HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing.

Science.gov (United States)

Haque, Syed A; Cañete, Socrates Jose P

2018-01-01

An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants. Three different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG). Both the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column. The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

A new imidazolium-embedded C{sub 18} stationary phase with enhanced performance in reversed-phase liquid chromatography

Energy Technology Data Exchange (ETDEWEB)

Qiu Hongdeng [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Mallik, Abul K. [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Takafuji, Makoto [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan); Liu Xia; Jiang Shengxiang [Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Ihara, Hirotaka, E-mail: ihara@kumamoto-u.ac.jp [Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kumamoto Institute for Photo-Electro Organics (Phoenics), Kumamoto 862-0901 (Japan)

2012-08-13

Highlights: Black-Right-Pointing-Pointer Imidazolium-embedded C{sub 18} stationary phase was prepared and characterized. Black-Right-Pointing-Pointer Enhanced chromatographic selectivity was observed in SiImC{sub 18} column. Black-Right-Pointing-Pointer Seven nucleosides and bases were separated using only water as eluent within 8 min. Black-Right-Pointing-Pointer Multiple-interactions induced by embedded polar imidazolium was investigated. - Abstract: In this paper, a new imidazolium-embedded C{sub 18} stationary phase (SiImC{sub 18}) for reversed-phase high-performance liquid chromatography is described. 1-Allyl-3-octadecylimidazolium bromide ionic liquid compound having a long alkyl chain and reactive groups was newly prepared and grafted onto 3-mercaptopropyltrimethoxysilane-modified silica via a surface-initiated radical-chain transfer addition reaction. The SiImC{sub 18} obtained was characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, diffuse reflectance infrared Fourier transform, and solid-state {sup 13}C and {sup 29}Si cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The selectivity toward polycyclic aromatic hydrocarbons relative to that toward alkylbenzenes exhibited by SiImC{sub 18} was higher than the corresponding selectivity exhibited by a conventional octadecyl silica (ODS) column, which could be explained by electrostatic {pi}-{pi} interaction cationic imidazolium and electron-rich aromatic rings. On the other hand, SiImC{sub 18} also showed high selectivity for polar compounds, which was based on the multiple interaction and retention mechanisms of this phase with different analytes. 1,6-Dinitropyrene and 1,8-dinitropyrene, which form a positional isomer pair of dipolar compounds, were separated successfully with the SiImC{sub 18} phase. Seven nucleosides and bases (i.e. cytidine, uracil, uridine, thymine, guanosine, xanthosine, and adenosine) were separated using only water as

[Genotyping of oncogenic human papilloma viruses in women with HG SIL diagnosis].

Science.gov (United States)

Kedzia, Witold; Pruski, Dominik; Józefiak, Agata; Rokita, Wojciech; Spaczyński, Marek

2010-10-01

Development of primary prevention of cervical cancer in other words a vaccination against selected, oncogenic HPV types, entails an increasing importance of epidemiological studies and prevalence of various types of human papilloma virus. The incidence of HPV varies depending on the geographic location of the population. The effectiveness of primary prevention against HPV 16, 18, in the context of reducing the incidence of cervical cancer will depend, among others, on the prevalence of these types in the population and virus-like antigens, which are partially cross-resistant. Identification of the most frequent, oncogenic HPV types in women with HG SIL diagnosis from Central and Western Poland to assess the merits of the development of primary prevention. For the purpose of molecular tests identifying the presence of 13 DNA oncogenic virus types, swabs were taken with the cyto-brush from 76 women diagnosed with CIN 2 or CIN 3 (HG SIL). Patients eligible for the study were diagnosed at the Laboratory of Pathophysiology of Uterine Cervix, Gynecology and Obstetrics Clinical Hospital of Karol Marcinkowski University of Medical Sciences. Patients came from Central and Western parts of Poland. Cell material in which the method of Amplicor HPV (Roche Diagnostics) identified the presence of DNA of oncogenic HPV types was in each case subsequently subjected to genotyping using the molecular test - Linear Array HPV Genotyping (Roche Diagnostics). Five most common oncogenic HPV types in order of detection included: 16, 33, 18, 31, 56. Together these five types of virus comprised 75.86% (88/116) of all detected HPV types. 1. In women from Central and Western Poland, diagnosed with HG SIL, the most common HPV genotypes were HPV 16, HPV33, HPV 18, HPV31, HPV56. 2. Two HPV types 16 and 18, against which vaccinations are directed, belong to the group of three genotypes of HPV most commonly identified in the evolution of CIN 2, CIN 3 diagnosed in women from Central and Western

Paysans du Brésil

Directory of Open Access Journals (Sweden)

Dominique Temple

2007-01-01

Full Text Available Eric Sabourin, « Paysans du Brésil : Entre échange marchand et réciprocité » Paris, Editions Quae, 241p, 30 euros, (préface de Maxime Haubert, 2007Dans la présentation du livre, Maxime Haubert dit :«Cet ouvrage propose une analyse socio-anthropologique et agronomique des sociétés rurales et paysannes du Brésil et des transformations qu'elles ont connues ces dernières décennies, en particulier face aux interventions de l'Etat et à l'expansion du marché capitaliste (.... «Le livre pose d'abor...

Inhibition of HIV by Legalon-SIL is independent of its effect on cellular metabolism

Energy Technology Data Exchange (ETDEWEB)

McClure, Janela [Department of Laboratory Medicine, University of Washington, Seattle, WA (United States); Margineantu, Daciana H. [Department of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Sweet, Ian R. [Department of Medicine (Division of Metabolism, Endocrinology, and Nutrition), University of Washington, Seattle, WA (United States); Polyak, Stephen J., E-mail: polyak@uw.edu [Department of Laboratory Medicine, University of Washington, Seattle, WA (United States); Department of Global Health, University of Washington, Seattle, WA (United States)

2014-01-20

In this report, we further characterized the effects of silibinin (SbN), derived from milk thistle extract, and Legalon-SIL (SIL), a water-soluble derivative of SbN, on T cell metabolism and HIV infection. We assessed the effects of SbN and SIL on peripheral blood mononuclear cells (PBMC) and CEM-T4 cells in terms of cellular growth, ATP content, metabolism, and HIV infection. SIL and SbN caused a rapid and reversible (upon removal) decrease in cellular ATP levels, which was associated with suppression of mitochondrial respiration and glycolysis. SbN, but not SIL inhibited glucose uptake. Exposure of T cells to SIL (but not SbN or metabolic inhibitors) during virus adsorption blocked HIV infection. Thus, both SbN and SIL rapidly perturb T cell metabolism in vitro, which may account for its anti-inflammatory and anti-proliferative effects that arise with prolonged exposure of cells. However, the metabolic effects are not involved in SIL's unique ability to block HIV entry. - Highlights: • Silibinin (SbN) and Legalon-SIL (SIL) are cytoprotective mixtures of natural products. • SbN and SIL reduce T cell oxidative phosphorylation and glycolysis in vitro. • SIL but not SbN blocks entry of multiple HIV isolates into T cells in vitro. • SIL's suppression of HIV appears independent of its effects on T cell metabolism. • Metabolic effects of SIL and SbN may be relevant in inflammatory diseases.

Inhibition of HIV by Legalon-SIL is independent of its effect on cellular metabolism

International Nuclear Information System (INIS)

McClure, Janela; Margineantu, Daciana H.; Sweet, Ian R.; Polyak, Stephen J.

2014-01-01

In this report, we further characterized the effects of silibinin (SbN), derived from milk thistle extract, and Legalon-SIL (SIL), a water-soluble derivative of SbN, on T cell metabolism and HIV infection. We assessed the effects of SbN and SIL on peripheral blood mononuclear cells (PBMC) and CEM-T4 cells in terms of cellular growth, ATP content, metabolism, and HIV infection. SIL and SbN caused a rapid and reversible (upon removal) decrease in cellular ATP levels, which was associated with suppression of mitochondrial respiration and glycolysis. SbN, but not SIL inhibited glucose uptake. Exposure of T cells to SIL (but not SbN or metabolic inhibitors) during virus adsorption blocked HIV infection. Thus, both SbN and SIL rapidly perturb T cell metabolism in vitro, which may account for its anti-inflammatory and anti-proliferative effects that arise with prolonged exposure of cells. However, the metabolic effects are not involved in SIL's unique ability to block HIV entry. - Highlights: • Silibinin (SbN) and Legalon-SIL (SIL) are cytoprotective mixtures of natural products. • SbN and SIL reduce T cell oxidative phosphorylation and glycolysis in vitro. • SIL but not SbN blocks entry of multiple HIV isolates into T cells in vitro. • SIL's suppression of HIV appears independent of its effects on T cell metabolism. • Metabolic effects of SIL and SbN may be relevant in inflammatory diseases

Multidrug-Resistant CTX-M-(15, 9, 2)- and KPC-2-Producing Enterobacter hormaechei and Enterobacter asburiae Isolates Possessed a Set of Acquired Heavy Metal Tolerance Genes Including a Chromosomal sil Operon (for Acquired Silver Resistance).

Science.gov (United States)

Andrade, Leonardo N; Siqueira, Thiago E S; Martinez, Roberto; Darini, Ana Lucia C

2018-01-01

Bacterial resistance to antibiotics is concern in healthcare-associated infections. On the other hand, bacterial tolerance to other antimicrobials, like heavy metals, has been neglected and underestimated in hospital pathogens. Silver has long been used as an antimicrobial agent and it seems to be an important indicator of heavy metal tolerance. To explore this perspective, we searched for the presence of acquired silver resistance genes ( sil operon: silE, silS, silR, silC, silF, silB, silA , and silP ) and acquired extended-spectrum cephalosporin and carbapenem resistance genes ( bla CTX-M and bla KPC ) in Enterobacter cloacae Complex (EcC) ( n = 27) and Enterobacter aerogenes ( n = 8) isolated from inpatients at a general hospital. Moreover, the genetic background of the silA (silver-efflux pump) and the presence of other acquired heavy metal tolerance genes, pcoD (copper-efflux pump), arsB (arsenite-efflux pump), terF (tellurite resistance protein), and merA (mercuric reductase) were also investigated. Outstandingly, 21/27 (78%) EcC isolates harbored silA gene located in the chromosome. Complete sil operon was found in 19/21 silA -positive EcC isolates. Interestingly, 8/20 (40%) E. hormaechei and 5/6 (83%) E. asburiae co-harbored silA/pcoD genes and bla CTX-M-(15,2,or9) and/or bla KPC-2 genes. Frequent occurrences of arsB, terF , and merA genes were detected, especially in silA/pcoD -positive, multidrug-resistant (MDR) and/or CTX-M-producing isolates. Our study showed co-presence of antibiotic and heavy metal tolerance genes in MDR EcC isolates. In our viewpoint, there are few studies regarding to bacterial heavy metal tolerance and we call attention for more investigations and discussion about this issue in different hospital pathogens.

Multidrug-Resistant CTX-M-(15, 9, 2- and KPC-2-Producing Enterobacter hormaechei and Enterobacter asburiae Isolates Possessed a Set of Acquired Heavy Metal Tolerance Genes Including a Chromosomal sil Operon (for Acquired Silver Resistance

Directory of Open Access Journals (Sweden)

Leonardo N. Andrade

2018-03-01

Full Text Available Bacterial resistance to antibiotics is concern in healthcare-associated infections. On the other hand, bacterial tolerance to other antimicrobials, like heavy metals, has been neglected and underestimated in hospital pathogens. Silver has long been used as an antimicrobial agent and it seems to be an important indicator of heavy metal tolerance. To explore this perspective, we searched for the presence of acquired silver resistance genes (sil operon: silE, silS, silR, silC, silF, silB, silA, and silP and acquired extended-spectrum cephalosporin and carbapenem resistance genes (blaCTX−M and blaKPC in Enterobacter cloacae Complex (EcC (n = 27 and Enterobacter aerogenes (n = 8 isolated from inpatients at a general hospital. Moreover, the genetic background of the silA (silver-efflux pump and the presence of other acquired heavy metal tolerance genes, pcoD (copper-efflux pump, arsB (arsenite-efflux pump, terF (tellurite resistance protein, and merA (mercuric reductase were also investigated. Outstandingly, 21/27 (78% EcC isolates harbored silA gene located in the chromosome. Complete sil operon was found in 19/21 silA-positive EcC isolates. Interestingly, 8/20 (40% E. hormaechei and 5/6 (83% E. asburiae co-harbored silA/pcoD genes and blaCTX−M−(15,2,or9 and/or blaKPC−2 genes. Frequent occurrences of arsB, terF, and merA genes were detected, especially in silA/pcoD-positive, multidrug-resistant (MDR and/or CTX-M-producing isolates. Our study showed co-presence of antibiotic and heavy metal tolerance genes in MDR EcC isolates. In our viewpoint, there are few studies regarding to bacterial heavy metal tolerance and we call attention for more investigations and discussion about this issue in different hospital pathogens.

SIL1 mutations and clinical spectrum in patients with Marinesco-Sjogren syndrome.

Science.gov (United States)

Krieger, Michael; Roos, Andreas; Stendel, Claudia; Claeys, Kristl G; Sonmez, Fatma Mujgan; Baudis, Michael; Bauer, Peter; Bornemann, Antje; de Goede, Christian; Dufke, Andreas; Finkel, Richard S; Goebel, Hans H; Häussler, Martin; Kingston, Helen; Kirschner, Janbernd; Medne, Livija; Muschke, Petra; Rivier, François; Rudnik-Schöneborn, Sabine; Spengler, Sabrina; Inzana, Francesca; Stanzial, Franco; Benedicenti, Francesco; Synofzik, Matthis; Lia Taratuto, Ana; Pirra, Laura; Tay, Stacey Kiat-Hong; Topaloglu, Haluk; Uyanik, Gökhan; Wand, Dorothea; Williams, Denise; Zerres, Klaus; Weis, Joachim; Senderek, Jan

2013-12-01

Marinesco-Sjögren syndrome is a rare autosomal recessive multisystem disorder featuring cerebellar ataxia, early-onset cataracts, chronic myopathy, variable intellectual disability and delayed motor development. More recently, mutations in the SIL1 gene, which encodes an endoplasmic reticulum resident co-chaperone, were identified as the main cause of Marinesco-Sjögren syndrome. Here we describe the results of SIL1 mutation analysis in 62 patients presenting with early-onset ataxia, cataracts and myopathy or combinations of at least two of these. We obtained a mutation detection rate of 60% (15/25) among patients with the characteristic Marinesco-Sjögren syndrome triad (ataxia, cataracts, myopathy) whereas the detection rate in the group of patients with more variable phenotypic presentation was below 3% (1/37). We report 16 unrelated families with a total of 19 different SIL1 mutations. Among these mutations are 15 previously unreported changes, including single- and multi-exon deletions. Based on data from our screening cohort and data compiled from the literature we found that SIL1 mutations are invariably associated with the combination of a cerebellar syndrome and chronic myopathy. Cataracts were observed in all patients beyond the age of 7 years, but might be missing in infants. Six patients with SIL1 mutations had no intellectual disability, extending the known wide range of cognitive capabilities in Marinesco-Sjögren syndrome to include normal intelligence. Modestly constant features were somatic growth retardation, skeletal abnormalities and pyramidal tract signs. Examination of mutant SIL1 expression in cultured patient lymphoblasts suggested that SIL1 mutations result in severely reduced SIL1 protein levels irrespective of the type and position of mutations. Our data broaden the SIL1 mutation spectrum and confirm that SIL1 is the major Marinesco-Sjögren syndrome gene. SIL1 patients usually present with the characteristic triad but cataracts might be

No limite do silêncio: a cena mínima de Samuel Beckett

Directory of Open Access Journals (Sweden)

Fernando Mesquita de Faria

2014-07-01

Full Text Available http://dx.doi.org/10.5007/2176-8552.2013n16p133 O artigo pretende demonstrar, por reconhecimento, a apropriação do silêncio na dramaturgia de Samuel Beckett. As múltiplas funções e as possibilidades de articulação dramatúrgicas tornam o silêncio tão importante quanto os sons e seu estudo passa a ser essencial para compreendermos os aspectos sonoro-musicais que envolvem a obra do autor, sobretudo por virem associadas a uma linguagem verbal. A estrutura elíptica das suas peças, a exploração sonora de palavras e frases, a escassez de cenários e objetos cênicos, somados ao silêncio, podem produzir um efeito sinestésico no leitor/espectador e são indícios que nos levam a uma reflexão, servindo como álibi para melhor decifrarmos a obra beckettiana.

Preparation, characterization and application of a reversed phase liquid chromatography/hydrophilic interaction chromatography mixed-mode C18-DTT stationary phase.

Science.gov (United States)

Wang, Qing; Long, Yao; Yao, Lin; Xu, Li; Shi, Zhi-Guo; Xu, Lanying

2016-01-01

A mixed-mode chromatographic stationary phase, C18-DTT (dithiothreitol) silica (SiO2) was prepared through "thiol-ene" click chemistry. The obtained material was characterized by fourier transform infrared spectroscope, nitrogen adsorption analysis and contact angle analysis. Chromatographic performance of the C18-DTT was systemically evaluated by studying the effect of acetonitrile content, pH, buffer concentration of the mobile phase and column temperature. It was demonstrated that the novel stationary phase possessed reversed phase liquid chromatography (RPLC)/hydrophilic interaction liquid chromatography (HILIC) mixed-mode property. The stop-flow test revealed that C18-DTT exhibited excellent compatibility with 100% aqueous mobile phase. Additionally, the stability and column-to-column reproducibility of the C18-DTT material were satisfactory, with relative standard deviations of retention factor of the tested analytes (verapamil, fenbufen, guanine, tetrandrine and nicotinic acid) in the range of 1.82-3.72% and 0.85-1.93%, respectively. Finally, the application of C18-DTT column was demonstrated in the separation of non-steroidal anti-inflammatory drugs, aromatic carboxylic acids, alkaloids, nucleo-analytes and polycyclic aromatic hydrocarbons. It had great resolving power in the analysis of various compounds in HILIC and RPLC chromatographic conditions and was a promising RPLC/HILIC mixed-mode stationary phase. Copyright © 2015 Elsevier B.V. All rights reserved.

One column method to prepare 11C-labelled methyl iodide

International Nuclear Information System (INIS)

Kovacs, Z.; Priboczki, E.

1999-01-01

A new method in which the [ 11 C]methyl iodide is prepared on one alumina column is presented. A high specific surface alumina column, previously impregnated with lithium aluminium hydride solution, was used for direct trapping from the target gas and reduction into radiocomplex. The complex was then reacted on this column with HI to form [ 11 C]methyl iodide. The use of one alumina column, instead of a freezing trap, reaction vessel and separate unit for iodination, simplifies the apparatus, shortens the synthesis time and is well suitable for automation. (K.A.)

Research System Integration Laboratory (SIL)

Data.gov (United States)

Federal Laboratory Consortium — The VEA Research SIL (VRS) is essential to the success of the TARDEC 30-Year Strategy. The vast majority of the TARDEC Capability Sets face challenging electronics...

Economic and outcomes consequences of TachoSil®: a systematic review.

Science.gov (United States)

Colombo, Giorgio L; Bettoni, Daria; Di Matteo, Sergio; Grumi, Camilla; Molon, Cinzia; Spinelli, Daniela; Mauro, Gaetano; Tarozzo, Alessia; Bruno, Giacomo M

2014-01-01

TachoSil(®) is a medicated sponge coated with human fibrinogen and human thrombin. It is indicated as a support treatment in adult surgery to improve hemostasis, promote tissue sealing, and support sutures when standard surgical techniques are insufficient. This review systematically analyses the international scientific literature relating to the use of TachoSil in hemostasis and as a surgical sealant, from the point of view of its economic impact. We carried out a systematic review of the PubMed literature up to November 2013. Based on the selection criteria, papers were grouped according to the following outcomes: reduction of time to hemostasis; decrease in length of hospital stay; and decrease in postoperative complications. Twenty-four scientific papers were screened, 13 (54%) of which were randomized controlled trials and included a total of 2,116 patients, 1,055 of whom were treated with TachoSil. In the clinical studies carried out in patients undergoing hepatic, cardiac, or renal surgery, the time to hemostasis obtained with TachoSil was lower (1-4 minutes) than the time measured with other techniques and hemostatic drugs, with statistically significant differences. Moreover, in 13 of 15 studies, TachoSil showed a statistically significant reduction in postoperative complications in comparison with the standard surgical procedure. The range of the observed decrease in the length of hospital stay for TachoSil patients was 2.01-3.58 days versus standard techniques, with a statistically significant difference in favor of TachoSil in eight of 15 studies. This analysis shows that TachoSil has a role as a supportive treatment in surgery to improve hemostasis and promote tissue sealing when standard techniques are insufficient, with a consequent decrease in postoperative complications and hospital costs.

Caracterización y significado de las rocas silíceas y ferruginosas del Paleoceno de Zamora

OpenAIRE

Bustillo, Mª Ángeles; Martín Serrano, Ángel

1980-01-01

Se estudian las rocas silíceas y ferruginosas del Paleógeno de la provincia de Zamora dentro del contexto general de la sedimentación fluvial. El análisis detallado de las muestras es realizado por técnicas petrográficas en lámina delgada y probeta pulida, determinando además su composición mineralógica por difracción de Rayos X. Los minerales silíceos detectados son ópalo C y ópalo C-T mientras que como minerales de hierro aparecen hidróxidos amorfos, hematites y goetita. Las conclusiones...

Sil: a Streptococcus iniae bacteriocin with dual role as an antimicrobial and an immunomodulator that inhibits innate immune response and promotes S. iniae infection.

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Mo-fei Li

Full Text Available Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacteriocin, Sil, and examined its biological activity. Sil is composed of 101 amino acid residues and shares 35.6% overall sequence identity with the lactococcin 972 of Lactococcus lactis. Immunoblot analysis showed that Sil was secreted by S. iniae into the extracellular milieu. Purified recombinant Sil (rSil exhibited a dose-dependent inhibitory effect on the growth of Bacillus subtilis but had no impact on the growths of other 16 Gram-positive bacteria and 10 Gram-negative bacteria representing 23 different bacterial species. Treatment of rSil by heating at 50°C abolished the activity of rSil. rSil bound to the surface of B. subtilis but induced no killing of the target cells. Cellular study revealed that rSil interacted with turbot (Scophthalmus maximus head kidney monocytes and inhibited the innate immune response of the cells, which led to enhanced cellular infection of S. iniae. Antibody blocking of the extracellular Sil produced by S. iniae significantly attenuated the infectivity of S. iniae. Consistent with these in vitro observations, in vivo study showed that administration of turbot with rSil prior to S. iniae infection significantly increased bacterial dissemination and colonization in fish tissues. Taken together, these results indicate that Sil is a novel virulence-associated bacteriostatic and an immunoregulator that promotes S. iniae infection by impairing the immune defense of host fish.

Radial heterogeneity of some analytical columns used in high-performance liquid chromatography.

Science.gov (United States)

Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

2009-04-10

An on-column electrochemical microdetector was used to determine accurately the radial distribution of the mobile phase velocity and of the column efficiency at the exit of three common analytical columns, namely a 100 mm x 4.6mm C18 bonded silica-based monolithic column, a 150 mm x 4.6mm column packed with 2.7 microm porous shell particles of C18 bonded silica (HALO), and a 150 mm x 4.6mm column packed with 3 microm fully porous C18 bonded silica particles (LUNA). The results obtained demonstrate that all three columns are not radially homogeneous. In all three cases, the efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius). The decrease in local efficiency from the core to the wall regions was lower in the case of the monolith (ca. 25%) than in that of the two particle-packed columns (ca. 35-50%). The mobile phase velocity was found to be ca. 1.5% higher in the wall than in the core region of the monolithic column while, in contrast, it was ca. 2.5-4.0% lower in the wall region for the two particle-packed columns.

Malindi, Kenya Stable Isotope Data (delta 18O, delta 13C) for 1801-1994

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Malindi annual oxygen isotopic composition, 1801-1994. Notes on the data: File includes columns for Year AD, Coral d18O, and SST (degrees C). The SST data are sparse...

Three dimensional nilpotent singularity and Sil'nikov bifurcation

International Nuclear Information System (INIS)

Li Xindan; Liu Haifei

2007-01-01

In this paper, by using the normal form, blow-up theory and the technique of global bifurcations, we study the singularity at the origin with threefold zero eigenvalue for nonsymmetric vector fields with nilpotent linear part and 4-jet C ∼ -equivalent toy-bar -bar x+z-bar -bar y+ax 3 y-bar -bar z,with a 0, and analytically prove the existence of Sil'nikov bifurcation, and then of the strange attractor for certain subfamilies of the nonsymmetric versal unfoldings of this singularity under some conditions

Column selectivity in reversed-phase liquid chromatography I. A general quantitative relationship.

Science.gov (United States)

Wilson, N S; Nelson, M D; Dolan, J W; Snyder, L R; Wolcott, R G; Carr, P W

2002-07-05

Retention factors k have been measured for 67 neutral, acidic and basic solutes of highly diverse molecular structure (size, shape, polarity, hydrogen bonding, pKa, etc.) on 10 different C18 columns (other conditions constant). These data have been combined with k values from a previous study (86 solutes, five different C8 and C18 columns) to develop a six-term equation for the correlation of retention as a function of solute and column. Values of k can be correlated with an accuracy of +/- 1-2% (1 standard deviation). This suggests that all significant contributions to column selectivity have been identified (and can be measured) for individual alkyl-silica columns which do not have an embedded polar group. That is, columns of the latter kind can be quantitatively characterized in terms of selectivity for use in the separation of any sample.

Retention behavior of resorcinarene-based cavitands on C8 and C18 stationary phases.

Science.gov (United States)

Bartó, Endre; Prauda, Ibolya; Kilár, Ferenc; Kiss, Ibolya; Felinger, Attila

2015-09-01

The understanding of the retention behavior of large molecules is an area of interest in liquid chromatography. Resorcinarene-based cavitands are cavity-shaped cyclic oligomers that can create host-guest interactions. We have investigated the chromatographic behavior of two types of cyclic tetramers as analytes in high-performance liquid chromatography. The experiments were performed at four different temperatures (15, 25, 35, 45°C) on two types of reversed stationary phases (C8 and C18 ) from two different manufacturers. We have found a huge difference between the retention of resorcinarenes and cavitands. In some cases, the retention factor of cavitands was even a hundred times larger than the retention factor of resorcinarenes. The retention of methylated derivates was two to four times larger compared to that of demethylated compounds on every column. The opposite retention behavior of the resorcinarenes and cavitands on the two types of stationary phases showed well the difference of the selectivity of the XTerra and BDS Hypersil columns. The retention mechanism was studied by the thermodynamic parameters calculated from the van't Hoff equation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Shakespeare dans le Brésil du 19e siècle : un exemple de transfert culturel

OpenAIRE

Segurado, Livia

2015-01-01

Partant de l’Angleterre vers l’Europe continentale au 18ème siècle, les pièces de Shakespeare arrivent au Brésil au 19ème siècle via des modèles français. Ce transfert culturel se fait d’abord par la perception de la culture étrangère imposée au Brésil lors de sa colonisation, suivie d’une graduelle interaction avec elle, puis d’une réinvention adaptée à la couleur locale. L’acteur João Caetano débute en 1835 une approche plus nationaliste, mais c’est la littérature qui voit surgir un authent...

Preconcentration of trace manganese from natural waters by complexation with dithiocarbamate and adsorption onto C18-solid phase extraction column for neutron activation analysis

International Nuclear Information System (INIS)

Sarmani, S.B.; Abdullah, M.P.; Bobaker, A.M.

2004-01-01

A method was developed for the preconcentration and separation of trace manganese from natural water samples by complexation with dithiocarbamate followed by adsorption onto C 18 -solid phase extraction column prior to irradiation. The Mn recovery was better than 99.8% without interference from iron(III) at 5 mg x l -1 , copper(II), zinc(II), aluminum(III) and cobalt(II) at 0.5 mg x l -1 and sodium(I), potassium(I), magnesium(II) and calcium(II) at 1 mg x l -1 . The separation factor was 100 and the detection limit was 0.01 μg x l -1 with good precision and accuracy with a relative error lower than 3%. The method was applied to the determination of Mn in tap, well, river and treated water samples. (author)

Cheap C18-modified silica monolith particles as HPLC stationary phase of good separation efficiency

Energy Technology Data Exchange (ETDEWEB)

Ali, Ashraf; Ali, Faiz; Cheong, Woo Jo [Dept. of of Chemistry, Inha University, Incheon (Korea, Republic of)

2015-06-15

The columns packed with particles have a high efficiency but they are accompanied with a high column back pressure due to lower permeability, while the monolithic columns have a high permeability but they result in inferior separation efficiency for the analysis of small molecules in HPLC. In our laboratory,we have been using the pseudo-monolithic silica particles with C-18 ligand or polystyrene film. The column to column reproducibility was evaluated based on three columns made of three different batches of silica monolith particles, and better than 4.5% in N, and 1.6% in retention time were observed. The day to day reproducibility of a single column for three consecutive days was found better than 1.5% both in N and retention time. The van Deemter plots were derived for awide range of flow rates. The trends of van Deemter plots were similar to those of common patterns and the optimal flow rate was found to be 25 μL/min.

ÉTUDE DE CAS — Governador Valdares, Brésil : Le jardinage s ...

International Development Research Centre (IDRC) Digital Library (Canada)

16 déc. 2010 ... À Governador Valadares, au Brésil, un programme municipal d'agriculture urbaine contribue à garnir la table des citadins des quartiers à faible revenu. Les protagonistes vont et viennent, mais les jardiniers tiennent bon, grâce à l'appui bien coordonné de nombreux acteurs locaux.

Derringer desirability and kinetic plot LC-column comparison approach for MS-compatible lipopeptide analysis.

Science.gov (United States)

D'Hondt, Matthias; Verbeke, Frederick; Stalmans, Sofie; Gevaert, Bert; Wynendaele, Evelien; De Spiegeleer, Bart

2014-06-01

Lipopeptides are currently re-emerging as an interesting subgroup in the peptide research field, having historical applications as antibacterial and antifungal agents and new potential applications as antiviral, antitumor, immune-modulating and cell-penetrating compounds. However, due to their specific structure, chromatographic analysis often requires special buffer systems or the use of trifluoroacetic acid, limiting mass spectrometry detection. Therefore, we used a traditional aqueous/acetonitrile based gradient system, containing 0.1% (m/v) formic acid, to separate four pharmaceutically relevant lipopeptides (polymyxin B 1 , caspofungin, daptomycin and gramicidin A 1 ), which were selected based upon hierarchical cluster analysis (HCA) and principal component analysis (PCA). In total, the performance of four different C18 columns, including one UPLC column, were evaluated using two parallel approaches. First, a Derringer desirability function was used, whereby six single and multiple chromatographic response values were rescaled into one overall D -value per column. Using this approach, the YMC Pack Pro C18 column was ranked as the best column for general MS-compatible lipopeptide separation. Secondly, the kinetic plot approach was used to compare the different columns at different flow rate ranges. As the optimal kinetic column performance is obtained at its maximal pressure, the length elongation factor λ ( P max / P exp ) was used to transform the obtained experimental data (retention times and peak capacities) and construct kinetic performance limit (KPL) curves, allowing a direct visual and unbiased comparison of the selected columns, whereby the YMC Triart C18 UPLC and ACE C18 columns performed as best. Finally, differences in column performance and the (dis)advantages of both approaches are discussed.

TRACING H2 COLUMN DENSITY WITH ATOMIC CARBON (C I) AND CO ISOTOPOLOGS

International Nuclear Information System (INIS)

Lo, N.; Bronfman, L.; Cunningham, M. R.; Jones, P. A.; Lowe, V.; Cortes, P. C.; Simon, R.; Fissel, L.; Novak, G.

2014-01-01

We present the first results of neutral carbon ([C I] 3 P 1 - 3 P 0 at 492 GHz) and carbon monoxide ( 13 CO, J = 1-0) mapping in the Vela Molecular Ridge cloud C (VMR-C) and the G333 giant molecular cloud complexes with the NANTEN2 and Mopra telescopes. For the four regions mapped in this work, we find that [C I] has very similar spectral emission profiles to 13 CO, with comparable line widths. We find that [C I] has an opacity of 0.1-1.3 across the mapped region while the [C I]/ 13 CO peak brightness temperature ratio is between 0.2 and 0.8. The [C I] column density is an order of magnitude lower than that of 13 CO. The H 2 column density derived from [C I] is comparable to values obtained from 12 CO. Our maps show that C I is preferentially detected in gas with low temperatures (below 20 K), which possibly explains the comparable H 2 column density calculated from both tracers (both C I and 12 CO underestimate column density), as a significant amount of the C I in the warmer gas is likely in the higher energy state transition ([C I] 3 P 2 - 3 P 1 at 810 GHz), and thus it is likely that observations of both the above [C I] transitions are needed in order to recover the total H 2 column density

Dicty_cDB: Contig-U16183-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available r*csigkgirmvnsfkdsf*tsfkksfiq*rl*skfdsnssryg*nw*siss* wcr*dfihwftryw*tcyesck**shssyfrtrw*rsndcfr*c*iglgisnctkrlfh* frsklyfires...hwftryw*tcyesck**shssyfrtrw*rsndcfr*c*iglgisnctkrlfh*fr sklyfiresics*edl*sil*tng**nqfsqtrstrrrsfrfwfndyastg*...c*iglgisnctkrlfh* frsklyfiresics*edl*sil*tng**nqfsqtrstrrrsfrfwfndyastg**g*tss lappskrvphy*lvvkeiqliqrvtisfq...yfs ssssnfcr*csigkgirmvnsfkdsf*tsfkksfiq*rl*skfdsnssryg*nw*siss* wcr*dfihwftryw*tcyesck**shssyfrtrw*rsndcfr*

Comparison of three different C18 HPLC columns with different particle sizes for the optimization of aflatoxins analysis.

Science.gov (United States)

Medina, A; Magan, N

2012-03-15

In this work we compared the performance of chromatography columns with particles of 5 and 3 μm with the new 2.7 μm solid core particles for the analysis of aflatoxins B1, G1, B2, and G2 using trifluoroacetic acid pre-column derivatization. Three different columns have been used and chromatographic parameters as retention time, resolution, limit of detection (LOD), limit of quantification (LOQ) were obtained from all of them and compared. The results show that comparing with the traditional columns, shorter columns (100 mm × 4.6 mm) with the new solid core particles are suitable for the analysis of these mycotoxins and allowed the reduction of the analysis time by 45.5% and 33.3% with respect to columns with particle size 5 μm (150 mm × 4.6 mm) and 3 μm (150 mm × 4.6 mm) respectively, without any detrimental effect on performance. This leads to the reduction of the analysis costs by saving on organic solvents and increasing the total number of analyses per day. The capability of these columns for analyzing samples, in different culture media, was assessed by analyzing different samples from: yeasts extract sucrose medium, corn meal agar medium and fresh hazelnut media. Copyright © 2012 Elsevier B.V. All rights reserved.

Semi-permeable surface analytical reversed-phase column for the improved trace analysis of acidic pesticides in water with coupled-column reversed-phase liquid chromatography with UV detection. Determination of bromoxynil and bentazone in surface water.

Science.gov (United States)

Hogendoorn, E A; Westhuis, K; Dijkman, E; Heusinkveld, H A; den Boer, A C; Evers, E A; Baumann, R A

1999-10-08

The coupled-column (LC-LC) configuration consisting of a 3 microm C18 column (50 x 4.6 mm I.D.) as the first column and a 5 microm C18 semi-permeable-surface (SPS) column (150 x 4.6 mm I.D.) as the second column appeared to be successful for the screening of acidic pesticides in surface water samples. In comparison to LC-LC employing two C18 columns, the combination of C18/SPS-C18 significantly decreased the baseline deviation caused by the hump of the co-extracted humic substances when using UV detection (217 nm). The developed LC-LC procedure allowed the simultaneous determination of the target analytes bentazone and bromoxynil in uncleaned extracts of surface water samples to a level of 0.05 microg/l in less than 15 min. In combination with a simple solid-phase extraction step (200 ml of water on a 500 mg C18-bonded silica) the analytical procedure provides a high sample throughput. During a period of about five months more than 200 ditch-water samples originating from agricultural locations were analyzed with the developed procedure. Validation of the method was performed by randomly analyzing recoveries of water samples spiked at levels of 0.1 microg/l (n=10), 0.5 microg/l (n=7) and 2.5 microg/l (n=4). Weighted regression of the recovery data showed that the method provides overall recoveries of 95 and 100% for bentazone and bromoxynil, respectively, with corresponding intra-laboratory reproducibilities of 10 and 11%, respectively. Confirmation of the analytes in part of the samples extracts was carried out with GC-negative ion chemical ionization MS involving a derivatization step with bis(trifluoromethyl)benzyl bromide. No false negatives or positives were observed.

Clinical significance of determination of serum IGF-I and SIL-2R levels in patients with prostatic cancer

International Nuclear Information System (INIS)

Zhang Zaigao; Lv Yuliang; Li Jiacheng

2006-01-01

Objective: To investigate the significance of changes of serum IGF-I and SIL-2R levels in patients with prostatic cancer. Methods: Serum IGF-I levels (with RIA) and SIL-2R levels (with ELISA) were measured in 31 patients with prostatic cancer and 30 controls. Results: Serum levels of IGF-I and SIL-2R in the 31 patients were significantly higher than those in controls (P<0.01), serum IGF-I and SIL-2R levels were mutually positively correlated (r=0.6182, P<0.01). Conclusion: Serum IGF-I and SIL-2R were useful markers for prostatic cancer. (authors)

Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

Science.gov (United States)

Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

2015-08-19

Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. Copyright © 2015. Published by Elsevier B.V.

Le cas du Brésil

International Development Research Centre (IDRC) Digital Library (Canada)

pwust

important volet des activités de coopération du Brésil dans les pays en développement, ...... attention à l'Amérique latine ou aux Caraïbes, malgré la priorité accordée à .... prudente et sélective face aux opérations triangulaires, afin d'éviter la ...

Silêncio nas organizações: uma revisão e discussão da literatura.

Directory of Open Access Journals (Sweden)

Marcos Júnior de Moura-Paula

2014-10-01

Full Text Available O objetivo deste trabalho é apresentar como o silêncio tem sido estudado por pesquisadores de gestão ou áreas afins (como psicologia ou comunicação organizacionais. Ignorado por longo tempo, o silêncio emerge como uma área frutífera de pesquisa devido a diversas consequências que ele pode causar para os empregados (estresse, angústia, baixa autoestima e dissonância cognitiva, para as organizações (absenteísmo, maior rotatividade, baixa produtividade e para a sociedade (não denúncia de ilegalidades cometidas pelas organizações. Faz-se um levantamento bibliográfico com base na divisão em três ondas de pesquisa sobre a evolução dos estudos de voz e silêncio nas organizações baseado em Brinsfield, Edwards e Greenberg (2009, com foco no silêncio. Da primeira onda (1970-1980 são apresentados: o conceito de voz e a subsunção do silêncio ao conceito de lealdade; as “espirais de silêncio” e o “efeito mudo” (MUM effect. Da segunda onda (1980-2000: a “denúncia de irregularidades organizacionais” (whistleblowing; a “discordância organizacional baseada em princípios” (principled organizational dissent; a justiça organizacional; a “promoção de questões” (issue selling; a cidadania organizacional; o ostracismo social e a “síndrome do surdo” (deaf-ear syndrome. Da terceira onda (2000 em diante: o silêncio organizacional; o silêncio dos empregados; retirada do trabalho (job withdrawal; aprendizagem organizacional e transferência de conhecimento. Observou-se que as pesquisas, principalmente no caso da terceira onda, têm evoluído de pesquisas conceituais e qualitativas para pesquisas quantitativas, havendo questionamentos de alguns pesquisadores sobre a necessidade de se utilizar outras abordagens teórico-metodológicas além das de inspiração positivista. A pesquisa brasileira sobre silêncio, apesar do pequeno volume, contribui para a compreensão do fenômeno na medida em que se insere na

Evaluation of chromatographic columns packed with semi- and fully porous particles for benzimidazoles separation.

Science.gov (United States)

Gonzalo-Lumbreras, Raquel; Sanz-Landaluze, Jon; Cámara, Carmen

2015-07-01

The behavior of 15 benzimidazoles, including their main metabolites, using several C18 columns with standard or narrow-bore diameters and different particle size and type were evaluated. These commercial columns were selected because their differences could affect separation of benzimidazoles, and so they can be used as alternative columns. A simple screening method for the analysis of benzimidazole residues and their main metabolites was developed. First, the separation of benzimidazoles was optimized using a Kinetex C18 column; later, analytical performances of other columns using the above optimized conditions were compared and then individually re-optimized. Critical pairs resolution, analysis run time, column type and characteristics, and selectivity were considered for chromatographic columns comparison. Kinetex XB was selected because it provides the shortest analysis time and the best resolution of critical pairs. Using this column, the separation conditions were re-optimized using a factorial design. Separations obtained with the different columns tested can be applied to the analysis of specific benzimidazoles residues or other applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Soil reaction and absorption of silicon by rice Reação do solo e absorção de silício pelo arroz

Directory of Open Access Journals (Sweden)

Mônica Sartori de Camargo

2007-01-01

Full Text Available The solubility and availability of silicon can be influenced by soil reaction. A pot experiment with a clayey textured Rhodic Acrustox was conducted under greenhouse conditions to evaluate the effect of soil reaction on silicon availability to rice plants. The experiment was set up in a completely randomized design, using a factorial scheme (4 x 4 with four materials (calcitic lime, calcium and magnesium silicate, pure silicic acid, and wollastonite, four rates (0, 2500, 5000 and 7500 mg per 5 kg-pot and four replicates. After 60 days, dry matter yield and silicon absorption by the rice shoot plants, pH CaCl2, and soluble silicon (0.5 mol L-1 acetic acid and 0.01 mol L-1CaCl2 in the soil were evaluated. The materials increased soil pH as the applied rates increased, except silicic acid. Soluble silicon extracted by 0.5 mol L-1 acetic acid also increased with applied rates. For calcium chloride, soluble silicon increased in the soil only with wollastonite and calcium and magnesium silicate, agreeing with its total content. Silicon absorption by the above-ground part of the rice plants was linearly correlated with rates of wollastonite, followed by calcium and magnesium silicate, silicic acid and calcitic lime. Soil pH increase with lime was not sufficient to provide silicon to the rice. The 0.01 mol L-1 CaCl2 soluble silicon had the best correlation with silicon absorption by plants. More studies are necessary under field conditions and other soils to corroborate the presented results.A solubilidade e disponibilidade de silício podem ser influenciadas pela reação do solo. Com o objetivo de estudar o efeito da reação do solo sobre a disponibilidade de silício para a cultura do arroz, foi conduzido experimento em Latossolo Vermelho álico textura argilosa em casa-de-vegetação. O experimento foi conduzido em fatorial 4 x 4, delineamento em blocos inteiramente casualizados e quatro repetições. Quatro materiais (calcário, silicato de c

Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

Science.gov (United States)

Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

2018-02-02

An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

Soluble interleukin 6 receptor (sIL-6R) mediates colonic tumor cell adherence to the vascular endothelium: a mechanism for metastatic initiation?

LENUS (Irish Health Repository)

Dowdall, J F

2012-02-03

The mechanisms by which surgery increases metastatic proliferation remain poorly characterized, although endotoxin and immunocytes play a role. Recent evidence suggests that endothelial adherence of tumor cells may be important in the formation of metastases. Soluble receptors of interleukin-6 (sIL-6R) shed by activated neutrophils exert IL-6 effects on endothelial cells, which are unresponsive under normal circumstances. This study examined the hypothesis that sIL-6R released by surgical stress increases tumor cell adherence to the endothelium. Neutrophils (PMN) were stimulated with lipopolysaccharide, C-reactive protein (CRP), and tumor necrosis factor-alpha. Soluble IL-6R release was measured by enzyme-linked immunosorbent assay. Colonic tumor cells transfected with green fluorescent protein and endothelial cells were exposed to sIL-6R, and tumor cell adherence and transmigration were measured by fluorescence microscopy. Basal release of sIL-6R from PMN was 44.7 +\\/- 8.2 pg\\/ml at 60 min. This was significantly increased by endotoxin and CRP (131 +\\/- 16.8 and 84.1 +\\/- 5.3, respectively; both P < 0.05). However, tumor necrosis factor-alpha did not significantly alter sIL-6R release. Endothelial and tumor cell exposure to sIL-6R increased tumor cell adherence by 71.3% within 2 h but did not significantly increase transmigration, even at 6 h. Mediators of surgical stress induce neutrophil release of a soluble receptor for IL-6 that enhances colon cancer cell endothelial adherence. Since adherence to the endothelium is now considered to be a key event in metastatic genesis, these findings have important implications for colon cancer treatment strategies.

Biocatalytically active silCoat-composites entrapping viable Escherichia coli.

Science.gov (United States)

Findeisen, A; Thum, O; Ansorge-Schumacher, M B

2014-02-01

Application of whole cells in industrial processes requires high catalytic activity, manageability, and viability under technical conditions, which can in principle be accomplished by appropriate immobilization. Here, we report the identification of carrier material allowing exceptionally efficient adsorptive binding of Escherichia coli whole cells hosting catalytically active carbonyl reductase from Candida parapsilosis (CPCR2). With the immobilizates, composite formation with both hydrophobic and hydrophilized silicone was achieved, yielding advanced silCoat-material and HYsilCoat-material, respectively. HYsilCoat-whole cells were viable preparations with a cell loading up to 400 mg(E. coli) · g(-1)(carrier) and considerably lower leaching than native immobilizates. SilCoat-whole cells performed particularly well in neat substrate exhibiting distinctly increased catalytic activity.

Improved quality control of [18F]fluoromethylcholine

International Nuclear Information System (INIS)

Nader, Michael; Reindl, Dietmar; Eichinger, Reinhard; Beheshti, Mohsen; Langsteger, Werner

2011-01-01

Objectives: With respect to the broad application of [ 18 F-methyl]fluorocholine (FCH), there is a need for a safe, but also efficient and convenient way for routine quality control of FCH. Therefore, a GC- method should be developed and validated which allows the simultaneous quantitation of all chemical impurities and residual solvents such as acetonitrile, ethanol, dibromomethane and N,N-dimethylaminoethanol. Methods: Analytical GC has been performed with a GC-capillary column Optima 1701 (50 m×0.32 mm), and a pre-column deactivated capillary column phenyl-Sil (10 m×0.32) in line with a flame ionization detector (FID) was used. The validation includes the following tests: specificity, range, accuracy, linearity, precision, limit of detection (LOD) and limit of quantitation (LOQ) of all listed substances. Results: The described GC method has been successfully used for the quantitation of the listed chemical impurities. The specificity of the GC separation has been proven by demonstrating that the appearing peaks are completely separated from each other and that a resolution R≥1.5 for the separation of the peaks could be achieved. The specified range confirmed that the analytical procedure provides an acceptable degree of linearity, accuracy and precision. For each substance, a range from 2% to 120% of the specification limit could be demonstrated. The corresponding LOD values were determined and were much lower than the specification limits. Conclusions: An efficient and convenient GC method for the quality control of FCH has been developed and validated which meets all acceptance criteria in terms of linearity, specificity, precision, accuracy, LOD and LOQ.

Localization and analysis of error sources for the numerical SIL proof; Lokalisierung und Analyse von Fehlerquellen beim numerischen SIL-Nachweis

Energy Technology Data Exchange (ETDEWEB)

Duepont, D.; Litz, L. [Technische Univ. Kaiserslautern (Germany). Lehrstuhl fuer Automatisierungstechnik; Netter, P. [Infraserv GmbH und Co. Hoechst KG, Frankfurt am Main (Germany)

2008-07-01

According to the standard IEC 61511 each safety-related loop is assigned to one of the four Safety Integrity Levels (SILs). For every safety-related loop a SIL-specific Probability of Failure on Demand (PFD) must be proven. Usually, the PFD calculation is performed based upon the failure rates of each loop component aided by commercial software tools. However, this bottom-up approach suffers from many uncertainties. Especially, a lack of reliable failure rate data causes many problems. Reference data collected in different environments are available to solve this situation. However, this pragmatism leads to a PFD bandwidth, not to a single PFD value as desired. In order to make a decision for a numerical value appropriate for the chemical and pharmaceutical process industry a data ascertainment has been initiated by the European NAMUR. Its results display large deficiencies for the bottom-up approach. The error sources leading to this situation are located and analyzed. (orig.)

Preparation of 11C-labelled methanol on alumina column

International Nuclear Information System (INIS)

Sarkadi, E.; Kovacs, Z.; Horvath, G.

1998-01-01

The [ 11 C]methyl iodide is an important intermedia to synthesize 11 C-labelled radiopharmaceuticals for medical diagnostics in positron emission tomography. Recently a new method has been developed to produce [ 11 C]methanol intermedia. The advantage of this method of radiomethanol preparation is the application of an alumina column at room temperature instead of a complicated cooling unit used with the conventional reaction vessel. The yield and purity of radiomethanol was the same as in the previous methods. (K.A.)

Le CRDI au Brésil

International Development Research Centre (IDRC) Digital Library (Canada)

Les recherches subventionnées par le CRDI au Brésil ont permis d'éclairer les débats sur nombre de questions, dont la démocratie, la croissance économique, la santé, les services sociaux, l'innovation, la foresterie et l'eau. Pendant la dictature militaire, qui a pris fin en 1985, le CRDI s'est employé à assurer la survie de la ...

Characterization of retentivity of reversed phase liquid chromatography columns.

Science.gov (United States)

Ying, P T; Dorsey, J G

1991-03-01

There are dozens of commercially available reversed phase columns, most marketed as C-8 or C-18 materials, but with no useful way of classifying their retentivity. A useful way of ranking these columns in terms of column "strength" or retentivity is presented. The method utilizes a value for ln k'(w), the estimated retention of a solute from a mobile phase of 100% water, and the slope of the plot of ln k' vsE(T)(30), the solvent polarity. The method is validated with 26 solutes varying in ln k'(w) from about 2 to over 20, on 14 different reversed phase columns. In agreement with previous work, it is found that the phase volume ratio of the column is the most important parameter in determining retentivity. It is strongly suggested that manufacturers adopt a uniform method of calculating this value and that it be made available in advertising, rather than the uninterpretable "% carbon".

Blaise Cendrars e o Brasil: "Brésil, des hommes sont venus"

OpenAIRE

Wimmer, Norma [UNESP

2013-01-01

The paper intitled Blaise Cendrars and Brazil: Brésil, des hommes sont venus discusses the way Cendrars portrays Brazil, and also debates his influence on the artists of the Semana de Arte Moderna (Modern Art Week) in 1922. O texto intitulado Blaise Cendrars e o Brasil: Brésil, des hommes sont venus tece considerações acerca da perspectiva sob a qual Cendrars vê o Brasil, bem como de sua relação com os artistas da Semana de Arte Moderna de 1922.

Steroids in porcine follicular fluid: analysis by HPLC, capillary CG and capillary CG/MS after purification on SEP-PAK C18 and ion exchange chromatography.

Science.gov (United States)

Khalil, M W; Lawson, V

1983-04-01

Steroids in porcine follicular fluid have been concentrated by reverse phase chromatography in SEP-PAK C18 and purified further on the cation exchanger SP-Sephadex C-25. Fractionation into unconjugated neutral and phenolic steroids, glucuronides and sulfates was carried out on triethylaminohydroxypropyl Sephadex LH-20 (TEAP-LH-20). The unconjugated neutral fraction was analysed by high pressure liquid chromatography (HPLC) on a C18 radial cartridge 5 mm I.D.; 10 mu, or on a C18 5 mu RESOLVE column, and by capillary gas chromatography (GC) on a 12 M OV-1 cross linked fused silica column. Testosterone, progesterone and androstenedione were the major steroids detected by HPLC monitored at 254 nm, although 17- hydroxy-, 20 alpha-dihydro- and 20 beta-dihydroprogesterone were also present. Pregnenolone, pregnanediol, dehydroepiandrosterone, 17-hydroxypregnenolone and androsterone were detected by capillary CG as their 0-methyloxime trimethylsilyether derivatives. Further confirmation of structure was provided by complete mass spectral data or by selective ion monitoring (SIM).

Synthesis of the C(18)-C(34) fragment of amphidinolide C and the C(18)-C(29) fragment of amphidinolide F.

Science.gov (United States)

Roy, Sudeshna; Spilling, Christopher D

2010-11-19

A convergent synthesis of the C(18)-C(34) fragment of amphidinolide C and the C(18)-C(29) fragment of amphidinolide F is reported. The approach involves the synthesis of the common intermediate tetrahydrofuranyl-β-ketophosphonate via cross metathesis, Pd(0)-catalyzed cyclization, and hydroboration-oxidation. The β-ketophosphonate was coupled to three side chain aldehydes using a Horner-Wadsworth-Emmons (HWE) olefination reaction to give dienones, which were reduced with l-selectride to give the fragments of amphidinolide C and F.

Testing for HPV as an objective measure for quality assurance in gynecologic cytology: positive rates in equivocal and abnormal specimens and comparison with the ASCUS to SIL ratio.

