Microcolumn Formation due to Induced-Charge Electroosmosis in a Floating Mode

NASA Astrophysics Data System (ADS)

Sugioka, Hideyuki; Dan, Hironobu; Hanazawa, Yuya

2017-10-01

Self-organization of particles is important since it may provide new functional materials. Previously, by using two-dimensional multiphysics simulations, we theoretically showed microcolumn formation due to induced-charge electroosmosis (ICEO). In this study, we experimentally demonstrate that gold leaves on a water surface move slowly and dynamically form a microcolumn due to a hydrodynamic interaction under an ac electric field. Further, by numerically analyzing video data, we show the time evolutions of the maximum cluster length and the maximum cluster area. In addition, by cluster analysis, we show the dependences of the average velocity on the applied voltage and frequency to clarify the phenomena. We believe that our findings make a new stage in the development of new functional materials on a water surface.

Direct probing of chromatography columns by laser-induced fluorescence

NASA Astrophysics Data System (ADS)

McGuffin, V. L.

1992-12-01

This report summarizes the progress and accomplishments of this research project from 1 Sep. 1989 to 28 Feb. 1993. During this period, we have accomplished all of the primary scientific objectives of the research proposal: (1) constructed and evaluated a laser-induced fluorescence detection system that allows direct examination of the chromatographic column, (2) examined nonequilibrium processes that occur upon solute injection and elution, (3) examined solute retention in liquid chromatography as a function of temperature and pressure, (4) examined solute zone dispersion in liquid chromatography as a function of temperature and pressure, and (5) developed appropriate theoretical models to describe these phenomena. In each of these studies, substantial knowledge has been gained of the fundamental processes that are responsible for chromatographic separations. In addition to these primary research objectives, we have made significant progress in three related areas: (1) examined pyrene as a fluorescent polarity probe in supercritical fluids and liquids as a function of temperature and pressure, (2) developed methods for the class-selective identification of polynuclear aromatic hydrocarbons in coal-derived fluids by microcolumn liquid chromatography with fluorescence quenching detection, and (3) developed methods for the determination of saturated and unsaturated (including omega-3) fatty acids in fish oil extracts by microcolumn liquid chromatography with laser-induced fluorescence detection. In these studies, the advanced separation and detection techniques developed in our laboratory are applied to practical problems of environmental and biomedical significance.

Cracking the barcode of fullerene-like cortical microcolumns.

PubMed

Tozzi, Arturo; Peters, James F; Ori, Ottorino

2017-03-22

Artificial neural systems and nervous graph theoretical analysis rely upon the stance that the neural code is embodied in logic circuits, e.g., spatio-temporal sequences of ON/OFF spiking neurons. Nevertheless, this assumption does not fully explain complex brain functions. Here we show how nervous activity, other than logic circuits, could instead depend on topological transformations and symmetry constraints occurring at the micro-level of the cortical microcolumn, i.e., the embryological, anatomical and functional basic unit of the brain. Tubular microcolumns can be flattened in fullerene-like two-dimensional lattices, equipped with about 80 nodes standing for pyramidal neurons where neural computations take place. We show how the countless possible combinations of activated neurons embedded in the lattice resemble a barcode. Despite the fact that further experimental verification is required in order to validate our claim, different assemblies of firing neurons might have the appearance of diverse codes, each one responsible for a single mental activity. A two-dimensional fullerene-like lattice, grounded on simple topological changes standing for pyramidal neurons' activation, not just displays analogies with the real microcolumn's microcircuitry and the neural connectome, but also the potential for the manufacture of plastic, robust and fast artificial networks in robotic forms of full-fledged neural systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential intravenous injection of anionic polymer and cationic lipoplex of siRNA could effectively deliver siRNA to the liver.

PubMed

Hattori, Yoshiyuki; Arai, Shohei; Okamoto, Ryou; Hamada, Megumi; Kawano, Kumi; Yonemochi, Etsuo

2014-12-10

In this study, we developed novel siRNA transfer method to the liver by sequential intravenous injection of anionic polymer and cationic liposome/cholesterol-modified siRNA complex (cationic lipoplex). When cationic lipoplex was intravenously injected into mice, the accumulation of siRNA was mainly observed in the lungs. In contrast, when cationic lipoplex was intravenously injected at 1 min after intravenous injection of poly-L-glutamic acid (PGA) or chondroitin sulfate C (CS), siRNA was accumulated in the liver. In terms of suppression of gene expression in vivo, apolipoprotein B (ApoB) mRNA in the liver and low-density-lipoprotein (LDL) and very low-density-lipoprotein (VLDL) cholesterol level in serum were reduced at 48 h after single sequential injection of PGA or CS plus cationic lipoplex of cholesterol-modified ApoB siRNA. Furthermore, sequential injections of PGA plus cationic lipoplex of cholesterol-modified luciferase siRNA could reduce luciferase activity in tumor xenografts bearing liver metastasis of human breast tumor MCF-7-Luc. From these findings, sequential injection of anionic polymer and cationic lipoplex of siRNA might produce a systemic vector of siRNA to the liver. Copyright © 2014 Elsevier B.V. All rights reserved.

In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model.

PubMed

Cressman, Erik N K; Shenoi, Mithun M; Edelman, Theresa L; Geeslin, Matthew G; Hennings, Leah J; Zhang, Yan; Iaizzo, Paul A; Bischof, John C

2012-01-01

To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.

Accelerated drug release and clearance of PEGylated epirubicin liposomes following repeated injections: a new challenge for sequential low-dose chemotherapy

PubMed Central

Yang, Qiang; Ma, Yanling; Zhao, Yongxue; She, Zhennan; Wang, Long; Li, Jie; Wang, Chunling; Deng, Yihui

2013-01-01

Background Sequential low-dose chemotherapy has received great attention for its unique advantages in attenuating multidrug resistance of tumor cells. Nevertheless, it runs the risk of producing new problems associated with the accelerated blood clearance phenomenon, especially with multiple injections of PEGylated liposomes. Methods Liposomes were labeled with fluorescent phospholipids of 1,2-dipalmitoyl-snglycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) and epirubicin (EPI). The pharmacokinetics profile and biodistribution of the drug and liposome carrier following multiple injections were determined. Meanwhile, the antitumor effect of sequential low-dose chemotherapy was tested. To clarify this unexpected phenomenon, the production of polyethylene glycol (PEG)-specific immunoglobulin M (IgM), drug release, and residual complement activity experiments were conducted in serum. Results The first or sequential injections of PEGylated liposomes within a certain dose range induced the rapid clearance of subsequently injected PEGylated liposomal EPI. Of note, the clearance of EPI was two- to three-fold faster than the liposome itself, and a large amount of EPI was released from liposomes in the first 30 minutes in a complement-activation, direct-dependent manner. The therapeutic efficacy of liposomal EPI following 10 days of sequential injections in S180 tumor-bearing mice of 0.75 mg EPI/kg body weight was almost completely abolished between the sixth and tenth day of the sequential injections, even although the subsequently injected doses were doubled. The level of PEG-specific IgM in the blood increased rapidly, with a larger amount of complement being activated while the concentration of EPI in blood and tumor tissue was significantly reduced. Conclusion Our investigation implied that the accelerated blood clearance phenomenon and its accompanying rapid leakage and clearance of drug following sequential low-dose injections may reverse the unique pharmacokinetic–toxicity profile of liposomes which deserved our attention. Therefore, a more reasonable treatment regime should be selected to lessen or even eliminate this phenomenon. PMID:23576868

Microfluidic direct injection method for analysis of urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) using molecularly imprinted polymers coupled on-line with LC-MS/MS.

PubMed

Shah, Kumar A; Peoples, Michael C; Halquist, Matthew S; Rutan, Sarah C; Karnes, H Thomas

2011-01-25

The work described in this paper involves development of a high-throughput on-line microfluidic sample extraction method using capillary micro-columns packed with MIP beads coupled with tandem mass spectrometry for the analysis of urinary NNAL. The method was optimized and matrix effects were evaluated and resolved. The method enabled low sample volume (200 μL) and rapid analysis of urinary NNAL by direct injection onto the microfluidic column packed with molecularly imprinted beads engineered to NNAL. The method was validated according to the FDA bioanalytical method validation guidance. The dynamic range extended from 20.0 to 2500.0 pg/mL with a percent relative error of ±5.9% and a run time of 7.00 min. The lower limit of quantitation was 20.0 pg/mL. The method was used for the analysis of NNAL and NNAL-Gluc concentrations in smokers' urine. Copyright © 2010 Elsevier B.V. All rights reserved.

Nanophotonic production, modulation and switching of ions by silicon microcolumn arrays

DOEpatents

Vertes, Akos; Walker, Bennett N.

2013-09-10

The production and use of silicon microcolumn arrays that harvest light from a laser pulse to produce ions are described. The systems of the present invention seem to behave like a quasi-periodic antenna array with ion yields that show profound dependence on the plane of laser light polarization and the angle of incidence. By providing photonic ion sources, this enables enhanced control of ion production on a micro/nano scale and direct integration with miniaturized analytical devices.

Nanophotonic production, modulation and switching of ions by silicon microcolumn arrays

DOEpatents

Vertes, Akos; Walker, Bennett N

2015-04-07

The production and use of silicon microcolumn arrays that harvest light from a laser pulse to produce ions are described. The systems of the present invention seem to behave like a quasi-periodic antenna array with ion yields that show profound dependence on the plane of laser light polarization and the angle of incidence. By providing photonic ion sources, this enables enhanced control of ion production on a micro/nano scale and direct integration with miniaturized analytical devices.

Nanophotonic production, modulation and switching of ions by silicon microcolumn arrays

DOEpatents

Vertes, Akos [Reston, VA; Walker, Bennett N [Washington, DC

2012-02-07

The production and use of silicon microcolumn arrays that harvest light from a laser pulse to produce ions are described. The systems of the present invention seem to behave like a quasi-periodic antenna array with ion yields that show profound dependence on the plane of laser light polarization and the angle of incidence. By providing photonic ion sources, this enables enhanced control of ion production on a micro/nano scale and direct integration with miniaturized analytical devices.

Cu2+-imprinted cross-linked chitosan resin as micro-column packing materials for online chemiluminescence determination of trace copper.

PubMed

Nie, Feng; Hao, Liang; Gao, Mei; Wu, Yingchun; Li, Xinsheng; Yu, Sha

2011-01-01

The Cu(2+)-imprinted cross-linked chitosan resin was synthesized and the binding characteristic of the resin to Cu(2+) was evaluated. The prepared resin was packed into a micro-glass column and used as micro-separating column. The micro-separating column was connected into the chemiluminescence flow system and placed in front of the window of the photomultiplier tube. Based on the luminol-hydrogen peroxide chemiluminescence system, a flow injection online chemiluminescence method for determination of trace copper was developed and trace Cu(2+) in complex samples was successfully determined. The proposed method improved the shortcomings of chemiluminescence method's poor selectivity. Copyright © 2010 John Wiley & Sons, Ltd.

Systematic research on the pretreatment of peptides for quantitative proteomics using a C₁₈ microcolumn.

PubMed

Zhai, Linhui; Chang, Cheng; Li, Ning; Duong, Duc M; Chen, Hao; Deng, Zixin; Yang, Jian; Hong, Xuechuan; Zhu, Yunping; Xu, Ping

2013-08-01

Reversed phase microcolumns have been widely used for peptide pretreatment to desalt and remove interferences before tandem LC-MS in proteomics studies. However, few studies have characterized the effects of experimental parameters as well as column characteristics on the composition of identified peptides. In this study, several parameters including the concentration of ACN in washing buffer, the microcolumn's purification effect, the peptide recovery rate, and the dynamic-binding capacity were characterized in detail, based upon stable isotope labeling by amino acids in a cell culture quantitative approach. The results showed that peptide losses can be reduced with low ACN concentration in washing buffers resulting in a recovery rate of approximately 82%. Furthermore, the effects of ACN concentration and loading amount on the properties of identified peptides were also evaluated. We found that the dynamic-binding capacity of the column was approximately 26 μg. With increased loading amounts, more hydrophilic peptides were replaced by hydrophobic peptides. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Laser desorption ionization and peptide sequencing on laser induced silicon microcolumn arrays

DOEpatents

Vertes, Akos [Reston, VA; Chen, Yong [San Diego, CA

2011-12-27

The present invention provides a method of producing a laser-patterned silicon surface, especially silicon wafers for use in laser desorption ionization (LDI-MS) (including MALDI-MS and SELDI-MS), devices containing the same, and methods of testing samples employing the same. The surface is prepared by subjecting a silicon substrate to multiple laser shots from a high-power picosecond or femtosecond laser while in a processing environment, e.g., underwater, and generates a remarkable homogenous microcolumn array capable of providing an improved substrate for LDI-MS.

Polymeric microchip for the simultaneous determination of anions and cations by hydrodynamic injection using a dual-channel sequential injection microchip electrophoresis system.

PubMed

Gaudry, Adam J; Nai, Yi Heng; Guijt, Rosanne M; Breadmore, Michael C

2014-04-01

A dual-channel sequential injection microchip capillary electrophoresis system with pressure-driven injection is demonstrated for simultaneous separations of anions and cations from a single sample. The poly(methyl methacrylate) (PMMA) microchips feature integral in-plane contactless conductivity detection electrodes. A novel, hydrodynamic "split-injection" method utilizes background electrolyte (BGE) sheathing to gate the sample flows, while control over the injection volume is achieved by balancing hydrodynamic resistances using external hydrodynamic resistors. Injection is realized by a unique flow-through interface, allowing for automated, continuous sampling for sequential injection analysis by microchip electrophoresis. The developed system was very robust, with individual microchips used for up to 2000 analyses with lifetimes limited by irreversible blockages of the microchannels. The unique dual-channel geometry was demonstrated by the simultaneous separation of three cations and three anions in individual microchannels in under 40 s with limits of detection (LODs) ranging from 1.5 to 24 μM. From a series of 100 sequential injections the %RSDs were determined for every fifth run, resulting in %RSDs for migration times that ranged from 0.3 to 0.7 (n = 20) and 2.3 to 4.5 for peak area (n = 20). This system offers low LODs and a high degree of reproducibility and robustness while the hydrodynamic injection eliminates electrokinetic bias during injection, making it attractive for a wide range of rapid, sensitive, and quantitative online analytical applications.

Simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by 3-(2-aminoethylamino) propyltrimethoxysilane modified multi-wall carbon nanotubes packed microcolumn solid phase extraction and ICP-MS.

PubMed

Peng, Hanyong; Zhang, Nan; He, Man; Chen, Beibei; Hu, Bin

2015-01-01

Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L(-1) KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L(-1) with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L(-1), n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters. Copyright © 2014 Elsevier B.V. All rights reserved.

Microfluidic Device for Sequential Injection and Flushing of Solutions and its Application to Immunosensing

NASA Astrophysics Data System (ADS)

Nashida, Norihiro; Suzuki, Hiroaki

A microfluidic system with injecting and flushing functions was developed. In the system, hydrophilic flow channels have a dry-film photoresist layer which facilitates the introduction of solutions from four injection ports. The injection and flushing of solutions are controlled by valves operated by electrowetting. The valves consist of gold working electrodes in the flow channels or a through-hole in the glass substrate. Solutions can be sequentially introduced through the injection ports into a reaction chamber and flushed through a valve in the through-hole. Necessary immunoassay steps can be conducted on the chip, and a target antibody can be detected electrochemically.

Sequential-Injection Analysis: Principles, Instrument Construction, and Demonstration by a Simple Experiment

ERIC Educational Resources Information Center

Economou, A.; Tzanavaras, P. D.; Themelis, D. G.

2005-01-01

The sequential-injection analysis (SIA) is an approach to sample handling that enables the automation of manual wet-chemistry procedures in a rapid, precise and efficient manner. The experiments using SIA fits well in the course of Instrumental Chemical Analysis and especially in the section of Automatic Methods of analysis provided by chemistry…

Exploring Liquid Sequential Injection Chromatography to Teach Fundamentals of Separation Methods: A Very Fast Analytical Chemistry Experiment

ERIC Educational Resources Information Center

Penteado, Jose C.; Masini, Jorge Cesar

2011-01-01

Influence of the solvent strength determined by the addition of a mobile-phase organic modifier and pH on chromatographic separation of sorbic acid and vanillin has been investigated by the relatively new technique, liquid sequential injection chromatography (SIC). This technique uses reversed-phase monolithic stationary phase to execute fast…

Mercury(II) and methyl mercury determinations in water and fish samples by using solid phase extraction and cold vapour atomic absorption spectrometry combination.

PubMed

Tuzen, Mustafa; Karaman, Isa; Citak, Demirhan; Soylak, Mustafa

2009-07-01

A method has been developed for mercury(II) and methyl mercury speciation on Staphylococcus aureus loaded Dowex Optipore V-493 micro-column in the presented work, by using cold vapour atomic absorption spectrometry. Selective and sequential elution with 0.1 molL(-1) HCl for methyl mercury and 2 molL(-1) HCl for mercury(II) were performed at the pH range of 2-6. Optimal analytical conditions including pH, amounts of biosorbent, sample volumes were investigated. The detection limits of the analytes were 2.5 ngL(-1) for Hg(II) and 1.7 ngL(-1) for methyl mercury. The capacity of biosorbent for mercury(II) and methyl mercury was 6.5 and 5.4 mgg(-1), respectively. The validation of the presented procedure is performed by the analysis of standard reference material. The speciation procedure established was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and microwave digested fish samples.

Highly Multiplexed RNA Aptamer Selection using a Microplate-based Microcolumn Device.

PubMed

Reinholt, Sarah J; Ozer, Abdullah; Lis, John T; Craighead, Harold G

2016-07-19

We describe a multiplexed RNA aptamer selection to 19 different targets simultaneously using a microcolumn-based device, MEDUSA (Microplate-based Enrichment Device Used for the Selection of Aptamers), as well as a modified selection process, that significantly reduce the time and reagents needed for selections. We exploited MEDUSA's reconfigurable design between parallel and serially-connected microcolumns to enable the use of just 2 aliquots of starting library, and its 96-well microplate compatibility to enable the continued use of high-throughput techniques in downstream processes. Our modified selection protocol allowed us to perform the equivalent of a 10-cycle selection in the time it takes for 4 traditional selection cycles. Several aptamers were discovered with nanomolar dissociation constants. Furthermore, aptamers were identified that not only bound with high affinity, but also acted as inhibitors to significantly reduce the activity of their target protein, mouse decapping exoribonuclease (DXO). The aptamers resisted DXO's exoribonuclease activity, and in studies monitoring DXO's degradation of a 30-nucleotide substrate, less than 1 μM of aptamer demonstrated significant inhibition of DXO activity. This aptamer selection method using MEDUSA helps to overcome some of the major challenges with traditional aptamer selections, and provides a platform for high-throughput selections that lends itself to process automation.

Reconstitution of full‐thickness skin by microcolumn grafting

PubMed Central

Wang, Ying; Vuong, Linh N.; Fisher, Jeremy M.; Farinelli, William A.; Anderson, R. Rox

2016-01-01

Abstract In addition to providing a physical barrier, skin also serves a diverse range of physiological functions through different specialized resident cell types/structures, including melanocytes (pigmentation and protection against ultraviolet radiation), Langerhans cells (adaptive immunity), fibroblasts (maintaining extracellular matrix, paracrine regulation of keratinocytes), sweat glands (thermoregulation) and hair follicles (hair growth, sensation and a stem cell reservoir). Restoration of these functional elements has been a long‐standing challenge in efforts to engineer skin tissue, while autologous skin grafting is limited by the scarcity of donor site skin and morbidity caused by skin harvesting. We demonstrate an alternative approach of harvesting and then implanting μm‐scale, full‐thickness columns of human skin tissue, which can be removed from a donor site with minimal morbidity and no scarring. Fresh human skin microcolumns were used to reconstitute skin in wounds on immunodeficient mice. The restored skin recapitulated many key features of normal human skin tissue, including epidermal architecture, diverse skin cell populations, adnexal structures and sweat production in response to cholinergic stimulation. These promising preclinical results suggest that harvesting and grafting of microcolumns may be useful for reconstituting fully functional skin in human wounds, without donor site morbidity. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. PMID:27296503

Development of enantioselective chemiluminescence flow- and sequential-injection immunoassays for alpha-amino acids.

PubMed

Silvaieh, Hossein; Schmid, Martin G; Hofstetter, Oliver; Schurig, Volker; Gübitz, Gerald

2002-01-01

The development of an enantioselective flow-through chemiluminescence immunosensor for amino acids is described. The approach is based on a competitive assay using enantioselective antibodies. Two different instrumental approaches, a flow-injection (FIA) and a sequential-injection system (SIA), are used. Compared to the flow-injection technique, the sequential injection-mode showed better repeatability. Both systems use an immunoreactor consisting of a flow cell packed with immobilized haptens. The haptens (4-amino-L- or D-phenylalanine) are immobilized onto a hydroxysuccinimide-activated polymer (Affi-prep 10) via a tyramine spacer. Stereoselective antibodies, raised against 4-amino-L- or D-phenylalanine, are labeled with an acridinium ester. Stereoselective inhibition of binding of the acridinum-labeled antibodies to the immobilized hapten by amino acids takes place. Chiral recognition was observed not only for the hapten molecule but also for a series of different amino acids. One assay cycle including regeneration takes 6:30 min in the FIA mode and 4:40 min in the SIA mode. Using D-phenylalanine as a sample, the detection limit was found to be 6.13 pmol/ml (1.01 ng/ml) for the flow-injection immunoassay (FIIA) and 1.76 pmol/ml (0.29 ng/ml ) for the sequential-injection immunoassay (SIIA) which can be lowered to 0.22 pmol/ml (0.036 ng/ml) or 0.064 pmol/ml (0.01 ng/ml) by using a stopped flow system. The intra-assay repeatability was found to be about 5% RSD and the inter-assay repeatability below 6% (within 3 days).

Determination of ambroxol hydrochloride, methylparaben and benzoic acid in pharmaceutical preparations based on sequential injection technique coupled with monolithic column.

PubMed

Satínský, Dalibor; Huclová, Jitka; Ferreira, Raquel L C; Montenegro, Maria Conceição B S M; Solich, Petr

2006-02-13

The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection. A Chromolith SpeedROD RP-18e, 50-4.6 mm column with 10 mm precolumn and a FIAlab 3000 system with a six-port selection valve and 5 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-tetrahydrofuran-0.05M acetic acid (10:10:90, v/v/v), pH 3.75 adjusted with triethylamine, flow rate 0.48 mlmin(-1), UV-detection was at 245 nm. The analysis time was <11 min. A new SIC method was validated and compared with HPLC. The method was found to be useful for the routine analysis of the active compounds ambroxol and preservatives (methylparaben or benzoic acid) in various pharmaceutical syrups and drops.

Separation and preconcentration of actinides from concentrated nitric acid by extraction chromatography in microsystems.

PubMed

Losno, Marion; Pellé, Julien; Marie, Mylène; Ferrante, Ivan; Brennetot, René; Descroix, Stéphanie; Mariet, Clarisse

2018-08-01

An original method of monolith impregnation in microsystem for the analysis of radionuclides in nitric acid is reported. Three microcolumns made of monolith poly(AMA-co-EDMA) were impregnated in COC microsystems. The robustness of the microsystems in nitric acid media until 8 M was demonstrated. High exchange capacity and affinity for tetravalent and hexavalent actinides in concentrated nitric media were obtained. The retention characteristics of the microcolumns impregnated by TBP, TBP-CMPO and DAAP were compared with those of the equivalent commercial particulate resins TBP™, TRU™ and UTEVA™ respectively. The separation of U, Th and Eu was validated in a classical microsystem and a procedure is proposed in a centrifugal microsystem. Copyright © 2018. Published by Elsevier B.V.

Determination of nitrite and nitrate in water samples by an automated hydrodynamic sequential injection method.

PubMed

Somnam, Sarawut; Jakmunee, Jaroon; Grudpan, Kate; Lenghor, Narong; Motomizu, Shoji

2008-12-01

An automated hydrodynamic sequential injection (HSI) system with spectrophotometric detection was developed. Thanks to the hydrodynamic injection principle, simple devices can be used for introducing reproducible microliter volumes of both sample and reagent into the flow channel to form stacked zones in a similar fashion to those in a sequential injection system. The zones were then pushed to the detector and a peak profile was recorded. The determination of nitrite and nitrate in water samples by employing the Griess reaction was chosen as a model. Calibration graphs with linearity in the range of 0.7 - 40 muM were obtained for both nitrite and nitrate. Detection limits were found to be 0.3 muM NO(2)(-) and 0.4 muM NO(3)(-), respectively, with a sample throughput of 20 h(-1) for consecutive determination of both the species. The developed system was successfully applied to the analysis of water samples, employing simple and cost-effective instrumentation and offering higher degrees of automation and low chemical consumption.

Sequential capillary electrophoresis analysis using optically gated sample injection and UV/vis detection.

PubMed

Liu, Xiaoxia; Tian, Miaomiao; Camara, Mohamed Amara; Guo, Liping; Yang, Li

2015-10-01

We present sequential CE analysis of amino acids and L-asparaginase-catalyzed enzyme reaction, by combing the on-line derivatization, optically gated (OG) injection and commercial-available UV-Vis detection. Various experimental conditions for sequential OG-UV/vis CE analysis were investigated and optimized by analyzing a standard mixture of amino acids. High reproducibility of the sequential CE analysis was demonstrated with RSD values (n = 20) of 2.23, 2.57, and 0.70% for peak heights, peak areas, and migration times, respectively, and the LOD of 5.0 μM (for asparagine) and 2.0 μM (for aspartic acid) were obtained. With the application of the OG-UV/vis CE analysis, sequential online CE enzyme assay of L-asparaginase-catalyzed enzyme reaction was carried out by automatically and continuously monitoring the substrate consumption and the product formation every 12 s from the beginning to the end of the reaction. The Michaelis constants for the reaction were obtained and were found to be in good agreement with the results of traditional off-line enzyme assays. The study demonstrated the feasibility and reliability of integrating the OG injection with UV/vis detection for sequential online CE analysis, which could be of potential value for online monitoring various chemical reaction and bioprocesses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A microfluidic chip with a staircase pH gradient generator, a packed column and a fraction collector for chromatofocusing of proteins.

PubMed

Rho, Hoon Suk; Hanke, Alexander Thomas; Ottens, Marcel; Gardeniers, Han J G E

2018-04-01

A microfluidic device for pH gradient chromatofocusing is presented, which performs creation of a micro-column, pH gradient generation, and fraction collection in a single device. Using a sieve micro-valve, anion exchange particles were packed into a microchannel in order to realize a solid-phase absorption column. To fractionate proteins according to their isoelectric points, elution buffer solutions with a stepwise pH gradient were prepared in 16 parallel mixing reactors and flowed through the micro-column, wherein a protein mixture was previously loaded. The volume of the column is only 20 nL, hence it allows extremely low sample consumption and fast analysis compared with a conventional system. We demonstrated separation of two proteins, albumin-fluorescein isothiocyanate conjugate (FITC-BSA) and R-Phycoerythrin (R-PE), by using a microcolumn of commercial charged polymeric particles (Source 15Q). The microfluidic device can be used as a rapid diagnostic tool to analyse crude mixtures of proteins or nucleic acids and determine adsorption/desorption characteristics of various biochemical products, which can be helpful for scientific fundamental understanding as well as instrumental in various industrial applications, especially in early stage screening and process development. © 2018 The Authors Electrophoresis Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanometer-sized alumina packed microcolumn solid-phase extraction combined with field-amplified sample stacking-capillary electrophoresis for the speciation analysis of inorganic selenium in environmental water samples.

PubMed

Duan, Jiankuan; Hu, Bin; He, Man

2012-10-01

In this paper, a new method of nanometer-sized alumina packed microcolumn SPE combined with field-amplified sample stacking (FASS)-CE-UV detection was developed for the speciation analysis of inorganic selenium in environmental water samples. Self-synthesized nanometer-sized alumina was packed in a microcolumn as the SPE adsorbent to retain Se(IV) and Se(VI) simultaneously at pH 6 and the retained inorganic selenium was eluted by concentrated ammonia. The eluent was used for FASS-CE-UV analysis after NH₃ evaporation. The factors affecting the preconcentration of both Se(IV) and Se(VI) by SPE and FASS were studied and the optimal CE separation conditions for Se(IV) and Se(VI) were obtained. Under the optimal conditions, the LODs of 57 ng L⁻¹ (Se(IV)) and 71 ng L⁻¹ (Se(VI)) were obtained, respectively. The developed method was validated by the analysis of a certified reference material of GBW(E)080395 environmental water and the determined value was in a good agreement with the certified value. It was also successfully applied to the speciation analysis of inorganic selenium in environmental water samples, including Yangtze River water, spring water, and tap water. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reconstitution of full-thickness skin by microcolumn grafting.

