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Intestinal failure defined by measurements of intestinal energy and wet weight absorption

Jeppesen, P; Mortensen, P
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/2000 EN
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BACKGROUND AND AIMS—Intestinal failure defined by the minimal energy and wet weight absorption required to avoid home parenteral nutrition (HPN) is not well described. Thus the aim of this study was to identify the minimal level of gut function necessary to avoid parenteral support using objective measurements of intestinal function.
METHODS—Energy (bomb calorimetry) and wet weight absorption were measured during 48 hour balance studies in 45 HPN patients with intestinal failure and in 44 non-HPN borderline patients with a short bowel or malabsorption exceeding 2 MJ/day.
RESULTS—In the non-HPN patients, the lower 5% confidence interval of the absorption of energy was 84% of the basal metabolic rate (BMR, the Harris-Benedict equations), equivalent to 4.9 MJ/day. Wet weight absorption was 1.4 kg/day. The HPN patients absorbed less of either or both. The non-HPN patients absorbed 24-86% (range) of the energy and 23-95% of the wet weight. Absorption in the HPN patients ranged from below 0% (net secretion) in patients with very short bowels to 100% absorption of an insufficient oral intake in patients with pseudo-obstruction. Non-HPN patients who absorbed less than half of their intake avoided HPN by hyperphagia (200-400% of BMR equivalent to 10-24 MJ/day...

Broadening of vibrational levels in X-ray absorption spectroscopy of molecular nitrogen in compound semiconductors

Petravic, Mladen; Gao, Qiang; Llewellyn, David; Deenapanray, Prakash; MacDonald, Daniel; Crotti, C
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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We have used high-resolution near-edge X-ray absorption fine structure spectroscopy to study the N 1s → 1π* resonance of N2 trapped below the surface of several compound semiconductors. The vibrational fine structure, observed from all samples under co

Two-photon and Three-photon Absorption in an Organometallic Dendrimer

Samoc, Marek; Morrall, Joseph; Dalton, Gulliver; Cifuentes, Marie; Humphrey, Mark
Fonte: Wiley-VCH Verlag GMBH Publicador: Wiley-VCH Verlag GMBH
Tipo: Artigo de Revista Científica
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Three at a time: The wavelength dependence of nonlinear absorption and non-linear refraction of a peripherally nitrophenylethynyl-functionalized first-generation arylethynylruthenium dendrimer (see picture; dppe = 1,2-bis(diphenylphosphanyl)ethane) was ex

Assignment of the Qy Absorption Spectrum of Photosystem-I from Thermosynechococcus elongatus Based on the CAM-B3LYP Calculations at the PW91-Optimized Protein Structure

Yin, Shiwe; Dahlbom, Mats; Canfield, Peter; Hush, Noel S; Kobayashi, Rika; Reimers, Jeffrey R
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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461.20242%
The Qy absorption spectrum of Photosystem-I from Thermosynecochoccus elongatus (formerly Synecochoccus elongatus) is calculated using the CAM-B3LYP density functional and INDO schemes based on a quantummechanically refined structure for the entire photosy

Measurement of soil CO2 efflux using soda lime absorption: both quantitative and reliable

Keith, Heather; Wong, Suan Chin
Fonte: Pergamon-Elsevier Ltd Publicador: Pergamon-Elsevier Ltd
Tipo: Artigo de Revista Científica
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Measurement of soil CO2 efflux using a non-flow-through steady-state (NFT-SS) chamber with alkali absorption of CO2 by soda lime was tested and compared with a flow-through non-steady-state (FT-NSS) IRGA method to assess suitability of using soda lime for

Femtosecond Laser Structuring of As2S3 Glass for Erasable and Permanent Optical Memory

Juodkazis, Saulius; Rode, Andrei V; Kondo, Toshiaki; Misawa, Hiroaki; Samoc, Marek; Luther-Davies, Barry
Fonte: Materials Research Society Publicador: Materials Research Society
Tipo: Artigo de Revista Científica
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363.9562%
The nonlinear absorption coefficient of As2S3 glass has been measured to be 2.0 cm/GW for femtosecond pulses at 800 nm. Femtosecond laser structuring via two photon absorption in bulk As2S3 glass by erasable and permanent photo-darkening is demonstrated u