Science.gov (United States)

Ko, Vincent; Nanji, Shabin; Tambouret, Rosemary H; Wilbur, David C

2007-04-25

Inappropriate use of the category of atypical squamous cells of undetermined significance (ASCUS) can result in overtreatment or undertreatment of patients, which may decrease the cost effectiveness of screening. Quality assurance tools, such as the ASCUS to squamous intraepithelial lesion ratio (ASCUS:SIL) and case review, are imperfect. High-risk HPV (hrHPV) testing is an objective test for a known viral carcinogen, and hrHPV may be more useful in monitoring the quality of ASCUS interpretations. hrHPV rates for cytologic diagnoses and patient age groups were calculated for a 2-year period. All hrHPV results for ASCUS and SIL over a 17-month period were analyzed by patient age group, over time, and by individual cytopathologist to compare hrHPV rates with the corresponding ASCUS:SIL. The hrHPV positive rate for SIL was >90%, and it was 32.6% for ASCUS. Stratification by patient age showed that approximately 50% of patients younger than 30 years and older than 70 years of age were hrHPV positive, whereas other patients had a lower rate ranging from 14% to 34%. The overall ASCUS:SIL was 1.42, and the overall hrHPV positive rate was 39.9%. Over time and by individual cytopathologist, the hrHPV rate performed similarly to the ASCUS:SIL. The analysis by patient age showed a high statistical correlation (R(2) = 0.9772) between the 2 methods. Despite differences between these techniques, the hrHPV rate closely recapitulates the ASCUS:SIL. When used together, the 2 methods can complement each other. The desirable hrHPV-positive range appears to be 40% to 50%; however, this may vary based on the patient population. The hrHPV rate is as quick and cost effective as determining the ASCUS:SIL. (c) 2007 American Cancer Society.

Clinical significance of changes of serum levels of SIL-2R and CEA in patients with lung cancer after chemotherapy

International Nuclear Information System (INIS)

Rui Zhilian

2004-01-01

Objective: To investigate the changes of serum levels of SIL-2R and CEA after chemotherapy in patients with lung cancer. Methods: Serum levels of SIL-2R (with ELISA) and CEA (with RIA) were measured in 31 patients with lung cancer both before and after chemotherapy as well as in 35 cantrols. Results: Before chemotherapy, both serum SIL-2R and CEA levels in the patients were significantly higher than those in the controls (P 0.05), but the serum SIL-2R levels in the patients remained significantly higher than those in the controls (P<0.05). Conclusion: Determination of changes of serum SIL-2R and CEA levels after chemotherapy might be helpful for predicting the treatment outcomes in patients with lung cancer. (author)

A SIL quantification approach based on an operating situation model for safety evaluation in complex guided transportation systems

International Nuclear Information System (INIS)

Beugin, J.; Renaux, D.; Cauffriez, L.

2007-01-01

Safety analysis in guided transportation systems is essential to avoid rare but potentially catastrophic accidents. This article presents a quantitative probabilistic model that integrates Safety Integrity Levels (SIL) for evaluating the safety of such systems. The standardized SIL indicator allows the safety requirements of each safety subsystem, function and/or piece of equipment to be specified, making SILs pivotal parameters in safety evaluation. However, different interpretations of SIL exist, and faced with the complexity of guided transportation systems, the current SIL allocation methods are inadequate for the task of safety assessment. To remedy these problems, the model developed in this paper seeks to verify, during the design phase of guided transportation system, whether or not the safety specifications established by the transport authorities allow the overall safety target to be attained (i.e., if the SIL allocated to the different safety functions are sufficient to ensure the required level of safety). To meet this objective, the model is based both on the operating situation concept and on Monte Carlo simulation. The former allows safety systems to be formalized and their dynamics to be analyzed in order to show the evolution of the system in time and space, and the latter make it possible to perform probabilistic calculations based on the scenario structure obtained

Preparation and Characterization of a Polymeric Monolithic Column for Use in High-Performance Liquid Chromatography (HPLC)

Science.gov (United States)

Bindis, Michael P.; Bretz, Stacey Lowery; Danielson, Neil D.

2011-01-01

The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C[subscript]18 silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different…

Two-column sequential injection chromatography for fast isocratic separation of two analytes of greatly differing chemical properties.

Science.gov (United States)

Šatínský, Dalibor; Chocholouš, Petr; Válová, Olga; Hanusová, Lucia; Solich, Petr

2013-09-30

This paper deals with a novel approach to separate two analytes with different chemical properties and different lipophilicity. The newly described methodology is based on the two column system that was used for isocratic separation of two analytes with very different lipophilicity-dexamethasone and cinchocaine. Simultaneous separation of model compounds cinchocaine and dexamethasone was carried under the following conditions in two-column sequential injection chromatography system (2-C SIC). A 25×4.6 mm C-18 monolithic column was used in the first dimension for retention and separation of dexamethasone with mobile phase acetonitrile:water 30:70 (v/v), flow rate 0.9 mL min(-1) and consumption of 1.7 mL. A 10×4.6 mm C-18 monolithic column with 5×4.6 mm C-18 precolumn was used in the second dimension for retention and separation of cinchocaine using mobile phase acetonitrile:water 60:40 (v/v), flow rate 0.9 mL min(-1) and consumption 1.5 mL. Whole analysis time including both mobile phase's aspirations and both column separations was performed in less than 4 min. The method was fully validated and used for determination of cinchocaine and dexamethasone in pharmaceutical otic drops. The developed 2-C SIC method was compared with HPLC method under the isocratic conditions of separation on monolithic column (25×4.6 mm C-18). Spectrophotometric detection of both compounds was performed at wavelength 240 nm. System repeatability and method precision were found in the range (0.39-3.12%) for both compounds. Linearity of determination was evaluated in the range 50-500 μg mL(-1) and coefficients of determination were found to be r(2)=0.99912 for dexamethasone and r(2)=0.99969 for cinchocaine. Copyright © 2013 Elsevier B.V. All rights reserved.

Quem Cala, Consente? Uma Leitura de “Calúnia” e de The Handmaid’s Tale sob a Perspectiva do Silêncio

Directory of Open Access Journals (Sweden)

Relines Rufino de Abreu

2016-07-01

Full Text Available Este artigo visa perscrutar o silêncio nas obras The Handmaid’s Tale (1985, de Margaret Atwood e “Calúnia” (1981, de Lillian Hellman, como elemento promotor de significação, principalmente no que se refere aos papéis sociais representados pelas personagens. Através das vozes sociais do discurso, observase a implantação da política do silêncio por duas vias: o silêncio local e o silêncio constitutivo. Os textos aqui analisados mostram a intersecção dessas duas formas do silêncio ao mesmo tempo em que apresentam diferentes métodos de aplicação dessa política.

Changes of serum IL-1 and sIL-2R levels after intravenous photo-coagulation in patients with varicose greater saphenous vein

International Nuclear Information System (INIS)

Han Li'na; Gu Ying; Liu Fanguang

2004-01-01

Objective: To determine the changes of serum interleukin 2 (IL-2) and soluble interleukin 2 receptor (sIL-2R) levels in patients with varicose greater saphenous vein after intravenous photocoagulation. Methods: Fifty patients with varicose greater saphenous vein were divided into two groups (mild and severe) according to their clinical symptoms. Serum IL-2 and sIL-2R levels were determined with RIA and ELISA respectively in these patients and 30 controls. Results: Serum levels of IL-2 and sIL-2R in patients of the mild group were about the same as those in the controls. In patients of the severe group, levels of IL-2 decreased and levels of sIL-2R increased significantly. After photocoagulation, the IL-2 levels dropped at first but gradually rose; the reverse was true for the sIL-2R levels. The final levels of IL-2 and sIL-2R approached those before treatment in the mild group. In the severe group, the final IL-2 levels were higher and sIL-2R levels lower than those before photocoagulation. Conclusion: Determination of serum IL-2 and sIL-2R levels revealed information about the immune status of the patients and could be applied for judgement of the treatment effect

Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

Science.gov (United States)

Gritti, Fabrice; Guiochon, Georges

2008-04-11

The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

Simultaneous identification/determination system for phentolamine and sildenafil as adulterants in soft drinks advertising roborant nutrition.

Science.gov (United States)

Mikami, Eiichi; Ohno, Tsutomu; Matsumoto, Hiroshi

2002-12-04

An easily available, simultaneous identification/determination procedure for phentolamine (PHE) and sildenafil (SIL) in adulterated dietary supplements was established by using a combination of three different analytical methods; thin-layer chromatography (TLC), liquid chromatography-mass spectrometry (LC/MS) and a high-performance liquid chromatography (HPLC)/photo-diode-array. The sample solution for TLC was applied to silica gel 60 F(254) plates with chloroform/ammonia solution (28)/methanol (70:5:3, lower layer) and chloroform/diethylamine/methanol (15:3:2) as the developing solvent. Spots were located under UV radiation at 254 nm. Mass spectra of PHE and SIL by LC/MS were investigated with electrospray ionization (ESI) interface, under both positive and negative ion mode. The HPLC analysis was performed on a column of Wakosil 5C18 (4.6 mm x 150 mm, 5 microm) with water/methanol/acetonitrile/triethylamine (580:250:170:1) adjusted with phosphoric acid to pH 3.0 as the mobile phase, and the effluent was monitored with a photo-diode-array detector. Quantitative HPLC analysis of PHE and SIL were detected at 280 nm. When this procedure was applied to commercial soft drinks, PHE and SIL were identified and determined at a concentration of 17 mg PHE and 44 mg SIL per bottle, respectively. The procedure described here is available for the screening of PHE and SIL in adulterated supplements. Copyright 2002 Elsevier Science Ireland Ltd.

Clinical significance of changes of serum FT3, FT4 and SIL-2R levels after treatment in patients with hyperthyroidism

International Nuclear Information System (INIS)

Ye Qing

2008-01-01

Objective: To explore the clinical significance of changes of serum FT 3 , FT 4 , SIL-2R levels after treatment in patients with hyperthyroidism. Methods: Serum FT 3 , FT 4 , TSH (with RIA) and SIL-2R (with ELISA) levels were measured in 55 patients with hyperthyroidism both before and after treatment as well as in 35 controls. Results: Before treatment, in the patients the serum FT 3 , FT 4 , SIL-2R levels were significantly higher than those in the controls (P 3 , FT 4 , SIL-2 levels were not significantly different from those in controls (P>0.05). Conclusion: Detection of serum FT 3 , FT 4 , SIL-2R levels is valuable for treatment outcome prediction in patients with hyperthyroidism. (authors)

SEISMIC B E H AV I OUR OF R.C.C BUILDING WITH AND WITHOUT FLOATING COLUMNS

OpenAIRE

E. ANUSHA; E. V. RAGHVA RAO; N. CHENNA KESAVA

2018-01-01

The main purpose of the project is to study the seismic behaviour of R.C.C building with and without floating column,G+5 structures has been selected for carrying out the project work. The building models are generated using software STAAD.

HPLC analysis of o-, m- and p-isomers using a betacyclodextrin column

International Nuclear Information System (INIS)

Haeger, J.

1994-01-01

The irradiation of foodstuffs containing protein leads to the hydroxylation of phenylalanine, due to which the position isomers o-tyrosine and m-tyrosine are formed in addition to the naturally occurring p-tyrosine. HPLC analysis of tyrosine isomers following sample processing and purification is generally carried out in a RP-C 18 column. In actual practice, the peaks of p-tyrosine and m-tyrosine overlap and a separation of o-tyrosine from baseline cannot always be achieved. Those separation problems may be solved, if a beta-cyclodextrin column is used in addition or as an alternative to the RP-C 18 column. The completely different separation characteristics of the latter provide a new pattern of elution for the tyrosine isomers. It is thus possible for p-tyrosine, which occurs in much higher concentrations than the other tyrosines, to be clearly separated chromatographically. (orig./vhe) [de

Separation of cannabinoids on three different mixed-mode columns containing carbon/nanodiamond/amine-polymer superficially porous particles.

Science.gov (United States)

Hung, Chuan-Hsi; Zukowski, Janusz; Jensen, David S; Miles, Andrew J; Sulak, Clayton; Dadson, Andrew E; Linford, Matthew R

2015-09-01

Three mixed-mode high-performance liquid chromatography columns packed with superficially porous carbon/nanodiamond/amine-polymer particles were used to separate mixtures of cannabinoids. Columns evaluated included: (i) reversed phase (C18 ), weak anion exchange, 4.6 × 33 mm, 3.6 μm, and 4.6 × 100 mm, 3.6 μm, (ii) reversed phase, strong anion exchange (quaternary amine), 4.6×33 mm, 3.6 μm, and (iii) hydrophilic interaction liquid chromatography, 4.6 × 150 mm, 3.6 μm. Different selectivities were achieved under various mobile phase and stationary phase conditions. Efficiencies and peak capacities were as high as 54 000 N/m and 56, respectively. The reversed phase mixed-mode column (C18 ) retained tetrahydrocannabinolic acid strongly under acidic conditions and weakly under basic conditions. Tetrahydrocannabinolic acid was retained strongly on the reversed phase, strong anion exchange mixed-mode column under basic polar organic mobile phase conditions. The hydrophilic interaction liquid chromatography column retained polar cannabinoids better than the (more) neutral ones under basic conditions. A longer reversed phase (C18 ) mixed-mode column (4.6 × 100 mm) showed better resolution for analytes (and a contaminant) than a shorter column. Fast separations were achieved in less than 5 min and sometimes 2 min. A real world sample (bubble hash extract) was also analyzed by gradient elution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fluorine-18 labelling of a novel series of chimeric, mdm2 oncogene targeting, peptide-pna oligomers using [18F]FPyME

International Nuclear Information System (INIS)

Kuhnast, B.; Hinnen, F.; Boisgard, R.; Tavitian, B.; Dolle, F.; Nielsen, P.

2011-01-01

Complete text of publication follows: Peptide nucleic acids (PNAs) form a unique class of synthetic macromolecules, originally designed as ligands for the recognition of double stranded DNA, where the deoxyribose phosphate backbone of original DNA is replaced by a pseudo-peptide N-(2-aminoethyl)glycyl backbone, while retaining the nucleobases of DNA. PNAs have already showed promising therapeutic potential as antisense and anti-gene agents and are inspiring the development of a variety of research and diagnostic assays, including their use as imaging tools. Within our intensive programs of development of oligonucleotide-based probes for PET-imaging, a novel series of chimeric peptide-PNA oligomers has been designed as complementary antisense probes targeting a specific 15-base sequence located at the intron-exon junction of the pre-mRNA of the murine double minute (mdm2) oncogene. This gene codes for a p53 interacting protein that represses p53 transcriptional activity, and appears to be over expressed in several tumor types including soft tissue sarcomas and osteosarcomas as well as breast tumors. For in vivo 3D-imaging purposes, all oligomers include a cysteine thus providing a sulfhydryl function permitting prosthetic conjugation with maleimide-based reagents such as AlexaFluor680 R (AF680) for optical fluorescence imaging and [ 18 F]FPyME (1-[3-(2-[ 18 F]fluoropyridin-3-yloxy)propyl]pyrrole-2, 5-dione), a prosthetic reagent labeled with the positron-emitter fluorine-18 for PET imaging, which latter work is presented herein. Methods: [ 18 F]FPyME was prepared using a three-step radiochemical pathway already reported and includes an HPLC-purification (semi-preparative SiO 2 Zorbax R Rx-SIL, Hewlett Packard). [ 18 F]FPyME was conjugated with the peptide-PNA oligomers (PNA3132, PNA3133, and PNA3135, 0.25-0.30 micro-moles) in 1/9 (v:v) mixture (1 mL) of DMSO and 0.1 M aq. PBS (pH 8) at room temperature for 15 min. The [ 18 F]FPyME-conjugated products (c-[ 18 F

Design of internally heat-integrated distillation column (HIDiC): Uniform heat transfer area versus uniform heat distribution

Energy Technology Data Exchange (ETDEWEB)

Suphanit, B. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Pracha Utit Rd., Tungkru, Bangkok 10140 (Thailand)

2010-03-15

The internally heat-integrated distillation column (HIDiC) is a complex column configuration which is more energy efficient than the equivalent conventional column or the distillation column with direct vapor recompression scheme (VRC). Exploiting the heat integration between two diabatic sections operating at different pressures of the HIDiC can greatly enhance the energy performance of the system. On the other hand, the design and optimization of HIDiC is more difficult than those of the conventional distillation column or the column with VRC. The former involves many design parameters, and the most critical one is the pressure ratio between both diabatic sections. However, the heat distribution along the diabatic sections is also another significant factor not yet thoroughly investigated. In this work, two typical distribution schemes, i.e. uniform heat transfer area and uniform heat distribution, are studied by applying a novel approach to solve the simulation problem in Aspen Plus 2004.1. The comparison of both distributing schemes is discussed via two widely-used case studies, namely benzene-toluene separation and propylene-propane splitter. (author)

18FFPyKYNE, a fluoro-pyridine-based alkyne reagent designed for the fluorine-18 labelling of macromolecules using click chemistry

International Nuclear Information System (INIS)

Kuhnast, B.; Hinnen, F.; Tavitian, B.; Dolle, F.; Tavitian, B.

2008-01-01

[ 18 F]FPyKYNE (2-fluoro-3-pent-4-yn-1-yloxy-pyridine) is a novel fluoro-pyridine-based structure, designed for the fluorine-18 labelling of macromolecules using copper-catalysed Huisgen 1,3-dipolar cycloaddition (click chemistry). FPyKYNE (non-labelled as reference), as well as the 2-bromo, 2-nitro and 2-trimethylammonium analogues (as precursors for labelling with fluorine-18), was synthesized in 44, 95, 60 and 41%, respectively, from commercially available 5-chloro-pent-1-yne and the appropriate 2-substituted-3-hydroxypyridines. [ 18 F]FPyKYNE was synthesized in one single radiochemical step by reaction of no-carrier-added K[ 18 F]F-Kryptofix 222 (DMSO, 165 degrees C, 3-5 min) followed by C-18 SepPak cartridge pre-purification and finally semi-preparative HPLC purification on a Hewlett Packard SiO 2 Zorbax (R) Rx-SIL. Using the 2-nitropyridine or the pyridin-2-yl-trimethylammonium trifluoro-methanesulphonate precursor for labelling (30 and 10 μ mol, respectively), incorporation yields up to 90% were observed and 7.0-8.9 GBq (190-240 mCi) of [F-18]FPyKYNE ([ 18 F]-1) could be isolated within 60-70 min (HPLC purification included), starting from a 37.0 GBq (1.0 Ci) [ 18 F]fluoride batch (overall decay-corrected and isolated yields: 30-35%). (authors)

Synthesis of the C(18)–C(34) Fragment of Amphidinolide C and the C(18)–C(29) Fragment of Amphidinolide F

Science.gov (United States)

Roy, Sudeshna; Spilling, Christopher D.

2010-01-01

A convergent synthesis of the C(18)–C(34) fragment of amphidinolide C and the C(18)–C(29) fragment of amphidinolide F is reported. The approach involves the synthesis of the common intermediate tetrahydrofuranyl-β-ketophosphonate via cross metathesis, Pd(0)-catalyzed cyclization and hydroboration-oxidation. The β-ketophosphonate was coupled to three side chain aldehydes using a Horner-Wadsworth-Emmons (HWE) olefination reaction to give dienones, which were reduced with L-selectride to give the fragments of amphidinolide C and F. PMID:21028791

Vertebral column decancellation in Pott's deformity: use of Surgimap Spine for preoperative surgical planning, retrospective review of 18 patients.

Science.gov (United States)

Hu, Wenhao; Zhang, Xuesong; Yu, Jiayi; Hu, Fanqi; Zhang, Hao; Wang, Yan

2018-01-15

In the late stage of Spinal tuberculosis, the bony destruction and vertebral collapse often leads to significant kyphosis, presenting clinically as a painful gibbus deformity, with increased instability, vertebral body translations and increased risk of neurologic involvement. Vertebral column decancellation is thought to be suitable for most patients with severe rigid kyphosis. Surgimap Spine, could offer a pragmatic graphical method for the surgical planning of osteotomies. The aim of this study was to evaluate the efficacy of Vertebral column decancellation planned preoperatively with the computer software-assistance in the patients with Pott's kyphosis. Between May 2012 and May 2015, 18 patients with Pott's kyphosis underwent the Vertebral column decancellation using Surgimap Spine for preoperative surgical planning. Preoperative and postoperative Konstam's angle, sagittal vertical angle, lumbar lordosis, thoracic kyphosis, pelvic tilt and pelvic incidence were measured. Visual analog scale and American Spinal Injury Association were documented. The Konstam's angles decreased from 88.1° (range, 70-105°) preoperatively to 18.5° (range, 7-31°) (P column decancellation is an effective treatment option for severe Pott's kyphosis. The surgical planning software Surgimap Spine can be a reliable and helpful tool that provides a simplified method to evaluate and analyze the spino-pelvic parameters and simulate the osteotomy procedure. According to individual character, the appropriate surgery strategy should be selected.

Kinetic performance of a 50mm long 1.8μm chiral column in supercritical fluid chromatography.

Science.gov (United States)

Berger, Terry A

2016-08-12

Reduced plate heights (hr) of supercritical fluid chromatography (SFC). The enantiomers of trans-stilbene oxide, were separated on a 4.6×50mm, 1.8μm R,R-Whelk-O1 column, with hr as low as 1.93. The plumbing of a commercial SFC instrument was modified to create a low dispersion version. Without the modification performance was considerably worse. vanDeemter like plots of reduced plate height vs. flow rate, for trans-stilbene oxide, indicate that the optimum flow varied with% modifier. On a 4.6×250mm, 5μm R,R- Whelk-O1 column, the optimum flow was >4mL/min for 5% methanol in CO2, decreasing to 5mL/min with 2.5%, 5%, and 10% methanol, decreasing to between 3 and 3.5mL/min at 40% methanol. This is the first time such shifts have been characterized. Since the solutes were the same in all cases, the differences are likely due to changes in solute diffusion coefficients caused by changes in modifier concentration, and pressure. Pump pressure requirements sometimes exceeded 500bar. It is shown that a 5mL/min flow rate is inadequate for use with 1.8μm particles in a 4.6mm ID column format. Instead, it is suggested to decrease the ID of the column to 3mm, where the optimum flow rates are on the order of 2mL/min with decreased tubing variance. Nevertheless, a number of sub-1min chromatograms are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

[Online enrichment ability of restricted-access column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride].

Science.gov (United States)

Zhang, Xiaohui; Wang, Rong; Xie, Hua; Yin, Qiang; Li, Xiaoyun; Jia, Zhengping; Wu, Xiaoyu; Zhang, Juanhong; Li, Wenbin

2013-05-01

The online enrichment ability of the restricted-access media (RAM) column coupled with high performance liquid chromatography by column switching technique for benazepril hydrochloride in plasma was studied. The RAM-HPLC system consisted of an RAM column as enrichment column and a C18 column as analytical column coupled via the column switching technique. The effects of the injection volume on the peak area and the systematic pressure were studied. When the injection volume was less than 100 microL, the peak area increased with the increase of the injection volume. However, when the injection volume was more than 80 microL, the pressure of whole system increased obviously. In order to protect the whole system, 80 microL was chosen as the maximum injection volume. The peak areas of ordinary injection and the large volume injection showed a good linear relationship. The enrichment ability of RAM-HPLC system was satisfactory. The system was successfully used for the separation and detection of the trace benazepril hydrochloride in rat plasma after its administration. The sensitivity of HPLC can be improved by RAM pre-enrichment. It is a simple and economic measurement method.

Influência do hipoclorito de sódio como fungicida na absorção de cálcio e silício pela soja

OpenAIRE

Resende, Anselmo; Souza, Jurandir Rodrigues de; Souza, Plínio Itamar de Mello de; Blum, Luiz Eduardo Bassay

2009-01-01

O objetivo da pesquisa foi verificar a ação do hipoclorito de sódio (NaOCl) no combate ao oídio na soja, quando aplicado só ou associado ao uso de fungicida, e a possível influência na absorção de cálcio e silício pela soja. Foram realizadas oito aplicações de NaOCl em parcelas que receberam apenas o sanitizante, com concentrações de 0,2%, 0,4% e 0,6%, parcelas que receberam essas mesmas concentrações e duas aplicações de fungicida e uma parcela controle. Não foram observadas diferenças es...

Tequila authenticity assessment by headspace SPME-HRGC-IRMS analysis of 13C/12C and 18O/16O ratios of ethanol.

Science.gov (United States)

Aguilar-Cisneros, Blanca O; López, Mercedes G; Richling, Elke; Heckel, Frank; Schreier, Peter

2002-12-18

By use of headspace SPME sampling and a PLOT column, on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the delta(13)C(VPDB) and delta(18)O(VSMOW) values of ethanol in authentic (n = 14) and commercial tequila samples (n = 15) as well as a number of other spirits (n = 23). Whereas with delta(13)C(VPDB) values ranging from -12.1 to -13.2 per thousand and from -12.5 to -14.8 per thousand similar variations were found for 100% agave and mixed tequilas, respectively, the delta(18)O(VSMOW) data differed slightly within these categories: ranges from +22.1 to +22.8 per thousand and +20.8 to +21.7 per thousand were determined for both the authentic 100% agave and mixed products, respectively. The data recorded for commercial tequilas were less homogeneous; delta(13)C(VPDB) data from -10.6 to -13.9 per thousand and delta(18)O(VSMOW) values from +15.5 to +22.7 per thousand were determined in tequilas of both categories. Owing to overlapping data, attempts to differentiate between white, rested, and aged tequilas within each of the two categories failed. In addition, discrimination of tequila samples from other spirits by means of delta(13)C(VPDB) and delta(18)O(VSMOW) data of ethanol was restricted to the products originating from C(3) as well as C(4)/CAM raw materials.

{sup 18}FFPyKYNE, a fluoro-pyridine-based alkyne reagent designed for the fluorine-18 labelling of macromolecules using click chemistry

Energy Technology Data Exchange (ETDEWEB)

Kuhnast, B.; Hinnen, F.; Tavitian, B.; Dolle, F. [CEA, Serv Hosp FredericJoliot, I2BM, Inst Imagerie Biomed, F-91401 Orsay (France); Tavitian, B. [INSERM, Serv Hosp Frederic Joliot, U803, F-91401 Orsay (France)

2008-07-01

[{sup 18}F]FPyKYNE (2-fluoro-3-pent-4-yn-1-yloxy-pyridine) is a novel fluoro-pyridine-based structure, designed for the fluorine-18 labelling of macromolecules using copper-catalysed Huisgen 1,3-dipolar cycloaddition (click chemistry). FPyKYNE (non-labelled as reference), as well as the 2-bromo, 2-nitro and 2-trimethylammonium analogues (as precursors for labelling with fluorine-18), was synthesized in 44, 95, 60 and 41%, respectively, from commercially available 5-chloro-pent-1-yne and the appropriate 2-substituted-3-hydroxypyridines. [{sup 18}F]FPyKYNE was synthesized in one single radiochemical step by reaction of no-carrier-added K[{sup 18}F]F-Kryptofix 222 (DMSO, 165 degrees C, 3-5 min) followed by C-18 SepPak cartridge pre-purification and finally semi-preparative HPLC purification on a Hewlett Packard SiO{sub 2} Zorbax (R) Rx-SIL. Using the 2-nitropyridine or the pyridin-2-yl-trimethylammonium trifluoro-methanesulphonate precursor for labelling (30 and 10 {mu} mol, respectively), incorporation yields up to 90% were observed and 7.0-8.9 GBq (190-240 mCi) of [F-18]FPyKYNE ([{sup 18}F]-1) could be isolated within 60-70 min (HPLC purification included), starting from a 37.0 GBq (1.0 Ci) [{sup 18}F]fluoride batch (overall decay-corrected and isolated yields: 30-35%). (authors)

Comparative study of the performance of columns packed with several new fine silica particles. Would the external roughness of the particles affect column properties?

Science.gov (United States)

Gritti, Fabrice; Guiochon, Georges

2007-09-28

We measured and compared the characteristics and performance of columns packed with particles of five different C(18)-bonded silica, 3 and 5 microm Luna, 3 microm Atlantis, 3.5 microm Zorbax, and 2.7 microm Halo. The average particle size of each material was derived from the SEM pictures of 200 individual particles. These pictures contrast the irregular morphology of the external surface of the Zorbax and Halo particles and the smooth surface of the Luna and Atlantis particles. In a wide range of mobile phase velocities (from 0.010 to 3 mL/min) and at ambient temperature, we measured the first and second central moments of the peaks of naphthalene, insulin, and bovine serum albumin (BSA). These moments were corrected for the contributions of the extra-column volumes to calculate the reduced HETPs. The C-terms of naphthalene and insulin are largest for the Halo and Zorbax materials and the A-term smallest for the Halo-packed column. The Halo column performs the best for the low molecular weight compound naphthalene (minimum reduced HETP, 1.4) but is not as good as the Atlantis or Luna columns for the large molecular weight compound insulin. The Zorbax column is the least efficient column because of its large C-term. The lowest sample diffusivity through these particles, alone, does not account for the results. It is most likely that the roughness of the external surface of the Halo and Zorbax particles limit the performance of these columns at high flow rates generating an unusually high film mass transfer resistance.

Clinical significance of measurement of changes of serum IL-2, SIL-2R levels after chemotherapy in patients with lung carcinoma

International Nuclear Information System (INIS)

Lu Men; Duo Huanzhi; Luo Guorong

2004-01-01

Objective: To study the changes of serum IL-2 and SIL-2R levels after chemotherapy in 36 patients with lung carcinoma. Methods: Serum IL-2 (with RIA) and SIL-2R (with ELISA) levels were measured in 36 patients with lung carcinoma both before and after chemotherapy as well as in 35 controls. Results: Before chemotherapy, in the patients the serum IL-2 levels were significantly lower and serum SIL-2R levels were significantly higher than those in the controls (P<0.01). Six months after chemotherapy, those patients without recurrence (n=20) had their IL-2 and SIL-2R levels returned to normal but in those with recurrences (n=12) the levels were about the same as before. Conclusion: Cytokines IL-2 and SIL-2R levels changes could reflect the immunostatus of the patient as well as the progress of disease and could be of prognostic value. (authors)

Gas-phase Absorptions of {{\\rm{C}}}_{42}{{\\rm{H}}}_{18}^{+} near 8300 Å below 10 K: Astronomical Implications

Science.gov (United States)

Campbell, E. K.; Maier, J. P.

2017-11-01

The gas-phase electronic spectrum of {{{C}}}42{{{H}}}18+ ({{HBC}}+) with an origin band at 8281 \\mathringA has been measured below 10 {{K}} by photofragmentation of helium complexes ({{{C}}}42{{{H}}}18+{--}{{He}}n) in a radiofrequency trap. {{HBC}}+ is a medium-sized polycyclic aromatic hydrocarbon (PAH) cation, and using an ion trapping technique it has been possible to record a high-quality gas-phase spectrum to directly compare with astronomical observations. No diffuse interstellar bands (DIBs) have been reported at the wavelengths of the strongest absorption bands in the {{{C}}}42{{{H}}}18+ spectrum. Measurement of absolute absorption cross sections in the ion trap allows upper limits to the column density of this ion to be {10}12 {{cm}}-2, indicating that even PAH cations of this size, which are believed to be stable in the interstellar medium, should be excluded as candidates for at least the strong DIBs.

Clinical significance of measurement of changes of serum IL-2, SIL-2R levels after treatment in patients with thrombocytopenic purpura

International Nuclear Information System (INIS)

Feng Yue

2005-01-01

Objective: To study the changes of serum IL-2 and SIL-2R levels after treatment in 31 patients with thrombocytopenic purpura. Methods: Serum IL-2 (with RIA) and SIL-2R (with ELISA) levels were measured in 31 patients with thrombocytopenic purpura both before and after treatment as well as in 35 controls. Results: Before treatment, in the patients the serum IL-2 levels were significantly lower and serum SIL-2R levels were significantly higher than those in the controls ( P 0.05). Conclusion: Cytokines IL-2 and SIL-2R levels changes could reflect the immunostatus of the patients as well as the progress of diseases and could be of prognostic values. (authors)

Clinical significance of the changes of serum IL-2, SIL-2R and VEGF levels in pediatric patients with pulmonary tuberculosis

International Nuclear Information System (INIS)

Zeng Dongliang; Wu Chunfeng; Jiang Huanhao

2005-01-01

Objective: To explore the clinical significance of the changes of serum IL-2, soluble IL-2 receptor (SIL-2R) and vascular endothelial growth factor (VEGF) levels in pediatric patients with tuberculosis. Methods: Serum IL-2 (with RIA) and SIL-2R, VEGF (with ELISA) levels were determined in 68 pediatric patients with tuberculosis (30 active and 38 non- active) and 30 controls. Results: In the patients with active tuberculosis, the serum IL-2 levels were significantly lower and SIL-2R, VEGF levels were significantly higher than those in the controls (P<0.01). Conclusion: Determination of serum IL-2, SIL-2R and VEGF levels was useful for monitoring the activity of tuberculosis in pediatric patients. (authors)

High-resolution ultrahigh-pressure long column reversed-phase liquid chromatography for top-down proteomics

Energy Technology Data Exchange (ETDEWEB)

Shen, Yufeng; Tolic, Nikola; Piehowski, Paul D.; Shukla, Anil K.; Kim, Sangtae; Zhao, Rui; Qu, Yi; Robinson, E. W.; Smith, Richard D.; Pasa-Tolic, Ljiljana

2017-05-01

We report development of an approach providing high-resolution RPLC of proteins and its utility for mass spectrometry-based top-down proteomics. A chromatographic peak capacity of ~450 was achieved for proteins and large polypeptides having MWs up to 43 kDa in the context of proteomics applications. RPLC column lengths from 20 to 200 cm, particle sizes from 1.5 to 5 m, bonding alkyl chains from C1 to C2, C4, C8, and C18, and particle surface structures that spanned porous, superficially porous (porous shell, core-shell), and nonporous were investigated at pressures up to14K psi. Column length was found as the most important factor for >20 kDa proteins in gradient RPLC, and shortening column length degraded RPLC resolution and sensitivity regardless of the size and surface structure of the packing particles used. The alkyl chains bonded to the silica particle surface significantly affected the RPLC recovery and efficiency, and short alkyl C1-C4 phases provided higher sensitivity and resolution than C8 and C18 phases. Long gradient separations (e.g., >10 hours) with long columns (e.g., 100 cm) were particularly effective in conjunction with use of high accuracy mass spectrometers (e.g., the Orbitrap Elite) for top-down proteomics with improved proteoform coverage by allowing multiple HCD, CID, and ETD dissociation modes. It was also found that HCD produced small fragments useful for proteoform identification, while low energy CID and ETD often complemented HCD by providing large fragments.

A new divided-wall heat integrated distillation column (HIDiC) for batch processing: Feasibility and analysis

International Nuclear Information System (INIS)

Jana, Amiya K.

2016-01-01

Highlights: • A novel heat integrated configuration is proposed for batch distillation. • The shell is divided into two closed semi-cylinders by a metal wall. • An open-loop variable manipulation policy is formulated. • The column improves its energy efficiency and economic performance. - Abstract: This work introduces a new heat integrated distillation column (HIDiC) for batch processing. Under this scheme, the entire cylindrical shell is proposed to divide vertically by a metal wall into two closed semi-cylinders. Aiming to generate an internal heat source, a heat pump system is employed over the left hand division to elevate the pressure of the right hand part with the application of HIDiC concept. This new divided-wall HIDiC column utilizes its own energy source by transferring heat from the high pressure (HP) to low pressure (LP) side, thereby reducing the utility consumption in both the still and condenser. To make this thermal integration technology more effective, a typical tray configuration is proposed in both sides of the divided-wall. Unlike the continuous flow distillation, the batch column shows unsteady state process characteristics that make its operation more challenging. With this, an open-loop variable manipulation policy is formulated so that the dynamics of the heat integrated column remain close, if not same, with its conventional counterpart. This is a necessary condition required for a fair comparison between them. Finally, the proposed configuration is illustrated by a binary column, showing an improvement in energy savings, entropy generation and cost over its conventional analogous. This thermally integrated configuration is relatively simple than the traditional HIDiC in terms of design and operation.

Study of alkylphenols, indol and pyridinic nucleus of HPAN compounds by SPE/SI and SPE/C{sub 18}/NEC: application of SPE/Si phase to oils from the Alagoas sub-basin

Energy Technology Data Exchange (ETDEWEB)

Reboucas, L.M.C.; Nogueira, F.A.R.; Sabino, A.R.; Araujo, O.R.P.; Sant' Ana, A.E.G. [Universidade Federal de Alagoas (LABIS/UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia. Lab. de Analise de Biomarcadores e Semioquimicos], E-mail: lmcr@qui.ufal.br

2008-10-15

Alkylphenols (AP) and hydrocarbon polycyclic aromatic nitrogen (HPAN) compounds are important to study secondary migrations of petroleum. The behavior of AP and HPAN standards was investigated by solid phase extraction (SPE) on silica gel (SPE/Si) and C{sub 18}/NEC (SPE/C{sub 18}) stationary phases. The AP standards were eluted with dichloromethane (DCM) in the F2 fraction, on both SPE/Si and SPE/C{sub 18} phases. The basic and neutral HPAN compounds were eluted together with DCM, in F2 fraction, when a SPE/C18 column was used. However in the SPE/Si column the HPAN compounds were separated by their basic and neutral character in two different fractions. The neutral HPAN compounds were eluted with DCM, F2 fraction, and the HPAN basic compounds were eluted with the mixture DCM:isopropanol 5%, F3 fraction. In general, the quantity of recovered AP and HPAN compounds was higher with SPE/Si than SPE/C{sub 18}. The nine oil samples were analyzed by SPE/Si and the saturated and aromatic hydrocarbon were separated from the polar AP and HPAN. (author)

Study on the diagnostic value of combined determination of serum CA125, CA199 and SIL-2R levels in patients with endometriosis

International Nuclear Information System (INIS)

Yang Jingxiu; Shi Shaohong; Wang Yuping; Xie Xueqin; Qin Jibao

2005-01-01

Objective: To investigate the diagnostic values of combined determination of serum CA125, CA199 and SIL-2R levels in patients with endometriosis. Methods: Serum CA125, CA199 were measured with RIA and SIL-2R levels with ELISA in 54 patients with endometriosis and 35 controls. Results: The serum levels of CA125, CA199 and SIL-2R in patients with endometriosis were significantly higher than those in controls (P<0.01). The sensitivity and speciality of CA125 for endometriosis was 70.2% and 80.4% respectively, the sensitivity and speciality of CA199 for endometriosis was 62.4% and 71.8% respectively, the sensitivity and speciality of SIL-2R was 89.5% and 60.2% respectively. The sensitivity of the combined determination of CA125, CA199 and SIL-2R for endometriosis was 86.8% being significantly higher than that of CA125 and CA199 respectively. Conclusion: Combined determination of the serum CA125, CA199 and SIL-2R levels in serum can increase the diagnostic sensitivity for endometriosis. (authors)

Simultaneous determination of 18α-glycyrrhetinic acid and 18β-glycyrrhetinic acid in Glycyrrhiza glabra root by reversed phase high-performance liquid chromatography

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Ambika Chamoli

2016-01-01

Full Text Available Background: The aim of the present research work is to develop a high-performance liquid chromatography (HPLC method for simultaneous analysis of 18α-glycyrrhetinic acid (18α-GA and 18β-GA (18β-GA of Glycyrrhiza glabra. Materials and Methods: About 20 μL aliquots of each 18α-GA and 18β-GA were analyzed using reversed-phase C-18 column. The mobile phase was acetonitrile:tetrahydrofuran:water (10:80:10, v/v/v. The run time was 10 min at flow rate of 1 ml/min. Ultraviolet detection was carried out at 254 nm. Results: 18α-GA and 18β-GA were well resolved in reversed phase C-18 column using mobile phase acetonitrile: tetrahydrofuran: water (10:80:10, v/v/v, pH 7.9. The Rtof 18α-GA and 18β-GA was detected at 2.091 and 2.377 min, respectively. Conclusion: The developed chromatography method could be extended for potential quantification or simultaneous determination of these markers in plant as well as in herbal formulation.

Clinical significance of determination of changes of serum NSE, SIL-2R and TNF levels in patients with lung cancer undergoing chemotherapy

International Nuclear Information System (INIS)

Tan Zongxian

2005-01-01

Objective: To detect the changes of serum NSE, SIL-2R and TNF levels in the 33 patients with lung cancer undergoing chemotherapy. Methods: Serum NSE, SIL-2R and TNF levels were determined with RIA and SIL-2R levels with ELISA in 33 lung cancer patients both before and after chemotherapy (n=28) as well as in 30 controls. Results: Before chemotherapy, serum NSE, SIL-2R and TNF levels in the patients were significantly higher than those in the controls (P<0.01). After chemotherapy, in 20 cases without recurrence at 6 months, the levels were much lower but still significantly higher than those in controls (P < 0.05 ). However, in the 8 patients with recurrence, the levels increased again to approaching those before chemotherapy. Conclusion: Serum levels of NSE, SIL-2R and TNF might be useful for diagnosis and predicting therapeutic effects after chemotherapy in patients with lung cancer. (authors)

Dicty_cDB: Contig-U05044-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available pSkeMus1 Xenopus (Sil... 40 0.47 3 ( CB078367 ) hj66g06.g1 Hedyotis terminalis flower - Stage 2 (... 36 0.48...) 1092343402430 Global-Ocean-Sampling_GS-27-01-01-1... 44 0.013 2 ( CR389591 ) Gallus gallus finished cDNA, ...cigd039p01, 3' en... 48 9e-04 2 ( EJ556699 ) 1092959507186 Global-Ocean-Sampling_GS-29-01-01-1... 42 0.001 2... ( EJ554022 ) 1092959481122 Global-Ocean-Sampling_GS-29-01-01-1... 42 0.001 2 ( FM928382 ) Brachionus pli...s ML CMVsport jasme... 50 0.18 1 ( EK107136 ) 1092963062468 Global-Ocean-Sampli

AIMgSil Alloy Characterization Using Transmission Electron Microscope (TEM)

International Nuclear Information System (INIS)

Masrukan; Elman, P.

1996-01-01

The aging alloy of AIMgSil containing Mg 2 Si of 1.29 % has been done with the following steps: e.q (a) part of the specimen was heated at 400 o C during 3 hours, and (b) the other part was done with solution treatment at 550 o C followed by quenching. After quenching a part of the specimen was aged at room temperature and other specimen was aged at 160 o C during 16 hours. After the specimen had been heated, then it was shaped into thin foil to be examined by Transmission Electron Microscope. The result showed that the heating at temperature of 400 o C during 3 hours created a second phase (i.e.Mg 2 Si) was like stick shape with the hexagonal structure at [0111] orientation and matrix [001], and the hardness was 31 HB. The aging of specimen at room temperature gave result a GP zone which was like the needles shape in the dislocation area of the face center cubic structure at [111] orientation and [111] matrix. The hardness obtained was 64 HB. In the other hand the aging process at temperature of 160 o C within 16 hours have resulted the precipitate which was greater than that of the former needle shaped as the face center cubic structure without dislocation at matrix with [111] orientation and [114] matrix. The hardness at this condition was 94 HB

The relation between the column density structures and the magnetic field orientation in the Vela C molecular complex

Science.gov (United States)

Soler, J. D.; Ade, P. A. R.; Angilè, F. E.; Ashton, P.; Benton, S. J.; Devlin, M. J.; Dober, B.; Fissel, L. M.; Fukui, Y.; Galitzki, N.; Gandilo, N. N.; Hennebelle, P.; Klein, J.; Li, Z.-Y.; Korotkov, A. L.; Martin, P. G.; Matthews, T. G.; Moncelsi, L.; Netterfield, C. B.; Novak, G.; Pascale, E.; Poidevin, F.; Santos, F. P.; Savini, G.; Scott, D.; Shariff, J. A.; Thomas, N. E.; Tucker, C. E.; Tucker, G. S.; Ward-Thompson, D.

2017-07-01

We statistically evaluated the relative orientation between gas column density structures, inferred from Herschel submillimetre observations, and the magnetic field projected on the plane of sky, inferred from polarized thermal emission of Galactic dust observed by the Balloon-borne Large-Aperture Submillimetre Telescope for Polarimetry (BLASTPol) at 250, 350, and 500 μm, towards the Vela C molecular complex. First, we find very good agreement between the polarization orientations in the three wavelength-bands, suggesting that, at the considered common angular resolution of 3.´0 that corresponds to a physical scale of approximately 0.61 pc, the inferred magnetic field orientation is not significantly affected by temperature or dust grain alignment effects. Second, we find that the relative orientation between gas column density structures and the magnetic field changes progressively with increasing gas column density, from mostly parallel or having no preferred orientation at low column densities to mostly perpendicular at the highest column densities. This observation is in agreement with previous studies by the Planck collaboration towards more nearby molecular clouds. Finally, we find a correspondencebetween (a) the trends in relative orientation between the column density structures and the projected magnetic field; and (b) the shape of the column density probability distribution functions (PDFs). In the sub-regions of Vela C dominated by one clear filamentary structure, or "ridges", where the high-column density tails of the PDFs are flatter, we find a sharp transition from preferentially parallel or having no preferred relative orientation at low column densities to preferentially perpendicular at highest column densities. In the sub-regions of Vela C dominated by several filamentary structures with multiple orientations, or "nests", where the maximum values of the column density are smaller than in the ridge-like sub-regions and the high-column density

Single incision laparoscopic surgery (SILS) inguinal hernia repair - recent clinical experiences of this novel technique.

Science.gov (United States)

Yussra, Y; Sutton, P A; Kosai, N R; Razman, J; Mishra, R K; Harunarashid, H; Das, S

2013-01-01

Inguinal hernia remains the most commonly encountered surgical problem. Various methods of repair have been described, and the most suitable one debated. Single port access (SPA) surgery is a rapidly evolving field, and has the advantage of affording 'scarless' surgery. Single incision laparoscopic surgery (SILS) for inguinal hernia repair is seen to be feasible in both total extraperitoneal (TEP) and transabdominal pre-peritoneal (TAPP) approaches. Data and peri-operative information on both of these however are limited. We aimed to review the clinical experience, feasibility and short term complications related to laparoscopic inguinal hernia repair via single port access. A literature search was performed using Google Scholar, Springerlink Library, Highwire Press, Surgical Endoscopy Journal, World Journal of Surgery and Medscape. The following search terms were used: laparoscopic hernia repair, TAPP, TEP, single incision laparoscopic surgery (SILS). Fourteen articles in English language related to SILS inguinal hernia repair were identified. Nine articles were related to TEP repair and the remaining 5 to TAPP. A total of 340 patients were reported within these studies: 294 patients having a TEP repair and 46 a TAPP. Only two cases of recurrence were reported. Various ports have been utilized, including the SILS port, Tri-Port and a custom- made port using conventional laparoscopic instruments. The duration of surgery was 40-100 minutes and the average length of hospital stay was one day. Early outcomes of this novel technique show it to be feasible, safe and with potentially better cosmetic outcome.

HIGH-PRECISION C17O, C18O, AND C16O MEASUREMENTS IN YOUNG STELLAR OBJECTS: ANALOGUES FOR CO SELF-SHIELDING IN THE EARLY SOLAR SYSTEM

International Nuclear Information System (INIS)

Smith, Rachel L.; Young, Edward D.; Pontoppidan, Klaus M.; Morris, Mark R.; Van Dishoeck, Ewine F.

2009-01-01

Using very high resolution (λ/Δλ ∼ 95 000) 4.7 μm fundamental and 2.3 μm overtone rovibrational CO absorption spectra obtained with the Cryogenic Infrared Echelle Spectrograph infrared spectrometer on the Very Large Telescope (VLT), we report detections of four CO isotopologues-C 16 O, 13 CO, C 18 O, and the rare species, C 17 O-in the circumstellar environment of two young protostars: VV CrA, a binary T Tauri star in the Corona Australis molecular cloud, and Reipurth 50, an intermediate-mass FU Ori star in the Orion Molecular Cloud. We argue that the observed CO absorption lines probe a protoplanetary disk in VV CrA, and a protostellar envelope in Reipurth 50. All CO line profiles are spectrally resolved, with intrinsic line widths of ∼3-4 km s -1 (FWHM), permitting direct calculation of CO oxygen isotopologue ratios with 5%-10% accuracy. The rovibrational level populations for all species can be reproduced by assuming that CO absorption arises in two temperature regimes. In the higher temperature regime, in which the column densities are best determined, the derived oxygen isotope ratios in VV CrA are: [C 16 O]/[C 18 O] =690 ± 30; [C 16 O]/[C 17 O] =2800 ± 300, and [C 18 O]/[C 17 O]=4.1 ± 0.4. For Reipurth 50, we find [C 16 O]/[C 18 O] =490 ± 30; [C 16 O]/[C 17 O] =2200 ± 150, [C 18 O]/[C 17 O] = 4.4 ± 0.2. For both objects, 12 C/ 13 C are on the order of 100, nearly twice the expected interstellar medium (ISM) ratio. The derived oxygen abundance ratios for the VV CrA disk show a significant mass-independent deficit of C 17 O and C 18 O relative to C 16 O compared to ISM baseline abundances. The Reipurth 50 envelope shows no clear differences in oxygen CO isotopologue ratios compared with the local ISM. A mass-independent fractionation can be interpreted as being due to selective photodissociation of CO in the disk surface due to self-shielding. The deficits in C 17 O and C 18 O in the VV CrA protoplanetary disk are consistent with an analogous

Clinical significance of determination of changes of serum IL-2, SIL-2R and TNF-α levels after treatment in patients with endometriosis

International Nuclear Information System (INIS)

Shao Xuefeng; Li Linlin; Shao Jun; Yao Hui

2008-01-01

Objective: To explore the clinical significance of changes of serum IL-2, SIL-2R and TNF-α levels after treatment in patients with endometriosis. Methods: Serum IL-2 and TNF-α (with RIA) and SIL-2R (with ELISA) levels were determined in 42 patients with endometriosis both before and after treatment as well as in 35 controls. Results: Before treatment, the serum SIL-2R and TNF-α levels in patients were significantly higher than those in the controls (P 0.05). Conclusion: Development of endometriosis were closely related to the serum levels of IL-2, SIL-2R and TNF-α. (authors)

Ideal versus real automated twin column recycling chromatography process.

Science.gov (United States)

Gritti, Fabrice; Leal, Mike; McDonald, Thomas; Gilar, Martin

2017-07-28

The full baseline separation of two compounds (selectivity factors αchromatography is used to confirm that the speed-resolution performance of the TCRSP is intrinsically superior to that of the single-column process. This advantage is illustrated in this work by developing an automated TCRSP for the challenging separation of two polycyclic aromatic hydrocarbon (PAH) isomers (benzo[a]anthracene and chrysene) in the reversed-phase retention mode at pressure smaller than 5000psi. The columns used are the 3.0mm×150mm column packed with 3.5μm XBridge BEH-C 18 material (α=1.010) and the 3.0mm or 4.6mm×150mm columns packed with the same 3.5μm XSelect HSST 3 material (α=1.025). The isocratic mobile phase is an acetonitrile-water mixture (80/20, v/v). Remarkably, significant differences are observed between the predicted retention times and efficiencies of the ideal TCRSP (given by the number of cycles multiplied by the retention time and efficiency of one column) and those of the real TCRSP. The fundamental explanation lies in the pressure-dependent retention of these PAHs or in the change of their partial molar volume as they are transferred from the mobile to the stationary phase. A revisited retention and efficiency model is then built to predict the actual performance of real TCRSPs. The experimental and calculated resolution data are found in very good agreement for a change, Δv m =-10cm 3 /mol, of the partial molar volume of the two PAH isomers upon transfer from the acetonitrile-water eluent mixture to the silica-C 18 stationary phase. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical significance of measurements of changes of serum IL-2, SIL-2R, TNF-α levels after chemotherapy in patients with ovary cancer

International Nuclear Information System (INIS)

Ma Zhongwei

2005-01-01

Objective: To study the changes of serum IL-2, SIL-2R and TNF-α levels after chemotherapy in 34 patients with ovary cancer. Methods: Serum IL-2, TNF-α (with RIA) and SIL-2R (with ELISA) levels were measured in 34 patients with ovary cancers both before and 6 months after chemotherapy as well as in 30 controls. Results: Before chemotherapy in the patients the serum IL-2 levels were significantly lower and serum SIL-2R and TNF-α levels were significantly higher than those in the controls (P<0.01). Six months after chemotherapy, those patients without recurrence (n=21) had their IL-2, SIL-2R and TNF-α levels returned to normal, but in those with recurrences (n=10) the levels were about the same as before. Conclusion: Serum IL-2, SIL-2R and TNF-α levels changes could reflect the immunostatus of the patients as well as the progress of diseases and could be of prognostic value. (authors)

Elevated Plasma Levels of sIL-2R in Complex Regional Pain Syndrome: A Pathogenic Role for T-Lymphocytes?

Directory of Open Access Journals (Sweden)

Krishna D. Bharwani

2017-01-01

Full Text Available The immune system has long been thought to be involved in the pathophysiology of complex regional pain syndrome (CRPS. However, not much is known about the role of the immune system and specifically T-cells in the onset and maintenance of this disease. In this study, we aimed to evaluate T-cell activity in CRPS by comparing blood soluble interleukin-2 receptor (sIL-2R levels between CRPS patients and healthy controls. CRPS patients had statistically significant elevated levels of sIL-2R as compared to healthy controls (median sIL-2R levels: 4151 pg/ml (Q3 − Q1 = 5731 pg/ml − 3546 pg/ml versus 1907 pg/ml (Q3 − Q1: 2206 pg/ml − 1374 pg/ml, p<0.001, resp.. Furthermore, sIL-2R level seems to be a good discriminator between CRPS patients and healthy controls with a high sensitivity (90% and specificity (89.5%. Our finding indicates increased T-cell activity in patients with CRPS. This finding is of considerable relevance as it could point towards a T-cell-mediated inflammatory process in this disease. This could pave the way for new anti-inflammatory therapies in the treatment of CRPS. Furthermore, sIL-2R could be a promising new marker for determining inflammatory disease activity in CRPS.