PubMed

Tam, Joshua; Wang, Ying; Vuong, Linh N; Fisher, Jeremy M; Farinelli, William A; Anderson, R Rox

2017-10-01

In addition to providing a physical barrier, skin also serves a diverse range of physiological functions through different specialized resident cell types/structures, including melanocytes (pigmentation and protection against ultraviolet radiation), Langerhans cells (adaptive immunity), fibroblasts (maintaining extracellular matrix, paracrine regulation of keratinocytes), sweat glands (thermoregulation) and hair follicles (hair growth, sensation and a stem cell reservoir). Restoration of these functional elements has been a long-standing challenge in efforts to engineer skin tissue, while autologous skin grafting is limited by the scarcity of donor site skin and morbidity caused by skin harvesting. We demonstrate an alternative approach of harvesting and then implanting μm-scale, full-thickness columns of human skin tissue, which can be removed from a donor site with minimal morbidity and no scarring. Fresh human skin microcolumns were used to reconstitute skin in wounds on immunodeficient mice. The restored skin recapitulated many key features of normal human skin tissue, including epidermal architecture, diverse skin cell populations, adnexal structures and sweat production in response to cholinergic stimulation. These promising preclinical results suggest that harvesting and grafting of microcolumns may be useful for reconstituting fully functional skin in human wounds, without donor site morbidity. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

The Development of Molybdenum Speciation as a Paleoredox Tool

NASA Astrophysics Data System (ADS)

Rodley, J.; Peacock, C.; Mosselmans, J. F. W.; Poulton, S.

2017-12-01

The redox state of the oceans has changed throughout geological time and an understanding of these changes is essential to elucidate links between ocean chemistry, climate and life. Due to its abundance in seawater and redox-sensitive nature, molybdenum has enormous potential as a paleoredox proxy. Although a significant amount of research has been done on molybdenum in ancient and modern sediments in terms of its concentrations and isotopic ratios there remains a limited understanding of the drawdown mechanisms of molybdenum under different redox conditions restricting its use in identifying a range of redox states. In order to address these uncertainties, we have developed a novel sequential extraction technique to examine molybdenum concentrations in six sediment fractions from modern samples that represent oxic, nitrogenous, ferruginous and euxinic environments. In addition we use µ-XRF and µ-XANES synchrotron spectroscopy to examine the molybdenum speciation within these fractions and environments. To interpret our µ-XANES data we have developed an extensive library of molybdenum XANES standards that represent molybdenum sequestration by the sediment fractions identified from the sequential extraction. To further verify our synchrotron results we developed a series of µ-XANES micro-column experiments to examine preferential uptake pathways of molybdenum to different sediment phases under a euxinic water column. The initial data from both the sequential extraction and µ-XANES methods indicate that molybdenum is not limited to a single burial pathway in any of the redox environments. We find that each of the redox environments can be characterised by a limited set of molybdenum phase associations, with molybdenum adsorption to pyrite likely the dominant burial pathway. These findings agree with existing research for molybdenum speciation in euxinic environments suggesting that both pyrite and sulphidised organic matter act as important molybdenum sinks. Our new research shows that pyrite is also an important sink for molybdenum in other redox environments.

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

PubMed

van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

2002-09-01

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method.

Highly efficient proteome analysis with combination of protein pre-fractionation by preparative microscale solution isoelectric focusing and identification by μRPLC-MS/MS with serially coupled long microcolumn.

PubMed

Tao, Dingyin; Sun, Liangliang; Zhu, Guijie; Liang, Yu; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2011-01-01

To improve the efficiency of proteome analysis, a strategy with the combination of protein pre-fractionation by preparative microscale solution isoelectric focusing, peptide separation by μRPLC with serially coupled long microcolumn and protein identification by ESI-MS/MS was proposed. By preparative microscale solution isoelectric focusing technique, proteins extracted from whole cell lysates of Escherichia coli were fractionated into five chambers divided by isoelectric membranes, respectively with pH range from 3.0 to 4.6, 4.6 to 5.4, 5.4 to 6.2, 6.2 to 7.0 and 7.0 to 10.0. Compared to the traditional on-gel IFF, the protein recovery could be obviously improved to over 95%. Subsequently, the enriched and fractionated proteins in each chamber were digested, and further separated by a 30-cm long serially coupled RP microcolumn. Through the detection by ESI-MS/MS, about 200 proteins were identified in each fraction, and in total 835 proteins were identified even with one-dimensional μRPLC-MS/MS system. All these results demonstrate that by such a combination strategy, highly efficient proteome analysis could be achieved, not only due to the in-solution protein enrichment and pre-fractionation with improved protein recovery but also owing to the increased separation capacity of serially coupled long μRPLC columns. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous versus Sequential Intratympanic Steroid Treatment for Severe-to-Profound Sudden Sensorineural Hearing Loss.

PubMed

Yoo, Myung Hoon; Lim, Won Sub; Park, Joo Hyun; Kwon, Joong Keun; Lee, Tae-Hoon; An, Yong-Hwi; Kim, Young-Jin; Kim, Jong Yang; Lim, Hyun Woo; Park, Hong Ju

2016-01-01

Severe-to-profound sudden sensorineural hearing loss (SSNHL) has a poor prognosis. We aimed to compare the efficacy of simultaneous and sequential oral and intratympanic steroids for this condition. Fifty patients with severe-to-profound SSNHL (>70 dB HL) were included from 7 centers. The simultaneous group (27 patients) received oral and intratympanic steroid injections for 2 weeks. The sequential group (23 patients) was treated with oral steroids for 2 weeks and intratympanic steroids for the subsequent 2 weeks. Pure-tone averages (PTA) and word discrimination scores (WDS) were compared before treatment and 2 weeks and 1 and 2 months after treatment. Treatment outcomes according to the modified American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria were also analyzed. The improvement in PTA and WDS at the 2-week follow-up was 23 ± 21 dB HL and 20 ± 39% in the simultaneous group and 31 ± 29 dB HL and 37 ± 42% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-week follow-up was observed in 26% of the simultaneous group and 30% of the sequential group; this was also not significant. The improvement in PTA and WDS at the 2-month follow-up was 40 ± 20 dB HL and 37 ± 35% in the simultaneous group and 41 ± 25 dB HL and 48 ± 41% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-month follow-up was observed in 33% of the simultaneous group and 35% of the sequential group; this was also not significant. Seven patients in the sequential group did not need intratympanic steroid injections for sufficient improvement after oral steroids alone. Simultaneous oral/intratympanic steroid treatment yielded a recovery similar to that produced by sequential treatment. Because the addition of intratympanic steroids can be decided upon based on the improvement after an oral steroid, the sequential regimen can be recommended to avoid unnecessary intratympanic injections. © 2017 S. Karger AG, Basel.

Solid-phase extraction microfluidic devices for matrix removal in trace element assay of actinide materials

DOE PAGES

Gao, Jun; Manard, Benjamin Thomas; Castro, Alonso; ...

2017-02-02

Advances in sample nebulization and injection technology have significantly reduced the volume of solution required for trace impurity analysis in plutonium and uranium materials. Correspondingly, we have designed and tested a novel chip-based microfluidic platform, containing a 100-µL or 20-µL solid-phase microextraction column, packed by centrifugation, which supports nuclear material mass and solution volume reductions of 90% or more compared to standard methods. Quantitative recovery of 28 trace elements in uranium was demonstrated using a UTEVA chromatographic resin column, and trace element recovery from thorium (a surrogate for plutonium) was similarly demonstrated using anion exchange resin AG MP-1. Of ninemore » materials tested, compatibility of polyvinyl chloride (PVC), polypropylene (PP), and polytetrafluoroethylene (PTFE) chips with the strong nitric acid media was highest. Finally, the microcolumns can be incorporated into a variety of devices and systems, and can be loaded with other solid-phase resins for trace element assay in high-purity metals.« less

Solid-phase extraction microfluidic devices for matrix removal in trace element assay of actinide materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Jun; Manard, Benjamin Thomas; Castro, Alonso

Advances in sample nebulization and injection technology have significantly reduced the volume of solution required for trace impurity analysis in plutonium and uranium materials. Correspondingly, we have designed and tested a novel chip-based microfluidic platform, containing a 100-µL or 20-µL solid-phase microextraction column, packed by centrifugation, which supports nuclear material mass and solution volume reductions of 90% or more compared to standard methods. Quantitative recovery of 28 trace elements in uranium was demonstrated using a UTEVA chromatographic resin column, and trace element recovery from thorium (a surrogate for plutonium) was similarly demonstrated using anion exchange resin AG MP-1. Of ninemore » materials tested, compatibility of polyvinyl chloride (PVC), polypropylene (PP), and polytetrafluoroethylene (PTFE) chips with the strong nitric acid media was highest. Finally, the microcolumns can be incorporated into a variety of devices and systems, and can be loaded with other solid-phase resins for trace element assay in high-purity metals.« less

A Method To Determine the Kinetics of Solute Mixing in Liquid/Liquid Formulation Dual-Chamber Syringes.

PubMed

Werk, Tobias; Mahler, Hanns-Christian; Ludwig, Imke Sonja; Luemkemann, Joerg; Huwyler, Joerg; Hafner, Mathias

Dual-chamber syringes were originally designed to separate a solid substance and its diluent. However, they can also be used to separate liquid formulations of two individual drug products, which cannot be co-formulated due to technical or regulatory issues. A liquid/liquid dual-chamber syringe can be designed to achieve homogenization and mixing of both solutions prior to administration, or it can be used to sequentially inject both solutions. While sequential injection can be easily achieved by a dual-chamber syringe with a bypass located at the needle end of the syringe barrel, mixing of the two fluids may provide more challenges. Within this study, the mixing behavior of surrogate solutions in different dual-chamber syringes is assessed. Furthermore, the influence of parameters such as injection angle, injection speed, agitation, and sample viscosity were studied. It was noted that mixing was poor for the commercial dual-chamber syringes (with a bypass designed as a longitudinal ridge) when the two liquids significantly differ in their physical properties (viscosity, density). However, an optimized dual-chamber syringe design with multiple bypass channels resulted in improved mixing of liquids. Dual-chamber syringes were originally designed to separate a solid substance and its diluent. However, they can also be used to separate liquid formulations of two individual drug products. A liquid/liquid dual-chamber syringe can be designed to achieve homogenization and mixing of both solutions prior to administration, or it can be used to sequentially inject both solutions. While sequential injection can be easily achieved by a dual-chamber syringe with a bypass located at the needle end of the syringe barrel, mixing of the two fluids may provide more challenges. Within this study, the mixing behavior of surrogate solutions in different dual-chamber syringes is assessed. Furthermore, the influence of parameters such as injection angle, injection speed, agitation, and sample viscosity were studied. It was noted that mixing was poor for the commercially available dual-chamber syringes when the two liquids significantly differ in viscosity and density. However, an optimized dual-chamber syringe design resulted in improved mixing of liquids. © PDA, Inc. 2017.

Development of a sequential injection-square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode.

PubMed

dos Santos, Luciana B O; Infante, Carlos M C; Masini, Jorge C

2010-03-01

This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level.

Micro-column plasma emission liquid chromatograph

DOEpatents

Gay, Don D.

1984-01-01

In a direct current plasma emission spectrometer for use in combination with a micro-column liquid chromatograph, an improved plasma source unit. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

Micro-column plasma emission liquid chromatograph. [Patent application

DOEpatents

Gay, D.D.

1982-08-12

In a direct current plasma emission spectrometer for use in combination with a microcolumn liquid chromatograph, an improved plasma source unit is claimed. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

Efficient flow injection and sequential injection methods for spectrophotometric determination of oxybenzone in sunscreens based on reaction with Ni(II).

PubMed

Chisvert, A; Salvador, A; Pascual-Martí, M C; March, J G

2001-04-01

Spectrophotometric determination of a widely used UV-filter, such as oxybenzone, is proposed. The method is based on the complexation reaction between oxybenzone and Ni(II) in ammoniacal medium. The stoichiometry of the reaction, established by the Job method, was 1:1. Reaction conditions were studied and the experimental parameters were optimized, for both flow injection (FI) and sequential injection (SI) determinations, with comparative purposes. Sunscreen formulations containing oxybenzone were analyzed by the proposed methods and results compared with those obtained by HPLC. Data show that both FI and SI procedures provide accurate and precise results. The ruggedness, sensitivity and LOD are adequate to the analysis requirements. The sample frequency obtained by FI is three-fold higher than that of SI analysis. SI is less reagent-consuming than FI.

Age-related reduction in microcolumnar structure correlates with cognitive decline in ventral but not dorsal area 46 of the rhesus monkey.

PubMed

Cruz, L; Roe, D L; Urbanc, B; Inglis, A; Stanley, H E; Rosene, D L

2009-02-18

The age-related decline in cognitive function that is observed in normal aging monkeys and humans occurs without significant loss of cortical neurons. This suggests that cognitive impairment results from subtle, sub-lethal changes in the cortex. Recently, changes in the structural coherence in mini- or microcolumns without loss of neurons have been linked to loss of function. Here we use a density map method to quantify microcolumnar structure in both banks of the sulcus principalis (prefrontal cortical area 46) of 16 (ventral) and 19 (dorsal) behaviorally tested female rhesus monkeys from 6 to 33 years of age. While total neuronal density does not change with age in either of these banks, there is a significant age-related reduction in the strength of microcolumns in both regions on the order of 40%. This likely reflects a subtle but definite loss of organization in the structure of the cortical microcolumn. The reduction in strength in ventral area 46 correlates with cognitive impairments in learning and memory while the reduction in dorsal area 46 does not. This result is congruent with published data attributing cognitive functions to ventral area 46 that are similar to our particular cognitive battery which does not optimally tap cognitive functions attributed to dorsal area 46. While the exact mechanisms underlying this loss of microcolumnar organization remain to be determined, it is plausible that they reflect age-related alterations in dendritic and/or axonal organization which alter connectivity and may contribute to age-related declines in cognitive performance.

Laser desorption/ionization from nanostructured surfaces: nanowires, nanoparticle films and silicon microcolumn arrays

NASA Astrophysics Data System (ADS)

Chen, Yong; Luo, Guanghong; Diao, Jiajie; Chornoguz, Olesya; Reeves, Mark; Vertes, Akos

2007-04-01

Due to their optical properties and morphology, thin films formed of nanoparticles are potentially new platforms for soft laser desorption/ionization (SLDI) mass spectrometry. Thin films of gold nanoparticles (with 12±1 nm particle size) were prepared by evaporation-driven vertical colloidal deposition and used to analyze a series of directly deposited polypeptide samples. In this new SLDI method, the required laser fluence for ion detection was equal or less than what was needed for matrix-assisted laser desorption/ionization (MALDI) but the resulting spectra were free of matrix interferences. A silicon microcolumn array-based substrate (a.k.a. black silicon) was developed as a new matrix-free laser desorption ionization surface. When low-resistivity silicon wafers were processed with a 22 ps pulse length 3×ω Nd:YAG laser in air, SF6 or water environment, regularly arranged conical spikes emerged. The radii of the spike tips varied with the processing environment, ranging from approximately 500 nm in water, to ~2 µm in SF6 gas and to ~5 µm in air. Peptide mass spectra directly induced by a nitrogen laser showed the formation of protonated ions of angiotensin I and II, substance P, bradykinin fragment 1-7, synthetic peptide, pro14-arg, and insulin from the processed silicon surfaces but not from the unprocessed areas. Threshold fluences for desorption/ionization were similar to those used in MALDI. Although compared to silicon nanowires the threshold laser pulse energy for ionization is significantly (~10×) higher, the ease of production and robustness of microcolumn arrays offer complementary benefits.

Recent Electrochemical and Optical Sensors in Flow-Based Analysis

PubMed Central

Chailapakul, Orawon; Ngamukot, Passapol; Yoosamran, Alongkorn; Siangproh, Weena; Wangfuengkanagul, Nattakarn

2006-01-01

Some recent analytical sensors based on electrochemical and optical detection coupled with different flow techniques have been chosen in this overview. A brief description of fundamental concepts and applications of each flow technique, such as flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA), and multipumped FIA (MPFIA) were reviewed.

Living organisms as an alternative to hyphenated techniques for metal speciation. Evaluation of baker's yeast immobilized on silica gel for Hg speciation*1

NASA Astrophysics Data System (ADS)

Pérez-Corona, Teresa; Madrid-Albarrán, Yolanda; Cámara, Carmen; Beceiro, Elisa

1998-02-01

The use of living organisms for metal preconcentration and speciation is discussed. Among substrates, Saccharomyces cerevisiae baker's yeast has been successfully used for the speciation of mercury [Hg(II) and CH 3Hg +], selenium [Se(IV) and Se(VI)] and antimony [Sb(III) and Sb(V)]. To illustrate the capabilities of these organisms, the analytical performance of baker's yeast immobilized on silica gel for on-line preconcentration and speciation of Hg(II) and methylmercury is reported. The immobilized cells were packed in a PTFE microcolumn, through which mixtures of organic and inorganic mercury solutions were passed. Retention of inorganic and organic mercury solutions took place simultaneously, with the former retained in the silica and the latter on the yeast. The efficiency uptake for both species was higher than 95% over a wide pH range. The speciation was carried out by selective and sequential elution with 0.02 mol L -1 HCl for methylmercury and 0.8 mol L -1 CN - for Hg(II). This method allows both preconcentration and speciation of mercury. The preconcentration factors were around 15 and 100 for methylmercury and mercury(II), respectively. The method has been successfully applied to spiked sea water samples.

EVALUATING CAPACITIES OF GAC PRELOADED WITH NATURAL WATER

EPA Science Inventory

Adsorption studies are conducted to determine how preloading a natural groundwater onto GAC affects the adsorption of cis-1,2-dichloroexthene in small-scale and pilot-scale columns. Capacities are determined from batch-isotherm tests, microcolumns, and pilot columns, which are p...

Micro-fractional ablative skin resurfacing with two novel erbium laser systems.

PubMed

Dierickx, Christine C; Khatri, Khalil A; Tannous, Zeina S; Childs, James J; Cohen, Richard H; Erofeev, Andrei; Tabatadze, David; Yaroslavsky, Ilya V; Altshuler, Gregory B

2008-02-01

Fractional ablation offers the potential benefits of full-surface ablative skin resurfacing while minimizing adverse effects. The purpose of this study was to evaluate the safety, damage profile, and efficacy of erbium fractional lasers. Histology from animal and human skin as well as clinical evaluations were conducted with erbium YAG (2,940 nm) and erbium YSGG (2,790 nm) fractional lasers varying pulse width, microbeam (microb) energy, number of passes, and stacking of pulses. Single-pulse treatment parameters from 1 to 12 mJ per 50-70 microm diameter microbeam and 0.25-5 milliseconds pulse widths produced microcolumns of ablation with border coagulation of up to 100 microm width and 450 microm depth. Stacking of pulses generated deeper microcolumns. Clinical observations and in vivo histology demonstrate rapid re-epithelization and limited adverse side effects. Facial treatments were performed in the periorbital and perioral areas using 1-8 passes of single and stacked pulses. Treatments were well-tolerated and subjects could resume their normal routine in 4 days. A statistically significant reduction in wrinkle scores at 3 months was observed for both periorbital and perioral wrinkles using blinded grading. For periorbital treatments of four passes or more, over 90% had > or =1 score wrinkle reduction (0-9 scale) and 42% had > or =2. For perioral wrinkles, over 50% had substantial improvements (> or =2). The clinical observations and histology findings demonstrate that micro-fractional ablative treatment with 2,790 and 2,940 nm erbium lasers resulted in safe and effective wrinkle reduction with minimal patient downtime. The depth and width of the ablated microcolumns and varying extent of surrounding coagulation can be controlled and used to design new treatment procedures targeted for specific indications and areas such as moderate to severe rhytides and photodamaged skin.

Highly integrated autonomous lab-on-a-chip device for on-line and in situ determination of environmental chemical parameters.

PubMed

Martinez-Cisneros, Cynthia; da Rocha, Zaira; Seabra, Antonio; Valdés, Francisco; Alonso-Chamarro, Julián

2018-06-05

The successful integration of sample pretreatment stages, sensors, actuators and electronics in microfluidic devices enables the attainment of complete micro total analysis systems, also known as lab-on-a-chip devices. In this work, we present a novel monolithic autonomous microanalyzer that integrates microfluidics, electronics, a highly sensitive photometric detection system and a sample pretreatment stage consisting on an embedded microcolumn, all in the same device, for on-line determination of relevant environmental parameters. The microcolumn can be filled/emptied with any resin or powder substrate whenever required, paving the way for its application to several analytical processes: separation, pre-concentration or ionic-exchange. To promote its autonomous operation, avoiding issues caused by bubbles in photometric detection systems, an efficient monolithic bubble removal structure was also integrated. To demonstrate its feasibility, the microanalyzer was successfully used to determine nitrate and nitrite in continuous flow conditions, providing real time and continuous information.

Determination of Hg(2+) by on-line separation and pre-concentration with atmospheric-pressure solution-cathode glow discharge atomic emission spectrometry.

PubMed

Li, Qing; Zhang, Zhen; Wang, Zheng

2014-10-03

A simple and sensitive method to determine Hg(2+) was developed by combining solution-cathode glow discharge atomic emission spectrometry (SCGD-AES) with flow injection (FI) based on on-line solid-phase extraction (SPE). We synthesized l-cysteine-modified mesoporous silica and packed it in an SPE microcolumn, which was experimentally determined to possess a good mercury adsorption capacity. An enrichment factor of 42 was achieved under optimized Hg(2+) elution conditions, namely, an FI flow rate of 2.0 mL min(-1) and an eluent comprised of 10% thiourea in 0.2 mol L(-1) HNO3. The detection limit of FI-SCGD-AES was determined to be 0.75 μg L(-1), and the precision of the 11 replicate Hg(2+) measurements was 0.86% at a concentration of 100 μg L(-1). The proposed method was validated by determining Hg(2+) in certified reference materials such as human hair (GBW09101b) and stream sediment (GBW07310). Copyright © 2014. Published by Elsevier B.V.

Imaging the photoinduced charge injection in CdS/TiO2 nanoparticles by the sequential fluorescence mapping method

NASA Astrophysics Data System (ADS)

Frederice, Rafael; Lencione, Diego; Gehlen, Marcelo H.

2017-03-01

The combination of a sensitizer and TiO2 nanoparticles forming a photocatalytic material is a central issue in many fields of applied photochemistry. The charge injection of emissive sensitizers into the conduction band of the semiconductor TiO2 may form a photoactive region that becomes dark, or it has a very low emission signal due to the generation of sensitizer radicals. However, by sequential coupling of a selected photoredox dye, such as resazurin, the dark region may become fluorescent at the interfaces where the charge injection has taken place due to the concomitant formation of fluorescent resorufin by cascade electron transfer. Using this strategy and a total internal reflection fluorescence microscopy (TIRFM) image, the charge injection in TiO2/CdS and SiO2/TiO2/CdS nanoparticles is investigated The method allows the charge injection efficiency of the excited CdS into TiO2 to be evaluated qualitatively, explaining the differences observed for these photocatalytic materials in H2 generation.

Imaging the photoinduced charge injection in CdS/TiO2 nanoparticles by the sequential fluorescence mapping method.

PubMed

Frederice, Rafael; Lencione, Diego; Gehlen, Marcelo H

2017-02-10

The combination of a sensitizer and TiO 2 nanoparticles forming a photocatalytic material is a central issue in many fields of applied photochemistry. The charge injection of emissive sensitizers into the conduction band of the semiconductor TiO 2 may form a photoactive region that becomes dark, or it has a very low emission signal due to the generation of sensitizer radicals. However, by sequential coupling of a selected photoredox dye, such as resazurin, the dark region may become fluorescent at the interfaces where the charge injection has taken place due to the concomitant formation of fluorescent resorufin by cascade electron transfer. Using this strategy and a total internal reflection fluorescence microscopy (TIRFM) image, the charge injection in TiO 2 /CdS and SiO 2 /TiO 2 /CdS nanoparticles is investigated The method allows the charge injection efficiency of the excited CdS into TiO 2 to be evaluated qualitatively, explaining the differences observed for these photocatalytic materials in H 2 generation.

Sequential Injection Analysis for Optimization of Molecular Biology Reactions

PubMed Central

Allen, Peter B.; Ellington, Andrew D.

2011-01-01

In order to automate the optimization of complex biochemical and molecular biology reactions, we developed a Sequential Injection Analysis (SIA) device and combined this with a Design of Experiment (DOE) algorithm. This combination of hardware and software automatically explores the parameter space of the reaction and provides continuous feedback for optimizing reaction conditions. As an example, we optimized the endonuclease digest of a fluorogenic substrate, and showed that the optimized reaction conditions also applied to the digest of the substrate outside of the device, and to the digest of a plasmid. The sequential technique quickly arrived at optimized reaction conditions with less reagent use than a batch process (such as a fluid handling robot exploring multiple reaction conditions in parallel) would have. The device and method should now be amenable to much more complex molecular biology reactions whose variable spaces are correspondingly larger. PMID:21338059

Sequential injection spectrophotometric determination of oxybenzone in lipsticks.

PubMed

Salvador, A; Chisvert, A; Camarasa, A; Pascual-Martí, M C; March, J G

2001-08-01

A sequential injection (SI) procedure for the spectrophotometric determination of oxybenzone in lipsticks is reported. The colorimetric reaction between nickel and oxybenzone was used. SI parameters such as sample solution volume, reagent solution volume, propulsion flow rate and reaction coil length were studied. The limit of detection was 3 microg ml(-1). The sensitivity was 0.0108+/-0.0002 ml microg(-1). The relative standard deviations of the results were between 6 and 12%. The real concentrations of samples and the values obtained by HPLC were comparable. Microwave sample pre-treatment allowed the extraction of oxybenzone with ethanol, thus avoiding the use of toxic organic solvents. Ethanol was also used as carrier in the SI system. Seventy-two injections per hour can be performed, which means a sample frequency of 24 h(-1) if three replicates are measured for each sample.

Simultaneous detection of creatine and creatinine using a sequential injection analysis/biosensor system.

PubMed

Stefan-van Staden, Raluca-Ioana; Bokretsion, Rahel Girmai; van Staden, Jacobus F; Aboul-Enein, Hassan Y

2006-01-01

Carbon paste based biosensors for the determination of creatine and creatinine have been integrated into a sequential injection system. Applying the multi-enzyme sequence of creatininase (CA), and/or creatinase (CI) and sarcosine oxidase (SO), hydrogen peroxide has been detected amperometrically. The linear concentration ranges are of pmol/L to nmol/L magnitude, with very low limits of detection. The proposed SIA system can be utilized reliably for the on-line simultaneous detection of creatine and creatinine in pharmaceutical products, as well as in serum samples, with a rate of 34 samples per hour and RSD values better than 0.16% (n=10).

Developing Inquiry-Based Labs Using Micro-Column Chromatography

ERIC Educational Resources Information Center

Barden-Gabbei, Laura M.; Moffitt, Deborah L.

2006-01-01

Chromatography is a process by which mixtures can be separated or substances can be purified. Biological and chemical laboratories use many different types of chromatographic processes. For example, the pharmaceutical industry uses chromatographic techniques to purify drugs, medical labs use them to identify blood components such as cholesterol,…

Sequential elution process

DOEpatents

Kingsley, I.S.

1987-01-06

A process and apparatus are disclosed for the separation of complex mixtures of carbonaceous material by sequential elution with successively stronger solvents. In the process, a column containing glass beads is maintained in a fluidized state by a rapidly flowing stream of a weak solvent, and the sample is injected into this flowing stream such that a portion of the sample is dissolved therein and the remainder of the sample is precipitated therein and collected as a uniform deposit on the glass beads. Successively stronger solvents are then passed through the column to sequentially elute less soluble materials. 1 fig.

40 CFR 799.6784 - TSCA water solubility: Column elution method; shake flask method.

Code of Federal Regulations, 2010 CFR

2010-07-01

... reaction quality should be used to apply the test substance to the carrier material. Double distilled water... this section. (i) With this apparatus, the microcolumn must be modified. A stopcock with 2-way action... particles invalidates the results, and the test should be repeated with improvements in the filtering action...

Monitoring lipase/esterase activity by stopped flow in a sequential injection analysis system using p-nitrophenyl butyrate.

PubMed

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J

2015-01-27

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05-1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed.

Monitoring Lipase/Esterase Activity by Stopped Flow in a Sequential Injection Analysis System Using p-Nitrophenyl Butyrate

PubMed Central

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J.

2015-01-01

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05–1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed. PMID:25633600

Determination of dasatinib in the tablet dosage form by ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis.

PubMed

Gonzalez, Aroa Garcia; Taraba, Lukáš; Hraníček, Jakub; Kozlík, Petr; Coufal, Pavel

2017-01-01

Dasatinib is a novel oral prescription drug proposed for treating adult patients with chronic myeloid leukemia. Three analytical methods, namely ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis, were developed, validated, and compared for determination of the drug in the tablet dosage form. The total analysis time of optimized ultra high performance liquid chromatography and capillary zone electrophoresis methods was 2.0 and 2.2 min, respectively. Direct ultraviolet detection with detection wavelength of 322 nm was employed in both cases. The optimized sequential injection analysis method was based on spectrophotometric detection of dasatinib after a simple colorimetric reaction with folin ciocalteau reagent forming a blue-colored complex with an absorbance maximum at 745 nm. The total analysis time was 2.5 min. The ultra high performance liquid chromatography method provided the lowest detection and quantitation limits and the most precise and accurate results. All three newly developed methods were demonstrated to be specific, linear, sensitive, precise, and accurate, providing results satisfactorily meeting the requirements of the pharmaceutical industry, and can be employed for the routine determination of the active pharmaceutical ingredient in the tablet dosage form. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of simultaneous and sequential administration of fentanyl-propofol for surgical abortion: a randomized single-blinded controlled trial.

