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Sample records for adme absorption distribution

  1. Identification of Absorption, Distribution, Metabolism, and Excretion (ADME) Genes Relevant to Steatosis Using a Differential Gene Expression Approach

    EPA Science Inventory

    Absorption, distribution, metabolism, and excretion (ADME) parameters represent important connections between exposure to chemicals and the activation of molecular initiating events of Adverse Outcome Pathways (AOPs) in cellular, tissue, and organ level targets. ADME parameters u...

  2. Use of In Vitro Absorption, Distribution, Metabolism, and Excretion (ADME) Data in Bioaccumulation Assessments for Fish

    SciTech Connect

    Nichols, John W.; Erhardt, Susan; Dyer, Scott; James, Margaret O.; Moore, Margo; Plotzke, Kathleen; Segner, Helmut; Schultz, Irvin R.; Thomas, Karluss; Vasiluk, Luba; Weisbrod, Anne V.

    2007-11-01

    A scientific workshop was held in 2006 to discuss the use of in vitro Absorption, Distribution, Metabolism, and Excretion (ADME) data in chemical bioaccumulation assessments for fish. Computer-based (in silico) modeling tools are widely used to estimate chemical bioaccumulation. These in silico methods have inherent limitations that result in inaccurate estimates for many compounds. Based on a review of the science workshop participants concluded that two factors, absorption and metabolism, represent the greatest sources of uncertainty in current bioaccumulation models. Both factors can be investigated experimentally using in vitro test systems.

  3. Evaluation of in vitro absorption, distribution, metabolism, and excretion (ADME) properties of mitragynine, 7-hydroxymitragynine, and mitraphylline.

    PubMed

    Manda, Vamshi K; Avula, Bharathi; Ali, Zulfiqar; Khan, Ikhlas A; Walker, Larry A; Khan, Shabana I

    2014-05-01

    Mitragyna speciosa (kratom) is a popular herb in Southeast Asia, which is traditionally used to treat withdrawal symptoms associated with opiate addiction. Mitragynine, 7-hydroxymitragynine, and mitraphylline are reported to be the central nervous system active alkaloids which bind to the opiate receptors. Mitraphylline is also present in the bark of Uncaria tomentosa (cat's claw). Several therapeutic properties have been reported for these compounds but limited information is available on the absorption and distribution properties. This study focuses on evaluating the absorption, distribution, metabolism, and excretion (ADME) properties of these compounds and their effect on major efflux transporter P-glycoprotein, using in vitro methods. Quantitative analysis was performed by the Q-TOF LC-MS system. Mitragynine was unstable in simulated gastric fluid with 26 % degradation but stable in simulated intestinal fluid. 7-Hydroxymitragynine degraded up to 27 % in simulated gastric fluid, which could account for its conversion to mitragynine (23 %), while only 6 % degradation was seen in simulated intestinal fluid. Mitraphylline was stable in simulated gastric fluid but unstable in simulated intestinal fluid (13.6 % degradation). Mitragynine and 7-hydroxymitragynine showed moderate permeability across Caco-2 and MDR-MDCK monolayers with no significant efflux. However, mitraphylline was subjected to efflux mediated by P-glycoprotein in both Caco-2 and MDR-MDCK monolayers. Mitragynine was found to be metabolically stable in both human liver microsomes and S9 fractions. In contrast, both 7-hydroxymitragynine and mitraphylline were metabolized by human liver microsomes with half-lives of 24 and 50 min, respectively. All three compounds exhibited high plasma protein binding (> 90 %) determined by equilibrium dialysis. Mitragynine and 7-hydroxymitragynine inhibited P-glycoprotein with EC50 values of 18.2 ± 3.6 µM and 32.4 ± 1.9 µM, respectively

  4. Evaluation of in vitro absorption, distribution, metabolism, and excretion (ADME) properties of mitragynine, 7-hydroxymitragynine, and mitraphylline.

    PubMed

    Manda, Vamshi K; Avula, Bharathi; Ali, Zulfiqar; Khan, Ikhlas A; Walker, Larry A; Khan, Shabana I

    2014-05-01

    Mitragyna speciosa (kratom) is a popular herb in Southeast Asia, which is traditionally used to treat withdrawal symptoms associated with opiate addiction. Mitragynine, 7-hydroxymitragynine, and mitraphylline are reported to be the central nervous system active alkaloids which bind to the opiate receptors. Mitraphylline is also present in the bark of Uncaria tomentosa (cat's claw). Several therapeutic properties have been reported for these compounds but limited information is available on the absorption and distribution properties. This study focuses on evaluating the absorption, distribution, metabolism, and excretion (ADME) properties of these compounds and their effect on major efflux transporter P-glycoprotein, using in vitro methods. Quantitative analysis was performed by the Q-TOF LC-MS system. Mitragynine was unstable in simulated gastric fluid with 26 % degradation but stable in simulated intestinal fluid. 7-Hydroxymitragynine degraded up to 27 % in simulated gastric fluid, which could account for its conversion to mitragynine (23 %), while only 6 % degradation was seen in simulated intestinal fluid. Mitraphylline was stable in simulated gastric fluid but unstable in simulated intestinal fluid (13.6 % degradation). Mitragynine and 7-hydroxymitragynine showed moderate permeability across Caco-2 and MDR-MDCK monolayers with no significant efflux. However, mitraphylline was subjected to efflux mediated by P-glycoprotein in both Caco-2 and MDR-MDCK monolayers. Mitragynine was found to be metabolically stable in both human liver microsomes and S9 fractions. In contrast, both 7-hydroxymitragynine and mitraphylline were metabolized by human liver microsomes with half-lives of 24 and 50 min, respectively. All three compounds exhibited high plasma protein binding (> 90 %) determined by equilibrium dialysis. Mitragynine and 7-hydroxymitragynine inhibited P-glycoprotein with EC50 values of 18.2 ± 3.6 µM and 32.4 ± 1.9 µM, respectively

  5. THE ACQUISITION AND APPLICATION OF ABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION (ADME) DATA IN AGRICULTURAL CHEMICAL SAFETY ASSESSMENTS

    EPA Science Inventory

    A multi-sector international group of government, academic, and industry scientists has developed a proposal for an improved testing scheme for assessing the safety of crop protection chemicals. Incorporation of pharmacokinetic studies describing the absorption, distribution, me...

  6. Predicting laser-induced bulk damage and conditioning for deuterated potassium di-hydrogen phosphate crystals using ADM (absorption distribution model)

    SciTech Connect

    Liao, Z M; Spaeth, M L; Manes, K; Adams, J J; Carr, C W

    2010-02-26

    We present an empirical model that describes the experimentally observed laser-induced bulk damage and conditioning behavior in deuterated Potassium dihydrogen Phosphate (DKDP) crystals in a self-consistent way. The model expands on an existing nanoabsorber precursor model and the multi-step absorption mechanism to include two populations of absorbing defects, one with linear absorption and another with nonlinear absorption. We show that this model connects previously uncorrelated small-beam damage initiation probability data to large-beam damage density measurements over a range of ns pulse widths relevant to ICF lasers such as the National Ignition Facility (NIF). In addition, this work predicts the damage behavior of laser-conditioned DKDP and explains the upper limit to the laser conditioning effect. The ADM model has been successfully used during the commissioning and early operation of the NIF.

  7. Absorption, Distribution, Metabolism and Excretion (ADME) Study with 2,2',4,4',5,6' Hexabromodiphenyl Ether(BDE 154)in Male Sprague-Dawley Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polybrominated diphenyl ethers(PBDEs)are among the most abundant brominated flame retardants in use in many consumer products. A particular subset of five PBDEs are known to be environmentally persistent, i.e. BDE-47, -99, -100, 153, and -154. Mammalian ADME studies have already been performed for...

  8. Key factors influencing ADME properties of therapeutic proteins: A need for ADME characterization in drug discovery and development

    PubMed Central

    Tibbitts, Jay; Canter, David; Graff, Ryan; Smith, Alison; Khawli, Leslie A.

    2016-01-01

    abstract Protein therapeutics represent a diverse array of biologics including antibodies, fusion proteins, and therapeutic replacement enzymes. Since their inception, they have revolutionized the treatment of a wide range of diseases including respiratory, vascular, autoimmune, inflammatory, infectious, and neurodegenerative diseases, as well as cancer. While in vivo pharmacokinetic, pharmacodynamic, and efficacy studies are routinely carried out for protein therapeutics, studies that identify key factors governing their absorption, distribution, metabolism, and excretion (ADME) properties have not been fully investigated. Thorough characterization and in-depth study of their ADME properties are critical in order to support drug discovery and development processes for the production of safer and more effective biotherapeutics. In this review, we discuss the main factors affecting the ADME characteristics of these large macromolecular therapies. We also give an overview of the current tools, technologies, and approaches available to investigate key factors that influence the ADME of recombinant biotherapeutic drugs, and demonstrate how ADME studies will facilitate their future development. PMID:26636901

  9. ADME-Tox profiles of some food additives and pesticides

    NASA Astrophysics Data System (ADS)

    Craciun, Dana; Modra, Dorina; Isvoran, Adriana

    2015-12-01

    Within this study we compute the Absorption, Distribution, Metabolism, Excretion and Toxicity (ADME-Tox) profiles of several commonly used food additives and some pesticides. As expected, all the food additives considered in this study provided to be safe, their ADME-Tox profiles indicating that they have a good oral bioavailability and they do not produce phosphoslipidosis. The ADME-Tox profiles of the pesticides indicate that, with a few exceptions, they are highly toxic (some of them being not approved in the EU, but still used in other countries) and may cause many diseases. Our results are in good agreement with published data concerning the considered food additives and pesticides revealing that the ADME-Tox profiling method may be successfully used to test other chemicals than drug candidates.

  10. Current Approaches for Absorption, Distribution, Metabolism, and Excretion Characterization of Antibody-Drug Conjugates: An Industry White Paper.

    PubMed

    Kraynov, Eugenia; Kamath, Amrita V; Walles, Markus; Tarcsa, Edit; Deslandes, Antoine; Iyer, Ramaswamy A; Datta-Mannan, Amita; Sriraman, Priya; Bairlein, Michaela; Yang, Johnny J; Barfield, Matthew; Xiao, Guangqing; Escandon, Enrique; Wang, Weirong; Rock, Dan A; Chemuturi, Nagendra V; Moore, David J

    2016-05-01

    An antibody-drug conjugate (ADC) is a unique therapeutic modality composed of a highly potent drug molecule conjugated to a monoclonal antibody. As the number of ADCs in various stages of nonclinical and clinical development has been increasing, pharmaceutical companies have been exploring diverse approaches to understanding the disposition of ADCs. To identify the key absorption, distribution, metabolism, and excretion (ADME) issues worth examining when developing an ADC and to find optimal scientifically based approaches to evaluate ADC ADME, the International Consortium for Innovation and Quality in Pharmaceutical Development launched an ADC ADME working group in early 2014. This white paper contains observations from the working group and provides an initial framework on issues and approaches to consider when evaluating the ADME of ADCs.

  11. In silico ADME/Tox: the state of the art.

    PubMed

    Ekins, Sean; Rose, John

    2002-01-01

    The field of computational (in silico) ADME/Tox (absorption, distribution, metabolism, excretion, and toxicity) is receiving increased attention due a better appreciation that these molecular properties should be considered earlier in the drug discovery process. This report briefly reviews selected papers presented at the 220th National Meeting of the American Chemical Society, Washington, DC, 20-24 August, 2000, and describes the types of ADME/Tox computational models presented, the results obtained, and relevant recent publications that coincide with the work reported.

  12. In Silico Approaches for Predicting Adme Properties

    NASA Astrophysics Data System (ADS)

    Madden, Judith C.

    A drug requires a suitable pharmacokinetic profile to be efficacious in vivo in humans. The relevant pharmacokinetic properties include the absorption, distribution, metabolism, and excretion (ADME) profile of the drug. This chapter provides an overview of the definition and meaning of key ADME properties, recent models developed to predict these properties, and a guide as to how to select the most appropriate model(s) for a given query. Many tools using the state-of-the-art in silico methodology are now available to users, and it is anticipated that the continual evolution of these tools will provide greater ability to predict ADME properties in the future. However, caution must be exercised in applying these tools as data are generally available only for "successful" drugs, i.e., those that reach the marketplace, and little supplementary information, such as that for drugs that have a poor pharmacokinetic profile, is available. The possibilities of using these methods and possible integration into toxicity prediction are explored.

  13. The Affymetrix DMET Plus Platform Reveals Unique Distribution of ADME-Related Variants in Ethnic Arabs

    PubMed Central

    Wakil, Salma M.; Nguyen, Cao; Muiya, Nzioka P.; Andres, Editha; Lykowska-Tarnowska, Agnieszka; Baz, Batoul; Meyer, Brian F.; Morahan, Grant

    2015-01-01

    Background. The Affymetrix Drug Metabolizing Enzymes and Transporters (DMET) Plus Premier Pack has been designed to genotype 1936 gene variants thought to be essential for screening patients in personalized drug therapy. These variants include the cytochrome P450s (CYP450s), the key metabolizing enzymes, many other enzymes involved in phase I and phase II pharmacokinetic reactions, and signaling mediators associated with variability in clinical response to numerous drugs not only among individuals, but also between ethnic populations. Materials and Methods. We genotyped 600 Saudi individuals for 1936 variants on the DMET platform to evaluate their clinical potential in personalized medicine in ethnic Arabs. Results. Approximately 49% each of the 437 CYP450 variants, 56% of the 581 transporters, 56% of 419 transferases, 48% of the 104 dehydrogenases, and 58% of the remaining 390 variants were detected. Several variants, such as rs3740071, rs6193, rs258751, rs6199, rs11568421, and rs8187797, exhibited significantly either higher or lower minor allele frequencies (MAFs) than those in other ethnic groups. Discussion. The present study revealed some unique distribution trends for several variants in Arabs, which displayed partly inverse allelic prevalence compared to other ethnic populations. The results point therefore to the need to verify and ascertain the prevalence of a variant as a prerequisite for engaging it in clinical routine screening in personalized medicine in any given population. PMID:25802476

  14. The absorption, distribution, metabolism and excretion of procyanidins.

    PubMed

    Zhang, Liang; Wang, Yijun; Li, Daxiang; Ho, Chi-Tang; Li, Junsong; Wan, Xiaochun

    2016-03-01

    Procyanidins (PAs) are polyphenols in plant food that have many health benefits, including cancer prevention, cardiovascular protection and diabetes prevention. PAs have been known to have low oral bioavailability. In this review, we summarize the published results on the ADME (absorption, distribution, metabolism and excretion) of PAs in vivo and in vitro. After oral administration, in the stomach the decomposition of PAs is highly dependent on the pH value of gastric juice, which is also affected by food intake. In the small intestine, PA polymers and oligomers with DP > 4 are not directly absorbed in vivo, but minor PA monomers and dimers could be detected in the plasma. Methylated and glucuronidated PA dimers and monomers are the main metabolites of PAs in plasma. In the colon, PAs are catabolized by colonic microflora into a series of low molecular weight phenolic acids, such as phenyl valerolactone, phenylacetic acids and phenylpropionic acids. We reviewed the degradation of PAs in gastric digestion, the absorption of PAs in the small intestine and the metabolic pathway of PAs by colonic microflora. To clearly explain the in vivo pharmacokinetics of PAs, a systematic comparative analysis on previously published data on PAs was conducted. PMID:26814915

  15. The absorption, distribution, metabolism and excretion of procyanidins.

    PubMed

    Zhang, Liang; Wang, Yijun; Li, Daxiang; Ho, Chi-Tang; Li, Junsong; Wan, Xiaochun

    2016-03-01

    Procyanidins (PAs) are polyphenols in plant food that have many health benefits, including cancer prevention, cardiovascular protection and diabetes prevention. PAs have been known to have low oral bioavailability. In this review, we summarize the published results on the ADME (absorption, distribution, metabolism and excretion) of PAs in vivo and in vitro. After oral administration, in the stomach the decomposition of PAs is highly dependent on the pH value of gastric juice, which is also affected by food intake. In the small intestine, PA polymers and oligomers with DP > 4 are not directly absorbed in vivo, but minor PA monomers and dimers could be detected in the plasma. Methylated and glucuronidated PA dimers and monomers are the main metabolites of PAs in plasma. In the colon, PAs are catabolized by colonic microflora into a series of low molecular weight phenolic acids, such as phenyl valerolactone, phenylacetic acids and phenylpropionic acids. We reviewed the degradation of PAs in gastric digestion, the absorption of PAs in the small intestine and the metabolic pathway of PAs by colonic microflora. To clearly explain the in vivo pharmacokinetics of PAs, a systematic comparative analysis on previously published data on PAs was conducted.

  16. The effects of microRNA on the absorption, distribution, metabolism and excretion of drugs

    PubMed Central

    He, Y; Chevillet, J R; Liu, G; Kim, T K; Wang, K

    2015-01-01

    The importance of genetic factors (e.g. sequence variation) in the absorption, distribution, metabolism, excretion (ADME) and overall efficacy of therapeutic agents is well established. Our ability to identify, interpret and utilize these factors is the subject of much clinical investigation and therapeutic development. However, drug ADME and efficacy are also heavily influenced by epigenetic factors such as DNA/histone methylation and non-coding RNAs [especially microRNAs (miRNAs)]. Results from studies using tools, such as in silico miRNA target prediction, in vitro functional assays, nucleic acid profiling/sequencing and high-throughput proteomics, are rapidly expanding our knowledge of these factors and their effects on drug metabolism. Although these studies reveal a complex regulation of drug ADME, an increased understanding of the molecular interplay between the genome, epigenome and transcriptome has the potential to provide practically useful strategies to facilitate drug development, optimize therapeutic efficacy, circumvent adverse effects, yield novel diagnostics and ultimately become an integral component of personalized medicine. PMID:25296724

  17. Distributed Bragg Reflectors With Reduced Optical Absorption

    DOEpatents

    Klem, John F.

    2005-08-16

    A new class of distributed Bragg reflectors has been developed. These distributed Bragg reflectors comprise interlayers positioned between sets of high-index and low-index quarter-wave plates. The presence of these interlayers is to reduce photon absorption resulting from spatially indirect photon-assisted electronic transitions between the high-index and low-index quarter wave plates. The distributed Bragg reflectors have applications for use in vertical-cavity surface-emitting lasers for use at 1.55 .mu.m and at other wavelengths of interest.

  18. Pharmacokinetic properties and in silico ADME modeling in drug discovery.

    PubMed

    Honório, Kathia M; Moda, Tiago L; Andricopulo, Adriano D

    2013-03-01

    The discovery and development of a new drug are time-consuming, difficult and expensive. This complex process has evolved from classical methods into an integration of modern technologies and innovative strategies addressed to the design of new chemical entities to treat a variety of diseases. The development of new drug candidates is often limited by initial compounds lacking reasonable chemical and biological properties for further lead optimization. Huge libraries of compounds are frequently selected for biological screening using a variety of techniques and standard models to assess potency, affinity and selectivity. In this context, it is very important to study the pharmacokinetic profile of the compounds under investigation. Recent advances have been made in the collection of data and the development of models to assess and predict pharmacokinetic properties (ADME--absorption, distribution, metabolism and excretion) of bioactive compounds in the early stages of drug discovery projects. This paper provides a brief perspective on the evolution of in silico ADME tools, addressing challenges, limitations, and opportunities in medicinal chemistry.

  19. ABSORPTION MEASURE DISTRIBUTION IN Mrk 509

    SciTech Connect

    Adhikari, T. P.; Różańska, A.; Sobolewska, M.; Czerny, B.

    2015-12-20

    In this paper we model the observed absorption measure distribution (AMD) in Mrk 509, which spans three orders of magnitude in ionization level with a single-zone absorber in pressure equilibrium. AMD is usually constructed from observations of narrow absorption lines in radio-quiet active galaxies with warm absorbers. We study the properties of the warm absorber in Mrk 509 using recently published broadband spectral energy distribution observed with different instruments. This spectrum is an input in radiative transfer computations with full photoionization treatment using the titan code. We show that the simplest way to fully reproduce the shape of AMD is to assume that the warm absorber is a single zone under constant total pressure. With this assumption, we found theoretical AMD that matches the observed AMD determined on the basis of the 600 ks reflection grating spectrometer XMM-Newton spectrum of Mrk 509. The softness of the source spectrum and the important role of the free–free emission breaks the usual degeneracy in the ionization state calculations, and the explicit dependence of the depths of AMD dips on density open a new path to the density diagnostic for the warm absorber. In Mrk 509, the implied density is of the order of 10{sup 8} cm{sup −3}.

  20. Evaluation of in vitro absorption, distribution, metabolism, and excretion (ADME) properties of mitragynine, 7-hydroxymitragynine, and mitraphylline

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mitragyna speciosa (Kratom) is a popular herb in Southeast Asia which is traditionally used to treat withdrawal symptoms associated with opiate addiction. Mitragynine, 7-hydroxymitragynine and mitraphylline are reported to be the central nervous system (CNS) active alkaloids which bind to the opiat...

  1. The Acquisition and Application of Absorption, Distribution, Metabolism, and Excretion (ADME) Data in Agricultural Chemical Safety Assessments

    SciTech Connect

    Barton, H. A.; Pastoor, Timothy P.; Baetcke, Karl; Chambers, Janice E.; Diliberto, Janet; Doerrer, Nancy G.; Driver, Jeffrey H.; Hastings, Charles E.; Iyengar, Seshadri; Krieger, Robert; Stahl, Bernhard; Timchalk, Chuck

    2006-01-01

    The ILSI Health and Environmental Sciences Institute (HESI) formed the Agricultural Chemical Safety Assessment (ACSA) Technical Committee in the year 2000 to design a toxicity testing scheme that would incorporate current understanding of pesticide toxicology and exposure and recognize the specificity of agricultural products. The purpose of and background for the ACSA project are described in detail in the companion paper by Carmichael et al. (2006). As the proposed tiered testing approach for agricultural chemical safety assessment evolved, the ACSA Technical Committee and its task forces (Carmichael et al., 2006; Cooper et al., 2006; Doe et al., 2006) worked toward the following objectives: (1) Provide information that can be applied to a range of relevant human exposure situations. (2) Characterize effects that have the potential to damage human health at exposure levels approximating those that might be encountered in the use of these compounds. (3) Avoid high doses that cause unnecessary public concern (e.g., safety assessments should focus on doses that are relevant to realistic human exposures while maintaining adequate power for the experimental studies to detect toxicity). (4) Use the minimum number of animals necessary to produce a thorough safety assessment of the chemicals of interest. (5) Inflict the minimum amount of distress on animals. (6) Minimize excessive and unnecessary use of resources by regulatory authorities and industry, which could be used to address other issues of concern. (7) Increase both the efficiency and relevance of the current safety assessment process.

  2. Identification of Absorption, Distribution, Metabolism, and Excretion (ADME) Genes Relevant to Steatosis Using a Systems Biology Approach

    EPA Science Inventory

    Ensuring chemical safety and sustainability form a main priority of the U.S. Environmental Protection Agency. This entails efforts on multiple fronts to characterize the potential hazard posed by chemicals currently in use and those to be commercialized in the future. The use of ...

  3. The use of machine learning and nonlinear statistical tools for ADME prediction.

    PubMed

    Sakiyama, Yojiro

    2009-02-01

    Absorption, distribution, metabolism and excretion (ADME)-related failure of drug candidates is a major issue for the pharmaceutical industry today. Prediction of ADME by in silico tools has now become an inevitable paradigm to reduce cost and enhance efficiency in pharmaceutical research. Recently, machine learning as well as nonlinear statistical tools has been widely applied to predict routine ADME end points. To achieve accurate and reliable predictions, it would be a prerequisite to understand the concepts, mechanisms and limitations of these tools. Here, we have devised a small synthetic nonlinear data set to help understand the mechanism of machine learning by 2D-visualisation. We applied six new machine learning methods to four different data sets. The methods include Naive Bayes classifier, classification and regression tree, random forest, Gaussian process, support vector machine and k nearest neighbour. The results demonstrated that ensemble learning and kernel machine displayed greater accuracy of prediction than classical methods irrespective of the data set size. The importance of interaction with the engineering field is also addressed. The results described here provide insights into the mechanism of machine learning, which will enable appropriate usage in the future.

  4. The use of machine learning and nonlinear statistical tools for ADME prediction.

    PubMed

    Sakiyama, Yojiro

    2009-02-01

    Absorption, distribution, metabolism and excretion (ADME)-related failure of drug candidates is a major issue for the pharmaceutical industry today. Prediction of ADME by in silico tools has now become an inevitable paradigm to reduce cost and enhance efficiency in pharmaceutical research. Recently, machine learning as well as nonlinear statistical tools has been widely applied to predict routine ADME end points. To achieve accurate and reliable predictions, it would be a prerequisite to understand the concepts, mechanisms and limitations of these tools. Here, we have devised a small synthetic nonlinear data set to help understand the mechanism of machine learning by 2D-visualisation. We applied six new machine learning methods to four different data sets. The methods include Naive Bayes classifier, classification and regression tree, random forest, Gaussian process, support vector machine and k nearest neighbour. The results demonstrated that ensemble learning and kernel machine displayed greater accuracy of prediction than classical methods irrespective of the data set size. The importance of interaction with the engineering field is also addressed. The results described here provide insights into the mechanism of machine learning, which will enable appropriate usage in the future. PMID:19239395

  5. Towards a new age of virtual ADME/TOX and multidimensional drug discovery.

    PubMed

    Ekins, Sean; Boulanger, Bruno; Swaan, Peter W; Hupcey, Maggie A Z

    2002-01-01

    With the continual pressure to ensure follow-up molecules to billion dollar blockbuster drugs, there is a hurdle in profitability and growth for pharmaceutical companies in the next decades. With each success and failure we increasingly appreciate that a key to the success of synthesized molecules through the research and development process is the possession of drug-like properties. These properties include an adequate bioactivity as well as adequate solubility, an ability to cross critical membranes (intestinal and sometimes blood-brain barrier), reasonable metabolic stability and of course safety in humans. Dependent on the therapeutic area being investigated it might also be desirable to avoid certain enzymes or transporters to circumvent potential drug-drug interactions. It may also be important to limit the induction of these same proteins that can result in further toxicities. We have clearly moved the assessment of in vitro absorption, distribution, metabolism, excretion and toxicity (ADME/TOX) parameters much earlier in the discovery organization than a decade ago with the inclusion of higher throughput systems. We are also now faced with huge amounts of ADME/TOX data for each molecule that need interpretation and also provide a valuable resource for generating predictive computational models for future drug discovery. The present review aims to show what tools exist today for visualizing and modeling ADME/TOX data, what tools need to be developed, and how both the present and future tools are valuable for virtual filtering using ADME/TOX and bioactivity properties in parallel as a viable addition to present practices.

  6. Terahertz absorption spectra and potential energy distribution of liquid crystals.

    PubMed

    Chen, Zezhang; Jiang, Yurong; Jiang, Lulu; Ma, Heng

    2016-01-15

    In this work, the terahertz (THz) absorption spectra of a set of nematic liquid crystals were studied using the density functional theories (DFT). An accurate assignment of the vibrational modes corresponding to absorption frequencies were performed using potential energy distribution (PED) in a frequency range of 0-3 THz. The impacts of different core structures on THz absorption spectra were discussed. The results indicate that scope of application must be considered in the LC-based THz device designing. This proposed work may give a useful suggestion on the design of novel liquid crystal material in THz wave. PMID:26476072

  7. Open Source Bayesian Models. 1. Application to ADME/Tox and Drug Discovery Datasets

    PubMed Central

    2015-01-01

    On the order of hundreds of absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) models have been described in the literature in the past decade which are more often than not inaccessible to anyone but their authors. Public accessibility is also an issue with computational models for bioactivity, and the ability to share such models still remains a major challenge limiting drug discovery. We describe the creation of a reference implementation of a Bayesian model-building software module, which we have released as an open source component that is now included in the Chemistry Development Kit (CDK) project, as well as implemented in the CDD Vault and in several mobile apps. We use this implementation to build an array of Bayesian models for ADME/Tox, in vitro and in vivo bioactivity, and other physicochemical properties. We show that these models possess cross-validation receiver operator curve values comparable to those generated previously in prior publications using alternative tools. We have now described how the implementation of Bayesian models with FCFP6 descriptors generated in the CDD Vault enables the rapid production of robust machine learning models from public data or the user’s own datasets. The current study sets the stage for generating models in proprietary software (such as CDD) and exporting these models in a format that could be run in open source software using CDK components. This work also demonstrates that we can enable biocomputation across distributed private or public datasets to enhance drug discovery. PMID:25994950

  8. Open Source Bayesian Models. 1. Application to ADME/Tox and Drug Discovery Datasets.

    PubMed

    Clark, Alex M; Dole, Krishna; Coulon-Spektor, Anna; McNutt, Andrew; Grass, George; Freundlich, Joel S; Reynolds, Robert C; Ekins, Sean

    2015-06-22

    On the order of hundreds of absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) models have been described in the literature in the past decade which are more often than not inaccessible to anyone but their authors. Public accessibility is also an issue with computational models for bioactivity, and the ability to share such models still remains a major challenge limiting drug discovery. We describe the creation of a reference implementation of a Bayesian model-building software module, which we have released as an open source component that is now included in the Chemistry Development Kit (CDK) project, as well as implemented in the CDD Vault and in several mobile apps. We use this implementation to build an array of Bayesian models for ADME/Tox, in vitro and in vivo bioactivity, and other physicochemical properties. We show that these models possess cross-validation receiver operator curve values comparable to those generated previously in prior publications using alternative tools. We have now described how the implementation of Bayesian models with FCFP6 descriptors generated in the CDD Vault enables the rapid production of robust machine learning models from public data or the user's own datasets. The current study sets the stage for generating models in proprietary software (such as CDD) and exporting these models in a format that could be run in open source software using CDK components. This work also demonstrates that we can enable biocomputation across distributed private or public datasets to enhance drug discovery.

  9. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods.

    PubMed

    Han, Seung Yon; You, Byoung Hoon; Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice.

  10. Pharmacokinetics, absorption and tissue distribution of tanshinone IIA solid dispersion.

    PubMed

    Hao, Haiping; Wang, Guangji; Cui, Nan; Li, Jing; Xie, Lin; Ding, Zuoqi

    2006-11-01

    This study was designed to elucidate the pharmacokinetics, absorption, tissue distribution and plasma protein binding properties of tanshinone IIA, a highly lipophilic compound isolated from Salvia miltiorrhiza. Tanshinone IIA was isolated using a previously well developed LC-MS/MS method. Its pharmacokinetic characteristics, absolute bioavailability, tissue distribution and plasma protein binding properties were determined. The membrane permeability was evaluated using Caco-2 cells in monolayer. The pharmacokinetic plasma profile of tanshinone IIA after a single intravenous dosing exhibited a triexponential pattern consisting of rapid distribution (t1/2 alpha, 0.024 h), slow redistribution (t1/2 beta, 0.34 h) and terminal elimination phase (t1/2 gamma, 7.5 h). Tanshinone IIA preferentially distributed into the reticuloendothelial system, especially into liver and lung, after either intravenous or oral doses. Tanshinone IIA (99.2 %) bound highly to plasma proteins, among which lipoprotein played an important role (77.5 %). Tanshinone IIA absorption was extremely poor with an absolute bioavailability below 3.5 %. Absorptive saturation was deduced from the fact that the AUC and Cmax increased less proportionally to dose and Tmax was significantly prolonged. The poor absorption of tanshinone IIA may be caused by its low aqueous solubility and limited membrane permeability. There were no significant differences of the apparent permeability coefficient for all tested concentrations and for the apical to basolateral and reverse direction transport, suggesting a passive transport mode and no involvement of an efflux protein. In conclusion, tanshinone IIA has a suitable pharmacokinetic behavior except for its poor absorption. A pharmaceutical strategy for promoting its absorption should be designed to develop tanshinone IIA as a new drug candidate. PMID:17024606

  11. Exploring different strategies for imbalanced ADME data problem: case study on Caco-2 permeability modeling.

    PubMed

    Pham-The, Hai; Casañola-Martin, Gerardo; Garrigues, Teresa; Bermejo, Marival; González-Álvarez, Isabel; Nguyen-Hai, Nam; Cabrera-Pérez, Miguel Ángel; Le-Thi-Thu, Huong

    2016-02-01

    In many absorption, distribution, metabolism, and excretion (ADME) modeling problems, imbalanced data could negatively affect classification performance of machine learning algorithms. Solutions for handling imbalanced dataset have been proposed, but their application for ADME modeling tasks is underexplored. In this paper, various strategies including cost-sensitive learning and resampling methods were studied to tackle the moderate imbalance problem of a large Caco-2 cell permeability database. Simple physicochemical molecular descriptors were utilized for data modeling. Support vector machine classifiers were constructed and compared using multiple comparison tests. Results showed that the models developed on the basis of resampling strategies displayed better performance than the cost-sensitive classification models, especially in the case of oversampling data where misclassification rates for minority class have values of 0.11 and 0.14 for training and test set, respectively. A consensus model with enhanced applicability domain was subsequently constructed and showed improved performance. This model was used to predict a set of randomly selected high-permeability reference drugs according to the biopharmaceutics classification system. Overall, this study provides a comparison of numerous rebalancing strategies and displays the effectiveness of oversampling methods to deal with imbalanced permeability data problems. PMID:26643659

  12. Exploring different strategies for imbalanced ADME data problem: case study on Caco-2 permeability modeling.

    PubMed

    Pham-The, Hai; Casañola-Martin, Gerardo; Garrigues, Teresa; Bermejo, Marival; González-Álvarez, Isabel; Nguyen-Hai, Nam; Cabrera-Pérez, Miguel Ángel; Le-Thi-Thu, Huong

    2016-02-01

    In many absorption, distribution, metabolism, and excretion (ADME) modeling problems, imbalanced data could negatively affect classification performance of machine learning algorithms. Solutions for handling imbalanced dataset have been proposed, but their application for ADME modeling tasks is underexplored. In this paper, various strategies including cost-sensitive learning and resampling methods were studied to tackle the moderate imbalance problem of a large Caco-2 cell permeability database. Simple physicochemical molecular descriptors were utilized for data modeling. Support vector machine classifiers were constructed and compared using multiple comparison tests. Results showed that the models developed on the basis of resampling strategies displayed better performance than the cost-sensitive classification models, especially in the case of oversampling data where misclassification rates for minority class have values of 0.11 and 0.14 for training and test set, respectively. A consensus model with enhanced applicability domain was subsequently constructed and showed improved performance. This model was used to predict a set of randomly selected high-permeability reference drugs according to the biopharmaceutics classification system. Overall, this study provides a comparison of numerous rebalancing strategies and displays the effectiveness of oversampling methods to deal with imbalanced permeability data problems.

  13. RP-HPTLC Retention Data in Correlation with the In-silico ADME Properties of a Series of s-triazine Derivatives

    PubMed Central

    Jevrić, Lidija R; Podunavac-Kuzmanović, Sanja O; Švarc-Gajić, Jaroslava V; Kovačević, Strahinja Z; Jovanović, Bratislav Ž

    2014-01-01

    The properties relevant to pharmacokinetics and pharmacodynamics of four series of synthesized s-triazine derivatives have been studied by Quantitative structure-retention relationship (QSRR) approach. The chromatographic behavior of these compounds was investigated by using reversed-phase high performance thin-layer chromatography (RP-HPTLC). Chromatographic retention (RM0) was correlated with selected physicochemical parameters relevant to pharmacokinetics, i.e. ADME (absorption, distribution, metabolism and excretion). In addition, the ability to act as kinase inhibitors and protease inhibitors was predicted for all investigated triazine classes. Also, in order to confirm similarities/dissimilarities between series of examined compounds, principal component analysis (PCA) based on calculated ADME properties was conducted. The RM0 values of the s-triazine derivatives have been recommended for description and evaluation of pharmacokinetic properties. According to results of this study, the synthesized s-triazine derivatives meet pharmacokinetic criteria of preselection for drug candidates. PMID:25587308

  14. Physiologically based pharmacokinetics joined with in vitro-in vivo extrapolation of ADME: a marriage under the arch of systems pharmacology.

    PubMed

    Rostami-Hodjegan, A

    2012-07-01

    Classic pharmacokinetics (PK) rarely takes into account the full knowledge of physiology and biology of the human body. However, physiologically based PK (PBPK) is built mainly from drug-independent "system" information. PBPK is not a new concept, but it has shown a very rapid rise in recent years. This has been attributed to a greater connectivity to in vitro-in vivo extrapolation (IVIVE) techniques for predicting drug absorption, distribution, metabolism, and excretion (ADME) and their variability in humans. The marriage between PBPK and IVIVE under the overarching umbrella of "systems biology" has removed many constraints related to cutoff approaches on prediction of ADME. PBPK-IVIVE linked models have repeatedly shown their value in guiding decisions when predicting the effects of intrinsic and extrinsic factors on PK of drugs. A review of the achievements and shortcomings of the models might suggest better strategies in extending the success of PBPK-IVIVE to pharmacodynamics (PD) and drug safety.

  15. The distribution of absorptive power dissipation in irradiated nanoparticulate system

    NASA Astrophysics Data System (ADS)

    Li, Jiayu; Yang, Jian; Gu, Xiaobing

    2016-10-01

    The knowledge of local radiant absorption is important to the nanostructure optimization, it is beneficial to the applications in energy harvesting, optical heating, photocatalysis, etc. In this paper, FDTD model is constructed for the distribution of absorptive power dissipation in irradiated nanoparticulate system. The theoretical model extended from Mie theory is used to examine the FDTD model, the parameters and conditions set for FDTD simulation are confirmed based on the comparison. Then, the influence of Ag nanoparticle on the absorptive properties of nearby TiO2 nanoparticle is investigated by FDTD simulation at the wavelength of 0.25 μm. It is indicated that suitable distance between TiO2 and Ag particles is beneficial to the spectral radiant absorption of TiO2 particle. Considering the agglomeration of nanoparticles and the oxidation at the TiO2-Ag interface, the Ag core coated with Al2O3 shell is suggested, and the simulated results indicated that the shell thickness and the Ag core size need to be optimized for enhancing the radiant absorption of TiO2 particle.

  16. Sound propagation and absorption in foam - A distributed parameter model.

    NASA Technical Reports Server (NTRS)

    Manson, L.; Lieberman, S.

    1971-01-01

    Liquid-base foams are highly effective sound absorbers. A better understanding of the mechanisms of sound absorption in foams was sought by exploration of a mathematical model of bubble pulsation and coupling and the development of a distributed-parameter mechanical analog. A solution by electric-circuit analogy was thus obtained and transmission-line theory was used to relate the physical properties of the foams to the characteristic impedance and propagation constants of the analog transmission line. Comparison of measured physical properties of the foam with values obtained from measured acoustic impedance and propagation constants and the transmission-line theory showed good agreement. We may therefore conclude that the sound propagation and absorption mechanisms in foam are accurately described by the resonant response of individual bubbles coupled to neighboring bubbles.

  17. Measurements of parallel electron velocity distributions using whistler wave absorption.

    PubMed

    Thuecks, D J; Skiff, F; Kletzing, C A

    2012-08-01

    We describe a diagnostic to measure the parallel electron velocity distribution in a magnetized plasma that is overdense (ω(pe) > ω(ce)). This technique utilizes resonant absorption of whistler waves by electrons with velocities parallel to a background magnetic field. The whistler waves were launched and received by a pair of dipole antennas immersed in a cylindrical discharge plasma at two positions along an axial background magnetic field. The whistler wave frequency was swept from somewhat below and up to the electron cyclotron frequency ω(ce). As the frequency was swept, the wave was resonantly absorbed by the part of the electron phase space density which was Doppler shifted into resonance according to the relation ω - k([parallel])v([parallel]) = ω(ce). The measured absorption is directly related to the reduced parallel electron distribution function integrated along the wave trajectory. The background theory and initial results from this diagnostic are presented here. Though this diagnostic is best suited to detect tail populations of the parallel electron distribution function, these first results show that this diagnostic is also rather successful in measuring the bulk plasma density and temperature both during the plasma discharge and into the afterglow.

  18. Measurements of parallel electron velocity distributions using whistler wave absorption

    SciTech Connect

    Thuecks, D. J.; Skiff, F.; Kletzing, C. A.

    2012-08-15

    We describe a diagnostic to measure the parallel electron velocity distribution in a magnetized plasma that is overdense ({omega}{sub pe} > {omega}{sub ce}). This technique utilizes resonant absorption of whistler waves by electrons with velocities parallel to a background magnetic field. The whistler waves were launched and received by a pair of dipole antennas immersed in a cylindrical discharge plasma at two positions along an axial background magnetic field. The whistler wave frequency was swept from somewhat below and up to the electron cyclotron frequency {omega}{sub ce}. As the frequency was swept, the wave was resonantly absorbed by the part of the electron phase space density which was Doppler shifted into resonance according to the relation {omega}-k{sub ||v||} = {omega}{sub ce}. The measured absorption is directly related to the reduced parallel electron distribution function integrated along the wave trajectory. The background theory and initial results from this diagnostic are presented here. Though this diagnostic is best suited to detect tail populations of the parallel electron distribution function, these first results show that this diagnostic is also rather successful in measuring the bulk plasma density and temperature both during the plasma discharge and into the afterglow.

  19. Advanced Distribution Management System

    NASA Astrophysics Data System (ADS)

    Avazov, Artur R.; Sobinova, Liubov A.

    2016-02-01

    This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  20. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods.

    PubMed

    Han, Seung Yon; You, Byoung Hoon; Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice. PMID:26176540

  1. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods

    PubMed Central

    Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5–20 mg/kg and oral doses of 10–100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice. PMID:26176540

  2. Defining Desirable Central Nervous System Drug Space through the Alignment of Molecular Properties, in Vitro ADME, and Safety Attributes

    PubMed Central

    2010-01-01

    As part of our effort to increase survival of drug candidates and to move our medicinal chemistry design to higher probability space for success in the Neuroscience therapeutic area, we embarked on a detailed study of the property space for a collection of central nervous system (CNS) molecules. We carried out a thorough analysis of properties for 119 marketed CNS drugs and a set of 108 Pfizer CNS candidates. In particular, we focused on understanding the relationships between physicochemical properties, in vitro ADME (absorption, distribution, metabolism, and elimination) attributes, primary pharmacology binding efficiencies, and in vitro safety data for these two sets of compounds. This scholarship provides guidance for the design of CNS molecules in a property space with increased probability of success and may lead to the identification of druglike candidates with favorable safety profiles that can successfully test hypotheses in the clinic. PMID:22778836

  3. Distribution, synthesis, and absorption of kynurenic acid in plants.

    PubMed

    Turski, Michal P; Turska, Monika; Zgrajka, Wojciech; Bartnik, Magdalena; Kocki, Tomasz; Turski, Waldemar A

    2011-05-01

    Kynurenic acid (KYNA) is an endogenous antagonist of the ionotropic glutamate receptors and the α7 nicotinic acetylcholine receptor as well as an agonist of the G-protein-coupled receptor GPR35. In this study, KYNA distribution and synthesis in plants as well as its absorption was researched. KYNA level was determined by means of the high-performance liquid chromatography with fluorescence detection. KYNA was found in leaves, flowers, and roots of tested medicinal herbs: dandelion (Taraxacum officinale), common nettle (Urtica dioica), and greater celandine (Chelidoniummajus). The highest concentration of this compound was detected in leaves of dandelion--a mean value of 0.49 µg/g wet weight. It was shown that KYNA can be synthesized enzymatically in plants from its precursor, L-kynurenine, or absorbed by plants from the soil. Finally, the content of KYNA was investigated in 21 herbal tablets, herbal tea, herbs in sachets, and single herbs in bags. The highest content of KYNA in a maximum daily dose of herbal medicines appeared in St. John's wort--33.75 µg (tablets) or 32.60 µg (sachets). The pharmacological properties of KYNA and its presence in high concentrations in medicinal herbs may suggest that it possesses therapeutic potential, especially in the digestive system and should be considered a new valuable dietary supplement. PMID:21157681

  4. Sequestering ADM ethanol plant carbon dioxide

    USGS Publications Warehouse

    Finley, R.J.; Riddle, D.

    2008-01-01

    Archer Daniels Midland Co. (ADM) and the Illinois State Geological Survey (ISGS) are collaborating on a project in confirming that a rock formation can store carbon dioxide from the plant in its pores. The project aimed to sequester the gas underground permanently to minimize release of the greenhouse gas into the atmosphere. It is also designed to store one million tons of carbon dioxide over a three-year period. The project is worth $84.3M, funded by $66.7M from the US Department Energy, supplemented by co-funding from ADM and other corporate and state resources. The project will start drilling of wells to an expected depth over 6500 feet into the Mount Simon Sandstone formation.

  5. Duality, Entropy and ADM Mass in Supergravity

    SciTech Connect

    Cerchiai, Bianca L.; Ferrara, Sergio; Marrani, Alessio; Zumino, Bruno

    2009-02-23

    We consider the Bekenstein-Hawking entropy-area formula in four dimensional extended ungauged supergravity and its electric-magnetic duality property. Symmetries of both"large" and"small" extremal black holes are considered, as well as the ADM mass formula for N=4 and N=8 supergravity, preserving different fraction of supersymmetry. The interplay between BPS conditions and duality properties is an important aspect of this investigation.

  6. Duality, entropy, and ADM mass in supergravity

    SciTech Connect

    Cerchiai, Bianca L.; Zumino, Bruno; Ferrara, Sergio; Marrani, Alessio

    2009-06-15

    We consider the Bekenstein-Hawking entropy-area formula in four dimensional extended ungauged supergravity and its electric-magnetic duality property. Symmetries of both 'large' and 'small' extremal black holes are considered, as well as the ADM mass formula for N=4 and N=8 supergravity, preserving different fraction of supersymmetry. The interplay between BPS conditions and duality properties is an important aspect of this investigation.

  7. Netupitant PET imaging and ADME studies in humans

    PubMed Central

    Spinelli, Tulla; Calcagnile, Selma; Giuliano, Claudio; Rossi, Giorgia; Lanzarotti, Corinna; Mair, Stuart; Stevens, Lloyd; Nisbet, Ian

    2014-01-01

    Netupitant is a new, selective NK1 receptor antagonist under development for the prevention of chemotherapy-induced nausea and vomiting. Two studies were conducted to evaluate the brain receptor occupancy (RO) and disposition (ADME) of netupitant in humans. Positron emission tomography (PET) imaging with the NK1 receptor-binding–selective tracer [11C]-GR205171 was used to evaluate the brain penetration of different doses of netupitant (100, 300, and 450 mg) and to determine the NK1-RO duration. A NK1-RO of 90% or higher was achieved with all doses in the majority of the tested brain regions at Cmax, with a long duration of RO. The netupitant minimal plasma concentration predicted to achieve a NK1-RO of 90%, C90%, in the striatum was 225 ng/mL; after administration of netupitant 300 mg, concentrations exceeded the C90%. In the ADME study, a single nominal dose of [14C]-netupitant 300 mg was used to assess its disposition. Absorption was rapid and netupitant was extensively metabolized via Phase I and II hepatic metabolism. Elimination of >90% was predicted at day 29 and was principally via hepatic/biliary route (>85%) with a minor contribution of the renal route (<5%). In conclusion, these studies demonstrate that netupitant is a potent agent targeting NK1 receptors with long lasting RO. In addition, netupitant is extensively metabolized and is mainly eliminated through the hepatic/biliary route and to a lesser extent via the kidneys. PMID:24122871

  8. Pump absorption and temperature distribution in erbium-doped double-clad fluoride-glass fibers.

    PubMed

    Gorjan, Martin; Marincek, Marko; Copic, Martin

    2009-10-26

    We investigate diode pump absorption and temperature distribution in three erbium-doped double-clad fluoride fibers. Absorption is measured via fluorescence intensity and temperature distribution is measured with thermal imaging. Ray-tracing calculations of absorption and heat-equation modeling of temperature distribution are also conducted. We found excellent agreement between measurements and calculations for all fibers. Results indicate that erbium-doped fluoride fiber lasers have already reached maximum output powers allowed under natural convection cooling, with fiber end being the most critical. We propose cooling and fiber design optimizations that may allow an order-of-magnitude further power-scaling.

  9. Effect of Clouds on the Calculated Vertical Distribution of Shortwave Absorption in the Tropics

    SciTech Connect

    McFarlane, Sally A.; Mather, James H.; Ackerman, Thomas P.; Liu, Zheng

    2008-09-23

    High vertical resolution profiles of cloud properties were obtained from cloud radars operated by the Atmospheric Radiation Measurement (ARM) program on the islands of Nauru and Manus in the Tropical Western Pacific (TWP). Broadband flux calculations using a correlated k-distribution model were performed to estimate the effect of clouds on the total column and vertical distribution of shortwave absorption at these tropical sites. Sensitivity studies were performed to examine the role of precipitable water vapor, cloud vertical location, optical depth, and particle size on the SW column absorption. On average, observed clouds had little impact on the calculated total SW column absorption at the two sites, but a significant impact on the vertical distribution of SW absorption. Differences in the column amount, vertical profiles, and diurnal cycle of SW absorption at the two sites were due primarily to differences in cirrus cloud frequency.

  10. PBTK modelling platforms and parameter estimation tools to enable animal-free risk assessment: recommendations from a joint EPAA--EURL ECVAM ADME workshop.

    PubMed

    Bessems, Jos G; Loizou, George; Krishnan, Kannan; Clewell, Harvey J; Bernasconi, Camilla; Bois, Frederic; Coecke, Sandra; Collnot, Eva-Maria; Diembeck, Walter; Farcal, Lucian Romeo; Geraets, Liesbeth; Gundert-Remy, Ursula; Kramer, Nynke; Küsters, Gabriele; Leite, Sofia B; Pelkonen, Olavi R; Schröder, Klaus; Testai, Emanuela; Wilk-Zasadna, Iwona; Zaldívar-Comenges, José-Manuel

    2014-02-01

    Information on toxicokinetics is critical for animal-free human risk assessment. Human external exposure must be translated into human tissue doses and compared with in vitro actual cell exposure associated to effects (in vitro-in vivo comparison). Data on absorption, distribution, metabolism and excretion in humans (ADME) could be generated using in vitro and QSAR tools. Physiologically-based toxicokinetic (PBTK) computer modelling could serve to integrate disparate in vitro and in silico findings. However, there are only few freely-available PBTK platforms currently available. And although some ADME parameters can be reasonably estimated in vitro or in silico, important gaps exist. Examples include unknown or limited applicability domains and lack of (high-throughput) tools to measure penetration of barriers, partitioning between blood and tissues and metabolic clearance. This paper is based on a joint EPAA--EURL ECVAM expert meeting. It provides a state-of-the-art overview of the availability of PBTK platforms as well as the in vitro and in silico methods to parameterise basic (Tier 1) PBTK models. Five high-priority issues are presented that provide the prerequisites for wider use of non-animal based PBTK modelling for animal-free chemical risk assessment.

  11. Tropospheric ozone distributions measured with an airborne laser absorption spectrometer

    NASA Technical Reports Server (NTRS)

    Menzies, R. T.; Shumate, M. S.

    1978-01-01

    Measurements of tropospheric ozone have been made in the southern and middle California regions and over the Pacific Ocean during two series of flights in February and May 1977. The data were obtained by using a laser absorption spectrometer, a nadir-viewing instrument which remotely measures the ozone column abundance between ground level and aircraft altitude by interacting with ozone at specific wavelengths near 9.5 microns. The measurements indicate significantly lower ozone abundances above the Mojave Desert region as compared with farm, forest, and urban areas. The average tropospheric column density was found to be 0.0027 atm cm/km over the California region and 0.0035 atm cm/km over the Pacific Ocean region 1000-2000 km west of the coast of Mexico.

  12. Absorption, distribution, metabolism, and excretion of isoflavonoids after soy intake.

    PubMed

    Franke, Adrian A; Lai, Jennifer F; Halm, Brunhild M

    2014-10-01

    Soy is the major source of dietary exposure to isoflavonoids (IFLs). Accumulating evidence supports a role for soy and IFLs in the protection against many chronic diseases including cancer. After soy intake we found a biphasic IFL appearance pattern in plasma as well as in urine that we suggest to be due to IFL absorption in the small intestine (ca. 10%) during the first 2h after intake and IFL absorption in the large intestine (ca. 90%) 4-6 h after intake. While each IFL disappears from the circulation at different times excellent correlations between urinary and circulating IFL values were discovered and algorithms to convert urinary excretion values into circulating levels were established. We suggest the term 'apparent bioavailability' when using urinary data to describe IFL exposure. The IFL bioavailability was found to be influenced by gut bacteria, oral antibiotic treatment (OABX), and an individual's age and health status. While daidzein (DE) and genistein start to be absorbed minutes after intake, equol (EQ) appears in plasma only after a minimum of 8h following soy intake owing to the required transit time of DE to the colon where the conversion of DE to EQ takes place by intestinal microbiota. We have also shown that the apparent IFL bioavailability is higher in children than adults, higher in healthy versus non-healthy individuals, and decreased in children but increased in adults during OABX. Finally, we propose to use a urinary EQ/DE ratio of 0.018 with a DE threshold to identify EQ producers. With this cutoff definition we observed that EQ production is inconsistent over time in 5-30% of both premenopausal and postmenopausal women.

  13. Absorption and distribution of orally administered jojoba wax in mice.

    PubMed

    Yaron, A; Samoiloff, V; Benzioni, A

    1982-03-01

    The liquid wax obtained from the seeds of the arid-land shrub jojoba (Simmondsia chinensis) is finding increasing use in skin treatment preparations. The fate of this wax upon reaching the digestive tract was studied. 14C-Labeled wax was administered intragastrically to mice, and the distribution of the label in the body was determined as a function of time. Most of the wax was excreted, but a small amount was absorbed, as was indicated by the distribution of label in the internal organs and the epididymal fat. The label was incorporated into the body lipids and was found to diminish with time.

  14. Differences in excitability properties of FDI and ADM motor axons.

    PubMed

    Bae, Jong Seok; Sawai, Setsu; Misawa, Sonoko; Kanai, Kazuaki; Isose, Sagiri; Kuwabara, Satoshi

    2009-03-01

    The first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles are innervated by the same ulnar nerve, but studies have shown that the former is much more severely affected in amyotrophic lateral sclerosis. In this study, threshold tracking was used to investigate whether membrane properties differ between FDI and ADM motor axons. In 12 normal subjects, compound muscle action potentials were recorded from FDI and ADM after ulnar nerve stimulation at the wrist. The strength-duration time constant was significantly longer in the FDI axons than in the ADM axons, and latent addition studies showed greater threshold changes at the conditioning-test stimulus of 0.2 ms in FDI than in ADM axons. These findings suggest that nodal persistent sodium conductances are more prominent in FDI axons than in ADM axons, and therefore excitability is physiologically higher in FDI axons. Even in the same nerve at the same sites, membrane properties of FDI and ADM motor axons differ significantly, and thus their axonal/neuronal responses to disease may also differ.

  15. Decabromodiphenyl ether in the rat: absorption, distribution, metabolism, and excretion.

    PubMed

    Morck, Anna; Hakk, Heldur; Orn, Ulrika; Klasson Wehler, Eva

    2003-07-01

    Among the group of polybrominated diphenyl ethers used as flame-retardants, the fully brominated diphenyl ether, decabromodiphenyl ether (decaBDE), is the most commonly used. Despite the large usage of decaBDE, neither the metabolic pathways nor the absorption have been addressed, and there are very few studies on its toxicology. In this work, it is shown that after a single oral dose of 14C-labeled decaBDE to rats, at least 10% of the decaBDE dose is absorbed. The major excretion route in conventional rats is via feces that contained 90% of the decaBDE dose. The excretion in bile was close to 10% of the dose and represented mainly metabolites. It cannot be excluded that greater than 10% of the oral dose had been absorbed since 65% of the radioactivity excreted in feces was metabolites. The highest concentrations on a lipid weight basis were found in plasma and blood-rich tissues, and the adipose tissue had the lowest concentration of decaBDE. After derivatization of a phenolic fraction, gas chromatography-mass spectrometry (GC/MS) analyses indicated that metabolites with five to seven bromine atoms had formed, and they possessed a guaiacol structure (a hydroxy and a methoxy group) in one of the rings. In addition, traces of nonabrominated diphenyl ethers and monohydroxylated metabolites were found by GC/MS. Metabolites, characterized by their chemical properties, were interpreted to be covalently bound to macromolecules, either proteins or lipids. In addition, water solubility was suggested. The metabolic pathway was indicated to include a reactive intermediate. PMID:12814967

  16. SPATIAL DISTRIBUTIONS OF ABSORPTION, LOCAL SUPPRESSION, AND EMISSIVITY REDUCTION OF SOLAR ACOUSTIC WAVES IN MAGNETIC REGIONS

    SciTech Connect

    Chou, D.-Y.; Yang, M.-H.; Zhao Hui; Liang Zhichao; Sun, M.-T.

    2009-11-20

    Observed acoustic power in magnetic regions is lower than the quiet Sun because of absorption, emissivity reduction, and local suppression of solar acoustic waves in magnetic regions. In the previous studies, we have developed a method to measure the coefficients of absorption, emissivity reduction, and local suppression of sunspots. In this study, we go one step further to measure the spatial distributions of three coefficients in two active regions, NOAA 9055 and 9057. The maps of absorption, emissivity reduction, and local suppression coefficients correlate with the magnetic map, including plage regions, except the emissivity reduction coefficient of NOAA 9055 where the emissivity reduction coefficient is too weak and lost among the noise.

  17. A Laminated Microfluidic Device for Comprehensive Preclinical Testing in the Drug ADME Process.

    PubMed

    An, Fan; Qu, Yueyang; Luo, Yong; Fang, Ning; Liu, Yang; Gao, Zhigang; Zhao, Weijie; Lin, Bingcheng

    2016-01-01

    New techniques are urgently needed to replace conventional long and costly pre-clinical testing in the new drug administration process. In this study, a laminated microfluidic device was fabricated to mimic the drug ADME response test in vivo. This proposed device was loaded and cultured with functional cells for drug response investigation and organ tissues that are involved in ADME testing. The drug was introduced from the top of the device and first absorbed by the Caco-2 cell layer, and then metabolized by the primary hepatocyte layer. It subsequently interacted with the MCF-7 cell layer, distributed in the lung, heart and fat tissues, and was finally eliminated through the dialysis membrane. Throughout this on-chip ADME process, the proposed device can be used as a reliable tool to simultaneously evaluate the drug anti-tumor activity, hepatotoxicity and pharmacokinetics. Furthermore, this device was proven to be able to reflect the hepatic metabolism of a drug, drug distribution in the target tissues, and the administration method of a drug. Furthermore, this microdevice is expected to reduce the number of drug candidates and accelerate the pre-clinical testing process subject to animal testing upon adaptation in new drug discovery. PMID:27122192

  18. A Laminated Microfluidic Device for Comprehensive Preclinical Testing in the Drug ADME Process

    PubMed Central

    An, Fan; Qu, Yueyang; Luo, Yong; Fang, Ning; Liu, Yang; Gao, Zhigang; Zhao, Weijie; Lin, Bingcheng

    2016-01-01

    New techniques are urgently needed to replace conventional long and costly pre-clinical testing in the new drug administration process. In this study, a laminated microfluidic device was fabricated to mimic the drug ADME response test in vivo. This proposed device was loaded and cultured with functional cells for drug response investigation and organ tissues that are involved in ADME testing. The drug was introduced from the top of the device and first absorbed by the Caco-2 cell layer, and then metabolized by the primary hepatocyte layer. It subsequently interacted with the MCF-7 cell layer, distributed in the lung, heart and fat tissues, and was finally eliminated through the dialysis membrane. Throughout this on-chip ADME process, the proposed device can be used as a reliable tool to simultaneously evaluate the drug anti-tumor activity, hepatotoxicity and pharmacokinetics. Furthermore, this device was proven to be able to reflect the hepatic metabolism of a drug, drug distribution in the target tissues, and the administration method of a drug. Furthermore, this microdevice is expected to reduce the number of drug candidates and accelerate the pre-clinical testing process subject to animal testing upon adaptation in new drug discovery. PMID:27122192

  19. Effects of dietary calcium on lead absorption, distribution, and elimination kinetics in rats

    SciTech Connect

    Aungst, B.J.; Fung, H.L.

    1985-01-01

    A pharmacokinetic analysis of lead absorption, distribution, and elimination was conducted in rats maintained on calcium-deficient, control, and calcium-supplemented diets. Dietary calcium affected lead disposition in a number of ways. Systematic lead clearance after a 10-mg/kg intracardiac lead dose was approximately 25% lower than control in rats administered dietary calcium supplements. In rats maintained on a calcium-deficient diet, systemic lead clearance was estimated to be 40% less than control. The apparent volume of lead distribution was increased. The apparent systemic availability of 1-, 10-, and 100-mg.kg oral lead doses was three- to fourfold greater than control in calcium-deficient rats. The percentage absorption was dose-dependent in control and calcium-deficient rats. The observed changes in lead absorption and systemic clearance associated with the calcium-deficient diet represent synergistic effects that could elevate blood lead accumulation and thus potentially influence susceptibility to lead toxicity.

  20. High-throughput approaches for evaluating absorption, distribution, metabolism and excretion properties of lead compounds.

    PubMed

    Tarbit, M H; Berman, J

    1998-06-01

    Combinatorial chemistry methods and high-throughput screening for leads in industrial drug discovery have generated a potential bottleneck in the optimisation processes that seek to align potency with good pharmacokinetics in order to produce good medicines. This has resulted in the need for higher throughput methods of screening for absorption, distribution, metabolism and excretion properties. Significant progress has been made in throughput of in vivo pharmacokinetic studies, with the introduction of cassette, or multiple-in-one, protocols. In this technique, typically up to ten compounds are administered in one dose and analysed concomitantly on the mass spectrometer. High-throughput methods in in vitro absorption, distribution, metabolism and excretion are less well-developed as yet, and current approaches comprise automation of well-established methods for absorption using cell lines and metabolism using liver microsomes.

  1. A review of ADM1 extensions, applications, and analysis: 2002-2005.

    PubMed

    Batstone, D J; Keller, J; Steyer, J P

    2006-01-01

    Since publication of the Scientific and Technical Report (STR) describing the ADM1, the model has been extensively used, and analysed in both academic and practical applications. Adoption of the ADM1 in popular systems analysis tools such as the new wastewater benchmark (BSM2), and its use as a virtual industrial system can stimulate modelling of anaerobic processes by researchers and practitioners outside the core expertise of anaerobic processes. It has been used as a default structural element that allows researchers to concentrate on new extensions such as sulfate reduction, and new applications such as distributed parameter modelling of biofilms. The key limitations for anaerobic modelling originally identified in the STR were: (i) regulation of products from glucose fermentation, (ii) parameter values, and variability, and (iii) specific extensions. Parameter analysis has been widespread, and some detailed extensions have been developed (e.g., sulfate reduction). A verified extension that describes regulation of products from glucose fermentation is still limited, though there are promising fundamental approaches. This is a critical issue, given the current interest in renewable hydrogen production from carbohydrate-type waste. Critical analysis of the model has mainly focused on model structure reduction, hydrogen inhibition functions, and the default parameter set recommended in the STR. This default parameter set has largely been verified as a reasonable compromise, especially for wastewater sludge digestion. One criticism of note is that the ADM1 stoichiometry focuses on catabolism rather than anabolism. This means that inorganic carbon can be used unrealistically as a carbon source during some anabolic reactions. Advances and novel applications have also been made in the present issue, which focuses on the ADM1. These papers also explore a number of novel areas not originally envisaged in this review.

