 10 μM. The isotherms had calculated K/sub s/ values of 0.09, 8.9, and 54 μM for intact seedlings. The uptake of TcO 4 - (0.25 μM) was inhibited by a fourfold concentration excess of sulfate, phosphate, and selenate, but not by borate, nitrate, tungstate, perrhenate, iodate or vanadate. Kinetic studies demonstrated that sulfate, phosphate, and selenate were competitive inhibitors of TcO 4 - absorption. Once absorbed, Tc was readily transported as TcO 4 - to shoot tissues of soybean and subsequently associated with protein constituents. The chemical fate of Tc in plants varies with plant species. Plants high in nonprotein sulfhydryl compounds (Allium species) exhibited markedly different root/shoot distribution and protein incorporation patterns from species with low sulfur requirements (soybean, alfalfa, mustard). Based on these differences, Tc/S/Se tracer studies were employed to resolve the comparative fate of these probable analogs. 20 references, 5 figures, 5 tables

  5. Intestinal absorption of chromium as affected by wheat bran

    International Nuclear Information System (INIS)

    Keim, K.S.; Holloway, C.L.; Hegsted, M.

    1986-01-01

    This study was designed to investigate the influence of dietary fiber, as found in wheat bran, on the absorption of chromium. Twenty male Sprague-Dawley rats were divided into two groups of 10. The control was fed a semi-purified diet containing casein, methionine, cornstarch, sucrose, corn oil, mineral and vitamin mix, and choline bitartrate. The experimental group was fed the same diet but with soft red winter wheat bran added to a level of 35% of the diet at the expense of sucrose. To determine chromium absorption and uptake by selected tissues, rats were fasted for 24 hr, fed 5 g of the respective diet, 2 hr later intubated with 100μCi of Cr-51of sacrificed 24 hr later. The rats wee housed in metabolic cages after the Cr-51 intubation. The addition of wheat brand to the diet did not significantly affect chromium absorption as measured by percent dose of Cr-51 in the 24 hr urine. The percent dose in the control group was 0.68 +/- 0.20% (mean +/- SEM) and in the experimental group 0.63 +/- 0.24% (mean +/-SEM) (N.S.). The cr-51 uptake of liver, spleen, jejunum, and blood was not statistically different between groups. These results indicate that dietary fiber as found in wheat bran does not impair intestinal absorption of chromium

  6. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I; Klemsdal, E [Gaz de France (GDF), 75 - Paris (France); Le Goff, P; Hornut, J M [LSGC-ENSIC, 54 - Nancy (France)

    1998-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  7. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I.; Klemsdal, E. [Gaz de France (GDF), 75 - Paris (France); Le Goff, P.; Hornut, J.M. [LSGC-ENSIC, 54 - Nancy (France)

    1997-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  8. Lactulose stimulates calcium absorption in postmenopausal women

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muijs, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Animal studies have indicated that calcium absorption is increased by lactulose, a synthetic disaccharide. Therefore, the influence of lactulose on calcium absorption was measured in postmenopausal women who may benefit from the possible enhancing effect of lactulose on calcium absorption. Twelve

  9. Uniform semiclassical approximation for absorptive scattering systems

    International Nuclear Information System (INIS)

    Hussein, M.S.; Pato, M.P.

    1987-07-01

    The uniform semiclassical approximation of the elastic scattering amplitude is generalized to absorptive systems. An integral equation is derived which connects the absorption modified amplitude to the absorption free one. Division of the amplitude into a diffractive and refractive components is then made possible. (Author) [pt

  10. Iron absorption in relation to iron status

    International Nuclear Information System (INIS)

    Magnusson, B.; Bjoern-Rasmussen, E.; Hallberg, L.; Rossander, L.

    1981-01-01

    The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r= -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigarors. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 μg/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 45%, or possibly a serum ferritin level of 30 μg/l. (author)

  11. Efficacy of modest dose irradiation in combination with long-term endocrinal treatment for high-risk prostate cancer. A preliminary report

    International Nuclear Information System (INIS)

    Sasaki, Tomonari; Nakamura, Katsumasa; Shioyama, Yoshiyuki

    2004-01-01

    Although radiotherapy in combination with endocrinal manipulation has been identified as an effective treatment for patients with high-risk prostate cancer, the optimal dose for locoregional control of prostate cancer in combination with hormonal therapy has not yet been determined. The efficacy of modest doses of irradiation (60-62 Gy) combined with long-term endocrinal treatment for patients with high-risk prostate cancer (defined as a pretreatment prostate-specific antigen (PSA) level greater than 20 ng/ml or a Gleason's score of 8-10 or T3-T4 disease) was analyzed in 60 Japanese patients. The patients included in this study had received radical radiotherapy with long-term endocrinal manipulation in the period between 1993 and 2000. The median age of the patients was 70 years (range, 56-83). Neoadjuvant hormonal therapy with a median duration of 3.9 months was performed prior to radiotherapy, and hormonal therapy was continued until recurrence. A median dose of 61.4 Gy (range, 44-71.4) was delivered to the prostate. Pelvic node irradiation was performed in 49 patients (81.6%). After a median follow-up period of 28.5 months, the overall survival, cause-specific survival and biochemical relapse-free survival at 3 years were 94.4%, 96% and 89.8%, respectively. Local failure was observed in one patient, distant metastases were observed in three patients and a late toxic effect greater than Grade 2 was not observed in any patients. This study, though preliminary due to a short-term follow-up period, reveals the possibility that modest doses of irradiation combined with long-term endocrinal treatment could be an effective means of achieving excellent local control of high-risk prostate cancer. (author)

  12. 331 cases of clinically node-negative supraglottic carcinoma of the larynx: a study of a modest size fixed field radiotherapy approach

    International Nuclear Information System (INIS)

    Sykes, Andrew J.; Slevin, Nicholas J.; Gupta, Nirmal K.; Brewster, Allison E.

    2000-01-01

    Purpose: For node-negative supraglottic carcinoma of the larynx, radiotherapy with surgery in reserve commonly provides very good results in terms of both local control and survival, while preserving function. However uncertainty exists over the treatment of the node-negative neck. Elective whole neck radiotherapy, while effective, may be associated with significant morbidity. The purpose of this study was to examine our practice of treating a modest size, fixed field to a high biologically effective dose and compare it with the patterns of recurrence from other centers that use different dose/volume approaches. Methods and Materials: Over a 10-year period 331 patients with node-negative supraglottic carcinoma of the larynx were treated with radiotherapy at the Christie Hospital Manchester. Patients were treated with doses of 50-55 Gy in 16 fractions over 3 weeks. Data were collected retrospectively for local and regional control, survival, and morbidity. Results: Overall local control, after surgical salvage in 17 cases, was 79% (T1-92%, T2-81%, T3-67%, T4-73%). Overall regional lymph node control, after surgical salvage in 13 cases, was 84% (T1-91%, T2-88%, T3-81%, T4-72%). Five-year crude survival was 50%, but after correcting for intercurrent deaths was 70% (T1-83%, T2-78%, T3-53%, T4-61%). Serious morbidity requiring surgery was seen in 7 cases (2.1%) and was related to prescribed dose (50 Gy-0%, 52.5 Gy-1.3%, 55 Gy-3.4%). Discussion: Our results confirm that treating a modest size, fixed field to a high biologically effective dose is highly effective. It enables preservation of the larynx in most cases, with acceptable regional control and no loss of survival compared to whole neck radiotherapy regimes

  13. Absorption, transport, and chemical fate of plutonium in soybean plants

    International Nuclear Information System (INIS)

    Garland, T.R.; Cataldo, D.A.; Wildung, R.E.

    1981-01-01

    Absorption of plutonium (Pu) by soybean plants (Glycine max cv. Williams) is limited by Pu solubility in soils. Changes in Pu concentration in different tissues with time to senescence indicate Pu is freely transported through the xylem during growth but not subject to remobilization on flowering. Studies in which the DTPA complex of 238 Pu was supplied to the plant suggest a change in chemical form following root absorption. Of the Pu in roots, stems, and leaves at senescence, 28, 54, and 67%, respectively, were soluble. The Pu in the solluble fraction was primarily associated with components of >10000 equivalent molecular weight in leaves and roots, whereas stems exhibited an equal distribution between components in the >10000 and <500 molecular weight fractions. Plutonium associated with mature seeds is concentrated in the seed hull (85%) and cotyledons (14%). The Pu associated with the cotyledon was primarily in the insoluble residues and soluble soy whey

  14. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  15. Phytases for Improved Iron Absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Nyffenegger, Christian; Meyer, Anne S.

    2014-01-01

    Microbial phytases (EC 3.1.3.8) catalyse dephosphorylation of phytic acid, which is the primary storage compound for phosphorous in cereal kernels. The negatively charged phosphates in phytic acid chelate iron (Fe3+) and thus retards iron bioavailability in humans 1. Supplementation of microbial...... phytase can improve iron absorption from cereal-based diets 2. In order for phytase to catalyse iron release in vivo the phytase must be robust to low pH and proteolysis in the gastric ventricle. Our work has compared the robustness of five different microbial phytases, evaluating thermal stability...

  16. Iodine Absorption Cells Purity Testing

    Czech Academy of Sciences Publication Activity Database

    Hrabina, Jan; Zucco, M.; Philippe, Ch.; Pham, Minh Tuan; Holá, Miroslava; Acef, O.; Lazar, Josef; Číp, Ondřej

    2017-01-01

    Roč. 17, č. 1 (2017), s. 1-13, č. článku 17010102. ISSN 1424-8220 R&D Projects: GA ČR GA15-18430S; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : iodine cells * absorption spectroscopy * laser spectroscopy * laser standards * frequency stability Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.677, year: 2016

  17. Microwave Absorption Characteristics of Tire

    Science.gov (United States)

    Zhang, Yuzhe; Hwang, Jiann-Yang; Peng, Zhiwei; Andriese, Matthew; Li, Bowen; Huang, Xiaodi; Wang, Xinli

    The recycling of waste tires has been a big environmental problem. About 280 million waste tires are produced annually in the United States and more than 2 billion tires are stockpiled, which cause fire hazards and health issues. Tire rubbers are insoluble elastic high polymer materials. They are not biodegradable and may take hundreds of years to decompose in the natural environment. Microwave irradiation can be a thermal processing method for the decomposition of tire rubbers. In this study, the microwave absorption properties of waste tire at various temperatures are characterized to determine the conditions favorable for the microwave heating of waste tires.

  18. Calcified-tissue investigations using synchrotron x-ray microscopy

    International Nuclear Information System (INIS)

    Jones, K.W.; Spanne, P.; Schidlovsky, G.; Dejun, X.; Bockman, R.S.; Hammond, P.B.; Bornschein, R.L.; Hoeltzel, D.A.

    1990-10-01

    Synchrotron x-ray microscopy (SXRM) in both emission and absorption modes has been used to examine elemental distributions in specimens of rat tibia, human deciduous teeth, and an orthopedic implant phantom. The work was performed with a spatial resolution of 8 μm for the emission work and 25 μm for the absorption work. The results illustrate the usefulness of SXRM for measurements of different types of calcified tissue. 3 figs

  19. Iodine Absorption Cells Purity Testing

    Directory of Open Access Journals (Sweden)

    Jan Hrabina

    2017-01-01

    Full Text Available This article deals with the evaluation of the chemical purity of iodine-filled absorption cells and the optical frequency references used for the frequency locking of laser standards. We summarize the recent trends and progress in absorption cell technology and we focus on methods for iodine cell purity testing. We compare two independent experimental systems based on the laser-induced fluorescence method, showing an improvement of measurement uncertainty by introducing a compensation system reducing unwanted influences. We show the advantages of this technique, which is relatively simple and does not require extensive hardware equipment. As an alternative to the traditionally used methods we propose an approach of hyperfine transitions’ spectral linewidth measurement. The key characteristic of this method is demonstrated on a set of testing iodine cells. The relationship between laser-induced fluorescence and transition linewidth methods will be presented as well as a summary of the advantages and disadvantages of the proposed technique (in comparison with traditional measurement approaches.

  20. Mixed Connective Tissue Disease

    Science.gov (United States)

    Mixed connective tissue disease Overview Mixed connective tissue disease has signs and symptoms of a combination of disorders — primarily lupus, scleroderma and polymyositis. For this reason, mixed connective tissue disease ...

  1. Undifferentiated Connective Tissue Disease

    Science.gov (United States)

    ... Home Conditions Undifferentiated Connective Tissue Disease (UCTD) Undifferentiated Connective Tissue Disease (UCTD) Make an Appointment Find a Doctor ... by Barbara Goldstein, MD (February 01, 2016) Undifferentiated connective tissue disease (UCTD) is a systemic autoimmune disease. This ...

  2. Soft Tissue Sarcoma

    Science.gov (United States)

    ... muscles, tendons, fat, and blood vessels. Soft tissue sarcoma is a cancer of these soft tissues. There ... have certain genetic diseases. Doctors diagnose soft tissue sarcomas with a biopsy. Treatments include surgery to remove ...

  3. [Gastric cancer detection using kubelka-Munk spectral function of DNA and protein absorption bands].

    Science.gov (United States)

    Li, Lan-quan; Wei, Hua-jiang; Guo, Zhou-yi; Yang, Hong-qin; Xie, Shu-sen; Chen, Xue-mei; Li, Li-bo; He, Bol-hua; Wu, Guo-yong; Lu, Jian-jun

    2009-09-01

    Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5% (p function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8% (p function f(r infinity) and logarithmic Kubelka-Munk function log[f(r infinity)] of the carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5% (p < 0.05), 73% (p < 0

  4. Phosphorus absorption in drip irrigation

    International Nuclear Information System (INIS)

    Guennelon, R.; Habib, R.

    1979-01-01

    Introducing the use of solute phosphate with drip irrigation may be an unsatisfying practice on account of the very weak mobility of PO 4 anion. Nevertheless P can move down to 30-40 cm depth by following the saturated flux along earth-worms holes or crakes, or by displacement in very narrow structural porosity, even in heavy soils. In this case roots cannot easily absorb PO 4 from soil solution, as soon as the soil is quite saturated. On the other hand, it seems that P absorption occurs very quickly and easily when the implantation of 32 P tagged solution is carried out at the border of zone which is concerned by the irrigation effects [fr

  5. HI Absorption in Merger Remnants

    Science.gov (United States)

    Teng, Stacy H.; Veileux, Sylvain; Baker, Andrew J.

    2012-01-01

    It has been proposed that ultraluminous infrared galaxies (ULIRGs) pass through a luminous starburst phase, followed by a dust-enshrouded AGN phase, and finally evolve into optically bright "naked" quasars once they shed their gas/dust reservoirs through powerful wind events. We present the results of our recent 21- cm HI survey of 21 merger remnants with the Green Bank Telescope. These remnants were selected from the QUEST (Quasar/ULIRG Evolution Study) sample of ULIRGs and PG quasars; our targets are all bolometrically dominated by AGN and sample all phases of the proposed ULIRG -> IR-excess quasar -> optical quasar sequence. We explore whether there is an evolutionary connection between ULIRGs and quasars by looking for the occurrence of HI absorption tracing neutral gas outflows; our results will allow us to identify where along the sequence the majority of a merger's gas reservoir is expelled.

  6. Multistage quantum absorption heat pumps.

    Science.gov (United States)

    Correa, Luis A

    2014-04-01

    It is well known that heat pumps, while being all limited by the same basic thermodynamic laws, may find realization on systems as "small" and "quantum" as a three-level maser. In order to quantitatively assess how the performance of these devices scales with their size, we design generalized N-dimensional ideal heat pumps by merging N-2 elementary three-level stages. We set them to operate in the absorption chiller mode between given hot and cold baths and study their maximum achievable cooling power and the corresponding efficiency as a function of N. While the efficiency at maximum power is roughly size-independent, the power itself slightly increases with the dimension, quickly saturating to a constant. Thus, interestingly, scaling up autonomous quantum heat pumps does not render a significant enhancement beyond the optimal double-stage configuration.

  7. Sound absorption with green materials

    Science.gov (United States)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-07-01

    Green materials are a valid alternative to traditional materials that are by-products of processing oil. At the end of their useful life, green materials can be disposed of without polluting the environment. They are now being used in the construction and automotive industries. While, studies are currently being carried out in the aviation sector on the use of green materials for non-structural components of airplanes. Green materials can be used to improve the acoustic comfort inside buildings as well as mitigate reverberation, echoes effects and reduce the transmission of noise between rooms. In this paper, the acoustic measurements of the properties of green materials are reported. The absorption coefficient of samples of the materials were measured in the frequency range from 200 Hz to 2,000 Hz with an impedance tube, with the flow resistance being measured.

  8. Mixture for plugging absorption zones

    Energy Technology Data Exchange (ETDEWEB)

    Sitinkov, G V; Kovalenko, N G; Makarov, L V; Zinnatulchin, Ts Kh

    1981-01-17

    A mixture is proposed for plugging absorption zones. The mixture contains synthetic polymer and a solvent. So as to increase the penetrability of the mixture through a reduction in its viscosity and an increase in insulation properties, the compound contains either Capron or Neilon as the synthetic polyamide resin polmyer, and concentrated chloride as the solvent. The mixture is prepared in a special AzINMASh-30 unit (acid cart). After the mixture has been produced, it is injected into the borehole by means of an acid cart pump. So as to prevent coaggulation at the point when the mixture in injected into the stratum through tubes, the mixture is placed betwen chemically inert fluids, for example, a clay mortar. The inert and compressed fluids are injected by means of a cementing unit. The entire process of production and application of the mixture is simple and fully automated through the use of well-known equipment.

  9. Aspects of neptunium behavior in plants; absorption, distribution, and fate

    International Nuclear Information System (INIS)

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.

    1984-03-01

    The availability of Np(V) for absorption by plants and its subsequent transport and fate are described. Plant uptake of Np from solutions containing 7 x 10 -7 to 473 μg Np/ml is proportional to concentration, exhibiting some saturation at higher concentrations. Soil studies using Np concentrations of 5.2 x 10 -7 to 4.1 μg/g soil show CR values to be constant at approx. 2 at soil concentrations below 4 x 10 -4 μg/g, and increase to 12 at higher soil levels. Soil/plant CR values vary with plant species and range from 0.5 to 4; seed concentrations are a factor of 10 lower than vegetative tissues. Fractionation of plant tissues show Np to be substantially more soluble than Pu, with approx. 50% of the soluble Np being associated with plant ligands of < 5000 MW. 6 references, 5 figures, 1 table

  10. Boosted classification trees result in minor to modest improvement in the accuracy in classifying cardiovascular outcomes compared to conventional classification trees

    Science.gov (United States)

    Austin, Peter C; Lee, Douglas S

    2011-01-01

    Purpose: Classification trees are increasingly being used to classifying patients according to the presence or absence of a disease or health outcome. A limitation of classification trees is their limited predictive accuracy. In the data-mining and machine learning literature, boosting has been developed to improve classification. Boosting with classification trees iteratively grows classification trees in a sequence of reweighted datasets. In a given iteration, subjects that were misclassified in the previous iteration are weighted more highly than subjects that were correctly classified. Classifications from each of the classification trees in the sequence are combined through a weighted majority vote to produce a final classification. The authors' objective was to examine whether boosting improved the accuracy of classification trees for predicting outcomes in cardiovascular patients. Methods: We examined the utility of boosting classification trees for classifying 30-day mortality outcomes in patients hospitalized with either acute myocardial infarction or congestive heart failure. Results: Improvements in the misclassification rate using boosted classification trees were at best minor compared to when conventional classification trees were used. Minor to modest improvements to sensitivity were observed, with only a negligible reduction in specificity. For predicting cardiovascular mortality, boosted classification trees had high specificity, but low sensitivity. Conclusions: Gains in predictive accuracy for predicting cardiovascular outcomes were less impressive than gains in performance observed in the data mining literature. PMID:22254181

  11. Modest Salt Reduction Lowers Blood Pressure and Albumin Excretion in Impaired Glucose Tolerance and Type 2 Diabetes Mellitus: A Randomized Double-Blind Trial.

    Science.gov (United States)

    Suckling, Rebecca J; He, Feng J; Markandu, Nirmala D; MacGregor, Graham A

    2016-06-01

    The role of salt restriction in patients with impaired glucose tolerance and diabetes mellitus is controversial, with a lack of well controlled, longer term, modest salt reduction trials in this group of patients, in spite of the marked increase in cardiovascular risk. We carried out a 12-week randomized double-blind, crossover trial of salt restriction with salt or placebo tablets, each for 6 weeks, in 46 individuals with diet-controlled type 2 diabetes mellitus or impaired glucose tolerance and untreated normal or high normal blood pressure (BP). From salt to placebo, 24-hour urinary sodium was reduced by 49±9 mmol (2.9 g salt). This reduction in salt intake led to fall in clinic BP from 136/81±2/1 mm Hg to 131/80±2/1 mm Hg, (systolic BP; Pdiabetes mellitus with normal or mildly raised BP. The reduction in urinary albumin excretion may carry additional benefits in reducing cardiovascular disease above the effects on BP. © 2016 American Heart Association, Inc.

  12. Lifelong exercise and locally produced insulin-like growth factor-1 (IGF-1) have a modest influence on reducing age-related muscle wasting in mice.

    Science.gov (United States)

    McMahon, C D; Chai, R; Radley-Crabb, H G; Watson, T; Matthews, K G; Sheard, P W; Soffe, Z; Grounds, M D; Shavlakadze, T

    2014-12-01

    The age-related loss of skeletal muscle mass and function is termed sarcopenia and has been attributed to a decline in concentrations of insulin-like growth factor-1 (IGF-1). We hypothesized that constitutively expressed IGF-1 within skeletal muscles with or without exercise would prevent sarcopenia. Male transgenic mice that overexpress IGF-1 Ea in skeletal muscles were compared with wild-type littermates. Four-month-old mice were assigned to be sedentary, or had access to free-running wheels, until 18 or 28 months of age. In wild-type mice, the mass of the quadriceps muscles was reduced at 28 months and exercise prevented such loss, without affecting the diameter of myofibers. Conversely, increased IGF-1 alone was ineffective, whereas the combination of exercise and IGF-1 was additive in maintaining the diameter of myofibers in the quadriceps muscles. For other muscles, the combination of IGF-1 and exercise was variable and either increased or decreased the mass at 18 months of age, but was ineffective thereafter. Despite an increase in the diameter of myofibers, grip strength was not improved. In conclusion, our data show that exercise and IGF-1 have a modest effect on reducing aged-related wasting of skeletal muscle, but that there is no improvement in muscle function when assessed by grip strength. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Study on absorption, accumulation and distribution of 90Sr in yellow-feather broiler

    International Nuclear Information System (INIS)

    Shang Zhaorong; Xu Shiming; Zhao Wenhu; Hou Lanxin

    1993-04-01

    The feeding experiment was carried out for yellow-feather broiler with 90 Sr(NO 3 ) 2 having activities of 1.85 x 10 0 ∼ 1.85 x 10 4 Bq/chicken to observe the regular pattern of absorption and distribution of 90 Sr in its organs and tissues. The results are as follows: The absorption rate of 90 Sr by oral feeding is very low. The most of 90 Sr is drained away by daily excreta from the body. The half-time of its feeding is within 24 hours. The accumulated dose varies with the time and different feeding methods. The more 90 Sr is fed, the more 90 Sr is absorbed, however, the uptake rate of 90 Sr is decreasing. The distribution of 90 Sr for bone is very strong and the partition ratio is about 90%. The absorption coefficient of 90 Sr in organs and tissues of broiler is presented

  14. Regularity on absorption and accumulation of 90Sr in yellow-feather broiler (Hypeco)

    International Nuclear Information System (INIS)

    Xu Shiming; Hou Lanxin; Zhao Wenhu; Li Xia; Yang Zhongyuan

    1996-02-01

    The feeding experiment was carried for yellow-feather broiler (Hypeco) with 90 Sr[NO 3 ] 2 having of 1.85 x 10 2 ∼1.85 x 10 5 Bq/chicken to observe the regular pattern of absorption and accumulation of 90 Sr in its organs and tissues. The absorption rate of 90 Sr by oral feeding is very low. The most of 90 Sr is drained away by daily excreta from the body. The half-time of its feeding is within 24 hours. The more 90 Sr is fed, the more 90 Sr is absorbed, however, the uptake rate of 90 Sr is decreasing. The affinity of 90 Sr for bone is very strong and the partition ratio is about 90%∼99%. The absorption coefficient of 90 Sr in organs and tissues of broiler is presented. (2 refs., 9 tabs.)

  15. Understanding the Oral Mucosal Absorption and Resulting Clinical Pharmacokinetics of Asenapine

    NARCIS (Netherlands)

    Bartlett, Jeremy A.; Maarschalk, Kees van der Voort

    2012-01-01

    Absorption of drugs from the oral cavity into the mucosal tissues is typically a fast event. Dissolved drugs partition into the mucosal membranes and within minutes will reach equilibrium with drug in solution in the oral cavity. However, this does not always equate to rapid drug appearance in the

  16. Phytosterol glycosides reduce cholesterol absorption in humans

    OpenAIRE

    Lin, Xiaobo; Ma, Lina; Racette, Susan B.; Anderson Spearie, Catherine L.; Ostlund, Richard E.

    2009-01-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series ...

  17. Vitamin B12 absorption from eggs.

    Science.gov (United States)

    Doscherholmen, A; McMahon, J; Ripley, D

    1975-09-01

    The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12.

  18. Flame emission, atomic absorption and fluorescence spectrometry

    International Nuclear Information System (INIS)

    Horlick, G.

    1980-01-01

    Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular absorption spectrometry; electrothermal atomization atomic absorption spectroscopy; hydride generation techniques; graphite furnace atomic emission spectrometry; atomic fluorescence spectrometry; and analytical comparisons

  19. CD163 promotes hematoma absorption and improves neurological functions in patients with intracerebral hemorrhage

    Directory of Open Access Journals (Sweden)

    Wen-jing Xie

    2016-01-01

    Full Text Available Clinical outcomes are positively associated with hematoma absorption. The monocyte-macrophage scavenger receptor, CD163, plays an important role in the metabolism of hemoglobin, and a soluble form of CD163 is present in plasma and other tissue fluids; therefore, we speculated that serum CD163 affects hematoma absorption after intracerebral hemorrhage. Patients with intracerebral hemorrhage were divided into high- and low-level groups according to the average CD163 level (1,977.79 ± 832.91 ng/mL. Compared with the high-level group, the low-level group had a significantly slower hematoma absorption rate, and significantly increased National Institutes of Health Stroke Scale scores and modified Rankin Scale scores. These results suggest that CD163 promotes hematoma absorption and the recovery of neurological function in patients with intracerebral hemorrhage.