PubMed

Gao, Wei; Sha, Baoyong; Zhao, Yuan; Fan, Zhe; Liu, Lin; Shen, Xin

2017-08-01

Propofol lipid emulsion (PLE) is a nanosized sedative, and it is used with a combination of salted antalgic prodrug, fentanyl citrate (FC). To illustrate the synergistic effect of mixing, we compared the sedation/analgesia resulting from simultaneous and sequential administration in surgically induced abortion (No. ChiCTR-IPC-15006153). Simultaneous group showed lower bispectral index, blood pressure, and heart rate, when cannula was inserted into the uterus. It also showed less frequency of hypertension, sinus tachycardia, movement, pain at the injection site, and additional FC. Therefore, premixing of PLE and FC enhanced the sedation and analgesia; stabilized the hemodynamics; lessened the incidence of movement and injection pain; and reduced the requirement of drugs.

Ceramic microsystem incorporating a microreactor with immobilized biocatalyst for enzymatic spectrophotometric assays.

PubMed

Baeza, Mireia; López, Carmen; Alonso, Julián; López-Santín, Josep; Alvaro, Gregorio

2010-02-01

Low-temperature cofired ceramics (LTCC) technology is a versatile fabrication technique used to construct microflow systems. It permits the integration of several unitary operations (pretreatment, separation, (bio)chemical reaction, and detection stage) of an analytical process in a modular or monolithic way. Moreover, because of its compatibility with biological material, LTCC is adequate for analytical applications based on enzymatic reactions. Here we present the design, construction, and evaluation of a LTCC microfluidic system that integrates a microreactor (internal volume, 24.28 microL) with an immobilized beta-galactosidase from Escherichia coli (0.479 activity units) and an optical flow cell to measure the product of the enzymatic reaction. The enzyme was immobilized on a glyoxal-agarose support, maintaining its activity along the time of the study. As a proof of concept, the LTCC-beta-galactosidase system was tested by measuring the conversion of ortho-nitrophenyl beta-D-galactopyranoside, the substrate usually employed for activity determinations. Once packed in a monolithically integrated microcolumn, the miniaturized flow system was characterized, the operational conditions optimized (flow rate and injection volume), and its performance successfully evaluated by determining the beta-galactosidase substrate concentration at the millimolar level.

Sequential Injection/Electrochemical Immunoassay for Quantifying the Pesticide Metabolite 3, 5, 6-Trichloro-2-Pyridinol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Riechers, Shawn L.; Timchalk, Chuck

2005-12-04

An automated and sensitive sequential injection electrochemical immunoassay was developed to monitor a potential insecticide biomarker, 3, 5, 6-trichloro-2-pyridinol. The current method involved a sequential injection analysis (SIA) system equipped with a thin-layer electrochemical flow cell and permanent magnet, which was used to fix 3,5,6-trichloro-2-pyridinol (TCP) antibody coated magnetic beads (TCP-Ab-MBs) in the reaction zone. After competitive immunoreactions among TCP-Ab-MBs, TCP analyte, and horseradish peroxidase (HRP) labeled TCP, a 3, 3?, 5, 5?-tetramethylbenzidine dihydrochloride and hydrogen peroxide (TMB-H2O2) substrate solution was injected to produce an electroactive enzymatic product. The activity of HRP tracers was monitored by a square wave voltammetricmore » scanning electroactive enzymatic product in the thin-layer flow cell. The voltammetric characteristics of the substrate and the enzymatic product were investigated under batch conditions, and the parameters of the immunoassay were optimized in the SIA system. Under the optimal conditions, the system was used to measure as low as 6 ng L-1 (ppt) TCP, which is around 50-fold lower than the value indicated by the manufacturer of the TCP RaPID Assay? kit (0.25 ug/L, colorimetric detection). The performance of the developed immunoassay system was successfully evaluated on tap water and river water samples spiked with TCP. This technique could be readily used for detecting other environmental contaminants by developing specific antibodies against contaminants and is expected to open new opportunities for environmental and biological monitoring.« less

Simultaneous injection-effective mixing analysis of palladium.

PubMed

Teshima, Norio; Noguchi, Daisuke; Joichi, Yasutaka; Lenghor, Narong; Ohno, Noriko; Sakai, Tadao; Motomizu, Shoji

2010-01-01

A novel concept of simultaneous injection-effective mixing analysis (SIEMA) is proposed, and a SIEMA method applied to the spectrophotometric determination of palladium using a water-soluble chromogenic reagent has been demonstrated. The flow configuration of SIEMA is a hybrid format of flow injection analysis (FIA), sequential injection analysis (SIA) and multicommutation in flow-based analysis. Sample and reagent solutions are aspirated into each holding coil through each solenoid valve by a syringe pump, and then the zones are simultaneously dispensed (injected) into a mixing coil by reversed flow toward a detector through a confluence point. This results in effective mixing and rapid detection with low reagent consumption.

Differential effects of progesterone and genital stimulation on sequential inhibition of estrous behavior and progesterone receptor expression in the rat brain.

PubMed

Gómez-Camarillo, Madaí A; Beyer, Carlos; Lucio, Rosa Angélica; García-Juárez, Marcos; González-Arenas, Aliesha; Camacho-Arroyo, Ignacio; Komisaruk, Barry R; González-Flores, Oscar

2011-05-30

The effect of genital stimulation, either by vaginocervical stimulation (VCS) using a calibrated vaginal probe combined with manual flank stimulation (FS), or by mounts performed by the male, on the hypothalamus and preoptic area concentration of the progesterone receptors A (PR-A) and B (PR-B) was assessed in ovariectomized (ovx) estrogen-primed rats. VCS/FS or stimulation provided by male mounts, even without intromission, significantly decreased PR-B concentration in the hypoythalamus. Down regulation of PR produced by genital stimulation was quantitatively similar to that elicited by progesterone (P) administration. Bilateral or unilateral transection of the pelvic or the pudendal nerves prevented down regulation elicited by VCS/FS. Repeated VCS/FS elicited lordosis behavior in most ovx estrogen primed rats, but the lordosis intensity was lower than that observed in response to P. P administered to ovx estrogen primed rats, induced sequential inhibition, i.e., failure to display estrous behavior in response to a second P injection (24h after the initial P injection). VCS/FS failed to elicit sequential inhibition, since rats responded with normal estrous behavior to the second injection of P. This suggests that down regulation by VCS, by contrast with P, failed to inhibit the subpopulation of PR involved in the facilitation of estrous behavior by P. Copyright © 2011 Elsevier Inc. All rights reserved.

[Separation/preconcentration of trace rare earth elements in Tricholoma giganteum by micro-column with nanometer A1203 and their determination by ICP-AES].

PubMed

Liu, Hong-gao; Wang, Yuan-zhong

2010-01-01

Using a micro-column packed with immobilized 1-phenyl-3-methyl-4-bonzoil-5-pyrazone(PMBP) on nanometer Al2O3 powder as the adsorption material, the adsorption and elution behaviors of rare earth ions (Sc3+, Y3+ and La3+) on the above material under dynamic conditions were studied with inductively coupled plasma-atomic emission spectrometry. The conditions for preconcentration of rare earth ions were optimized, and the results show that the studied ions can be adsorbed quantitatively on the above material at pH 4.5 and the analytes adsorbed on the column can be eluted with 0.5 mol x L(-1) HCl solution. The detection limits of the method for Sc, Y and La were 0.15, 0.18 and 0.34 microg x L(-1), respectively, and the relative standard deviations were 2.5%, 3.0% and 1.7%, respectively (n=12, c = 0.5 mg x L(-1)). The proposed method was applied to the determination of trace amount of Sc, Y and La in Tricholoma giganteum with satisfactory results.

Sequential injection gas guns for accelerating projectiles

DOEpatents

Lacy, Jeffrey M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID

2011-11-15

Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

Energetic electron injections and dipolarization events in Mercury's magnetotail: Substorm dynamics

NASA Astrophysics Data System (ADS)

Dewey, R. M.; Slavin, J. A.; Raines, J. M.; Imber, S.; Baker, D. N.; Lawrence, D. J.

2017-12-01

Despite its small size, Mercury's terrestrial-like magnetosphere experiences brief, yet intense, substorm intervals characterized by features similar to at Earth: loading/unloading of the tail lobes with open magnetic flux, dipolarization of the magnetic field at the inner edge of the plasma sheet, and, the focus of this presentation, energetic electron injection. We use the Gamma-Ray Spectrometer's high-time resolution (10 ms) energetic electron measurements to determine the relationship between substorm activity and energetic electron injections coincident with dipolarization fronts in the magnetotail. These dipolarizations were detected on the basis of their rapid ( 2 s) increase in the northward component of the tail magnetic field (ΔBz 30 nT), which typically persists for 10 s. We estimate the typical flow channel to be 0.15 RM, planetary convection speed of 750 km/s, cross-tail potential drop of 7 kV, and flux transport of 0.08 MWb for each dipolarization event, suggesting multiple simultaneous and sequential dipolarizations are required to unload the >1 MWb of magnetic flux typically returned to the dayside magnetosphere during a substorm interval. Indeed, while we observe most dipolarization-injections to be isolated or in small chains of events (i.e., 1-3 events), intervals of sawtooth-like injections with >20 sequential events are also present. The typical separation between dipolarization-injection events is 10 s. Magnetotail dipolarization, in addition to being a powerful source of electron acceleration, also plays a significant role in the substorm process at Mercury.

Design of LabVIEW®-based software for the control of sequential injection analysis instrumentation for the determination of morphine

PubMed Central

Lenehan, Claire E.; Lewis, Simon W.

2002-01-01

LabVIEW®-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 × 10-10 to 5 × 10-6 M) with a line of best fit of y=1.05x+8.9164 (R2 =0.9959), where y is the log10 signal (mV) and x is the log10 morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 × 10-8 M). The limit of detection (3σ) was determined as 5 × 10-11 M morphine. PMID:18924729

Design of LabVIEW-based software for the control of sequential injection analysis instrumentation for the determination of morphine.

PubMed

Lenehan, Claire E; Barnett, Neil W; Lewis, Simon W

2002-01-01

LabVIEW-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 x 10(-10) to 5 x 10(-6) M) with a line of best fit of y=1.05(x)+8.9164 (R(2) =0.9959), where y is the log10 signal (mV) and x is the log10 morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 x 10(-8) M). The limit of detection (3sigma) was determined as 5 x 10(-11) M morphine.

Tenascin-C Prevents Articular Cartilage Degeneration in Murine Osteoarthritis Models.

PubMed

Matsui, Yuriyo; Hasegawa, Masahiro; Iino, Takahiro; Imanaka-Yoshida, Kyoko; Yoshida, Toshimichi; Sudo, Akihiro

2018-01-01

Objective The objective of this study was to determine whether intra-articular injections of tenascin-C (TNC) could prevent cartilage damage in murine models of osteoarthritis (OA). Design Fluorescently labeled TNC was injected into knee joints and its distribution was examined at 1 day, 4 days, 1 week, 2 weeks, and 4 weeks postinjection. To investigate the effects of TNC on cartilage degeneration after surgery to knee joints, articular spaces were filled with 100 μg/mL (group I), 10 μg/mL (group II) of TNC solution, or control (group III). TNC solution of 10 μg/mL was additionally injected twice after 3 weeks (group IV) or weekly after 1 week, 2 weeks, and 3 weeks (group V). Joint tissues were histologically assessed using the Mankin score and the modified Chambers system at 2 to 8 weeks after surgery. Results Exogenous TNC was maintained in the cartilage and synovium for 1 week after administration. Histological scores in groups I and II were better than scores in group III at 4 and 6 weeks, but progressive cartilage damage was seen in all groups 8 weeks postoperatively. Sequential TNC injections (groups IV and V) showed significantly better Mankin score than single injection (group II) at 8 weeks. Conclusion TNC administered exogenously remained in the cartilage of knee joints for 1 week, and could decelerate articular cartilage degeneration in murine models of OA. We also showed that sequential administration of TNC was more effective than a single injection. TNC could be an important molecule for prevention of articular cartilage damage.

Rapid micro-scale proteolysis of proteins for MALDI-MS peptide mapping using immobilized trypsin

NASA Astrophysics Data System (ADS)

Gobom, Johan; Nordhoff, Eckhard; Ekman, Rolf; Roepstorff, Peter

1997-12-01

In this study we present a rapid method for tryptic digestion of proteins using micro-columns with enzyme immobilized on perfusion chromatography media. The performance of the method is exemplified with acyl-CoA-binding protein and reduced carbamidomethylated bovine serum albumin. The method proved to be significantly faster and yielded a better sequence coverage and an improved signal-to-noise ratio for the MALDI-MS peptide maps, compared to in-solution- and on-target digestion. Only a single sample transfer step is required, and therefore sample loss due to adsorption to surfaces is reduced, which is a critical issue when handling low picomole to femtomole amounts of proteins. An example is shown with on-column proteolytic digestion and subsequent elution of the digest into a reversed-phase micro-column. This is useful if the sample contains large amounts of salt or is too diluted for MALDI-MS analysis. Furthermore, by step-wise elution from the reversedphase column, a complex digest can be fractionated, which reduces signal suppression and facilitates data interpretation in the subsequent MS-analysis. The method also proved useful for consecutive digestions with enzymes of different cleavage specificity. This is exemplified with on-column tryptic digestion, followed by reversed-phase step-wise elution, and subsequent on-target V8 protease digestion.

Comparison of a gel microcolumn assay with the conventional tube test for red blood cell alloantibody titration.

PubMed

Finck, Rachel; Lui-Deguzman, Carrie; Teng, Shih-Mao; Davis, Rebecca; Yuan, Shan

2013-04-01

Titration is a semiquantitative method used to estimate red blood cell (RBC) alloantibody reactivity. The conventional tube test (CTT) technique is the traditional method for performing titration studies. The gel microcolumn assay (GMA) is also a sensitive method to detect RBC alloantibodies. The aim of this study was to compare a GMA with the CTT technique in the performance of Rh and K alloantibody titration. Patient serum samples that contained an RBC alloantibody with a singular specificity were identified by routine blood bank workflow. Parallel titration studies were performed on these samples by both the CTT method and a GMA (ID-Micro Typing System anti-IgG gel card, Micro Typing Systems, Inc., an Ortho-Clinical Diagnostics Company). Forty-eight samples were included, including 11 anti-D, five anti-c, 13 anti-E, one anti-C, three anti-e, and 15 anti-K. Overall, the two methods generated identical results in 21 of 48 samples. For 42 samples (87.5%) the two methods generated results that were within one serial dilution, and for the remaining six samples, results were within two dilutions. GMA systems may perform comparably to the CTT in titrating alloantibodies to Rh and Kell antigens. © 2012 American Association of Blood Banks.

Analysis of Anthrax Immune Globulin Intravenous with Antimicrobial Treatment in Injection Drug Users, Scotland, 2009-2010.

PubMed

Cui, Xizhong; Nolen, Leisha D; Sun, Junfeng; Booth, Malcolm; Donaldson, Lindsay; Quinn, Conrad P; Boyer, Anne E; Hendricks, Katherine; Shadomy, Sean; Bothma, Pieter; Judd, Owen; McConnell, Paul; Bower, William A; Eichacker, Peter Q

2017-01-01

We studied anthrax immune globulin intravenous (AIG-IV) use from a 2009-2010 outbreak of Bacillus anthracis soft tissue infection in injection drug users in Scotland, UK, and we compared findings from 15 AIG-IV recipients with findings from 28 nonrecipients. Death rates did not differ significantly between recipients and nonrecipients (33% vs. 21%). However, whereas only 8 (27%) of 30 patients at low risk for death (admission sequential organ failure assessment score of 0-5) received AIG-IV, 7 (54%) of the 13 patients at high risk for death (sequential organ failure assessment score of 6-11) received treatment. AIG-IV recipients had surgery more often and, among survivors, had longer hospital stays than did nonrecipients. AIG-IV recipients were sicker than nonrecipients. This difference and the small number of higher risk patients confound assessment of AIG-IV effectiveness in this outbreak.

Drug delivery into the cochlear apex: Improved control to sequentially affect finely spaced regions along the entire length of the cochlear spiral.

PubMed

Lichtenhan, J T; Hartsock, J; Dornhoffer, J R; Donovan, K M; Salt, A N

2016-11-01

Administering pharmaceuticals to the scala tympani of the inner ear is a common approach to study cochlear physiology and mechanics. We present here a novel method for in vivo drug delivery in a controlled manner to sealed ears. Injections of ototoxic solutions were applied from a pipette sealed into a fenestra in the cochlear apex, progressively driving solutions along the length of scala tympani toward the cochlear aqueduct at the base. Drugs can be delivered rapidly or slowly. In this report we focus on slow delivery in which the injection rate is automatically adjusted to account for varying cross sectional area of the scala tympani, therefore driving a solution front at uniform rate. Objective measurements originating from finely spaced, low- to high-characteristic cochlear frequency places were sequentially affected. Comparison with existing methods(s): Controlled administration of pharmaceuticals into the cochlear apex overcomes a number of serious limitations of previously established methods such as cochlear perfusions with an injection pipette in the cochlear base: The drug concentration achieved is more precisely controlled, drug concentrations remain in scala tympani and are not rapidly washed out by cerebrospinal fluid flow, and the entire length of the cochlear spiral can be treated quickly or slowly with time. Controlled administration of solutions into the cochlear apex can be a powerful approach to sequentially effect objective measurements originating from finely spaced cochlear regions and allows, for the first time, the spatial origin of CAPs to be objectively defined. Copyright © 2016 Elsevier B.V. All rights reserved.

Drug delivery into the cochlear apex: Improved control to sequentially affect finely spaced regions along the entire length of the cochlear spiral

PubMed Central

Lichtenhan, JT; Hartsock, J; Dornhoffer, JR; Donovan, KM; Salt, AN

2016-01-01

Background Administering pharmaceuticals to the scala tympani of the inner ear is a common approach to study cochlear physiology and mechanics. We present here a novel method for in vivo drug delivery in a controlled manner to sealed ears. New method Injections of ototoxic solutions were applied from a pipette sealed into a fenestra in the cochlear apex, progressively driving solutions along the length of scala tympani toward the cochlear aqueduct at the base. Drugs can be delivered rapidly or slowly. In this report we focus on slow delivery in which the injection rate is automatically adjusted to account for varying cross sectional area of the scala tympani, therefore driving a solution front at uniform rate. Results Objective measurements originating from finely spaced, low- to high-characteristic cochlear frequency places were sequentially affected. Comparison with existing methods(s): Controlled administration of pharmaceuticals into the cochlear apex overcomes a number of serious limitations of previously established methods such as cochlear perfusions with an injection pipette in the cochlear base: The drug concentration achieved is more precisely controlled, drug concentrations remain in scala tympani and are not rapidly washed out by cerebrospinal fluid flow, and the entire length of the cochlear spiral can be treated quickly or slowly with time. Conclusions Controlled administration of solutions into the cochlear apex can be a powerful approach to sequentially effect objective measurements originating from finely spaced cochlear regions and allows, for the first time, the spatial origin of CAPs to be objectively defined. PMID:27506463

Pre-evaluation of metal ions as a catalyst on chemiluminometric sequential injection analysis with luminol-H2O2 system.

PubMed

Takayanagi, Toshio; Inaba, Yuya; Kanzaki, Hiroyuki; Jyoichi, Yasutaka; Motomizu, Shoji

2009-09-15

Catalytic effect of metal ions on luminol chemiluminescence (CL) was investigated by sequential injection analysis (SIA). The SIA system was set up with two solenoid micropumps, an eight-port selection valve, and a photosensor module with a fountain-type chemiluminescence cell. The SIA system was controlled and the CL signals were collected by a LabVIEW program. Aqueous solutions of luminol, H(2)O(2), and a sample solution containing metal ion were sequentially aspirated to the holding coil, and the zones were immediately propelled to the detection cell. After optimizing the parameters using 1 x 10(-5)M Fe(3+) solution, catalytic effect of some metal species was compared. Among 16 metal species examined, relatively strong CL responses were obtained with Fe(3+), Fe(2+), VO(2+), VO(3)(-), MnO(4)(-), Co(2+), and Cu(2+). The limits of detection by the present SIA system were comparable to FIA systems. Permanganate ion showed the highest CL sensitivity among the metal species examined; the calibration graph for MnO(4)(-) was linear at the concentration level of 10(-8)M and the limit of detection for MnO(4)(-) was 4.0 x 10(-10)M (S/N=3).

Microcellular injection molding process for producing lightweight thermoplastic polyurethane with customizable properties

NASA Astrophysics Data System (ADS)

Ellingham, Thomas; Kharbas, Hrishikesh; Manitiu, Mihai; Scholz, Guenter; Turng, Lih-Sheng

2018-03-01

A three-stage molding process involving microcellular injection molding with core retraction and an "out-of-mold" expansion was developed to manufacture thermoplastic polyurethane into lightweight foams of varying local densities, microstructures, and mechanical properties in the same microcellular injection molded part. Two stages of cavity expansion through sequential core retractions and a third expansion in a separate mold at an elevated temperature were carried out. The densities varied from 0.25 to 0.42 g/cm3 (77% to 62% weight reduction). The mechanical properties varied as well. Cyclic compressive strengths and hysteresis loss ratios, together with the microstructures, were characterized and reported.

Efficient spin-current injection in single-molecule magnet junctions

NASA Astrophysics Data System (ADS)

Xie, Haiqing; Xu, Fuming; Jiao, Hujun; Wang, Qiang; Liang, J.-Q.

2018-01-01

We study theoretically spin transport through a single-molecule magnet (SMM) in the sequential and cotunneling regimes, where the SMM is weakly coupled to one ferromagnetic and one normal-metallic leads. By a master-equation approach, it is found that the spin polarization injected from the ferromagnetic lead is amplified and highly polarized spin-current can be generated, due to the exchange coupling between the transport electron and the anisotropic spin of the SMM. Moreover, the spin-current polarization can be tuned by the gate or bias voltage, and thus an efficient spin injection device based on the SMM is proposed in molecular spintronics.

Effectiveness of leukocyte immunotherapy in primary recurrent spontaneous abortion (RSA).

PubMed

Gharesi-Fard, Behrouz; Zolghadri, Jaleh; Foroughinia, Leila; Tavazoo, Fahimeh; Samsami Dehaghani, Alamtaj

2007-09-01

Recurrent spontaneous abortion (RSA) is defined as three or more sequential abortions before the twentieth week of gestation. There are evidences to support an allo-immunologic mechanism for RSA. One of the methods for treatment of RSA is leukocyte therapy; however there is still controversy about effectiveness of this method. To evaluate the effectiveness of leukocyte therapy for treatment of RSA. Ninety two non-pregnant women with at least three sequential abortions (60 primary & 32 secondary aborters) recognized as RSA were referred to our Laboratory for immunotherapy. All the cases were immunized by isolated lymphocytes from their husbands. Fifty to 100 million washed and resuspended mononuclear cells were injected by I.V., S.C., and I.D. route. The result of each injection was checked by WBC cross matching between couples after four weeks of injections. Immunization was repeated in fifth week to a maximum of 3 times if needed. Eighty one age-matched non-pregnant RSA women (52 primary and 29 secondary aborters) with at least three sequential abortions were also included in this study as controls. The control group was not immunized. 67 out of 92 (72.8%) immunized cases and 44 out of 81 controls (54.3%) showed a successful outcome of pregnancy (p<0.02). Comparison of primary and secondary aborters indicated a significantly better outcome only in primary (75% vs. 42.3%. p<0.001) but not in secondary aborters (68.8% vs. 75.9%, p = 0.7). The present investigation showed the effectiveness of leukocyte therapy in primary but not in secondary RSA patients. Despite the current controversy and limitation of leukocyte therapy in RSA, the results of our investigation provide evidence supporting the use of allo-immunization in improving the outcome of pregnancy in primary RSA patients.

Sub-1min separation in sequential injection chromatography for determination of synthetic water-soluble dyes in pharmaceutical formulation.

PubMed

Davletbaeva, Polina; Chocholouš, Petr; Bulatov, Andrey; Šatínský, Dalibor; Solich, Petr

2017-09-05

Sequential Injection Chromatography (SIC) evolved from fast and automated non-separation Sequential Injection Analysis (SIA) into chromatographic separation method for multi-element analysis. However, the speed of the measurement (sample throughput) is due to chromatography significantly reduced. In this paper, a sub-1min separation using medium polar cyano monolithic column (5mm×4.6mm) resulted in fast and green separation with sample throughput comparable with non-separation flow methods The separation of three synthetic water-soluble dyes (sunset yellow FCF, carmoisine and green S) was in a gradient elution mode (0.02% ammonium acetate, pH 6.7 - water) with flow rate of 3.0mLmin -1 corresponding with sample throughput of 30h -1 . Spectrophotometric detection wavelengths were set to 480, 516 and 630nm and 10Hz data collection rate. The performance of the separation was described and discussed (peak capacities 3.48-7.67, peak symmetries 1.72-1.84 and resolutions 1.42-1.88). The method was represented by validation parameters: LODs of 0.15-0.35mgL -1 , LOQs of 0.50-1.25mgL -1 , calibration ranges 0.50-150.00mgL -1 (r>0.998) and repeatability at 10.0mgL -1 of RSD≤0.98% (n=6). The method was used for determination of the dyes in "forest berries" colored pharmaceutical cough-cold formulation. The sample matrix - pharmaceuticals and excipients were not interfering with vis determination because of no retention in the separation column and colorless nature. The results proved the concept of fast and green chromatography approach using very short medium polar monolithic column in SIC. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous determination of rutin and ascorbic acid in a sequential injection lab-at-valve system.

PubMed

Al-Shwaiyat, Mohammed Khair E A; Miekh, Yuliia V; Denisenko, Tatyana A; Vishnikin, Andriy B; Andruch, Vasil; Bazel, Yaroslav R

2018-02-05

A green, simple, accurate and highly sensitive sequential injection lab-at-valve procedure has been developed for the simultaneous determination of ascorbic acid (Asc) and rutin using 18-molybdo-2-phosphate Wells-Dawson heteropoly anion (18-MPA). The method is based on the dependence of the reaction rate between 18-MPA and reducing agents on the solution pH. Only Asc is capable of interacting with 18-MPA at pH 4.7, while at pH 7.4 the reaction with both Asc and rutin proceeds simultaneously. In order to improve the precision and sensitivity of the analysis, to minimize reagent consumption and to remove the Schlieren effect, the manifold for the sequential injection analysis was supplemented with external reaction chamber, and the reaction mixture was segmented. By the reduction of 18-MPA with reducing agents one- and two-electron heteropoly blues are formed. The fraction of one-electron heteropoly blue increases at low concentrations of the reducer. Measurement of the absorbance at a wavelength corresponding to the isobestic point allows strictly linear calibration graphs to be obtained. The calibration curves were linear in the concentration ranges of 0.3-24mgL -1 and 0.2-14mgL -1 with detection limits of 0.13mgL -1 and 0.09mgL -1 for rutin and Asc, respectively. The determination of rutin was possible in the presence of up to a 20-fold molar excess of Asc. The method was applied to the determination of Asc and rutin in ascorutin tablets with acceptable accuracy and precision (1-2%). Copyright © 2017 Elsevier B.V. All rights reserved.

Miniaturizing and automation of free acidity measurements for uranium (VI)-HNO3 solutions: Development of a new sequential injection analysis for a sustainable radio-analytical chemistry.

PubMed

Néri-Quiroz, José; Canto, Fabrice; Guillerme, Laurent; Couston, Laurent; Magnaldo, Alastair; Dugas, Vincent

2016-10-01

A miniaturized and automated approach for the determination of free acidity in solutions containing uranium (VI) is presented. The measurement technique is based on the concept of sequential injection analysis with on-line spectroscopic detection. The proposed methodology relies on the complexation and alkalimetric titration of nitric acid using a pH 5.6 sodium oxalate solution. The titration process is followed by UV/VIS detection at 650nm thanks to addition of Congo red as universal pH indicator. Mixing sequence as well as method validity was investigated by numerical simulation. This new analytical design allows fast (2.3min), reliable and accurate free acidity determination of low volume samples (10µL) containing uranium/[H(+)] moles ratio of 1:3 with relative standard deviation of <7.0% (n=11). The linearity range of the free nitric acid measurement is excellent up to 2.77molL(-1) with a correlation coefficient (R(2)) of 0.995. The method is specific, presence of actinide ions up to 0.54molL(-1) does not interfere on the determination of free nitric acid. In addition to automation, the developed sequential injection analysis method greatly improves the standard off-line oxalate complexation and alkalimetric titration method by reducing thousand fold the required sample volume, forty times the nuclear waste per analysis as well as the analysis time by eight fold. These analytical parameters are important especially in nuclear-related applications to improve laboratory safety, personnel exposure to radioactive samples and to drastically reduce environmental impacts or analytical radioactive waste. Copyright © 2016 Elsevier B.V. All rights reserved.

Injection order effects on efficacy of calcium chloride and sodium tripolyphosphate in controlling the pink color defect in uncured, intact turkey breast.

PubMed

Claus, James R; Sawyer, Christopher A; Vogel, Kurt D

2010-04-01

An experiment was conducted to test sequential injection of sodium tripolyphosphate (STP; 0.5% meat weight basis, mwb) followed by injection with or without addition of calcium chloride (CaCl(2), 500 ppm mwb), and to test the effect of post-injection delay prior to cooking. A second experiment evaluated the impact of injection order and delay time between independent addition of CaCl(2) (500 ppm mwb) and STP (0.5% mwb). Turkey was formulated without an added pink generating ligand (NONE), with nicotinamide (NIC; 0.1% mwb), or with sodium nitrite (NIT; 10 ppm mwb). A white colloid was observed in the extracellular space of treatments containing both STP and CaCl(2.) Addition of CaCl(2) decreased nitrosylhemochrome but did not reduce levels of nicotinamide hemochrome or CIE a(*) values. Injection order or delay between injections did not contribute to controlling the pink defect in cooked, intact turkey breast. Published by Elsevier Ltd.