Clinical significance of measurements of changes of serum IL-2, SIL-2R and TNF-α levels after treatment in patients with rheumatoid arthritis

International Nuclear Information System (INIS)

Yu Songsan

2007-01-01

Objective: To study the changes of serum IL-2, SIL-2R and TNF-α levels after treatment in 39 patients with rheumatoid arthritis. Methods: Serum IL-2, TNF-α (with RIA) and SIL-2R (with ELISA) levels were measured in 39 patients with rheumatoid arthritis. Both before and one year after treatment as well as in 35 controls. Results: Before treatment in the patients the serum IL-2 levels were significantly lower and serum SIL-2R and TNF-α levels, were significantly higher than those in the controls (P<0.01), one year after treatment, the patients without recurrence (n=31) had their serum IL-2, SIL-2R and TNF-α levels returned to normal, but in patients with recurrences (n=8) the levels were about the same as those before treatment. Conclusion: Serum IL-2, SIL-2R and TNF-α lends were closely related to the diseases process and could be of prognostic value. (authors)

Partial strengthening of R.C square columns using CFRP

Directory of Open Access Journals (Sweden)

Ahmed Shaban Abdel-Hay

2014-12-01

An experimental program was undertaken testing ten square columns 200 × 200 × 2000 mm. One of them was a control specimen and the other nine specimens were strengthened with CFRP. The main parameters studied in this research were the compressive strength of the upper part, the height of the upper poor concrete part, and the height of CFRP wrapped part of column. The experimental results including mode of failure, ultimate load, concrete strain, and fiber strains were analyzed. The main conclusion of this research was, partial strengthening of square column using CFRP can be permitted and gives good results of the column carrying capacity.

Determination of phenolic acids and flavonoids in raw propolis by silica-supported ionic liquid-based matrix solid phase dispersion extraction high performance liquid chromatography-diode array detection.

Science.gov (United States)

Wang, Zhibing; Sun, Rui; Wang, Yuanpeng; Li, Na; Lei, Lei; Yang, Xiao; Yu, Aimin; Qiu, Fangping; Zhang, Hanqi

2014-10-15

The silica-supported ionic liquid (S-SIL) was prepared by impregnation and used as the dispersion adsorbent of matrix solid phase dispersion (MSPD) for the simultaneous extraction of eight phenolic acids and flavonoids, including caffeic acid, ferulic acid, morin, luteolin, quercetin, apigenin, chrysin, and kaempferide in raw propolis. High performance liquid chromatography with a Zorbax SB-C18 column (150mm×4.6mm, 3.5μm) was used for separation of the analytes. The mobile phase consisted of 0.2% phosphoric acid aqueous solution and acetonitrile and the flow rate of the mobile phase was 0.5mL/min. The experimental conditions for silica-supported ionic liquid-based matrix solid phase dispersion (S-SIL-based MSPD) were optimized. S-SIL containing 10% [C6MIM]Cl was used as dispersant, 20mL of n-hexane as washing solvent and 15mL of methanol as elution solvent. The ratio of S-SIL to sample was selected to be 4:1. The standard curves showed good linear relationship (r>0.9995). The limits of detection and quantification were in the range of 5.8-22.2ngmL(-1) and 19.2-74.0ngmL(-1), respectively. The relative standard deviations (RSDs) of intra-day and inter-day determination were lower than 8.80% and 11.19%, respectively. The recoveries were between 65.51% and 92.32% with RSDs lower than 8.95%. Compared with ultrasound-assisted extraction (UAE) and soxhlet extraction, the present method consumed less sample, organic solvent, and extraction time, although the extraction yields obtained by S-SIL-based MSPD are slightly lower than those obtained by UAE. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of load eccentricity on the buckling of thin-walled laminated C-columns

Science.gov (United States)

Wysmulski, Pawel; Teter, Andrzej; Debski, Hubert

2018-01-01

The study investigates the behaviour of short, thin-walled laminated C-columns under eccentric compression. The tested columns are simple-supported. The effect of load inaccuracy on the critical and post-critical (local buckling) states is examined. A numerical analysis by the finite element method and experimental tests on a test stand are performed. The samples were produced from a carbon-epoxy prepreg by the autoclave technique. The experimental tests rest on the assumption that compressive loads are 1.5 higher than the theoretical critical force. Numerical modelling is performed using the commercial software package ABAQUS®. The critical load is determined by solving an eigen problem using the Subspace algorithm. The experimental critical loads are determined based on post-buckling paths. The numerical and experimental results show high agreement, thus demonstrating a significant effect of load inaccuracy on the critical load corresponding to the column's local buckling.

The clinical significance of T-cells, sIL-2R and TNF in evaluating patients with splenic autotransplantation

International Nuclear Information System (INIS)

Wang Haowei; Wu Haorong; Li Juncheng; Wu Jingchang

2002-01-01

To study the immunological effects of splenic autotransplantation, forty patients with splenic trauma were divided into two groups equally. One group underwent splenic autotransplantation and another underwent splenectomy. Control group included ten cases. Splenic autotransplantation and splenectomy group were compared with the control group. In the group of splenic autotransplantation, CD3 + , CD4 + , CD8 + , CD4 + /CD8 + dropped and sIL-2R, TNF rose after a week of operation. Then CD3 + , CD4 + , CD8 + , CD4 + /CD8 + rose and sIL-2R, TNF dropped three months later. In the group of splenectomy, CD 3+ , CD4 + , CD8 + and CD4 + /CD8 + dropped persistently, while sIL-2R and TNF rose postoperatively. Result showed splenic autotransplantation can help body to maintain T-cells level and improve the anti-infective ability

Production of fluorine-18 from eithium carbonate in a research reactor

International Nuclear Information System (INIS)

Gasiglia, H.T.

1978-01-01

A method for the production of fluorine-18 in a research reactor, from irradiated lithium carbonate, is described. Fluorine-18 is separated from impurities in a alumina column, which is an appropriate procedure for its production as a carrier-free radioisotope for oral administration. Characteristics of the product, when fluorine is separated from irradiated target in an usual alumina column, are compared with those when fluorine is separated in a previously calcined(1000 0 C) alumina column: Yields of chemical separation and chemical forms of radioisotope obtained are studied. Fluorine elution is investigated for several eluant concentrations and the use of a lower concentrated eluant is emphasized. Purity degree of fluorine-18 solutions separated. A routine production procedure is determined by irradiating enriched lithium carbonate (95% 6 Li). Theoretical yields are compared with fluorine-18 production yields obtained in several irradiations [pt

Histone fractionation by high-performance liquid chromatography on cyanoalkylsilane (CN) reverse-phase columns

International Nuclear Information System (INIS)

Gurley, L.R.; Prentice, D.A.; Valdez, J.G.; Spall, W.D.

1983-01-01

Previous work described conditions for the rapid fractionation of histones by high-performance liquid chromatography (HPLC) using a reverse-phase μBondapak C 18 column. That procedure resolved the major classes of histones with one exception: the more hydrophobic H2A variant, (MHP)H2A, was not resolved from the H4 histone class. This report extends that work describing experiments using a μBondapak CN column which better resolves the classes of histones from each other including the resolution of (MHP)H2A from the H4. In addition, the less hydrophobic H2A variant, (LHP)H2A, is partially resolved from the (MHP)H2A, and the less hydrophobic H3 variant, (LHP)H3, is resolved from the more hydrophobic H3 variant, (MHP)H3. Lower trifluoroacetic acid (TFA) concentrations (0.1%) in the eluting water/acetonitrile solvent were used with the CN column than were used with the C 18 column which increased the sensitivity of histone detection by ultraviolet absorption at 206 nm. Greater than 95% of the total [ 3 H]lysine-labeled protein applied to the CN column was eluted from the column. Contaminating nonhistone proteins were found to chromatograph in the region of histone elution. These were greatly reduced by isolating nuclei prior to histone preparation. The fractionation of the histones appears to be based on the hydrophobic properties of the proteins. The histone fractions (identified by their electrophoretic mobilities) were eluted from the CN column in the following order: H1, H2B, (LHP)H2A, (MHP)H2A, H4, (LHP)H3, and (MHP)H3. Phosphorylated and acetylated histone species were not resolved from their unmodified parental species

Column Selection for Biomedical Analysis Supported by Column Classification Based on Four Test Parameters.

Science.gov (United States)

Plenis, Alina; Rekowska, Natalia; Bączek, Tomasz

2016-01-21

This article focuses on correlating the column classification obtained from the method created at the Katholieke Universiteit Leuven (KUL), with the chromatographic resolution attained in biomedical separation. In the KUL system, each column is described with four parameters, which enables estimation of the FKUL value characterising similarity of those parameters to the selected reference stationary phase. Thus, a ranking list based on the FKUL value can be calculated for the chosen reference column, then correlated with the results of the column performance test. In this study, the column performance test was based on analysis of moclobemide and its two metabolites in human plasma by liquid chromatography (LC), using 18 columns. The comparative study was performed using traditional correlation of the FKUL values with the retention parameters of the analytes describing the column performance test. In order to deepen the comparative assessment of both data sets, factor analysis (FA) was also used. The obtained results indicated that the stationary phase classes, closely related according to the KUL method, yielded comparable separation for the target substances. Therefore, the column ranking system based on the FKUL-values could be considered supportive in the choice of the appropriate column for biomedical analysis.

VPLIV VAN DER WAALSOVIH SIL NA TVORBO ASOCIIRANIH MOLEKUL

OpenAIRE

Kuster, Bernarda

2014-01-01

Namen diplomske naloge je preučiti vpliv van der Waalsovih sil na tvorbo asociiranih molekul. V ta namen smo izbrali površinsko aktivne snovi, ki imajo amfifilne lastnosti in vplivajo na povšinske in medfazne napetosti ter pri določeni koncentraciji, imenovani kritična micelna koncentracija (CMC), tvorijo molekulske skupke, ki jim pravimo micele. Kritično micelno koncentracijo smo določili trem površinsko aktivnim snovem: heksadeciltrimetilamonijevemu bromidu, tetradeciltrimetilamonijevemu b...

Facile preparation of an alternating copolymer-based high molecular shape-selective organic phase for reversed-phase liquid chromatography.

Science.gov (United States)

Mallik, Abul K; Noguchi, Hiroki; Rahman, Mohammed Mizanur; Takafuji, Makoto; Ihara, Hirotaka

2018-06-22

The synthesis of a new alternating copolymer-grafted silica phase is described for the separation of shape-constrained isomers of polycyclic aromatic hydrocarbons (PAHs) and tocopherols in reversed-phase high-performance liquid chromatography (RP-HPLC). Telomerization of the monomers (octadecyl acrylate and N-methylmaleimide) was carried out with a silane coupling agent; 3-mercaptopropyltrimethoxysilane (MPS), and the telomer (T) was grafted onto porous silica surface to prepare the alternating copolymer-grafted silica phase (Sil-alt-T). The new hybrid material was characterized by elemental analyses, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and solid-state 13 C and 29 Si cross-polarization magic-angle spinning (CP/MAS) NMR spectroscopy. The results of 13 C CP/MAS NMR demonstrated that the alkyl chains of the grafted polymers in Sil-alt-T remained disordered, amorphous, and mobile represented by gauche conformational form. Separation abilities and molecular-shape selectivities of the prepared organic phase were evaluated by the separation of PAHs isomers and Standard Reference Material 869b, Column Selectivity Test Mixture for Liquid Chromatography, respectively and compared with commercially available octadecylsilylated silica (ODS) and C 30 columns as well as previously reported alternating copolymer-based column. The effectiveness of this phase is also demonstrated by the separation of tocopherol isomers. Oriented functional groups along the polymer main chains and cavity formations are investigated to be the driving force for better separation with multiple-interactions with the solutes. One of the advantages of the Sil-alt-T phase to that of the previously reported phase is the synthesis of the telomer first and then immobilized onto silica surface. In this case, the telomer was characterized easily with simple spectroscopic techniques and the molecular mass and polydispersity index of the telomer were determined by size exclusion

Highly hydrophilic and nonionic poly(2-vinyloxazoline)-grafted silica: a novel organic phase for high-selectivity hydrophilic interaction chromatography.

Science.gov (United States)

Mallik, Abul K; Cheah, Wee Keat; Shingo, Kaori; Ejzaki, Aika; Takafuji, Makoto; Ihara, Hirotaka

2014-07-01

A new hydrophilic and nonionic poly(2-vinyloxazoline)-grafted silica (Sil-VOX(n)) phase was synthesized and applied for the separation of nucleosides and nucleobases in hydrophilic interaction chromatography (HILIC). Polymerization and immobilization onto silica were confirmed by using characterization techniques including (1)H NMR spectroscopy, elemental analysis, and diffuse reflectance infrared Fourier transform spectroscopy. The hydrophilicity or wettability of Sil-VOX(n) was observed by measuring the contact angle (59.9°). The chromatographic results were compared with those obtained with a conventional HILIC silica column. The Sil-VOX(n) phase showed much better separation of polar test analytes than the silica column, and the elution order was different. Differences in selectivity between these two columns indicate that the stationary phase cannot function merely as an inert support for a water layer into which the solutes are partitioned from the bulk mobile phase. To elucidate the interaction mechanism, the separation of dihydroxybenzene isomers was performed on both columns in normal-phase liquid chromatography. Sil-VOX(n) was very sensitive to the dipole moments of the positional isomers of polycyclic aromatic compounds in normal-phase liquid chromatography. The interaction mechanism for Sil-VOX(n) in HILIC separation is also described.

SILWeb – analisador fonológico silábico-acentual de texto escrito

Directory of Open Access Journals (Sweden)

Ana Cristina Fricke Matte

2012-11-01

Full Text Available Este artigo apresenta o programa SilWeb – um programa analisador de texto escrito cuja finalidade é obter informações lexicais sobre acento e tipo de unidade fonológica –, e discute o processo de sua elaboração, cuja peculiaridade foi ser o resultado de uma interação entre lingüistas e engenheiros. Em função dessa interação, o processo contou com um estudo mattosiano da estrutura da transcrição fonológica adotada, bem como contou com o algoritmo do programa. Ambos os estudos estão relatados no presente artigo. Além da separação silábica tradicional, o programa possui uma versão para separação de unidades vogal avogal.

Case-mix study of single incision laparoscopic surgery (SILS) vs. Conventional laparoscopic surgery in colonic cancer resections

DEFF Research Database (Denmark)

Mynster, Tommie; Wille-Jørgensen, Peer

2013-01-01

of administrations or amount of opioids were seen. Conclusion. With reservation of a small study group we find SILS is like worthy to CLS in colorectal cancer surgery and a benefit in postoperative recovery and pain is possible, but has to be investigated in larger randomised studies.......Single incision laparoscopic surgery (SILS) may be even less invasive to a patient than conventional laparoscopic surgery (CLS). Aim of the study of the applicability of the procedure, the first 1½ year of experiences and comparison with CLS for colonic cancer resections Material and methods. Since...

Development of a hysteresis model for R/C columns subjected to bi-axial lateral loading

International Nuclear Information System (INIS)

Dutta, Sekhar Chandra; Chowdhury, Rajib; Roy, Raghupati; Reddy, G. Rami

2003-01-01

Recent investigations on dynamic response of reinforced concrete (R/C) structures have confirmed that the R/C structural members undergo much more inelastic deformation in each of the two mutually perpendicular directions under bi-directional seismic loading, than that observed only under unidirectional ground motion. To predict the seismic response of R/C structure with fair accuracy demands, a faithful model that can incorporate the effect of biaxial bending interaction in column. This model should not have high computational demand but should adequately reflect the stiffness degrading and strength deterioration characteristics of R/C structural members. Present study is an effort to develop such a bi-directional hysteresis model accounting the effect of interaction between lateral loadings in two orthogonal directions. The development of the present model is based on the yield surface approach and it can incorporate both strength and stiffness degradation characteristics, which is unavoidable in R/C structures during cyclic loading. The performance of the proposed model/ is demonstrated through the prediction of available experimental results of a reinforced concrete column, subjected to biaxial loading. (author)

The comparison of 18C(n; γ)19C and 18C(α; n)21O reaction rates: consequences for the r-process

International Nuclear Information System (INIS)

Dan, M.; Singh, G.; Chatterjee, R.; Shubhchintak

2017-01-01

Neutron rich light and medium mass nuclei play a major role in determining the reaction flow towards the r-process seed nuclei production. In this text, we calculate the neutron capture rate of 18 C and compare it with that of α-capture by the same nucleus in the temperature range T 9 = 0:1 - 10. This temperature range roughly equals to an energy range of 1 keV to 1 MeV in centre of mass frame, where it is very difficult to perform direct reaction experiments. Further, the theoretical construction of 18 C-n continuum state for the 18 C(n; γ) 19 C direct reaction is a tedious job

A comparative study of homemade C18 and commercial C18 sorbents for preconcentration of lead by minicolumn solid phase extraction

International Nuclear Information System (INIS)

Maltez, H.F.; Curtius, A.J.; Carasek, E.; Melo, L.F.C.; Sales Fontes Jardim, I.C.; Nascimento de Queiroz do, S.C.

2004-01-01

A comparative study of commercial C 18 chemically immobilized on silica and homemade C 18 , as sorbents for Pb complexed with 0,0-diethyl-dithiophosphate (DDTP) in a flow injection preconcentration system is reported. The homemade C 18 sorbent was obtained by sorption of poly(methyloctadecylsiloxane) (PMODS) on the silica support followed by immobilization using thermal treatment. The method follows the concept of green chemistry, since there are no toxic residues after synthesis. The complexed Pb was formed in 1.0 mol L -1 HCI medium and retained on the minicolumn filled with the sorbents. The elution was carried out using ethanol, and the richest 210 μL fraction was collected and analyzed by flame atomic absorption spectrometry. Chemical and flow variables were optimized for each sorbent. The results demonstrated that the performance of the proposed homemade C 18 sorbent for preconcentration of Pb complexed with DDTP is very similar to commercial C 18 chemically bonded on silica. By processing 25 mL, the enrichment factors were 129 and 125 for commercial C 18 and homemade C 18 , respectively. The limit of detection for commercial and homemade C 18 was 0.2 μg L -1 and 0.6 μg L -1 , respectively. The relative standard deviation (RSD) was lower than 1.2 % for both sorbents for a Pb concentration of 100 μg L -1 . The method was also applied successfully to the analysis of water samples, and the accuracy was tested by recovery measurements on spiked samples and biological reference material. (author)

A totally heat-integrated distillation column (THIDiC) - the effect of feed pre-heating by distillate

Energy Technology Data Exchange (ETDEWEB)

Huang Kejin [School of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)], E-mail: huangkj@mail.buct.edu.cn; Shan Lan; Zhu Qunxiong [School of Information Science and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Qian Jixin [School of Information Science and Technology, Zhejiang University, Zhejiang 300027 (China)

2008-06-15

An ideal heat-integrated distillation column (ideal HIDiC) is characterized by external zero-reflux and zero-reboil ratio operation. Since the distillate is a high-pressure vapor phase flow, it can be used to pre-heat the feed to be separated, thereby giving rise to a totally heat-integrated distillation column (THIDiC). Although the THIDiC is more thermodynamically efficient than the ideal HIDiC, it is found that the heat integration between the distillate and feed turns it into an open-loop integrating process and poses additional difficulties to process operation. Therefore, a careful decision must be made on the selection between the ideal HIDiC and the THIDiC during process development. In this paper, separation of a binary equimolar mixture of benzene and toluene is selected as an illustrative example. Both process design and operability analysis are conducted, with special emphasis focused on the characteristics of feed pre-heating with distillate. The results obtained show deep insight into the design and operation of the THIDiC.

A totally heat-integrated distillation column (THIDiC) - the effect of feed pre-heating by distillate

International Nuclear Information System (INIS)

Huang Kejin; Shan Lan; Zhu Qunxiong; Qian Jixin

2008-01-01

An ideal heat-integrated distillation column (ideal HIDiC) is characterized by external zero-reflux and zero-reboil ratio operation. Since the distillate is a high-pressure vapor phase flow, it can be used to pre-heat the feed to be separated, thereby giving rise to a totally heat-integrated distillation column (THIDiC). Although the THIDiC is more thermodynamically efficient than the ideal HIDiC, it is found that the heat integration between the distillate and feed turns it into an open-loop integrating process and poses additional difficulties to process operation. Therefore, a careful decision must be made on the selection between the ideal HIDiC and the THIDiC during process development. In this paper, separation of a binary equimolar mixture of benzene and toluene is selected as an illustrative example. Both process design and operability analysis are conducted, with special emphasis focused on the characteristics of feed pre-heating with distillate. The results obtained show deep insight into the design and operation of the THIDiC

Development of gas chromatography-flame ionization detection system with a single column and liquid nitrogen-free for measuring atmospheric C2-C12 hydrocarbons.

Science.gov (United States)

Liu, Chengtang; Mu, Yujing; Zhang, Chenglong; Zhang, Zhibo; Zhang, Yuanyuan; Liu, Junfeng; Sheng, Jiujiang; Quan, Jiannong

2016-01-04

A liquid nitrogen-free GC-FID system equipped with a single column has been developed for measuring atmospheric C2-C12 hydrocarbons. The system is consisted of a cooling unit, a sampling unit and a separation unit. The cooling unit is used to meet the temperature needs of the sampling unit and the separation unit. The sampling unit includes a dehydration tube and an enrichment tube. No breakthrough of the hydrocarbons was detected when the temperature of the enrichment tube was kept at -90 °C and sampling volume was 400 mL. The separation unit is a small round oven attached on the cooling column. A single capillary column (OV-1, 30 m × 0.32 mm I.D.) was used to separate the hydrocarbons. An optimal program temperature (-60 ∼ 170 °C) of the oven was achieved to efficiently separate C2-C12 hydrocarbons. There were good linear correlations (R(2)=0.993-0.999) between the signals of the hydrocarbons and the enrichment amount of hydrocarbons, and the relative standard deviation (RSD) was less than 5%, and the method detection limits (MDLs) for the hydrocarbons were in the range of 0.02-0.10 ppbv for sampling volume of 400 mL. Field measurements were also conducted and more than 50 hydrocarbons from C2 to C12 were detected in Beijing city. Copyright © 2015 Elsevier B.V. All rights reserved.

Ácidos silícicos como catalizadores y fuente de silicio/metal para zeolitas

OpenAIRE

Barea Berzosa, Eva María

2011-01-01

Barea Berzosa, EM. (2005). Ácidos silícicos como catalizadores y fuente de silicio/metal para zeolitas [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/1868.

Solid phase extraction for multiresidue analysis of anabolic steroids and related substances from calf urine using C18 and alumina columns

NARCIS (Netherlands)

Koole, A; Franke, JP; de Zeeuw, RA

1999-01-01

A solid phase extraction method for anabolic steroids and related substances in calf urine is reported, that is suitable as a screening method for illegal growth promoters. Two types of sorbent were used: a reversed phase C18 material and a polar alumina material. After overnight enzymatic

Clinical significance of determination of changes of serum IL-2, sIL-2R and TGF-β levels in patients with Graves' ophthalmopathy

International Nuclear Information System (INIS)

Li Han

2009-01-01

Objective: To study the relationship between progress of the disease and the changes of serum IL-2, sIL-2R and TGF-β levels in patients with Graves' ophthalmopathy. Methods: Serum TGF-β(with RIA) and IL-2, sIL-2R(with ELISA) levels were determined in 30 patients with Graves' ophthalmopathy both before and after six months' treatment with prednisonlone as well as in 30 controls. Results: The serum IL-2 levels in the patients before treatment were significantly lower than those in controls (P 0.05). Both serum sIL-2R and TGF-β levels in the patients before treatment were significantly higher than those in controls (P<0.01). After treatment, the levels dropped markedly, but still remained significantly higher than those in controls (P<0.05 and P<0.01). Conclusion: Determination of changes of serum IL-2, sIL-2R and TGF-β levels in patients with Graves' ophthalmopathy might be helpful for outcome prediction. (authors)

Elevated Plasma Levels of sIL-2R in Complex Regional Pain Syndrome: A Pathogenic Role for T-Lymphocytes?

Science.gov (United States)

Stronks, Dirk L.; Dik, Willem A.; Schreurs, Marco W. J.

2017-01-01

The immune system has long been thought to be involved in the pathophysiology of complex regional pain syndrome (CRPS). However, not much is known about the role of the immune system and specifically T-cells in the onset and maintenance of this disease. In this study, we aimed to evaluate T-cell activity in CRPS by comparing blood soluble interleukin-2 receptor (sIL-2R) levels between CRPS patients and healthy controls. CRPS patients had statistically significant elevated levels of sIL-2R as compared to healthy controls (median sIL-2R levels: 4151 pg/ml (Q3 − Q1 = 5731 pg/ml − 3546 pg/ml) versus 1907 pg/ml (Q3 − Q1: 2206 pg/ml − 1374 pg/ml), p CRPS patients and healthy controls with a high sensitivity (90%) and specificity (89.5%). Our finding indicates increased T-cell activity in patients with CRPS. This finding is of considerable relevance as it could point towards a T-cell-mediated inflammatory process in this disease. This could pave the way for new anti-inflammatory therapies in the treatment of CRPS. Furthermore, sIL-2R could be a promising new marker for determining inflammatory disease activity in CRPS. PMID:28634419

A Profilaxia do Silêncio: Nietzsche e a Virtude da Vita Contemplativa

Directory of Open Access Journals (Sweden)

Jelson Roberto Oliveira

2011-12-01

Full Text Available http://dx.doi.org/10.5007/1677-2954.2011v10n1p133 Pretende-se mostrar como o tema do silêncio, apresentado como parte do projeto nietzscheano de revitalização da vita contemplativa, adquire importância no chamado segundo período de sua produção, ligado àquela que poderia ser considerada a primeira e mais contundente das virtudes humanas apontadas por Nietzsche: o cultivo de si. Nesse sentido, trata-se de uma noção requisitada como parte do projeto crítico da modernidade implementado pelo filósofo alemão, cujo ponto de partida é uma revisão da própria tarefa da filosofia, conduzindo a uma crítica radical da moralidade vigente, da hipertrofia da racionalidade e da importância da linguagem. O silêncio, associado à solidão, aparece como uma profilaxia e radical aprofundamento em relação à anulação de si no arrulho da multidão moderna.

Silica particles encapsulated poly(styrene-divinylbenzene) monolithic stationary phases for micro-high performance liquid chromatography.

Science.gov (United States)

Bakry, R; Stöggl, W M; Hochleitner, E O; Stecher, G; Huck, C W; Bonn, G K

2006-11-03

In the paper we demonstrate a new approach for the preparation and application of continuous silica bed columns that involve encapsulation (entrapment) of functionalized silica microparticles, which can be used as packing material in micro high performance liquid chromatography (micro-HPLC) and capillary electrochromatography (CEC). Like traditional packed columns, these capillaries possess characterized silica particles that offer high phase ratio and narrow pore size distribution leading to high retention and separation efficiency, respectively. More importantly, immobilization of the microparticles stabilizes the separation bed and eliminates the need for retaining frits. The developed capillary columns were fabricated in exactly the same way as a packed capillary column (slurry packing) but with an additional entrapment step. This immobilization of the packed bed was achieved by in situ polymerization of styrene and divinylbenzene in presence of decanol as a porogen and azobisisobutyronitrile as thermal initiator. Silica particles with different particle sizes and pore sizes ranging from 60 to 4000 A were studied. In addition different modified silica was used, including C-18 reversed phase, anion exchange and chiral stationary phases. Efficient separation of polyphenolic compounds, peptides, proteins and even DNA mutation were achieved using the developed technique depending on the properties of the silica particles used (particles pore size). For example, using 3 microm ProntoSIL C-18 particles with 300 A pore size, separation efficiencies in the range of 120,000-200,000 plates/m were obtained for protein separation, in a 6 cm x 200 microm i.d. capillary column. Using encapsulated silica C-18 with 1000 A pore size, separation of DNA homo and hetero duplexes were achieved under denaturing HPLC conditions for mutation detection. In addition, nucleotides were separated using anion exchange material encapsulated with poly(styrene-divinylbenzene) (PS/DVB), which

Study on the changes of serum soluble IL-2 receptor (SIL-2R) levels and distribution pattern of peripheral blood T-cell subsets after treatment in pediatric patients with Bronchopneumonia

International Nuclear Information System (INIS)

Chen Chuanbin

2005-01-01

Objective:To investigate the significance of changes of serum SIL-2R levels and T-cell subsets distribution type after treatment in pediatric patients with bronchopneumonia. Methods: Serum SIL-2R levels (with ELISA) and peripheral blood T-cell subset distribution pattern (with monoclonal antibody technique) were determined in 33 pediatric patients with broncho-pneumonia and 30 controls. Results: Before treatment, the serum SIL-2R levels in the patients were significantly higher than those in normal controls (P 0.05). Serum SIL-2R levels were positively correlated with CD4/CD8 ratio. Conclusion: Detection of serum SIL-2R levels and CD4/CD8 ratio is clinically useful in the management of pediatric patients with bronchopneumonia. (authors)

Use of a Fibrinogen/Thrombin-Based Collagen Fleece (TachoComb, TachoSil) With a Stapled Closure to Prevent Pancreatic Fistula Formation Following Distal Pancreatectomy.

Science.gov (United States)

Mita, Kazuhito; Ito, Hideto; Murabayashi, Ryo; Asakawa, Hideki; Nabetani, Masashi; Kamasako, Akira; Koizumi, Kazuya; Hayashi, Takashi

2015-12-01

Postoperative pancreatic fistula formation remains a source of significant morbidity following distal pancreatectomy. The aim of this study was to evaluate the rate of clinically significant fistulas (International Study Group on Pancreatic Fistula grade B and grade C) after distal pancreatectomy using a fibrinogen/thrombin-based collagen fleece (TachoComb, TachoSil) with a stapled closure. Seventy-five patients underwent distal pancreatectomy at our institution between January 2005 and March 2014. A fibrinogen/thrombin-based collagen fleece was applied to the staple line of the pancreas before stapling. Twenty-six patients (34.7%) developed a pancreatic fistula, 8 patients (10.7%) developed a grade B fistula, and no patients developed a grade C fistula. The duration of the drain was significantly different in patients with or without a pancreatic fistula (8.0 ± 4.5 vs. 5.4 ± 1.3 days, P = .0003). Histological analysis showed that there was a tight covering with the fibrinogen/thrombin-based collagen fleece. The fibrinogen/thrombin-based collagen fleece (TachoComb, TachoSil) with a stapled closure has low rates of fistula formation and provides a safe alternative to the conventional stapled technique in distal pancreatectomy. © The Author(s) 2015.

Mobile Column Measurements of HCHO, NO2, NH3, and C2H6 in Colorado during FRAPPE

Science.gov (United States)

Kille, N.; Volkamer, R. M.; Baidar, S.; Ortega, I.; Sinreich, R.; Hannigan, J. W.; Cooper, O. R.; Nussbaumer, E.; Pfister, G.

2015-12-01

Gases from anthropogenic sources have the potential to have a profound impact on air quality. Emissions from large cattle feedlots and ONG (Oil and Natural Gas) sites are comprised of NH3 (ammonia) and C2H6 (ethane) as pollutants. C2H6 contributes to photochemical ozone (O3) production and oxidation production of HCHO (formaldehyde). NH3 is a major source for reactive nitrogen to form particulate matter 2.5, which negatively affects human health. NO2 (nitrogen dioxide), emitted during combustion, is considered a large-scale pollutant and contributes to the formation of O3. Deploying an innovative suite of remote sensing instruments in a mobile laboratory, a Multi Axis Differential Optical Absorption Spectrometer (MAX-DOAS), a UV-Vis Spectrometer, and a Fourier Transform Infrared Spectrometer, we obtain mobile column measurements at high spatial and temporal resolution, 2 seconds for the UV-Vis and IR spectrometers and 20 seconds for the MAX-DOAS. Within the scope of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) we measure total columns of HCHO, NO2, NH3, and C2H6 using the University of Colorado mobile laboratory. Emissions of urban areas, agriculture, and ONG sites were studied. For the measurement of total columns the solar occultation flux method has been applied. We measured significant variability in the columns. The measurement of total columns allows one to determine the emission flux and source strength when driving a closed box around or upwind and downwind of a source with the mobile laboratory. We present results from select research drives.

Innovations in Endosurgery-Journey into the Past of the Future: To Ride the SILS Bandwagon or Not?

Science.gov (United States)

Agarwal, Brij B; Chintamani; Ali, Kamran; Goyal, Karan; Mahajan, Krishan C

2012-06-01

Progress in surgical practice has paralleled the civilizational evolution. Surgery has progressed from being the last resort in saving life to being form and function preserver. Post-renaissance Industrial age gave an impetus to this march of surgery. The currently on going digital technological revolution has further catalysed this march. Having achieved the stabilized and acceptable clinical outcomes, the surgeon has embarked on a journey of improving patient reported outcomes (PRO). Improvement in PROs with the advent of laparoscopic surgery with the attendant emphasis on minimising invasion has led to debates about invasion being just parietal or holistic in physiological sense. There is a concern that parietal invasiveness shouldn't be a trade-off for compromised clinical outcomes. Single Incision Laparoscopic Surgery (SILS) in its current avatar with current instrumentation seems to be an enthusiastic bandwagon rolling on with the cosmetic benefits acting as veil to hide the potential clinical concerns. History of surgical innovations is riddled with tales of vindictiveness and vicissitude. Lest the same fate befalls SILS we would do better to examine the SILS bandwagon in its current form till the emerging technologies address the current concerns.

High Performance Liquid Chromatographic Analysis of Phytoplankton Pigments Using a C16-Amide Column

Science.gov (United States)

A reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed to analyze in a single run, most polar and non-polar chlorophylls and carotenoids from marine phytoplankton. The method is based on a RP-C16-Amide column and a ternary gradient system consistin...

The effect of re-dissolution solvents and HPLC columns on the analysis of mycosporine-like amino acids in the eulittoral macroalgae Prasiola crispa and Porphyra umbilicalis

Science.gov (United States)

Karsten, Ulf; Escoubeyrou, Karine; Charles, François

2009-09-01

Many macroalgal species that are regularly exposed to high solar radiation such as the eulittoral green alga Prasiola crispa and the red alga Porphyra umbilicalis synthesize and accumulate high concentrations of mycosporine-like amino acids (MAAs) as UV-sunscreen compounds. These substances are typically extracted with a widely used standard protocol following quantification by various high performance liquid chromatography (HPLC) techniques. However, further preparation steps prior to HPLC analysis as well as different HPLC column types have not been systematically checked regarding separation quality and reproducibility. Therefore pure methanol, distilled water and HPLC eluent were evaluated as re-dissolution solvent for dried Prasiola and Porphyra extracts, which were subsequently analyzed on three reversed-phase C8 and C18 HPLC columns. The data indicate that distilled water and the HPLC eluent gave almost identical peak patterns and MAA contents on the C8 and C18 columns. In contrast, the application of the widely used methanol led to double peaks or even the loss of specific peaks as well as to a strong decline in total MAA amounts ranging from about 35% of the maximum in P. crispa to 80% of the maximum in P. umbilicalis. Consequently, methanol should be avoided as re-dissolution solvent for the HPLC sample preparation. An improved protocol for the MAA analysis in macroalgae in combination with a reliable C18 column is suggested.

Les facteurs territoriaux de la compétitivité de la filière soja au Brésil

Directory of Open Access Journals (Sweden)

Bertrand Jean-Pierre

2001-05-01

Full Text Available Ce papier discute les facteurs de progression du complexe soja dans les régions de Cerrados du Nord du Brésil, proches de la forêt amazonienne. Le Mato Grosso est déjà le premier État producteur de soja du Brésil, tandis que le Para entre dans le processus de production intensif. Les deux États obtiennent des rendements élevés ; mais ils risquent de connaître des problèmes environnementaux du fait d’un usage excessif des pesticides.

Clinical significance of determination of changes of serum IL-2, SIL-2R, TNF-α contents and T-cell subgroup distribution type in patients with psoriasis

International Nuclear Information System (INIS)

Mou Xudong

2005-01-01

Objective: To investigate the changes of serum IL-2, SIL-2R, TNF-α contents and T-cell subgroup distribution type in patients with psoriasis. Methods: Serum IL-2 and TNF-α levels were measured with RIA, SIL-2R levels was measured with ELISA and T-cell subgroup distribution type was detected with monoclonal antibody in 40 patients with psoriasis and 35 controls. Results: The serum IL-2 levels and CD 4 /CD 8 values were significantly lower in the patients than those in controls (P<0.01), while the serum SIL-2R, TNF-α levels were significantly higher (P<0.01). Conclusion: Determination of serum IL-2, SIL-2R, TNF-α contents and T-cell subgroup distribution type is clinically useful for understanding the disturbances of immuno-modulation in these patients. (authors)

Le Brésil et sa généreuse diplomatie : un dragon amical ou un tigre de papier ?

Directory of Open Access Journals (Sweden)

Robert Muggah

2012-04-01

Full Text Available Jouissant d’une démocratie stable et d’une croissance économique vertigineuse, le Brésil est en passe de devenir une puissance mondiale. Le pays s’attelle aujourd’hui à renforcer ses relations multilatérales et bilatérales en vue de promouvoir le commerce et de réduire sa vulnérabilité à l’étranger et au niveau national. Cet article montre comment le Brésil a progressivement aligné sa politique étrangère sur la coopération Sud-Sud (CSS dans le but d’atteindre ces objectifs parallèles. Si les priorités politiques du Brésil en matière de commerce ont retenu l’attention, il en est tout autrement de ses politiques et de ses pratiques en matière d’aide au développement. En outre, il est surprenant de constater que le lien explicite entre ces deux piliers de la politique étrangère brésilienne que sont le commerce et l’aide ne suscite guère de débat. Le présent article cherche à démontrer que le nouveau programme d’aide du Brésil repose fondamentalement sur des considérations commerciales. Au cours des dix dernières années, le Brésil s’est en effet attaché à positionner son programme de politique étrangère de manière à remodeler les termes mondiaux de l’échange en sa faveur et à diminuer sa dépendance aux niveaux international et national. Les attributions relativement modestes de l’aide au développement du Brésil augmentent avec l’effort plus général de faire progresser le commerce, l’investissement étranger direct et le transfert technologique. En cherchant de nouveaux marchés pour ses produits, services et investissements, le Brésil escompte que sa position en faveur de la coopération pour le développement Sud-Sud (CDSS l’aidera à renforcer son influence dans les organisations bilatérales et multilatérales, y compris au sein de l’Organisation mondiale du commerce (OMC et du Conseil de sécurité de l’ONU.

4- 18F]fluoroarylalkylethers via an improved synthesis of n.c.a. 4- 18F]fluorophenol

International Nuclear Information System (INIS)

Ludwig, Thomas; Ermert, Johannes; Coenen, Heinz H.

2002-01-01

This paper describes the improved synthesis of n.c.a. 4- 18 F]fluorophenol for the preparation of 18 F-labeled alkylarylethers. Nucleophilic fluorination of substituted benzophenone derivatives yielded n.c.a. 4- 18 F]fluoro-4'-substituted benzophenones with 80- 90 % RCY, which were converted to benzoic acid phenylesters by treatment with peracetic acid. Strong electron-withdrawing substituents like nitro, cyano and trifluoromethyl favor a fluorophenyl-to-oxygen migration resulting in the formation of corresponding benzoic acid fluorophenylesters. N.c.a. 18 F]fluorophenol is almost quantitatively formed after hydrolysis and can easily be converted with alkylhalides into n.c.a. 18 F]fluoroarylalkylethers

Evaluation of highly polar ionic liquid gas chromatographic column for the determination of the fatty acids in milk fat.

Science.gov (United States)

Delmonte, Pierluigi; Fardin-Kia, Ali Reza; Kramer, John K G; Mossoba, Magdi M; Sidisky, Len; Tyburczy, Cynthia; Rader, Jeanne I

2012-04-13

The SLB-IL111, a new ionic liquid capillary column for gas chromatography available from Supelco Inc., was recently shown to provide enhanced separation of unsaturated geometric and positional isomers of fatty acid (FAs) when it was compared to cyanopropylsiloxane (CPS) columns currently recommended for the analysis of fatty acid methyl esters (FAMEs). A 200 m SLB-IL111 capillary column, operated under a combined temperature and eluent flow gradient, was successfully used to resolve most of the FAs contained in milk fat in a single 80 min chromatographic separation. The selected chromatographic conditions provided a balanced, simultaneous separation of short-chain (from 4:0), long-chain polyunsaturated fatty acids (PUFAs), and most of the unsaturated FA positional/geometric isomers contained in milk fat. Among the monounsaturated fatty acids (MUFAs), these conditions separated t11-18:1 and t10-18:1 FAs, the two most abundant trans fatty acids (t-FA) contained in most dairy products. These t-FAs reportedly have different biological activities. The conjugated linoleic acid (CLA) isomers commonly found in dairy products were separated from each other, including t7,c9-18:2 from c9,t11-18:2, which eliminated the need for their complementary silver ion HPLC analysis. The application of the SLB-IL111 column provided a complementary elution profile of FAMEs to those obtained by CPS columns, allowing for a more comprehensive FA analysis of total milk fat. The FAMEs were identified by the use of available reference materials, previously synthesized and characterized reference mixtures, and prior separations of the milk fat FAMEs by silver ion chromatography based on the number/geometry of double bonds. Published by Elsevier B.V.

Comparison of column chromatographic and precipitation methods for the purification of a macrocyclic polyether extractant

Energy Technology Data Exchange (ETDEWEB)

Dietz, M.L.; Felinto, C.; Rhoads, S.; Clapper, M.; Finch, J.W.; Hay, B.P.

1999-11-01

Column chromatography on aminopropyl-derivatized silica and precipitation of a complex with perchloric acid have been evaluated as methods for the purification of di-tert-butylcyclohexano-18-crown-6 (DtBuCH18C6), a compound frequently employed for the selective extraction of strontium from acidic nitrate media. Both methods are shown to provide a simple and effective means of eliminating inactive sample components (i.e., impurities or stereoisomers incapable of extracting strontium) from the crown ether and enriching the material in 4(z),4{prime}(z) cis-syn-cis DtBuCH18C6, a stereoisomer capable of highly efficient strontium extraction.

Comparison of column chromatographic and precipitation methods for the purification of a macrocyclic polyether extractant

International Nuclear Information System (INIS)

Dietz, M.L.; Felinto, C.; Rhoads, S.; Clapper, M.; Finch, J.W.; Hay, B.P.

1999-01-01

Column chromatography on aminopropyl-derivatized silica and precipitation of a complex with perchloric acid have been evaluated as methods for the purification of di-tert-butylcyclohexano-18-crown-6 (DtBuCH18C6), a compound frequently employed for the selective extraction of strontium from acidic nitrate media. Both methods are shown to provide a simple and effective means of eliminating inactive sample components (i.e., impurities or stereoisomers incapable of extracting strontium) from the crown ether and enriching the material in 4(z),4 prime(z) cis-syn-cis DtBuCH18C6, a stereoisomer capable of highly efficient strontium extraction

Exploring the effect of mesopore size reduction on the column performance of silica-based open tubular capillary columns.

Science.gov (United States)

Hara, Takeshi; Futagami, Shunta; De Malsche, Wim; Baron, Gino V; Desmet, Gert

2018-06-01

We report on a modification in the hydrothermal treatment process of monolithic silica layers used in porous-layered open tubular (PLOT) columns. Lowering the temperature from the customary 95 °C to 80 °C, the size of the mesopores reduced by approximately about 35% from 12-13.5 nm to 7.5-9 nm, while the specific pore volume essentially remains unaltered. This led to an increase of the specific surface area (SA) of about 40%, quasi-independent of the porous layer thickness. The increased surface area provided a corresponding increase in retention, somewhat more (48%) than expected based on the increase in SA for the thin layer columns, and somewhat less than expected (34%) for the thick layer columns. The recipes were applied in 5 μm i.d.-capillaries with a length of 60 cm. Efficiencies under retained conditions amounted up to N = 137,000 for the PLOT column with a layer thickness (d f ) of 300 nm and to N = 109,000 for the PLOT column with d f  = 550 nm. Working under conditions of similar retention, the narrow pore/high SA columns produced with the new 80 °C recipe generated the same number of theoretical plates as the wide pore size/low SA columns produced with the 95 °C recipe. This shows the 80 °C-hydrothermal treatment process allows for an increase in the phase ratio of the PLOT columns without affecting their intrinsic mass transfer properties and separation kinetics. This is further corroborated by the fact that the plate height curves generated with the new and former recipe can both be well-fitted with the Golay-Aris equation without having to change the intra-layer diffusion coefficient. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparison of LC Columns Packed with 2.6 lm Core-Shell and Sub-2 lm Porous Particles for Gradient Separation of Antibiotics

Czech Academy of Sciences Publication Activity Database

Tylová, Tereza; Kameník, Zdeněk; Flieger, Miroslav; Olšovská, Jana

2011-01-01

Roč. 74, 1-2 (2011), s. 19-27 ISSN 0009-5893 R&D Projects: GA MŠk 1M06011 Institutional research plan: CEZ:AV0Z50200510 Keywords : Column liquid chromatography * Sub-2 mu m particles * Acquity BEH C18 column Subject RIV: EE - Microbiology, Virology Impact factor: 1.195, year: 2011

Dynamic effects of diabatization in distillation columns

DEFF Research Database (Denmark)

Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

2013-01-01

The dynamic effects of diabatization in distillation columns are investigated in simulation emphasizing the heat-integrated distillation column (HIDiC). A generic, dynamic, first-principle model has been formulated, which is flexible enough to describe various diabatic distillation configurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found and control...

Dynamic Effects of Diabatization in Distillation Columns

DEFF Research Database (Denmark)

Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

2012-01-01

The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found. Control...

HybridSil Icephobic Nanocomposites for Next Generation Aircraft In-Flight Icing Measurement and Mitigation, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of this SBIR program is to adapt NanoSonic's HybridSil® nanocomposites and combine high erosion resistance, low ice adhesion, and passive anti-icing...

Evaluating Long-Term Impacts of Soil-Mixing Source-Zone Treatment using Cryogenic Core Collection

Science.gov (United States)

2017-06-01

using an autosampler. The method utilized a Restek Rxi-624Sil MS column, with the following dimensions: 30-m length, 0.25-mm OD, and 1.4-μm film ...at 40°C. The method utilized a Restek Rt-Q-BOND column, with the following dimensions: 30-m length, 0.32-mm OD, and 10-μm film thickness...Page Intentionally Left Blank B-1 APPENDIX B GEOLOGIC LOGS Geologic cross-section plots are shown in landscape orientation

The nature of the Syntaxin4 C-terminus affects Munc18c-supported SNARE assembly.

Directory of Open Access Journals (Sweden)

Asma Rehman

Full Text Available Vesicular transport of cellular cargo requires targeted membrane fusion and formation of a SNARE protein complex that draws the two apposing fusing membranes together. Insulin-regulated delivery and fusion of glucose transporter-4 storage vesicles at the cell surface is dependent on two key proteins: the SNARE integral membrane protein Syntaxin4 (Sx4 and the soluble regulatory protein Munc18c. Many reported in vitro studies of Munc18c:Sx4 interactions and of SNARE complex formation have used soluble Sx4 constructs lacking the native transmembrane domain. As a consequence, the importance of the Sx4 C-terminal anchor remains poorly understood. Here we show that soluble C-terminally truncated Sx4 dissociates more rapidly from Munc18c than Sx4 where the C-terminal transmembrane domain is replaced with a T4-lysozyme fusion. We also show that Munc18c appears to inhibit SNARE complex formation when soluble C-terminally truncated Sx4 is used but does not inhibit SNARE complex formation when Sx4 is C-terminally anchored (by a C-terminal His-tag bound to resin, by a C-terminal T4L fusion or by the native C-terminal transmembrane domain in detergent micelles. We conclude that the C-terminus of Sx4 is critical for its interaction with Munc18c, and that the reported inhibitory role of Munc18c may be an artifact of experimental design. These results support the notion that a primary role of Munc18c is to support SNARE complex formation and membrane fusion.

Rapid Determination of the Monosaccharide Composition and Contents in Tea Polysaccharides from Yingshuang Green Tea by Pre-Column Derivatization HPLC

OpenAIRE

Ai, Yujie; Yu, Zhi; Chen, Yuqiong; Zhu, Xiaojing; Ai, Zeyi; Liu, Shuyuan; Ni, Dejiang

2016-01-01

A pre-column derivatization high-performance liquid chromatography (HPLC) method was developed and optimized to characterize and quantify the monosaccharides present in tea polysaccharides (TPS) isolated from Yingshuang green tea. TPS sample was hydrolyzed with trifluoroacetic acid, subjected to pre-column derivatization using 1-phenyl-3-methyl-5-pyrazolone (PMP), and separated on an Agilent TC-C18 column (4.6 mm × 250 mm, 5 μm) with UV detection at 250 nm. A mixture of ten PMP derivatives of...

The possibility of a fully automated procedure for radiosynthesis of fluorine-18-labeled fluoromisonidazole using a simplified single, neutral alumina column purification procedure

International Nuclear Information System (INIS)

Nandy, Saikat; Rajan, M.G.R.; Korde, A.; Krishnamurthy, N.V.

2010-01-01

A novel fully automated radiosynthesis procedure for [ 18 F]Fluoromisonidazole using a simple alumina cartridge-column for purification instead of conventionally used semi-preparative HPLC was developed. [ 18 F]FMISO was prepared via a one-pot, two-step synthesis procedure using a modified nuclear interface synthesis module. Nucleophilic fluorination of the precursor molecule 1-(2'-nitro-1'-imidazolyl) -2-O-tetrahydropyranyl-3-O-toluenesulphonylpropanediol (NITTP) with no-carrier added [ 18 F]fluoride followed by hydrolysis of the protecting group with 1 M HCl. Purification was carried out using a single neutral alumina cartridge-column instead of semi-preparative HPLC. The maximum overall radiochemical yield obtained was 37.49±1.68% with 10 mg NITTP (n=3, without any decay correction) and the total synthesis time was 40±1 min. The radiochemical purity was greater than 95% and the product was devoid of other chemical impurities including residual aluminum and acetonitrile. The biodistribution study in fibrosarcoma tumor model showed maximum uptake in tumor, 2 h post injection. Finally, PET/CT imaging studies in normal healthy rabbit, showed clear uptake in the organs involved in the metabolic process of MISO. No bone uptake was observed excluding the presence of free [ 18 F]fluoride. The reported method can be easily adapted in any commercial FDG synthesis module.

Synthesis of n.c.a. 18F-fluorinated NMDA- and D4-receptor ligands via [18F]fluorobenzenes

International Nuclear Information System (INIS)

Ludwig, T.

2005-11-01

In this thesis new strategies were developed and evaluated for the no-carrier-added (n.c.a.) 18 F-labelling of receptor ligands as radiodiagnostics for characterization of brain receptors using positron-emission-tomography (PET). Special emphasis was placed on the synthesis of n.c.a. (±)-3-(4-hydroxy-4-(4-[ 18 F]fluorophenyl)-piperidin-l-yl)chroman-4,7-diol, a ligand with high affinity for the NR2B subtype of NMDA receptors and n.c.a. (3-(4-[ 18 F]fluorphenoxy)propyl)-(2-(4-tolylphenoxy)ethyl)amine ([ 18 F]FPTEA) a dopamine D 4 receptor ligand. In order to synthesize n.c.a. (±)-3-(4-hydroxy-4-(4-[ 18 F]fluorophenyl)-piperidin-l-yl)chroman-4,7-diol the 18 F-fluoroarylation method via metallorganic intermediates was modified and improved. The suitability of the organometallic 18 F-fluoroarylation agents was proven with several model compounds. High radiochemical yields of 20-30% were obtained also with piperidinone-derivatives. The preparation of a suitable precursor for the synthesis of the NMDA receptor ligand, however, could not be achieved by synthesis of appropriate 1,3-dioxolane protected piperidinone derivatives. Further, the synthesis of n.c.a. ([ 18 F]fluoroaryloxy)alkylamines via n.c.a. 4-[ 18 F]fluorophenol was developed and evaluated. The synthesis of n.c.a. [ 18 F]fluoroarylethers with corresponding model compounds was optimized and led to a radiochemical yield of 25-60%, depending on the alkylhalide used. The preparation of n.c.a. 1-(3-bromopropoxy)-4-[ 18 F]fluorobenzene proved advantageous in comparison to direct use of 4-[ 18 ]fluorophenol for coupling with a corresponding N-protected precursor for the synthesis of n.c.a. [ 18 F]FPTEA. With regard to the radiochemical yields and the loss of activity during the synthesis and isolation of n.c.a. 4-[ 18 F]fluorophenol and n.c.a. 1-(3-bromopropoxy)-4-[ 18 F]fluorobenzene, [ 18 F]FPTEA was obtained by reaction with 2-(4-tolyloxy)ethylamine in radiochemical yields of about 25-30% in ethanol or 2-butanone

Observation/confirmation of hindered E2 strength in {sup 18}C/{sup 16}C

Energy Technology Data Exchange (ETDEWEB)

Ong, H.J. [Osaka University, RCNP, Ibaraki, Osaka (Japan); Imai, N. [KEK, Tsukuba, Ibaraki (Japan); Suzuki, D.; Iwasaki, H.; Onishi, T.K.; Suzuki, M.K.; Nakao, T.; Ichikawa, Y. [University of Tokyo, Department of Physics, Bunkyo,Tokyo (Japan); Sakurai, H.; Takeuchi, S.; Kondo, Y.; Aoi, N.; Baba, H.; Bishop, S.; Ishihara, M.; Kubo, T.; Motobayashi, T.; Yanagisawa, Y. [RIKEN, RIKEN Nishina Center, Wako, Saitama (Japan); Ota, S. [University of Tokyo, RIKEN Campus, CNS, Wako, Saitama (Japan); Togano, Y.; Kurita, K. [Rikkyo University, Department of Physics, Toshima, Tokyo (Japan); Nakamura, T.; Okumura, T. [Tokyo Institute of Technology, Department of Physics, Meguro, Tokyo (Japan)

2009-12-15

We have measured the lifetime of the first excited 2{sup +} state in {sup 18}C using an upgraded recoil shadow method to determine the electric quadrupole transition. The measured mean lifetime is 18.9{+-}0.9 (stat){+-}4.4 (syst) ps, corresponding to B(E2;2{sub 1} {sup +}{yields} 0{sup +} {sub gs}) = 4.3{+-}0.2{+-}1.0 e{sup 2}fm{sup 4}, or about 1.5 Weisskopf units. The mean lifetime of the first 2{sup +} state in {sup 16}C was remeasured to be 18.3{+-}1.4{+-}4.8 ps, about four times shorter than the value reported previously. The discrepancy is explained by incorporating the {gamma} -ray angular distribution obtained in this work into the previous measurement. The observed transition strengths in {sup 16,18}C are hindered compared to the empirical values, indicating that the anomalous E2 strength observed in {sup 16}C persists in {sup 18}C. (orig.)