  20. Gastrointestinal absorption and retention of polonium in adult and newborn rats and guinea pigs

    International Nuclear Information System (INIS)

    Haines, J.W.; Naylor, G.P.L.; Pottinger, H.; Harrison, J.D.

    1993-01-01

    The gastrointestinal absorption of 210 Po was determined by comparing tissue retention after oral and systemic administration. The results indicate an increase in absorption in adult rats for 210 Po administered in liver compared with 210 Po nitrate with estimated absorption of 5 and 13%, respectively. For 210 Po citrate, values of about 7% were obtained in 1-day-old neonate and adult rats while absorption in guinea pigs was estimated to be about 23% in 1-day-old neonates, 17% in 5-day-old neonates, and 9% in adults. Gut retention of ingested 210 Po in neonates was high in rats but not guinea pigs. In adult animals, but not neonates, the liver accounted for a greater proportion of 210 Po reaching the bloodstream after ingestion than after systemic injection. The significance of these results is discussed in relation to current assumptions made in the calculation of doses from 210 Po. (author)

  1. Evolution of Multispectral Aerosol Absorption Properties in a Biogenically-Influenced Urban Environment during the CARES Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Gyawali, Madhu; Arnott, W.; Zaveri, Rahul; Song, Chen; Flowers, Bradley; Dubey, Manvendra; Setyan, Ari; Zhang, Qi; China, Swarup; Mazzoleni, Claudio; Gorkowski, Kyle; Subramanian, R.; Moosmüller, Hans

    2017-11-01

    We present the evolution of multispectral optical properties as urban aerosols aged and interacted with biogenic emissions resulting in stronger short wavelength absorption and formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made during June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area. Data on black carbon and non-refractory aerosol mass and composition were collected at both sites. In addition, photoacoustic (PA) instruments with integrating nephelometers were used to measure spectral absorption and scattering coefficients for wavelengths ranging from 355 to 870 nm. The daytime absorption Ångström exponent (AAE) indicated a modest wavelength-dependent enhancement of absorption at both sites throughout the study. From the 22nd to the 28th of June, secondary organic aerosol mass increased significantly at both sites due to increased biogenic emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the median BC mass-normalized absorption cross-section (MAC) values for 405 nm and 532 nm at T1 increased by ~23% and ~35%, respectively, compared to the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for the 870 nm wavelength were similar for both sites. These results suggest formation of moderately brown secondary organic aerosols in biogenically-influenced urban air.

  2. Tissue bionics: examples in biomimetic tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Green, David W [Bone and Joint Research Group, Developmental Origins of Health and Disease, General Hospital, University of Southampton, SO16 6YD (United Kingdom)], E-mail: Hindoostuart@googlemail.com

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  3. Tissue bionics: examples in biomimetic tissue engineering

    International Nuclear Information System (INIS)

    Green, David W

    2008-01-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic

  4. Emission and Absorption Entropy Generation in Semiconductors

    DEFF Research Database (Denmark)

    Reck, Kasper; Varpula, Aapo; Prunnila, Mika

    2013-01-01

    While emission and absorption entropy generation is well known in black bodies, it has not previously been studied in semiconductors, even though semiconductors are widely used for solar light absorption in modern solar cells [1]. We present an analysis of the entropy generation in semiconductor...... materials due to emission and absorption of electromagnetic radiation. It is shown that the emission and absorption entropy generation reduces the fundamental limit on the efficiency of any semiconductor solar cell even further than the Landsberg limit. The results are derived from purely thermodynamical...

  5. X-ray absorption in atomic potassium

    International Nuclear Information System (INIS)

    Gomilsek, Jana Padeznik; Kodre, Alojz; Arcon, Iztok; Nemanic, Vincenc

    2008-01-01

    A new high-temperature absorption cell for potassium vapor is described. X-ray absorption coefficient of atomic potassium is determined in the energy interval of 600 eV above the K edge where thresholds for simultaneous excitations of 1s and outer electrons, down to [1s2p] excitation, appear. The result represents also the atomic absorption background for XAFS (X-ray absorption fine structure) structure analysis. The K ionization energy in the potassium vapor is determined and compared with theoretical data and with the value for the metal

  6. Microwave hyperthermia enhancement of methotrexate absorption in rat brains

    International Nuclear Information System (INIS)

    Lin, J.C.; Yuen, M.K.; Jung, D.T.

    1987-01-01

    The author studied enhanced absorption of methotrexate (MTX) in brains of male Wistar (10 weeks old, 500g) subjected to microwave hyperthermia. The rat was anesthetized using 40 mg/kg of sodium pentobarbital, IP and was placed in a stereotaxic head holder. Microwave energy (2450 MHz, 2.6 W/cm/sup 2/, CW) were applied directly to the left side of the rat's head by a coaxial applicator for 20 min. The body temperature was kept at 37.8 0 C. The brain temperature recorded in a similar group of animals using a Vitek probe was about 45 0 C. Three different MTX dosages, 50, 100 and 200 mg/kg, were injected intravenously immediately following microwave irradiation into three groups of rats in 1.5, 3 and 6 min., respectively. MTX was allowed to circulate for five min. before brains were removed for analysis. Standard HPLC procedures were applied to samples from anterior and posterior left hemisphere of the cerebrum, and the cerebellum. Samples from the right hemisphere were used for controls. The average absorption at the posterior left hemisphere was found to be 2.4, 9.6 and 12.4μg of MTX/g of brain tissue for 50, 100 and 200 mg/kg, respectively. These results indicate that MTX absorption is significantly increased in rat brains subjected to microwave hyperthermia treatment

  7. Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption.

    Science.gov (United States)

    Jo, Mi-Rae; Yu, Jin; Kim, Hyoung-Jun; Song, Jae Ho; Kim, Kyoung-Min; Oh, Jae-Min; Choi, Soo-Jin

    2016-11-29

    Titanium dioxide (TiO₂) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO₂ NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO₂ NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO₂ (f-TiO₂) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO₂ (g-TiO₂) NPs. The effect of the interactions between the TiO₂ NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO₂ NPs compared to g-TiO₂ NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO₂ NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry.

  8. Absorption by water vapour in the 1 to 2 μm region

    International Nuclear Information System (INIS)

    Smith, K.M.; Ptashnik, I.; Newnham, D.A.; Shine, K.P.

    2004-01-01

    The near-IR (in the range 5000-10 000 cm -1 , 1-2 μm) bands of water vapour have been measured in absorption in the laboratory at sub-Doppler spectral resolution (up to 0.0054 cm -1 after numerical apodisation) by Fourier transform spectroscopy. Measurements have been made at 296 K on pure water vapour (at pressures between 2 and 20 hPa) and mixtures of water and air (at total pressures of 100 and 1000 hPa), at optical path lengths in the range 0.26-9.75 m. Measured absorption intensities have been compared with values calculated using the HITRAN 2000 molecular database. These comparisons indicate that the intensities of the 2ν(1.4 μm) and 2ν+δ(1.14 μm) bands are underestimated in HITRAN 2000 by approximately 15% and 20%, respectively, for pure water vapour measurements, and 12% for both bands in the case of water-air mixtures. The ν+δ (1.86 μm) band is in good agreement (0.4% for pure water vapour and less than 6% for mixtures with air) with HITRAN 2000. For typical atmospheric conditions, these absorption bands are sufficiently strong that radiation is fully absorbed at wavelengths in the region of the band centres. Hence the extra absorption that has been identified has only a modest impact (0.16 W m -2 or about 0.2%) on the global-mean clear-sky absorption of solar radiation. The impact in the upper troposphere is several times larger

  9. Assessment of tissue viability by polarization spectroscopy

    Science.gov (United States)

    Nilsson, G.; Anderson, C.; Henricson, J.; Leahy, M.; O'Doherty, J.; Sjöberg, F.

    2008-09-01

    A new and versatile method for tissue viability imaging based on polarization spectroscopy of blood in superficial tissue structures such as the skin is presented in this paper. Linearly polarized light in the visible wavelength region is partly reflected directly by the skin surface and partly diffusely backscattered from the dermal tissue matrix. Most of the directly reflected light preserves its polarization state while the light returning from the deeper tissue layers is depolarized. By the use of a polarization filter positioned in front of a sensitive CCD-array, the light directly reflected from the tissue surface is blocked, while the depolarized light returning from the deeper tissue layers reaches the detector array. By separating the colour planes of the detected image, spectroscopic information about the amount of red blood cells (RBCs) in the microvascular network of the tissue under investigation can be derived. A theory that utilizes the differences in light absorption of RBCs and bloodless tissue in the red and green wavelength region forms the basis of an algorithm for displaying a colour coded map of the RBC distribution in a tissue. Using a fluid model, a linear relationship (cc. = 0.99) between RBC concentration and the output signal was demonstrated within the physiological range 0-4%. In-vivo evaluation using transepidermal application of acetylcholine by the way of iontophoresis displayed the heterogeneity pattern of the vasodilatation produced by the vasoactive agent. Applications of this novel technology are likely to be found in drug and skin care product development as well as in the assessment of skin irritation and tissue repair processes and even ultimately in a clinic case situation.

  10. Contrasting effects of the stomach and small intestine of rats on copper absorption

    International Nuclear Information System (INIS)

    Fields, M.; Craft, N.; Lewis, C.; Holbrook, J.; Rose, A.; Reiser, S.; Smith, J.C.

    1986-01-01

    Since the severity of copper deficiency has been shown to be enhanced by feeding diets containing fructose but ameliorated by diets containing starch, we decided to investigate the effect of fructose or starch on copper absorption. As copper transport has been reported to occur also from the stomach, it was possible that copper absorption is inhibited by fructose already from that tissue. Under anesthesia, stomachs of 72 rats fed copper-deficient or supplemented diets containing fructose or starch were ligated prior to the oral administration of 64 Cu. Gastric absorption of 64 Cu was studied when the isotope was administered by gastric tube either in diet containing fructose or starch or in water. 64 Cu was not absorbed from the stomach regardless of the type of dietary treatment, copper status or whether the copper was administered either in diet or in water. In addition, the absorption of 64 Cu from a diet containing either fructose or starch or from a saline solution was studied using the isolated ligated duodenal loop. When 64 Cu was administered with dietary fructose 64 Cu retention and absorption were impaired when compared to starch. When 64 Cu was administered in saline solution, differences in retention and absorption between the four dietary groups disappeared. It is suggested that the requirements for copper rather than the decreased absorption of copper are responsible at least in part for the more pronounced severity of copper deficiency in rats fed fructose compared to those fed starch

  11. Absorption, distribution, and fate of neptunium in plants

    International Nuclear Information System (INIS)

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.

    1988-01-01

    Soil-plant concentration ratios (CR) for neptunium (Np) in bushbean, measured over the range of 5.2 /times/ 10/sup /minus/7/ to 4.1 mg of Np/g of soil, are approximately 2 at soil concentrations below 4 /times/ 10/sup /minus/4/ mg/g and increase to 12 at higher soil levels. The CR values determined for soybean, bushbean, barley, and alfalfa range from 0.5 to 4 at a soil concentration of 2.6 /times/ 10/sup /minus/6/ mg/g. Root absorption by soybean seedlings of Np from solutions containing 7 /times/ 10/sup /minus/7/ to 473 mg of Np(V)/mL is generally proportional to concentration but exhibits some saturation in root absorption at higher concentrations. Seed concentrations in bushbean and wheat are a factor of 10 lower than vegetative tissues. Neptunium is transported within the plant in organic complexes containing one or more organic acid residues. Fractionation of plant tissues indicates that Np is substantially more soluble than plutonium, especially in seeds, with approximately 50% of the soluble Np in roots and leaves associated with plant ligands of less than 5000 molecular weight

  12. Effect of gastric anacidity on the intestinal absorption of liver bound 57Co-labelled cobalamins

    International Nuclear Information System (INIS)

    Kittang, E.

    1987-01-01

    57 Co-labelled cyanocobalamin injected in rabbit was transformed within the liver to 57 Co-labelled desoxyadenosylcobalamin and methylcovalamin. The absorption of 57 Co-labelled liver bound cobalamins could be determined with acceptable accuracy by the double isotope fecal excretion method. Treatment with the H 2-receptor antagonist, ranitidine, did not result in decreased absorption of 57 Co-labelled liver bound cobalamins in healthy individuals. R-protein and the R-proteincobalamin complex were determined by the FPLC Mono S chromatography method with a high degree of correlation to the charcoal method in saliva, gastric and duodenal juice, and with a high degree of reproducibility. Omeprazole markedly inhibited the gastric acid and pepsin secretion, but did nor inhibit the IF secretion. Omeprazole treatment resulted in anacidity in 14 of 17 individuals, but did not reduce the absorption of liver bound 57 Co-labelled cobalamins. The intrinsic factor concentration in gastric aspirates measured during the study was unchanged during omeprazole treatment. The release of cobalamins from liver homogenate was markedly inhibited by neutralized gastric juice in vitro, probably due to decreased pepsin mediated proteolysis. In vivo the cobalamin release from liver homogenate was modestly inhibited in the stomach but was unaffected in jejunum during omeprazole treatment. The major part of 57 Co-labelled liver cobalamins bound to R-protein in acid and neutral gastric juice in vitro, and omeprazole induced anacidity, did not influence the cobalamin binding either in gastric or jejunal juice in vivo

  13. Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

    KAUST Repository

    Tiwari, Surya Prakash; Zarokanellos, Nikolaos; Kheireddine, Malika; Shanmugam, Palanisamy; Jones, Burton

    2018-01-01

    This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non

  14. A pilot, short-term dietary manipulation of branched chain amino acids has modest influence on fasting levels of branched chain amino acids.

    Science.gov (United States)

    Cavallaro, Nicole Landa; Garry, Jamie; Shi, Xu; Gerszten, Robert E; Anderson, Ellen J; Walford, Geoffrey A

    2016-01-01

    Elevated fasting levels of branched chain amino acids (BCAAs: valine, isoleucine, leucine) in venous blood are associated with a variety of metabolic impairments, including increased risk of type 2 diabetes (T2D). Fasting BCAA levels are influenced by non-dietary factors. However, it is unknown whether fasting BCAAs can be altered through manipulation of dietary intake alone. To test whether a specific dietary intervention, using differences in BCAA intake, alters fasting BCAA levels independent of other factors. Five healthy male volunteers underwent 4 days of a low and 4 days of a high BCAA content dietary intervention (ClinicalTrials.gov [NCT02110602]). All food and supplements were provided. Fasting BCAAs were measured from venous blood samples by mass spectrometry at baseline and after each intervention. Diets were isocaloric; contained equal percentages of calories from carbohydrate, fats, and protein; and differed from each other in BCAA content (1.5±0.1 vs. 14.0±0.6 g for valine; 4.5±0.9 g vs. 13.8±0.5 g for isoleucine; 2.1±0.2 g vs. 27.1±1.0 g for leucine; pBCAA content vs. the high BCAA content diet levels. The inter-individual response to the dietary interventions was variable and not explained by adherence. Short-term dietary manipulation of BCAA intake led to modest changes in fasting levels of BCAAs. The approach from our pilot study can be expanded to test the metabolic implications of dietary BCAA manipulation.

  15. Depletion of cytotoxic T-cells does not protect NUP98-HOXD13 mice from myelodysplastic syndrome but reveals a modest tumor immunosurveillance effect.

    Directory of Open Access Journals (Sweden)

    Sheryl M Gough

    Full Text Available Myelodysplastic syndrome (MDS and aplastic anemia (AA patients both present with symptoms of bone marrow failure. In many AA patients, these features are thought to result from an oligoclonal expansion of cytotoxic T-cells that destroy haematopoietic stem or progenitor cells. This notion is supported by the observation that AA patients respond to immunosuppressive therapy. A fraction of MDS patients also respond well to immunosuppressive therapy suggesting a similar role for cytotoxic T-cells in the etiology of MDS, however the role of cytotoxic T-cells in MDS remains unclear. Mice that express a NUP98-HOXD13 (NHD13 transgene develop a MDS that closely mimics the human condition in terms of dysplasia, ineffective hematopoiesis, and transformation to acute myeloid leukemia (AML. We followed a cohort of NHD13 mice lacking the Rag1 protein (NHD13/Rag1KO to determine if the absence of lymphocytes might 1 delay the onset and/or diminish the severity of the MDS, or 2 effect malignant transformation and survival of the NHD13 mice. No difference was seen in the onset or severity of MDS between the NHD13 and NHD13/Rag1KO mice. However, NHD13/Rag1KO mice had decreased survival and showed a trend toward increased incidence of transformation to AML compared to the NHD13 mice, suggesting protection from AML transformation by a modest immuno-surveillance effect. In the absence of functional Tcrb signaling in the NHD13/Rag1KO T-cell tumors, Pak7 was identified as a potential Tcrb surrogate survival signal.

  16. Modest blood pressure reduction with valsartan in acute ischemic stroke: a prospective, randomized, open-label, blinded-end-point trial.

    Science.gov (United States)

    Oh, Mi Sun; Yu, Kyung-Ho; Hong, Keun-Sik; Kang, Dong-Wha; Park, Jong-Moo; Bae, Hee-Joon; Koo, Jaseong; Lee, Juneyoung; Lee, Byung-Chul

    2015-07-01

    To assess the efficacy and safety of modest blood pressure (BP) reduction with valsartan within 48 h after symptom onset in patients with acute ischemic stroke and high BP. This was a multicenter, prospective, randomized, open-label, blinded-end-point trial. A total of 393 subjects were recruited at 28 centers and then randomly assigned in a 1:1 ratio to receive valsartan (n = 195) or no treatment (n = 198) for seven-days after presentation. The primary outcome was death or dependency, defined as a score of 3-6 on the modified Rankin Scale (mRS) at 90 days after symptom onset. Early neurological deterioration (END) within seven-days and 90-day major vascular events were also assessed. There were 372 patients who completed the 90-day follow-up. The valsartan group had 46 of 187 patients (24·6%) with a 90-day mRS 3-6, compared with 42 of 185 patients (22·6%) in the control group (odds ratio [OR], 1·11; 95% confidence interval [CI], 0·69-1·79; P = 0·667). The rate of major vascular events did not differ between groups (OR, 1·41; 95% CI, 0·44-4·49; P = 0·771). There was a significant increase of END in the valsartan group (OR, 2·43; 95% CI, 1·25-4·73; P = 0·008). Early reduction of BP with valsartan did not reduce death or dependency and major vascular events at 90 days, but increased the risk of END. © 2015 World Stroke Organization.

  17. A pilot, short-term dietary manipulation of branched chain amino acids has modest influence on fasting levels of branched chain amino acids

    Directory of Open Access Journals (Sweden)

    Nicole Landa Cavallaro

    2016-01-01

    Full Text Available Background: Elevated fasting levels of branched chain amino acids (BCAAs: valine, isoleucine, leucine in venous blood are associated with a variety of metabolic impairments, including increased risk of type 2 diabetes (T2D. Fasting BCAA levels are influenced by non-dietary factors. However, it is unknown whether fasting BCAAs can be altered through manipulation of dietary intake alone. Objective: To test whether a specific dietary intervention, using differences in BCAA intake, alters fasting BCAA levels independent of other factors. Design: Five healthy male volunteers underwent 4 days of a low and 4 days of a high BCAA content dietary intervention (ClinicalTrials.gov [NCT02110602]. All food and supplements were provided. Fasting BCAAs were measured from venous blood samples by mass spectrometry at baseline and after each intervention. Results: Diets were isocaloric; contained equal percentages of calories from carbohydrate, fats, and protein; and differed from each other in BCAA content (1.5±0.1 vs. 14.0±0.6 g for valine; 4.5±0.9 g vs. 13.8±0.5 g for isoleucine; 2.1±0.2 g vs. 27.1±1.0 g for leucine; p<0.0001 for all. Fasting valine was significantly lower (p=0.02 and fasting isoleucine and leucine were numerically lower following the low BCAA content vs. the high BCAA content diet levels. The inter-individual response to the dietary interventions was variable and not explained by adherence. Conclusion: Short-term dietary manipulation of BCAA intake led to modest changes in fasting levels of BCAAs. The approach from our pilot study can be expanded to test the metabolic implications of dietary BCAA manipulation.

  18. Modest Associations Between Electronic Health Record Use and Acute Myocardial Infarction Quality of Care and Outcomes: Results From the National Cardiovascular Data Registry.

    Science.gov (United States)

    Enriquez, Jonathan R; de Lemos, James A; Parikh, Shailja V; Simon, DaJuanicia N; Thomas, Laine E; Wang, Tracy Y; Chan, Paul S; Spertus, John A; Das, Sandeep R

    2015-11-01

    In 2009, national legislation promoted wide-spread adoption of electronic health records (EHRs) across US hospitals; however, the association of EHR use with quality of care and outcomes after acute myocardial infarction (AMI) remains unclear. Data on EHR use were collected from the American Hospital Association Annual Surveys (2007-2010) and data on AMI care and outcomes from the National Cardiovascular Data Registry Acute Coronary Treatment and Interventions Outcomes Network Registry-Get With The Guidelines. Comparisons were made between patients treated at hospitals with fully implemented EHR (n=43 527), partially implemented EHR (n=72 029), and no EHR (n=9270). Overall EHR use increased from 82.1% (183/223) hospitals in 2007 to 99.3% (275/277) hospitals in 2010. Patients treated at hospitals with fully implemented EHRs had fewer heparin overdosing errors (45.7% versus 72.8%; P<0.01) and a higher likelihood of guideline-recommended care (adjusted odds ratio, 1.40 [confidence interval, 1.07-1.84]) compared with patients treated at hospitals with no EHR. In non-ST-segment-elevation AMI, fully implemented EHR use was associated with lower risk of major bleeding (adjusted odds ratio, 0.78 [confidence interval, 0.67-0.91]) and mortality (adjusted odds ratio, 0.82 [confidence interval, 0.69-0.97]) compared with no EHR. In ST-segment-elevation MI, outcomes did not significantly differ by EHR status. EHR use has risen to high levels among hospitals in the National Cardiovascular Data Registry. EHR use was associated with less frequent heparin overdosing and modestly greater adherence to acute MI guideline-recommended therapies. In non-ST-segment-elevation MI, slightly lower adjusted risk of major bleeding and mortality were seen in hospitals implemented with full EHRs; however, in ST-segment-elevation MI, differences in outcomes were not seen. © 2015 American Heart Association, Inc.

  19. Anti-müllerian hormone levels are associated with live birth rates in ART, but the predictive ability of anti-müllerian hormone is modest.

    Science.gov (United States)

    Alson, Sara S E; Bungum, Leif J; Giwercman, Aleksander; Henic, Emir

    2018-06-01

    The aim was to evaluate the association between serum Anti-Müllerian Hormone (AMH) level and cumulative live birth rates (LBR) in patients undergoing their first in vitro fertilization (IVF) treatment cycle, and to compare serum AMH levels with Antral Follicle Count (AFC) and Ovarian Sensitivity Index (OSI) as predictors of live birth. A prospective cohort study of 454 patients under the age of 40 and with a regular menstrual cycle of 21-35 days, undergoing their first IVF treatment cycles between September 2010 and June 2015. Participants were divided into three groups based on their AMH level, (AMH ≤10, AMH 10-distribution between patients with or without live birth was analyzed using a Mann-Whitney-test, and live birth rates were compared between groups by a chi-squared test for linear trend. The ability of AMH, OSI and AFC as predictors of live birth was assessed by a receiver operating characteristics-analysis and the area under the curve (AUC) was calculated. Patients with live birth had a higher AMH, median (range) 26 [0-137] pmol/l, compared with patients without live birth, AMH 22 [0-154] pmol/l, p = 0.035. Mean live birth rate (SD) was 0.36 (0.48) in the total cohort, 0.26 (0.44) in AMH-group birth rates increased with 8% per AMH-group (95% CI: 0.02 -0.14, p = 0.015). The AUC for AFC was 0.56, for AMH 0.57 and for OSI 0.63, respectively. AMH concentration in serum is associated with live birth rates after IVF. Our results suggest that both AMH, AFC and OSI have an equal but modest predictive ability in relation to live birth rate. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Infrared multiphoton absorption and decomposition

    International Nuclear Information System (INIS)

    Evans, D.K.; McAlpine, R.D.