Immunogenicity of simultaneous versus sequential administration of a 23-valent pneumococcal polysaccharide vaccine and a quadrivalent influenza vaccine in older individuals: A randomized, open-label, non-inferiority trial.

PubMed

Nakashima, Kei; Aoshima, Masahiro; Ohfuji, Satoko; Yamawaki, Satoshi; Nemoto, Masahiro; Hasegawa, Shinya; Noma, Satoshi; Misawa, Masafumi; Hosokawa, Naoto; Yaegashi, Makito; Otsuka, Yoshihito

2018-03-21

It is unclear whether simultaneous administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) and a quadrivalent influenza vaccine (QIV) produces immunogenicity in older individuals. This study tested the hypothesis that the pneumococcal antibody response elicited by simultaneous administration of PPSV23 and QIV in older individuals is not inferior to that elicited by sequential administration of PPSV23 and QIV. We performed a single-center, randomized, open-label, non-inferiority trial comprising 162 adults aged ≥65 years randomly assigned to either the simultaneous (simultaneous injections of PPSV23 and QIV) or sequential (control; PPSV23 injected 2 weeks after QIV vaccination) groups. Pneumococcal immunoglobulin G (IgG) titers of serotypes 23F, 3, 4, 6B, 14, and 19A were assessed. The primary endpoint was the serotype 23F response rate (a ≥2-fold increase in IgG concentrations 4-6 weeks after PPSV23 vaccination). With the non-inferiority margin set at 20% fewer patients, the response rate of serotype 23F in the simultaneous group (77.8%) was not inferior to that of the sequential group (77.6%; difference, 0.1%; 90% confidence interval, -10.8% to 11.1%). None of the pneumococcal IgG serotype titers were significantly different between the groups 4-6 weeks after vaccination. Simultaneous administration did not show a significant decrease in seroprotection odds ratios for H1N1, H3N2, or B/Phuket influenza strains other than B/Texas. Additionally, simultaneous administration did not increase adverse reactions. Hence, simultaneous administration of PPSV23 and QIV shows an acceptable immunogenicity that is comparable to sequential administration without an increase in adverse reactions. (This study was registered with ClinicalTrials.gov [NCT02592486]).

Visual detection and sequential injection determination of aluminium using a cinnamoyl derivative.

PubMed

Elečková, Lenka; Alexovič, Michal; Kuchár, Juraj; Balogh, Ioseph S; Andruch, Vasil

2015-02-01

A cinnamoyl derivative, 3-[4-(dimethylamino)cinnamoyl]-4-hydroxy-6-methyl-3,4-2H-pyran-2-one, was used as a ligand for the determination of aluminium. Upon the addition of an acetonitrile solution of the ligand to an aqueous solution containing Al(III) and a buffer solution at pH 8, a marked change in colour from yellow to orange is observed. The colour intensity is proportional to the concentration of Al(III); thus, the 'naked-eye' detection of aluminium is possible. The reaction is also applied for sequential injection determination of aluminium. Beer׳s law is obeyed in the range from 0.055 to 0.66 mg L(-1) of Al(III). The limit of detection, calculated as three times the standard deviation of the blank test (n=10), was found to be 4 μg L(-1) for Al(III). The method was applied for the determination of aluminium in spiked water samples and pharmaceutical preparations. Copyright © 2014 Elsevier B.V. All rights reserved.

Sequential Injection Chromatography with an Ultra-short Monolithic Column for the Low-Pressure Separation of α-Tocopherol and γ-Oryzanol in Vegetable Oils and Nutrition Supplements.

PubMed

Thaithet, Sujitra; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai

2017-01-01

A low-pressure separation procedure of α-tocopherol and γ-oryzanol was developed based on a sequential injection chromatography (SIC) system coupled with an ultra-short (5 mm) C-18 monolithic column, as a lower cost and more compact alternative to the HPLC system. A green sample preparation, dilution with a small amount of hexane followed by liquid-liquid extraction with 80% ethanol, was proposed. Very good separation resolution (R s = 3.26), a satisfactory separation time (10 min) and a total run time including column equilibration (16 min) were achieved. The linear working range was found to be 0.4 - 40 μg with R 2 being more than 0.99. The detection limits of both analytes were 0.28 μg with the repeatability within 5% RSD (n = 7). Quantitative analyses of the two analytes in vegetable oil and nutrition supplement samples, using the proposed SIC method, agree well with the results from HPLC.

Time-lapse evaluation of human embryo development in single versus sequential culture media--a sibling oocyte study.

PubMed

Ciray, Haydar Nadir; Aksoy, Turan; Goktas, Cihan; Ozturk, Bilgen; Bahceci, Mustafa

2012-09-01

To compare the dynamics of early development between embryos cultured in single and sequential media. Randomized, comparative study. Private IVF centre. A total of 446 metaphase II oocytes from 51 couples who underwent oocyte retrieval procedure for intracytoplasmic sperm injection. Forty-nine resulted in embryo transfer. Oocytes were split between single and sequential media produced by the same manufacturer and cultured in a time-lapse incubator. Morphokinetic parameters until the embryos reached the 5-cell stage (t5), utilization, clinical pregnancy and implantation rates. Embryos cultured in single media were advanced from the first mitosis cycle and reached 2- to 5-cell stages earlier. There was not any difference between the durations for cell cycle two (cc2 = t3-t2) and s2 (t4-t3). The utilization, clinical pregnancy and implantation rates did not differ between groups. The proportion of cryopreserved day 6 embryos to two pronuclei oocytes was significantly higher in sequential than in single media. Morphokinetics of embryo development vary between single and sequential culture media at least until the 5-cell stage. The overall clinical and embryological parameters remain similar regardless of the culture system.

Sequential injection system for simultaneous determination of sucrose and phosphate in cola drinks using paired emitter-detector diode sensor.

PubMed

Saetear, Phoonthawee; Khamtau, Kittiwut; Ratanawimarnwong, Nuanlaor; Sereenonchai, Kamonthip; Nacapricha, Duangjai

2013-10-15

This work presents the simultaneous determination of sucrose and phosphate by using sequential injection (SI) system with a low cost paired emitter-detector diode (PEDD) light sensor. The PEDD uses two 890 nm LEDs. Measurement of sucrose in Brix unit was carried out based on the detection of light refraction occurring at the liquid interface (the schlieren effect) between the sucrose solution and water. Phosphate was measured from the formation of calcium phosphate with turbidimetric detection. With careful design of the loading sequence and volume (sample--precipitating reagent--sample), simultaneous detection of sucrose and phosphate was accomplished with the single PEDD detector. At the optimized condition, linear calibrations from 1 to 7 Brix sucrose and from 50 to 200mg PO4(3-)L(-1) were obtained. Good precision at lower than 2% RSD (n=10) for both analytes with satisfactory throughput of 21 injections h(-1) was achieved. The method was successfully applied for the determination of sucrose and phosphate in cola drinks. The proposed method is readily applicable for automation and is found to be an alternative method to conventional procedures for on-line quality control process in cola drink industry. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Strategy for the extraction of yeast DNA from artisan agave must for quantitative PCR analysis.

PubMed

Kirchmayr, Manuel Reinhart; Segura-Garcia, Luis Eduardo; Flores-Berrios, Ericka Patricia; Gschaedler, Anne

2011-11-01

An efficient method for the direct extraction of yeast genomic DNA from agave must was developed. The optimized protocol, which was based on silica-adsorption of DNA on microcolumns, included an enzymatic cell wall degradation step followed by prolonged lysis with hot detergent. The resulting extracts were suitable templates for subsequent qPCR assays that quantified mixed yeast populations in artisan Mexican mezcal fermentations. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

The duration of hyaluronidase and optimal timing of hyaluronic acid (HA) filler reinjection after hyaluronidase injection.

PubMed

Kim, H J; Kwon, S B; Whang, K U; Lee, J S; Park, Y L; Lee, S Y

2018-02-01

Hyaluronidase injection is a commonly performed treatment for overcorrection or misplacement of hyaluronic acid (HA) filler. Many patients often wants the HA filler reinjection after the use of hyaluronidase, though the optimal timing of reinjection of HA filler still remains unknown. To provide the optimal time interval between hyaluronidase injections and HA filler reinjections. 6 Sprague-Dawley rats were injected with single monophasic HA filler. 1 week after injection, the injected sites were treated with hyaluronidase. Then, HA fillers were reinjected sequentially with differing time intervals from 30 minutes to 14 days. 1 hour after the reinjection of the last HA filler, all injection sites were excised for histologic evaluation. 3 hours after reinjection of HA filler, the appearance of filler material became evident again, retaining its shape and volume. 6 hours after reinjection, the filler materials restored almost its original volume and there were no significant differences from the positive control. Our data suggest that the hyaluronidase loses its effect in dermis and subcutaneous tissue within 3-6 hours after the injection and successful engraftment of reinjected HA filler can be accomplished 6 hours after the injection.

9 CFR 113.43 - Detection of chlamydial agents.

Code of Federal Regulations, 2014 CFR

2014-01-01

... in a filed Outline of Production. (a) The yolk sac of 6-day-old chicken embryos shall be injected. Three groups of 10 embryos shall be used sequentially. (1) The inoculum for each embryo in the first... embryos shall be harvested, pooled, homogenized as a 20 percent suspension in phosphate buffered saline...

9 CFR 113.43 - Detection of chlamydial agents.

Code of Federal Regulations, 2011 CFR

2011-01-01

... in a filed Outline of Production. (a) The yolk sac of 6-day-old chicken embryos shall be injected. Three groups of 10 embryos shall be used sequentially. (1) The inoculum for each embryo in the first... embryos shall be harvested, pooled, homogenized as a 20 percent suspension in phosphate buffered saline...

9 CFR 113.43 - Detection of chlamydial agents.

Code of Federal Regulations, 2013 CFR

2013-01-01

... in a filed Outline of Production. (a) The yolk sac of 6-day-old chicken embryos shall be injected. Three groups of 10 embryos shall be used sequentially. (1) The inoculum for each embryo in the first... embryos shall be harvested, pooled, homogenized as a 20 percent suspension in phosphate buffered saline...

9 CFR 113.43 - Detection of chlamydial agents.

Code of Federal Regulations, 2012 CFR

2012-01-01

... in a filed Outline of Production. (a) The yolk sac of 6-day-old chicken embryos shall be injected. Three groups of 10 embryos shall be used sequentially. (1) The inoculum for each embryo in the first... embryos shall be harvested, pooled, homogenized as a 20 percent suspension in phosphate buffered saline...

A Simple Automated Method for the Determination of Nitrate and Nitrite in Infant Formula and Milk Powder Using Sequential Injection Analysis

PubMed Central

Pistón, Mariela; Mollo, Alicia; Knochen, Moisés

2011-01-01

A fast and efficient automated method using a sequential injection analysis (SIA) system, based on the Griess, reaction was developed for the determination of nitrate and nitrite in infant formulas and milk powder. The system enables to mix a measured amount of sample (previously constituted in the liquid form and deproteinized) with the chromogenic reagent to produce a colored substance whose absorbance was recorded. For nitrate determination, an on-line prereduction step was added by passing the sample through a Cd minicolumn. The system was controlled from a PC by means of a user-friendly program. Figures of merit include linearity (r2 > 0.999 for both analytes), limits of detection (0.32 mg kg−1 NO3-N, and 0.05 mg kg−1 NO2-N), and precision (sr%) 0.8–3.0. Results were statistically in good agreement with those obtained with the reference ISO-IDF method. The sampling frequency was 30 hour−1 (nitrate) and 80 hour−1 (nitrite) when performed separately. PMID:21960750

LabVIEW-based sequential-injection analysis system for the determination of trace metals by square-wave anodic and adsorptive stripping voltammetry on mercury-film electrodes.

PubMed

Economou, Anastasios; Voulgaropoulos, Anastasios

2003-01-01

The development of a dedicated automated sequential-injection analysis apparatus for anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (AdSV) is reported. The instrument comprised a peristaltic pump, a multiposition selector valve and a home-made potentiostat and used a mercury-film electrode as the working electrodes in a thin-layer electrochemical detector. Programming of the experimental sequence was performed in LabVIEW 5.1. The sequence of operations included formation of the mercury film, electrolytic or adsorptive accumulation of the analyte on the electrode surface, recording of the voltammetric current-potential response, and cleaning of the electrode. The stripping step was carried out by applying a square-wave (SW) potential-time excitation signal to the working electrode. The instrument allowed unattended operation since multiple-step sequences could be readily implemented through the purpose-built software. The utility of the analyser was tested for the determination of copper(II), cadmium(II), lead(II) and zinc(II) by SWASV and of nickel(II), cobalt(II) and uranium(VI) by SWAdSV.

LabVIEW-based sequential-injection analysis system for the determination of trace metals by square-wave anodic and adsorptive stripping voltammetry on mercury-film electrodes

PubMed Central

Economou, Anastasios; Voulgaropoulos, Anastasios

2003-01-01

The development of a dedicated automated sequential-injection analysis apparatus for anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (AdSV) is reported. The instrument comprised a peristaltic pump, a multiposition selector valve and a home-made potentiostat and used a mercury-film electrode as the working electrodes in a thin-layer electrochemical detector. Programming of the experimental sequence was performed in LabVIEW 5.1. The sequence of operations included formation of the mercury film, electrolytic or adsorptive accumulation of the analyte on the electrode surface, recording of the voltammetric current-potential response, and cleaning of the electrode. The stripping step was carried out by applying a square-wave (SW) potential-time excitation signal to the working electrode. The instrument allowed unattended operation since multiple-step sequences could be readily implemented through the purpose-built software. The utility of the analyser was tested for the determination of copper(II), cadmium(II), lead(II) and zinc(II) by SWASV and of nickel(II), cobalt(II) and uranium(VI) by SWAdSV. PMID:18924623

Sequential injection system with multi-parameter analysis capability for water quality measurement.

PubMed

Kaewwonglom, Natcha; Jakmunee, Jaroon

2015-11-01

A simple sequential injection (SI) system with capability to determine multi-parameter has been developed for the determination of iron, manganese, phosphate and ammonium. A simple and compact colorimeter was fabricated in the laboratory to be employed as a detector. The system was optimized for suitable conditions for determining each parameter by changing software program and without reconfiguration of the hardware. Under the optimum conditions, the methods showed linear ranges of 0.2-10 mg L(-1) for iron and manganese determinations, and 0.3-5.0 mg L(-1) for phosphate and ammonium determinations, with correlation coefficients of 0.9998, 0.9973, 0.9987 and 0.9983, respectively. The system provided detection limits of 0.01, 0.14, 0.004 and 0.02 mg L(-1) for iron, manganese, phosphate and ammonium, respectively. The proposed system has good precision, low chemical consumption and high throughput. It was applied for monitoring water quality of Ping river in Chiang Mai, Thailand. Recoveries of the analysis were obtained in the range of 82-119%. Copyright © 2015 Elsevier B.V. All rights reserved.

Deferiprone, a non-toxic reagent for determination of iron in samples via sequential injection analysis

NASA Astrophysics Data System (ADS)

Pragourpun, Kraivinee; Sakee, Uthai; Fernandez, Carlos; Kruanetr, Senee

2015-05-01

We present for the first time the use of deferiprone as a non-toxic complexing agent for the determination of iron by sequential injection analysis in pharmaceuticals and food samples. The method was based on the reaction of Fe(III) and deferiprone in phosphate buffer at pH 7.5 to give a Fe(III)-deferiprone complex, which showed a maximum absorption at 460 nm. Under the optimum conditions, the linearity range for iron determination was found over the range of 0.05-3.0 μg mL-1 with a correlation coefficient (r2) of 0.9993. The limit of detection and limit of quantitation were 0.032 μg mL-1 and 0.055 μg mL-1, respectively. The relative standard deviation (%RSD) of the method was less than 5.0% (n = 11), and the percentage recovery was found in the range of 96.0-104.0%. The proposed method was satisfactorily applied for the determination of Fe(III) in pharmaceuticals, water and food samples with a sampling rate of 60 h-1.

Sequential PLD in oxygen/argon gas mixture of Al-doped ZnO thin films with improved electrical and optical properties

NASA Astrophysics Data System (ADS)

Coman, Tudor; Timpu, Daniel; Nica, Valentin; Vitelaru, Catalin; Rambu, Alicia Petronela; Stoian, George; Olaru, Mihaela; Ursu, Cristian

2017-10-01

Highly conductive transparent Al-doped ZnO (AZO) thin films were obtained at room temperature through sequential PLD (SPLD) from Zn and Al metallic targets in an oxygen/argon gas mixture. We have investigated the structural, electrical and optical properties as a function of the oxygen/argon pressure ratio in the chamber. The measured Hall carrier concentration was found to increase with argon injection from 1.3 × 1020 to 6.7 × 1020 cm-3, while the laser shots ratio for Al/Zn targets ablation was kept constant. This increase was attributed to an enhancement of the substitution doping into the ZnO lattice. The argon injection also leads to an increase of the Hall mobility up to 20 cm2 V-1 s-1, attributed to a reduction of interstitial-type defects. Thus, the approach of using an oxygen/argon gas mixture during SPLD from metallic targets allows obtaining at room temperature AZO samples with high optical transmittance (about 90%) and low electrical resistivity (down to 5.1 × 10-4 Ω cm).

On-line sequential injection-capillary electrophoresis for near-real-time monitoring of extracellular lactate in cell culture flasks.

PubMed

Alhusban, Ala A; Gaudry, Adam J; Breadmore, Michael C; Gueven, Nuri; Guijt, Rosanne M

2014-01-03

Cell culture has replaced many in vivo studies because of ethical and regulatory measures as well as the possibility of increased throughput. Analytical assays to determine (bio)chemical changes are often based on end-point measurements rather than on a series of sequential determinations. The purpose of this work is to develop an analytical system for monitoring cell culture based on sequential injection-capillary electrophoresis (SI-CE) with capacitively coupled contactless conductivity detection (C(4)D). The system was applied for monitoring lactate production, an important metabolic indicator, during mammalian cell culture. Using a background electrolyte consisting of 25mM tris(hydroxymethyl)aminomethane, 35mM cyclohexyl-2-aminoethanesulfonic acid with 0.02% poly(ethyleneimine) (PEI) at pH 8.65 and a multilayer polymer coated capillary, lactate could be resolved from other compounds present in media with relative standard deviations 0.07% for intraday electrophoretic mobility and an analysis time of less than 10min. Using the human embryonic kidney cell line HEK293, lactate concentrations in the cell culture medium were measured every 20min over 3 days, requiring only 8.73μL of sample per run. Combining simplicity, portability, automation, high sample throughput, low limits of detection, low sample consumption and the ability to up- and outscale, this new methodology represents a promising technique for near real-time monitoring of chemical changes in diverse cell culture applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Exploiting an automated microfluidic hydrodynamic sequential injection system for determination of phosphate.

PubMed

Khongpet, Wanpen; Pencharee, Somkid; Puangpila, Chanida; Kradtap Hartwell, Supaporn; Lapanantnoppakhun, Somchai; Jakmunee, Jaroon

2018-01-15

A microfluidic hydrodynamic sequential injection (μHSI) spectrophotometric system was designed and fabricated. The system was built by laser engraving a manifold pattern on an acrylic block and sealing with another flat acrylic plate to form a microfluidic channel platform. The platform was incorporated with small solenoid valves to obtain a portable setup for programmable control of the liquid flow into the channel according to the HSI principle. The system was demonstrated for the determination of phosphate using a molybdenum blue method. An ascorbic acid, standard or sample, and acidic molybdate solutions were sequentially aspirated to fill the channel forming a stack zone before flowing to the detector. Under the optimum condition, a linear calibration graph in the range of 0.1-6mg P L -1 was obtained. The detection limit was 0.1mgL -1 . The system is compact (5.0mm thick, 80mm wide × 140mm long), durable, portable, cost-effective, and consumes little amount of chemicals (83μL each of molybdate and ascorbic acid, 133μL of the sample solution and 1.7mL of water carrier/run). It was applied for the determination of phosphate content in extracted soil samples. The percent recoveries of the analysis were obtained in the range of 91.2-107.3. The results obtained agreed well with those of the batch spectrophotometric method. Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential injection titration method using second-order signals: determination of acidity in plant oils and biodiesel samples.

PubMed

del Río, Vanessa; Larrechi, M Soledad; Callao, M Pilar

2010-06-15

A new concept of flow titration is proposed and demonstrated for the determination of total acidity in plant oils and biodiesel. We use sequential injection analysis (SIA) with a diode array spectrophotometric detector linked to chemometric tools such as multivariate curve resolution-alternating least squares (MCR-ALS). This system is based on the evolution of the basic specie of an acid-base indicator, alizarine, when it comes into contact with a sample that contains free fatty acids. The gradual pH change in the reactor coil due to diffusion and reaction phenomenona allows the sequential appearance of both species of the indicator in the detector coil, recording a data matrix for each sample. The SIA-MCR-ALS method helps to reduce the amounts of sample, the reagents and the time consumed. Each determination consumes 0.413ml of sample, 0.250ml of indicator and 3ml of carrier (ethanol) and generates 3.333ml of waste. The frequency of the analysis is high (12 samples h(-1) including all steps, i.e., cleaning, preparing and analysing). The utilized reagents are of common use in the laboratory and it is not necessary to use the reagents of perfect known concentration. The method was applied to determine acidity in plant oil and biodiesel samples. Results obtained by the proposed method compare well with those obtained by the official European Community method that is time consuming and uses large amounts of organic solvents.

Injectable 3-D Fabrication of Medical Electronics at the Target Biological Tissues

NASA Astrophysics Data System (ADS)

Jin, Chao; Zhang, Jie; Li, Xiaokang; Yang, Xueyao; Li, Jingjing; Liu, Jing

2013-12-01

Conventional transplantable biomedical devices generally request sophisticated surgery which however often causes big trauma and serious pain to the patients. Here, we show an alternative way of directly making three-dimensional (3-D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and liquid metal ink. As the most typical electronics, a variety of medical electrodes with different embedded structures were demonstrated to be easily formed at the target tissues. Conceptual in vitro experiments provide strong evidences for the excellent performances of the injectable electrodes. Further in vivo animal experiments disclosed that the formed electrode could serve as both highly efficient ECG (Electrocardiograph) electrode and stimulator electrode. These findings clarified the unique features and practicability of the liquid metal based injectable 3-D fabrication of medical electronics. The present strategy opens the way for directly manufacturing electrophysiological sensors or therapeutic devices in situ via a truly minimally invasive approach.

Attenuation-difference radar tomography: results of a multiple-plane experiment at the U.S. Geological Survey Fractured-Rock Research Site, Mirror Lake, New Hampshire

USGS Publications Warehouse

Lane, J.W.; Day-Lewis, F. D.; Harris, J.M.; Haeni, F.P.; Gorelick, S.M.

2000-01-01

Attenuation-difference, borehole-radar tomography was used to monitor a series of sodium chloride tracer injection tests conducted within the FSE, wellfield at the U.S. Geological Survey Fractured-Rock Hydrology Research Site in Grafton County, New Hampshire, USA. Borehole-radar tomography surveys were conducted using the sequential-scanning and injection method in three boreholes that form a triangular prism of adjoining tomographic image planes. Results indicate that time-lapse tomography methods provide high-resolution images of tracer distribution in permeable zones.

Phantom auditory sensation in rats: an animal model for tinnitus.

PubMed

Jastreboff, P J; Brennan, J F; Coleman, J K; Sasaki, C T

1988-12-01

In order to measure tinnitus induced by sodium salicylate injections, 84 pigmented rats, distributed among 14 groups in five experiments, were used in a conditioned suppression paradigm. In Experiment 1, all groups were trained with a conditioned stimulus (CS) consisting of the offset of a continuous background noise. One group began salicylate injections before Pavlovian training, a second group started injections after training, and a control group received daily saline injections. Resistance to extinction was profound when injections started before training, but minimal when initiated after training, which suggests that salicylate-induced effects acquired differential conditioned value. In Experiment 2 we mimicked the salicylate treatments by substituting a 7 kHz tone in place of respective injections, resulting in effects equivalent to salicylate-induced behavior. In a third experiment we included a 3 kHz CS, and again replicated the salicylate findings. In Experiment 4 we decreased the motivational level, and the sequential relation between salicylate-induced effects and suppression training was retained. Finally, no salicylate effects emerged when the visual modality was used. These findings support the demonstration of phantom auditory sensations in animals.

Effects of neostriatal 6-OHDA lesion on performance in a rat sequential reaction time task.

PubMed

Domenger, D; Schwarting, R K W

2008-10-31

Work in humans and monkeys has provided evidence that the basal ganglia, and the neurotransmitter dopamine therein, play an important role for sequential learning and performance. Compared to primates, experimental work in rodents is rather sparse, largely due to the fact that tasks comparable to the human ones, especially serial reaction time tasks (SRTT), had been lacking until recently. We have developed a rat model of the SRTT, which allows to study neural correlates of sequential performance and motor sequence execution. Here, we report the effects of dopaminergic neostriatal lesions, performed using bilateral 6-hydroxydopamine injections, on performance of well-trained rats tested in our SRTT. Sequential behavior was measured in two ways: for one, the effects of small violations of otherwise well trained sequences were examined as a measure of attention and automation. Secondly, sequential versus random performance was compared as a measure of sequential learning. Neurochemically, the lesions led to sub-total dopamine depletions in the neostriatum, which ranged around 60% in the lateral, and around 40% in the medial neostriatum. These lesions led to a general instrumental impairment in terms of reduced speed (response latencies) and response rate, and these deficits were correlated with the degree of striatal dopamine loss. Furthermore, the violation test indicated that the lesion group conducted less automated responses. The comparison of random versus sequential responding showed that the lesion group did not retain its superior sequential performance in terms of speed, whereas they did in terms of accuracy. Also, rats with lesions did not improve further in overall performance as compared to pre-lesion values, whereas controls did. These results support previous results that neostriatal dopamine is involved in instrumental behaviour in general. Also, these lesions are not sufficient to completely abolish sequential performance, at least when acquired before lesion as tested here.

Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10).

PubMed

Beltrán, Blanca; Avivar, Jessica; Mola, Montserrat; Ferrer, Laura; Cerdà, Víctor; Leal, Luz O

2013-09-03

A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

On-line ionic liquid-based preconcentration system coupled to flame atomic absorption spectrometry for trace cadmium determination in plastic food packaging materials.

PubMed

Martinis, Estefanía M; Olsina, Roberto A; Altamirano, Jorgelina C; Wuilloud, Rodolfo G

2009-05-15

A novel on-line preconcentration method based on liquid-liquid (L-L) extraction with room temperature ionic liquids (RTILs) coupled to flame atomic absorption spectrometry (FAAS) was developed for cadmium determination in plastic food packaging materials. The methodology is based on the complexation of Cd with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) reagent after sample digestion followed by extraction of the complex with the RTIL 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF(6)]). The mixture was loaded into a flow injection analysis (FIA) manifold and the RTIL rich-phase was retained in a microcolumn filled with silica gel. The RTIL rich-phase was then eluted directly into FAAS. A enhancement factor of 35 was achieved with 20 mL of sample. The limit of detection (LOD), obtained as IUPAC recommendation, was 6 ng g(-1) and the relative standard deviation (R.S.D.) for 10 replicates at 10 microg L(-1) Cd concentration level was 3.9%, calculated at the peak heights. The calibration graph was linear and a correlation coefficient of 0.9998 was achieved. The accuracy of the method was evaluated by both a recovery study and comparison of results with direct determination by electrothermal atomic absorption spectrometry (ETAAS). The method was successfully applied for Cd determination in plastic food packaging materials and Cd concentrations found were in the range of 0.04-10.4 microg g(-1).

On-line ion-exchange preconcentration and determination of traces of platinum by electrothermal atomic absorption spectrometry.

PubMed

González García, M M; Sánchez Rojas, F; Bosch Ojeda, C; García de Torres, A; Cano Pavón, J M

2003-04-01

A method to determine trace amounts of platinum in different samples based on electrothermal atomic absorption spectrometry is described. The preconcentration step is performed on a chelating resin microcolumn [1,5-bis(2-pyridyl)-3-sulfophenyl methylene thiocarbonohydrazide (PSTH) immobilized on an anion-exchange resin (Dowex 1x8-200)] placed in the autosampler arm. The combination of a peristaltic pump for sample loading and the atomic absorption spectrometer pumps for elution through a selection valve simplifies the hardware. The peristaltic pump and the selection valve are easily controlled electronically with two switches placed in the autosampler, which are activated when the autosampler arm is down. Thus, the process is fully automated without any modification of the software of the atomic absorption spectrometer. Under the optimum conditions with a 60-s preconcentration time, a sample flow rate of 2.4 mL min(-1), and an injection volume of eluent of 40 microL, a linear calibration graph was obtained in the range 0-100 ng mL(-1). The enrichment factor was 14. The detection limit under these conditions is 1 ng mL(-1), and the relative standard deviation (RSD) is 1.6% for 10 ng mL(-1) of Pt. The method has been applied to the determination of platinum in catalyst, vegetation, soil, and natural water samples. The results showed good agreement with the certified value and the recoveries of Pt added to samples were 98-105%.