Longitudinal imaging of Alzheimer pathology using [11C]PIB, [18F]FDDNP and [18F]FDG PET

International Nuclear Information System (INIS)

Ossenkoppele, Rik; Tolboom, Nelleke; Adriaanse, Sofie F.; Foster-Dingley, Jessica C.; Boellaard, Ronald; Yaqub, Maqsood; Windhorst, Albert D.; Lammertsma, Adriaan A.; Berckel, Bart N.M. van; Barkhof, Frederik; Scheltens, Philip; Flier, Wiesje M. van der

2012-01-01

[ 11 C]PIB and [ 18 F]FDDNP are PET tracers for in vivo detection of the neuropathology underlying Alzheimer's disease (AD). [ 18 F]FDG is a glucose analogue and its uptake reflects metabolic activity. The purpose of this study was to examine longitudinal changes in these tracers in patients with AD or mild cognitive impairment (MCI) and in healthy controls. Longitudinal, paired, dynamic [ 11 C]PIB and [ 18 F]FDDNP (90 min each) and static [ 18 F]FDG (15 min) PET scans were obtained in 11 controls, 12 MCI patients and 8 AD patients. The mean interval between baseline and follow-up was 2.5 years (range 2.0-4.0 years). Parametric [ 11 C]PIB and [ 18 F]FDDNP images of binding potential (BP ND ) and [ 18 F]FDG standardized uptake value ratio (SUVr) images were generated. A significant increase in global cortical [ 11 C]PIB BP ND was found in MCI patients, but no changes were observed in AD patients or controls. Subsequent regional analysis revealed that this increase in [ 11 C]PIB BP ND in MCI patients was most prominent in the lateral temporal lobe (p 18 F]FDDNP, no changes in global BP ND were found. [ 18 F]FDG uptake was reduced at follow-up in the AD group only, especially in frontal, parietal and lateral temporal lobes (all p 11 C]PIB binding (ρ = -0.42, p 18 F]FDG uptake (ρ = 0.54, p 18 F]FDDNP binding (ρ = -0.18, p = 0.35) were not. [ 11 C]PIB and [ 18 F]FDG track molecular changes in different stages of AD. We found increased amyloid load in MCI patients and progressive metabolic impairment in AD patients. [ 18 F]FDDNP seems to be less useful for examining disease progression. (orig.)

Rapid determination of 18 glucocorticoids in serum using reusable on-line SPE polymeric monolithic column coupled with LC-quadrupole/orbitrap high-resolution mass spectrometer.

Science.gov (United States)

Li, Hui; Ai, Lianfeng; Fan, Sufang; Wang, Yan; Sun, Dianxing

2017-10-15

A simple, rapid and sensitive method for the simultaneous determination of 18 glucocorticoids in serum was developed by coupling on-line solid-phase extraction (SPE) polymeric monolithic column to a liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometer. A simple poly(ethylene glycol dimethacrylate) monolith column (10mm×2.1mm i.d.) was fabricated, and the morphology, surface area and extraction performance of the monolithic column were characterized. Serum samples were extracted by acetonitrile (ACN). Then, online SPE was achieved on the synthesized monolithic column using a 10mmol/L ammonium acetate solution as the loading solvent. After the transfer from the monolith into analytical column (Capcell Pak ADME column) using ACN, the adsorbed analytes were separated on the analytical column and detected with a high-resolution hybrid quadrupole/orbitrap mass spectrometer with full scan/ddMS 2 scan mode Under optimized conditions, the method was linear with target linear correlation coefficient (R 2 ) higher than 0.995. Detection limits were in range of 0.1-0.6ng/mL, and the quantification limits were 0.3-1.5ng/mL. The recovery was between 71.9% and 89.2% in three spike levels with precision (n=5) of 5.40-12.1%. The serum sample was directly analyzed after a simple extraction procedure, and the on-line SPE and determination were achieved within only 16min. The method was used to analyze the dynamic contents variation of cortisone and hydrocortisone in serum before and after the surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

Energy saving in multicomponent separation using an internally heat-integrated distillation column (HIDiC)

Energy Technology Data Exchange (ETDEWEB)

Iwakabe, Koichi [Department of Chemical Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro, Tokyo 152-8552 (Japan); Nakaiwa, Masaru; Huang, Kejin; Ohmori, Takao; Endo, Akira; Yamamoto, Takuji [Energy-Efficient Chemical Systems Group, Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Nakanishi, Toshinari [R and D Department, Kimura Chemical Plants Co., Ltd, 2-1-2, Terajima Kuise, Amagasaki, Hyogo 660-8567 (Japan); Roesjorde, Audun [Department of Chemistry, Norwegian University of Science and Technology, 7491 Tronheim (Norway)

2006-09-15

Energy savings by an internally heat-integrated distillation column (HIDiC) for the separation of multicomponent mixtures were studied. The design and the operating variables of a HIDiC were defined for this purpose, and were systematically varied to carry out a sensitivity analysis. Benzene-toluene-p-xylene (BTX) mixture and 12-component hydrocarbons (12HC) mixture were chosen as model systems. Sensitivity analysis showed that the HIDiC is able to reduce energy consumption by about 30% for the BTX system and an even better 50% for the 12HC system. The effects on energy consumption of the design and the operating variables were also examined. (author)

Identification and quantification of flavonoids in human urine samples by column switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

DEFF Research Database (Denmark)

Nielsen, S. E.; Freese, R.; Cornett, Claus

2000-01-01

A rapid and sensitive high-performance liquid chromatographic mass spectrometric (HPLC-MS) method is described for the determination and quantification of 12 dietary flavonoid glycosides and aglycons in human urine samples. Chromatographic separation of the analytes of interest was achieved...... by column-switching, using the first column (a Zorbax 300SB C-3 column) for sample cleanup and eluting the heart-cut flavonoid fraction onto the second column (a Zorbax SE C-18 column) for separation and detection by ultraviolet and atmospheric pressure chemical ionization MS using single ion monitoring...... of variation for the analysis of the 12 different flavonoids in quality control urine samples were 12.3% on average (range 11.0-13.7%, n = 24, reproducibility) and the repeatability of the assay were 5.0% (mean, range 0.1-14.8%, it = 12). A subset of 10 urine samples from a human dietary intervention study...

Reversed Phase Column HPLC-ICP-MS Conditions for Arsenic Speciation Analysis of Rice Flour.

Science.gov (United States)

Narukawa, Tomohiro; Matsumoto, Eri; Nishimura, Tsutomu; Hioki, Akiharu

2015-01-01

New measurement conditions for arsenic speciation analysis of rice flour were developed using HPLC-ICP-MS equipped with a reversed phase ODS column. Eight arsenic species, namely, arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA), trimethylarsine oxide (TMAO), tetramethylarsonium (TeMA), arsenobetaine (AsB) and arsenocholine (AsC), were separated and determined under the proposed conditions. In particular, As(III) and MMAA and DMAA and AsB were completely separated using a newly proposed eluent containing ammonium dihydrogen phosphate. Importantly, the sensitivity changes, in particular those of As(V) and As(III) caused by coexisting elements and by complex matrix composition, which had been problematical in previously reported methods, were eliminated. The new eluent can be applied to C8, C18 and C30 ODS columns with the same effectiveness and with excellent repeatability. The proposed analytical method was successfully applied to extracts of rice flour certified reference materials.

Radiochemical synthesis of 3-(4-[18F] Fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c] pyridin-5-one: A putative dopamine D$4 receptor PET imaging agent

International Nuclear Information System (INIS)

Li, G.C.; Yin, D.Z.; Wang, M.W.; Cheng, D.F.; Wang, Y.X.

2005-01-01

Introduction: The dopamine D 4 receptor has lately received increasing interest since it has been hypothesized to be involved in the pathology and pharmacotherapy of schizophrenia. While this receptor is expressed in lower density in various extrastriatal brain regions and its distribution is still unclear due to the lack of suitable imaging agent and its level change in schizophrenia is controversial. Herein, based on the structure-activity analysis of chromeno[3, 4-c]pyridine- 5-ones as potential dopamine D 4 receptor ligands, a putative D 4 subtype positron emission tomography (PET) radioligand, 3-(4-[ 18 F]fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one ([ 18 F]FHTP), was designed and synthesized. Methods: The radiochemical synthesis route was shown in Figure 1. [ 18 F]Fluoride was produced with a Cyclone-30 (IBA, Belgium) by 18 O(p, n) 18 F reaction using enriched 18 O-H 2 O and eluted from a Dowex 1-X8 anion-exchange column with aqueous potassium carbonate (20 mg/mL). 4-[ 18 F]Fluorobenzaldehyde was prepared according to the method reported by Alan A. Wilson and et al.. Then, 8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one, sodium cyanoborohydride, methanol and acetic acid were added to the dry residue, The mixture was then sealed and heated at 120 degree C for 12 min. At the end of the reaction, the mixture was cooled, diluted with ethyl acetate and washed with water. The extracted organic layer was passed through a small anhydrous magnesium sulfate column. After removal of the solvents in the mixture at 50 degree C under a stream of nitrogen, the obtained residue was redissolved in methanol and purified with a semi-preparative HPLC system, then the desired product was collected. Results: The radiochemical synthesis of [ 18 F]FHTP took around 110 min at EOS with an overall radiochemical yield 19% (decay-corrected) and its radiochemical purity was higher than 95%. Conclusion: A presumed dopamine D 4 receptor PET

Soluble intercellular adhesion molecule-1 (sICAM-1) and soluble interleukin-2 receptors (sIL-2R) in scleroderma skin

DEFF Research Database (Denmark)

Søndergaard, Klaus; Deleuran, Mette; Heickendorff, Lene

1998-01-01

In order to investigate whether soluble intercellular adhesion molecule-1 (sICAM-1) and soluble interleukin-2 receptors (sIL-2R) were present in scleroderma skin, and to compare their levels to concentrations measured in plasma and clinical parameters, we examined suction blister fluid and plasma...... from 13 patients with systemic sclerosis and 11 healthy volunteers. Suction blisters and biopsies were from the transition zone between normal skin and scleroderma, and uninvolved abdominal skin. The levels of sICAM-1 and sIL-2R were significantly increased in both plasma and suction blister fluid from...

Blind column selection protocol for two-dimensional high performance liquid chromatography.

Science.gov (United States)

Burns, Niki K; Andrighetto, Luke M; Conlan, Xavier A; Purcell, Stuart D; Barnett, Neil W; Denning, Jacquie; Francis, Paul S; Stevenson, Paul G

2016-07-01

The selection of two orthogonal columns for two-dimensional high performance liquid chromatography (LC×LC) separation of natural product extracts can be a labour intensive and time consuming process and in many cases is an entirely trial-and-error approach. This paper introduces a blind optimisation method for column selection of a black box of constituent components. A data processing pipeline, created in the open source application OpenMS®, was developed to map the components within the mixture of equal mass across a library of HPLC columns; LC×LC separation space utilisation was compared by measuring the fractional surface coverage, fcoverage. It was found that for a test mixture from an opium poppy (Papaver somniferum) extract, the combination of diphenyl and C18 stationary phases provided a predicted fcoverage of 0.48 and was matched with an actual usage of 0.43. OpenMS®, in conjunction with algorithms designed in house, have allowed for a significantly quicker selection of two orthogonal columns, which have been optimised for a LC×LC separation of crude extractions of plant material. Copyright © 2016 Elsevier B.V. All rights reserved.

Anomalous electrical signals associated with microbial activity: Results from Iron and Nitrate-Reducing Columns

Science.gov (United States)

Aaron, R. B.; Zheng, Q.; Flynn, P.; Singha, K.; Brantley, S.

2008-12-01

Three flow-through columns outfitted with Ag/AgCl electrodes were constructed to test the effects of different microbial processes on the geophysical measurements of self potential (SP), bulk electrical conductivity (σ b), and induced polarization (IP). The columns were filled with sieved, Fe-bearing subsurface sediment from the Delmarva Peninsula near Oyster, VA, inoculated (9:1 ratio) with a freshly-collected, shallow subsurface sediment from a wetland floodplain (Dorn Creek) near Madison, WI. Each of the columns was fed anoxic and sterile PIPES buffered artificial groundwater (PBAGW) containing different concentrations of acetate and nitrate. The medium fed to Column 1 (nitrate-reducing) was amended with 100 μM acetate and 2 mM nitrate. Column 2 (iron-reducing) was run with PBAGW containing 1.0 mM acetate and 0 mM nitrate. Column 3 (alternating redox state) was operated under conditions designed to alternately stimulate nitrate-reducing and iron-reducing populations to provide conditions, i.e., the presence of both nitrate and microbially-produced Fe(II), that would allow growth of nitrate-dependent Fe(II)-oxidizing populations. We operated Column 3 with a cycling strategy of 14-18 days of high C medium (1 mM acetate and 100 μ M nitrate) followed by 14-18 days of low C medium (100 μ M acetate and 2 mM nitrate). Effluent chemistry (NO3-, NO2-, NH4+, acetate, and Fe2+) was sampled daily for four months so as to be concurrent with the electrical measurements. We observed chemical evidence of iron reduction (dissolved [Fe(II)] = 0.2mM) in the effluent from the iron reduction and alternating redox columns. Chemical depletion of NO3- ([NO3-] ranged from 1 to 0.02mM), the production of NO2-, and possible production of NH4+ (0.2 mM) was observed in the nitrate reducing column as well as the alternating redox column. All three columns displayed loss of acetate as microbial activity progressed. σ b remained constant in the alternating redox column (~0.15 S

O caminho do silêncio: Mallarmé e Blanchot = The way of silence: Mallarmé and Blanchot

Directory of Open Access Journals (Sweden)

Stroparo, Sandra M.

2013-01-01

Full Text Available A mudança de paradigma representada pela poesia moderna implica uma série de particularidades dentre as quais o silêncio e suas possibilidades elocutórias se afirmam em embate e fertilidade. Contando com a leitura da obra de Mallarmé, e particularmente de alguns ensaios e do poema “Um lance de dados”, o texto busca apresentar o trajeto pelo qual a descoberta do que Mallarmé chamou de Nada, destruição e silêncio, pôde gerar para a crítica moderna, e especialmente para o crítico e autor Maurice Blanchot, uma vertente de compreensão da nova poesia bem como de suas próprias possibilidades de análise e compreensão

Open tubular capillary column for the separation of cytochrome C tryptic digest in capillary electrochromatography.

Science.gov (United States)

Ali, Faiz; Cheong, Won Jo

2015-10-01

A silica capillary of 50 μm internal diameter and 500 mm length (416 mm effective length) was chemically modified with 4-(trifluoromethoxy) phenyl isocyanate in the presence of dibutyl tin dichloride as catalyst. Sodium diethyl dithiocarbamate was reacted with the terminal halogen of the bound ligand to incorporate the initiator moiety, and in situ polymerization was performed using a monomer mixture of styrene, N-phenylacrylamide, and methacrylic acid. The resultant open tubular capillary column immobilized with the copolymer layer was used for the separation of tryptic digest of cytochrome C in capillary electrochromatography. The sample was well eluted and separated into many components. The elution patterns of tryptic digest of cytochrome C were studied with respect to pH and water content in the mobile phase. This preliminary study demonstrates that open tubular capillary electrochromatography columns with a modified copolymer layer composed of proper nonpolar and polar units fabricated by reversible addition-fragmentation transfer polymerization can be useful as separation media for proteomic analysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An unexpected role for the yeast nucleotide exchange factor Sil1 as a reductant acting on the molecular chaperone BiP

Science.gov (United States)

Siegenthaler, Kevin D; Pareja, Kristeen A; Wang, Jie; Sevier, Carolyn S

2017-01-01

Unfavorable redox conditions in the endoplasmic reticulum (ER) can decrease the capacity for protein secretion, altering vital cell functions. While systems to manage reductive stress are well-established, how cells cope with an overly oxidizing ER remains largely undefined. In previous work (Wang et al., 2014), we demonstrated that the chaperone BiP is a sensor of overly oxidizing ER conditions. We showed that modification of a conserved BiP cysteine during stress beneficially alters BiP chaperone activity to cope with suboptimal folding conditions. How this cysteine is reduced to reestablish 'normal' BiP activity post-oxidative stress has remained unknown. Here we demonstrate that BiP's nucleotide exchange factor – Sil1 – can reverse BiP cysteine oxidation. This previously unexpected reductant capacity for yeast Sil1 has potential implications for the human ataxia Marinesco-Sjögren syndrome, where it is interesting to speculate that a disruption in ER redox-signaling (due to genetic defects in SIL1) may influence disease pathology. DOI: http://dx.doi.org/10.7554/eLife.24141.001 PMID:28257000

Dense cores in dark clouds. I. CO observations and column densities of high-extinction regions

International Nuclear Information System (INIS)

Meyers, P.C.; Linke, R.A.; Benson, P.J.

1983-01-01

Ninety small (approx.5') visually opaque regions have been selected from Palomar Sky Atlas prints and surveyed in the 2.7 mm J = 1→0 lines of C 18 O and 13 CO. The regions are primarily in complexes of obscuration, including those in Taurus and Ophiuchus. The typical C 18 O emission region has C 18 O line width 0.6 km s - 1 , optical depth 0.4, excitation temperature 10 K, and column density 2 x 10 15 cm - 2 . It has size 0.3 pc, visual extinction approx.11 mag, and mass approx.30 M/sub sun/. Comparison with equilibrium and collapse models indicates that purely thermal supporting motions are consistent with the present data, but unlikely. If the full C 18 O line width reflects turbulent supporting motions, nearly all of the observed clouds are consistent with stable equilibrium. If only part of the C 18 O line width reflects supporting motions, many clouds are also consistent with turbulent contraction. More than half of the clouds have significant departures from Gaussian line shape. The most common asymmetry is a blueshifted peak in the 13 CO line, which is consistent with contracting motion

Gas Chromatograph Method Optimization Trade Study for RESOLVE: 20-meter Column v. 8-meter Column

Science.gov (United States)

Huz, Kateryna

2014-01-01

RESOLVE is the payload on a Class D mission, Resource Prospector, which will prospect for water and other volatile resources at a lunar pole. The RESOLVE payload's primary scientific purpose includes determining the presence of water on the moon in the lunar regolith. In order to detect the water, a gas chromatograph (GC) will be used in conjunction with a mass spectrometer (MS). The goal of the experiment was to compare two GC column lengths and recommend which would be best for RESOLVE's purposes. Throughout the experiment, an Inficon Fusion GC and an Inficon Micro GC 3000 were used. The Fusion had a 20m long column with 0.25mm internal diameter (Id). The Micro GC 3000 had an 8m long column with a 0.32mm Id. By varying the column temperature and column pressure while holding all other parameters constant, the ideal conditions for testing with each column length in their individual instrument configurations were determined. The criteria used for determining the optimal method parameters included (in no particular order) (1) quickest run time, (2) peak sharpness, and (3) peak separation. After testing numerous combinations of temperature and pressure, the parameters for each column length that resulted in the most optimal data given my three criteria were selected. The ideal temperature and pressure for the 20m column were 95 C and 50psig. At this temperature and pressure, the peaks were separated and the retention times were shorter compared to other combinations. The Inficon Micro GC 3000 operated better at lower temperature mainly due to the shorter 8m column. The optimal column temperature and pressure were 70 C and 30psig. The Inficon Micro GC 3000 8m column had worse separation than the Inficon Fusion 20m column, but was able to separate water within a shorter run time. Therefore, the most significant tradeoff between the two column lengths was peak separation of the sample versus run time. After performing several tests, it was concluded that better

Higher proliferation of peritumoral endothelial cells to IL-6/sIL-6R than tumoral endothelial cells in hepatocellular carcinoma

International Nuclear Information System (INIS)

Zhuang, Peng-Yuan; Wang, Jian-Dong; Tang, Zhao-Hui; Zhou, Xue-Ping; Quan, Zhi-Wei; Liu, Ying-Bin; Shen, Jun

2015-01-01

This study aimed to explore the responses to the interleukin-6 (IL-6)/soluble interleukin-6 receptor (sIL-6R) complex in peritumoral endothelial cells (PECs) and tumor endothelial cells (TECs), as well as determine the signaling pathways in the angiogenesis of hepatocellular carcinoma (HCC). The expression of IL-6, IL-6R, gp130, CD68, HIF-1α, and microvessel density (MVD) were assessed with an orthotopic xenograft model in nude mice. ECs were incubated under hypoxic conditions to detect IL-6 and gp130. The proliferation of PECs and TECs in the presence of IL-6 and sIL-6R, as well as the expression of gp130, JAK2/STAT3, PI3K/AKT in endothelial cells were measured. Peritumoral IL-6, IL-6R, gp130, CD68, and HIF-1α expression, as well as MVD, gradually increased during tumor growth. Hypoxia could directly induce IL-6 expression, but not gp130 in PECs. The co-culture of IL-6/sIL-6R induced much higher PEC proliferation and gp130 expression, as well as the elevated phosphorylation of JAK2 and STAT3, however not the phosphorylation of PI3K and AKT. PECs exhibited higher proliferation in response to IL-6/sIL-6R co-treatment compared with TECs in HCC via the up-regulation of gp130 /JAK2/STAT3. PEC and its associated peritumoral angiogenesis microenvironment may be a potential novel target for anti-angiogenic treatment. The online version of this article (doi:10.1186/s12885-015-1763-2) contains supplementary material, which is available to authorized users

4- {sup 18}F]fluoroarylalkylethers via an improved synthesis of n.c.a. 4- {sup 18}F]fluorophenol

Energy Technology Data Exchange (ETDEWEB)

Ludwig, Thomas; Ermert, Johannes E-mail: j.ermert@fz-juelich.de; Coenen, Heinz H

2002-02-01

This paper describes the improved synthesis of n.c.a. 4- {sup 18}F]fluorophenol for the preparation of {sup 18}F-labeled alkylarylethers. Nucleophilic fluorination of substituted benzophenone derivatives yielded n.c.a. 4- {sup 18}F]fluoro-4'-substituted benzophenones with 80- 90 % RCY, which were converted to benzoic acid phenylesters by treatment with peracetic acid. Strong electron-withdrawing substituents like nitro, cyano and trifluoromethyl favor a fluorophenyl-to-oxygen migration resulting in the formation of corresponding benzoic acid fluorophenylesters. N.c.a. {sup 18}F]fluorophenol is almost quantitatively formed after hydrolysis and can easily be converted with alkylhalides into n.c.a. {sup 18}F]fluoroarylalkylethers.

Automated Synthesis of 18F-Fluoropropoxytryptophan for Amino Acid Transporter System Imaging

Directory of Open Access Journals (Sweden)

I-Hong Shih

2014-01-01

Full Text Available Objective. This study was to develop a cGMP grade of [18F]fluoropropoxytryptophan (18F-FTP to assess tryptophan transporters using an automated synthesizer. Methods. Tosylpropoxytryptophan (Ts-TP was reacted with K18F/kryptofix complex. After column purification, solvent evaporation, and hydrolysis, the identity and purity of the product were validated by radio-TLC (1M-ammonium acetate : methanol = 4 : 1 and HPLC (C-18 column, methanol : water = 7 : 3 analyses. In vitro cellular uptake of 18F-FTP and 18F-FDG was performed in human prostate cancer cells. PET imaging studies were performed with 18F-FTP and 18F-FDG in prostate and small cell lung tumor-bearing mice (3.7 MBq/mouse, iv. Results. Radio-TLC and HPLC analyses of 18F-FTP showed that the Rf and Rt values were 0.9 and 9 min, respectively. Radiochemical purity was >99%. The radiochemical yield was 37.7% (EOS 90 min, decay corrected. Cellular uptake of 18F-FTP and 18F-FDG showed enhanced uptake as a function of incubation time. PET imaging studies showed that 18F-FTP had less tumor uptake than 18F-FDG in prostate cancer model. However, 18F-FTP had more uptake than 18F-FDG in small cell lung cancer model. Conclusion. 18F-FTP could be synthesized with high radiochemical yield. Assessment of upregulated transporters activity by 18F-FTP may provide potential applications in differential diagnosis and prediction of early treatment response.

Column-to-column packing variation of disposable pre-packed columns for protein chromatography.

Science.gov (United States)

Schweiger, Susanne; Hinterberger, Stephan; Jungbauer, Alois

2017-12-08

In the biopharmaceutical industry, pre-packed columns are the standard for process development, but they must be qualified before use in experimental studies to confirm the required performance of the packed bed. Column qualification is commonly done by pulse response experiments and depends highly on the experimental testing conditions. Additionally, the peak analysis method, the variation in the 3D packing structure of the bed, and the measurement precision of the workstation influence the outcome of qualification runs. While a full body of literature on these factors is available for HPLC columns, no comparable studies exist for preparative columns for protein chromatography. We quantified the influence of these parameters for commercially available pre-packed and self-packed columns of disposable and non-disposable design. Pulse response experiments were performed on 105 preparative chromatography columns with volumes of 0.2-20ml. The analyte acetone was studied at six different superficial velocities (30, 60, 100, 150, 250 and 500cm/h). The column-to-column packing variation between disposable pre-packed columns of different diameter-length combinations varied by 10-15%, which was acceptable for the intended use. The column-to-column variation cannot be explained by the packing density, but is interpreted as a difference in particle arrangement in the column. Since it was possible to determine differences in the column-to-column performance, we concluded that the columns were well-packed. The measurement precision of the chromatography workstation was independent of the column volume and was in a range of±0.01ml for the first peak moment and±0.007 ml 2 for the second moment. The measurement precision must be considered for small columns in the range of 2ml or less. The efficiency of disposable pre-packed columns was equal or better than that of self-packed columns. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

O medo e o silêncio na ficção de Boris Schnaiderman

Directory of Open Access Journals (Sweden)

Ivone Gomes de Assis

2014-05-01

Full Text Available Este artigo aborda duas poéticas apresentadas em Guerra em surdina, de Boris Schnaiderman: o medo e o silêncio. Não se trata de uma condição isolada, mas, de experiências relatadas pelo personagem João Afonso, durante seu período de combate, na Segunda Guerra Mundial, na Itália

Preparation and HPLC isolation of L-[U-14C]tryptophan from enzyme hydrolysate labelled with 14C

International Nuclear Information System (INIS)

Novak, J.; Tintera, S.; Hromadkova, B.

1990-01-01

Tryptophan was obtained from biomass of the blue-green alga Synechococcus elongatus cultivated under 14 CO 2 . After partial purification, the protein fraction was subjected to enzymatic hydrolysis using pronase. Semipreparative isolation of L-[U- 14 C]tryptophan was accomplished on a HPLC column of Separon S Hema 1000 CM, 2% ethanol were added to the eluent, and a precolumn packed with the basic anion exchanger Spheron 1000 DEAE was used. Always after the passage of L-[U- 14 C]tryptophan, the precolumn was decoupled. The substance was collected in 96% ethanol. After removing the solvent by vacuum evaporation, the sample was analyzed on a column packed with Separon SIX C 18 in the eluent of 0.1M-NaH 2 PO 4 , 2% methanol. When the desired radiochemical purity was not attained, the sample was purified on Separon SIX C 18 using 2% methanol. The final radiochemical purity achieved by using this method is 98%. (P.A.). 5 figs., 2 tabs., 4 refs

HEAT TRANSFER ANALYSIS FOR FIXED CST AND RF COLUMNS

International Nuclear Information System (INIS)

Lee, S

2007-01-01

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of ∼130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 C initial temperature is about 6 days. Modeling results for a column actively cooled with external wall jackets and the internal coolant pipe (inlet coolant water temperature: 25 C) indicate that the CST column can be maintained non-boiling under these conditions indefinitely. The results also show that the maximum temperature of an RF-salt solution column containing 133 Ci/liter of Cs-137 (maximum expected loading) will never reach boiling under any conditions (maximum predicted temperature without cooling: 88 C). The results indicate that a 6-in cooling pipe at the center of the column provides the most effective cooling mechanism for reducing the maximum

Column, particularly extraction column, for fission and/or breeder materials

International Nuclear Information System (INIS)

Vietzke, H.; Pirk, H.

1980-01-01

An absorber rod with a B 4 C insert is situated in the long extraction column for a uranyl nitrate solution or a plutonium nitrate solution. The geometrical dimensions are designed for a high throughput with little corrosion. (DG) [de

Efficacy and safety of TachoSil® versus standard treatment of air leakage after pulmonary lobectomy

DEFF Research Database (Denmark)

Marta, Gabriel Mihai; Facciolo, Francesco; Ladegaard, Lars

2010-01-01

Alveolar air leakage remains a serious problem in lung surgery, being associated with increased postoperative morbidity, prolonged hospital stay and greater health-care costs. The aim of this study was to evaluate the sealing efficacy and safety of the surgical patch, TachoSil®, in lung surgery....

40 CFR 721.10175 - 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18 and C18-unsatd...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Propanaminium, N-(3-aminopropyl)-2... 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18 and C18-unsatd. acyl... chemical substance identified as 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12...

Combining results of two GC separations partly achieves determination of all cis and trans 16:1, 18:1, 18:2 and 18:3 except CLA isomers of milk fat as demonstrated using Ag-ion SPE fractionation.

Science.gov (United States)

Kramer, John K G; Hernandez, Marta; Cruz-Hernandez, Cristina; Kraft, Jana; Dugan, Michael E R

2008-03-01

Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short-, long- and branch-chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver-ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100-m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 degrees C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t-18:2 and the c/c/t-18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag(+)-SPE columns, and comparing the fractions to the total milk fat. The Ag(+)-SPE technique was modified to obtain pure saturated, trans- and cis-monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver-ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag(+)-HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200

Clinical significance of the changes of serum levels of the rheumatoid activity markers IL-2, sIL-2R, HA and VEGF

International Nuclear Information System (INIS)

Bao Yong; Long Wubin; Yu Ke; Zeng Ying; Liu Deying

2004-01-01

Objective: To explore the relationship between rheumatoid activity and serum levels of the cytokines interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R), hyaluronic acid (HA), vascular endothelial growth factor (VEGF) in patients with rheumatoid arthritis. Methods: Serum IL-2, HA(with RIA) and sIL-2R, VEGF (with ELISA) levels were determined in 30 controls, 30 patients with active rheumatoid arthritis and 30 patients with rheumatoid arthritis in remission. Sensitivity and specificity for each marker were analyzed. Results: In patients with active rheumatoid arthritis, the serum levels of sIL-2R, HA, VEGF were significantly higher and serum levels of IL-2 significantly lower than those in patients in remission and controls (p<0.01). Determination of VEGF levels possessed the highest specificity (93.3%) and also a high sensitivity (93.3% as well). Conclusion: Determination of the serum levels of any of these markers was valuable for monitoring the activity of the rheumatoid process. It is more desirable to take measurements of VEGF levels due to its highest specificity

Aspectos bioquímicos da resistência do algodoeiro à ramulose potencializada pelo silício

Directory of Open Access Journals (Sweden)

Antonia Mirian Nogueira de Moura Guerra

2013-01-01

Full Text Available Objetivou-se avaliar o efeito do silício (Si sobre a ramulose e aspectos bioquímicos da resistência do algodoeiro a essa doença. Os cultivares BRS Araçá e FM 993 foram desenvolvidos em solução nutritiva contendo (+Si ou não (-Si silício. Avaliou-se o período de incubação (PI, incidência (I, área abaixo da curva do índice da ramulose (AACIR e concentração foliar de Si (CFSi. A CFSi e o PI aumentaram em 76% e 19,5%, respectivamente, nas plantas +Si em relação às -Si, e a I e a AACIR diminuíram em 64% e 18%, respectivamente. A concentração dos compostos fenólicos solúveis totais (CFST e dos derivados da lignina-ácido tioglicólico (DLATG dos dois cultivares supridos com Si aumentou durante o progresso da ramulose, porém essa concentração foi inferior à daquelas que não receberam Si. No cultivar BRS Araçá +Si a atividade das enzimas quitinase (QUI e glicanase (GLI aumentou até os 10 dai em relação às plantas -Si. A atividade das enzimas peroxidase (POX e polifenoloxidase (PPO no cultivar BRS Araçá +Si aumentou entre 20 e 30 dai em relação às plantas -Si, enquanto na FM 993 +Si o aumento foi de até 10 dai. No cultivar FM 993 +Si, a atividade da fenilalanina amônia-liase (FAL aumentou. O fornecimento de Si às plantas de algodoeiro aumentou a resistência à ramulose mediante incremento na concentração CFST e de DLATG nos dois cultivares e na atividade das POX, PPO, QUI e GLI na BRS Araçá, e de POX e FAL na FM 993.

HPLC separation of triacylglycerol positional isomers on a polymeric ODS column.

Science.gov (United States)

Kuroda, Ikuma; Nagai, Toshiharu; Mizobe, Hoyo; Yoshimura, Nobuhito; Gotoh, Naohiro; Wada, Shun

2008-07-01

A polymeric ODS column was applied to the resolution of triacylglycerol positional isomers (TAG-PI), i.e. 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), with a recycle HPLC system. To investigate the ODS column species and the column temperatures for the resolution of a TAG-PI pair, a mixture of OPO and OOP was subjected to an HPLC system equipped with a non-endcapped polymeric, endcapped monomeric, endcapped intermediate, or non-endcapped monomeric ODS column at three different column temperatures (40, 25, or 10 degrees C). Only the non-endcapped polymeric ODS column achieved the separation of OPO and OOP, and the lowest column temperature (10 degrees C) showed the best resolution for them. The other pair of TAG-PI, a mixture of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO) was also subjected to the system equipped with a non-endcapped polymeric or monomeric ODS column at five different column temperatures (40, 32, 25, 17, and 10 degrees C). Thus, POP and PPO were also separated on only the non-endcapped polymeric ODS column at 25 degrees C. However, no clear peak appeared at 10 degrees C. These results would indicate that the polymeric ODS stationary phase has an ability to recognize the structural differences between TAG-PI pairs. Also, the column temperature is a very important factor for separating the TAG-PI pair, and the optimal temperature would relate to the solubility of TAG-PI in the mobile phase. Furthermore, the recycle HPLC system provided measurements for the separation and analysis of TAG-PI pairs.

Highly Flexible, Fire Resistant HybridSil Foams for Next Generation Fireproofing, Insulation, and Energy Absorption NASA Applications, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this Phase I STTR program is to adapt NanoSonic's HybridSil™ nanocomposite technology for the creation of next generation highly flexible, fire...

Distillation columns inspection through gamma scanning

International Nuclear Information System (INIS)

Garcia, Marco

1999-09-01

The application of nuclear energy is very wide and it allows the saving of economic resources since the investigation of a certain process is carried out without stop the plant. The gamma scanning of oil c racking c olumns are practical examples, they allow to determine the hydraulic operation of the inspected columns. A source of Co-60 22mCi and a detector with a crystal of INa(TI) are used. This paper shows the results got from a profile carried out in a column distillation

Biogeochemical impacts of aquifer thermal energy storage at 5, 12, 25 and 60°C investigated with anoxic column experiments

Science.gov (United States)

Bonte, M.; van Breukelen, B. M.; Van Der Wielen, P. W. J. J.; Stuyfzand, P. J.

2012-04-01

Aquifer thermal energy storage (ATES) uses groundwater to store energy for heating or cooling purposes in the built environment. ATES systems are often located in the same aquifers used for public drinking water supply, leading to urgent questions on its environmental impacts. This contribution presents the results of research on the biogeochemical impacts of ATES in anoxic column experiments at 5, 12, 25, and 60° C. In- and effluents are analyzed for major ions, trace elements, heavy metals, dissolved organic carbon (DOC) and UV extinction. Terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA genes and analysis of adenosine triphosphate (ATP) were used to detect changes in the microbiological population and activity. Results from the column experiments at 5, 25, and 60° C compared to the reference column at 12° C showed a number of changes in biogeochemical conditions: At 5° C, only changes were observed in alkalinity and calcium concentrations, resulting from calcite dissolution. The 25° C and 60° C column effluents from a sediment containing Fe-(hydr)oxides showed an increase in arsenic concentrations, well above the drinking water limit. This is due to either (reductive) dissolution of, or desorption from, iron(hydro)xides containing arsenic. In addition, at these two temperatures sulfate reduction occurred while this was undetectable at 5 and 12° C within the given timeframe (25 days) and analytical accuracy. The carbon source for sulfate reduction is inferred to be sedimentary organic carbon. Increasing DOC with residence time in the 60° C effluent suggests that at 60° C the terminal sulfate reduction step is rate limiting, while at 25° C the enzymatic hydrolization step in sulfate reducing bacteria is overall rate limiting. Specific ultraviolet absorption (SUVA, the ratio of UV extinction and DOC) however shows a clear decrease in reactivity of the humic acid fraction in DOC. This means that the DOC accumulation at 60° C could

Temperature-assisted On-column Solute Focusing: A General Method to Reduce Pre-column Dispersion in Capillary High Performance Liquid Chromatography

Science.gov (United States)

Groskreutz, Stephen R.; Weber, Stephen G.

2014-01-01

Solvent-based on-column focusing is a powerful and well known approach for reducingthe impact of pre-column dispersion in liquid chromatography. Here we describe an orthogonal temperature-based approach to focusing called temperature-assisted on-column solute focusing (TASF). TASF is founded on the same principles as the more commonly used solvent-based method wherein transient conditions are created thatlead to high solute retention at the column inlet. Combining the low thermal mass of capillary columns and the temperature dependence of solute retentionTASF is used effectivelyto compress injection bands at the head of the column through the transient reduction in column temperature to 5 °C for a defined 7 mm segment of a 6 cm long 150 μm I.D. column. Following the 30 second focusing time, the column temperature is increased rapidly to the separation temperature of 60 °C releasing the focused band of analytes. We developed a model tosimulate TASF separations based on solute retention enthalpies, focusing temperature, focusing time, and column parameters. This model guides the systematic study of the influence of sample injection volume on column performance.All samples have solvent compositions matching the mobile phase. Over the 45 to 1050 nL injection volume range evaluated, TASF reducesthe peak width for all soluteswith k’ greater than or equal to 2.5, relative to controls. Peak widths resulting from injection volumes up to 1.3 times the column fluid volume with TASF are less than 5% larger than peak widths from a 45 nL injection without TASF (0.07 times the column liquid volume). The TASF approach reduced concentration detection limits by a factor of 12.5 relative to a small volume injection for low concentration samples. TASF is orthogonal to the solvent focusing method. Thus, it canbe used where on-column focusing is required, but where implementation of solvent-based focusing is difficult. PMID:24973805

Preparation of 18F in a research reactor, from irradiated lithium carbonate

International Nuclear Information System (INIS)

Gariglia, H.T.; Silva, C.P.G. da.

1978-01-01

A procedure for preparation of carrier - free fluorine-18 is described. The 18 F is produced by neutron irradiation of lithium carbonate and is separated by passing the dissolved material through a 1000 0 C calcinated aluminium oxyde column. The yield is about 90%, the tritium content 2%; other radioactive impurities are not found. The radiochemical purity is about 93% and the lithium content of the solution is [pt

Resposta do silício em condições de estresse salino em feijão caupi variedade Gurgéia

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Anatercia Ferreira Alves

2014-12-01

Full Text Available Conduziu-se um experimento em casa de vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras com o objetivo de avaliar o efeito do silício na produção de matéria seca na cultura de feijão caupi variedade Gurgéia, submetidas a estresse salino. Adotou-se esquema fatorial em delineamento inteiramente casualizado, com 4 repetições e duas plantas por vaso de 3 L de capacidade, em que o primeiro fator referiu-se aos níveis de  NaCl (0; 25; 50; 100 e 150 mmol.L-1 e o segundo  aos níveis de SiO2 (0 e 50 mg.L-1. As soluções foram renovadas em intervalos de 15 dias e aos 90 dias após a semeadura, as plantas foram colhidas e separadas em parte aérea, vagens e raízes, em seguida foram secas para determinação da produção de matéria seca. Observou-se que a adição de silício na dose de 50 ml.L -1 de solução nutritiva contendo NaCl  diminuiu o teor de matéria seca na parte aérea e raíz, com exceção das vagens. Na ausência de silício, a produção de matéria seca nas raízes e parte aérea foram maiores nas mesmas condições de estresse salino e em baixas concentrações de NaCl. A produção de matéria seca foi estimulada na ausência de silício.

Fontes de silício no desenvolvimento de plântulas de bananeira 'Maçã' micropropagadas Sources of silicon in the development of micropropagated seedlings of banana 'Maçã'

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Simone Abreu Asmar

2011-07-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes fontes de silício durante a fase de enraizamento in vitro de bananeira 'Maçã' por meio de análise fisiológica, fitotécnica e ultraestrutural. Foram utilizados propágulos já estabelecidos in vitro e inoculados em meio MURASHIGE & SKOOG (MS, adicionado de 30g L-1 de sacarose, 1mg L-1 de ANA (ácido naftalenoacético e solidificado com 1,8g L-1 de PhytagelTM. Foram testadas três fontes de silicato acrescidas ao meio MS, silicato de sódio, silicato de potássio e silicato de cálcio, na dosagem de 1g L-1 e o meio MS sem silicato como testemunha. O delineamento experimental foi o inteiramente casualizado, com quinze repetições. Os propágulos foram mantidos por 45 dias em sala de crescimento, sob condições controladas. Verificou-se aumento nos teores de clorofila a, b e total na presença de silicato de cálcio. A suplementação do meio de cultura com silicato de sódio promoveu aumento de comprimento, massa fresca e seca de parte aérea. O silício proporciona adequado desenvolvimento das plântulas.The objective of the research was to evaluate the effect of different sources of silicon during the in vitro rooting phase of 'Maçã' banana tree by means of physiological, phytotechnical and ultrastructural analysis. It was used propagules already established in vitro which were inoculated in MURASHIGE & SKOOG (MS medium, added of 30g L-1 of sucrose, 1mg L-1 of NAA (naphthalene acetic acid and solidified with 1.8g L-1 of PhytagelTM. It was tested three sources of silicate added to MS medium, sodium silicate, potassium silicate and calcium silicate, at a dose of 1g L-1 and MS medium without silicate as a witness. The experimental design was completely randomized with fifteen replicates. The propagules were kept for 45 days in a growth room under controlled conditions. There was an increase in levels of chlorophyll a, b and total in the presence of calcium silicate

A dynamic soil chamber system coupled with a tunable diode laser for online measurements of delta-13C, delta-18O, and efflux rate of soil respired CO2

Energy Technology Data Exchange (ETDEWEB)

Powers, Heath H [Los Alamos National Laboratory; Mcdowell, Nate [Los Alamos National Laboratory; Hanson, David [UNM; Hunt, John [LANDCARE RESEARCH

2009-01-01

High frequency observations of the stable isotopic composition of CO(2) effluxes from soil have been sparse due in part to measurement challenges. We have developed an open-system method that utilizes a flow-through chamber coupled to a tunable diode laser (TDL) to quantify the rate of soil CO(2) efflux and its delta(13)C and delta(18)O values (delta(13)C(R) and delta(18)O(R), respectively). We tested the method first in the laboratory using an artificial soil test column and then in a semi-arid woodland. We found that the CO(2) efflux rates of 1.2 to 7.3 micromol m(-2) s(-1) measured by the chamber-TDL system were similar to measurements made using the chamber and an infrared gas analyzer (IRGA) (R(2) = 0.99) and compared well with efflux rates generated from the soil test column (R(2) = 0.94). Measured delta(13)C and delta(18)O values of CO(2) efflux using the chamber-TDL system at 2 min intervals were not significantly different from source air values across all efflux rates after accounting for diffusive enrichment. Field measurements during drought demonstrated a strong dependency of CO(2) efflux and isotopic composition on soil water content. Addition of water to the soil beneath the chamber resulted in average changes of +6.9 micromol m(-2) s(-1), -5.0 per thousand, and -55.0 per thousand for soil CO(2) efflux, delta(13)C(R) and delta(18)O(R), respectively. All three variables initiated responses within 2 min of water addition, with peak responses observed within 10 min for isotopes and 20 min for efflux. The observed delta(18)O(R) was more enriched than predicted from temperature-dependent H(2)O-CO(2) equilibration theory, similar to other recent observations of delta(18)O(R) from dry soils (Wingate L, Seibt U, Maseyk K, Ogee J, Almeida P, Yakir D, Pereira JS, Mencuccini M. Global Change Biol. 2008; 14: 2178). The soil chamber coupled with the TDL was found to be an effective method for capturing soil CO(2) efflux and its stable isotope composition at high

Modeling and analysis of conventional and heat-integrated distillation columns

DEFF Research Database (Denmark)

Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

2015-01-01

A generic model that can cover diabatic and adiabatic distillation column configurations is presented, with the aim ofproviding a consistent basis for comparison of alternative distillation column technologies. Both a static and a dynamic formulation of the model, together with a model catalogue...... consisting of the conventional, the heat-integrated and the mechanical vapor recompression distillation columns are presented. The solution procedure of the model is outlined and illustrated in three case studies. One case study being a benchmark study demonstrating the size of the model and the static...... properties of two different heat-integrated distillation column (HIDiC) schemes and the mechanical vapor recompression column. The second case study exemplifies the difference between a HIDiC and a conventional distillation column in the composition profiles within a multicomponent separation, whereas...

Efeito da adição de diferentes fontes de cálcio no movimento de cátions em colunas de solo Effect of several calcium sources on cation leaching using soil columns

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I.C. de Maria

1993-05-01

Full Text Available No estudo realizado em colunas de solo montadas em laboratório, procurou-se avaliar o movimento do cálcio, e de outros cátions, após aplicação de calcário agrícola, gesso, calcário calcinado e uma mistura de calcário agrícola e gesso, comparados com um tratamento testemunha, em dois latossolos vermelho escuros de texturas diferentes: média e argilosa. Utilizaram-se colunas de PVC, com 5cm de diâmetro e 45cm de altura, e aplicaram-se em cada coluna 1,8 litros de água, parcelados em quatro vezes. Determinaram-se os cátions trocáveis presentes na água percolada e, no final do experimento, em cinco profundidades de cada solo. Os resultados mostraram que nos tratamentos gesso e calcário mais gesso as quantidades de Ca2+, Mg2+, K+ e Al3+ na solução percolada foram maiores, enquanto que os tratamentos calcário agrícola e calcário calcinado não promoveram perdas significativas de cátions. As maiores perdas ocorreram na primeira percolação no solo de textura média e na segunda no solo de textura argilosa. O gesso não modificou o pH dos solos, mas reduziu teores de bases no solo argiloso, enquanto que os calcários corrigiram o solo apenas próximo à camada de incorporação.Soil columns under controlled conditions were used to determine the movement of calcium and other cations after the application of lime, calcium oxide, gypsum and a mixture of Ume and gypsum, compared with a control treatment. Two Oxisols with different textures were used: clayey and silty. Rigid polyvinyl chloride (PVC columns (length, 45cm; diam, 5cm were used, applying 1.8 1 of water to each divided into four applications. Exchangeable cations were determined in the drainage water in 4 periods and in 5 dephts of the soil columns at the end of the experiment. The results showed that losses of Ca2+, Mg2+, K+ and A1(3+, were higher in the treatments with gypsum and lime plus gypsum. Amendments h'ke lime and calcium oxide did not promote significant losses

18F- and 11C-labelling of quantum dots with n.c.a. [18F]fluoroethyltosylate and [11C]methyliodide. A feasibility study

International Nuclear Information System (INIS)

Patt, M.; Schildan, A.; Habermann, B.; Mishchenko, O.; Patt, J.T.; Sabri, O.

2010-01-01

Quantum dots functionalized on the outer surface with either amino- or carboxyl functions were labelled with [ 18 F]fluoroethyltosylate and [ 11 C]methyliodide in order to use the positron emitter-labelled fluorescence agents for multimodality imaging techniques, i.e. fluorescence imaging and positron emission tomography. 18 F-Labelling of both compounds was realized with yields up to 5% as determined by size exclusion chromatography, which is twice as much as reported in literature before [1]. 11 C-Labelling of amino- and carboxyl-QDs proceeded with good yields (up to 45 and 35%, respectively) under optimized reaction conditions. In general for both QD-types and both labelling agents the labelling yield increased with the amount of QDs used in the reaction as well as with reaction time and reaction temperature. (author)

Limiares de reconhecimento de sentenças no silêncio em campo livre versus limiares tonais em fone em indivíduos com perda auditiva coclear Sentence recognition thresholds in silence in free field versus pure tone thresholds in individuals with hearing loss

Directory of Open Access Journals (Sweden)

Nilvia Herondina Soares Aurélio

2008-01-01

Full Text Available OBJETIVO: investigar a correlação existente entre os limiares tonais e os Limiares de Reconhecimento de Sentenças no Silêncio (LRSS e verificar, se é possível, através do audiograma estabelecer um prognóstico deste paciente sobre a sua habilidade de reconhecer a fala. MÉTODOS: foram analisados 42 indivíduos com perda auditiva coclear de grau moderado, 18 do sexo feminino e 24 do masculino, com idades entre 41 e 76 anos. Primeiramente foi realizada avaliação audiológica básica e, em seguida, a pesquisa dos Limiares de Reconhecimento de Sentenças no Silêncio, em campo livre, por meio do teste Listas de Sentenças em Português. RESULTADOS: a análise estatística evidenciou correlação significante entre o limiar de reconhecimento de sentenças no silêncio e a média das freqüências de 0,5, 1 e 2 kHz. Por sua vez, ao correlacionar os Limiares de Reconhecimento de Sentenças no Silêncio com a média das freqüências de 3, 4 e 6 kHz, não houve correlação significante. CONCLUSÃO: o prognóstico provável da habilidade de reconhecimento de fala no silêncio, pode ser feito apenas com base nos limiares das freqüências de 0,5, 1 e 2 kHz em perdas auditivas cocleares.PURPOSE: to investigate the existent correlation among pure tone thresholds and Sentence Recognition Thresholds in Silence (TRSS and to check if it is possible, through the audiogram, to set up a prognostic of the patients about their communication ability. METHODS: 42 individuals with moderate cochlear hearing loss, 18 females and 24 males, 41 to 76-year old were studied. Firstly, a basic audiologic evaluation was carried out, then a search of TRSS in free field, through the Portuguese Sentence List Test (PSLT (Costa, 1998. RESULTS: The statistical analysis showed significant correlation between the sentence recognition thresholds in silence and the average of frequencies of 0.5, 1 and 2 kHz. However, when correlating with the average frequencies of 3, 4 e 6 k

Systèmes d'innovation des pays BRICS (Brésil, Russie, Inde, Chine ...

International Development Research Centre (IDRC) Digital Library (Canada)

Le Brésil, la Russie, l'Inde, la Chine et l'Afrique du Sud (dits pays BRICS) ont placé l'innovation au coeur de leur stratégie de développement. Toutefois, les chercheurs disposent de très peu de connaissances sur le système d'innovation de chacun de ces pays et sur les répercussions qu'il a sur l'économie. La subvention ...

Superdiffusion of Carbon by Vacancies Irradiated with Soft X-Rays in CZ Silicon / Superdifūzija Ar Vakancēm Iestarota Ar Mīkstajiem Rentgenstariem CZ Silīcijā

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Janavičius A. J.

2015-10-01

Full Text Available Rezumējums: Rentgena staru fotoni, absorbēti Si atoma iekšējos slāņos, izstaro fotoelektronus un Ožē elektronus, ģenerējot vakances, starpmezglu silīcija atomus, vakanču un skābekļa kompleksus. Čohraļska silīcija kristāli, kas pārklāti ar oglekli 0.1 μm biezuma kārtā, tika apstaroti ar rentgena stariem, izmantojot krievu difraktometru DRON-3M. Oglekļa un skābekļa difūzija un koncentrāciju izmaiņa silīcijā tika izmērīta izmantojot infrasarkano staru FTIR spektroskopiju. Rentgena staru ģenerētās ļoti ātrās oglekļa difūzijas vai superdifūzijas koeficients istabas temperatūrā silīcijā ir simtiem tūkstošu reižu lielāks nekā termodifūzijas gadījumā.

Effects of taxonomy, sediment, and water column on C:N:P stoichiometry of submerged macrophytes in Yangtze floodplain shallow lakes, China.

Science.gov (United States)

Su, Haojie; Wu, Yao; Xie, Ping; Chen, Jun; Cao, Te; Xia, Wulai

2016-11-01

Carbon (C), nitrogen (N) and phosphorus (P) are the three most important essential elements limiting growth of primary producers. Submerged macrophytes generally absorb nutrients from sediments by root uptake. However, the C:N:P stoichiometric signatures of plant tissue are affected by many additional factors such as taxonomy, nutrient availability, and light availability. We first revealed the relative importance of taxonomy, sediment, and water column on plant C:N:P stoichiometry using variance partitioning based on partial redundancy analyses. Results showed that taxonomy was the most important factor in determining C:N:P stoichiometry, then the water column and finally the sediment. In this study, a significant positive relationship was found between community C concentration and macrophyte community biomass, indicating that the local low C availability in macrophytes probably was the main reason why submerged macrophytes declined in Yangtze floodplain shallow lakes. Based on our study, it is suggested that submerged macrophytes in Yangtze floodplain shallow lakes are primarily limited by low light levels rather than nutrient availability.