  2. Using integrating spheres as absorption cells: path-length distribution and application of Beer's law.

    PubMed

    Hodgkinson, Jane; Masiyano, Dackson; Tatam, Ralph P

    2009-10-20

    We have modeled the path-length distribution in an integrating sphere used as a multipass optical cell for absorption measurements. The measured radiant flux as a function of analyte concentration is nonlinear as a result, deviating from that expected for a single path length. We have developed a full numerical model and introduce a new analytical relationship that describes this behavior for high reflectivity spheres. We have tested both models by measuring the optical absorption of methane at 1651 nm in a 50 mm diameter sphere, with good agreement with experimental data in the absorption range of 0-0.01 cm(-1). Our results compare well with previous work on the temporal response of integrating spheres.

  3. Polarized Synchrotron Emissivities and Absorptivities for Relativistic Thermal, Power-law, and Kappa Distribution Functions

    NASA Astrophysics Data System (ADS)

    Pandya, Alex; Zhang, Zhaowei; Chandra, Mani; Gammie, Charles F.

    2016-05-01

    Synchrotron emission and absorption determine the observational appearances of many astronomical systems. In this paper, we describe a numerical scheme for calculating synchrotron emissivities and absorptivities in all four Stokes parameters for arbitrary gyrotropic electron distribution functions, building on earlier work by Leung, Gammie, and Noble. We use this technique to evaluate the emissivities and the absorptivities for a thermal (Maxwell-Jüttner), isotropic power-law, and an isotropic kappa distribution function. The latter contains a power-law tail at high particle energies that smoothly merges with a thermal core at low energies, as is characteristic of observed particle spectra in collisionless plasmas. We provide fitting formulae and error bounds on the fitting formulae for use in codes that solve the radiative transfer equation. The numerical method and the fitting formulae are implemented in a compact C library called symphony. We find that the kappa distribution has a source function that is indistinguishable from a thermal spectrum at low frequency and transitions to the characteristic self-absorbed synchrotron spectrum, \\propto {ν }5/2, at high frequency; the linear polarization fraction for a thermal spectrum is near unity at high frequency; and all distributions produce O(10%) circular polarization at low frequency for lines of sight sufficiently close to the magnetic field vector.

  4. Absorption, distribution, metabolism, excretion, and kinetics of 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid ammonium salt following a single dose in rat, mouse, and cynomolgus monkey.

    PubMed

    Gannon, Shawn A; Fasano, William J; Mawn, Michael P; Nabb, Diane L; Buck, Robert C; Buxton, L William; Jepson, Gary W; Frame, Steven R

    2016-01-18

    Ammonium, 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate has been developed as a processing aid used in the manufacture of fluoropolymers. The absorption, distribution, elimination, and distribution (ADME) and kinetic behavior of this substance has been evaluated in rats, mice, and cynomolgus monkeys by oral and intravenous routes of exposure and studied in both plasma and urine. The test substance is rapidly and completely absorbed in both rats and mice and both in vivo and in vitro experiments indicate that it is not metabolized. The test substance is rapidly eliminated exclusively in the urine in both rats and mice, with rats eliminating it more quickly than mice (approximately 5h elimination half-life in rats, 20 h half-life in mice). Pharmacokinetic analysis in monkeys, rats, and mice indicate rapid, biphasic elimination characterized by a very fast alpha phase and a slower beta phase. The beta phase does not contribute to potential accumulation after multiple dosing in rats or monkeys. Comparative pharmacokinetics in rats, mice, and monkeys indicates that the rat is more similar to the monkey and is therefore a more appropriate rodent model for pharmacokinetics in primates. PMID:26743852

  5. Recent progresses in the exploration of machine learning methods as in-silico ADME prediction tools.

    PubMed

    Tao, L; Zhang, P; Qin, C; Chen, S Y; Zhang, C; Chen, Z; Zhu, F; Yang, S Y; Wei, Y Q; Chen, Y Z

    2015-06-23

    In-silico methods have been explored as potential tools for assessing ADME and ADME regulatory properties particularly in early drug discovery stages. Machine learning methods, with their ability in classifying diverse structures and complex mechanisms, are well suited for predicting ADME and ADME regulatory properties. Recent efforts have been directed at the broadening of application scopes and the improvement of predictive performance with particular focuses on the coverage of ADME properties, and exploration of more diversified training data, appropriate molecular features, and consensus modeling. Moreover, several online machine learning ADME prediction servers have emerged. Here we review these progresses and discuss the performances, application prospects and challenges of exploring machine learning methods as useful tools in predicting ADME and ADME regulatory properties.

  6. Nutrient Distribution and Absorption in the Colonial Hydroid Podocoryna carnea Is Sequentially Diffusive and Directional

    PubMed Central

    Buss, Leo W.; Anderson, Christopher P.; Perry, Elena K.; Buss, Evan D.; Bolton, Edward W.

    2015-01-01

    The distribution and absorption of ingested protein was characterized within a colony of Podocoryna carnea when a single polyp was fed. Observations were conducted at multiple spatial and temporal scales at three different stages of colony ontogeny with an artificial food item containing Texas Red conjugated albumin. Food pellets were digested and all tracer absorbed by digestive cells within the first 2–3 hours post-feeding. The preponderance of the label was located in the fed polyp and in a transport-induced diffusion pattern surrounding the fed polyp. After 6 hours post-feeding particulates re-appeared in the gastrovascular system and their absorption increased the area over which the nutrients were distributed, albeit still in a pattern that was centered on the fed polyp. At later intervals, tracer became concentrated in some stolon tips, but not in others, despite the proximity of these stolons either to the fed polyp or to adjacent stolons receiving nutrients. Distribution and absorption of nutrients is sequentially diffusive and directional. PMID:26359660

  7. Matrix trace operators: from spectral moments of molecular graphs and complex networks to perturbations in synthetic reactions, micelle nanoparticles, and drug ADME processes.

    PubMed

    Gonzalez-Diaz, Humberto; Arrasate, Sonia; Juan, Asier Gomez-San; Sotomayor, Nuria; Lete, Esther; Speck-Planche, Alejandro; Ruso, Juan M; Luan, Feng; Cordeiro, Maria Natalia Dias Soeiro

    2014-01-01

    The study of quantitative structure-property relationships (QSPR) is important to study complex networks of chemical reactions in drug synthesis or metabolism or drug-target interaction networks. A difficult but possible goal is the prediction of drug absorption, distribution, metabolism, and excretion (ADME) process with a single QSPR model. For this QSPR modelers need to use flexible structural parameters useful for the description of many different systems at different structural scales (multi-scale parameters). Also they need to use powerful analytical methods able to link in a single multi-scale hypothesis structural parameters of different target systems (multi-target modeling) with different experimental properties of these systems (multi-output models). In this sense, the QSPR study of complex bio-molecular systems may benefit substantially from the combined application of spectral moments of graph representations of complex systems with perturbation theory methods. On one hand, spectral moments are almost universal parameters that can be calculated to many different matrices used to represent the structure of the states of different systems. On the other hand, perturbation methods can be used to add "small" variation terms to parameters of a known state of a given system in order to approach to a solution of another state of the same or similar system with unknown properties. Here we present one state-of-art review about the different applications of spectral moments to describe complex bio-molecular systems. Next, we give some general ideas and formulate plausible linear models for a general-purpose perturbation theory of QSPR problems of complex systems. Last, we develop three new QSPR-Perturbation theory models based on spectral moments for three different problems with multiple in-out boundary conditions that are relevant to biomolecular sciences. The three models developed correctly classify more than pairs 115,600; 48,000; 134,900 cases of the

  8. In vivo drug metabolite identification in preclinical ADME studies by means of UPLC/TWIMS/high resolution-QTOF MS(E) and control comparison: cost and benefit of vehicle-dosed control samples.

    PubMed

    Fiebig, Lukas; Laux, Ralf; Binder, Rudolf; Ebner, Thomas

    2016-10-01

    1. Liquid chromatography (LC)-high resolution mass spectrometry (HRMS) techniques proved to be well suited for the identification of predicted and unexpected drug metabolites in complex biological matrices. 2. To efficiently discriminate between drug-related and endogenous matrix compounds, however, sophisticated postacquisition data mining tools, such as control comparison techniques are needed. For preclinical absorption, distribution, metabolism and excretion (ADME) studies that usually lack a placebo-dosed control group, the question arises how high-quality control data can be yielded using only a minimum number of control animals. 3. In the present study, the combination of LC-traveling wave ion mobility separation (TWIMS)-HRMS(E) and multivariate data analysis was used to study the polymer patterns of the frequently used formulation constituents polyethylene glycol 400 and polysorbate 80 in rat plasma and urine after oral and intravenous administration, respectively. 4. Complex peak patterns of both constituents were identified underlining the general importance of a vehicle-dosed control group in ADME studies for control comparison. Furthermore, the detailed analysis of administration route, blood sampling time and gender influences on both vehicle peak pattern as well as endogenous matrix background revealed that high-quality control data is obtained when (i) control animals receive an intravenous dose of the vehicle, (ii) the blood sampling time point is the same for analyte and control sample and (iii) analyte and control samples of the same gender are compared.

  9. DEVELOPMENT OF ADME DATA IN AGRICULTURAL CHEMICAL SAFETY ASSESSMENTS

    EPA Science Inventory

    DEVELOPMENT OF ADME DATA IN AGRICULTURAL CHEMICAL SAFETY ASSESSMENTS
    Pastoor, Timothy1, Barton, Hugh2
    1 Syngenta Crop Protection, Greensboro, NC, USA.
    2 EPA, Office of Research and Development-NHEERL, RTP, NC, USA.

    A multi-stakeholder series of discussions d...

  10. ADM. Tanks: from left to right: fuel oil tank, fuel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Tanks: from left to right: fuel oil tank, fuel pump house (TAN-611), engine fuel tank, water pump house, water storage tank. Camera facing northwest. Not edge of shielding berm at left of view. Date: November 25, 1953. INEEL negative no. 9217 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  11. Variable stoichiometry with thermodynamic control in ADM1.

    PubMed

    Rodríguez, J; Lema, J M; van Loosdrecht, M C M; Kleerebezem, R

    2006-01-01

    The effect of a variable stoichiometry of the carbohydrate fermentation process in the IWA Anaerobic Digestion Model No.1 (ADM1) is investigated. Most existing anaerobic digestion models including ADM1 consider a fixed-stoichiometry for their conversion processes. The ADM1 model was first transformed into an only mol based model to remove some errors derived from the mixed COD-mol based standard model and to allow for implementation of the variable stoichiometry. Consequently, the values of the butyrate and acetate catabolic yields of carbohydrate fermentation are made dependent on the hydrogen concentration and the reactor pH according to the predictions of a recently developed mixed culture fermentation model based on thermodynamic considerations. The simulation results obtained showed no significantly different responses in terms of effluent quality and system robustness between the standard and the variable stoichiometry ADM1 under overload conditions, and for both single- and two-step anaerobic digestion configurations. This behaviour is explained by the non-limiting acetogenic activity that compensated for the changes in the acidogenic products, typical behaviour for serial processes close to equilibrium. Based on the results obtained, thermodynamic rather than kinetic control for these conversions is suggested. Depending on the objectives to be met, lumping of carbohydrate fermenters and oxidative acetogens into a single biomass group with a variable stoichiometry is proposed for further consideration.

  12. Impact of inhomogeneous optical scattering coefficient distribution on recovery of optical absorption coefficient maps using tomographic photoacoustic data.

    PubMed

    Li, Xiaoqi; Jiang, Huabei

    2013-02-21

    We present a study through extensive simulation that considers the impact of inhomogeneous optical scattering coefficient distribution on recovery of optical absorption coefficient maps using tomographic photoacoustic data collected from media mimicking breast tissue. We found that while the impact of scattering heterogeneities/targets is modest on photoacoustic recovery of optical absorption coefficients, the impact of scattering contrast caused by adipose tissue, a layer of normal tissue along the boundary of the breast, is dramatic on reconstruction of optical absorption coefficients using photoacoustic data-up to 25.8% relative error in recovering the absorption coefficient is estimated in such cases. To overcome this problem, we propose a new method to enhance photoacoustic recovery of the optical absorption coefficient in heterogeneous media by considering inhomogeneous scattering coefficient distribution provided by diffuse optical tomography (DOT). Results from extensive simulations show that photoacoustic recovery of absorption coefficient maps can be improved considerably with a priori scattering information from DOT.

  13. An analytical solution for the model of drug distribution and absorption in small intestine

    NASA Astrophysics Data System (ADS)

    Mingyu, Xu

    1990-11-01

    According to the physiological and anatomical characteristics of small intestine, neglecting the effect of its motility on the distribution and absorption of drug and nutrient, Y. Miyamoto et al.[1] proposed a model of two-dimensional laminar flow in a circular porous tube with permeable wall and calculated the concentration profile of drug by numerical analysis. In this paper, we give a steady state analytical solution of the above model including deactivation term. The obtained results are in agreement with the results of their numerical analysis. Moreover the analytical solution presented in this paper reveals the relation among the physiological parameters of the model and describes the basic absorption rule of drug and nutrient through the intestinal wall and hence provides a theoretical basis for determining the permeability and reflection coefficient through in situ experiments.

  14. Cell-based medicinal chemistry optimization of high-throughput screening (HTS) hits for orally active antimalarials. Part 1: challenges in potency and absorption, distribution, metabolism, excretion/pharmacokinetics (ADME/PK).

    PubMed

    Chatterjee, Arnab K

    2013-10-24

    Malaria represents a significant health issue, and novel and effective drugs are needed to address parasite resistance that has emerged to the current drug arsenal. Antimalarial drug discovery has historically benefited from a whole-cell (phenotypic) screening approach to identify lead molecules. This approach has been utilized by several groups to optimize weakly active antimalarial pharmacophores, such as the quinolone scaffold, to yield potent and highly efficacious compounds that are now poised to enter clinical trials. More recently, GNF/Novartis, GSK, and others have employed the same approach in high-throughput screening (HTS) of large compound libraries to find novel scaffolds that have also been optimized to clinical candidates by GNF/Novartis. This perspective outlines some of the inherent challenges in cell-based medicinal chemistry optimization, including optimization of oral exposure and hERG activity.

  15. Similarity based SAR (SIBAR) as tool for early ADME profiling.

    PubMed

    Klein, Christian; Kaiser, Dominik; Kopp, Stephan; Chiba, Peter; Ecker, Gerhard F

    2002-11-01

    Estimation of bioavailability and toxicity at the very beginning of the drug development process is one of the big challenges in drug discovery. Most of the processes involved in ADME are driven by rather unspecific interactions between drugs and biological macromolecules. Within the past decade, drug transport pumps such as P-glycoprotein (Pgp) have gained increasing interest in the early ADME profiling process. Due to the high structural diversity of ligands of Pgp, traditional QSAR methods were only successful within analogous series of compounds. We used an approach based on similarity calculations to predict Pgp-inhibitory activity of a series of propafenone analogues. This SIBAR approach is based on selection of a highly diverse reference compound set and calculation of similarity values to these reference compounds. The similarity values (denoted as SIBAR descriptors) are then used for PLS analysis. Our results show, that for a set of 131 propafenone type compounds, models with good predictivity were obtained both in cross validation procedures and with a 31-compound external test set. Thus, these new descriptors might be a versatile tool for generation of predictive ADME models. PMID:12825790

  16. Biogas from grass silage - Measurements and modeling with ADM1.

    PubMed

    Koch, Konrad; Lübken, Manfred; Gehring, Tito; Wichern, Marc; Horn, Harald

    2010-11-01

    Mono fermentation of grass silage without the addition of manure was performed over a period of 345days under mesophilic conditions (38 degrees C). A simulation study based on the IWA Anaerobic Digestion Model No. 1 (ADM1) was done in order to show its applicability to lignocellulosic biomass. Therefore, the influent was fractioned by established fodder analysis (Weender analysis and van Soest method). ADM1 was modified with a separate compound of inert decay products similar to the approach of Activated Sludge Model No. 1 (ASM1). Furthermore, a function, which described the influence of solids on the process of hydrolysis, has been integrated to reproduce reliable ammonium concentrations. The model was calibrated by using the modified Nash-Sutcliffe coefficient to evaluate simulation quality. It was possible to fit observed data by changing only hydrogen inhibition constants and the maximum acetate uptake rate. The extended ADM1 model showed good agreement with measurements and was suitable for modeling anaerobic digestion of grass silage.

  17. Velocity distribution function of sputtered Cu atoms obtained by time resolved optical absorption spectroscopy

    SciTech Connect

    Kang, Namjun; Gaboriau, Freddy; Ricard, Andre; Oh, Soo-ghee

    2010-01-15

    A new method based on time resolved optical absorption spectroscopy is proposed to determine the velocity distribution function of sputtered Cu atoms in a magnetron plasma discharge. The method consists of applying a short pulse of 1.5 {mu}s and of recording time variations in copper atom density in off pulse at different positions (1, 2, and 3 cm) from target surface under 3-30 mTorr. The time evolution of the density is then converted into velocity distribution. We estimate that only sputtered atoms with radial velocity component lower than 0.5 km/s are detected. The average velocity of Cu atoms is evaluated as the first order moment of the velocity distribution functions. The velocity distribution functions become the more dispersive the farther from target surface. The average velocities vary in the range of 2.5-3 km/s at the vicinity of target surface whereas at 3 cm a decrease from 2.5 to 1.2 km/s is observed at 30 mTorr.

  18. Longitudinal dose distribution and energy absorption in PMMA and water cylinders undergoing CT scans

    SciTech Connect

    Li, Xinhua; Zhang, Da; Liu, Bob

    2014-10-15

    Purpose: The knowledge of longitudinal dose distribution provides the most direct view of the accumulated dose in computed tomography (CT) scanning. The purpose of this work was to perform a comprehensive study of dose distribution width and energy absorption with a wide range of subject sizes and beam irradiated lengths. Methods: Cumulative dose distribution along the z-axis was calculated based on the previously published CT dose equilibration data by Li, Zhang, and Liu [Med. Phys. 40, 031903 (10pp.) (2013)] and a mechanism for computing dose on axial lines by Li, Zhang, and Liu [Med. Phys. 39, 5347–5352 (2012)]. Full width at half maximum (FWHM), full width at tenth maximum (FWTM), the total energy (E) absorbed in a small cylinder of unit mass per centimeter square about the central or peripheral axis, and the energy (E{sub in}) absorbed inside irradiated length (L) were subsequently extracted from the dose distribution. Results: Extensive results of FWHM, FWTM, and E{sub in}/E were presented on the central and peripheral axes of infinitely long PMMA (diameters 6–50 cm) and water (diameters 6–55 cm) cylinders with L < 100 cm. FWHM was greater than the primary beam width only on the central axes of large phantoms and also with L ranging from a few centimeter to about 33 cm. FWTM generally increased with phantom diameter, and could be up to 32 cm longer than irradiated length, depending on L, phantom diameter and axis, but was insensitive to phantom material (PMMA or water). E{sub in}/E increased with L and asymptotically approached unity for large L. As phantom diameter increased, E{sub in}/E generally decreased, but asymptotically approached constant levels on the peripheral axes of large phantoms. A heuristic explanation of dose distribution width results was presented. Conclusions: This study enables the reader to gain a comprehensive view of dose distribution width and energy absorption and provides useful data for estimating doses to organs inside or

  19. Conservative mastectomies and immediate reconstruction with the use of ADMs

    PubMed Central

    Govshievich, Alexander; Somogyi, Ron B.

    2015-01-01

    Background In recent years, a novel approach to immediate breast reconstruction has been introduced with the advent of acellular dermal matrix (ADM). In the setting of conservative mastectomies where the native skin envelope is preserved, placement of ADM at the lower pole in continuity with the pectoralis major muscle (PMM) provides additional support, allowing direct-to-implant breast reconstruction. The following manuscript presents the senior author’s experience with ADM-assisted reconstruction and provides a detailed description of surgical technique along with a comprehensive discussion of patient selection and potential complications. Methods A retrospective chart review of patients undergoing direct-to-implant breast reconstruction following skin sparing or nipple sparing mastectomy with the use of ADM (AlloDerm; LifeCell Corp., Branchburg, USA) was conducted at Women’s College Hospital in Toronto over a 5-year period [2008-2013]. Demographic data, previous radiation therapy and post-operative complications were recorded. Results A total of 72 patients representing 119 breasts were identified. Average follow-up was 16 months (range, 3-51 months). Twenty-seven complications were recorded for a complication rate of 22.7% (27/119). Complications included six cases of capsular contracture (Baker III/IV), five cases of red skin syndrome, four cases of rippling, three cases of dehiscence and two cases of seroma. Overall, direct-to-implant reconstruction was successfully completed in 97.5% of breasts (116/119). One case of infection was treated with explantation and conversion to autogenous reconstruction. Two breasts with tissue necrosis or dehiscence had the implants removed and replaced with tissue expanders. Overall reoperation rate was 9.7% (7/72 patients). Conclusions ADM assisted direct-to-implant breast reconstruction has been shown to be a safe option for women who are candidates for skin sparing or nipple sparing mastectomies. Judicious patient

  20. Can we estimate the accuracy of ADME-Tox predictions?

    PubMed

    Tetko, Igor V; Bruneau, Pierre; Mewes, Hans-Werner; Rohrer, Douglas C; Poda, Gennadiy I

    2006-08-01

    There have recently been developments in the methods used to access the accuracy of the prediction and applicability domain of absorption, distribution, metabolism, excretion and toxicity models, and also in the methods used to predict the physicochemical properties of compounds in the early stages of drug development. The methods are classified into two main groups: those based on the analysis of similarity of molecules, and those based on the analysis of calculated properties. An analysis of octanol-water distribution coefficients is used to exemplify the consistency of estimated and calculated accuracy of the ALOGPS program (http://www.vcclab.org) to predict in-house and publicly available datasets.

  1. Enhancement of light absorption in polyazomethines due to plasmon excitation on randomly distributed metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Wróbel, P.; Antosiewicz, T. J.; Stefaniuk, T.; Ciesielski, A.; Iwan, A.; Wronkowska, A. A.; Wronkowski, A.; Szoplik, T.

    2015-05-01

    In photovoltaic devices, metal nanoparticles embedded in a semiconductor layer allow the enhancement of solar-toelectric energy conversion efficiency due to enhanced light absorption via a prolonged optical path, enhanced electric fields near the metallic inclusions, direct injection of hot electrons, or local heating. Here we pursue the first two avenues. In the first, light scattered at an angle beyond the critical angle for reflection is coupled into the semiconductor layer and confined within such planar waveguide up to possible exciton generation. In the second, light is trapped by the excitation of localized surface plasmons on metal nanoparticles leading to enhanced near-field plasmon-exciton coupling at the peak of the plasmon resonance. We report on results of a numerical experiment on light absorption in polymer- (fullerene derivative) blends, using the 3D FDTD method, where exact optical parameters of the materials involved are taken from our recent measurements. In simulations we investigate light absorption in randomly distributed metal nanoparticles dispersed in polyazomethine-(fullerene derivative) blends, which serve as active layers in bulkheterojunction polymer solar cells. In the study Ag and Al nanoparticles of different diameters and fill factors are diffused in two air-stable aromatic polyazomethines with different chemical structures (abbreviated S9POF and S15POF) mixed with phenyl-C61-butyric acid methyl ester (PCBM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The mixtures are spin coated on a 100 nm thick Al layer deposited on a fused silica substrate. Optical constants of the active layers are taken from spectroscopic ellipsometry and reflectance measurements using a rotating analyzer type ellipsometer with auto-retarder performed in the wavelength range from 225 nm to 2200 nm. The permittivities of Ag and Al particles of diameters from 20 to 60 nm are assumed to be equal to those measured on 100 to 200 nm thick metal films.

  2. Absorption Line Studies and the Distribution of Neutral Gas in the Local Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Bruhweiler, F. C.

    1984-01-01

    Previous published absorption line studies performed at ultraviolet and visual wavelengths are combined with new ultraviolet data in order to map out the distribution of HI within 150 pc of the Sun. Newly presented data for distances less than 50 pc further support the local cloud model as presented by Bruhweiler (1982). The Sun is embedded, near the edge of a diffuse cloud with total column density 2 x 10 to the 19th power/sq cm. Most observed directions within 50 pc away from the cloud body reveal trace amounts of gas (N)HI) approximately 10 to the 18th power/sq cm presumably arising in the outer skin of the local cloud. At greater distances (50 approximately or d approximately or 150 pc) most directions show significant absorption with N(HI) 10(19)/sq cm. Two directions, one toward the northern galactic pole (NGP), the other toward beta CMa exhibit unusually low HI column densities out to distances of 150 to 200 pc. However, substantial amounts of gas N(HI) 10 to the 19th power/sq cm, are seen toward the NGP at greater distances. The implicatons of these results on astronomy at wavelengths shortward of 912A are discussed.

  3. Structural models and atomic distribution of bimetallic nanoparticles as investigated by X-ray absorption spectroscopy.

    PubMed

    Hwang, Bing-Joe; Sarma, Loka Subramanyam; Chen, Jiun-Ming; Chen, Ching-Hsiang; Shih, Shou-Chu; Wang, Guo-Rung; Liu, Din-Goa; Lee, Jyh-Fu; Tang, Mau-Tsu

    2005-08-10

    In this report, we describe a general methodology to determine the extent of alloying or atomic distribution quantitatively in bimetallic nanoparticles (NPs) by X-ray absorption spectroscopy (XAS). The structural parameters determined in these studies serve as a quantitative index and provide a general route to determine the structural aspects of the bimetallic NPs. We have derived various types of possible structural models based on the extent of alloying and coordination number parameters of bimetallic NPs. We also discussed the nature of homo- and heterometallic interactions in bimetallic NPs based on the extent of alloying. Herein, we use carbon-supported platinum-ruthenium bimetallic nanoparticles to demonstrate the proposed methodology, and this can be extended further to get more insights into the alloying extent or atomic distribution of other bimetallic systems. The results demonstrated in this paper open up methods to determine the atomic distribution of bimetallic NPs, which is an extremely important parameter that strongly influences the physicochemical properties of NPs and their applications.

  4. The velocity distribution of interstellar gas observed in strong UV absorption lines

    NASA Technical Reports Server (NTRS)

    Cowie, L. L.; York, D. G.

    1978-01-01

    Observations of three strong interstellar UV absorption lines of N I (1199 A), N II (1083 A), and Si III (1206 A) in 47 stars of widely varying distance and a variety of spectral types are analyzed to obtain a velocity distribution function for the interstellar gas. A technique based on the maximum and minimum velocities observed along a line of sight is adopted because of heavy line blending, and results are discussed for both power-law and exponential distribution functions. The expected distribution of radiative-phase supernova remnants (SNRs) in the interstellar medium is calculated as a function of SNR birthrate and of the interstellar density in which they evolve. The results are combined with observed distance estimates, and it is shown that an interstellar density in excess of 0.1 per cu cm would be required to keep the SNRs sufficiently confined so that their cross sections are consistent with the observed number of components. The alternative possibility is considered that SNRs do not enter the radiative phase before escaping from the Galaxy or colliding with neighboring remnants.

  5. Absorption, distribution, and excretion of /sup 14/C-trihalomethanes in mice and rats

    SciTech Connect

    Mink, F.L.; Brown, T.J.; Rickabaugh, J.

    1986-11-01

    Chloroform and other trihalomethanes have been shown to originate from reactions between chlorine and naturally-occurring organic precursors in water. Chloroform (TCM) has been shown, at high dose levels, to increase the tumor incidence in mice and rats. Studies by lardiff demonstrated chloroform was not mutagenic in the Ames bioassay using Salmonella typhimurium strains TA100 and TA1535. Bromodichloromethane, dibromochloromethane and bromoform demonstrated a dose-related mutagenic response. Differences in biological responses between mice and rats have been attributed to differences in their relative rates of TCM metabolism. Several predictive studies estimate that the mouse metabolizes TCM at a significantly different rate than the rat. This study was initiated to determine the absorption, distribution and excretion characteristics of four trihalomethanes (TCM, TBM, DBCM and BDCM) using the carbon 14 labeled compounds under identical experimental conditions in both the mouse and rat.

  6. Absorption, distribution, and elimination of graded oral doses of methylmercury in juvenile white sturgeon.

    PubMed

    Huang, Susie Shih-Yin; Strathe, Anders Bjerring; Fadel, James G; Lin, Pinpin; Liu, Tsung-Yun; Hung, Silas S O

    2012-10-15

    Mercury (Hg) is toxic and is released into the environment from a wide variety of anthropogenic sources. Methylmercury (MeHg), a product of microbial methylation, enables rapid Hg bioaccumulation and biomagnification in the biota. Methylmercury is sequestered and made available to the rest of the biota through the benthic-detrital component leading to the high risk of exposure to benthic fish species, such as white sturgeon (Acipenser transmontanus). In the present study, a combined technique of stomach intubation, dorsal aorta cannulation, and urinary catheterization was utilized to characterize the absorption, distribution, and elimination of Hg in white sturgeon over a 48h exposure. Mercury, as methylmercury chloride, at either 0, 250, 500, or 1000 μg Hg/kg body weight, was orally intubated into white sturgeon, in groups of five. The blood was repeatedly sampled and urine collected from the fish over the 48h post intubation period, and at 48h, the fish were sacrificed for Hg tissue concentration and distribution determinations. The fractional rate of absorption (K), blood Hg concentration (μg/ml), tissue concentration (μg/g dry weight) and distribution (%), and urinary Hg elimination flux (μg/kg/h) are significantly different (p<0.05) among the MeHg doses. Complete blood uptake of Hg was observed in all MeHg treated fish by 12h. The maximal observed blood Hg concentration peaks are 0.56±0.02, 0.70±0.02, and 2.19±0.07 μg/ml (mean±SEM) for the 250, 500, and 1000 μgHg/kg body weight dose groups, respectively. Changes in blood Hg profiles can be described by a monomolecular function in all of the MeHg treated fish. The Hg concentration asymptote (A) and K are dose dependent. The relationship between A and the intubation dose, however, is nonlinear. Mercury levels in certain tissues are comparable to field data and longer-term study, indicating that the lower doses used in the current study are ecologically relevant for the species. Tissue Hg concentrations

  7. Absorption, distribution, metabolism and excretion of YM466, a novel factor Xa inhibitor, in rats.

    PubMed

    Mano, Yuji; Sonoda, Takuya; Nakamura, Eiji; Usui, Takashi; Kamimura, Hidetaka

    2004-09-01

    YM466 is a novel factor Xa inhibitor for the treatment of thrombosis. The absorption, distribution, metabolism and excretion of YM466 were investigated in male Fisher rats after a single oral administration. YM466 was absorbed rapidly from all segments of the gastrointestinal tract except the stomach. After oral dosing, the plasma concentration of (14)C-YM466 reached a maximum within 0.5 h, and declined rapidly with an elimination half-life of 0.64 h. The unchanged YM466 accounted for almost all of its radioactivity, suggesting a minimal metabolism in rats. This was also supported by the finding that no metabolites were observed in bile and urine after oral dosing of (14)C-YM466. The distribution of (14)C-YM466 in tissue was evaluated and the liver and kidney were the organs with radioactivity concentrations consistently higher than that of plasma. Cumulative biliary and urinary excretion of radioactivity in bile duct-cannulated rats was 29.5% and 7.6%, respectively, indicating prominent excretion into bile after oral dosing. This was consistent with the finding that 76.1% and 25.2% of radioactivity dosed were excreted to faeces and urine, respectively, after i.v. dosing. These results suggest that YM466 was rapidly absorbed and then subjected to biliary excretion with a minimal metabolism after oral dosing to rats. PMID:15334624

  8. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry.

    PubMed

    Rey-Raap, Natalia; Gallardo, Antonio

    2012-05-01

    In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52±0.4ppb of mercury in the vapor phase, 204.16±8.9ppb of mercury in the phosphor powder, and 18.74±0.5ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  9. Absorption, distribution, metabolism and excretion of novel phosphodiesterase type 4 inhibitor ASP3258 in rats.

    PubMed

    Ohtsu, Yoshiaki; Sonoda, Takuya; Susaki, Yoko; Tohda, Toshifumi; Fukunaga, Yasuhisa; Iwatsubo, Takafumi; Noguchi, Kiyoshi

    2015-01-01

    The potent and selective phosphodiesterase 4 inhibitor ASP3258 is a novel therapeutic agent for asthma and chronic obstructive pulmonary disease (COPD). After a single oral administration to rats, ASP3258 is rapidly absorbed with a bioavailability of 106%. In situ absorption data indicated that ASP3258 is mainly absorbed in the small intestine. Tissue distribution data after oral administration of (14)C-ASP3258 showed rapid and extensive distribution to various tissues. Excluding the gastrointestinal tract, the tissues with the highest concentrations were liver, heart and plasma. Liquid chromatography-nuclear magnetic resonance spectroscopy data revealed that O-glucuronidation of the carboxylic acid moiety of ASP3258 (formation of an acyl glucuronide) plays a key role in metabolism. No indication was found that the acyl glucuronide reacted with proteins in plasma or tissues. When (14)C-ASP3258 was orally administered to intact rats, urinary and fecal excretion accounted for 1.3% and 100.6% of the administered radioactivity, respectively. After a single oral administration of (14)C-ASP3258 to bile-cannulated rats, urinary and biliary excretion accounted for 0.7% and 93.8% of the administered radioactivity, respectively. These findings suggest that fecal excretion via bile plays an important role in the elimination of ASP3258-derived radioactivity. In vitro metabolic profiles were relatively similar among the species examined, suggesting that our findings in rats may help us to understand pharmacokinetics, efficacy and safety profiles in humans and other species.

  10. Comparing Spatial Distributions of Solar Prominence Mass Derived from Coronal Absorption

    NASA Technical Reports Server (NTRS)

    Gilbert, Holly; Kilper, Gary; Alexander, David; Kucera, Therese

    2010-01-01

    In the present work we extend the use of this mass-inference technique to a sample of prominences observed in at least two coronal lines. This approach, in theory, allows a direct calculation of prominence mass and helium abundance and how these properties vary spatially and temporally. Our motivation is two-fold: to obtain a He(exp 0)/H(exp 0) abundance ratio, and to determine how the relative spatial distribution of the two species varies in prominences. The first of these relies on the theoretical expectation that the amount of absorption at each EUV wavelength is well-characterized. However, in this work we show that due to a saturation of the continuum absorption in the 625 A and 368 A lines (which have much higher opacity compared to 195 A-) the uncertainties in obtaining the relative abundances are too high to give meaningful estimates. This is an important finding because of its impact on future studies in this area. The comparison of the spatial distribution of helium and hydrogen presented here augments previous observational work indicating that cross-field diffusion of neutrals is an important mechanism for mass loss. Significantly different loss timescales for neutral He and H (helium drains much more rapidly than hydrogen) can impact prominence structure, and both the present and past studies suggest this mechanism is playing a role in structure and possibly dynamics. Section 2 of this paper contains a description of the observations and Section 3 summarizes the method used to infer mass along with the criteria imposed in choosing prominences appropriate for this study. Section 3 also contains a discussion of the problems due to limitations of the available data and the implications for determining relative abundances. We present our results in Section 4, including plots of radial-like scans of prominence mass in different lines to show the spatial distribution of the different species. The last section contains a discussion summarizing the importance

  11. ADM. Aerial view of administration area. Camera facing westerly. From ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Aerial view of administration area. Camera facing westerly. From left to right in foregound: Substation (TAN-605), Warehouse (TAN-628), Gate House (TAN-601), Administration Building (TAN-602). Left to right middle ground: Service Building (TAN-603), Warehouse (later known as Maintenance Shop or Craft Shop, TAN-604), Water Well Pump Houses, Fuel Tanks and Fuel Pump Houses, and Water Storage Tanks. Change House (TAN-606) on near side of berm. Large building beyond berm is A&M. Building, TAN-607. Railroad tracks beyond lead from (unseen) turntable to the IET. Date: June 6, 1955. INEEL negative no. 13201 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  12. Gamma camera imaging for studying intestinal absorption and whole-body distribution of selenomethionine.

    PubMed

    Madsen, Jan L; Sjögreen-Gleisner, Katarina; Elema, Dennis R; Søndergaard, Lasse R; Rasmussen, Palle; Fuglsang, Stefan; Ljungberg, Michael; Damgaard, Morten

    2014-02-01

    Se metabolism in humans is not well characterised. Currently, the estimates of Se absorption, whole-body retention and excretion are being obtained from balance and tracer studies. In the present study, we used gamma camera imaging to evaluate the whole-body retention and distribution of radiolabelled selenomethionine (SeMet), the predominant form of Se present in foods. A total of eight healthy young men participated in the study. After consumption of a meal containing 4 MBq [⁷⁵Se]L-SeMet ([⁷⁵Se]SeMet), whole-body gamma camera scanning was performed for 45 min every hour over a 6 h period, every second hour for the next 18 h and once on each of the subsequent 6 d. Blood, urine and faecal samples were collected to determine the plasma content of [⁷⁵Se]SeMet as well as its excretion in urine and faeces. Imaging showed that 87·9 (sd 3·3)% of the administered activity of [⁷⁵Se]SeMet was retained within the body after 7 d. In contrast, the measured excretion in urine and faeces for the 7 d period was 8·2 (sd 1·1)% of the activity. Time-activity curves were generated for the whole body, stomach, liver, abdomen (other than the stomach and the liver), brain and femoral muscles. Gamma camera imaging allows for the assessment of the postprandial absorption of SeMet. This technique may also permit concurrent studies of organ turnover of SeMet.

  13. Total Absorption Gamma-ray Spectrometer (TAGS) Intensity Distributions from INL's Gamma-Ray Spectrometry Center

    DOE Data Explorer

    Greenwood, R. E.

    A 252Cf fission-product source and the INL on-line isotope separator were used to supply isotope-separated fission-product nuclides to a total absorption -ray spectrometer. This spectrometer consisted of a large (25.4-cm diameter x 30.5-cm long) NaI(Tl) detector with a 20.3-cm deep axial well in which is placed a 300-mm2 x 1.0-mm Si detector. The spectra from the NaI(Tl) detector are collected both in the singles mode and in coincidence with the B-events detected in the Si detector. Ideally, this detector would sum all the energy of the B- rays in each cascade following the population of daughter level by B- decay, so that the event could be directly associated with a particular daughter level. However, there are losses of energy from attenuation of the rays before they reach the detector, transmission of rays through the detector, escape of secondary photons from Compton scattering, escape of rays through the detector well, internal conversion, etc., and the measured spectra are thus more complicated than the ideal case and the analysis is more complex. Analysis methods have been developed to simulate all of these processes and thus provide a direct measure of the B- intensity distribution as a function of the excitation energy in the daughter nucleus. These data yield more accurate information on the B- distribution than conventional decay-scheme studies for complex decay schemes with large decay energies, because in the latter there are generally many unobserved and observed but unplaced rays. The TAGS data have been analyzed and published [R. E. Greenwood et al., Nucl Instr. and metho. A390(1997)] for 40 fission product-nuclides to determine the B- intensity distributions. [Copied from the TAGS page at http://www.inl.gov/gammaray/spectrometry/tags.shtml]. Those values are listed on this page for quick reference.

  14. The Use of Correlated k-Distributions to Account for the Radiative Effect of Molecular Absorption Upon Satellite Measured Radiances

    NASA Technical Reports Server (NTRS)

    Kratz, David P.

    1998-01-01

    Establishing the radiative effect of molecular absorption (emission) in the atmosphere is critical to the proper interpretation of satellite retrieved radiances. Without an accurate accounting for molecular absorption, the assignment of radiative transfer processes to observed radiative effects could be fraught errors. Moreover, since the spectral characteristics of molecular absorption can change quickly with wavenumber, the adaptation of climate model parameterizations has the potential to lead to dubious results unless the chosen spectral range corresponds closely to the response function of the satellite instrument. Thus, an initiative has been undertaken to construct parameterizations that will account for the molecular absorption found in the spectral ranges of several satellite radiometers. Because of its efficiency and accuracy in calculating the molecular absorption for nonhomogeneous paths, the correlated k-distribution procedure has proven to be the most effective parameterization (Fu and Liou, 1992, and Kratz, 1995). A further advantage of the correlated k- distribution procedure is its ability to be incorporated directly into multiple scattering routines that consider scattering, as well as absorption, by clouds and aerosol particles.

  15. Distributed nerve gases sensor based on IR absorption in hollow optical fiber

    NASA Astrophysics Data System (ADS)

    Viola, R.; Liberatore, N.; Luciani, D.; Mengali, S.; Pierno, L.

    2010-10-01

    The Nerve gases are persistent gases that appear as very challenging menace in homeland security scenarios, due to the low pressure vapor at ambient temperature, and the very low lethal concentrations. A novel approach to the detection and identification of these very hazardous volatile compounds in large areas such as airports, underground stations, big events arenas, aimed to a high selectivity (Low false alarm probability), has been explored under the SENSEFIB Corporate Project of Finmeccanica S.p.A. The technical demonstrator under development within the Project is presented. It is based on distributed line sensors performing infrared absorption measurements to reveal even trace amounts of target compounds from the retrieval of their spectral fingerprint. The line sensor is essentially constituted by a widely tunable external cavity quantum cascade laser (EC-QCL), coupled to IR thermoelectrically cooled MCT fast detectors by means of a infrared hollow core fibers (HCF). The air is sampled through several micro-holes along the HCF, by means of a micropump, while the infrared radiation travels inside the fiber from the source to the detector, that are optically coupled with the opposite apertures of the HCF. The architecture of the sensor and its principle of operation, in order to cover large areas with a few line sensors instead of with a grid of many point sensors, are illustrated. The sensor is designed to use the HCF as an absorption cell, exploiting long path length and very small volume, (e.g fast response), at the same time. Furthermore the distributed sensor allows to cover large areas and/or not easily accessible locations, like air ducts, with a single line sensor by extending the HCF for several tens of meters. The main components implemented in the sensor are described, in particular: the EC-QCL source to span the spectral range of wavelength between 9.15um and 9.85um; and the hollow core fiber, exhibiting a suitably low optical loss in this spectral

  16. Total ozone column distribution over peninsular Malaysia from scanning imaging absorption spectrometer for atmospheric cartography (SCIAMACHY)

    NASA Astrophysics Data System (ADS)

    Tan, K. C.; Lim, H. S.; MatJafri, M. Z.

    2012-10-01

    Increasing of atmospheric ozone concentrations have received great attention around the whole because of its characteristic, in order to degrade air quality and brings hazard to human health and ecosystems. Ozone, one of the most pollutants source and brings a variety of adverse effects on plant life and human being. Continuous monitoring on ozone concentrations at atmosphere provide information and precautions for the high ozone level, which we need to be established. Satellite observation of ozone has been identified that it can provide the precise and accurate data globally, which sensitive to the small regional biases. We present measurements from Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) included on the European environmental satellite ENVISAT, launched on 1st of March 2002. Main objective of this study is to examine the ozone distribution over Peninsular Malaysia using SCIAMACHY level-2 of total ozone column WFMD version 1.0 with spatial resolution 1° x 1.25°. Maps of time averaged (yearly, tri-monthly) ozone was generated and analyzed over Peninsular Malaysia for the year 2003 using PCI Geomatica 10.3 image processing software. It was retrieved using the interpolation technique. The concentration changes within boundary layer at all altitude levels are equally sensitive through the SCIAMACHY nearinfrared nadir observations. Hence, we can make observation of ozone at surface source region. The results successfully identify the area with highest and lowest concentration of ozone at Peninsular Malaysia using SCIAMACHY data. Therefore, the study is suitable to examine the distribution of ozone at tropical region.

  17. Anticancer efficacy and absorption, distribution, metabolism, and toxicity studies of aspergiolide A in early drug development.

    PubMed

    Wang, Yuanyuan; Qi, Xin; Li, Dehai; Zhu, Tianjiao; Mo, Xiaomei; Li, Jing

    2014-01-01

    Since the first anthracycline was discovered, many other related compounds have been studied in order to overcome its defects and improve efficacy. In the present paper, we investigated the anticancer effects of a new anthracycline, aspergiolide A (ASP-A), from a marine-derived fungus in vitro and in vivo, and we evaluated the absorption, distribution, metabolism, and toxicity drug properties in early drug development. We found that ASP-A had activity against topoisomerase II that was comparable to adriamycin. ASP-A decreased the growth of various human cancer cells in vitro and induced apoptosis in BEL-7402 cells via a caspase-dependent pathway. The anticancer efficacy of ASP-A on the growth of hepatocellular carcinoma xenografts was further assessed in vivo. Results showed that, compared with the vehicle group, ASP-A exhibited significant anticancer activity with less loss of body weight. A pharmacokinetics and tissue distribution study revealed that ASP-A was rapidly cleared in a first order reaction kinetics manner, and was enriched in cancer tissue. The maximal tolerable dose (MTD) of ASP-A was more than 400 mg/kg, and ASP-A was not considered to be potentially genotoxic or cardiotoxic, as no significant increase of micronucleus rates or inhibition of the hERG channel was seen. Finally, an uptake and transport assay of ASP-A was performed in monolayers of Caco-2 cells, and ASP-A was shown to be absorbed through the active transport pathway. Altogether, these results indicate that ASP-A has anticancer activity targeting topoisomerase II, with a similar structure and mechanism to adriamycin, but with much lower toxicity. Nonetheless, further molecular structure optimization is necessary.

  18. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry

    SciTech Connect

    Rey-Raap, Natalia

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer New treatments for CFL are required considering the aim of Directive 202/96/CE. Black-Right-Pointing-Pointer It is shown that most of the mercury introduced into a CFL is in the phosphor powder. Black-Right-Pointing-Pointer Experimental conditions for microwave-assisted sample digestion followed by AAS measurements are described. Black-Right-Pointing-Pointer By washing the glass it is possible to reduce the concentration below legal limits. - Abstract: In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 {+-} 0.4 ppb of mercury in the vapor phase, 204.16 {+-} 8.9 ppb of mercury in the phosphor powder, and 18.74 {+-} 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  19. Intestinal absorption and tissue distribution of ( sup 14 C)pyrroloquinoline quinone in mice

    SciTech Connect

    Smidt, C.R.; Unkefer, C.J.; Houck, D.R.; Rucker, R.B. )

    1991-05-01

    Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, such as methanol dehydrogenase and membrane-bound glucose dehydrogenase. In animals fed chemically defined diets, PQQ improves reproductive outcome and neonatal growth. Consequently, the present study was undertaken to determine the extent to which PQQ is absorbed by the intestine, its tissue distribution, and route of excretion. About 28 micrograms of PQQ (0.42 microCi/mumol), labeled with {sup 14}C derived from L-tyrosine, was administered orally to Swiss-Webster mice (18-20 g) to estimate absorption. PQQ was readily absorbed (62%, range 19-89%) in the lower intestine, and was excreted by the kidneys (81% of the absorbed dose) within 24 hr. The only tissues that retained significant amounts of ({sup 14}C)PQQ at 24 hr were skin and kidney. For kidney, it was assumed that retention of ({sup 14}C)PQQ represented primarily PQQ destined for excretion. For skin, the concentration of ({sup 14}C)PQQ increased from 0.3% of the absorbed dose at 6 hr to 1.3% at 24 hr. Furthermore, most of the ({sup 14}C)PQQ in blood (greater than 95%) was associated with the blood cell fraction, rather than plasma.

  20. [Absorption and distribution of K, Na and Mg in Avicennia marina seedlings under cadmium stress].

    PubMed

    Lu, Zhi-qiang; Chen, Chang-xu; Ma, Li; Zheng, Wen-jiao

    2015-05-01

    In this paper, mangrove seedlings Avicennia marina were treated with various contents of cadmium (0, 0.5, 5, 25, 50, 100, 150 mg · L(-1)). These seedlings were cultivated by man-made seawater with a salinity of 15 in sand for 90 days in a greenhouse. The absorption and distribution of elements contents (K, Na and Mg) under cadmium stress were investigated at 45th and 90th day, respectively. The results showed that the enrichment of cadmium in the different components of seedlings increased with the increasing cadmium stress level and exposure time. The cadmium contents in roots and cotyledons were relatively higher than in the other components, accounting for 66.9% and 16.3% of cadmium in the seedlings under the 150 mg · L(-1) cadmium stress, respectively. The fall of cotyledons could reduce the damage of cadmium stress to the whole seedlings. The Na contents increased in roots and stems and decreased in leaves and cotyledons after cadmium stress for 90 days. The K content decreased in roots and cotyledons, while had no significant change in stems and leaves. The Mg content in roots, stems, leaves and cotyledons of seedlings treated with cadmium for 90 days were lower than those of the control, and were negatively related to the cadmium content. PMID:26571646

  1. Signatures of a conical intersection in photofragment distributions and absorption spectra: Photodissociation in the Hartley band of ozone

    SciTech Connect

    Picconi, David; Grebenshchikov, Sergy Yu.

    2014-08-21

    Photodissociation of ozone in the near UV is studied quantum mechanically in two excited electronic states coupled at a conical intersection located outside the Franck-Condon zone. The calculations, performed using recent ab initio PESs, provide an accurate description of the photodissociation dynamics across the Hartley/Huggins absorption bands. The observed photofragment distributions are reproduced in the two electronic dissociation channels. The room temperature absorption spectrum, constructed as a Boltzmann average of many absorption spectra of rotationally excited parent ozone, agrees with experiment in terms of widths and intensities of diffuse structures. The exit channel conical intersection contributes to the coherent broadening of the absorption spectrum and directly affects the product vibrational and translational distributions. The photon energy dependences of these distributions are strikingly different for fragments created along the adiabatic and the diabatic paths through the intersection. They can be used to reverse engineer the most probable geometry of the non-adiabatic transition. The angular distributions, quantified in terms of the anisotropy parameter β, are substantially different in the two channels due to a strong anticorrelation between β and the rotational angular momentum of the fragment O{sub 2}.

  2. Conference report: a hitchhiker's guide to outsourcing ADME studies: the inside of outsourcing.

    PubMed

    Pritchard, J Fred; Anderson, Shelby R; Breuckner, Claudia; Premkumar, Noel D; Polli, Joseph W

    2013-02-01

    This report gives a summary of the key points raised during a roundtable discussion convened at the American Association of Pharmaceutical Scientists 2012 Annual Meeting and Exposition held in Chicago on 17 October 2012. The science of ADME continues to grow, as does the impact of these studies on drug development. Understanding ADME requires efforts from several scientific specialties. With reductions in pharmaceutical company R&D staff there has been a corresponding growth in CROs with the capabilities and expertise to perform ADME work. This roundtable explored the challenges inherent in understanding ADME and the issues that arise when ADME studies shift from in-house study directors to external scientists working within the business model of a CRO. Pharmaceutical industry scientists and procurement specialists can satisfy their expectations by awareness of the growing expertise within CROs and the need for open communication among all partners involved in outsourced work.

  3. Reconstruction of combustion temperature and gas concentration distributions using line-of-sight tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Zhirong; Sun, Pengshuai; Pang, Tao; Xia, Hua; Cui, Xiaojuan; Li, Zhe; Han, Luo; Wu, Bian; Wang, Yu; Sigrist, Markus W.; Dong, Fengzhong

    2016-07-01

    Spatial temperature and gas concentration distributions are crucial for combustion studies to characterize the combustion position and to evaluate the combustion regime and the released heat quantity. Optical computer tomography (CT) enables the reconstruction of temperature and gas concentration fields in a flame on the basis of line-of-sight tunable diode laser absorption spectroscopy (LOS-TDLAS). A pair of H2O absorption lines at wavelengths 1395.51 and 1395.69 nm is selected. Temperature and H2O concentration distributions for a flat flame furnace are calculated by superimposing two absorption peaks with a discrete algebraic iterative algorithm and a mathematical fitting algorithm. By comparison, direct absorption spectroscopy measurements agree well with the thermocouple measurements and yield a good correlation. The CT reconstruction data of different air-to-fuel ratio combustion conditions (incomplete combustion and full combustion) and three different types of burners (one, two, and three flat flame furnaces) demonstrate that TDLAS has the potential of short response time and enables real-time temperature and gas concentration distribution measurements for combustion diagnosis.

  4. Reconstruction of combustion temperature and gas concentration distributions using line-of-sight tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Zhirong; Sun, Pengshuai; Pang, Tao; Xia, Hua; Cui, Xiaojuan; Li, Zhe; Han, Luo; Wu, Bian; Wang, Yu; Sigrist, Markus W.; Dong, Fengzhong

    2016-07-01

    Spatial temperature and gas concentration distributions are crucial for combustion studies to characterize the combustion position and to evaluate the combustion regime and the released heat quantity. Optical computer tomography (CT) enables the reconstruction of temperature and gas concentration fields in a flame on the basis of line-of-sight tunable diode laser absorption spectroscopy (LOS-TDLAS). A pair of H2O absorption lines at wavelengths 1395.51 and 1395.69 nm is selected. Temperature and H2O concentration distributions for a flat flame furnace are calculated by superimposing two absorption peaks with a discrete algebraic iterative algorithm and a mathematical fitting algorithm. By comparison, direct absorption spectroscopy measurements agree well with the thermocouple measurements and yield a good correlation. The CT reconstruction data of different air-to-fuel ratio combustion conditions (incomplete combustion and full combustion) and three different types of burners (one, two, and three flat flame furnaces) demonstrate that TDLAS has the potential of short response time and enables real-time temperature and gas concentration distribution measurements for combustion diagnosis.

  5. ADME studies of [5-(3)H]-2'-O-methyluridine nucleoside in mice: a building block in siRNA therapeutics.

    PubMed

    Lozac'h, Frederic; Christensen, Jesper; Faller, Thomas; van de Kerkhof, Esther; Krauser, Joel; Garnier, Maxime; Litherland, Karine; Catoire, Alexandre; Natt, Francois; Hunziker, Jurg; Swart, Piet

    2016-02-01

    The chemical modification 2'-O-methyl of nucleosides is often used to increase siRNA stability towards nuclease activities. However, the metabolic fate of modified nucleosides remains unclear. Therefore, the aim of this study was to determine the mass balance, pharmacokinetic, and absorption, distribution, metabolism, and excretion (ADME)-properties of tritium-labeled 2'-O-methyluridine, following a single intravenous dose to male CD-1 mice. The single intravenous administration of [5-(3)H]-2'-O-methyluridine was well tolerated in mice. Radioactivity was rapidly and widely distributed throughout the body and remained detectable in all tissues investigated throughout the observation period of 48 h. After an initial rapid decline, blood concentrations of total radiolabeled components declined at a much slower rate. [(3)H]-2'-O-Methyluridine represented a minor component of the radioactivity in plasma (5.89% of [(3)H]-AUC 0-48 h). Three [(3)H]-2'-O-methyluridine metabolites namely uridine (M1), cytidine (M2), and uracil (M3) were the major circulating components representing 32.8%, 8.11%, and 23.6% of radioactivity area under the curve, respectively. The highest concentrations of total radiolabeled components and exposures were observed in kidney, spleen, pineal body, and lymph nodes. The mass balance, which is the sum of external recovery of radioactivity in excreta and remaining radioactivity in carcass and cage wash, was complete. Renal excretion accounted for about 52.7% of the dose with direct renal excretion of the parent in combination with metabolism to the endogenous compounds cytidine, uracil, cytosine, and cytidine. PMID:26977299

  6. Intestinal absorption, organ distribution, and urinary excretion of the rare sugar D-psicose

    PubMed Central

    Tsukamoto, Ikuko; Hossain, Akram; Yamaguchi, Fuminori; Hirata, Yuko; Dong, Youyi; Kamitori, Kazuyo; Sui, Li; Nonaka, Machiko; Ueno, Masaki; Nishimoto, Kazuyuki; Suda, Hirofumi; Morimoto, Kenji; Shimonishi, Tsuyoshi; Saito, Madoka; Song, Tao; Konishi, Ryoji; Tokuda, Masaaki

    2014-01-01

    Background The purpose of this study was to evaluate intestinal absorption, organ distribution, and urinary elimination of the rare sugar D-psicose, a 3-carbon stereoisomer of D-fructose that is currently being investigated and which has been found to be strongly effective against hyperglycemia and hyperlipidemia. Methods This study was performed using radioactive D-psicose, which was synthesized enzymatically from radioactive D-allose. Concentrations in whole blood, urine, and organs were measured at different time points until 2 hours after both oral and intravenous administrations and 7 days after a single oral administration (100 mg/kg body weight) to Wistar rats. Autoradiography was also performed by injecting 100 mg/kg body weight of 14C-labeled D-psicose or glucose intravenously to C3H mice. Results Following oral administration, D-psicose easily moved to blood. The maximum blood concentration (48.5±15.6 μg/g) was observed at 1 hour. Excretion to urine was 20% within 1 hour and 33% within 2 hours. Accumulation to organs was detected only in the liver. Following intravenous administration, blood concentration was decreased with the half-life=57 minutes, and the excretion to urine was up to almost 50% within 1 hour. Similarly to the results obtained with oral administration, accumulation to organs was detected only in the liver. Seven days after the single-dose oral administration, the remaining amounts in the whole body were less than 1%. Autoradiography of mice showed results similar to those in rats. High signals of 14C-labeled D-psicose were observed in liver, kidney, and bladder. Interestingly, no accumulation of D-psicose was observed in the brain. Conclusion D-psicose was absorbed well after oral administration and eliminated rapidly after both oral and intravenous administrations, with short duration of action. The study provides valuable pharmacokinetic data for further drug development of D-psicose. Because the findings were mainly based on animal

  7. Reconstruction of spatial distributions of sound velocity and absorption in soft biological tissues using model ultrasonic tomographic data

    NASA Astrophysics Data System (ADS)

    Burov, V. A.; Zotov, D. I.; Rumyantseva, O. D.

    2014-07-01

    A two-step algorithm is used to reconstruct the spatial distributions of the acoustic characteristics of soft biological tissues-the sound velocity and absorption coefficient. Knowing these distributions is urgent for early detection of benign and malignant neoplasms in biological tissues, primarily in the breast. At the first stage, large-scale distributions are estimated; at the second step, they are refined with a high resolution. Results of reconstruction on the base of model initial data are presented. The principal necessity of preliminary reconstruction of large-scale distributions followed by their being taken into account at the second step is illustrated. The use of CUDA technology for processing makes it possible to obtain final images of 1024 × 1024 samples in only a few minutes.

  8. Essential Set of Molecular Descriptors for ADME Prediction in Drug and Environmental Chemical Space

    EPA Science Inventory

    Historically, the disciplines of pharmacology and toxicology have embraced quantitative structure-activity relationships (QSAR) and quantitative structure-property relationships (QSPR) to predict ADME properties or biological activities of untested chemicals. The question arises ...

  9. ADM. Warehouse (TAN604). Construction view of structural steel being placed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Warehouse (TAN-604). Construction view of structural steel being placed for roof. Date: October 1, 1953. INEEL negative no. 8950 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  10. ADM. Service Building (TAN603) as completed. Camera facing westerly. Date: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Service Building (TAN-603) as completed. Camera facing westerly. Date: October 19, 1954. INEEL negative no. 12578 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  11. Spatial and temporal variations in NO(2) distributions over Beijing, China measured by imaging differential optical absorption spectroscopy.

    PubMed

    Lee, Hanlim; Kim, Young J; Jung, Jinsang; Lee, Chulkyu; Heue, Klaus-Peter; Platt, Ulrich; Hu, Min; Zhu, Tong

    2009-04-01

    During the CAREBEIJING campaign in 2006, imaging differential optical absorption spectroscopy (I-DOAS) measurements were made from 08:00 to 16:00 on September 9 and 10 over Beijing, China. Detailed images of the near-surface NO(2) differential slant column density (DSCD) distribution over Beijing were obtained. Images with less than a 30-min temporal resolution showed both horizontal and vertical variations in NO(2) distributions. For DSCD to mixing ratio conversion, path length along the lines of I-DOAS lines of sight was estimated using the light-extinction coefficient and Angstrom exponent data obtained by a transmissometer and a sunphotometer, respectively. Mixing ratios measured by an in-situ NO(2) analyzer were compared with those estimated by the I-DOAS instrument. The obtained temporal and spatial variations in NO(2) distributions measured by I-DOAS for the two days are interpreted with consideration of the locations of the major NO(x) sources and local wind conditions. I-DOAS measurements have been applied in this study for estimating NO(2) distribution over an urban area with multiple and distributed emission sources. Results are obtained for estimated temporal and spatial NO(2) distributions over the urban atmosphere; demonstrating the capability of the I-DOAS technique. We discuss in this paper the use of I-DOAS measurements to estimate the NO(2) distribution over an urban area with multiple distributed emission sources. PMID:19111964

  12. Esthetic Outcomes of ADM-Assisted Expander-Implant Breast Reconstruction

    PubMed Central

    Nguyen, Khang T.; Mioton, Lauren M.; Smetona, John T.; Seth, Akhil K.; Kim, John Y.

    2012-01-01

    Objective: Adjunct acellular dermal matrices (ADM) are thought to improve esthetic outcomes of breast reconstruction but the existing evidence is largely anecdotal. In this study, we provide comparative data on esthetic outcomes of expander-implant breast reconstruction with and without ADM. Methods: Chart review was performed on a consecutive series of expander-implant reconstructions by the senior author. Demographic, oncologic, surgical, and photographic data were obtained for each patient. Photographic data were scored using a 3-point (0-1-2) breast-specific esthetic scale by 3 blinded, independent reviewers not involved in patient care. Results: ADM-assisted breast reconstructions had significantly higher scores than the non-ADM reconstructions for breast mound volume (1.38 vs 1.11; P = .0102), breast mound placement (1.57 vs 1.39; P = .0217), and the inframammary fold (1.39 vs 1.23; P = .0458). Conclusions: ADM may improve breast volume, placement, and inframammary fold definition. These specific findings may help plastic surgeons better utilize ADM to improve outcomes for breast reconstruction. PMID:23308305

  13. Effect of quantum dot size and size distribution on the intersublevel transitions and absorption coefficients of III-V semiconductor quantum dot

    SciTech Connect

    Kabi, Sanjib; Perera, A. G. Unil

    2015-03-28

    The intersublevel absorption peak energy and absorption coefficient of non-uniform quantum dot (QD) ensembles are calculated analytically. The effect of size variations and size distribution of QDs on their energy states is analyzed. The dots are considered as a quantum box with finite potential at the barriers and the size distribution described by a Gaussian function. The influence of the aspect ratio (base to height ratio) of the QDs on the optical transitions is studied. Our model predicts the dot size (height and base) accurately to determine the absorption peaks and corresponding absorption coefficient. We also compute the absorption coefficient of the QD with different size distributions to verify the results calculated using this model with the reported experimental and other theoretical results.

  14. Absorption, Distribution, Excretion, and Pharmacokinetics of 14C-Pyronaridine Tetraphosphate in Male and Female Sprague-Dawley Rats

    PubMed Central

    Park, Sang Hyun; Pradeep, Kannampalli

    2010-01-01

    The main objective of this investigation was to determine the absorption, distribution, excretion, and pharmacokinetics of the antimalarial drug pyronaridine tetraphosphate (PNDP) in Sprague-Dawley rats. Following oral administration of a single dose (10 mg/Kg) of 14C-PNDP, it was observed that the drug was readily absorbed from the small intestine within 1 hour following oral administration and was widely distributed in most of the tissues investigated as determined from the observed radioactivity in the tissues. The peak value of the drug in the blood was reached at around 8 hours postadministration, and radioactivity was detected in most of the tissues from 4 hours onwards. 14C-PNDP showed a poor permeability across the blood-brain barrier, and the absorption, distribution, and excretion of 14C-PNDP were found to be gender-independent as both male and female rats showed a similar pattern of radioactivity. Excretion of the drug was predominantly through the urine with a peak excretion post 24 hours of administration. A small amount of the drug was also excreted in the feces and also in the breath. It was found that the Cmax, AUC (0-inf), and Tmax values were similar to those observed in the Phase II clinical trials of pyronaridine/artesunate (Pyramax) conducted in Uganda. PMID:20379367

  15. Effects of Kaolin Application on Light Absorption and Distribution, Radiation Use Efficiency and Photosynthesis of Almond and Walnut Canopies

    PubMed Central

    Rosati, Adolfo; Metcalf, Samuel G.; Buchner, Richard P.; Fulton, Allan E.; Lampinen, Bruce D.