Effect of nicergoline on cerebral blood flow

PubMed Central

Iliff, L. D.; Boulay, G. H. Du; Marshall, John; Russell, R. W. Ross; Symon, Lindsay

1977-01-01

Cerebral blood flow (CBF) was measured before and after intravenous injection of the cerebral vasodilator nicergoline in 13 patients with cerebrovascular disease. CBF increased in seven. The possibility that the effect of the drug in the remainder may have been masked by a fall of CBF which occurs during sequential measurement of patients at rest is discussed. PMID:925694

Identification of inorganic improvised explosive devices using sequential injection capillary electrophoresis and contactless conductivity detection.

PubMed

Blanco, Gustavo A; Nai, Yi H; Hilder, Emily F; Shellie, Robert A; Dicinoski, Greg W; Haddad, Paul R; Breadmore, Michael C

2011-12-01

A simple sequential injection capillary electrophoresis (SI-CE) instrument with capacitively coupled contactless conductivity detection (C(4)D) has been developed for the rapid separation of anions relevant to the identification of inorganic improvised explosive devices (IEDs). Four of the most common explosive tracer ions, nitrate, perchlorate, chlorate, and azide, and the most common background ions, chloride, sulfate, thiocyanate, fluoride, phosphate, and carbonate, were chosen for investigation. Using a separation electrolyte comprising 50 mM tris(hydroxymethyl)aminomethane, 50 mM cyclohexyl-2-aminoethanesulfonic acid, pH 8.9 and 0.05% poly(ethyleneimine) (PEI) in a hexadimethrine bromide (HDMB)-coated capillary it was possible to partially separate all 10 ions within 90 s. The combination of two cationic polymer additives (PEI and HDMB) was necessary to achieve adequate selectivity with a sufficiently stable electroosmotic flow (EOF), which was not possible with only one polymer. Careful optimization of variables affecting the speed of separation and injection timing allowed a further reduction of separation time to 55 s while maintaining adequate efficiency and resolution. Software control makes high sample throughput possible (60 samples/h), with very high repeatability of migration times [0.63-2.07% relative standard deviation (RSD) for 240 injections]. The separation speed does not compromise sensitivity, with limits of detection ranging from 23 to 50 μg·L(-1) for all the explosive residues considered, which is 10× lower than those achieved by indirect absorbance detection and 2× lower than those achieved by C(4)D using portable benchtop instrumentation. The combination of automation, high sample throughput, high confidence of peak identification, and low limits of detection makes this methodology ideal for the rapid identification of inorganic IED residues.

Coupled Hydro-Mechanical Modeling of Fluid Geological Storage

NASA Astrophysics Data System (ADS)

Castelletto, N.; Garipov, T.; Tchelepi, H. A.

2013-12-01

The accurate modeling of the complex coupled physical processes occurring during the injection and the post-injection period is a key factor for assessing the safety and the feasibility of anthropogenic carbon dioxide (CO2) sequestration in subsurface formations. In recent years, it has become widely accepted the importance of the coupling between fluid flow and geomechanical response in constraining the sustainable pressure buildup caused by fluid injection relative to the caprock sealing capacity, induced seismicity effects and ground surface stability [e.g., Rutqvist, 2012; Castelletto et al., 2013]. Here, we present a modeling approach based on a suitable combination of Finite Volumes (FVs) and Finite Elements (FEs) to solve the coupled system of partial differential equations governing the multiphase flow in a deformable porous medium. Specifically, a FV method is used for the flow problem while the FE method is adopted to address the poro-elasto-plasticity equations. The aim of the present work is to compare the performance and the robustness of unconditionally stable sequential-implicit schemes [Kim et al., 2011] and the fully-implicit method in solving the algebraic systems arising from the discretization of the governing equations, for both normally conditioned and severely ill-conditioned problems. The two approaches are tested against well-known analytical solutions and experimented with in a realistic application of CO2 injection in a synthetic aquifer. References: - Castelletto N., G. Gambolati, and P. Teatini (2013), Geological CO2 sequestration in multi-compartment reservoirs: Geomechanical challenges, J. Geophys. Res. Solid Earth, 118, 2417-2428, doi:10.1002/jgrb.50180. - Kim J., H. A. Tchelepi, and R. Juanes (2011), Stability, accuracy and efficiency of sequential methods for coupled flow and geomechanics, SPE J., 16(2), 249-262. - Rutqvist J. (2012), The geomechanics of CO2 storage in deep sedimentary formations, Geotech. Geol. Eng., 30, 525-551.

Sequential Systemic Administrations of Combretastatin A4 Phosphate and Radioiodinated Hypericin Exert Synergistic Targeted Theranostic Effects with Prolonged Survival on SCID Mice Carrying Bifocal Tumor Xenografts

PubMed Central

Li, Junjie; Cona, Marlein Miranda; Chen, Feng; Feng, Yuanbo; Zhou, Lin; Zhang, Guozhi; Nuyts, Johan; de Witte, Peter; Zhang, Jian; Yu, Jie; Oyen, Raymond; Verbruggen, Alfons; Ni, Yicheng

2013-01-01

Objectives: Based on the soil-to-seeds principle, we explored the small-molecular sequential dual-targeting theranostic strategy (SMSDTTS) for prolonged survival and imaging detectability in a xenograft tumor model. Materials and Methods: Thirty severe combined immunodeficiency (SCID) mice bearing bilateral radiation-induced fibrosarcoma-1 (RIF-1) subcutaneously were divided into group A of SMSDTTS with sequential intravenous injections of combretastatin A4 phosphate (CA4P) and 131I-iodohypericin (131I-Hyp) at a 24 h interval; group B of single targeting control with CA4P and vehicle of 131I-Hyp; and group C of vehicle control (10 mice per group). Tumoricidal events were monitored by in vivo magnetic resonance imaging (MRI) and planar gamma scintiscan, and validated by ex vivo autoradiography and histopathology. Besides, 9 mice received sequential intravenous injections of CA4P and 131I-Hyp were subjected to biodistribution analysis at 24, 72 and 120 h. Results: Gamma counting revealed fast clearance of 131I-Hyp from normal organs but intense accumulation in necrotic tumor over 120 h. After only one treatment, significantly prolonged survival (p<0.001) was found in group A compared to group B and C with median survival of 33, 22, and 21 days respectively. Tumor volume on day 15 was 2.0 ± 0.89, 5.66 ± 1.66, and 5.02 ± 1.0 cm3 with tumor doubling time 7.8 ± 2.8, 4.4 ± 0.67, and 4.5 ± 0.5 days respectively. SMSDTTS treated tumors were visualized as hot spots on gamma scintiscans, and necrosis over tumor ratio remained consistently high on MRI, autoradiography and histology. Conclusion: The synergistic antitumor effects, multifocal targetability, simultaneous theranostic property, and good tolerance of the SMSDTTS were evident in this experiment, which warrants further development for preclinical and clinical applications. PMID:23423247

Sequential Bayesian Geostatistical Inversion and Evaluation of Combined Data Worth for Aquifer Characterization at the Hanford 300 Area

NASA Astrophysics Data System (ADS)

Murakami, H.; Chen, X.; Hahn, M. S.; Over, M. W.; Rockhold, M. L.; Vermeul, V.; Hammond, G. E.; Zachara, J. M.; Rubin, Y.

2010-12-01

Subsurface characterization for predicting groundwater flow and contaminant transport requires us to integrate large and diverse datasets in a consistent manner, and quantify the associated uncertainty. In this study, we sequentially assimilated multiple types of datasets for characterizing a three-dimensional heterogeneous hydraulic conductivity field at the Hanford 300 Area. The datasets included constant-rate injection tests, electromagnetic borehole flowmeter tests, lithology profile and tracer tests. We used the method of anchored distributions (MAD), which is a modular-structured Bayesian geostatistical inversion method. MAD has two major advantages over the other inversion methods. First, it can directly infer a joint distribution of parameters, which can be used as an input in stochastic simulations for prediction. In MAD, in addition to typical geostatistical structural parameters, the parameter vector includes multiple point values of the heterogeneous field, called anchors, which capture local trends and reduce uncertainty in the prediction. Second, MAD allows us to integrate the datasets sequentially in a Bayesian framework such that it updates the posterior distribution, as a new dataset is included. The sequential assimilation can decrease computational burden significantly. We applied MAD to assimilate different combinations of the datasets, and then compared the inversion results. For the injection and tracer test assimilation, we calculated temporal moments of pressure build-up and breakthrough curves, respectively, to reduce the data dimension. A massive parallel flow and transport code PFLOTRAN is used for simulating the tracer test. For comparison, we used different metrics based on the breakthrough curves not used in the inversion, such as mean arrival time, peak concentration and early arrival time. This comparison intends to yield the combined data worth, i.e. which combination of the datasets is the most effective for a certain metric, which will be useful for guiding the further characterization effort at the site and also the future characterization projects at the other sites.

Performance of an automated solid-phase red cell adherence system compared with that of a manual gel microcolumn assay for the identification of antibodies eluted from red blood cells.

PubMed

Finck, R H; Davis, R J; Teng, S; Goldfinger, D; Ziman, A F; Lu, Q; Yuan, S

2011-01-01

IgG antibodies coating red blood cells (RBCs) can be removed by elution procedures and their specificity determined by antibody identification studies. Although such testing is traditionally performed using the tube agglutination assay, prior studies have shown that the gel microcolumn (GMC) assay may also be used with comparable results. The purpose of this study was to compare an automated solid-phase red cell adherence (SPRCA) system with a GMC assay for the detection of antibodies eluted from RBCs. Acid eluates from 51 peripheral blood (PB) and 7 cord blood (CB) samples were evaluated by both an automated SPRCA instrument and a manual GMC assay. The concordance rate between the two systems for peripheral RBC samples was 88.2 percent (45 of 51), including cases with alloantibodies (n = 8), warm autoantibodies (n = 12), antibodies with no identifiable specificity (n = 2), and negative results (n = 23). There were six discordant cases, of which four had alloantibodies (including anti-Jka, -E, and -e) demonstrable by the SPRCA system only. In the remaining 2 cases, anti-Fya and antibodies with no identifiable specificity were demonstrable by the GMC assay only. All seven CB specimens produced concordant results, showing anti-A (n = 3), -B (n = 1), maternal anti-Jka (n = 2), or a negative result (n = 1). Automated SPRCA technology has a performance that is comparable with that of a manual GMC assay for identifying antibodies eluted from PB and CB RBCs.

Antibody screening in multitransfused patients: a prerequisite before each transfusion.

PubMed

Lamba, Divjot S; Mittal, Kshitija; Sood, Tanvi; Bedi, Ravneet Kaur; Kaur, Paramjit; Kaur, Gagandeep

2014-10-01

Life-long red blood cell (RBC) transfusions remain the main treatment for severe thalassemia. We hereby report a case of anti S and anti Lu(a) in a β-thalassemia major patient detected incidentally on antibody screening. The patient was a known case of β-thalassemia major and was on regular blood transfusion every 3 weeks from the institute from the age of 6 months. Subsequently, on one occasion, patient's crossmatch was compatible despite positive antibody screen using microcolumn gel technique. Autocontrol and direct antiglobulin test were negative on microcolumn gel. Anti S and anti Lu(a) antibodies were identified. Blood unit found compatible was negative for S and Lu(a) antigens. Antibody titers were 1:1 for both anti S and anti Lu(a) in AHG phase using tube technique and antibodies were of IgG type. Blood unit was transfused uneventfully to the patient. Donors were traced back (last three donations) and called for repeat blood sample testing for S and Lu(a) antigen. Two out of three donors were found to be S antigen positive and one out of these two was Lu(a) antigen positive. Anti S and anti Lu(a) antibodies were again identified on patient's subsequent visit for transfusion. The present case re-emphasize the importance of antibody screening at each visit in earlier detection of antibodies in multi transfused patients. Encouraging patients to receive transfusion from one center and dedicating donors could reduce alloimmunization rate but larger studies are required. Copyright © 2014 Elsevier Ltd. All rights reserved.

Deltoid Injections of Risperidone Long-acting Injectable in Patients with Schizophrenia

PubMed Central

Quiroz, Jorge A.; Rusch, Sarah; Thyssen, An; Kushner, Stuart

2011-01-01

Background Risperidone long-acting injectable was previously approved for treatment of schizophrenia as biweekly injections in the gluteal muscle only. We present data on local injection-site tolerability and safety of risperidone long-acting injectable and comparability of systemic exposure of deltoid versus gluteal injections. Methods Risperidone long-acting injectable was administered in an open-label, single-dose, two-way crossover study, with patients randomized to receive either 25mg gluteal/37.5mg deltoid crossover in two treatment periods or 50mg gluteal/50mg deltoid injections crossover; each treatment period was separated by an 85-day observation period (Study 1) and an open-label, multiple-dose study (4 sequential 37.5mg or 50mg deltoid injections every 2 weeks) (Study 2). The pharmacokinetic results from both the studies have already been published. Results In Study 1 (n=170), the majority of patients had no local injection-site findings, based on investigator and patient-rated evaluations. In Study 2 (n=53), seven of the 51 patients who received at least two deltoid injections discontinued (primary endpoint). However, none of the discontinuations were due to injection-site related reasons. The 90-percent upper confidence limit of the true proportion of injection-site issue withdrawals was 5.7 percent. No moderate or severe injection-site reactions were reported. Conclusion Intramuscular injections via the deltoid and gluteal sites are equivalent routes of administration of risperidone long-acting injectable with respect to local injection-site tolerability. The overall safety and tolerability profile of risperidone long-acting injectable was comparable when administered as an intramuscular injection in the deltoid (37.5mg and 50mg) and gluteal (25mg and 50mg) sites. PMID:21779538

[Pharmacokinetics and safety of aripiprazole long-acting injection, following multiple deltoid administrations in schizophrenia patients in Japan].

PubMed

Ishigooka, Jun; Noda, Takamasa; Nishiyama, Kosuke; Tamaru, Noriko; Shima, Tomoko; Yamasaki, Yumiko; Tadori, Yoshihiro

2016-06-01

Aripiprazole once-monthly (AOM) was previously approved for treatment of schizophrenia as monthly injections in the gluteal muscle. The deltoid muscle provides a more accessible injection site. The present study was conducted in Japanese schizophrenia patients as a 24-week, open-label trial that assessed the pharmacokinetics and safety of 5 sequential doses of AOM 400 mg (AOM 400) once every 4 weeks administered in the deltoid muscle. Patients treated with an oral atypical antipsychotic (other than aripiprazole) continued to receive their pre-study medication up to 14 days after the first AOM 400 injection. The completion rate was 76.5% (n = 13/17). Mean aripiprazole plasma C(min) almost reached steady-state by the fourth AOM 400 injection. After the fifth AOM 400 injection, mean aripiprazole AUC(28d), C(max) and C(min) were 165 μg x h/ml, 331 ng/ml and 201 ng/ml, respectively, which were similar to previously published pharmacokinetic parameters after the fifth gluteal injection of AOM 400. The most common treatment-emergent adverse event (TEAE) was injection site pain (35.3%). Most TEAEs were classified as mild in intensity. In conclusion, the deltoid injection of AOM can be considered an alternative route of administration, as deltoid and gluteal injections are interchangeable in terms of aripiprazole plasma concentrations, with no additional safety issues.

Enhanced capabilities of separation in Sequential Injection Chromatography--fused-core particle column and its comparison with narrow-bore monolithic column.

PubMed

Chocholouš, Petr; Kosařová, Lucie; Satínský, Dalibor; Sklenářová, Hana; Solich, Petr

2011-08-15

In the Sequential Injection Chromatography (SIC) only monolithic columns for chromatographic separations have been used so far. This article presents the first use of fused-core particle packed column in an attempt to extend of the chromatographic capabilities of the SIC system. A new fused-core particle column (2.7 μm) Ascentis(®) Express C18 (Supelco™ Analytical) 30 mm × 4.6 mm brings high separation efficiency within flow rates and pressures comparable to monolithic column Chromolith(®) Performance RP-18e 100-3 (Merck(®)) 100 mm × 3 mm. Both columns matches the conditions of the commercially produced SIC system - SIChrom™ (8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with 4 mL reservoir - maximal work pressure 1000 PSI) (FIAlab(®), USA). The system was tested by the separation of four estrogens with similar structure and an internal standard - ethylparaben. The mobile phase composed of acetonitrile/water (40/60 (v/v)) was pumped isocratic at flow rate 0.48 mL min(-1). Spectrophotometric detection was performed at wavelength of 225 nm and injected volume of sample solutions was 10 μL. The chromatographic characteristics of both columns were compared. Obtained results and conclusions have shown that both fused-core particle column and longer narrow shaped monolithic column bring benefits into the SIC method. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of short-term sequential administration of nonsteroidal anti-inflammatory drugs on the stomach and proximal portion of the duodenum in healthy dogs.

PubMed

Dowers, Kristy L; Uhrig, Samantha R; Mama, Khursheed R; Gaynor, James S; Hellyer, Peter W

2006-10-01

To evaluate effects of injection with a nonsteroidal anti-inflammatory drug (NSAID) followed by oral administration of an NSAID on the gastrointestinal tract (GIT) of healthy dogs. 6 healthy Walker Hounds. In a randomized, crossover design, dogs were administered 4 treatments consisting of an SC injection of an NSAID or control solution (day 0), followed by oral administration of an NSAID or inert substance for 4 days (days 1 through 4). Treatment regimens included carprofen (4 mg/kg) followed by inert substance; saline (0.9% NaCl) solution followed by deracoxib (4 mg/kg); carprofen (4 mg/kg) followed by carprofen (4 mg/kg); and carprofen (4 mg/kg) followed by deracoxib (4 mg/kg). Hematologic, serum biochemical, and fecal evaluations were conducted weekly, and clinical scores were obtained daily. Endoscopy of the GIT was performed before and on days 1, 2, and 5 for each treatment. Lesions were scored by use of a 6-point scale. No significant differences existed for clinical data, clinicopathologic data, or lesion scores in the esophagus, cardia, or duodenum. For the gastric fundus, antrum, and lesser curvature, an effect of time was observed for all treatments, with lesions worsening from before to day 2 of treatments but improving by day 5. Sequential administration of NSAIDs in this experiment did not result in clinically important gastroduodenal ulcers. A larger study to investigate the effect of sequential administration of NSAIDs for longer durations and in dogs with signs of acute and chronic pain is essential to substantiate these findings.

Micro-Columnated Loop Heat Pipe: The Future of Electronic Substrates

NASA Astrophysics Data System (ADS)

Dhillon, Navdeep Singh

The modern world is run by semiconductor-based electronic systems. Due to continuous improvements in semiconductor device fabrication, there is a clear trend in the market towards the development of electronic devices and components that not only deliver enhanced computing power, but are also more compact. Thermal management has emerged as the primary challenge in this scenario where heat flux dissipation of electronic chips is increasing exponentially, but conventional cooling solutions such as conduction and convection are no longer feasible. To keep device junction temperatures within the safe operating limit, there is an urgent requirement for ultra-high-conductivity thermal substrates that not only absorb and transport large heat fluxes, but can also provide localized cooling to thermal hotspots. This dissertation describes the design, modeling, and fabrication of a phase change-based, planar, ultra-thin, passive thermal transport system that is inspired by the concept of loop heat pipes and capillary pumped loops. Fabricated on silicon and Pyrex wafers using microfabrication techniques, the micro-columnated loop heat pipe (muCLHP) can be integrated directly with densely packed or multiply-stacked electronic substrates, to provide localized high-heat-flux thermal management. The muCLHP employs a dual-scale coherent porous silicon(CPS)-based micro-columnated wicking structure, where the primary CPS wick provides large capillary forces for fluid transport, while a secondary surface-wick maximizes the rate of thin-film evaporation. To overcome the wick thickness limitation encountered in conventional loop heat pipes, strategies based on MEMS surface micromachining techniques were developed to reduce parasitic heat flow from the evaporator to the compensation chamber of the device. Finite element analysis was used to confirm this reduction in a planar evaporator design, thus enabling the generation of a large motive temperature head for continuous device operation. To predict the overall heat carrying capacity of the muCLHP in the capillary pumping limit, an analytical model was developed to account for a steady state pressure balance in the device flow loop. Based on this model, a design optimization study, employing monotonicity analysis and numerical optimization techniques, was undertaken. It was found that an optimized muCLHP device can absorb heat fluxes as large as 1293 W/cm2 when water is used as a working fluid. A finite volume method-based numerical model was also developed to compute the rates of thin-film evaporation from the patterned surface of the secondary wick. The numerical results indicated that, by properly optimizing the dual-scale wick topology, allowable evaporative heat fluxes can be made commensurate with the heat flux performance predicted by the capillary pumping limit. The latter part of the dissertation deals with the fabrication, packaging, and experimental testing of several in-plane-wicking micro loop heat pipe (muLHP) prototypes. These devices were fabricated on silicon and Pyrex substrates and closely resemble the muCLHP design philosophy, with the exception that the CPS wick is substituted with an easier to fabricate in-plane wick. A novel thermal-flux method was developed for the degassing and fluid charging of the muLHP prototypes. Experiments were conducted to study the process of evaporation and dynamics of the liquid and vapor phases in the device flow loop. Using these results, the overall device and individual component topologies critical to the operation of the two-phase flow loop were identified. A continuous two-phase device flow loop was demonstrated for applied evaporator heat fluxes as high as 41 W/cm2. The performance of these devices, currently found to be limited by the motive temperature head requirement, can be significantly improved by implementing the parasitic heat flow-reduction strategies developed in this work. The 3-D thin-film evaporation model, when integrated into the overall device modeling framework, will enable a design optimization of the micro-columnated wick for further device performance enhancements.

Brain serotonin content - Increase following ingestion of carbohydrate diet.

NASA Technical Reports Server (NTRS)

Fernstrom, J. D.; Wurtman, R. J.

1971-01-01

In the rat, the injection of insulin or the consumption of carbohydrate causes sequential increases in the concentrations of tryptophan in the plasma and the brain and of serotonin in the brain. Serotonin-containing neurons may thus participate in systems whereby the rat brain integrates information about the metabolic state in its relation to control of homeostasis and behavior.

Determination of yeast assimilable nitrogen content in wine fermentations by sequential injection analysis with spectrophotometric detetection.

PubMed

Muik, Barbara; Edelmann, Andrea; Lendl, Bernhard; Ayora-Cañada, María José

2002-09-01

An automated method for measuring the primary amino acid concentration in wine fermentations by sequential injection analysis with spectrophotometric detection was developed. Isoindole-derivatives from the primary amino acid were formed by reaction with o-phthaldialdehyde and N-acetyl- L-cysteine and measured at 334 nm with respect to a baseline point at 700 nm to compensate the observed Schlieren effect. As the reaction kinetic was strongly matrix dependent the analytical readout at the final reaction equilibrium has been evaluated. Therefore four parallel reaction coils were included in the flow system to be capable of processing four samples simultaneously. Using isoleucine as the representative primary amino acid in wine fermentations a linear calibration curve from 2 to 10 mM isoleucine, corresponding to 28 to 140 mg nitrogen/L (N/L) was obtained. The coefficient of variation of the method was 1.5% at a throughput of 12 samples per hour. The developed method was successfully used to monitor two wine fermentations during alcoholic fermentation. The results were in agreement with an external reference method based on high performance liquid chromatography. A mean-t-test showed no significant differences between the two methods at a confidence level of 95%.

Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

PubMed

Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

2002-12-06

Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

PubMed

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

Marker retention in the cochlea following injections through the round window membrane

PubMed Central

Salt, Alec N.; Sirjani, Davud B.; Hartsock, Jared J.; Gill, Ruth M.; Plontke, Stefan K.

2007-01-01

Local delivery of drugs to the inner ear is increasingly being used in both clinical and experimental studies. Although direct injection of drugs into perilymph appears to be the most promising way of administering drugs quantitatively, no studies have yet demonstrated the pharmacokinetics in perilymph following direct injections. In this study, we have investigated the retention of substance in perilymph following a single injection into the basal turn of scala tympani (ST). The substance injected was a marker, trimethylphenylammonium (TMPA) that can be detected in low concentrations with ion-selective microelectrodes. Perilymph pharmacokinetics of TMPA was assessed using sequential apical sampling to obtain perilymph for analysis. The amount of TMPA retained in perilymph was compared for different injection and sampling protocols. TMPA concentrations measured in fluid samples were close to those predicted by simulations when the injection pipette was sealed into the bony wall of ST but were systematically lower when the injection pipette was inserted through the round window membrane (RWM). In the latter condition it was estimated that over 60% of the injected TMPA was lost due to leakage of perilymph around the injection pipette at a rate estimated to be 0.09 μL/min. The effects of leakage during and after injections through the RWM were dramatically reduced when the round window niche was filled with 1% sodium hyaluronate gel before penetrating the RWM with the injection pipette. The findings demonstrate that in order to perform quantitative drug injections into perilymph, even small rates of fluid leakage at the injection site must be controlled. PMID:17662546

Combined treatment in punctate inner choroidopathy

PubMed Central

Terelak-Borys, Barbara; Zagajewska, Katarzyna; Jankowska-Lech, Irmina; Tesla, Piotr; Grabska-Liberek, Iwona

2016-01-01

Purpose The purpose of this study was to describe a combination treatment for choroidal neovascular (CNV) membrane, secondary to punctate inner choroidopathy (PIC). Patient and methods A 44-year-old female patient was diagnosed with PIC complicated by the development of recurrent juxtafoveal neovascular membrane. The treatment included a sequence of monotherapy regimens: systemic steroid therapy, photodynamic therapy, and intravitreal injections of vascular endothelial growth factor (VEGF) inhibitor (anti-VEGF). Owing to the CNV membrane resistance to various types of monotherapy, a combination treatment consisting of local injections of steroid underneath the Tenon’s capsule and intravitreal anti-VEGF injections was used. Results Systemic steroid therapy resulted in rapid local improvement with a very short remission period. No positive effects of photodynamic therapy were observed. Sequential anti-VEGF injections led to remission periods of several months. Permanent regression of CNV membrane was achieved following combined local application of steroid and intravitreal anti-VEGF injections. Conclusion A combination treatment including steroid and anti-VEGF medication characterized by anti-inflammatory and antiangiogenic effects may be a very beneficial option for the treatment of recurrent CNV membrane as a complication of PIC. PMID:27729795

Issues surrounding lethal injection as a means of capital punishment.

PubMed

Romanelli, Frank; Whisman, Tyler; Fink, Joseph L

2008-12-01

Lethal injection as a method of state-sanctioned capital punishment was initially proposed in the United States in 1977 and used for the first time in 1982. Most lethal injection protocols use a sequential drug combination of sodium thiopental, pancuronium bromide, and potassium chloride. Lethal injection was originally introduced as a more humane form of execution compared with existing mechanical methods such as electrocution, toxic gassing, hanging, or firing squad. Lethal injection has not, however, been without controversy. Several states are considering whether lethal injection meets constitutional scrutiny forbidding cruel and unusual punishment. Recently in the case of Ralph Baze and Thomas C. Bowling, Petitioners, v John D. Rees, Commissioner, Kentucky Department of Corrections et al, the United States Supreme Court upheld the constitutionality of the lethal injection protocol as carried out in the Commonwealth of Kentucky. Most of the debate has surrounded the dosing and procedures used in lethal injection and whether the drug combinations and measures for administering the drugs truly produce a timely, pain-free, and fail-safe death. Many have also raised issues regarding the "medicalization" of execution and the ethics of health care professionals' participation in any part of the lethal injection process. As a result of all these issues, the future of lethal injection as a means of execution in the United States is under significant scrutiny. Outcomes of ongoing legislative and judicial reviews might result in cessation of lethal injection in totality or in alterations involving specific drug combinations or administration procedures.

An analog neural hardware implementation using charge-injection multipliers and neutron-specific gain control.

PubMed

Massengill, L W; Mundie, D B

1992-01-01

A neural network IC based on a dynamic charge injection is described. The hardware design is space and power efficient, and achieves massive parallelism of analog inner products via charge-based multipliers and spatially distributed summing buses. Basic synaptic cells are constructed of exponential pulse-decay modulation (EPDM) dynamic injection multipliers operating sequentially on propagating signal vectors and locally stored analog weights. Individually adjustable gain controls on each neutron reduce the effects of limited weight dynamic range. A hardware simulator/trainer has been developed which incorporates the physical (nonideal) characteristics of actual circuit components into the training process, thus absorbing nonlinearities and parametric deviations into the macroscopic performance of the network. Results show that charge-based techniques may achieve a high degree of neural density and throughput using standard CMOS processes.

Laser ablation and column formation in silicon under oxygen-rich atmospheres

NASA Astrophysics Data System (ADS)

Pedraza, A. J.; Fowlkes, J. D.; Lowndes, D. H.

2000-11-01

The microstructure formed at the surface of silicon by cumulative pulsed-laser irradiation in oxygen-rich atmospheres consists of an array of microcolumns surrounded by microcanyons and microholes. Formation of SiOx at the exposed surface of silicon is most likely responsible for the occurrence of etching/ablation that causes the continuous deepening of canyons and holes. The growth mechanism of columns that is supported by the experimental evidence presented here is a process in which the columns are fed at their tips by the silicon-rich ablation plasma produced during pulsed-laser irradiation.