    1984-01-01

    The discovery of infrared laser induced multiphoton absorption (IRMPA) and decomposition (IRMPD) by Isenor and Richardson in 1971 generated a great deal of interest in these phenomena. This interest was increased with the discovery by Ambartzumian, Letokhov, Ryadbov and Chekalin that isotopically selective IRMPD was possible. One of the first speculations about these phenomena was that it might be possible to excite a particular mode of a molecule with the intense infrared laser beam and cause decomposition or chemical reaction by channels which do not predominate thermally, thus providing new synthetic routes for complex chemicals. The potential applications to isotope separation and novel chemistry stimulated efforts to understand the underlying physics and chemistry of these processes. At ICOMP I, in 1977 and at ICOMP II in 1980, several authors reviewed the current understandings of IRMPA and IRMPD as well as the particular aspect of isotope separation. There continues to be a great deal of effort into understanding IRMPA and IRMPD and we will briefly review some aspects of these efforts with particular emphasis on progress since ICOMP II. 31 references

  1. Extent of cutaneous metabolism during percutaneous absorption of xenobiotics.

    Science.gov (United States)

    Bronaugh, R L; Stewart, R F; Storm, J E

    1989-07-01

    In vitro percutaneous absorption studies generally do not determine whether biotransformation occurs during passage of a substance through the skin. Since it has recently been demonstrated that several chemicals are metabolized during skin permeation, we investigated the metabolism of five additional compounds (14C-labeled) after application to fuzzy rat skin: caffeine, p,p'-DDT, butylated hydroxytoluene (BHT), salicylic acid, and acetyl ethyl tetramethyltetralin (AETT). The viability of skin was maintained with a tissue culture medium. Radioactivity of each substrate and any metabolites in skin and receptor fluid was measured so that the absorption and metabolism of water-insoluble compounds would be accurately determined. Percutaneous absorption ranged from a low of 13% of the applied dose for BHT to a high of 49% for DDT. BHT was metabolized in skin to 4-hydroxy-BHT and an unknown metabolite. Of the absorbed radioisotope, 6.6% was isolated in biotransformed products found mainly in the receptor fluid. AETT was also metabolized during absorption, with 1.9% of the absorbed radioisotope found in two unknown peaks. Caffeine, DDT, and salicylic acid were not metabolized during skin permeation. Skin and liver microsomal metabolism was measured for all compounds except DDT. Metabolism in skin was observed only for the compounds also biotransformed in the diffusion cell; BHT and AETT were metabolized at 113 and 2.5 pmol/min/mg protein, respectively. In this study, as in others, skin metabolism was substantially less than the corresponding metabolism in liver. Therefore, a low rate of liver metabolism such as that found for caffeine, salicylic acid, and DDT might often be predictive of the absence of measurable metabolism during skin permeation. It seems likely that for many compounds, the biotransformations in skin will be small in terms of the percentage of absorbed material that is metabolized. Nevertheless, with potent compounds, even small quantities of a metabolite

  2. A Low-Cost Quantitative Absorption Spectrophotometer

    Science.gov (United States)

    Albert, Daniel R.; Todt, Michael A.; Davis, H. Floyd

    2012-01-01

    In an effort to make absorption spectrophotometry available to high school chemistry and physics classes, we have designed an inexpensive visible light absorption spectrophotometer. The spectrophotometer was constructed using LEGO blocks, a light emitting diode, optical elements (including a lens), a slide-mounted diffraction grating, and a…

  3. Spectral interferences in atomic absorption spectrometry, (5)

    International Nuclear Information System (INIS)

    Daidoji, Hidehiro

    1979-01-01

    Spectral interferences were observed in trace element analysis of concentrated solutions by atomic absorption spectrometry. Molecular absorption and emission spectra for strontium chloride and nitrate, barium chloride and nitrate containing 12 mg/ml of metal ion in airacetylene flame were measured in the wavelength range from 200 to 700 nm. The absorption and emission spectra of SrO were centered near 364.6 nm. The absorption spectra of SrOH around 606.0, 671.0 and 682.0 nm were very strong. And, emission spectrum of BaOH in the wavelength range from 480 to 550 nm was stronger. But, the absorption of this band spectrum was very weak. In the wavelength range from 200 to 400 nm, some unknown bands of absorption were observed for strontium and barium. Absorption spectra of SrCl and BaCl were observed in the argon-hydrogen flame. Also, in the carbon tube atomizer, the absorption spectra of SrCl and BaCl were detected clearly in the wavelength range from 185 to 400 nm. (author)

  4. Process for neptunium analysis by absorption spectrophotometry

    International Nuclear Information System (INIS)

    Wagner, J.F.

    1987-01-01

    An aqueous solution of a neptunium compounds is treated by a reagent, preferentially a vanadyl sulfate oxidized by cerium IV ions, to obtain neptunium V by oxidation of neptunium IV and reduction of neptunium VI. The reagent is chosen for a negligible absorption at the wavelength used for neptunium V absorption spectrophotometry for instance 981 nm [fr

  5. Photoelectric absorption cross sections with variable abundances

    Science.gov (United States)

    Balucinska-Church, Monika; Mccammon, Dan

    1992-01-01

    Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

  6. Anomalous infrared absorption in granular superconductors

    International Nuclear Information System (INIS)

    Carr, G.L.; Garland, J.C.; Tanner, D.B.

    1983-01-01

    Granular superconductors are shown to have a far-infrared absorption that is larger when the samples are superconducting than when they are normal. By constrast, theoretical models for these materials predict that when the samples become superconducting, the absorption should decrease

  7. Cimetidine absorption in humans during sucralfate coadministration.

    OpenAIRE

    D'Angio, R; Mayersohn, M; Conrad, K A; Bliss, M

    1986-01-01

    Cimetidine absorption after a single 300 mg oral dose was evaluated in six normal subjects in the absence or presence of sucralfate. Sucralfate was ingested four times a day for 2 days prior to and for two additional doses on the day of cimetidine ingestion. Sucralfate coadministration had no statistically significant influence on the rate or extent of cimetidine absorption.

  8. Ultrafast THz Saturable Absorption in Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate THz saturable absorption in n-doped semiconductors GaAs, GaP, and Ge in a nonlinear THz time-domain spectroscopy experiment. Saturable absorption is caused by sample conductivity modulation due to electron heating and satellite valley scattering in the field of a strong THz pulse....

  9. Unveiling the Microfoundations of Absorptive Capacity

    DEFF Research Database (Denmark)

    Distel, Andreas Philipp

    2017-01-01

    to absorptive capacity at the organizational level and that this relationship is mediated through a microlevel process. The findings reveal that knowledge workers’ cognitive process of perspective taking and their creative behavior are important microfoundations of absorptive capacity. Moreover, the results...... emphasize the critical role of key employees in explaining firm-level heterogeneity in building organizational capabilities....

  10. Oligofructose stimulates calcium absorption in adolescents

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muys, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Background: In rats, nondigestible oligosaccharides stimulate calcium absorption. Recently, this effect was also found in human subjects. Objective: The objective of the study was to investigate whether consumption of 15 g oligofructose/d stimulates calcium absorption in male adolescents. Design:

  11. A transient absorption study of allophycocyanin

    Indian Academy of Sciences (India)

    Transient dynamics of allophycocyanin trimers and monomers are observed by using the pump-probe, transient absorption technique. The origin of spectral components of the transient absorption spectra is discussed in terms of both kinetics and spectroscopy. We find that the energy gap between the ground and excited ...

  12. Absorption of controlled-release iron

    International Nuclear Information System (INIS)

    Cook, J.D.; Lipschitz, D.A.; Skikne, B.S.

    1982-01-01

    A multiple-dose double radioiron technic was used to compare absorption of iron administered as a controlled release (CR) capsule and as an elixir; both formulations contained 50 mg elemental iron as ferrous sulfate. When taken by normal subjects in the fasting state, mean absorption from the elixir and CR capsule averaged 4.92% and 4.38%, which gave a CR capsule:elixir ratio of 0.89. This difference was not significant, but when taken with meals that inhibit absorption of dietary iron by different degrees, absorption of the CR formulation was superior. CR capsule:elixir absorption ratios averaged 1.70 from a meal that is mildly inhibitory and 3.13 from a meal that causes more marked inhibition. It is concluded that CR iron formulations may offer a therapeutic advantage to patients who take oral iron with meals to avoid gastrointestinal side effects

  13. Ex-vivo absorption study of lysine R-lipoate salt, a new pharmaceutical form of R-ALA.

    Science.gov (United States)

    Amenta, Francesco; Buccioni, Michela; Ben, Diego Dal; Lambertucci, Catia; Navia, Aleix Martí; Ngouadjeu Ngnintedem, Michael A; Ricciutelli, Massimo; Spinaci, Andrea; Volpini, Rosaria; Marucci, Gabriella

    2018-06-15

    Alpha-lipoic acid (ALA) oral supplements were used in many pathologies associated with increased oxidative stress. Although only R-ALA is considered the biologically active form, R,S-ALA is used in therapeutic applications even showing poor water solubility. The aim of this work was to study the absorption and transport mechanism across the intestinal barrier of new R-ALA stable and water soluble form, consisting in the lysine R-ALA salt, in presence and absence of specific inhibitors of Na + /multivitamin (SMVT) and monocarboxylic acids (MCT). The absorption of a new ALA form was investigated at rat everted sacs in comparison with R-ALA, S-ALA, and R,S-ALA. Results showed that duodenum is the best portion of intestine for ALA forms absorption. The absorption percentage of R-ALA, S-ALA, R,S-ALA, and lysine R-ALA salt was 66%, 43%, 55%, and 70%, respectively. The modest effect of the SMVT inhibitor biotin demonstrated that this transporter system is not principally involved in the absorption of lysine R-lipoate salt across the rat intestinal barrier. On the contrary, the MCT inhibitor octanoic acid significantly reduced the transport of this salt, whit an absorption decrease of R-ALA and lysine R-lipoate salt of 28% and 24%, respectively. Since the highest concentration of these inhibitors did not completely inhibit the absorption of lysine R-lipoate salt, other transport mechanisms probably operate for its intracellular delivery. The new form of ALA, lysine R-lipoate salt, was the most absorbed respect to the other ALA forms demonstrating that this compound is more suitable for oral administration. This new salt could represent a promising candidate for ALA oral supplementation. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Heavy metals burden in Kidney and heart tissues of Scarus ...

    African Journals Online (AJOL)

    Levels of selected heavy metals (Pb, Co, Cu, Ni, Zn, Mn and Cd) in the heart and kidney tissues of parrot fish, collected from the Arabian Gulf, Eastern Province of Saudi Arabia, were determined by wet-digestion based atomic absorption method. The results showed that accumulation pattern of analyzed metals in the kidney ...

  15. Plant tissue culture techniques

    Directory of Open Access Journals (Sweden)

    Rolf Dieter Illg

    1991-01-01

    Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

  16. Plant Tissue Culture

    Indian Academy of Sciences (India)

    Admin

    Plant tissue culture is a technique of culturing plant cells, tissues and organs on ... working methods (Box 2) and discovery of the need for B vita- mins and auxins for ... Kotte (Germany) reported some success with growing isolated root tips.

  17. Breast reconstruction - natural tissue

    Science.gov (United States)

    ... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

  18. FRD tissue archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fishery genetics tissue collection has over 80,000 tissues stored in 95% ethanol representing fishes and invertebrates collected globally but with a focus on the...

  19. Tissue banking in australia.

    Science.gov (United States)

    Ireland, Lynette; McKelvie, Helen

    2003-01-01

    The legal structure for the regulation of tissue banking has existed for many years. In Australia, the donation of human tissue is regulated by legislation in each of the eight States and Territories. These substantially uniform Acts were passed in the late 1970's and early 1980's, based on model legislation and underpinned by the concept of consensual giving. However, it was not until the early 1990's that tissue banking came under the notice of regulatory authorities. Since then the Australian Government has moved quickly to oversee the tissue banking sector in Australia. Banked human tissue has been deemed to be a therapeutic good under the Therapeutic Goods Act 1989, and tissue banks are required to be licensed by the Therapeutic Goods Administration and are audited for compliance with the Code of Good Manufacturing Practice- Human Blood and Tissues. In addition, tissue banks must comply with a myriad of other standards, guidelines and recommendations.

  20. Breast Cancer Tissue Repository

    National Research Council Canada - National Science Library

    Iglehart, J

    1997-01-01

    The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

  1. Outcomes of Modestly Hypofractionated Radiation for Lung Tumors: Pre- and Mid-Treatment Positron Emission Tomography-Computed Tomography Metrics as Prognostic Factors.

    Science.gov (United States)

    Harris, Jeremy P; Chang-Halpenny, Christine N; Maxim, Peter G; Quon, Andrew; Graves, Edward E; Diehn, Maximilian; Loo, Billy W

    2015-11-01

    Many patients with lung tumors have tumors too large for stereotactic ablative radiotherapy and comorbidities precluding concurrent chemotherapy. We report the outcomes of 29 patients treated with hypofractionated radiotherapy (RT) to 60 to 66 Gy in 3-Gy fractions. We also report an exploratory analysis of the prognostic value of the pre- and mid-RT positron emission tomography-computed tomography. Modestly hypofractionated radiation therapy (HypoRT; 60-66 Gy in 3-Gy fractions) allows patients with locally advanced thoracic tumors and poor performance status to complete treatment within a shorter period without concurrent chemotherapy. We evaluated the outcomes and imaging prognostic factors of HypoRT. We retrospectively reviewed the data from all patients with primary and metastatic intrathoracic tumors treated with HypoRT from 2006 to 2012. We analyzed the survival and toxicity outcomes, including overall survival (OS), progression-free survival (PFS), local recurrence (LR), and distant metastasis. We also evaluated the following tumor metrics in an exploratory analysis: gross tumor volume (GTV), maximum standardized uptake value (SUVMax), and metabolic tumor volume using a threshold of ≥ 50% of the SUVMax (MTV50%) or the maximum gradient of fluorine-18 fluorodeoxyglucose uptake (MTVEdge). We assessed the association of these metrics and their changes from before to mid-RT using positron emission tomography-computed tomography (PET-CT) with OS and PFS. We identified 29 patients, all with pre-RT and 20 with mid-RT PET-CT scans. The median follow-up period was 15 months. The 2-year overall and non-small-cell lung cancer-only rate for OS, PFS, and LR, was 59% and 59%, 52% and 41%, and 27% and 32%, respectively. No grade ≥ 3 toxicities developed. The median decrease in GTV, SUVMax, and MTVEdge was 11%, 24%, and 18%, respectively. Inferior OS was associated with a larger pre-RT MTVEdge (P = .005) and pre-RT MTV50% (P = .007). Inferior PFS was associated with a

  2. Threshold nonlinear absorption in Zeeman transitions

    International Nuclear Information System (INIS)

    Narayanan, Andal; Hazra, Abheera; Sandhya, S N

    2010-01-01

    We experimentally study the absorption spectroscopy from a collection of gaseous 87 Rb atoms at room temperature irradiated with three fields. Two of these fields are in a pump-probe saturation absorption configuration. The third field co-propagates with the pump field. The three fields address Zeeman degenerate transitions between hyperfine levels 5S 1/2 , F = 1 and 5P 3/2 , F = 0, F = 1 around the D2 line. We find a sub-natural absorption resonance in the counter-propagating probe field for equal detunings of all three fields. This absorption arises in conjunction with the appearance of increased transmission due to electro-magnetically induced transparency in the co-propagating fields. The novel feature of this absorption is its onset only for the blue of 5P 3/2 , F = 0, as the laser frequency is scanned through the excited states 5P 3/2 , F = 0, F = 1 and F = 2. The absorption rapidly rises to near maximum values within a narrow band of frequency near 5P 3/2 , F = 0. Our experimental results are compared with a dressed atom model. We find the threshold absorption to be a result of coherent interaction between the dressed states of our system.

  3. Gastrointestinal absorption of Np in rats

    International Nuclear Information System (INIS)

    Wirth, R.; Volf, V.

    1985-01-01

    The effect of Np mass and the acidity of the administered Np solutions as well as the age, sex and nutritional status of the animals injected or gavaged with 239Np or 237Np were determined. The latter factor proved to be dominant for absorption of Np from the gut. Thus in fasting weanling and young adult male rats, the absorption of 239Np was sixfold higher (0.18% and 0.12%, respectively) than in fed ones (0.03% and 0.02%, respectively). Absorption by fasted adult females was 0.05% of the administered 239Np, about half of that of adult males. Raising the Np-mass gavaged to fasted female rats to 1 and 10 mg 237Np/kg resulted in an absorption of 0.23% and 0.26%, respectively. Thus, an increased absorption of Np in adult rats seems to be expected only if a large mass is ingested. No dependence of the absorption of Np on nitric acid concentration was found. The data obtained after oral administration of 238Pu and 239Np to adult rats suggest that the f1 factor recommended by the ICRP for fractional absorption of soluble Np compounds from the gut should be decreased, whereas the f1 factor for soluble Pu compounds should be raised

  4. Aerosol Angstrom Absorption Coefficient Comparisons during MILAGRO.

    Science.gov (United States)

    Marley, N. A.; Marchany-Rivera, A.; Kelley, K. L.; Mangu, A.; Gaffney, J. S.

    2007-12-01

    Measurements of aerosol absorption were obtained as part of the MAX-Mex component of the MILAGRO field campaign at site T0 (Instituto Mexicano de Petroleo in Mexico City) by using a 7-channel aethalometer (Thermo- Anderson) during the month of March, 2006. The absorption measurements obtained in the field at 370, 470, 520, 590, 660, 880, and 950 nm were used to determine the aerosol Angstrom absorption exponents by linear regression. Since, unlike other absorbing aerosol species (e.g. humic like substances, nitrated PAHs), black carbon absorption is relatively constant from the ultraviolet to the infrared with an Angstrom absorption exponent of -1 (1), a comparison of the Angstrom exponents can indicate the presence of aerosol components with an enhanced UV absorption over that expected from BC content alone. The Angstrom exponents determined from the aerosol absorption measurements obtained in the field varied from - 0.7 to - 1.3 during the study and was generally lower in the afternoon than the morning hours, indicating an increase in secondary aerosol formation and photochemically generated UV absorbing species in the afternoon. Twelve-hour integrated samples of fine atmospheric aerosols (Petroleo (IMP) and CENICA.

  5. The effect of volatility on percutaneous absorption.

    Science.gov (United States)

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  6. Development of tissue bank

    Directory of Open Access Journals (Sweden)

    R P Narayan

    2012-01-01

    Full Text Available The history of tissue banking is as old as the use of skin grafting for resurfacing of burn wounds. Beneficial effects of tissue grafts led to wide spread use of auto and allograft for management of varied clinical conditions like skin wounds, bone defects following trauma or tumor ablation. Availability of adequate amount of tissues at the time of requirement was the biggest challenge that forced clinicians to find out techniques to preserve the living tissue for prolonged period of time for later use and thus the foundation of tissue banking was started in early twentieth century. Harvesting, processing, storage and transportation of human tissues for clinical use is the major activity of tissue banks. Low temperature storage of processed tissue is the best preservation technique at present. Tissue banking organization is a very complex system and needs high technical expertise and skilled personnel for proper functioning in a dedicated facility. A small lapse/deviation from the established protocol leads to loss of precious tissues and or harm to recipients as well as the risk of transmission of deadly diseases and tumors. Strict tissue transplant acts and stringent regulations help to streamline the whole process of tissue banking safe for recipients and to community as whole.

  7. Connective Tissue Disorders

    Science.gov (United States)

    ... of connective tissue. Over 200 disorders that impact connective tissue. There are different types: Genetic disorders, such as Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta Autoimmune disorders, such as lupus and scleroderma Cancers, like some types of soft tissue sarcoma Each ...

  8. Glucose absorption in acute peritoneal dialysis.

    Science.gov (United States)

    Podel, J; Hodelin-Wetzel, R; Saha, D C; Burns, G

    2000-04-01

    During acute peritoneal dialysis (APD), it is known that glucose found in the dialysate solution contributes to the provision of significant calories. It has been well documented in continuous ambulatory peritoneal dialysis (CAPD) that glucose absorption occurs. In APD, however, it remains unclear how much glucose absorption actually does occur. Therefore, the purpose of this study was to determine whether it is appropriate to use the formula used to calculate glucose absorption in CAPD (Grodstein et al) among patients undergoing APD. Actual measurements of glucose absorption (Method I) were calculated in 9 patients undergoing APD treatment for >24 hours who were admitted to the intensive care unit. Glucose absorption using the Grodstein et al formula (Method II) was also determined and compared with the results of actual measurements. The data was then further analyzed based on the factors that influence glucose absorption, specifically dwell time and concentration. The mean total amount of glucose absorbed was 43% +/- 15%. However, when dwell time and concentration were further examined, significant differences were noted. Method I showed a cumulative increase over time. Method II showed that absorption was fixed. This suggests that with the variation in dwell time commonly seen in the acute care setting, the use of Method II may not be accurate. In each of the 2 methods, a significant difference in glucose absorption was noted when comparing the use of 1.5% and 4.25% dialysate concentrations. The established formula designed for CAPD should not be used for calculating glucose absorption in patients receiving APD because variation in dwell time and concentration should be taken into account. Because of the time constraints and staffing required to calculate each exchange individually, combined with the results of the study, we recommend the use of the percentage estimate of 40% to 50%.

  9. Modulation of intestinal absorption of calcium

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, P; Dupuis, Y [Ecole Pratique des Hautes Etudes, 75 - Paris (France); Paris-11 Univ., 92 - Chatenay-Malabry (France))

    1975-01-01

    Absorption of ingested calcium (2ml of a 10mM CaCl/sub 2/ solution + /sup 45/Ca) by the adult rat was shown to be facilitated by the simultaneous ingestion of an active carbohydrate, L-arabinose. As the carbohydrate concentration is increased from 10 to 200mM, the absorption of calcium is maximised at a level corresponding to about twice the control absorption level. A similar doubling of calcium absorption is obtained when a 100mM concentration of any one of a number of other carbohydrates is ingested simultaneously with a 10mM CaCl/sub 2/ solution. Conversely, the simultaneous ingestion of increasing doses (10 to 100mM) of phosphate (NaH/sub 2/PO/sub 4/) with a 10mM CaCl/sub 2/ solution results in decreased /sup 45/Ca absorption and retention by the adult rat. The maximum inhibition of calcium absorption by phosphate is independent of the concentration of the ingested calcium solution (from 5 to 50mM CaCl/sub 2/). The simultaneous ingestion of CaCl/sub 2/ (10mM) with lactose and sodium phosphate (50 and 10mM respectively) shows that the activation effect of lactose upon /sup 45/Ca absorption may be partly dissimulated by the presence of phosphate. These various observations indicate that, within a large concentration range (2 to 50mM CaCl/sub 2/) calcium absorption appears to be a precisely modulated diffusion process. Calcium absorption varies (between minimum and maximum levels) as a function of the state of saturation by the activators (carbohydrates) and inhibitors (phosphate) of the calcium transport system.

  10. Measurement of the thyroid's iodine absorption utilizing minimal /sup 131/I dose

    Energy Technology Data Exchange (ETDEWEB)

    Paz A, B.; Villegas A, J.; Delgado B, C. (Universidad Nacional San Agustin de Arequipa (Peru). Departamento de Bioquimica)

    1981-03-01

    We utilize a minimal dose of /sup 131/I thus limiting the contact of the thyroid tissues with the isotopic materials to determine the absorption of /sup 131/I by the thyroid from 6 to 24 hours in 90 pupils of the locality of Arequipa. The average rate of absorption in 6 and 24 hours in the case considered are of 24.15% and 35.42% respectively, with a standard deviation of 6.93% and 9.61%. No significant differences were reported from the results of those of adults and our own results in all the probes which were undertaken.

  11. In vivo determination of the absorption and scattering spectra of the human prostate during photodynamic therapy

    Science.gov (United States)

    Finlay, Jarod C.; Zhu, Timothy C.; Dimofte, Andreea; Stripp, Diana C. H.; Malkowicz, S. B.; Whittington, Richard; Miles, Jeremy; Glatstein, Eli; Hahn, Stephen M.

    2004-06-01

    A continuing challenge in photodynamic therapy is the accurate in vivo determination of the optical properties of the tissue being treated. We have developed a method for characterizing the absorption and scattering spectra of prostate tissue undergoing PDT treatment. Our current prostate treatment protocol involves interstitial illumination of the organ via cylindrical diffusing optical fibers (CDFs) inserted into the prostate through clear catheters. We employ one of these catheters to insert an isotropic white light point source into the prostate. An isotropic detection fiber connected to a spectrograph is inserted into a second catheter a known distance away. The detector is moved along the catheter by a computer-controlled step motor, acquiring diffuse light spectra at 2 mm intervals along its path. We model the fluence rate as a function of wavelength and distance along the detector"s path using an infinite medium diffusion theory model whose free parameters are the absorption coefficient μa at each wavelength and two variables A and b which characterize the reduced scattering spectrum of the form μ"s = Aλ-b. We analyze our spectroscopic data using a nonlinear fitting algorithm to determine A, b, and μa at each wavelength independently; no prior knowledge of the absorption spectrum or of the sample"s constituent absorbers is required. We have tested this method in tissue simulating phantoms composed of intralipid and the photosensitizer motexafin lutetium (MLu). The MLu absorption spectrum recovered from the phantoms agrees with that measured in clear solution, and μa at the MLu absorption peak varies linearly with concentration. The ´"s spectrum reported by the fit is in agreement with the known scattering coefficient of intralipid. We have applied this algorithm to spectroscopic data from human patients sensitized with MLu (2 mg kg-1) acquired before and after PDT. Before PDT, the absorption spectra we measure include the characteristic MLu absorption

  12. Effect of oils on drug absorption

    OpenAIRE

    Palin, K.J.

    1981-01-01

    Oil and emulsion vehicles have been shown to alter the oral absorption of many drugs. This may be due to enhanced lymph flow and/or altered gastro-intestinal motility in the presence of the oils. The oral absorption of a model compound (DOT) in the presence of three chemically different oils, arachis oil, Miglyol 812 and liquid paraffin was investigated in rats, the influence of lymphatic absorption and gastro-intestinal motility being determined. The findings were applied to the for.mulation...

  13. Absorption spectrum of Iodine around 5915 A

    International Nuclear Information System (INIS)

    1990-01-01

    The iodine absorption spectrum around 5915 A is of interest for many authors especially the hyperfine structure of the iodine line. Lodine absorption spectrum was obtained due to the interaction of iodine vapour with dye laser [(R6G) (0.5A) scanning range around 5915 A] which is pumped by(Ar + )laser absorption spectrum. The decrease in the peak of the transmission line around 5915 A shows the signal futher decreased by heating the iodine cell. This analysis has been done using a monochromator

  14. Absorption of proteins and amino acids

    International Nuclear Information System (INIS)

    Jeejeebhoy, K.N.

    1976-01-01

    Although the absorption of proteins and amino acids is an important issue in nutrition, its measurement is not common because of the methodological difficulties. Complications are attributable in particular to the magnitude of endogenous protein secretion and to the diversity of absorption mechanisms for amino acids either as individual units or as peptides. Methods for studying absorption include balance techniques, tolerance tests, tracer techniques using proteins or amino acids labelled with 131 I, 3 H, or 15 N, intestinal perfusion studies, and others; they must be selected according to the nature of the information sought. Improvements over the current methods would be useful. (author)

  15. Evidence for pion absorption on four nucleons

    International Nuclear Information System (INIS)

    Rzehorz, B.; Backenstoss, G.; Dzemidzic, M.; Zagreb Univ.; Furic, M.; Zagreb Univ.; Hoffart, A.; Petkovic, T.; Zagreb Univ.; Ullrich, H.; Weyer, H.J.; Weiser, D.; Wildi, M.