    2007-01-01

    Background and Aims Kaolin applied as a suspension to plant canopies forms a film on leaves that increases reflection and reduces absorption of light. Photosynthesis of individual leaves is decreased while the photosynthesis of the whole canopy remains unaffected or even increases. This may result from a better distribution of light within the canopy following kaolin application, but this explanation has not been tested. The objective of this work was to study the effects of kaolin application on light distribution and absorption within tree canopies and, ultimately, on canopy photosynthesis and radiation use efficiency. Methods Photosynthetically active radiation (PAR) incident on individual leaves within the canopy of almond (Prunus dulcis) and walnut (Juglans regia) trees was measured before and after kaolin application in order to study PAR distribution within the canopy. The PAR incident on, and reflected and transmitted by, the canopy was measured on the same day for kaolin-sprayed and control trees in order to calculate canopy PAR absorption. These data were then used to model canopy photosynthesis and radiation use efficiency by a simple method proposed in previous work, based on the photosynthetic response to incident PAR of a top-canopy leaf. Key Results Kaolin increased incident PAR on surfaces of inner-canopy leaves, although there was an estimated 20 % loss in PAR reaching the photosynthetic apparatus, due to increased reflection. Assuming a 20 % loss of PAR, modelled photosynthesis and photosynthetic radiation use efficiency (PRUE) of kaolin-coated leaves decreased by only 6·3 %. This was due to (1) more beneficial PAR distribution within the kaolin-sprayed canopy, and (2) with decreasing PAR, leaf photosynthesis decreases less than proportionally, due to the curvature of the photosynthesis response-curve to PAR. The relatively small loss in canopy PRUE (per unit of incident PAR), coupled with the increased incident PAR on the leaf surface on

  16. Human studies on the absorption, distribution, metabolism, and excretion of tea polyphenols.

    PubMed

    Clifford, Michael N; van der Hooft, Justin J J; Crozier, Alan

    2013-12-01

    Recent research on the bioavailability of flavan-3-ols after ingestion of green tea by humans is reviewed. Glucuronide, sulfate, and methyl metabolites of (epi)catechin and (epi)gallocatechin glucuronide reach peak nanomolar per liter plasma concentrations 1.6-2.3 h after intake, indicating absorption in the small intestine. The concentrations then decline, and only trace amounts remain 8 h after ingestion. Urinary excretion of metabolites over a 24-h period after green tea consumption corresponded to 28.5% of the ingested (epi)catechin and 11.4% of (epi)gallocatechin, suggesting higher absorption than that of most other flavonoids. The fate of (-)-epicatechin-3-O-gallate, the main flavan-3-ol in green tea, is unclear because it appears unmetabolized in low concentrations in plasma but is not excreted in urine. Possible enterohepatic recirculation of flavan-3-ols is discussed along with the impact of dose and other food components on flavan-3-ol bioavailability. Approximately two-thirds of the ingested flavan-3-ols pass from the small to the large intestine where the action of the microbiota results in their conversion to C-6-C-5 phenylvalerolactones and phenylvaleric acids, which undergo side-chain shortening to produce C-6-C-1 phenolic and aromatic acids that enter the bloodstream and are excreted in urine in amounts equivalent to 36% of flavan-3-ol intake. Some of these colon-derived catabolites may have a role in vivo in the potential protective effects of tea consumption. Although black tea, which contains theaflavins and thearubigins, is widely consumed in the Western world, there is surprisingly little research on the absorption and metabolism of these compounds after ingestion and their potential impact on health.

  17. SYNCHROTRON POLARIZATION AND SYNCHROTRON SELF-ABSORPTION SPECTRA FOR A POWER-LAW PARTICLE DISTRIBUTION WITH FINITE ENERGY RANGE

    SciTech Connect

    Fouka, M.; Ouichaoui, S. E-mail: souichaoui@usthb.dz

    2011-12-10

    We have derived asymptotic forms for the degree of polarization of the optically thin synchrotron and for synchrotron self-absorption (SSA) spectra assuming a power-law particle distribution of the form N({gamma}) {approx} {gamma}{sup -p} with {gamma}{sub 1} < {gamma} < {gamma}{sub 2}, especially for a finite high-energy limit, {gamma}{sub 2}, in the case of an arbitrary pitch angle. The new results inferred concern more especially the high-frequency range x >> {eta}{sup 2} with parameter {eta} = {gamma}{sub 2}/{gamma}{sub 1}. The calculated SSA spectra concern instantaneous photon emission where cooling effects are not considered. They have been obtained by also ignoring likely effects such as Comptonization, pair creation and annihilation, as well as magnetic photon splitting. To that aim, in addition to the two usual absorption frequencies, a third possible one has been derived and expressed in terms of the Lambert W function based on the analytical asymptotic form of the absorption coefficient, {alpha}{sub {nu}}, for the high-frequency range {nu} >> {nu}{sub 2} (with {nu}{sub 2} the synchrotron frequency corresponding to {gamma}{sub 2}). We have shown that the latter frequency may not have realistic applications in astrophysics, except in the case of an adequate set of parameters allowing one to neglect Comptonization effects. More detailed calculations and discussions are presented.

  18. Iron absorption from the whole diet: comparison of the effect of two different distributions of daily calcium intake.

    PubMed

    Gleerup, A; Rossander-Hulthén, L; Gramatkovski, E; Hallberg, L

    1995-01-01

    The possibility of reducing calcium inhibition of iron absorption by decreasing calcium intake in lunch and dinner meals, which provided the most dietary iron, was examined in 21 healthy female volunteers. During a 10-d period, nonheme iron in all meals was extrinsically labeled with radioisotopic iron to a uniform specific activity. Iron absorption from two identical 10-d periods was compared when meals were labeled with two different iron radioisotopes and when the same amount of calcium (937 mg) was distributed in two ways, in either mainly breakfast and late evening meals or more evenly in all meals. About 30-50% more iron was absorbed when no milk or cheese was served with lunch or dinner. The difference was statistically significant. Median iron requirements (1.61 mg/d) calculated from body weight and menstrual iron losses agreed with the mean value of median iron absorption in the two 10-d periods (1.54 mg/d), which supports the validity of the present method. A reasonable separation of calcium and iron intakes would improve iron nutrition.

  19. Effective utilization of quantum-cascade distributed-feedback lasers in absorption spectroscopy.

    PubMed

    Kosterev, A A; Curl, R F; Tittel, F K; Gmachl, C; Capasso, F; Sivco, D L; Baillargeon, J N; Hutchinson, A L; Cho, A Y

    2000-08-20

    A variable duty cycle quasi-cw frequency scanning technique was applied to reduce thermal effects resulting from the high heat dissipation of type I quantum-cascade lasers. This technique was combined with a 100-m path-length multipass cell and a zero-air background-subtraction technique to enhance detection sensitivity to a parts-in-10(9) (ppb) concentration level for spectroscopic trace-gas detection of CH4, N2O, H2O, and C2H5OH in ambient air at 7.9 micrometers. A new technique for analysis of dense high resolution absorption spectra was applied to detection of ethanol in ambient air, yielding a 125-ppb detection limit.

  20. The effects of unsaturated dietary fats on absorption, excretion, synthesis, and distribution of cholesterol in man

    PubMed Central

    Grundy, Scott M.; Ahrens, E. H.

    1970-01-01

    Cholesterol balance studies were carried out in 11 patients with various types of hyperlipoproteinemia to determine the mechanism by which unsaturated fats lower plasma cholesterol. Unsaturated fats produced no increase in fecal endogenous neutral steroids in 10 of 11 patients and no decrease in absorption of exogenous cholesterol in 5 patients who received cholesterol in the diet. In 8 of 11 patients no changes occurred in excretion of bile acids during the period on unsaturated fat when plasma cholesterol was declining. However, in 3 of 11 patients small but significant increases in bile acid excretion were found during this transitional period; in 2 others increases also occurred after plasma cholesterol had become constant at lower levels on unsaturated fat. Since the majority of patients showed no change in cholesterol or bile acid excretions during the transitional period, we propose that when excretion changes did occur they were probably not the cause of the plasma cholesterol change. Furthermore, turnover data and specific activity curves suggested that cholesterol synthesis was not influenced by exchange of dietary fats. Thus, excluding changes in excretion and synthesis, we conclude that it is most likely that unsaturated fats cause plasma cholesterol to be redistributed into tissue pools. We have also examined the possibility that cholesterol which is redistributed into tissues could be secondarily excreted as neutral steroids or bile acids. In at least 5 of 11 patients excretion patterns were consistent with this explanation. However, we cannot rule out that excretion changes may have been due to alterations in transit time, to changes in bacterial flora, or to transitory changes in absorption or synthesis of cholesterol or bile acids. Our conclusion that unsaturated fats cause a redistribution of cholesterol between plasma and tissue pools points to the necessity in future to explore where cholesterol is stored, to what extent stored cholesterol can

  1. Absorption and distribution kinetics of the 13C-labeled tomato carotenoid phytoene in healthy adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoene is a tomato carotenoid which may contribute to the apparent health benefits of tomato consumption. While phytoene is a less prominent tomato carotenoid than lycopene, it is a major carotenoid in various human tissues. Phytoene distribution to plasma lipoproteins and tissues differs from lyc...

  2. Analysis for nonlinear inversion technique developed to estimate depth-distribution of absorption by spatially resolved backscattering measurement

    NASA Astrophysics Data System (ADS)

    Nishida, Kazuhiro; Namita, Takeshi; Kato, Yuji; Shimizu, Koichi

    2015-03-01

    We have proposed a new nonlinear inversion technique to estimate the spatial distribution of the absorption coefficient (μa) in the depth direction of a turbid medium by spatially resolved backscattering measurement. With this technique, we can obtain cross-sectional image of μa as deep as the backscattered light traveled even when the transmitted light through the medium cannot be detected. In this technique, the depth distribution of absorption coefficient is determined by iterative calculation using the spatial path-length distribution (SPD) of traveled photons as a function of source-detector distance. In this calculation, the variance of path-length of many photons in each layer is also required. The SPD and the variance of path-length are obtained by Monte Carlo simulation using a known reduced scattering coefficient (μs'). Therefore, we need to know the μs' of the turbid medium beforehand. We have shown in computer simulation that this technique works well when the μs' is the typical values of mammalian body tissue, or 1.0 /mm. In this study, the accuracy of the μa estimation was analyzed and its dependence on the μs' was clarified quantitatively in various situations expected in practice. 10% deviations in μs' resulted in about 30% error in μa estimation, in average. This suggested that the measurement or the appropriate estimation of μs' is required to utilize the proposed technique effectively. Through this analysis, the effectiveness and the limitation of the newly proposed technique were clarified, and the problems to be solved were identified.

  3. Improved ADM1 model for anaerobic digestion process considering physico-chemical reactions.

    PubMed

    Zhang, Yang; Piccard, Sarah; Zhou, Wen

    2015-11-01

    The "Anaerobic Digestion Model No. 1" (ADM1) was modified in the study by improving the bio-chemical framework and integrating a more detailed physico-chemical framework. Inorganic carbon and nitrogen balance terms were introduced to resolve the discrepancies in the original bio-chemical framework between the carbon and nitrogen contents in the degraders and substrates. More inorganic components and solids precipitation processes were included in the physico-chemical framework of ADM1. The modified ADM1 was validated with the experimental data and used to investigate the effects of calcium ions, magnesium ions, inorganic phosphorus and inorganic nitrogen on anaerobic digestion in batch reactor. It was found that the entire anaerobic digestion process might exist an optimal initial concentration of inorganic nitrogen for methane gas production in the presence of calcium ions, magnesium ions and inorganic phosphorus. PMID:26253912

  4. Application of ADM1 for modeling of biogas production from anaerobic digestion of Hydrilla verticillata.

    PubMed

    Chen, Xiaojuan; Chen, Zhihua; Wang, Xun; Huo, Chan; Hu, Zhiquan; Xiao, Bo; Hu, Mian

    2016-07-01

    The present study focused on the application of anaerobic digestion model no. 1 (ADM1) to simulate biogas production from Hydrilla verticillata. Model simulation was carried out by implementing ADM1 in AQUASIM 2.0 software. Sensitivity analysis was used to select the most sensitive parameters for estimation using the absolute-relative sensitivity function. Among all the kinetic parameters, disintegration constant (kdis), hydrolysis constant of protein (khyd_pr), Monod maximum specific substrate uptake rate (km_aa, km_ac, km_h2) and half-saturation constants (Ks_aa, Ks_ac) affect biogas production significantly, which were optimized by fitting of the model equations to the data obtained from batch experiments. The ADM1 model after parameter estimation was able to well predict the experimental results of daily biogas production and biogas composition. The simulation results of evolution of organic acids, bacteria concentrations and inhibition effects also helped to get insight into the reaction mechanisms.

  5. Improved ADM1 model for anaerobic digestion process considering physico-chemical reactions.

    PubMed

    Zhang, Yang; Piccard, Sarah; Zhou, Wen

    2015-11-01

    The "Anaerobic Digestion Model No. 1" (ADM1) was modified in the study by improving the bio-chemical framework and integrating a more detailed physico-chemical framework. Inorganic carbon and nitrogen balance terms were introduced to resolve the discrepancies in the original bio-chemical framework between the carbon and nitrogen contents in the degraders and substrates. More inorganic components and solids precipitation processes were included in the physico-chemical framework of ADM1. The modified ADM1 was validated with the experimental data and used to investigate the effects of calcium ions, magnesium ions, inorganic phosphorus and inorganic nitrogen on anaerobic digestion in batch reactor. It was found that the entire anaerobic digestion process might exist an optimal initial concentration of inorganic nitrogen for methane gas production in the presence of calcium ions, magnesium ions and inorganic phosphorus.

  6. Protocol for the prevention and management of complications related to ADM implant-based breast reconstructions.

    PubMed

    Citron, Isabelle; Dower, Rory; Ho-Asjoe, Mark

    2016-01-01

    Acellular dermal matrix (ADM) implant-based reconstructions have transformed direct-to-implant breast reconstruction (DTI). But like all surgery, it is not deplete of complications such as seroma, infections and wound healing problems. These are cited with varying frequencies in the literature. With increased experience and through a series of measures instituted to minimize complications, we have been able to improve outcomes for our patients. We report our technical refinements for prevention of ADM reconstruction associated complications including patient selection, implant selection, drains, dressing and our post operative antibiotic regime. We also outline our protocol for the management of ADM associated complications including seroma, simple and complex infection and red breast syndrome, such that the sequelae of complications are minimized and patients achieve a better long-term outcome. PMID:26816672

  7. Protocol for the prevention and management of complications related to ADM implant-based breast reconstructions

    PubMed Central

    Citron, Isabelle; Dower, Rory; Ho-Asjoe, Mark

    2016-01-01

    Acellular dermal matrix (ADM) implant-based reconstructions have transformed direct-to-implant breast reconstruction (DTI). But like all surgery, it is not deplete of complications such as seroma, infections and wound healing problems. These are cited with varying frequencies in the literature. With increased experience and through a series of measures instituted to minimize complications, we have been able to improve outcomes for our patients. We report our technical refinements for prevention of ADM reconstruction associated complications including patient selection, implant selection, drains, dressing and our post operative antibiotic regime. We also outline our protocol for the management of ADM associated complications including seroma, simple and complex infection and red breast syndrome, such that the sequelae of complications are minimized and patients achieve a better long-term outcome. PMID:26816672

  8. Non-parametric PCM to ADM conversion. [Pulse Code to Adaptive Delta Modulation

    NASA Technical Reports Server (NTRS)

    Locicero, J. L.; Schilling, D. L.

    1977-01-01

    An all-digital technique to convert pulse code modulated (PCM) signals into adaptive delta modulation (ADM) format is presented. The converter developed is shown to be independent of the statistical parameters of the encoded signal and can be constructed with only standard digital hardware. The structure of the converter is simple enough to be fabricated on a large scale integrated circuit where the advantages of reliability and cost can be optimized. A concise evaluation of this PCM to ADM translation technique is presented and several converters are simulated on a digital computer. A family of performance curves is given which displays the signal-to-noise ratio for sinusoidal test signals subjected to the conversion process, as a function of input signal power for several ratios of ADM rate to Nyquist rate.

  9. Algebraic dynamic multilevel (ADM) method for fully implicit simulations of multiphase flow in porous media

    NASA Astrophysics Data System (ADS)

    Cusini, Matteo; van Kruijsdijk, Cor; Hajibeygi, Hadi

    2016-06-01

    This paper presents the development of an algebraic dynamic multilevel method (ADM) for fully implicit simulations of multiphase flow in homogeneous and heterogeneous porous media. Built on the fine-scale fully implicit (FIM) discrete system, ADM constructs a multilevel FIM system describing the coupled process on a dynamically defined grid of hierarchical nested topology. The multilevel adaptive resolution is determined at each time step on the basis of an error criterion. Once the grid resolution is established, ADM employs sequences of restriction and prolongation operators in order to map the FIM system across the considered resolutions. Several choices can be considered for prolongation (interpolation) operators, e.g., constant, bilinear and multiscale basis functions, all of which form partition of unity. The adaptive multilevel restriction operators, on the other hand, are constructed using a finite-volume scheme. This ensures mass conservation of the ADM solutions, and as such, the stability and accuracy of the simulations with multiphase transport. For several homogeneous and heterogeneous test cases, it is shown that ADM applies only a small fraction of the full FIM fine-scale grid cells in order to provide accurate solutions. The sensitivity of the solutions with respect to the employed fraction of grid cells (determined automatically based on the threshold value of the error criterion) is investigated for all test cases. ADM is a significant step forward in the application of dynamic local grid refinement methods, in the sense that it is algebraic, allows for systematic mapping across different scales, and applicable to heterogeneous test cases without any upscaling of fine-scale high resolution quantities. It also develops a novel multilevel multiscale method for FIM multiphase flow simulations in natural subsurface formations.

  10. New Deep Dermal ADM Incorporates Well in Case Series of Complex Breast Reconstruction Patients.

    PubMed

    Wilson, Henry Benjamin

    2015-05-01

    Breast cancer patients with significant comorbidities present reconstructive challenges due to a predictably high complication rate. During expander-based breast reconstruction, human acellular dermal matrix (ADM) is often used to prevent pectoralis muscle retraction, facilitate early expansion, and improve cosmetic outcome. Device infection and chronic seroma have been correlated to the addition of the graft by some large database reports but not others. This study describes the first reported experience with a new deep dermal ADM, FlexHD® Pliable™ (MTF, Edison, NJ). Sixteen breasts in 10 consecutive patients identified retrospectively and followed prospectively had immediate expander-based breast reconstruction utilizing the new ADM. Patient comorbidities were catalogued, complications were recorded, and overall reconstructive success was assessed. At implant exchange, the ADM was examined for tissue ingrowth and biopsied for histologic examination. All 16 breasts had successful reconstructions. Two breasts (12.5%) developed device infection, requiring removal and later replacement of the expander. One breast (6.7%) developed chronic seroma, also requiring expander removal and later replacement. All the complicated patients had significant comorbidities, including obesity in all 3. At expander removal, the FlexHD Pliable showed near-complete visual tissue incorporation in 14 of 16 breasts (88%). This case series demonstrates significant reconstructive success in challenging patients utilizing a novel ADM. Visual and histologic assessment of tissue ingrowth into the graft suggests the high rate of complication may be due to patient comorbidities rather than addition of ADM. Additional experience is needed to confirm and the study is ongoing. PMID:26020380

  11. Determination of exhaled nitric oxide distributions in a diverse sample population using tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Namjou, K.; Roller, C. B.; Reich, T. E.; Jeffers, J. D.; McMillen, G. L.; McCann, P. J.; Camp, M. A.

    2006-11-01

    A liquid-nitrogen free mid-infrared tunable diode laser absorption spectroscopy (TDLAS) system equipped with a folded-optical-path astigmatic Herriott cell was used to measure levels of exhaled nitric oxide (eNO) and exhaled carbon dioxide (eCO2) in breath. Quantification of absolute eNO concentrations was performed using NO/CO2 absorption ratios measured by the TDLAS system coupled with absolute eCO2 concentrations measured with a non-dispersive infrared sensor. This technique eliminated the need for routine calibrations using standard cylinder gases. The TDLAS system was used to measure eNO in children and adults (n=799, ages 5 to 64) over a period of more than one year as part of a field study. Volunteers for the study self-reported data including age, height, weight, and health status. The resulting data were used to assess system performance and to generate eNO and eCO2 distributions, which were found to be log-normal and Gaussian, respectively. There were statistically significant differences in mean eNO levels for males and females as well as for healthy and steroid naïve asthmatic volunteers not taking corticosteroid therapies. Ambient NO levels affected measured eNO concentrations only slightly, but this effect was not statistically significant.

  12. Principles and techniques in the design of ADMS+. [advanced data-base management system

    NASA Technical Reports Server (NTRS)

    Roussopoulos, Nick; Kang, Hyunchul

    1986-01-01

    'ADMS+/-' is an advanced data base management system whose architecture integrates the ADSM+ mainframe data base system with a large number of work station data base systems, designated ADMS-; no communications exist between these work stations. The use of this system radically decreases the response time of locally processed queries, since the work station runs in a single-user mode, and no dynamic security checking is required for the downloaded portion of the data base. The deferred update strategy used reduces overhead due to update synchronization in message traffic.

  13. Sensitive absorption spectroscopy with a room-temperature distributed-feedback quantum-cascade laser.

    PubMed

    Namjou, K; Cai, S; Whittaker, E A; Faist, J; Gmachl, C; Capasso, F; Sivco, D L; Cho, A Y

    1998-02-01

    We report what we believe are the first spectroscopic measurements to be made with a room-temperature quantum-cascade distributed-feedback laser. Using wavelength modulation spectroscopy, we detected N(2)O and CH(4) in the chemical fingerprint wavelength range near 8microm . The noise equivalent absorbance for our measurement was 5 parts in 10(5), limited by excess amplitude modulation on the laser output, which corresponds to a 1-Hz bandwidth detection limit of 250 parts N(2)O in 10(9) parts N(2) in a 1-m path length.

  14. Approximating the imbibition and absorption behavior of a distribution of matrix blocks by an equivalent spherical block

    SciTech Connect

    Zimmerman, R.W.; Bodvarsson, G.S.

    1994-03-01

    A theoretical study is presented of the effect of matrix block shape and matrix block size distribution on liquid imbibition and solute absorption in a fractured rock mass. It is shown that the behavior of an individual irregularly-shaped matrix block can be modeled with reasonable accuracy by using the results for a spherical matrix block, if one uses an effective radius {tilde a} = 3V/A, where V is the volume of the block and A is its surface area. In the early-time regime of matrix imbibition, it is shown that a collection of blocks of different sizes can be modeled by a single equivalent block, with an equivalent radius of {sup {minus}1}, where the average is taken on a volumetrically-weighted basis. In an intermediate time regime, it is shown for the case where the radii are normally distributed that the equivalent radius is reasonably well approximated by the mean radius . In the long-time limit, where no equivalent radius can be rigorously defined, an asymptotic expression is derived for the cumulative diffusion as a function of the mean and the standard deviation of the radius distribution function.

  15. [Studies on the remote measurement of the distribution of city gaseous pollutant by mobile passive differential optical absorption spectroscopy].

    PubMed

    Wu, Feng-cheng; Li, Ang; Xie, Pin-hua; Xu, Jin; Shi, Peng; Qin, Min; Wang, Man-hua; Wang, Jie; Zhang, Yong

    2011-03-01

    An optical remote sensing method based on passive differential optical absorption spectroscopy for the measurement of the distribution of city gaseous pollutant was studied. The passive DOAS system, which was installed in a car, successively measures the interested area (such as city, industrial area) and the column density was obtained by DOAS fitting process using the zenith scattered sunlight. The mobile DOAS was applied to measurement in Shenzhen City during the continuous six days and got the distribution of SO2, NO2 in this paper. It showed that the pollution in the west is higher than in the east. The average concentration in the west is 2.0 times higher than the eastern for SO2 and 3.6 times for NO2. And comparison of the values between mobile DOAS and the point instrument was carried out in Baguang site. There was an agreement between the two instruments, the correlation coefficient was 0.86 for SO2, while 0.57 for NO2. The results indicate that this optical remote sensing method based on passive DOAS is an effective means of rapidly determining the distribution of city gaseous pollutant. PMID:21595196

  16. Nuclear microscopy: a tool for imaging elemental distribution and percutaneous absorption in vivo.

    PubMed

    Veríssimo, Ana; Alves, Luís C; Filipe, Paulo; Silva, João N; Silva, Raquel; Ynsa, Maria Dolores; Gontier, Etienne; Moretto, Philippe; Pallon, Jan; Pinheiro, Teresa

    2007-04-01

    Nuclear microscopy is a technique based on a focused beam of accelerated particles that has the ability of imaging the morphology of the tissue in vivo and of producing the correspondent elemental maps, whether in major, minor, or trace concentrations. These characteristics constitute a strong advantage in studying the morphology of human skin, its elemental distributions and the permeation mechanisms of chemical compounds. In this study, nuclear microscopy techniques such as scanning transmission ion microscopy and particle induced X-ray emission were applied simultaneously, to cryopreserved human skin samples with the purpose of obtaining high-resolution images of cells and tissue morphology. In addition, quantitative elemental profiling and mapping of phosphorus, calcium, chlorine, and potassium in skin cross-sections were obtained. This procedure accurately distinguishes the epidermal strata and dermis by overlapping in real time the elemental information with density images obtained from the transmitted beam. A validation procedure for elemental distributions in human skin based on differential density of epidermal strata and dermis was established. As demonstrated, this procedure can be used in future studies as a tool for the in vivo examination of trans-epidermal and -dermal delivery of products.

  17. Simulation studies of multi-line line-of-sight tunable-diode-laser absorption spectroscopy performance in measuring temperature probability distribution function

    NASA Astrophysics Data System (ADS)

    Zhang, Guang-Le; Liu, Jian-Guo; Kan, Rui-Feng; Xu, Zhen-Yu

    2014-12-01

    Line-of-sight tunable-diode-laser absorption spectroscopy (LOS-TDLAS) with multiple absorption lines is introduced for non-uniform temperature measurement. Temperature binning method combined with Gauss—Seidel iteration method is used to measure temperature probability distribution function (PDF) along the line-of-sight (LOS). Through 100 simulated measurements, the variation of measurement accuracy is investigated with the number of absorption lines, the number of temperature bins and the magnitude of temperature non-uniformity. A field model with 2-T temperature distribution and 15 well-selected absorption lines are used for the simulation study. The Gauss—Seidel iteration method is discussed for its reliability. The investigation result about the variation of measurement accuracy with the number of temperature bins is different from the previous research results.

  18. Lead transfer in maternal milk, and the absorption, retention, distribution and excretion of lead in suckling mice

    SciTech Connect

    Keller, Charles Arthur

    1980-01-01

    Suckling mice were found to absorb and retain a greater fraction of an oral lead dose than did adult mice. Pinocytotic activity and lead uptake (in vivo) were found to be greatest in the distal small intestinal tissue. Cortisone pretreatment results in precocious cessation of pinocytotic activity in the intestine of suckling mice. Cortisone pretreatment of adult mice had no effect on whole body lead retention or intestinal tissue content of lead following an oral dose. The data indicate that the distal small intestine is the site of active pinocytosis of lead, and that pinocytosis is the major mechanism involved in lead absorption in suckling mice. Developmental differences were also observed in the percentage of lead retained in the whole body. Both groups exhibited dose-independent lead retention, indicating a first-order absorption process for each age group. Lead distribution and elimination from organs also differed between suckling and adult mice. Developmental differences were observed in organ lead concentration for kidneys and brain following oral doses. Relative distribution of lead to the brains of suckling mice were greater than to adult brains. Whole body and bone lead elimination rates were reduced in suckling compared to adult mice. Brain lead elimination rates did not differ in suckling and adult mice. A lactating mouse model was developed to study lead transfer to suckling offspring. Lead was transferred in milk to suckling offspring from mothers which had previously ingested lead in the drinking water. Relative lead transfer to suckled offspring during lactation greatly exceeded transfer to fetuses during gestation. Lactation resulted in an increased rate of maternal lead elimination. Lead concentration in milk exceeded plasma concentration by a factor of approximately 25. (ERB)

  19. Absorption and distribution of high specific radioactivity 2-C-abscisic Acid in cotton seedlings.

    PubMed

    Shindy, W W; Asmundson, C M; Smith, O E; Kumamoto, J

    1973-11-01

    High specific radioactivity (26.3 mc/mmole) racemic 2-(14)C-abscisic acid was synthesized. An aliquot of abscisic acid, 1.2 x 10(-4)m in aqueous methanolic solution, was applied to the surface of either a cotyledon or the first true leaf of 8- to 32-day-old cotton seedlings (Gossypium hirsutum L.). After various intervals (6-192 hours), the seedlings were processed for autoradiography, counting, and identification of the radioactivity. After 6 hours, radioactivity was observed moving basipetally out of the treated leaf toward the roots. Four days later, radioactivity could be detected throughout the whole seedling. After 8 days, 10% of the recovered radioactivity was found in the roots, and 80% remained in the treated leaf blade. Neither leaf type nor age had any effect on the abscisic acid movement or pattern of distribution. Isolated radioactivity from the roots was identified as abscisic acid, based on comparison with an authentic standard by thin layer chromatography, gas-liquid chromatography, or gas-liquid chromatography-mass spectrometry.

  20. Absorption, distribution, and excretion of 8-methoxypsoralen in HRA/Skh mice

    SciTech Connect

    Muni, I.A.; Schneider, F.H.; Olsson, T.A. III; King, M.

    1984-12-01

    The tissue distribution and excretion of (/sup 3/H)8-methoxypsoralen (8-MOP), a well-accepted therapeutic agent for the treatment of psoriasis, was studied in hairless HRA/Skh female mice. Mice were given single oral doses of 6 mg of (/sup 3/H)8-MOP or 5-(/sup 14/C)8-MOP/kg in corn oil. Radiochemical analyses of tissues and excreta were accomplished by liquid scintillation counting. The 8-MOP appeared to be rapidly absorbed through the gastrointestinal tract, where the tritium levels were highest, followed by skin, blood, and liver; levels were lowest in fat (adipose tissue). In female HRA/Skh mice which had not been irradiated with UVA (320-400 nm), 84% of the carbon-14 and 58% of the tritium were recovered in the urine and feces within 24 hours of oral administration of 5-(/sup 14/C)8-MOP or (/sup 3/H)8-MOP, respectively. Animals that were exposed to UVA and received (3H)8-MOP excreted approximately 12% less tritium in the urine and feces compared with the animals which received no UVA.

  1. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    PubMed

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz. PMID:26253286

  2. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    PubMed

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  3. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    DOE PAGES

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; Perfetto, Anthony; Geckler, Sam; Partridge, William P.

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in themore » intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.« less

  4. Fast Spatially Resolved Exhaust Gas Recirculation (EGR) Distribution Measurements in an Internal Combustion Engine Using Absorption Spectroscopy

    SciTech Connect

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E.; Perfetto, Anthony; Geckler, Sam; Partridge, William P.

    2015-09-01

    One effective method of reducing NOx emissions while improving efficiency is exhaust gas recirculation (EGR) in internal combustion engines. But, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder nonuniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. Furthermore, a sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. Our study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  5. ADM. Administration Building (TAN602). Early room layout, door and room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Administration Building (TAN-602). Early room layout, door and room schedules. Ralph M. Parsons 902-2-ANP-602-A 31. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 033-0602-00-693-106710 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  6. ADM. Warehouse (TAN604) Floor plan. General warehouse and chemical storage. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Warehouse (TAN-604) Floor plan. General warehouse and chemical storage. Ralph M. Parsons 902-2-ANP-604-A 55. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0604-00-693-106727 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  7. ADM. Water System Pump House (TAN610). Elevations, plan, and sections. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Water System Pump House (TAN-610). Elevations, plan, and sections. Ralph M. Parsons 902-2-ANP-610-A 74. Date: February 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0610-00-693-106739 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  8. ADM. Warehouse (TAN604). Elevations and sections. Ralph M. Parsons 9022ANP604A ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Warehouse (TAN-604). Elevations and sections. Ralph M. Parsons 902-2-ANP-604-A 56. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0604-00-693-106728 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  9. ADM. Administration Building (TAN602). Elevations, sections, details. Shows areas that ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Administration Building (TAN-602). Elevations, sections, details. Shows areas that were soon remodeled or added onto. Ralph M. Parsons 902-2-ANP-602-A 32 Date: August 1955. Approved by INEEL Classification Office for public release. INEEL index code no. 033-0602-00-693-106711 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  10. ADM. Water well pump houses (TAN612 and TAN613). Plans, elevations, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Water well pump houses (TAN-612 and TAN-613). Plans, elevations, floor and other details. Ralph M. Parsons 902-2-ANP-612-613-A S & P 82. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0612-00-693-106743 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  11. ADM. Change House (TAN606). Elevations and floor plan. Room Names. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Change House (TAN-606). Elevations and floor plan. Room Names. Ralph M. Parsons 902-2-ANP-606-A 65. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0606-00-693-106733 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  12. Implementing ADM1 for plant-wide benchmark simulations in Matlab/Simulink.

    PubMed

    Rosen, C; Vrecko, D; Gernaey, K V; Pons, M N; Jeppsson, U

    2006-01-01

    The IWA Anaerobic Digestion Model No.1 (ADM1) was presented in 2002 and is expected to represent the state-of-the-art model within this field in the future. Due to its complexity the implementation of the model is not a simple task and several computational aspects need to be considered, in particular if the ADM1 is to be included in dynamic simulations of plant-wide or even integrated systems. In this paper, the experiences gained from a Matlab/Simulink implementation of ADM1 into the extended COST/IWA Benchmark Simulation Model (BSM2) are presented. Aspects related to system stiffness, model interfacing with the ASM family, mass balances, acid-base equilibrium and algebraic solvers for pH and other troublesome state variables, numerical solvers and simulation time are discussed. The main conclusion is that if implemented properly, the ADM1 will also produce high-quality results in dynamic plant-wide simulations including noise, discrete sub-systems, etc. without imposing any major restrictions due to extensive computational efforts.

  13. ADM. Fuel Pump House (TAN611). Elevations, floor plan. Drawing includes ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Fuel Pump House (TAN-611). Elevations, floor plan. Drawing includes elevation and plans for "H.M." structures (Hose Storage?). Ralph M. Parsons 902-2-ANP-611-A 78 Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 035-0611-00-693-106741 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  14. ADM. Service Building (TAN603). Floor plan. Names of functional areas. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Service Building (TAN-603). Floor plan. Names of functional areas. Ralph M. Parsons 902-2-ANY-603-A 43. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 033-0603-00-693-106718 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  15. Investigating the Distribution of Chemical Forms of Sulfur in Prostate Cancer Tissue Using X-ray Absorption Spectroscopy.

    PubMed

    Czapla-Masztafiak, Joanna; Okoń, Krzysztof; Gałka, Marek; Huthwelker, Thomas; Kwiatek, Wojciech M

    2016-02-01

    The use of synchrotron radiation may shed more light on the study of prostate cancer, one of the leading diseases among men. In the presented study the microbeam setup at the PSI Swiss Light Source combined with fluorescence detected X-ray absorption spectroscopy (XAS) was applied to determine two-dimensional (2D) imaging of distributions of various chemical sulfur forms in prostate cancer tissue sections, since sulfur is considered important and essential in cancer progression. The research focused on prostate tissues obtained during routine prostatectomies on patients suffering from prostate cancer.Our previous studies using μ-XAS point measurements on prostate cancer cell lines showed the differences in fractions of various forms of sulfur between cancerous and non-cancerous cells. Therefore, in this experiment the chosen areas of prostate cancer tissues were scanned to get the full picture of the chemical composition of tissue, which is highly heterogeneous. The incident X-ray beams of energies tuned to spectroscopic features of the near-edge region of sulfur K-edge absorption spectra were used to provide contrast between chemical species presented in the tissue. Next, the relative content of the three main sulfur forms, found in biological systems, was calculated and the results are presented in a form of 2D color maps. These maps are correlated with the microscopic histological image of the scanned area.The main findings show that sulfur occurs in prostate tissue mainly in reduced form. The oxidized form of sulfur is present mostly in prostatic stroma, while sulfur in intermediate oxidation state is present in trace amount.

  16. GRBs Radiative Processes: Synchrotron and Synchrotron Self-Absorption From a Power Law Electrons Distribution with Finite Energy Range

    SciTech Connect

    Fouka, M.; Ouichaoui, S.

    2010-10-31

    Synchrotron emission behind relativistic magnetic internal-external shocks in gamma-ray bursts cosmological explosions is assumed to be the basic emission mechanism for prompt and afterglow emissions. Inverse Compton from relativistic electrons can also have appreciable effects by upscattering initial synchrotron or blackbody photons or other photons fields up to GeV-TeV energies. For extreme physical conditions such as high magnetic fields (e.g., B>10{sup 5} Gauss) self-absorption is not negligible and can hardly affect spectra at least for the low energy range. In this paper we present calculations of the synchrotron power, P{sub {nu}}, and their asymptotic forms, generated by a power law relativistic electron distribution of type N{sub e}({gamma}) = C{gamma}{sup -p} with {gamma}{sub 1}<{gamma}<{gamma}{sub 2}, especially for finite values of the higher limit {gamma}{sub 2}. For this aim we defined the dimensionless parametric function Z{sub p}(x,{eta}) with x = {nu}/{nu}{sub 1} and {eta} = {gamma}{sub 2}/{gamma}{sub 1} so that P{sub {nu}{proportional_to}Zp}({nu}/{nu}{sub 1},{eta}), with {nu}{sub 1} = (3/4{pi}){gamma}{sub 1}{sup 2}qBsin{theta}/mc({theta} being the pitch angle). Asymptotic forms of this later are derived for three different frequency ranges, i.e., x<<1, 1<>{eta}{sup 2}. These results are then used to calculate the absorption coefficient, {alpha}{sub {nu}}, and the source function, S{sub {nu}}, together with their asymptotic forms through the dimensionless parametric functions H{sub p}(x,{eta}) and Y{sub p}(x,{eta}), respectively. Further calculation details are also presented and discussed.

  17. Chemoprotective effect of monoisoamyl 2, 3-dimercaptosuccinate (MiADMS) on cytokines expression in cadmium chloride treated human lung cells.

    PubMed

    Odewumi, Caroline O; Fils-Aime, Shiela; Badisa, Veera L D; Latinwo, Lekan M; Ruden, Michael L; Ikediobi, Christopher; Badisa, Ramesh B

    2015-01-01

    Cadmium is commercially profitable element, but it causes toxicity in humans and animals leading to diseases in various organs. The main route of cadmium exposure to humans is through inhalation. Lungs respond to insult through secretion of cytokines. In this study, the chemoprotective effect of monoisoamyl 2, 3-dimercaptosuccinate (MiADMS) was evaluated on viability and cytokines expression in CdCl2 treated human lung A549 cells by cytokine array. Cells were treated with 0, 50, 75, and 100 µM CdCl2 alone, 300 µM MiADMS alone, and co-treated with 300 µM MiADMS and 75 µM CdCl2 for 24 h. The viability was measured by crystal violet dye. The level of cytokines in the cells' lysate and cell culture medium was measured using Ray Biotech's Human Cytokine Array 6 in control cells, 75 µM CdCl2 alone and MiADMS co-treated cells. Array results were validated by ELISA kit. The CdCl2 caused a dose dependent decrease in cell viability, while MiADMS co-treatment resulted in a significant increase in viability of CdCl2 treated cells. Morphology of the cells treated with CdCl2 was destroyed, while MiADMS restored the lost shape in CdCl2 treated cells. In addition, the cells co-treated with MiADMS and CdCl2 showed modulation of cytokines expression in comparison to the CdCl2 alone treated cells. The ELISA results showed the similar pattern of cytokine expression as Human Cytokine Array and validated the array results. These results clearly show the chemoprotective effect of MiADMS and suggest that MiADMS can be used as antidote at moderate dose against CdCl2 toxicity.

  18. Porous nano-hydroxyapatite/collagen scaffold containing drug-loaded ADM-PLGA microspheres for bone cancer treatment.

    PubMed

    Rong, Zi-Jie; Yang, Lian-Jun; Cai, Bao-Ta; Zhu, Li-Xin; Cao, Yan-Lin; Wu, Guo-Feng; Zhang, Zan-Jie

    2016-05-01

    To develop adriamycin (ADM)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles in a porous nano-hydroxyapatite/collagen scaffold (ADM-PLGA-NHAC). To provide novel strategies for future treatment of osteosarcoma, the properties of the scaffold, including its in vitro extended-release properties, the inhibition effects of ADM-PLGA-NHAC on the osteosarcoma MG63 cells, and its bone repair capacity, were investigated in vivo and in vitro. The PLGA copolymer was utilized as a drug carrier to deliver ADM-PLGA nanoparticles (ADM-PLGA-NP). Porous nano-hydroxyapatite and collagen were used to materials to produce the porous nano-hydroxyapatite/collagen scaffold (NHAC), into which the ADM-PLGA-NP was loaded. The performance of the drug-carrying scaffold was assessed using multiple techniques, including scanning electron microscopy and in vitro extended release. The antineoplastic activities of scaffold extracts on the human osteosarcoma MG63 cell line were evaluated in vitro using the cell counting kit-8 (CCK8) method and live-dead cell staining. The bone repair ability of the scaffold was assessed based on the establishment of a femoral condyle defect model in rabbits. ADM-PLGA-NHAC and NHAC were implanted into the rat muscle bag for immune response experiments. A tumor-bearing nude mice model was created, and the TUNEL and HE staining results were observed under optical microscopy to evaluate the antineoplastic activity and toxic side effects of the scaffold. The composite scaffold demonstrated extraordinary extended-release properties, and its extracts also exhibited significant inhibition of the growth of osteosarcoma MG63 cells. In the bone repair experiment, no significant difference was observed between ADM-PLGA-NHAC and NHAC by itself. In the immune response experiments, ADM-PLGA-NHAC exhibited remarkable biocompatibility. The in vivo antitumor experiment revealed that the implantation of ADM-PLGA-NHAC in the tumor resulted in a improved antineoplastic

  19. Porous nano-hydroxyapatite/collagen scaffold containing drug-loaded ADM-PLGA microspheres for bone cancer treatment.

    PubMed

    Rong, Zi-Jie; Yang, Lian-Jun; Cai, Bao-Ta; Zhu, Li-Xin; Cao, Yan-Lin; Wu, Guo-Feng; Zhang, Zan-Jie

    2016-05-01

    To develop adriamycin (ADM)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles in a porous nano-hydroxyapatite/collagen scaffold (ADM-PLGA-NHAC). To provide novel strategies for future treatment of osteosarcoma, the properties of the scaffold, including its in vitro extended-release properties, the inhibition effects of ADM-PLGA-NHAC on the osteosarcoma MG63 cells, and its bone repair capacity, were investigated in vivo and in vitro. The PLGA copolymer was utilized as a drug carrier to deliver ADM-PLGA nanoparticles (ADM-PLGA-NP). Porous nano-hydroxyapatite and collagen were used to materials to produce the porous nano-hydroxyapatite/collagen scaffold (NHAC), into which the ADM-PLGA-NP was loaded. The performance of the drug-carrying scaffold was assessed using multiple techniques, including scanning electron microscopy and in vitro extended release. The antineoplastic activities of scaffold extracts on the human osteosarcoma MG63 cell line were evaluated in vitro using the cell counting kit-8 (CCK8) method and live-dead cell staining. The bone repair ability of the scaffold was assessed based on the establishment of a femoral condyle defect model in rabbits. ADM-PLGA-NHAC and NHAC were implanted into the rat muscle bag for immune response experiments. A tumor-bearing nude mice model was created, and the TUNEL and HE staining results were observed under optical microscopy to evaluate the antineoplastic activity and toxic side effects of the scaffold. The composite scaffold demonstrated extraordinary extended-release properties, and its extracts also exhibited significant inhibition of the growth of osteosarcoma MG63 cells. In the bone repair experiment, no significant difference was observed between ADM-PLGA-NHAC and NHAC by itself. In the immune response experiments, ADM-PLGA-NHAC exhibited remarkable biocompatibility. The in vivo antitumor experiment revealed that the implantation of ADM-PLGA-NHAC in the tumor resulted in a improved antineoplastic

  20. Absorption and distribution of cadmium in mice fed diets containing either inorganic or oyster-incorporated cadmium

    SciTech Connect

    Sullivan, M.F.; Hardy, J.T.; Miller, B.M.; Buschbom, R.L.; Siewicki, T.C.

    1984-02-01

    To determine the absorption, organ distribution, and retention of organically bound cadmium (Cd) and the effects of dietary zinc (Zn) on Cd metabolism, groups of mice were fed five different diets. The organic Cd used in the diets was in the form of lyophilized oyster (Crassostrea virginica) that had accumulated radiolabeled 109Cd through a plankton food chain. The mice were fed either a standard basal mouse diet (AIN-76) or diets containing five or eight times the Zn concentration of the basal diet. The source of Zn was either oyster tissue or ZnCO3. The concentration of organic and inorganic Cd provided a dose of approximately 0.4 mg/kg. Diets prepared from oyster tissue probably contained all of the Cd and 85% of the Zn in organic form. Diets prepared with inorganic metals contained about the same Cd and Zn concentrations as the diets prepared with oyster. There was very little difference between the retention of Cd by mice that ingested organic (oyster bound) Cd and those fed inorganic Cd (CdCl2). However, when the Cd retained in the intestine was excluded, retention of organic Cd was significantly greater than that of inorganic Cd. The organ distribution of Cd differed significantly according to the chemical form of Cd fed (organic or inorganic) and the Zn level in the diet. The kidneys of mice fed organically bound Cd retained a higher percentage of the metal than the kidneys of those fed inorganic Cd. On the other hand, the livers of animals fed a low-Zn diet retained a higher percentage of the Cd than the livers of those fed a high-Zn diet, regardless of the dietary source of Cd.

  1. Quantitative description of the absorption spectra of the coenzyme in glycogen phosphorylases based on log-normal distribution curves.

    PubMed Central

    Donoso, J; Muñoz, F; Garcia Blanco, F

    1993-01-01

    The absorption spectra of the coenzyme [pyridoxal 5'-phosphate (PLP)] in glycogen phosphorylase a (GPha), glycogen phosphorylase b (GPhb) and of the latter bound to various effectors and substrates were analysed on the basis of log-normal distribution curves. The results obtained showed that the ionization state of the PLP and GPha environment differs from that of GPhb. This divergence was interpreted in terms of tautomeric equilibria between some forms of the Schiff base of PLP and enzymic Lys-679. The ionic forms are slightly more predominant in GPha than they are in GPhb, so ionic and/or hydrogen-bonding interactions between the aromatic ring of PLP and GPha must be stronger than with GPhb. This confirms the purely structural role of the aromatic ring of the coenzyme. Binding of GPhb to AMP and Mg2+ results in the coenzyme adopting a similar state as in GPha. On the other hand, binding to IMP gives rise to no detectable changes in the tautomeric equilibrium of the coenzyme. PMID:8503849

  2. Spectroscopic Character and Spatial Distribution of Hydroxyl and Water Absorption Features Measured on the Lunar Surface by the Moon Mineralogy Mapper Imaging Spectrometer on Chandrayaan-1

    NASA Astrophysics Data System (ADS)

    Green, R. O.; Pieters, C. M.; Goswami, J.; Clark, R. N.; Annadurai, M.; Boardman, J. W.; Buratti, B. J.; Combe, J.; Dyar, M. D.; Head, J. W.; Hibbitts, C.; Hicks, M.; Isaacson, P.; Klima, R. L.; Kramer, G. Y.; Kumar, S.; Livo, K. E.; Lundeen, S.; Malaret, E.; McCord, T. B.; Mustard, J. F.; Nettles, J. W.; Petro, N. E.; Runyon, C. J.; Staid, M.; Sunshine, J. M.; Taylor, L. A.; Tompkins, S.; Varanasi, P.

    2009-12-01

    The Moon Mineralogy Mapper imaging spectrometer on Chandrayaan-1 has a broad spectral range from 430 to 3000 nm. By design, the range was specified to extend to 3000 nm to allow for possible detection of trace volatile compounds that possess absorption bands near 3000 nm. Soon after acquisition and calibration of a large fraction of the lunar surface in early February 2009, absorption features in the 2700 to 3000 nm region were detected over unexpectedly large regional areas. This extraordinary discovery has withstood extensive re-analysis and falsification efforts. We have concluded these absorption features are fundamentally present in the M3 measurements and are indicators of extensive hydroxyl and water-bearing materials occurring on the surface of the Moon. Based on current analyses, these absorption features appear strongest at high latitudes, but also occur in association with several fresh feldspathic craters. Interestingly, the distribution of these absorption features are not directly correlated with existing neutron spectrometer hydrogen abundance data for the sunlight surface. This may indicate that the formation and retention of hydroxyl and water is an active process largely restricted to the upper most surface. We present the detailed spectroscopic character of these absorption features in the 2700 to 3000 nm spectral region, including selected examples through all levels of measurement processing from raw data to calibrated apparent surface reflectance. In summary we show the measured strength and latitudinal distribution of the absorptions as well as selected localized occurrences in association with fresh feldspathic craters. The presence of hydroxyl and water bearing material over extensive regions of the lunar surface provides a new and unexpected source of volatiles. Options for harvesting these elements directly from the regolith may provide an alternate supply of volatiles for long term human exploration objectives.

  3. Enhancement of the static extinction ratio by using a dual-section distributed feedback laser integrated with an electro-absorption modulator

    NASA Astrophysics Data System (ADS)

    Cho, Chun-Hyung; Kim, Jongseong; Sung, Hyuk-Kee

    2016-09-01

    We report on the enhancement of the static extinction ratio by using a dual-section distributed feedback laser diode integrated with an electro-absorption modulator. A directly- modulated dual-section laser can provide improved modulation performance under a low bias level ( i.e., below the threshold level) compared with a standard directly-modulated laser. By combining the extinction ratio from a dual-section laser with that from an electro-absorption modulator section, a total extinction ratio of 49.6. dB are successfully achieved.

  4. ADM Analysis of gravity models within the framework of bimetric variational formalism

    SciTech Connect

    Golovnev, Alexey; Karčiauskas, Mindaugas; Nyrhinen, Hannu J. E-mail: mindaugas.karciauskas@helsinki.fi

    2015-05-01

    Bimetric variational formalism was recently employed to construct novel bimetric gravity models. In these models an affine connection is generated by an additional tensor field which is independent of the physical metric. In this work we demonstrate how the ADM decomposition can be applied to study such models and provide some technical intermediate details. Using ADM decomposition we are able to prove that a linear model is unstable as has previously been indicated by perturbative analysis. Moreover, we show that it is also very difficult if not impossible to construct a non-linear model which is ghost-free within the framework of bimetric variational formalism. However, we demonstrate that viable models are possible along similar lines of thought. To this end, we consider a set up in which the affine connection is a variation of the Levi-Civita one. As a proof of principle we construct a gravity model with a massless scalar field obtained this way.

  5. Constraint propagation of C{sup 2}-adjusted formulation: Another recipe for robust ADM evolution system

    SciTech Connect

    Tsuchiya, Takuya; Yoneda, Gen; Shinkai, Hisa-aki

    2011-03-15

    With a purpose of constructing a robust evolution system against numerical instability for integrating the Einstein equations, we propose a new formulation by adjusting the ADM evolution equations with constraints. We apply an adjusting method proposed by Fiske (2004) which uses the norm of the constraints, C{sup 2}. One of the advantages of this method is that the effective signature of adjusted terms (Lagrange multipliers) for constraint-damping evolution is predetermined. We demonstrate this fact by showing the eigenvalues of constraint propagation equations. We also perform numerical tests of this adjusted evolution system using polarized Gowdy-wave propagation, which show robust evolutions against the violation of the constraints than that of the standard ADM formulation.

  6. Consensus hologram QSAR modeling for the prediction of human intestinal absorption.

    PubMed

    Moda, Tiago L; Andricopulo, Adriano D

    2012-04-15

    Consistent in silico models for ADME properties are useful tools in early drug discovery. Here, we report the hologram QSAR modeling of human intestinal absorption using a dataset of 638 compounds with experimental data associated. The final validated models are consistent and robust for the consensus prediction of this important pharmacokinetic property and are suitable for virtual screening applications.

  7. ADM. Service Building (TAN603). Elevations of all facades with door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ADM. Service Building (TAN-603). Elevations of all facades with door details and detail of kitchen. Section through garage area shows second level of steel decking. Equipment and laboratory furniture schedule. Ralph M. Parsons 902-2-ANP-603-A 44. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 033-0603-00-693-106719 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  8. Enabling the Distributed Generation Market of High Temperature Fuel Cell and Absorption Chiller Systems to Support Critical and Commercial Loads

    NASA Astrophysics Data System (ADS)

    DiMola, Ashley M.

    Buildings account for over 18% of the world's anthropogenic Greenhouse Gas (GHG) emissions. As a result, a technology that can offset GHG emissions associated with buildings has the potential to save over 9 Giga-tons of GHG emissions per year. High temperature fuel cell and absorption chiller (HTFC/AC) technology offers a relatively low-carbon option for meeting cooling and electric loads for buildings while producing almost no criteria pollutants. GHG emissions in the state of California would decrease by 7.48 million metric tons per year if every commercial building in the State used HTFC/AC technology to meet its power and cooling requirements. In order to realize the benefits of HTFC/AC technology on a wide scale, the distributed generation market needs to be exposed to the technology and informed of its economic viability and real-world potential. This work characterizes the economics associated with HTFC/AC technology using select scenarios that are representative of realistic applications. The financial impacts of various input factors are evaluated and the HTFC/AC simulations are compared to the economics of traditional building utilities. It is shown that, in addition to the emissions reductions derived from the systems, HTFC/AC technology is financially preferable in all of the scenarios evaluated. This work also presents the design of a showcase environment, centered on a beta-test application, that presents (1) system operating data gathered using a custom data acquisition module, and (2) HTFC/AC technology in a clear and approachable manner in order to serve the target audience of market stakeholders.

  9. SYNCHROTRON AND SYNCHROTRON SELF-ABSORPTION FOR A POWER-LAW PARTICLE DISTRIBUTION: ASYMPTOTIC FORMS FOR FINITE ENERGY RANGE

    SciTech Connect

    Fouka, M.; Ouichaoui, S.

    2009-12-10

    We calculate and plot the synchrotron power, P {sub n}u, the absorption coefficient, alpha{sub n}u, and the source function, S {sub n}u, for a power-law distribution of charged particles with Lorentz parameter values gamma{sub 1} <= gamma <= gamma{sub 2}. For this purpose, we define parametric functions Z{sub p} (x, eta), H{sub p} (x, eta), and Y{sub p} (x, eta) with eta = gamma{sub 2}/gamma{sub 1}, such that P {sub n}u propor to Z{sub p} (gamma{sup -2} {sub 1}nu/nu{sub 0}, eta), alpha{sub n}u propor to H{sub p} (gamma{sup -2} {sub 1}nu/nu{sub 0}, eta), and S {sub n}u propor to Y{sub p} (gamma{sup -2} {sub 1}nu/nu{sub 0}, eta). Corresponding asymptotic forms are also calculated and plotted for three frequency ranges, i.e., x << 1, 1 << x << eta{sup 2}, and x >> eta{sup 2}, especially in the case of finite parameter eta. Asymptotic forms of the middle range are possible for functions Z{sub p} and Y{sub p} for p>1/3, and for function H{sub p} for all positive values of index p. A characteristic value, eta {sub c}(p, epsilon) (with epsilon << 1), is then defined for each of the above functions so that for eta approx> eta {sub c}(p, epsilon) the middle range asymptotic forms could be considered. Further calculation details are also presented and discussed.

  10. Ingestion of chromium(VI) in drinking water by human volunteers: Absorption, distribution, and excretion of single and repeated doses

    SciTech Connect

    Kerger, B.D.; Corbett, G.E.; Dodge, D.G.

    1997-01-01

    This study examines the magnitude of hexavalent chromium [Cr(VI)] absorption, distribution, and excretion following oral exposure to 5 and 10 mg Cr(VI)/L in drinking water administered as a single bolus dose or for 3 d at a dosage of 1 L/d. Adult male volunteers were used. In the bolus dose studies, a fairly consistent pattern of urinary chromium excretion was observed, with an average half life of about 39 h. However, 4-d total urinary chromium excretion and peak concentrations in urine and blood varied considerably among the 5 volunteers. Studies of repeated exposure to small volumes ingested at a more gradual rate showed similar urinary chromium excretion patterns but generally lower chromium uptake/excretion. These data suggest that virtually all of the ingested Cr(VI) at 5 and 10 mg Cr(VI)/L was reduced to Cr(III) before entering the bloodstream. The interindividual differences in total chromium uptake and excretion are plausibly explained by ingestion of appreciable doses on an empty stomach, likely results in the formation of well-absorbed Cr(III) organic complexes. No clinical indications of toxicity in the volunteers and the patterns of blood uptake and urinary excretion of chromium are consistent with a predominant uptake of Cr(III) organic complexes that are excreted more slowly than inorganic forms of Cr(III). Therefore, it appears that the endogenous reducing agents within the upper gastrointestinal tract and the blood provide sufficient reducing potential to prevent any substantial systemic uptake of Cr(VI) following drinking-water exposures at 5-10 mg Cr(VI)/L. Based on these data, the chemical environment in the gastrointestinal tract and the blood is effective even under relative fasting condition in reducing Cr(VI) to one or more forms of Cr(III). 54 refs., 5 figs., 1 tab.

  11. Industrial applications of the IWA anaerobic digestion model No. 1 (ADM1).

    PubMed

    Batstone, D J; Keller, J

    2003-01-01

    In this paper, the IWA anaerobic digestion model No. 1 (ADM1) is applied to two case studies from contract work on industrial treatment plants. The first was the assessment of acid addition for pH decrease and avoidance of calcium carbonate (CaCO3) precipitation in a paper mill fed UASB. The simulation work found, with a high degree of confidence, that acid dosing was neither economical for pH control, nor had any real effect on the CaCO3 levels present in the reactor. A specific calcium carbonate precipitation equation was added to the ADM1 to undertake this study. The second case study was an assessment of the benefits of thermophilic (as opposed to mesophilic operation) for reduced ammonia inhibition, improved stability and gas production in a solids digester at a gelatine production facility. Here, it was predicted that thermophilic operation could not attain either goal to a satisfactory extent. In addition to demonstrating the application of the ADM1 to the two systems, we have also assessed the predictions generated in the case studies in terms of quality and utility. PMID:12926689

  12. Application of ADM1 for modeling of biogas production from anaerobic digestion of Hydrilla verticillata.

    PubMed

    Chen, Xiaojuan; Chen, Zhihua; Wang, Xun; Huo, Chan; Hu, Zhiquan; Xiao, Bo; Hu, Mian

    2016-07-01

    The present study focused on the application of anaerobic digestion model no. 1 (ADM1) to simulate biogas production from Hydrilla verticillata. Model simulation was carried out by implementing ADM1 in AQUASIM 2.0 software. Sensitivity analysis was used to select the most sensitive parameters for estimation using the absolute-relative sensitivity function. Among all the kinetic parameters, disintegration constant (kdis), hydrolysis constant of protein (khyd_pr), Monod maximum specific substrate uptake rate (km_aa, km_ac, km_h2) and half-saturation constants (Ks_aa, Ks_ac) affect biogas production significantly, which were optimized by fitting of the model equations to the data obtained from batch experiments. The ADM1 model after parameter estimation was able to well predict the experimental results of daily biogas production and biogas composition. The simulation results of evolution of organic acids, bacteria concentrations and inhibition effects also helped to get insight into the reaction mechanisms. PMID:27010339

  13. Enhanced visible-light absorption and dopant distribution of iodine-TiO{sub 2} nanoparticles synthesized by a new facile two-step hydrothermal method

    SciTech Connect

    Hong Xiaoting; Luo Zhiping; Batteas, James D.

    2011-08-15

    In order to prepare visible-light responsive iodine-doped TiO{sub 2}, a new facile synthetic approach was proposed, which started with the cost-efficient and environmentally friendly precursor of undoped anatase TiO{sub 2} to form nanotube structures as templates that collapsed and recrystallized into I-TiO{sub 2} nanopowders in HIO{sub 3} solution, followed by annealing at different temperatures. The modification of TiO{sub 2} to incorporate iodine and form titanium dioxide with significantly enhanced absorption in the visible range of the spectrum was investigated. The extent of iodine dopant incorporation was determined by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDX) and was found to be homogenously distributed on each nanostructure as determined by electron energy-loss spectroscopy (EELS) elemental mapping and EDX spectroscopy. The modified TiO{sub 2} exhibits a dramatically extended absorption edge beyond 800 nm as compared to the original and unmodified TiO{sub 2}. - Graphical abstract: As-synthesized I-TiO{sub 2} nanoparticles show significantly enhanced visible-light absorption, with the dopant iodine homogenously dispersed on each I-TiO{sub 2} nanostructure based on EELS elemental mapping. Highlights: > Iodine-TiO{sub 2} nanoparticles by a new facile two-step hydrothermal method. > Significantly enhanced light absorption in the visible range of the spectrum. > Homogenous dopant distribution within each nanostructure.

  14. Measurement of nonuniform temperature and concentration distributions by combining line-of-sight tunable diode laser absorption spectroscopy with regularization methods.

    PubMed

    Liu, Chang; Xu, Lijun; Cao, Zhang

    2013-07-10

    Regularization methods were combined with line-of-sight tunable diode laser absorption spectroscopy (TDLAS) to measure nonuniform temperature and concentration distributions along the laser path when a priori information of the temperature distribution tendency is available. Relying on measurements of 12 absorption transitions of water vapor from 1300 to 1350 nm, the nonuniform temperature and concentration distributions were retrieved by making the use of nonlinear and linear regularization methods, respectively. To examine the effectiveness of regularization methods, a simulated annealing algorithm for nonlinear regularization was implemented to reconstruct the temperature distribution, while three linear regularization methods, namely truncated singular value decomposition, Tikhonov regularization, and a revised Tikhonov regularization method, were implemented to retrieve the concentration distribution. The results show that regularization methods not only can be used to retrieve temperature and concentration distributions closer to the original but also are less sensitive to measurement noise. When no sufficient optical access is available for TDLAS tomography, the methods proposed in the paper can be used to obtain more details of the combustion field with higher accuracy and robustness, which are expected to play a more important role in combustion diagnosis.

  15. Effects of particulate complex refractive index and particle size distribution variations on atmospheric extinction and absorption for visible through middle ir wavelengths.

    PubMed

    Jennings, S G; Pinnick, R G; Auvermann, H J

    1978-12-15

    A comprehensive sensitivity study has been made using Mie theory to determine the effect of realistic variations in values of real and imaginary parts of the complex index of refraction on volume extinction and absorption coefficients for a wide range of log normal particle size distributions (defined by geometric mean radius r(g) and geometric standard deviation sigma(g)). Wavelengths lambda from the visible (0.55 microm) through the middle ir (10.6 microm) were considered. Extinction is independent of the complex index to within 20% for the majority of realistic particle size distributions, providing lambda < 2 microm. However, changes in extinction by up to an order of magnitude are caused by realistic variations in refractive indexes for 2 microm distribution for values of refractive indexes typical of atmospheric constituents. For bimodal size distributions representative of desert aerosols, values of the complex refractive index that result in minimum and maximum extinction coefficients are given. Absorption is generally less dependent on size distribution than is extinction and is not, in general, linear with the imaginary index, especially for broad particle distributions.

  16. A solely radiance-based spectral anisotropic distribution model and its application in deriving clear-sky spectral fluxes

    NASA Astrophysics Data System (ADS)

    Song, L.; Huang, X.