On automatic absorption detection for Imaging spectroscopy: A comparative study

Fu, Zhouyu; Robles-Kelly, Antonio; Caelli, Terry; Tan, Robby
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
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465.82164%
In this paper, we aim at presenting a survey on automatic absorption recovery methods for imaging spectroscopy. We commence by viewing the algorithms in the literature from a technical perspective and presenting an overview of the derivative analysis, fin

Two-colour mid-infrared absorption in an InAs/GaSb-based type II and broken-gap quantum well

Wei, XF; Xu, Wen; Zeng, Z.
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artigo de Revista Científica
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365.82164%
We examine theoretically the contribution from different transition channels to optical absorption in an InAs/GaSb-based type II and broken-gap quantum well in which both electron and hole subbands in different layers are occupied by carriers. We find tha

Invariant Object Material Identification via Discriminant Learning on Absorption Features

Fu, Zhouyu; Robles-Kelly, Antonio; Tan, Robby; Caelli, Terry
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
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In this paper, we propose a novel approach to object material identification in spectral imaging by combining the use of absorption features and statistical machine learning techniques. We depart from the significance of spectral absorption features for m

Nonlinear Optical and Two-Photon Absorption Properties of Octupolar Tris(bipyridyl)metal Complexes

Feuvrie, Christophe; Maury, Olivier; Bozec, Hubert Le; Ledoux, Isabelle; Morrall, Joseph; Dalton, Gulliver; Samoc, Marek; Humphrey, Mark
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
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The linear (absorption and emission) and nonlinear optical (NLO) properties of a series of D3 [(Fe(II), Ru(II), Ni(II), Cu(II), Zn(II)] octupolar metal complexes featuring the 4,4'-bis[(dibutylamino)styryl]-2,2'- bipyridine ligand are reported. Zinc(II),

Thomson Thick X-ray Absorption in a Broad Absorption Line Quasar, PG 0946+301

Mathur, Smita; Green, Paul; Arav, Nahum; Brotherton, Michael; Crenshaw, M; de Kool, Marthijn; Elvis, M; Goodrich, R.; Hamann, F; Hines, D C; Kashyap, V; Korista, Kirk; Peterson, Byron; Shields, John; Shlosman, I; van Breugel, Willem Johannes Maria; Voit,
Fonte: IOP Publishing Publicador: IOP Publishing
Tipo: Artigo de Revista Científica
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We present a deep ASCA observation of a broad absorption line quasar (BALQSO) PG 0946+301. The source was clearly detected in one of the gas imaging spectrometers, but not in any other detector. If BALQSOs have intrinsic X-ray spectra similar to normal radio-quiet quasars, our observations imply that there is Thomson thick X-ray absorption (NH ≳ 1024 cm-2) toward PG 0946+301. This is the largest column density estimated so far toward a BALQSO. The absorber must be at least partially ionized and may be responsible for attenuation in the optical and UV. If the Thomson optical depth toward BALQSOs is close to 1, as inferred here, then spectroscopy in hard X-rays with large telescopes like XMM would be feasible.

Profiles of 14C fixation through spinach leaves in relation to light absorption and photosynthetic capacity

Evans, John; Vogelmann, Thomas C
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
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365.82164%
The profile of photosynthetic rate with depth through a leaf depends on the profiles of light absorption and photosynthetic capacity. Using a combination of several techniques, a comprehensive description of spinach leaves has been obtained. Profiles of CO2 fixation were obtained by exposing leaves to 14CO2 for 10 s under blue or green light before freeze clamping and paradermal sectioning. Profiles of light absorption were measured on adjacent parts of the leaf by quantifying chlorophyll fluorescence images of the transversely cut face obtained when blue or green light was applied to the adaxial or abaxial surface. The profile of CO2 fixation was modelled using the measured profiles of light absorption and photosynthetic capacity. There was remarkably good agreement between the observed and modelled CO2 fixation profiles for the eight combinations of colour, orientation and irradiance tested. Gas exchange of an intact leaf was also measured concurrently with conventional chlorophyll fluorescence under blue or green light. These data were consistent with the multi-layer leaf model with the exception of blue light applied to the abaxial surface, where chlorophyll fluorescence appeared to come from layers deeper than expected. Photosynthetic capacity matched the profile of green but not white light absorption through the leaf.