    1996-01-01

    Experimental spectra from the coincident detection of three nucleons after the pion absorption in 4 He are displayed. The presence of a mechanism with four nucleons participating in the absorption process is made obvious. The total cross-sections for this absorption mode are: σ 4NA abs =(1.0±0.2)mb at T π =120 MeV and σ 4NA abs =(2.18± 0.65) mb at T π =210 MeV. (orig.)

  16. Gastrointestinal absorption of uranium in man

    International Nuclear Information System (INIS)

    Larsen, R.P.; Orlandini, K.A.

    1984-01-01

    A method has been established for determining the fractional absorption of uranium directly in man. Measurements are made of the urinary excretion rates of uranium for individuals whose drinking water has a high 234 U to 238 U activity ratio and is the primary source of 234 U in their diets. For two individuals, the values obtained for the fractional absorption of 234 U were 0.004 and 0.006. The values obtained for the fractional absorption of 238 U, using a literature value for the 238 U intake from food, were 0.008 and 0.015. The present ICRP value is 0.20. 7 references, 1 table

  17. Optical absorption in a thin nickel wire

    OpenAIRE

    INAGAKI, Takashi; Goudonnet, J.P.; ARAKAWA, E.T.

    1986-01-01

    Absorption of a 633-nm phonton in a cylindrical nickel wire with diameter 13 m was measured by a photoacoustic method as a function of angle of phonton incidence . A good photoacoustic signal was obtained with a 6-m W He-Ne laser as a light source without employing focusing optics. The absorption measured for p-polarized phontons was found to be in good agreement with geometrical optics calculation. For s-polarized light, however, significant excess absorption was found for >35.

  18. Optical absorption in a thin nickel wire

    International Nuclear Information System (INIS)

    Inagaki, T.; Goudonnet, J.P.; Arakawa, E.T.

    1986-01-01

    Absorption of a 633-nm photon in a cylindrical nickel wire with diameter 13 μm was measured by a photoacoustic method as a function of angle of photon incidence theta. A good photoacoustic signal was obtained with a 6-mW He-Ne laser as a light source without employing focusing optics. The absorption measured for p-polarized photons was found to be in good agreement with geometrical optics calculation. For s-polarized light, however, significant excess absorption was found for theta > 35 0

  19. Total absorption by degenerate critical coupling

    Energy Technology Data Exchange (ETDEWEB)

    Piper, Jessica R., E-mail: jrylan@stanford.edu; Liu, Victor; Fan, Shanhui, E-mail: shanhui@stanford.edu [Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-06-23

    We consider a mirror-symmetric resonator with two ports. We show that, when excited from a single port, complete absorption can be achieved through critical coupling to degenerate resonances with opposite symmetry. Moreover, any time two resonances with opposite symmetry are degenerate in frequency and absorption is always significantly enhanced. In contrast, when two resonances with the same symmetry are nearly degenerate, there is no absorption enhancement. We numerically demonstrate these effects using a graphene monolayer on top of a photonic crystal slab, illuminated from a single side in the near-infrared.

  20. Gas treating absorption theory and practice

    CERN Document Server

    Eimer, Dag

    2014-01-01

    Gas Treating: Absorption Theory and Practice provides an introduction to the treatment of natural gas, synthesis gas and flue gas, addressing why it is necessary and the challenges involved.  The book concentrates in particular on the absorption-desorption process and mass transfer coupled with chemical reaction. Following a general introduction to gas treatment, the chemistry of CO2, H2S and amine systems is described, and selected topics from physical chemistry with relevance to gas treating are presented. Thereafter the absorption process is discussed in detail, column hardware is explain

  1. The Driving Forces of Subsidiary Absorptive Capacity

    DEFF Research Database (Denmark)

    Schleimer, Stephanie C.; Pedersen, Torben

    2013-01-01

    The study investigates how a multinational corporation (MNC) can promote the absorptive capacity of its subsidiaries. The focus is on what drives the MNC subsidiary's ability to absorb marketing strategies that are initiated by the MNC parent, as well as how the subsidiary enacts on this absorptive...... as a purposeful response to this dual embeddedness. An analysis of marketing strategy absorptions undertaken by 213 subsidiaries reveals that MNCs can assist their subsidiaries to compete in competitive and dynamic focal markets by forming specific organizational mechanisms that are conducive to the development...

  2. Saturable absorption in detonation nanodiamond dispersions

    Science.gov (United States)

    Vanyukov, Viatcheslav; Mikheev, Gennady; Mogileva, Tatyana; Puzyr, Alexey; Bondar, Vladimir; Lyashenko, Dmitry; Chuvilin, Andrey

    2017-07-01

    We report on a saturable absorption in aqueous dispersions of nanodiamonds with femtosecond laser pulse excitation at a wavelength of 795 nm. The open aperture Z-scan experiments reveal that in a wide range of nanodiamond particle sizes and concentrations, a light-induced increase of transmittance occurs. The transmittance increase originates from the saturation of light absorption and is associated with a light absorption at 1.5 eV by graphite and dimer chains (Pandey dimer chains). The obtained key nonlinear parameters of nanodiamond dispersions are compared with those of graphene and carbon nanotubes, which are widely used for the mode-locking.

  3. Absorption and recovery of n-hexane in aqueous solutions of fluorocarbon surfactants.

    Science.gov (United States)

    Xiao, Xiao; Yan, Bo; Fu, Jiamo; Xiao, Xianming

    2015-11-01

    n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants (FSN100 and FSO100) were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions (0.01%-0.30%), the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration, indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90sec heating at 80-85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases. Copyright © 2015. Published by Elsevier B.V.

  4. Influence of dietary minerals and fat on the absorption of lead. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Barltrop, D.; Khoo, H.E.

    1976-01-01

    The nutritional factors influencing the absorption of lead from the gut were studied using both intact animals and ligated gut loop preparation. Short-term feeding studies were made in groups of six rats using diets of constant lead content (0.075%) but in which the nutritional components were varied sequentially. Dietary lead was labelled with /sup 203/Pb. Absorption was determined in the carcass and individual organs by means of a small-animal whole-body counter. The results showed that absorption was enhanced to twenty-times control value by diets deficient in minerals and seven-fold by diets of high fat content. Conversely, high mineral diets were shown to result in a two-fold reduction in lead absorption. The interaction of lead with individual dietary components was further studied under controlled conditions using ligated gut loop preparations. Using this technique the relative roles of luminal interaction and tissue response for lead absorption were explored and the kinetics of lead absorption determined.

  5. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    “Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  6. Gintonin absorption in intestinal model systems

    Directory of Open Access Journals (Sweden)

    Byung-Hwan Lee

    2018-01-01

    Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

  7. On pair-absorption in intrinsic vapours

    International Nuclear Information System (INIS)

    Hotop, R.; Niemax, K.; Schlueter, D.

    1982-01-01

    The bound-state pair-absorption bands Cs(6 2 S 1 sub(/) 2 ) + Cs(6 2 S 1 sub(/) 2 ) + hν → Cs(5 2 D 5 sub(/) 2 sub(,) 3 sub(/) 2 ) + Cs(6 2 P 1 sub(/) 2 ) and the K-K continuum-state pair-absorptions in the wavelength region 2.350 <= lambda <= 2.850 Angstroem have been investigated experimentally. In the case of the bound-state pair-absorption bands a theoretical approach for the absorption cross section at the band centre is given which is in good agreement with the experimental observation. Differences between our and the theoretical formulas given by the Stanford group are discussed. (orig.)

  8. evaluation of atomic absorption spectrophotometry (ashing, non ...

    African Journals Online (AJOL)

    cistvr

    1Department of Agricultural and Food Science and 2Department of ... used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and ..... fact that more preparation steps were involved in the Ashing procedure and thus.

  9. Radiant absorption characteristics of corrugated curved tubes

    Directory of Open Access Journals (Sweden)

    Đorđević Milan Lj.

    2017-01-01

    Full Text Available The utilization of modern paraboloidal concentrators for conversion of solar radiation into heat energy requires the development and implementation of compact and efficient heat absorbers. Accurate estimation of geometry influence on absorption characteristics of receiver tubes is an important step in this process. This paper deals with absorption characteristics of heat absorber made of spirally coiled tubes with transverse circular corrugations. Detailed 3-D surface-to-surface Hemicube method was applied to compare radiation performances of corrugated and smooth curved tubes. The numerical results were obtained by varying the tube curvature ratio and incident radiant heat flux intensity. The details of absorption efficiency of corrugated tubes and the effect of curvature on absorption properties for both corrugated and smooth tubes were presented. The results may have significance to further analysis of highly efficient heat absorbers exposed to concentrated radiant heating. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 42006

  10. Enriching Absorptive Capacity Through Social Interaction

    DEFF Research Database (Denmark)

    Hotho, Jasper Jaap; Becker-Ritterspach, Florian; Saka-Helmhout, Ayse

    their organization’s capacity to put new knowledge to use. To address this shortcoming we conduct an in-depth comparative case study of a headquarters-initiated knowledge transfer initiative at two subsidiaries of the same MNE. The findings demonstrate that social interaction is a key requirement for subsidiary....... These insights contribute to the absorptive capacity literature by demonstrating the scale and scope of social interaction as the key link between individual- and organizational-level absorptive capacity.......Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within MNEs. But how individual behaviour translates to absorptive capacity at the subsidiary level, and exactly how this is contingent on subsidiaries’ social context, remains under-addressed. This not only...

  11. Enriching Absorptive Capacity through Social Interaction

    DEFF Research Database (Denmark)

    Hotho, Jasper J.; Saka-Helmhout, Ayse; Becker-Ritterspach, Florian

    2012-01-01

    their organization's capacity to put new knowledge to use. To address this shortcoming we conduct an in-depth comparative case study of a headquarters-initiated knowledge transfer at two subsidiaries of the same multinational enterprise. The findings demonstrate that social interaction is a prerequisite...... or constraining local interaction patterns. These insights contribute to the absorptive capacity literature by demonstrating the scale and scope of social interaction as a key link between individual- and organizational-level absorptive capacity.......Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within multinational enterprises. But how individual behaviour translates into absorptive capacity at the subsidiary level, and how this is contingent on subsidiaries' social context, remains under...

  12. Absorption chillers: Part of the solution

    International Nuclear Information System (INIS)

    Occhionero, A.J.; Hughes, P.J.; Reid, E.A.

    1991-01-01

    Acid rain, ozone depletion, global warming, and implementation economics are considered as they relate to the advisability of expanding the application of absorption chillers. Introductory and background information are provided to put the discussion in the proper context. Then all four issues are discussed separately as they relate to absorption chillers. Acid rain and ozone depletion concerns, and implementation economics, are found to support the expanded use of absorption chillers. The global warming concern is found to be more of a gray area, but the areas of benefit correspond well with the conditions of greatest economic advantage. All things considered, absorption chillers are believed to be part of the environmental and economic solution. It is further believed that integrated resource planning (IRP) processes that consider electric and gas technologies on an equal footing would come to the same conclusion for many regions of the United States. 9 refs., 3 tabs

  13. Electromagnetically induced absorption via incoherent collisions

    International Nuclear Information System (INIS)

    Yang Xihua; Sheng Jiteng; Xiao Min

    2011-01-01

    We conduct theoretical studies on electromagnetically induced absorption via incoherent collisions in an inhomogeneously broadened ladder-type three-level system with the density-matrix approach. The effects of the collision-induced coherence decay rates as well as the probe laser field intensity on the probe field absorption are examined. It is shown that with the increase of the collisional decay rates in a moderate range, a narrow dip due to electromagnetically induced transparency superimposed on the Doppler-broadened absorption background can be turned into a narrow peak under the conditions that the probe field intensity is not very weak as compared to the pump field, which results from the enhancement of constructive interference and suppression of destructive interference between one-photon and multiphoton transition pathways. The physical origin of the collision-assisted electromagnetically induced absorption is analyzed with a power-series solution of the density-matrix equations.

  14. (EXAFS) X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1983-01-01

    The technique EXAFS (Extended X-Ray Absorption Fine Structure) is presented and its applications using the synchrotron radiation as an incidente beam in Science of Materials and Biophysics are shown. (L.C.) [pt

  15. Extending Organizational Antecedents Of Absorptive Capacity

    DEFF Research Database (Denmark)

    Burcharth, Ana Luiza de Araújo; Lettl, Christopher; Ulhøi, John Parm

    2015-01-01

    on organizational characteristics that encourage experimentation. Specifically, we argue that characteristics such as slack resources, tolerance for failure, willingness to cannibalize and external openness are important organizational antecedents for knowledge absorption activities as they prevent inertia. Drawing...

  16. The origin of electromagnetically induced absorption

    International Nuclear Information System (INIS)

    Park, Jong Dae; Hwang, Sung Tae; Lee, Ho Seong; Park, Sung Jong; Cho, Hyuck; Choi, Won Sik

    2000-01-01

    Recently, there have been a lot of interests in the coherence superposition of atomic states which are formed by laser fields. Coherent population trapping(CTP), electromagnetically induced transparency(EIT), enhancement of the refractive index without absorption, lasing without inversion(LWI), and electromagnetically induced absorption(EIA) are the examples where coherence effects are important. Previously, the spontaneous transfer of the light-induced coherence from the excited level to the ground one was emphasized for the essential ingredient for electromagnetically induced absorption. In this paper, we have considered a case where linearly polarized coupling laser and probe laser are applied to the same degenerated ground and excited levels. We have solved the master equations for density matrix using time varying Hamiltonian and studied the absorption spectra at various conditions. We demonstrate that EIA can be observed without spontaneous transfer of the light-induced coherence in F g = 1 -> F e = 2 D2 transitions of Hydrogen atoms

  17. investigating water absorption and thickness swelling tendencies

    African Journals Online (AJOL)

    HOD

    In addition, G30E (30% reinforced glass fibre in the epoxy composite) was more resilient to moisture ... determine its suitability as per its water absorption and thickness ... lower thermal conductivity and low density as outlined in the Tables.

  18. Attosecond transient absorption spectroscopy of molecular hydrogen

    International Nuclear Information System (INIS)

    Martín, Fernando; González-Castrillo, Alberto; Palacios, Alicia; Argenti, Luca; Cheng, Yan; Chini, Michael; Wang, Xiaowei; Chang, Zenghu

    2015-01-01

    We extend attosecond transient absorption spectroscopy (ATAS) to the study of hydrogen molecules, demonstrating the potential of the technique to resolve – simultaneously and with state resolution – both the electronic and nuclear dynamics. (paper)

  19. Engineering Complex Tissues

    Science.gov (United States)

    MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

    2010-01-01

    This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

  20. Inert gas transport in blood and tissues.

    Science.gov (United States)

    Baker, A Barry; Farmery, Andrew D

    2011-04-01

    This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues-first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper- and hypobaric conditions on inert gas transport. © 2011 American Physiological Society. Compr Physiol 1:569-592, 2011.

  1. Ultrafast THz Saturable Absorption in Doped Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields.......We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields....

  2. Seasonal Solar Thermal Absorption Energy Storage Development.

    Science.gov (United States)

    Daguenet-Frick, Xavier; Gantenbein, Paul; Rommel, Mathias; Fumey, Benjamin; Weber, Robert; Gooneseker, Kanishka; Williamson, Tommy

    2015-01-01

    This article describes a thermochemical seasonal storage with emphasis on the development of a reaction zone for an absorption/desorption unit. The heat and mass exchanges are modelled and the design of a suitable reaction zone is explained. A tube bundle concept is retained for the heat and mass exchangers and the units are manufactured and commissioned. Furthermore, experimental results of both absorption and desorption processes are presented and the exchanged power is compared to the results of the simulations.

  3. Determination of hafnium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yoshida, Isao; Kobayashi, Hiroshi; Ueno, Keihei.

    1977-01-01

    Optimum conditions for atomic absorption spectrophotometric determination of hafnium were investigated by use of a Jarrel-Ash AA-1 instrument which was equipped with a premixed gas burner slotted 50 mm in length and 0.4 mm in width. Absorption of hafnium, which was atomized in an nitrous oxide-acetylene flame, was measured on a resonance line at 307.29 nm. The absorption due to hafnium was enhanced in the presence of ammonium fluoride and iron(III) ion, as shown in Figs. 2 and 3, depending on their concentration. The highest absorption was attained by the addition of (0.15 -- 0.3)M ammonium fluoride, 0.07 M of iron(III) ion and 0.05 M of hydrochloric acid. An excess of the additives decreased the absorption. The presence of zirconium, which caused a significant interference in the ordinary analytical methods, did not affect the absorption due to hafnium, if the zirconium concentration is less than 0.2 M. A standard procedure was proposed; A sample containing a few mg of hafnium was dissolved in a 25-ml volumetric flask, and ammonium fluoride, ferric nitrate and hydrochloric acid were added so that the final concentrations were 0.3, 0.07 and 0.05 M, respectively. Atomic absorption was measured on the aqueous solution in a nitrous oxide-acetylene flame and the hafnium content was calculated from the absorbance. Sensitivity was as high as 12.5 μg of Hf/ml/l% absorption. The present method is especially recommendable to the direct determination of hafnium in samples containing zirconium. (auth.)

  4. Systemic Absorption of Nanomaterials by Oral Exposure

    DEFF Research Database (Denmark)

    Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

    This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

  5. Variations in the spectral values of specific absorption of phytoplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Sathyendranath, S.; Lazzara, L.; Prieur, L.

    Absorption spectra of laboratory cultures of eight species of phytoplankton were studied. These spectra, normalized per unit of chlorophyll a concentration (specific absorption) show variability in magnitude and spectral form. Specific absorption...

  6. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  7. Absorption Spectra of Gold Nanoparticle Suspensions

    Science.gov (United States)

    Anan'eva, M. V.; Nurmukhametov, D. R.; Zverev, A. S.; Nelyubina, N. V.; Zvekov, A. A.; Russakov, D. M.; Kalenskii, A. V.; Eremenko, A. N.

    2018-02-01

    Three gold nanoparticle suspensions are obtained, and mean radii in distributions - (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm - are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450-800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie-Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

  8. Engineering Musculoskeletal Tissue Interfaces

    Directory of Open Access Journals (Sweden)

    Ece Bayrak

    2018-04-01

    Full Text Available Tissue engineering aims to bring together biomaterials, cells, and signaling molecules within properly designed microenvironments in order to create viable treatment options for the lost or malfunctioning tissues. Design and production of scaffolds and cell-laden grafts that mimic the complex structural and functional features of tissues are among the most important elements of tissue engineering strategy. Although all tissues have their own complex structure, an even more complex case in terms of engineering a proper carrier material is encountered at the tissue interfaces, where two distinct tissues come together. The interfaces in the body can be examined in four categories; cartilage-bone and ligament-bone interfaces at the knee and the spine, tendon-bone interfaces at the shoulder and the feet, and muscle-tendon interface at the skeletal system. These interfaces are seen mainly at the soft-to-hard tissue transitions and they are especially susceptible to injury and tear due to the biomechanical inconsistency between these tissues where high strain fields are present. Therefore, engineering the musculoskeletal tissue interfaces remain a challenge. This review focuses on recent advancements in strategies for musculoskeletal interface engineering using different biomaterial-based platforms and surface modification techniques.

  9. Absorption of nutrients in the MNF-80 potato crop

    International Nuclear Information System (INIS)

    Cabalceta, Gilberto; Alvarado, Alfredo; Saldias, Miren

    2005-01-01

    Absorption curves of nutrients of MNF-80 potato variety cycle were determined at the Irazu (3000 masl) and Juan Vinas (1500 masl) sites, planted on Andisols of medium fertility status. Tissue samples were taken every 15 days after planting; separated into aerial biomass, tuber and root, to estimate dry weight and nutrient contents. At Juan Vinas the crop matured after 80-90 days, contrasting with 135 days at Irazu, due to temperature, total radiation, and growth rate reductions at the higher elevation. Higher amounts of absorbed K and N in both farms (>100 kg ha -1 ) were followed by smaller amounts of P, Ca, Mg y S (8-20 kg ha -1 ). At the Irazu site, the potato yielded 36 t ha -1 , and absorbed 110, 15, 166, 12, 10 and 11 kg ha -1 on N, P, K, Ca, Mg and S, respectively. Also, 904, 68, 162, 317 and 42 g ha -1 of Fe, Cu, Zn, Mn and B, respectively. At the Juan Vinas site, the potato yielded 28 t ha -1 , and absorbed 133, 8, 173, 22, 10 and 10 Kg ha -1 of N, P, K, Ca, Mg and S, respectively. Also, 1097, 68, 181, 651 and 84 g ha -1 of Fe, Cu, Zn, Mn and B, respectively. At the Irazu site most of N, P, K, Ca, Mg and S were absorbed up to 60 days after planting, and except for Ca, the other elements showed a second peak of absorption at the end of the crop cycle. At the Juan Vinas site only one peak of absorption was observed up to 45 days after planting. (author) [es

  10. Computational methods for describing the laser-induced mechanical response of tissue

    Energy Technology Data Exchange (ETDEWEB)

    Trucano, T.; McGlaun, J.M.; Farnsworth, A.

    1994-02-01

    Detailed computational modeling of laser surgery requires treatment of the photoablation of human tissue by high intensity pulses of laser light and the subsequent thermomechanical response of the tissue. Three distinct physical regimes must be considered to accomplish this: (1) the immediate absorption of the laser pulse by the tissue and following tissue ablation, which is dependent upon tissue light absorption characteristics; (2) the near field thermal and mechanical response of the tissue to this laser pulse, and (3) the potential far field (and longer time) mechanical response of witness tissue. Both (2) and (3) are dependent upon accurate constitutive descriptions of the tissue. We will briefly review tissue absorptivity and mechanical behavior, with an emphasis on dynamic loads characteristic of the photoablation process. In this paper our focus will center on the requirements of numerical modeling and the uncertainties of mechanical tissue behavior under photoablation. We will also discuss potential contributions that computational simulations can make in the design of surgical protocols which utilize lasers, for example, in assessing the potential for collateral mechanical damage by laser pulses.

  11. Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

    International Nuclear Information System (INIS)

    Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

    2015-01-01

    We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

  12. 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...

  13. Absorption and distribution of 3H in horned cattle of different age

    International Nuclear Information System (INIS)

    Sirotkin, A.N.; Rusakov, N.V.

    1979-01-01

    Studied are the regularity of absorption of the tritium oxide in the gastrointestinal tract, the character of the distribution among the organs and of the radionuclide accumulation in horned cattle of different are. To determine the tritium absorption in the gastrointestinal tract the method of single oral and intravenous injection of radionuclide were used. The tritium concentration values in organs and tissues of horned cattle are presented. The results obtained show that tritium distribution in the organism occurs uniformly and does not depend on the way of intake. With the age the tritium concentration in dry residue increases and in the water phase decreases. The tritium absorption value calculated in the digestive tract of the horned cattle practically does not depend on the animals' age and constitutes 96.2% in average

  14. Tissue engineering in dentistry.

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

    2014-08-01

    of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the

  15. Biomaterials for Tissue Engineering

    Science.gov (United States)

    Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

    2013-01-01

    Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

  16. Optical measurements of absorption changes in two-layered diffusive media

    International Nuclear Information System (INIS)

    Fabbri, Francesco; Sassaroli, Angelo; Henry, Michael E; Fantini, Sergio

    2004-01-01

    We have used Monte Carlo simulations for a two-layered diffusive medium to investigate the effect of a superficial layer on the measurement of absorption variations from optical diffuse reflectance data processed by using: (a) a multidistance, frequency-domain method based on diffusion theory for a semi-infinite homogeneous medium; (b) a differential-pathlength-factor method based on a modified Lambert-Beer law for a homogeneous medium and (c) a two-distance, partial-pathlength method based on a modified Lambert-Beer law for a two-layered medium. Methods (a) and (b) lead to a single value for the absorption variation, whereas method (c) yields absorption variations for each layer. In the simulations, the optical coefficients of the medium were representative of those of biological tissue in the near-infrared. The thickness of the first layer was in the range 0.3-1.4 cm, and the source-detector distances were in the range 1-5 cm, which is typical of near-infrared diffuse reflectance measurements in tissue. The simulations have shown that (1) method (a) is mostly sensitive to absorption changes in the underlying layer, provided that the thickness of the superficial layer is ∼0.6 cm or less; (2) method (b) is significantly affected by absorption changes in the superficial layer and (3) method (c) yields the absorption changes for both layers with a relatively good accuracy of ∼4% for the superficial layer and ∼10% for the underlying layer (provided that the absorption changes are less than 20-30% of the baseline value). We have applied all three methods of data analysis to near-infrared data collected on the forehead of a human subject during electroconvulsive therapy. Our results suggest that the multidistance method (a) and the two-distance partial-pathlength method (c) may better decouple the contributions to the optical signals that originate in deeper tissue (brain) from those that originate in more superficial tissue layers

  17. Absorption of ultraviolet radiation by antarctic phytoplankton

    Energy Technology Data Exchange (ETDEWEB)

    Vernet, M.; Mitchell, B.G. (Univ. of California-San Diego, La Jolla (United States))

    1990-01-09

    Antarctic phytoplankton contain UV-absorbing compounds that may block damaging radiation. Compounds that absorb from 320-340 nm were observed in spectral absorption of both particulates and in methanol extracts of the particulates. The decrease in the total concentration of these UV compounds with respect to chlorophyll a, as measured by the ratio of in vitro absorption at 335 nm to absorption at 665 nm is variable and decreases with depth. We observed up to 5-fold decrease in this ratio for samples within the physically mixes surface layer. The absorption of UV radiation in methanol extracts, which peaks from 320 to 340 nm, may be composed of several compounds. Shifts in peak absorption with depth (for example, from 331 nm at surface to 321 nm at 75 m), may be interpreted as a change in composition. Ratios of protective yellow xanthophylls (diadinoxanthin + diatoxanthin) to photosynthetic fucoxanthin-like pigments have highest values in surface waters. As these pigments also absorb in the near UV, their function might extend to protection as well as utilization of UV radiation for photosynthesis. We document strong absorption in the UV from 320-330 nm for Antarctic marine particulates. Below this region of the solar energy spectrum, absolute energy levels of incident radiation drop off dramatically. Only wavelengths shorter than about 320 nm will be significantly enhanced due to ozone depletion. If the absorption we observed serves a protective role for phytoplankton photosynthesis, it appears the peak band is in the region where solar energy increases rapidly, and not in the region where depletion would cause significant variations in absolute flux.