Fast synthesis of 11C-Raclopride and its initial PET study on animal model

International Nuclear Information System (INIS)

Zhang Jinming; Tian Jiahe; Yao Shulin; Ding Weimin; Yin Dayi; Liu Boli

2008-01-01

Objective: 11 C-Raclopride is a type-2 dopamine receptor (D 2 R) binding agent used in the study of Parkinson's disease. This study introduced a fast and convenient method for preparation of 11 C- Raclopride and reported on the preclinical trial of this receptor tracer on animal studies. Methods: 11 C- Raclopride was synthesized via reaction of 11 C-CH 3 -Triflate with Nor-Raclopride. The mixture of primary product was water-diluted and loaded on Sep-Pak C18 column for separation. The final product, 11 C-Raclopride, was purified by column chromatography and then eluted from the C18 column with ethanol. The bio-distribution was studied in SD rats and the in vivo imaging pattern was studied in hem ipark insonjan mon- keys. Results: Within 16 min from beginning of processing with 11 CO 2 , the synthetic yield of 11 C-Raclopride was 60%, radiochemical purity (RCP) > 95% and specific activity 8 GBq/mmol. The uptake ratios of striatum to cerebellum and cerebral cortex were 4.67 and 6.20, respectively, at 30 min after 11 C-Raclopride administration. The striatal uptake in normal rat brain could be blocked by N-methylspiperone (NMSP) and raclopride, but not by Nor-raclopride. PET imaging showed higher striatal D 2 R uptake on the D 2 receptor up-regulated side of the experimental monkeys relative to the contralateral side. Conclusions: Column chromatography for purification of 11 C-Raclopride was fast, convenient and with a RCP similar to that of high performance liquid chromatography purification. Preliminary PET findings using animal model suggested that 11 C-Raclopride by column chromatogram purification might be considered for clinical use. (authors)

Column chromatographic method for the separation of neodymium from uranium and other elements using poly(dibenzo-18-crown-6)

International Nuclear Information System (INIS)

Lad, Shila N.; Mohite, Baburao S.

2014-01-01

A simple and efficient column chromatographic method has been developed for the separation of U (VI), Nd (III) and other metals using poly (dibenzo-18-crown-6) as stationary phase and hippuric acid as a counter ion. The various eluting agents were found efficient eluents for Nd (III). The capacity of crown polymer for Nd (III) was found to be 0.55±0.01mmol/g. The tolerance limits of various cations and anions for Nd (III) were determined. Nd (III) was quantitatively separated from other metal ions in binary as well as multicomponent mixtures. The good separation yields were obtained and had good reproducibility (±2%). The method was simple, rapid and selective. (author)

Skeletal muscle munc18c and syntaxin 4 in human obesity

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Bessesen Daniel H

2008-07-01

Full Text Available Abstract Background Animal and cell culture data suggest a critical role for Munc18c and Syntaxin 4 proteins in insulin mediated glucose transport in skeletal muscle, but no studies have been published in humans. Methods We investigated the effect of a 12 vs. 48 hr fast on insulin action and skeletal muscle Munc18c and Syntaxin 4 protein in lean and obese subjects. Healthy lean (n = 14; age = 28.0 +/- 1.4 yr; BMI = 22.8 +/- 0.42 kg/m2 and obese subjects (n = 11; age = 34.6 +/- 2.3 yr; BMI = 36.1 +/- 1.5 kg/m2 were studied twice following a 12 and 48 hr fast. Skeletal muscle biopsies were obtained before a 3 hr 40 mU/m2/min hyperinsulinemic-euglycemic clamp with [6,6-2H2]glucose infusion. Results Glucose rate of disappearance (Rd during the clamp was lower in obese vs. lean subjects after the 12 hr fast (obese: 6.25 +/- 0.67 vs. lean: 9.42 +/- 1.1 mg/kgFFM/min, p = 0.007, and decreased significantly in both groups after the 48 hr fast (obese 3.49 +/- 0.31 vs. lean: 3.91 +/- 0.42 mg/kgFFM/min, p = 0.002. Munc18c content was not significantly different between lean and obese subjects after the 12 hour fast, and decreased after the 48 hr fast in both groups (p = 0.013. Syntaxin 4 content was not altered by obesity or fasting duration. There was a strong positive relationship between plasma glucose concentration and Munc18c content in lean and obese subjects during both 12 and 48 hr fasts (R2 = 0.447, p = 0.0015. Significant negative relationships were also found between Munc18c and FFA (p = 0.041, beta-hydroxybutyrate (p = 0.039, and skeletal muscle AKT content (p = 0.035 in lean and obese subjects. Conclusion These data indicate Munc18c and Syntaxin 4 are present in human skeletal muscle. Munc18c content was not significantly different between lean and obese subjects, and is therefore unlikely to explain obesity-induced insulin resistance. Munc18c content decreased after prolonged fasting in lean and obese subjects concurrently with reduced insulin

Fast analysis of capsaicinoids in Naga Jolokia extracts (Capsicum chinense) by high-performance liquid chromatography using fused core columns.

Science.gov (United States)

Stipcovich, Tea; Barbero, Gerardo F; Ferreiro-González, Marta; Palma, Miguel; Barroso, Carmelo G

2018-01-15

A rapid high-performance liquid chromatography method with a C18 reverse-phase fused-core column has been developed for the determination and quantification of the main capsaicinoids (nornordihydrocapsaicin, nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin and homodihydrocapsaicin) present in Naga Jolokia peppers. A fused-core Kinetex™ C18 column (50×2.1mm i.d.; 2.6μm) was used for the analysis. The chromatographic separation was obtained with a gradient method in which the mobile phase was water (0.1% acetic acid) as solvent A and acetonitrile (0.1% acetic acid) as solvent B. The separation of all compounds was achieved in less than 3min with a total analysis time (sample-to-sample) of 10min. The robustness of the method was evaluated. The method showed excellent repeatability and intermediate precision expressed as coefficient of variance of less than 2%. The developed method was employed for the quantification of the major capsaicinoids present in different peppers and commercial products containing chilli peppers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fatty Acid Composition of Meat from Ruminants, with Special Emphasis on trans Fatty Acids

DEFF Research Database (Denmark)

Leth, Torben; Ovesen, L.; Hansen, K.

1998-01-01

The fatty acid composition was determined in 39 samples of beef, 20 samples of veal, and 34 samples of lamb, representative of the supply of ruminant meat in Denmark. Five cuts of beef and veal and three cuts of lamb with increasing fat content were selected, and analysis of the fatty acid methyl...... esters was performed by gas-liquid chromatography (GLC) on a polar 50-m capillary column CP Sil 88 with flame-ionization detection. Lamb had the highest content of saturated fatty acids (52.8 +/- 1.8 g/100 g fatty acids), higher than beef and veal (45.3 +/- 3.1 and 45.4 +/- 0.8 g/100 g fatty acids......, respectively). Cis monounsaturated fatty acids were 49.2 +/- 3.1, 44.9 +/- 1.8, and 37.7 +/- 1.7, and polyunsaturated fatty acids were 3.3 +/- 0.7, 5.8 +/- 2.0, and 5.0 +/- 0.1 g/100 g fatty acids in beef, veal, and lamb, respectively. Beef contained 2.1 +/- 0.8 g trans C-18:1 per 100 g fatty acids, about half...

Behavior of partially defected R.C columns strengthened using steel jackets

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Ahmed Shaban Abdel-Hay

2015-08-01

The main parameters studied were the type of steel jacket used and height of partial strengthened part of column. One of the tested specimens was a control specimen and the other six were partially strengthened with different types of steel jackets such as using 4 steel angles at corners connected with straps, using external ties with different spacings, and using 4 steel plates with different thicknesses welded together and connected to column by anchor bolts. Finally, the experimental results were analyzed and compared with results obtained from finite element analysis using ANSYS program.

Hédonismes et leurres d’un Brésil indien 

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Alessandra Russo

2005-06-01

Full Text Available Comment exposer aujourd’hui des objets "non-occidentaux" dans un parcours muséographique à la fois original et précis, conjurant les dangers du "politically correct" ? Sans doute, s’agit-il là de l’un des grands débats du XXIe siècle. A l’heure où les plus importants musées d’anthropologie du monde réaménagent leurs collections (Mexico, Vienne, Paris, Genève,…, l’exposition Brésil indien présentée au Grand Palais de Paris donne matière à réfléchir. En invitant le public à "une approch...

Stage wise modeling of liquid-extraction column (RDC)

International Nuclear Information System (INIS)

Bastani, B.

2004-01-01

Stage wise forward mixing model considering coalescence and re dispersion of drops was used to predict the performance of Rotating Disk Liquid Extraction Contactors. Experimental data previously obtained in two RDC columns of 7-62 cm diameter, 73.6 cm height and 21.9 cm diameter,150 cm height were used to evaluate the model predications. Drops-side mass transfer coefficients were predicted applying Hand los-baron drop model and onley's model was used to predict velocities. According to the results obtained the followings could be concluded: (1) If the height of coalescence and re dispersion i.e.:h=h p Q p / Q could be estimated, the stage wise forward mixing with coalescence and re dispersion model will predict the column height and efficiency with the acceptable accuracy, (2) The stage wise modeling predictions are highly dependent on the number of stages used when the number of stages is less than 10 and (3) Application of continuous phase mass transfer axial dispersion coefficients (k c and E c ) obtained from the solute concentration profile along the column height will predict the column performance more accurately than the Calder bank and moo-young (for K c ) and Kumar-Heartland (for E c ) correlations

Longitudinal imaging of Alzheimer pathology using [{sup 11}C]PIB, [{sup 18}F]FDDNP and [{sup 18}F]FDG PET

Energy Technology Data Exchange (ETDEWEB)

Ossenkoppele, Rik; Tolboom, Nelleke; Adriaanse, Sofie F. [VU University Medical Center, Department of Neurology and Alzheimer Center, PO Box 7057, Amsterdam (Netherlands); VU University Medical Center, Department of Nuclear Medicine and PET Research, Amsterdam (Netherlands); Foster-Dingley, Jessica C.; Boellaard, Ronald; Yaqub, Maqsood; Windhorst, Albert D.; Lammertsma, Adriaan A.; Berckel, Bart N.M. van [VU University Medical Center, Department of Nuclear Medicine and PET Research, Amsterdam (Netherlands); Barkhof, Frederik [VU University Medical Center, Department of Radiology, Amsterdam (Netherlands); Scheltens, Philip [VU University Medical Center, Department of Neurology and Alzheimer Center, PO Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Center, Department of Neurology and Alzheimer Center, PO Box 7057, Amsterdam (Netherlands); VU University Medical Center, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands)

2012-06-15

[{sup 11}C]PIB and [{sup 18}F]FDDNP are PET tracers for in vivo detection of the neuropathology underlying Alzheimer's disease (AD). [{sup 18}F]FDG is a glucose analogue and its uptake reflects metabolic activity. The purpose of this study was to examine longitudinal changes in these tracers in patients with AD or mild cognitive impairment (MCI) and in healthy controls. Longitudinal, paired, dynamic [{sup 11}C]PIB and [{sup 18}F]FDDNP (90 min each) and static [{sup 18}F]FDG (15 min) PET scans were obtained in 11 controls, 12 MCI patients and 8 AD patients. The mean interval between baseline and follow-up was 2.5 years (range 2.0-4.0 years). Parametric [{sup 11}C]PIB and [{sup 18}F]FDDNP images of binding potential (BP{sub ND}) and [{sup 18}F]FDG standardized uptake value ratio (SUVr) images were generated. A significant increase in global cortical [{sup 11}C]PIB BP{sub ND} was found in MCI patients, but no changes were observed in AD patients or controls. Subsequent regional analysis revealed that this increase in [{sup 11}C]PIB BP{sub ND} in MCI patients was most prominent in the lateral temporal lobe (p < 0.05). For [{sup 18}F]FDDNP, no changes in global BP{sub ND} were found. [{sup 18}F]FDG uptake was reduced at follow-up in the AD group only, especially in frontal, parietal and lateral temporal lobes (all p < 0.01). Changes in global [{sup 11}C]PIB binding ({rho} = -0.42, p < 0.05) and posterior cingulate [{sup 18}F]FDG uptake ({rho} = 0.54, p < 0.01) were correlated with changes in Mini-Mental-State Examination score over time across groups, whilst changes in [{sup 18}F]FDDNP binding ({rho} = -0.18, p = 0.35) were not. [{sup 11}C]PIB and [{sup 18}F]FDG track molecular changes in different stages of AD. We found increased amyloid load in MCI patients and progressive metabolic impairment in AD patients. [{sup 18}F]FDDNP seems to be less useful for examining disease progression. (orig.)

Microbial exopolysaccharides: Effect on corrosion and partial chemical characterization

Digital Repository Service at National Institute of Oceanography (India)

Majumdar, I; DeSouza, F.P.; Bhosle, N.B.

gas chromatograph MICROBIAL EXOPOLYSACCHARIDES 543 Fig. I. Changes in the biofilm organic carbon (a) and EPS (b) associated with corrosion products and corrosion rate (c) of mild steel. Fig. 2. Linear correlation coeffiient (r) between EPS and organic... carbon (a), corrosion rate and organic carbon (b). and corrosion rate and EPS (c). (Chrompack model CP-9002) equipped with a fused silica capillary column coated with CP Sil-88 (25 m, i.d. = 0.32 mm) and flame ionization detector (FID) was used...

Simulation and optimization of stable isotope 18O separation by water vacuum distillation

International Nuclear Information System (INIS)

Chen Yuyan; Qin Chuanjiang; Xiao Bin; Xu Jing'an

2012-01-01

In the research, a stable isotope 18 O separation column was set up by water vacuum distillation with 20 m packing height and 0.1 m diameter of the column. The self-developed special packing named PAC- 18 O was packed inside the column. Firstly, a model was created by using the Aspen Plus software, and then the simulation results were validated by test results. Secondly, a group of simulation results were created by Aspen Plus, and the optimal operation conditions were gotten by using the artificial neural network (ANN) and Statistica software. Considering comprehensive factors drawn from column pressure and from withdrawing velocity, conclusions were reached on the study of the impact on the abundance of the isotope 18 O. The final results show that the abundance of the isotope 18 O increases as column pressure dropping and withdrawing velocity decreasing. Besides, the optimal column pressure and the incidence formula between the abundance of the isotope 18 O and withdrawing velocity were gotten. The conclusion is that the method of simulation and optimization can be applied to 18 O industrial design and will be popular in traditional distillation process to realize optimization design. (authors)

Biblioteca escolar: espaço de silêncio e interdição | School library: a place of silence and prohibition

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Gustavo Grandini Bastos

2011-10-01

Full Text Available Resumo Postulamos que a biblioteca, ao legitimar e instaurar o silêncio em seu espaço impede de proporcionar aos leitores um espaço de possibilidades de construção de sentidos, de fuga e de contestação da ordem em que vivemos. Marcamos que, ainda mais pelo fato de trabalhar muito com alunos é complexo imaginar os mesmos se relacionando bem em um espaço tão sisudo. Ocorre ainda que quem comanda a biblioteca crê no silêncio como a ausência de sentido, ato vazio de qualquer rastro, buscando garantir uma ausência de quebrar uma segurança aparente, censurando o aluno, impedindo-o de enunciar outros sentidos além dos apresentados pelo professor, na sala de aula. Procuramos nesse trabalho, à luz da teoria discursiva, questionar e expor que o silêncio está longe de ser oco de sentidos e significados. Palavras-chave discurso; biblioteca escolar; silêncio; sentido; leitores Abstract We postulated that the library, when legitimating and to establish the silence in your space impedes of providing to the readers a space of possibilities of construction of senses, of escape and of reply of the order in that lived. We marked that, still more for the fact of working a lot with students is complex to imagine the same ones linking well in such a discerning space. It happens although who commands the library has faith in the silence as the sense absence, empty act of any trace, looking for to guarantee an absence of breaking an apparent safety, censuring the student, impeding him/it of enunciating other senses besides introduced them by the teacher, in the class room. We sought in that work, to the light of the discursive theory, to question and to expose that the silence is far away from being hollow of senses and meanings. Keywords discourse; school library; silence; sense; readers

A simple, versatile, low-cost and remotely operated apparatus for [11C]acetate, [11C]choline, [11C]methionine and [11C]PIB synthesis

International Nuclear Information System (INIS)

Cheung Manki; Ho Chilai

2009-01-01

A simple, efficient and remotely operated synthesis apparatus for carrying out routine [ 11 C]carboxylation, on-column and bubbling [ 11 C]methylation was essential for reliable, day-to-day production of [ 11 C]-labelled PET radiopharmaceuticals. We developed an in-house apparatus specifically applied to the synthesis of [ 11 C]acetate, [ 11 C]choline, [ 11 C]methionine and 2-(4'-N-[ 11 C]methylaminophenyl)-6-hydroxybenzothiazole ([ 11 C]PIB), where high radiochemical purity (≥97%) and moderate radiochemical yields (18% for [ 11 C]PIB, 41-55% for the others) could be achieved. These findings provided evidence that this was a fast, versatile and reliable apparatus suitable for a PET/CT centre with limited financial budget and hot cell space for synthesis of [ 11 C]-labelled radiopharmaceuticals

Effect of IX column maintenance on carbon-14 concentration in moderator systems

International Nuclear Information System (INIS)

Gallagher, C.L.; Tripple, A.W.

2006-01-01

The radionuclide 14 C is produced in CANDU reactors primarily by the (n,α) reaction with 17 O. Because of high neutron fluxes in the core, the majority of the 14 C (94.5%) is produced in the moderator. In the moderator system, 14 C is present mainly as CO 2 in the cover gas in dynamic equilibrium with dissolved carbonates, bicarbonates and CO 2 in the moderator water. Emissions of 14 C from reactors occur through venting or leakage of the cover gas. By controlling the dissolved carbonates in the moderator water with an ion exchange (IX) purification system, the amount of 14 C in the cover gas is minimized and thus the emissions of 14 C can be reduced. A study was conducted to measure the 14 C concentrations in the moderator system at Gentilly 2 in order to determine the effectiveness of the purification system in removing 14 C. Moderator water samples were obtained from the inlet and outlet of the purification system from 2004 January 14 to July 12, covering the operation of two IX columns (IX-1 and IX-3). The moderator water samples contained high levels of tritium (∼2 TBq·L -1 ). As both tritium and 14 C are β-radiation emitters, direct counting of moderator water for 14 C is impossible as the signal due to tritium dominates over that of other β-emitters. Therefore, a procedure developed by Caron et al. was used in this study, which involved acidifying the sample to release the dissolved 14 CO 2 as gas and collecting the 14 CO 2 in a base (NaOH), which could then be measured by liquid scintillation counting to determine the 14 C concentration. Both of the IX columns started with 14 C removal efficiencies of about 95%. The efficiency began to decrease almost immediately with the IX-1 column dropping to 80% efficiency after ∼1115 hours. This drop in efficiency also led to an increase in the inlet concentration over time. IX-1 column was removed from service after ∼1745 hours with a 14 C removal efficiency of ∼31%. IX-3 column was then placed in service

Interdito e silêncio: uma abordagem no quadrado das oposições

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Fabio Elias Verdiani Tfouni

2010-03-01

Full Text Available O presente trabalho, situado no campo da análise do discurso de Pêcheux, numainterface com a psicanálise, trata o interdito e o silêncio como constitutivos efundadores do discurso. Resumidamente, afirmamos que para que seja possívelque se diga algo é preciso que não se diga tudo. Fazemos uma abordagemdessas questões com base nas modalidades aléticas da lógica aristotélica. Paratal tarefa, tratamos a questão do dizer a partir do quadrado lógico aristotélico.Propusemos e construímos um quadrado do dito e da enunciação.

Thermally stable dexsil-400 glass capillary columns

International Nuclear Information System (INIS)

Maskarinec, M.P.; Olerich, G.

1980-01-01

The factors affecting efficiency, thermal stability, and reproducibility of Dexsil-400 glass capillary columns for gas chromatography in general, and for polycyclic aromatic hydrocarbons (PAHs) in particular were investigated. Columns were drawn from Kimble KG-6 (soda-lime) glass or Kimox (borosilicate) glass. All silylation was carried out at 200 0 C. Columns were coated according to the static method. Freshly prepared, degassed solutions of Dexsil-400 in pentane or methylene chloride were used. Thermal stability of the Dexsil 400 columns with respect to gas chromatography/mass spectrometry (GC/MS) were tested. Column-to-column variability is a function of each step in the fabrication of the columns. The degree of etching, extent of silylation, and stationary phase film thickness must be carefully controlled. The variability in two Dexsil-400 capillary column prepared by etching, silylation with solution of hexa methyl disilazone (HMDS), and static coating is shown and also indicates the excellent selectivity of Dexsil-400 for the separation of alkylated aromatic compounds. The wide temperature range of Dexsil-400 and the high efficiency of the capillary columns also allow the analysis of complex mixtures with minimal prefractionation. Direct injection of a coal liquefaction product is given. Analysis by GC/MS indicated the presence of parent PAHs, alkylated PAHs, nitrogen and sulfur heterocycles, and their alkylated derivatives. 4 figures

The use of TachoSil for the prevention of postoperative complications after groin dissection in cases of gynecologic malignancy.

Science.gov (United States)

Buda, Alessandro; Fruscio, Robert; Pirovano, Cecilia; Signorelli, Mauro; Betti, Marta; Milani, Rodolfo

2012-06-01

To evaluate the effect of TachoSil in preventing postoperative complications after groin dissection performed for primary or recurrent gynecologic malignancy. In a case-control analysis, the incidence of postoperative complications-including lymphocyst formation, wound breakdown and/or infection, and chronic lymphedema-was examined among 8 patients who received TachoSil and 16 controls (standard technique) treated for vulvar cancer or recurrent ovarian/breast cancer at San Gerardo Hospital, Monza, Italy, from 2008 to 2011. Thirty-eight inguinal dissections were performed in the 24 patients. Bilateral groin dissection was performed in 14 patients (n=4 in the study group; n=10 in the control group). Patients in the study group had a lower mean daily drainage volume than those in the control group (133 mL [range, 50-356 mL] vs 320 mL [range, 67-472 mL]; Pgynecologic malignancy. Copyright © 2012 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Determination of zearalenone content in cereals and feedstuffs by immunoaffinity column coupled with liquid chromatography.

Science.gov (United States)

Fazekas, B; Tar, A

2001-01-01

The zearalenone content of maize, wheat, barley, swine feed, and poultry feed samples was determined by immunoaffinity column cleanup followed by liquid chromatography (IAC-LC). Samples were extracted in methanol-water (8 + 2, v/v) solution. The filtered extract was diluted with distilled water and applied to immunoaffinity columns. Zearalenone was eluted with methanol, dried by evaporation, and dissolved in acetonitrile-water (3 + 7, v/v). Zearalenone was separated by isocratic elution of acetonitrile-water (50 + 50, v/v) on reversed-phase C18 column. The quantitative analysis was performed by fluorescence detector and confirmation was based on the UV spectrum obtained by a diode array detector. The mean recovery rate of zearalenone was 82-97% (RSD, 1.4-4.1%) on the original (single-use) immunoaffinity columns. The limit of detection of zearalenone by fluorescence was 10 ng/g at a signal-to-noise ratio of 10:1 and 30 ng/g by spectral confirmation in UV. A good correlation was found (R2 = 0.89) between the results obtained by IAC-LC and by the official AOAC-LC method. The specificity of the method was increased by using fluorescence detection in parallel with UV detection. This method was applicable to the determination of zearalenone content in cereals and other kinds of feedstuffs. Reusability of immunoaffinity columns was examined by washing with water after sample elution and allowing columns to stand for 24 h at room temperature. The zearalenone recovery rate of the regenerated columns varied between 79 and 95% (RSD, 3.2-6.3%). Columns can be regenerated at least 3 times without altering their performance and without affecting the results of repeated determinations.

An automated GC-C-GC-IRMS setup to measure palaeoatmospheric δ13C-CH4, δ15N-N2O and δ18O-N2O in one ice core sample

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P. Sperlich

2013-08-01

Full Text Available Air bubbles in ice core samples represent the only opportunity to study the mixing ratio and isotopic variability of palaeoatmospheric CH4 and N2O. The highest possible precision in isotope measurements is required to maximize the resolving power for CH4 and N2O sink and source reconstructions. We present a new setup to measure δ13C-CH4, δ15N-N2O and δ18O-N2O isotope ratios in one ice core sample and with one single IRMS instrument, with a precision of 0.09, 0.6 and 0.7‰, respectively, as determined on 0.6–1.6 nmol CH4 and 0.25–0.6 nmol N2O. The isotope ratios are referenced to the VPDB scale (δ13C-CH4, the N2-air scale (δ15N-N2O and the VSMOW scale (δ18O-N2O. Ice core samples of 200–500 g are melted while the air is constantly extracted to minimize gas dissolution. A helium carrier gas flow transports the sample through the analytical system. We introduce a new gold catalyst to oxidize CO to CO2 in the air sample. CH4 and N2O are then separated from N2, O2, Ar and CO2 before they get pre-concentrated and separated by gas chromatography. A combustion unit is required for δ13C-CH4 analysis, which is equipped with a constant oxygen supply as well as a post-combustion trap and a post-combustion GC column (GC-C-GC-IRMS. The post-combustion trap and the second GC column in the GC-C-GC-IRMS combination prevent Kr and N2O interferences during the isotopic analysis of CH4-derived CO2. These steps increase the time for δ13C-CH4 measurements, which is used to measure δ15N-N2O and δ18O-N2O first and then δ13C-CH4. The analytical time is adjusted to ensure stable conditions in the ion source before each sample gas enters the IRMS, thereby improving the precision achieved for measurements of CH4 and N2O on the same IRMS. The precision of our measurements is comparable to or better than that of recently published systems. Our setup is calibrated by analysing multiple reference gases that were injected over bubble-free ice samples. We show

Optimization study of distillation column based on Type I absorption heat pump

International Nuclear Information System (INIS)

Li, Yan; Wang, Lu; Zhu, Meng; Wang, Weiqin

2017-01-01

Highlights: • Propose a new distillation system based on Type I absorption heat pump. • The optimum condition of the system is obtained. • The energy consumption of the system is reduced by 23.3% significantly. • The benefits of economy and energy-saving for the new distillation system are distinct. - Abstract: Due to the thermodynamic deficiencies in general pressurized distillation process, a new distillation system based on Type I AHP (absorption heat pump) is proposed in this paper. The proposed system uses AHP to recover the waste heat from column condenser and reheat the feed materials of column; meanwhile, the cooling capacity of column condenser can be increased, which leads to the decrease of the pressure in distillation column. With general distillation system of depropanizing column (C-101) as an example, using numerical simulation software Aspen Plus, the effect of inner parameters on the energy consumption has been conducted to approach the general rules of energy saving in distillation. Then the new distillation system is adopted and the optimization of its energy consumption is conducted to determine the optimum operating condition. The numerical simulation results show that the steam consumption can be decreased by 23.3% compared with general C-101 system, reaching the minimum. Moreover, the extra heat output of AHP is treated as the heat source for the reboilers of deethanization column (C-102) and refined propylene column (C-103), which reduces the total steam consumption of three-column processes by 22.1%.

Correlación clínico patológica del cáncer cervical y precursores en una población de Lima periférica

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Victoria Valer

2005-06-01

Full Text Available Objetivo: Determinar la prevalencia y los factores de riesgo del cáncer cervical y sus precursores en un grupo poblacional, con especial énfasis en el manejo de la enfermedad cervical preinvasiva. Diseño: Estudio prospectivo y descriptivo no aleatorio. Materiales y Métodos: Estudio realizado durante el año 2003, en mujeres del Centro de Salud de Piedra Liza (San Juan de Lurigancho en 120 pacientes con diagnóstico citológico de ASC, AGC, L-SIL, H-SIL y carcinoma; se realizó biopsia de las lesiones cervicales en 49 casos, para confirmar el diagnóstico citológico y correlacionarlo con el cuadro clínico y la colposcopia. Resultados: De los 120 casos de estudio citológico, 14 (11,5% fueron ASC; 67 (56% L-SIL, 34 (29% H-SIL, 3 (2,5% carcinoma escamoso y 2 (2% adenocarcinoma. De 49 biopsias, 12 casos fueron L-SIL, 32 H-SIL, 3 carcinoma escamoso invasor y 2 adenocarcinoma cervical, uno de ellos in situ. Conclusiones: Los resultados citológicos muestran que las lesiones escamosas intraepiteliales y el carcinoma cervical tuvieron alta prevalencia en este grupo poblacional.

Cre-/IoxP-Mediated Recombination between the SIL and SCL Genes Leads to a Block in T-Cell Development at the CD4-CD8- to CD4+CD8+ Transition

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Yue Cheng

2007-04-01

Full Text Available In the most common form of stem cell leukemia (SCL gene rearrangement, an interstitial deletion of 82 kb brings SCL under the control of regulatory elements that normally govern expression of the ubiquitously expressed SCL interrupting locus (SIL gene, which is located directly upstream of SCL. To investigate the effect of this fusion in a mouse model, a bacterial artificial chromosome (BAC clone containing both human SIL and SCL genes was isolated, and IoxP sites were inserted into intron 1 of both the SIL and SCL genes, corresponding to the sites at which recombination occurs in human T-cell acute lymphocytic leukemia patients. This BAC clone was used to generate transgenic SILIoxloxSCL mice. These transgenic mice were subsequently bred to Lck-Cre mice that express the Cre recombinase specifically in the thymus. The BAC transgene was recombined between the two IoxP sites in over 50% of the thymocytes from SILIoxloxSCL/Cre double-transgenic mice, bringing the SCL gene under the direct control of SIL regulatory elements. Aberrant SCL gene expression in the thymus was verified by reverse transcription- polymerase chain reaction. Using FACS analysis, we found that mice carrying both SILIoxloxSCL and Cre transgenes have increased CD4-/CD8- thymocytes compared with transgenenegative mice. In the spleen, these transgenic mice show a marked reduction in the number of mature CD4+ or CD8+ cells. These results demonstrate that conditional activation of SCL under control of SIL regulatory elements can impair normal T-cell development.

High-efficiency liquid chromatography on conventional columns and instrumentation by using temperature as a variable I. Experiments with 25 cm x 4.6 mm I.D., 5 microm ODS columns.

Science.gov (United States)

Lestremau, François; Cooper, Andrew; Szucs, Roman; David, Frank; Sandra, Pat

2006-03-24

High plate numbers were obtained in conventional LC by coupling columns and by using temperature to reduce the viscosity of the mobile phase. At 80 degrees C up to eight columns of 25 cm x 4.6 mm I.D. packed with 5 microm ODS particles could be coupled generating 180,000 effective plates while the pressure drop was only 350bar. For routine work, a set of four columns is preferred. The analysis times on one column operated at 30 degrees C and 1 mL/min flow rate and on four columns at 80 degrees C and 2 mL/min flow rate are the same in isoeluotropic conditions while the resolution is doubled. Multicolumn systems were successfully applied in isocratic and gradient mode for the analysis of pharmaceutical and environmental samples.

[Detection of monoamine neurotransmitters and its metabolites by high performance liquid chromatograph after pre-column derivatization of dansyl chloride column].

Science.gov (United States)

Huang, Xiao; Chen, Jia-wen; He, Li-ping; Kang, Xue-jun

2012-12-01

To develop a high performance liquid chromatography (HPLC) for detection of monoamine neurotransmitters and its metabolites after pre-column derivatization with dansyl chloride. The C(18) chromatograph column (150 mm×4.6 mm×5 µm) was selected for detection, and derived by dansyl chloride (10 mg/ml) under the condition of 50°C water bath by pH11 buffer solution. 20 µl acetic acid acetone solution (1.0 mol/L) was then mixed in for termination of the reaction. Then the solution was cooling to room temperature, 0.1 mol/L acetic acid zinc-acetonitrile-tetrahydrofuran solution was adopted for mobile phrase, with the volume ratio at 62:35:3. The flow rate was 1.0 ml/min between 0-10 min, 2.0 ml/min between 10-35 min. The ultraviolet detection wavelength was 286 nm. The above method separately detected monoamine neurotransmitters and its metabolites and evaluated the limit of detection, accurate degree and accuracy degree. The linear relations between each component was good in the range of 1 - 20 µg/ml (r = 0.999). The lowest detection limit of norepinephrine, dopamine, 5-hydroxytryptamine and the metabolites 3-methoxy-4-benzoglycols, homovanillic acid and 5-heteroauxin were separately 0.60, 0.80, 0.41, 0.21, 0.19 and 0.1 µg/ml; while the average recovery rates were between 78.5% - 95.9%, and the relative standard deviation (RSD) was 6.62%, 7.64%, 2.98%, 3.60%, 5.09% and 3.09%, respectively. In the process of selection and optimization of the chromatographic conditions, we observed the importance of metal ions to discretion, and discussed the temperature, pH of the buffer solution and dosage of dansyl chloride in derivation. Under the above conditions, the reaction was perfect, and the baseline of the detected materials thoroughly separated. The method to detect monoamine neurotransmitters and its metabolites by HPLC and pre-column derivatization with dansyl chloride was established; and this method could provide reference for the detection of polyamine by HPLC.

Cervical vertebral column morphology in patients with obstructive sleep apnoea assessed using lateral cephalograms and cone beam CT. A comparative study

DEFF Research Database (Denmark)

Sonnesen, L; Jensen, K E; Petersson, A R

2013-01-01

beam CT (CBCT) in adult patients with OSA and to compare 2D lateral cephalograms with three-dimensional (3D) CBCT images. METHODS: For all 57 OSA patients, the cervical vertebral column morphology was evaluated on lateral cephalograms and CBCT images and compared according to fusion anomalies...... and posterior arch deficiency. RESULTS: The CBCT assessment showed that 21.1% had fusion anomalies of the cervical column, i.e. fusion between two cervical vertebrae (10.5%), block fusions (8.8%) or occipitalization (1.8%). Posterior arch deficiency occurred in 14% as partial cleft of C1 and in 3...

Adhesions, inflammatory response and foreign body giant cells infiltration of the topical hemostats TachoSil®, Hemopatch™ and Veriset™

DEFF Research Database (Denmark)

Schiøtt Nissen, Line; Hunter, Jacob; Schrøder, Henrik Daa

2017-01-01

Background: When liver bleeding cannot be controlled by conventional methods, a topical hemostatic patch can be applied during surgery. In recent years new hemostats have become available. The aim of this study was to investigate the degree of adhesion and inflammation for three topical hemostatic...... patches, TachoSil®, Hemopatch™ and Veriset™. Methods: In 60 adult male Sprague Dawley rats liver two lesions were induced with a scalpel. Each rat was treated with two of the three patches tested. After 1, 2 and 3 months the animals were euthanized and macroscopic evaluation of adhesions and histological...... assessment of inflammation and macrophage infiltration were performed. Results: A significant higher (pforeign body giant cells (FBGCs) was found in Hemopatch™ and Veriset™, whereas both had a lower degree of infl ammatory and macrophage infiltration compared to TachoSil®. No differences...

Modeling Stone Columns.

Science.gov (United States)

Castro, Jorge

2017-07-11

This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the "unit cell", longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

Aziridines in the synthesis of 11C- and 18F-labelled compounds

International Nuclear Information System (INIS)

Gillings, N.M.

1998-01-01

Racemic [4- 11 C]aspartic acid, [4- 11 C]asparagine and 2,4-diamino[4- 11 C]butyric acid were synthesised by the ring-opening of an N-activated aziridine-2-carboxylate with 11 C]cyanide, followed by preparative HPLC and hydrolysis/reduction. These labelled amino acids arise from nucleophilic attack at the β-carbon of the aziridine ring. A radioactive by-product of ca. 25% was attributed to the product of α-attack. Several N-activated 2-aryl aziridines were synthesised for the attempted synthesis of β-[ 18 F] fluorophenylalanine and β-[ 18 F]fluorodopa. Ring-opening with [ 18 F]fluoride showed no evidence of β-fluorinated products and it is proposed that attack occurs exclusively at the α-carbon, giving the corresponding α-[ 18 F]fluoro-β-amino acids. Further evidence for this was the reaction of the β-unsubstituted N-activated aziridine-2-carboxylate with [ 18 F]fluoride. This reaction was totally regiospecific and afforded exclusively the α-substituted product, α-[ 18 F]fluoro-β-alanine. Aziridine precursors were resolved by chiral HPLC. On labelling the chiral aziridines, however, racemic 11 C- and 18 F-labelled amino acids were obtained. This was attributed to racemisation of the initially formed ring-opened products. The use of [ 11 C]methyl lithium as a nucleophile for aziridine ring-opening was investigated. Reaction was expected to occur at low temperature, thus potentially avoiding racemisation. No products corresponding to aziridine ring-opening with [ 11 C]methyl lithium were, however, observed. A difluorinated analogue of amphetamine was synthesised by fluorination of an azirine (via an aziridine). This racemic compound was resolved as its chiral tartarate salts and subsequently labelled by methylation with [ 11 C]methyl iodide, giving the novel compound β, β-difluoro[N-methyl- 11 C]methamphetamine in high specific activity for in vivo binding studies using positron emission tomography. The non-radioactive reference compound was also

Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18

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R. F. Weiss

2012-05-01

Full Text Available Atmospheric observations and trends are presented for the high molecular weight perfluorocarbons (PFCs: decafluorobutane (C4F10, dodecafluoropentane (C5F12, tetradecafluorohexane (C6F14, hexadecafluoroheptane (C7F16 and octadecafluorooctane (C8F18. Their atmospheric histories are based on measurements of 36 Northern Hemisphere and 46 Southern Hemisphere archived air samples collected between 1973 to 2011 using the Advanced Global Atmospheric Gases Experiment (AGAGE "Medusa" preconcentration gas chromatography-mass spectrometry systems. A new calibration scale was prepared for each PFC, with estimated accuracies of 6.8% for C4F10, 7.8% for C5F12, 4.0% for C6F14, 6.6% for C7F16 and 7.9% for C8F18. Based on our observations the 2011 globally averaged dry air mole fractions of these heavy PFCs are: 0.17 parts-per-trillion (ppt, i.e., parts per 1012 for C4F10, 0.12 ppt for C5F12, 0.27 ppt for C6F14, 0.12 ppt for C7F16 and 0.09 ppt for C8F18. These atmospheric mole fractions combine to contribute to a global average radiative forcing of 0.35 mW m−2, which is 6% of the total anthropogenic PFC radiative forcing (Montzka and Reimann, 2011; Oram et al., 2012. The growth rates of the heavy perfluorocarbons were largest in the late 1990s peaking at 6.2 parts per quadrillion (ppq, i.e., parts per 1015 per year (yr for C4F10, at 5.0 ppq yr−1 for C5F12 and 16.6 ppq yr−1 for C6F14 and in the early 1990s for C7F16 at 4.7 ppq yr−1 and in the mid 1990s for C8F18 at 4.8 ppq yr−1. The 2011 globally averaged mean atmospheric growth rates of these PFCs are subsequently lower at 2.2 ppq yr−1 for C4F10, 1.4 ppq yr−1 for C5F12, 5.0 ppq yr−1 for C6F14, 3.4 ppq yr−1 for C7F16 and 0.9 ppq yr−1 for C8F18. The more recent slowdown in the growth rates suggests that emissions are declining as compared to the 1980s and 1990s.

26 CFR 1.501(c)(18)-1 - Certain funded pension trusts.

Science.gov (United States)

2010-04-01

... qualification. A trust described in section 501(c)(18) must meet the following requirements: (1) Local law. The trust must be a valid, existing trust under local law, and must be evidenced by an executed written... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Certain funded pension trusts. 1.501(c)(18)-1...

Le Brésil au cœur des stratégies spatiales du recrutement des clubs européens de football

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Bertrand Piraudeau

2009-10-01

Full Text Available Depuis la fin des années 1990, le nombre de footballeurs brésiliens évoluant dans les clubs professionnels internationaux augmente constamment. Les principaux championnats européens (Allemagne, Angleterre, Espagne, France, Italie et Portugal sont très courtisés par les joueurs brésiliens. L'histoire des relations entre les territoires et les stratégies spatiales du recrutement développées par les clubs de football européens font apparaître un système productif de joueurs brésiliens et des canaux migratoires très organisés entre l'Europe et le Brésil.Depuis la fin des années 1990, le nombre de footballeurs brésiliens évoluant dans les clubs professionnels internationaux augmente constamment. Les principaux championnats européens (Allemagne, Angleterre, Espagne, France, Italie et Portugal sont très courtisés par les joueurs brésiliens. L'histoire des relations entre les territoires et les stratégies spatiales du recrutement développées par les clubs de football européens font apparaître un système productif de joueurs brésiliens et des canaux migratoires très organisés entre l'Europe et le Brésil.Desde o fim dos anos 1990, o número de jogadores de futebol brasileiros que jogam nos clubes profissionais internacionais aumenta constantemente. Os principais campeonatos europeus (Alemanha, Inglaterra, Espanha, França, Itália e Portugal são  muito procurados pelos jogadores brasileiros. A história das relações entre os territórios e as estratégias espaciais de recrutamento desenvolvidas pelos clubes de futebol europeus indica um sistema produtivo de jogadores brasileiros e canais migratórios muito organizados entre a Europa e o Brasil.Since the end of the 1990s, the number of Brazilian footballers playing in the international professional clubs increases constantly. The principal European championships (Germany, England, Spain, France, Italy and Portugal are very courted by the Brazilian players. The history

Hollow-Core FRP–Concrete–Steel Bridge Columns under Torsional Loading

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Sujith Anumolu

2017-11-01

Full Text Available This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm and applied load height of 96 in. (2438 mm with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube. A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not.

Full Automatic synthesis of [18F]FMISO

International Nuclear Information System (INIS)

Seung Jun Oh; Se Hun Kang; Jin-Sook Ryu; Dae Hyuk Moon

2004-01-01

[ 18 F]FMISO is a radiopharmaceutical for hypoxia imaging. Although it was developed in 1986, there has been no report about automatic synthesis. In this experiment, we established the full automatic synthesis of [ 18 F]FMISO and evaluate the stability according to ICH guideline. Method: We used GE MicroLab MX for automatic synthesis. Sequence program was modified to control of the module as follows: [ 18 F]Fluoride drying→[ 18 F]fluorination→trapping of reaction mixture on C18 cartridge→purification-elution of reaction mixture→hydrolysis and HPLC purification. We used disposable cassette for each synthesis and discard it after synthesis. To find optimal synthesis condition, we tested 90 120 degree C as reaction temperature, 5 15 mg of 1-(2-nitro-1-imidazolyl) -2-O-tetrahtdropyranyl-3-O-toluenesulfonyl-propanediol as precursor and 5 15 min as [ 18 F]fluorination time. HPLC purification condition was EtOH:H20 = 5:95, 5ml/min with Alltech Econosil column. To check the stability of production, we performed 30 times of run. We checked the radiochemical stability until 6 hours at 25 degree C and 40% humidity condition. We also performed the stability test at 50 70 degree C with 60-80% humidity condition or under UV light for 6 hours after synthesis for acceleration test, Results: The optimal [ 18 F] fluorination condition was 10mg of precursor and 15 min incubation at 110 degree C. Hydrolysis was performed at 105 degree C for 5 min. After HPLC purification, radiochemical yields and purity were 45±2.8 and 98±1.2%, respectively. Total synthesis time was 60±5.2 min. [ 18 F]FMISO was stable until 6 hours after production with 97±2.4% of radiochemical purity. [ 18 F]FMISO was also stable in acceleration test and photochemical test with 97±2.4 and 97±2.8% of radiochemical purity, respectively. Conclusion: We established the full automatic synthesis method of [ 18 F]FMISO with reproducible high production yield. [18F]FMISO synthesized by this method was stable

Clinical significance of measurement of changes of serum IL-2, SIL-2R levels, B lymphocyte number and T-cell subsets after chemotherapy in patients with malignant hydatidiform mole

International Nuclear Information System (INIS)

Zhang Guangcai

2007-01-01

Objective: To study the clinical significance of changes of serum IL-2, SIL-2R level, peripheral blood B lymphocyte number and T-cell subsets after chemotherapy in patients with malignant hydatidiform mole. Methods: Serum IL-2 ( with RIA), SIL-2R level (with ELISA) and peripheral blood B lymphocytes number as well as T subsets (with monoclonal antibody technique) were measured both before and after chemotherapy in 32 patients with malignant hydatidiform mole as well as in 35 controls. Results: Before chemotherapy serum SIL-2R level and B lymphocyte were significantly higher in the patients than those in controls (P<0.01), while the serum IL-2 level, CD3, CD4, CD4/CD8 were significantly lower (P<0.01). Six months after chemotherapy the levels changed markedly toward normal, but remained significantly different from those in controls (P<0.05). Conclusion: Abnormal immuno-regulation were present in patients with malignant mole. (authors)

Cervical column morphology and craniofacial profiles in monozygotic twins.

Science.gov (United States)

Sonnesen, Liselotte; Pallisgaard, Carsten; Kjaer, Inger

2008-02-01

Previous studies have described the relationships between cervical column morphology and craniofacial morphology. The aims of the present study were to describe cervical column morphology in 38 pairs of adult monozygotic (MZ) twins, and compare craniofacial morphology in twins with fusions with craniofacial morphology in twins without fusion. Visual assessment of cervical column morphology and cephalometric measurements of craniofacial morphology were performed on profile radiographs. In the cervical column, fusion between corpora of the second and third vertebrae was registered as fusion. In the twin group, 8 twin pairs had fusion of the cervical column in both individuals within the pair (sub-group A), 25 pairs had no fusions (subgroup B), and in 5 pairs, cervical column morphology was different within the pair (subgroup C), as one twin had fusion and the other did not. Comparison of craniofacial profiles showed a tendency to increased jaw retrognathia, larger cranial base angle, and larger mandibular inclination in subgroup A than in subgroup B. The same tendency was observed within subgroup C between the individual twins with fusion compared with those without fusion. These results confirm that cervical fusions and craniofacial morphology may be interrelated in twins when analysed on profile radiographs. The study also documents that differences in cervical column morphology can occur in individuals within a pair of MZ twins. It illustrates that differences in craniofacial morphology between individuals within a pair of MZ twins can be associated with cervical fusion.

ADAPTIVE STRATEGIES FOR INLAND TOURISTIC DESTINATIONS (SIL CANYON, GALICIA, NW SPAIN

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Elena De Uña-Álvarez

2017-01-01

Full Text Available El potencial del turismo está relacionado en gran medida con la capacidad de reorganización e innovación de los destinos. Durante los últimos quince años, la evolución del turismo en el sector occidental del Cañón del Sil (Galicia, NO España refleja las transformaciones ante momentos de crisis. Asumiendo que el turismo es un sistema adaptativo complejo, los objetivos de esta investigación sobre un destino de interior están centrados en la interpretación de las estrategias turísticas. El estudio de la evolución del destino turístico incluye la lectura de los actores clave. Las estrategias de turismo rural cambian integrando las estrategias de turismo en la naturaleza y cultural.

Humidification Dehumidification Spray Column Direct Contact Condenser Part I: Countercurrent Flow

International Nuclear Information System (INIS)

Shouman, L.; Karameldin, A.; Fadel, D.

2015-01-01

Humidification-dehumidification (HDH) is a low grade energy desalination technology. The waste heat from power plant (such NPP) can be used as heat source to preheat water (in evaporator) and air (in condenser) . Hot humid air and cooled spray water in counter current flow with direct contact is theoretically analyzing in the present work. Direct contact spray condenser is studied to provide the effect of various parameters on its performance. A computer programme describing the theoretical model is designed to solve a one-dimensional differential equations by using Rung–Kutta method. The programme predicts the droplet radius, velocity and temperature, besides, the humidity and temperature of air. The results show that, the length of column has great effect on the performance of spray condenser. At column height of 0.762, 2, 5, 10, and 20 m the humidity of the output air decreases by 50%, 72%, 89%, 97%, and 99% respectively. The condensate increases about 35% when the length increase from 5 to 10 m at ΔT = 25°C while increase only 18% at ΔT = 30°C. Also, it is found that, at ΔT = 25°C the condensate decrease from H = 10 to 5 m about 31% and increases from 10 to 20 m about 32%. While these results for ΔT = 25°C are 32% from H = 10 to 5 m and 36% from 10 to 20 m.The increase of both water and air mass fluxes increases the condensate mass flow rate. (author)

Column Chromatography Of Co(II), Zn(II) And Eu(III) Using Pistachio Shell And Different Mobile Phases

International Nuclear Information System (INIS)

Abdel-Fattah, A.A.

2009-01-01

Pistachio shell particles (0.5-1 mm) have been applied as the stationary phase for studying the column chromatography of Co(II), Zn(II) and Eu(III) at room temperature; 26 + - 1 oC. This solid sorbent has been characterized by thermogravimetric analysis, infra-red spectroscopy and X-ray diffraction. Its surface area and percent of swelling have been also determined. Different eluting agents have been used for eluting the sorbed elements. The elution curves have been done from which the distribution coefficients (K d ), number of theoretical plates (N) and heights equivalent to theoretical plates (H) have been determined. Column performance studies have been conducted for a representative system under certain experimented conditions and Van Deemter equation has been applied. Thermodynamic studies have been applied and thermodynamic functions ( δG 0 ,δH 0 andδ S 0 ) have been calculated for this representative system by determining K d at three different room temperatures (18, 26 and 37 + - 1o C).

Quantitation of triacylglycerols in edible oils by off-line comprehensive two-dimensional liquid chromatography-atmospheric pressure chemical ionization mass spectrometry using a single column.

Science.gov (United States)

Wei, Fang; Hu, Na; Lv, Xin; Dong, Xu-Yan; Chen, Hong

2015-07-24

In this investigation, off-line comprehensive two-dimensional liquid chromatography-atmospheric pressure chemical ionization mass spectrometry using a single column has been applied for the identification and quantification of triacylglycerols in edible oils. A novel mixed-mode phenyl-hexyl chromatographic column was employed in this off-line two-dimensional separation system. The phenyl-hexyl column combined the features of traditional C18 and silver-ion columns, which could provide hydrophobic interactions with triacylglycerols under acetonitrile conditions and can offer π-π interactions with triacylglycerols under methanol conditions. When compared with traditional off-line comprehensive two-dimensional liquid chromatography employing two different chromatographic columns (C18 and silver-ion column) and using elution solvents comprised of two phases (reversed-phase/normal-phase) for triacylglycerols separation, the novel off-line comprehensive two-dimensional liquid chromatography using a single column can be achieved by simply altering the mobile phase between acetonitrile and methanol, which exhibited a much higher selectivity for the separation of triacylglycerols with great efficiency and rapid speed. In addition, an approach based on the use of response factor with atmospheric pressure chemical ionization mass spectrometry has been developed for triacylglycerols quantification. Due to the differences between saturated and unsaturated acyl chains, the use of response factors significantly improves the quantitation of triacylglycerols. This two-dimensional liquid chromatography-mass spectrometry system was successfully applied for the profiling of triacylglycerols in soybean oils, peanut oils and lord oils. A total of 68 triacylglycerols including 40 triacylglycerols in soybean oils, 50 triacylglycerols in peanut oils and 44 triacylglycerols in lord oils have been identified and quantified. The liquid chromatography-mass spectrometry data were analyzed

Analysis of the radiochemical purity of 18F-FDG by HPLC

International Nuclear Information System (INIS)

Chen Liguang; Tang Anwu; He Shanzhen; Chen Yulong

2001-01-01

The radiochemical purity (RCP) of 18 F-FDG is analyzed by HPLC. Eighty-five percent acetonitrile is used as the eluting solution. Carbon hydrate column is used as separation column. The t R of 18 F - is 6.50 min and 18 F-FDG is 9.00 min. HPLC take less time and has higher sensitivity than TLC for the same sample at the same time. So HPLC excels TLC in analyzing RCP of 18 F-FDG

Synthesis of n.c.a. {sup 18}F-fluorinated NMDA- and D{sub 4}-receptor ligands via [{sup 18}F]fluorobenzenes; Traegerarme Synthese {sup 18}F-markierter, ausgewaehlter NMDA- und D{sub 4}-Rezeptorliganden durch Einsatz geeigneter [{sup 18}F]Fluorbenzolderivate

Energy Technology Data Exchange (ETDEWEB)

Ludwig, T

2005-11-01

In this thesis new strategies were developed and evaluated for the no-carrier-added (n.c.a.) {sup 18}F-labelling of receptor ligands as radiodiagnostics for characterization of brain receptors using positron-emission-tomography (PET). Special emphasis was placed on the synthesis of n.c.a. ({+-})-3-(4-hydroxy-4-(4-[{sup 18}F]fluorophenyl)-piperidin-l-yl)chroman-4,7-diol, a ligand with high affinity for the NR2B subtype of NMDA receptors and n.c.a. (3-(4-[{sup 18}F]fluorphenoxy)propyl)-(2-(4-tolylphenoxy)ethyl)amine ([{sup 18}F]FPTEA) a dopamine D{sub 4} receptor ligand. In order to synthesize n.c.a. ({+-})-3-(4-hydroxy-4-(4-[{sup 18}F]fluorophenyl)-piperidin-l-yl)chroman-4,7-diol the {sup 18}F-fluoroarylation method via metallorganic intermediates was modified and improved. The suitability of the organometallic {sup 18}F-fluoroarylation agents was proven with several model compounds. High radiochemical yields of 20-30% were obtained also with piperidinone-derivatives. The preparation of a suitable precursor for the synthesis of the NMDA receptor ligand, however, could not be achieved by synthesis of appropriate 1,3-dioxolane protected piperidinone derivatives. Further, the synthesis of n.c.a. ([{sup 18}F]fluoroaryloxy)alkylamines via n.c.a. 4-[{sup 18}F]fluorophenol was developed and evaluated. The synthesis of n.c.a. [{sup 18}F]fluoroarylethers with corresponding model compounds was optimized and led to a radiochemical yield of 25-60%, depending on the alkylhalide used. The preparation of n.c.a. 1-(3-bromopropoxy)-4-[{sup 18}F]fluorobenzene proved advantageous in comparison to direct use of 4-[{sup 18}]fluorophenol for coupling with a corresponding N-protected precursor for the synthesis of n.c.a. [{sup 18}F]FPTEA. With regard to the radiochemical yields and the loss of activity during the synthesis and isolation of n.c.a. 4-[{sup 18}F]fluorophenol and n.c.a. 1-(3-bromopropoxy)-4-[{sup 18}F]fluorobenzene, [{sup 18}F]FPTEA was obtained by reaction with 2-(4-tolyloxy

Assembly for connecting the column ends of two capillary columns

International Nuclear Information System (INIS)

Kolb, B.; Auer, M.; Pospisil, P.