Key cofactors of Photosystem II cores from four organisms identified by 1.7-K absorption, CD and MCD

Peterson Arskold, Sindra; Smith, Paul; Shen, Jian-Ren; Pace, Ronald; Krausz, Elmars
Fonte: Kluwer Academic Publishers Publicador: Kluwer Academic Publishers
Tipo: Artigo de Revista Científica
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Active Photosystem II (PS II) cores were prepared from spinach, pea, Synechocystis PCC 6803, and Thermosynechococcus vulcanus, the latter of which has been structurally determined [Kamiya and Shen (2003) Proc Natl Acad Sci USA 100: 98-103]. Electrochromic shifts resulting from QA reduction by 1.7-K illumination were recorded, and the Qx and Qy absorption bands of the redox-active pheophytin a thus identified in the different organisms. The Qx transition is ∼3 nm (100 cm-1) to higher energy in cyanobacteria than in the plants. The predominant Qy shift appears in the range 683-686 nm depending on species, and does not appear to have a systematic shift. Low-temperature absorption, circular dichroism (CD) and magnetic circular dichroism (MCD) spectra of the chlorophyll Qy region are very similar in spinach and pea, but vary in cyanobacteria. We assigned CP43 and CP47 trap-chlorophyll absorption features in all species, as well as a P680 transition. Each absorption identified has an area of one chlorophyll a. The MCD deficit, introduced previously for spinach as an indicator of P680 activity, occurs in the same spectral region and has the same area in all species, pointing to a robustness of this as a signature for P680. MCD and CD characteristics point towards a significant variance in P680 structure between cyanobacteria...

Oligomeric but not monomeric silica prevents aluminium absorption in humans

Jugdaohsingh, Ravin; Reeves, Raymond; Oldham, Claire; Day, J P; Fifield, L Keith; Thompson, Richard; Powell, Jonathan
Fonte: American Society of Clinical Nutrition Publicador: American Society of Clinical Nutrition
Tipo: Artigo de Revista Científica
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Background: Soluble silica, a ubiquitous component of the diet, may be the natural ligand for dietary aluminum and may prevent its accumulation and toxicity in animals. However, previous studies on the inhibition of aluminum absorption and toxicity by soluble silica have produced conflicting results. We recently identified a soluble silica polymer, oligomeric silica, that has a much higher affinity for aluminum than does monomeric silica and that may be involved in the sequestration of aluminum. Objective: By using26Al as a tracer, we investigated the effects of oligomeric and monomeric silica on the bioavailability of aluminum (study 1) and compared the availability of silicon from oligomeric and monomeric silica in the human gastrointestinal tract (study 2). Design: In study 1, three healthy volunteers each ingested aluminum alone (control), aluminum with oligomeric silica (17 mg), and aluminum with monomeric silica (17 mg). In study 2, five healthy volunteers ingested both the oligomeric and monomeric forms of silica (34 mg). Serum and urine samples were analyzed for aluminum and silicon. Results: Oligomeric silica reduced the availability of aluminum by 67% (P = 0.01) compared with the control, whereas monomeric silica had no effect (P = 0.40). Monomeric silica was readily taken up from the gastrointestinal tract and then excreted in urine (53%)...

Nonlinear Optical Absorption and Temporal Response of Arsenic-and Oxygen-Implantated GaAs

Lederer, Maximilian; Luther-Davies, Barry; Tan, Hoe Hark; Jagadish, Chennupati; Haiml, M; Siegner, U; Keller, U
Fonte: American Institute of Physics (AIP) Publicador: American Institute of Physics (AIP)
Tipo: Artigo de Revista Científica
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The nonlinear optical absorption of arsenic and oxygen implanted epitaxial GaAs for a range of ion doses and annealing temperatures were examined. Results showed that ion implantation decreases response time (τA) and parameter (Mmax), with the decrease i

The Role of Absorption in Intermediate Energy Elastic Electron Scattering from Krypton

Cho, H Y; McEachran, Robert; Tanaka, Hiroshi; Buckman, Stephen
Fonte: Institute of Physics Publishing Publicador: Institute of Physics Publishing
Tipo: Artigo de Revista Científica
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Recent measurements of the elastic differential cross section in the backward direction in electron krypton scattering just above the inelastic threshold of 4p55s J = 2 state at 9.915 eV illustrated the importance of including absorption effects in any theoretical calculation. Subsequently, there have been theoretical predictions of a substantial reduction in the backward direction of the elastic differential cross section in electron krypton scattering in the intermediate energy range up to 100 eV when absorption is included. In this paper we present the first measurement of the elastic differential cross section for krypton in the backward direction in this intermediate energy range; these measurements are generally in good agreement with the recent theoretical predictions.