    2011-12-01

    Anisotropic distribution model (ADM) plays a uniquely central role in converting broadband radiance measurement to broadband flux. Scene type classifications are usually needed for such ADM and such classifications are usually done with auxiliary measurements and information since broadband radiance does not contain detailed information about temperature, humidity, and clouds. Recently Huang et al. (2008 and 2010) has developed spectral ADM based on such scene type classifications and successfully derived spectral flux from spectral radiance measurement. Unlike broadband radiances, the spectrally resolved radiances indeed contain rich information about temperature, humidity, and clouds. Therefore, it is meaningful to explore whether it is possible to develop scene-type classification solely based on spectral radiance and consequently to construct spectral ADM solely base on radiances measurement. Using AIRS spectrum as an example, here we develop a clear-sky scene classification algorithm solely based on AIRS radiances. The definitions of scene types are similar to those of clear-sky scene types used in CERES SSF algorithm, which are discrete intervals based on surface skin temperature, lapse rate (temperature change of the first 300 mb above the surface), and the total precipitable water (TPW). Brightness temperature of AIRS channel at 963.8 cm-1 are used for determine corresponding discrete intervals of surface skin temperature. This channel is also used in conjunction with a channel at 748.6 cm-1 for categorizing the lapse rate. Given the slow varying of water vapor continuum in the window region and the dominant weight of lower tropospheric humidity in TPW, a double-differential technique is used to categorize the TPW. By choosing two pairs of AIRS channels with similar frequency intervals, the technique can classify the TPW without any a priori information about continuum absorption since double differencing largely remove the slow-varying continuum

  17. An ASM/ADM model interface for dynamic plant-wide simulation.

    PubMed

    Nopens, Ingmar; Batstone, Damien J; Copp, John B; Jeppsson, Ulf; Volcke, Eveline; Alex, Jens; Vanrolleghem, Peter A

    2009-04-01

    Mathematical modelling has proven to be very useful in process design, operation and optimisation. A recent trend in WWTP modelling is to include the different subunits in so-called plant-wide models rather than focusing on parts of the entire process. One example of a typical plant-wide model is the coupling of an upstream activated sludge plant (including primary settler, and secondary clarifier) to an anaerobic digester for sludge digestion. One of the key challenges when coupling these processes has been the definition of an interface between the well accepted activated sludge model (ASM1) and anaerobic digestion model (ADM1). Current characterisation and interface models have key limitations, the most critical of which is the over-use of X(c) (or lumped complex) variable as a main input to the ADM1. Over-use of X(c) does not allow for variation of degradability, carbon oxidation state or nitrogen content. In addition, achieving a target influent pH through the proper definition of the ionic system can be difficult. In this paper, we define an interface and characterisation model that maps degradable components directly to carbohydrates, proteins and lipids (and their soluble analogues), as well as organic acids, rather than using X(c). While this interface has been designed for use with the Benchmark Simulation Model No. 2 (BSM2), it is widely applicable to ADM1 input characterisation in general. We have demonstrated the model both hypothetically (BSM2), and practically on a full-scale anaerobic digester treating sewage sludge.

  18. Intensity-Stabilized Fast-Scanned Direct Absorption Spectroscopy Instrumentation Based on a Distributed Feedback Laser with Detection Sensitivity down to 4 × 10−6

    PubMed Central

    Zhao, Gang; Tan, Wei; Jia, Mengyuan; Hou, Jiajuan; Ma, Weiguang; Dong, Lei; Zhang, Lei; Feng, Xiaoxia; Wu, Xuechun; Yin, Wangbao; Xiao, Liantuan; Axner, Ove; Jia, Suotang

    2016-01-01

    A novel, intensity-stabilized, fast-scanned, direct absorption spectroscopy (IS-FS-DAS) instrumentation, based on a distributed feedback (DFB) diode laser, is developed. A fiber-coupled polarization rotator and a fiber-coupled polarizer are used to stabilize the intensity of the laser, which significantly reduces its relative intensity noise (RIN). The influence of white noise is reduced by fast scanning over the spectral feature (at 1 kHz), followed by averaging. By combining these two noise-reducing techniques, it is demonstrated that direct absorption spectroscopy (DAS) can be swiftly performed down to a limit of detection (LOD) (1σ) of 4 × 10−6, which opens up a number of new applications. PMID:27657082

  19. Development of formulae for estimating amylose content, amylopectin chain length distribution, and resistant starch content based on the iodine absorption curve of rice starch.

    PubMed

    Nakamura, Sumiko; Satoh, Hikaru; Ohtsubo, Ken'ichi

    2015-01-01

    Not only amylose but also amylopectin greatly affects the gelatinization properties of rice starch and the quality of cooked rice grains. We here characterized the starches of 32 rice cultivars and evaluated the relationship between their iodine absorption curve, apparent amylose content (AAC), pasting property, resistant starch (RS) content, and chain length distribution of amylopectin. We found that the iodine absorption curve differed among the various sample rice cultivars. Using the wavelength at which absorbance becomes maximum on iodine staining of starch (λmax), we propose a novel index, "new λmax" (AAC/(λmax of sample rice starches-λmax of glutinous rice starch)). We developed the novel estimation formulae for AAC, RS contents, and amylopectin fractions with the use of λmax and "new λmax." These formulae would lead to the improved method for estimating starch properties using an easy and rapid iodine colorimetric method.

  20. The debate on animal ADME studies in drug development: an update.

    PubMed

    Pellegatti, Mario

    2014-12-01

    The preparation and release of the International Conference on Harmonisation guideline on safety evaluation of human metabolites and the technical progresses in bioanalysis have triggered an intense debate on the value of absorption, distribution, metabolism and excretion radiolabelled studies in animals. Some authors have radically challenged the traditional approach whereas others, while accepting the need of significant changes, argue that these studies remain an irreplaceable component of the preclinical registration dossier. This paper reviews some of the representative positions and describes the potential evolution.

  1. Non-negative matrix factorization for the near real-time interpretation of absorption effects in elemental distribution images acquired by X-ray fluorescence imaging.

    PubMed

    Alfeld, Matthias; Wahabzada, Mirwaes; Bauckhage, Christian; Kersting, Kristian; Wellenreuther, Gerd; Barriobero-Vila, Pere; Requena, Guillermo; Boesenberg, Ulrike; Falkenberg, Gerald

    2016-03-01

    Elemental distribution images acquired by imaging X-ray fluorescence analysis can contain high degrees of redundancy and weakly discernible correlations. In this article near real-time non-negative matrix factorization (NMF) is described for the analysis of a number of data sets acquired from samples of a bi-modal α+β Ti-6Al-6V-2Sn alloy. NMF was used for the first time to reveal absorption artefacts in the elemental distribution images of the samples, where two phases of the alloy, namely α and β, were in superposition. The findings and interpretation of the NMF results were confirmed by Monte Carlo simulation of the layered alloy system. Furthermore, it is shown how the simultaneous factorization of several stacks of elemental distribution images provides uniform basis vectors and consequently simplifies the interpretation of the representation. PMID:26917147

  2. Modified ADM1 for modelling an UASB reactor laboratory plant treating starch wastewater and synthetic substrate load tests.

    PubMed

    Hinken, L; Huber, M; Weichgrebe, D; Rosenwinkel, K-H

    2014-11-01

    A laboratory plant consisting of two UASB reactors was used for the treatment of industrial wastewater from the wheat starch industry. Several load tests were carried out with starch wastewater and the synthetic substrates glucose, acetate, cellulose, butyrate and propionate to observe the impact of changing loads on gas yield and effluent quality. The measurement data sets were used for calibration and validation of the Anaerobic Digestion Model No. 1 (ADM1). For a precise simulation of the detected glucose degradation during load tests with starch wastewater and glucose, it was necessary to incorporate the complete lactic acid fermentation into the ADM1, which contains the formation and degradation of lactate and a non-competitive inhibition function. The modelling results of both reactors based on the modified ADM1 confirm an accurate calculation of the produced gas and the effluent concentrations. Especially, the modelled lactate effluent concentrations for the load cases are similar to the measurements and justified by literature.

  3. Total Structure Determination of Au21(S-Adm)15 and Geometrical/Electronic Structure Evolution of Thiolated Gold Nanoclusters.

    PubMed

    Chen, Shuang; Xiong, Lin; Wang, Shuxin; Ma, Zhongyun; Jin, Shan; Sheng, Hongting; Pei, Yong; Zhu, Manzhou

    2016-08-31

    The larger size gold nanoparticles typically adopt a face-centered cubic (fcc) atomic packing, while in the ultrasmall nanoclusters the packing styles of Au atoms are diverse, including fcc, hexagonal close packing (hcp), and body-centered cubic (bcc), depending on the ligand protection. The possible conversion between these packing structures is largely unknown. Herein, we report the growth of a new Au21(S-Adm)15 nanocluster (S-Adm = adamantanethiolate) from Au18(SR)14 (SR = cyclohexylthiol), with the total structure determined by X-ray crystallography. It is discovered that the hcp Au9-core in Au18(SR)14 is transformed to a fcc Au10-core in Au21(S-Adm)15. Combining with density functional theory (DFT) calculations, we provide critical information about the growth mechanism (geometrical and electronic structure) and the origin of fcc-structure formation for the thiolate-protected gold nanoclusters. PMID:27552520

  4. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+641. 2.5

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km/s) spectrum of the broad-absorption line QSO PG 1351+64 between 915-1180 angstroms, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III lambda977, Ly-beta, O VI lambda-lambda-1032,1038, Ly-alpha, N V lambda-lambda-1238,1242, Si IV lambda-lambda-1393,1402, and C IV lambda-lambda-1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km/s with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly-alpha flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The ultraviolet continuum shows a significant change in slope near 1050 angstroms in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21)/s, unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  5. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64. 3.1

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km s(exp -1) spectrum of the mini broad absorption line QSO PG 1351+64 between 915-1180 A, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III (lambda)977, Ly(beta), O VI (lambda)(lambda)1032,1038, Ly(alpha), N V (lambda)(lambda)1238,1242, Si IV (lambda)(lambda)1393,1402, and C IV (lambda)(lambda)1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km s(exp -1) with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly(alpha) flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The UV (ultraviolet) continuum shows a significant change in slope near 1050 A in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21) cm(exp -2), unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  6. Aggregated distance metric learning (ADM) for image classification in presence of limited training data.

    PubMed

    Xiao, Gaoyu; Madabhushi, Anant

    2011-01-01

    The focus of image classification through supervised distance metric learning is to find an appropriate measure of similarity between images. Although this approach is effective in the presence of large amounts of training data, classification accuracy will deteriorate when the number of training samples is small, which, unfortunately, is often the situation in several medical applications. We present a novel image classification method called aggregated distance metric (ADM) learning for situations where the training image data are limited. Our approach is novel in that it combines the merits of boosted distance metric learning (BDM, a recently published learning scheme) and bagging theory. This approach involves selecting several sub-sets of the original training data to form a number of new training sets and then performing BDM on each of these training sub-sets. The distance metrics learned from each of the training sets are then combined for image classification. We present a theoretical proof of the superiority of classification by ADM over BDM. Using both clinical (X-ray) and non-clinical (toy car) images in our experiments (with altogether 10 sets of different parameters) and image classification accuracy as the measure, our method is shown to be more accurate than BDM and the traditional bagging strategy. PMID:22003681

  7. Aggregated distance metric learning (ADM) for image classification in presence of limited training data.

    PubMed

    Xiao, Gaoyu; Madabhushi, Anant

    2011-01-01

    The focus of image classification through supervised distance metric learning is to find an appropriate measure of similarity between images. Although this approach is effective in the presence of large amounts of training data, classification accuracy will deteriorate when the number of training samples is small, which, unfortunately, is often the situation in several medical applications. We present a novel image classification method called aggregated distance metric (ADM) learning for situations where the training image data are limited. Our approach is novel in that it combines the merits of boosted distance metric learning (BDM, a recently published learning scheme) and bagging theory. This approach involves selecting several sub-sets of the original training data to form a number of new training sets and then performing BDM on each of these training sub-sets. The distance metrics learned from each of the training sets are then combined for image classification. We present a theoretical proof of the superiority of classification by ADM over BDM. Using both clinical (X-ray) and non-clinical (toy car) images in our experiments (with altogether 10 sets of different parameters) and image classification accuracy as the measure, our method is shown to be more accurate than BDM and the traditional bagging strategy.

  8. ESA's Spaceborne Lidar Mission ADM-Aeolus; Recent Achievements and Preparations for Launch

    NASA Astrophysics Data System (ADS)

    Grete Straume, Anne; Elfving, Anders; Wernham, Denny; Culoma, Alain; Mondin, Linda; de Bruin, Frank; Kanitz, Thomas; Schuettemeyer, Dirk; Buscaglione, Fabio; Dehn, Angelika

    2016-06-01

    Within ESA's Living Planet Programme, the Atmospheric Dynamics Mission (ADM-Aeolus) was chosen as the second Earth Explorer Core mission in 1999. It shall demonstrate the potential of high spectral resolution Doppler Wind lidars for operational measurements of wind profiles and their use in Numerical Weather Prediction (NWP). Spin-off products are profiles of cloud and aerosol optical properties. ADM-Aeolus carries the novel Doppler Wind lidar instrument ALADIN. Recently the two ALADIN laser transmitters were successfully qualified and delivered for further instrument integration. The instrument delivery will follow later this year and the satellite qualification and launch readiness is scheduled for 2016. In February 2015, an Aeolus Science and Calibration and Validation (CAL/VAL) Workshop was held in ESA-ESRIN, Frascati, Italy, bringing industry, the user community and ESA together to prepare for the Aeolus Commissioning and Operational Phases. During the Workshop the science, instrument and product status, commissioning phase planning and the extensive number of proposals submitted in response to the Aeolus CAL/VAL call in 2014 were presented and discussed. A special session was dedicated to the Aeolus CAL/VAL Implementation Plan. In this paper, the Aeolus mission, status and launch preparation activities are described.

  9. Reversal effect of arsenic sensitivity in human leukemia cell line K562 and K562/ADM using realgar transforming solution.

    PubMed

    Wang, Xin; Zhang, Xu; Xu, Zhiliang; Wang, Zhizeng; Yue, Xiaoxuan; Li, Hongyu

    2013-01-01

    The success of arsenic trioxide (ATO) in treatment of acute promyelocytic leukemia (APL) attracts a great deal of attention to researchers to explore its activity of anti-leukemia. However, ATO has unavailable effect on chronic myeloid leukemia (CML), especially multidrug resistant (MDR)-CML, unless using high concentration. Realgar (As(4)S(4)) has been employed in Chinese traditional medicine for 1500 years. Research evidences confirmed realgar has similar effect on treating with APL as ATO, but the problem of large dose and long period in the CML/MDR-CML treatment still exist. By using a microbial leaching process with Acidithiobacillus ferrooxidans, we obtained realgar transforming solution (RTS) which showed significantly higher extent in inhibiting CML cell line K562 and MDR-CML cell line K562/ADM, and then trigger apoptosis. Both K562 and K562/ADM showed arsenic-dose-dependent effect on RTS. Interestingly, the overexpression of MDR1 mRNA and P-glucoprotein (P-gp) in K562/ADM cells were down-regulated by RTS, where there are no obvious effects on ATO and realgar and arsenic can be subsequently accumulated in K562/ADM cells efficiently. The intracellular accumulation of arsenic in K562/ADM cells treated with RTS for 4 h was 2-fold and 16-folds higher than those treated with realgar or ATO. Meanwhile, Western blot analysis of AQP9, the main transporter of arsenic, was increased by RTS treatment particularly in K562/ADM. Thus, these results suggested that the effect from a certain arsenical or a variety of arsenicals in RTS might be a promising candidate both for treating CML/MDR-CML alone and as combinations with currently used anti-CML/MDR-CML drug, although arsenical forms in RTS are undefined.

  10. Two-dimensional temperature distribution measurement of flames by absorption CT employing CO{sub 2} (Experimental study on the wave number employed and the accuracy of measurement)

    SciTech Connect

    Wakai, Kazunori; Moroto, Masakazu; Takahashi, Shuhei; Bhattacharjee, S.

    1999-07-01

    The authors have developed the algorithm of infrared two-band absorption CT (computed tomography) not only for short optical path where Lambert-Beer law is applicable but also for long optical path where some band model should be applied. The authors have also shown employing CO{sub 2} as an absorption medium, statistical model as a band model and Curtis-Godson model to treat non-uniform temperature fields that when optical path is long and spectrum has steep change, there are suitable wavelengths and widths to keep good accuracy. However, it was done only by computer simulation, and in this report, those results are discussed experimentally. The flat burner was used to compare temperature measured by above method with the temperature measured by sodium D-line reversal method. The results showed good correspondence and it means that the predicted suitable wavelengths and widths are experimentally confirmed. The accuracy, namely, standard deviation of the temperature, at the best wavelength conditions was lower than 20K. Temperature distributions around non-uniform temperature distribution on the flat disk burner and domestic boiler were also measured as applications and the results show that this method is applicable for the measurement of rather complicated two-dimensional temperature distributions.

  11. Use of tube radial distribution of ternary mixed carrier solvents for introduction of absorption reagent for metal ion separation and online detection into capillary.

    PubMed

    Fujinaga, Satoshi; Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2011-10-01

    When ternary mixed solvents consisting of water-hydrophilic/hydrophobic organic solvents are fed into a micro-space under laminar flow conditions, the solvent molecules are radially distributed in the micro-space. The specific fluidic behavior of the solvents is called the "tube radial distribution phenomenon (TRDP)". A novel capillary chromatography method was developed based on the TRDP that creates the inner major and outer minor phases in a tube, where the outer phase acts as a pseudo-stationary phase. This is called "tube radial distribution chromatography (TRDC)". In this study, Chrome Azurol S as an absorption reagent was introduced into the TRDC system for metal ion separation and online detection. The fused-silica capillary tube (75 μm id and 110 cm length) and water-acetonitrile-ethyl acetate mixture (3:8:4 volume ratio) including 20 mM Chrome Azurol S as a carrier solution were used. Metal ions, i.e. Co(II), Cu(II), Ni(II), Al(III), and Fe(III), as models were injected into the present TRDC system. Characteristic individual absorption characteristics and elution times were obtained as the result of complex formation between the metal ions and Chrome Azurol S in the water-acetonitrile-ethyl acetate mixture solution. The elution times of the metal ions were examined based on their absorption behavior; Co(II), Ni(II), Al(III), Fe(III), and Cu(II) were eluted in this order over the elution times of 4.7-6.8 min. The elution orders were determined from the molar ratios of metal ion to Chrome Azurol S and Irving-Williams series for bivalent metal ions.

  12. The ℓ-distribution method for modeling non-gray absorption in uniform and non-uniform gaseous media

    NASA Astrophysics Data System (ADS)

    André, Frédéric

    2016-08-01

    The ℓ-distribution modeling is proposed for radiative heat transfer in uniform and non-uniform non-gray gaseous media. The method is partly based on the application of results from the k-moment method. It combines this technique with several concepts from probability theory: the notion of rank transmutation maps allows extending the k-moment method to an infinite number of k-moments; copula models appear naturally to extend the method from uniform to non-uniform gas paths. The ℓ-distribution approach is shown to provide results: (1) more accurate - up to three orders of magnitude - than usual k-distribution approaches in uniform media, (2) as precise as correlated-k models in non-uniform situations. All these results are obtained at a computational cost lower than k-distribution models. Differences and similarities between k- and ℓ-distribution methods are discussed.

  13. Effects of ADA and ADM when Utilized in the Measure of Educational Need in State School Finance Plans. Occasional Paper #16.

    ERIC Educational Resources Information Center

    McLoone, Eugene P.

    From the 1920s through the 1950s, most states used average daily attendance (ADA) in state equalization plans. Beginning in the middle of the 1950s, many states began to use average daily membership (ADM) in such plans. The essential features of any equalization aid plan are (1) a measure of need (such as ADA or ADM), (2) a measure of wealth or…

  14. Spatial distribution of carbon dioxide absorption and emission in Chungcheongbuk-do, South Korea using RS and GIS method

    NASA Astrophysics Data System (ADS)

    Park, Jin-Ki; Na, Sang-il; Park, Jong-Hwa

    2011-11-01

    Climate change has been an important issue particularly in recent years. Climate change has been reported as a phenomena caused by human activities as identified in the IPCC Fourth Assessment Report (AR4) in 2007, and in order to prevent negative impacts to our planet, conscious efforts to reduce greenhouse gases are necessary worldwide. In addition, Korea's interest in global climate change is growing. In reality, symptoms of global warming on the Korean Peninsula are visible in the air, on the land and in changes patterns to the normal levels and contents of Korea's oceans. Impacts of global warming result in abnormal temperature fluctuation, typhoons, regional flooding and desertification with such extreme and that are arguably more frequent occurrences of natural disasters quickly becoming a general problem for the community as a whole. On the other hand, the development of IT technology and the improvement and use of satellite technology have ensured better access to RS technique and utilization. Due to RS technology is ability to monitor it has become widely used in farming applications, environment prediction and planning and ecology studies and analysis. The purpose of this study is to assess emission and absorption in relation to geographical features and to be better able to deliver environment information to produce a spatial map of carbon dioxide in Chungbuk by using RS and GIS with a focus on carbon dioxide emission and its direct absorption caused by tree growth according to energy consumption.

  15. Measurement of vapor/liquid distributions in a binary-component fuel spray using laser imaging of droplet scattering and vapor absorption

    NASA Astrophysics Data System (ADS)

    Li, Shiyan; Zhang, Yuyin; Wu, Shenqi; Xu, Bin

    2014-08-01

    Fuel volatility has a great effect on its evaporation processes and the mixture formation and thus combustion and emissions formation processes in internal combustion engines. To date, however, instead of the actual gasoline or diesel fuel, many researchers have been using single-component fuel in their studies, because the composition of the former is too complicated to understand the real physics behind the evaporation and combustion characteristics. Several research groups have reported their results on droplets evaporation in a spray of multi-component fuel, carried out both numerically and experimentally. However, there are plenty of difficulties in quantitative determination of vapor concentration and droplet distributions of each component in a multicomponent fuel spray. In this study, to determine the vapor phase concentration and droplet distributions in an evaporating binary component fuel spray, a laser diagnostics based on laser extinction by droplet scattering and vapor absorption was developed. In practice, measurements of the vapor concentration distributions of the lower (n-tridencane) and higher (n-octane) volatility components in the binary component fuel sprays have been carried out at ambient temperatures of 473K and 573K, by substituting p-xylene for noctane or α-methylnaphthalene for n-tridecane. p-Xylene and α-methylnaphthalene were selected as the substitutes is because they have strong absorption band near 266nm and transparent near 532nm and, their thermo-physical properties are similar to those of the original component. As a demonstration experiment, vapor/liquid distribution of the lower boiling point (LBP) and higher boiling point (HBP) components in the binary component fuel spray have been obtained.

  16. Silencing clusterin gene transcription on effects of multidrug resistance reversing of human hepatoma HepG2/ADM cells.

    PubMed

    Zheng, Wenjie; Sai, Wenli; Yao, Min; Gu, Hongbin; Yao, Yao; Qian, Qi; Yao, Dengfu

    2015-05-01

    Abnormal clusterin (CLU) expression is associated with multidrug resistance (MDR) of hepatocellular carcinoma (HCC). In the present study, the CLU expression was analyzed in human hepatoma cells and chemoresistant counterpart HepG2/ADM cells. Compared with L02 cells, the overexpression of cellular CLU was identified in HepG2, HepG2/ADM, SMMC7721, Hep3B ,and PLC cells and relatively lower expression in Bel-7404, SNU-739, and MHCC97H cells. Specific short hairpin RNAs (shRNAs) to silence CLU gene transcription were designed, and the most effective sequences were screened. After the HepG2/ADM cells transfected with shRNA-1, the inhibition of CLU expression was 73.68 % at messenger RNA (mRNA) level by real-time quantitative RT-PCR with obvious enhancement in cell chemosensitivity, increasing apoptosis induced by doxorubicin using fluorescence kit, and Rh-123 retention qualified with flow cytometry. Knockdown CLU also significantly decreased the drug efflux pump activity through the depression of MDR1/P-glycoprotein (q = 11.739, P < 0.001). Moreover, silencing CLU led to downregulation of β-catenin (q = 13.544, P = 0.001), suggesting that downregulation of CLU might be a key point to reverse multidrug resistance of HepG2/ADM cells. PMID:25600802

  17. Performance optimization and validation of ADM1 simulations under anaerobic thermophilic conditions.

    PubMed

    Atallah, Nabil M; El-Fadel, Mutasem; Ghanimeh, Sophia; Saikaly, Pascal; Abou-Najm, Majdi

    2014-12-01

    In this study, two experimental sets of data each involving two thermophilic anaerobic digesters treating food waste, were simulated using the Anaerobic Digestion Model No. 1 (ADM1). A sensitivity analysis was conducted, using both data sets of one digester, for parameter optimization based on five measured performance indicators: methane generation, pH, acetate, total COD, ammonia, and an equally weighted combination of the five indicators. The simulation results revealed that while optimization with respect to methane alone, a commonly adopted approach, succeeded in simulating methane experimental results, it predicted other intermediary outputs less accurately. On the other hand, the multi-objective optimization has the advantage of providing better results than methane optimization despite not capturing the intermediary output. The results from the parameter optimization were validated upon their independent application on the data sets of the second digester.

  18. Canonical ADM tetrad gravity: From metrological inertial gauge variables to dynamical tidal Dirac observables

    NASA Astrophysics Data System (ADS)

    Lusanna, Luca

    2015-02-01

    In this updated review of canonical ADM tetrad gravity in a family of globally hyperbolic asymptotically Minkowskian space-times without super-translations I show which is the status-of-the-art in the search of a canonical basis adapted to the first-class Dirac constraints and of the Dirac observables of general relativity (GR) describing the tidal degrees of freedom of the gravitational field. In these space-times the asymptotic ADM Poincaré group replaces the Poincaré group of particle physics, there is a York canonical basis diagonalizing the York-Lichnerowicz approach and a post-Minkowskian linearization is possible with the associated description of gravitational waves in the family of non-harmonic 3-orthogonal Schwinger time gauges. Moreover I show that every fixation of the inertial gauge variables (i.e. the choice of a non-inertial frame) of every generally covariant formulation of GR is equivalent to a set of conventions for the metrology of the space-time (like the GPS ones near the Earth): for instance the freedom in clock synchronization is described by the inertial gauge variable York time (the trace of the extrinsic curvature of the instantaneous 3-spaces). This inertial gauge freedom and the non-Euclidean nature of the instantaneous 3-spaces required by the equivalence principle are connected with the dark side of the universe and could explain the presence of dark matter or at least part of it by means of the adoption of suitable metrical conventions for the ICRS celestial reference system. Also some comments on a canonical quantization of GR coherent with this viewpoint are done.

  19. Report from the EPAA workshop: in vitro ADME in safety testing used by EPAA industry sectors.

    PubMed

    Schroeder, K; Bremm, K D; Alépée, N; Bessems, J G M; Blaauboer, B; Boehn, S N; Burek, C; Coecke, S; Gombau, L; Hewitt, N J; Heylings, J; Huwyler, J; Jaeger, M; Jagelavicius, M; Jarrett, N; Ketelslegers, H; Kocina, I; Koester, J; Kreysa, J; Note, R; Poth, A; Radtke, M; Rogiers, V; Scheel, J; Schulz, T; Steinkellner, H; Toeroek, M; Whelan, M; Winkler, P; Diembeck, W

    2011-04-01

    There are now numerous in vitro and in silico ADME alternatives to in vivo assays but how do different industries incorporate them into their decision tree approaches for risk assessment, bearing in mind that the chemicals tested are intended for widely varying purposes? The extent of the use of animal tests is mainly driven by regulations or by the lack of a suitable in vitro model. Therefore, what considerations are needed for alternative models and how can they be improved so that they can be used as part of the risk assessment process? To address these issues, the European Partnership for Alternative Approaches to Animal Testing (EPAA) working group on prioritization, promotion and implementation of the 3Rs research held a workshop in November, 2008 in Duesseldorf, Germany. Participants included different industry sectors such as pharmaceuticals, cosmetics, industrial- and agro-chemicals. This report describes the outcome of the discussions and recommendations (a) to reduce the number of animals used for determining the ADME properties of chemicals and (b) for considerations and actions regarding in vitro and in silico assays. These included: standardisation and promotion of in vitro assays so that they may become accepted by regulators; increased availability of industry in vivo kinetic data for a central database to increase the power of in silico predictions; expansion of the applicability domains of in vitro and in silico tools (which are not necessarily more applicable or even exclusive to one particular sector) and continued collaborations between regulators, academia and industry. A recommended immediate course of action was to establish an expert panel of users, developers and regulators to define the testing scope of models for different chemical classes. It was agreed by all participants that improvement and harmonization of alternative approaches is needed for all sectors and this will most effectively be achieved by stakeholders from different

  20. X-ray absorption spectroscopy of an investigational anticancer gallium(III) drug: interaction with serum proteins, elemental distribution pattern, and coordination of the compound in tissue.

    PubMed

    Hummer, Alfred A; Bartel, Caroline; Arion, Vladimir B; Jakupec, Michael A; Meyer-Klaucke, Wolfram; Geraki, Tina; Quinn, Paul D; Mijovilovich, Ana; Keppler, Bernhard K; Rompel, Annette

    2012-06-14

    Tris(8-quinolinolato)gallium(III) (1, KP46) is a very promising investigational anticancer drug. Its interaction with serum proteins, elemental distribution, and coordination in tissue were investigated with X-ray absorption (XAS) methods. Model compounds with mixed O, N, and/or S donor atoms are reported. The coordination and structure of 1 in cell culture medium (minimum essential medium, MEM) and fetal calf serum (FCS) were probed by XANES and EXAFS. The interaction of 1 with the serum proteins apotransferrin (apoTf) and human serum albumin (HSA) was addressed as well. By application of micro-XAS to tissue samples from mice treated with 1, the gallium distribution pattern was analyzed and compared to those of physiological trace elements. The complex 1 turned out to be very stable under physiological conditions, in cell culture media and in tissue samples. The coordination environment of the metal center remains intact in the presence of apoTf and HSA. The gallium distribution pattern in tumor and liver tissue revealed high similarities to the distribution patterns of Zn and Fe, minor similarities to Cu and Ni, and no similarity to Ca.

  1. Distribution and speciation of bromine in mammalian tissue and fluids by X-ray fluorescence imaging and X-ray absorption spectroscopy.

    PubMed

    Ceko, Melanie J; Hummitzsch, Katja; Hatzirodos, Nicholas; Bonner, Wendy; James, Simon A; Kirby, Jason K; Rodgers, Raymond J; Harris, Hugh H

    2015-05-01

    Bromine is one of the most abundant and ubiquitous trace elements in the biosphere and until recently had not been shown to perform any essential biological function in animals. A recent study demonstrated that bromine is required as a cofactor for peroxidasin-catalysed formation of sulfilimine crosslinks in Drosophila. In addition, bromine dietary deficiency is lethal in Drosophila, whereas bromine replenishment restores viability. The aim of this study was to examine the distribution and speciation of bromine in mammalian tissues and fluids to provide further insights into the role and function of this element in biological systems. In this study we used X-ray fluorescence (XRF) imaging and inductively coupled plasma-mass spectrometry (ICP-MS) to examine the distribution of bromine in bovine ovarian tissue samples, follicular fluid and aortic serum, as well as human whole blood and serum and X-ray absorption spectroscopy (XAS) to identify the chemical species of bromine in a range of mammalian tissue (bovine, ovine, porcine and murine), whole blood and serum samples (bovine, ovine, porcine, murine and human), and marine samples (salmon (Salmo salar), kingfish (Seriola lalandi) and Scleractinian coral). Bromine was found to be widely distributed across all tissues and fluids examined. In the bovine ovary in particular it was more concentrated in the sub-endothelial regions of arterioles. Statistical comparison of the near-edge region of the X-ray absorption spectra with a library of bromine standards led to the conclusion that the major form of bromine in all samples analysed was bromide.

  2. Distribution and speciation of bromine in mammalian tissue and fluids by X-ray fluorescence imaging and X-ray absorption spectroscopy.

    PubMed

    Ceko, Melanie J; Hummitzsch, Katja; Hatzirodos, Nicholas; Bonner, Wendy; James, Simon A; Kirby, Jason K; Rodgers, Raymond J; Harris, Hugh H

    2015-05-01

    Bromine is one of the most abundant and ubiquitous trace elements in the biosphere and until recently had not been shown to perform any essential biological function in animals. A recent study demonstrated that bromine is required as a cofactor for peroxidasin-catalysed formation of sulfilimine crosslinks in Drosophila. In addition, bromine dietary deficiency is lethal in Drosophila, whereas bromine replenishment restores viability. The aim of this study was to examine the distribution and speciation of bromine in mammalian tissues and fluids to provide further insights into the role and function of this element in biological systems. In this study we used X-ray fluorescence (XRF) imaging and inductively coupled plasma-mass spectrometry (ICP-MS) to examine the distribution of bromine in bovine ovarian tissue samples, follicular fluid and aortic serum, as well as human whole blood and serum and X-ray absorption spectroscopy (XAS) to identify the chemical species of bromine in a range of mammalian tissue (bovine, ovine, porcine and murine), whole blood and serum samples (bovine, ovine, porcine, murine and human), and marine samples (salmon (Salmo salar), kingfish (Seriola lalandi) and Scleractinian coral). Bromine was found to be widely distributed across all tissues and fluids examined. In the bovine ovary in particular it was more concentrated in the sub-endothelial regions of arterioles. Statistical comparison of the near-edge region of the X-ray absorption spectra with a library of bromine standards led to the conclusion that the major form of bromine in all samples analysed was bromide. PMID:25675086

  3. The H + OCS hot atom reaction - CO state distributions and translational energy from time-resolved infrared absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Nickolaisen, Scott L.; Cartland, Harry E.

    1993-01-01

    Time-resolved infrared diode laser spectroscopy has been used to probe CO internal and translational excitation from the reaction of hot H atoms with OCS. Product distributions should be strongly biased toward the maximum 1.4 eV collision energy obtained from 278 nm pulsed photolysis of HI. Rotations and vibrations are both colder than predicted by statistical density of states theory, as evidenced by large positive surprisal parameters. The bias against rotation is stronger than that against vibration, with measurable population as high as v = 4. The average CO internal excitation is 1920/cm, accounting for only 13 percent of the available energy. Of the energy balance, time-resolved sub-Doppler line shape measurements show that more than 38 percent appears as relative translation of the separating CO and SH fragments. Studies of the relaxation kinetics indicate that some rotational energy transfer occurs on the time scale of our measurements, but the distributions do not relax sufficiently to alter our conclusions. Vibrational distributions are nascent, though vibrational relaxation of excited CO is unusually fast in the OCS bath, with rates approaching 3 percent of gas kinetic for v = 1.

  4. The pre-clinical absorption, distribution, metabolism and excretion properties of IPI-926, an orally bioavailable antagonist of the hedgehog signal transduction pathway.

    PubMed

    Smith, Sherri; Hoyt, Jennifer; Whitebread, Nigel; Manna, Joseph; Peluso, Marisa; Faia, Kerrie; Campbell, Veronica; Tremblay, Martin; Nair, Somarajan; Grogan, Michael; Castro, Alfredo; Campbell, Matthew; Ferguson, Jeanne; Arsenault, Brendan; Nevejans, Jylle; Carter, Bennett; Lee, John; Dunbar, Joi; McGovern, Karen; Read, Margaret; Adams, Julian; Constan, Alexander; Loewen, Gordon; Sydor, Jens; Palombella, Vito; Soglia, John

    2013-10-01

    1. IPI-926 is a novel semisynthetic cyclopamine derivative that is a potent and selective Smoothened inhibitor that blocks the hedgehog signal transduction pathway. 2. The in vivo clearance of IPI-926 is low in mouse and dog and moderate in monkey. The volume of distribution is high across species. Oral bioavailability ranges from moderate in monkey to high in mouse and dog. Predicted human clearance using simple allometry is low (24 L h(-1)), predicted volume of distribution is high (469 L) and predicted half-life is long (20 h). 3. IPI-926 is highly bound to plasma proteins and has minimal interaction with human α-1-acid glycoprotein. 4. In vitro metabolic stability ranges from stable to moderately stable. Twelve oxidative metabolites were detected in mouse, rat, dog, monkey and human liver microsome incubations and none were unique to human. 5. IPI-926 is not a potent reversible inhibitor of CYP1A2, 2C8, 2C9 or 3A4 (testosterone). IPI-926 is a moderate inhibitor of CYP2C19, 2D6 and 3A4 (midazolam) with KI values of 19, 16 and 4.5 µM, respectively. IPI-926 is both a substrate and inhibitor (IC50 = 1.9 µM) of P-glycoprotein. 6. In summary, IPI-926 has desirable pre-clinical absorption, distribution, metabolism and excretion properties. PMID:23527529

  5. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

    SciTech Connect

    Kim, Sooyoung; Yoon, Suk-Jin; Chung, Chul; Lee, Young-Wook; Caldwell, Nelson; Schiavon, Ricardo P.; Kang, Yongbeom; Rey, Soo-Chang

    2013-05-10

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.

  6. Cation distribution in Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} using X-ray absorption spectroscopy

    SciTech Connect

    Yadav, A. K. Jha, S. N.; Bhattacharyya, D.; Sahoo, N. K.; Jadhav, J.; Biswas, S.

    2014-04-24

    Spinel ferrite samples of Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (for x=0.2, 0.4, 0.5, 0.6 and 0.8) nanoparticles prepared by a novel chemical synthesis method have been characterized by X-ray Absorption Spectroscopy (XAS) technique to investigate the distribution of cations in the unit cell. XANES region clearly shows that as Ni concentration increases, the pre-edge feature, which is a characteristic of tetrahedral coordination of Fe, is enhanced. A quantitative determination of the relative occupancy of iron cation in the octahedral and tetrahedral sites of the spinel structure was obtained from EXAFS data analysis. It has been found that as atomic fraction of Ni is increased from 0.2 to 0.8, Fe occupancy at tetrahedral to octahedral sites is increased from 13:87 and to 39:61.

  7. Flavonoid interactions during digestion, absorption, distribution and metabolism: a sequential structure-activity/property relationship-based approach in the study of bioavailability and bioactivity.

    PubMed

    Gonzales, Gerard Bryan; Smagghe, Guy; Grootaert, Charlotte; Zotti, Moises; Raes, Katleen; Van Camp, John

    2015-05-01

    Flavonoids are a group of polyphenols that provide health-promoting benefits upon consumption. However, poor bioavailability has been a major hurdle in their use as drugs or nutraceuticals. Low bioavailability has been associated with flavonoid interactions at various stages of the digestion, absorption and distribution process, which is strongly affected by their molecular structure. In this review, we use structure-activity/property relationship to discuss various flavonoid interactions with food matrices, digestive enzymes, intestinal transporters and blood proteins. This approach reveals specific bioactive properties of flavonoids in the gastrointestinal tract as well as various barriers for their bioavailability. In the last part of this review, we use these insights to determine the effect of different structural characteristics on the overall bioavailability of flavonoids. Such information is crucial when flavonoid or flavonoid derivatives are used as active ingredients in foods or drugs. PMID:25633078

  8. The distribution of carotenoids in hens fed on biofortified maize is influenced by feed composition, absorption, resource allocation and storage

    PubMed Central

    Moreno, Jose Antonio; Díaz-Gómez, Joana; Nogareda, Carmina; Angulo, Eduardo; Sandmann, Gerhard; Portero-Otin, Manuel; Serrano, José C. E.; Twyman, Richard M.; Capell, Teresa; Zhu, Changfu; Christou, Paul

    2016-01-01

    Carotenoids are important dietary nutrients with health-promoting effects. The biofortification of staple foods with carotenoids provides an efficient delivery strategy but little is known about the fate and distribution of carotenoids supplied in this manner. The chicken provides a good model of human carotenoid metabolism so we supplemented the diets of laying hens using two biofortified maize varieties with distinct carotenoid profiles and compared the fate of the different carotenoids in terms of distribution in the feed, the hen’s livers and the eggs. We found that after a period of depletion, pro-vitamin A (PVA) carotenoids were preferentially diverted to the liver and relatively depleted in the eggs, whereas other carotenoids were transported to the eggs even when the liver remained depleted. When retinol was included in the diet, it accumulated more in the eggs than the livers, whereas PVA carotenoids showed the opposite profile. Our data suggest that a transport nexus from the intestinal lumen to the eggs introduces bottlenecks that cause chemically-distinct classes of carotenoids to be partitioned in different ways. This nexus model will allow us to optimize animal feed and human diets to ensure that the health benefits of carotenoids are delivered in the most effective manner. PMID:27739479

  9. Tunable diode laser absorption spectroscopy-based tomography system for on-line monitoring of two-dimensional distributions of temperature and H2O mole fraction

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Liu, Chang; Jing, Wenyang; Cao, Zhang; Xue, Xin; Lin, Yuzhen

    2016-01-01

    To monitor two-dimensional (2D) distributions of temperature and H2O mole fraction, an on-line tomography system based on tunable diode laser absorption spectroscopy (TDLAS) was developed. To the best of the authors' knowledge, this is the first report on a multi-view TDLAS-based system for simultaneous tomographic visualization of temperature and H2O mole fraction in real time. The system consists of two distributed feedback (DFB) laser diodes, a tomographic sensor, electronic circuits, and a computer. The central frequencies of the two DFB laser diodes are at 7444.36 cm-1 (1343.3 nm) and 7185.6 cm-1 (1391.67 nm), respectively. The tomographic sensor is used to generate fan-beam illumination from five views and to produce 60 ray measurements. The electronic circuits not only provide stable temperature and precise current controlling signals for the laser diodes but also can accurately sample the transmitted laser intensities and extract integrated absorbances in real time. Finally, the integrated absorbances are transferred to the computer, in which the 2D distributions of temperature and H2O mole fraction are reconstructed by using a modified Landweber algorithm. In the experiments, the TDLAS-based tomography system was validated by using asymmetric premixed flames with fixed and time-varying equivalent ratios, respectively. The results demonstrate that the system is able to reconstruct the profiles of the 2D distributions of temperature and H2O mole fraction of the flame and effectively capture the dynamics of the combustion process, which exhibits good potential for flame monitoring and on-line combustion diagnosis.

  10. Absorption and distribution of deuterium-labeled trans- and cis-11-octadecenoic acid in human plasma and lipoprotein lipids

    SciTech Connect

    Emken, E.A.; Rohwedder, W.K.; Adlof, R.O.; DeJarlais, W.J.; Gulley, R.M.

    1986-09-01

    Triglycerides of deuterium-labeled trans-11-, trans-11-cis-11- and cis-9-octadecenoic acid (11t-18:1-2H, 11c-18:1-2H) were simultaneously fed to two young adult male subjects. Plasma lipids from blood samples collected periodically for 48 hr were analyzed by gas chromatography-mass spectroscopy. The results indicate the delta 11-18:1-2H acids and 9c-18:1-2H were equally well absorbed; relative turnover rates were higher for the delta 11-18-1-2H acids in plasma triglycerides; incorporation of the delta 11-18:1-2H acids into plasma phosphatidylcholine was similar to 9c-18:1-2H, but distribution at the 1- and 2-acyl positions was substantially different; esterification of cholesterol with 11t-18:1 was extremely low; chain shortening of the delta 11-18:1-2H acids was 2-3 times greater than for 9c-18:1-2H; no evidence for desaturation or elongation of the 18:1-2H acids was detected; and a 40% isotopic dilution of the 18:1-2H acids in the chylomicron triglyceride fraction indicated the presence of a substantial intestinal triglyceride pool. Based on our present knowledge, these metabolic results for delta 11-18:1 acids present in hydrogenated oils and animal fats indicate that the delta 11 isomers are no more likely than 9c-18:1 to contribute to dietary fat-related health problems.

  11. Absorption, tissue distribution, and elimination of residues after 2,4,6-trinitro[14C]toluene administration to sheep.

    PubMed

    Smith, D J; Craig, A M; Duringer, J M; Chaney, R L

    2008-04-01

    The compound 2,4,6-trinitrotoluene (TNT) is a persistent contaminant of some industrial and military sites. Biological bioremediation techniques typically rely on the immobilization of TNT reduction products rather than on TNT mineralization. We hypothesized that sheep ruminal microbes would be suitable for TNT destruction after phytoremediation of TNT-contaminated soils by cool-season grasses. Therefore we investigated the fate of [14C]TNT in ruminating sheep to determine the utility of ruminant animals as a portion of the bioremediation process. Three wether sheep were dosed with 35.5 mg each of dietary unlabeled TNT for 21 consecutive days. On day 22 sheep (41.9 +/- 3.0 kg) were orally dosed with 35.5 mg of [14C]TNT (129 microCi; 99.1% radiochemical purity). Blood, urine, and feces were collected at regular intervals for 72 h. At slaughter, tissues were quantitatively collected. Tissues and blood were analyzed for total radioactive residues (TRR); excreta were analyzed for TRR, bound residues, and TNT metabolites. Plasma radioactivity peaked within 1 h of dosing and was essentially depleted within 18 h. Approximately 76% of the radiocarbon was excreted in feces, 17% in urine, with 5% being retained in the gastrointestinal tract and 1% retained in tissues. Parent TNT, dinitroamino metabolites, and diaminonitro metabolites were not detected in excreta. Ruminal and fecal radioactivity was essentially nonextractable using ethyl acetate, acetone, and methanol; covalent binding of fecal radioactive residues was evenly distributed among extractable organic molecules (i.e., soluble organic matter, soluble carbohydrate, protein, lipid, and nucleic acid fractions) and undigested fibers (cellulose, hemicellulose, and lignin). This study demonstrated that TNT reduction within the ruminant gastrointestinal tract leads to substantial immobilization of residues to organic matter, a fate similar to TNT in other strongly reducing environments. PMID:18504997

  12. Thermal pretreatment and hydraulic retention time in continuous digesters fed with sewage sludge: assessment using the ADM1.

    PubMed

    Souza, Theo S O; Ferreira, Liliana Catarina; Sapkaite, Ieva; Pérez-Elvira, Sara I; Fdz-Polanco, Fernando

    2013-11-01

    Thermal pretreatment is an interesting technique not only for increasing sludge biodegradability, leading to higher methane productivity, but also for improving degradation rates, allowing full-scale plants to reduce the size of digesters. In this study, the Anaerobic Digestion Model No. 1 (ADM1) was used as a tool to assess the effects of thermal pretreatment and hydraulic retention time (HRT) on the performance of three pilot-scale digesters fed with mixed sludge with/without pretreatment applied to the waste activated sludge fraction. Calibration procedures using batch tests showed an increase of up to five times in the model disintegration coefficient due to the pretreatment, and the validations performed presented good accuracy with the experimental data, with under/overestimation lower than 15% in both average and global accumulated CH4 productions. Therefore, the ADM1 demonstrated its feasibility and usefulness in predicting and assessing the behavior of the digesters under these conditions.

  13. Dataset of the associations of aldosterone to renin ratio with MR-proANP and MR-proADM.

    PubMed

    Then, Cornelia; Rottenkolber, Marietta; Lechner, Andreas; Meisinger, Christa; Heier, Margit; Koenig, Wolfgang; Peters, Annette; Rathmann, Wolfgang; Bidlingmaier, Martin; Reincke, Martin; Seissler, Jochen

    2016-09-01

    This article contains data related to the research article entitled "Altered relation of the renin-aldosterone system and vasoactive peptides in type 2 diabetes: the KORA F4 study" (Then et al., 2016) [1] and describes the association of the aldosterone to renin ratio with midregional-pro atrial natriuretic peptide (MR-proANP) and midregional-pro adrenomedullin (MR-proADM) in 1261 participants from the KORA F4 cohort. PMID:27595128

  14. Absorption, distribution and excretion of GT31-104, a novel bile acid sequestrant, in rats and dogs after acute and subchronic administration.

    PubMed

    Rosenbaum, D P; Petersen, J S; Ducharme, S; Markham, P; Goldberg, D I

    1997-05-01

    The absorption, distribution, and excretion of GT31-104, a novel bile acid sequestrant, was studied in rats and dogs after both acute and subchronic oral administration. The polyallylamine backbone of GT31-104 was labeled with tritium and one of the alkyl side chains was labeled with 14C. The mean blood and plasma concentration of [3H, 14C]GT31-104 in rats, in both treatment regimens, was negligible at all time points, with the highest amount observed being 0.69 microgram eq/g blood; in dogs the mean blood and plasma concentration of [3H, 14C]GT31-104 was below the limit of quantitation (< 0.001% total dose) at all time points. In both rats and dogs, the mean total urinary excretion of [3H, 14C]GT31-104 was approximately 0.06% of the total dose. The fecal excretion data indicates that both 3H- and 14C-derived radioactivity was excreted entirely in the feces. Mean total radioactivity excreted in the feces ranged from approximately 95 to 105% in the rats and 92 to 102% in the dogs. Across the different treatment regimens, in both species, tissue concentrations were negligible (< 0.01% total dose) and no differences in tissue profile were noted, indicating that there was no effect of pretreatment on [3H, 14C]GT31-104 absorption. GT31-104 was extracted with water, and the water-soluble portion contained radioactivity that would correlate to approximately 0.19% of the 3H dose and 0.41% of the 14C dose; this portion probably accounted for the negligible radioactivity observed systemically. Analysis of gastrointestinal (GI) tract tissues with contents indicated that GT31-104 is rapidly cleared from the GI tract. These data indicate that GT31-104 is not absorbed from the GI tract in rats and dogs.

  15. A Bottom-Up Whole-Body Physiologically Based Pharmacokinetic Model to Mechanistically Predict Tissue Distribution and the Rate of Subcutaneous Absorption of Therapeutic Proteins.

    PubMed

    Gill, Katherine L; Gardner, Iain; Li, Linzhong; Jamei, Masoud

    2016-01-01

    The ability to predict subcutaneous (SC) absorption rate and tissue distribution of therapeutic proteins (TPs) using a bottom-up approach is highly desirable early in the drug development process prior to clinical data being available. A whole-body physiologically based pharmacokinetic (PBPK) model, requiring only a few drug parameters, to predict plasma and interstitial fluid concentrations of TPs in humans after intravenous and subcutaneous dosing has been developed. Movement of TPs between vascular and interstitial spaces was described by considering both convection and diffusion processes using a 2-pore framework. The model was optimised using a variety of literature sources, such as tissue lymph/plasma concentration ratios in humans and animals, information on the percentage of dose absorbed following SC dosing via lymph in animals and data showing loss of radiolabelled IgG from the SC dosing site in humans. The resultant model was used to predict t max and plasma concentration profiles for 12 TPs (molecular weight 8-150 kDa) following SC dosing. The predicted plasma concentration profiles were generally comparable to observed data. t max was predicted within 3-fold of reported values, with one third of the predictions within 0.8-1.25-fold. There was no systematic bias in simulated C max values, although a general trend for underprediction of t max was observed. No clear trend between prediction accuracy of t max and TP isoelectric point or molecular size was apparent. The mechanistic whole-body PBPK model described here can be applied to predict absorption rate of TPs into blood and movement into target tissues following SC dosing.

  16. Optimization of important early ADME(T) parameters of NADPH oxidase-4 inhibitor molecules.

    PubMed

    Borbély, Gábor; Huszár, Ménika; Varga, Attila; Futosi, Krisztina; Mócsai, Attila; Orfi, László; Idei, Miklós; Mandl, József; Kéri, György; Vántus, Tibor

    2012-03-01

    Through their reactive oxygen species (ROS) producing function, NADPH oxidase (NOX) enzymes have been linked to several oxidative stress related diseases. In our recently published paper [1] we have already shown the NOX4 inhibitory effect of diverse, molecule sub-libraries and their biological importance. We also presented our work connected to potential anti-tumour molecules and the relationship between their biological activity and physico-chemical properties [2]. As an extension of these studies further physico-chemical and biological investigation has been carried out on a molecule group included NOX4 inhibitory chromanone compounds. Here we describe the optimization of early ADME(T) parameters determining lipophilicity, phospholipophilicity and permeability linked to structure-activity relationship. We prove that optimal lipo- and phospholipophilicty can be also determined in case of NOX4 inhibitors and a comparison will be made between the chemically similar isochromanone and chromanone molecular libraries. It will be also shown how to predict the effect of different substituents on permeability, lipo- and phospholipophilicity and also the biological differences between anti-tumour molecules and NOX4 inhibitors according to their penetration ability.

  17. Integration of equalisation tanks within control strategies for anaerobic reactors. Validation based on ADM1 simulations.

    PubMed

    Alferes, J; García-Heras, J L; Roca, E; García, C; Irizar, I

    2008-01-01

    The combination of equalisation tanks and anaerobic digesters represents a typical design scenario within the treatment of industrial wastewaters. In this context, if the hydraulic capacity of the equalisation tanks is effectively handled, significant improvements in the performance of anaerobic digesters can be achieved in terms of process stability and biogas production. This paper presents a rule-based control strategy for anaerobic reactors with the objective of maximising in the long-term the net production of biogas. The control algorithm combines real-time information about the state of the anaerobic digester with on-line measurements about the wastewater volume of the equalisation tank in order to set permanently the appropriate production of biogas. Such a strategy guarantees a continuous influent flow so that emptying and overflowing episodes in the equalisation tank can be prevented. Aiming at a further full-scale implementation, only reliable and cost-effective on-line instrumentation has been considered within the control architecture. The performance of the proposed control approach has been validated for an anaerobic hybrid configuration (AHR) by simulation using the IWA ADM1 model. PMID:18401148

  18. The role of ADME pharmacogenomics in early clinical trials: perspective of the Industry Pharmacogenomics Working Group (I-PWG).

    PubMed

    Tremaine, Larry; Brian, William; DelMonte, Terrye; Francke, Stephan; Groenen, Peter; Johnson, Keith; Li, Lei; Pearson, Kimberly; Marshall, Jean-Claude

    2015-12-01

    Genetic polymorphisms in metabolizing enzymes and drug transporters have been shown to significantly impact the exposure of drugs having a high dependence on a single mechanism for their absorption, distribution or clearance, such that genotyping can lead to actionable steps in disease treatment. Recently, global regulatory agencies have provided guidance for assessment of pharmacogenomics during early stages of drug development, both in the form of formal guidance and perspectives published in scientific journals. The Industry Pharmacogenomics Working Group (I-PWG), conducted a survey among member companies to assess the practices relating to absorption, distribution, metabolism, excretion pharmacogenomics) during early stages of clinical development, to assess the impact of the recent Regulatory Guidance issued by the US FDA and EMA on Industry practices.

  19. Thermal structure and CO distribution for the Venus mesosphere/lower thermosphere: 2001-2009 inferior conjunction sub-millimeter CO absorption line observations

    NASA Astrophysics Data System (ADS)

    Clancy, R. Todd; Sandor, Brad J.; Moriarty-Schieven, Gerald

    2012-02-01

    Sub-millimeter 12CO (346 GHz) and 13CO (330 GHz) line absorptions, formed in the mesosphere and lower thermosphere of Venus (70-120 km), have been mapped across the nightside Venus disk during 2001-2009 inferior conjunctions, employing the James Clerk Maxwell Telescope (JCMT). Radiative transfer analysis of these thermal line absorptions supports temperature and CO mixing profile retrievals, as well as Doppler wind fields (described in the companion paper, Clancy et al., 2012). Temporal sampling over the hourly, daily, weekly and interannual timescales was obtained over 2001-2009. On timescales inferred as several weeks, we observe changes between very distinctive CO and temperature nightside distributions. Retrieved nightside CO, temperature distributions for January 2006 and August 2007 observations display strong local time, latitudinal gradients consistent with early morning (2-3 am), low-to-mid latitude (0-40NS) peaks of 100-200% in CO and 20-30 K in temperature. The temperature increases are most pronounced above 100 km altitudes, whereas CO variations extend from 105 km (top altitude of retrieval) down to below 80 km in the mesosphere. In contrast, the 2004 and 2009 periods of observation display modest temperature (5-10 K) and CO (30-60%) increases, that are centered on antisolar (midnight) local times and equatorial latitudes. Doppler wind derived global (zonal and should be SSAS) circulations from the same data do not exhibit variations correlated with these CO, temperature short-term variations. However, large-scale residual wind fields not fit by the zonal, SSAS circulations are observed in concert with the strong temperature, CO gradients observed in 2006 and 2007 (Clancy et al., 2010). These short term variations in nightside CO, temperature distributions may also be related to observed nightside variations in O 2 airglow (Hueso, H., Sánchez-Lavega, A., Piccioni, G., Drossart, P., Gérard, J.C., Khatuntsev, I., Zasova, L., Migliorini, A. [2008]. J

  20. Comparison of ADM and Connective Tissue Graft as the Membrane in Class II Furcation Defect Regeneration: A Randomized Clinical Trial

    PubMed Central

    Esfahanian, Vahid; Farhad, Shirin; Sadighi Shamami, Mehrnaz

    2014-01-01

    Background and aims. Furcally-involved teeth present unique challenges to the success of periodontal therapy and influence treatment outcomes. This study aimed to assess to compare use of ADM and connective tissue membrane in class II furcation defect regeneration. Materials and methods. 10 patient with 2 bilaterally class II furcation defects in first and/or second maxilla or man-dibular molar without interproximal furcation involvement, were selected. Four weeks after initial phase of treatment, before and thorough the surgery pocket depth (PD), clinical attachment level to stent (CAL-S), free gingival margin to stent(FGM-S) , crestal bone to stent (Crest-S), horizontal defect depth to stent (HDD-S) and vertical defect depth to stent (VDD-S) and crestal bone to defect depth measured from stent margin. Thereafter, one side randomly treated using connective tissue and DFDBA (study group) and opposite side received ADM and DFDBA (control group). After 6 months, soft and hard tissue parameters measured again in re-entry. Results. Both groups presented improvements after therapies (P & 0.05). No inter-group differences were seen in PD re-duction (P = 0.275), CAL gain (P = 0.156), free gingival margin (P = 0.146), crest of the bone (P = 0.248), reduction in horizontal defects depth (P = 0.139) and reduction in vertical defects depth (P = 0.149). Conclusion. Both treatments modalities have potential of regeneration without any adverse effect on healing process. Connective tissue grafts did not have significant higher bone fill compared to that of ADM. PMID:25093054

  1. Absorption, Distribution, and Excretion of the Investigational Agent Orteronel (TAK-700) in Healthy Male Subjects: A Phase 1, Open-Label, Single-Dose Study.

    PubMed

    Suri, Ajit; Pusalkar, Sandeepraj; Li, Yuexian; Prakash, Shimoga

    2016-05-01

    This study evaluated the absorption, distribution, and excretion of orteronel, an investigational, nonsteroidal, reversible, selective 17,20-lyase inhibitor. Six healthy male subjects received a single 400-mg dose of radiolabeled [(14) C]-orteronel (18.5 kBq). The pharmacokinetics of [(14) C]-radioactivity, orteronel, and the primary metabolite M-I were characterized by ultra-performance liquid chromatography-tandem mass spectrometry, and mass balance recovery of [(14) C]-radioactivity was determined by liquid scintillation counting and accelerator mass spectrometry. Median time to maximum observed concentration of [(14) C]-radioactivity was 2.5 hours (plasma/whole blood) and of orteronel was 1 hour (plasma). Mean terminal half-life for [(14) C]-radioactivity in plasma and whole blood was 9.46 and 7.39 hours, respectively. For [(14) C]-radioactivity, the geometric mean whole blood-to-plasma ratios for maximum observed plasma/whole-blood concentration, area under the plasma concentration-time curve from time 0 to last quantifiable concentration (AUC0-last ), and AUC0-inf (AUC from time 0 to infinity) were 1.04, 0.92, and 0.93, respectively. Dose recovery accounted for 95.9% of the administered orteronel dose; the majority of excretion occurred by 96 hours postdose. The principal excretion route was via urine (mean, 77.5%; including 49.7% unchanged drug and 16.3% M-I) compared with 18.4% via feces. Three mild adverse events were reported; none were considered serious or related to orteronel. PMID:27163496

  2. Development and validation of an UPLC-MS/MS method for the quantification of ethoxzolamide in plasma and bioequivalent buffers: Applications to absorption, brain distribution, and pharmacokinetic studies

    PubMed Central

    Gao, Song; Zhao, Jing; Yin, Taijun; Ma, Yong; Xu, Beibei; Moore, Anthony N.; Dash, Pramod K.; Hu, Ming

    2015-01-01

    The purpose of this study is to develop and validate an UPLC-MS/MS method to quantify ethoxzolamide in plasma (EZ) and apply the method to absorption, brain distribution, as well as pharmacokinetic studies. A C18 column was used with 0.1% of formic acid in acetonitrile and 0.1% of formic acid in water as the mobile phases to resolve EZ. The mass analysis was performed in a triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) with positive scan mode. The results show that the linear range of EZ is 4.88–10,000.00 nM. The intra-day variance is less than 12.43 % and the accuracy is between 88.88–08.00 %. The inter-day variance is less than 12.87 % and accuracy is between 89.27–115.89 %. Protein precipitation was performed using methanol to extract EZ from plasma and brain tissues. Only 40 µL of plasma is needed for analysis due to the high sensitivity of this method, which could be completed in less than three minutes. This method was used to study the pharmacokinetics of EZ in SD rats, and the transport of EZ in Caco-2 and MDCK-MDR1 overexpressing cell culture models. Our data show that EZ is not a substrate for p-glycoprotein (P-gp) and its entry into the brain may not limited by the blood-brain barrier. PMID:25706567

  3. CdTe quantum dots with daunorubicin induce apoptosis of multidrug-resistant human hepatoma HepG2/ADM cells: in vitro and in vivo evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Gen; Shi, Lixin; Selke, Matthias; Wang, Xuemei

    2011-06-01

    Cadmium telluride quantum dots (Cdte QDs) have received significant attention in biomedical research because of their potential in disease diagnosis and drug delivery. In this study, we have investigated the interaction mechanism and synergistic effect of 3-mercaptopropionic acid-capped Cdte QDs with the anti-cancer drug daunorubicin (DNR) on the induction of apoptosis using drug-resistant human hepatoma HepG2/ADM cells. Electrochemical assay revealed that Cdte QDs readily facilitated the uptake of the DNR into HepG2/ADM cells. Apoptotic staining, DNA fragmentation, and flow cytometry analysis further demonstrated that compared with Cdte QDs or DNR treatment alone, the apoptosis rate increased after the treatment of Cdte QDs together with DNR in HepG2/ADM cells. We observed that Cdte QDs treatment could reduce the effect of P-glycoprotein while the treatment of Cdte QDs together with DNR can clearly activate apoptosis-related caspases protein expression in HepG2/ADM cells. Moreover, our in vivo study indicated that the treatment of Cdte QDs together with DNR effectively inhibited the human hepatoma HepG2/ADM nude mice tumor growth. The increased cell apoptosis rate was closely correlated with the enhanced inhibition of tumor growth in the studied animals. Thus, Cdte QDs combined with DNR may serve as a possible alternative for targeted therapeutic approaches for some cancer treatments.

  4. Comparison of the complex terrain algorithms incorporated into two commonly used local-scale air pollution dispersion models (ADMS and AERMOD) using a hybrid model.

    PubMed

    Carruthers, David J; Seaton, Martin D; McHugh, Christine A; Sheng, Xiangyu; Solazzo, Efisio; Vanvyve, Emilie

    2011-11-01

    ADMS and AERMOD are the two most widely used dispersion models for regulatory purposes. It is, therefore, important to understand the differences in the predictions of the models and the causes of these differences. The treatment by the models of flat terrain has been discussed previously; in this paper the focus is on their treatment of complex terrain. The paper includes a discussion of the impacts of complex terrain on airflow and dispersion and how these are treated in ADMS and AERMOD, followed by calculations for two distinct cases: (i) sources above a deep valley within a relatively flat plateau area (Clifty Creek power station, USA); (ii) sources in a valley in hilly terrain where the terrain rises well above the stack tops (Ribblesdale cement works, England). In both cases the model predictions are markedly different. At Clifty Creek, ADMS suggests that the terrain markedly increases maximum surface concentrations, whereas the AERMOD complex terrain module has little impact. At Ribblesdale, AERMOD predicts very large increases (a factor of 18) in the maximum hourly average surface concentrations due to plume impaction onto the neighboring hill; although plume impaction is predicted by ADMS, the increases in concentration are much less marked as the airflow model in ADMS predicts some lateral deviation of the streamlines around the hill.