1984-01-01

In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A ''straight-forward operation'' having capillary columns connected in series and a ''flush-back operation'' are possible. The dead volume between the capillary columns can be kept small

Internet delivered question and answer column for patients with schizophrenia.

Science.gov (United States)

Maijala, Riikka; Anttila, Minna; Koivunen, Marita; Pitkänen, Anneli; Kuosmanen, Lauri; Välimäki, Maritta

2015-01-01

The purpose of this study was to describe the use of an Internet delivered question and answer column among patients with schizophrenia. The column was developed for research purposes. The study sample consisted of patients (N = 100) admitted to acute inpatient psychiatric care in two hospital districts. Descriptive data were collected from the column to which a nurse replied within 3 days and analysed using qualitative content analysis. The column had four to five questions weekly. The most common age of users was 18-24 years, and the gender distribution was almost equal. Column use was heaviest among students (44%) and least among unemployed people (19%). Out of 85 questions or comments sent to the column, 25 (29%) were related to program training and the remaining 60 (71%) were related to medication (31%), illness and tests (25%), other questions or comments (9%), daily life and coping with it (4%), and places to receive treatment (2%). An Internet delivered question and answer column can be included in the care of patients with schizophrenia. However, it requires a new type of basic and additional education in the field of mental health care in order for nurses to be able to provide nursing via the Internet forum.

STM study of C60F18 high dipole moment molecules on Au(111)

Science.gov (United States)

Bairagi, K.; Bellec, A.; Chumakov, R. G.; Menshikov, K. A.; Lagoute, J.; Chacon, C.; Girard, Y.; Rousset, S.; Repain, V.; Lebedev, A. M.; Sukhanov, L. P.; Svechnikov, N. Yu.; Stankevich, V. G.

2015-11-01

Scanning tunneling microscopy and spectroscopy studies of C60F18 molecules deposited on Au(111) are reported and compared to C60 molecules both at liquid helium temperature and room temperature (RT). Whereas adsorption and electronic properties of C60F18 single molecules were studied at low temperature (LT), self-assemblies were investigated at RT. In both cases, the fluorine atoms of the C60F18 molecules are pointed towards the surface. Individual C60F18 molecules on Au(111) have a HOMO-LUMO gap of 2.9 eV. The self-assembled islands exhibit a close-packed hexagonal lattice with amorphous borders. The comparison with C60 molecules clearly demonstrates the influence of the C60F18 electric dipole moment (EDM) on the electronic properties of single molecules and on the thermodynamics of self-assembled islands. Besides, the apparent height value of a separate molecule increases in a self-assembly environment as a result of a depolarization phenomenon.

Aqaba Core 18, Jordan Isotope (delta 18O, delta 13C) Data for 1788 to 1992

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Site: Aqaba, Jordan, Marine Science Station Reef, cores C18 and C19 (29ó 26' N, 34ó 58' E) Water Depth 1m. collected 11/01/92 (upper 0-120cm), 11/01/93 (120-320cm)...

Fast comprehensive two-dimensional gas chromatography method for fatty acid methyl ester separation and quantification using dual ionic liquid columns.

Science.gov (United States)

Nosheen, Asia; Mitrevski, Blagoj; Bano, Asghari; Marriott, Philip J

2013-10-18

Safflower oil is a complex mixture of C18 saturated and unsaturated fatty acids amongst other fatty acids, and achieving separation between these similar structure components using one dimensional gas chromatography (GC) may be difficult. This investigation aims to obtain improved separation of fatty acid methyl esters in safflower oil, and their quantification using comprehensive two-dimensional GC (GC×GC). Here, GC×GC separation is accomplished by the coupling of two ionic liquid (IL) column phases: the combination of SLB-IL111 with IL59 column phases was finally selected since it provided excellent separation of a FAME standard mixture, as well as fatty acids in safflower and linseed oil, compared to other tested column sets. Safflower oil FAME were well separated in a short run of 16min. FAME validation was demonstrated by method reproducibility, linearity over a range up to 500mgL(-1), and limits of detection which ranged from 1.9mgL(-1) to 5.2mgL(-1) at a split ratio of 20:1. Quantification was carried out using two dilution levels of 200-fold for major components and 20-fold for trace components. The fatty acids C15:0 and C17:0 were not reported previously in safflower oil. The SLB-IL111/IL59 column set proved to be an effective and novel configuration for separation and quantification of vegetable and animal oil fatty acids. Copyright © 2013 Elsevier B.V. All rights reserved.

Solubility of DCH18C6 and n-octanol in nitric acid system

International Nuclear Information System (INIS)

He Qiange; Wang Jianchen; Chen Jing

2011-01-01

Equilibrium solubility of DCH18C6 and n-octanol in aqueous solution were determined by GC. And effects of temperature, concentration of Sr 2+ or HNO 3 were studied. The results indicate that solubility of DCH18C6 is substantial and make the crown ether continually drain from organic phase which could be 3% at most. As diluent, n-octanol could dissolve in water with certain quantity. So n-octanol, and then kerosene should be used to extract DCH18C6 and n-octanol from aqueous phase. Or toluene is taken to recover DCH18C6 and n-octanol at the same time. Above extractants could recover more than 99% of solute from aqueous solution in the volume ratio 1:1. (author)

Optimization of a divided wall column for the separation of C4-C6 normal paraffin mixture using Box-Behnken design

Directory of Open Access Journals (Sweden)

Sangal Vikas K.

2013-01-01

Full Text Available In the present study, simulation of a divided wall column (DWC was carried out to study the product quality and energy efficiency as a function of reflux rate, liquid spilt and vapour split for the separation of C4-C6 normal paraffin ternary mixture. Rigorous simulation of the DWC was carried out using Multifrac model of ASPEN Plus software. Box-Behnken design (BBD was used for the optimization of parameters and to evaluate the effects and interaction of the process parameters such as reflux rate (r, liquid split (l and vapour split (v. It was found that the number of simulation runs reduced significantly for the optimization of DWC by BBD. Optimization by BBD under response surface methodology (RSM vividly underscores interactions between variables and their effects. The predictions agree well with the results of the rigorous simulation.

Estudio de la efectividad de las columnas de extracción de octadecilo C18 en la evaluación del amargor (K225 del aceite de oliva virgen. Error y esquema analítico del método de evaluación

Directory of Open Access Journals (Sweden)

Perdiguero Camacho, S.

1992-04-01

Full Text Available The present study developed two objetives: 1 to study the possibility of repeatedly using disposable C18 columns 2 to determine an appropriate analytical scheme and the inherent systematic error in the method to evaluate bitter substances in virgin olive oil. The results confirmed that we were able to recover the principles of olive oil without reducing the effectiveness of the C18 a columns with repeated uses at least ten times. The evaluation method errors of the bitter taste have been determined, in order to determine it precision. The confidence limits calculated for defined work schemes have given sufficient precision.El presente trabajo ha perseguido dos objetivos fundamentales: 1 estudiar la posibilidad de utilizar repetidamente las columnas "disposable" (de un sólo uso C18 y 2 determinar el error y esquema analítico apropiado del método de evaluación del amargor del aceite de oliva virgen. Los resultados obtenidos nos permiten afirmar que las recuperaciones de los productos responsables del amargor del aceite no disminuyen al reutilizarse las columnas al menos durante las diez utilizaciones probadas. Se han determinado los errores del método de evaluación del amargor para determinar su precisión. Los límites de confianza calculados para definir los esquemas de trabajo han dado suficiente precisión.

Separation of mercury(II), methylmercury and phenylmercury by micellar high-performance liquid chromatography on short columns

International Nuclear Information System (INIS)

Hutta, M.; Megova, S.; Halko, R.

1998-01-01

Three environmentally and agrochemically important mercury species: methylmercury, phenylmercury and mercury(II) are separated within 4 minutes as bromocomplexes by micellar liquid chromatography using very short reversed-phase (RP) C18 columns (up to 30 mm). The micellar mobile phase containing 0.05M cetyltrimethylammonium bromide (CTMA + Br - ), 1% (v/v) 2-propanol, 0.001M cyclohexylenediaminetetraacetic acid (DCTA) and sulfuric acid (pH 2) showed good selectivity in mixed reversed-phase and anion-exchange mode. The above mentioned separation order in which organomercurials are eluted far behind the void volume of the column, but before the mercury(II) peak is advantageous in all instances where mercury(II) is present in real samples in great excess. Environmental and agrochemical samples contain humic material which does not interfere in this particular system. The low cost photometric detection at 500 nm after post-column derivatization by CTMA + Br - micellized dithizone is almost free from interferences and enables detection limits at the 1-3 ng level (e.g., 0.1 ppm Hg) for 20 μl samples. (author)

Clinical significance of measurement of changes of serum IL-2, SIL-2R, TNF-α levels, B lymphocyte count and T subsets distribution type after treatment in patients with vitiligo

International Nuclear Information System (INIS)

Xie Chuntao

2007-01-01

Objective: To study the changes of serum IL-2, SIL-2R, TNF-α levels B lymphocytes count and T lyonphocyte subsets distribation type after treatment in patients with vitiligo. Methods: Serum IL-2, TNF-α (with RIA), SIL-2R (with ELISA) levels, B lymphocytes count and T subsets (with monoclonal antibody technique) were examined in 40 patients with vitiligo both before and after treatment as well as in 35 controls. Results: Before treatment, serum SIL-2R, TNF-α levels and B lymphocytes count were significantly higher than those in controls (P<0.01), while the serum IL-2, CD3, CD4 levels CD4/CD8 ratio were significantly lower(P<0.01). After treatment for 6 months, the data were greatly corrected but remanied significantly different from those in controls (P<0.05). Conclusion: Vitiligo is a kind of auto-immune diseases with abnormal immuno-regulation. (authors)

Milligram quantities of homogeneous recombinant full-length mouse Munc18c from Escherichia coli cultures.

Directory of Open Access Journals (Sweden)

Asma Rehman

Full Text Available Vesicle fusion is an indispensable cellular process required for eukaryotic cargo delivery. The Sec/Munc18 protein Munc18c is essential for insulin-regulated trafficking of glucose transporter4 (GLUT4 vesicles to the cell surface in muscle and adipose tissue. Previously, our biophysical and structural studies have used Munc18c expressed in SF9 insect cells. However to maximize efficiency, minimize cost and negate any possible effects of post-translational modifications of Munc18c, we investigated the use of Escherichia coli as an expression host for Munc18c. We were encouraged by previous reports describing Munc18c production in E. coli cultures for use in in vitro fusion assay, pulldown assays and immunoprecipitations. Our approach differs from the previously reported method in that it uses a codon-optimized gene, lower temperature expression and autoinduction media. Three N-terminal His-tagged constructs were engineered, two with a tobacco etch virus (TEV or thrombin protease cleavage site to enable removal of the fusion tag. The optimized protocol generated 1-2 mg of purified Munc18c per L of culture at much reduced cost compared to Munc18c generated using insect cell culture. The purified recombinant Munc18c protein expressed in bacteria was monodisperse, monomeric, and functional. In summary, we developed methods that decrease the cost and time required to generate functional Munc18c compared with previous insect cell protocols, and which generates sufficient purified protein for structural and biophysical studies.

Características anatômicas de mudas de morangueiro micropropagadas com diferentes fontes de silício Anatomical characteristics of the strawberry seedlings micropropagated using different sources of silicon

Directory of Open Access Journals (Sweden)

Francyane Tavares Braga

2009-02-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes fontes de silício, utilizadas na micropropagação, nas características anatômicas de mudas de morangueiro (Fragaria x ananassa. Foram utilizados propágulos da cv. Oso Grande cultivados em meio Murashige e Skoog (MS, acrescido de 30 gL-1 de sacarose, 6 gL-1 de ágar e 1 mgL-1 de 6-benzilaminopurina. Os tratamentos consistiram da adição ao meio MS dos silicatos de cálcio, de sódio e de potássio, na dosagem de 1 gL-1. O tratamento testemunha foi o meio MS sem fonte de silício. Odelineamento experimental foi o inteiramente ao acaso, com dez repetições. Os propágulos foram mantidos por 45 dias em sala de crescimento, em condições controladas. Avaliaram-se características fitotécnicas e anatômicas dos propágulos in vitro. Verificou-se que o aumento da massa de matéria fresca e seca dos propágulos de morangueiro ocorreu na presença de silicato de sódio. Asuplementação do meio de cultura com silício proporcionou maior teor de clorofila. Aadição de silicato de sódio ao meio MS resultou em aumento da espessura dos tecidos do limbo foliar e da deposição de cera epicuticular e na formação de depósito de silício nas células.The objective of this work was to evaluate the effect of different silicon sources, used in micropropagation, on the anatomical characteristics of strawberry's (Fragaria x ananassa seedlings. Propagules of cv.Oso Grande were cultivated on a Murashige and Skoog (MS medium containing 30 gL-1 of sucrose, 6 gL-1 of agar and 1mgL-1 of 6-benzylamino purine. The treatments consisted of calcium, sodium, or potassium silicates added to the MS medium, at the dosage of 1 gL-1. The MS medium without added silicon was the check treatment. The experimental design was completely randomized with ten replications. The propagules were maintained during 45days in a growth chamber, under controlled conditions. Developmental and anatomical characteristics of the

Oxidative stability of structured lipids containing C18:0, C18:1, C18:2, C18:3 or CLA in sn 2-position - as bulk lipids and in milk drinks

DEFF Research Database (Denmark)

Timm Heinrich, Maike; Nielsen, Nina Skall; Xu, Xuebing

2004-01-01

In this study, we compared the oxidative stability of a specific structured lipid (SL) containing conjugated linoleic acid (CLA) in the sn2-position with SL containing other C18 fatty acids of different degree of unsaturation (stearic, oleic, linoleic or linolenic acid). SL was produced...... by enzymatic interesterification with caprylic acid. Oxidative stability was compared in the five lipids themselves and in milk drinks containing 5% of the different SL. During storage, samples were taken for chemical and physical analyses. Moreover, sensory assessments were performed on milk drinks....... The oxidative stability of our SL was very different when comparing (a) bulk lipids and milk drink and (b) the five different batches of each product. SL based on oleic acid was the most unstable as bulk lipid, while SL based on linoleic acid was the most unstable in milk drink. SL based on CLA was the second...

The Semi-automatic Synthesis of 18F-fluoroethyl-choline by Domestic FDG Synthesizer

Directory of Open Access Journals (Sweden)

ZHOU Ming

2016-02-01

Full Text Available As an important complementary imaging agent for 18F-FDG, 18F-fluoroethyl-choline (18F-FECH has been demonstrated to be promising in brain and prostate cancer imaging. By using domestic PET-FDG-TI-I CPCU synthesizer, 18F-FECH was synthesized by different reagents and consumable supplies. The C18 column was added before the product collection bottle to remove K2.2.2. The 18F-FECH was synthesized by PET-FDG-IT-I synthesizer efficiently about 30 minutes by radiochemical yield of 42.0% (no decay corrected, n=5, and the radiochemical purity was still more than 99.0% after 6 hours. The results showed the domestic PET-FDG-IT-I synthesizer could semi-automatically synthesize injectable 18F-FECH in high efficiency and radiochemical purity

L’impact environnemental de l’usine hydroélectrique de Porto Primavera (Brésil

Directory of Open Access Journals (Sweden)

Jailton Dias

2002-12-01

Full Text Available L’implantation de l’usine hydroélectrique de Porto Primavera sur le cours du haut Paraná, au Centre-Sud du Brésil, a entraîné de grandes transformations de l’environnement et de l’organisation de l’espace. L’ampleur et la rapidité des modifications se prêtent à un suivi par télédétection. Les images Landsat™ démontrent que la construction du barrage a donné une nouvelle impulsion au développement économique régional.

Synthesis and characterization of Mn-doped ZnO column arrays

International Nuclear Information System (INIS)

Yang Mei; Guo Zhixing; Qiu Kehui; Long Jianping; Yin Guangfu; Guan Denggao; Liu Sutian; Zhou Shijie

2010-01-01

Mn-doped ZnO column arrays were successfully synthesized by conventional sol-gel process. Effect of Mn/Zn atomic ratio and reaction time were investigated, and the morphology, tropism and optical properties of Mn-doped ZnO column arrays were characterized by SEM, XRD and photoluminescence (PL) spectroscopy. The result shows that a Mn/Zn atomic ratio of 0.1 and growth time of 12 h are the optimal condition for the preparation of densely distributed ZnO column arrays. XRD analysis shows that Mn-doped ZnO column arrays are highly c-axis oriented. As for Mn-doped ZnO column arrays, obvious increase of photoluminescence intensity is observed at the wavelength of ∼395 nm and ∼413 nm, compared to pure ZnO column arrays.

Graphite oxidation and structural strength of graphite support column in VHTR

International Nuclear Information System (INIS)

Park, Byung Ha; No, Hee Cheno; Kim, Eung Soo; Oh, Chang H.

2009-01-01

The air-ingress event by a large pipe break is an important accident considered in design of very high-temperature gas-cooled reactors (VHTR). Core-collapse prediction is a main safety issue. Structural failure model are technically required. The objective of this study is to develop structural failure model for the supporting graphite material in the lower plenum of the GT-MHR (gas-turbine-modular high temperature reactor). Graphite support column is important for VHTR structural integrity. Graphite support columns are under the axial load. Critical strength of graphite column is related to slenderness ratio and bulk density. Through compression tests for fresh and oxidized graphite columns we show that compressive strength of IG-110 was 79.46 MPa. And, the buckling strength of IG-110 column was expressed by the empirical formula: σ 0 =σ straight-line - C L/r, σ straight-line =91.31 MPa, C=1.01. The results of uniform and non-uniform oxidation tests show that the strength degradation of oxidized graphite column is expressed in the following non-dimensional form: σ/σ 0 =exp(-kd), k=0.111. Also, from the results of the uniform oxidation test with a complicated-shape column, we found out that the above non-dimensional equation obtained from the uniform oxidation test is applicable to a uniform oxidation case with a complicated-shape column. (author)

Moderniser la démarche visant la qualité de l'eau au Brésil | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

20 sept. 2017 ... Après la rupture d'un grand barrage au sud-est du Brésil, des déchets métalliques et de boue contaminèrent l'eau et causèrent la pire catastrophe écologique de l'histoire de la nation. La recherche d'Adalto Bianchini aide son pays à réviser sa règlementation relative à une de ses ressources les plus ...

Evaluation of pesticide adsorption in gas chromatographic injector and column

Directory of Open Access Journals (Sweden)

Gevany Paulino de Pinho

2012-01-01

Full Text Available Components in complex matrices can cause variations in chromatographic response during analysis of pesticides by gas chromatography. These variations are related to the competition between analytes and matrix components for adsorption sites in the chromatographic system. The capacity of the pesticides chlorpyrifos and deltamethrin to be adsorbed in the injector and chromatographic column was evaluated by constructing three isotherms and changing the column heating rate to 10 and 30 ºC min-1. By using ANCOVA to compare the slope of calibration graphs, results showed that the higher the injector temperature (310 ºC the lower the pesticide adsorption. Also, deltamethrin influenced the adsorption of chlorpyrifos on the column chromatographic.

Preparation of open tubular capillary columns by in situ ring-opening polymerization and their applications in cLC-MS/MS analysis of tryptic digest.

Science.gov (United States)

Wang, Hongwei; Yao, Yating; Li, Ya; Ma, Shujuan; Peng, Xiaojun; Ou, Junjie; Ye, Mingliang

2017-08-01

An open tubular (OT) column (25 μm i.d.) was prepared by in situ ring-opening polymerization of octaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes (POSS-epoxy) with 4-aminophenyl disulfide (APDS) in a binary porogenic system of ethanol/H 2 O. It was found that porogenic composition played an important role in the formation of OT stationary phases. The ratio of ethanol/H 2 O at 6/1 (v/v) would lead to the fabrication of hybrid monoliths, while the ratio of ethanol/H 2 O at 13/1 (v/v) would result in the synthesis of OT phases. In addition, the effects of precursor content and reaction duration on the thickness of OT stationary phases were investigated. Either lower precursor content or shorter reaction duration would produce thinner layer of OT column. The repeatability of OT columns was evaluated through relative standard deviation (RSD%) with benzene as the analyte. The run-to-run, column-to-column and batch-to-batch repeatabilities were 1.7%, 4.8% and 5.6%, respectively, exhibiting satisfactory repeatability of the OT column. Then tryptic digest of mouse liver proteins was used to evaluate the performance of the resulting OT columns (25 μm i.d. × 2.5 m in length) by cLC-MS/MS analysis, demonstrating their potential in proteome analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal Modeling Analysis Of CST Media In The Small Column Ion Exchange Project

International Nuclear Information System (INIS)

Lee, S.

2010-01-01

immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed (a primary heat transfer mechanism), inadvertent column drainage, and loss of active cooling in the column. The calculation results showed that for a wet CST column with active cooling through one central and four outer tubes and 35 C ambient external air, the peak temperature for the fully-loaded column is about 63 C under the loss of fluid flow accident, which is well below the supernate boiling point. The peak temperature for the naturally-cooled (no active, engineered cooling) wet column is 156 C under fully-loaded conditions, exceeding the 130 C boiling point. Under these conditions, supernate boiling would maintain the column temperature near 130 C until all supernate was vaporized. Without active engineered cooling and assuming a dry column suspended in unventilated air at 35 C, the fully-loaded column is expected to rise to a maximum of about 258 C due to the combined loss-of coolant and column drainage accidents. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. Results for the in-tank modeling calculations clearly indicate that when realistic heat transfer boundary conditions are imposed on the bottom surface of the tank wall, as much as 450 gallons of ground CST (a volume equivalent to two ion exchange processing cycles) in an ideal hemispherical shape (the most conservative geometry) can be placed in the tank without exceeding the 100 C wall temperature limit. Furthermore, in the case of an evenly-distributed flat layer, the tank wall reaches the temperature limit after the ground CST material reaches a height of approximately 8 inches.

Performance and microbial community composition dynamics of aerobic granular sludge from sequencing batch bubble column reactors operated at 20 degrees C, 30 degrees C, and 35 degrees C.

Science.gov (United States)

Ebrahimi, Sirous; Gabus, Sébastien; Rohrbach-Brandt, Emmanuelle; Hosseini, Maryam; Rossi, Pierre; Maillard, Julien; Holliger, Christof

2010-07-01

Two bubble column sequencing batch reactors fed with an artificial wastewater were operated at 20 degrees C, 30 degrees C, and 35 degrees C. In a first stage, stable granules were obtained at 20 degrees C, whereas fluffy structures were observed at 30 degrees C. Molecular analysis revealed high abundance of the operational taxonomic unit 208 (OTU 208) affiliating with filamentous bacteria Leptothrix spp. at 30 degrees C, an OTU much less abundant at 20 degrees C. The granular sludge obtained at 20 degrees C was used for the second stage during which one reactor was maintained at 20 degrees C and the second operated at 30 degrees C and 35 degrees C after prior gradual increase of temperature. Aerobic granular sludge with similar physical properties developed in both reactors but it had different nutrient elimination performances and microbial communities. At 20 degrees C, acetate was consumed during anaerobic feeding, and biological phosphorous removal was observed when Rhodocyclaceae-affiliating OTU 214 was present. At 30 degrees C and 35 degrees C, acetate was mainly consumed during aeration and phosphorous removal was insignificant. OTU 214 was almost absent but the Gammaproteobacteria-affiliating OTU 239 was more abundant than at 20 degrees C. Aerobic granular sludge at all temperatures contained abundantly the OTUs 224 and 289 affiliating with Sphingomonadaceae indicating that this bacterial family played an important role in maintaining stable granular structures.

IMPLEMENTATION OF COLUMN-ORIENTED DATABASE IN POSTGRESQL FOR OPTIMIZATION OF READ-ONLY QUERIES

OpenAIRE

Aditi D. Andurkar

2012-01-01

The era of column-oriented database systems has truly begun with open source database systems like C-Store, MonetDb, LucidDb and commercial ones like Vertica. Column-oriented database stores data column-by-column which means it stores information of single attribute collectively. The need for Column-oriented database arose from the need of business intelligence for efficient decision making where traditional row-oriented database gives poor performance. PostgreSql is an open so...

Validation of an HPLC method for determination of chemical purity of [18F]fluoromisonidazole ([18F]FMISO)

International Nuclear Information System (INIS)

Nascimento, Natalia C.E.S.; Oliveira, Mércia L.; Lima, Fernando R.A.; Silveira, Marina B.; Ferreira, Soraya Z.; Silva, Juliana B.

2017-01-01

[ 18 F]Fluoromisonidazole ([ 18 F]FMISO) is a nitroimidazole derivative labelled with fluorine-18 that selectively binds to hypoxic cells. It has been shown to be a suitable PET tracer for imaging hypoxia in tumors as well as in noncancerous tissues. [ 18 F]FMISO was prepared using a TRACERlabMX FDG ® module (GE) with cassettes, software sequence and reagents kits from ABX. In this work, we aimed to develop and to validate a new high performance liquid chromatography (HPLC) method for determination of chemical purity of [ 18 F]FMISO. Analyses were performed with an Agilent chromatograph equipped with radioactivity and UV detectors. [ 18 F]FMISO and impurities were separated on a C18 column by gradient elution with water and acetonitrile. Selectivity, linearity, detection limit (DL), quantification limit (LQ), precision, accuracy and robustness were assessed to demonstrate that the HPLC method is adequate for its intended purpose. The HPLC method showed a good precision, as all RSD values were lower than 5%. Robustness was evaluated considering a variation on parameters such mobile phase gradient and flow rate. Results evidenced that the HPLC method is validated and is suitable for radiochemical purity evaluation of [ 18 F]FMISO, considering operational conditions of our laboratory. As an extension of this work, other analytical methods used for [ 18 F]FMISO quality control should be evaluated, in compliance with good manufacture practice. (author)

Contributions to reversed-phase column selectivity: III. Column hydrogen-bond basicity.

Science.gov (United States)

Carr, P W; Dolan, J W; Dorsey, J G; Snyder, L R; Kirkland, J J

2015-05-22

Column selectivity in reversed-phase chromatography (RPC) can be described in terms of the hydrophobic-subtraction model, which recognizes five solute-column interactions that together determine solute retention and column selectivity: hydrophobic, steric, hydrogen bonding of an acceptor solute (i.e., a hydrogen-bond base) by a stationary-phase donor group (i.e., a silanol), hydrogen bonding of a donor solute (e.g., a carboxylic acid) by a stationary-phase acceptor group, and ionic. Of these five interactions, hydrogen bonding between donor solutes (acids) and stationary-phase acceptor groups is the least well understood; the present study aims at resolving this uncertainty, so far as possible. Previous work suggests that there are three distinct stationary-phase sites for hydrogen-bond interaction with carboxylic acids, which we will refer to as column basicity I, II, and III. All RPC columns exhibit a selective retention of carboxylic acids (column basicity I) in varying degree. This now appears to involve an interaction of the solute with a pair of vicinal silanols in the stationary phase. For some type-A columns, an additional basic site (column basicity II) is similar to that for column basicity I in primarily affecting the retention of carboxylic acids. The latter site appears to be associated with metal contamination of the silica. Finally, for embedded-polar-group (EPG) columns, the polar group can serve as a proton acceptor (column basicity III) for acids, phenols, and other donor solutes. Copyright © 2015 Elsevier B.V. All rights reserved.

Column: Every Last Byte

Directory of Open Access Journals (Sweden)

Simson Garfinkel

2011-06-01

Full Text Available Inheritance powder is the name that was given to poisons, especially arsenic, that were commonly used in the 17th and early 18th centuries to hasten the death of the elderly. For most of the 17th century, arsenic was deadly but undetectable, making it nearly impossible to prove that someone had been poisoned. The first arsenic test produced a gas—hardly something that a scientist could show to a judge. Faced with a growing epidemic of poisonings, doctors and chemists spent decades searching for something better.(see PDF for full column

Precast Concrete Beam-to-Column Connection System

OpenAIRE

ECT Team, Purdue

2007-01-01

Compared to conventional concrete constructions, precast concrete is a better option which is more cost-effective for production, transport, and erection when columns and beams can be fabricated independently. The BSF connection is a hidden beam and connection for gravity loads that eliminates the need for projecting column corbels. From a steel box cast into the concrete beam end, a sliding steel “knife” plate with a safety notch is cantilevered into a steel box that has been cast into the c...

Impact Analysis of Reinforced Concrete Columns with Side Openings Subjected to Eccentric Axial Loads

Directory of Open Access Journals (Sweden)

Nazar Kamil Ali

2015-02-01

Full Text Available In this research the behavior of reinforced concrete columns with large side openings under impact loads was studied. The overall cross sectional dimensions of the column specimens used in this research were (500*1400 mm with total height of (14000 mm. The dimensions of side openings were (600*2000 mm. The column was reinforced with (20 mm diameter in longitudinal direction, while (12 mm ties were used in the transverse direction. The effect of eccentric impact loads on the horizontal and vertical displacement for this column was studied. Nonlinear finite element analysis has been carried out using ready computer finite element package (ANSYS to simulate the behavior of the reinforced concrete column with large side openings. Two load cases were considered in this investigation (C1, C2 with three different load values for each case. In the first case (C1 the loads was applied to one side of the column and in the second case (C2 the loads was applied to both sides. An Equilateral triangular load-time function was used for simulation the impact load results from gantry cranes supported by the column with total time duration (0.1 sec. In order to verify the analysis method, as no experimental data exist for comparing the obtained results, another analysis is made for tested conventional column under impact load at mid-height and good agreement has been obtained. For the above mentioned column, the maximum displacements were (33.3, 22.2 mm in the horizontal and longitudinal direction respectively, location of the maximum horizontal displacement was at the crown of the column. By comparing the results of the first loading case with the second one it is shown that in the horizontal direction, maximum displacement increases by (139%, (208%, and (147% respectively, also the maximum vertical displacement increases by (150%, (172%, and (172% respectively.

The Fire Resistance Performance of Recycled Aggregate Concrete Columns with Different Concrete Compressive Strengths.

Science.gov (United States)

Dong, Hongying; Cao, Wanlin; Bian, Jianhui; Zhang, Jianwei

2014-12-08

In order to ascertain the fire resistance performance of recycled aggregate concrete (RAC) components with different concrete compressive strengths, four full-scaled concrete columns were designed and tested under high temperature. Two of the four specimens were constructed by normal concrete with compressive strength ratings of C20 and C30, respectively, while the others were made from recycled coarse aggregate (RCA) concrete of C30 and C40, respectively. Identical constant axial forces were applied to specimens while being subjected to simulated building fire conditions in a laboratory furnace. Several parameters from the experimental results were comparatively analyzed, including the temperature change, vertical displacement, lateral deflection, fire endurance, and failure characteristics of specimens. The temperature field of specimens was simulated with ABAQUS Software (ABAQUS Inc., Provindence, RI, USA) and the results agreed quite well with those from the experiments. Results show that the rate of heat transfer from the surface to the interior of the column increases with the increase of the concrete's compressive strength for both RAC columns and normal concrete columns. Under the same initial axial force ratio, for columns with the same cross section, those with lower concrete compressive strengths demonstrate better fire resistance performance. The fire resistance performance of RAC columns is better than that of normal concrete columns, with the same concrete compressive strength.

The Fire Resistance Performance of Recycled Aggregate Concrete Columns with Different Concrete Compressive Strengths

Science.gov (United States)

Dong, Hongying; Cao, Wanlin; Bian, Jianhui; Zhang, Jianwei

2014-01-01

In order to ascertain the fire resistance performance of recycled aggregate concrete (RAC) components with different concrete compressive strengths, four full-scaled concrete columns were designed and tested under high temperature. Two of the four specimens were constructed by normal concrete with compressive strength ratings of C20 and C30, respectively, while the others were made from recycled coarse aggregate (RCA) concrete of C30 and C40, respectively. Identical constant axial forces were applied to specimens while being subjected to simulated building fire conditions in a laboratory furnace. Several parameters from the experimental results were comparatively analyzed, including the temperature change, vertical displacement, lateral deflection, fire endurance, and failure characteristics of specimens. The temperature field of specimens was simulated with ABAQUS Software (ABAQUS Inc., Provindence, RI, USA) and the results agreed quite well with those from the experiments. Results show that the rate of heat transfer from the surface to the interior of the column increases with the increase of the concrete’s compressive strength for both RAC columns and normal concrete columns. Under the same initial axial force ratio, for columns with the same cross section, those with lower concrete compressive strengths demonstrate better fire resistance performance. The fire resistance performance of RAC columns is better than that of normal concrete columns, with the same concrete compressive strength. PMID:28788279

JCE Feature Columns

Science.gov (United States)

Holmes, Jon L.

1999-05-01

The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

Compósitos SiCf /SiC utilizados em sistemas de proteção térmica SiCf /SiC composites for thermal protection systems

Directory of Open Access Journals (Sweden)

M. Florian

2005-09-01

Full Text Available Compósitos de carbeto de silício (SiC reforçado com fibras de carbeto de silício (SiCf são materiais candidatos em potencial para utilização em sistemas de proteção térmica em altas temperaturas devido principalmente à boa condutividade térmica na direção da fibra e muito baixa condutividade térmica na direção transversal à fibra, alta dureza, estabilidade térmica e à corrosão por oxidação. O compósito SiCf/SiC possui uma matriz de SiC reforçada com fibras contínuas policristalinas de SiC e é obtido por reações de conversão em altas temperaturas e atmosfera controlada, utilizando o compósito carbono/carbono como precursor. O processo de Reação Química em Vapor (CVR foi utilizado para a fabricação de compósitos SiCf/SiC com alta pureza na fase de SiC-beta. O compósito precursor de carbono/carbono foi fabricado com fibra de carbono não estabilizada e matriz carbonosa derivada da resina fenólica na forma de carbono isotrópico. O compósito convertido exibiu uma densidade de 1,75 g/cm³, com 40% de porosidade aberta e resistência à flexão de 80 MPa medida por ensaio flexão em 4 pontos. A área especifica medida pela técnica de BET é dependente da temperatura de conversão e das condições inicias do precursor de carbono, podendo chegar a 18 m²/g.Composites based on silicon carbide are potential candidate materials for thermal protection systems mainly due to its good thermal conductivity in fiber direction and very low transversal thermal conductivity, high hardness, corrosion and thermal resistance. SiCf/SiC composite presents a SiC matrix reinforced with SiC polycrystalline continuous fibers. The composite was obtained by conversion reactions at high temperature and controlled atmosphere from a carbon/carbon composite precursor. The CVR process was used to fabricate SiC /SiC composite with crystalline high-purity beta-SiC from a carbon-carbon precursor fabricated with non-stabilized carbon fiber and

Silicon leaf application and physiological quality of white oat and wheat seedsAplicação foliar de silício e qualidade fisiológica de sementes de aveia-branca e trigo

Directory of Open Access Journals (Sweden)

Mariane Sayuri Ishizuka

2012-10-01

Full Text Available Plant nutrition can positively influence quality of seeds by improving plant tolerance to adverse climate. In this context, silicon is currently considered a micronutrient and it is beneficial to plant growth, especially Poaceaes such as white oat and wheat, thereby improving physiological quality of seeds. This study had the objective of evaluating the effects of silicon leaf application on plant tillering, silicon levels and physiological quality of white oat and wheat seeds besides establishing correlations between them. Two experiments were carried out in winter with white oat and wheat. The experimental design was the completely randomized block with eight replications. Treatments consisted of foliar application of silicon (0.8% of soluble silicon, as stabilized orthosilicic acid and a control (with no application. Silicon levels in leaves were determined at flowering whereas the number of plants and panicles/spikes per area was counted right before harvest. Seed quality was evaluated right after harvest through mass, germination and vigor tests. Data was submitted to variance analysis and means were compared by the Tukey test at a probability level of 5%. Person’s linear correlation test was performed among silicon level in plants, tillering and seed quality data. Silicon leaf application increases root and total length of white oat seedlings as an effect of higher Si level in leaves. Silicon leaf application increases mass of wheat seeds without affecting germination or vigor. A nutrição das plantas pode influenciar positivamente a qualidade das sementes por proporcionar maior tolerância às adversidades climáticas. Neste contexto, o silício é atualmente considerado um micronutriente e tem efeito benéfico no crescimento das plantas, especialmente Poaceaes como aveia-branca e trigo, consequentemente melhorando a qualidade fisiológica das sementes. Este estudo objetivou avaliar os efeitos da aplicação foliar de silício no

Revised Thermal Analysis of LANL Ion Exchange Column

Energy Technology Data Exchange (ETDEWEB)

Laurinat, J

2006-04-11

This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation of pendant ethyl benzene groups at the termini of the resin polymer chains by nitric acid. The ethyl benzene groups are converted to benzoic acid moities. The resin can be treated to permanently remove the LTE by heating a resin suspension in 8M HNO{sub 3} for 30-45 minutes. No degradation of the resin performance is observed after the LTE removal treatment. In fact, heating the resin in boiling ({approx}115-120 C) 12 M HNO{sub 3} for 3 hr displays thermal stability analogous to resin that has been treated to remove the LTE. The analysis is based on a previous study of the SRS Frames Waste Recovery (FWR) column, performed in support of the Pu-238 production campaign for NASA's Cassini mission. In that study, temperature transients

Determination of organic phosphorous in oil production waters by ICP-AES and ICP-MS after preconcentration on silica immobilized C{sub 18}; Determinacao de fosforo organico em aguas de producao petrolifera por ICP-AES e ICP-MS apos pre-concentracao em coluna de silica C{sub 18}

Energy Technology Data Exchange (ETDEWEB)

Rocha, Anderson Araujo; Miekeley, Norbert; Silveira, Carmem Lucia Porto da [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Quimica; Bezerra, Maria Carmem Moreira [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

1998-10-01

Results on the optimization analytical methods for the determination of phosphorous in phosphino-poly carboxylate (PPCA), used frequently as scale inhibitor during oil production, by ICP-AES and ICP-MS are presented. Due to the complex matrix of production waters (brines) and their high concentration in inorganic phosphorus, the separation of organic phosphorus prior to its determination in necessary. In this work, mini columns of silica immobilized C{sub 18} were used. Optimization of the separation step resulted in the following working conditions: (1) pre washing of the column with methanol (80% v/v); (2) use of a flow rate of 5 m L/min and 10 m L/min, respectively, for the preconditioning step and for percolation of the water sample; (3) final elution of organic phosphorus with 7 m L of buffer of H{sub 3} BO{sub 3}/Na OH (0.05 M, p H 9) with a flow rate of 1 m L/min. Sample detection limits (3{sigma}) for different combinations of nebulizers and spectrometric methods, based on 10 m L water aliquots, are: ICP-AES-Cross flow (47 mg/L) and Ultrasonic (18 {mu}g/L); ICP-M S-Cross flow (1.2 {mu}g/L) and Ultrasonic (0.5 {mu}g/L). Typical recoveries of organic phosphorous are between 90 and 95% and the repeatability of the whole procedure is better than 10%. The developed methodology was applied successfully to samples from the oil-well N A 46, platform PNA 2, Campos basin, Brazil. Assessment of the PPCA inhibitor was possible at lower concentrations than achieved by current analytical methods., resulting in benefits such as reduced cost of chemicals, postponed oil production and lower environmental impacts. (author)

Rapid determination of amino acids in biological samples using a monolithic silica column.

Science.gov (United States)

Song, Yanting; Funatsu, Takashi; Tsunoda, Makoto

2012-05-01

A high-performance liquid chromatography method in which fluorescence detection is used for the simultaneous determination of 21 amino acids is proposed. Amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and then separated on a monolithic silica column (MonoClad C18-HS, 150 mm×3 mm i.d.). A mixture of 25 mM citrate buffer containing 25 mM sodium perchlorate (pH 5.5) and acetonitrile was used as the mobile phase. We found that the most significant factor in the separation was temperature, and a linear temperature gradient from 30 to 49°C was used to control the column temperature. The limits of detection and quantification for all amino acids ranged from 3.2 to 57.2 fmol and 10.8 to 191 fmol, respectively. The calibration curves for the NBD-amino acid had good linearity within the range of 40 fmol to 40 pmol when 6-aminocaproic acid was used as an internal standard. Using only conventional instruments, the 21 amino acids could be analyzed within 10 min. This method was found to be suitable for the quantification of the contents of amino acids in mouse plasma and adrenal gland samples.

LA RÉCENTE DINAMIQUE GEOECONOMIQUE DE LA CHAINE DE PRODUCTION DE SOJA AU BRÉSIL ET DANS LE MONDE

Directory of Open Access Journals (Sweden)

Roberto César Cunha

2015-07-01

Full Text Available L’agro-industrie de soja consolidé, au Brésil, à partir des années 1980, se constitue comme une des principales chaînes productives de la structure agricole brésilienne, offrant des grains, son de blé e d’huiles pour l’approvisionnement du marché interne et externe. Dans la récolte 2013/2014, la production a atteint plus de 87 millions de tonnes cultivées en trente millions hectares, qui représentent juste 8,9% dans la domaine cultivées au Bresil. Les exportations de soja em grains couvrent 42 millions de tonnes dans l’année agricole 2012/2013, l’équivalent a U$ 22,8 milliards. Les segments de grains, huile e son de blé ont gagné U$ S 31 milliards, qui signifie 12,8 % de toutes les ventes externes du Brésil et 31 % des exportations de l’agro-industrie brésiliens. Ce texte a pour objectif d’identifier les facteurs responsables de la recente dinamique de cette chaîne productive dans le territoire bresilien et son insertion au marché mondial.

Development of a new distillation unit combined with compressed heat pump (heat integrated distillation column (HIDiC)) (eco-energy city project)

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Toshinari; Aso, Kazumasa [Kimura Chemical Plants Co., Ltd., Amagasaki City, Hyogo (Japan); Takamatsu, Takeichiro [Research Inst. of Industrial Technology, Suita-City, Osaka (Japan); Nakaiwa, Masaru [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan); Noda, Hideo; Kuratani, Nobuyuki [Kansai Chemical Engineearing Co., Ltd., Amagasaki-city, Hyogo (Japan); Yoshida, Kazufumi [Maruzen Petrochemical Co., Ltd., 25-10, Tokyo (Japan)

1999-07-01

To reduce the irreversible loss the Heat Integrated Distillation Column (HIDiC) is proposed by application of heat-pump technology. (Distillation column, which is an energy consuming separation unit, has been widely used in oil refinery and the other chemical-related plants. The reason why it is a major energy consumer is that a large amount of irreversible loss occurs in heat transfer within the process.) In this paper, current results on the study of HIDiC in both simulations and experiments are shown. HIDiC must be operated at a higher pressure in the rectifying section so as to make its temperature higher than that of the stripping section which stands parallel with the rectifying section. That makes heat transfer from the rectifying section to the stripping section. Because of vaporization in the stripping section and condensation in the rectifying section, the energy for the reboiler can be saved. The degree of energy saving can be expected to be much more than 30%, although the exact value depends on the characteristics of mixture to be separated. (The degree of energy saving is higher than the above, if the exhaust vapor from the HIDiC is used to heat the feed or the other processes.) To save energy by the HIDiC, high separation performances and heat transfer capabilities are required. It has been found out that the HIDiC, whose shape is like vertical shell and tube heat exchanger was enough to be practical use of the HIDiC from the static design principle points of view. (orig.)

Automated synthesis of n.c.a. [18F]FDOPA via nucleophilic aromatic substitution with [18F]fluoride

International Nuclear Information System (INIS)

Shen, B.; Ehrlichmann, W.; Uebele, M.; Machulla, H.-J.; Reischl, G.

2009-01-01

An improved, automated synthesis of [ 18 F]FDOPA including four synthetic steps (fluorination, reductive iodination, alkylation and hydrolysis) is reported with each step optimized individually. In a home-made automatic synthesizer, 9064±3076 MBq of [ 18 F]FDOPA were produced within 120 min from EOB (n=5). Radiochemical purity and enantiomeric excess were both ≥95%. Specific activity was ca. 50 GBq/μmol at EOS. This automatically operable synthesis is well suited for the multi-patient-dose routine production of n.c.a. [ 18 F]FDOPA.

Column Chromatography Of Co(II), Zn(II) And Eu(III) Using Pistachio Shell And Different Mobile Phases

Energy Technology Data Exchange (ETDEWEB)

Abdel-Fattah, A A [Nuclear Chemistry Department, Radioisotopes Production Division, Hot Laboratories Centre, Atomic Energy Authority, Cairo (Egypt)

2009-07-01

Pistachio shell particles (0.5-1 mm) have been applied as the stationary phase for studying the column chromatography of Co(II), Zn(II) and Eu(III) at room temperature; 26{sup +}-{sup 1}oC. This solid sorbent has been characterized by thermogravimetric analysis, infra-red spectroscopy and X-ray diffraction. Its surface area and percent of swelling have been also determined. Different eluting agents have been used for eluting the sorbed elements. The elution curves have been done from which the distribution coefficients (K{sub d}), number of theoretical plates (N) and heights equivalent to theoretical plates (H) have been determined. Column performance studies have been conducted for a representative system under certain experimented conditions and Van Deemter equation has been applied. Thermodynamic studies have been applied and thermodynamic functions ( {delta}G{sup 0} ,{delta}H{sup 0} and{delta} S{sup 0}) have been calculated for this representative system by determining K{sub d} at three different room temperatures (18, 26 and 37{sup +}-{sup 1o}C)

Column Liquid Chromatography.

Science.gov (United States)

Majors, Ronald E.; And Others

1984-01-01

Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

Metodología para el cálculo del nivel integrado de seguridad (sil, aplicada al caso: estudio de un sistema instrumentado de seguridad (sis de nivel en calderas industriales de alta presión

Directory of Open Access Journals (Sweden)

Walter Gastelbondo-Barragan

2008-01-01

Full Text Available In this paper develops the methodology for calculating the Safety Integrity Level of level at a boiler of industrial high pressure. The Safety Integrity Level (SIL, is derived from reliability dynamics representation of each of the elements that are part of safety instrumented function, through which is obtained the Probability of Failure on Demand, being this the basic parameter for determining Safety Integrity Level of a Safety Instrumented System.

Determination of Imidacloprid and metabolites by liquid chromatography with an electrochemical detector and post column photochemical reactor

Energy Technology Data Exchange (ETDEWEB)

Rancan, M. [Consiglio per la Ricerca e la Sperimentazione in Agricoltura (CRA), Istituto Nazionale di Apicoltura, Via di Saliceto 80, I-40128 Bologna (Italy)]. E-mail: mrancan@inapicoltura.org; Sabatini, A.G. [Consiglio per la Ricerca e la Sperimentazione in Agricoltura (CRA), Istituto Nazionale di Apicoltura, Via di Saliceto 80, I-40128 Bologna (Italy); Achilli, G. [Euroservice s.r.l., Piazza Maggiolini 3A, I-20015 Parabiago, Milan (Italy); Galletti, G.C. [Dipartimento di Chimica ' G.Ciamician' , University of Bologna, Via F. Selmi 2, I-40126 Bologna (Italy)

2006-01-05

A procedure for the determination of Imidacloprid and its main metabolites was set up by means of liquid chromatography with an electrochemical detector and post-column photochemical reactor (LC-h{nu}-ED). Sample clean-up was developed for bees, filter paper and maize leaves. Chromatographic conditions were based on a reversed-phase C-18 column operated by phosphate buffer 50 mM/CH{sub 3}CN (80/20, v/v) at pH 2.9. Detection of Imidacloprid and its metabolites was performed at a potential of 800 mV after photoactivation at 254 nm. Compared to conventional techniques such as gas chromatography/mass spectrometry (GC/MS) or LC coupled to other detectors, the present method allows simultaneous trace-level determination of both Imidacloprid (0.6 ng ml{sup -1}) and its main metabolites (2.4 ng ml{sup -1})

Determination of Imidacloprid and metabolites by liquid chromatography with an electrochemical detector and post column photochemical reactor

International Nuclear Information System (INIS)

Rancan, M.; Sabatini, A.G.; Achilli, G.; Galletti, G.C.

2006-01-01

A procedure for the determination of Imidacloprid and its main metabolites was set up by means of liquid chromatography with an electrochemical detector and post-column photochemical reactor (LC-hν-ED). Sample clean-up was developed for bees, filter paper and maize leaves. Chromatographic conditions were based on a reversed-phase C-18 column operated by phosphate buffer 50 mM/CH 3 CN (80/20, v/v) at pH 2.9. Detection of Imidacloprid and its metabolites was performed at a potential of 800 mV after photoactivation at 254 nm. Compared to conventional techniques such as gas chromatography/mass spectrometry (GC/MS) or LC coupled to other detectors, the present method allows simultaneous trace-level determination of both Imidacloprid (0.6 ng ml -1 ) and its main metabolites (2.4 ng ml -1 )

Dicty_cDB: FC-AI18 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available FC (Link to library) FC-AI18 (Link to dictyBase) - - - Contig-U15590-1 FC-AI18P (Li...nk to Original site) FC-AI18F 621 FC-AI18Z 703 FC-AI18P 1324 - - Show FC-AI18 Library FC (Link to library) Clone ID FC-AI...nal site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/FC/FC-AI/FC-AI18Q.Seq.d/ Representative seq. ID FC-AI...18P (Link to Original site) Representative DNA sequence >FC-AI18 (FC-AI18Q) /CSM/FC/FC-AI/FC-AI...AVWPLIPGYERA DGEKQYPVAAMLCNFTKPTPTTPSLLTHDEVVTFFHEFGHVMHNMSTKVHYSMFSGTSVE RDFVECPSQLFEFWCWNKDVLVNKLSGHXKDHSKKLPTDLVERMIAAKNLNVAI

[Determination of triterpenoic acids in fruits of Ziziphus jujuba using HPLC-MS with polymeric ODS column].

Science.gov (United States)

Zhang, Yong; Zhou, An; Xie, Xiao-Mei

2013-03-01

A simple and sensitive method has been developed to simultaneously determine betunilic acid, oleanolic acid and ursolic acid in the fruits of Ziziphus jujuba from different regions by HPLC-MS. This HPLC assay was performed on PAH polymeric C18 bonded stationary phase column with mobile phase contained acetonitrile-water (90: 10) and with negative ESI detection mode. The developed approach was characterized by short time consumption for chromatographic separation, high sensitivity and good reliability so as to meet the requirements for rapid analysis of large-batch fruits of Z. jujuba from different habitats.

18 CFR 1c.1 - Prohibition of natural gas market manipulation.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Prohibition of natural gas market manipulation. 1c.1 Section 1c.1 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES PROHIBITION OF ENERGY MARKET MANIPULATION § 1c.1...

18 CFR 1c.2 - Prohibition of electric energy market manipulation.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Prohibition of electric energy market manipulation. 1c.2 Section 1c.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES PROHIBITION OF ENERGY MARKET MANIPULATION § 1c.2...

Supervisory Model Predictive Control of the Heat Integrated Distillation Column

DEFF Research Database (Denmark)

Meyer, Kristian; Bisgaard, Thomas; Huusom, Jakob Kjøbsted

2017-01-01

This paper benchmarks a centralized control system based on model predictive control for the operation of the heat integrated distillation column (HIDiC) against a fully decentralized control system using the most complete column model currently available in the literature. The centralized control...... system outperforms the decentralized system, because it handles the interactions in the HIDiC process better. The integral absolute error (IAE) is reduced by a factor of 2 and a factor of 4 for control of the top and bottoms compositions, respectively....

28 CFR 45.3 - Disciplinary proceedings under 18 U.S.C. 207(j).

Science.gov (United States)

2010-07-01

.... 207(j). 45.3 Section 45.3 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.3 Disciplinary proceedings under 18 U.S.C. 207(j). (a) Upon a determination by the Assistant... authorized by 18 U.S.C. 207(j), or subjected to other appropriate disciplinary action under that statute. The...

Photoluminescence emission at room temperature in zinc oxide nano-columns

International Nuclear Information System (INIS)

Rocha, L.S.R.; Deus, R.C.; Foschini, C.R.; Moura, F.; Garcia, F. Gonzalez; Simões, A.Z.