  18. Detection of cancerous kidney tissue areas by means of infrared spectroscopy of intercellular fluid

    Science.gov (United States)

    Urboniene, V.; Jankevicius, F.; Zelvys, A.; Steiner, G.; Sablinskas, V.

    2014-03-01

    In this work the infrared absorption spectra of intercellular fluid of normal and tumor kidney tissue were recorded and analyzed. The samples were prepared by stamping freshly resected tissue onto a CaF2 substrate. FT-IR spectra obtained from intracellular fluid of tumor tissue exhibit stronger absorption bands in the spectral region from 1000-1200 cm-1 and around 1750 cm-1 than those obtained from normal tissue. It is likely the spectra of extracellular matrix of kidney tumor tissue with large increases in the intensities of these bands represent a higher concentration of fatty acids and glycerol. Amide I and amide II bands are stronger in spectra of normal tissue indicating a higher level of proteins. The results demonstrate that FT-IR spectroscopy of intercellular fluids is a novel approach for a quick diagnosis during surgical resection, which can improve the therapy of kidney tumors.

  19. 23Na+- and 39K+-NMR studies of cation-polyanion interactions in vascular connective tissue

    International Nuclear Information System (INIS)

    Siegel, G.; Walter, A.; Bostanjoglo, M.

    1987-01-01

    The ion binding properties of vascular connective tissue as well as of substances derived therefrom were studied in dependence on cation concentration by NMR and atomic absorption techniques. 16 refs.; 8 figs

  20. Double wavelength differential absorption as a technique for early diagnosis of breast cancer

    Science.gov (United States)

    Liger, Vladimir V.; Zybin, Alexander V.; Niemax, Kay; Kuritsyn, Yuri A.; Bolshov, Mikhail A.

    2005-08-01

    The double-wavelength differential molecular absorption technique with diode lasers is proposed for sensitive detection of functional status of breast tissues. The method is based on the measurement of the transmitted intensity differences of the two beams of diode lasers tuned to selected wavelengths within a broad absorption band of a human breast tissue within 700 - 800 nm spectral range. The strategy for the optimum selection of the diode laser wavelengths and initial adjustment of the detection scheme is developed. The method is demonstrated by the detection of the relative concentrations of two dyes, the optical properties of which are similar to those of a mixture of oxy- and deoxy- hemoglobin. The results of the first clinical tests of the proposed technique are briefly described.

  1. Thermodynamic performance optimization of the absorption-generation process in an absorption refrigeration cycle

    International Nuclear Information System (INIS)

    Chen, Yi; Han, Wei; Jin, Hongguang

    2016-01-01

    Highlights: • This paper proposes a new thermal compressor model with boost pressure ratio. • The proposed model is an effective way to optimize the absorption-generation process. • Boost pressure ratio is a key parameter in the proposed thermal compressor model. • The optimum boost pressure ratios for two typical refrigeration systems are obtained. - Abstract: The absorption refrigeration cycle is a basic cycle that establishes the systems for utilizing mid-low temperature heat sources. A new thermal compressor model with a key parameter of boost pressure ratio is proposed to optimize the absorption-generation process. The ultimate generation pressure and boost pressure ratio are used to represent the potential and operating conditions of the thermal compressor, respectively. Using the proposed thermal compressor model, the operation mechanism and requirements of the absorption refrigeration system and absorption-compression refrigeration system are elucidated. Furthermore, the two typical heat conversion systems are optimized based on the thermal compressor model. The optimum boost pressure ratios of the absorption refrigeration system and the absorption-compression refrigeration system are 0.5 and 0.75, respectively. For the absorption refrigeration system, the optimum generation temperature is 125.31 °C at the cooling water temperature of 30 °C, which is obtained by simple thermodynamic calculation. The optimized thermodynamic performance of the absorption-compression refrigeration system is 16.7% higher than that of the conventional absorption refrigeration system when the generation temperature is 100 °C. The thermal compressor model proposed in this paper is an effective method for simplifying the optimization of the thermodynamic systems involving an absorption-generation process.

  2. Iron absorption after antrectomy with gastroduodenostomy

    International Nuclear Information System (INIS)

    Magnusson, B.E.O.

    1976-01-01

    Haematological values were studied in 177 unselected patients 3-6 years after antrectomy with gastroduodenostomy. The majority (76%) had been operated upon for duodenal ulcer, 20% for gastric ulcer and the remaining patients had had both a duodenal and a gastric ulcer before the operation. In 65 patients a vagotomy had been added to the resection. 10% of the males and 15% of the females had a haemoglobin concentration below 13.0 or 12.0 g/100 ml, respectively. The corresponding frequencies for iron defifiency, defined as absence or only traces of haemosiderin in bone marrow smears, were 7% and 15%. The absorption of a small test dose of inorganic iron (0.56 mg Fe ++ as ferrous ascorbate) was studied in all the antrectomized patients. The absorption was also investigated in normal men and in patients who had had a Billroth II partial gastrectomy. No malabsorption of inorganic iron could be found in any of the groups. An inverse relationship between iron absorption and the grading of haemosiderin in bone marrow smears was found in normal subjects as well as in operated patients. Thus, an adequate increase of the absorption of ferrous iron was found even in operated patients with iron deficiency. Gastric acid secretion, measured as the peak acid output (PAO) after stimulation, was determined in all antrectomized patients. In patients having the same grading of haemosiderin (grade II) a slight but significant positive correlation was found between PAO and the absorption from the test dose (Fe ++ ). The absorption of food iron from a composite meal and the absorption from an iron salt (3.0 mg Fe ++ as ferrous ascorbate) was studied in 4 different groups: 1) normal males, 2) non-operated patients with peptic ulcer, 3) antrectomized patients with gastroduodenostomy and 4) patients operated upon with Billroth II partial gastrectomy. The range and mean absorption values from the test dose of inorganic iron were about the same in all groups. The absorption of food iron

  3. UV laser long-path absorption spectroscopy

    Science.gov (United States)

    Dorn, Hans-Peter; Brauers, Theo; Neuroth, Rudolf

    1994-01-01

    Long path Differential Optical Absorption Spectroscopy (DOAS) using a picosecond UV laser as a light source was developed in our institute. Tropospheric OH radicals are measured by their rotational absorption lines around 308 nm. The spectra are obtained using a high resolution spectrograph. The detection system has been improved over the formerly used optomechanical scanning device by application of a photodiode array which increased the observed spectral range by a factor of 6 and which utilizes the light much more effectively leading to a considerable reduction of the measurement time. This technique provides direct measurements of OH because the signal is given by the product of the absorption coefficient and the OH concentration along the light path according to Lambert-Beers law. No calibration is needed. Since the integrated absorption coefficient is well known the accuracy of the measurement essentially depends on the extent to which the OH absorption pattern can be detected in the spectra. No interference by self generated OH radicals in the detection lightpath has been observed. The large bandwidth (greater than 0.15 nm) and the high spectral resolution (1.5 pm) allows absolute determination of interferences by other trace gas absorptions. The measurement error is directly accessible from the absorption-signal to baseline-noise ratio in the spectra. The applicability of the method strongly depends on visibility. Elevated concentrations of aerosols lead to considerable attenuation of the laser light which reduces the S/N-ratio. In the moderately polluted air of Julich, where we performed a number of OH measurement spectra. In addition absorption features of unidentified species were frequently detected. A quantitative deconvolution even of the known species is not easy to achieve and can leave residual structures in the spectra. Thus interferences usually increase the noise and deteriorate the OH detection sensitivity. Using diode arrays for sensitive

  4. Absorption of radionuclide through wounded skin

    International Nuclear Information System (INIS)

    Kusama, Tomoko; Ogaki, Kazushi; Yoshizawa, Yasuo

    1982-01-01

    The translocation and absorption of 58 Co(CoCl 2 ) through a wound was investigated experimentally with mice. Physical and chemical skin damages became the objects of the investigation. Abrasion, puncture and incision were made for types of the physical damage. The chemical damage included both acid and alkaline burns. The absorptions of the radionuclide through the contaminated wounds were measured with both a 2 inches NaI(Tl) scintillation detector and an auto well gamma counter at 15,30 and 60 min after the contamination. The radionuclide was hardly absorbed through an undamaged skin. After 30 min, 20 to 40% of the radionuclide applied on the physically damaged skin was absorbed, but was not absorbed through the chemically damaged skin. The absorption rate through the physically damaged skin reached a maximum at 15 to 60 min after the contamination. The velocity of the absorption through the physically damaged skin was 100 times as much as the chemically damaged skin. The absorption rates through the physically and the chemically damaged skins were expressed by the following formulas: A=a(1-e sup(-bt)) and A=a(e sup(bt)-1), where a and b is constant, respectively. (author)

  5. Phytosterol glycosides reduce cholesterol absorption in humans

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B.; Anderson Spearie, Catherine L.; Ostlund, Richard E.

    2009-01-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series of three single-meal tests given at intervals of 2 wk to each of 11 healthy subjects. In a randomized crossover design, participants received ∼300 mg of added phytosterols in the form of phytosterol glycosides or phytosterol esters, or placebo in a test breakfast also containing 30 mg cholesterol-d7. Cholesterol absorption was estimated by mass spectrometry of plasma cholesterol-d7 enrichment 4–5 days after each test. Compared with the placebo test, phytosterol glycosides reduced cholesterol absorption by 37.6 ± 4.8% (P lecithin are bioactive in humans and should be included in methods of phytosterol analysis and tables of food phytosterol content. PMID:19246636

  6. Identifying the perfect absorption of metamaterial absorbers

    Science.gov (United States)

    Duan, G.; Schalch, J.; Zhao, X.; Zhang, J.; Averitt, R. D.; Zhang, X.

    2018-01-01

    We present a detailed analysis of the conditions that result in unity absorption in metamaterial absorbers to guide the design and optimization of this important class of functional electromagnetic composites. Multilayer absorbers consisting of a metamaterial layer, dielectric spacer, and ground plane are specifically considered. Using interference theory, the dielectric spacer thickness and resonant frequency for unity absorption can be numerically determined from the functional dependence of the relative phase shift of the total reflection. Further, using transmission line theory in combination with interference theory we obtain analytical expressions for the unity absorption resonance frequency and corresponding spacer layer thickness in terms of the bare resonant frequency of the metamaterial layer and metallic and dielectric losses within the absorber structure. These simple expressions reveal a redshift of the unity absorption frequency with increasing loss that, in turn, necessitates an increase in the thickness of the dielectric spacer. The results of our analysis are experimentally confirmed by performing reflection-based terahertz time-domain spectroscopy on fabricated absorber structures covering a range of dielectric spacer thicknesses with careful control of the loss accomplished through water absorption in a semiporous polyimide dielectric spacer. Our findings can be widely applied to guide the design and optimization of the metamaterial absorbers and sensors.

  7. Phytosterol glycosides reduce cholesterol absorption in humans.

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B; Anderson Spearie, Catherine L; Ostlund, Richard E

    2009-04-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series of three single-meal tests given at intervals of 2 wk to each of 11 healthy subjects. In a randomized crossover design, participants received approximately 300 mg of added phytosterols in the form of phytosterol glycosides or phytosterol esters, or placebo in a test breakfast also containing 30 mg cholesterol-d7. Cholesterol absorption was estimated by mass spectrometry of plasma cholesterol-d7 enrichment 4-5 days after each test. Compared with the placebo test, phytosterol glycosides reduced cholesterol absorption by 37.6+/-4.8% (Pphytosterol esters 30.6+/-3.9% (P=0.0001). These results suggest that natural phytosterol glycosides purified from lecithin are bioactive in humans and should be included in methods of phytosterol analysis and tables of food phytosterol content.

  8. Dynamics of water absorption through superabsorbent polymer

    Science.gov (United States)

    Chang, Sooyoung; Kim, Wonjung

    2017-11-01

    Superabsorbent polymers (SAPs) consist of hydrophilic cross-linked polymer networks that can absorb and retain a great amount of water relative to their own mass, so that they are widely used for disposable diapers and holding soil moisture in agriculture. SAPs are typically available in the form of submillimeter-sized particles, and the water absorption is driven by capillary flows between particles as well as diffusion that entail swelling. Although the control of water absorption of SAPs is important in engineering applications, but the dynamics of water absorption in SAP particles has not been fully understood. We examine the dynamics of the water absorption of sodium polyacrylate, one of the most common SAP. We experimentally measured the water absorption of sodium polyacrylate particles in one-dimensional confined channel. The water flows through the particles were analyzed by capillarity dominant at the early stage and by diffusion involving volume expansion critical at a later stage. The results provide a quantitative basis of the hydrodynamic analysis of the water flow through SAP particles from a macroscopic point of view, facilitating the prediction of water uptake of SAPs in hygienic and agricultural applications. This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP) (No.2015R1A2A2A04006181).

  9. Absorption coefficients of silicon: A theoretical treatment

    Science.gov (United States)

    Tsai, Chin-Yi

    2018-05-01

    A theoretical model with explicit formulas for calculating the optical absorption and gain coefficients of silicon is presented. It incorporates direct and indirect interband transitions and considers the effects of occupied/unoccupied carrier states. The indirect interband transition is calculated from the second-order time-independent perturbation theory of quantum mechanics by incorporating all eight possible routes of absorption or emission of photons and phonons. Absorption coefficients of silicon are calculated from these formulas. The agreements and discrepancies among the calculated results, the Rajkanan-Singh-Shewchun (RSS) formula, and Green's data are investigated and discussed. For example, the RSS formula tends to overestimate the contributions of indirect transitions for cases with high photon energy. The results show that the state occupied/unoccupied effect is almost negligible for silicon absorption coefficients up to the onset of the optical gain condition where the energy separation of Quasi-Femi levels between electrons and holes is larger than the band-gap energy. The usefulness of using the physics-based formulas, rather than semi-empirical fitting ones, for absorption coefficients in theoretical studies of photovoltaic devices is also discussed.

  10. Biotin absorption by distal rat intestine

    International Nuclear Information System (INIS)

    Bowman, B.B.; Rosenberg, I.H.

    1987-01-01

    We used the in vivo intestinal loop approach, with short (10-min) and long (3-h) incubations, to examine biotin absorption in proximal jejunum, distal ileum, cecum and proximal colon. In short-term studies, luminal biotin disappearance from rat ileum was about half that observed in the jejunum, whereas absorption by proximal colon was about 12% of that in the jejunum. In 3-h closed-loop studies, the absorption of 1.0 microM biotin varied regionally. Biotin absorption was nearly complete in the small intestine after 3 h; however, only about 15% of the dose had been absorbed in the cecum and 27% in the proximal colon after 3 h. Independent of site of administration, the major fraction of absorbed biotin was recovered in the liver; measurable amounts of radioactive biotin were also present in kidney and plasma. The results support the potential nutritional significance for the rat of biotin synthesized by bacteria in the distal intestine, by demonstrating directly an absorptive capability of mammalian large bowel for this vitamin

  11. Optical absorption in recycled waste plastic polyethylene

    Science.gov (United States)

    Aji, M. P.; Rahmawati, I.; Priyanto, A.; Karunawan, J.; Wati, A. L.; Aryani, N. P.; Susanto; Wibowo, E.; Sulhadi

    2018-03-01

    We investigated the optical properties of UV spectrum absorption in recycled waste plastic from polyethylene polymer type. Waste plastic polyethylene showed an optical spectrum absorption after it’s recycling process. Spectrum absorption is determined using spectrophotometer UV-Nir Ocean Optics type USB 4000. Recycling method has been processed using heating treatment around the melting point temperature of the polyethylene polymer that are 200°C, 220°C, 240°C, 260°C, and 280°C. In addition, the recycling process was carried out with time variations as well, which are 1h, 1.5h, 2h, and 2.5h. The result of this experiment shows that recycled waste plastic polyethylene has a spectrum absorption in the ∼ 340-550 nm wavelength range. The absorbance spectrum obtained from UV light which is absorbed in the orbital n → π* and the orbital π → π*. This process indicates the existence of electron transition phenomena. This mechanism is affected by the temperature and the heating time where the intensity of absorption increases and widens with the increase of temperature and heating time. Furthermore this study resulted that the higher temperature affected the enhancement of the band gap energy of waste plastic polyethylene. These results show that recycled waste plastic polyethylene has a huge potential to be absorber materials for solar cell.

  12. Heavy nucleus resonance absorption in heterogeneous lattices

    International Nuclear Information System (INIS)

    Coste, M.; Tellier, H.; Brienne-Raepsaet, C.; Van Der Gucht, C.

    1992-01-01

    To compute easily the neutron reaction rates in the resonance energy range, the reactor physicists use the self-shielding formalism and the effective cross-section concept. Usually, for these calculations, and equivalence process is used, in such a way that the absorption rate is correctly computed for the whole fuel pin. This procedure does not allow to preserve the spatial absorption rate distribution inside the pin. It is an important handicap if we want to reproduce the plutonium distribution in a spent fuel. To avoid this inconvenience, new improvements of the self-shielding formalism have been recently introduced in the new assembly calculation code of the French Atomic Energy Commission, APOLLO 2. With this improved formalism, it is now possible to represent the spatial and energetic dependence of the heavy nucleus absorption inside the fuel pin and to use a fine energy dependent equivalence process. As it does not exist clean experimental results for the spatial and energetic dependence of the absorption, the authors used reference calculations to qualify the self-shielding formalism. For the strongly self-shielded nuclei of interest in reactor physics, U238, Pu240 and Th232, the agreement between the self-shielding calculation and the reference ones is fairly good for the spatial and energetic dependence of the absorption rate

  13. Zinc absorption in inflammatory bowel disease

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

    1986-01-01

    Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered

  14. Iron absorption from adequate Filipinos meals

    International Nuclear Information System (INIS)

    Trinidad, T.P.; Madriaga, J.R.; Valdez, D.H.; Cruz, E.M.; Mallillin, A.C.; Sison, C.C.; Kuizon, M.D.

    1989-01-01

    Iron absorption from adequate Filipino meals representing the three major island groups of the Philippines (Luzon, Visayas, and Mindanao) was studied using double isotope extrinsic tag method. Mean iron absorption of the one-day meal for Metro Manila was 6.6 +- 1.26%. Central Visayas, 6.3 +- 1.15% and Southern Mindanao, 6.4 +- 1.19%. Comparison between meals (breakfast, lunch, dinner) for each region as well as one-day meal for the three regions showed no significant differences (P>0.01). Correlation tests done between iron absorption and the following iron enhancers: ascorbic acid, amount of fish, meat or poultry; and inhibitors: phytic acid and tannic acid, did not give significant results. The overall average of 6.4 +- 1.20% may be used as the iron absorption level from an adequate Filipino meal. This value can be considered as one of the bases for arriving at recommended dietary allowances for iron among Filipinos instead of the 10% iron absorption assumed in 1976. (Auth.). 21 refs.; 3 tabs.; 3 annexes

  15. Iron absorption from adequate Filipino meals

    International Nuclear Information System (INIS)

    Trinidad, T.P.; Madriaga, J.R.; Valdez, D.H.; Cruz, E.M.; Mallillin, A.C.; Sison, C.C.; Kuizon, M.D.

    1991-01-01

    Iron absorption from adequate Filipino meals representing the three major island groups of the Philippines (Luzon, Visayas and Mindanao) was studied using double isotope extrinsic tag method. Mean iron absorption of the one-day meal for Metro Manila was 6.6 ± 1.26%, Central Visayas, 6.3 ± 1.15% and Southern Mindanao, 6.4 ± 1.19%. Comparison between meals (breakfast, lunch, dinner) for each region as well as one-day meal for the three regions showed no significant differences (P > .01). Correlation tests done between iron absorption and the following iron enhancers: ascorbic acid, amount of fish, meat or poultry and inhibitors: phytic acid and tannic acid did not give significant results. The overall bar x of 6.4 ± 1.20% may be used as the non-heme iron absorption level from an adequate Filipino meal. This value can be considered as one of the bases for arriving at recommended dietary allowances for iron among Filipinos instead of the 10% iron absorption assumed in 1976

  16. Intestinal absorption and distribution of 14C-palmitic acid in an young Indian freshwater major carp, Labeo rohita (Hamilton)

    International Nuclear Information System (INIS)

    Sinha, G.M.; Chakrabarti, P.

    1983-01-01

    The mechanism of absorption and distribution of radioactive lipids in the various regions of the intestine and hepatopancreas of young Labeo rohita (Ham.) was investigated after feeding with small-sized earthworms (Pheretima posthuma), preinjected with 14 C-Palmitic acid. Dietary free fatty acids were mainly absorbed in the various regions (anterior, middle and posterior) of the intestine-the absorption capacity, however, varying greatly from region to region. The absorption of free fatty acids through the luminal brush border of the various regions of the intestine started at 24 hr of post-feeding (h.p.f.) with labelled diet and recorded its peak during 32 +- 2 h.p.f. However, middle intestine was found to be more active for such absorption than the other two regions (anterior and posterior). Incorporation of labelled Palmitic acid in the columnar epithelial cells and its subsequent transportation in the hepatic tissues, via lymphatic systems took place with in a short interval after absorption. However, absorption was completed within 40 h.p.f. when deposition of radioactive lipids was found to be maximum in the columnar epithelial cells of the various regions of the intestine and hepatic tissues. (author)

  17. Can tissues be owned?

    African Journals Online (AJOL)

    2013-06-17

    Jun 17, 2013 ... Regulations Regarding Rendering of Clinical Forensic Medicine ... 1 Special Interest Research Group on Biotechnology and Medical Law of the College of Law, University of ... persons for the following medical and dental purposes: ... tissue to the international market were taking tissue without consent.

  18. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

  19. The absorption of carbon monoxide in COSORB solutions: absorption rate and capacity

    NARCIS (Netherlands)

    Hogendoorn, Kees; van Swaaij, Willibrordus Petrus Maria; Versteeg, Geert

    1995-01-01

    Absorption rate experiments and equilibrium experiments were carried out for the COSORB reaction at 300 K. The equilibrium data at 300 K could reasonably well be described with the following relation: [...] Determination of the kinetics and mechanism of a chemical reaction by means of absorption

  20. Reproducibility of The Random Incidence Absorption Coefficient Converted From the Sabine Absorption Coefficient

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Chang, Ji-ho

    2015-01-01

    largely depending on the test room. Several conversion methods for porous absorbers from the Sabine absorption coefficient to the random incidence absorption coefficient were suggested by considering the finite size of a test specimen and non-uniformly incident energy onto the specimen, which turned out...... resistivity optimization outperforms the surface impedance optimization in terms of the reproducibility....

  1. Absorption lines, Faraday rotation, and magnetic field estimates for QSO absorption-line clouds

    International Nuclear Information System (INIS)

    Kronberg, P.P.; Perry, J.J.

    1982-01-01

    We have estimated the extragalactic component of Faraday rotation for a sample of 37 QSOs for which there is good absorption line data, which we have also analyzed. Statistical evidence is presented which suggests that we have isolated a component of Faraday rotation which is occurring in the absorption clouds of some QSOs

  2. Photodisruption in biological tissues using femtosecond laser pulses

    Science.gov (United States)

    Shen, Nan

    Transparent materials do not ordinarily absorb visible or near-infrared light. However, the intensity of a tightly focused femtosecond laser pulse is great enough that nonlinear absorption of the laser energy takes place in transparent materials, leading to optical breakdown and permanent material modification. Because the absorption process is nonlinear, absorption and material modification are confined to the extremely small focal volume. Optical breakdown in transparent or semi-transparent biological tissues depends on intensity rather than energy. As a result, focused femtosecond pulses induce optical breakdown with significantly less pulse energy than is required with longer pulses. The use of femtosecond pulses therefore minimizes the amount of energy deposited into the targeted region of the sample, minimizing mechanical and thermal effects that lead to collateral damage in adjacent tissues. We demonstrate photodisruptive surgery in animal skin tissue and single cells using 100-fs laser pulses. In mouse skin, we create surface incisions and subsurface cavities with much less collateral damage to the surrounding tissue than is produced with picosecond pulses. Using pulses with only a few nanojoules of energy obtained from an unamplified femtosecond oscillator, we destroy single mitochondria in live cells without affecting cell viability, providing insights into the structure of the mitochondrial network. An apparatus is constructed to perform subcellular surgery and multiphoton 3D laser scanning imaging simultaneously with a single laser and objective lens.

  3. Analytic descriptions of ion cyclotron absorption

    International Nuclear Information System (INIS)

    Bers, A.; Francis, G.; Fuchs, V.; Lashmore-Davies, C.N.; Ram, A.K.

    1987-05-01

    Analysis of energy propagation and absorption in ion-cyclotron heating of tokamak plasmas has relied on numerical solutions of fourth (and sixth) order differential equations for slab models of the plasma (poloidal) cross section. Realistic two-dimensional and fully toroidal geometry analyses would become quite unwieldy. It is shown here that the analysis of the slab model can be simplified considerably. A first-order differential equation is shown to describe the transmission coefficient for the fast wave, and it is solved analytically. A second order differential equation is shown to adequately describe both transmission and reflection. Conditions for ion absorption or mode conversion are derived. Including toroidal effects in propagation, conditions for electron absorption on the mode-converted ion-Bernstein waves are also described analytically

  4. Anomalous water absorption in porous materials

    CERN Document Server

    Lockington, D A

    2003-01-01

    The absorption of fluid by unsaturated, rigid porous materials may be characterized by the sorptivity. This is a simple parameter to determine and is increasingly being used as a measure of a material's resistance to exposure to fluids (especially moisture and reactive solutes) in aggressive environments. The complete isothermal absorption process is described by a nonlinear diffusion equation, with the hydraulic diffusivity being a strongly nonlinear function of the degree of saturation of the material. This diffusivity can be estimated from the sorptivity test. In a typical test the cumulative absorption is proportional to the square root of time. However, a number of researchers have observed deviation from this behaviour when the infiltrating fluid is water and there is some potential for chemo-mechanical interaction with the material. In that case the current interpretation of the test and estimation of the hydraulic diffusivity is no longer appropriate. Kuentz and Lavallee (2001) discuss the anomalous b...