  5. Physiologically Based In vitro Models to Predict the Oral Dissolution and Absorption of a Solid Drug Delivery System.

    PubMed

    Li, Ziqiang; He, Xin

    2015-01-01

    To understand the sophisticated dynamic behaviors of drug elution and permeation in the gastrointestinal tract (GIT), researchers have tried to reemerge it by employing various in vitro experimental models. However, official in vitro apparatuses routinely used for quality control purposes, employ simple, non-physiologic buffers, and hydrodynamics conditions, and can not accurately perform continuous, dynamic in vivo pharmacokinetics (PK) behaviors. Therefore, different angles of GI physiology information are incorporate into novel models to forecast the dissolution and permeation of drug solid dosage forms. This review, in general, discusses some related studies of physiologically-based mechanical models to predict human absorption following oral administration in four sections. First the GIT, taken out of a complex physiological environment, where the drug is absorbed, distributed, metabolized and excreted (ADME) in the human body, is considered as the physiological basis for active pharmaceutics ingredients (API) dissolved and permeated through the epithelial cell. The second part embodies the theoretical foundation of in vitro models to predict human absorption and the corresponding in vitro.in vivo correlations (IVIVC). The third section summarizes physiologically based dissolution models developed recently, ranging from dynamic compartmental dissolution models, to biorelevant dissolution models based on certain physiological factors, to biphasic dissolution models. The last part is devoted to combined dissolution and absorption models that can be employed to simulate the continuous, dynamic behavior of oral drug delivery being dissolved and subsequently permeated across the GIT. Along with physiologically-based mechanically models spring up, pharmaceutical researchers will harvest better level A IVIVC for oral drug delivery systems, especially for sustained and controlled release preparations. On the other way hand, it will successively promote more effective

  6. Addressing the analytical throughput challenges in ADME screening using rapid ultra-performance liquid chromatography/tandem mass spectrometry methodologies.

    PubMed

    Plumb, Robert S; Potts, Warren B; Rainville, Paul D; Alden, Peter G; Shave, Darcy H; Baynham, Geneen; Mazzeo, Jeffery R

    2008-07-01

    High-throughput ADME screening for compound drug development properties has become an essential part of the modern drug discovery process, allowing more informed decisions to be made on the best compounds to take forward in the discovery/development process. This however is a time-consuming process requiring multiple tests to be performed, demanding a significant amount of liquid chromatography/mass spectrometry (LC/MS) instrument time. This article focuses on the use of sub-2 microm porous particle LC coupled to tandem quadrupole MS/MS mass spectrometry for the rapid screening of ADME properties. Using this approach analysis times from 30 s to 1 min were achievable allowing analysis times to be cut by 80%. The use of the small particles coupled to high flow rates allowed for sufficient resolution, even with very short analysis time, to resolve the analytes of interest from similar compounds that would interfere with the assay. The use of dedicated, intelligent, software packages allowed for the user-free generation of MS/MS conditions and the processing of the data.

  7. Protective Effect of Adrenomedullin on Rat Leydig Cells from Lipopolysaccharide-Induced Inflammation and Apoptosis via the PI3K/Akt Signaling Pathway ADM on Rat Leydig Cells from Inflammation and Apoptosis

    PubMed Central

    Zhou, Pang-Hu; Hu, Wei; Zhang, Xiao-Bin; Wang, Wei; Zhang, Li-Jun

    2016-01-01

    This study was carried out to investigate whether ADM can modulate LPS-induced inflammation and apoptosis in rat Leydig cells. Leydig cells were treated with ADM before LPS-induced cytotoxicity. We determined the concentrations of ROS, MDA, GSH, LDH, and testosterone and the MMP. The mRNA levels of IL-1, IL-6, iNOS, and COX-2 were obtained, and the concentrations of IL-1, IL-6, NO, and PGE2 were determined. Apoptosis was assessed by TUNEL and detection of DNA fragmentation. The levels of mRNA and protein were determined for Bcl-2, Bax, caspase-3, and PARP. The protein contents for total and p-Akt were measured. ADM pretreatment significantly elevated the MMP and testosterone concentration and reduced the levels of ROS, MDA, GSH, and LDH. ADM pretreatment significantly decreased the mRNA levels of IL-1, IL-6, iNOS, and COX-2 and the concentrations of IL-1, IL-6, NO, and PGE2. LPS-induced TUNEL-positive Leydig cells were significantly decreased by ADM pretreatment, a result further confirmed by decreased DNA fragmentation. ADM pretreatment decreased apoptosis by significantly promoting Bcl-2 and inhibiting Bax, caspase-3, and PARP expressions. The LPS activity that reduced p-Akt level was significantly inhibited by ADM pretreatment. ADM protected rat Leydig cells from LPS-induced inflammation and apoptosis, which might be associated with PI3K/Akt mitochondrial signaling pathway. PMID:27212810

  8. Design and development of a probe-based multiplexed multi-species absorption spectroscopy sensor for characterizing transient gas-parameter distributions in the intake systems of I.C. engines

    DOE PAGES

    Jatana, Gurneesh; Geckler, Sam; Koeberlein, David; Partridge, William

    2016-09-01

    We designed and developed a 4-probe multiplexed multi-species absorption spectroscopy sensor system for gas property measurements on the intake side of commercial multi-cylinder internal-combustion (I.C.) engines; the resulting cycle- and cylinder-resolved concentration, temperature and pressure measurements are applicable for assessing spatial and temporal variations in the recirculated exhaust gas (EGR) distribution at various locations along the intake gas path, which in turn is relevant to assessing cylinder charge uniformity, control strategies, and CFD models. Furthermore, the diagnostic is based on absorption spectroscopy and includes an H2O absorption system (utilizing a 1.39 m distributed feedback (DFB) diode laser) for measuring gasmore » temperature, pressure, and H2O concentration, and a CO2 absorption system (utilizing a 2.7 m DFB laser) for measuring CO2 concentration. The various lasers, optical components and detectors were housed in an instrument box, and the 1.39- m and 2.7- m lasers were guided to and from the engine-mounted probes via optical fibers and hollow waveguides, respectively. The 5kHz measurement bandwidth allows for near-crank angle resolved measurements, with a resolution of 1.2 crank angle degrees at 1000 RPM. Our use of compact stainless steel measurement probes enables simultaneous multi-point measurements at various locations on the engine with minimal changes to the base engine hardware; in addition to resolving large-scale spatial variations via simultaneous multi-probe measurements, local spatial gradients can be resolved by translating individual probes. Along with details of various sensor design features and performance, we also demonstrate validation of the spectral parameters of the associated CO2 absorption transitions using both a multi-pass heated cell and the sensor probes.« less

  9. Relationship of high molecular weight glutenin subunit composition and molecular weight distribution of wheat flour protein with water absorption and color characteristics of noodle dough

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colors of noodle doughs made from hard white winter wheat flours from Oregon were measured at optimum noodle water absorptions (NWA). Partial correlations, removing effect of protein concentration, indicated that NWA had negative relationships with 0 hr L* and 24 hr b*, and positive relationships wi...

  10. Local structure of germanium selenide glasses around the rigidity percolation threshold using atomic pair distribution function and X-ray absorption fine structure techniques

    NASA Astrophysics Data System (ADS)

    Shatnawi, Moneeb Taiseer

    A search for a structural response to a recently proposed self-organized and stress-free intermediate phase [1, 2] in semiconductor chalcogenide Ge xSe1-x glasses has been performed in this study. These glasses, according to the mean-field approach, undergo a structural phase transition from floppy to rigid network that occurs at a mean coordination number of 2.4. Based on thermodynamic and spectroscopic measurements, these glasses appear to exhibit two transitions instead of one [3]. The region between these transitions has been called the intermediate phase (IP) [3, 4]. The original theoretical work assumed that the network was generic and the connectivity random [5]. It was therefore suggested [1] that the IP phase is a region of finite width in composition where the network could self-organize in such a way that maintains a rigid but unstressed state. However, it has proved difficult to establish this result experimentally. High-resolution atomic pair distribution functions (PDF), derived from high energy synchrotron radiation, coupled with high-resolution X-ray absorption fine structure (XAFS) measurements on 18 compositions of well-prepared Ge xSe1-x glasses that span the range of the IP have been performed to elucidate aspects of rigidity percolation and the IP. These data sets are the most complete and the highest resolution data set on this system to date. Analysis of the structure functions (in reciprocal space) and the PDFs (in real space) as well as the XAFS data at both Ge and Se edges show no correlations with the IP. The network evolves smoothly without any break in slope or discontinuity that might be linked due to the IP. The results obtained in this study contradict previously published work [1, 2] that claim experimental evidence for a structural origin of the IP. The so-called first sharp diffraction peak (FSDP), which is a signature of the medium range order in these glasses, changes systematically with Ge content. It develops smoothly from a

  11. Modelling of the mesophilic anaerobic co-digestion of olive mill wastewater with olive mill solid waste using anaerobic digestion model No. 1 (ADM1).

    PubMed

    Boubaker, Fezzani; Ridha, Ben Cheikh

    2008-09-01

    The anaerobic digestion model No. 1 (ADM1), conceived by the international water association (IWA) task group for mathematical modelling of anaerobic digestion processes is a structured generic model which includes multiples steps describing biochemical and physicochemical processes encountered in the anaerobic degradation of complex organic substrates and a common platform for further model enhancement and validation of dynamic simulations for a variety of anaerobic processes. In this study the ADM1 model was modified and applied to simulate the mesophilic anaerobic co-digestion of olive mill wastewater (OMW) with olive mill solid waste (OMSW). The ADM1 equations were coded and implemented using the simulation software package MATLAB/Simulink. The most sensitive parameters were calibrated and validated using updated experimental data of our previous work. The results indicated that the ADM1 model could simulate with good accuracy: gas flows, methane and carbon-dioxide contents, pH and total volatile fatty acids (TVFA) concentrations of effluents for various feed concentrations digested at different hydraulic retention times (HRTs) and especially at HRTs of 36 and 24 days. Furthermore, effluent alkalinity and ammonium nitrogen were successfully predicted by the model at HRTs of 12 and 24 days for some feed concentrations. PMID:18187320

  12. Modelling mono-digestion of grass silage in a 2-stage CSTR anaerobic digester using ADM1.

    PubMed

    Thamsiriroj, T; Murphy, J D

    2011-01-01

    This paper examines 174 days of experimental data and modelling of mono-digestion of grass silage in a two stage wet process with recirculation of liquor; the two vessels have an effective volume of 312 L each. The organic loading rate is initiated at 0.5 kg VS m(-3) d(-1) (first 74 days) and subsequently increased to 1 kg VS m(-3) d(-1). The experimental data was used to generate a mathematical model (ADM1) which was calibrated over the first 74 days of operation. Good accuracy with experimental data was found for the subsequent 100 days. Results of the model would suggest starting the process without recirculation and thus building up the solids content of the liquor. As the level of VFA increases, recirculation should be employed to control VFA. Recirculation also controls solids content and pH. Methane production was estimated at 88% of maximum theoretical production.

  13. Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Terra Satellite. Part 1; Methodology

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Kato, S.; Loukachine, K.; Smith, N. M.

    2004-01-01

    The Clouds and Earth's Radiant Energy System (CERES) provides coincident global cloud and aerosol properties together with reflected solar, emitted terrestrial longwave and infrared window radiative fluxes. These data are needed to improve our understanding and modeling of the interaction between clouds, aerosols and radiation at the top of the atmosphere, surface, and within the atmosphere. This paper describes the approach used to estimate top-of-atmosphere (TOA) radiative fluxes from instantaneous CERES radiance measurements on the Terra satellite. A key component involves the development of empirical angular distribution models (ADMs) that account for the angular dependence of Earth's radiation field at the TOA. The CERES Terra ADMs are developed using 24 months of CERES radiances, coincident cloud and aerosol retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological parameters from the Global Modeling and Assimilation Office (GMA0) s Goddard Earth Observing System DAS (GEOS-DAS V4.0.3) product. Scene information for the ADMs is from MODIS retrievals and GEOS-DAS V4.0.3 properties over ocean, land, desert and snow, for both clear and cloudy conditions. Because the CERES Terra ADMs are global, and far more CERES data is available on Terra than was available from CERES on the Tropical Rainfall Measuring Mission (TRMM), the methodology used to define CERES Terra ADMs is different in many respects from that used to develop CERES TRMM ADMs, particularly over snow/sea-ice, under cloudy conditions, and for clear scenes over land and desert.

  14. Next-Generation Angular Distribution Models for Top-of-Atmosphere Radiative Flux Calculation from the CERES Instruments: Methodology

    NASA Technical Reports Server (NTRS)

    Su, W.; Corbett, J.; Eitzen, Z.; Liang, L.

    2015-01-01

    The top-of-atmosphere (TOA) radiative fluxes are critical components to advancing our understanding of the Earth's radiative energy balance, radiative effects of clouds and aerosols, and climate feedback. The Clouds and the Earth's Radiant Energy System (CERES) instruments provide broadband shortwave and longwave radiance measurements. These radiances are converted to fluxes by using scene-type-dependent angular distribution models (ADMs). This paper describes the next-generation ADMs that are developed for Terra and Aqua using all available CERES rotating azimuth plane radiance measurements. Coincident cloud and aerosol retrievals, and radiance measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological parameters from Goddard Earth Observing System (GEOS) data assimilation version 5.4.1 are used to define scene type. CERES radiance measurements are stratified by scene type and by other parameters that are important for determining the anisotropy of the given scene type. Anisotropic factors are then defined either for discrete intervals of relevant parameters or as a continuous functions of combined parameters, depending on the scene type. Significant differences between the ADMs described in this paper and the existing ADMs are over clear-sky scene types and polar scene types. Over clear ocean, we developed a set of shortwave (SW) ADMs that explicitly account for aerosols. Over clear land, the SW ADMs are developed for every 1 latitude1 longitude region for every calendar month using a kernel-based bidirectional reflectance model. Over clear Antarctic scenes, SW ADMs are developed by accounting the effects of sastrugi on anisotropy. Over sea ice, a sea-ice brightness index is used to classify the scene type. Under cloudy conditions over all surface types, the longwave (LW) and window (WN) ADMs are developed by combining surface and cloud-top temperature, surface and cloud emissivity, cloud fraction, and precipitable water

  15. ABSORPTION ANALYZER

    DOEpatents

    Brooksbank, W.A. Jr.; Leddicotte, G.W.; Strain, J.E.; Hendon, H.H. Jr.

    1961-11-14

    A means was developed for continuously computing and indicating the isotopic assay of a process solution and for automatically controlling the process output of isotope separation equipment to provide a continuous output of the desired isotopic ratio. A counter tube is surrounded with a sample to be analyzed so that the tube is exactly in the center of the sample. A source of fast neutrons is provided and is spaced from the sample. The neutrons from the source are thermalized by causing them to pass through a neutron moderator, and the neutrons are allowed to diffuse radially through the sample to actuate the counter. A reference counter in a known sample of pure solvent is also actuated by the thermal neutrons from the neutron source. The number of neutrons which actuate the detectors is a function of a concentration of the elements in solution and their neutron absorption cross sections. The pulses produced by the detectors responsive to each neu tron passing therethrough are amplified and counted. The respective times required to accumulate a selected number of counts are measured by associated timing devices. The concentration of a particular element in solution may be determined by utilizing the following relation: T2/Ti = BCR, where B is a constant proportional to the absorption cross sections, T2 is the time of count collection for the unknown solution, Ti is the time of count collection for the pure solvent, R is the isotopic ratlo, and C is the molar concentration of the element to be determined. Knowing the slope constant B for any element and when the chemical concentration is known, the isotopic concentration may be readily determined, and conversely when the isotopic ratio is known, the chemical concentrations may be determined. (AEC)

  16. The potent and selective α4β2*/α6*-nicotinic acetylcholine receptor partial agonist 2-[5-[5-((S)Azetidin-2-ylmethoxy)-3-pyridinyl]-3-isoxazolyl]ethanol demonstrates antidepressive-like behavior in animal models and a favorable ADME-tox profile

    PubMed Central

    Yu, Li-Fang; Brek Eaton, J; Zhang, Han-Kun; Sabath, Emily; Hanania, Taleen; Li, Guan-Nan; van Breemen, Richard B; Whiteaker, Paul; Liu, Qiang; Wu, Jie; Chang, Yong-Chang; Lukas, Ronald J; Brunner, Dani; Kozikowski, Alan P

    2014-01-01

    Preclinical and clinical studies demonstrated that the inhibition of cholinergic supersensitivity through nicotinic antagonists and partial agonists can be used successfully to treat depressed patients, especially those who are poor responders to selective serotonin reuptake inhibitors (SSRIs). In our effort to develop novel antidepressant drugs, LF-3-88 was identified as a potent nicotinic acetylcholine receptor (nAChR) partial agonist with subnanomolar to nanomolar affinities for β2-containing nAChRs (α2β2, α3β2, α4β2, and α4β2*) and superior selectivity away from α3β4 − (Ki > 104 nmol/L) and α7-nAChRs (Ki > 104 nmol/L) as well as 51 other central nervous system (CNS)-related neurotransmitter receptors and transporters. Functional activities at different nAChR subtypes were characterized utilizing 86Rb+ ion efflux assays, two-electrode voltage-clamp (TEVC) recording in oocytes, and whole-cell current recording measurements. In mouse models, administration of LF-3-88 resulted in antidepressive-like behavioral signatures 15 min post injection in the SmartCube® test (5 and 10 mg/kg, i.p.; about 45-min session), decreased immobility in the forced swim test (1–3 mg/kg, i.p.; 1–10 mg/kg, p.o.; 30 min pretreatment, 6-min trial), and decreased latency to approach food in the novelty-suppressed feeding test after 29 days chronic administration once daily (5 mg/kg but not 10 mg/kg, p.o.; 15-min trial). In addition, LF-3-88 exhibited a favorable profile in pharmacokinetic/ADME-Tox (absorption, distribution, metabolism, excretion, and toxicity) assays. This compound was also shown to cause no mortality in wild-type Balb/CJ mice when tested at 300 mg/kg. These results further support the potential of potent and selective nicotinic partial agonists for use in the treatment of depression. PMID:25505580

  17. Effect of colchicine on rat small intestinal absorptive cells. II. Distribution of label after incorporation of (/sup 3/H)fucose into plasma membrane glycoproteins

    SciTech Connect

    Ellinger, A.; Pavelka, M.; Gangl, A.

    1983-12-01

    By means of radioautography the influence was tested of various periods (5, 15, 30, 40 min, 2 hr) of pretreatment with colchicine, administered intraperitoneally to rats at a dosage of 0.5 mg/100 g of body weight, on the intracellular pathway of (/sup 3/H)fucose in absorptive cells of the small intestine. Administration of colchicine for 30 min and longer time intervals causes delay in the insertion of (/sup 3/H)fucose into the oligosaccharide chains of glycoconjugates in the Golgi apparatus, and results in redistribution of the label apparent over the different portions of the plasma membrane. In controls, at 2 and 4 hr after administration of (/sup 3/H)fucose the apical plasma membrane is strongly labeled. Colchicine causes equalization of the reaction of apical and basolateral regions of the plasma membrane: the number of silver grains attributable to the apical plasma membrane is reduced; following treatment with colchicine, apical portions of the plasma membrane comprise 31.6 +/- 1.8% of the silver grains, 38.6 +/- 3.8% are attributable to basolateral membrane regions. The colchicine-induced equalization of the density of label of apical and basolateral regions of the plasma membrane, in addition to the occurrence of basolateral microvillus borders, suggests microtubules to be important in the maintenance of the polar organization of small intestinal absorptive cells.

  18. THE 3-5 {mu}m SPECTRUM OF NGC 1068 AT HIGH ANGULAR RESOLUTION: DISTRIBUTION OF EMISSION AND ABSORPTION FEATURES ACROSS THE NUCLEAR CONTINUUM SOURCE

    SciTech Connect

    Geballe, T. R.; Mason, R. E.; Rodriguez-Ardila, A.; Axon, D. J.

    2009-08-20

    We report moderate resolution 3-5 {mu}m spectroscopy of the nucleus of NGC 1068 obtained at 0.''3 (20 pc) resolution with the spectrograph slit aligned approximately along the ionization cones of the active galactic nucleus. The deconvolved full width at half-maximum of the nuclear continuum source in this direction is 0.''3. Four coronal lines of widely different excitations were detected; the intensity of each peaks near radio knot C, approximately 0.''3 north of the infrared continuum peak, where the radio jet changes direction. Together with the broadened line profiles observed near that location, this suggests that shock ionization is the dominant excitation mechanism of the coronal lines. The depth of the 3.4 {mu}m hydrocarbon absorption is maximum at and just south of the continuum peak, similar to the 10 {mu}m silicate absorption. That and the similar and rapid variations of the optical depths of both features across the nucleus suggest that substantial portions of both arise in a dusty environment just in front of the continuum source(s). A new and tighter limit is set on the column density of CO. Although clumpy models of the dust screen might explain the shallowness of the silicate feature, the presence of the 3.4 {mu}m feature and the absence of CO are strongly reminiscent of Galactic diffuse cloud environments and a consistent explanation for them and the observed silicate feature is found if all three phenomena occur in such an environment, existing as close as 10 pc to the central engine.

  19. Effective absorption in cladding-pumped fibers

    NASA Astrophysics Data System (ADS)

    Zervas, Michalis N.; Marshall, Andy; Kim, Jaesun

    2011-02-01

    We investigate experimentally and theoretically the wavelength dependence of the pump absorption along Yb3+-doped fibers, for cladding-pumped single as well as coupled multimode (GTWaveTM) fibers. We show that significant spectral absorption distortions occur along the length with the 976nm absorption peak affected the most. We have developed a novel theoretical approach, based on coupled mode theory, to explain the observed effects. We have also investigated the mode mixing requirements in order to improve the absorption spectral distribution along the increase the overall absorption efficiency and discuss the implications on fiber laser performance.

  20. Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P-gp and MRP-1.

    PubMed

    Yi, Ying-Jie; Jia, Xiu-Hong; Wang, Jian-Yong; Li, You-Jie; Wang, Hong; Xie, Shu-Yang

    2016-05-01

    Multidrug resistance (MDR) of leukemia cells is a major obstacle in chemotherapeutic treatment. The high expression and constitutive activation of P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) have been reported to play a vital role in enhancing cell resistance to anticancer drugs in many tumors. The present study aimed to investigate the reversal of MDR by silencing homeobox A10 (HOXA10) in adriamycin (ADR)-resistant human chronic myelogenous leukemia (CML) K562/ADM cells by modulating the expression of P-gp and MRP-1. K562/ADM cells were stably transfected with HOXA10-targeted short hairpin RNA (shRNA). The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis showed that the mRNA and protein expression of HOXA10 was markedly suppressed following transfection with a shRNA-containing vector. The sensitivity of the K562/ADM cells to ADR was enhanced by the silencing of HOXA10, due to the increased intracellular accumulation of ADR. The accumulation of ADR induced by the silencing of HOXA10 may be due to the downregulation of P-gp and MRP-1. Western blot analysis revealed that downregulating HOXA10 inhibited the protein expression of P-gp and MRP-1. Taken together, these results suggest that knockdown of HOXA10 combats resistance and that HOXA10 is a potential target for resistant human CML. PMID:27035504

  1. Advances in Computationally Modeling Human Oral Bioavailability

    PubMed Central

    Wang, Junmei; Hou, Tingjun

    2015-01-01

    Although significant progress has been made in experimental high throughput screening (HTS) of ADME (absorption, distribution, metabolism, excretion) and pharmacokinetic properties, the ADME and Toxicity (ADME-Tox) in silico modeling is still indispensable in drug discovery as it can guide us to wisely select drug candidates prior to expensive ADME screenings and clinical trials. Compared to other ADME-Tox properties, human oral bioavailability (HOBA) is particularly important but extremely difficult to predict. In this paper, the advances in human oral bioavailability modeling will be reviewed. Moreover, our deep insight on how to construct more accurate and reliable HOBA QSAR and classification models will also discussed. PMID:25582307

  2. Atmospheric correction of ocean color imagery: use of the junge power-law aerosol size distribution with variable refractive index to handle aerosol absorption.

    PubMed

    Chomko, R M; Gordon, H R

    1998-08-20

    When strongly absorbing aerosols are present in the atmosphere, the usual two-step procedure of processing ocean color data-(1) atmospheric correction to provide the water-leaving reflectance (rho(w)), followed by (2) relating rho(w) to the water constituents-fails and simultaneous estimation of the ocean and aerosol optical properties is necessary. We explore the efficacy of using a simple model of the aerosol-a Junge power-law size distribution consisting of homogeneous spheres with arbitrary refractive index-in a nonlinear optimization procedure for estimating the relevant oceanic and atmospheric parameters for case 1 waters. Using simulated test data generated from more realistic aerosol size distributions (sums of log-normally distributed components with different compositions), we show that the ocean's pigment concentration (C) can be retrieved with good accuracy in the presence of weakly or strongly absorbing aerosols. However, because of significant differences in the scattering phase functions for the test and power-law distributions, large error is possible in the estimate of the aerosol optical thickness. The positive result for C suggests that the detailed shape of the aerosol-scattering phase function is not relevant to the atmospheric correction of ocean color sensors. The relevant parameters are the aerosol single-scattering albedo and the spectral variation of the aerosol optical depth. We argue that the assumption of aerosol sphericity should not restrict the validity of the algorithm and suggest an avenue for including colored aerosols, e.g., wind-blown dust, in the procedure. A significant advantage of the new approach is that realistic multicomponent aerosol models are not required for the retrieval of C.

  3. A study of the distribution of aluminium in human placental tissues based on alkaline solubilization with determination by electrothermal atomic absorption spectrometry.

    PubMed

    Kruger, Pamela C; Schell, Lawrence M; Stark, Alice D; Parsons, Patrick J

    2010-09-01

    Aluminium (Al) is a nonessential element known to induce neurotoxic effects, such as dialysis dementia, in patients on hemodialysis, with compromised kidney function. The role of Al in the progression of some neurodegenerative diseases, such as Alzheimer's disease (AD), is controversial, and remains unclear. The effects of Al on other vulnerable populations, such as fetuses and infants, have been infrequently studied. In the present study, Al has been measured in human placenta samples, comprising ∼160 each of placenta bodies, placenta membranes, and umbilical cords, using electrothermal atomic absorption spectrometry (ETAAS) after atmospheric pressure digestion with tetramethylammonium hydroxide (TMAH) and ethylenediaminetetraacidic acid (EDTA). The sensitivity, or characteristic mass (m(0)), for Al at the 309.3-nm line was found to be 30 ± 4 pg. The instrumental detection limit (IDL) (3s) for Al in solution was calculated as 0.72 μg L(-1) while the method detection limit (MDL) (3s) was 0.25 μg g(-1). Accuracy was assessed through analysis of quality control (QC) materials, including certified reference materials (CRMs), in-house reference materials (RMs), and spike recovery experiments, of varying matrices. Placental tissue analyses revealed geometric mean concentrations of approximately 0.5 μg g(-1) Al in placenta bodies (n = 165) and membranes (n = 155), while Al concentrations in umbilical cords (n = 154) were about 0.3 μg g(-1). Al was detected in 95% of placenta bodies, and 81% of placenta membranes, but only in 46% of umbilical cords.

  4. Derivation of local-in-time fourth post-Newtonian ADM Hamiltonian for spinless compact binaries

    NASA Astrophysics Data System (ADS)

    Jaranowski, Piotr; Schäfer, Gerhard

    2015-12-01

    The paper gives full details of the computation within the canonical formalism of Arnowitt, Deser, and Misner of the local-in-time part of the fourth post-Newtonian, i.e. of power eight in one over speed of light, conservative Hamiltonian of spinless compact binary systems. The Hamiltonian depends only on the bodies' positions and momenta. Dirac delta distributions are taken as source functions. Their full control is furnished by dimensional continuation, by means of which the occurring ultraviolet (UV) divergences are uniquely regularized. The applied near-zone expansion of the time-symmetric Green function leads to infrared (IR) divergences. Their analytic regularization results in one single ambiguity parameter. Unique fixation of it was successfully performed in T. Damour, P. Jaranowski, and G. Schäfer, Phys. Rev. D 89, 064058 (2014) through far-zone matching. Technically as well as conceptually (backscatter binding energy), the level of the Lamb shift in quantum electrodynamics is reached. In a first run a computation of all terms is performed in three-dimensional space using analytic Riesz-Hadamard regularization techniques. Then divergences are treated locally (i.e., around particles' positions for UV and in the vicinity of spatial infinity for IR divergences) by means of combined dimensional and analytic regularization. Various evolved analytic expressions are presented for the first time. The breakdown of the Leibniz rule for distributional derivatives is addressed as well as the in general nondistributive law when regularizing value of products of functions evaluated at their singular point.

  5. Element distribution and iron speciation in mature wheat grains (Triticum aestivum L.) using synchrotron X-ray fluorescence microscopy mapping and X-ray absorption near-edge structure (XANES) imaging.

    PubMed

    De Brier, Niels; Gomand, Sara V; Donner, Erica; Paterson, David; Smolders, Erik; Delcour, Jan A; Lombi, Enzo

    2016-08-01

    Several studies have suggested that the majority of iron (Fe) and zinc (Zn) in wheat grains are associated with phytate, but a nuanced approach to unravel important tissue-level variation in element speciation within the grain is lacking. Here, we present spatially resolved Fe-speciation data obtained directly from different grain tissues using the newly developed synchrotron-based technique of X-ray absorption near-edge spectroscopy imaging, coupling this with high-definition μ-X-ray fluorescence microscopy to map the co-localization of essential elements. In the aleurone, phosphorus (P) is co-localized with Fe and Zn, and X-ray absorption near-edge structure imaging confirmed that Fe is chelated by phytate in this tissue layer. In the crease tissues, Zn is also positively related to P distribution, albeit less so than in the aleurone. Speciation analysis suggests that Fe is bound to nicotianamine rather than phytate in the nucellar projection, and that more complex Fe structures may also be present. In the embryo, high Zn concentrations are present in the root and shoot primordium, co-occurring with sulfur and presumably bound to thiol groups. Overall, Fe is mainly concentrated in the scutellum and co-localized with P. This high resolution imaging and speciation analysis reveals the complexity of the physiological processes responsible for element accumulation and bioaccessibility. PMID:27038325

  6. Element distribution and iron speciation in mature wheat grains (Triticum aestivum L.) using synchrotron X-ray fluorescence microscopy mapping and X-ray absorption near-edge structure (XANES) imaging.

    PubMed

    De Brier, Niels; Gomand, Sara V; Donner, Erica; Paterson, David; Smolders, Erik; Delcour, Jan A; Lombi, Enzo

    2016-08-01

    Several studies have suggested that the majority of iron (Fe) and zinc (Zn) in wheat grains are associated with phytate, but a nuanced approach to unravel important tissue-level variation in element speciation within the grain is lacking. Here, we present spatially resolved Fe-speciation data obtained directly from different grain tissues using the newly developed synchrotron-based technique of X-ray absorption near-edge spectroscopy imaging, coupling this with high-definition μ-X-ray fluorescence microscopy to map the co-localization of essential elements. In the aleurone, phosphorus (P) is co-localized with Fe and Zn, and X-ray absorption near-edge structure imaging confirmed that Fe is chelated by phytate in this tissue layer. In the crease tissues, Zn is also positively related to P distribution, albeit less so than in the aleurone. Speciation analysis suggests that Fe is bound to nicotianamine rather than phytate in the nucellar projection, and that more complex Fe structures may also be present. In the embryo, high Zn concentrations are present in the root and shoot primordium, co-occurring with sulfur and presumably bound to thiol groups. Overall, Fe is mainly concentrated in the scutellum and co-localized with P. This high resolution imaging and speciation analysis reveals the complexity of the physiological processes responsible for element accumulation and bioaccessibility.

  7. Migrant labor absorption in Malaysia.

    PubMed

    Nayagam, J

    1992-01-01

    The use of migrant workers to ease labor shortages caused by rapid industrialization in Malaysia during the twentieth century is examined. "This paper will focus on: (1) the extent, composition and distribution of migrant workers; (2) the labor shortage and absorption of migrant workers; and (3) the role of migrant workers in the government's economic restructuring process."

  8. Migrant labor absorption in Malaysia.

    PubMed

    Nayagam, J

    1992-01-01

    The use of migrant workers to ease labor shortages caused by rapid industrialization in Malaysia during the twentieth century is examined. "This paper will focus on: (1) the extent, composition and distribution of migrant workers; (2) the labor shortage and absorption of migrant workers; and (3) the role of migrant workers in the government's economic restructuring process." PMID:12285766

  9. Diurnal Variation and Spatial Distribution Effects on Sulfur Speciation in Aerosol Samples as Assessed by X-Ray Absorption Near-Edge Structure (XANES)

    PubMed Central

    Pongpiachan, Siwatt; Thumanu, Kanjana; Na Pattalung, Warangkana; Hirunyatrakul, Phoosak; Kittikoon, Itthipon; Ho, Kin Fai; Cao, Junji

    2012-01-01

    This paper focuses on providing new results relating to the impacts of Diurnal variation, Vertical distribution, and Emission source on sulfur K-edge XANES spectrum of aerosol samples. All aerosol samples used in the diurnal variation experiment were preserved using anoxic preservation stainless cylinders (APSCs) and pressure-controlled glove boxes (PCGBs), which were specially designed to prevent oxidation of the sulfur states in PM10. Further investigation of sulfur K-edge XANES spectra revealed that PM10 samples were dominated by S(VI), even when preserved in anoxic conditions. The “Emission source effect” on the sulfur oxidation state of PM10 was examined by comparing sulfur K-edge XANES spectra collected from various emission sources in southern Thailand, while “Vertical distribution effects” on the sulfur oxidation state of PM10 were made with samples collected from three different altitudes from rooftops of the highest buildings in three major cities in Thailand. The analytical results have demonstrated that neither “Emission source” nor “Vertical distribution” appreciably contribute to the characteristic fingerprint of sulfur K-edge XANES spectrum in PM10. PMID:22988545

  10. Gene expression analysis of precision-cut human liver slices indicates stable expression of ADME-Tox related genes

    SciTech Connect

    Elferink, M.G.L.; Olinga, P.; van Leeuwen, E.M.; Bauerschmidt, S.; Polman, J.; Schoonen, W.G.; Heisterkamp, S.H.; Groothuis, G.M.M.

    2011-05-15

    In the process of drug development it is of high importance to test the safety of new drugs with predictive value for human toxicity. A promising approach of toxicity testing is based on shifts in gene expression profiling of the liver. Toxicity screening based on animal liver cells cannot be directly extrapolated to humans due to species differences. The aim of this study was to evaluate precision-cut human liver slices as in vitro method for the prediction of human specific toxicity by toxicogenomics. The liver slices contain all cell types of the liver in their natural architecture. This is important since drug-induced toxicity often is a multi-cellular process. Previously we showed that toxicogenomic analysis of rat liver slices is highly predictive for rat in vivo toxicity. In this study we investigated the levels of gene expression during incubation up to 24 h with Affymetrix microarray technology. The analysis was focused on a broad spectrum of genes related to stress and toxicity, and on genes encoding for phase-I, -II and -III metabolizing enzymes and transporters. Observed changes in gene expression were associated with cytoskeleton remodeling, extracellular matrix and cell adhesion, but for the ADME-Tox related genes only minor changes were observed. PCA analysis showed that changes in gene expression were not associated with age, sex or source of the human livers. Slices treated with acetaminophen showed patterns of gene expression related to its toxicity. These results indicate that precision-cut human liver slices are relatively stable during 24 h of incubation and represent a valuable model for human in vitro hepatotoxicity testing despite the human inter-individual variability.

  11. Anaerobic digestion of different organic wastes for biogas production and its operational control performed by the modified ADM1.

    PubMed

    Zhou, Haidong; Li, Han; Wang, Fengfei

    2012-01-01

    Anaerobic digestion (AD) of different organic wastes for biogas production under variable operating conditions was simulated with a steady-state implementation of the modified IWA Anaerobic Digestion Model No. 1 (ADM1), and an input-output feedback control system using the model as a test platform was developed. The main aim of this study was to compare the characteristics of organic wastes in the AD processes and manage to keep the processes stable based on the results of simulation. The two important operating factors, solid retention time (SRT) and organic loading rate (OLR) (or the ratio of input flows for co-digestion), were investigated. Anaerobic digestion of biowaste was characterized with lower biogas production and instability of the processes, especially at OLR 2.5 kgCOD/m(3)·d or more, although longer SRT could increase the biogas production. Moreover, the co-substrate composed of biowaste and corn silage would lead to instability of the processes and much lower biogas production. Biowaste was, however, preferable to be co-digested with manures of living stock or sewage sludge. Manure could contribute to the stability of the AD processes, and its co-substrates with organic wastes rich in carbohydrates such as biowaste and corn silage would improve the biogas production and the proportion of methane. Longer SRTs would improve the biogas production from manure as well as its co-substrates except the co-substrate with biowaste as the production was not distinctly raised. The test of the developed input-output feedback control system showed that the control system could reject a realistic set of random disturbances and keep the AD processes stable under the desired operational conditions with a minimal use of measurement facilities.

  12. Antileishmanial activity of novel indolyl-coumarin hybrids: Design, synthesis, biological evaluation, molecular docking study and in silico ADME prediction.

    PubMed

    Sangshetti, Jaiprakash N; Khan, Firoz A Kalam; Kulkarni, Abhishek A; Patil, Rajendra H; Pachpinde, Amol M; Lohar, Kishan S; Shinde, Devanand B

    2016-02-01

    In present work we have designed and synthesized total twelve novel 3-(3-(1H-indol-3-yl)-3-phenylpropanoyl)-4-hydroxy-2H-chromen-2-one derivatives 13(a-l) using Ho(3+) doped CoFe2O4 nanoparticles as catalyst and evaluated for their potential antileishmanial and antioxidant activities. The compounds 13a, 13d and 13h were found to possess significant antileishmanial activity (IC50 value=95.50, 95.00 and 99.00μg/mL, respectively) when compared to the standard sodium stibogluconate (IC50=490.00 μg/mL). The compounds 13a (IC50=12.40 μg/mL), 13d (IC50=13.49 μg/mL), 13g (IC50=13.24 μg/mL) and 13l (IC50=13.74 μg/mL) had shown good antioxidant activity when compared with standards butylated hydroxy toluene (IC50=16.5 μg/mL) and ascorbic acid (IC50=12.8 μg/mL). After performing molecular docking studies, it was found that compounds 13a and 13d had potential to inhibit pteridine reductase 1 enzyme. In silico ADME pharmacokinetic parameters had shown promising results and none of the synthesized compounds had violated Lipinski's rule of five. Thus, suggesting that compounds from the present series can serve as important gateway for the design and development of new antileishmanial as well as antioxidant agent. PMID:26778149

  13. Antileishmanial activity of novel indolyl-coumarin hybrids: Design, synthesis, biological evaluation, molecular docking study and in silico ADME prediction.

    PubMed

    Sangshetti, Jaiprakash N; Khan, Firoz A Kalam; Kulkarni, Abhishek A; Patil, Rajendra H; Pachpinde, Amol M; Lohar, Kishan S; Shinde, Devanand B

    2016-02-01

    In present work we have designed and synthesized total twelve novel 3-(3-(1H-indol-3-yl)-3-phenylpropanoyl)-4-hydroxy-2H-chromen-2-one derivatives 13(a-l) using Ho(3+) doped CoFe2O4 nanoparticles as catalyst and evaluated for their potential antileishmanial and antioxidant activities. The compounds 13a, 13d and 13h were found to possess significant antileishmanial activity (IC50 value=95.50, 95.00 and 99.00μg/mL, respectively) when compared to the standard sodium stibogluconate (IC50=490.00 μg/mL). The compounds 13a (IC50=12.40 μg/mL), 13d (IC50=13.49 μg/mL), 13g (IC50=13.24 μg/mL) and 13l (IC50=13.74 μg/mL) had shown good antioxidant activity when compared with standards butylated hydroxy toluene (IC50=16.5 μg/mL) and ascorbic acid (IC50=12.8 μg/mL). After performing molecular docking studies, it was found that compounds 13a and 13d had potential to inhibit pteridine reductase 1 enzyme. In silico ADME pharmacokinetic parameters had shown promising results and none of the synthesized compounds had violated Lipinski's rule of five. Thus, suggesting that compounds from the present series can serve as important gateway for the design and development of new antileishmanial as well as antioxidant agent.

  14. Potential therapeutic targets for oral cancer: ADM, TP53, EGFR, LYN, CTLA4, SKIL, CTGF, CD70.

    PubMed

    Bundela, Saurabh; Sharma, Anjana; Bisen, Prakash S

    2014-01-01

    In India, oral cancer has consistently ranked among top three causes of cancer-related deaths, and it has emerged as a top cause for the cancer-related deaths among men. Lack of effective therapeutic options is one of the main challenges in clinical management of oral cancer patients. We interrogated large pool of samples from oral cancer gene expression studies to identify potential therapeutic targets that are involved in multiple cancer hallmark events. Therapeutic strategies directed towards such targets can be expected to effectively control cancer cells. Datasets from different gene expression studies were integrated by removing batch-effects and was used for downstream analyses, including differential expression analysis. Dependency network analysis was done to identify genes that undergo marked topological changes in oral cancer samples when compared with control samples. Causal reasoning analysis was carried out to identify significant hypotheses, which can explain gene expression profiles observed in oral cancer samples. Text-mining based approach was used to detect cancer hallmarks associated with genes significantly expressed in oral cancer. In all, 2365 genes were detected to be differentially expressed genes, which includes some of the highly differentially expressed genes like matrix metalloproteinases (MMP-1/3/10/13), chemokine (C-X-C motif) ligands (IL8, CXCL-10/-11), PTHLH, SERPINE1, NELL2, S100A7A, MAL, CRNN, TGM3, CLCA4, keratins (KRT-3/4/13/76/78), SERPINB11 and serine peptidase inhibitors (SPINK-5/7). XIST, TCEAL2, NRAS and FGFR2 are some of the important genes detected by dependency and causal network analysis. Literature mining analysis annotated 1014 genes, out of which 841 genes were statistically significantly annotated. The integration of output of various analyses, resulted in the list of potential therapeutic targets for oral cancer, which included targets such as ADM, TP53, EGFR, LYN, CTLA4, SKIL, CTGF and CD70.

  15. Drug design tools--in silico, in vitro and in vivo ADME/PK prediction and interpretation: is PK in monkey an essential part of a good human PK prediction?

    PubMed

    Hosea, Natilie A

    2011-01-01

    Quantitative human pharmacokinetic (PK) predictions play a critical role in assessing the quality of potential drug candidates and in selecting a human starting dose for clinical evaluation, where the parameters of clearance, volume of distribution, and bioavailability as well as the plasma concentration time profiles are the desired endpoints. While there are numerous reports validating the use of different methods for predictions, it still remains an open question as to what animal species to include when extrapolating the animal PK to human. Given toxicological assessment is generally conducted in two species, a rodent and a non-rodent species, prior to evaluation in human subjects, rat, dog and/or monkey are typically the species ADME scientists employ to evaluate PK. However, the question is, can we achieve an adequate prediction without the use of larger species such as monkey? In the end, the data and tools utilized for human PK predictions will depend on a number of factors such as information from observed human PK for structurally related compounds; the primary mechanism of clearance, and the availability of in silico and in vitro tools applicable to the respective clearance mechanism. Despite these dependencies, for most situations, adequate predictions can be achieved without the use of monkey PK for predicting human.

  16. The absorption, distribution, excretion, and metabolism of a single oral dose of O-ethyl O-4-nitrophenyl phenylphosphonothioate in hens

    SciTech Connect

    Abou-Donia, M.B.; Reichert, B.L.; Ashry, M.A.

    1983-08-01

    The disposition and metabolism of a single oral 10 mg/kg (LD50) of uniformly phenyl-labeled (/sup 14/C)EPN (O-ethyl O-4-nitrophenyl (/sup 14/C)phenylphosphonothioate) were studied in adult hens. The birds were protected from acute toxicity with atropine sulfate. Three treated hens were killed at each time interval (days): 0.5, 2, 4, 8, 12. Radioactivity was adsorbed from the gastrointestinal tract and distributed in all tissues. Most of the dose was excreted in the combined urinary-fecal excreta (74%). Only traces of the radioactivity (0.2%) were detected in expired CO/sub 2/. Most of the excreted radioactive materials were identified as phenylphosphonic acid (PPA), O-ethyl phenylphosphonic acid (EPPA), and O-ethyl phenylphosphonothioc acid (EPPTA). Radioactivity in tissues reached a peak of 11.8% in 12 days. The highest concentration of radioactivity was present in the liver followed by bile, kidney, adipose tissue, and muscle. EPN was the major compound identified in brain, spinal cord, sciatic nerve, kidney, and plasma. Most of the radioactivity in the liver was identified as EPPA followed by EPPTA and PPA. Kinetic studies showed that EPN disappeared exponentially from tissues. The half-life of the elimination of EPN from plasma was 16.5 days corresponding to a constant rate value of 0.04 day-1. Relative residence (RR) of EPN relative to plasma was shortest in liver and longest in adipose tissue followed by sciatic nerve and spinal cord.

  17. Absorption, Distribution, Metabolism, Excretion, and Toxicity Evaluation in Drug Discovery. 14. Prediction of Human Pregnane X Receptor Activators by Using Naive Bayesian Classification Technique.

    PubMed

    Shi, Huali; Tian, Sheng; Li, Youyong; Li, Dan; Yu, Huidong; Zhen, Xuechu; Hou, Tingjun

    2015-01-20

    The activation of pregnane X receptor (PXR), a member of the nuclear receptor (NR) superfamily, can mediate potential drug-drug interactions, and therefore, prediction of PXR activation is of great importance for evaluating drug metabolism and toxicity. In this study, based on 532 structurally diverse compounds, we present a comprehensive analysis with the aim to build accurate classification models for distinguishing PXR activators from nonactivators by using a naive Bayesian classification technique. First, the distributions of eight important molecular physicochemical properties of PXR activators versus nonactivators were compared, illustrating that the hydrophobicity-related molecular descriptors (AlogP and log D) show slightly better capability to discriminate PXR activators from nonactivators than the others. Then, based on molecular physicochemical properties, VolSurf descriptors, and molecular fingerprints, naive Bayesian classifiers were developed to separate PXR activators from nonactivators. The results demonstrate that the introduction of molecular fingerprints is quite essential to enhance the prediction accuracy of the classifiers. The best Bayesian classifier based on the 21 physicochemical properties, VolSurf descriptors, and LCFC_10 fingerprints descriptors yields a prediction accuracy of 92.7% for the training set based on leave-one-out (LOO) cross-validation and of 85.2% for the test set. Moreover, by exploring the important structural fragments derived from the best Bayesian classifier, we observed that flexibility is an important structural pattern for PXR activation. In addition, chemical compounds containing more halogen atoms, unsaturated alkanes chains relevant to π-π stacking, and fewer nitrogen atoms tend to be PXR activators. We believe that the naive Bayesian classifier can be used as a reliable virtual screening tool to predict PXR activation in the drug design and discovery pipeline.

  18. Absorption, distribution, metabolism and excretion of the novel SARM GTx-024 [(S)-N-(4-cyano-3-(trifluoromethyl)phenyl)-3-(4-cyanophenoxy)-2-hydroxy-2-methylpropanamide] in rats.

    PubMed

    Kim, Juhyun; Wang, Ronghua; Veverka, Karen A; Dalton, James T

    2013-11-01

    1. GTx-024, a novel selective androgen receptor modulator, is currently being investigated as an oral treatment for muscle wasting disorders associated with cancer and other chronic conditions. 2. Absorption of GTx-024 was rapid and complete, with high oral bioavailability. A wide tissue distribution of [(14)C]GTx-024 derived radioactivity was observed. [(14)C]GTx-024-derived radioactivity had a moderate plasma clearance (117.7 and 74.5 mL/h/kg) and mean elimination half-life of 0.6 h and 16.4 h in male and female rats, respectively. 3. Fecal excretion was the predominant route of elimination, with ∼70% of total radioactivity recovered in feces and 21-25% in urine within 48 h. Feces of intact rats contained primarily unchanged [(14)C]GTx-024 (49.3-64.6%). Metabolites were identified in urine and feces resulting from oxidation of the cyanophenol ring (M8, 17.6%), hydrolysis and/or further conjugation of the amide moiety (M3, 8-12%) and the cyanophenol ring (M4, 1.3-1.5%), and glucuronidation of [(14)C]GTx-024 at the tertiary alcohol (M6, 3.5-3.7%). There was no quantifiable metabolite in plasma. 4. In summary, in the rat GTx-024 is completely absorbed, widely distributed, biotransformed through several metabolic pathways, and eliminated in feces primarily as an unchanged drug.

  19. Water absorption in mortar determined by NMR.

    PubMed

    Pel, L; Hazrati, K; Kopinga, K; Marchand, J

    1998-01-01

    Nuclear magnetic resonance (NMR) offers the possibility to determine moisture profiles in porous building materials. Moreover, the relaxation of the nuclear magnetic resonance signal can provide additional information on the water distribution in the microstructure. For mortar, it is shown that the transverse relaxation yields information on the distribution of water in the gel pores and capillary pores. Moisture profiles and relaxation were measured during water absorption. The effect of the drying treatment on the microstructure and the water absorption was investigated.

  20. Involvement of miR-133a and miR-326 in ADM resistance of HepG2 through modulating expression of ABCC1.

    PubMed

    Ma, Jin; Wang, Ting; Guo, Rui; Yang, Xiaoyan; Yin, Jie; Yu, Jia; Xiang, Qiong; Pan, Xia; Tang, Huifang; Lei, Xiaoyong

    2015-01-01

    Recent studies have shown that a class of small, functional RNAs, named microRNAs, may regulate multidrug resistance-associated protein 1 (ABCC1). Since ABCC1 is an important efflux transporter responsible for cellular drug disposition, the discovery of microRNAs (miRNA) brings an idea that there may be some other unknown multidrug resistance (MDR) mechanisms exist. Using computational programs, we predicted that the 3'untranslated region (3'UTR) of ABCC1 contains a potential miRNA binding site for miR-133a and also two other for miR-326. These binding sites were confirmed by luciferase reporter assay. ABCC1 mRNA degradation was accelerated dramatically in cells transfected with miR-133a or miR-326 mimics using qRT-PCR, Furthermore, western blot analysis indicated that ABCC1 protein expression was significantly down-regulated in hepatocellular carcinoma cells line HepG2 after transfection with miR-133a or miR-326 mimics, suggesting the involvement of mRNA degradation and protein expression mechanism. The effects of the two miRNAs on adriamycin (ADM) sensitivity to HepG2 cells were determined by MTT assay. Compared with mock transfection, miR-133a or miR-326 mimics transfection sensitized these cells to ADM. These findings for the first time demonstrated that the involvement of miR-133a and miR-326 in MDR is mediated by ABCC1 in hepatocellular carcinoma cell line HepG2 and suggested that miR-133a and miR-326 may be efficient agents for preventing and reversing ADM resistance in cancer cells.

  1. Distribution of Cold (≲300 K) Atomic Gas in Galaxies: Results from the GBT H i Absorption Survey Probing the Inner Halos (ρ < 20 kpc) of Low-z Galaxies

    NASA Astrophysics Data System (ADS)

    Borthakur, Sanchayeeta

    2016-10-01

    We present the Green Bank Telescope absorption survey of cold atomic hydrogen (≲300 K) in the inner halo of low-redshift galaxies. The survey aims to characterize the cold gas distribution and to address where the condensation—the process where ionized gas accreted by galaxies condenses into cold gas within the disks of galaxies—occurs. Our sample consists of 16 galaxy–quasar pairs with impact parameters of ≤20 kpc. We detected an H i absorber associated with J0958+3222 (NGC 3067) and H i emission from six galaxies. We also found two Ca ii absorption systems in the archival SDSS data associated with galaxies J0958+3222 and J1228+3706. Our detection rate of H i absorbers with optical depths of ≥0.06 is ∼7%. We also find that the cold H i phase (≲300 K) is 44(±18)% of the total atomic gas in the sightline probing J0958+3222. We find no correlation between the peak optical depth and impact parameter or stellar and H i radii normalized impact parameters, ρ/R 90 and ρ/R H i . We conclude that the process of condensation of inflowing gas into cold (≲300 K) H i occurs at the ρ ≪ 20 kpc. However, the warmer phase of neutral gas (T ∼ 1000 K) can exist out to much larger distances, as seen in emission maps. Therefore, the process of condensation of warm to cold H i is likely occurring in stages from ionized to warm H i in the inner halo and then to cold H i very close to the galaxy disk. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  2. Equivalence of ADM Hamiltonian and Effective Field Theory approaches at next-to-next-to-leading order spin1-spin2 coupling of binary inspirals

    SciTech Connect

    Levi, Michele; Steinhoff, Jan E-mail: jan.steinhoff@ist.utl.pt

    2014-12-01

    The next-to-next-to-leading order spin1-spin2 potential for an inspiralling binary, that is essential for accuracy to fourth post-Newtonian order, if both components in the binary are spinning rapidly, has been recently derived independently via the ADM Hamiltonian and the Effective Field Theory approaches, using different gauges and variables. Here we show the complete physical equivalence of the two results, thereby we first prove the equivalence of the ADM Hamiltonian and the Effective Field Theory approaches at next-to-next-to-leading order with the inclusion of spins. The main difficulty in the spinning sectors, which also prescribes the manner in which the comparison of the two results is tackled here, is the existence of redundant unphysical spin degrees of freedom, associated with the spin gauge choice of a point within the extended spinning object for its representative worldline. After gauge fixing and eliminating the unphysical degrees of freedom of the spin and its conjugate at the level of the action, we arrive at curved spacetime generalizations of the Newton-Wigner variables in closed form, which can also be used to obtain further Hamiltonians, based on an Effective Field Theory formulation and computation. Finally, we make use of our validated result to provide gauge invariant relations among the binding energy, angular momentum, and orbital frequency of an inspiralling binary with generic compact spinning components to fourth post-Newtonian order, including all known sectors up to date.

  3. The HI absorption "Zoo"

    NASA Astrophysics Data System (ADS)

    Geréb, K.; Maccagni, F. M.; Morganti, R.; Oosterloo, T. A.

    2015-03-01

    We present an analysis of the H I 21 cm absorption in a sample of 101 flux-selected radio AGN (S1.4 GHz> 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). We detect H I absorption in 32 objects (30% of the sample). In a previous paper, we performed a spectral stacking analysis on the radio sources, while here we characterize the absorption spectra of the individual detections using the recently presented busy function. The H I absorption spectra show a broad variety of widths, shapes, and kinematical properties. The full width half maximum (FWHM) of the busy function fits of the detected H I lines lies in the range 32 km s-1absorption (FW20) lies in the range 63 km s-1 200 km s-1). We study the kinematical and radio source properties of each group, with the goal of identifying different morphological structures of H I. Narrow lines mostly lie at the systemic velocity and are likely produced by regularly rotating H I disks or gas clouds. More H I disks can be present among galaxies with lines of intermediate widths; however, the H I in these sources is more unsettled. We study the asymmetry parameter and blueshift/redshift distribution of the lines as a function of their width. We find a trend for which narrow profiles are also symmetric, while broad lines are the most asymmetric. Among the broadest lines, more lines appear blueshifted than redshifted, similarly to what was found by previous studies. Interestingly, symmetric broad lines are absent from the sample. We argue that if a profile is broad, it is also asymmetric and shifted relative to the systemic velocity because it is tracing unsettled H I gas. In particular, besides three of the broadest (up to FW20 = 825 km s-1

  4. Top-of-Atmosphere Albedo Estimation from Angular Distribution Models using Scene Identification from Satellite Cloud Property Retrievals

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Parol, F.; Buriez, J.-C.; Vanbauce, C.

    2000-01-01

    The next generation of Earth radiation budget satellite instruments will routinely merge estimates of global top-of-atmosphere radiative fluxes with cloud properties. This information will offer many new opportunities for validating radiative transfer models and cloud parameterizations in climate models. In this study, five months of POLarization and Directionality of the Earth's Reflectances (POLDER) 670 nm radiance measurements are considered in order to examine how satellite cloud property retrievals can be used to define empirical Angular Distribution Models (ADMs) for estimating top-of-atmosphere (TOA) albedo. ADMs are defined for 19 scene types defined by satellite retrievals of cloud fraction and cloud optical depth. Two approaches are used to define the ADM scene types: The first assumes there are no biases in the retrieved cloud properties and defines ADMs for fixed discrete intervals of cloud fraction and cloud optical depth (fixed-tau approach). The second approach involves the same cloud fraction intervals, but uses percentile intervals of cloud optical depth instead (percentile-tau approach). Albedos generated using these methods are compared with albedos inferred directly from the mean observed reflectance field. Albedos based on ADMs that assume cloud properties are unbiased (fixed-tau approach) show a strong systematic dependence on viewing geometry. This dependence becomes more pronounced with increasing solar zenith angle, reaching approximately equals 12% (relative) between near-nadir and oblique viewing zenith angles for solar zenith angles between 60 deg and 70 deg. The cause for this bias is shown to be due to biases in the cloud optical depth retrievals. In contrast, albedos based on ADMs built using percentile intervals of cloud optical depth (percentile-tau approach) show very little viewing zenith angle dependence and are in good agreement with albedos obtained by direct integration of the mean observed reflectance field (less than 1

  5. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  6. Correlation between the compact regions predicted by the average distance map (ADM) and the biologically active sites in atrial natriuretic peptide.

    PubMed

    Kikuchi, T

    1992-10-01

    The prediction of the short-range compact regions of human atrial natriuretic peptide (alpha-hANP), one of the biologically active peptides, has been made by means of the Average Distance Map(ADM). We found out that the location of the predicted short-range compact regions is consistent with the structural units determined by the NMR analysis (Kobayashi et al., 1988). Furthermore, the short-range compact regions correspond well to the biologically active areas of atriopeptin (103-125)-amide (which is homologous peptide to alpha-hANP), detected by the glycine substitution technique (Konishi et al., 1987). The results suggest that a predicted short-range compact region can be regarded as a possible active site in a biologically active peptide.

  7. Algebraic solution of the mass balanced ADM1 to predict the steady state and to optimise the design of the anaerobic digestion of sewage sludge.

    PubMed

    de Gracia, M; Huete, E; García-Heras, J L; Ayesa, E

    2007-01-01

    This paper proposes an algebraic solution of the mass and charge balanced ADM1 model to predict the steady state performance of an anaerobic digester for sewage sludge treatment. The algebraic solution consists of three sequential stages: a kinetic stage that considers only the slowest transformations of the model, a stoichiometric stage based on the complete mass fluxes of the biological process and a physicochemical stage from which some digester outputs are calculated. The predictive capacity and the applicability of this model solution are corroborated by its comparison to the differential equation's model solution and the experimental data of a real case study. The algebraic solution is used to explore the digester response under different operational conditions. An example of application is used to verify the potential of the algebraic solution to be used, together with optimisation algorithms, for optimising the design of the digester and the operational conditions for specified performance criteria, such as effluent quality. PMID:18025740

  8. Solar absorption surface panel

    DOEpatents

    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.

  9. EVALUATION OF MULTIPLE PHARMACOKINETIC MODELING STRUCTURES FOR TRICHLOROETHYLENE

    EPA Science Inventory

    A series of PBPK models were developed for trichloroethylene (TCE) to evaluate biological processes that may affect the absorption, distribution, metabolism and excretion (ADME) of TCE and its metabolites.

  10. NCL Objective #3 - Nanotechnology Characterization Lab (NCL)

    Cancer.gov

    The Nanotechnology Characterization Lab (NCL) Objective #3: Identify and Characterize Critical Parameters Related to Nanomaterials' Absorption, Distribution, Metabolism, Excretion, and Acute Toxicity (ADME/Tox) Profile in Animal Models.

  11. Quasar Absorption Studies

    NASA Technical Reports Server (NTRS)

    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.

  12. Absorption heat pump system

    DOEpatents

    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.

  13. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

    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.

  14. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  15. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2004-08-31

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  16. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2003-10-14

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  17. Optical absorption measurement system

    DOEpatents

    Draggoo, Vaughn G.; Morton, Richard G.; Sawicki, Richard H.; Bissinger, Horst D.

    1989-01-01

    The system of the present invention contemplates 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.

  18. Opto-acoustic measurement of the local light absorption coefficient in turbid media: 1. Monte-Carlo simulation of laser fluence distribution at the beam axis beneath the surface of a turbid medium

    SciTech Connect

    Pelivanov, Ivan M; Barskaya, M I; Podymova, N B; Khokhlova, Tanya D; Karabutov, Aleksander A

    2009-09-30

    A new method for measuring the local light absorption coefficient in turbid media, for example, biological tissues, is proposed. The method is based on the fact that the amplitude of the excited opto-acoustic (OA) signal is proportional to the absorbed laser power density (the product of the light absorption coefficient and the laser fluence) at the medium interface. In the first part of the paper, the influence of the laser beam diameter, the light absorption and reduced scattering coefficients on the maximal amplitude of the laser fluence at the laser beam axis in the near-surface layer of the turbid medium is studied by using the Monte-Carlo simulation. The conditions are predicted under which the amplitude of the OA signal detected in a transparent medium in contact with the scattering medium should remain proportional to the light absorption coefficient of the medium under study, when the scattering coefficient in it changes more than twice. The results of the numerical simulation are used for the theoretical substantiation of the OA method being proposed. (measurement of parametrs of laser radiation)

  19. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, R.C.; Biermann, W.J.

    1989-05-09

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

  20. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  1. Calculation of laser absorption by metal powders in additive manufacturing.

    PubMed

    Boley, C D; Khairallah, S A; Rubenchik, A M

    2015-03-20

    We have calculated the absorption of laser light by a powder of metal spheres, typical of the powder employed in laser powder-bed fusion additive manufacturing. Using ray-trace simulations, we show that the absorption is significantly larger than its value for normal incidence on a flat surface, due to multiple scattering. We investigate the dependence of absorption on powder content (material, size distribution, and geometry) and on beam size.

  2. A study of the atmospheric dispersion of a high release of krypton-85 above a complex coastal terrain, comparison with the predictions of Gaussian models (Briggs, Doury, ADMS4).

    PubMed

    Leroy, C; Maro, D; Hébert, D; Solier, L; Rozet, M; Le Cavelier, S; Connan, O

    2010-11-01

    Atmospheric releases of krypton-85, from the nuclear fuel reprocessing plant at the AREVA NC facility at La Hague (France), were used to test Gaussian models of dispersion. In 2001-2002, the French Institute for Radiological Protection and Nuclear Safety (IRSN) studied the atmospheric dispersion of 15 releases, using krypton-85 as a tracer for plumes emitted from two 100-m-high stacks. Krypton-85 is a chemically inert radionuclide. Krypton-85 air concentration measurements were performed on the ground in the downwind direction, at distances between 0.36 and 3.3 km from the release, by neutral or slightly unstable atmospheric conditions. The standard deviation for the horizontal dispersion of the plume and the Atmospheric Transfer Coefficient (ATC) were determined from these measurements. The experimental results were compared with calculations using first generation (Doury, Briggs) and second generation (ADMS 4.0) Gaussian models. The ADMS 4.0 model was used in two configurations; one takes account of the effect of the built-up area, and the other the effect of the roughness of the surface on the plume dispersion. Only the Briggs model correctly reproduced the measured values for the width of the plume, whereas the ADMS 4.0 model overestimated it and the Doury model underestimated it. The agreement of the models with measured values of the ATC varied according to distance from the release point. For distances less than 2 km from the release point, the ADMS 4.0 model achieved the best agreement between model and measurement; beyond this distance, the best agreement was achieved by the Briggs and Doury models.