Two-photon absorption and up-converted emission in blue-emitting stilbene dye

Jordan, Grace; Kobayashi, Takeyuki; Blau, Werner J; Tillmann, Hartwig; Pfeiffer, Steffen; Horhold, Hans-Heinrich; Samoc, Marek; Luther-Davies, Barry
Fonte: Old City Publishing Inc Publicador: Old City Publishing Inc
Tipo: Artigo de Revista Científica
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We have carried out investigations into the two-photon absorption properties of a novel blue emitting molecule; 1,4-bis(4-diphenylaminostyryl) benzene. The open aperture z-scan technique was employed to measure the two-photon absorption coefficient of this material in solution over a range of concentrations in chloroform at 800 nm. We measured the two-photon absorption cross-section to be 197 × 10-50 cm4 s photon -1. We have also demonstrated strong up-converted emission in solutions of the same molecule highlighting the potential of this material for applications such as up-conversion and two-photon fluorescence microscopy.

Infrared absorption spectra and structures of zwitterions of glycyl-L-alanine and its N -deuterated isotopomer in a KBr matrix

Jacob, Rebecca; Fischer, Gad
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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The IR absorption spectra of zwitterions of glycyl-L-alanine and its N-deuterated isotopomer isolated in a KBr matrix have been measured using a novel sampling technique involving dissolution, spray and deposition. In a parallel theoretical study the number of conformers, their IR absorption spectra and structures have been determined by ab initio molecular orbital calculations. The calculations were carried out at both the density functional theory and Hartree-Fock levels, and were of the non-aqueous self-consistent reaction field type, using the Onsager dipole-sphere model. Four conformers were identified. The trans conformer was found to have the lowest energy at all levels of theory and for the range of cavity radii studied. Its structure was found to be closely similar to that of glycyl-L-alanine in the crystal. Comparison of the predicted spectra of the four conformers with the measured spectra showed that both the trans and/or cis conformers could be present in the KBr matrix. Good agreement between measured and calculated spectra, both cis and trans, has been obtained for the majority of the prominent bands in the spectrum.

Broadband optical absorption in a two-dimensional electron gas in the presence of spin-orbit interaction and high magnetic fields

Yang, C.H.; Xu, Wen; Zhang, J.; Zeng, Z.; Zhang, Chao; Tang, C S
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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We examine the selection rules for electron-photon interaction in a two-dimensional electron gas (2DEG) in the presence of the Rashba spin-orbit interaction (RSOI) and quantizing magnetic fields. In such a case, new channels open up for electronic transition accompanied by the absorption of photons. As a result, two absorption peaks and a broadband absorption spectrum can be observed for high-mobility samples at relatively high magnetic fields. We find that electronic transitions between the neighboring Landau levels within the same spin orientation are the main channels for optical absorption in a spin-split 2DEG.

Adaptation of the Self-Absorption Scale to Brazilian adults; Adaptação da Escala de Autoabsorção para adultos brasileiros

da Silveira, Amanda da Costa; UFRGS; de Castro, Thiago Gomes; UFRGS; Gomes, William Barbosa; UFRGS
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; avaliado por pares; Formato: application/pdf
Publicado em 01/10/2011 POR
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Self-absorption is defined as an excessive perseveration of attention that one displays toward their own reflections. The Self-Absorption Scale (SAS) measures this negative deconstructive dimension of self-consciousness and distinguishes whether its focus is related to private or public aspects of oneself. The objective of this study was to adapt the SAS to Brazil and to gather evidences of factorial and convergent validity for the Scale. Seven hundred and twenty two Brazilian adults answered the translated version of SAS, the Self-Consciousness Scale (SCS), and the Rumination-Reflection Questionnaire (RRQ). Factor analysis revealed two main components (private and public self-absorption). The adapted SAS fulfilled expectations concerning factorial and convergent validity. It can be used in future research in Brazil. Keywords: self-consciousness; self-absorption; rumination; psychometrics; adaptation.; Autoabsorção é definida como perseveração excessiva da atenção que o indivíduo destina às suas reflexões internas. A Escala de Autoabsorção (EAA) propõe mensurar essa faceta negativa e desconstrutiva da autoconsciência humana e distinguir se seu foco está voltado para aspectos públicos ou privados. O objetivo desse estudo foi adaptar a EAA para o Brasil e reunir evidências de validade fatorial e convergente. Setecentos e vinte e dois brasileiros adultos responderam a versão traduzida da EAA...