  5. Rotational averaging of multiphoton absorption cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Friese, Daniel H., E-mail: daniel.h.friese@uit.no; Beerepoot, Maarten T. P.; Ruud, Kenneth [Centre for Theoretical and Computational Chemistry, University of Tromsø — The Arctic University of Norway, N-9037 Tromsø (Norway)

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  6. Gold analysis by the gamma absorption technique

    International Nuclear Information System (INIS)

    Kurtoglu, Arzu; Tugrul, A.B.

    2003-01-01

    Gold (Au) analyses are generally performed using destructive techniques. In this study, the Gamma Absorption Technique has been employed for gold analysis. A series of different gold alloys of known gold content were analysed and a calibration curve was obtained. This curve was then used for the analysis of unknown samples. Gold analyses can be made non-destructively, easily and quickly by the gamma absorption technique. The mass attenuation coefficients of the alloys were measured around the K-shell absorption edge of Au. Theoretical mass attenuation coefficient values were obtained using the WinXCom program and comparison of the experimental results with the theoretical values showed generally good and acceptable agreement

  7. Absorption of carbon dioxide in waste tanks

    International Nuclear Information System (INIS)

    Hobbs, D.T.

    1987-01-01

    Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

  8. Time-resolved absorption measurements on OMEGA

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; DaSilva, L.; Delettrez, J.; Gregory, G.G.; Richardson, M.C.

    1986-01-01

    Time-resolved measurements of the incident laser light that is scattered and/or refracted from targets irradiated by the 24 uv-beam OMEGA laser at LLE, have provided some interesting features related to time-resolved absorption. The decrease in laser absorption characteristic of irradiating a target that implodes during the laser pulse has been observed. The increase in absorption expected as the critical density surface moves from a low to a high Z material in the target has also been noted. The detailed interpretation of these results is made through comparisons with simulation using the code LILAC, as well as with streak data from time-resolved x-ray imaging and spectroscopy. In addition, time and space-resolved imaging of the scattered light yields information on laser irradiation uniformity conditions on the target. The report consists of viewgraphs

  9. A Review: Characteristics of Noise Absorption Material

    Science.gov (United States)

    Amares, S.; Sujatmika, E.; Hong, T. W.; Durairaj, R.; Hamid, H. S. H. B.

    2017-10-01

    Noise is always treated as a nuisance to human and even noise pollution appears in the environmental causing discomfort. This also concerns the engineering design that tends to cultivate this noise propagation. Solution such as using material to absorb the sound have been widely used. The fundamental of the sound absorbing propagation, sound absorbing characteristics and its factors are minimally debated. Furthermore, the method in order to pertain sound absorbing related to the sound absorption coefficient is also limited, as many studies only contributes in result basis and very little in literature aspect. This paper revolves in providing better insight on the importance of sound absorption and the materials factors in obtaining the sound absorption coefficient.

  10. Selective gas absorption by ionic liquids

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Kegnæs, Søren; Due-Hansen, Johannes

    2010-01-01

    Reversible absorption performance for the flue gas components CO 2, NO and SO2 has been tested for several different ionic liquids (ILs) at different temperatures and flue gas compositions. Furthermore, different porous, high surface area carriers have been applied as supports for the ionic liquids...... to obtain Supported Ionic Liquid-Phase (SILP) absorber materials. The use of solid SILP absorbers with selected ILs were found to significantly improve the absorption capacity and sorption dynamics at low flue gas concentration, thus making the applicability of ILs viable in technical, continuous flow...... processes for flue gas cleaning. The results show that CO 2, NO and SO2 can be reversible and selective absorbed using different ILs and that Supported Ionic Liquid-Phase (SILP) absorbers are promising materials for industrial flue gas cleaning. Absorption/desorption dynamics can be tuned by temperatures...

  11. Absorption spectra of AA-stacked graphite

    International Nuclear Information System (INIS)

    Chiu, C W; Lee, S H; Chen, S C; Lin, M F; Shyu, F L

    2010-01-01

    AA-stacked graphite shows strong anisotropy in geometric structures and velocity matrix elements. However, the absorption spectra are isotropic for the polarization vector on the graphene plane. The spectra exhibit one prominent plateau at middle energy and one shoulder structure at lower energy. These structures directly reflect the unique geometric and band structures and provide sufficient information for experimental fitting of the intralayer and interlayer atomic interactions. On the other hand, monolayer graphene shows a sharp absorption peak but no shoulder structure; AA-stacked bilayer graphene has two absorption peaks at middle energy and abruptly vanishes at lower energy. Furthermore, the isotropic features are expected to exist in other graphene-related systems. The calculated results and the predicted atomic interactions could be verified by optical measurements.

  12. Tunable electromagnetically induced absorption based on graphene

    Science.gov (United States)

    Cao, Maoyong; Wang, Tongling; Zhang, Huiyun; Zhang, Yuping

    2018-04-01

    In this paper, an electronically induced absorption (EIA) structure based on graphene at the infrared frequency is proposed. A pair of nanorods is coupled to a ring resonator, resulting in electronically induced transparency (EIT), and then, Babinet's principle is applied to transform the EIT structure into an EIA structure. Based on the bright and dark modes of the coupling schemes, the adjustment of the coupling strength between the dark and bright modes can be achieved by changing the asymmetry degree. In addition, the transparency window and the absorption peak can be tuned by changing the Fermi energy of graphene. This graphene-based EIA structure can develop the path in narrow-band filtering and, absorptive switching in the future.

  13. Review on absorption technology with emphasis on small capacity absorption machines

    Directory of Open Access Journals (Sweden)

    Labus Jerko M.

    2013-01-01

    Full Text Available The aim of this paper is to review the past achievements in the field of absorption systems, their potential and possible directions for future development. Various types of absorption systems and research on working fluids are discussed in detail. Among various applications, solar cooling and combined cooling, heating and power (CCHP are identified as two most promising applications for further development of absorption machines. Under the same framework, special attention is given to the small capacity absorption machines and their current status at the market. Although this technology looks promising, it is still in development and many issues are open. With respect to that fact, this paper covers all the relevant aspects for further development of small capacity absorption machines.

  14. Absorption of acoustic waves by sunspots. II - Resonance absorption in axisymmetric fibril models

    Science.gov (United States)

    Rosenthal, C. S.

    1992-01-01

    Analytical calculations of acoustic waves scattered by sunspots which concentrate on the absorption at the magnetohydrodynamic Alfven resonance are extended to the case of a flux-tube embedded in a uniform atmosphere. The model is based on a flux-tubes of varying radius that are highly structured, translationally invariant, and axisymmetric. The absorbed fractional energy is determined for different flux-densities and subphotospheric locations with attention given to the effects of twist. When the flux is highly concentrated into annuli efficient absorption is possible even when the mean magnetic flux density is low. The model demonstrates low absorption at low azimuthal orders even in the presence of twist which generally increases the range of wave numbers over which efficient absorption can occur. Resonance absorption is concluded to be an efficient mechanism in monolithic sunspots, fibril sunspots, and plage fields.

  15. Intestinal absorption of copper: influence of carbohydrates.

    Science.gov (United States)

    Wapnir, R A; Balkman, C

    1992-02-01

    Macronutrients can modulate the intestinal absorption of trace elements by binding the metal or altering mucosal function. We investigated whether certain simple and complex carbohydrates modify copper (Cu) absorption, using an in vivo perfusion technique in the rat. Corn syrup solids, which contain a mixture of glucose polymers of diverse length, added at either 20 or 50 mosm/kg enhanced Cu absorption from a 31.5 microM (2 mg/liter) Cu solution (128 +/- 11 and 130 +/- 11 pmol/min x cm, respectively, vs 101 +/- 4 pmol/min x cm, P less than 0.05, in the absence of carbohydrate). This was concomitant with a stimulation of net water absorption (1.05 +/- 0.08 and 0.84 +/- 0.08 microliter/min x cm, respectively, vs 0.63 +/- 0.02 microliter/min x cm with no carbohydrate, P less than 0.05). Glucose, fructose, lactose, or sucrose had no influence on Cu absorption, although they altered water exchanges, an effect attributable to a reduction of the outflow component of fluid recirculation. Low concentrations of lactose resulted in a greater accumulation of Cu in the intestinal mucosa (8.75 +/- 0.71 micrograms/g vs 5.77 +/- 0.68 micrograms/g for controls, P less than 0.05). Hence, solutes that moderately stimulate mucosa-to-serosa fluid influx in a progressive manner, such as glucose polymers, may contribute to functionally increase Cu absorption. Conversely, conditions which tend to reduce water inflow or increase water outflow across the small intestinal mucosa, as may occur with high lactose diets or in cases of chronic diarrhea, may have negative effects.

  16. Opto-acoustic measurement of the local light absorption coefficient in turbid media: 2. On the possibility of light absorption coefficient measurement in a turbid medium from the amplitude of the opto-acoustic signal

    International Nuclear Information System (INIS)

    Pelivanov, Ivan M; Barskaya, M I; Podymova, N B; Khokhlova, Tanya D; Karabutov, Aleksander A

    2009-01-01

    The second part of this work describes the experimental technique of measuring the local light absorption in turbid media. The technique is based on the measurement of the amplitude of an opto-acoustic (OA) signal excited in a turbid medium under the condition of one-sided access to the object under study. An OA transducer is developed to perform the proposed measurement procedure. Experiments are conducted for the turbid media with different optical properties (light absorption and reduced scattering coefficients) and for different diameters of the incident laser beam. It is found that the laser beam diameter can be chosen so that the dependences of the measured OA signal amplitude on the light absorption coefficient coincide upon varying the reduced scattering coefficient by more than twice. The obtained numerical and experimental results demonstrate that the OA method is applicable for measuring the local light absorption coefficient in turbid media, for example, in biological tissues. (measurement of parametrs of laser radiation)

  17. Quantitative frequency-domain fluorescence spectroscopy in tissues and tissue-like media

    Science.gov (United States)

    Cerussi, Albert Edward

    1999-09-01

    In the never-ending quest for improved medical technology at lower cost, modern near-infrared optical spectroscopy offers the possibility of inexpensive technology for quantitative and non-invasive diagnoses. Hemoglobin is the dominant chromophore in the 700-900 nm spectral region and as such it allows for the optical assessment of hemoglobin concentration and tissue oxygenation by absorption spectroscopy. However, there are many other important physiologically relevant compounds or physiological states that cannot be effectively sensed via optical methods because of poor optical contrast. In such cases, contrast enhancements are required. Fluorescence spectroscopy is an attractive component of optical tissue spectroscopy. Exogenous fluorophores, as well as some endogenous ones, may furnish the desperately needed sensitivity and specificity that is lacking in near-infrared optical tissue spectroscopy. The main focus of this thesis was to investigate the generation and propagation of fluorescence photons inside tissues and tissue-like media (i.e., scattering dominated media). The standard concepts of fluorescence spectroscopy have been incorporated into a diffusion-based picture that is sometimes referred to as photon migration. The novelty of this work lies in the successful quantitative recovery of fluorescence lifetimes, absolute fluorescence quantum yields, fluorophore concentrations, emission spectra, and both scattering and absorption coefficients at the emission wavelength from a tissue-like medium. All of these parameters are sensitive to the fluorophore local environment and hence are indicators of the tissue's physiological state. One application demonstrating the capabilities of frequency-domain lifetime spectroscopy in tissue-like media is a study of the binding of ethidium bromide to bovine leukocytes in fresh milk. Ethidium bromide is a fluorescent dye that is commonly used to label DNA, and hence visualize chromosomes in cells. The lifetime of

  18. Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

    KAUST Repository

    Tiwari, Surya Prakash

    2018-03-16

    This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non-algal particles (aNAP) to the total particulate absorption coefficients are determined using a numerical decomposition method (NDM). The NDM is validated by comparing the NDM derived values of aph and aNAP with simulated values of aph and aNAP are found to be in excellent agreement for the selected wavelengths (i.e., 443, 490, 555, and 676nm) with high correlation coefficient (R2), low root mean square error (RMSE), mean relative error (MRE), and with a slope close to unity. Further analyses showed that the total particulate absorption coefficients (i.e., ap(443)average = 0.01995m−1) were dominated by phytoplankton absorption (i.e., aph(443)average = 0.01743m−1) with a smaller contribution by non-algal particles absorption (i.e., aNAP(443)average = 0.002524m−1). The chlorophyll a is computed using the absorption based Line Height Method (LHM). The derived chlorophyll-specific absorption ((a⁎ph = aph(λ)/ChlLH)) showed more variability in the blue part of spectrum as compared to the red part of spectrum representative of the package effect and changes in pigment composition. A new parametrization proposed also enabled the reconstruction of a⁎ph(λ) for the Red Sea. Comparison of derived spectral constants with the spectral constants of existing models showed that our study A(λ) values are consistent with the existing values, despite there is a divergence with the B(λ) values. This study provides valuable information derived from the particulate absorption properties and its spectral variability and this would help us to determine the relationship between the phytoplankton absorption coefficients and chlorophyll a and its host of variables for the Red Sea.

  19. Pion absorption in flight on 3He

    International Nuclear Information System (INIS)

    Ljungfelt, S.H.

    1985-02-01

    Pion absorption in flight on 3 He has been measured in a kinematically complete manner. The experiment was done in the πE1-channel at the Swiss Institute for Nuclear Research, SIN, using π + - and π - -beams of 120 and 165 MeV kinetic energy. Two of the emitted particles were measured in coincidence and identified by their time-of-flight/pulseheight relation. The obtained two-dimensional energy representation enabled a separation of the different kinematical regions and exhibited a clear enhancement in the region of quasifree absorption, QFA. (orig./WL)

  20. Porosity and liquid absorption of cement paste

    DEFF Research Database (Denmark)

    Krus, M.; Hansen, Kurt Kielsgaard; Kunzel, H. M.

    1997-01-01

    be a slowing-down effect which is related to water because the absorption of organic liquids, such as hexane, is quite normal. Measurements of the porosity of hardened cement paste determined by helium pycnometry and water saturation show that water molecules can enter spaces in the microstructure which...... are not accessible to the smaller helium atoms. Considering the results of dilatation tests both before and after water and hexane saturation, it seems possible that a contraction of capillary pores due to moisture-related swelling of the cement gel leads to the non-linear water absorption over the square root...

  1. XUV Absorption by Solid Density Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, C A

    2009-09-21

    An inverse bremsstrahlung model for plasmas and simple metals that approximates the cold, solid Al experimental data below the L-edge is applied to matter conditions relevant to XUV laser applications. The model involves an all-order calculation using a semi-analytical effective electron-ion interaction. The predicted increases in XUV absorption with rising temperature occur via two effects: increased availability of final states from reduced electron degeneracy and a stronger electron-ion interaction from reduced screening. Discrepancies in the temperature dependence as well as other details between the present approach and a recently proposed absorption model are discussed.

  2. Absorptive routines and international patent performance

    Directory of Open Access Journals (Sweden)

    Fernando E. García-Muiña

    2017-04-01

    We enrich the treatment of the absorptive capacity phases including the moderating effects between routines associated to the traditional potential-realized absorptive capacities. Taking into account external knowledge search strategies, the deeper external relationships, the better transference and appropriation of specific external knowledge. Nevertheless, when the moderating role of assimilation is included, cooperation agreements appear as the most efficient source of external knowledge. Finally, we show that technological tools let firms store and structure the information making easier its use for international patenting. This positive effect is reinforced in the presence of exploitation routines, since technological knowledge will better fit to the industry's key factors of success.

  3. Calculated optical absorption of different perovskite phases

    DEFF Research Database (Denmark)

    Castelli, Ivano Eligio; Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

    2015-01-01

    We present calculations of the optical properties of a set of around 80 oxides, oxynitrides, and organometal halide cubic and layered perovskites (Ruddlesden-Popper and Dion-Jacobson phases) with a bandgap in the visible part of the solar spectrum. The calculations show that for different classes...... of perovskites the solar light absorption efficiency varies greatly depending not only on bandgap size and character (direct/indirect) but also on the dipole matrix elements. The oxides exhibit generally a fairly weak absorption efficiency due to indirect bandgaps while the most efficient absorbers are found...... in the classes of oxynitride and organometal halide perovskites with strong direct transitions....

  4. Optical absorption spectra of Ag-11 isomers

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Fernandez, E. M.

    2009-01-01

    The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground-stale confi......The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground...

  5. Absorption of pentacaine from ulcerous rat stomach

    International Nuclear Information System (INIS)

    Tomcikova, O.; Babulova, A.; Durisova, M.; Trnovec, T.; Benes, L.

    1985-01-01

    Pentacaine is a local anaesthetic which exhibited positive effects on healing of model ulcers in the rat stomach. The in situ disappearance of pentacaine from the ulcerous and intact rat stomach was studied. Gastric ulcers were produced by oral administration of phenylbutazone (200 mg/kg) 3.5 h before absorption experiment. Pentacaine exhibited a biexponential decrease from the lumen of the stomach, the rate of which was essentially the same in both groups. The total amount of pentacaine absorbed was small because of extremly low absorption rate. (author)

  6. Statistical evidences of absorption at high latitudes

    International Nuclear Information System (INIS)

    Fesenko, B.I.

    1980-01-01

    Evidences are considered which indicate to the significant effect of the irregular interstellar absorption at high latitudes b. The number density of faint galaxies grows with the increasing |b| even at the values of |b| exceeding 50 deg. The effects of interstellar medium are traced even in the directions of the stars and globular clusters with very low values of the colour excess. The coefficient of absorption, Asub(B)=0.29+-0.05, was estimated from the colours of the bright E-galaxies [ru

  7. Theory of attosecond absorption spectroscopy in krypton

    DEFF Research Database (Denmark)

    Baggesen, Jan Conrad; Lindroth, Eva; Madsen, Lars Bojer

    2012-01-01

    A theory for time-domain attosecond pump–attosecond probe photoabsorption spectroscopy is formulated and related to the atomic response. The theory is illustrated through a study of attosecond absorption spectroscopy in krypton. The atomic parameters entering the formulation such as energies...... of the hole in this manner. In a second example, a hole is created in an inner shell by the first pulse, and the second probe pulse couples an even more tightly bound state to that hole. The hole decays in this example by Auger electron emission, and the absorption spectroscopy follows the decay of the hole...

  8. Heat transfer modelling of pulsed laser-tissue interaction

    Science.gov (United States)

    Urzova, J.; Jelinek, M.

    2018-03-01

    Due to their attributes, the application of medical lasers is on the rise in numerous medical fields. From a biomedical point of view, the most interesting applications are the thermal interactions and the photoablative interactions, which effectively remove tissue without excessive heat damage to the remaining tissue. The objective of this work is to create a theoretical model for heat transfer in the tissue following its interaction with the laser beam to predict heat transfer during medical laser surgery procedures. The dimensions of the ablated crater (shape and ablation depth) were determined by computed tomography imaging. COMSOL Multiphysics software was used for temperature modelling. The parameters of tissue and blood, such as density, specific heat capacity, thermal conductivity and diffusivity, were calculated from the chemical ratio. The parameters of laser-tissue interaction, such as absorption and reflection coefficients, were experimentally determined. The parameters of the laser beam were power density, repetition frequency, pulse length and spot dimensions. Heat spreading after laser interaction with tissue was captured using a Fluke thermal camera. The model was verified for adipose tissue, skeletal muscle tissue and heart muscle tissue.

  9. Adsorption and absorption of polycyclic aromatic hydrocarbons to rice roots

    International Nuclear Information System (INIS)

    Jiao, X.C.; Xu, F.L.; Dawson, R.; Chen, S.H.; Tao, S.

    2007-01-01

    Rice roots and surrounding air, soil and water samples were collected for polycyclic aromatic hydrocarbon (PAH) analysis. The rice roots were separated into lateral roots and nodal roots, and the PAH concentration in the former was found to be higher than that in the latter. In addition, root physiological characteristics including root biotic mass, root lipid content and specific surface area are also discussed. When normalizing the total, adsorption and absorption PAH fractions on a dry root weight basis to root biomass, root lipid, and surface area bases respectively, the differences between PAHs in the two types of roots diminished by 2 to 3 times on average. Results from sequential extraction indicated that PAHs were more easily absorbed by interior rice roots than adsorbed on the surface. In addition, more than 60% of total PAHs accumulated in root tissue for both lateral and nodal roots. However, the results were highly related to the solvent used, extraction time and methodology. Correlation analysis between bioconcentration factors (root over environment) and K OA , K OW showed water to be more significant for PAH adsorption in rice roots than other environmental media. - A sequential extraction method was applied to divide the PAHs accumulated on rice roots into PAHs in root exudates, PAHs adsorbed on root surfaces, and PAHs absorbed in root tissue

  10. [Lasers in dentistry. Part B--Interaction with biological tissues and the effect on the soft tissues of the oral cavity, the hard tissues of the tooth and the dental pulp].

    Science.gov (United States)

    Moshonov, J; Stabholz, A; Leopold, Y; Rosenberg, I; Stabholz, A

    2001-10-01

    The interaction of laser energy with target tissue is mainly determined by two non operator-dependent factors: the specific wavelength of the laser and the optical properties of the target tissues. Power density, energy density, pulse repetition rate, pulse duration and the mode of energy transferring to the tissue are dictated by the clinician. Combination of these factors enables to control optimal response for the clinical application. Four responses are described when the laser beam hits the target tissue: reflection, absorption, transmission and scattering. Three main mechanisms of interaction between the laser and the biological tissues exist: photothermic, photoacoustic and photochemical. The effect of lasers on the soft tissues of the oral cavity is based on transformation of light energy into thermal energy which, in turn heats the target tissue to produce the desirable effect. In comparison to the scalpel used in surgical procedures, the laser beam is characterized by tissue natural sterility and by minimum bleeding during the surgical procedures due to blood vessels welding. The various effects achieved by the temperature elevation during the laser application on the soft tissue are: I. coagulation and hemostasis II. tissue sterilization III. tissue welding IV. incision and excision V. ablation and vaporization Ablation and melting are the two basic modalities by which the effect of lasers on the hard tissues of the tooth is produced. When discussing the effect of laser on dental hard tissues, the energy absorption in the hydroxyapatite plays a major role in addition to its absorption in water. When laser energy is absorbed in the water of the hard tissues, a rapid volume expansion of the evaporating water occurs as a result of a substantial temperature elevation in the interaction site. Microexplosions are produced causing hard tissue disintegration. If pulp temperatures are raised beyond 5 degrees C level, damage to the dental pulp is irreversible

  11. Examination of the Measurement of Absorption Using the Reverberant Room Method for Highly Absorptive Acoustic Foam

    Science.gov (United States)

    Hughes, William O.; McNelis, Anne M.; Chris Nottoli; Eric Wolfram

    2015-01-01

    The absorption coefficient for material specimens are needed to quantify the expected acoustic performance of that material in its actual usage and environment. The ASTM C423-09a standard, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberant Room Method" is often used to measure the absorption coefficient of material test specimens. This method has its basics in the Sabine formula. Although widely used, the interpretation of these measurements are a topic of interest. For example, in certain cases the measured Sabine absorption coefficients are greater than 1.0 for highly absorptive materials. This is often attributed to the diffraction edge effect phenomenon. An investigative test program to measure the absorption properties of highly absorbent melamine foam has been performed at the Riverbank Acoustical Laboratories. This paper will present and discuss the test results relating to the effect of the test materials' surface area, thickness and edge sealing conditions. A follow-on paper is envisioned that will present and discuss the results relating to the spacing between multiple piece specimens, and the mounting condition of the test specimen.

  12. Nasal Absorption of Macromolecules from Powder Formulations and Effects of Sodium Carboxymethyl Cellulose on Their Absorption.

    Directory of Open Access Journals (Sweden)

    Akiko Tanaka

    Full Text Available The nasal absorption of macromolecules from powder formulations and the effect of sodium carboxymethyl cellulose (CMC-Na as a pharmaceutical excipient on their absorption were studied. Model macromolecules were fluorescein isothiocyanate-labeled dextran (average molecular weight of 4.4kDa, FD4 and insulin. The plasma concentration of FD4 after application of the powder containing 50% starch (control was higher than that after application of the solution, and the absorption from 50% starch powder was enhanced by the substitution of starch with CMC-Na. The fractional absorption of FD4 after administration of the CMC-Na powder formulation was 30% and 40% higher than that after administration from the solution and the starch powder, respectively. The nasal absorption of insulin from the powder and the effect of CMC-Na were similar with those of FD4. The effective absorption of FD4 and insulin after application of powder with CMC-Na could be due to the increase in the nasal residence of FD4 and insulin. No damage in the nasal mucosa or dysfunction of the mucociliary clearance was observed after application of the drug powder and CMC-Na. The present findings indicate that nasal delivery of powder formulations with the addition of CMC-Na as an excipient is a promising approach for improving the nasal absorption of macromolecules.

  13. Water absorption characteristic of interlocking compressed earth brick units

    Science.gov (United States)

    Bakar, B. H. Abu; Saari, S.; Surip, N. A.

    2017-10-01

    This study aims to investigate the water absorption characteristic of interlocking compressed earth brick (ICEB) units. Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties. The units were tested for 24 h water absorption and 5 h boiling water absorption. A total of 170 ICEB units from four ICEB types underwent both tests. For the 24 h water absorption, the ICEB units were dried in the oven for 24 h and then cooled before being weighed. Thereafter, each brick was immersed in water for 24 h and weighed. The same specimens used for the 24 h water absorption test were re-used for the 5 h boiling water absorption test. After completing the 24 h water absorption test, the brick was boiled for 5-hours and weighed. The highest water absorption for the ICEBs in the 24-hour water absorption and 5 h boiling water absorption tests are 15.09% and 17.18%, respectively. The half brick has the highest water absorption (15.87%), whereas the beam brick has the lowest (13.20%). The water absorption of an ICEB unit is higher than that of normal bricks, although the water absorption of the former remains below the maximum rate of the brick water absorption (21%).

  14. Mechanism of pion absorption in complex nuclei

    International Nuclear Information System (INIS)

    Doss, K.G.N.; Wharton, W.R.

    Basic geometrical arguments are used to analyze the A dependence of the total pion absorption cross section, the effective number of nucleons sharing the pion momentum and energy, and the proton yields from π + - and π - -induced reactions. The results are consistent with the pions penetrating some distance through the nuclear volume and annihilating on a pair of nucleons. 3 figures

  15. Absorptive coating for aluminum solar panels

    Science.gov (United States)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  16. Dermal absorption and toxicological risk assessment

    NARCIS (Netherlands)

    Buist, H.