  3. Less increase of copeptin and MR-proADM due to intervention with selenium and coenzyme Q10 combined: Results from a 4-year prospective randomized double-blind placebo-controlled trial among elderly Swedish citizens.

    PubMed

    Alehagen, Urban; Aaseth, Jan; Johansson, Peter

    2015-01-01

    Intervention with selenium and coenzyme Q10 have recently been found to reduce mortality and increase cardiac function. The mechanisms behind these effects are unclear. As selenium and coenzyme Q10 is involved in the anti-oxidative defence, the present study aimed to evaluate effects of selenium and coenzyme Q10 on copeptin and adrenomedullin as oxidative stress biomarkers. Therefore 437 elderly individuals were included and given intervention for 4 years. Clinical examination and blood samples were undertaken at start and after 18 and 48 months. Evaluations of copeptin and MR-proADM changes were performed using repeated measures of variance. Cardiovascular mortality was evaluated using a 10-year-period of follow-up, and presented in Kaplan-Meier plots. A significant increase in copeptin level could be seen in the placebo group during the intervention period (from 9.4 pmol/L to 15.3 pmol/L), compared to the active treatment group. The difference between the groups was confirmed in the repeated measurement of variance analyses (P = 0.031) with less copeptin increase in the active treatment group. Furthermore, active treatment appeared to protect against cardiovascular death both in those with high and with low copeptin levels at inclusion. Less increase of MR-proADM could also be seen during the intervention in the active treatment group compared to controls (P = 0.026). Both in those having an MR-proADM level above or below median level, significantly less cardiovascular mortality could be seen in the active treatment group (P = 0.0001, and P = 0.04 respectively). In conclusion supplementation with selenium and coenzyme Q10 during four years resulted in less concentration of both copeptin and MR-proADM. A cardioprotective effect of the supplementation was registered, irrespective of the initial levels of these biomarkers, and this protection was recognized also after 10 years of observation.

  4. Modelling the anaerobic digestion of solid organic waste - Substrate characterisation method for ADM1 using a combined biochemical and kinetic parameter estimation approach.

    PubMed

    Poggio, D; Walker, M; Nimmo, W; Ma, L; Pourkashanian, M

    2016-07-01

    This work proposes a novel and rigorous substrate characterisation methodology to be used with ADM1 to simulate the anaerobic digestion of solid organic waste. The proposed method uses data from both direct substrate analysis and the methane production from laboratory scale anaerobic digestion experiments and involves assessment of four substrate fractionation models. The models partition the organic matter into a mixture of particulate and soluble fractions with the decision on the most suitable model being made on quality of fit between experimental and simulated data and the uncertainty of the calibrated parameters. The method was tested using samples of domestic green and food waste and using experimental data from both short batch tests and longer semi-continuous trials. The results showed that in general an increased fractionation model complexity led to better fit but with increased uncertainty. When using batch test data the most suitable model for green waste included one particulate and one soluble fraction, whereas for food waste two particulate fractions were needed. With richer semi-continuous datasets, the parameter estimation resulted in less uncertainty therefore allowing the description of the substrate with a more complex model. The resulting substrate characterisations and fractionation models obtained from batch test data, for both waste samples, were used to validate the method using semi-continuous experimental data and showed good prediction of methane production, biogas composition, total and volatile solids, ammonia and alkalinity.

  5. Modelling the anaerobic digestion of solid organic waste - Substrate characterisation method for ADM1 using a combined biochemical and kinetic parameter estimation approach.

    PubMed

    Poggio, D; Walker, M; Nimmo, W; Ma, L; Pourkashanian, M

    2016-07-01

    This work proposes a novel and rigorous substrate characterisation methodology to be used with ADM1 to simulate the anaerobic digestion of solid organic waste. The proposed method uses data from both direct substrate analysis and the methane production from laboratory scale anaerobic digestion experiments and involves assessment of four substrate fractionation models. The models partition the organic matter into a mixture of particulate and soluble fractions with the decision on the most suitable model being made on quality of fit between experimental and simulated data and the uncertainty of the calibrated parameters. The method was tested using samples of domestic green and food waste and using experimental data from both short batch tests and longer semi-continuous trials. The results showed that in general an increased fractionation model complexity led to better fit but with increased uncertainty. When using batch test data the most suitable model for green waste included one particulate and one soluble fraction, whereas for food waste two particulate fractions were needed. With richer semi-continuous datasets, the parameter estimation resulted in less uncertainty therefore allowing the description of the substrate with a more complex model. The resulting substrate characterisations and fractionation models obtained from batch test data, for both waste samples, were used to validate the method using semi-continuous experimental data and showed good prediction of methane production, biogas composition, total and volatile solids, ammonia and alkalinity. PMID:27156366

  6. Annonaceous acetogenins reverses drug resistance of human hepatocellular carcinoma BEL-7402/5-FU and HepG2/ADM cell lines

    PubMed Central

    Qian, Jun-Qiang; Sun, Pei; Pan, Zhan-Yu; Fang, Zhi-Zhong

    2015-01-01

    Hepatocellular carcinoma (HCC) is the most common tumor in worldwide and chemotherapy resistant is a severe obstacle in HCC treatment. Annonaceous acetogenins was a nature compound from Uvaria accuminata and it has show the anti-tumor proliferation activity in many types cancer. In this study, we showed that annonaceous acetogenins is correlated with the drug resistance reversal in human hepatocellular carcinoma BEL-7402/5-FU and HepG2/ADM cell lines. We found that cell apoptosis was improved and cell cycle was arrested, further, multidrug-resistance proteins such as MDR1, MRP1, Topo-IIα, GST-π, cyclin D1, Survivin and bcl-2 are down-regulated, however, intracellular Rh-123 and caspase-3/8 was up-regulated by Annonaceous acetogenins treatment. We also found that there was a decreased activity of NF-κB and Akt in Annonaceous acetogenins treatment groups. Therefore, we demonstrate that Akt/NF-κB pathway was involved in Annonaceous acetogenins reverses drug resistance of human hepatocellular carcinoma cells. PMID:26617951

  7. Bacterial Peptide deformylase inhibition of cyano substituted biaryl analogs: Synthesis, in vitro biological evaluation, molecular docking study and in silico ADME prediction.

    PubMed

    Khan, Firoz A Kalam; Patil, Rajendra H; Shinde, Devanand B; Sangshetti, Jaiprakash N

    2016-08-15

    Herein, we report the synthesis and screening of cyano substituted biaryl analogs 5(a-m) as Peptide deformylase (PDF) enzyme inhibitors. The compounds 5a (IC50 value=13.16μM), 5d (IC50 value=15.66μM) and 5j (IC50 value=19.16μM) had shown good PDF inhibition activity. The compounds 5a (MIC range=11.00-15.83μg/mL), 5b (MIC range=23.75-28.50μg/mL) and 5j (MIC range=7.66-16.91μg/mL) had also shown potent antibacterial activity when compared with ciprofloxacin (MIC range=25-50μg/mL). Thus, the active derivatives were not only potent PDF inhibitors but also efficient antibacterial agents. In order to gain more insight on the binding mode of the compounds with PDF, the synthesized compounds 5(a-m) were docked against PDF enzyme of Escherichia coli and compounds exhibited good binding properties. In silico ADME properties of synthesized compounds were also analyzed and showed potential to develop as good oral drug candidates. PMID:27269198

  8. Comparison of RIMPUFF, HYSPLIT, ADMS atmospheric dispersion model outputs, using emergency response procedures, with (85)Kr measurements made in the vicinity of nuclear reprocessing plant.

    PubMed

    Connan, Olivier; Smith, Kilian; Organo, Catherine; Solier, Luc; Maro, Denis; Hébert, Didier

    2013-10-01

    The Institut de Radioprotection et de Sureté Nucléaire (IRSN) performed a series of (85)Kr air sampling campaigns at mesoscale distances (18-50 km) from the AREVA NC La Hague nuclear reprocessing plant (North West France) between 2007 and 2009. The samples were collected in order to test and optimise a technique to measure low krypton-85 ((85)Kr) air concentrations and to investigate the performance of three atmospheric dispersion models (RIMPUFF, HYSPLIT, and ADMS), This paper presents the (85)Kr air concentrations measured at three sampling locations which varied from 2 to 8000 Bq m(-3), along with the (85)Kr air concentrations output by the dispersion models. The dispersion models made reasonable estimates of the mean concentrations of (85)Kr field measurements during steady wind conditions. In contrast, the models failed to accurately predict peaks in (85)Kr air concentration during periods of rapid and large changes in wind speed and/or wind direction. At distances where we made the comparisons (18-50 km), in all cases, the models underestimated the air concentration activities.

  9. Absorption heat pump system

    DOEpatents

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

    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.

  10. The New MODIS-Terra, and the Proposed COBRA Mission: First Global Aerosol Distribution and Properties Over Land and Ocean, and Plans to Measure Global Black Carbon Absorption Over the Ocean Glint

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Tanre, Didier; Remer, Lorraine; Martins, Vanderlei; Schoeberl, Mark; Lau, William K. M. (Technical Monitor)

    2001-01-01

    The MODIS instrument was launched on the NASA Terra satellite in Dec. 1999. Since last Oct, the sensor and the aerosol algorithm reached maturity and provide global daily retrievals of aerosol optical thickness and properties. MODIS has 36 spectral channels in the visible to IR with resolution down to 250 m. This allows accurate cloud screening and multi-spectral aerosol retrievals. We derive the aerosol optical thickness over the ocean and most of the land areas, distinguishing between fine (mainly man-made aerosol) and coarse (mainly natural) aerosol particles. New methods to derive the aerosol absorption of sunlight are also being developed. These measurements are use to track different aerosol sources, transport and the radiative forcing at the top and bottom of the atmosphere. However MODIS or any present satellite sensor cannot measure absorption by Black Carbon over the oceans, a critical component in studying climate change and human health. For this purpose we propose the COBRA mission that observes the ocean at glint and off glint simultaneously measuring the spectral polarized light and deriving precisely the aerosol absorption.

  11. Simultaneous determination of phenoxyethanol and its major metabolite, phenoxyacetic acid, in rat biological matrices by LC-MS/MS with polarity switching: Application to ADME studies.

    PubMed

    Kim, Tae Hwan; Kim, Min Gi; Kim, Min Gyu; Shin, Beom Soo; Kim, Kyu-Bong; Lee, Jong Bong; Paik, Soo Heui; Yoo, Sun Dong

    2015-11-01

    This study describes the development of a simple LC-ESI-MS/MS method with polarity switching for the simultaneous analysis of phenoxyethanol (PE) and its major metabolite, phenoxyacetic acid (PAA), in rat plasma, urine, and 7 different tissues. The assay was validated to demonstrate the linearity, precision, accuracy, LLOQ, recovery, and stability by using the matrix matched QC samples. The assay achieved the LLOQ of 10 and 20 ng/mL of PE and PAA, respectively, for plasma samples and the LLOQ of 20 and 50 ng/mL of PE and PAA, respectively, for urine and tissue samples. This method was successfully applied to the percutaneous absorption, distribution, metabolism, and excretion studies in rats. The absolute topical bioavailability of PE was 75.4% and 76.0% for emulsion and lotion, respectively. Conversion of PE to PAA was extensive, with the average AUCPAA-to-AUCPE ratio being 4.4 and 5.3 for emulsion and lotion, respectively. The steady-state tissue-to-plasma PE concentration ratio (Kp) was higher than unity for kidney, spleen, heart, brain, and testis and was lower (≤0.6) for lung and liver, while the metabolite Kp ratio was higher than unity for kidney, liver, lung, and testis and was lower (≤0.3) for other tissues. Findings of this study may be useful to evaluate the relationship between exposure and toxic potential of PE in risk assessment. PMID:26452788

  12. Simultaneous determination of phenoxyethanol and its major metabolite, phenoxyacetic acid, in rat biological matrices by LC-MS/MS with polarity switching: Application to ADME studies.

    PubMed

    Kim, Tae Hwan; Kim, Min Gi; Kim, Min Gyu; Shin, Beom Soo; Kim, Kyu-Bong; Lee, Jong Bong; Paik, Soo Heui; Yoo, Sun Dong

    2015-11-01

    This study describes the development of a simple LC-ESI-MS/MS method with polarity switching for the simultaneous analysis of phenoxyethanol (PE) and its major metabolite, phenoxyacetic acid (PAA), in rat plasma, urine, and 7 different tissues. The assay was validated to demonstrate the linearity, precision, accuracy, LLOQ, recovery, and stability by using the matrix matched QC samples. The assay achieved the LLOQ of 10 and 20 ng/mL of PE and PAA, respectively, for plasma samples and the LLOQ of 20 and 50 ng/mL of PE and PAA, respectively, for urine and tissue samples. This method was successfully applied to the percutaneous absorption, distribution, metabolism, and excretion studies in rats. The absolute topical bioavailability of PE was 75.4% and 76.0% for emulsion and lotion, respectively. Conversion of PE to PAA was extensive, with the average AUCPAA-to-AUCPE ratio being 4.4 and 5.3 for emulsion and lotion, respectively. The steady-state tissue-to-plasma PE concentration ratio (Kp) was higher than unity for kidney, spleen, heart, brain, and testis and was lower (≤0.6) for lung and liver, while the metabolite Kp ratio was higher than unity for kidney, liver, lung, and testis and was lower (≤0.3) for other tissues. Findings of this study may be useful to evaluate the relationship between exposure and toxic potential of PE in risk assessment.

  13. Lipids: Absorption and transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the hydrophobic nature of lipids, dietary fat is handled differently than protein or carbohydrate with respect with digestion and absorption. Dietary fats are broken down throughout the gastrointestinal system. A unique group of enzymes and cofactors allows this process to proceed in an eff...

  14. Absorption driven focus shift

    NASA Astrophysics Data System (ADS)

    Harrop, N.; Wolf, S.; Maerten, O.; Dudek, K.; Ballach, S.; Kramer, R.

    2016-03-01

    Modern high brilliance near infrared lasers have seen a tremendous growth in applications throughout the world. Increased productivity has been achieved by higher laser power and increased brilliance of lasers. Positive impacts on the performance and costs of parts are opposed to threats on process stability and quality, namely shift of focus position over time. A high initial process quality will be reduced by contamination of optics, eventually leading to a focus shift or even destruction of the optics. Focus analysis at full power of multi-kilowatt high brilliance lasers is a very demanding task because of high power densities in the spot and the high power load on optical elements. With the newly developed high power projection optics, the High-Power Micro-Spot Monitor High Brilliance (HP-MSM-HB) is able to measure focus diameter as low as 20 μm at power levels up to 10 kW at very low internal focus shift. A main driving factor behind thermally induced focus shift is the absorption level of the optical element. A newly developed measuring system is designed to determine the relative absorption level in reference to a gold standard. Test results presented show a direct correlation between absorption levels and focus shift. The ability to determine the absorption level of optical elements as well as their performance at full processing power before they are put to use, enables a high level of quality assurance for optics manufacturers and processing head manufacturers alike.

  15. Two-Phonon Absorption

    ERIC Educational Resources Information Center

    Hamilton, M. W.

    2007-01-01

    A nonlinear aspect of the acousto-optic interaction that is analogous to multi-photon absorption is discussed. An experiment is described in which the second-order acousto-optically scattered intensity is measured and found to scale with the square of the acoustic intensity. This experiment using a commercially available acousto-optic modulator is…

  16. Cholesterol Absorption and Metabolism.

    PubMed

    Howles, Philip N

    2016-01-01

    Inhibitors of cholesterol absorption have been sought for decades as a means to treat and prevent cardiovascular diseases (CVDs) associated with hypercholesterolemia. Ezetimibe is the one clear success story in this regard, and other compounds with similar efficacy continue to be sought. In the last decade, the laboratory mouse, with all its genetic power, has become the premier experimental model for discovering the mechanisms underlying cholesterol absorption and has become a critical tool for preclinical testing of potential pharmaceutical entities. This chapter briefly reviews the history of cholesterol absorption research and the various gene candidates that have come under consideration as drug targets. The most common and versatile method of measuring cholesterol absorption is described in detail along with important considerations when interpreting results, and an alternative method is also presented. In recent years, reverse cholesterol transport (RCT) has become an area of intense new interest for drug discovery since this process is now considered another key to reducing CVD risk. The ultimate measure of RCT is sterol excretion and a detailed description is given for measuring neutral and acidic fecal sterols and interpreting the results. PMID:27150091

  17. Cavity induced perfect absorption in metamaterials

    NASA Astrophysics Data System (ADS)

    Luu Dang, Hong; Nguyen, Hoang Tung; Dung Nguyen, Van; Bui, Son Tung; Tuyen Le, Dac; Ngo, Quang Minh; Vu, Dinh Lam

    2016-03-01

    We present novel resonant modes at the THz regime in a structure combining conventional metamaterial absorber (MA) with a cavity (MAC). The well-known structure consisting of three individual layers of periodic metallic dishes on the top, a dielectric layer in the middle, and a metallic film in the bottom is used, and the cavity is formed on the top layer by changing the geometry of the metallic dishes. MACs with various cavity parameters are designed and their absorption characteristics, such as magnetic field distribution, surface current, and power loss density at resonant frequencies of the designed structure, are numerically investigated. Resonant effects in this work may find applications in THz tunable and broadband MA, and our investigation on the dependence of the absorption frequency and absorption intensity on the geometric cavity of the designed structure will provide a general guideline for MAC design.

  18. Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part 1; Methodology

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Smith, N. M.; Kato, S.; Miller, W. F.; Gupta, S. K.; Minnis, P.; Wielicki, B. A.

    2003-01-01

    Clouds and the Earth s Radiant Energy System (CERES) investigates the critical role that clouds and aerosols play in modulating the radiative energy flow within the Earth-atmosphere system. CERES builds upon the foundation laid by previous missions, such as the Earth Radiation Budget Experiment, to provide highly accurate top-of-atmosphere (TOA) radiative fluxes together with coincident cloud and aerosol properties inferred from high-resolution imager measurements. This paper describes the method used to construct empirical angular distribution models (ADMs) for estimating shortwave, longwave, and window TOA radiative fluxes from CERES radiance measurements on board the Tropical Rainfall Measuring Mission satellite. To construct the ADMs, multiangle CERES measurements are combined with coincident high-resolution Visible Infrared Scanner measurements and meteorological parameters from the European Centre for Medium-Range Weather Forecasts data assimilation product. The ADMs are stratified by scene types defined by parameters that have a strong influence on the angular dependence of Earth's radiation field at the TOA. Examples of how the new CERES ADMs depend upon the imager-based parameters are provided together with comparisons with existing models.

  19. 69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  20. Water-related absorption in fibrous diamonds

    NASA Astrophysics Data System (ADS)

    Zedgenizov, D. A.; Shiryaev, A. A.; Kagi, H.; Navon, O.

    2003-04-01

    Cubic and coated diamonds from several localities (Brasil, Canada, Yakutia) were investigated using spectroscopic techniques. Special emphasis was put on investigation of water-related features of transmission Infra-red and Raman spectra. Presence of molecular water is inferred from broad absorption bands in IR at 3420 and 1640 cm-1. These bands were observed in many of the investigated samples. It is likely that molecular water is present in microinclusions in liquid state, since no clear indications of solid H_2O (ice VI-VII, Kagi et al., 2000) were found. Comparison of absorption by HOH and OH vibrations shows that diamonds can be separated into two principal groups: those containing liquid water (direct proportionality of OH and HOH absorption) and those with stronger absorption by OH group. Fraction of diamonds in every group depends on their provenance. There might be positive correlation between internal pressure in microinclusions (determined using quartz barometer, Navon et al., 1988) and affiliation with diamonds containing liquid water. In many cases absorption by HOH vibration is considerably lower than absorption by hydroxyl (OH) group. This may be explained if OH groups are partially present in mineral and/or melt inclusions. This hypothesis is supported by following fact: in diamonds with strong absorption by silicates and other minerals shape and position of the OH band differs from that in diamonds with low absorption by minerals. Moreover, in Raman spectra of individual inclusions sometimes the broad band at 3100 cm-1 is observed. This band is OH-related. In some samples water distribution is not homogeneous. Central part of the diamond usually contains more water than outer parts, but this is not a general rule for all the samples. Water absorption usually correlated with absorption of other components (carbonates, silicates and others). At that fibrous diamonds with relatively high content of silicates are characterized by molecular water. OH

  1. Monitoring Emergent Absorption Troughs in Quasars

    NASA Astrophysics Data System (ADS)

    Hall, Patrick; Rodriguez Hidalgo, Paola; Brandt, W. Niel; Rogerson, Jesse; Filiz Ak, Nur; Chajet, Laura

    2014-02-01

    Outflows from luminous AGN are important ingredients in galaxy formation. These outflows manifest as broad absorption line (BAL) troughs in quasar spectra. Trough variability can be used to constrain the physical parameters of these absorbing structures through comparison to models and simulations of accretion disk winds. Monitoring appearing/disappearing BAL troughs can constrain the distribution of BAL trough lifetimes along our line of sight. By comparing spectra from the SDSS Data Release (DR) 7 and DR 9, we identified 68 quasars in whose spectra new absorption troughs have appeared over 300-1200 restframe days, including one trough outflowing at v=60,000 km/s. We propose to complete our third-epoch GMOS spectroscopy of the brightest of those quasars (48 in 2013AB and 9 proposed here) to measure the absorption strength in newly appeared troughs <=365 restframe days after their previous measurement. Preliminary 2013AB results indicate that troughs are not on average still strengthening between SDSS and Gemini epochs; we therefore propose observations of 40 targets to probe shorter rest-frame time separations. We also target 8 objects showing simultaneous absorption variations in multiple ionization states, to help develop methods to distinguish absorption variations from cloud motion vs. those from ionization changes within clouds.

  2. Vaginal Absorption of Penicillin.

    PubMed

    Rock, J; Barker, R H; Bacon, W B

    1947-01-01

    Except during the last two months of pregnancy, penicillin is easily absorbed from cocoa butter suppositories in the vagina, ordinarily to give therapeutic blood levels for from 4 to 6 hours. Penicillin in the dosage used seems to have a good effect on vaginal infections. In nonpregnant women, during the ovulation phase, considered as including days 14 +/- 2 in the ordinary menstrual cycle of about 28 days, absorption seemed to be somewhat diminished. Higher levels were found in patients who were near the end of their menstrual cycles and in two patients who were menopausal. Patients who were very near term absorbed little or no penicillin, whereas patients 10 days post partum showed excellent absorption.

  3. Photothermal absorption correlation spectroscopy.

    PubMed

    Octeau, Vivien; Cognet, Laurent; Duchesne, Laurence; Lasne, David; Schaeffer, Nicolas; Fernig, David G; Lounis, Brahim

    2009-02-24

    Fluorescence correlation spectroscopy (FCS) is a popular technique, complementary to cell imaging for the investigation of dynamic processes in living cells. Based on fluorescence, this single molecule method suffers from artifacts originating from the poor fluorophore photophysics: photobleaching, blinking, and saturation. To circumvent these limitations we present here a new correlation method called photothermal absorption correlation spectroscopy (PhACS) which relies on the absorption properties of tiny nano-objects. PhACS is based on the photothermal heterodyne detection technique and measures akin FCS, the time correlation function of the detected signals. Application of this technique to the precise determination of the hydrodynamic sizes of different functionalized gold nanoparticles are presented, highlighting the potential of this method. PMID:19236070

  4. THE ABSORPTION OF ADRENALIN

    PubMed Central

    Lyon, D. Murray

    1923-01-01

    1. Adrenalin solution given subcutaneously is usually rapidly absorbed, probably by lymphatic channels. 2. The speed of this process may be influenced by the circulation rate. 3. The relative amounts of adrenalin at any moment unabsorbed at the site of inoculation, carried in the circulating fluids, and taken up by the reacting tissues can be calculated from figures extracted from the curve of the blood pressure changes. The relative rates of transference of adrenalin into the blood and from the circulation into the tissues can also be estimated. 4. When absorption takes place rapidly a large quantity of the drug comes into action at once and the maximum occurs early, the curve of blood pressure reaches a considerable height, and subsides quickly. When absorption is slow the apex appears later and does not reach so high a level. 5. The response to adrenalin bears a logarithmic relationship to the dose employed and a method of allowing for this is indicated. PMID:19868816

  5. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

    Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

  6. First pass intestinal and liver metabolism of paracetamol in a microfluidic platform coupled with a mathematical modeling as a means of evaluating ADME processes in humans.

    PubMed

    Prot, Jean Matthieu; Maciel, Luis; Bricks, Thibault; Merlier, Franck; Cotton, Jérôme; Paullier, Patrick; Bois, Fréderic Yves; Leclerc, Eric

    2014-10-01

    We developed a microfluidic platform to investigate paracetamol intestinal and liver first pass metabolism. This approach was coupled with a mathematical model to estimate intrinsic in vitro parameters and to predict in vivo processes. The kinetic modeling estimated the paracetamol and paracetamol sulfate permeabilities, the sulfate and glucuronide effluxes in the intestine compartment. Based on a gut model, we estimated intrinsic intestinal clearance of between 26 and 77 L/h for paracetamol in humans, a permeability of 10 L/h, and a gut availability between 0.17 and 0.53 (compared to 0.95-1 in vivo). The role played by the liver in paracetamol metabolism was estimated via in vitro intrinsic clearances of 7.6, 13.6, and 11.5 µL/min/10(6) cells for HepG2/C3a, rat primary hepatocytes, and human primary hepatocytes, respectively. Based on a parallel tube model to describe the liver, the paracetamol hepatic clearance, and the paracetamol hepatic availability in humans were estimated at 6.5 mL/min/kg of bodyweight (BDW) and 0.7, respectively (when compared to 5 mL/min/kg of BDW and 0.77 to 0.88 for in vivo values, respectively). The drug availability was predicted ranging between 0.24 and 0.41 (0.88 in vivo). The overall approach provided a first step in an integrated strategy combining in silico/in vitro methods based on microfluidic for evaluating drug absorption, distribution and metabolism processes.

  7. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  8. Comparison of ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and satellite DOAS measurements of NO2 distribution over Ulaanbaatar (Mongolia) during summer 2013

    NASA Astrophysics Data System (ADS)

    Böhnke, Sebastian; Behrendt, Thomas; Bruse, Michael; Meixner, Franz X.; Mamtimin, Buhalqem

    2014-05-01

    Cities are immense sources of air pollutants; however, emission inventories in many of them still are highly uncertain, particularly in developing countries. Ulaanbaatar is the most populous and polluted area in Mongolia. Tropospheric NO2 is proved to be harmful to both, the atmospheric environment and human health. It might be meaningful and important to observe pollutant concentrations in an area-integrated form (satellite observations) to create a sound data basis for air quality control measures. In our study, we preliminary present the results of both satellite and ground-based Differential Optical Absorption Spectroscopy (DOAS) measurements of vertical column densities (VCDs) of NO2 in Ulaanbaatar (urban area). As a ground validation tool, the MAX-DOAS measurements carried out in Ulaanbaatar (Mongolia) summer 2013 and are applied at 3 different sites in the west of Ulaanbaatar (106.73° E / 47.83° N), the city center (106.92° E / 47.92° N) and in the east (107.12° E / 47.87° N). Additionally, Automatic Weather Stations (AWS) have been set up and ozone was measured by UV absorption technique also at the 3 sites. Preliminary results show that the NO2 column densities increase during sunset and decrease after sunrise, which is most likely caused by a longer light path resulting from high solar zenith angles (SZA). The maximum DSCDs (Differential Slant Column Densities) are observed around sunset and sunrise (up to 10^17 molec cm-², mainly a measurement effect as stated above). The daily minima of the vertical column densities (VCD) appear in the morning and in the afternoon (DSCD ~2×10^15 molec cm-²) while, around noon, a second maximum can be observed (DSCD ~4×10^16 molec cm-²). Satellite data show mean VCDs of about 3×10^15 molec cm-² in July and a varying agreement with MAX-DOAS measurements.

  9. New formulation of chemical peeling agent: 30% salicylic acid in polyethylene glycol. Absorption and distribution of 14C-salicylic acid in polyethylene glycol applied topically to skin of hairless mice.

    PubMed

    Ueda, Setsuko; Mitsugi, Koichi; Ichige, Kazumi; Yoshida, Kenji; Sakuma, Tomoko; Ninomiya, Shin-ichi; Sudou, Tetsuji

    2002-04-01

    Salicylic acid is used in chemical peeling procedures. However, they have caused many side effects, even salicylism. To achieve a salicylic acid peeling that would be safer for topical use, we recently developed a new formulation consisting of 30% salicylic acid in polyethylene glycol (PEG) vehicle. In an extension of our previous research, we studied the absorption of 30% salicylic acid labeled with 14C in PEG vehicle applied topically to the intact and damaged skin of male hairless mice. An ointment containing 3 mg salicylic acid in 10 mg vehicle was applied to both groups. In animals with intact skin, 1 h after application the plasma concentration of radioactivity was 1665.1 ng eq/ml, significantly lower than the 21437.6 ng eq/ml observed in mice with damaged skin. Microautoradiograms of intact skin showed that the level of radioactivity in the cornified cell layer was similar at 6 h after application. However, in damaged skin, the overall level of radioactivity showed a decrease by 3 h after application. In the carcasses remaining after the treated intact and damaged skin had been removed, 0.09 and 11.38% of the applied radioactivity remained, respectively. These findings confirm that 30% salicylic acid in PEG vehicle is little absorbed through the intact skin of hairless mice, and suggest that salicylism related to absorption through the skin of quantities of topically applied salicylic acid is not likely to occur in humans with intact skin during chemical peeling with this preparation. This new preparation of 30% salicylic acid in PEG vehicle is believed to be safe for application as a chemical peeling agent.

  10. Absorption spectroscopy with quantum cascade lasers

    NASA Technical Reports Server (NTRS)

    Kosterev, A. A.; Curl, R. F.; Tittel, F. K.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Baillargeon, J. N.; Hutchinson, A. L.; Cho, A. Y.

    2001-01-01

    Novel pulsed and cw quantum cascade distributed feedback (QC-DFB) lasers operating near lambda=8 micrometers were used for detection and quantification of trace gases in ambient air by means of sensitive absorption spectroscopy. N2O, 12CH4, 13CH4, and different isotopic species of H2O were detected. Also, a highly selective detection of ethanol vapor in air with a sensitivity of 125 parts per billion by volume (ppb) was demonstrated.

  11. Acoustic Absorption Characteristics of People.

    ERIC Educational Resources Information Center

    Kingsbury, H. F.; Wallace, W. J.

    1968-01-01

    The acoustic absorption characteristics of informally dressed college students in typical classroom seating are shown to differ substantially from data for formally dressed audiences in upholstered seating. Absorption data, expressed as sabins per person or absorption coefficient per square foot, shows that there is considerable variation between…

  12. An Evaluation of Biosurveillance Grid—Dynamic Algorithm Distribution Across Multiple Computer Nodes

    PubMed Central

    Tsai, Ming-Chi; Tsui, Fu-Chiang; Wagner, Michael M.

    2007-01-01

    Performing fast data analysis to detect disease outbreaks plays a critical role in real-time biosurveillance. In this paper, we described and evaluated an Algorithm Distribution Manager Service (ADMS) based on grid technologies, which dynamically partition and distribute detection algorithms across multiple computers. We compared the execution time to perform the analysis on a single computer and on a grid network (3 computing nodes) with and without using dynamic algorithm distribution. We found that algorithms with long runtime completed approximately three times earlier in distributed environment than in a single computer while short runtime algorithms performed worse in distributed environment. A dynamic algorithm distribution approach also performed better than static algorithm distribution approach. This pilot study shows a great potential to reduce lengthy analysis time through dynamic algorithm partitioning and parallel processing, and provides the opportunity of distributing algorithms from a client to remote computers in a grid network. PMID:18693936

  13. Absorption heat pumps

    NASA Astrophysics Data System (ADS)

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  14. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, Michael E.; Bien, Fritz; Bernstein, Lawrence S.

    1986-01-01

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

  15. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, M.E.; Bien, F.; Bernstein, L.S.

    1986-12-09

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined. 5 figs.

  16. Modular total absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Karny, M.; Rykaczewski, K. P.; Fijałkowska, A.; Rasco, B. C.; Wolińska-Cichocka, M.; Grzywacz, R. K.; Goetz, K. C.; Miller, D.; Zganjar, E. F.

    2016-11-01

    The design and performance of the Modular Total Absorption Spectrometer built and commissioned at the Oak Ridge National Laboratory is presented. The active volume of the detector is approximately one ton of NaI(Tl), which results in very high full γ energy peak efficiency of 71% at 6 MeV and nearly flat efficiency of around 81.5% for low energy γ-rays between 300 keV and 1 MeV. In addition to the high peak efficiency, the modular construction of the detector permits the use of a γ-coincidence technique in data analysis as well as β-delayed neutron observation.

  17. Light absorption properties and absorption budget of Southeast Pacific waters

    NASA Astrophysics Data System (ADS)

    Bricaud, Annick; Babin, Marcel; Claustre, Hervé; Ras, JoséPhine; TièChe, Fanny

    2010-08-01

    Absorption coefficients of phytoplankton, nonalgal particles (NAPs), and colored dissolved organic matter (CDOM), and their relative contributions to total light absorption, are essential variables for bio-optical and biogeochemical models. However, their actual variations in the open ocean remain poorly documented, particularly for clear waters because of the difficulty in measuring very low absorption coefficients. The Biogeochemistry and Optics South Pacific Experiment (BIOSOPE) cruise investigated a large range of oceanic regimes, from mesotrophic waters around the Marquesas Islands to hyperoligotrophic waters in the subtropical gyre and eutrophic waters in the upwelling area off Chile. The spectral absorption coefficients of phytoplankton and NAPs were determined using the filter technique, while the CDOM absorption coefficients were measured using a 2 m capillary waveguide. Over the whole transect, the absorption coefficients of both dissolved and particulate components covered approximately two orders of magnitude; in the gyre, they were among the lowest ever reported for open ocean waters. In the oligotrophic and mesotrophic waters, absorption coefficients of phytoplankton and NAPs were notably lower than those measured in other oceanic areas with similar chlorophyll contents, indicating some deviation from the standard chlorophyll-absorption relationships. The contribution of absorption by NAPs to total particulate absorption showed large vertical and horizontal variations. CDOM absorption coefficients covaried with algal biomass, albeit with a high scatter. The spectral slopes of both NAP and CDOM absorption revealed structured spatial variability in relation with the trophic conditions. The relative contributions of each component to total nonwater absorption were (at a given wavelength) weakly variable over the transect, at least within the euphotic layer.

  18. Models of isospin violating ADM

    SciTech Connect

    Okada, Nobuchika; Seto, Osamu

    2014-06-24

    The isospin violating dark matter (IVDM) scenario offers an interesting possibility to reconcile conflicting results among direct dark matter search experiments for a mass range around 10 GeV. We consider two simple renormalizable IVDM models with a complex scalar dark matter and a Dirac fermion dark matter, respectively, whose stability is ensured by the conservation of “dark matter number.” Although both models successfully work as the IVDM scenario with destructive interference between effective couplings to proton and neutron, the dark matter annihilation cross section is found to exceed the cosmological/astrophysical upper bounds. Then, we propose a simple scenario to reconcile the IVDM scenario with the cosmological/astrophysical bounds, namely, the IVDM being asymmetric. We also discuss collider experimental constraints on the models and an implication to Higgs boson physics.

  19. Effect of partial absorption on diffusion with resetting.

    PubMed

    Whitehouse, Justin; Evans, Martin R; Majumdar, Satya N

    2013-02-01

    The effect of partial absorption on a diffusive particle which stochastically resets its position with a finite rate r is considered. The particle is absorbed by a target at the origin with absorption "velocity" a; as the velocity a approaches ∞ the absorption property of the target approaches that of a perfectly absorbing target. The effect of partial absorption on first-passage time problems is studied, in particular, it is shown that the mean time to absorption (MTA) is increased by an additive term proportional to 1/a. The results are extended to multiparticle systems where independent searchers, initially uniformly distributed with a given density, look for a single immobile target. It is found that the average survival probability P(av) is modified by a multiplicative factor which is a function of 1/a, whereas the decay rate of the typical survival probability P(typ) is decreased by an additive term proportional to 1/a.

  20. Effect of partial absorption on diffusion with resetting

    NASA Astrophysics Data System (ADS)

    Whitehouse, Justin; Evans, Martin R.; Majumdar, Satya N.

    2013-02-01

    The effect of partial absorption on a diffusive particle which stochastically resets its position with a finite rate r is considered. The particle is absorbed by a target at the origin with absorption “velocity” a; as the velocity a approaches ∞ the absorption property of the target approaches that of a perfectly absorbing target. The effect of partial absorption on first-passage time problems is studied, in particular, it is shown that the mean time to absorption (MTA) is increased by an additive term proportional to 1/a. The results are extended to multiparticle systems where independent searchers, initially uniformly distributed with a given density, look for a single immobile target. It is found that the average survival probability Pav is modified by a multiplicative factor which is a function of 1/a, whereas the decay rate of the typical survival probability Ptyp is decreased by an additive term proportional to 1/a.

  1. Analyzing Water's Optical Absorption

    NASA Technical Reports Server (NTRS)

    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.

  2. Radiation Emission and Re-Absorption Mechanisms in Dense Mediums

    NASA Astrophysics Data System (ADS)

    Mahdavi, M.; Ghazizadeh, S. F.

    2012-09-01

    In this paper, the Bremsstrahlung emission and re-absorption mechanisms are studied mainly through Inverse Bremsstrahlung and Compton Scattering. The Radiation Specific Power is calculated numerically assuming the suitable forms of Energy Distribution Function in plasma conditions. The calculation of Spectral Emission shows that, the Bremsstrahlung emission is strongly forward and backward peak relative to electron direction in overdense and high temperature plasma. Finally, some of the conditions for dominant of the re-absorption mechanism are explained.

  3. Percutaneous absorption in preterm infants.

    PubMed

    West, D P; Halket, J M; Harvey, D R; Hadgraft, J; Solomon, L M; Harper, J I

    1987-11-01

    The skin of preterm infants varies considerably in its level of maturity. To understand skin absorption in premature infants better, we report a technique for the assessment of percutaneous absorption at various gestational and postnatal ages using stable, isotope-labeled (13C6) benzoic acid. Our results indicate that in the preterm infant, this method detects enhanced skin absorption in the first postnatal days, which declines over three weeks to that expected of a full-term infant. This approach also indicates an inverse relationship between gestational age and skin absorption, as well as postnatal age and skin absorption. The reported technique is a safe and noninvasive method using a model skin penetrant for the study of percutaneous absorption in preterm infants from which basic data may be derived to add to our understanding of skin barrier function. PMID:3422856

  4. Flameless atomic-absorption determination of gold in geological materials

    USGS Publications Warehouse

    Meier, A.L.

    1980-01-01

    Gold in geologic material is dissolved using a solution of hydrobromic acid and bromine, extracted with methyl isobutyl ketone, and determined using an atomic-absorption spectrophotometer equipped with a graphite furnace atomizer. A comparison of results obtained by this flameless atomic-absorption method on U.S. Geological Survey reference rocks and geochemical samples with reported values and with results obtained by flame atomic-absorption shows that reasonable accuracy is achieved with improved precision. The sensitivity, accuracy, and precision of the method allows acquisition of data on the distribution of gold at or below its crustal abundance. ?? 1980.

  5. Osthole shows the potential to overcome P-glycoprotein‑mediated multidrug resistance in human myelogenous leukemia K562/ADM cells by inhibiting the PI3K/Akt signaling pathway.

    PubMed

    Wang, Hong; Jia, Xiu-Hong; Chen, Jie-Ru; Wang, Jian-Yong; Li, You-Jie

    2016-06-01

    P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) has been reported to play a pivotal role in tumor chemotherapy failure. Study after study has illustrated that the phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is involved in the MDR phenotype and is correlated with P-gp expression in many human malignancies. In the present study, osthole, an O-methylated coumarin, exhibited potent reversal capability of MDR in myelogenous leukemia K562/ADM cells. Simultaneously, the uptake and efflux of Rhodamine-123 (Rh-123) and the accumulation of doxorubicin assays combined with flow cytometric analysis suggested that osthole could increase intracellular drug accumulation. Furthermore, osthole decreased the expression of multidrug resistance gene 1 (MDR1) at both the mRNA and protein levels. Further experiments elucidated that osthole could suppress P-gp expression by inhibiting the PI3K/Akt signaling pathway which might be the main mechanism accounting for the reversal potential of osthole in the MDR in K562/ADM cells. In conclusion, osthole combats MDR and could be a promising candidate for the development of novel MDR reversal modulators. PMID:27109742

  6. X-ray Absorption Spectroscopy

    SciTech Connect

    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.

  7. Absorption of lead through the skin.

    PubMed

    Rastogi, S C; Clausen, J

    1976-01-01

    Absorption of lead through the skin was studied by comparing the effect produced by lead naphthenate or lead acetate solution, when coated on the skin of rats, with data obtained from subcutaneous injections of these solutions. Body weight and liver size and weight decreased in the case of rats receiving the subcutaneous dose. delta-Aminolevulinic acid dehydratase (ALA-D) in liver was decreased in all rats having been treated with lead compounds. The distribution of absorbed lead has been evaluated by assay of the lead content in brain, liver, kidney, spleen and muscle in the rats. The results of this study seem to verify that absorption of lead through the skin does occur and the findings confirm lead naphthenate to be more toxic than lead acetate.

  8. Absorption of impinging water droplet in porous stones.

    PubMed

    Lee, J B; Radu, A I; Vontobel, P; Derome, D; Carmeliet, J

    2016-06-01

    This paper presents an experimental investigation and numerical analysis of the absorption of water droplets impacting porous stones. The absorption process of an impinging droplet is here fully characterized from spreading to evaporation in terms of absorbed mass during droplet depletion and moisture content distribution in a time-resolved manner for three different natural stones. High-speed imaging and neutron radiography are used to quantify moisture absorption in porous stones of varying moisture properties from deposition until depletion. During impact and spreading, the droplet exhibits a dynamic non-wetting behavior. At maximum spreading, the droplet undergoes pinning, resulting into the contact radius remaining constant until droplet depletion. Absorption undergoes two phases: initially, absorption is hindered due a contact resistance attributed to entrapped air; afterwards, a more perfect capillary contact occurs and absorption goes on until depletion, concurrently with evaporation and further redistribution. A finite-element numerical model for isothermal unsaturated moisture transport in porous media captures the phases of mass absorption in good agreement with the experimental data. Droplet spreading and absorption are highly determined by the impact velocity of the droplet, while moisture content redistribution after depletion is much less dependent on impact conditions.

  9. Epidermal melanin absorption in human skin

    NASA Astrophysics Data System (ADS)

    Norvang Nilsen, Lill T.; Fiskerstrand, Elisanne J.; Nelson, J. Stuart; Berns, Michael W.; Svaasand, Lars O.

    1996-01-01

    The principle of laser induced selective photothermolysis is to induced thermal damage to specific targets in such a manner that the temperature of the surrounding tissue is maintained below the threshold for thermal damage. The selectivity is obtained by selection of a proper wavelength and pulse duration. The technique is presently being used in the clinic for removal of port-wine stains. The presence of melanin in the epidermal layer can represent a limitation to the selectivity. Melanin absorption drops off significantly with increasing wavelength, but is significant in the entire wavelength region where the blood absorption is high. Treatment of port-wine stain in patients with high skin pigmentation may therefore give overheating of the epidermis, resulting in epidermal necrosis. Melanosomal heating is dependent on the energy and duration of the laser pulse. The heating mechanism for time scales less than typically 1 microsecond(s) corresponds to a transient local heating of the individual melanosomes. For larger time scales, heat diffusion out of the melanosomes become of increased importance, and the temperature distribution will reach a local steady state condition after typically 10 microsecond(s) . For even longer pulse duration, heat diffusing from neighboring melanosomes becomes important, and the temperature rise in a time scale from 100 - 500 microsecond(s) is dominated by this mechanism. The epidermal heating during the typical 450 microsecond(s) pulse used for therapy is thus dependent on the average epidermal melanin content rather than on the absorption coefficient of the individual melanosomes. This study will present in vivo measurements of the epidermal melanin absorption of human skin when exposed to short laser pulses (< 0.1 microsecond(s) ) from a Q-switched ruby laser and with long laser pulses (approximately 500 microsecond(s) ) from a free-running ruby laser or a long pulse length flashlamp pumped dye laser. The epidermal melanin

  10. Subgap Absorption in Conjugated Polymers

    DOE R&D Accomplishments Database

    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 < 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. Optical absorption of silicon nanowires

    SciTech Connect

    Xu, T.; Lambert, Y.; Krzeminski, C.; Grandidier, B.; Stievenard, D.; Leveque, G.; Akjouj, A.; Pennec, Y.; Djafari-Rouhani, B.

    2012-08-01

    We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods: the first one, based on the Green function formalism, is useful to calculate the scattering and absorption properties of a single or a finite set of NWs. The second one, based on the finite difference time domain (FDTD) method, is well-adapted to deal with a periodic set of NWs. In both cases, an increase of the onset energy for the absorption is found with increasing diameter. Such effect is experimentally illustrated, when photoconductivity measurements are performed on single tapered Si nanowires connected between a set of several electrodes. An increase of the nanowire diameter reveals a spectral shift of the photocurrent intensity peak towards lower photon energies that allow to tune the absorption onset from the ultraviolet radiations to the visible light spectrum.

  12. Gas-absorption process

    DOEpatents

    Stephenson, Michael J.; Eby, Robert S.

    1978-01-01

    This invention is an improved gas-absorption process for the recovery of a desired component from a feed-gas mixture containing the same. In the preferred form of the invention, the process operations are conducted in a closed-loop system including a gas-liquid contacting column having upper, intermediate, and lower contacting zones. A liquid absorbent for the desired component is circulated through the loop, being passed downwardly through the column, regenerated, withdrawn from a reboiler, and then recycled to the column. A novel technique is employed to concentrate the desired component in a narrow section of the intermediate zone. This technique comprises maintaining the temperature of the liquid-phase input to the intermediate zone at a sufficiently lower value than that of the gas-phase input to the zone to effect condensation of a major part of the absorbent-vapor upflow to the section. This establishes a steep temperature gradient in the section. The stripping factors below this section are selected to ensure that virtually all of the gases in the downflowing absorbent from the section are desorbed. The stripping factors above the section are selected to ensure re-dissolution of the desired component but not the less-soluble diluent gases. As a result, a peak concentration of the desired component is established in the section, and gas rich in that component can be withdrawn therefrom. The new process provides important advantages. The chief advantage is that the process operations can be conducted in a single column in which the contacting zones operate at essentially the same pressure.

  13. Intestinal Folate Absorption

    PubMed Central

    Olinger, Edward J.; Bertino, Joseph R.; Binder, Henry J.

    1973-01-01

    These studies were designed to determine whether pteroylmonoglutamic acid (PGA) at physiologic concentrations is transported across the small intestine unaltered or is reduced and methylated to the circulating folate form (5-methyltetrahydrofolate [5-MeFH4]) during absorption. [3H]PGA was incubated in vitro on the mucosal side of rat jejunum. Of the folate transferred to the serosal side, the percent identified as 5-MeFH4 by DEAE-Sephadex chromtography was inversely related to the initial mucosa PGA concentration: at 7, 20, and 2,000 nM, 44%, 34%, and 2%, respectively, was converted to 5-MeFH4. In contrast, less than 4% of the folate transferred across ileal mucosa was 5-MeFH4 when the initial mucosa concentration was 20 nM. Specific activity of dihydrofolate (DHF) reductase, the enzyme responsible for converting PGA to tetrahydrofolic acid, was measured in villus homogenates and was significantly greater in the jejunum than in the ileum. 1,000 nM methotrexate (MTX), a DHF reductase inhibitor, markedly inhibited PGA conversion to 5-MeFH4 by the jejunum. Studies of transmural flux, initial rate of mucosal entry (influx) and mucosal accumulation (uptake) of folate were also performed. Although MTX did not alter the influx of PGA, MTX decreased jejunal mucosal uptake but increased transmural movement. Transmural folate movement across ileal mucosa was greater than across jejunal mucosa although mucosal uptake was greater in the jejunum than in the ileum. These results could explain previous studies which have failed to identify conversion of PGA to 5-MeFH4 when intestinal preparations have been exposed to higher and less physiologic concentrations of PGA. Further, these studies suggest that 5-MeFH4 may be retained by the jejunal mucosa. PMID:4727453

  14. Gastrointestinal citrate absorption in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

  15. Percutaneous absorption of Octopirox.

    PubMed

    Black, J G; Kamat, V B

    1988-01-01

    containing 1% Octopirox is 29,400, so that the possibility of systemic effects due to absorption through the skin is remote. PMID:3345970

  16. Resonant Absorption of Bessel Beams

    NASA Astrophysics Data System (ADS)

    Fan, J.; Parra, E.; Milchberg, H. M.

    1999-11-01

    We report the first observation of enhanced laser-plasma optical absorption in a subcritical density plasma resulting from spatial resonances, here in the laser breakdown of a gas with a Bessel beam. The enhancement in absorption is directly correlated to enhancements both in confinement of laser radiation to the plasma and in its heating. Under certain conditions, azimuthal asymmetry in the laser beam is essential for efficient gas breakdown. Simulations of this absorption consistently explain the experimental observations. This work is supported by the National Science Foundation (PHY-9515509) and the US Department of Energy (DEF G0297 ER 41039).

  17. Light absorption measurements: new techniques.

    PubMed

    Hänel, G; Busen, R; Hillenbrand, C; Schloss, R

    1982-02-01

    A new radiometer is described which simplifies measurement of the radiation supply of solar wavelengths. Two methods of measuring the radiant energy absorbed by aerosol particles are described: A photometric technique is used for particles collected on filters, and a calorimetric technique is used for in situ measurements. Data collected with the radiometer and the light absorption techniques yield the heating rate of the atmosphere due to light absorption by the particles. Sample measurements show substantial atmospheric temperature increases due to absorption, especially in industrial regions.

  18. Optical absorption and scattering properties in the East China Sea

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; He, Xian-qiang; Chen, Xiao-yan; Hao, Zeng-zhou; Huang, Haiqing; Zhu, Qiankun

    2011-11-01

    The absorption and particulate backscattering coefficients are the basic parameters of the water inherent optical properties (IOPs), which are also the basic parameters for the development and validation of the semi-analysis models of the ocean color remote sensing. In this work, the absorption and backscattering coefficients in the East China Sea (ECS) were measured in the summer and winter of 2009 using the three in-situ optical instruments, including the WET Labs acs, and the HOBI Labs HydroScat-6. Based on the in-situ measured data, the distribution of the absorption and backscattering coefficients in the ECS are analyzed. The results show that in the summer the water absorption coefficient at 440nm (a(440nm),excluding the absorption of the pure sea water) in the surface layer is ranged from 0.022 to 0.067 m-1, and the particulate backscattering coefficient at 442nm(bbp(442nm), is between 0.00064 and 0.03274 m-1. As a whole, both of the absorption and backscattering coefficients decrease with the offshore direction, and the high values located at the mouth of Changjiang River. In the winter, a(440nm) is between 0.051 and 0.887 m-1, and bbp(442nm) is ranged from 0.000639 to 0.14614 m-1 at the surface layer. The spatial distributions in winter are similar as the summer, with the high value in the coast and low value in the offshore. The absorption and backscattering coefficients in winter are significantly larger than the summer's, especially in coastal area near the mouth of Changjiang River, which maybe caused by the southward Fujian-Zhejiang coastal current occurring in winter. As the vertical profile distributions, we find that both of the absorption and backscattering coefficients present a layer structure, which caused by the stratification of the sea water in the summer; while in the winter, affected by the strong wind disturbing, both of the absorption and backscattering coefficients are thoroughly vertical mixing. To our knowledge, it is the first time

  19. Spectral properties of microwave graphs with local absorption.

    PubMed

    Allgaier, Markus; Gehler, Stefan; Barkhofen, Sonja; Stöckmann, H-J; Kuhl, Ulrich

    2014-02-01

    The influence of absorption on the spectra of microwave graphs has been studied experimentally. The microwave networks were made up of coaxial cables and T junctions. First, absorption was introduced by attaching a 50Ω load to an additional vertex for graphs with and without time-reversal symmetry. The resulting level-spacing distributions were compared with a generalization of the Wigner surmise in the presence of open channels proposed recently by Poli et al. [Phys. Rev. Lett. 108, 174101 (2012)]. Good agreement was found using an effective coupling parameter. Second, absorption was introduced along one individual bond via a variable microwave attenuator, and the influence of absorption on the length spectrum was studied. The peak heights in the length spectra corresponding to orbits avoiding the absorber were found to be independent of the attenuation, whereas, the heights of the peaks belonging to orbits passing the absorber once or twice showed the expected decrease with increasing attenuation.

  20. Collision--induced absorption in dense atmospheres of cool stars

    SciTech Connect

    Borysow, Aleksandra; Joergensen, Uffe Graae

    1999-04-01

    In the atmosphere of the Sun the major interaction between the matter and the radiation is through light absorption by ions (predominantly the negative ion of hydrogen atoms), neutral atoms and a small amount of polar molecules. The majority of stars in the universe are, however, cooler and denser than our Sun, and for a large fraction of these, the above absorption processes are very weak. Here, collision-induced absorption (CIA) becomes the dominant opacity source. The radiation is absorbed during very short mutual passages ('collisions') of two non-polar molecules (and/or atoms), while their electric charge distributions are temporarily distorted which gives rise to a transient dipole moment. We present here a review of the present-day knowledge about the impact of collision-induced absorption processes on the structure and the spectrum of such stars.

  1. Modification of light transmission channels by inhomogeneous absorption in random media.

    PubMed

    Liew, Seng Fatt; Cao, Hui

    2015-05-01

    Optical absorption is omnipresent and often distributed non-uniformly in space. We present a numerical study on the effects of inhomogeneous absorption on transmission eigenchannels of light in highly scattering media. In the weak absorption regime, the spatial profile of a transmission channel remains similar to that without absorption, and the effect of inhomogeneous absorption can be stronger or weaker than homogeneous absorption depending on the spatial overlap of the localized absorbing region with the field intensity maximum of the channel. In the strong absorption regime, the high transmission channels redirect the energy flows to circumvent the absorbing regions to minimize loss. The attenuation of high transmission channels by inhomogeneous absorption is lower than that by homogeneous absorption, regardless of the location of the absorbing region. The statistical distribution of transmission eigenvalues in the former becomes broader than that in the latter, due to a longer tail at high transmission. The maximum enhancement factor of total transmission increases with absorption, eventually exceeds that without absorption.

  2. Neutron absorption constraints on the composition of 4 Vesta

    USGS Publications Warehouse

    Prettyman, Thomas H.; Mittlefehldt, David W.; Yamashita, Naoyuki; Beck, Andrew W.; Feldman, William C.; Hendricks, John S.; Lawrence, David J.; McCoy, Timothy J.; McSween, Harry Y.; Paplowski, Patrick N.; Reedy, Robert C.; Toplis, Michael J.; Le Corre, Lucille; Mizzon, Hugau; Reddy, Vishnu; Titus, Timothy N.; Raymond, Carol A.; Russell, Christopher T.

    2013-01-01

    Global maps of the macroscopic thermal neutron absorption cross section of Vesta's regolith by the Gamma Ray and Neutron Detector (GRaND) on board the NASA Dawn spacecraft provide constraints on the abundance and distribution of Fe, Ca, Al, Mg, and other rock-forming elements. From a circular, polar low-altitude mapping orbit, GRaND sampled the regolith to decimeter depths with a spatial resolution of about 300 km. At this spatial scale, the variation in neutron absorption is about seven times lower than that of the Moon. The observed variation is consistent with the range of absorption for howardite whole-rock compositions, which further supports the connection between Vesta and the howardite, eucrite, and diogenite meteorites. We find a strong correlation between neutron absorption and the percentage of eucritic materials in howardites and polymict breccias, which enables petrologic mapping of Vesta's surface. The distribution of basaltic eucrite and diogenite determined from neutron absorption measurements is qualitatively similar to that indicated by visible and near infrared spectroscopy. The Rheasilvia basin and ejecta blanket has relatively low absorption, consistent with Mg-rich orthopyroxene. Based on a combination of Fe and neutron absorption measurements, olivine-rich lithologies are not detected on the spatial scales sampled by GRaND. The sensitivity of GRaND to the presence of mantle material is described and implications for the absence of an olivine signature are discussed. High absorption values found in Vesta's “dark” hemisphere, where exogenic hydrogen has accumulated, indicate that this region is richer in basaltic eucrite, representative of Vesta's ancient upper crust.

  3. Percutaneous nitroglycerin absorption in rats.

    PubMed

    Horhota, S T; Fung, H L

    1979-05-01

    Percutaneous nitroglycerin absorption was studied in shaved rats by monitoring unchanged plasma drug concentrations for up to 4 hr. Drug absorption from the neat liquid state or from an alcoholic solution was considerably poorer than that from a commercial ointment. This observation was unanticipated since the driving force for percutaneous drug absorption was assumed to be drug thermodynamics. Potential artifacts such as drug volatilization from the skin, reduction of surface area through droplet formation, and vehicle occlusion were investigated, but they did not appear to be responsible for the observed results. Two experimental aqueous nitroglycerin gels were prepared with polyethylene glycol 400. One gel contained just sufficient polyethylene glycol to solubilize the nitroglycerin; the other had excess polyethylene glycol to solubilize nitroglycerin far below saturation. Both gels gave extremely low plasma nitroglycerin levels. The composite data suggested that percutaneous nitroglycerin absorption is highly vehicle dependent and that this dependency cannot be explained by simple consideration of drug thermodynamic activity.

  4. Circadian Regulation of Macronutrient Absorption.

    PubMed

    Hussain, M Mahmood; Pan, Xiaoyue

    2015-12-01

    Various intestinal functions exhibit circadian rhythmicity. Disruptions in these rhythms as in shift workers and transcontinental travelers are associated with intestinal discomfort. Circadian rhythms are controlled at the molecular level by core clock and clock-controlled genes. These clock genes are expressed in intestinal cells, suggesting that they might participate in the circadian regulation of intestinal functions. A major function of the intestine is nutrient absorption. Here, we will review absorption of proteins, carbohydrates, and lipids and circadian regulation of various transporters involved in their absorption. A better understanding of circadian regulation of intestinal absorption might help control several metabolic disorders and attenuate intestinal discomfort associated with disruptions in sleep-wake cycles.

  5. [Spectral calibration for space-borne differential optical absorption spectrometer].

    PubMed

    Zhou, Hai-Jin; Liu, Wen-Qing; Si, Fu-Qi; Zhao, Min-Jie; Jiang, Yu; Xue, Hui

    2012-11-01

    Space-borne differential optical absorption spectrometer is used for remote sensing of atmospheric trace gas global distribution. This instrument acquires high accuracy UV/Vis radiation scattered or reflected by air or earth surface, and can monitor distribution and variation of trace gases based on differential optical absorption spectrum algorithm. Spectral calibration is the premise and base of quantification of remote sensing data of the instrument, and the precision of calibration directly decides the level of development and application of the instrument. Considering the characteristic of large field, wide wavelength range, high spatial and spectral resolution of the space-borne differential optical absorption spectrometer, a spectral calibration method is presented, a calibration device was built, the equation of spectral calibration was calculated through peak searching and regression analysis, and finally the full field spectral calibration of the instrument was realized. The precision of spectral calibration was verified with Fraunhofer lines of solar light.

  6. NMR microscopy of heavy metal absorption in calcium alginate beads

    SciTech Connect

    Nestle, N.; Kimmich, R.

    1996-01-01

    In recent years, heavy metal uptake by biopolymer gels, such as Cal-Alginate or chitosan, has been studied by various methods. This is of interest because such materials might be an alternative to synthetical ion-exchange resins in the treatment of industrial waste waters. Most of the work done in this field consisted of studies of equilibrium absorption of different heavy metal ions with dependence on various experimental parameters. In some publications, the kinetics of absorption were studied, too. However, no experiments on the spatial distribution of heavy metals during the absorption process are known to us. Using Cu as an example, it is demonstrated in this article that NMR microscopy is an appropriate tool for such studies. By the method presented here, it is possible to monitor the spatial distribution of heavy metal ions with a time resolution of about 5 min and a spatial resolution of 100 {mu}m or even better. 14 refs., 10 figs.

  7. Experimental study of neutrino absorption on carbon

    SciTech Connect

    Krakauer, D.A.; Talaga, R.L. ); Allen, R.C.; Chen, H.H.; Hausammann, R.; Lee, W.P.; Mahler, H.J.; Lu, X.Q.; Wang, K.C. ); Bowles, T.J.; Burman, R.L.; Carlini, R.D.; Cochran, D.R.F.; Doe, P.J.; Frank, J.S.; Piasetzky, E.; Potter, M.E.; Sandberg, V.D. )

    1992-05-01

    The process of electron emission from {similar to}30 MeV neutrino absorption on carbon, {sup 12}C({nu}{sub {ital e}},{ital e}{sup {minus}}){sup 12}N, has been observed. The flux-weighted total cross section for the exclusive neutrino-induced nuclear transition {sup 12}C({nu}{sub {ital e}},{ital e}{sup {minus}}){sup 12}N(g.s.) is (1.05{plus minus}0.10(stat){plus minus}0.10(syst)){times}10{sup {minus}41} cm{sup 2}. The measured cross section and angular distribution {ital d}{sigma}/{ital d}{Omega} are in agreement with theoretical estimates. The inclusive {nu}{sub {ital e}} {sup 12}C reaction rate, which accounted for the majority of all neutrino interactions observed in this experiment, was determined from a detailed fit of energy and angular distributions for the observed electrons. The inclusive {sup 12}C({nu}{sub {ital e}},{ital e}{sup {minus}}){ital X} cross section is measured to be (1.41{plus minus}0.23(tot)){times}10{sup {minus}41} cm{sup 2}. An upper limit for the sum of the {sup 13}C({nu}{sub {ital e}},{ital e}{sup {minus}}){ital X}+{sup 27}Al({nu}{sub {ital e}},{ital e}{sup {minus}}){ital X} inclusive absorption cross sections is presented.

  8. Incomplete intestinal absorption of fructose.

    PubMed

    Kneepkens, C M; Vonk, R J; Fernandes, J

    1984-08-01

    Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children with bowel disorders showed incomplete absorption. Seven children were tested again with an equal amount of glucose, and in three of them also of galactose, added to the fructose. The mean maximum breath hydrogen increases were 5 and 10 ppm, respectively, compared with 103 ppm after fructose alone. In one boy several tests were performed with various sugars; fructose was the only sugar incompletely absorbed, and the effect of glucose on fructose absorption was shown to be dependent on the amount added. It is concluded that children have a limited absorptive capacity for fructose. We speculate that the enhancing effect of glucose and galactose on fructose absorption may be due to activation of the fructose carrier. Apple juice in particular contains fructose in excess of glucose and could lead to abdominal symptoms in susceptible children.

  9. Incomplete intestinal absorption of fructose.

    PubMed Central

    Kneepkens, C M; Vonk, R J; Fernandes, J

    1984-01-01

    Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children with bowel disorders showed incomplete absorption. Seven children were tested again with an equal amount of glucose, and in three of them also of galactose, added to the fructose. The mean maximum breath hydrogen increases were 5 and 10 ppm, respectively, compared with 103 ppm after fructose alone. In one boy several tests were performed with various sugars; fructose was the only sugar incompletely absorbed, and the effect of glucose on fructose absorption was shown to be dependent on the amount added. It is concluded that children have a limited absorptive capacity for fructose. We speculate that the enhancing effect of glucose and galactose on fructose absorption may be due to activation of the fructose carrier. Apple juice in particular contains fructose in excess of glucose and could lead to abdominal symptoms in susceptible children. PMID:6476870

  10. Stencil lithography of gold-black IR absorption coatings

    NASA Astrophysics Data System (ADS)

    Panjwani, Deep; Yesiltas, Mehmet; Singh, Simranjit; Barco, Enrique Del; Peale, R. E.; Hirschmugl, Carol; Sedlemair, Julia

    2014-09-01

    Gold black coatings are deposited through a stencil shadow mask to produce infrared-absorbing patterns with sub-mm lateral dimensions. Such dimensions match the characteristic pitch of Long Wave Infrared (LWIR) array bolometers. Infrared spectral imaging with sub-micron spatial resolution reveals the spatial distribution of absorption across the pattern.