2014-01-01

Highlights: • ZnO nanoparticles were obtained by microwave-hydrothermal method. • X-ray diffraction reveals a hexagonal structure. • Photoluminescence emission evidenced two absorption peaks, at around 480 nm and 590 nm wavelengths. - Abstract: Hydrothermal microwave method (HTMW) was used to synthesize crystalline zinc oxide (ZnO) nano-columns at the temperature of 120 °C with a soaking time of 8 min. ZnO nano-columns were characterized by using X-ray analyses (XRD), infrared spectroscopy (FT-IR), thermogravimetric analyses (TG-DTA), field emission gun and transmission electron microscopy (FEG-SEM and TEM) and photoluminescence properties (PL). XRD results indicated that the ZnO nano-columns are free of any impurity phase and crystallize in the hexagonal structure. Typical FT-IR spectra for ZnO nano-columns presented well defined bands, indicating a substantial short-range order in the system. PL spectra consist of a broad band at 590 nm and narrow band at 480 nm corresponding to a near-band edge emission related to the recombination of excitons and level emission related to structural defects. These results show that the HTMW synthesis route is rapid, cost effective, and could be used as an alternative to obtain ZnO nano-columns in the temperature of 120 °C for 8 min

Photoluminescence emission at room temperature in zinc oxide nano-columns

Energy Technology Data Exchange (ETDEWEB)

Rocha, L.S.R.; Deus, R.C. [Universidade Estadual Paulista – Unesp, Faculdade de Engenharia de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, Bairro Portal das Colinas, CEP 12516-410 Guaratinguetá, SP (Brazil); Foschini, C.R. [Universidade Estadual Paulista – Unesp, Instituto de Química, Laboratório Interdisciplinar em Cerâmica (LIEC), Rua Professor Francisco Degni s/n, CEP 14800-90 Araraquara, SP (Brazil); Moura, F.; Garcia, F. Gonzalez [Universidade Federal de Itajubá – Unifei, Campus Itabira, Rua São Paulo, 377, Bairro Amazonas, CEP 35900-37 Itabira, MG (Brazil); Simões, A.Z., E-mail: alezipo@yahoo.com [Universidade Estadual Paulista – Unesp, Faculdade de Engenharia de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, Bairro Portal das Colinas, CEP 12516-410 Guaratinguetá, SP (Brazil)

2014-02-01

Highlights: • ZnO nanoparticles were obtained by microwave-hydrothermal method. • X-ray diffraction reveals a hexagonal structure. • Photoluminescence emission evidenced two absorption peaks, at around 480 nm and 590 nm wavelengths. - Abstract: Hydrothermal microwave method (HTMW) was used to synthesize crystalline zinc oxide (ZnO) nano-columns at the temperature of 120 °C with a soaking time of 8 min. ZnO nano-columns were characterized by using X-ray analyses (XRD), infrared spectroscopy (FT-IR), thermogravimetric analyses (TG-DTA), field emission gun and transmission electron microscopy (FEG-SEM and TEM) and photoluminescence properties (PL). XRD results indicated that the ZnO nano-columns are free of any impurity phase and crystallize in the hexagonal structure. Typical FT-IR spectra for ZnO nano-columns presented well defined bands, indicating a substantial short-range order in the system. PL spectra consist of a broad band at 590 nm and narrow band at 480 nm corresponding to a near-band edge emission related to the recombination of excitons and level emission related to structural defects. These results show that the HTMW synthesis route is rapid, cost effective, and could be used as an alternative to obtain ZnO nano-columns in the temperature of 120 °C for 8 min.

Quantification of [18F]FDOPA and [18F]-3-OMFD in pig serum - a new TLC method in comparison with HPLC

International Nuclear Information System (INIS)

Pawelke, B.; Fuechtner, F.; Bergmann, R.; Brust, P.

2002-01-01

A novel TLC method for convenient quantification of [ 18 F]FDOPA and [ 18 F]-3-OMFD in routine operation was developed and the results assessed in comparison with an HPLC analysis. The two methods were found to correlate well. [ 18 F]fluoride which resisted determination on HPLC RP-18 columns was also quantified by TLC. (orig.)

Hydrogen isotope exchange in metal hydride columns

International Nuclear Information System (INIS)

Wiswall, R.; Reilly, J.; Bloch, F.; Wirsing, E.

1977-01-01

Several metal hydrides were shown to act as chromatographic media for hydrogen isotopes. The procedure was to equilibrate a column of hydride with flowing hydrogen, inject a small quantity of tritium tracer, and observe its elution behavior. Characteristic retention times were found. From these and the extent of widening of the tritium band, the heights equivalent to a theoretical plate could be calculated. Values of around 1 cm were obtained. The following are the metals whose hydrides were studied, together with the temperature ranges in which chromatographic behavior was observed: vanadium, 0 to 70 0 C; zirconium, 500 to 600 0 C; LaNi 5 , -78 to +30 0 C; Mg 2 Ni, 300 to 375 0 C; palladium, 0 to 70 0 C. A dual-temperature isotope separation process based on hydride chromatography was demonstrated. In this, a column was caused to cycle between two temperatures while being supplied with a constant stream of tritium-traced hydrogen. Each half-cycle was continued until ''breakthrough,'' i.e., until the tritium concentration in the effluent was the same as that in the feed. Up to that point, the effluent was enriched or depleted in tritium, by up to 20%

A column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry method to determine anandamide and 2-arachidonoylglycerol in plasma samples.

Science.gov (United States)

Marchioni, Camila; de Souza, Israel Donizeti; Grecco, Caroline Fernandes; Crippa, José Alexandre; Tumas, Vitor; Queiroz, Maria Eugênia Costa

2017-05-01

This study reports a fast, sensitive, and selective column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the endocannabinoids (eCBs), anandamide (AEA), and 2-arachidonoylglycerol (2-AG) in plasma samples. This bidimensional system used a restricted access media column (RP-8 ADS, 25 mm × 4 mm × 25 μM) in the first dimension and a core-shell Kinetex C18 (100 mm × 2, 1.7 mm × 1 μM) column in the second dimension, followed by detection in a mass spectrometer triple quadrupole (multiple reactions monitoring mode) operating in the positive mode. RP-8 ADS was used for trace enrichment of eCBs (reverse phase partitioning) and macromolecular matrix size exclusion; the core-shell column was used for the chromatographic separation. The column switching UHPLC-MS/MS method presented a linear range spanning from 0.1 ng mL -1 (LOQ) to 6 ng mL -1 for AEA and from 0.04 ng mL -1 (LOQ) to 10 ng mL -1 for 2-AG. Excluding the LLOQ values, the precision assays provided coefficients of variation lower than 8% and accuracy with relative standard error values lower than 14%. Neither carryover nor matrix effects were detected. This high-throughput column switching method compared to conventional methods is time saving as it involves fewer steps, consumes less solvent, and presents lower LLOQ. The column switching UHPLC-MS/MS method was successfully applied to determine AEA and 2-AG in plasma samples obtained from Alzheimer's disease patients. Graphical abstract A column switching ultra high-performance liquid chromatography-tandem mass spectrometry method using RP-8 ADS column and core shell column to determine endocannabinoids in plasma samples.

O silêncio no cotidiano do adolescente com HIV/AIDS

Directory of Open Access Journals (Sweden)

Maria da Graça Corso da Motta

2013-06-01

Full Text Available Este estudo caracteriza-se por ser uma pesquisa qualitativa que objetivou desvelar a percepção e a vivência em relação ao tratamento antirretroviral do adolescente com síndrome da imunodeficiência adquirida. A pesquisa foi realizada em serviços de referência em dois municípios na região sul do Brasil. A produção dos dados foi desenvolvida com a dinâmica de criatividade e sensibilidade mapa falante, por cinco participantes. Foi aplicada a técnica de análise temática do conteúdo. Das produções artísticas e depoimentos emergiram o cotidiano do uso dos medicamentos e o silêncio do diagnóstico da doença e do tratamento que implicam o cuidado à saúde. Conclui-se que é necessário o envolvimento dos profissionais de saúde, possibilitando espaços para a família e promovendo diálogos desta com o adolescente, visando à adesão ao tratamento.

Aziridines in the synthesis of {sup 11}C- and {sup 18}F-labelled compounds

Energy Technology Data Exchange (ETDEWEB)

Gillings, N.M

1998-07-01

Racemic [4-{sup 11}C]aspartic acid, [4-{sup 11}C]asparagine and 2,4-diamino[4-{sup 11}C]butyric acid were synthesised by the ring-opening of an N-activated aziridine-2-carboxylate with [{sup 11}C]cyanide, followed by preparative HPLC and hydrolysis/reduction. These labelled amino acids arise from nucleophilic attack at the {beta}-carbon of the aziridine ring. A radioactive by-product of ca. 25% was attributed to the product of {alpha}-attack. Several N-activated 2-aryl aziridines were synthesised for the attempted synthesis of {beta}-[{sup 18}F] fluorophenylalanine and {beta}-[{sup 18}F]fluorodopa. Ring-opening with [{sup 18}F]fluoride showed no evidence of {beta}-fluorinated products and it is proposed that attack occurs exclusively at the {alpha}-carbon, giving the corresponding {alpha}-[{sup 18}F]fluoro-{beta}-amino acids. Further evidence for this was the reaction of the {beta}-unsubstituted N-activated aziridine-2-carboxylate with [{sup 18}F]fluoride. This reaction was totally regiospecific and afforded exclusively the {alpha}-substituted product, {alpha}-[{sup 18}F]fluoro-{beta}-alanine. Aziridine precursors were resolved by chiral HPLC. On labelling the chiral aziridines, however, racemic {sup 11}C- and {sup 18}F-labelled amino acids were obtained. This was attributed to racemisation of the initially formed ring-opened products. The use of [{sup 11}C]methyl lithium as a nucleophile for aziridine ring-opening was investigated. Reaction was expected to occur at low temperature, thus potentially avoiding racemisation. No products corresponding to aziridine ring-opening with [{sup 11}C]methyl lithium were, however, observed. A difluorinated analogue of amphetamine was synthesised by fluorination of an azirine (via an aziridine). This racemic compound was resolved as its chiral tartarate salts and subsequently labelled by methylation with [{sup 11}C]methyl iodide, giving the novel compound {beta}, {beta}-difluoro[N-methyl-{sup 11}C]methamphetamine in high

76 FR 68243 - Social Security Rulings, SSR 91-1c and SSR 66-18c; Rescission of Social Security Rulings (SSR) 66...

Science.gov (United States)

2011-11-03

..., Social Security Online, at http://www.socialsecurity.gov . SUPPLEMENTARY INFORMATION: SSRs make available... SOCIAL SECURITY ADMINISTRATION [Docket No. SSA-2011-0068] Social Security Rulings, SSR 91-1c and SSR 66-18c; Rescission of Social Security Rulings (SSR) 66-18c and SSR 91-1c AGENCY: Social Security...

A simple subcritical chromatographic test for an extended ODS high performance liquid chromatography column classification.

Science.gov (United States)

Lesellier, Eric; Tchapla, Alain

2005-12-23

This paper describes a new test designed in subcritical fluid chromatography (SFC) to compare the commercial C18 stationary phase properties. This test provides, from a single analysis of carotenoid pigments, the absolute hydrophobicity, the silanol activity and the steric separation factor of the ODS stationary phases. Both the choice of the analytical conditions and the validation of the information obtained from the chromatographic measurements are detailed. Correlations of the carotenoid test results with results obtained from other tests (Tanaka, Engelhard, Sander and Wise) performed both in SFC and HPLC are discussed. Two separation factors, calculated from the retention of carotenoid pigments used as probe, allowed to draw a first classification diagram. Columns, which present identical chromatographic behaviors are located in the same area on this diagram. This location can be related to the stationary phase properties: endcapping treatments, bonding density, linkage functionality, specific area or silica pore diameter. From the first classification, eight groups of columns are distinguished. One group of polymer coated silica, three groups of polymeric octadecyl phases, depending on the pore size and the endcapping treatment, and four groups of monomeric stationary phases. An additional classification of the four monomeric groups allows the comparison of these stationary phases inside each group by using the total hydrophobicity. One hundred and twenty-nine columns were analysed by this simple and rapid test, which allows a comparison of columns with the aim of helping along their choice in HPLC.

Espiritu Santo, Vanuatu Stable Isotope (delta 18O, delta 13C) Data for 1806 to 1979

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Site: Espiritu Santo Island, Vanuatu, 15S, 167E. 173 year record of d18O and d13C. Variable names: QSR Age, QSR 13C, QSR 18O, GRL Age, GRL Qtrly 13C, GRL Qtrly 18O,...

Simultaneous determination of kasugamycin and validamycin-A residues in cereals by consecutive solid-phase extraction combined with liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Zhang, Hong; Wang, Chenchen; Li, Huidong; Nie, Yan; Fang, Liping; Chen, Zilei

2018-03-01

Two polar aminoglycosides, kasugamycin and validamycin-A, were determined in cereals (brown rice, wheat and corn) by high-performance liquid chromatography-tandem mass spectrometry. The analytes were extracted from samples using methanol and water (70:30, v/v) at pH 5.5, purified using both a hydrophilic-hydrophobic-balanced cartridge and a strong cation-exchange cartridge, and then analysed using multiple reaction monitoring in positive electrospray ionisation mode with a special ReproSil 100 C 18 high-performance liquid chromatography column. This newly proposed method yielded good sensitivity and excellent chromatographic performance. The limits of quantification for kasugamycin and validamycin-A were 4.1 µg/kg and 1.0 µg/kg, respectively. The recoveries for both compounds at three fortification levels (4, 100 and 500 µg/kg for kasugamycin; 1, 10 and 100 µg/kg for validamycin-A) ranged from 75% to 110%, and the relative standard deviations were below 15%.

Evolution of the quality of the oil and the product in semi-industrial frying

Directory of Open Access Journals (Sweden)

Beatriz, M.

1994-06-01

Full Text Available Changes in the quality of two commercial brands of cooking oil were studied under the frying conditions traditionally used in the Portuguese hospitality trade. Three hundred rissoles were fried at a temperature of 160-170°C for 1 hour. Values of peroxide, p-anisidine, Totox, acidity and total polar compounds were determined. Isomeric cis and trans fatty acids were quantified using CP-Sil 88-packed capillary column via gas chromatography.

La evolución de la calidad de dos marcas comerciales de aceite comestible fue estudiada según la forma tradicional de fritura usada en el mercado portugués, por el cual trescientas empanadillas rellenas fueron fritas a temperatura de 160-170°C durante un período de una hora. Se determinaron los índices de peróxido , p-anisidina, Totox, acidez y compuestos polares totales. Los ácidos grasos isoméricos cis y trans fueron cuantificados por cromatografía gaseosa en columna capilar rellena con CP-Sil 88.

Solid immersion lenses for enhancing the optical resolution of thermal and electroluminescence mapping of GaN-on-SiC transistors

International Nuclear Information System (INIS)

Pomeroy, J. W.; Kuball, M.

2015-01-01

Solid immersion lenses (SILs) are shown to greatly enhance optical spatial resolution when measuring AlGaN/GaN High Electron Mobility Transistors (HEMTs), taking advantage of the high refractive index of the SiC substrates commonly used for these devices. Solid immersion lenses can be applied to techniques such as electroluminescence emission microscopy and Raman thermography, aiding the development device physics models. Focused ion beam milling is used to fabricate solid immersion lenses in SiC substrates with a numerical aperture of 1.3. A lateral spatial resolution of 300 nm is demonstrated at an emission wavelength of 700 nm, and an axial spatial resolution of 1.7 ± 0.3 μm at a laser wavelength of 532 nm is demonstrated; this is an improvement of 2.5× and 5×, respectively, when compared with a conventional 0.5 numerical aperture objective lens without a SIL. These results highlight the benefit of applying the solid immersion lenses technique to the optical characterization of GaN HEMTs. Further improvements may be gained through aberration compensation and increasing the SIL numerical aperture

The brassinosteroid receptor BRI1 can generate cGMP enabling cGMP-dependent downstream signaling

CSIR Research Space (South Africa)

Wheeler, J

2017-06-01

Full Text Available ) with the ll PickUp Injection mode using the loading pump at 15 ll min�1 flow rate for 3 min. Samples were then loaded on a RSLC, 75 lm 9 500 mm, nanoVi- per, C18, 2 lm, 100 �A column (Acclaim, PepMap) retrofitted to an EASY-spray source with a flow rate of 300... receptor BRI1 can generate cGMP enabling cGMP-dependent downstream signaling Janet I. Wheeler1,2,†, Aloysius Wong3,4, Claudius Marondedze3,5, Arnoud J. Groen5, Lusisizwe Kwezi1,6, Lubna Freihat1, Jignesh Vyas1, Misjudeen A. Raji7, Helen R. Irving1...

Separating Long-Lived Metal Ions from {sup 18}F During H{sub 2} {sup 18}O Recovery

Energy Technology Data Exchange (ETDEWEB)

Schueller, Michael John; Alexoff, David L.; Schlyer, David James [Medical Department, Brookhaven National Laboratory, 57 Cornell Street, Upton NY 11973 (United States)

2009-07-01

Cyclotron targets for the production of [{sup 18}F]fluoride usually use a thin metal window to contain the {sup 18}O enriched water during irradiation. This window is activated by the proton beam, and undesired radioisotopes can enter the target water. A pre-packaged strong anion exchange resin is commonly used for [{sup 18}O]-water recovery. A two-column method has been developed which delivers >95% of the [18F]fluoride for radiosynthesis while rejecting >99.9% of the contaminants. (author)

A green strategy for desorption of trihalomethanes adsorbed by humin and reuse of the fixed bed column.

Science.gov (United States)

Cunha, G C; Romão, L P C; Santos, M C; Costa, A S; Alexandre, M R

2012-03-30

The objective of the present work was to develop a thermal desorption method for the removal of trihalomethanes (THM) adsorbed by humin, followed by multiple recycling of the fixed bed column in order to avoid excessive consumption of materials and reduce operating costs. The results obtained for adsorption on a fixed bed column confirmed the effectiveness of humin as an adsorbent, extracting between 45.9% and 90.1% of the total THM (TTHM). In none of the tests was the column fully saturated after 10h. Experiments involving thermal desorption were used to evaluate the potential of the technique for column regeneration. The adsorptive capacity of the humin bed increased significantly (p<0.05) between the first and fifth desorption cycle, by 18.9%, 18.1%, 24.2%, 20.2% and 24.2% for CHBr(3), CHBr(2)Cl, CHBrCl(2), CHCl(3) and TTHM, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

Time-efficient and convenient synthesis of [18F]altanserin for human PET imaging by a new work-up procedure

International Nuclear Information System (INIS)

Massarweh, G.; Kovacevic, M.; Rosa-Neto, P.; Evans, A.C.; Diksic, M.; Schirrmacher, R.

2009-01-01

[ 18 F]Altanserin, an important PET radioligand for the in vivo imaging of the 5-HT 2A receptor, was synthesized from its precursor nitro-altanserin in DMF or DMSO at high temperatures of 150 deg. C in an overall radiochemical yield (EOB) of 23-25% after 75 min. A new solid phase work-up procedure involving the acidification of the crude reaction mixture and a C18-SepPak-solid phase separation preceded the final HPLC purification. This led to a significantly reduced synthesis time as a result of a stable and early elution from the HPLC column using improved HPLC conditions (MeOH/THF/NaOAc 0.05 N pH 5: 27/18/55, flow: 5 mL/min, Symetry Prep 7 μm C18 (Waters)). The synthesis was performed semi-automatically in a modified GE TracerLab synthesis module using an in-house-developed program. The synthesized [ 18 F]altanserin was used in our ongoing human and animal PET imaging studies.

Comparing monolithic and fused core HPLC columns for fast chromatographic analysis of fat-soluble vitamins.

Science.gov (United States)

Kurdi, Said El; Muaileq, Dina Abu; Alhazmi, Hassan A; Bratty, Mohammed Al; Deeb, Sami El

2017-06-27

HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs > 5) and precision (RSD ≤ 0.6 %). Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.

Preparation, isolation and identification of non-conjugated C18:2 fatty acid isomers.

Science.gov (United States)

Fardin-Kia, Ali Reza

2016-12-01

Non-conjugated geometric/positional isomers of linoleic acid (c9,c12-18:2) are often present in processed foods and oils. The following work presents a simple addition/elimination reaction for preparation of non-conjugated 18:2 fatty acid isomers. A mixture containing positional and geometric isomers of C18:2 fatty acids was produced by addition of hydrobromic acid to the fatty acid double bonds, followed by its elimination with a strong sterically hindered base. Pure 8,12-, 8,13-, 9,12-, and 9,13-18:2 fatty acid methyl esters were isolated from the synthetic mixture by a combination of sub-ambient RP-HPLC and Ag + -HPLC. The determination of the double bond position was achieved by GC-MS using picolinyl esters derivatives. The determination of the fatty acid double bond geometric configuration was obtained by partial hydrogenation of the isolated isomer with hydrazine, followed by the GC-FID analysis. Published by Elsevier Ireland Ltd.

Moessbauer study of C18N/Fe Langmuir-Blodgett layers

Energy Technology Data Exchange (ETDEWEB)

Kuzmann, Erno [Institute of Chemistry, Eoetvoes Lorand University (Hungary); Telegdi, Judit [Institute of Nanochemistry and Catalysis, Chemical Research Center, HAS (Hungary); Nemeth, Zoltan, E-mail: hentes@chem.elte.hu; Vertes, Attila [Institute of Chemistry, Eoetvoes Lorand University (Hungary); Nyikos, Lajos [Institute of Nanochemistry and Catalysis, Chemical Research Center, HAS (Hungary)

2012-03-15

Langmuir-Blodgett (LB) films of octadecanoyl hydroxamic acid (C18N) complexed with Fe{sup 3 + } ions have been prepared at various subphase pH values. The LB films consisting of different number of layers were investigated by {sup 57}Fe conversion electron Moessbauer spectroscopy (CEM) at room temperature. The CEM detector contained a piece of {alpha}-iron, enriched with {sup 57}Fe, using as an internal standard. The Moessbauer pattern of the C18N/Fe LB films is a doublet with parameters {delta} = 0.35 mm/s and {Delta} = 0.74 mm/s. A gradual increase of the relative occurrence of the doublet compared to the sextet of the internal standard was observed with the increasing number of layers, indicating the nearly uniform distribution of Fe among the LB layers.

Determination of alpidem, an imidazopyridine anxiolytic, and its metabolites by column-switching high-performance liquid chromatography with fluorescence detection.

Science.gov (United States)

Flaminio, L; Ripamonti, M; Ascalone, V

1994-05-13

Alpidem, 6-chloro-2-(4-chlorophenyl)-N,N-dipropylimidazo[1,2-a]pyridine- 3-acetamide, is an anxiolytic imidazopyridine that undergoes a first-pass elimination after oral administration to humans; it is actively metabolized and three circulating metabolites have been identified in plasma due to N-dealkylation, oxidation or a combination of both processes. For the determination of the unchanged drug and its metabolites in human plasma, a column-switching HPLC method was developed. The method, based on solid-phase extraction (performed on-line), involves the automatic injection of plasma samples (200 microliters) on to a precolumn filled with C18 material, clean-up of the sample with water in order to remove protein and salts and transfer of the analytes to the analytical column (after valve switching) by means of the mobile phase. All the processes were performed in the presence of an internal standard, a compound chemically related to alpidem. During the analytical chromatography, the precolumn was flushed with different solvents and after regeneration with water, it was ready for further injections. The analytical column was a C8 type and the mobile phase was acetonitrile-methanol-phosphate buffer solution (45:15:45, v/v/v) at a flow-rate of 1.5 ml min-1. The column was connected to a fluorimetric detector operating at excitation and emission wavelengths of 255 and 423 nm, respectively. The limits of quantitation of alpidem and three metabolites were 2.5 and 1.5 ng ml-1, respectively, in human plasma.

Overexpression of ceramide synthase 1 increases C18-ceramide and leads to lethal autophagy in human glioma

Science.gov (United States)

Wang, Zheng; Wen, Lijun; Zhu, Fei; Wang, Yanping; Xie, Qing; Chen, Zijun; Li, Yunsen

2017-01-01

Ceramide synthase 1 (CERS1) is the most highly expressed CERS in the central nervous system, and ceramide with an 18-carbon–containing fatty acid chain (C18-ceramide) in the brain plays important roles in signaling and sphingolipid development. However, the roles of CERS1 and C18-ceramide in glioma are largely unknown. In the present study, measured by electrospray ionization linear ion trap mass spectrometry, C18-ceramide was significantly lower in glioma tumor tissues compared with controls (P overexpression of CERS1, which has been shown to specifically induce the generation of C18-ceramide. Overexpression of CERS1 or adding exogenous C18-ceramide inhibited cell viability and induced cell death by activating endoplasmic reticulum stress, which induced lethal autophagy and inhibited PI3K/AKT signal pathway in U251 and A172 glioma cells. Moreover, overexpression of CERS1 or adding exogenous C18-ceramide increased the sensitivity of U251 and A172 glioma cells to teniposide (VM-26). Thus, the combined therapy of CERS1/C18-ceramide and VM-26 may be a novel therapeutic strategy for the treatment of human glioma. PMID:29262618

Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

Use of emulsified vegetable oil to support bioremediation of TCE DNAPL in soil columns.

Science.gov (United States)

Harkness, Mark; Fisher, Angela

2013-08-01

The interaction between emulsified vegetable oil (EVO) and trichloroethylene (TCE) dense non-aqueous phase liquid (DNAPL) was observed using two soil columns and subsequent reductive dechlorination of TCE was monitored over a three year period. Dyed TCE DNAPL (~75 g) was emplaced in one column (DNAPL column), while the second was DNAPL-free (plume column). EVO was added to both columns and partitioning of the EVO into the TCE DNAPL was measured and quantified. TCE (1.9 mM) was added to the influent of the plume column to simulate conditions down gradient of a DNAPL source area and the columns were operated independently for more than one year, after which they were connected in series. Initially limited dechlorination of TCE to cDCE was observed in the DNAPL column, while the plume column supported complete reductive dechlorination of TCE to ethene. Upon connection and reamendment of the plume column with EVO, near saturation levels of TCE from the effluent of the DNAPL column were rapidly dechlorinated to c-DCE and VC in the plume column; however, this high rate dechlorination produced hydrochloric acid which overwhelmed the buffering capacity of the system and caused the pH to drop below 6.0. Dechlorination efficiency in the columns subsequently deteriorated, as measured by the chloride production and Dehalococcoides counts, but was restored by adding sodium bicarbonate buffer to the influent groundwater. Robust dechlorination was eventually observed in the DNAPL column, such that the TCE DNAPL was largely removed by the end of the study. Partitioning of the EVO into the DNAPL provided significant operational benefits to the remediation system both in terms of electron donor placement and longevity. Copyright © 2013 Elsevier B.V. All rights reserved.

Assessment of radiochemical purity of [18F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

International Nuclear Information System (INIS)

Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z.

2011-01-01

The quality control of [ 18 F]fludeoxyglucose ( 18 FDG) has received attention due to its increasing clinical use. Although the quality requirements of 18 FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of 18 FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. 18 FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of 18 FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of 18 FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of 18 FDG, considering operational conditions of our laboratory. (author)

Seasonal & Daily Amazon Column CO2 & CO Observations from Ground & Space Used to Evaluate Tropical Ecosystem Models

Science.gov (United States)

Dubey, M. K.; Parker, H. A.; Wennberg, P. O.; Wunch, D.; Jacobson, A. R.; Kawa, S. R.; Keppel-Aleks, G.; Basu, S.; O'Dell, C.; Frankenberg, C.; Michalak, A. M.; Baker, D. F.; Christofferson, B.; Restrepo-Coupe, N.; Saleska, S. R.; De Araujo, A. C.; Miller, J. B.

2016-12-01

The Amazon basin stores 150-200 PgC, exchanges 18 PgC with the atmosphere every year and has taken up 0.42-0.65 PgC/y over the past two decades. Despite its global significance, the response of the tropical carbon cycle to climate variability and change is ill constrained as evidenced by the large negative and positive feedbacks in future climate simulations. The complex interplay of radiation, water and ecosystem phenology remains unresolved in current tropical ecosystem models. We use high frequency regional scale TCCON observations of column CO2, CO and CH4 near Manaus, Brazil that began in October 2014 to understand the aforementioned interplay of processes in regulating biosphere-atmosphere exchange. We observe a robust daily column CO2 uptake of about 2 ppm (4 ppm to 0.5 ppm) over 8 hours and evaluate how it changes as we transition to the dry season. Back-trajectory calculations show that the daily CO2 uptake footprint is terrestrial and influenced by the heterogeneity of the Amazon rain forests. The column CO falls from above 120 ppb to below 80 ppb as we transition from the biomass burning to wet seasons. The daily mean column CO2 rises by 3 ppm from October through June. Removal of biomass burning, secular CO2 increase and variations from transport (by Carbon tracker simulations) implies an increase of 2.3 ppm results from tropical biospheric processes (respiration and photosynthesis). This is consistent with ground-based remote sensing and eddy flux observations that indicate that leaf development and demography drives the tropical carbon cycle in regions that are not water limited and is not considered in current models. We compare our observations with output from 7 CO2 inversion transport models with assimilated meteorology and find that while 5 models reproduce the CO2 seasonal cycle all of them under predict the daily drawdown of CO2 by a factor of 3. This indicates that the CO2 flux partitioning between photosynthesis and respiration is incorrect

HASILT: An intelligent software platform for HAZOP, LOPA, SRS and SIL verification

International Nuclear Information System (INIS)

Cui, Lin; Shu, Yidan; Wang, Zhaohui; Zhao, Jinsong; Qiu, Tong; Sun, Wenyong; Wei, Zhenqiang

2012-01-01

Incomplete process hazard analysis (PHA) and poor knowledge management have been two major reasons that have caused numerous lamentable disasters in the chemical process industry (CPI). To improve PHA quality, a new integration framework that combines HAZOP, layer of protection analysis (LOPA), safety requirements specification (SRS) and safety integrity level (SIL) validation is proposed in this paper. To facilitate the integrated work flow and improve the relevant knowledge management, an intelligent software platform named HASILT has been developed by our research team. Its key components and functions are described in this paper. Furthermore, since the platform keeps all history data in a central case base and case-based reasoning is used to automatically retrieve similar old cases for helping resolve new problems, a recall opportunity is created to reduce information loss which has been cited many times as a common root cause in investigations of accidents.

Column-Oriented Database Systems (Tutorial)

NARCIS (Netherlands)

D. Abadi; P.A. Boncz (Peter); S. Harizopoulos

2009-01-01

textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as

Peak distortion in the column liquid chromatographic determination of omeprazole dissolved in borax buffer.

Science.gov (United States)

Arvidsson, T; Collijn, E; Tivert, A M; Rosén, L

1991-11-22

Injection of a sample containing omeprazole dissolved in borax buffer (pH 9.2) into a reversed-phase liquid chromatographic system consisting of a mixture of acetonitrile and phosphate buffer (pH 7.6) as the mobile phase and a C18 surface-modified silica as the solid phase resulted under special conditions in split peaks of omeprazole. The degree of peak split and the retention time of omeprazole varied with the concentration of borax in the sample solution and the ionic strength of the mobile phase buffer as well as with the column used. Borax is eluted from the column in a broad zone starting from the void volume of the column. The retention is probably due to the presence of polyborate ions. The size of the zone varies with the concentration of borax in the sample injected. In the borax zone the pH is increased compared with the pH of the mobile phase, and when omeprazole (a weak acid) is co-eluting in the borax zone its retention is affected. In the front part and in the back part of the borax zone, pH gradients are formed, and these gradients can induce the peak splitting. When the dissolving medium is changed to a phosphate buffer or an ammonium buffer at pH 9 no peak distortion of omeprazole is observed.

{sup 11}C- and {sup 18}F Production at TPC RK2 Laboratory

Energy Technology Data Exchange (ETDEWEB)

Solin, O.; Johansson, S.; Eriksson, P-O.; Rajander, J.; Kokkomäki, E.; Helin, S.; Arponen, E.; Aromaa, J.; Savisto, N.; Bergman, J.; Heselius, S-J. [Turku PET Centre, Radiopharmaceutical Chemistry Laboratory and Accelerator Laboratory, Porthaninkatu 3, 20500 Turku (Finland)

2009-07-01

Four gas targets for production of [{sup 11}C]CO{sub 2} and [{sup 11}C]CH{sub 4} as well as static and one circulating water target for [{sup 18}F]fluoride production have been installed on the external beam line of the CC18/9 cyclotron (Efremov Institute for Electrophysical Apparatuses, St. Petersburg, Russia) at TPC. The cyclotron is capable of accelerating 18 MeV protons (9 MeV deuterons) at particle beam intensities in excess of 100 μA. The aim with these radionuclide production systems is high yield, high specific radioactivity precursor production for PET radiopharmaceuticals.

Economic optimization of heat pump-assisted distillation columns in methanol-water separation

International Nuclear Information System (INIS)

Shahandeh, Hossein; Jafari, Mina; Kasiri, Norollah; Ivakpour, Javad

2015-01-01

Finding efficient alternative to CDiC (Conventional Distillation Column) for methanol-water separation has been an attractive field of study in literature. In this work, five heat pump-assisted schemes are proposed and compared to each other to find the optimal one; (1) VRC (Vapor Recompression Column), (2) external HIDiC (Heat-Integrated Distillation Column), (3) intensified HIDiC with feed preheater, (4) double compressor intensified HIDiC-1, and (5) double compressor intensified HIDiC-2. GA (Genetic Algorithm) is then implemented for optimization of the schemes when TAC (Total Annual Cost) is its objective function. During optimization, two new variables are added for using only appropriate amount of the overhead stream in VRC and double compressor intensified HIDiCs, and another new binary variable is also used for considering feed preheating. Although TAC of the intensified HIDiC with feed preheater is found higher than CDiC by 25.0%, all optimal VRC, external HIDiC, double compressor intensified HIDiCs schemes are reached lower optimal TAC by 3.1%, 27.2%, 24.4%, and 34.2%. Introduced for the first time, the optimal scheme is the double compressor intensified HIDiC-2 with 34.2% TAC saving, 70.4% TEC (Total Energy Consumption) reduction with payback period of 3.30 years. - Highlights: • Study of an industrial distillation unit in methanol-water separation. • Optimization of different heat pump-assisted distillation columns. • Implementation of genetic algorithm during optimization. • Economic and thermodynamic comparisons of optimal results with the industrial case

Family of columns isospectral to gravity-loaded columns with tip force: A discrete approach

Science.gov (United States)

Ramachandran, Nirmal; Ganguli, Ranjan

2018-06-01

A discrete model is introduced to analyze transverse vibration of straight, clamped-free (CF) columns of variable cross-sectional geometry under the influence of gravity and a constant axial force at the tip. The discrete model is used to determine critical combinations of loading parameters - a gravity parameter and a tip force parameter - that cause onset of dynamic instability in the CF column. A methodology, based on matrix-factorization, is described to transform the discrete model into a family of models corresponding to weightless and unloaded clamped-free (WUCF) columns, each with a transverse vibration spectrum isospectral to the original model. Characteristics of models in this isospectral family are dependent on three transformation parameters. A procedure is discussed to convert the isospectral discrete model description into geometric description of realistic columns i.e. from the discrete model, we construct isospectral WUCF columns with rectangular cross-sections varying in width and depth. As part of numerical studies to demonstrate efficacy of techniques presented, frequency parameters of a uniform column and three types of tapered CF columns under different combinations of loading parameters are obtained from the discrete model. Critical combinations of these parameters for a typical tapered column are derived. These results match with published results. Example CF columns, under arbitrarily-chosen combinations of loading parameters are considered and for each combination, isospectral WUCF columns are constructed. Role of transformation parameters in determining characteristics of isospectral columns is discussed and optimum values are deduced. Natural frequencies of these WUCF columns computed using Finite Element Method (FEM) match well with those of the given gravity-loaded CF column with tip force, hence confirming isospectrality.

Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

Science.gov (United States)

Gumuscu, Burcu; Erdogan, Zeynep; Guler, Mustafa O; Tekinay, Turgay

2014-01-01

In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

Comparing monolithic and fused core HPLC columns for fast chromatographic analysis of fat-soluble vitamins

Directory of Open Access Journals (Sweden)

Kurdi Said El

2017-06-01

Full Text Available HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs > 5 and precision (RSD ≤ 0.6 %. Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.

Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

International Nuclear Information System (INIS)

Clark, E.A.

1992-01-01

Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (AHL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns

Distillation Column Flooding Predictor

Energy Technology Data Exchange (ETDEWEB)

George E. Dzyacky

2010-11-23

The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

Annular pulse column development studies

International Nuclear Information System (INIS)

Benedict, G.E.

1980-01-01

The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-sectional area of these columns. This can be accomplished through the use of a column having an annular cross section. The preliminary testing of a pilot-plant-scale annular column has been completed and is reported herein. The column is made from 152.4-mm (6-in.) glass pipe sections with an 89-mm (3.5-in.) o.d. internal tube, giving an annular width of 32-mm (1.25-in.). Louver plates are used to swirl the column contents to prevent channeling of the phases. The data from this testing indicate that this approach can successfully provide larger-cross-section critically safe pulse columns. While the capacity is only 70% of that of a cylindrical column of similar cross section, the efficiency is almost identical to that of a cylindrical column. No evidence was seen of any non-uniform pulsing action from one side of the column to the other

Validation of an HPLC method for determination of chemical purity of [{sup 18}F]fluoromisonidazole ([{sup 18}F]FMISO)

Energy Technology Data Exchange (ETDEWEB)

Nascimento, Natalia C.E.S.; Oliveira, Mércia L.; Lima, Fernando R.A., E-mail: nataliafleming@hotmail.com, E-mail: mercial@cnen.gov.br, E-mail: falima@cnen.gov.br [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Silveira, Marina B.; Ferreira, Soraya Z.; Silva, Juliana B., E-mail: mbs@cdtn.br, E-mail: zandims@cdtn.br, E-mail: silvajb@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

[{sup 18}F]Fluoromisonidazole ([{sup 18}F]FMISO) is a nitroimidazole derivative labelled with fluorine-18 that selectively binds to hypoxic cells. It has been shown to be a suitable PET tracer for imaging hypoxia in tumors as well as in noncancerous tissues. [{sup 18}F]FMISO was prepared using a TRACERlabMX{sub FDG}® module (GE) with cassettes, software sequence and reagents kits from ABX. In this work, we aimed to develop and to validate a new high performance liquid chromatography (HPLC) method for determination of chemical purity of [{sup 18}F]FMISO. Analyses were performed with an Agilent chromatograph equipped with radioactivity and UV detectors. [{sup 18}F]FMISO and impurities were separated on a C18 column by gradient elution with water and acetonitrile. Selectivity, linearity, detection limit (DL), quantification limit (LQ), precision, accuracy and robustness were assessed to demonstrate that the HPLC method is adequate for its intended purpose. The HPLC method showed a good precision, as all RSD values were lower than 5%. Robustness was evaluated considering a variation on parameters such mobile phase gradient and flow rate. Results evidenced that the HPLC method is validated and is suitable for radiochemical purity evaluation of [{sup 18}F]FMISO, considering operational conditions of our laboratory. As an extension of this work, other analytical methods used for [{sup 18}F]FMISO quality control should be evaluated, in compliance with good manufacture practice. (author)

Column-Oriented Database Systems (Tutorial)

OpenAIRE

Abadi, D.; Boncz, Peter; Harizopoulos, S.

2009-01-01

textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subset of a table’s columns becomes faster, at the potential expense of excessive disk-head s...

18F fluoroethylations: different strategies for the rapid translation of 11C-methylated radiotracers

International Nuclear Information System (INIS)

Wadsak, Wolfgang; Mien, Leonhard-Key; Ettlinger, Dagmar E.; Eidherr, Harald; Haeusler, Daniela; Sindelar, Karoline-Maria; Keppler, Bernhard K.; Dudczak, Robert; Kletter, Kurt; Mitterhauser, Markus

2007-01-01

Introduction: The translation of 11 C-labeled compounds into their respective 18 F-labeled derivatives is an important tool in the rapid development of positron emission tomography (PET) tracers. Thus, our aim was the development of a general method for the preparation of 18 F-fluoroethylated compounds that (a) is applicable to a variety of precursors, (b) can be performed in a fully automated commercially available synthesizer and (c) enables this rapid translation of 11 C-methylated tracers into their 18 F-fluoroethylated analogs sharing the same precursor molecules. Methods: Ten methods for the preparation and purification of different 18 F-fluoroethylating agents were compared. Subsequently, five 18 F-labeled PET tracers were synthesized under fully automated conditions. Results: Radiochemical yields ranged from 34.4% to 60.8%, and time consumption ranged from 20 to 55 min for all methods. Use of 1-bromo-2-[ 18 F]fluoroethane and distillation evinced as the method of choice. Conclusions: We were able to develop a general method for the preparation of a variety of 18 F-fluoroethylated molecules. The provided tool is solely based on commercially available resources and has the potential to simplify and accelerate innovative PET tracer development in the future

An improved method of 18F peptide labeling: hydrazone formation with HYNIC-conjugated c(RGDyK)

International Nuclear Information System (INIS)

Lee, Yun-Sang; Jeong, Jae Min; Kim, Hyung Woo; Chang, Young Soo; Kim, Young Joo; Hong, Mee Kyung; Rai, Ganesha B.; Chi, Dae Yoon; Kang, Won Jun; Kang, Joo Hyun; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul; Suh, Young-Ger

2006-01-01

Radiolabeled α v β 3 -integrin antagonists are increasingly investigated as a means of imaging angiogenesis. Several methods of labeling α v β 3 -integrin binding peptide with 18 F have been reported recently. In the present study, we devised a straightforward means for labeling Arg-Gly-Asp (RGD) peptide with 18 F via hydrazone formation between c(RGDyK)-hydrazinonicotinic acid (HYNIC) (3) and 4-[ 18 F]-fluorobenzaldehyde ([ 18 F]4). The resulting reaction mixture was purified by HPLC to give 4'-[ 18 F]-fluorobenzylidenehydrazone-6-nicotinamide-c(RGDyK) ([ 18 F]5). The conjugation efficiency of 3 and 4 to form [ 18 F]5 was 95.2%, and the radiochemical purity of [ 18 F]5 after purification was >99%. The specific activity of [ 18 F]5 estimated by radio-HPLC was 20.5 GBq/μmol (end of synthesis). Competitive binding assay of c(RGDyK) (1) and 5 was performed using [ 125 I]iodo-c(RGDyK) as a radioligand, and K i values were found to be 2.8 and 21.7 nM, respectively. For the biodistribution study, the angiogenic mouse model was established by inducing unilateral ischemia on the left hindlimbs of ICR mice after femoral artery ablation. Seven days after inducing ischemia, [ 18 F]5 was administered to the mice through the tail vein. Ischemic muscle uptake of [ 18 F]5 was significantly higher than that of normal muscle (P 18 F]5. Here, we successfully labeled RGD peptide with 18 F via hydrazone formation between 3 and 4, resulting to [ 18 F]5. [ 18 F]5 was found to have high affinity for α v β 3 -integrin and to accumulate specifically in ischemic hindlimb muscle of mice. We suggest that 18 F labeling via formation of hydrazone between HYNIC peptide and [ 18 F]4 is a useful method for labeling c(RGDyK), which can be applied for imaging angiogenesis

Determination of lansoprazole enantiomers in dog plasma by column-switching liquid chromatography with tandem mass spectrometry and its application to a preclinical pharmacokinetic study.

Science.gov (United States)

Wang, Hao; Sun, Yantong; Meng, Xiangjun; Yang, Bo; Wang, Jian; Yang, Yan; Gu, Jingkai

2015-09-01

Lansoprazole, a selective proton pump inhibitor, has a chiral benzimidazole sulfoxide structure and is used for the treatment of gastric acid hypersecretory related diseases. To investigate its stereoselective pharmacokinetics, a column-switching liquid chromatography with tandem mass spectrometry method was developed for the determination of lansoprazole enantiomers in dog plasma using (+)-pantoprazole as an internal standard. After a simple protein precipitation procedure with acetonitrile, matrix components left behind after sample preparation were further eliminated from the sample by reversed-phase chromatography on a C18 column. The fluent was fed to a chiral column for the separation of lansoprazole enantiomers. Baseline separation of lansoprazole enantiomers was achieved on a Chiralcel OZ-RH column using acetonitrile/0.1% formic acid in water (35:65, v/v) as the mobile phase at 40°C. The linearity of the calibration curves ranged from 3 to 800 ng/mL for each enantiomer. Intra- and inter-day precisions ranged from 2.1 to 7.3% with an accuracy of ±1.7% for (+)-lansoprazole, and from 1.6 to 6.9% with an accuracy of ±3.5% for (-)-lansoprazole, respectively. The validated method was successfully applied for the stereoselective pharmacokinetic study of lansoprazole in beagle dog after intravenous infusion. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nuclear reactor control column

International Nuclear Information System (INIS)

Bachovchin, D.M.

1982-01-01

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest crosssectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor

Aspectos microscópicos da interação feijoeiro-Colletotrichum lindemuthianum mediados pelo silício

Directory of Open Access Journals (Sweden)

Maria Fernanda Antunes Cruz

2014-09-01

Full Text Available A antracnose, causada pelo fungo Colletotrichum lindemuthianum, é uma das doenças mais destrutivas que afetam a cultura do feijoeiro. Com o objetivo de encontrar alternativas para o controle dessa doença, o presente trabalho investigou, em nível microscópico, o efeito do silício (Si na resistência do feijoeiro à infecção por C. lindemuthianum. Plantas de feijoeiro (cv. Pérola foram cultivadas em solução nutritiva contendo 0 (-Si ou 2 mM (+Si de Si e inoculadas no estádio de crescimento V4 com uma suspensão de conídios de C. lindemuthianum. A severidade da antracnose decresceu cerca de 52% nas folhas das plantas supridas com Si (4,4% em relação às folhas das plantas não supridas (8,5%. Observações de folhas de feijoeiro das plantas não supridas com Si no microscópio eletrônico de varredura revelaram alterações morfológicas nas nervuras em contraste com as folhas de plantas supridas com Si. Utilizando-se a microanálise de raios-X, verificou-se maior concentração dos minerais enxofre, potássio e Si nas folhas das plantas supridas com Si. Em conclusão, o suprimento de Si em plantas de feijoeiro foi importante para reduzir os sintomas da antracnose.

Desempenho de escolares com dislexia do desenvolvimento em tarefas fonológicas e silábicas Performance of students with developmental dyslexia in phonological and syllabic tasks

Directory of Open Access Journals (Sweden)

Giseli Donadon Germano

2009-06-01

Full Text Available OBJETIVO: caracterizar o desempenho em tarefas fonológicas e silábicas de escolares com dislexia do desenvolvimento e comparar estes achados com o desempenho de discentes com bom desempenho escolar. MÉTODOS: participaram do estudo 26 alunos de oito a 12 anos de idade, de ambos os sexos, de 2ª. a 4ª. séries do Ensino Fundamental municipal na cidade de Marilia-SP, divididas em GI: composto por 13 escolares com dislexia atendidos no Centro de Estudos da Educação e Saúde - CEES/UNESP e GII: composto por 13 alunos com bom desempenho acadêmico, pareados segundo sexo, idade e escolaridade com o GI. Como procedimento foi utilizada a Prova de Consciência Fonológica - Instrumento de Avaliação Seqüencial - CONFIAS. Os resultados foram analisados estatisticamente pelo Teste Mann-Whitney (comparação entre os grupos e Teste dos Postos Sinalizados-Wilcoxon (comparação entre as variáveis. RESULTADOS: os resultados evidenciaram diferença estatisticamente significante, sugerindo melhor desempenho do GII em relação ao GI quanto às tarefas fonêmicas e silábicas. O GI apresentou diferença estatisticamente significativa nas tarefas silábicas e fonêmicas, com melhor desempenho nas primeiras. Entre os escolares do GII não houve grande diferença estatística entre tarefas silábicas, apenas entre tarefas fonêmicas. CONCLUSÃO: o estudo concluiu que escolares com dislexia do desenvolvimento apresentam dificuldades quanto à identificação de rima e produção de palavras com o som dado, apontando para um déficit em acessar os códigos e as representações fonológicas.PURPOSE: to characterize and to compare the performance in phonological and syllabic tasks of developmental dyslexia to good readers. METHODS: twenty-six students participated, with age varying between 8 and 12 years, both genders, of 2nd and 4th grades of the municipal elementary education of the city of Marília-SP. They were divided into GI: 13 developmental dyslexic

Le candomblé au Brésil, ou l'Afrique réinventée

OpenAIRE

Capone , Stefania

2005-01-01

Le Brésil est historiquement associé à l'idée d'un métissage – culturel et « racial » – qui aurait donné naissance à une société dépourvue de tensions raciales. La « démocratie raciale » brésilienne est ainsi devenue, dans les années 1950, un modèle à suivre pour le reste du monde. Depuis la fin des années 1970, les leaders du mouvement noir brésilien et certains représentants des maisons de culte de candomblé ont commencé à miner en profondeur ce modèle, en mettant en avant un discours « eth...

Improvements in solvent extraction columns

International Nuclear Information System (INIS)

Aughwane, K.R.

1987-01-01

Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

V{sub 18}P{sub 9}C{sub 2}. A complex phosphide carbide

Energy Technology Data Exchange (ETDEWEB)

Boller, Herbert [Linz Univ. (Austria). Inst. fuer Anorganische Chemie; Effenberger, Herta [Wien Univ. (Austria). Inst. fuer Mineralogie und Kristallographie

2016-08-01

V{sub 18}P{sub 9}C{sub 2} crystallizes in the orthorhombic space group Pmma with the lattice parameters a = 17.044(3), b = 3.2219(7), and c = 13.030(2) Aa, Z = 2. The crystal structure is composed of 19 symmetry-independent atoms. The crystal structure is considered as a network formed by the transition metal atoms exhibiting cubic, trigonal prismatic, and octahedral voids centered by V, P, and C atoms, respectively. Vice versa, the V and P atoms form a three-dimensional network. The two CV{sub 6} octahedra are edge- and corner-connected to chains running parallel to [010]. The five unique P atoms are trigonal prismatically coordinated by V atoms with one to three faces capped again by a V atom. The V atoms have mainly cubic environments formed solely by V or by V and P atoms. V{sub 18}P{sub 9}C{sub 2} exhibits some structural relations to other compounds of the ternary system V-P-C as well as to other intermetallic phases. Despite the low carbon content, V{sub 18}P{sub 9}C{sub 2} is considered as a ternary compound rather than an interstitially stabilized (binary) phosphide in view of its special structural features.

Vertical migration of some herbicides through undisturbed and homogenized soil columns

Directory of Open Access Journals (Sweden)

Md. Wasim Aktar

2009-01-01

Full Text Available A laboratory experiment was conducted by using three herbicides, two from dinitroaniline group and one from thiocarbamate group to know their degree of downward movement (leachability through soil columns and their contribution in ground water contamination. Soil columns were loaded with Pendimethalin, Benthiocarb and Oryzalin @ 10.0, 10.0 and 7.7 kg a.i. ha-1, respectively. After 30 days soil samples were analyzed from each segments (i.e. 0-6, 6-12, 12-18, and 18-24 and 24-30 cm for Benthiocarb and Pendimethalin by GLC equipped with Ni63 electron capture detector (ECD and for Oryzalin by HPLC coupled with UV-VIS detector. The results obtained in the present study reveal that the residues of the three herbicides under investigation were predominantly confined to the upper soil layer (0-6 cm. Comparatively, low mobility of these herbicides in soils could be due to strong adsorption of these chemical to soil colloids.

Vertical migration of some herbicides through undisturbed and homogenized soil columns

Science.gov (United States)

Aktar, Md. Wasim; Sengupta, Dwaipayan; Purkait, Swarnali; Chowdhury, Ashim

2008-01-01

A laboratory experiment was conducted by using three herbicides, two from dinitroaniline group and one from thiocarbamate group to know their degree of downward movement (leachability) through soil columns and their contribution in ground water contamination. Soil columns were loaded with Pendimethalin, Benthiocarb and Oryzalin at doses of 10.0, 10.0 and 7.7 kg/ha, respectively. After 30 days soil samples were analyzed from each segments (i.e. 0–6, 6–12, 12–18, 18–24 and 24–30 cm) for Benthiocarb and Pendimethalin by GLC equipped with Ni63 electron capture detector (ECD) and for Oryzalin by HPLC coupled with UV-VIS detector. The results obtained in the present study reveal that the residues of the three herbicides under investigation were predominantly confined to the upper soil layer (0–6 cm). Comparatively, low mobility of these herbicides in soils could be due to strong adsorption of these chemical to soil colloids. PMID:21218121

Vertical migration of some herbicides through undisturbed and homogenized soil columns

Directory of Open Access Journals (Sweden)

Md. Wasim Aktar

2008-12-01

Full Text Available A laboratory experiment was conducted by using three herbicides, two from dinitroaniline group and one from thiocarbamate group to know their degree of downward movement (leachability through soil columns and their contribution in ground water contamination. Soil columns were loaded with Pendimethalin, Benthiocarb and Oryzalin @ 10.0, 10.0 and 7.7 kg a.i. ha-1, respectively. After 30 days soil samples were analyzed from each segments (i.e. 0-6, 6-12, 12-18, and 18-24 and 24-30 cm for Benthiocarb and Pendimethalin by GLC equipped with Ni63 electron capture detector (ECD and for Oryzalin by HPLC coupled with UV-VIS detector. The results obtained in the present study reveal that the residues of the three herbicides under investigation were predominantly confined to the upper soil layer (0-6 cm. Comparatively, low mobility of these herbicides in soils could be due to strong adsorption of these chemical to soil colloids.