    2016-01-01

    Absorption of toxic substances via the skin is an important phenomenon in the assessment of the risk of exposure to these substances. People are exposed to a variety of substances and products via the skin, either directly or indirectly, while at work, at home or in public space. Pesticides,

  17. X-ray absorption spectroscopy (EXAFS)

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1983-01-01

    The experimental technics of Extended X-ray Absorption Fine Structure (EXAFS) is presented and several uses of it in atomic, molecular and bio physics are shown. The recent progresses of this technics, both theoretical and experimental, are discussed and the future perspectives on this subject are commented. (L.C.) [pt

  18. Nonlinear cyclotron absorption and stimulated scattering

    International Nuclear Information System (INIS)

    Chung, T.H.

    1986-01-01

    In electron cyclotron resonance heating (ECRH), wave sources heating a plasma linearly with respect to intensity; but as the intensity of ECRH gets larger, there might appear nonlinear effects that would result in cutoff of net absorption. This thesis uses quantum mechanical theory to derive a threshold microwave intensity for nonlinear absorption. The quantum mechanical theory estimates that the threshold microwave intensity for nonlinear absorption is about 10 5 watts/cm 2 for a microwave heating experiment (T/sub e/ = 100 ev, λ = 3,783 cm, B = 2.5 kG). This value seems large considering the present power capabilities of microwave sources (10 2 ∼ 10 3 watts/cm 2 ), but for a low temperature plasma, this threshold will go down. There is another nonlinear phenomenon called stimulated cyclotron scattering that enhances photon scattering by electrons gyrating in a magnetic field. This is expected to prevent incoming photons from arriving at the central region of the fusion plasma, where absorption mainly takes place. Theory based on a photon transport model predicts that the threshold intensity for the stimulated cyclotron scattering is about 10 4 watts/cm 2 for the plasma parameters mentioned above. This value seems large also, but a longer wavelength of microwaves and a larger magnitude magnetic field, which will be the case in reactor type facilities, will lower the threshold intensity to levels comparable with the currently developed microwave sources

  19. Fluoride absorption: independence from plasma fluoride levels

    International Nuclear Information System (INIS)

    Whitford, G.M.; Williams, J.L.

    1986-01-01

    The concept that there are physiologic mechanisms to homeostatically regulate plasma fluoride concentrations has been supported by results in the literature suggesting an inverse relationship between plasma fluoride levels and the absorption of the ion from the gastrointestinal tract of the rat. The validity of the relationship was questioned because of possible problems in the experimental design. The present work used four different methods to evaluate the effect of plasma fluoride levels on the absorption of the ion in rats: (i) the percentage of the daily fluoride intake that was excreted in the urine; (ii) the concentration of fluoride in femur epiphyses; (iii) the net areas under the time-plasma fluoride concentration curves after intragastric fluoride doses; and (iv) the residual amounts or fluoride in the gastrointestinal tracts after the intragastric fluoride doses. None of these methods indicated that plasma fluoride levels influence the rate or the degree or fluoride absorption. It was concluded that, unless extremely high plasma fluoride levels are involved (pharmacologic or toxic doses), the absorption of the ion is independent of plasma levels. The results provide further evidence that plasma fluoride concentrations are not homeostatically regulated

  20. Morphology of Southern Hemisphere Riometer Auroral Absorption

    Science.gov (United States)

    2006-06-01

    Tecnológico under Proyecto No 1940934. Annex The percentage probability, QA, that an absorption A dB is exceed, is given as: Where Am is...Geofísica Facultad de Ciencias Físicas y Matemáticas Universidad de Concepción foppiano@udec.cl IST Specialists’ Meeting/Symposium on “Characterising

  1. Controlling enhanced absorption in graphene metamaterial

    Science.gov (United States)

    Zhou, Qihui; Liu, Peiguo; Bian, Li-an; Liu, Hanqing; Liu, Chenxi; Chen, Genghui

    2018-04-01

    In this paper, a controllable terahertz (THz) metamaterial absorber (MA) is designed with the circuit analog method. Taking advantage of the patterned graphene on SiO2/doped Si/polyimide substrates with a gold reflector, the controllable MA achieves perfect absorption at 0.75 THz. The chemical potential of graphene is regulated by controlling the voltage between graphene and doped Si layers. As the chemical potential varies from 0 eV to 0.5 eV, the MA is changed from reflection (0.99). The distributions of surface current and electric field are illustrated to analyze the resonant characteristic of patterned graphene. According to the resonant characteristic, we introduce patterned graphene elements with different dimension in a unit cell, which effectively extends the effective absorption bandwidth (absorption > 0 . 9) from 0.67-0.93 THz to 0.52-0.95 THz. Moreover, replacing part of the graphene structure with gold, the switchable MA is turned into a frequency tunable MA. The absorption peak moves from 0.62 THz to 0.92 THz as the chemical potential increases from 0.1 eV to 0.5 eV. These designs overcome limitation of traditional absorbers and exhibit great potentials in many practical applications.

  2. Experimental methodology for obtaining sound absorption coefficients

    Directory of Open Access Journals (Sweden)

    Carlos A. Macía M

    2011-07-01

    Full Text Available Objective: the authors propose a new methodology for estimating sound absorption coefficients using genetic algorithms. Methodology: sound waves are generated and conducted along a rectangular silencer. The waves are then attenuated by the absorbing material covering the silencer’s walls. The attenuated sound pressure level is used in a genetic algorithm-based search to find the parameters of the proposed attenuation expressions that include geometric factors, the wavelength and the absorption coefficient. Results: a variety of adjusted mathematical models were found that make it possible to estimate the absorption coefficients based on the characteristics of a rectangular silencer used for measuring the attenuation of the noise that passes through it. Conclusions: this methodology makes it possible to obtain the absorption coefficients of new materials in a cheap and simple manner. Although these coefficients might be slightly different from those obtained through other methodologies, they provide solutions within the engineering accuracy ranges that are used for designing noise control systems.

  3. A method optimization study for atomic absorption ...

    African Journals Online (AJOL)

    Sadia Ata

    2014-04-24

    Apr 24, 2014 ... Manufacturer brand Win 2.1 software was used for data inte- gration and processing. ... reagents and analyst) is suitable for the intended application. The % relative standard deviation for absorbance ... flame atomic absorption spectrometry. Table 2 Linearity data for analysis of zinc in insulin using AAS.

  4. Plasma Sprayed Coatings for RF Wave Absorption

    Czech Academy of Sciences Publication Activity Database

    Nanobashvili, S.; Matějíček, Jiří; Žáček, František; Stöckel, Jan; Chráska, Pavel; Brožek, Vlastimil

    307-311, - (2002), s. 1334-1338 ISSN 0022-3115 Grant - others: COST (XE) Euratom DV4/04(TWO) Institutional research plan: CEZ:AV0Z2043910 Keywords : boron carbide, thermal spray coatings, fusion materials, RF wave absorption Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.730, year: 2002

  5. Acetaminophen (paracetamol) oral absorption and clinical influences.

    Science.gov (United States)

    Raffa, Robert B; Pergolizzi, Joseph V; Taylor, Robert; Decker, John F; Patrick, Jeffrey T

    2014-09-01

    Acetaminophen (paracetamol) is a widely used nonopioid, non-NSAID analgesic that is effective against a variety of pain types, but the consequences of overdose can be severe. Because acetaminophen is so widely available as a single agent and is increasingly being formulated in fixed-ratio combination analgesic products for the potential additive or synergistic analgesic effect and/or reduced adverse effects, accidental cumulative overdose is an emergent concern. This has rekindled interest in the sites, processes, and pharmacokinetics of acetaminophen oral absorption and the clinical factors that can influence these. The absorption of oral acetaminophen occurs primarily along the small intestine by passive diffusion. Therefore, the rate-limiting step is the rate of gastric emptying into the intestines. Several clinical factors can affect absorption per se or the rate of gastric emptying, such as diet, concomitant medication, surgery, pregnancy, and others. Although acetaminophen does not have the abuse potential of opioids or the gastrointestinal bleeding or organ adverse effects of NSAIDs, excess amounts can produce serious hepatic injury. Thus, an understanding of the sites and features of acetaminophen absorption--and how they might be influenced by factors encountered in clinical practice--is important for pain management using this agent. It can also provide insight for design of formulations that would be less susceptible to clinical variables. © 2013 World Institute of Pain.

  6. Optimization of Flame Atomic Absorption Spectrometry for ...

    African Journals Online (AJOL)

    Optimization of Flame Atomic Absorption Spectrometry for Measurement of High Concentrations of Arsenic and Selenium. ... This procedure allowed a rapid determination of As from minimum 4.462 mg/L to higher concentrations without sample pretreatment. Besides As, this method successfully measured Se concentrations ...

  7. The Absorption Refrigerator as a Thermal Transformer

    Science.gov (United States)

    Herrmann, F.

    2009-01-01

    The absorption refrigerator can be considered a thermal transformer, that is, a device that is analogous to the electric transformer. The analogy is based on the correspondence between the extensive quantities, entropy and electric charge and the intensive variables, temperature and electric potential. (Contains 1 footnote and 6 figures.)

  8. The absorption refrigerator as a thermal transformer

    International Nuclear Information System (INIS)

    Herrmann, F

    2009-01-01

    The absorption refrigerator can be considered a thermal transformer, that is, a device that is analogous to the electric transformer. The analogy is based on the correspondence between the extensive quantities, entropy and electric charge and the intensive variables, temperature and electric potential

  9. Realistic absorption coefficient of ultrathin films

    International Nuclear Information System (INIS)

    Cesaria, M; Caricato, A P; Martino, M

    2012-01-01

    Both a theoretical algorithm and an experimental procedure are discussed of a new route to determine the absorption/scattering properties of thin films deposited on transparent substrates. Notably, the non-measurable contribution of the film–substrate interface is inherently accounted for. While the experimental procedure exploits only measurable spectra combined according to a very simple algorithm, the theoretical derivation does not require numerical handling of the acquired spectra or any assumption on the film homogeneity and substrate thickness. The film absorption response is estimated by subtracting the measured absorption spectrum of the bare substrate from that of the film on the substrate structure but in a non-straightforward way. In fact, an assumption about the absorption profile of the overall structure is introduced and a corrective factor accounting for the relative film-to-substrate thickness. The method is tested on films of a well known material (ITO) as a function of the film structural quality and influence of the film–substrate interface, both deliberately changed by thickness tuning and doping. Results are found fully consistent with information obtained by standard optical analysis and band gap values reported in the literature. Additionally, comparison with a conventional method demonstrates that our route is generally more accurate even if particularly suited for very thin films. (paper)

  10. Realistic absorption coefficient of ultrathin films

    Science.gov (United States)

    Cesaria, M.; Caricato, A. P.; Martino, M.

    2012-10-01

    Both a theoretical algorithm and an experimental procedure are discussed of a new route to determine the absorption/scattering properties of thin films deposited on transparent substrates. Notably, the non-measurable contribution of the film-substrate interface is inherently accounted for. While the experimental procedure exploits only measurable spectra combined according to a very simple algorithm, the theoretical derivation does not require numerical handling of the acquired spectra or any assumption on the film homogeneity and substrate thickness. The film absorption response is estimated by subtracting the measured absorption spectrum of the bare substrate from that of the film on the substrate structure but in a non-straightforward way. In fact, an assumption about the absorption profile of the overall structure is introduced and a corrective factor accounting for the relative film-to-substrate thickness. The method is tested on films of a well known material (ITO) as a function of the film structural quality and influence of the film-substrate interface, both deliberately changed by thickness tuning and doping. Results are found fully consistent with information obtained by standard optical analysis and band gap values reported in the literature. Additionally, comparison with a conventional method demonstrates that our route is generally more accurate even if particularly suited for very thin films.

  11. A method optimization study for atomic absorption ...

    African Journals Online (AJOL)

    A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring ...

  12. A cylindrical furnace for absorption spectral studies

    Indian Academy of Sciences (India)

    A cylindrical furnace with three heating zones, capable of providing a temperature of 1100°C, has been fabricated to enable recording of absorption spectra of high temperature species. The temperature of the furnace can be controlled to ± 1°C of the set temperature. The salient feature of this furnace is that the material ...

  13. Evaluation of atomic absorption Spectrophotometry (ashing, non ...

    African Journals Online (AJOL)

    Three commonly used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and AAS-Non Ashing) and titrimetry (potassium permanganate titration) have been evaluated in this study to determine the calcium content in six food samples whose calcium levels ranged from 0 to more than 250mg/100g ...

  14. Regularity of the Interband Light Absorption Coefficient

    Indian Academy of Sciences (India)

    In this paper we consider the interband light absorption coefficient (ILAC), in a symmetric form, in the case of random operators on the -dimensional lattice. We show that the symmetrized version of ILAC is either continuous or has a component which has the same modulus of continuity as the density of states.

  15. Oral Exposure and Absorption of Toxicants

    Science.gov (United States)

    This chapter provides an overview of the toxicokinetics of orally absorbed xenobiotics. This includes a description of the basic anatomy and physiology of the digestive tract most relevant to the absorption process. In addition, differences in anatomy and physiology between human...

  16. Laser Absorption by Over-Critical Plasmas

    Science.gov (United States)

    May, J.; Tonge, J.; Fiuza, F.; Fonseca, R. A.; Silva, L. O.; Mori, W. B.

    2015-11-01

    Absorption of high intensity laser light by matter has important applications to emerging sciences and technology, such as Fast Ignition ICF and ion acceleration. As such, understanding the underlying mechanisms of this absorption is key to developing these technologies. Critical features which distinguish the interaction of high intensity light - defined here as a laser field having a normalized vector potential greater than unity - are that the reaction of the material to the fields results in sharp high-density interfaces; and that the movement of the electrons is in general relativistic, both in a fluid and a thermal sense. The results of these features are that the absorption mechanisms are qualitatively distinct from those at lower intensities. We will review previous work, by our group and others, on the absorption mechanisms, and highlight current research. We will show that the standing wave structure of the reflected laser light is key to particle dynamics for normally incident lasers. The authors acknowledge the support of the Department of Energy under contract DE-NA 0001833 and the National Science Foundation under contract ACI 1339893.

  17. Sustainable Absorption Panels from Agricultural Wastes

    Directory of Open Access Journals (Sweden)

    Ismail F.Z.

    2014-01-01

    Full Text Available Noise has become a serious environmental problem and there are demands for alternative sustainable materials which capable to reduce the noise level at various frequency ranges. Therefore, the aim of this research is to study the potential of turning the agricultural waste and waste paper into a sound absorption panel. For the purpose of this study, combination of two materials was under studied; coconut coir fibre from agriculture waste and shredded waste paper from the office. There were two main objective of the research; first is to develop absorption panels from coconut coir powder that available locally with a combination of shredded paper at different percentage of mixture. Second objective is to identify the absorption rate of the panels. The study encompasses the fabrication of the particle board using the coconut husk powder mix with shredded waste paper and using the gypsum powder as the binder for the two materials. Four acoustic panels of size 0.5m x 0.5m and 0.012 m thick were fabricated with different mix ratio; 25% of coconut coir powder mixed with 75% of shredded waste papers for sample 1, 50% both of the material for sample 2, 75% of coconut coir powder mixed with 25% of shredded waste paper for sample 3, and lastly 100% of coconut coir powder for sample 4. The absorption coefficient of the panels was tested in a reverberation chamber and in accordance with ISO 354:1985 standards. Based on the results, sample 1 gave the highest absorption coefficient compared to sample 2, 3 and 4. It can be concluded that the acoustic panel made from a mixture of 25% coconut coir powder with 75% shredded waste paper provided higher absorption coefficient compared to the performance of the other samples. This might be caused by the size of the coir powder which is very small, creating less void space in between the panel and thus causing it to absorb less sound. Since sound absorption is very much affected by the availability of void space of

  18. The effects of metamaterial on electromagnetic fields absorption characteristics of human eye tissues.

    Science.gov (United States)

    Gasmelseed, Akram; Yunus, Jasmy

    2014-01-01

    The interaction of a dipole antenna with a human eye model in the presence of a metamaterial is investigated in this paper. The finite difference time domain (FDTD) method with convolutional perfectly matched layer (CPML) formulation have been used. A three-dimensional anatomical model of the human eye with resolution of 1.25 mm × 1.25 mm × 1.25 mm was used in this study. The dipole antenna was driven by modulated Gaussian pulse and the numerical study is performed with dipole operating at 900 MHz. The analysis has been done by varying the size and value of electric permittivity of the metamaterial. By normalizing the peak SAR (1 g and 10 g) to 1 W for all examined cases, we observed how the SAR values are not affected by the different permittivity values with the size of the metamaterial kept fixed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Synovial tissue research

    DEFF Research Database (Denmark)

    Orr, Carl; Sousa, Elsa; Boyle, David L

    2017-01-01

    The synovium is the major target tissue of inflammatory arthritides such as rheumatoid arthritis. The study of synovial tissue has advanced considerably throughout the past few decades from arthroplasty and blind needle biopsy to the use of arthroscopic and ultrasonographic technologies that enable...... easier visualization and improve the reliability of synovial biopsies. Rapid progress has been made in using synovial tissue to study disease pathogenesis, to stratify patients, to discover biomarkers and novel targets, and to validate therapies, and this progress has been facilitated by increasingly...... diverse and sophisticated analytical and technological approaches. In this Review, we describe these approaches, and summarize how their use in synovial tissue research has improved our understanding of rheumatoid arthritis and identified candidate biomarkers that could be used in disease diagnosis...

  20. The day to night absorption ratio in auroral and subauroral zone riometer measurements during auroral absorption

    International Nuclear Information System (INIS)

    Ranta, H.; Ranta, A.; Rosenberg, T.J.

    1984-01-01

    The day to night ratio of auroral absorption has been studied using data from auroral and subauroral latitudes and by application of different kinds of statistical analyses. Ratios between 0.5 and 3.0 are obtained, depending on the criteria applied to the selection of data. Previous studies obtained similar ratios, but reached different conclusions about the effective solar control of auroral absorption. It is concluded here that evidence of solar control of the day to night ratio of auroral absorption, or the lack thereof, cannot be extracted by these statistical analyses. (author)

  1. Optical tomography of tissues

    International Nuclear Information System (INIS)

    Zimnyakov, D A; Tuchin, Valerii V

    2002-01-01

    Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed. (review)

  2. Monitoring of tissue optical properties during thermal coagulation of ex vivo tissues.

    Science.gov (United States)

    Nagarajan, Vivek Krishna; Yu, Bing

    2016-09-01

    Real-time monitoring of tissue status during thermal ablation of tumors is critical to ensure complete destruction of tumor mass, while avoiding tissue charring and excessive damage to normal tissues. Currently, magnetic resonance thermometry (MRT), along with magnetic resonance imaging (MRI), is the most commonly used technique for monitoring and assessing thermal ablation process in soft tissues. MRT/MRI is very expensive, bulky, and often subject to motion artifacts. On the other hand, light propagation within tissue is sensitive to changes in tissue microstructure and physiology which could be used to directly quantify the extent of tissue damage. Furthermore, optical monitoring can be a portable, and cost-effective alternative for monitoring a thermal ablation process. The main objective of this study, is to establish a correlation between changes in tissue optical properties and the status of tissue coagulation/damage during heating of ex vivo tissues. A portable diffuse reflectance spectroscopy system and a side-firing fiber-optic probe were developed to study the absorption (μa (λ)), and reduced scattering coefficients (μ's (λ)) of native and coagulated ex vivo porcine, and chicken breast tissues. In the first experiment, both porcine and chicken breast tissues were heated at discrete temperature points between 24 and 140°C for 2 minutes. Diffuse reflectance spectra (430-630 nm) of native and coagulated tissues were recorded prior to, and post heating. In a second experiment, porcine tissue samples were heated at 70°C and diffuse reflectance spectra were recorded continuously during heating. The μa (λ) and μ's (λ) of the tissues were extracted from the measured diffuse reflectance spectra using an inverse Monte-Carlo model of diffuse reflectance. Tissue heating was stopped when the wavelength-averaged scattering plateaued. The wavelength-averaged optical properties, and , for native porcine tissues (n = 66) at room temperature, were 5.4

  3. Optical signature of nerve tissue-Exploratory ex vivo study comparing optical, histological, and molecular characteristics of different adipose and nerve tissues.

    Science.gov (United States)

    Balthasar, Andrea J R; Bydlon, Torre M; Ippel, Hans; van der Voort, Marjolein; Hendriks, Benno H W; Lucassen, Gerald W; van Geffen, Geert-Jan; van Kleef, Maarten; van Dijk, Paul; Lataster, Arno

    2018-05-14

    During several anesthesiological procedures, needles are inserted through the skin of a patient to target nerves. In most cases, the needle traverses several tissues-skin, subcutaneous adipose tissue, muscles, nerves, and blood vessels-to reach the target nerve. A clear identification of the target nerve can improve the success of the nerve block and reduce the rate of complications. This may be accomplished with diffuse reflectance spectroscopy (DRS) which can provide a quantitative measure of the tissue composition. The goal of the current study was to further explore the morphological, biological, chemical, and optical characteristics of the tissues encountered during needle insertion to improve future DRS classification algorithms. To compare characteristics of nerve tissue (sciatic nerve) and adipose tissues, the following techniques were used: histology, DRS, absorption spectrophotometry, high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, and solution 2D 13 C- 1 H heteronuclear single-quantum coherence spectroscopy. Tissues from five human freshly frozen cadavers were examined. Histology clearly highlights a higher density of cellular nuclei, collagen, and cytoplasm in fascicular nerve tissue (IFAS). IFAS showed lower absorption of light around 1200 nm and 1750 nm, higher absorption around 1500 nm and 2000 nm, and a shift in the peak observed around 1000 nm. DRS measurements showed a higher water percentage and collagen concentration in IFAS and a lower fat percentage compared to all other tissues. The scattering parameter (b) was highest in IFAS. The HR-MAS NMR data showed three extra chemical peak shifts in IFAS tissue. Collagen, water, and cellular nuclei concentration are clearly different between nerve fascicular tissue and other adipose tissue and explain some of the differences observed in the optical absorption, DRS, and HR-NMR spectra of these tissues. Some differences observed between fascicular

  4. Strontium metabolism and mechanism of interaction with mineralized tissues

    International Nuclear Information System (INIS)

    Wadkins, C.L.; Fu Peng, C

    1981-01-01

    This paper examines the administration of strontium to birds and mammals which results in limited incorporation into skeletal tissue, depressed intestinal calcium absorption, and development of rachitic bone lesions. Comparison of radiostrontium and radiocalcium incorporation by intact animals reveals discrimination against strontium in favor of calcium. Comparison of the Sr 85 - Ca 2+ and Ca 45 - Ca 2+ exchange reveals discrimination against strontium in favor of calcium. Thus, this system manifests product specificity, strontium inhibition, strontium exchange, and discrimination observed with intact animals

  5. Photon activation analysis of soft tissues of marine invertebrates

    International Nuclear Information System (INIS)

    Fukushima, M.; Tamate, H.

    2001-01-01

    We have determined levels of elements in soft tissues of 23 species of marine invertebrates by photon activation analysis and atomic absorption spectrometry. Concentration levels of Mg and Rb were almost same for all samples determined. On the contrary, relatively high concentration of elements were observed for Ni in mid-gut gonads of ear shells, As in gills, hepatopancreas, and muscles of several species of Crustaceans. (author)

  6. Cosmological Evolution of QSO Absorption Systems

    Science.gov (United States)

    Stengler-Larrea, Erik

    1995-08-01

    First, the evolution with cosmic time of the hydrogen clouds which produce the Lyman-alpha absorption lines is studied in dependence on the strength of these lines. From the analysis it is concluded that the results show no evidence of a dependence in the sense of stronger lines evolving faster, although for the resolution at which the used observations were done, it can not be ruled out. Within the same analysis, a distribution of the Doppler parameter of the lines was obtained, with large values and a wide spread. This parameter being an indicator of the gas temperature, this result is in accordance with high temperatures and, consequently, large ionised fractions and a large fraction of the baryonic matter of the universe being associated with these clouds. However, recent high resolution studies seem to reveal that much lower temperatures are characteristic of the clouds. The main content of this thesis, however, focuses on the redshift evolution of the absorbing systems producing absorption at the Lyman limit and of the amount of CIV producing CIV absorption lines. Regarding the CIV absorbers, previous predictions on the effects underlying their redshift distribution pointed to an increase with redshift of the absorbing column densities. In this thesis the first direct measurements of such column densities by profile fitting of a large number of absorption systems (73) are presented, confirming the predictions of a decrease of at least a factor of 3 between z=1.5 and z=3.0. The study on the evolution of Lyman limit absorption systems (LLSs) puts an end to previous discrepancies between the results of different groups. Both a smooth single power law dependence of the LLS number density on redshift indicating no evolution in number density for 0.4 Team of the HST Key Project on QSO absorption lines, and in particular to estimate the necessary exposure times, the magnitudes of several of these objects had to be re-measured. The acquisition of their images and the

  7. Uranium absorption study pile; Empilement pour le controle de l'absorption de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V; Sautiez, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF{sub 3} counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10{sup -6} boron per gr. of uranium) or better. (author) [French] Nous decrivons un dispositif permettant de mesurer l'absorption des elements combustibles d'une pile. Ce dispositif est constitue par un empilement de graphite dont la region centrale est formee par un reseau regulier de barres d'uranium. Des sources de RaBe et des compteurs a BF{sub 3} sont places de part et d'autre de cette region. En comparant un chargement d'uranium a un chargement etalon d'environ 560 kg, on peut determiner la difference d'absorption entre ces deux chargements. La sensibilite permettrait de deceler une variation d'absorption de l'ordre du ppm de bore (10{sup -6} g de bore par gramme d'uranium) et peut-etre mieux. (auteur)

  8. [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.

  9. Autopsy Tissue Program

    International Nuclear Information System (INIS)

    Fox, T.; Tietjen, G.