A new rat model of portal hypertension induced by intraportal injection of microspheres

PubMed Central

Li, Xiang-Nong; Benjamin, IS; Alexander, B

1998-01-01

AIM: To produce a new rat model of portal hypertension by intraportal injection of microspheres. METHODS: Measured aliquots of single or different-sized microspheres (15, 40, 80μm) were injected into the portal vein to block intrahepatic portal radicals. The resultant changes in arterial,portal,hepatic venous and splenic pulp pressures were monitored. The liver and lungs were excised for histological examination. RESULTS: Portal venous pressure was elevated from basal value of 0.89-1.02 kPa to a steady-state of 1.98-3.19 kPa following the sequential injections of single- or different-sized microspheres, with a markedly lowered mean arterial pressure. However, a small-dose injection of 80 μm microspheres (1.8 × 105) produced a steady-state portal venous pressure of 2.53 × 0.17 kPa, and all rats showed normal arterial pressures. In addition, numerous microspheres were found in the lungs in all experimental groups. CONCLUSION: Portal hypertension can be reproduced in rats by intraportal injection of microspheres at a small dose of 80 μm (1.8 × 105). Intrahepatic portal-systemic shunts probably exist in the normal rat liver. PMID:11819236

Single well tracer method to evaluate enhanced recovery

DOEpatents

Sheely, Jr., Clyde Q.; Baldwin, Jr., David E.

1978-01-01

Data useful to evaluate the effectiveness of or to design an enhanced recovery process (the recovery process involving mobilizing and moving hydrocarbons through a hydrocarbon-bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well) are obtained by a process which comprises sequentially: determining hydrocarbon saturation in the formation in a volume in the formation near a well bore penetrating the formation, injecting sufficient of the mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore penetrating the formation, and determining by the single well tracer method a hydrocarbon saturation profile in a volume from which hydrocarbons are moved. The single well tracer method employed is disclosed by U.S. Pat. No. 3,623,842. The process is useful to evaluate surfactant floods, water floods, polymer floods, CO.sub.2 floods, caustic floods, micellar floods, and the like in the reservoir in much less time at greatly reduced costs, compared to conventional multi-well pilot test.

A prospective randomized study comparing two commercially available types of human embryo culture media: G1-PLUS™/G2-PLUS™ sequential medium (Vitrolife) and the GL BLAST™ sole medium (Ingamed).

PubMed

Ceschin, Ianae I; Ribas, Mariana H; Ceschin, Alvaro P; Nishikawa, Lucileine; Rocha, Claudia C; Pic-Taylor, Aline; Baroneza, José Eduardo

2016-03-01

To check the efficacy of two types of commercially available embryo culture medium: G1-PLUS™/G2-PLUS™ sequential (Vitrolife, Gothenburg, Sweden) and GV BLAST™ sole (Ingamed, Maringá, Brazil) with regards to fertilization, cleavage, blastocyst and pregnancy rates. Prospective and randomized study conducted from March to July 2015, using the medical records of 60 patients submitted to Intracytoplasmic Sperm Injection techniques (ICSI). Data regarding the age of patients, together with fertilization, cleavage, blastocyst and pregnancy rates, were collected and compared in relation to the: G1-PLUS™/G2-PLUS™ sequential and GV BLAST™ sole mediums. The data were tabulated and compared using the Pearson's Chi-Square test (95% CI). There was no significant difference when comparing patients divided into higher and lower fertility age. No significant statistical difference was noted between the fertilization rates (P=0.59), cleavage (P=0.91), evolution to blastocyst (P=0.33) and total pregnancy (P=0.83) when comparing the embryos cultured in the different media analysed. We conclude that the G1-PLUS™/G2-PLUS™ sequential and GV BLAST™ sole mediums are equally effective with regards to fertilization, cleavage, blastocyst development and total pregnancy rates.

A novel sequential process for remediating rare-earth wastewater.

PubMed

Cui, Mingcan; Jang, Min; Kang, Kyounglim; Kim, Dukmin; Snyder, Shane A; Khim, Jeehyeong

2016-02-01

A novel and economic sequential process consisting of precipitation, adsorption, and oxidation was developed to remediate actual rare-earth (RE) wastewater containing various toxic pollutants, including radioactive species. In the precipitation step, porous air stones (PAS) containing waste oyster shell (WOS), PASWOS, was prepared and used to precipitate most heavy metals with >97% removal efficiencies. The SEM-EDS analysis revealed that PAS plays a key role in preventing the surface coating of precipitants on the surface of WOS and in releasing the dissolved species of WOS successively. For the adsorption step, a polyurethane (PU) impregnated by coal mine drainage sludge (CMDS), PUCMDS, was synthesized and applied to deplete fluoride (F), arsenic (As), uranium (U), and thorium (Th) that remained after precipitation. The continuous-mode sequential process using PAS(WOS), PU(CMDS), and ozone (O3) had 99.9-100% removal efficiencies of heavy metals, 99.3-99.9% of F and As, 95.8-99.4% of U and Th, and 92.4% of COD(Cr) for 100 days. The sequential process can treat RE wastewater economically and effectively without stirred-tank reactors, pH controller, continuous injection of chemicals, and significant sludge generation, as well as the quality of the outlet met the EPA recommended limits. Copyright © 2015 Elsevier Ltd. All rights reserved.

Human mesenchymal stem cell behavior on femtosecond laser-textured Ti-6Al-4V surfaces.

PubMed

Cunha, Alexandre; Zouani, Omar Farouk; Plawinski, Laurent; Botelho do Rego, Ana Maria; Almeida, Amélia; Vilar, Rui; Durrieu, Marie-Christine

2015-01-01

The aim of the present work was to investigate ultrafast laser surface texturing as a surface treatment of Ti-6Al-4V alloy dental and orthopedic implants to improve osteoblastic commitment of human mesenchymal stem cells (hMSCs). Surface texturing was carried out by direct writing with an Yb:KYW chirped-pulse regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. The surface topography and chemical composition were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively. Three types of surface textures with potential interest to improve implant osseointegration can be produced by this method: laser-induced periodic surface structures (LIPSSs); nanopillars (NPs); and microcolumns covered with LIPSSs, forming a bimodal roughness distribution. The potential of the laser treatment in improving hMSC differentiation was assessed by in vitro study of hMSCs spreading, adhesion, elongation and differentiation using epifluorescence microscopy at different times after cell seeding, after specific stainings and immunostainings. Cell area and focal adhesion area were lower on the laser-textured surfaces than on a polished reference surface. Obviously, the laser-textured surfaces have an impact on cell shape. Osteoblastic commitment was observed independently of the surface topography after 2 weeks of cell seeding. When the cells were cultured (after 4 weeks of seeding) in osteogenic medium, LIPSS- and NP- textured surfaces enhanced matrix mineralization and bone-like nodule formation as compared with polished and microcolumn-textured surfaces. The present work shows that surface nanotextures consisting of LIPSSs and NPs can, potentially, improve hMSC differentiation into an osteoblastic lineage.

Examination of Glycan Profiles from IgG-Depleted Human Immunoglobulins Facilitated by Microscale Affinity Chromatography

PubMed Central

Svoboda, Martin; Mann, Benjamin F.; Goetz, John A.; Novotny, Milos V.

2012-01-01

Among the most important proteins involved in the disease and healing processes are the immunoglobulins (Igs). Although many of the Igs have been studied through proteomics, aside from IgG, immunoglobulin carbohydrates have not been extensively characterized in different states of health. It seems valuable to develop techniques that permit us to understand changes in the structures and abundances of Ig glycans in the context of disease onset and progression. We have devised a strategy for characterization of the glycans for the Ig classes other than IgG (i.e. A, D, E, and M) that contain kappa light chains, while using only a few microliters of biological material. First, we designed a microcolumn containing the recombinant Protein L that was immobilized on macroporous silica particles. A similarly designed Protein G microcolumn was utilized to first perform an on-line depletion of the IgG from the sample, human blood serum, and thereby facilitate enrichment of the other Igs. While only 3 μL of serum were used in these analyses, we were able to recover a significantly-enriched fraction of non-IgG immunoglobulins. The enrichment properties of the Protein L column were characterized using a highly sensitive label-free quantitative proteomics LC-MS/MS approach, and the glycomic profiles of enriched immunoglobulins were measured by MALDI-TOF-MS. As a proof-of-principle, a comparative study was conducted using blood serum from a small group of lung cancer patients and a group of age-matched cancer-free individuals to demonstrate that the method is suitable for investigation of glycosylation changes in disease. The results were in agreement with a glycomic investigation of whole blood serum from a much larger lung cancer cohort. PMID:22360417

Continuous inline blending of antimisting kerosene

NASA Technical Reports Server (NTRS)

Parikh, P.; Yavrouian, A.; Sarohia, V.

1985-01-01

A continuous inline blender was developed to blend polymer slurries with a stream of jet A fuel. The viscosity of the slurries ranged widely. The key element of the blender was a static mixer placed immediately downstream of the slurry injection point. A positive displacement gear pump for jet A was employed, and a progressive cavity rotary screw pump was used for slurry pumping. Turbine flow meters were employed for jet A metering while the slurry flow rate was calibrated against the pressure drop in the injection tube. While using one of the FM-9 variant slurries, a provision was made for a time delay between the addition of slurry and the addition of amine sequentially into the jet A stream.

Optimization of 64-MDCT urography: effect of dual-phase imaging with furosemide on collecting system opacification and radiation dose.

PubMed

Portnoy, Orith; Guranda, Larisa; Apter, Sara; Eiss, David; Amitai, Marianne Michal; Konen, Eli

2011-11-01

The purpose of this study was to compare opacification of the urinary collecting system and radiation dose associated with three-phase 64-MDCT urographic protocols and those associated with a split-bolus dual-phase protocol including furosemide. Images from 150 CT urographic examinations performed with three scanning protocols were retrospectively evaluated. Group A consisted of 50 sequentially registered patients who underwent a three-phase protocol with saline infusion. Group B consisted of 50 sequentially registered patients who underwent a reduced-radiation three-phase protocol with saline. Group C consisted of 50 sequentially registered patients who underwent a dual-phase split-bolus protocol that included a low-dose furosemide injection. Opacification of the urinary collecting system was evaluated with segmental binary scoring. Contrast artifacts were evaluated, and radiation doses were recorded. Results were compared by analysis of variance. A significant reduction in mean effective radiation dose was found between groups A and B (p < 0.001) and between groups B and C (p < 0.001), resulting in 65% reduction between groups A and C (p < 0.001). This reduction did not significantly affect opacification score in any of the 12 urinary segments (p = 0.079). In addition, dense contrast artifacts overlying the renal parenchyma observed with the three-phase protocols (groups A and B) were avoided with the dual-phase protocol (group C) (p < 0.001). A dual-phase protocol with furosemide injection is the preferable technique for CT urography. In comparison with commonly used three-phase protocols, the dual-phase protocol significantly reduces radiation exposure dose without reduction in image quality.

SR high-speed K-edge subtraction angiography in the small animal (abstract)

NASA Astrophysics Data System (ADS)

Takeda, T.; Akisada, M.; Nakajima, T.; Anno, I.; Ueda, K.; Umetani, K.; Yamaguchi, C.

1989-07-01

To assess the ability of the high-speed K-edge energy subtraction system which was made at beamline 8C of Photon Factory, Tsukuba, we performed an animal experiment. Rabbits were used for the intravenous K-edge subtraction angiography. In this paper, the actual images of the artery obtained by this system, are demonstrated. The high-speed K-edge subtraction system consisted of movable silicon (111) monocrystals, II-ITV, and digital memory system. Image processing was performed by 68000-IP computer. The monochromatic x-ray beam size was 50×60 mm. Photon energy above and below iodine K edge was changed within 16 ms and 32 frames of images were obtained sequentially. The rabbits were anaesthetized by phenobarbital and a 5F catheter was inserted into inferior vena cava via the femoral vein. 1.5 ml/kg of contrast material (Conlaxin H) was injected at the rate of 0.5 ml/kg/s. TV images were obtained 3 s after the starting point of injection. By using this system, the clear K-edge subtracted images were obtained sequentially as a conventional DSA system. The quality of the images were better than that obtained by DSA. The dynamical blood flow was analyzed, and the best arterial image could be selected from the sequential images. The structures of aortic arch, common carotid arteries, right subclavian artery, and internal thoracic artery were obtained at the chest. Both common carotid arteries and vertebral arteries were recorded at the neck. The diameter of about 0.3-0.4 mm artery could be clearly revealed. The high-speed K-edge subtraction system demonstrates the very sharp arterial images clearly and dynamically.

Concomitant or sequential administration of live attenuated japanese encephalitis chimeric virus vaccine and yellow fever 17D vaccine

PubMed Central

Nasveld, Peter E; Marjason, Joanne; Bennett, Sonya; Aaskov, John; Elliott, Suzanne; McCarthy, Karen; Kanesa-thasan, Niranjan; Feroldi, Emmanuel

2010-01-01

A randomized, double-blind, study was conducted to evaluate the safety, tolerability and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) co-administered with live attenuated yellow fever (YF) vaccine (YF-17D strain; Stamaril®, Sanofi Pasteur) or administered sequentially. Participants (n = 108) were randomized to receive: YF followed by JE-CV 30 days later, JE followed by YF 30 days later, or the co-administration of JE and YF followed or preceded by placebo 30 days later or earlier. Placebo was used in a double-dummy fashion to ensure masking. Neutralizing antibody titers against JE-CV, YF-17D and selected wild-type JE virus strains was determined using a 50% serum-dilution plaque reduction neutralization test (PRNT50). Seroconversion was defined as the appearance of a neutralizing antibody titer above the assay cut-off post-immunization when not present pre-injection at day 0, or a least a four-fold rise in neutralizing antibody titer measured before the pre-injection day 0 and later post vaccination samples. There were no serious adverse events. Most adverse events (AEs) after JE vaccination were mild to moderate in intensity, and similar to those reported following YF vaccination. Seroconversion to JE-CV was 100% and 91% in the JE/YF and YF/JE sequential vaccination groups, respectively, compared with 96% in the co-administration group. All participants seroconverted to YF vaccine and retained neutralizing titers above the assay cut-off at month six. Neutralizing antibodies against JE vaccine were detected in 82–100% of participants at month six. These results suggest that both vaccines may be successfully co-administered simultaneously or 30 days apart. PMID:20864814

Electrochemical immunoassay for vitellogenin based on sequential injection using antigen-immobilized magnetic microbeads.

PubMed

Hirakawa, Koji; Katayama, Masaaki; Soh, Nobuaki; Nakano, Koji; Imato, Toshihiko

2006-01-01

A rapid and sensitive immunoassay for the determination of vitellogenin (Vg) is described. The method involves a sequential injection analysis (SIA) system equipped with an amperometric detector and a neodymium magnet. Magnetic beads, onto which an antigen (Vg) was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of magnetic beads in an immunoreaction cell were controlled by means of the neodymium magnet and by adjusting the flow of the carrier solution. The immunoassay was based on an indirect competitive immunoreaction of an alkaline phosphatase (ALP) labeled anti-Vg monoclonal antibody between the fraction of Vg immobilized on the magnetic beads and Vg in the sample solution. The immobilization of Vg on the beads involved coupling an amino group moiety of Vg with the magnetic beads after activation of a carboxylate moiety on the surface of magnetic beads that had been coated with a polylactate film. The Vg-immobilized magnetic beads were introduced and trapped in the immunoreaction cell equipped with the neodymium magnet; a Vg sample solution containing an ALP labeled anti-Vg antibody at a constant concentration and a p-aminophenyl phosphate (PAPP) solution were sequentially introduced into the immunoreaction cell. The product of the enzyme reaction of PAPP with ALP on the antibody, paminophenol, was transported to an amperometric detector, the applied voltage of which was set at +0.2 V vs. an Ag/AgCl reference electrode. A sigmoid calibration curve was obtained when the logarithm of the concentration of Vg was plotted against the peak current of the amperometric detector using various concentrations of standard Vg sample solutions (0-500 ppb). The time required for the analysis is less than 15 min.

Sequential variable fuel injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weglarz, M.W.; Vincent, M.T.; Prestel, J.F.

This patent describes a fuel injection system for an engine of an automotive vehicle including cylinders, a spark plug for each of the cylinders, a distributor electrically connected to the spark plug, a throttle body having a throttle valve connected to the engine to allow or prevent air to the cylinders, a fuel source at least one fuel line connected to the fuel source, fuel injectors connected to the fuel line for delivering fuel to the cylinders, a sensor located near the distributor for sensing predetermined states of the distributor, and an electronic control unit (ECU) electrically connected to themore » sensor, distributor and fuel injectors. It comprises calculating a desired total injector on time for current engine conditions; calculating a variable injection time (VIT) and a turn on time based on the VIT; and firing the fuel injectors at the calculated turn on time for the calculated total injector on time.« less

Solid State Television Camera (CID)

NASA Technical Reports Server (NTRS)

Steele, D. W.; Green, W. T.

1976-01-01

The design, development and test are described of a charge injection device (CID) camera using a 244x248 element array. A number of video signal processing functions are included which maximize the output video dynamic range while retaining the inherently good resolution response of the CID. Some of the unique features of the camera are: low light level performance, high S/N ratio, antiblooming, geometric distortion, sequential scanning and AGC.

Kinetics of the neuroinflammation-oxidative stress correlation in rat brain following the injection of fibrillar amyloid-beta onto the hippocampus in vivo.

PubMed

Rosales-Corral, Sergio; Tan, Dun-Xian; Reiter, Russel J; Valdivia-Velázquez, Miguel; Acosta-Martínez, J Pablo; Ortiz, Genaro G

2004-05-01

The purpose of this study was to describe-following the injection of a single intracerebral dose of fibrillar amyloid-beta(1-40) in vivo-some correlations between proinflammatory cytokines and oxidative stress indicators in function of time, as well as how these variables fit in a regression model. We found a positive, significant correlation between interleukin (IL)-1beta or IL-6 and the activity of the glutathione peroxidase enzyme (GSH-Px), but IL-1beta or IL-6 maintained a strong, negative correlation with the lipid peroxidation (LPO). The first 12 h marked a positive correlation between IL-6 and tumor necrosis factor-alpha (TNF-alpha), but starting from the 36 h, this relationship became negative. We found also particular patterns of behavior through the time for IL-1beta, nitrites and IL-6, with parallel or sequential interrelationships. Results shows clearly that, in vivo, the fibrillar amyloid-beta (Abeta) disrupts the oxidative balance and initiate a proinflammatory response, which in turn feeds the oxidative imbalance in a coordinated, sequential way. This work contributes to our understanding of the positive feedbacks, focusing the "cytokine cycle" along with the oxidative stress mediators in a complex, multicellular, and interactive environment.

The sequential injection system with adsorptive stripping voltammetric detection.

PubMed

Kubiak, W W; Latonen, R M; Ivaska, A

2001-03-16

Two sequential injection systems have been developed for adsorptive stripping voltammetric measurement. One is for substances adsorbing at mercury, e.g. riboflavin. In this case, a simple arrangement with only sample aspiration is needed. Reproducibility was 3% and detection limit 0.07 muM. The measuring system was applied to determination of riboflavin in vitamin pills and to study the photodegradation process of riboflavin in aqueous solutions. In the second case, metal ions were determined. They have to be complexed before deposition on the mercury surface. Thus, both the sample and the ligand have to be aspirated in the system. In this case, the reproducibility was approximately 6% and the detection limit <0.1 ppm for cadmium, lead and copper when complexation with oxine was used. Dimethylglyoxime was used in determination of nickel and cobalt and nioxime complexes were used in determination of nickel and copper. With these complexing agents, the reproducibility was the same as with oxine, but the metals could be determined at concentrations lower than 0.01 ppm. Application of two ligands in a SIA system with AdSV detection was also studied. Simultaneous determination of copper, lead, cadmium and cobalt was possible by using oxine and dimethylglyoxime. Copper and nickel were simultaneously determined by using dimethylglyoxime and nioxime.

A 400 MHz Wireless Neural Signal Processing IC With 625 $\\times$ On-Chip Data Reduction and Reconfigurable BFSK/QPSK Transmitter Based on Sequential Injection Locking.

PubMed

Teng, Kok-Hin; Wu, Tong; Liu, Xiayun; Yang, Zhi; Heng, Chun-Huat

2017-06-01

An 8-channel wireless neural signal processing IC, which can perform real-time spike detection, alignment, and feature extraction, and wireless data transmission is proposed. A reconfigurable BFSK/QPSK transmitter (TX) at MICS/MedRadio band is incorporated to support different data rate requirement. By using an Exponential Component-Polynomial Component (EC-PC) spike processing unit with an incremental principal component analysis (IPCA) engine, the detection of neural spikes with poor SNR is possible while achieving 625× data reduction. For the TX, a dual-channel at 401 MHz and 403.8 MHz are supported by applying sequential injection locked techniques while attaining phase noise of -102 dBc/Hz at 100 kHz offset. From the measurement, error vector magnitude (EVM) of 4.60%/9.55% with power amplifier (PA) output power of -15 dBm is achieved for the QPSK at 8 Mbps and the BFSK at 12.5 kbps. Fabricated in 65 nm CMOS with an active area of 1 mm 2 , the design consumes a total current of 5  ∼ 5.6 mA with a maximum energy efficiency of 0.7 nJ/b.

Bioremediation of PAHs contaminated river sediment by an integrated approach with sequential injection of co-substrate and electron acceptor: Lab-scale study.

PubMed

Liu, Tongzhou; Zhang, Zhen; Dong, Wenyi; Wu, Xiaojing; Wang, Hongjie

2017-11-01

In this study, the feasibility of employing an integrated bioremediation approach in contaminated river sediment was evaluated. Sequential addition of co-substrate (acetate) and electron acceptor (NO 3 - ) in a two-phase treatment was capable of effectively removing polycyclic aromatic hydrocarbons (PAHs) in river sediment. The residual concentration of total PAHs decreased to far below effect range low (ERL) value within 91 days of incubation, at which concentration it could rarely pose biological impairment. The biodegradation of high molecular weight PAHs were found to be mainly occurred in the sediment treated with co-substrates (i.e. acetate or methanol), in which acetate was found to be more suitable for PAHs degradation. The role of co-substrates in influencing PAHs biodegradation was tentatively discussed herein. Additionally, the sediment odorous problem and blackish appearance were intensively addressed by NO 3 - injection. The results of this study demonstrated that integrating two or more approaches/processes would be a helpful option in sediment remediation. It can lead to a more effective remediation performance, handle multiple contamination issues, as well as mitigate environmental risks caused by one of the single methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prime-boost vaccination with plasmid and adenovirus gene vaccines control HER2/neu+ metastatic breast cancer in mice.

PubMed

Wang, Xiaoyan; Wang, Jian-Ping; Rao, Xiao-Mei; Price, Janet E; Zhou, Heshan S; Lachman, Lawrence B

2005-01-01

Once metastasis has occurred, the possibility of completely curing breast cancer is unlikely, particularly for the 30 to 40% of cancers overexpressing the gene for HER2/neu. A vaccine targeting p185, the protein product of the HER2/neu gene, could have therapeutic application by controlling the growth and metastasis of highly aggressive HER2/neu+ cells. The purpose of this study was to determine the effectiveness of two gene vaccines targeting HER2/neu in preventive and therapeutic tumor models. The mouse breast cancer cell line A2L2, which expresses the gene for rat HER2/neu and hence p185, was injected into the mammary fat pad of mice as a model of solid tumor growth or was injected intravenously as a model of lung metastasis. SINCP-neu, a plasmid containing Sindbis virus genes and the gene for rat HER2/neu, and Adeno-neu, an E1,E2a-deleted adenovirus also containing the gene for rat HER2/neu, were tested as preventive and therapeutic vaccines. Vaccination with SINCP-neu or Adeno-neu before tumor challenge with A2L2 cells significantly inhibited the growth of the cells injected into the mammary fat or intravenously. Vaccination 2 days after tumor challenge with either vaccine was ineffective in both tumor models. However, therapeutic vaccination in a prime-boost protocol with SINCP-neu followed by Adeno-neu significantly prolonged the overall survival rate of mice injected intravenously with the tumor cells. Naive mice vaccinated using the same prime-boost protocol demonstrated a strong serum immunoglobulin G response and p185-specific cellular immunity, as shown by the results of ELISPOT (enzyme-linked immunospot) analysis for IFNgamma. We report herein that vaccination of mice with a plasmid gene vaccine and an adenovirus gene vaccine, each containing the gene for HER2/neu, prevented growth of a HER2/neu-expressing breast cancer cell line injected into the mammary fat pad or intravenously. Sequential administration of the vaccines in a prime-boost protocol was therapeutically effective when tumor cells were injected intravenously before the vaccination. The vaccines induced high levels of both cellular and humoral immunity as determined by in vitro assessment. These findings indicate that clinical evaluation of these vaccines, particularly when used sequentially in a prime-boost protocol, is justified.

Rapid separation on copper powder of total mercury in blood and determination of mercury by flameless atomic absorption spectrometry.

PubMed

Dogan, S; Haerdi, W

1979-01-01

The determination of mercury in blood by flameless atomic absorption spectrometry (FAAS) has been described. Prior to its analysis, the sample was decomposed by combustion and separated on a copper powder micro-column. A special type of cell has been used which gives a better sensitivity compared with the types of cells described in the literature and the method of FAAS analysis has been improved. The sensitivity of 0.1 ng for 1% absorbance was observed and the standard deviation for six determinations at this level was found to be +/- 0.05 ng, for 95% probability.

Analytical Glycobiology at High Sensitivity: Current Approaches and Directions

PubMed Central

Novotny, Milos V.; Alley, William R.; Mann, Benjamin F.

2013-01-01

This review summarizes the analytical advances made during the last several years in the structural and quantitative determinations of glycoproteins in complex biological mixtures. The main analytical techniques used in the fields of glycomics and glycoproteomics involve different modes of mass spectrometry and their combinations with capillary separation methods such as microcolumn liquid chromatography and capillary electrophoresis. The needs for high-sensitivity measurements have been emphasized in the oligosaccharide profiling used in the field of biomarker discovery through MALDI mass spectrometry. High-sensitivity profiling of both glycans and glycopeptides from biological fluids and tissue extracts has been aided significantly through lectin preconcentration and the uses of affinity chromatography. PMID:22945852

Successful pregnancy after spermatid injection.

PubMed

Bernabeu, R; Cremades, N; Takahashi, K; Sousa, M

1998-07-01

We present nine cases of spermatid intracytoplasmic injection for the treatment of non-obstructive azoospermia. In eight cases, no elongated spermatids or spermatozoa were found in previous spermiograms or testicular biopsies. In these patients, treatment was performed using ejaculated (n = 6) and testicular (n = 2) retrieved round spermatids (Sa type). In cases where ejaculated round spermatids were used, they were isolated on the day before oocyte retrieval and left in culture for 24 h before intracytoplasmic sperm injection (ICSI). No pregnancy was obtained in either group, although culturing seemed to increase the fertilization rate. In one other case, elongated spermatids were observed in the previous spermiogram and thus a normal ICSI procedure was scheduled. However, on the day of oocyte retrieval, no spermatids could be recovered from fresh sequential ejaculates, and a testicular open biopsy was then performed. Both round and elongated spermatids were found in the testicular tissue, but only the more mature germinal cells (Sb2) were injected. From this case, a normal pregnancy was obtained which resulted in the birth by Caesarean section at 37 weeks of gestation of a normal healthy baby girl, weighing 2700 g.

Method for gasification of deep, thin coal seams. [DOE patent

DOEpatents

Gregg, D.W.

1980-08-29

A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face is given. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

Method for gasification of deep, thin coal seams

DOEpatents

Gregg, David W.

1982-01-01

A method of gasification of coal in deep, thin seams by using controlled bending subsidence to confine gas flow to a region close to the unconsumed coal face. The injection point is moved sequentially around the perimeter of a coal removal area from a production well to sweep out the area to cause the controlled bending subsidence. The injection holes are drilled vertically into the coal seam through the overburden or horizontally into the seam from an exposed coal face. The method is particularly applicable to deep, thin seams found in the eastern United States and at abandoned strip mines where thin seams were surface mined into a hillside or down a modest dip until the overburden became too thick for further mining.

Drug injection into fat tissue with a laser based microjet injector

NASA Astrophysics Data System (ADS)

Han, Tae-hee; Hah, Jung-moo; Yoh, Jack J.

2011-05-01

We have investigated a new micro drug jet injector using laser pulse energy. An infrared laser beam of high energy (˜3 J/pulse) is focused inside a driving fluid in a small chamber. The pulse then induces various energy releasing processes, and generates fast microjets through a micronozzle. The elastic membrane of this system plays an important role in transferring mechanical pressure and protecting drug from heat release. In this paper, we offer the sequential images of microjet generation taken by a high speed camera as an evidence of the multiple injections via single pulse. Furthermore, we test the proposed system to penetrate soft animal tissues in order to evaluate its feasibility as an advanced transdermal drug delivery method.

[Studies on a sequential injection renewable surface reflectance spectrophotometric system using a microchip flow cell].