  11. Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth's Radiant Energy System Instrument on the Tropical Rainfall Measuring Mission Satellite. Part II; Validation

    NASA Technical Reports Server (NTRS)

    Loeb, N. G.; Loukachine, K.; Wielicki, B. A.; Young, D. F.

    2003-01-01

    Top-of-atmosphere (TOA) radiative fluxes from the Clouds and the Earth s Radiant Energy System (CERES) are estimated from empirical angular distribution models (ADMs) that convert instantaneous radiance measurements to TOA fluxes. This paper evaluates the accuracy of CERES TOA fluxes obtained from a new set of ADMs developed for the CERES instrument onboard the Tropical Rainfall Measuring Mission (TRMM). The uncertainty in regional monthly mean reflected shortwave (SW) and emitted longwave (LW) TOA fluxes is less than 0.5 W/sq m, based on comparisons with TOA fluxes evaluated by direct integration of the measured radiances. When stratified by viewing geometry, TOA fluxes from different angles are consistent to within 2% in the SW and 0.7% (or 2 W/sq m) in the LW. In contrast, TOA fluxes based on ADMs from the Earth Radiation Budget Experiment (ERBE) applied to the same CERES radiance measurements show a 10% relative increase with viewing zenith angle in the SW and a 3.5% (9 W/sq m) decrease with viewing zenith angle in the LW. Based on multiangle CERES radiance measurements, 18 regional instantaneous TOA flux errors from the new CERES ADMs are estimated to be 10 W/sq m in the SW and, 3.5 W/sq m in the LW. The errors show little or no dependence on cloud phase, cloud optical depth, and cloud infrared emissivity. An analysis of cloud radiative forcing (CRF) sensitivity to differences between ERBE and CERES TRMM ADMs, scene identification, and directional models of albedo as a function of solar zenith angle shows that ADM and clear-sky scene identification differences can lead to an 8 W/sq m root-mean-square (rms) difference in 18 daily mean SW CRF and a 4 W/sq m rms difference in LW CRF. In contrast, monthly mean SW and LW CRF differences reach 3 W/sq m. CRF is found to be relatively insensitive to differences between the ERBE and CERES TRMM directional models.

  12. Modulation of ganciclovir intestinal absorption in presence of absorption enhancers.

    PubMed

    Shah, Pranav; Jogani, Viral; Mishra, Pushpa; Mishra, Anil Kumar; Bagchi, Tamishraha; Misra, Ambikanandan

    2007-10-01

    The purpose of this investigation was to study the influences of absorption enhancers in increasing oral bioavailability of Ganciclovir (GAN) by assessing the transepithelial permeation across cell monolayers in vitro and bioavailability in rats in vivo. The permeation of GAN across Caco-2 and MDCK cell monolayers in the absence/presence of dimethyl-beta-cyclodextrin (DMbetaCD), chitosan hydrochloride (CH), sodium lauryl sulphate (SLS), and their combinations was studied for a 2-h period. GAN was administered to rats in absence/presence of absorption enhancers and drug contents in plasma were estimated. We found that the apparent permeability coefficient (Papp) of GAN in absence of absorption enhancers (control) were 0.261 +/- 0.072 x 10(-6) and 0.486 +/- 0.063 x 10(-6) cm/s in Caco-2 and MDCK cell monolayers, respectively, whereas in the presence of DMbetaCD, CH, SLS, and their combinations, Papp of GAN increased by 5- to 25-fold and 7- to 33-fold as compared to control in Caco-2 and MDCK cell monolayers, respectively. However, in rats, the maximum enhancement in bioavailability of GAN during coadministration of these absorption enhancers was only fivefold compared to GAN control. To conclude, the absorption enhancers-DMbetaCD, CH, SLS, and their combinations demonstrated significant improvement in transepithelial permeation and bioavailability of GAN.

  13. Converting Sabine absorption coefficients to random incidence absorption coefficients.

    PubMed

    Jeong, Cheol-Ho

    2013-06-01

    Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a sample and non-uniform intensity in the reverberation chambers under test. In this study, conversion methods from Sabine absorption 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 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 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 do not guarantee reliable estimations, particularly at frequencies below 250 Hz and beyond 2500 Hz.

  14. Fat-soluble vitamin intestinal absorption: absorption sites in the intestine and interactions for absorption.

    PubMed

    Goncalves, Aurélie; Roi, Stéphanie; Nowicki, Marion; Dhaussy, Amélie; Huertas, Alain; Amiot, Marie-Josèphe; Reboul, Emmanuelle

    2015-04-01

    The interactions occurring at the intestinal level between the fat-soluble vitamins A, D, E and K (FSVs) are poorly documented. We first determined each FSV absorption profile along the duodenal-colonic axis of mouse intestine to clarify their respective absorption sites. We then investigated the interactions between FSVs during their uptake by Caco-2 cells. Our data show that vitamin A was mostly absorbed in the mouse proximal intestine, while vitamin D was absorbed in the median intestine, and vitamin E and K in the distal intestine. Significant competitive interactions for uptake were then elucidated among vitamin D, E and K, supporting the hypothesis of common absorption pathways. Vitamin A also significantly decreased the uptake of the other FSVs but, conversely, its uptake was not impaired by vitamins D and K and even promoted by vitamin E. These results should be taken into account, especially for supplement formulation, to optimise FSV absorption.

  15. Sound absorption by suspensions of nonspherical particles: measurements compared with predictions using various particle sizing techniques.

    PubMed

    Richards, Simon D; Leighton, Timothy G; Brown, Niven R

    2003-10-01

    Knowledge of the particle size distribution is required in order to predict ultrasonic absorption in polydisperse particulate suspensions. This paper shows that the method used to measure the particle size distribution can lead to important differences in the predicted absorption. A reverberation technique developed for measuring ultrasonic absorption by suspended particles is used to measure the absorption in suspensions of nonspherical particles. Two types of particulates are studied: (i) kaolin (china clay) particles which are platelike in form; and (ii) calcium carbonate particles which are more granular. Results are compared to theoretical predictions of visco-inertial absorption by suspensions of spherical particles. The particle size distributions, which are required for these predictions, are measured by laser diffraction, gravitational sedimentation and centrifugal sedimentation, all of which assume spherical particles. For a given sample, each sizing technique yields a different size distribution, leading to differences in the predicted absorption. The particle size distributions obtained by gravitational and centrifugal sedimentation are reinterpreted to yield a representative size distribution of oblate spheroids, and predictions for absorption by these spheroids are compared with the measurements. Good agreement between theory and measurement for the flat kaolin particles is obtained, demonstrating that these particles can be adequately represented by oblate spheroids. PMID:14587585

  16. Absorption, distribution, metabolism and excretion pharmacogenomics of drugs of abuse.

    PubMed

    Meyer, Markus R; Maurer, Hans H

    2011-02-01

    Pharmacologic and toxic effects of xenobiotics, such as drugs of abuse, depend on the genotype and phenotype of an individual, and conversely on the isoenzymes involved in their metabolism and transport. The current knowledge of such isoenzymes of frequently abused therapeutics such as opioids (oxycodone, hydrocodone, methadone, fentanyl, buprenorphine, tramadol, heroin, morphine and codeine), anesthetics (γ-hydroxybutyric acid, propofol, ketamine and phencyclidine) and cognitive enhancers (methylphenidate and modafinil), and some important plant-derived hallucinogens (lysergide, salvinorin A, psilocybin and psilocin), as well as of nicotine in humans are summarized in this article. The isoenzymes (e.g., cytochrome P450, glucuronyltransferases, esterases and reductases) involved in the metabolism of drugs and some pharmacokinetic data are discussed. The relevance of such data is discussed for predicting possible interactions with other xenobiotics, understanding pharmacokinetic behavior and pharmacogenomic variations, assessing toxic risks, developing suitable toxicological analysis procedures, and finally for interpretating drug testing results.

  17. Absorption and distribution of perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is found in biosolids, and the application of these biosolids to pastures has raised concerns about human exposure through the accumulation of PFOS in edible tissues of these animals. The United States Department of Agriculture (USDA) h...

  18. Sound absorption in metallic foams

    NASA Astrophysics Data System (ADS)

    Lu, T. J.; Hess, Audrey; Ashby, M. F.

    1999-06-01

    The sound absorption capacity of one type of aluminum alloy foams—trade name Alporas—is studied experimentally. The foam in its as-received cast form contains closed porosities, and hence does not absorb sound well. To make the foam more transparent to air motion, techniques based on either rolling or hole drilling are used. Under rolling, the faces of some of the cells break to form small sharp-edged cracks as observed from a scanning electronic microscope. These cracks become passage ways for the in-and-out movement of air particles, resulting in sound absorption improvement. The best performance is nevertheless achieved via hole drilling where nearly all of the sound can be absorbed at selected frequencies. Combining rolling with hole drilling does not appear to lend additional benefits for sound absorption. Image analysis is carried out to characterize the changes in cell morphologies due to rolling/compression, and the drop in elastic modulus due to the formation of cracks is recorded. The effects of varying the relative foam density and panel thickness on sound absorption are measured, and optimal relative density and thickness of the panel are identified. Analytical models are used to explain the measured increase in sound absorption due to rolling and/or drilling. Sound absorbed by viscous flow across small cracks appears to dominate over that dissipated via other mechanisms.

  19. Enhanced absorption cycle computer model

    NASA Astrophysics Data System (ADS)

    Grossman, G.; Wilk, M.

    1993-09-01

    Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperature boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorption systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system's components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H2O triple-effect cycles, LiCl-H2O solar-powered open absorption cycles, and NH3-H2O single-effect and generator-absorber heat exchange cycles. An appendix contains the user's manual.

  20. Absorption-heat-pump system

    DOEpatents

    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.

  1. Diabetic lipohypertrophy delays insulin absorption.

    PubMed

    Young, R J; Hannan, W J; Frier, B M; Steel, J M; Duncan, L J

    1984-01-01

    The effect of lipohypertrophy at injection sites on insulin absorption has been studied in 12 insulin-dependent diabetic patients. The clearance of 125I-insulin from sites with lipohypertrophy was significantly slower than from complementary nonhypertrophied sites (% clearance in 3 h, 43.8 +/- 3.5 +/- SEM) control; 35.3 +/- 3.9 lipohypertrophy, P less than 0.05). The degree of the effect was variable but sufficient in several patients to be of clinical importance. Injection-site lipohypertrophy is another factor that modifies the absorption of subcutaneously injected insulin.

  2. Solar powered absorption air conditioning

    NASA Astrophysics Data System (ADS)

    Vardon, J. M.

    1980-04-01

    Artificial means of providing or removing heat from the building are discussed along with the problem of the appropriate building design and construction for a suitable heat climate inside the building. The use of a lithium bromide-water absorption chiller, powered by a hot water store heated by an array of stationary flat collectors, is analyzed. An iterative method of predicting the cooling output from a LiBr-water absorption refrigeration plant having variable heat input is described and a model allowing investigation of the performance of a solar collector and thermal storage system is developed.

  3. Transient absorption spectroscopy of laser shocked explosives

    SciTech Connect

    Mcgrane, Shawn D; Dang, Nhan C; Whitley, Von H; Bolome, Cindy A; Moore, D S

    2010-01-01

    Transient absorption spectra from 390-890 nm of laser shocked RDX, PETN, sapphire, and polyvinylnitrate (PVN) at sub-nanosecond time scales are reported. RDX shows a nearly linear increase in absorption with time after shock at {approx}23 GPa. PETN is similar, but with smaller total absorption. A broad visible absorption in sapphire begins nearly immediately upon shock loading but does not build over time. PVN exhibits thin film interference in the absorption spectra along with increased absorption with time. The absorptions in RDX and PETN are suggested to originate in chemical reactions happening on picosecond time scales at these shock stresses, although further diagnostics are required to prove this interpretation.

  4. Aerosol Absorption Measurements in MILAGRO.

    NASA Astrophysics Data System (ADS)

    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

  5. Quasar Absorption Line Survey - Cycle 4 High

    NASA Astrophysics Data System (ADS)

    Bahcall, John

    1994-01-01

    The Absorption Line Survey of bright quasars provides a homogeneous data base for studying fundamental questions about the origin and evolution of gaseous systems in the universe. The initial results determine at small redshifts the number densities of Ly-ALPHA systems, of metal-lines and extragalactic halos, of Lyman-limit systems, of associated absorption systems, and the shapes and intensities of quasar emission lines and spectral energy distributions. The survey reveals that much of the sky is covered by high or very high velocity metal-line clouds present in the Galactic halo. A larger sample, which includes the requested Cycle 3 observations, is required to answer many important questions. For example, what is the correlation function of Ly-ALPHA systems at small redshifts? What fraction of the metal, the Ly-ALPHA, and the Ly-limit systems are associated with galaxies and what are the characteristic sizes of the outer gaseous regions of different types of galaxies? Do absorbing systems show evidence of the large-scale structure seen with galaxies and clusters of galaxies? The observations requested in Cycle 3 will extend the region of coverage of the Key Project sample from the redshift range of z = 0.0 to 1.0 (Cycles 1& 2) to z = 0.0 to 1.6 (Cycles 1-3). THIS FILE CONTAINS THE HIGH PRIORITY OBSERVATIONS FROM CYCLES 2 and 3 WHICH WERE NOT COMPLETED IN THOSE CYCLES.

  6. Concentration-modulated absorption spectroscopy.

    PubMed

    Langley, A J; Beaman, R A; Baran, J; Davies, A N; Jones, W J

    1985-07-01

    Concentration modulation is demonstrated to be a technique capable of markedly extending sensitivity limits in absorption spectroscopy. The gain generated relates in such a manner to sample transmittance that for the first reported time direct spectroscopic concentration measurements become possible. When concentration modulation is used with picosecond lasers, state lifetimes can be determined to a limit of approximately 20 psec.

  7. Ultraviolet and Light Absorption Spectrometry.

    ERIC Educational Resources Information Center

    Hargis, L. G.; Howell, J. A.

    1984-01-01

    Reviews developments in ultraviolet and light absorption spectrometry from December 1981 through November 1983, focusing on the chemistry involved in developing suitable reagents, absorbing systems, and methods of determination, and on physical aspects of the procedures. Includes lists of spectrophotometric methods for metals, non-metals, and…

  8. Phenoxyethanol absorption by polyvinyl chloride.

    PubMed

    Lee, M G

    1984-12-01

    Phenoxyethanol was found to be absorbed by polyvinyl chloride administration sets during continuous irrigation therapy. Depending upon the conditions of administration up to 20% loss of potency could occur. Absorption of the drug by the rigid plastic luer-lock fitting of the set caused softening and decreased rigidity of the plastic.

  9. Slow light and saturable absorption

    NASA Astrophysics Data System (ADS)

    Selden, A. C.

    2009-06-01

    Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semiconductor quantum devices and erbium-doped optical fibres, shows that the observations may be more simply interpreted as saturable absorption phenomena. A basic two-level model of a saturable absorber displays all the effects normally associated with slow light, namely phase shift and modulation gain of the transmitted signal, hole burning in the modulation frequency spectrum and power broadening of the spectral hole, each arising from the finite response time of the non-linear absorption. Only where hole-burning in the optical spectrum is observed (using independent pump and probe beams), or pulse delays exceeding the limits set by saturable absorption are obtained, can reasonable confidence be placed in the observation of slow light in such experiments. Superluminal (“fast light”) phenomena in media with reverse saturable absorption (RSA) may be similarly explained.

  10. H I ABSORPTION TOWARD H II REGIONS AT SMALL GALACTIC LONGITUDES

    SciTech Connect

    Jones, C.; Dickey, J. M.; Dawson, J. R.; McClure-Griffiths, N. M.; Anderson, L. D.; Bania, T. M.

    2013-09-10

    We make a comprehensive study of H I absorption toward H II regions located within |l| < 10 Degree-Sign . Structures in the extreme inner Galaxy are traced using the longitude-velocity space distribution of this absorption. We find significant H I absorption associated with the Near and Far 3 kpc Arms, the Connecting Arm, Bania's Clump 1, and the H I Tilted Disk. We also constrain the line-of-sight distances to H II regions, by using H I absorption spectra together with the H II region velocities measured by radio recombination lines.

  11. Analysis of data on absorption in the northern part of the milky way

    NASA Technical Reports Server (NTRS)

    Polishchuk, E. P.

    1973-01-01

    The values of absorption for different galactic longitudes are obtained on the basis of star cluster data. It is found that the distance up to the point, where the straightening of the absorption distribution curve begins, depends on the limiting magnitude of the catalogue and the density of absorbing matter near the sun. The picture of absorbing matter distribution in the northern part of the Milky Way is given.

  12. On energy absorption in classical electromagnetism

    NASA Astrophysics Data System (ADS)

    Goedecke, G. H.

    2001-02-01

    Using only classical electromagnetic energy conservation laws and causality, we show that the net average power absorbed by any mechanically isolated illuminated medium in steady state must be zero, but that for linear model media it is nonzero. This contradiction implies that all media must behave inelastically. We also show in general that the average power absorbed at an incident frequency, which is equal to the total taken from an incident wave minus that scattered elastically, is also equal to the average power scattered inelastically plus that carried off mechanically, if any. Finally, we infer that while the conventional linear theory cannot predict the spectral distribution of inelastic scattering, it may be applied as always to predict the propagation, absorption, and elastic scattering of weak illumination in passive media.

  13. Gas separation using ultrasound and light absorption

    DOEpatents

    Sinha, Dipen N.

    2012-07-31

    An apparatus and method for separating a chosen gas from a mixture of gases having no moving parts and utilizing no chemical processing is described. The separation of particulates from fluid carriers thereof has been observed using ultrasound. In a similar manner, molecular species may be separated from carrier species. It is also known that light-induced drift may separate light-absorbing species from carrier species. Therefore, the combination of temporally pulsed absorption of light with ultrasonic concentration is expected to significantly increase the efficiency of separation by ultrasonic concentration alone. Additionally, breaking the spatial symmetry of a cylindrical acoustic concentrator decreases the spatial distribution of the concentrated particles, and increases the concentration efficiency.

  14. Electron heating due to resonant absorption

    SciTech Connect

    Mizuno, K.; Spielman, R.B.; DeGroot, J.S.; Bollen, W.M.

    1980-01-01

    Intense, p-polarized microwaves (v/sub os//v/sub eo-/<1) are incident on an imhomogeneous plasma (10/sup 2/absorption near the critical surface (where the plasma frequency equals microwave frequency). Suprathermal electrons are heated by resonantly driven electrostatic field to produce a hot Maxwellian distribution. Most of the heated electrons flow towards the overdense region and are absorbed by the anode at the far end of the overdense region. At high power (v/sub os//v/sub eo-/>0.2), strong heating of thermal electrons, large amplitude ion acoustic turbulence, and a self-consistent dc electric field are observed near the critical surface. This dc electric field is enhanced by applying a weak magnetic field (..omega../sub ce//..omega../sub o/ approx. = 10/sup -2/).

  15. Differential absorption and scattering sensitivity predictions

    NASA Technical Reports Server (NTRS)

    Thompson, R. T., Jr.

    1976-01-01

    A set of general equations for evaluating the sensitivity of the Differential Absorption and Scattering (DAS) technique based upon a conventional analysis of statistical errors is derived. The equations are put in a proper form for evaluating total column density and range resolved concentration measurements of a variety of atmospheric species. The derived equation are subsequently used to analyze the sensitivity of DAS in three specific applications assuming realistic parameters for the optical and electronic components of proposed DAS systems. The three DAS applications evaluated are: (1) measurement of nitrogen at ground levels over a horizontal path; (2) measurement of atmospheric ozone depletion in the wake of a jet engine at 20 km altitude; and (3) measurements of the ozone distribution in the atmosphere from an orbiting space platform, in a downward viewing mode. The results of this study have shown that with reasonable laser energy and telescope receiver dimensions, DAS is capable of meeting requirements for performing these measurements.

  16. Infrared bulk and surface absorption by nearly transparent crystals.

    PubMed

    Rosenstock, H B; Gregory, D A; Harrington, J A

    1976-09-01

    We present an analysis of laser calorimetric data that deduces both the bulk and the surface absorption in a single run. The method involves use of long rod geometry combined with an analytical solution of the heat equation for the temperature distribution in a sample that is heated both internally and on the surfaces. Bulk and surface absorption coefficients, heat transfer coefficient, and thermal diffusivity appear as parameters; the last is treated as known, and the thermal rise curve is fitted to the three others. The solution obtained is valid at all points and times, and measurement of the temperature during and after laser heating at different points therefore narrows the possible fit considerably. Examples illustrating the method are presented for ZnSe, CaF(2) NaF:Li, NaCl, KBr, and KC1 at 2.7 microm, 3.8 microm, and 10.6 microm. Surface absorption is found to be dominant in all cases.

  17. Methane absorption variations in the spectrum of Pluto

    SciTech Connect

    Buie, M.W.; Fink, U.

    1987-06-01

    The lightcurve phases of 0.18, 0.35, 0.49, and 0.98 covered by 5600-10,500 A absolute spectrophotometry of Pluto during four nights include minimum (0.98) light and one near-maximum (0.49) light. The spectra are noted to exhibit significant methane band absorption depth variations at 6200, 7200, 7900, 8400, 8600, 8900, and 10,000 A, with the minimum absorption occurring at minimum light and thereby indicating a 30-percent change in the methane column abundance in the course of three days. An attempt is made to model this absorption strength variation with rotational phase terms of an isotropic surface distribution of methane frost and a clear layer of CH4 gas. 34 references.

  18. Influence of texture modifications in silicon solar cells on absorption in the intrinsic layers

    NASA Astrophysics Data System (ADS)

    Ermes, M.; Bittkau, K.; Carius, R.

    2012-06-01

    The influence of the front texture of an etched transparent conductive oxide with crater-like structures of various sizes on the absorption of a thin amorphous silicon (a-Si:H) layer is investigated by rigorous optical simulations as part of two simplified systems: A simplified single junction device, using a perfect metal as back contact and a top cell of an amorphous/microcrystalline silicon tandem device, using a microcrystalline silicon halfspace adjacent to the amorphous layer. The texture is modified by stretching either in height or laterally and the average absorption in the a-Si:H layer is investigated relative to the original structure. We investigate the average absorption for each wavelength as well as the total absorption, weighted with an AM1.5g spectrum. Furthermore, the local absorption distribution inside the a-Si:H layer is examined to improve the understanding of local texture features and their influence on absorption and cell performance. For both modifications, an optimal point can be found to improve the absorption in the amorphous layer by up to 15% and 6% for a simplified single junction and tandem top cell, respectively. In case of the top cell of the simplified tandem device, it is found that additionally, the transmission into the microcrystalline silicon can be improved. Also, the local absorption distribution shows that there is an optimal size of the surface craters for all modifications, while steeper crater rims in general lead to higher absorption.

  19. Disorder-induced enhancement of indirect absorption in a GeSn photodetector grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Li, H.; Chang, C.; Cheng, H. H.; Sun, G.; Soref, R. A.

    2016-05-01

    We report an investigation on the absorption mechanism of a GeSn photodetector with 2.4% Sn composition in the active region. Responsivity is measured and absorption coefficient is calculated. Square root of absorption coefficient linearly depends on photon energy indicating an indirect transition. However, the absorption coefficient is found to be at least one order of magnitude higher than that of most other indirect materials, suggesting that the indirect optical absorption transition cannot be assisted only by phonon. Our analysis of absorption measurements by other groups on the same material system showed the values of absorption coefficient on the same order of magnitude. Our study reveals that the strong enhancement of absorption for the indirect optical transition is the result of alloy disorder from the incorporation of the much larger Sn atoms into the Ge lattice that are randomly distributed.

  20. Higher-order-in-spin interaction Hamiltonians for binary black holes from source terms of Kerr geometry in approximate ADM coordinates

    SciTech Connect

    Hergt, Steven; Schaefer, Gerhard

    2008-05-15

    The Kerr metric outside the ergosphere is transformed into Arnowitt-Deser-Misner coordinates up to the orders 1/r{sup 4} and a{sup 2}, respectively, in radial coordinate r and reduced angular momentum variable a, starting from the Kerr solution in quasi-isotropic as well as harmonic coordinates. The distributional source terms for the approximate solution are calculated. To leading order in linear momenta, higher-order-in-spin interaction Hamiltonians for black hole binaries are derived.

  1. Landing gear energy absorption system

    NASA Technical Reports Server (NTRS)

    Hansen, Christopher P. (Inventor)

    1994-01-01

    A landing pad system is described for absorbing horizontal and vertical impact forces upon engagement with a landing surface where circumferentially arranged landing struts respectively have a clevis which receives a slidable rod member and where the upper portion of a slidable rod member is coupled to the clevis by friction washers which are force fit onto the rod member to provide for controlled constant force energy absorption when the rod member moves relative to the clevis. The lower end of the friction rod is pivotally attached by a ball and socket to a support plate where the support plate is arranged to slide in a transverse direction relative to a housing which contains an energy absorption material for absorbing energy in a transverse direction.

  2. Path length enhancement in disordered media for increased absorption.

    PubMed

    Mupparapu, Rajeshkumar; Vynck, Kevin; Svensson, Tomas; Burresi, Matteo; Wiersma, Diederik S

    2015-11-30

    We theoretically and numerically investigate the capability of disordered media to enhance the optical path length in dielectric slabs and augment their light absorption efficiency due to scattering. We first perform a series of Monte Carlo simulations of random walks to determine the path length distribution in weakly to strongly (single to multiple) scattering, non-absorbing dielectric slabs under normally incident light and derive analytical expressions for the path length enhancement in these two limits. Quite interestingly, while multiple scattering is expected to produce long optical paths, we find that media containing a vanishingly small amount of scatterers can still provide high path length enhancements due to the very long trajectories sustained by total internal reflection at the slab interfaces. The path length distributions are then used to calculate the light absorption efficiency of media with varying absorption coefficients. We find that maximum absorption enhancement is obtained at an optimal scattering strength, in-between the single-scattering and the diffusive (strong multiple-scattering) regimes. This study can guide experimentalists towards more efficient and potentially low-cost solutions in photovoltaic technologies.

  3. Photodetector with enhanced light absorption

    DOEpatents

    Kane, James

    1985-01-01

    A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

  4. Modeling the anaerobic digestion of cane-molasses vinasse: extension of the Anaerobic Digestion Model No. 1 (ADM1) with sulfate reduction for a very high strength and sulfate rich wastewater.

    PubMed

    Barrera, Ernesto L; Spanjers, Henri; Solon, Kimberly; Amerlinck, Youri; Nopens, Ingmar; Dewulf, Jo

    2015-03-15

    This research presents the modeling of the anaerobic digestion of cane-molasses vinasse, hereby extending the Anaerobic Digestion Model No. 1 with sulfate reduction for a very high strength and sulfate rich wastewater. Based on a sensitivity analysis, four parameters of the original ADM1 and all sulfate reduction parameters were calibrated. Although some deviations were observed between model predictions and experimental values, it was shown that sulfates, total aqueous sulfide, free sulfides, methane, carbon dioxide and sulfide in the gas phase, gas flow, propionic and acetic acids, chemical oxygen demand (COD), and pH were accurately predicted during model validation. The model showed high (±10%) to medium (10%-30%) accuracy predictions with a mean absolute relative error ranging from 1% to 26%, and was able to predict failure of methanogenesis and sulfidogenesis when the sulfate loading rate increased. Therefore, the kinetic parameters and the model structure proposed in this work can be considered as valid for the sulfate reduction process in the anaerobic digestion of cane-molasses vinasse when sulfate and organic loading rates range from 0.36 to 1.57 kg [Formula: see text]  m(-3) d(-1) and from 7.66 to 12 kg COD m(-3) d(-1), respectively. PMID:25589435

  5. Modeling the anaerobic digestion of cane-molasses vinasse: extension of the Anaerobic Digestion Model No. 1 (ADM1) with sulfate reduction for a very high strength and sulfate rich wastewater.

    PubMed

    Barrera, Ernesto L; Spanjers, Henri; Solon, Kimberly; Amerlinck, Youri; Nopens, Ingmar; Dewulf, Jo

    2015-03-15

    This research presents the modeling of the anaerobic digestion of cane-molasses vinasse, hereby extending the Anaerobic Digestion Model No. 1 with sulfate reduction for a very high strength and sulfate rich wastewater. Based on a sensitivity analysis, four parameters of the original ADM1 and all sulfate reduction parameters were calibrated. Although some deviations were observed between model predictions and experimental values, it was shown that sulfates, total aqueous sulfide, free sulfides, methane, carbon dioxide and sulfide in the gas phase, gas flow, propionic and acetic acids, chemical oxygen demand (COD), and pH were accurately predicted during model validation. The model showed high (±10%) to medium (10%-30%) accuracy predictions with a mean absolute relative error ranging from 1% to 26%, and was able to predict failure of methanogenesis and sulfidogenesis when the sulfate loading rate increased. Therefore, the kinetic parameters and the model structure proposed in this work can be considered as valid for the sulfate reduction process in the anaerobic digestion of cane-molasses vinasse when sulfate and organic loading rates range from 0.36 to 1.57 kg [Formula: see text]  m(-3) d(-1) and from 7.66 to 12 kg COD m(-3) d(-1), respectively.

  6. Broken-cloud enhancement of solar radiation absorption

    SciTech Connect

    Byrne, R.N.; Somerville, R.C.; Subasilar, B.

    1996-04-01

    Two papers recently published in Science have shown that there is more absorption of solar radiation than estimated by current atmospheric general circulation models (GCMs) and that the discrepancy is associated with cloudy scenes. We have devised a simple model which explains this as an artifact of stochastic radiative transport. We first give a heuristic description, unencumbered by mathematical detail. Consider a simple case with clouds distributed at random within a single level whose upper and lower boundaries are fixed. The solar zenith angle is small to moderate; this is therefore an energetically important case. Fix the average areal liquid water content of the cloud layer, and take the statistics of the cloud distribution to be homogeneous within the layer. Furthermore, assume that all the clouds in the layer have the same liquid water content, constant throughout the cloud, and that apart from their droplet content they are identical to the surrounding clear sky. Let the clouds occupy on the average a fraction p{sub cld} of the volume of the cloudy layer, and let them have a prescribed distribution of sizes about some mean. This is not a fractal distribution, because it has a scale. Cloud shape is unimportant so long as cloud aspect ratios are not far from unity. Take the single-scattering albedo to be unity for the droplets in the clouds. All of the absorption is due to atmospheric gases, so the absorption coefficient at a point is the same for cloud and clear sky. Absorption by droplets is less than 10% effect in the numerical stochastic radiation calculations described below, so it is reasonable to neglect it at this level of idealization.

  7. Lambertian thermal emitter based on plasmonic enhanced absorption.

    PubMed

    Wang, Chih-Ming; Tsai, Din Ping

    2016-08-01

    In this paper, a narrow band thermal emission at 10 μm is demonstrated using a one dimensional metasurface. The proposed metasurface structure provides magnetic resonance mode that enhances the phonon absorption of SiO2. The proposed metasurface thermal emitter shows a Lambertian distribution. Additionally, 5.8-folds enhancement of emissivity is achieved by optimizing the cavity thickness of the metasurfaces. This type of thermal emitter will be useful for IR sensing applications. PMID:27505801

  8. The Cloud Absorption Radiometer HDF Data User's Guide

    NASA Technical Reports Server (NTRS)

    Li, Jason Y.; Arnold, G. Thomas; Meyer, Howard G.; Tsay, Si-Chee; King, Michael D.

    1997-01-01

    The purpose of this document is to describe the Cloud Absorption Radiometer (CAR) Instrument, methods used in the CAR Hierarchical Data Format (HDF) data processing, the structure and format of the CAR HDF data files, and methods for accessing the data. Examples of CAR applications and their results are also presented. The CAR instrument is a multiwavelength scanning radiometer that measures the angular distributions of scattered radiation.

  9. Absorption, Creativity, Peak Experiences, Empathy, and Psychoticism.

    ERIC Educational Resources Information Center

    Mathes, Eugene W.; And Others

    Tellegen and Atkinson suggested that the trait of absorption may play a part in meditative skill, creativity, capacity for peak experiences, and empathy. Although the absorption-meditative skill relationship has been confirmed, other predictions have not been tested. Tellegen and Atkinson's Absorption Scale was completed by undergraduates in four…

  10. Global Latitudinal Differences of Molecular Absorption on Jupiter

    NASA Astrophysics Data System (ADS)

    Tejfel, V. G.

    2002-09-01

    In the future planetary monitoring from the groundbased observatories or space telescopes the selection of a number of planetary state indices will be necessary to obtain homogeneous temporal series of numerical planetary characteristics. In 1999 special observations of latitude-longitudinal distribution of absorption in the methane bands on Jupiter were carried out. CCD-spectra of the central meridian of Jupiter were recorded in each 3 minutes that corresponded a turning of Jupiter by 1.8 degrees. All the longitudes of the planet were twice covered and full number of spectrograms was 388. A comparison of the latitudinal dependence of absorption in the different absorption bands has revealed some noticeable global, longitudinally independent differences in the character of latitudinal variations of absorption. So, equatorial depression of absorption is well expressed in the bands at 725 and 887 nm, but it is absent in the band at 619 nm. It is interesting that for the band 798 nm, which is a combination of the methane and ammonia absorption, the similar depression is displaced significantly northward from the equator (minimum of the absorption take place at the latitude about +15 deg) in contrast with the depression observed for the band CH4 887 nm. Very small northward displacement is noticeable also for the CH4 725 nm equatorial depression. There is no determined relationship between the value of molecular absorption and visible albedo of the cloud belts. Standard deviations calculated at the longitudinally averaging of the central meridian profiles of the band central depths R are small and no more than 1-2 per cent of mean value. Thus the latitudinal differences are more clearly expressed than longitudinal variations and the global, longitudinally averaged N-S profiles of the absorption variations may be considered as one of characteristics of the current state of Jupiter (as well as of Saturn). There may be not significant mistake if the individual profiles R

  11. Study on Nonlinear Absorption Effect of Nanosecond Pulse Laser Irradiation for GaAs.

    PubMed

    Sun, Wenjun; Liu, Zhongyang; Zhou, Haijiao

    2016-04-01

    In order to research nonlinear absorption effect of pulse laser irradiation for GaAs, a physical model of Gaussian distribution pulse laser irradiation for semiconductor material was established by software COMSOL Multiphysics. The thermal effects of semiconductor material GaAs was analyzed under irradiation of nanosecond pulse laser with wavelength of 1064 nm. The radial and transverse temperature distribution of semiconductor material GaAs was calculated under irradiation of nanosecond pulse laser with different power density by solving the thermal conduction equations. The contribution of one-photon absorption, two-photon absorption and free carrier absorption to temperature of GaAs material were discussed. The results show that when the pulse laser power density rises to 10(10) W/cm2, free carrier absorption played a leading role and it was more than that of one-photon absorption of material. The temperature contribution of two-photon absorption and free carrier absorption could be ignored at laser power density lower than 10(8) W/cm2. The result is basically consistent with relevant experiments, which shows that physical model constructed is valid. PMID:27451733

  12. Study on Nonlinear Absorption Effect of Nanosecond Pulse Laser Irradiation for GaAs.

    PubMed

    Sun, Wenjun; Liu, Zhongyang; Zhou, Haijiao

    2016-04-01

    In order to research nonlinear absorption effect of pulse laser irradiation for GaAs, a physical model of Gaussian distribution pulse laser irradiation for semiconductor material was established by software COMSOL Multiphysics. The thermal effects of semiconductor material GaAs was analyzed under irradiation of nanosecond pulse laser with wavelength of 1064 nm. The radial and transverse temperature distribution of semiconductor material GaAs was calculated under irradiation of nanosecond pulse laser with different power density by solving the thermal conduction equations. The contribution of one-photon absorption, two-photon absorption and free carrier absorption to temperature of GaAs material were discussed. The results show that when the pulse laser power density rises to 10(10) W/cm2, free carrier absorption played a leading role and it was more than that of one-photon absorption of material. The temperature contribution of two-photon absorption and free carrier absorption could be ignored at laser power density lower than 10(8) W/cm2. The result is basically consistent with relevant experiments, which shows that physical model constructed is valid.

  13. Advanced regenerative absorption refrigeration cycles

    DOEpatents

    Dao, Kim

    1990-01-01

    Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

  14. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    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. NEUTRON ABSORPTION AND SHIELDING DEVICE

    DOEpatents

    Axelrad, I.R.

    1960-06-21

    A neutron absorption and shielding device is described which is adapted for mounting in a radiation shielding wall surrounding a radioactive area through which instrumentation leads and the like may safely pass without permitting gamma or neutron radiation to pass to the exterior. The shielding device comprises a container having at least one nonrectilinear tube or passageway means extending therethrough, which is adapted to contain instrumentation leads or the like, a layer of a substance capable of absorbing gamma rays, and a solid resinous composition adapted to attenuate fast-moving neutrons and capture slow- moving or thermal neutrons.

  16. Strange Latitudinal Variations of the Ammonia Absorption on Jupiter

    NASA Astrophysics Data System (ADS)

    Tejfel, V. G.; Karimov, A. M.; Vdovichenko, V. D.

    2005-08-01

    The ammonia absorption bands at near infrared spectrum of Jupiter are blended with stronger methane absorption and it is hard to study their variations on planetary disk. To extract the ammonia absorption we have used the ratio of Jupiter's spectra to the spectrum of Saturn where the ammonia absorption is very small or absent. Thus we could measure the profile and equivalent widths (W) of the NH3 band at 787 nm as well as the weaker band at 643 nm . More than 200 spectra of Jupiter were recorded in March-May 2004 with spectrograph SGS and CCD-camera ST-7XE at the slit oriented along central meridian or equator. All spectra were processed by this mean. Equatorial spectra show more or less uniform decrease of the NH3 absorption towards both limbs from the disk center. But most of spectra of CM show strange and clearly expressed wide depression of the NH3 band at 787 nm in the temperate latitudes of Northern hemisphere with minimal equivalent widths about 15 A or less when W in Southern hemisphere reach of 20 A or more. We have analyzed all probable artificial reasons of this effect but did not find any influence of instrumental factors. Then we processed a number of Jupiter's spectra recorded in 1997-1998 with other spectrograph and CCD ST-6V and detected the same peculiarity. Finally there were measured 100 zonal spectra ( with slit oriented parallel to equator) scanned all Jupiter's disk from North pole to South pole and recorded 3 May 2005 near upper culmination of the planet. The result is the same: the significant depression of the ammonia absorption in the N-hemisphere of Jupiter is confirmed. We shall continue the study and analysis of this effect to be sure that it is real peculiarity of the gaseous ammonia distribution and behavior on Jupiter.

  17. Infrared absorption mechanisms of black silicon

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengxi; Chen, Yongping; Ma, Bin

    2014-09-01

    Black silicon has a wide spectrum of non-spectral characteristics high absorption from visible to long wave infrared band .Based on semi-empirical impurity band model, free carrier absorption, radiation transitions between the valence band and the impurity band, radiation transitions between the impurity band and the conduction band were calculated, and absorption coefficients for each process were got. The results showed that the transitions from valence band to the impurity band induced absorption in the near-infrared waveband, but it has a rapid decay with wavelength. In the shortwave mid-wave and long-wave IR bands, transitions from the impurity band to the conduction band caused a huge absorption, and the absorption coefficient was slowly decreased with increasing wavelength. The free carrier absorption dominates in long-wave band. The calculation results agreed well with the test results of plant black silicon in magnitude and trends.

  18. Energy absorption of composite materials

    NASA Technical Reports Server (NTRS)

    Farley, G. L.

    1983-01-01

    Results of a study on the energy absorption characteristics of selected composite material systems are presented and the results compared with aluminum. Composite compression tube specimens were fabricated with both tape and woven fabric prepreg using graphite/epoxy (Gr/E), Kevlar (TM)/epoxy (K/E) and glass/epoxy (Gl/E). Chamfering and notching one end of the composite tube specimen reduced the peak load at initial failure without altering the sustained crushing load, and prevented catastrophic failure. Static compression and vertical impact tests were performed on 128 tubes. The results varied significantly as a function of material type and ply orientation. In general, the Gr/E tubes absorbed more energy than the Gl/E or K/E tubes for the same ply orientation. The 0/ + or - 15 Gr/E tubes absorbed more energy than the aluminum tubes. Gr/E and Gl/E tubes failed in a brittle mode and had negligible post crushing integrity, whereas the K/E tubes failed in an accordian buckling mode similar to the aluminum tubes. The energy absorption and post crushing integrity of hybrid composite tubes were not significantly better than that of the single material tubes.

  19. Percutaneous absorption of selenium sulfide

    SciTech Connect

    Farley, J.; Skelly, E.M.; Weber, C.B.

    1986-01-01

    The purpose of this study was to determine selenium levels in the urine of Tinea patients before and after overnight application of a 2.5% selenium sulfide lotion. Selenium was measured by atomic absorption spectroscopy (AAS). Hydride generation and carbon rod atomization were studied. It was concluded from this study that selenium is absorbed through intact skin. Selenium is then excreted, at least partially, in urine, for at least a week following treatment. The data show that absorption and excretion of selenium vary on an individual basis. Selenium levels in urine following a single application of selenium sulfide lotion do not indicate that toxic amounts of selenium are being absorbed. Repeated treatments with SeS/sub 2/ result in selenium concentrations in urine which are significantly higher than normal. Significant matrix effects are observed in the carbon rod atomization of urine samples for selenium determinations, even in the presence of a matrix modifier such as nickel. The method of standard additions is required to obtain accurate results in the direct determination of selenium in urine by carbon rod AAS.

  20. Iron Absorption in Drosophila melanogaster

    PubMed Central

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  1. Emission, absorption and polarization of gyrosynchrotron radiation of mildly relativistic particles

    NASA Technical Reports Server (NTRS)

    Petrosian, V.; Mctiernan, J. M.

    1983-01-01

    Approximate analytic expressions are presented for the emissivity and absorption coefficient of synchrotron radiation of mildly relativistic particles with an arbitrary energy spectrum and pitch angle distribution. From these, an expression for the degree of polarization is derived. The analytic results are compared with numerical results for both thermal and non-thermal (power law) distributions of particles.

  2. Effects of pharmacological fiber supplements on levothyroxine absorption.

    PubMed

    Chiu, A C; Sherman, S I

    1998-08-01

    To determine the effect of pharmacological fiber supplements, we measured levothyroxine (LT4) absorption without and with simultaneous ingestion of either calcium polycarbophil or psyllium hydrophilic mucilloid. Serum thyroxine (T4) levels in 8 volunteers were measured following ingestion of 600 microg of LT4 on 3 separate occasions at 4-week intervals: (1) LT4 alone; (2) LT4 together with 1000 mg polycarbophil; and (3) LT4 together with 3.4 g psyllium. The amount of absorbed LT4 was calculated as the incremental rise in serum T4 level during the first 6 hours multiplied by the volume of distribution for the hormone, and expressed as a percentage of the dose administered. Absorption of LT4 alone averaged 89% (95% confidence interval [CI]: 75%-104%), occurring at a median of 180 minutes. After simultaneous ingestion of calcium polycarbophil, LT4 absorption was 86% (95% CI: 74%-97%), occurring at 180 minutes. With simultaneous ingestion of psyllium and LT4, the absorption was 80% (95% CI: 64%-95%), occurring at 240 minutes. In summary, neither calcium polycarbophil nor psyllium hydrophilic mucilloid are likely to cause malabsorption of LT4 that could be detected by these methods.

  3. Absorption of ac fields in amorphous indium-oxide films

    SciTech Connect

    Ovadyahu, Z.

    2014-08-20

    Absorption data from applied ac fields in Anderson-localized amorphous indium-oxide (In{sub x}O) films are shown to be frequency and disorder dependent. The absorption shows a roll-off at a frequency which is much lower than the electron-electron scattering rate of the material when it is in the diffusive regime. This is interpreted as evidence for discreteness of the energy spectrum of the deeply localized regime. This is consistent with recent many-body localization scenarios. As the metal-insulator transition is approached, the absorption shifts to higher frequencies. Comparing with the previously obtained results on the crystalline version of indium-oxide (In{sub 2}O{sub 3−x}) implies a considerably higher inelastic electron-phonon scattering rate in the amorphous material. The range over which the absorption versus frequency decreases may indicate that a wide distribution of localization length is a common feature in these systems.

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

    SciTech Connect

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

    1984-10-01

    Root absorption characteristics for the pertechnetate ion (TcO/sub 4//sup -/) were determined using hydroponically grown soybean seedlings (Glycine max, cv. Williams). Absorption of TcO/sub 4//sup -/ was found to be linear with time, sensitive to metabolic inhibitors, and exhibit multiple absorption isotherms over the concentration range 0.02 to 10 ..mu..M. The isotherms had calculated K/sub s/ values of 0.09, 8.9, and 54 ..mu..M for intact seedlings. The uptake of TcO/sub 4//sup -/ (0.25 ..mu..M) 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/sub 4//sup -/ absorption. Once absorbed, Tc was readily transported as TcO/sub 4//sup -/ 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. Diagnostic potential of cosmic-neutrino absorption spectroscopy

    SciTech Connect

    Barenboim, Gabriela; Mena Requejo, Olga; Quigg, Chris; /Fermilab

    2004-12-01

    Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino background can give rise to absorption lines at energies corresponding to formation of the electroweak gauge boson Z{sup 0}. The positions of the absorption dips are set by the masses of the relic neutrinos. Suitably intense sources of extremely energetic (10{sup 21} - 10{sup 25}-eV) cosmic neutrinos might therefore enable the determination of the absolute neutrino masses and the flavor composition of the mass eigenstates. Several factors--other than neutrino mass and composition--distort the absorption lines, however. We analyze the influence of the time-evolution of the relic-neutrino density and the consequences of neutrino decay. We consider the sensitivity of the lineshape to the age and character of extremely energetic neutrino sources, and to the thermal history of the Universe, reflected in the expansion rate. We take into account Fermi motion arising from the thermal distribution of the relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics, and briefly consider unconventional neutrino histories. We ask what kinds of external information would enhance the potential of cosmic-neutrino absorption spectroscopy, and estimate the sensitivity required to make the technique a reality.

  6. Photonic band-edge-induced enhancement in absorption and emission

    NASA Astrophysics Data System (ADS)

    Ummer, Karikkuzhi Variyath; Vijaya, Ramarao

    2015-01-01

    An enhancement in photonic band-edge-induced absorption and emission from rhodamine-B dye doped polystyrene pseudo gap photonic crystals is studied. The band-edge-induced enhancement in absorption is achieved by selecting the incident angle of the excitation beam so that the absorption spectrum of the emitter overlaps the photonic band edge. The band-edge-induced enhancement in emission, on the other hand, is possible with and without an enhancement in band-edge-induced absorption, depending on the collection angle of emission. Through a simple set of measurements with suitably chosen angles for excitation and emission, we achieve a maximum enhancement of 70% in emission intensity with band-edge-induced effects over and above the intrinsic emission in the case of self-assembled opals. This is a comprehensive effort to interpret tunable lasing in opals as well as to predict the wavelength of lasing arising as a result of band-edge-induced distributed feedback effects.

  7. Light Absorption of Biogenic Aerosol Particles in Amazonia

    NASA Astrophysics Data System (ADS)

    Holanda, B. A.; Artaxo, P.; Ferreira De Brito, J.; Barbosa, H. M.; Andreae, M. O.; Saturno, J.; Pöhlker, C.; Holben, B. N.; Schafer, J.

    2014-12-01

    Aerosol absorption is a key issue in proper calculation of aerosol radiative forcing. Especially in the tropics with the dominance of natural biogenic aerosol and brown carbon, the so called anomalous absorption is of particular interest. A special experiment was designed to study the wavelength dependence of aerosol absorption for PM2.5 as well as for PM10 particles in the wet season in Central Amazonia. Aerosol analysis occurred from May to August 2014, in the ZF2 ecological reservation, situated at about 55 km North of Manaus in very pristine conditions Two 7 wavelengths AE33 Aethalometers were deployed measuring in parallel, but with a PM2.5 and PM10 inlets. Two MAAP (Multiangle Aerosol Absorption Photometer) were operated in parallel with the AE33 exactly at the same PM2.5 and PM10 inlets. Organic and elemental carbon was analyzed using collection with quartz filters and analysis using a Sunset OC/EC analyzer. Aerosol light scattering for 3 wavelengths was measured using Air Photon and TSI Nephelometers. Aerosol size distribution was measured with one TSI SMPS and a GRIMM OPC to have the size range from 10 nm to 10 micrometers. Particles were measured under dry conditions using diffusion dryers. Aerosol optical depth and absorption was also measured with an AERONET sunphotometer operated close to the site. As the experiment was run in the wet season, very low equivalent black carbon (EBC) were measured, with average concentrations around 50 ng/m³ during May, increasing to 130 ng/m³ in June and July. The measurements adjusted for similar wavelengths shows excellent agreement between the MAAP and AE33 for both inlets (PM2.5 and PM10). It was not possible statistically infer absorption from the coarse mode biogenic particles, since the absorption was completely dominated by fine mode particles. AERONET measurements shows very low values of AOD, at 0.17 at 500 nm and 0.13 at 870 nm, with very low absorption AOD values at 0.00086 at 676 nm and 0.0068 at 872 nm

  8. Fraunhofer effect atomic absorption spectrometry.

    PubMed

    Rust, Jennifer A; Nóbrega, Joaquim A; Calloway, Clifton P; Jones, Bradley T

    2005-02-15

    The dark lines in the solar spectrum were discovered by Wollaston and cataloged by Fraunhofer in the early days of the 19th century. Some years later, Kirchhoff explained the appearance of the dark lines: the sun was acting as a continuum light source and metals in the ground state in its atmosphere were absorbing characteristic narrow regions of the spectrum. This discovery eventually spawned atomic absorption spectrometry, which became a routine technique for chemical analysis in the mid-20th century. Laboratory-based atomic absorption spectrometers differ from the original observation of the Fraunhofer lines because they have always employed a separate light source and atomizer. This article describes a novel atomic absorption device that employs a single source, the tungsten coil, as both the generator of continuum radiation and the atomizer of the analytes. A 25-microL aliquot of sample is placed on the tungsten filament removed from a commercially available 150-W light bulb. The solution is dried and ashed by applying low currents to the coil in a three-step procedure. Full power is then applied to the coil for a brief period. During this time, the coil produces white light, which may be absorbed by any metals present in the atomization cloud produced by the sample. A high-resolution spectrometer with a charge-coupled device detector monitors the emission spectrum of the coil, which includes the dark lines from the metals. Detection limits are reported for seven elements: 5 pg of Ca (422.7 nm); 2 ng of Co (352.7 nm); 200 pg of Cr (425.4 nm); 7 pg of Sr (460.7 nm); 100 pg of Yb (398.8 nm); 500 pg of Mn (403.1 nm); and 500 pg of K (404.4 nm). Simultaneous multielement analyses are possible within a 4-nm spectral window. The relative standard deviations for the seven metals are below 8% for all metals except for Ca (10.7%), which was present in the blank at measurable levels. Analysis of a standard reference material (drinking water) resulted in a mean percent

  9. Effects of dietary salt on adrenomedullin and its receptor mRNAs in rat kidney.

    PubMed

    Jensen, B L; Gambaryan, S; Schmaus, E; Kurtz, A

    1998-07-01

    There is accumulating evidence that adrenomedullin (ADM) is involved in the control of salt and water homeostasis. ADM is considered to act primarily in a paracrine fashion, and since the kidneys are target organs for ADM, we investigated the localization and regulation of ADM and ADM receptor (ADM-R) mRNAs in the kidney. mRNAs for ADM and ADM-R were colocalized in renal vessels, glomeruli, and inner medullary collecting ducts. ADM mRNA was also detected in proximal tubules, whereas ADM-R mRNA was found in distal convoluted tubules. By ribonuclease protection assay, the abundance of ADM mRNA was fourfold higher in cortex than in outer medulla and papilla. In isolated glomeruli, ADM mRNA was threefold higher compared with cortex. Conversely, ADM-R mRNA was fourfold higher in papilla than in renal cortex. This distribution of mRNAs for ADM and ADM-R suggests a cortical source of ADM and a preferential action of ADM in the papilla. Ten days of feeding a low-salt (0.02%) or a high-salt diet (4%) did not change ADM mRNA or ADM-R mRNA in any kidney zone.

  10. HI Absorption in Merger Remnants

    NASA Technical Reports Server (NTRS)

    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.

  11. Computer programs for absorption spectrophotometry.

    PubMed

    Jones, R N

    1969-03-01

    Brief descriptions are given of twenty-two modular computer programs for performing the basic numerical computations of absorption spectrophotometry. The programs, written in Fortran IV for card input and output, are available from the National Research Council of Canada. The input and output formats are standardized to permit easy interfacing to yield more complex data processing systems. Though these programs were developed for ir spectrophotometry, they are readily modified for use with digitized visual and uv spectrophotometers. The operations covered include ordinate and abscissal unit and scale interconversions, ordinate addition and subtraction, location of band maxima and minima, smoothing and differentiation, slit function convolution and deconvolution, band profile analysis and asymmetry quantification, Fourier transformation to time correlation curves, multiple overlapping band separation in terms of Cauchy (Lorentz), Gauss, Cauchy-Gauss product, and Cauchy-Gauss sum functions and cell path length determination from fringe spacing analysis. PMID:20072266

  12. Quantum-enhanced absorption refrigerators

    NASA Astrophysics Data System (ADS)

    Correa, Luis A.; Palao, José P.; Alonso, Daniel; Adesso, Gerardo

    2014-02-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

  13. Multistage quantum absorption heat pumps.

    PubMed

    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.

  14. Acoustic Absorption in Porous Materials

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.; Johnston, James C.

    2011-01-01

    An understanding of both the areas of materials science and acoustics is necessary to successfully develop materials for acoustic absorption applications. This paper presents the basic knowledge and approaches for determining the acoustic performance of porous materials in a manner that will help materials researchers new to this area gain the understanding and skills necessary to make meaningful contributions to this field of study. Beginning with the basics and making as few assumptions as possible, this paper reviews relevant topics in the acoustic performance of porous materials, which are often used to make acoustic bulk absorbers, moving from the physics of sound wave interactions with porous materials to measurement techniques for flow resistivity, characteristic impedance, and wavenumber.

  15. Backscatter absorption gas imaging system

    DOEpatents

    McRae, T.G. Jr.

    A video imaging system for detecting hazardous gas leaks. Visual displays of invisible gas clouds are produced by radiation augmentation of the field of view of an imaging device by radiation corresponding to an absorption line of the gas to be detected. The field of view of an imager is irradiated by a laser. The imager receives both backscattered laser light and background radiation. When a detectable gas is present, the backscattered laser light is highly attenuated, producing a region of contrast or shadow on the image. A flying spot imaging system is utilized to synchronously irradiate and scan the area to lower laser power requirements. The imager signal is processed to produce a video display.

  16. Backscatter absorption gas imaging system

    DOEpatents

    McRae, Jr., Thomas G.

    1985-01-01

    A video imaging system for detecting hazardous gas leaks. Visual displays of invisible gas clouds are produced by radiation augmentation of the field of view of an imaging device by radiation corresponding to an absorption line of the gas to be detected. The field of view of an imager is irradiated by a laser. The imager receives both backscattered laser light and background radiation. When a detectable gas is present, the backscattered laser light is highly attenuated, producing a region of contrast or shadow on the image. A flying spot imaging system is utilized to synchronously irradiate and scan the area to lower laser power requirements. The imager signal is processed to produce a video display.

  17. Transient simulation of absorption machines

    NASA Astrophysics Data System (ADS)

    Anand, D. K.; Allen, R. W.; Kumar, B.

    A model for a water-cooled Lithium-Bromide/water absorption chiller is presented. Its transient response both during the start-up phase and during the shut-off period is predicted. The simulation model incorporates such influencing factors as the thermodynamic properties of the working fluid, the absorbent, the heat-transfer configuration of different components of the chiller and related physical data. The time constants of different components are controlled by a set of key parameters that have been identified. The results show a variable but at times significant amount of time delay before the chiller capacity gets close to its steady-state value. The model is intended to provide an insight into the mechanism of build-up to steady-state performance. By recognizing the significant factors contributing to transient degradation, steps can be taken to reduce such degradation.

  18. Quantum-enhanced absorption refrigerators.

    PubMed

    Correa, Luis A; Palao, José P; Alonso, Daniel; Adesso, Gerardo

    2014-01-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

  19. Olefin recovery via chemical absorption

    SciTech Connect

    Barchas, R.

    1998-06-01

    The recovery of fight olefins in petrochemical plants has generally been accomplished through cryogenic distillation, a process which is very capital and energy intensive. In an effort to simplify the recovery process and reduce its cost, BP Chemicals has developed a chemical absorption technology based on an aqueous silver nitrate solution. Stone & Webster is now marketing, licensing, and engineering the technology. The process is commercially ready for recovering olefins from olefin derivative plant vent gases, such as vents from polyethylene, polypropylene, ethylene oxide, and synthetic ethanol units. The process can also be used to debottleneck C{sub 2} or C{sub 3} splinters, or to improve olefin product purity. This paper presents the olefin recovery imp technology, discusses its applications, and presents economics for the recovery of ethylene and propylene.

  20. Neutron scattering and absorption properties

    SciTech Connect

    Holden, N.E.

    1993-12-01

    The Table in this report presents an evaluated set of values for the experimental quantities, which characterize the properties for scattering and absorption of neutrons. The neutron cross section is given for room temperature neutrons, 20.43{degree}C, corresponds to a thermal neutron energy of 0.0253 electron volts (eV) or a neutron velocity of 2200 meters/second. The neutron resonance integral is defined over the energy range from 0.5 eV to 0.1 {times} 10{sup 6} eV, or 0.1 MeV. A list of the major references used is given below. The literature cutoff data is October 1993. Uncertainties are given in parentheses. Parentheses with two or more numbers indicate values to the excited states(s) and to the ground state of the product nucleus.

  1. Graphene intracavity spaser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Lozovik, Yu. E.; Nechepurenko, I. A.; Dorofeenko, A. V.

    2016-09-01

    We propose an intracavity plasmon absorption spectroscopy method based on graphene active plasmonics. It is shown that the plasmonic cavity contribution to the sensitivity is proportional to the quality factor Q of the graphene plasmonic cavity and reaches two orders of magnitude. The addition of gain medium into the cavity increases the sensitivity of method. Maximum sensitivity is reached in the vicinity of the plasmon generation threshold. The gain contribution to the sensitivity is proportional to Q1/2. The giant amplification of sensitivity in the graphene plasmon generator is associated with a huge path length, limited only by the decoherence processes. An analytical estimation of the sensitivity to loss caused by analyzed particles (molecules, nanoparticles, etc.) normalized by the single pass plasmon scheme is derived. Usage of graphene nanoflakes as plasmonic cavity allows a high spatial resolution to be reached, in addition to high sensitivity.

  2. Energy absorption by polymer crazing

    NASA Technical Reports Server (NTRS)

    Pang, S. S.; Zhang, Z. D.; Chern, S. S.; Hsiao, C. C.

    1983-01-01

    During the past thirty years, a tremendous amount of research was done on the development of crazing in polymers. The phenomenon of crazing was recognized as an unusual deformation behavior associated with a process of molecular orientation in a solid to resist failure. The craze absorbs a fairly large amount of energy during the crazing process. When a craze does occur the surrounding bulk material is usually stretched to several hundred percent of its original dimension and creates a new phase. The total energy absorbed by a craze during the crazing process in creep was calculated analytically with the help of some experimental measurements. A comparison of the energy absorption by the new phase and that by the original bulk uncrazed medium is made.

  3. Absorption Changes in Bacterial Chromatophores

    PubMed Central

    Kuntz, Irwin D.; Loach, Paul A.; Calvin, Melvin

    1964-01-01

    The magnitude and kinetics of photo-induced absorption changes in bacterial chromatophores (R. rubrum, R. spheroides and Chromatium) have been studied as a function of potential, established by added redox couples. No photochanges can be observed above +0.55 v or below -0.15 v. The loss of signal at the higher potential is centered at +0.439 v and follows a one-electron change. The loss of signal at the lower potential is centered at -0.044 v and is also consistent with a one-electron change. Both losses are reversible. A quantitative relationship exists between light-minus-dark and oxidized-minus-reduced spectra in the near infrared from +0.30 to +0.55 v. Selective treatment of the chromatophores with strong oxidants irreversibly bleaches the bulk pigments but appears to leave intact those pigments responsible for the photo- and chemically-induced absorption changes. Kinetic studies of the photochanges in deaerated samples of R. rubrum chromatophores revealed the same rise time for bands at 433, 792, and 865 mμ (t½ = 50 msec.). However, these bands had different decay rates (t½ = 1.5, 0.5, 0.15 sec., respectively), indicating that they belong to different pigments. Analysis of the data indicates, as the simplest interpretation, a first-order (or pseudo first-order) forward reaction and two parallel first-order (or pseudo first-order) decay reactions at each wavelength. These results imply that all pigments whose kinetics are given are photooxidized and the decay processes are dark reductions. These experiments are viewed as supporting and extending the concept of a bacterial photosynthetic unit, with energy migration within it to specific sites of electron transfer. PMID:14185583

  4. Modelling of metal vapour in pulsed TIG including influence of self-absorption

    NASA Astrophysics Data System (ADS)

    Iwao, Toru; Mori, Yusuke; Okubo, Masato; Sakai, Tadashi; Tashiro, Shinichi; Tanaka, Manabu; Yumoto, Motoshige

    2010-11-01

    Pulsed TIG (tungsten inert gas) welding is used to improve the stability and speed of arc welding, and to allow greater control over the heat input to the weld. The temperature and the radiation power density of the pulsed arc vary as a function of time, as does the distribution of metal vapour, and its effects on the arc. A self-consistent two-dimensional model of the arc and electrodes is used to calculate the properties of the arc as a function of time. Self-absorption of radiation is treated by two methods, one taking into account absorption of radiation only within the control volume of emission, and the other taking into account absorption throughout the plasma. The relation between metal vapour and radiation power density is analysed by calculating the iron vapour distribution. The results show that the transport of iron vapour is strongly affected by the fast convective flow during the peak current period. During the base current period, the region containing a low concentration of metal vapour expands because of the low convective flow. The iron vapour distribution does not closely follow the current pulses. The temperature, iron vapour and radiation power density distributions depend on the self-absorption model used. The temperature distribution becomes broader when self-absorption of radiation from all directions is considered.

  5. Run-and-tumble particles, telegrapher’s equation and absorption problems with partially reflecting boundaries

    NASA Astrophysics Data System (ADS)

    Angelani, Luca

    2015-12-01

    Absorption problems of run-and-tumble particles, described by the telegrapher's equation, are analyzed in one space dimension considering partially reflecting boundaries. Exact expressions for the probability distribution function in the Laplace domain and for the mean time to absorption are given, discussing some interesting limits (Brownian and wave limit, large volume limit) and different case studies (semi-infinite segment, equal and symmetric boundaries, totally/partially reflecting boundaries).