    1979-01-01

    The Autopsy Tissue Program was begun in 1960. To date, tissues on 900 or more persons in 7 geographic regions have been collected and analyzed for plutonium content. The tissues generally consist of lung, liver, kidney, lymph, bone, and gonadal tissue for each individual. The original objective of the program was to determine the level of plutonium in human tissues due solely to fall-out from weapons testing. The baseline thus established was to be used to evaluate future changes. From the first, this program was beset with chemical and statistical difficulties. Many factors whose effects were not recognized and not planned for were found later to be important. Privacy and ethical considerations hindered the gathering of adequate data. Since the chemists were looking for amounts of plutonium very close to background, possible contamination was a very real problem. Widely used chemical techniques introduced a host of statistical problems. The difficulties encountered touch on areas common to large data sets, unusual outlier detection methods, minimum detection limits, problems with Aliquot sizes, and time-trends in the data. The conclusions point out areas to which the biologists will have to devote much more careful attention than was believed

  10. Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering.

    Science.gov (United States)

    Bremmer, Rolf H; van Gemert, Martin J C; Faber, Dirk J; van Leeuwen, Ton G; Aalders, Maurice C G

    2013-08-01

    Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20  mm-1 at reduced scattering coefficients of 1 and 11.5  mm-1, we observed excellent agreement (r2=0.994) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys.19, 879-888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the object's diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime

  11. Skin absorption through atopic dermatitis skin

    DEFF Research Database (Denmark)

    Halling-Overgaard, A-S; Kezic, S; Jakasa, I

    2017-01-01

    Patients with atopic dermatitis have skin barrier impairment in both lesional and non-lesional skin. They are typically exposed to emollients daily and topical anti-inflammatory medicaments intermittently, hereby increasing the risk of developing contact allergy and systemic exposed to chemicals...... ingredients found in these topical preparations. We systematically searched for studies that investigated skin absorption of various penetrants, including medicaments, in atopic dermatitis patients, but also animals with experimentally induced dermatitis. We identified 40 articles, i.e. 11 human studies...... examining model penetrants, 26 human studies examining atopic dermatitis drugs and 3 animal studies. We conclude that atopic dermatitis patients have nearly two-fold increased skin absorption when compared to healthy controls. There is a need for well-designed epidemiological and dermato...

  12. Spectrophotometry of six broad absorption line QSOs

    Science.gov (United States)

    Junkkarinen, Vesa T.; Burbidge, E. Margaret; Smith, Harding E.

    1987-01-01

    Spectrophotometric observations of six broad absorption-line QSOs (BALQSOs) are presented. The continua and emission lines are compared with those in the spectra of QSOs without BALs. A statistically significant difference is found in the emission-line intensity ratio for (N V 1240-A)/(C IV 1549-A). The median value of (N V)/(C IV) for the BALQSOs is two to three times the median for QSOs without BALs. The absorption features of the BALQSOs are described, and the column densities and limits on the ionization structure of the BAL region are discussed. If the dominant ionization mechanism is photoionization, then it is likely that either the ionizing spectrum is steep or the abundances are considerably different from solar. Collisional ionization may be a significant factor, but it cannot totally dominate the ionization rate.

  13. Medication absorption for patients with an ileostomy.

    Science.gov (United States)

    Moore, Susan

    The Association of Stoma Care Nurses UK (2013) has stressed that it is the role of the stoma care nurse to provide education to patients, carers, prescribers and other nurses. This includes the area of medication management. Ensuring patients with an ileostomy receive their medication in a form they can absorb is of importance to every stoma care nurse. Prescribing for patients with a stoma calls for special care. Each patient with an ileostomy requires assessment of their medication regimen for the purpose of identifying potential medical absorption issues. However, from an extensive literature search, it is evident that there is very little literature published on this subject. This article looks at the considerations to take into account when prescribing medication for ileostomy patients, and examines the results of a clinical audit on medication prescribers' knowledge of the impact of ileostomy formation on the absorption of medication.

  14. Current fluctuations in quantum absorption refrigerators

    Science.gov (United States)

    Segal, Dvira

    2018-05-01

    Absorption refrigerators transfer thermal energy from a cold bath to a hot bath without input power by utilizing heat from an additional "work" reservoir. Particularly interesting is a three-level design for a quantum absorption refrigerator, which can be optimized to reach the maximal (Carnot) cooling efficiency. Previous studies of three-level chillers focused on the behavior of the averaged cooling current. Here, we go beyond that and study the full counting statistics of heat exchange in a three-level chiller model. We explain how to obtain the complete cumulant generating function of the refrigerator in a steady state, then derive a partial cumulant generating function, which yields closed-form expressions for both the averaged cooling current and its noise. Our analytical results and simulations are beneficial for the design of nanoscale engines and cooling systems far from equilibrium, with their performance optimized according to different criteria, efficiency, power, fluctuations, and dissipation.

  15. Nucleon multiplicities after pion absorption in 160

    International Nuclear Information System (INIS)

    Hamers, R.

    1989-01-01

    The experiment described in this thesis concerns a simultaneous measurement of two- and higher-fold coincidences following positive and negative pion absorption in 16 0. The detected particles are protons, neutrons and deuterons. The detection and analysis of charged particles is discussed. The incident pion energy was 65 MeV, thus well below the delta resonance. The low pion energy was 65 MeV, thus well below the delta resonance. The low pion energy ensures that contributions of initial state interactions, i.e. pion-nucleon scattering preceding absorption, are minimized. The following reaction channels were selected and analyzed: π + ,pp), (π + ,pd). Evidence for quasifree reaction precessed has been investigated by comparing the data with phase-space calculations incorporating the geometry of the experimental setup. (author). 36 refs.; 1 figs.; 3 tabs

  16. Gamma ray auto absorption correction evaluation methodology

    International Nuclear Information System (INIS)

    Gugiu, Daniela; Roth, Csaba; Ghinescu, Alecse

    2010-01-01

    Neutron activation analysis (NAA) is a well established nuclear technique, suited to investigate the microstructural or elemental composition and can be applied to studies of a large variety of samples. The work with large samples involves, beside the development of large irradiation devices with well know neutron field characteristics, the knowledge of perturbing phenomena and adequate evaluation of correction factors like: neutron self shielding, extended source correction, gamma ray auto absorption. The objective of the works presented in this paper is to validate an appropriate methodology for gamma ray auto absorption correction evaluation for large inhomogeneous samples. For this purpose a benchmark experiment has been defined - a simple gamma ray transmission experiment, easy to be reproduced. The gamma ray attenuation in pottery samples has been measured and computed using MCNP5 code. The results show a good agreement between the computed and measured values, proving that the proposed methodology is able to evaluate the correction factors. (authors)

  17. Modelling absorption and photoluminescence of TPD

    Energy Technology Data Exchange (ETDEWEB)

    Vragovic, Igor [Dpto. de Fisica Aplicada and Inst. Universitario de Materiales de Alicante, Universidad de Alicante, E-03080 Alicante (Spain)], E-mail: igor.vragovic@ua.es; Calzado, Eva M.; Diaz Garcia, Maria A.; Himcinschi, C. [Max-Planck-Institut fuer Mikrostrukturphysik, D-06120 Halle (Germany); Gisslen, L.; Scholz, R. [Walter Schottky Institut, Technische Universitaet Muenchen, D-85748 Garching (Germany)

    2008-05-15

    We analyse the optical spectra of N,N{sup '}-diphenyl-N,N{sup '}-bis(3-methyl-phenyl)-(1,1{sup '}-biphenyl)-4,4{sup '}-diamine (TPD) doped polystyrene films. The aim of the present paper is to give a microscopic interpretation of the significant Stokes shift between absorption and photoluminescence, which makes this material suitable for stimulated emission. The optimized geometric structures and energies of a neutral TPD monomer in ground and excited states are obtained by ab initio calculations using Hartree-Fock and density functional theory. The results indicate that the second distinct peak observed in absorption may arise either from a group of higher electronic transitions of the monomer or from the lowest optical transitions of a TPD dimer.

  18. Modelling absorption and photoluminescence of TPD

    International Nuclear Information System (INIS)

    Vragovic, Igor; Calzado, Eva M.; Diaz Garcia, Maria A.; Himcinschi, C.; Gisslen, L.; Scholz, R.

    2008-01-01

    We analyse the optical spectra of N,N ' -diphenyl-N,N ' -bis(3-methyl-phenyl)-(1,1 ' -biphenyl)-4,4 ' -diamine (TPD) doped polystyrene films. The aim of the present paper is to give a microscopic interpretation of the significant Stokes shift between absorption and photoluminescence, which makes this material suitable for stimulated emission. The optimized geometric structures and energies of a neutral TPD monomer in ground and excited states are obtained by ab initio calculations using Hartree-Fock and density functional theory. The results indicate that the second distinct peak observed in absorption may arise either from a group of higher electronic transitions of the monomer or from the lowest optical transitions of a TPD dimer

  19. Absorption band Q model for the earth

    International Nuclear Information System (INIS)

    Anderson, D.L.; Given, J.W.

    1982-01-01

    Body wave, surface wave, and normal mode data are used to place constraints on the frequency dependence of Q in the mantle. With a simple absorption band model it is possible to satisfy the shear sensitive data over a broad frequency range. The quality factor Q/sub s/(ω) is proportional to ω/sup α/ in the band and to ω and ω -1 at higher and lower frequencies, respectively, as appropriate for a relaxation mechanism with a spectrum of relaxation time. The parameters of the band are Q(min) = 80, α = 0.15, and width, 5 decades. The center of the band varies from 10 1 seconds in the upper mantle, to 1.6 x 10 3 seconds in the lower mantle. The shift of the band with depth is consistent with the expected effects of temperature, pressure and stress. High Q, regions of the mantle are attributed to a shift of the absorption band to longer periods. To satisfy the gravest fundamental spheroidal modes and the ScS data, the absorption band must shift back into the short-period seismic band at the base of the mantle. This may be due to a high temperature gradient or high shear stresses. A preliminary attempt is also made to specify bulk dissipation in the mantle and core. Specific features of the absorption band model are low Q in the body wave band at both the top and the base of the mantle, low Q for long-period body waves in the outer core, an inner core Q 2 that increases with period, and low Q/sub p//Q/sub s/ at short periods in the middle mantel. The short-period Q/sub s/ increases rapidly at 400 km and is relatively constant from this depth to 2400 km. The deformational Q of the earth at a period of 14 months is predicted to be 463

  20. Oxalic acid decreases calcium absorption in rats

    International Nuclear Information System (INIS)

    Weaver, C.M.; Martin, B.R.; Ebner, J.S.; Krueger, C.A.

    1987-01-01

    Calcium absorption from salts and foods intrinsically labeled with 45 Ca was determined in the rat model. Calcium bioavailability was nearly 10 times greater for low oxalate kale, CaCO 3 and CaCl 2 than from CaC 2 O 4 (calcium oxalate) and spinach (high in oxalates). Extrinsic and intrinsic labeling techniques gave a similar assessment of calcium bioavailability from kale but not from spinach

  1. Physicochemical patterns of ozone absorption by wood

    Science.gov (United States)

    Mamleeva, N. A.; Lunin, V. V.

    2016-11-01

    Results from studying aspen and pine wood ozonation are presented. The effect the concentration of ozone, the reagent residence time, and the content of water in a sample of wood has on ozone consumption rate and ozone demand are analyzed. The residence time is shown to determine the degree of ozone conversion degree and the depth of substrate destruction. The main patterns of ozone absorption by wood with different moisture content are found. Ways of optimizing the ozonation of plant biomass are outlined.

  2. Understanding Energy Absorption Behaviors of Nanoporous Materials

    Science.gov (United States)

    2008-05-23

    induced liquid infiltration in nanopores. J. Appl. Phys. 100, 014308.1-3 (2006). 26. Surani, F. B. and Qiao, Y. Energy absorption of a polyacrylic ...that the infiltration pressure decreases as the cation size increases (Fig.K-2). The ionic radii of cesium, potassium , sodium and lithium are...REPORT DOCUMENTATION PAGE Form Approved OMB NO. 0704-0188 Public Reporting burden for this collection of information is estimated to average 1 hour

  3. Crown structure, radiation absorption, photosynthesis and transpiration

    OpenAIRE

    Wang, Yingping

    1988-01-01

    A complex simulation model, MAESTRO, has been developed and validated against field measurements in plantation in both Scotland and Australia. It has been shown that MAESTRO can reasonably predict the daily course of PAR (photosynetically active radiation) transmittance at points below the canopies of radiata pine and Sitka spruce plantations. 1. Four structural properties of the Sitka spruce tree crown have been identified and evaluation in relation to PAR absorption, photosynthesis and ...

  4. Absorptive capacity and mass customization capability

    OpenAIRE

    Zhang, Min; Zhao, Xiande; Lyles, Marjorie A.; Guo, Hangfei

    2015-01-01

    Purpose The purpose of this paper is to investigate the effects of a manufacturer’s absorptive capacity (AC) on its mass customization capability (MCC). Design/methodology/approach The authors conceptualize AC within the supply chain context as four processes: knowledge acquisition from customers, knowledge acquisition from suppliers, knowledge assimilation, and knowledge application. The authors then propose and empirically test a model on the relationships among AC processes and MCC using s...

  5. Moisture Absorption in Certain Tropical American Woods

    Science.gov (United States)

    1949-08-01

    surface area was in unobstructed contact with the salt water. Similar wire mesh racks were weighted and placed on top of the specimens to keep them...Oak (Quercus alba)" Br. Guiana Honduras United States (control) II II Total absorption by 2 x 2 x 6-inch uncoated specimens. Probably sapwood ...only. /2 ~~ Probably sapwood Table 3 (Continued) Species Source Increase over 40 percent Fiddlewood (Vit ex Gaumeri) Roble Blanco (Tabebuia

  6. Nonequilibrium gas absorption in rotating permeable media

    Science.gov (United States)

    Baev, V. K.; Bazhaikin, A. N.

    2016-08-01

    The absorption of ammonia, sulfur dioxide, and carbon dioxide by water and aqueous solutions in rotating permeable media, a cellular porous disk, and a set of spaced-apart thin disks has been considered. The efficiency of cleaning air to remove these impurities is determined, and their anomalously high solubility (higher than equilibrium value) has been discovered. The results demonstrate the feasibility of designing cheap efficient rotor-type absorbers to clean gases of harmful impurities.

  7. Preferential campesterol incorporation into various tissues in apolipoprotein E*3-Leiden mice consuming plant sterols or stanols

    NARCIS (Netherlands)

    Plat, J.; Jong, A.de; Volger, O.L.; Princen, H.M.G.; Mensink, R.P.

    2008-01-01

    Intestinal absorption of plant sterols and stanols is much lower as compared with that of cholesterol; and therefore, serum concentrations are low. Circulating plant sterols and stanols are incorporated into tissues. However, hardly any data are available about tissue distributions of individual

  8. The forward and inverse problem in tissue optics based on the radiative transfer equation: A brief review

    International Nuclear Information System (INIS)

    Klose, Alexander D.

    2010-01-01

    This note serves as an introduction to two papers by Klose et al. and provides a brief review of the latest developments in optical tomography of scattering tissue. We discuss advancements made in solving the forward model for light propagation based on the radiative transfer equation, in reconstructing scattering and absorption cross sections of tissue, and in molecular imaging of luminescent sources.

  9. Differentiation of healthy and malignant tissue in colon cancer patients using optical spectroscopy: A tool for image-guided surgery

    NARCIS (Netherlands)

    Langhout, G.C.; Spliethoff, Jarich; Schmitz, S.J.; Aalbers, A.G.J.; van Velthuysen, M.L.; Hendriks, B.H.W.; Ruers, Theo J.M.; Kuhlmann, K.F.D.

    2015-01-01

    Background Surgery for colorectal cancer aims for complete tumor resection. Optical-based techniques can identify tumor and surrounding tissue through the tissue specific optical properties, absorption and scattering, which are both influenced by the biochemical and morphological composition of the

  10. Tissue Engineering Using Transfected Growth-Factor Genes

    Science.gov (United States)

    Madry, Henning; Langer, Robert S.; Freed, Lisa E.; Trippel, Stephen; Vunjak-Novakovic, Gordana

    2005-01-01

    A method of growing bioengineered tissues includes, as a major component, the use of mammalian cells that have been transfected with genes for secretion of regulator and growth-factor substances. In a typical application, one either seeds the cells onto an artificial matrix made of a synthetic or natural biocompatible material, or else one cultures the cells until they secrete a desired amount of an extracellular matrix. If such a bioengineered tissue construct is to be used for surgical replacement of injured tissue, then the cells should preferably be the patient s own cells or, if not, at least cells matched to the patient s cells according to a human-leucocyteantigen (HLA) test. The bioengineered tissue construct is typically implanted in the patient's injured natural tissue, wherein the growth-factor genes enhance metabolic functions that promote the in vitro development of functional tissue constructs and their integration with native tissues. If the matrix is biodegradable, then one of the results of metabolism could be absorption of the matrix and replacement of the matrix with tissue formed at least partly by the transfected cells. The method was developed for articular chondrocytes but can (at least in principle) be extended to a variety of cell types and biocompatible matrix materials, including ones that have been exploited in prior tissue-engineering methods. Examples of cell types include chondrocytes, hepatocytes, islet cells, nerve cells, muscle cells, other organ cells, bone- and cartilage-forming cells, epithelial and endothelial cells, connective- tissue stem cells, mesodermal stem cells, and cells of the liver and the pancreas. Cells can be obtained from cell-line cultures, biopsies, and tissue banks. Genes, molecules, or nucleic acids that secrete factors that influence the growth of cells, the production of extracellular matrix material, and other cell functions can be inserted in cells by any of a variety of standard transfection techniques.

  11. Atomic absorption analysis of serial titanium alloys

    International Nuclear Information System (INIS)

    Gorlova, M.N.; Feofanova, N.M.; Kornyushkova, Yu.D.

    1977-01-01

    Atom-absorption technique is described, which makes it possible to rapidly and precisely determine the following alloying elements and admixtures in titanium alloys: Al (2.0 - 8.5%); Mo (0.5 - 8%); Cr (0.5 - 12%); Si (0.2 - 0.5%); Mn(0.2 - 2.5%); V(0.5 - 6%); Sn(2.0 - 3.0%); Fe(0.1 - 1.0%); Zr(2.0 - 12.0%). The atom absorption method with flame atomization of the sample provides for best results if the alloy is dissolved in a mixture HCl + HBF 4 in the ratio 2:1. In order to obtain correct results the standard solutions must contain titanium in concentrations corresponding to the weight of the sample being analyzed. Sensitivity of zirconium determination may be increased approximately twofold by adding 10 mg/ml of FeCl 3 into the solution. Being as precise, as the classic analytical methods, the atom absorption technique is about 5 times more efficient

  12. Intestinal absorption of biotin in the rat

    International Nuclear Information System (INIS)

    Bowman, B.B.; Selhub, J.; Rosenberg, I.H.

    1986-01-01

    We examined the absorption of biotin using the in vivo intestinal loop technique. Jejunal segments from male rats were filled with solutions containing [ 3 H]biotin and [ 14 C]inulin in Krebs-Ringer phosphate buffer, pH 6.5. Absorption was determined on the basis of luminal tritium disappearance after correction for inulin recovery. At biotin concentrations of 0.1 and 5.0 microM, luminal biotin disappearance was linear for at least 10 min. At biotin concentrations ranging from 2.3 nM to 75 microM, 10-28% of the administered dose was absorbed in 10 min. The concentration dependence of luminal biotin disappearance is consistent with the presence of both saturable and nonsaturable (linear) components of biotin uptake, with estimated Km = 9.6 microM and Jmax = 75.2 pmol/(2.5 cm loop X min). The rate constant for nonsaturable uptake is 3.1 pmol/(2.5 cm loop X min X microM). We conclude that at biotin concentrations less than 5 microM, biotin absorption proceeds largely by the saturable process, whereas at concentrations above 25 microM, nonsaturable uptake predominates. Additional studies demonstrated significantly less biotin uptake in the ileum than in the jejunum, a finding in agreement with previous in vitro studies

  13. Wavelength mismatch effect in electromagnetically induced absorption

    Energy Technology Data Exchange (ETDEWEB)

    Bharti, Vineet [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Wasan, Ajay [Department of Physics, Indian Institute of Technology, Roorkee 247667 (India); Natarajan, Vasant [Department of Physics, Indian Institute of Science, Bangalore 560012 (India)

    2016-07-15

    We present a theoretical investigation of the phenomenon of electromagnetically induced absorption (EIA) in a 4-level system consisting of vee and ladder subsystems. The four levels are coupled using one weak probe field, and two strong control fields. We consider an experimental realization using energy levels of Rb. This necessitates dealing with different conditions of wavelength mismatch—near-perfect match where all three wavelengths are approximately equal; partial mismatch where the wavelength of one control field is less than the other fields; and complete mismatch where all three wavelengths are unequal. We present probe absorption profiles with Doppler averaging at room temperature to account for experiments in a room temperature Rb vapor cell. Our analysis shows that EIA resonances can be studied using Rydberg states excited with diode lasers. - Highlights: • Wavelength mismatch effect is investigated in electromagnetically induced absorption (EIA). • An experimental realization of 4-level vee + ladder system using energy levels of rubidium atom is presented. • EIA resonances are studied under different conditions of wavelength mismatch. • Possibility of observation of EIA using Rydberg states excited with diode lasers.

  14. Optical absorption in disordered monolayer molybdenum disulfide

    Science.gov (United States)

    Ekuma, C. E.; Gunlycke, D.

    2018-05-01

    We explore the combined impact of sulfur vacancies and electronic interactions on the optical properties of monolayer MoS2. First, we present a generalized Anderson-Hubbard Hamiltonian that accounts for both randomly distributed sulfur vacancies and the presence of dielectric screening within the material. Second, we parametrize this energy-dependent Hamiltonian from first-principles calculations based on density functional theory and the Green's function and screened Coulomb (GW) method. Third, we apply a first-principles-based many-body typical medium method to determine the single-particle electronic structure. Fourth, we solve the Bethe-Salpeter equation to obtain the charge susceptibility χ with its imaginary part being related to the absorbance A . Our results show that an increased vacancy concentration leads to decreased absorption both in the band continuum and from exciton states within the band gap. We also observe increased absorption below the band-gap threshold and present an expression, which describes Lifshitz tails, in excellent qualitative agreement with our numerical calculations. This latter increased absorption in the 1.0 -2.5 eV range makes defect engineering of potential interest for solar cell applications.

  15. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  16. Wavelength mismatch effect in electromagnetically induced absorption

    International Nuclear Information System (INIS)

    Bharti, Vineet; Wasan, Ajay; Natarajan, Vasant

    2016-01-01

    We present a theoretical investigation of the phenomenon of electromagnetically induced absorption (EIA) in a 4-level system consisting of vee and ladder subsystems. The four levels are coupled using one weak probe field, and two strong control fields. We consider an experimental realization using energy levels of Rb. This necessitates dealing with different conditions of wavelength mismatch—near-perfect match where all three wavelengths are approximately equal; partial mismatch where the wavelength of one control field is less than the other fields; and complete mismatch where all three wavelengths are unequal. We present probe absorption profiles with Doppler averaging at room temperature to account for experiments in a room temperature Rb vapor cell. Our analysis shows that EIA resonances can be studied using Rydberg states excited with diode lasers. - Highlights: • Wavelength mismatch effect is investigated in electromagnetically induced absorption (EIA). • An experimental realization of 4-level vee + ladder system using energy levels of rubidium atom is presented. • EIA resonances are studied under different conditions of wavelength mismatch. • Possibility of observation of EIA using Rydberg states excited with diode lasers.

  17. Experimental validation of a model for diffusion-controlled absorption of organic compounds in the trachea

    Energy Technology Data Exchange (ETDEWEB)

    Gerde, P. [National Inst. for Working Life, Solna (Sweden); Muggenburg, B.A.; Thornton-Manning, J.R. [and others

    1995-12-01

    Most chemically induced lung cancer originates in the epithelial cells in the airways. Common conceptions are that chemicals deposited on the airway surface are rapidly absorbed through mucous membranes, limited primarily by the rate of blood perfusion in the mucosa. It is also commonly thought that for chemicals to induce toxicity at the site of entry, they must be either rapidly reactive, readily metabolizable, or especially toxic to the tissues at the site of entry. For highly lipophilic toxicants, there is a third option. Our mathematical model predicts that as lipophilicity increases, chemicals partition more readily into the cellular lipid membranes and diffuse more slowly through the tissues. Therefore, absorption of very lipophilic compounds will be almost entirely limited by the rate of diffusion through the epithelium rather than by perfusion of the capillary bed in the subepithelium. We have reported on a preliminary model for absorption through mucous membranes of any substance with a lipid/aqueous partition coefficient larger than one. The purpose of this work was to experimentally validate the model in Beagle dogs. This validated model on toxicant absorption in the airway mucosa will improve risk assessment of inhaled

  18. Skeletal muscle connective tissue

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline

    in the structure of fibrous collagen and myofibers at high-resolution. The results demonstrate that the collagen composition in the extra cellular matrix of Gadus morhua fish muscle is much more complex than previously anticipated, as it contains type III, IV, V  and VI collagen in addition to type I. The vascular....... Consequently, functional structures, ensuring "tissue maintenance" must form a major role of connective tissue, in addition that is to the force transmitting structures one typically finds in muscle. Vascular structures have also been shown to change their mechanical properties with age and it has been shown...

  19. Generation of radicals in hard biological tissues under the action of laser radiation

    Science.gov (United States)

    Sviridov, Alexander P.; Bagratashvili, Victor N.; Sobol, Emil N.; Omelchenko, Alexander I.; Lunina, Elena V.; Zhitnev, Yurii N.; Markaryan, Galina L.; Lunin, Valerii V.

    2002-07-01

    The formation of radicals upon UV and IR laser irradiation of some biological tissues and their components was studied by the EPR technique. The radical decay kinetics in body tissue specimens after their irradiation with UV light were described by various models. By the spin trapping technique, it was shown that radicals were not produced during IR laser irradiation of cartilaginous tissue. A change in optical absorption spectra and the dynamics of optical density of cartilaginous tissue, fish scale, and a collagen film under exposure to laser radiation in an air, oxygen, and nitrogen atmosphere was studied.

  20. Water analysis. Determination of elements by atomic absorption

    International Nuclear Information System (INIS)

    Anon.

    Analysis of homogeneous water solutions (plain water, polluted waters, effluents...) by atomic absorption spectrometry with correction for non specific absorption. The quantity ratio is determined by comparison with standard solutions, correction tables are given [fr