Evaluation of glycidyl methacrylate-based monolith functionalized with weak anion exchange moiety inside 0.5 mm i.d. column for liquid chromatographic separation of DNA

Directory of Open Access Journals (Sweden)

Aprilia Nur Tasfiyati

2016-03-01

Full Text Available In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100 × 0.5 mm i.d. by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogenic solvents, with the presence of initiator α,α′-azobisisobutyronitrile (AIBN. The monolith matrix was modified with diethylamine to create weak anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by SEM. The properties of the monolithic column, such as permeability, mechanical stability, binding capacity and pore size distribution, were characterized in detail. From the results of the characterization, monoliths poly-(GMA-co-EDMA with total monomer percentage (%T 40 and crosslinker percentage (%C 25 was found to be the ideal composition of monomer and crosslinker. It has good mechanical stability and high permeability, adequate molecular recognition sites (represented with binding capacity value of 36 mg ml−1, and has relatively equal proportion of flow-through pore and mesopores (37.2% and 41.1% respectively. Poly-(GMA-co-EDMA with %T 40 and %C 25 can successfully separate oligo(dT12–18 and 50 bp DNA ladder with good resolution.

13C and 18O isotope enrichment by vibrational energy exchange pumping of CO

International Nuclear Information System (INIS)

Bergman, R.C.; Homicz, G.F.; Rich, J.W.; Wolk, G.L.

1983-01-01

Measurements of preferential vibration-to-vibration (V--V) pumping of high vibrational states of 13 C 16 O and 12 C 18 O in optically excited CO gas are reported. It is found that the v = 22, 25, 27, 30, and 32 states of 13 C 16 O and the v = 8, 10, and 12 states of 12 C 18 O are substantially overpopulated compared to the same states in 12 C 16 O in strongly V--V pumped CO. Such mixtures are observed to react, forming products enriched in 13 C. The results are in reasonable agreement with an analytical kinetic model of V--V pumping in binary mixtures of diatomic gases

Current status of PET imaging of neuroendocrine tumours ([18F]FDOPA, [68Ga]traces, [11C/[18F]-HTP)

International Nuclear Information System (INIS)

Ambrosini, A.; Morgini, J.J.; Nanni, C.; Castellucci, P.; Fanti, S.

2015-01-01

Neuroendocrine neoplasms (NEN) functional imaging is an evolving field that witnessed major advances in the past two decades. The routine use of PET/CT with an array of new radiotracers to specifically study NEN resulted in an increase in lesions detection. Currently, PET radiopharmaceuticals for NEN imaging include both metabolic ([18F]DOPA, [18F]FDG, [11C]/[18F]-HTP) and receptor-mediated compounds ([68Ga]DOTA-peptides). Discussion is still on-going regarding the clinical setting that may benefit the most from the use of one tracer over the other. [68Ga]DOTA-peptides are accurate for the detection of well differentiated NEN and are increasingly employed. Moreover, providing data on somatostatin receptors expression on NEN cells, they represent a fundamental procedure to be performed before starting therapy, as well as to guide treatment, with either hot or cold somatostatin analogues. The easy and economic synthesis process also favours their clinical employment even in centres without an on-site cyclotron. [18F]DOPA is accurate for studying well differentiated tumours however the difficult and expensive synthesis have limited its clinical employment. It currently can be successfully used for imaging tumours with variable to low expression of SSR (medullary thyroid carcinoma, neuroblastoma, pheocromocytoma), that cannot be accurately studied with [68Ga]DOTA-peptides. [11C]/[18F]-HTP has also been proposed to image well differentiated NEN, on the basis of serotonin pathway activity, for which [11C]/[18F]-HTP can be used as precursor. However, although preliminary data are encouraging, the feasibility of its widespread clinical use is still under discussion, mainly limited by a complex synthesis process and more proven advantages over other currently employed compounds. This review aims to provide an overview of the current status and clinical application of PET tracers to image well differentiated NEN and to focus on the still open-issues of debate

O silêncio de Deus em Morangos Silvestres e O Sétimo Selo de Ingmar Bergman

OpenAIRE

Sinay, Isadora Goldberg

2014-01-01

A presente dissertação de mestrado é composta da análise de dois longa-metragens de ficção, Morangos Silvestres e O Sétimo Selo, de Ingmar Bergman . A análise busca mapear nas duas obras a temática do silêncio de Deus, aspecto relevante na obra do cineasta em questão. Ingmar Bergman é um dos maiores nomes da arte contemporânea e seus filmes articulam filosofia e religião, tornando-os de interesse fundamental para as ciências da religião como manifestação de reflexões essenci...

( Anogeissus leiocarpus ) timber columns

African Journals Online (AJOL)

A procedure for designing axially loaded Ayin (Anogeissus leiocarpus) wood column or strut has been investigated. Instead of the usual categorization of columns into short, intermediate and slender according to the value of slenderness ratio, a continuous column formula representing the three categories was derived.

Synthesis and simulation of efficient divided wall column sequences for bioethanol recovery and purification from an actual lignocellulosic fermentation broth

DEFF Research Database (Denmark)

Torres-Ortega, Carlo Edgar; Rong, Ben-Guang

2016-01-01

Actual lignocellulosic fermentation broth has intrinsic multiphase and multicomponent nature and calls for complex separation systems in both bioethanol recovery and purification [Torres-Ortega, C. E.; Rong, B.-G. Ind. Eng. Chem. Res. 2016, 55, 210]. In this work, we present the synthesis...... of column sections as novel synthesis approaches to formulate hybrid units and divided wall columns. Rigorous simulation in Aspen Plus V8.0 was used to simulate the intensified separation systems. The new intensified alternatives achieved relevant savings, ranging from 17 to 23% in TAC (total annual costs......), and ranging from 18 to 28% in TEC (total energy consumption). Moreover, reduction of the number of separation units varied from the original eight units down to three units. Finally, we performed a sensitivity analysis varying the bioethanol concentration in the fermentation broth between the reference case...

Implications of the 14C(α,γ)18O reaction for nonstandard big bang nucleosynthesis

International Nuclear Information System (INIS)

Gai, M.

1992-01-01

The thermonuclear burning rates for the 14 C(α,γ) 18 O radiative capture reaction are calculated at temperatures (0.3 - state, at approximately 9.0 MeV in 18 O as would be deduced from the Yale-Michigan State University measurement of the beta-delayed alpha-particle emission of 18 N and suggested by the Notre Dame-Caltech measurement of the nonresonant 14 C(α,γ) 18 O cross section. The gamma widths of the proposed broad state is estimated using the Alhassid, Gai, and Bertsch sum rule, and an experimental study is proposed

HETP evaluation of structured packing distillation column

Directory of Open Access Journals (Sweden)

A. E. Orlando Jr.

2009-09-01

Full Text Available Several tests with a hydrocarbon mixture of known composition (C8-C14, obtained from DETEN Chemistry S.A., have been performed in a laboratory distillation column, having 40mm of nominal diameter and 2.2m high, with internals of Sulzer DX gauze stainless steel structured packing. The main purpose of this work was to evaluate HETP of a structured packing laboratory scale distillation column, operating continuously. Six HETP correlations available in the literature were compared in order to find out which is the most appropriate for structured packing columns working with medium distillates. Prior to the experimental tests, simulation studies using commercial software PRO/II® were performed in order to establish the optimum operational conditions for the distillation, especially concerning operating pressure, top and bottom temperatures, feed location and reflux ratio. The results of PRO/II® were very similar to the analysis of the products obtained during continuous operation, therefore permitting the use of the properties calculated by that software on the theoretical models investigated. The theoretical models chosen for HETP evaluation were: Bravo, Rocha and Fair (1985; Rocha, Bravo and Fair (1993, 1996; Brunazzi and Pagliant (1997; Carlo, Olujić and Pagliant (2006; Olujić et al., (2004. Modifications concerning calculation of specific areas were performed on the correlations in order to fit them for gauze packing HETP evaluation. As the laboratory distillation column was operated continuously, different HETP values were found by the models investigated for each section of the column. The low liquid flow rates in the top section of the column are a source of error for HETP evaluation by the models; therefore, more reliable HETP values were found in the bottom section, in which liquid flow rates were much greater. Among the theoretical models, Olujić et al. (2004 has shown good results relative to the experimental tests. In addition, the

Analysis of separation quality of scandium-46 and titanium using silica gel column

International Nuclear Information System (INIS)

Muhamad Basit Febrian; Yanuar Setiadi; Duyeh Setiawan; Titin Sri Mulyati; Nana Suherman

2015-01-01

In this study, quality test of scandium and titanium mixture separation system using a silica gel column has been conducted. This system will be used in the separation of medical radioisotopes of 47 Sc from TiO 2 enriched targets. 20 mg of TiO 2 and 5 mg of Sc 2 O 3 dissolved using 0.5 mL of 50% HF solvent with gentle heating at 60°C - 80°C for 1 hour then 4.5 mL H 2 O was added. Sc and Ti mixture is separated by passing it through a column of silica gel. In the determination of scandium released from silica gel, Sc-46 radiotracer was used. Only 51.60 ± 4.5% of 5 mg of scandium could be retained in the silica gel column. From 51.60% of absorbed scandium in the column, 98.29 ± 3.4% were eluted with 5 mL of H 2 O eluent. During elution of scandium from silica gel column, 2.81 grams of 20 mg of titanium came apart as breakthrough. In determination of recovery of titanium from silica gel, 51.76 ± 5.5% of the 20 mg Ti can be recovered from silica gel column using 5M HCl eluent, whereas remaining Ti were eluted using 40 ml of HCl 5M. Based on those result, it can be concluded that there are still titanium portion in scandium after the separation using a silica gel column. Further purification step using fresh silica gel column, can separate escaped titanium from scandium. (author)

LIQUID-LIQUID EXTRACTION COLUMNS

Science.gov (United States)

Thornton, J.D.

1957-12-31

This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

A novel approach to the simultaneous extraction and non-targeted analysis of the small molecules metabolome and lipidome using 96-well solid phase extraction plates with column-switching technology.

Science.gov (United States)

Li, Yubo; Zhang, Zhenzhu; Liu, Xinyu; Li, Aizhu; Hou, Zhiguo; Wang, Yuming; Zhang, Yanjun

2015-08-28

This study combines solid phase extraction (SPE) using 96-well plates with column-switching technology to construct a rapid and high-throughput method for the simultaneous extraction and non-targeted analysis of small molecules metabolome and lipidome based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry. This study first investigated the columns and analytical conditions for small molecules metabolome and lipidome, separated by an HSS T3 and BEH C18 columns, respectively. Next, the loading capacity and actuation duration of SPE were further optimized. Subsequently, SPE and column switching were used together to rapidly and comprehensively analyze the biological samples. The experimental results showed that the new analytical procedure had good precision and maintained sample stability (RSDmetabolome and lipidome to test the throughput. The resulting method represents a new analytical approach for biological samples, and a highly useful tool for researches in metabolomics and lipidomics. Copyright © 2015 Elsevier B.V. All rights reserved.

17 CFR 240.15c1-8 - Sales at the market.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Sales at the market. 240.15c1... Securities Exchange Act of 1934 Rules Relating to Over-The-Counter Markets § 240.15c1-8 Sales at the market... securities exchange that such security is being offered to such customer “at the market” or at a price...

A mechanistic study of Toxoplasma gondii ROP18 inhibiting differentiation of C17.2 neural stem cells

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Xian Zhang

2017-11-01

Full Text Available Abstract Background Congenital infection of Toxoplasma gondii is an important factor causing birth defects. The neural stem cells (NSCs are found to be one of the target cells for the parasite during development of the brain. As a key virulence factor of the parasite that hijacks host cellular functions, ROP18 has been demonstrated to mediate the inhibition of host innate and adaptive immune responses through specific binding different host immunity related molecules. However, its pathogenic actions in NSCs remain elusive. Results In the present study, ROP18 recombinant adenovirus (Ad-ROP18 was constructed and used to infect C17.2 NSCs. After 3d- or 5d–culture in differentiation medium, the differentiation of C17.2 NSCs and the activity of the Wnt/β-catenin signaling pathway were detected. The results showed that the protein level of βIII-tubulin, a marker of neurons, in the Ad-ROP18-transfected C17.2 NSCs was significantly decreased, indicating that the differentiation of C17.2 NSCs was inhibited by the ROP18. The β-catenin level in the Ad-ROP18-transfected C17.2 NSCs was found to be lower than that in the Ad group. Also, neurogenin1 (Ngn1 and neurogenin2 (Ngn2 were downregulated significantly (P < 0.05 in the Ad-ROP18-transfected C17.2 NSCs compared to the Ad group. Accordingly, the TOP flash/FOP flash dual-luciferase report system showed that the transfection of Ad-ROP18 decreased the Wnt/β-catenin pathway activity in the C17.2 NSCs. Conclusions The inhibition effect of the ROP18 from T. gondii (TgROP18 on the neuronal differentiation of C17.2 NSCs was at least partly mediated through inhibiting the activity of the Wnt/β-catenin signaling pathway, eventually resulting in the downregulation of Ngn1 and Ngn2. The findings help to better understand potential mechanisms of brain pathology induced by TgROP18.

Lack of association of -607 C/A and -137 G/C polymorphisms in interleukin 18 gene with susceptibility to gout disease in Chinese Han male population.

Science.gov (United States)

Li, Changgui; Yuan, Ying; Wang, Xinfeng; Han, Lin; Chu, Nan; Wang, Hui; Liu, Shiguo

2012-06-01

To identify association of IL18-607 C/A and -137 G/C polymorphism with susceptibility to gout in Chinese Han male population, We evaluate the genetic contribution of the IL18-607 C/A and -137 G/C polymorphism in 202 gout male patients and 493 gout-free control of Chinese Han population by allele-specific polymerase chain reaction assay. Our results reveal no significant association between the polymorphisms -607C/A and -137G/C in IL18 with gout. Our study might suggest that -607 C/A and -137 G/C polymorphisms in the promoter of IL18 are not associated with susceptibility to gout and thus do not play a major role in the development of gout in the Chinese Han male population.

The central column structure in SPHEX

International Nuclear Information System (INIS)

Duck, R.C.; French, P.A.; Browning, P.K.; Cunningham, G.; Gee, S.J.; al-Karkhy, A.; Martin, R.; Rusbridge, M.G.

1994-01-01

SPHEX is a gun injected spheromak in which a magnetised Marshall gun generates and maintains an approximately axisymmetric toroidal plasma within a topologically spherical flux conserving vessel. The central column has been defined as a region of high mean floating potential, f > up to ∼ 150 V, aligned with the geometric axis of the device. It has been suggested that this region corresponds to the open magnetic flux which is connected directly to the central electrode of the gun and links the toroidal annulus (in which f > ∼ 0 V). Poynting vector measurements have shown that the power required to drive toroidal current in the annulus is transmitted out of the column by the coherent 20 kHz mode which pervades the plasma. Measurements of the MHD dynamo in the column indicate an 'antidynamo' electric field due to correlated fluctuations in v and B at the 20 kHz mode frequency which is consistent with the time-averaged Ohm's Law. On shorting the gun electrodes, the density in the column region decays rapidly leaving a 'hole' of radius R c ∼ 7 cm. This agrees with the estimated dimension of the open flux from mean internal B measurements and axisymmetric force-free equilibrium modelling, but is considerably smaller than the radius of ∼ 13 cm inferred from the time-averaged potential. In standard operating conditions the gun delivers a current of I G ∼ 60 kA at V G ∼ 500 V for ∼ 1 ms, driving a toroidal current of I t ∼ 60 kA. Ultimately we wish to understand the mechanism which drives toroidal current in the annulus; the central column is of interest because of the crucial role it plays in this process. (author) 8 refs., 6 figs

Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

Science.gov (United States)

Gumuscu, Burcu; Erdogan, Zeynep; Guler, Mustafa O.; Tekinay, Turgay

2014-01-01

In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95–98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation. PMID:24905826

Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

Directory of Open Access Journals (Sweden)

Burcu Gumuscu

Full Text Available In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT; 2,4-dinitrotoluene (2,4-DNT; 2,6-dinitrotoluene (2,6-DNT; 2-aminodinitrotoluene (2-ADNT and 4-aminodinitrotoluene (4-ADNT molecules in high-performance liquid-chromatography (HPLC with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

Transport of perfluoroalkyl acids in a water-saturated sediment column investigated under near-natural conditions

International Nuclear Information System (INIS)

Vierke, Lena; Möller, Axel; Klitzke, Sondra

2014-01-01

The aim of this study was to gain an understanding of the transport of C 4–10 perfluoroalkyl carboxylic acids (PFCAs) and C 4,6,8 perfluoroalkyl sulfonic acids (PFSAs) in a water-saturated sediment column representing a riverbank filtration scenario under near-natural conditions. Short-chain PFCAs and PFSAs with up to six C-atoms showed complete tracer-like breakthrough. Longer chain ones were retarded due to sorption to the sediment or due to other processes in the aqueous phase. The study reports the first column derived sediment–water partition coefficients ranging from 0.01 cm 3 g −1 to 0.41 cm 3 g −1 for C 4,6 PFSAs and from 0.0 cm 3 g −1 to 6.5 cm 3 g −1 for C 4,5,6,8,9 PFCAs. The results clearly indicate that short-chain PFCAs and PFSAs may pose a problem if contaminated surface waters are used for drinking water production via riverbank filtration. Highlights: • Transport of per- and polyfluorinated compounds in a riverbank filtration scenario. • Investigations under near-natural conditions with a water-saturated sediment column. • Processes in water and sediment control the transport of analytes. • Short chain PFCAs and PFSAs are not retarded in the water-saturated sediment column. • First column derived sediment–water partition coefficients. -- Quantification of breakthrough of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) under conditions simulating a riverbank filtration scenario

Elastic and inelastic scattering of 18O ions on 12C nuclei

Directory of Open Access Journals (Sweden)

A. T. Rudchik

2009-12-01

Full Text Available Angular distributions of the 12C + 18O elastic and inelastic scattering were measured at the energy Elab(18O = 105 MeV (Ec.m. = 42 MeV. These data and data known from the literature at the energies Ec.m. = 12.9 - 56 МеV were analysed within the optical model and coupled-reactionchannels method. The sets of the Woods-Saxon (12С + 18O-potential parameters were deduced and their energy dependence was studied. It was found the isotopic differences in the (12С + 16O- and (12С + 18O-potentials parameters and in their surface forms. The mechanisms of elastic and inelastic (12С + 18O-scattering and role of transfer reactions were studied.

Scalability of pre-packed preparative chromatography columns with different diameters and lengths taking into account extra column effects.

Science.gov (United States)

Schweiger, Susanne; Jungbauer, Alois

2018-02-16

Small pre-packed columns are commonly used to estimate the optimum run parameters for pilot and production scale. The question arises if the experiments obtained with these columns are scalable, because there are substantial changes in extra column volume when going from a very small scale to a benchtop column. In this study we demonstrate the scalability of pre-packed disposable and non-disposable columns of volumes in the range of 0.2-20 ml packed with various media using superficial velocities in the range of 30-500 cm/h. We found that the relative contribution of extra column band broadening to total band broadening was not only high for columns with small diameters, but also for columns with a larger volume due to their wider diameter. The extra column band broadening can be more than 50% for columns with volumes larger than 10 ml. An increase in column diameter leads to high additional extra column band broadening in the filter, frits, and adapters of the columns. We found a linear relationship between intra column band broadening and column length, which increased stepwise with increases in column diameter. This effect was also corroborated by CFD simulation. The intra column band broadening was the same for columns packed with different media. An empirical engineering equation and the data gained from the extra column effects allowed us to predict the intra, extra, and total column band broadening just from column length, diameter, and flow rate. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

SEPARATION OF OCTYLPHENOL POLYETHER ALCOHOLS SURFACTANTS BY CAPILLARY COLUMN SFC AND HPLC

Science.gov (United States)

Separation of nonionic octylphenol polyether alcohols (OPA) by supercritical fluid chromatography (SFC) and HPLC is described. Using a density programming and a 50-μm i.d. capillary column, a total of 18 group oligomers was separated. The effects of the operating parameters, such...

Decoupling Solar Variability and Instrument Trends Using the Multiple Same-Irradiance-Level (MuSIL) Analysis Technique

Science.gov (United States)

Woods, Thomas N.; Eparvier, Francis G.; Harder, Jerald; Snow, Martin

2018-05-01

The solar spectral irradiance (SSI) dataset is a key record for studying and understanding the energetics and radiation balance in Earth's environment. Understanding the long-term variations of the SSI over timescales of the 11-year solar activity cycle and longer is critical for many Sun-Earth research topics. Satellite measurements of the SSI have been made since the 1970s, most of them in the ultraviolet, but recently also in the visible and near-infrared. A limiting factor for the accuracy of previous solar variability results is the uncertainties for the instrument degradation corrections, which need fairly large corrections relative to the amount of solar cycle variability at some wavelengths. The primary objective of this investigation has been to separate out solar cycle variability and any residual uncorrected instrumental trends in the SSI measurements from the Solar Radiation and Climate Experiment (SORCE) mission and the Thermosphere, Mesosphere, Ionosphere, Energetic, and Dynamics (TIMED) mission. A new technique called the Multiple Same-Irradiance-Level (MuSIL) analysis has been developed, which examines an SSI time series at different levels of solar activity to provide long-term trends in an SSI record, and the most common result is a downward trend that most likely stems from uncorrected instrument degradation. This technique has been applied to each wavelength in the SSI records from SORCE (2003 - present) and TIMED (2002 - present) to provide new solar cycle variability results between 27 nm and 1600 nm with a resolution of about 1 nm at most wavelengths. This technique, which was validated with the highly accurate total solar irradiance (TSI) record, has an estimated relative uncertainty of about 5% of the measured solar cycle variability. The MuSIL results are further validated with the comparison of the new solar cycle variability results from different solar cycles.

Gold electrodes modified with 16H, 18H-dibenzo[c,l]-7,9-dithia-16,18-diazapentacene for electrocatalytic oxidation of NADH

NARCIS (Netherlands)

Rosca, V.; Muresan, L.; Popescu, I.C.; Cristea, C.; Silberg, I.A.

2001-01-01

16H,18H-Dibenzo[c,l]-7,9-dithia-16,18-diazapentacene (DDDP), a new phenothiazine derivative containing two linearly condensed phenothiazine rings, strongly adsorbs on polyoriented gold resulting in a modified electrode with electrocatalytic activity for ß-nicotinamide adenine dinucleotide (NADH)

Evolução estrutural do filme cerâmico de forsterita obtido sobre o aço silício de grão orientado

Directory of Open Access Journals (Sweden)

Vasconcelos D. C. L.

2000-01-01

Full Text Available Neste trabalho é descrita a formação, sobre o aço silício de grão orientado, de um filme cerâmico obtido a partir de MgO contendo os aditivos TiO2 e SrSO4. O material foi tratado termicamente a 900 0C, 1000 0C e 1200 0C e por 15 horas a 1200 0C. O recobrimento foi analisado por microscopia eletrônica de varredura (MEV, microssonda eletrônica (EDS, difração de raios X e espectroscopia de centelhamento (GDS. A evolução morfológica observada se passa com a formação de uma camada contínua de óxidos na superfície mais externa do material. Com a elevação da temperatura a camada mais externa torna-se mais espessa e aumenta o teor de Mg nas partículas presentes na sub-camada. É possível verificar a presença de forsterita cristalina na superfície das amostras tratadas a temperaturas superiores a 1000 0C. A profundidade de penetração do Mg no material aumenta com a elevação da temperatura, passando de cerca de 75 nm a 900 0C para aproximadamente 1,9 mim a 1200 0C.

The physical properties of giant molecular cloud complexes in the outer Galaxy - Implications for the ratio of H2 column density to (C-12)O intensity

Science.gov (United States)

Sodroski, T. J.

1991-01-01

The physical properties of 35 giant molecular cloud complexes in the outer Galaxy were derived from the Goddard-Columbia surveys of the Galactic plane region (Dame et al., 1987). The spatial and radial velocity boundaries for the individual cloud complexes were estimated by analyzing the spatial and velocity structure of emission features in the (C-12)O surveys, and the distance to each cmplex was determined kinematically on the assumption of a flat rotation curve. The ratio of the H2 column density to the (C-12)O intensity for the outer Galaxy complexes was found to be about 6.0 x 10 to the 20th molecules/sq cm K per km/sec, which is by a factor of 2-3 greater than the value derived by other auhtors for the inner Galaxy complexes. This increase in the H2 column density/(C-12)O intensity with the distance from with the Galactic center is consistent with predictions of the optically thick cloudlet model of giant molecular cloud complexes.

Syntheses of 18F-labeled reduced haloperidol and 11C-labeled reduced 3-N-methylspiperone

International Nuclear Information System (INIS)

Ravert, H.T.; Dannals, R.F.; Wilson, A.A.; Wong, D.F.; Wagner, H.N. Jr.

1991-01-01

18 F-Labeled reduced haloperidol and 11 C-labeled reduced 3-N-methylspiperone were synthesized in a convenient and quantitative one step reduction from 18 F-labeled haloperidol and 11 C-labeled N-methylspiperone, respectively. Both products were purified by semipreparative HPLC and were obtained at high specific activity and radiochemical purity. (author)

Aspects regarding at 13C isotope separation column control using Petri nets system

International Nuclear Information System (INIS)

Boca, M L; Ciortea, M E

2015-01-01

This paper is intended to show that Petri nets can be also applicable in the chemical industry. It used linear programming, modeling underlying Petri nets, especially discrete event systems for isotopic separation, the purpose of considering and control events in real-time through graphical representations. In this paper it is simulate the control of 13 C Isotope Separation column using Petri nets. The major problem with 13 C comes from the difficulty of obtaining it and raising its natural fraction. Carbon isotopes can be obtained using many methods, one of them being the cryogenic distillation of carbon monoxide. Some few aspects regarding operating conditions and the construction of such cryogenic plants are known today, and even less information are available as far as the separation process modeling and control are concerned. In fact, the efficient control of the carbon monoxide distillation process represents a necessity for large-scale 13 C production. Referring to a classic distillation process, some models for carbon isotope separation have been proposed, some based on mass, component and energy balance equations, some on the nonlinear wave theory or the Cohen equations. For modeling the system it was used Petri nets because in this case it is deal with discrete event systems. In use of the non-timed and with auxiliary times Petri model, the transport stream was divided into sections and these sections will be analyzed successively. Because of the complexity of the system and the large amount of calculations required it was not possible to analyze the system as a unitary whole. A first attempt to model the system as a unitary whole led to the blocking of the model during simulation, because of the large processing times. (paper)

Optimization and simulation of tandem column supercritical fluid chromatography separations using column back pressure as a unique parameter.

Science.gov (United States)

Wang, Chunlei; Tymiak, Adrienne A; Zhang, Yingru

2014-04-15

Tandem column supercritical fluid chromatography (SFC) has demonstrated to be a useful technique to resolve complex mixtures by serially coupling two columns of different selectivity. The overall selectivity of a tandem column separation is the retention time weighted average of selectivity from each coupled column. Currently, the method development merely relies on extensive screenings and is often a hit-or-miss process. No attention is paid to independently adjust retention and selectivity contributions from individual columns. In this study, we show how tandem column SFC selectivity can be optimized by changing relative dimensions (length or inner diameter) of the coupled columns. Moreover, we apply column back pressure as a unique parameter for SFC optimization. Continuous tuning of tandem column SFC selectivity is illustrated through column back pressure adjustments of the upstream column, for the first time. In addition, we show how and why changing coupling order of the columns can produce dramatically different separations. Using the empirical mathematical equation derived in our previous study, we also demonstrate a simulation of tandem column separations based on a single retention time measurement on each column. The simulation compares well with experimental results and correctly predicts column order and back pressure effects on the separations. Finally, considerations on instrument and column hardware requirements are discussed.

Identification and quantification of genipin and geniposide from Genipa americana L. by HPLC-DAD using a fused-core column

Directory of Open Access Journals (Sweden)

Grazielle NÁTHIA-NEVES

2018-01-01

Full Text Available Abstract In this work, it was developed a fast, simple and selective method for quantification of genipin and geniposide from unripe fruits of genipap, which are known as natural colorants, blue and yellow, respectively. The compounds separation was performed in a fused-core C18 column using as mobile phase water (A and acetonitrile (B both acidified with 0.1% formic acid, with the following gradient: 0 min, 99% A; 9 min, 75% A; 10 min, 99% A and 13 min, 99% A. The temperature and flow rate that allowed the best chromatographic performance were 35 °C and 1.5 mL/min, respectively, resulting a total run time of 13 min, including column clean-up and re-equilibration. This short analysis time represents an advantage compared to the methods reported in the literature where the running times are 2-5 times greater. The detection wavelength was set at 240 nm. The method validation was performed based on specificity, linearity, detection and quantification limits, precision and accuracy, according to ICH methodology. Finally, the developed method was suitable for monitoring analysis of those compounds content in vegetable samples.

Epimerisation of 2-[18F]-Fluoro-2-Deoxy-D-Glucose under alkaline conditions. A convenient method for the preparation of 2-[18F]-Fluoro-2-Deoxy-D-Mannose

International Nuclear Information System (INIS)

Varelis, P.

1998-01-01

Full text: The intended goal of our study into the epimerisation of 2-[ 18 F]- fluoro-2-deoxy-D-glucose ([ 18 F]-FDG) was to obtain 2-[ 18 F]-fluoro- 2-deoxy-D-mannose ([ 18 F]-FDM) for the purpose of both development and validation of our analytical methods used to determine the diastereoisomeric excess of [ 18 F]-FDG prepared in our facility. The epimerisation of [ 18 F]-FDG is smoothly effected by heating an aqueous solution of this radiochemical with 1 M aqueous sodium hydroxide at 50-60 deg C for 30 min, which provides an ∼ 1:1 mixture of [ 18 F]-FDG and [ 18 F]-FDM. In addition to the value of this mixture in analytical method development, we also found it useful for gauging the performance of the HPLC column used in the analysis of [ 18 F]-FDG. The aqueous sample matrix can be conveniently changed by azeotropic evaporation of the water with dry acetonitrile. In summary, the base catalysed epimerisation of 2-[ 18 F]-fluoro-2- deoxy-D-glucose provides a convenient and reliable procedure for the preparation 2-[ 18 F]-fluoro-2-deoxy-D-mannose, the stable analogue of which is not commercially available

Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

Energy Technology Data Exchange (ETDEWEB)

Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

2011-07-01

The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

Labeling of complex molecules with 18F, 13N, and 11C

International Nuclear Information System (INIS)

Brownell, G.L.; Elmaleh, D.R.

1980-01-01

The overall objective during the period covered by this report was to develop a broad spectrum of radiopharmaceuticals labeled with short-lived cyclotron positron emitters, 11 C, 13 N and 18 F. The goals of the program during the last year were: (1) to complete the modular automated system for important precursor production - formaldehyde, methyliodide, cyanide; (2) to perform animal studies with the 18 F-glucose analogues 2FDG and 3FDG and measure the constants for both agents in different animals; and (3) to initiate the development of new fatty acid analogues for the myocardial imaging and metabolism. As part of a collaboration with other groups seeking new agents for myocardium and brain, 9-/sup 123m/Te-telluriumheptadecanoic acid as a myocardial imaging agent was studied. This compound could be used for designing new fatty acid analogues labeled with 11 C and 18 F that stay in the myocardium because of metabolic inhibition

Time-efficient and convenient synthesis of [{sup 18}F]altanserin for human PET imaging by a new work-up procedure

Energy Technology Data Exchange (ETDEWEB)

Massarweh, G. [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec (Canada)], E-mail: gassan.wassarweh@mcgill.ca; Kovacevic, M.; Rosa-Neto, P.; Evans, A.C.; Diksic, M. [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec (Canada); Schirrmacher, R. [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec (Canada)], E-mail: ralf.schirrmacher@mcgill.ca

2009-11-15

[{sup 18}F]Altanserin, an important PET radioligand for the in vivo imaging of the 5-HT{sub 2A} receptor, was synthesized from its precursor nitro-altanserin in DMF or DMSO at high temperatures of 150 deg. C in an overall radiochemical yield (EOB) of 23-25% after 75 min. A new solid phase work-up procedure involving the acidification of the crude reaction mixture and a C18-SepPak-solid phase separation preceded the final HPLC purification. This led to a significantly reduced synthesis time as a result of a stable and early elution from the HPLC column using improved HPLC conditions (MeOH/THF/NaOAc 0.05 N pH 5: 27/18/55, flow: 5 mL/min, Symetry Prep 7 {mu}m C18 (Waters)). The synthesis was performed semi-automatically in a modified GE TracerLab synthesis module using an in-house-developed program. The synthesized [{sup 18}F]altanserin was used in our ongoing human and animal PET imaging studies.

Confocal Raman Microscopy for in Situ Measurement of Octanol-Water Partitioning within the Pores of Individual C18-Functionalized Chromatographic Particles.

Science.gov (United States)

Kitt, Jay P; Harris, Joel M

2015-05-19

Octanol-water partitioning is one of the most widely used predictors of hydrophobicity and lipophilicity. Traditional methods for measuring octanol-water partition coefficients (K(ow)), including shake-flasks and generator columns, require hours for equilibration and milliliter quantities of sample solution. These challenges have led to development of smaller-scale methods for measuring K(ow). Recent advances in microfluidics have produced faster and smaller-volume approaches to measuring K(ow). As flowing volumes are reduced, however, separation of water and octanol prior to measurement and detection in small volumes of octanol phase are especially challenging. In this work, we reduce the receiver volume of octanol-water partitioning measurements from current practice by six-orders-of-magnitude, to the femtoliter scale, by using a single octanol-filled reversed-phase, octadecylsilane-modified (C18-silica) chromatographic particle as a collector. The fluid-handling challenges of working in such small volumes are circumvented by eliminating postequilibration phase separation. Partitioning is measured in situ within the pore-confined octanol phase using confocal Raman microscopy, which is capable of detecting and quantifying a wide variety of molecular structures. Equilibration times are fast (less than a minute) because molecular diffusion is efficient over distance scales of micrometers. The demonstrated amount of analyte needed to carry out a measurement is very small, less than 50 fmol, which would be a useful attribute for drug screening applications or testing of small quantities of environmentally sensitive compounds. The method is tested for measurements of pH-dependent octanol-water partitioning of naphthoic acid, and the results are compared to both traditional shake-flask measurements and sorption onto C18-modified silica without octanol present within the pores.

Long-chain alkylimidazolium ionic liquids, a new class of cationic surfactants coated on ODS columns for anion-exchange chromatography.

Science.gov (United States)

Qiu, Hongdeng; Zhang, Qinghua; Chen, Limei; Liu, Xia; Jiang, Shengxiang

2008-08-01

Separations of common inorganic anions were carried out on ODS columns coated with two long-chain alkylimidazolium ionic liquids ([C(12)MIm]Br and [C(14)MIm]Br) as new cationic surfactants for ion chromatography. With phthalate buffer solution as the mobile phases and non-suppressed conductivity detection, high column efficiencies and excellent selectivity were obtained in the separation of inorganic anions. Chromatographic parameters are calculated and the results show that the coated column possesses significant potential for the analysis of some inorganic anions such as CH(3)COO(-), IO(3)(-), Cl(-), BrO(3)(-), NO(2)(-), Br(-), NO(3)(-), SO(4)(2-), I(-), BF(4)(-), and SCN(-). The effect of eluent pH values on the separation of anions has been studied on the column coated with [C(12)MIm]Br. The stability of the coated columns was also examined.

Simultaneous determination of iodide and iodate in soil solution samples by HPLC with electrochemical detection and post-column reaction method

Energy Technology Data Exchange (ETDEWEB)

Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun' ichi [Department of Radioecology, Institute for Environmental Sciences, Aomori 039-3212 (Japan); Tsukada, Hirofumi [Department of Radioecology, Institute for Environmental Sciences, Aomori 039-3212 (Japan); Institute of Environmental Radioactivity, Fukushima University, Fukushima 960-1196 (Japan)

2014-07-01

Iodine-129 (half-life 1.6 x 10{sup 7} y) discharged into the atmosphere from nuclear facilities (e.g., a nuclear fuel reprocessing plant) is partly deposited on land and introduced into soil. Stable iodine ({sup 127}I) can be used as a natural analogue to predict the long-term behavior of {sup 129}I in the terrestrial environment. Iodine in soil mainly exists as I{sup -}, IO{sub 3}{sup -}, and organic iodine. Because the mobilities of these species in soil are quite different, iodine speciation in soil solution is a key for predicting the behavior of iodine in soil. We developed a new speciation method suitable for routine analysis of many soil solution samples, and successfully applied the method to real samples. The method involves determining the concentration of total iodine and then separately measuring the I{sup -} and IO{sub 3}{sup -} concentrations with an HPLC system. The HPLC system (Nano-space SI-2; Shiseido, Tokyo, Japan) consisted of a UV/Vis spectrometer and an electrochemical (amperometric) detector (50 mV Ag/AgCl). Two reverse-phase columns (2.0 x 50 mm Capcel Pak DD C8 and 2.0 x 250 mm Capcel Pak MGII C18; Shiseido) were serially connected, and a switching valve was set between them. I{sup -} and IO{sub 3}{sup -} in the sample solution were separated from each other in the DD C8 column. IO{sub 3}{sup -} eluted first from the column, while I{sup -} was retained. After IO{sub 3}{sup -} was further separated from other halogen acids with the C18 column, IO{sub 3}{sup -} was reacted with KBr and o-dianisidine in a thermos-reactor (90 deg. C), and absorption at 450 nm was measured with the UV/Vis spectrometer. The concentration of I{sup -} eluted from the first column was determined with the electrochemical detector. To determine the concentration of total iodine in the sample solution, organic iodine was decomposed by UV irradiation (UV digester 705; Metrohm AG, Herisau, Switzerland) for 30 min at 20 deg. C. The iodine in the solution was reduced to I

A novel high sensitivity HPLC assay for topiramate, using 4-chloro-7-nitrobenzofurazan as pre-column fluorescence derivatizing agent.

Science.gov (United States)

Bahrami, Gholamreza; Mohammadi, Bahareh

2007-05-01

A new, sensitive and simple high-performance liquid chromatographic method for analysis of topiramate, an antiepileptic agent, using 4-chloro-7-nitrobenzofurazan as pre-column derivatization agent is described. Following liquid-liquid extraction of topiramate and an internal standard (amlodipine) from human serum, derivatization of the drugs was performed by the labeling agent in the presence of dichloromethane, methanol, acetonitrile and borate buffer (0.05 M; pH 10.6). A mixture of sodium phosphate buffer (0.05 M; pH 2.4): methanol (35:65 v/v) was eluted as mobile phase and chromatographic separation was achieved using a Shimpack CLC-C18 (150 x 4.6 mm) column. In this method the limit of quantification of 0.01 microg/mL was obtained and the procedure was validated over the concentration range of 0.01 to 12.8 microg/mL. No interferences were found from commonly co-administrated antiepileptic drugs including phenytoin, phenobarbital carbamazepine, lamotrigine, zonisamide, primidone, gabapentin, vigabatrin, and ethosuximide. The analysis performance was carried-out in terms of specificity, sensitivity, linearity, precision, accuracy and stability and the method was shown to be accurate, with intra-day and inter-day accuracy from -3.4 to 10% and precise, with intra-day and inter-day precision from 1.1 to 18%.

C-glucosidic ellagitannins from Lythri herba (European Pharmacopoeia): chromatographic profile and structure determination.

Science.gov (United States)

Piwowarski, Jakub P; Kiss, Anna K

2013-01-01

Lythri herba, a pharmacopoeial plant material (European Pharmacopoea), is obtained from flowering parts of purple loosestrife (Lythrum salicaria L.). Although extracts from this plant material have been proven to possess some interesting biological activities and its pharmacopoeial standardisation is based on total tannin content determination, the phytochemical characterisation of this main group of compounds has not yet been fully conducted. To isolate ellagitannins from Lythri herba, determine their structures and develop chromatographic methods for their qualitative analysis. Five C-glucosidic ellagitannins - monomeric- vescalagin and castalagin together with new dimeric structures - salicarinins A-C, composed of vescalagin and stachyurin, vescalagin and casuarinin, castalagin and casuarinin units connected via formation of valoneoyl group, were isolated using column chromatography and preparative HPLC. Structures were determined according to (1) H and (13) C-NMR (one- and two-dimensional), electrospray ionisation-time of flight (ESI-TOF), electrospray ionisation-ion trap (ESI-MS(n) ) and circular dichroism (CD) spectra, together with acidic hydrolysis products analysis. HPTLC on RP-18 modified plates and HPLC-DAD-MS(n) on RP-18 column methods were developed for separation of the five main ellagitannins. Copyright © 2012 John Wiley & Sons, Ltd.

Microwave assisted solvent extraction and coupled-column reversed-phase liquid chromatography with UV detection use of an analytical restricted-access-medium column for the efficient multi-residue analysis of acidic pesticides in soils.

Science.gov (United States)

Hogendoom, E A; Huls, R; Dijkman, E; Hoogerbrugge, R

2001-12-14

A screening method has been developed for the determination of acidic pesticides in various types of soils. Methodology is based on the use of microwave assisted solvent extraction (MASE) for fast and efficient extraction of the analytes from the soils and coupled-column reversed-phase liquid chromatography (LC-LC) with UV detection at 228 nm for the instrumental analysis of uncleaned extracts. Four types of soils, including sand, clay and peat, with a range in organic matter content of 0.3-13% and ten acidic pesticides of different chemical families (bentazone, bromoxynil, metsulfuron-methyl, 2,4-D, MCPA, MCPP, 2,4-DP, 2,4,5-T, 2,4-DB and MCPB) were selected as matrices and analytes, respectively. The method developed included the selection of suitable MASE and LC-LC conditions. The latter consisted of the selection of a 5-microm GFF-II internal surface reversed-phase (ISRP, Pinkerton) analytical column (50 x 4.6 mm, I.D.) as the first column in the RAM-C18 configuration in combination with an optimised linear gradient elution including on-line cleanup of sample extracts and reconditioning of the columns. The method was validated with the analysis of freshly spiked samples and samples with aged residues (120 days). The four types of soils were spiked with the ten acidic pesticides at levels between 20 and 200 microg/kg. Weighted regression of the recovery data showed for most analyte-matrix combinations, including freshly spiked samples and aged residues, that the method provides overall recoveries between 60 and 90% with relative standard deviations of the intra-laboratory reproducibility's between 5 and 25%; LODs were obtained between 5 and 50 microg/kg. Evaluation of the data set with principal component analysis revealed that the parameters (i) increase of organic matter content of the soil samples and (ii) aged residues negatively effect the recovery of the analytes.

Superdiffusion of Carbon by Vacancies Irradiated with Soft X-Rays in CZ Silicon / Superdifūzija Ar Vakancēm Iestarota Ar Mīkstajiem Rentgenstariem CZ Silīcijā

Science.gov (United States)

Janavičius, A. J.; Mekys, A.; Purlys, R.; Norgėla, Ž.; Daugėla, S.; Rinkūnas, R.

2015-10-01

The soft X-ray photons absorbed in the inner K, L, M shells of Si atoms produce photoelectrons and Auger electrons, thus generating vacancies, interstitials and metastable oxygen complexes. The samples of Czochralski silicon crystals covered with 0.1 μm thickness layer of carbon have been irradiated by X-rays using different voltages of Cu anode of the Russian diffractometer DRON-3M. The influence of X-rays on the formation of point defects and vacancy complexes, and their dynamics in Cz-Si crystals have been studied by infrared absorption. We have measured and calculated dynamics of concentration of carbon and interstitial oxygen using FTIR spectroscopy at room temperature after irradiation by soft X-rays. Using transmittance measurements and nonlinear diffusion theory we have calculated densities increasing for substitutional carbon and interstitial oxygen by reactions and very fast diffusion. The superdiffusion coefficients of carbon in silicon at room temperature generated by X-rays are about hundred thousand times greater than diffusion coefficients obtained for thermodiffusion. Rezumējums: Rentgena staru fotoni, absorbēti Si atoma iekšējos slāņos, izstaro fotoelektronus un Ožē elektronus, ģenerējot vakances, starpmezglu silīcija atomus, vakanču un skābekļa kompleksus. Čohraļska silīcija kristāli, kas pārklāti ar oglekli 0.1 μm biezuma kārtā, tika apstaroti ar rentgena stariem, izmantojot krievu difraktometru DRON-3M. Oglekļa un skābekļa difūzija un koncentrāciju izmaiņa silīcijā tika izmērīta izmantojot infrasarkano staru FTIR spektroskopiju. Rentgena staru ģenerētās ļoti ātrās oglekļa difūzijas vai superdifūzijas koeficients istabas temperatūrā silīcijā ir simtiem tūkstošu reižu lielāks nekā termodifūzijas gadījumā.

Small Column Ion Exchange

International Nuclear Information System (INIS)

Huff, Thomas

2010-01-01

Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

Cholinergic PET imaging in infections and inflammation using 11C-donepezil and 18F-FEOBV

DEFF Research Database (Denmark)

Jørgensen, Nis Pedersen; Alstrup, Aage Kristian Olsen; Mortensen, Frank Viborg

2017-01-01

with Staphylococcus aureus, and PET scanned at 24, 72, 120, and 144 h post-inoculation. Four pigs with post-operative abscesses were also imaged. Finally, we present initial data from human patients with infections, inflammation, and renal and lung cancer. Results In mice, the FDG uptake in abscesses peaked at 24 h...... and remained stable. The 11C-donepezil and 18F-FEOBV uptake displayed progressive increase, and at 120–144 h was nearly at the FDG level. Moderate 11C-donepezil and slightly lower 18F-FEOBV uptake were seen in pig abscesses. PCR analyses suggested that the 11C-donepezil signal in inflammatory cells is derived...... from both acetylcholinesterase and sigma-1 receptors. In humans, very high 11C-donepezil uptake was seen in a lobar pneumonia and in peri-tumoral inflammation surrounding a non-small cell lung carcinoma, markedly superseding the 18F-FDG uptake in the inflammation. In a renal clear cell carcinoma no 11C...

Mass transfer model liquid phase catalytic exchange column simulation applicable to any column composition profile

Energy Technology Data Exchange (ETDEWEB)

Busigin, A. [NITEK USA Inc., Ocala, FL (United States)

2015-03-15

Liquid Phase Catalytic Exchange (LPCE) is a key technology used in water detritiation systems. Rigorous simulation of LPCE is complicated when a column may have both hydrogen and deuterium present in significant concentrations in different sections of the column. This paper presents a general mass transfer model for a homogenous packed bed LPCE column as a set of differential equations describing composition change, and equilibrium equations to define the mass transfer driving force within the column. The model is used to show the effect of deuterium buildup in the bottom of an LPCE column from non-negligible D atom fraction in the bottom feed gas to the column. These types of calculations are important in the design of CECE (Combined Electrolysis and Catalytic Exchange) water detritiation systems.

Modeling shoreline bioremediation: Continuous flow and seawater exchange columns

International Nuclear Information System (INIS)

Ramstad, S.; Sveum, P.; Bech, C.; Faksness, L.G.

1995-01-01

This paper describes the design and use of the columns in the study of bioremediation processes, and gives some results from an experiment designed to study the effects of different additives (fish meal, stick water, and Max Bac) on biodegradation of crude oil. There is significant difference in oil degradation(nC 17 /pristane ratio) between the column with additives and those without. Open system models in this type of open column give valuable data o how the chemical and biological parameters, including oil degradation, are affected by the additives, and simultaneously by the dilutive effect of seawater washing through the sediment, and for optimizing formulations. The system is designed with a large number of units and provides a good first approximation for mesocosm studies and field experiments, thus reducing the need for large numbers of such resource-demanding experiments

Silício na micropropagação de orquídeas: características morfofisiológicas

OpenAIRE

Soares, Joyce Dória Rodrigues

2013-01-01

O cultivo in vitro de espécies de orquídeas constitui a base para a propagação massal de mudas livre de doenças. Este trabalho objetivou estudar o desenvolvimento fitotécnico, o comportamento fisiológico e ultraestrutural em orquídeas micropropagadas. Três experimentos foram realizados, os quais avaliaram: 1) concentrações de silício e qualidade de luz no cultivo in vitro; 2) anatomia de espécies híbrida e nativa sob concentrações de silicio; 3) estiolamento e luz artificial na multiplicação ...

75 FR 69870 - Delegation of Authority Under 18 U.S.C. 249

Science.gov (United States)

2010-11-16

... DEPARTMENT OF JUSTICE 28 CFR Part 0 [Docket No. OAG 136; A.G. Order No. 3227-2010] Delegation of Authority Under 18 U.S.C. 249 AGENCY: Department of Justice. ACTION: Final rule. SUMMARY: This rule amends....S.C. 801 does not apply. List of Subjects in 28 CFR Part 0 Authority delegations (Government...

Mathematical model and simulation of the hydrodynamic of air-pulsed sieve plate columns

International Nuclear Information System (INIS)

Hannappel, J.; Pfeifer, W.; Rathjen, E.

1979-02-01

In this work the dynamic flow events in an air pulsed sieve plate column are described by a simulation model. The model consists of a system of differential equations. The pressure built up by the pulsed air is brought to equilibrium with the pressure losses of the oscillating liquid column in the pulsation tube and in the column. In case of definition of the a) column geometry, b) integral holdup of the column, c) density of the participating phases, d) control times of the pulsed air valves, e) pulse repetition frequency and pulsed air reservoir pressure the height of oscillation and hence the intensity of pulsation are calculated. It is shown by a concrete example that 1) the oscillation of the liquid column in the pulsation tube and in the column is sinusoidal in all cases; 2) generation of a defined pulsation is restricted to the range between 0.3 and 3 Hz; 3) the amount of air needed for pulsation depends on the geometry of the column and in the intensity of pulsation. It can be optimized by appropriate selection of the diameter of the pulsation tube. (orig.) [de

Pulsed Airborne Lidar Measurements of C02 Column Absorption

Science.gov (United States)

Abshire, James B.; Riris, Haris; Allan, Graham R.; Weaver, Clark J.; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William E.; Rodriquez, Michael; Browell, Edward V.

2011-01-01

We report on airborne lidar measurements of atmospheric CO2 column density for an approach being developed as a candidate for NASA's ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 measurement from aircraft in July and August 2009 over four locations. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The 2009 measurements have been analyzed in detail and the results show approx.1 ppm random errors for 8-10 km altitudes and approx.30 sec averaging times. Airborne measurements were also made in 2010 with stronger signals and initial analysis shows approx. 0.3 ppm random errors for 80 sec averaging times for measurements at altitudes> 6 km.

Topographic shear and the relation of ocular dominance columns to orientation columns in primate and cat visual cortex.

Science.gov (United States)

Wood, Richard J.; Schwartz, Eric L.

1999-03-01

Shear has been known to exist for many years in the topographic structure of the primary visual cortex, but has received little attention in the modeling literature. Although the topographic map of V1 is largely conformal (i.e. zero shear), several groups have observed topographic shear in the region of the V1/V2 border. Furthermore, shear has also been revealed by anisotropy of cortical magnification factor within a single ocular dominance column. In the present paper, we make a functional hypothesis: the major axis of the topographic shear tensor provides cortical neurons with a preferred direction of orientation tuning. We demonstrate that isotropic neuronal summation of a sheared topographic map, in the presence of additional random shear, can provide the major features of cortical functional architecture with the ocular dominance column system acting as the principal source of the shear tensor. The major principal axis of the shear tensor determines the direction and its eigenvalues the relative strength of cortical orientation preference. This hypothesis is then shown to be qualitatively consistent with a variety of experimental results on cat and monkey orientation column properties obtained from optical recording and from other anatomical and physiological techniques. In addition, we show that a recent result of Das and Gilbert (Das, A., & Gilbert, C. D., 1997. Distortions of visuotopic map match orientation singularities in primary visual cortex. Nature, 387, 594-598) is consistent with an infinite set of parameterized solutions for the cortical map. We exploit this freedom to choose a particular instance of the Das-Gilbert solution set which is consistent with the full range of local spatial structure in V1. These results suggest that further relationships between ocular dominance columns, orientation columns, and local topography may be revealed by experimental testing.

Laser Spectroscopy Monitoring of 13C18O16O and 12C17O16O of Atmospheric Carbon Dioxide

Science.gov (United States)

Shorter, J. H.; Nelson, D. D.; Ono, S.; McManus, J. B.; Zahniser, M. S.

2017-12-01

One of the main challenges to making accurate predictions of future changes in CO2 concentration is the capability to determine what fraction of human produced CO2 remains in the atmosphere. We present our progress in the application of Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) to the measurement of the primary clumped (13C18O16O) as well as 17O (12C17O16O) isotopologues of atmospheric CO2, as a tracer of its sources and sinks. We expect unique isotopologue signals in CO2 from high-temperature combustion sources, plants, soils, and air-sea exchange processes. High sampling frequency (a few minutes for each sample vs. reference cycle) achieved by a TILDAS instrument is expected to enable us to document local heterogeneous sources and temporal variations. The TILDAS is equipped with a newly developed 400-meter absorption cell. We designed a dual pressure measurement technique in which the clumped isotopologue, 13C18O16O, and 13C16O16O are first measured at 30 torr cell pressure. This is followed by measurement of 12C17O16O, 12C18O16O and 12C16O16O at lower ( 5 torr) cell pressure. Isotopologue ratios are compared between reference and sample gases. Preliminary tests demonstrated a precision approaching 0.03 ‰ for the ratio 13C18O16O/13C16O16O and 0.08‰ for Δ13C18O16O value (1σ repeatability for 4 min sample vs. reference cycle). Sample size for a single analysis is approximately 100 mL of air (1.6μmol of CO2). Given the previously observed range of variations for Δ13C18O16O and Δ17O values as large as 0.6 to 0.3 ‰, respectively, TILDAS offers a novel approach for real time monitoring of atmospheric CO2 isotopologues. It was found that achieving better than 0.1‰ requires careful matching of CO2 mixing ratios between reference and sample air. A primary cause of pressure and mixing ratio dependence is inaccurate baseline fitting (analogous to abundance sensitivity or pressure baseline for IRMS). Given that mixing ratios of atmospheric