  6. Inhibitory effect of nuts on iron absorption.

    PubMed

    Macfarlane, B J; Bezwoda, W R; Bothwell, T H; Baynes, R D; Bothwell, J E; MacPhail, A P; Lamparelli, R D; Mayet, F

    1988-02-01

    The effects on iron absorption of nuts, an important source of dietary protein in many developing countries, were measured in 137 Indian women. When the absorption from bread and nut meals (walnuts, almonds, peanuts, and hazelnuts) was compared with that from bread meals, the overall geometric mean absorption from the nut meals (1.8%) was significantly less than from the bread meals alone (6.6%, t = 9.8, p less than 0.0005). In contrast, coconut did not reduce absorption significantly. All the nuts tested contained significant amounts of two known inhibitors of Fe absorption (phytates and polyphenols) but the amounts in coconut were significantly less than in the other nuts. Fifty milligrams ascorbic acid overcame the inhibitory effects of two nuts that were tested (Brazil nuts and peanuts). This is different from that found previously for soy protein, another potent inhibitor of Fe absorption.

  7. Accidental death via intravaginal absorption of methamphetamine.

    PubMed

    Jones, Prentiss; Mutsvunguma, Romeo; Prahlow, Joseph A

    2014-06-01

    In this paper a drug fatality that involved an unintended drug delivery route is described. The decedent, a 23-year-old female in custody in a county jail on suspicion of a felony drug offense, was discovered in a holding cell unconscious and unresponsive. Following unsuccessful cardiopulmonary resuscitation attempts she was pronounced dead at the scene. At autopsy a wad of multiple small loosely wrapped plastic packages held together with another layer of clear plastic was found in the decedent's vagina. The smaller plastic packages contained an off-white pasty substance that was later identified as methamphetamine. Toxicological testing of specimens collected during autopsy revealed methamphetamine in the decedent's subclavian blood, vitreous fluid, and urine at extremely high concentrations (42.6, 20.1, and 771 mg/L, respectively). Amphetamine, the active metabolite of methamphetamine, was also present in the subclavian blood, vitreous fluid, and urine at significant concentrations (1.3, 0.5, and 20.4 mg/L, respectively). The cause of death was attributed to toxic effects of methamphetamine and the manner of death was ruled accidental. This report suggests that lethal concentrations of methamphetamine may be distributed to the systemic circulation via intravaginal absorption.

  8. Effective photons in weakly absorptive dielectric media and the Beer-Lambert-Bouguer law

    NASA Astrophysics Data System (ADS)

    Judge, A. C.; Brownless, J. S.; Bhat, N. A. R.; Sipe, J. E.; Steel, M. J.; de Sterke, C. Martijn

    2014-04-01

    We derive effective photon modes that facilitate an intuitive and convenient picture of photon dynamics in a structured Kramers-Kronig dielectric in the limit of weak absorption. Each mode is associated with a mode field distribution that includes the effects of both material and structural dispersion, and an effective line-width that determines the temporal decay rate of the photon. These results are then applied to obtain an expression for the Beer-Lambert-Bouguer law absorption coefficient for unidirectional propagation in structured media consisting of dispersive, weakly absorptive dielectric materials.

  9. Saturable and Reverse Saturable Absorption in Nanocomposite Films of Naphthol Green B Dye-polymer System

    NASA Astrophysics Data System (ADS)

    Devi, S. Maya; Sreeja, S.; Frobel, P. G. Louie; Suresh, S. R.; Muneera, C. I.

    2011-10-01

    Naphthol Green B dye-polyvinyl alcohol composite films were fabricated and their nonlinear absorption properties were investigated using the Z-scan technique under excitation with 5ns laser light pulses at 532 nm. The samples displayed a switchover from saturable absorption to reverse saturable absorption with increase in either intensity or concentration. The measured values of β and IS were found to be of the order of 10-7 cm/W and 109 W/cm2 respectively. The atomic force microscopic analysis of the composite films revealed homogeneous distribution of aggregated nanoclusters marked by a low average surface roughness ≈1.8 nm.

  10. Holographic volume absorption grating in glass-like polymer recording material.

    PubMed

    Matusevich, V; Matusevich, A; Kowarschik, R; Matusevich, Yu I; Krul, L P

    2008-02-01

    We investigated the contribution of the absorption and phase gratings to the total diffraction efficiency of volume holographic gratings written in glass-like polymer recording materials based on poly(methyl methacrylate) and its thermostable derivative (copolymer with acrylic acid) with distributed phenanthrenequinone. The typical maximal diffraction efficiency was 0.5%-2.0% for the absorption grating and 22-32% for the phase grating. The modulation of the absorption coefficient varied between 10 cm(-1) and 100 cm(-1) and the modulation of the refractive index was about 10(-4)-10(-3).

  11. Absorption bands in the spectrum of Io

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Jones, T. J.; Pilcher, C. B.

    1978-01-01

    Near-infrared spectra of Io in the region from 2.8 to 4.2 microns are reported which show distinct absorption features, the most notable at 4.1 microns. Frozen volatiles or atmospheric gases cannot account for these absorptions, nor do they resemble those seen in common silicate rocks. Several candidate substances, most notably nitrate and carbonate salts, show absorption features in this spectral region; the deepest band in the spectrum may be a nitrate absorption. The satellite surface is shown to be anhydrous, as indicated by the absence of the 3-micron bound water band.

  12. Neural regulation of intestinal nutrient absorption.

    PubMed

    Mourad, Fadi H; Saadé, Nayef E

    2011-10-01

    The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.

  13. Impact of MIE-Resonances on the Atmospheric Absorption of Water Clouds

    NASA Technical Reports Server (NTRS)

    Wiscombe, W.; Kinne, S.; Nussenzveig, H.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Clouds strongly modulate radiative transfer processes in the Earth's atmosphere. Studies, which simulate bulk properties of clouds, such as absorption, require methods that accurately account for multiple scattering among individual cloud particles. Multiple scattering processes are well described by MIE-theory, if interacting particles have a spherical shape. This is a good assumption for water droplets. Thus, simulations for water clouds (especially for interactions with solar radiation) usually apply readily available MIE-codes. The presence of different drop-sizes, however, necessitates repetitive calculations for many sizes. The usual representation by a few sizes is likely to miss contributions from densely distributed, sharp resonances. Despite their usually narrow width, integrated over the entire size-spectrum of a cloud droplet distribution, the impact of missed resonances could add up. The consideration of these resonances tends to increase cloud extinction and cloud absorption. This mechanism for a larger (than by MIE-methods predicted) solar absorption has the potential to explain observational evidence of larger than predicted cloud absorption at solar wavelengths. The presentation will address the absorption impact of added resonances for typical properties of water clouds (e.g. drop size distributions, drop concentrations and cloud geometry). Special attention will be given to scenarios with observational evidence of law than simulated solar absorption; particularly if simultaneous measurements of cloud micro- and macrophysical properties are available.

  14. Drug absorption in gastrointestinal disease and surgery. Clinical pharmacokinetic and therapeutic implications.

    PubMed

    Gubbins, P O; Bertch, K E

    1991-12-01

    Drug absorption from the gastrointestinal (GI) tract and the impact of GI surgery and disease on drug absorption are discussed. Recommendations are made to manage problems of drug malabsorption. Absorption from the GI tract is a first-order process described by its rate and extent. GI surgery changes the anatomy of the GI tract and alters important variables in the absorption process. In the wake of procedures which diminish small bowel surface area, the extent of absorption of phenytoin, digoxin, cyclosporin, aciclovir, hydrochlorothiazide and certain oral contraceptives is reported to be reduced. The underlying cause of the reduction is unknown. When gastric emptying time or pH are altered by surgery, the rate of drug absorption appears to be reduced. However, it is not clear which variable is more important in determining therapeutic effects. The effects of coeliac and inflammatory bowel diseases on the distribution and clearance of drugs must be considered before attributing abnormal serum concentrations of drugs to malabsorption. GI disease may slow gastric emptying and delay the complete absorption of drugs when their rate of absorption depends on gastric emptying time. Other inflammatory GI diseases such as graft-versus-host disease (GVHD) of the gut, Behçet's syndrome and scleroderma involving the GI tract may directly reduce absorption of drugs such as cyclosporin, amitriptyline, benzodiazepines, anticonvulsants, paracetamol (acetaminophen) and penicillamine. GI diseases which alter gut pH affect the absorption only of drugs with limited water solubility and pH-dependent dissolution such as ketoconazole. Clinicians should be aware of the variable absorption seen after GI disease and surgery and monitor their patients accordingly. PMID:1782738

  15. A four compartment open model with first-order absorption.

    PubMed

    Cherruault, Y; Sarin, V B

    1993-03-01

    This paper is related to the identification of pharmacokinetic parameters of a four-compartment open model with first order absorption from plasma level data. The eigenvalues of the characteristic matrix of the given system are obtained by transforming them into a single variable and the solution involves the minimization of the sum of squares of deviation of the model-predicted values of the state variables from an experimentally obtained values. The distribution volume and the lag time are also identified. Finally, the unicity of the absorption rate constant is obtained by the minimum energy principle. The results obtained with present method are compared with those obtained by the generalized least squares method.

  16. Absorption of femtosecond laser pulses in interaction with solid targets.

    PubMed

    Dong, Q L; Zhang, J; Teng, H

    2001-08-01

    We have studied the effects of the plasma density scale length on the absorption mechanism of the femtosecond (fs) laser pulses interacting with solid targets. Experiments and particle-in-cell (PIC) simulations demonstrate that the vacuum heating is the main absorption in the plasma in the interaction of fs laser pulses with solid targets when no prepulses are applied. The energy spectrum of hot electrons ejected out of or injected into the plasma show a bitemperature distribution. While the first temperature of the two groups of hot electrons can be attributed to the "pull-and-push" exertion of the laser field, the second temperature refers to the electrons accelerated by the static part (in front of the target) and the oscillating part (in the plasma layer) of the laser-induced electric field, respectively. PIC simulations also show that with an appropriate density scale length, the femtosecond laser energy can be absorbed locally through different mechanisms.

  17. Absorption-assisted mode transformation in butterfly compound eyes.

    PubMed

    Kim, Jaeyoun

    2014-01-01

    The ommatidium of the butterfly's afocal apposition eye exhibits angular performance that can only be achieved by transforming the diffraction pattern of its corneal lens into the fundamental mode of its rhabdom waveguide. A graded index model of the ommatidium has been proposed and verified but the efforts to extract the transformation's underlying physics from it have been hindered by its extreme complexity. Here we numerically investigate the ommatidium model and reveal that the current model, involving only the graded index distribution, is insufficient for the transformation. We further find that adding spatially varying absorption to the existing model dramatically improves its transformation performance, producing near-perfect mode matching with overlap integral exceeding 0.96. Such a combined action of spatially varying index and absorption for microscale mode transformation is new to researchers in optics and biology and will benefit both disciplines. PMID:25189377

  18. Ultra-Short Laser Absorption In Solid Targets

    SciTech Connect

    Harfouche, A.; Bendib, A.

    2008-09-23

    With the rapid development and continuously improving technology of subpicosecond laser pulse generation, new interesting physical problems are now investigated. Among them the laser light absorption in solid targets. During the interaction with solid targets, high intensity laser pulses are absorbed by electrons in optical skin depths, leading to rapid ionization before that significant ablation of solid material takes place. The ultra-short laser is absorbed in the overdense plasma through the electron-ion collisions (normal skin effect) or collisionless mechanisms (anomalous skin effect or sheath inverse bremsstrahlung). These two regimes depend on the laser intensity, the plasma temperature and the ionization state Z. In this work we solve numerically the Fokker-Planck equation to compute the electron distribution function in the skin layer. In the second step we compute the surface impedance and we deduce the absorption coefficient.

  19. Mapping of tritium emissions using absorption vapour samplers.

    PubMed

    Vodila, Gergely; Molnár, Mihály; Veres, Mihály; Svingor, Eva; Futó, István; Barnabás, István; Kapitány, Sándor

    2009-02-01

    Püspökszilágy Radioactive Waste Treatment and Disposal Facility (RWTDF) is a typical near-surface engineered repository designated to store low- and intermediate-level wastes from various institutes, research facilities and hospitals in Hungary. Two automatic combined (14)C-tritium sampling units installed at the facility sample the air 2 m above surface. The one installed near the vaults detects tritium (T) activities two orders of magnitude higher than the far reference sampling unit. To localize the T emissions, 19 small absorption vapour samplers filled with silica gel were settled onto the ground surface. After the saturation of the silica gel, the water was recovered and its T concentration was measured with a low-background liquid scintillation counter. The absorption vapour samplers are cheap, simple and easy-to-use. We present the samplers and the T distribution map constructed from the data, which helps to localize the T emission. PMID:19027205

  20. Energy absorption in cold inhomogeneous plasmas - The Herlofson paradox.

    NASA Technical Reports Server (NTRS)

    Crawford, F. W.; Harker, K. J.

    1972-01-01

    Confirmation of Barston's (1964) conclusions regarding the underlying mechanism of the Herlofson paradox by examining in detail several analytically tractable cases of delta-function and sinusoidal excitation. The effects of collisions and nonzero electron temperature in determining the steady state fields and dissipation are considered. Energy absorption without dissipation in plasmas is shown to be analogous to that occurring after application of a signal to a network of lossless resonant circuits. This analogy is pursued and is extended to cover Landau damping in a warm homogeneous plasma in which the resonating elements are the electron streams making up the velocity distribution. Some of the practical consequences of resonant absorption are discussed, together with a number of paradoxical plasma phenomena which can also be elucidated by considering a superposition of normal modes rather than a single Fourier component.

  1. Constraining the topology of reionization through Lyα absorption

    NASA Astrophysics Data System (ADS)

    Furlanetto, S. R.; Hernquist, L.; Zaldarriaga, M.

    2004-11-01

    The reionization of hydrogen in the intergalactic medium (IGM) is a crucial landmark in the history of the Universe, but the processes through which it occurs remain mysterious. In particular, recent numerical and analytic work suggest that reionization by stellar sources is driven by large-scale density fluctuations and must be inhomogeneous on scales of many comoving Mpc. We examine the prospects for constraining the topology of neutral and ionized gas through Lyα absorption of high-redshift sources. One method is to search for gaps in the Gunn-Peterson absorption troughs of luminous sources. These could occur if the line of sight passes sufficiently close to the centre of a large HII region. In contrast to previous work, we find a non-negligible (though still small) probability of observing such a gap before reionization is complete. In our model the transmission spike at z= 6.08 in the spectrum of SDSS J1148+5251 does not necessarily require overlap to have been completed at an earlier epoch. We also examine the IGM damping wing absorption of the Lyα emission lines of star-forming galaxies. Because most galaxies sit inside of large HII regions, we find that the severity of absorption is significantly smaller than previously thought and decoupled from the properties of the observed galaxy. While this limits our ability to constrain the mean neutral fraction of the IGM from observations of individual galaxies, it presents the exciting possibility of measuring the size distribution and evolution of the ionized bubbles by examining the distribution of damping wing optical depths in a large sample of galaxies.

  2. The First HeI* 10830 Broad Absorption Line Quasar

    NASA Astrophysics Data System (ADS)

    Leighly, Karen; Dietrich, M.; Barber, S.

    2010-03-01

    We report discovery of the first metastable HeI* broad absorption line quasar using SpeX on IRTF. The blue-shifted absorption profile extends in velocity space from about -1,000 to -11,000 km/s, and it shows considerable velocity structure of the order of 1,000 km/s. The maximum apparent optical depth is 0.6. Integration over the 10830 apparent optical depth profile yields a lower limit on the log HeI* column density of >14.3. Absorption is also seen in the HeI* λ3888Å line in optical spectra from SDSS and the MDM Hiltner telescope. These two transitions have the same lower level; thus, the covering fraction and optical depth can be determined. A pure partial covering model yields log HeI* column of 15.5-15.7, while a power law absorption distribution yields 16.1. These column densities are significantly larger than the lower limit because of the high ratio of the product of the wavelength and the oscillator strength (23.3). This property, plus the relatively low densities of HeI* in ionized gas, makes HeI* absorption a valuable probe of high column densities. Cloudy simulations were performed to investigate the nature of the absorber. The HeI* column density yielded a lower limit on the log ionization parameter of -0.2 and a corresponding lower limit on the log hydrogen column density of 23. The latter value is at least an order of magnitude larger than those generally obtained from BALQSOs with spectra amenable to partial covering analysis. The lack of Balmer absorption provided an upper limit on the log density of 7. The log kinetic luminosity was constrained to be between 46 and 48, corresponding to at least 0.3% to a large fraction of the bolometric luminosity. A proposed Suzaku observation may remove model degeneracy between the spectral energy distribution and ionization parameter. This work is funded by NSF AST-0707703.

  3. Quasilinear analysis of absorption of ion Bernstein waves by electrons

    SciTech Connect

    Cardinali, A.; Paoletti, F.; Bernabei, S.; Ono, M.

    1995-01-01

    The effects induced on plasma electrons by an externally launched ion Bernstein wave (IBW), in the presence of a lower hybrid wave (LHW) in the current drive regime, are studied by analytical integration of the IBW ray-tracing equations along with the amplitude transport equation (Poynting theorem). The electric field amplitude parallel and perpendicular to the external magnetic field, the quasilinear diffusion coefficient, and the modified electron distribution function are analytically calculated in the case of IBW. The analytical calculation is compared to the numerical solution obtained by using a 2-D Fokker-Planck code for the distribution function, without any approximation for the collision operator. The synergy between the IBW and LHW can be accounted for, and the absorption of the IBW power when the electron distribution function presents a tail generated by the LHW in the current drive regime can be calculated.

  4. Quasilinear analysis of absorption of ion Bernstein waves by electrons

    SciTech Connect

    Cardinali, A.; Paoletti, F.; Bernabei, S.; Ono, M.

    1995-05-01

    The effects induced on plasma electrons by an externally launched ion Bernstein wave (IBW), in the presence of a lower hybrid wave (LHW) in the current drive regime, are studied by analytical integration of the IBW ray-tracing equations, along with the amplitude transport equation (Poynting theorem). The electric field amplitude parallel and perpendicular to the external magnetic field, the quasilinear diffusion coefficient, and the modified electron distribution function are analytically calculated in the case of IBW. The analytical calculation is compared to the numerical solution obtained by using a two-dimensional (2-D) Fokker--Planck code for the distribution function, without any approximation for the collision operator. The synergy between the IBW and LHW can be accounted for, and the absorption of the IBW power when the electron distribution function presents a tail generated by the LHW in the current drive regime can be calculated.

  5. On the Ammonia Absorption on Saturn

    NASA Astrophysics Data System (ADS)

    Tejfel, Victor G.; Karimov, A. M.; Lyssenko, P. G.; Kharitonova, G. A.

    2015-11-01

    The ammonia absorption bands centered at wavelengths of 645 and 787 nm in the visible spectrum of Saturn are very weak and overlapped with more strong absorption bands of methane. Therefore, the allocation of these bands is extremely difficult. In fact, the NH3 band 787 nm is completely masked by methane. The NH3 645 nm absorption band is superimposed on a relatively weak shortwave wing of CH4 band, in which the absorption maximum lies at the wavelength of 667 nm. In 2009, during the equinox on Saturn we have obtained the series of zonal spectrograms by scanning of the planet disk from the southern to the northern polar limb. Besides studies of latitudinal variation of the methane absorption bands we have done an attempt to trace the behavior of the absorption of ammonia in the band 645 nm. Simple selection of the pure NH3 profile of the band was not very reliable. Therefore, after normalizing to the ring spectrum and to the level of the continuous spectrum for entire band ranging from 630 to 680 nm in the equivalent widths were calculated for shortwave part of this band (630-652 nm), where the ammonia absorption is present, and a portion of the band CH4 652-680 nm. In any method of eliminating the weak part of the methane uptake in the short wing show an increased ammonia absorption in the northern hemisphere compared to the south. This same feature is observed also in the behavior of weak absorption bands of methane in contrast to the more powerful, such as CH4 725 and 787 nm. This is due to the conditions of absorption bands formation in the clouds at multiple scattering. Weak absorption bands of methane and ammonia are formed on the large effective optical depths and their behavior reflects the differences in the degree of uniformity of the aerosol component of the atmosphere of Saturn.

  6. Direct interband light absorption in the cylindrical quantum dot with modified Pöschl-Teller potential

    NASA Astrophysics Data System (ADS)

    Hayrapetyan, D. B.; Kazaryan, E. M.; Tevosyan, H. Kh.

    2012-09-01

    In this paper the direct interband light absorption in cylindrical quantum dot with modified Pöschl-Teller potential made of GaAs is studied. For the regime of strong size quantization analytical expressions for the particle energy spectrum, absorption coefficient and dependencies of effective threshold frequencies of absorption on the geometrical sizes of quantum dot are obtained. The selection rules corresponding to different transitions between quantum levels are found. To facilitate the comparison of obtained results with the probable experimental data, size dispersion distribution of growing quantum dots by the geometrical sizes using two experimentally realizing distribution functions has been taken into account. Distribution functions of Lifshits-Slezov and Gaussian have been considered.

  7. Fluid absorption solar energy receiver

    NASA Technical Reports Server (NTRS)

    Bair, Edward J.

    1993-01-01

    A conventional solar dynamic system transmits solar energy to the flowing fluid of a thermodynamic cycle through structures which contain the gas and thermal energy storage material. Such a heat transfer mechanism dictates that the structure operate at a higher temperature than the fluid. This investigation reports on a fluid absorption receiver where only a part of the solar energy is transmitted to the structure. The other part is absorbed directly by the fluid. By proportioning these two heat transfer paths the energy to the structure can preheat the fluid, while the energy absorbed directly by the fluid raises the fluid to its final working temperature. The surface temperatures need not exceed the output temperature of the fluid. This makes the output temperature of the gas the maximum temperature in the system. The gas can have local maximum temperatures higher than the output working temperature. However local high temperatures are quickly equilibrated, and since the gas does not emit radiation, local high temperatures do not result in a radiative heat loss. Thermal radiation, thermal conductivity, and heat exchange with the gas all help equilibrate the surface temperature.

  8. Transient simulation of absorption machines

    NASA Astrophysics Data System (ADS)

    Anand, D. K.; Allen, R. W.; Kumar, B.

    1982-08-01

    This paper presents a model for a water-cooled Lithium-Bromide/water absorption chiller and predicts its transient response both during the start-up phase and during the shutoff period. The simulation model incorporates such influencing factors as the thermodynamic properties of the working fluid, the absorbent, the heat-transfer configuration of different components of the chiller and related physical data. The time constants of different components are controlled by a set of key parameters that have been identified in this study. The results show a variable but at times significant amount of time delay before the chiller capacity gets close to its steady-state value. The model is intended to provide an insight into the mechanism of build-up to steady-state performance. By recognizing the significant factors contributing to transient degradation, steps can be taken to reduce such degradation. The evaluation of the residual capacity in the shut-off period will yield more realistic estimates of chiller COP for a chiller satisfying dynamic space cooling load.

  9. The absorption of polymeric composites

    NASA Astrophysics Data System (ADS)

    Řídký, R.; Popovič, M.; Rolc, S.; Drdlová, M.; Krátký, J.

    2016-06-01

    An absorption capacity of soft, viscoelastic materials at high strain rates is important for wide range of practical applications. Nowadays there are many variants of numerical models suitable for this kind of analysis. The main difficulty is in selection of the most realistic numerical model and a correct setup of many unknown material constants. Cooperation between theoretical simulations and real testing is next crucial point in the investigation process. Standard open source material database offer material properties valid for strain rates less than 250 s-1. There are experiments suitable for analysis of material properties with strain rates close to 2000 s-1. The high strain-rate characteristics of a specific porous blast energy absorbing material measured by modified Split Hopkinson Pressure Bar apparatus is presented in this study. Testing these low impedance materials using a metallic split Hopkinson pressure bar setup results in poor signal to noise ratios due to impedance mismatching. These difficulties are overcome by using polymeric Hopkinson bars. Conventional Hopkinson bar analysis cannot be used on the polymeric bars due to the viscoelastic nature of the bar material. One of the possible solution leads to complex and frequency depended Young modulus of testing bars material. This testing technique was applied to materials composed of porous glass/ceramic filler and polymeric binder, with density of 125 - 300 kg/m3 and particle size in range of 50 µm - 2 mm. The achieved material model was verified in practical application of sandwich structure includes polymeric composites under a blast test.

  10. Low absorptance porcelain-on-aluminum coating

    NASA Technical Reports Server (NTRS)

    Leggett, H.

    1979-01-01

    Porcelain thermal-control coating for aluminum sheet and foil has solar absorptance of 0.22. Specially formulated coating absorptance is highly stable, changing only 0.03 after 1,000 hours of exposure to simulated sunlight and can be applied by standard commercial methods.

  11. A Low-Cost Quantitative Absorption Spectrophotometer

    ERIC Educational Resources Information Center

    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…

  12. High-Absorptance Radiative Heat Sink

    NASA Technical Reports Server (NTRS)

    Cafferty, T.

    1983-01-01

    Absorptance of black-painted open-cell aluminum honeycomb improved by cutting honeycomb at angle or bias rather than straight across. This ensures honeycomb cavities escapes. At each reflection radiation attenuated by absorption. Applications include space-background simulators, space radiators, solar absorbers, and passive coolers for terrestrial use.

  13. Absorption of ozone by porous particles

    SciTech Connect

    Afanas'ev, V.P.; Dorofeev, S.B.; Sinitsyn, V.I.; Smirnov, B.M.

    1981-11-01

    The absorption of ozone by porous zeolite, silica gel, and activated carbon particles has been studied experimentally. It was shown that in addition to absorption, dissociation of ozone on the surface plays an important and sometimes decisive role. The results obtained were used to analyze the nature of ball lightning.

  14. Do Atoms Really "Emit" Absorption Lines?

    ERIC Educational Resources Information Center

    Brecher, Kenneth

    1991-01-01

    Presents three absorption line sources that enhance student understanding of the phenomena associated with the interaction of light with matter and help dispel the misconception that atoms "emit" absorption lines. Sources include neodymium, food coloring and other common household liquids, and fluorescent materials. (MDH)

  15. Terahertz absorption spectrum of triacetone triperoxide (TATP)

    NASA Astrophysics Data System (ADS)

    Wilkinson, John; Konek, Christopher T.; Moran, Jesse S.; Witko, Ewelina M.; Korter, Timothy M.

    2009-08-01

    We report here, for the first time, the terahertz absorption spectrum of triacetone triperoxide (TATP). The experimental spectra are coupled with solid-state density functional theory, and preliminary assignments are provided to gain physical insight into the experimental spectrum. The calculated absorption coefficients are in excellent agreement with experiment.

  16. On the absorption of alendronate in rats.

    PubMed

    Lin, J H; Chen, I W; deLuna, F A

    1994-12-01

    Alendronate is an antiosteolytic agent under investigation for the treatment of a number of bone disorders. Since the compound is a zwitterion with five pKa values and is completely ionized in the intestine at the physiological pH, absorption is poor; less than 1% of an oral dose is available systemically in rats. In the present studies, absorption was found to be predominantly in the upper part of the small intestine. Administration of buffered solutions of alendronate (pH 2-11) did not improve absorption. Whereas food markedly impaired the absorption of alendronate, EDTA enhanced absorption in a dose-dependent manner. Pretreatment of rats with ulcerogenic agents, mepirizole, acetylsalicylic acid, or indomethacin, resulted in a 3-7-fold increase in the oral absorption of alendronate. The absorption of phenol red, added as an indicator of intestinal tissue damage, was also increased in rats with experimental peptic ulcers. The enhanced absorption of alendronate observed in rats with experimental peptic ulcers was attributed to the alteration of the integrity of the intestinal membrane. PMID:7891304

  17. Iron absorption from intrinsically-labeled lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low iron (Fe) absorption from important staple foods may contribute to Fe deficiency in developing countries. To date, there are few studies examining the Fe bioavailability of pulse crops as commonly prepared and consumed by humans. The objectives of this study were to characterize the Fe absorpt...

  18. VAPID: Voigt Absorption-Profile [Interstellar] Dabbler

    NASA Astrophysics Data System (ADS)

    Howarth, Ian D.

    2015-06-01

    VAPID (Voigt Absorption Profile [Interstellar] Dabbler) models interstellar absorption lines. It predicts profiles and optimizes model parameters by least-squares fitting to observed spectra. VAPID allows cloud parameters to be optimized with respect to several different data set simultaneously; those data sets may include observations of different transitions of a given species, and may have different S/N ratios and resolutions.

  19. Absorption imaging of a single atom.

    PubMed

    Streed, Erik W; Jechow, Andreas; Norton, Benjamin G; Kielpinski, David

    2012-07-03

    Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in a vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorption imaged at near wavelength resolution with a phase Fresnel lens. The observed image contrast of 3.1 (3)% is the maximum theoretically allowed for the imaging resolution of our set-up. The absorption of photons by single atoms is of immediate interest for quantum information processing. Our results also point out new opportunities in imaging of light-sensitive samples both in the optical and X-ray regimes.

  20. Single-molecule imaging by optical absorption

    NASA Astrophysics Data System (ADS)

    Celebrano, Michele; Kukura, Philipp; Renn, Alois; Sandoghdar, Vahid

    2011-02-01

    To date, optical studies of single molecules at room temperature have relied on the use of materials with high fluorescence quantum yield combined with efficient spectral rejection of background light. To extend single-molecule studies to a much larger pallet of substances that absorb but do not fluoresce, scientists have explored the photothermal effect, interferometry, direct attenuation and stimulated emission. Indeed, very recently, three groups have succeeded in achieving single-molecule sensitivity in absorption. Here, we apply modulation-free transmission measurements known from absorption spectrometers to image single molecules under ambient conditions both in the emissive and strongly quenched states. We arrive at quantitative values for the absorption cross-section of single molecules at different wavelengths and thereby set the ground for single-molecule absorption spectroscopy. Our work has important implications for research ranging from absorption and infrared spectroscopy to sensing of unlabelled proteins at the single-molecule level.

  1. Novel absorption detection techniques for capillary electrophoresis

    SciTech Connect

    Xue, Y.

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the {mu}M level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  2. Creating semiconductor metafilms with designer absorption spectra.

    PubMed

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L

    2015-01-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells. PMID:26184335

  3. Creating semiconductor metafilms with designer absorption spectra

    PubMed Central

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L.

    2015-01-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells. PMID:26184335

  4. A theoretical consideration of percutaneous drug absorption.

    PubMed

    Kubota, K; Ishizaki, T

    1985-02-01

    The percutaneous drug absorption process and its clinical significance are not fully known. In this article we propose a theoretical method to obtain two parameters (kd and kc) of percutaneous drug absorption from in vivo data. These parameters are related to diffusion of a drug through the skin and removal process at the skin-capillary boundary, respectively, characterizing several pharmacokinetic aspects of the drug applied to the skin. Moreover, by employing these two kinetic constants, a simulation of percutaneous drug absorption can be theoretically generated. On the basis of our theoretical considerations on the percutaneous drug absorption process described herein, we conclude that the percutaneous drug absorption process is better understood by employing two kinetic constants in a mathematical model and that its clinical application would be highly possible. PMID:4020622

  5. Broadband microwave absorption spectrometer for liquid media

    SciTech Connect

    Mukherjee, P.; Gosnell, T.R.; Bigio, I.J.

    1988-12-01

    A broadband, continuous-sweep microwave spectrometer has been constructed for measurements of the absorption coefficient of aqueous solutions and other liquid media. The spectrometer makes use of the phase fluctuation optical heterodyne technique, which provides a direct measure of the microwave power deposited in the sample. Consequently, in contrast to the standard dielectrometric techniques that indirectly determine the absorption coefficient via separate measurements of the real and imaginary parts of the dielectric constant, this spectrometer directly measures the microwave absorption coefficient. Broadband spectra are obtained using a transmission line to couple microwave power into the liquid sample. The absorption spectrum for deionized water in the range 3--20 GHz is presented as an example and shows excellent agreement with calculated values of the absorption coefficient based on previously published dielectric data.

  6. Creating semiconductor metafilms with designer absorption spectra

    NASA Astrophysics Data System (ADS)

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung; Brongersma, Mark L.

    2015-07-01

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate that near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells.

  7. Time-dependent oral absorption models

    NASA Technical Reports Server (NTRS)

    Higaki, K.; Yamashita, S.; Amidon, G. L.

    2001-01-01

    The plasma concentration-time profiles following oral administration of drugs are often irregular and cannot be interpreted easily with conventional models based on first- or zero-order absorption kinetics and lag time. Six new models were developed using a time-dependent absorption rate coefficient, ka(t), wherein the time dependency was varied to account for the dynamic processes such as changes in fluid absorption or secretion, in absorption surface area, and in motility with time, in the gastrointestinal tract. In the present study, the plasma concentration profiles of propranolol obtained in human subjects following oral dosing were analyzed using the newly derived models based on mass balance and compared with the conventional models. Nonlinear regression analysis indicated that the conventional compartment model including lag time (CLAG model) could not predict the rapid initial increase in plasma concentration after dosing and the predicted Cmax values were much lower than that observed. On the other hand, all models with the time-dependent absorption rate coefficient, ka(t), were superior to the CLAG model in predicting plasma concentration profiles. Based on Akaike's Information Criterion (AIC), the fluid absorption model without lag time (FA model) exhibited the best overall fit to the data. The two-phase model including lag time, TPLAG model was also found to be a good model judging from the values of sum of squares. This model also described the irregular profiles of plasma concentration with time and frequently predicted Cmax values satisfactorily. A comparison of the absorption rate profiles also suggested that the TPLAG model is better at prediction of irregular absorption kinetics than the FA model. In conclusion, the incorporation of a time-dependent absorption rate coefficient ka(t) allows the prediction of nonlinear absorption characteristics in a more reliable manner.

  8. Extending the ADM formalism to Weyl geometry

    NASA Astrophysics Data System (ADS)

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-01

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  9. Extending the ADM formalism to Weyl geometry

    SciTech Connect

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-26

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  10. Narrow absorption lines with two observations from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Chen, Zhi-Fu; Gu, Qiu-Sheng; Chen, Yan-Mei; Cao, Yue

    2015-07-01

    We assemble 3524 quasars from the Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of the narrow C IV λ λ 1548,1551 and Mg II λ λ 2796,2803 absorption doublets in spectral regions shortward of 7000 Å in the observed frame, which corresponds to time-scales of about 150-2643 d in the quasar rest frame. In these quasar spectra, we detect 3580 C IV absorption systems with zabs = 1.5188-3.5212 and 1809 Mg II absorption systems with zabs = 0.3948-1.7167. In term of the absorber velocity (β) distribution in the quasar rest frame, we find a substantial number of C IV absorbers with β < 0.06, which might be connected to absorption of quasar outflows. The outflow absorption peaks at υ ≈ 2000 km s^{-1} and drops rapidly below this peak value. Among 3580 C IV absorption systems, 52 systems (˜1.5 per cent) show obvious variations in equivalent widths in the absorber rest frame (Wr): 16 enhanced, 16 emerged, 12 weakened and 8 disappeared systems, respectively. We find that changes in Wrλ1548 are related neither to the time-scales of the two SDSS observations nor to absorber velocities in the quasar rest frame. Variable absorption in low-ionization species is important to constrain the physical conditions of the absorbing gas. There are two variable Mg II absorption systems measured from SDSS spectra detected by Hacker et al. However, in our Mg II absorption sample, we find that neither shows variable absorption with confident levels of >4σ for λ2796 lines and >3σ for λ2803 lines.

  11. The effect of particle size on absorption of inhaled lead.

    PubMed

    Rendall, R E; Baily, P; Soskolne, C L

    1975-03-01

    Baboons were exposed to dust clouds of Ph3O4 of different size distribution but of the same total gravimetric concentration. Blood samples were taken immediately after each exposure of 4 hours and the total blood lead was determined. The exposure to the lead-bearing dust was stopped after four weeks, but the blood sampling continued for another six weeks. Graphs are presented comparing the patterns of lead absorption obtained with different sized lead particles. The coarser lead particles resulted in a higher blood lead concentration than the finer.

  12. Spatially resolved concentration measurements based on backscatter absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Ze; Sanders, Scott T.; Robinson, Michael A.

    2016-06-01

    We demonstrate the feasibility of spatially resolved measurements of gas properties using direct absorption spectroscopy in conjunction with backscattered signals. We report a 1-D distribution of H2O mole fraction with a spatial resolution of 5 mm. The peak and average discrepancy between the measured and expected mole fraction are 21.1 and 8.0 %, respectively. The demonstration experiment is related to a diesel aftertreatment system; a selective catalytic reduction brick made of cordierite is used. The brick causes volume scattering interference; advanced baseline fitting based on a genetic algorithm is used to reduce the effects of this interference by a factor of 2.3.

  13. Effects of Galactic absorption on soft X-ray surveys

    NASA Technical Reports Server (NTRS)

    Zamorani, G.; Gioia, I. M.; Maccacaro, T.; Wolter, A.

    1988-01-01

    A bias in the spectral distribution of X-ray sources detected in X-ray surveys is discussed which is due to the combination of the intrinsic characteristics of X-ray telescopes and the effects of low-energy photoelectric absorption within the Galaxy. A statistical method for obtaining information on the average spectrum of X-ray sources detected in well-defined surveys is presented. This method can be applied to surveys performed with X-ray telescopes working at relatively soft X-ray energies, such as Einstein, Exosat, and Rosat.

  14. Absorption spectroscopy of a laboratory photoionized plasma experiment at Z

    SciTech Connect

    Hall, I. M.; Durmaz, T.; Mancini, R. C.; Bailey, J. E.; Rochau, G. A.; Golovkin, I. E.; MacFarlane, J. J.

    2014-03-15

    The Z facility at the Sandia National Laboratories is the most energetic terrestrial source of X-rays and provides an opportunity to produce photoionized plasmas in a relatively well characterised radiation environment. We use detailed atomic-kinetic and spectral simulations to analyze the absorption spectra of a photoionized neon plasma driven by the x-ray flux from a z-pinch. The broadband x-ray flux both photoionizes and backlights the plasma. In particular, we focus on extracting the charge state distribution of the plasma and the characteristics of the radiation field driving the plasma in order to estimate the ionisation parameter.

  15. Ultraviolet absorption by interstellar gas near 30 Doradus

    NASA Technical Reports Server (NTRS)

    De Boer, K. S.; Koornneef, J.; Savage, B. D.

    1980-01-01

    The IUE was used to obtain high-resolution far-UV spectra (1150-2070 A) of two stars in the 30 Dor H II region in the LMC. Interstellar absorption components are distinguished at +20, +220, +250, and +290 km/s. The +20 km/s component is produced by matter in the Galaxy; the high-velocity components are produced by absorbing gas near or in the LMC. A model of the line-of-sight distribution of the absorbing clouds is developed from the velocity pattern of the observed LMC features. The presence of Si IV, Al III, and C IV ions is discussed.

  16. Rapid Scan Absorption Spectroscopy with Applications for Remote Sensing

    NASA Astrophysics Data System (ADS)

    Douglass, K.; Maxwell, S. E.; Truong, G.; Van Zee, R. D.; Hodges, J. T.; Plusquellic, D.; Long, D.; Whetstone, J. R.

    2013-12-01

    Our objective is to develop accurate and reliable methods for quantifying distributed carbon sources and sinks to support both mitigation efforts and climate change research. The presentation will describe a method for rapid step-scan absorption spectroscopy in the near-infrared wavelength range for the measurement of greenhouse gases. The method utilizes a fiber coupled laser system and a free space confocal cavity to effectively scan the laser system over a bandwidth of 37.5 GHz (1.25 cm-1), with a step size of 300 MHz (0.01 cm-1) and a scan rate of 40 kHz. The laser system is scanned with microwave precision over a full absorption lineshape profile. Measurements have been demonstrated in a 45 m long multipass cell for detection of carbon dioxide near 1602.4 nm (6240.6 cm-1) and for methane near 1645.5 nm (6077.2 cm 1). Ambient level detection is demonstrated using the multipass cell with a signal-to-noise ratio of ~5:1 in a 5 ms integration time. The scan speed, resolution and bandwidth are well suited for remote sensing using integrated path and differential absorption LIDAR techniques.

  17. Gastrointestinal absorption of protactinium, uranium, and neptunium in the hamster

    SciTech Connect

    Harrison, J.D.; Stather, J.W.

    1981-10-01

    The gastrointestinal absorption of protactinium, uranium, and neptunium in adult hamsters was measured. The actinide preparations were administered intragastrically and animals were kept 2 to 4 weeks prior to the radiochemical analysis of selected tissue samples. Total absorption was estimated using data for the distribution of the actinides after intravenous injection in soluble form. The values obtained were 3.9 and 0.22% for /sup 231/Pa citrate and /sup 231/Pa fluoride, respectively; 0.77 and 0.11% for /sup 233/U (uranyl) nitrate and /sup 233/U dioxide, respectively; and 0.06 and 0.05% for /sup 237/Np citrate and /sup 237/Np nitrate, respectively. The absorption factors recommended by the International Commission on Radiological Protection for use in calculating annual limits on intake for occupationally exposed workers are: 0.1% for all compounds of Pa; 5 and 0.2% for soluble hexavalent and relatively insoluble tetravalent forms of U, respectively; and 1.0% for all chemical forms of Np. The experimental basis for these values is discussed.

  18. Light source heat absorption analysis of a Dyson type lithography lens

    NASA Astrophysics Data System (ADS)

    Hsu, Ming-Ying; Ho, Cheng-Fang; Chang, Shenq-Tsong; Huang, Ting-Ming

    2015-09-01

    The lithography system in a high energy light source, the system refractive lens, absorbs the heat from the light source. The light source's power is uniformly distributed on the reticle side. The incident rays' power density is calculated by radiometry in each lens' surface. The lens heat absorption ratio depends on the optical glass species, quality, and wavelength. The optical glass' higher internal transmittance means less heat absorption; meanwhile, in different conditions, the lens' refractive index will change with temperature. Other researchers have tried to calculate the lens temperature distribution; this study applies the Finite Element Method (FEM), radiometry, and ray tracing to solve the lens temperature distribution. Each incident ray's path was separated into many sections, and the heat absorption was calculated for each section. Therefore, the heat generated in incident ray sections were weighted to finite element grids and the temperature distribution was solved. The lens' non uniform temperature distribution will cause the incident ray's Optical Path Difference (OPD). Each incident ray's OPD can be fit by Zernike polynomials; the fitting results can be input into optical software to evaluate the thermal effect on lens heat absorption.

  19. Cloud Microphysics and Absorption Validation

    NASA Technical Reports Server (NTRS)

    Ackerman, Steven

    2002-01-01

    Vertical distributions of particle size and habit were developed from in-situ data collected from three midlatitude cirrus field campaigns (FIRE-1, FIRE-2, and ARM IOP). These new midlatitude microphysical models were used to develop new cirrus scattering models at a number of wavelengths appropriate for use with the MODIS imager (Nasiri et al. 2002). This was the first successful collaborative effort between all the investigators on this proposal. Recent efforts have extended the midlatitude cirrus cloud analyses to tropical cirrus, using in-situ data collected during the Tropical Rainfall Measurement Mission (TRMM) Kwajalein field campaign in 1999. We note that there are critical aspects to the work: a) Improvement in computing the scattering and radiative properties of ice crystals; b) Requirement for copious amounts of cirrus in-situ data, presented in terms of both particle size and habit distributions; c) Development of cirrus microphysical and optical models for various satellite, aircraft, and ground-based instruments based on the theoretical calculations and in-situ measurements; d) Application to satellite data.

  20. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    NASA Astrophysics Data System (ADS)

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-06-01

    We propose a method to measure the densities of vibrationally excited Cl2(v) molecules in levels up to v  =  3 in pure chlorine inductively coupled plasmas (ICPs). The absorption continuum of Cl2 in the 250-450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mechanism of the Cl2 feedstock in the plasma. In these line-integrated absorption measurements, the absorption by the hot (and therefore rarefied) Cl2 gas in the reactor centre is masked by the cooler (and therefore denser) Cl2 near the walls. These radial gradients in temperature and density make it difficult to assess the degree of vibrational excitation in the centre of the reactor. The observed line-averaged vibrational distributions, when analyzed taking into account the radial temperature gradient, suggest that vibrational and translational degrees of freedom in the plasma are close to local equilibrium. This can be explained by efficient vibrational-translational (VT) relaxation between Cl2 and Cl atoms. Besides the Cl2(v) absorption band, a weak continuum absorption is observed at shorter wavelengths, and is attributed to photodetachment of Cl- negative ions. Thus, line-integrated densities of negative ions in chlorine plasmas can be directly measured using broad-band absorption spectroscopy.

  1. Absorption Characteristics of Vertebrate Non-Visual Opsin, Opn3.

    PubMed

    Sugihara, Tomohiro; Nagata, Takashi; Mason, Benjamin; Koyanagi, Mitsumasa; Terakita, Akihisa

    2016-01-01

    Most animals possess multiple opsins which sense light for visual and non-visual functions. Here, we show spectral characteristics of non-visual opsins, vertebrate Opn3s, which are widely distributed among vertebrates. We successfully expressed zebrafish Opn3 in mammalian cultured cells and measured its absorption spectrum spectroscopically. When incubated with 11-cis retinal, zebrafish Opn3 formed a blue-sensitive photopigment with an absorption maximum around 465 nm. The Opn3 converts to an all-trans retinal-bearing photoproduct with an absorption spectrum similar to the dark state following brief blue-light irradiation. The photoproduct experienced a remarkable blue-shift, with changes in position of the isosbestic point, during further irradiation. We then used a cAMP-dependent luciferase reporter assay to investigate light-dependent cAMP responses in cultured cells expressing zebrafish, pufferfish, anole and chicken Opn3. The wild type opsins did not produce responses, but cells expressing chimera mutants (WT Opn3s in which the third intracellular loops were replaced with the third intracellular loop of a Gs-coupled jellyfish opsin) displayed light-dependent changes in cAMP. The results suggest that Opn3 is capable of activating G protein(s) in a light-dependent manner. Finally, we used this assay to measure the relative wavelength-dependent response of cells expressing Opn3 chimeras to multiple quantally-matched stimuli. The inferred spectral sensitivity curve of zebrafish Opn3 accurately matched the measured absorption spectrum. We were unable to estimate the spectral sensitivity curve of mouse or anole Opn3, but, like zebrafish Opn3, the chicken and pufferfish Opn3-JiL3 chimeras also formed blue-sensitive pigments. These findings suggest that vertebrate Opn3s may form blue-sensitive G protein-coupled pigments. Further, we suggest that the method described here, combining a cAMP-dependent luciferase reporter assay with chimeric opsins possessing the third

  2. Absorption Characteristics of Vertebrate Non-Visual Opsin, Opn3

    PubMed Central

    Sugihara, Tomohiro; Nagata, Takashi; Mason, Benjamin; Koyanagi, Mitsumasa; Terakita, Akihisa

    2016-01-01

    Most animals possess multiple opsins which sense light for visual and non-visual functions. Here, we show spectral characteristics of non-visual opsins, vertebrate Opn3s, which are widely distributed among vertebrates. We successfully expressed zebrafish Opn3 in mammalian cultured cells and measured its absorption spectrum spectroscopically. When incubated with 11-cis retinal, zebrafish Opn3 formed a blue-sensitive photopigment with an absorption maximum around 465 nm. The Opn3 converts to an all-trans retinal-bearing photoproduct with an absorption spectrum similar to the dark state following brief blue-light irradiation. The photoproduct experienced a remarkable blue-shift, with changes in position of the isosbestic point, during further irradiation. We then used a cAMP-dependent luciferase reporter assay to investigate light-dependent cAMP responses in cultured cells expressing zebrafish, pufferfish, anole and chicken Opn3. The wild type opsins did not produce responses, but cells expressing chimera mutants (WT Opn3s in which the third intracellular loops were replaced with the third intracellular loop of a Gs-coupled jellyfish opsin) displayed light-dependent changes in cAMP. The results suggest that Opn3 is capable of activating G protein(s) in a light-dependent manner. Finally, we used this assay to measure the relative wavelength-dependent response of cells expressing Opn3 chimeras to multiple quantally-matched stimuli. The inferred spectral sensitivity curve of zebrafish Opn3 accurately matched the measured absorption spectrum. We were unable to estimate the spectral sensitivity curve of mouse or anole Opn3, but, like zebrafish Opn3, the chicken and pufferfish Opn3-JiL3 chimeras also formed blue-sensitive pigments. These findings suggest that vertebrate Opn3s may form blue-sensitive G protein-coupled pigments. Further, we suggest that the method described here, combining a cAMP-dependent luciferase reporter assay with chimeric opsins possessing the third

  3. Microwave and optical saturable absorption in graphene.

    PubMed

    Zheng, Zhiwei; Zhao, Chujun; Lu, Shunbin; Chen, Yu; Li, Ying; Zhang, Han; Wen, Shuangchun

    2012-10-01

    We report on the first experiments on saturable absorption in graphene at microwave frequency band. Almost independent of the incident frequency, microwave absorbance of graphene always decreases with increasing the power and reaches at a constant level for power larger than 80 µW, evidencing the microwave saturable absorption property of graphene. Optical saturable absorption of the same graphene sample was also experimentally confirmed by an open-aperture Z-scan technique by one laser at telecommunication band and another pico-second laser at 1053 nm, respectively. Herein, we are able to conclude that graphene is indeed a broadband saturable absorber that can operate at both microwave and optical band.

  4. The gastrointestinal absorption of the actinide elements.

    PubMed

    Harrison, J D

    1991-03-01

    The greatest uncertainty in dose estimates for the ingestion of long-lived, alpha-emitting isotopes of the actinide elements is in the values used for their fractional absorption from the gastrointestinal tract (f1 values). Recent years have seen a large increase in the available data on actinide absorption. Human data are reviewed here, together with animal data, to illustrate the effect on absorption of chemical form, incorporation into food materials, fasting and other dietary factors, and age at ingestion. The f1 values recommended by the International Commission on Radiological Protection, by an Expert Group of the Nuclear Energy Agency and by the National Radiological Protection Board are discussed.

  5. Coherent Absorption of N00N States.

    PubMed

    Roger, Thomas; Restuccia, Sara; Lyons, Ashley; Giovannini, Daniel; Romero, Jacquiline; Jeffers, John; Padgett, Miles; Faccio, Daniele

    2016-07-01

    Recent results in deeply subwavelength thickness films demonstrate coherent control and logical gate operations with both classical and single-photon light sources. However, quantum processing and devices typically involve more than one photon and nontrivial input quantum states. Here we experimentally investigate two-photon N00N state coherent absorption in a multilayer graphene film. Depending on the N00N state input phase, it is possible to selectively choose between single- or two-photon absorption of the input state in the graphene film. These results demonstrate that coherent absorption in the quantum regime exhibits unique features, opening up applications in multiphoton spectroscopy and imaging. PMID:27447505

  6. Coherent Absorption of N00N States

    NASA Astrophysics Data System (ADS)

    Roger, Thomas; Restuccia, Sara; Lyons, Ashley; Giovannini, Daniel; Romero, Jacquiline; Jeffers, John; Padgett, Miles; Faccio, Daniele

    2016-07-01

    Recent results in deeply subwavelength thickness films demonstrate coherent control and logical gate operations with both classical and single-photon light sources. However, quantum processing and devices typically involve more than one photon and nontrivial input quantum states. Here we experimentally investigate two-photon N00N state coherent absorption in a multilayer graphene film. Depending on the N00N state input phase, it is possible to selectively choose between single- or two-photon absorption of the input state in the graphene film. These results demonstrate that coherent absorption in the quantum regime exhibits unique features, opening up applications in multiphoton spectroscopy and imaging.

  7. Extraordinary Absorption of Decorated Undoped Graphene

    NASA Astrophysics Data System (ADS)

    Stauber, T.; Gómez-Santos, G.; de Abajo, F. Javier García

    2014-02-01

    We theoretically study absorption by an undoped graphene layer decorated with arrays of small particles. We discuss periodic and random arrays within a common formalism, which predicts a maximum absorption of 50% for suspended graphene in both cases. The limits of weak and strong scatterers are investigated, and an unusual dependence on particle-graphene separation is found and explained in terms of the effective number of contributing evanescent diffraction orders of the array. Our results can be important to boost absorption by single-layer graphene due to its simple setup with potential applications to light harvesting and photodetection based on energy (Förster) rather than charge transfer.

  8. Selective coherent perfect absorption in metamaterials

    SciTech Connect

    Nie, Guangyu; Shi, Quanchao; Zhu, Zheng; Shi, Jinhui

    2014-11-17

    We show multi-band coherent perfect absorption (CPA) in simple bilayered asymmetrically split ring metamaterials. The selectivity of absorption can be accomplished by separately excited electric and magnetic modes in a standing wave formed by two coherent counterpropagating beams. In particular, each CPA can be completely switched on/off by the phase of a second coherent wave. We propose a practical scheme for realizing multi-band coherent perfect absorption of 100% that is allowed to work from microwave to optical frequency.

  9. Electric modulation of optical absorption in nanowires

    NASA Astrophysics Data System (ADS)

    Sakr, M. R.

    2016-11-01

    We have calculated the effect of an external electric field on the intersubband optical absorption of a nanowire subjected to a perpendicular magnetic field and Rashba effect. The absorption peaks due to optical transitions that are forbidden in the absence of the intersubband coupling experience strong amplitude modulation. This effect is quadratic in electric fields applied along the direction of quantum confinement or perpendicularly to tune the Rashba parameter. The electric field also induces frequency modulation in the associated spectrum. On the other hand, transitions that are normally allowed show, to a large extent, a parallel band effect, and accordingly they are responsible for strong optical absorption.

  10. Total absorption by degenerate critical coupling

    SciTech Connect

    Piper, Jessica R. Liu, Victor; Fan, Shanhui

    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.

  11. A Parallel Reconstruction Scheme in Fluorescence Tomography Based on Contrast of Independent Inversed Absorption Properties

    PubMed Central

    Yi, Ji; Bai, Jing

    2006-01-01

    Based on an independent forward model in fluorescent tomography, a parallel reconstructed scheme for inhomogeneous mediums with unknown absorption property is proposed in this paper. The method considers the two diffusion equations as separately describing the propagation of excited light in tissues with and without fluorescent probes inside. Then the concentration of fluorophores is obtained directly through the difference between two estimations of absorption coefficient which can be parallel inversed. In this way, the multiparameter estimation problem in fluorescent tomography is transformed into two independent single-coefficient determined schemes of diffusion optical tomography (DOT). Any algorithms proved to be efficient and effective in DOT can be directly applied here. In this study the absorption property is estimated from the independent diffusion equations by a gradient-based optimization method with finite element method (FEM) solving the forward model. Simulation results of three representative occasions show that the reconstructed method can well estimate fluorescent property and tissue absorption distribution. PMID:23165045

  12. Non-resonant below-bandgap two-photon absorption in quantum dot solar cells

    SciTech Connect

    Li, Tian; Dagenais, Mario

    2015-04-27

    We study the optically nonlinear sub-bandgap photocurrent generation facilitated by an extended tailing distribution of states in an InAs/GaAs quantum dots (QDs) solar cell. The tailing states function as both the energy states for low energy photon absorption and the photocarriers extraction pathway. One of the biggest advantages of our method is that it can clearly differentiate the photocurrent due to one-photon absorption (1PA) process and two-photon absorption (2PA) process. Both 1PA and 2PA photocurrent generation efficiency in an InAs/GaAs QD device operated at 1550 nm have been quantitatively evaluated. A two-photon absorption coefficient β = 5.7 cm/GW is extracted.

  13. Lactose and milk replacer influence on lead absorption and lead toxicity in calves

    SciTech Connect

    Zmudzki, J.; Bratton, G.R.; Womac, C.W.; Rowe, L.D. Jr.; Wagner, B.

    1986-03-01

    The absorption, tissue deposition, retention, and excretion of ingested lead is in large part due to associated dietary factors. Young suckling calves are extremely susceptible to low doses of lead, especially when maintained totally on milk. Unfortunately, the complexity of milk makes it difficult to determine which constituent is actually responsible for increased Pb absorption. Recent studies have shown that lactose, the major carbohydrate of milk, is a dietary factor that increases the absorption of several minerals including Pb in rats. The authors laboratory has recently demonstrated that milk greatly increased the tissue deposition of lead in calves. Lactose, however, has not been considered in the ruminant animal. Moreover, liquid milk seems to increase the absorption of lead more significantly than powdered milk. The purpose of this study was to assess the influence of lactose and powdered milk on lead uptake and tissue distribution in calves.

  14. A tunable fiber-coupled optical cavity for agile enhancement of detector absorption

    NASA Astrophysics Data System (ADS)

    Heath, Robert M.; Tanner, Michael G.; Kirkwood, Robert A.; Miki, Shigehito; Warburton, Richard J.; Hadfield, Robert H.

    2016-09-01

    Maximizing photon absorption into thin active structures can be the limiting factor for photodetector efficiency. In this work, a fiber-coupled tunable cavity is demonstrated, designed to achieve close to unity absorption of photons into a thin film superconducting nanowire single photon detector (SNSPD). A technique for defining a stable cavity between the end of a telecommunications optical fiber and a reflective substrate is described and realized. Cavity resonances are demonstrated both through the tuning of input wavelength and cavity length. The resulting optical cavity can tune the resonant absorption in situ over a wavelength range of 100 nm. This technique is used to maximize the single photon absorption into both a back-side-coupled Au mirror SNSPD and a front-side-coupled distributed Bragg reflector cavity SNSPD. The system detection efficiency (SDE) is limited by imperfections in the thin films, but in both cases we demonstrate an improvement of the SDE by 40% over bare fiber illumination.

  15. Absorption and impedance boundary conditions for phased geometrical-acoustics methods.

    PubMed

    Jeong, Cheol-Ho

    2012-10-01

    Defining accurate acoustical boundary conditions is of crucial importance for room acoustic simulations. In predicting sound fields using phased geometrical acoustics methods, both absorption coefficients and surface impedances of the boundary surfaces can be used, but no guideline has been developed on which boundary condition produces accurate results. In this study, various boundary conditions in terms of normal, random, and field incidence absorption coefficients and normal incidence surface impedance are used in a phased beam tracing model, and the simulated results are validated with boundary element solutions. Two rectangular rooms with uniform and non-uniform absorption distributions are tested. Effects of the neglect of reflection phase shift are also investigated. It is concluded that the impedance, random incidence, and field incidence absorption boundary conditions produce reasonable results with some exceptions at low frequencies for acoustically soft materials.

  16. Tunable ultranarrow spectrum selective absorption in a graphene monolayer at terahertz frequency

    NASA Astrophysics Data System (ADS)

    Wu, Jun

    2016-06-01

    Complete absorption in a graphene monolayer at terahertz frequency through the critical coupling effect is investigated. It is achieved by sandwiching the graphene monolayer between a dielectric grating and a Bragg grating. The designed graphene absorber exhibits near-unity absorption at resonance but with an ultranarrow spectrum and antenna-like response, which is attributed to the combined effects of guided mode resonance with dielectric grating and the photonic band gap with Bragg grating. In addition to numerical simulation, the electric field distributions are also illustrated to provide a physical understanding of the perfect absorption effect. Furthermore, the absorption performance can be tuned by only changing the Fermi level of graphene, which is beneficial for real application. It is believed that this study may be useful for designing next-generation graphene-based optoelectronic devices.

  17. Modeling of fast wave absorption by beam ions in DIII-D discharges

    SciTech Connect

    Mau, T. K.; Petty, C. C.; Porkolab, M.; Heidbrink, W. W.

    1999-09-20

    In recent discharges on DIII-D, neutron measurements indicated absorption of the fast wave by energetic deuterium beam ions when the fourth harmonic resonance is on axis, but little or no interaction for the fifth harmonic. In this work, a geometric optics code is used to quantify the beam ion absorption of fast waves as the frequency (or on-axis harmonic resonance) is varied. Isotropic and anisotropic Maxwellians are used to model the beam ion distribution. Wave power flow in this harmonic range has been found to exhibit a strong poloidal and toroidal behavior in its initial transits across the plasma. Absorption along the rays is calculated using the fully thermal and magnetized treatment. Competing with the beam ions for absorption are the minority hydrogen and background electrons. The modeling results are only in partial agreement with experimental observations, indicating that more detailed physics may need to be included. (c) 1999 American Institute of Physics.

  18. Microwave absorption behavior of ZnO whisker modified by nanosized Fe3O4 particles.

    PubMed

    Hu, Shuchun; Wu, Guofeng; Huang, Zhenhao; Chen, Xiaolang

    2010-11-01

    Tetra-needle-like ZnO whisker was magnetic modified through in situ synthesis of nanosized Fe3O4 particles on the surface of the whisker, and the microwave absorption behavior of the as-prepared product was investigated in detail. The result of the comparative microwave absorbing experiment showed that the magnetic modified ZnO whisker appeared more superior property of microwave absorption than that of the original ZnO whisker in 2-18 GHz. Further investigation indicated that the microwave absorption behavior of the product was influenced by ferrite content and Fe3O4 particles' distribution in the product. When the ferrite content of the product changed from 2 wt% to 9 wt%, the microwave absorbing ability of the product was increased; then, the microwave absorbing ability of the product decreased with the further increasing of ferrite content from 9 wt% to 16 wt%. The product with uniform distribution of Fe3O4 particles showed better microwave absorption property than that with irregular distribution of Fe3O4 particles, and this result inferred that the biphase interface between ZnO and Fe3O4 contributed to microwave absorption through interface polarization. PMID:21137989

  19. Absorption of Sunlight by Water Vapor in Cloudy Conditions: A Partial Explanation for the Cloud Absorption Anomaly

    NASA Technical Reports Server (NTRS)

    Crisp, D.

    1997-01-01

    The atmospheric radiative transfer algorithms used in most global general circulation models underestimate the globally-averaged solar energy absorbed by cloudy atmospheres by up to 25 W/sq m. The origin of this anomalous absorption is not yet known, but it has been attributed to a variety of sources including oversimplified or missing physical processes in these models, uncertainties in the input data, and even measurement errors. Here, a sophisticated atmospheric radiative transfer model was used to provide a more comprehensive description of the physical processes that contribute to the absorption of solar radiation by the Earth's atmosphere. We found that the amount of sunlight absorbed by a cloudy atmosphere is inversely proportional to the solar zenith angle and the cloud top height, and directly proportional to the cloud optical depth and the water vapor concentration within the clouds. Atmospheres with saturated, optically-thick, low clouds absorbed about 12 W/sq m more than clear atmospheres. This accounts for about 1/2 to 1/3 of the anomalous ab- sorption. Atmospheres with optically thick middle and high clouds usually absorb less than clear atmospheres. Because water vapor is concentrated within and below the cloud tops, this absorber is most effective at small solar zenith angles. An additional absorber that is distributed at or above the cloud tops is needed to produce the amplitude and zenith angle dependence of the observed anomalous absorption.

  20. Size segregated light absorption coefficient of the atmospheric aerosol

    NASA Astrophysics Data System (ADS)

    Horvath, H.

    The light absorption coefficient of atmospheric aerosols in the visible can be determined by depositing the particles on a filter and measuring its "transmission" in a special optical arrangement. With an impactor with rotating impaction plates producing a homogeneous deposit, it is possible to extend this technique to size segregated aerosol samples. A simultaneous determination of the mass size distribution is possible. Test measurements with black carbon aerosol have shown the feasibility of this method. Samples of the atmospheric aerosol have been taken in and near Vienna, in Naples and near Bologna. The light absorption of the aerosol is always highest for particle diameters between 0.1 and 0.2 μm. Only in the humid environment of the Po valley it had a slightly larger peak size, whereas the size of the nonabsorbing particles increased considerably. The light absorption of the atmospheric aerosol is always higher in an urban environment. 'The mass absorption coefficient of the aerosol at all four locations was very similar, and completely different from values which could be. expected using effective refractive indices which are frequently used in models. Using the data measured in this work two alternate models for the effective refractive index and black carbon content of the aerosol are suggested: (a) a size-dependent refractive index, where the imaginary part varies from -0.25 for particles smaller than 30 nm to - 0.003 for particles larger than 2 μm; this could especially be applied if an internal mixing of the aerosol is to be expected, or (2) a size-dependent fraction of elemental carbon in the case of external mixing with 43% of carbon particles for sizes below 30 nm decreasing to 10% for sizes up to 0.4 μm.