PubMed

Wang, Jian-ya; Fang, Zhao-lun

2002-02-01

A microchip flow cell was developed for flow injection renewable surface assay by reflectance spectrophotometry. The flow cell was coupled to a sequential injection system and optical fiber photometric detection system. The flow cell featured a three-layer structure. The flow channel was cut into a silicone rubber membrance which formed the middle layer, and a porous filter was inlayed across a widened section of the channel to trap microbeads introduced into the flow cell. The area of the detection window of the flow cell was approximately 3.6 mm2, the volume of the bead trapped in the flow cell was 2.2 microL, the depth of the bead layer was 600 microns. A multistrand bifurcated optical fiber was coupled with incident light, detector and flow cell. The chromogenic reaction of Cr(VI) with 1,5-diphenylcarbohydrazide (DPC) which was adsorbed on trapped Polysorb C-18 beads was used as a model reaction to optimize the flow cell design and the experimental system. The reflectance of the renewable reaction surface was monitored at 540 nm. With 100 microL sample loaded and 1.0 mL.min-1 carrier flow rate, the linear response range was 0-0.6 microgram.mL-1 Cr(VI). A detection limit (3 sigma) of 6 ng.mL-1, precision of 1.5% RSD(n = 11), and a throughput of 64 samples per hour were achieved. Considerations in system and flow cell design, the influence of depth of the bead layer, weight of beads used, and the flow rates of carrier stream on the performance were discussed.

A flow system for the spectrophotometric determination of lead in different types of waters using ion-exchange for pre-concentration and elimination of interferences.

PubMed

Mesquita, Raquel B R; Fernandes, Sílvia M V; Rangel, António O S S

2004-02-06

A flow system for the spectrophotometric determination of lead in natural and waste waters is proposed. The determination is based on the colorimetric reaction between malachite green and iodide, followed by the formation of a ternary complex between those reagents and lead cations. The developed flow system includes a lead pre-concentration step in a column packed with a cationic resin (Chelex 100) operating in a sequential injection mode. To improve the mixture of sample and reagents, a flow injection approach was adopted for the colorimetric determination. This way a hybrid flow system, involving both sequential and flow injection concepts was designed. Another feature of the proposed system is the efficient elimination of major interferent species, such as cadmium and copper. The elimination of cadmium interference is obtained by complexing Cd(2+) with chloride and retaining the formed negatively charged complexes in an anionic resin, AG1 X-8. As for copper, with the presence of both ionic resins as well as the conditions for cadmium elimination, it no longer acts as an interferent. Different ranges of lead concentration (50-300 and 300-1000mugl(-1)) can be determined with minor changes in the controlling software, useful for application to both natural and waste waters. Therefore, a detection limit of 25mugl(-1) was achieved. Repeatability was evaluated from 10 consecutive determinations being the results better than 4%. The recoveries of lead spikes added to the samples ranged from 93 to 102%. The sampling frequency was 17 and 24 determinations per hour, for 50-300 and 300-1000mugl(-1) ranges, respectively.

An open-pattern droplet-in-oil planar array for single cell analysis based on sequential inkjet printing technology.

PubMed

Wang, Chenyu; Liu, Wenwen; Tan, Manqing; Sun, Hongbo; Yu, Yude

2017-07-01

Cellular heterogeneity represents a fundamental principle of cell biology for which a readily available single-cell research tool is urgently required. Here, we present a novel method combining cell-sized well arrays with sequential inkjet printing. Briefly, K562 cells with phosphate buffer saline buffer were captured at high efficiency (74.5%) in a cell-sized well as a "primary droplet" and sealed using fluorinated oil. Then, piezoelectric inkjet printing technology was adapted to precisely inject the cell lysis buffer and the fluorogenic substrate, fluorescein-di-β-D-galactopyranoside, as a "secondary droplet" to penetrate the sealing oil and fuse with the "primary droplet." We thereby successfully measured the intracellular β-galactosidase activity of K562 cells at the single-cell level. Our method allows, for the first time, the ability to simultaneously accommodate the high occupancy rate of single cells and sequential addition of reagents while retaining an open structure. We believe that the feasibility and flexibility of our method will enhance its use as a universal single-cell research tool as well as accelerate the adoption of inkjet printing in the study of cellular heterogeneity.

Comparison of periodontal ligament injection and inferior alveolar nerve block in mandibular primary molars pulpotomy: a randomized control trial.

PubMed

Haghgoo, Roza; Taleghani, Ferial

2015-05-01

Inferior alveolar nerve block is a common technique for anesthesia of the primary mandibular molars. A number of disadvantages have been shown to be associated with this technique. Periodontal ligament (PDL) injection could be considered as an alternative to inferior alveolar nerve block. The aim of this study was to evaluate the effectiveness of PDL injection in the anesthesia of primary molar pulpotomy with mandibular block. This study was performed using a sequential double-blind randomized trial design. 80 children aged 3-7 years old who required pulpotomy in symmetrical mandibular primary molars were selected. The teeth of these children were anesthetized with periodontal injection on one side of the mandible and block on the other. Pulpotomy was performed on each patient during the same appointment. Signs of discomfort, including hand and body tension and eye movement, the verbal complaint and crying (SEM scale), were evaluated by a dental assistant who was blinded to the treatment allocation of the patients. Finally, the data were analyzed using the exact Fisher test and Pearson Chi-squared exact test. Success rate was 88/75 and 91/25 in the PDL injection and nerve block groups, respectively. There was no statistically significant difference between the two techniques (P = 0.250). Results showed that PDL injection can be used as an alternative to nerve block in pulpotomy of the mandibular primary molars.

Pharmacokinetics of dinalbuphine sebacate and nalbuphine in human after intramuscular injection of dinalbuphine sebacate in an extended-release formulation.

PubMed

Tien, Yu En; Huang, Wen-Chuan; Kuo, Hui-Yuan; Tai, Lily; Uang, Yow-Shieng; Chern, Wendy H; Huang, Jin-Ding

2017-11-01

Nalbuphine is a semi-synthetic opioid indicated for the relief of moderate to severe pain. Its short half-life requires frequent injections in clinical practice, resulting in a greater incidence of adverse events. A prodrug of nalbuphine has been developed, dinalbuphine sebacate (DNS), dissolved in a simple oil-based injectable formulation, which could deliver and maintain an effective blood level of nalbuphine. An open-label, prospective, two-period study was performed in healthy volunteers to verify the extended blood concentration profile of nalbuphine. Twelve healthy Taiwanese were randomized to receive an intramuscular injection of 20 mg nalbuphine HCl and 150 mg DNS sequentially with a washout period of 5 days. To prevent DNS hydrolysis during sample analysis, the effect of four esterase inhibitors was evaluated in the quantitation of DNS in human whole blood and thenoyltrifluoroacetone was chosen. The bioavailability of nalbuphine from intramuscularly injected DNS relative to that from nalbuphine HCl was 85.4%. The mean absorption time of nalbuphine from DNS was 145.2 h. It took approximately 6 days for the complete release of DNS into the blood stream where DNS was rapidly hydrolysed to nalbuphine; suggesting a single injection of 150 mg DNS in our extended-release formulation could provide long-lasting pain relief. Copyright © 2017 John Wiley & Sons, Ltd.

Efficacy of premixed versus sequential administration of clonidine as an adjuvant to hyperbaric bupivacaine intrathecally in cesarean section

PubMed Central

Sachan, Prachee; Kumar, Nidhi; Sharma, Jagdish Prasad

2014-01-01

Background: Density of the drugs injected intrathecally is an important factor that influences spread in the cerebrospinal fluid. Mixing adjuvants with local anesthetics (LA) alters their density and hence their spread compared to when given sequentially in seperate syringes. Aims: To evaluate the efficacy of intrathecal administration of hyperbaric bupivacaine (HB) and clonidine as a mixture and sequentially in terms of block characteristics, hemodynamics, neonatal outcome, and postoperative pain. Setting and Design: Prospective randomized single blind study at a tertiary center from 2010 to 2012. Materials and Methods: Ninety full-term parturient scheduled for elective cesarean sections were divided into three groups on the basis of technique of intrathecal drug administration. Group M received mixture of 75 μg clonidine and 10 mg HB 0.5%. Group A received 75 μg clonidine after administration of 10 mg HB 0.5% through separate syringe. Group B received 75 μg clonidine before HB 0.5% (10 mg) through separate syringe. Statistical analysis used: Observational descriptive statistics, analysis of variance with Bonferroni multiple comparison post hoc test, and Chi-square test. Results: Time to achieve complete sensory and motor block was less in group A and B in which drugs were given sequentially. Duration of analgesia lasted longer in group B (474.3 ± 20.79 min) and group A (472.50 ± 22.11 min) than in group M (337 ± 18.22 min) with clinically insignificant influence on hemodynamic parameters and sedation. Conclusion: Sequential technique reduces time to achieve complete sensory and motor block, delays block regression, and significantly prolongs the duration of analgesia. However, it did not matter much whether clonidine was administered before or after HB. PMID:25886098

Dual nozzle single pump fuel injection system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, C.

1992-02-25

This patent describes an improvement in a fuel injection system in a stratified charge hybrid internal combustion engine including a main combustion chamber, a precombustion chamber connected with the main chamber, fuel injectors in the main combustion chamber and precombustion chamber which open at higher and lower pressure levels respectively to sequentially inject fuel into the prechamber and the main chamber, timed spark ignition means in the prechamber for ignition of the fuel-air mixture therein, and an engine driven and timed fuel injection pump having a variable output capacity that varies with power level position, the injection pump is suppliedmore » by a low pressure charging pump. The improvement comprises: a shuttle valve including a bore therein; a shuttle spool means positioned within the bore defining a prechamber supply chamber on one side thereof and a spool activation chamber on the opposite side thereof the spool means having a first and second position; biasing means urging the spool towards it first position with the spool actuation chamber at its minimum volume; first conduit means connecting charging pressure to the prechamber supply camber in the first position oil the spool means; second conduit means connecting the injection pump to spool actuation chamber; third conduit means connecting the spool actuating chamber with the main injector; forth conduit means connecting the prechamber supply chamber with the prechamber injector; the initial charge from the injection pump actuates the spool means from its fir to its second position.« less

A Telescopic and Microscopic Examination of Acceleration in the June 2015 Geomagnetic Storm: Magnetospheric Multiscale and Van Allen Probes Study of Substorm Particle Injection

NASA Technical Reports Server (NTRS)

Baker, D. N.; Jaynes, A. N.; Turner, D. L.; Nakamura, R.; Schmid, D.; Mauk, B. H.; Cohen, I. J.; Fennell, J. F.; Blake, J. B.; Strangeway, R. J.;

Successful outcome after intravenous gasoline injection.

PubMed

Domej, Wolfgang; Mitterhammer, Heike; Stauber, Rudolf; Kaufmann, Peter; Smolle, Karl Heinz

2007-12-01

Gasoline, ingested intentionally or accidentally, is toxic. The majority of reported cases of gasoline intoxication involve oral ingestion or inhalation. Data are scarce on complications and outcomes following hydrocarbon poisoning by intravenous injection. Following a suicide attempt by intravenous self-injection of 10 ml of gasoline, a 26-year-old medical student was admitted to the intensive care unit (ICU) with hemoptysis, symptoms of acute respiratory failure, chest pain, and severe abdominal cramps. Gas exchange was severely impaired and a chest x-ray indicated chemical pneumonitis. Initial treatment consisted of mechanical ventilation, supportive hyperventilation, administration of nitrogen oxide (NO), and prednisone. Unfortunately, the patient developed multi-organ dysfunction syndrome (MODS) complicated by life-threatening severe vasoplegia within 24 hours after gasoline injection. High doses of vasopressors along with massive amounts of parenteral fluids were necessary. Despite fluid replacement, renal function worsened and required hemofiltration on 5 sequential days. After 12 days of intensive care management, the patient recovered completely and was discharged to a psychiatric care facility. Intravenous gasoline injection causes major injury to the lungs, the organ bearing the first capillary bed encountered. Treatment of gasoline poisoning is symptomatic because no specific antidote is available. Early and aggressive supportive care may be conducive to a favorable outcome with minimal residual pulmonary sequelae.

[The determination of molecular sulphur in Matsesta mineral water and its analog Novonukutskaya mineral water].

PubMed

Khutorianskiĭ, V A; Smirnov, A I; Matveev, D A

2014-01-01

The method of microcolumn reversed phase high performance liquid chromatography (rp-HPLC) was employed to determine the content of elemental sulphur in mineral waters. The study envisaged the analysis of the samples of sulphide-containing mineral waters Novonukutskaya and Matsesta obtained by the solid phase extraction technique. Based on these data, the authors discuss the origin and the circulation of sulphur in the hydrogen sulphide sources. The elution conditions selected in this study ensured the high-resolution separation of the octasulphur peak from the peaks of allotropic components of the extract whereas the two-wave detection technique allowed to identify the peaks of molecular sulphur.

Application of capillary gas chromatography mass spectrometry/computer techniques to synoptic survey of organic material in bed sediment

USGS Publications Warehouse

Steinheimer, T.R.; Pereira, W.E.; Johnson, S.M.

1981-01-01

A bed sediment sample taken from an area impacted by heavy industrial activity was analyzed for organic compounds of environmental significance. Extraction was effected on a Soxhlet apparatus using a freeze-dried sample. The Soxhlet extract was fractionated by silica gel micro-column adsorption chromatography. Separation and identification of the organic compounds was accomplished by capillary gas chromatography/mass spectrometry techniques. More than 50 compounds were identified; these include saturated hydrocarbons, olefins, aromatic hydrocarbons, alkylated polycyclic aromatic hydrocarbons, and oxygenated compounds such as aldehydes and ketones. The role of bed sediments as a source or sink for organic pollutants is discussed. ?? 1981.

Three-Dimensional Changes in the Midface Following Malar Calcium Hydroxyapatite Injection in a Cadaver Model.

PubMed

Gatherwright, James R; Brown, Matthew S; Katira, Kristopher M; Rowe, David J

2015-08-01

Three-dimensional (3D) changes in the midface following malar calcium hydroxyapatite (CaHa) injection have not been systematically analyzed. The authors analyzed 3D volume changes in midface and naso-labial fold (NLF) volume, as well as lateral movement in the NLF/naso-labial crease (NLC) junction following malar injection of CaHa in a cadaver model. A single surgeon injected CaHa in the supraperiosteal plane. Sequential images were obtained with the VECTRA 3D system pre- and post-1.5- and 3-cc CaHa injections. All measurements were performed by a single examiner. Injection location was verified anatomically. Injections were performed in 16 fresh cadaver hemi-faces. Maximal increases in projection were centered on the malar injection site, with associated decreases in projection and volume in the infero-medial locations. Relative mean increases in volume of 3.16 cc and 4.94 cc were observed following the 1.5-cc and 3-cc injections, respectively. There was a relative decrease in the volume of the NLF of -0.3 cc and -0.4 cc following the 1.5- and 3-cc injections, respectively. Injection of CaHa was associated with lateral movements of the NLF-NLC junction at the level of the nasal sill, philtral columns, and oral commissure, measuring 2.7, 2.5, and 1.9 mm and 2.8, 2.9, and 2.4 mm following the 1.5- and 3-cc injections, respectively. Anatomical dissection verified the location in the supraperiosteal space and within the middle malar fat pad. Following malar CaHa injection, 3D photographic analysis showed a measureable lifting effect with recruitment of ptotic tissue and lateral movement of the NLF-NLC junction in a cadaver model. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Sequential bottom-up assembly of mechanically stabilized synthetic cells by microfluidics

NASA Astrophysics Data System (ADS)

Weiss, Marian; Frohnmayer, Johannes Patrick; Benk, Lucia Theresa; Haller, Barbara; Janiesch, Jan-Willi; Heitkamp, Thomas; Börsch, Michael; Lira, Rafael B.; Dimova, Rumiana; Lipowsky, Reinhard; Bodenschatz, Eberhard; Baret, Jean-Christophe; Vidakovic-Koch, Tanja; Sundmacher, Kai; Platzman, Ilia; Spatz, Joachim P.

2018-01-01

Compartments for the spatially and temporally controlled assembly of biological processes are essential towards cellular life. Synthetic mimics of cellular compartments based on lipid-based protocells lack the mechanical and chemical stability to allow their manipulation into a complex and fully functional synthetic cell. Here, we present a high-throughput microfluidic method to generate stable, defined sized liposomes termed `droplet-stabilized giant unilamellar vesicles (dsGUVs)’. The enhanced stability of dsGUVs enables the sequential loading of these compartments with biomolecules, namely purified transmembrane and cytoskeleton proteins by microfluidic pico-injection technology. This constitutes an experimental demonstration of a successful bottom-up assembly of a compartment with contents that would not self-assemble to full functionality when simply mixed together. Following assembly, the stabilizing oil phase and droplet shells are removed to release functional self-supporting protocells to an aqueous phase, enabling them to interact with physiologically relevant matrices.

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice

NASA Astrophysics Data System (ADS)

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18F-FDG respectively to ascertain the technique‧s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice.

PubMed

Evans, Eleanor; Sawiak, Stephen J; Ward, Alexander O; Buonincontri, Guido; Hawkes, Robert C; Carpenter, T Adrian

2014-01-11

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18 F-FDG respectively to ascertain the technique's validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Application of silver nanoparticles to the chemiluminescence determination of cefditoren pivoxil using the luminol-ferricyanide system.

PubMed

Alarfaj, Nawal A; Aly, Fatma A; El-Tohamy, Maha F

2015-02-01

A new simple, accurate and sensitive sequential injection analysis chemiluminescence (CL) detection method for the determination of cefditoren pivoxil (CTP) has been developed. The developed method was based on the enhancement effect of silver nanoparticles on the CL signal arising from a luminol-potassium ferricyanide reaction in the presence of CTP. The optimum conditions relevant to the effect of luminol, potassium ferricyanide and silver nanoparticle concentrations were investigated. The proposed method showed linear relationships between relative CL intensity and the investigated drug concentration at the range 0.001-5000 ng/mL, (r = 0.9998, n = 12) with a detection limit of 0.5 pg/mL and quantification limit of 0.001 ng/mL. The relative standard deviation was 1.6%. The proposed method was employed for the determination of CTP in bulk drug, in its pharmaceutical dosage forms and biological fluids such as human serum and urine. The interference of some common additive compounds such as glucose, lactose, starch, talc and magnesium stearate was investigated. In addition, the interference of some related cephalosporins was tested. No interference was recorded. The obtained sequential injection analysis-CL results were statistically compared with those from a reported method and did not show any significant differences. Copyright © 2014 John Wiley & Sons, Ltd.

Sequential determination of multi-nutrient elements in natural water samples with a reverse flow injection system.

PubMed

Lin, Kunning; Ma, Jian; Yuan, Dongxing; Feng, Sichao; Su, Haitao; Huang, Yongming; Shangguan, Qipei

2017-05-15

An integrated system was developed for automatic and sequential determination of NO 2 - , NO 3 - , PO 4 3- , Fe 2+ , Fe 3+ and Mn 2+ in natural waters based on reverse flow injection analysis combined with spectrophotometric detection. The system operation was controlled by a single chip microcomputer and laboratory-programmed software written in LabVIEW. The experimental parameters for each nutrient element analysis were optimized based on a univariate experimental design, and interferences from common ions were evaluated. The upper limits of the linear range (along with detection limit, µmolL -1 ) of the proposed method was 20 (0.03), 200 (0.7), 12 (0.3), 5 (0.03), 5 (0.03), 9 (0.2) µmolL -1 , for NO 2 - , NO 3 - , PO 4 3- , Fe 2+ , Fe 3+ and Mn 2+ , respectively. The relative standard deviations were below 5% (n=9-13) and the recoveries varied from 88.0±1.0% to 104.5±1.0% for spiked water samples. The sample throughput was about 20h -1 . This system has been successfully applied for the determination of multi-nutrient elements in different kinds of water samples and showed good agreement with reference methods (slope 1.0260±0.0043, R 2 =0.9991, n=50). Copyright © 2017 Elsevier B.V. All rights reserved.

Sequential injection system with in-line solid phase extraction and soil mini-column for determination of zinc and copper in soil leachates.

PubMed

Paluch, Justyna; Mesquita, Raquel B R; Cerdà, Víctor; Kozak, Joanna; Wieczorek, Marcin; Rangel, António O S S

2018-08-01

A sequential injection (SI) system equipped with in-line solid phase extraction column and in-line soil mini-column is proposed for determination of zinc and copper in soil leachates. The spectrophotometric determination (560 nm) is based on the reaction of both analytes with 1-(2-Pyridylazo)-2-naphthol (PAN). Zinc is determined after retaining copper on a cationic resin (Chelex100) whereas copper is determined from the difference of the absorbance measured for both analytes, introduced into the system with the use of a different channel, and zinc absorbance. The influence of several potential interferences was studied. Using the developed method, zinc and copper were determined within the concentration ranges of 0.005-0.300 and 0.011-0.200 mg L -1 , and with a relative standard deviation lower than 6.0% and 5.1%, respectively. The detection limits are 1.4 and 3.0 µg/L for determination of zinc and copper, respectively. The developed SI method was verified by the determination of both analytes in synthetic and certified reference materials of water samples, and applied to the determination of the analytes in rain water and soil leachates from laboratory scale soil core column and in-line soil mini-column. Copyright © 2018 Elsevier B.V. All rights reserved.

A LabVIEW®-based software for the control of the AUTORAD platform: a fully automated multisequential flow injection analysis Lab-on-Valve (MSFIA-LOV) system for radiochemical analysis.

PubMed

Barbesi, Donato; Vicente Vilas, Víctor; Millet, Sylvain; Sandow, Miguel; Colle, Jean-Yves; Aldave de Las Heras, Laura

2017-01-01

A LabVIEW ® -based software for the control of the fully automated multi-sequential flow injection analysis Lab-on-Valve (MSFIA-LOV) platform AutoRAD performing radiochemical analysis is described. The analytical platform interfaces an Arduino ® -based device triggering multiple detectors providing a flexible and fit for purpose choice of detection systems. The different analytical devices are interfaced to the PC running LabVIEW ® VI software using USB and RS232 interfaces, both for sending commands and receiving confirmation or error responses. The AUTORAD platform has been successfully applied for the chemical separation and determination of Sr, an important fission product pertinent to nuclear waste.

Extracting dielectric fixed charge density on highly doped crystalline-silicon surfaces using photoconductance measurements

NASA Astrophysics Data System (ADS)

To, A.; Hoex, B.

2017-11-01

A novel method for the extraction of fixed interface charge, Qf, and the surface recombination parameters, Sn0 and Sp0, from the injection-level dependent effective minority carrier lifetime measurements is presented. Unlike conventional capacitance-voltage measurements, this technique can be applied to highly doped surfaces provided the surface carrier concentration transitions into strong depletion or inversion with increased carrier injection. By simulating the injection level dependent Auger-corrected inverse lifetime curve of symmetrically passivated and diffused samples after sequential annealing and corona charging, it was revealed that Qf, Sn0, and Sp0 have unique signatures. Therefore, these important electronic parameters, in some instances, can independently be resolved. Furthermore, it was shown that this non-linear lifetime behaviour is exhibited on both p-type and n-type diffused inverted surfaces, by demonstrating the approach with phosphorous diffused n+pn+ structures and boron diffused p+np+ structures passivated with aluminium oxide (AlOx) and silicon nitride, respectively (SiNx). The results show that the approximation of a mid-gap Shockley-Read-Hall defect level with equal capture cross sections is able to, in the samples studied in this work, reproduce the observed injection level dependent lifetime behaviour.

Flow analysis techniques for phosphorus: an overview.

PubMed

Estela, José Manuel; Cerdà, Víctor

2005-04-15

A bibliographical review on the implementation and the results obtained in the use of different flow analytical techniques for the determination of phosphorus is carried out. The sources, occurrence and importance of phosphorus together with several aspects regarding the analysis and terminology used in the determination of this element are briefly described. A classification as well as a brief description of the basis, advantages and disadvantages of the different existing flow techniques, namely; segmented flow analysis (SFA), flow injection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA), batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA (MSFIA) and multipumped FIA (MPFIA) is also carried out. The most relevant manuscripts regarding the analysis of phosphorus by means of flow techniques are herein classified according to the detection instrumental technique used with the aim to facilitate their study and obtain an overall scope. Finally, the analytical characteristics of numerous flow-methods reported in the literature are provided in the form of a table and their applicability to samples with different matrixes, namely water samples (marine, river, estuarine, waste, industrial, drinking, etc.), soils leachates, plant leaves, toothpaste, detergents, foodstuffs (wine, orange juice, milk), biological samples, sugars, fertilizer, hydroponic solutions, soils extracts and cyanobacterial biofilms are tabulated.

Microcolumn-based speciation analysis of thallium in soil and green cabbage.

PubMed

Jia, Yanlong; Xiao, Tangfu; Sun, Jialong; Yang, Fei; Baveye, Philippe C

2018-07-15

Thallium (Tl) is a toxic trace metal, whose geochemical behavior and biological effects are closely controlled by its chemical speciation in the environment. However, little tends to be known about this speciation of Tl in soil and plant systems that directly affect the safety of food supplies. In this context, the objective of the present study was to elaborate an efficient method to separate and detect Tl(I) and Tl(III) species for soil and plant samples. This method involves the selective adsorption of Tl(I) on microcolumns filled with immobilized oxine, in the presence of DTPA (diethylenetriaminepentaacetic acid), followed by DTPA-enhanced ultrasonic and heating-induced extraction, coupled with ICP-MS detection. The method was characterized by a LOD of 0.037 μg/L for Tl(I) and 0.18 μg/L for Tl(III) in 10  mL samples. With this method, a second objective of the research was to assess the speciation of Tl in pot and field soils and in green cabbage crops. Experimental results suggest that DTPA extracted Tl was mainly present as Tl(I) in soils (>95%). Tl in hyperaccumulator plant green cabbage was also mainly present as Tl(I) (>90%). With respect to Tl uptake in plants, this study provides direct evidence that green cabbage mainly takes up Tl(I) from soil, and transports it into the aboveground organs. In soils, Tl(III) is reduced to Tl(I) even at the surface where the chemical environment promotes oxidation. This observation is conducive to understanding the mechanisms of Tl isotope fractionation in the soil-plant system. Based on geochemical fraction studies, the reducible fraction was the main source of Tl getting accumulated by plants. These results indicate that the improved analytical method presented in this study offers an economical, simple, fast, and sensitive approach for the separation of Tl species present in soils at trace levels. Copyright © 2018 Elsevier B.V. All rights reserved.

Advanced biomaterial strategies to transplant preformed micro-tissue engineered neural networks into the brain

NASA Astrophysics Data System (ADS)

Harris, J. P.; Struzyna, L. A.; Murphy, P. L.; Adewole, D. O.; Kuo, E.; Cullen, D. K.

2016-02-01

Objective. Connectome disruption is a hallmark of many neurological diseases and trauma with no current strategies to restore lost long-distance axonal pathways in the brain. We are creating transplantable micro-tissue engineered neural networks (micro-TENNs), which are preformed constructs consisting of embedded neurons and long axonal tracts to integrate with the nervous system to physically reconstitute lost axonal pathways. Approach. We advanced micro-tissue engineering techniques to generate micro-TENNs consisting of discrete populations of mature primary cerebral cortical neurons spanned by long axonal fascicles encased in miniature hydrogel micro-columns. Further, we improved the biomaterial encasement scheme by adding a thin layer of low viscosity carboxymethylcellulose (CMC) to enable needle-less insertion and rapid softening for mechanical similarity with brain tissue. Main results. The engineered architecture of cortical micro-TENNs facilitated robust neuronal viability and axonal cytoarchitecture to at least 22 days in vitro. Micro-TENNs displayed discrete neuronal populations spanned by long axonal fasciculation throughout the core, thus mimicking the general systems-level anatomy of gray matter—white matter in the brain. Additionally, micro-columns with thin CMC-coating upon mild dehydration were able to withstand a force of 893 ± 457 mN before buckling, whereas a solid agarose cylinder of similar dimensions was predicted to withstand less than 150 μN of force. This thin CMC coating increased the stiffness by three orders of magnitude, enabling needle-less insertion into brain while significantly reducing the footprint of previous needle-based delivery methods to minimize insertion trauma. Significance. Our novel micro-TENNs are the first strategy designed for minimally invasive implantation to facilitate nervous system repair by simultaneously providing neuronal replacement and physical reconstruction of long-distance axon pathways in the brain. The micro-TENN approach may offer the ability to treat several disorders that disrupt the connectome, including Parkinson’s disease, traumatic brain injury, stroke, and brain tumor excision.

Large volume preconcentration and determination of nanomolar concentrations of iron in seawater using a renewable cellulose 8-hydroquinoline sorbent microcolumn and universal approach of post-column eluate utilization in a Lab-on-Valve system.

PubMed

Horstkotte, Burkhard; Chocholouš, Petr; Solich, Petr

2016-04-01

We report on a Lab-On-Valve (LOV) configuration for analyte preconcentration from milliliter sample volumes using confluent mixing in the holding coil for in-line addition of loading buffer. The system was applied to the spectrophotometric determination of iron(II) in acidified seawater using 1,10-phenanthroline as color reagent. A cellulose-based chelating sorbent containing 8-hydroxyquinoline was used for the first time in LOV and excellent retention behavior and loading capacity were found. The flow system employs a syringe pump for handling all solutions (sorbent suspension, loading buffer, water, eluent, and color reagent) and a peristaltic pump for sample propulsion and includes a fit-for-purpose 14 cm long detection glass flow cell and a bubble trap for in-line carrier degasification. Advantage was taken of the LOV flow-through port to keep the eluted analytes for re-aspiration for subsequent chromogenic reaction. In effect, a universal analyzer configuration and preconcentration procedure was developed, which is combinable with other analytes, sorbents, and reagents. Among the studied parameters were the compositions, pH, volumes, and flow rates of loading buffer, eluent, and color reagent, as well as the microcolumn size, repeatability, and system stability. Reproducibility of 4.1% RSD over the entire working range, a LOD of down to 5 nmol L(-1), sampling frequency of 12h(-1), and linearity up to 1 µmol L(-1) for 3.3 mL of sample were obtained and applicability to real samples was demonstrated. It was proven that both Fe(III) and Fe(II) were retained and yielded similar recovery and sensitivity values. The method was applied to coastal seawater samples and spiking experiments yielded recovery values close to 100%. Copyright © 2015 Elsevier B.V. All rights reserved.

Neuropeptide-Y both Improves and Impairs Delayed Matching-to-Sample Performance in Rats

DTIC Science & Technology

1991-01-01

Neuropeptide Y distribution in the 422 THOMAS AND AHLERS rat brain. Science 221:877-879; 1983. of animal learning. In: Roitblat , H. L.; Bever, T. G.; Terrace, H...Sources of proactive interference in memory. Hillsdale, NJ: Erlbaum; 1976. animal memory. J. Exp. Psychol. (Anim. Behav.) 1456-70; 1988. 32. Roitblat , H...memory processing by neuropeptide Y varies with brain 33. Roitblat , H. L., Scopatz, R. A. Sequential effects in pigeons de- injection site. Brain Res

Early detection of osteoarthritis in rabbits using MRI with a double-contrast agent.

PubMed

Onishi, Okihiro; Ikoma, Kazuya; Kido, Masamitsu; Kabuto, Yukichi; Ueshima, Keiichiro; Matsuda, Ken-Ichi; Tanaka, Masaki; Kubo, Toshikazu

2018-03-13

Articular cartilage degeneration has been evaluated by magnetic resonance imaging (MRI). However, this method has several problems, including its time-consuming nature and the requirement of a high magnetic field or specialized hardware. The purpose of this study was to sequentially assess early degenerative changes in rabbit knee articular cartilage using MRI with a new double-contrast agent. We induced osteoarthritis (OA) in the right knee of rabbits by anterior cruciate ligament transection and partial medial meniscectomy. Proton density-weighted images and T 2 -calculated images were obtained before and after contrast agent injection into the knee. The signal intensity ratio (SIR) values on the proton density-weighted images were calculated by dividing the signal intensity of the articular cartilage by that of joint fluid. Six rabbits were examined using MRI at 2 (designated 2-w OA) and 4 weeks (4-w OA) after the operation. Histological examination was performed 4 weeks after the operation. One rabbit was histologically examined 2 weeks after the operation. The control consisted of six rabbits that were not subjected to the operation. The SIR values, T 2 values and the thicknesses of the cartilage of the 2-w OA, 4-w OA and the control before and after contrast agent injection were analyzed. The Mankin score and OARSI (Osteoarthritis Research Society International) score were used for the histological evaluation. Significant differences in the SIR and T 2 values of the medial and lateral condyles of the femur were found between the control and the 4-w OA only after contrast agent injection. No significant differences were found in the SIR and T 2 values before contrast agent injection between the control, the 2-w OA and 4-w OA. The thickness of the articular cartilage revealed no significant differences. In the histological assessment, the Mankin score and OARSI score sequentially increased from the control to the 4-w OA. We evaluated the SIR and T 2 values of the knees in a rabbit OA model and a control model using a new double-contrast agent. MRI with this agent enabled OA detection earlier than using conventional MRI.

Comparison of Periodontal Ligament Injection and Inferior Alveolar Nerve Block in Mandibular Primary Molars Pulpotomy: A Randomized Control Trial

PubMed Central

Haghgoo, Roza; Taleghani, Ferial

2015-01-01

Background: Inferior alveolar nerve block is a common technique for anesthesia of the primary mandibular molars. A number of disadvantages have been shown to be associated with this technique. Periodontal ligament (PDL) injection could be considered as an alternative to inferior alveolar nerve block. The aim of this study was to evaluate the effectiveness of PDL injection in the anesthesia of primary molar pulpotomy with mandibular block. Methods: This study was performed using a sequential double-blind randomized trial design. 80 children aged 3-7 years old who required pulpotomy in symmetrical mandibular primary molars were selected. The teeth of these children were anesthetized with periodontal injection on one side of the mandible and block on the other. Pulpotomy was performed on each patient during the same appointment. Signs of discomfort, including hand and body tension and eye movement, the verbal complaint and crying (SEM scale), were evaluated by a dental assistant who was blinded to the treatment allocation of the patients. Finally, the data were analyzed using the exact Fisher test and Pearson Chi-squared exact test. Results: Success rate was 88/75 and 91/25 in the PDL injection and nerve block groups, respectively. There was no statistically significant difference between the two techniques (P = 0.250). Conclusion: Results showed that PDL injection can be used as an alternative to nerve block in pulpotomy of the mandibular primary molars. PMID:26028895

Sequential Actions of Rab5 and Rab7 Regulate Endocytosis in the Xenopus Oocyte

PubMed Central

Mukhopadhyay, Amitabha; Barbieri, Alejandro M.; Funato, Kouichi; Roberts, Richard; Stahl, Philip D.

1997-01-01

To explore the role of GTPases in endocytosis, we developed an assay using Xenopus oocytes injected with recombinant proteins to follow the uptake of the fluid phase marker HRP. HRP uptake was inhibited in cells injected with GTPγS or incubated with aluminum fluoride, suggesting a general role for GTPases in endocytosis. Injection of Rab5 into oocytes, as well as Rab5:Q79L, a mutant with decreased GTPase activity, increased HRP uptake. Injection of Rab5:S34N, the dominant-negative mutant, inhibited HRP uptake. Injection of N-ethylmaleimide–sensitive factor (NSF) stimulated HRP uptake, and ATPase-defective NSF mutants inhibited HRP uptake when coinjected with Rab5:Q79L, confirming a requirement for NSF in endocytosis. Surprisingly, injection of Rab7:WT stimulated both uptake and degradation/activation of HRP. The latter appears to be due to enhanced transport to a late endosomal/prelysosomal degradative compartment that is monensin sensitive. Enhancement of uptake by Rab7 appears to function via an Rab5-sensitive pathway in oocytes since the stimulatory effect of Rab7 was blocked by coinjection of Rab5:S34N. Stimulation of uptake by Rab5 was blocked by Rab5:S34N but not by Rab7:T22N. Our results suggest that Rab7, while functioning downstream of Rab5, may be rate limiting for endocytosis in oocytes. PMID:9087439

Testing a fall risk model for injection drug users.

PubMed

Pieper, Barbara; Templin, Thomas N; Goldberg, Allon

2012-01-01

Fall risk is a critical component of clinical assessment and has not been examined for persons who have injected illicit drugs and are aging. The aim of this study was to test and develop the Fall Risk Model for Injection Drug Users by examining the relationships among injection drug use, chronic venous insufficiency, lower extremity impairments (i.e., decreased ankle range of motion, reduced calf muscle endurance, and leg pain), age and other covariates, and the Tinetti balance and gait total score as a measure of fall risk. A cross-sectional comparative design was used with four crossed factors. Standardized instruments were used to assess the variables. Moderated multiple regression with linear and quadratic trends in age was used to examine the nature of the relationship between the Tinetti balance and gait total and age and the potential moderating role of injection drug use. A prespecified series of models was tested. Participants (n = 713) were men (46.9%) and women with a mean age of 46.26 years and primarily African American (61.7%) in methadone treatment centers. The fall risk of a 48-year-old leg injector was comparable with the fall risk of a 69-year-old who had not injected drugs. Variables were added to the model sequentially, resulting in some lost significance of some when they were explained by subsequent variables. Final significant variables in the model were employment status, number of comorbidities, ankle range of motion, leg pain, and calf muscle endurance. Fall risk was associated with route of drug use. Lower extremity impairments accounted for the effects of injection drug use and chronic venous insufficiency on risk for falls. Further understanding of fall risk in injection users is necessary as they age, attempt to work, and participate in activities.

In situ laser-induced photochemical silver substrate synthesis and sequential SERS detection in a flow cell.

PubMed

Herman, Krisztian; Szabó, László; Leopold, Loredana F; Chiş, Vasile; Leopold, Nicolae

2011-05-01

A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the laser on the 320 μm inner diameter glass capillary at 0.5 ml/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate mixture, a SERS active silver spot on the inner wall of the glass capillary was prepared in a few seconds. The test analytes, dacarbazine, 4-(2-pyridylazo)resorcinol (PAR) complex with Cu(II), and amoxicillin, were sequentially injected into the flow cell. Each analyte was adsorbed to the silver surface, enabling the recording of high intensity SERS spectra even at 2 s integration times, followed by desorption from the silver surface and being washed away from the capillary. Before and after each analyte passed the detection window, citrate background spectra were recorded, and thus, no "memory effects" perturbed the SERS detection. A good reproducibility of the SERS spectra obtained under flow conditions was observed. The laser-induced photochemically synthesized silver substrate enables high Raman enhancement, is characterized by fast preparation with a high success rate, and represents a valuable alternative for silver colloids as SERS substrate in flow approaches.

Kinetic Titration Series with Biolayer Interferometry

PubMed Central

Frenzel, Daniel; Willbold, Dieter

2014-01-01

Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1–42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations. PMID:25229647

Kinetic titration series with biolayer interferometry.

PubMed

Frenzel, Daniel; Willbold, Dieter

2014-01-01

Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1-42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations.

Targeted Drug Delivery in the Suprachoroidal Space by Swollen Hydrogel Pushing.

PubMed

Jung, Jae Hwan; Desit, Patcharin; Prausnitz, Mark R

2018-04-01

The purpose is to target model drug particles to the posterior region of the suprachoroidal space (SCS) of the eye controlled via pushing by hydrogel swelling. A particle formulation containing 1% hyaluronic acid (HA) with fluorescent polymer particles and a hydrogel formulation containing 4% HA were introduced in a single syringe as two layers without mixing, and injected sequentially into the SCS of the rabbit eye ex vivo and in vivo using a microneedle. Distribution of particles in the eye was determined by microscopy. During injection, the particle formulation was pushed toward the middle of the SCS by the viscous hydrogel formulation, but less than 12% of particles reached the posterior SCS. After injection, the particle formulation was pushed further toward the macula and optic nerve in the posterior SCS by hydrogel swelling and spreading. Heating the eye to 37°C, or injecting in vivo decreased viscosity and mechanical strength of the hydrogel, thereby allowing it to swell and flow further in the SCS. A high salt concentration (9% NaCl) in the hydrogel formulation further increased hydrogel swelling due to osmotic flow into the hydrogel. In this way, up to 76% of particles were delivered to the posterior SCS from an injection made near the limbus. This study shows that model drug particles can be targeted to the posterior SCS by HA hydrogel swelling and pushing without particle functionalization or administering external driving forces.

Histopathological Alterations after Single Epidural Injection of Ropivacaine, Methylprednizolone Acetate, or Contrast Material in Swine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitsou, Maria-Chrysanthi; Kostopanagiotou, Georgia; Kalimeris, Konstantinos

Purpose: The consequences from the injection of different types of drugs in the epidural space remains unknown. Increasing evidence suggests that localized inflammation, fibrosis, and arachnoiditis can complicate sequential epidural blockades, or even epidural contrast injection. We investigate the in vivo effect of epidural injections in the epidural space in an animal model. Materials and Methods: A group of ten male adult pigs, five punctures to each at distinct vertebral interspaces under general anesthesia, were examined, testing different drugs, used regularly in the epidural space (iopamidol, methylprednisolone acetate, ropivacaine). Each site was marked with a percutaneous hook wire marker. Histologicalmore » analysis of the epidural space, the meninges, and the underlying spinal cord of the punctured sites along with staining for caspase-3 followed 20 days later. Results: The epidural space did not manifest adhesions or any other pathology, and the outer surface of the dura was not impaired in any specimen. The group that had the contrast media injection showed a higher inflammation response compared to the other groups (P = 0.001). Positive staining for caspase-3 was limited to <5% of neurons with all substances used. Conclusion: No proof of arachnoiditis and/or fibrosis was noted in the epidural space with the use of the above-described drugs. A higher inflammation rate was noted with the use of contrast media.« less

Measurement of density and affinity for dopamine D2 receptors by a single positron emission tomography scan with multiple injections of [11C]raclopride

PubMed Central

Ikoma, Yoko; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Teramoto, Noboru; Minato, Kotaro; Iida, Hidehiro

2010-01-01

Positron emission tomography (PET) with [11C]raclopride has been used to investigate the density (Bmax) and affinity (Kd) of dopamine D2 receptors related to several neurological and psychiatric disorders. However, in assessing the Bmax and Kd, multiple PET scans are necessary under variable specific activities of administered [11C]raclopride, resulting in a long study period and unexpected physiological variations. In this paper, we have developed a method of multiple-injection graphical analysis (MI-GA) that provides the Bmax and Kd values from a single PET scan with three sequential injections of [11C]raclopride, and we validated the proposed method by performing numerous simulations and PET studies on monkeys. In the simulations, the three-injection protocol was designed according to prior knowledge of the receptor kinetics, and the errors of Bmax and Kd estimated by MI-GA were analyzed. Simulations showed that our method could support the calculation of Bmax and Kd, despite a slight overestimation compared with the true magnitudes. In monkey studies, we could calculate the Bmax and Kd of diseased or normal striatum in a 150 mins scan with the three-injection protocol of [11C]raclopride. Estimated Bmax and Kd values of D2 receptors in normal or partially dopamine-depleted striatum were comparable to the previously reported values. PMID:19904285

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors.

PubMed

Gassara, Fatma; Suri, Navreet; Stanislav, Paul; Voordouw, Gerrit

2015-10-20

Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.6 mM for toluene) is injected to improve the nitrate reduction capacity of the oil along the water flow path, followed by injection of nitrate, other nutrients (e.g., phosphate) and a consortium of NRB, if necessary. Hydrocarbon- and nitrate-mediated MEOR was tested in low- and high-pressure, water-wet sandpack bioreactors with 0.5 pore volumes of residual oil in place (ROIP). Compared to control bioreactors, those with 11-12 mM of toluene in the oil (gained by direct addition or by aqueous injection) and 80 mM of nitrate in the aqueous phase produced 16.5 ± 4.4% of additional ROIP (N = 10). Because toluene is a cheap commodity chemical, HN-MEOR has the potential to be a cost-effective method for additional oil production even in the current low oil price environment.

Structural and spectrophotometric characterization of 2-[4-(dimethylamino)styryl]-1-ethylquinolinium iodide as a reagent for sequential injection determination of tungsten

NASA Astrophysics Data System (ADS)

Bazel, Yaroslav; Lešková, Martina; Rečlo, Michal; Šandrejová, Jana; Simon, András; Fizer, Maksym; Sidey, Vasyl

2018-05-01

Structure, spectrophotometric and protolytic properties of the styryl dye 2-[4-(dimethylamino)styryl]-1-ethylquinolinium iodide (R) as well as its complex with tungsten were studied. The selective protonation of dimethylamino group was confirmed by density functional theory investigation through the computation of Fukui function, NPA partial atomic charges, and NICS(0) aromaticity indexes. The TD-DFT study explains the experimental change of color by excluding the dimethylamino group from HOMO orbital upon protonation. The acid dissociation constant, the optimum wavelength and the molar absorptivity of R were found to be: 3.02, 501 nm and 4.0 × 104 L mol-1 cm-1, respectively. The protolytic properties of the reagent were found to change significantly in the presence of tungsten(VI). Analysis of bond critical points between the anions and Quinaldine Red cation gives the selectivity raw HWO4- > MoO4-> H2VO4- > ReO4- > ClO4-, that perfectly match with the experimental data. Based on this observation, a non-extractive sequential-injection spectrophotometric method for the determination of tungsten was developed. The absorbance of the colored extracts obeys Beer's law up to 55.2 mg L-1 of W at 520 nm wavelength. The limit of detection calculated from a blank test (n = 10) based on 3 s was 0.96 mg L-1. The developed method was applied for the determination of tungsten in model samples.

Sequential changes in the expression of Wnt- and Notch-related genes in the vagina and uterus of ovariectomized mice after estrogen exposure.

PubMed

Nakamura, Takeshi; Miyagawa, Shinichi; Katsu, Yoshinao; Sato, Tomomi; Iguchi, Taisen; Ohta, Yasuhiko

2012-01-01

Estrogen regulates morphological changes in reproductive organs, such as the vagina and uterus, during the estrous cycles in mice. Estrogen depletion by ovariectomy in adults results in atrophy accompanied by apoptosis in vaginal and uterine cells, while estrogen treatment following ovariectomy elicits cell proliferation in both organs. Sequential changes in mRNA expression of wingless-related MMTV integration site (Wnt) and Notch signaling genes were analyzed in the vagina and uterus of ovariectomized adult mice after a single injection of 17β-estradiol to provide understanding over the molecular basis of differences in response to estrogen in these organs. We found estrogen-dependent up-regulation of Wnt4, Wnt5a and p21 and down-regulation of Wnt11, hairy/enhancer-of-split related with YRPW motif-1 (Hey1) and delta-like 4 (Dll4) in the vagina, and up-regulation of Wnt4, Wnt5a, Hey1, Heyl, Dll1, p21 and p53 and down-regulation of Wnt11, Hey2 and Dll4 in the uterus. The expression of Wnt4, Hey1, Hey2, Heyl, Dll1 and p53 showed different patterns after the estrogen injection. Expression patterns for Wnt5a, Wnt11, Dll4 and p21 in the vagina and uterus were similar, suggesting that these genes are involved in the proliferation of cells in both those organs in mice.

Digital Image Speckle Correlation for the Quantification of the Cosmetic Treatment with Botulinum Toxin Type A (BTX-A)

NASA Astrophysics Data System (ADS)

Bhatnagar, Divya; Conkling, Nicole; Rafailovich, Miriam; Dagum, Alexander

2012-02-01

The skin on the face is directly attached to the underlying muscles. Here, we successfully introduce a non-invasive, non-contact technique, Digital Image Speckle Correlation (DISC), to measure the precise magnitude and duration of facial muscle paralysis inflicted by BTX-A. Subjective evaluation by clinicians and patients fail to objectively quantify the direct effect and duration of BTX-A on the facial musculature. By using DISC, we can (a) Directly measure deformation field of the facial skin and determine the locus of facial muscular tension(b)Quantify and monitor muscular paralysis and subsequent re-innervation following injection; (c) Continuously correlate the appearance of wrinkles and muscular tension. Two sequential photographs of slight facial motion (frowning, raising eyebrows) are taken. DISC processes the images to produce a vector map of muscular displacement from which spatially resolved information is obtained regarding facial tension. DISC can track the ability of different muscle groups to contract and can be used to predict the site of injection, quantify muscle paralysis and the rate of recovery following BOTOX injection.

Redesigning flow injection after 40 years of development: Flow programming.

PubMed

Ruzicka, Jaromir Jarda

2018-01-01

Automation of reagent based assays, by means of Flow Injection (FI), is based on sample processing, in which a sample flows continuously towards and through a detector for quantification of the target analyte. The Achilles heel of this methodology, the legacy of Auto Analyzer®, is continuous reagent consumption, and continuous generation of chemical waste. However, flow programming, assisted by recent advances in precise pumping, combined with the lab-on-valve technique, allows the FI manifold to be designed around a single confluence point through which sample and reagents are sequentially directed by means of a series of flow reversals. This approach results in sample/reagent mixing analogous to the traditional FI, reduces sample and reagent consumption, and uses the stop flow technique for enhancement of the yield of chemical reactions. The feasibility of programmable Flow Injection (pFI) is documented by example of commonly used spectrophotometric assays of, phosphate, nitrate, nitrite and glucose. Experimental details and additional information are available in online tutorial http://www.flowinjectiontutorial.com/. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a dynamic coupled hydro-geomechanical code and its application to induced seismicity

NASA Astrophysics Data System (ADS)

Miah, Md Mamun

This research describes the importance of a hydro-geomechanical coupling in the geologic sub-surface environment from fluid injection at geothermal plants, large-scale geological CO2 sequestration for climate mitigation, enhanced oil recovery, and hydraulic fracturing during wells construction in the oil and gas industries. A sequential computational code is developed to capture the multiphysics interaction behavior by linking a flow simulation code TOUGH2 and a geomechanics modeling code PyLith. Numerical formulation of each code is discussed to demonstrate their modeling capabilities. The computational framework involves sequential coupling, and solution of two sub-problems- fluid flow through fractured and porous media and reservoir geomechanics. For each time step of flow calculation, pressure field is passed to the geomechanics code to compute effective stress field and fault slips. A simplified permeability model is implemented in the code that accounts for the permeability of porous and saturated rocks subject to confining stresses. The accuracy of the TOUGH-PyLith coupled simulator is tested by simulating Terzaghi's 1D consolidation problem. The modeling capability of coupled poroelasticity is validated by benchmarking it against Mandel's problem. The code is used to simulate both quasi-static and dynamic earthquake nucleation and slip distribution on a fault from the combined effect of far field tectonic loading and fluid injection by using an appropriate fault constitutive friction model. Results from the quasi-static induced earthquake simulations show a delayed response in earthquake nucleation. This is attributed to the increased total stress in the domain and not accounting for pressure on the fault. However, this issue is resolved in the final chapter in simulating a single event earthquake dynamic rupture. Simulation results show that fluid pressure has a positive effect on slip nucleation and subsequent crack propagation. This is confirmed by running a sensitivity analysis that shows an increase in injection well distance results in delayed slip nucleation and rupture propagation on the fault.

Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

PubMed

Dos Santos, Luciana B O; Masini, Jorge C

2007-05-15

This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

[Response of Calliphora vicina larval hemocytes to abiotic and biotic foreign particles injection].

PubMed

Kind, T V

2012-01-01

Human erythrocytes injection into the body cavity of Calliphora vicina postfeeding larvae results to their fast binding by thrombocytoidal fragments with agglutinates formation. There were almost none sites of lysis and degradation of erythrocytes in agglutinates even after shape modification and strands generation. Exceptions are zones of agglutinates with juvenile hemocytes, where destruction of erythrocytes is seen. The sequential injection of erythrocytes and charcoal particles leads to charcoal adhesion at first to agglutinates periphery and later to more deep stratum of cytoplasm between the erythrocytes. Under such conditions agglutinate formation period is accompanied with morphology variations which do not influence the intensity of agglutinating reaction. Juvenile plasmatocytes phagocytized the charcoal particles regardless of their concentration and duration of previous contact with erythrocytes. When mixture of abiotic and biotic particles was injected into post feeding larvae, crythrocytes and charcoal generate independent aggregations in the range of separate agglutinates. At the same time plasmatocytes form nodules consisting of temporary cell aggregations covered with cores of non phagocytized charcoal particles. These data testified that presumably lectin receptors responsible for foreign biotic and abiotic particles recognition are very near but not identical for different types of hemocytes. They may be specifical (for plasmatocytes) or integrated to different parts of cellular membrane (in thrombocytoids).

Maximizing the value of pressure data in saline aquifer characterization

NASA Astrophysics Data System (ADS)

Yoon, Seonkyoo; Williams, John R.; Juanes, Ruben; Kang, Peter K.

2017-11-01

The injection and storage of freshwater in saline aquifers for the purpose of managed aquifer recharge is an important technology that can help ensure sustainable water resources. As a result of the density difference between the injected freshwater and ambient saline groundwater, the pressure field is coupled to the spatial salinity distribution, and therefore experiences transient changes. The effect of variable density can be quantified by the mixed convection ratio, which is a ratio between the strength of two convection processes: free convection due to the density differences and forced convection due to hydraulic gradients. We combine a density-dependent flow and transport simulator with an ensemble Kalman filter (EnKF) to analyze the effects of freshwater injection rates on the value-of-information of transient pressure data for saline aquifer characterization. The EnKF is applied to sequentially estimate heterogeneous aquifer permeability fields using real-time pressure data. The performance of the permeability estimation is analyzed in terms of the accuracy and the uncertainty of the estimated permeability fields as well as the predictability of breakthrough curve arrival times in a realistic push-pull setting. This study demonstrates that injecting fluids at a rate that balances the two characteristic convections can maximize the value of pressure data for saline aquifer characterization.

Four-channel surface coil array for sequential CW-EPR image acquisition

NASA Astrophysics Data System (ADS)

Enomoto, Ayano; Emoto, Miho; Fujii, Hirotada; Hirata, Hiroshi

2013-09-01

This article describes a four-channel surface coil array to increase the area of visualization for continuous-wave electron paramagnetic resonance (CW-EPR) imaging. A 776-MHz surface coil array was constructed with four independent surface coil resonators and three kinds of switches. Control circuits for switching the resonators were also built to sequentially perform EPR image acquisition for each resonator. The resonance frequencies of the resonators were shifted using PIN diode switches to decouple the inductively coupled coils. To investigate the area of visualization with the surface coil array, three-dimensional EPR imaging was performed using a glass cell phantom filled with a solution of nitroxyl radicals. The area of visualization obtained with the surface coil array was increased approximately 3.5-fold in comparison to that with a single surface coil resonator. Furthermore, to demonstrate the applicability of this surface coil array to animal imaging, three-dimensional EPR imaging was performed in a living mouse with an exogenously injected nitroxyl radical imaging agent.

Monitoring proteins using in vivo near-infrared time-domain optical imaging after 2-O-hexyldiglycerol-mediated transfer to the brain.

PubMed

Hülper, Petra; Dullin, Christian; Kugler, Wilfried; Lakomek, Max; Erdlenbruch, Bernhard

2011-04-01

The aim of the present study was to gain insight into the penetration, biodistribution, and fate of globulins in the brain after 2-O-hexyldiglycerol-induced blood-brain barrier opening. The spatial distribution of fluorescence probes was investigated after blood-brain barrier opening with intracarotid 2-O-hexyldiglycerol injection. Fluorescence intensity was visualized by microscopy (mice and rats) and by in vivo time-domain optical imaging. There was an increased 2-O-hexyldiglycerol-mediated transfer of fluorescence-labeled globulins into the ipsilateral hemisphere. Sequential in vivo measurements revealed that the increase in protein concentration lasted at least 96 h after administration. Ex vivo detection of tissue fluorescence confirmed the results obtained in vivo. Globulins enter the healthy brain in conjunction with 2-O-hexyldiglycerol. Sequential in vivo near-infrared fluorescence measurements enable the visualization of the spatial distribution of antibodies in the brain of living small animals.

Use of High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS) for Sequential Multi-Element Determination of Metals in Seawater and Wastewater Samples

NASA Astrophysics Data System (ADS)

Peña-Vázquez, E.; Barciela-Alonso, M. C.; Pita-Calvo, C.; Domínguez-González, R.; Bermejo-Barrera, P.

2015-09-01

The objective of this work is to develop a method for the determination of metals in saline matrices using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Module SFS 6 for sample injection was used in the manual mode, and flame operating conditions were selected. The main absorption lines were used for all the elements, and the number of selected analytical pixels were 5 (CP±2) for Cd, Cu, Fe, Ni, Pb and Zn, and 3 pixels for Mn (CP±1). Samples were acidified (0.5% (v/v) nitric acid), and the standard addition method was used for the sequential determination of the analytes in diluted samples (1:2). The method showed good precision (RSD(%) < 4%, except for Pb (6.5%)) and good recoveries. Accuracy was checked after the analysis of an SPS-WW2 wastewater reference material diluted with synthetic seawater (dilution 1:2), showing a good agreement between certified and experimental results.

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap.

PubMed

Snyder, Dalton T; Szalwinski, Lucas J; Cooks, R Graham

2017-10-17

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MS n operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Spectrophotometric determination of sulphate in automotive fuel ethanol by sequential injection analysis using dimethylsulphonazo(III) reaction.

PubMed

de Oliveira, Fabio Santos; Korn, Mauro

2006-01-15

A sensitive SIA method was developed for sulphate determination in automotive fuel ethanol. This method was based on the reaction of sulphate with barium-dimethylsulphonazo(III) leading to a decrease on the magnitude of analytical signal monitored at 665 nm. Alcohol fuel samples were previously burned up to avoid matrix effects for sulphate determinations. Binary sampling and stop-flow strategies were used to increase the sensitivity of the method. The optimization of analytical parameter was performed by response surface method using Box-Behnker and central composite designs. The proposed sequential flow procedure permits to determine up to 10.0mg SO(4)(2-)l(-1) with R.S.D. <2.5% and limit of detection of 0.27 mg l(-1). The method has been successfully applied for sulphate determination in automotive fuel alcohol and the results agreed with the reference volumetric method. In the optimized condition the SIA system carried out 27 samples per hour.

Intratympanic Iodine Contrast Injection Diffuses Across the Round Window Membrane Allowing for Perilymphatic CT Volume Acquisition Imaging

PubMed Central

Abt, Nicholas B.; Lehar, Mohamed; Guajardo, Carolina Trevino; Penninger, Richard T.; Ward, Bryan K.; Pearl, Monica S.; Carey, John P.

2016-01-01

Hypothesis Whether the RWM is permeable to iodine-based contrast agents (IBCA) is unknown; therefore, our goal was to determine if IBCAs could diffuse through the RWM using CT volume acquisition imaging. Introduction Imaging of hydrops in the living human ear has attracted recent interest. Intratympanic (IT) injection has shown gadolinium's ability to diffuse through the round window membrane (RWM), enhancing the perilymphatic space. Methods Four unfixed human cadaver temporal bones underwent intratympanic IBCA injection using three sequentially studied methods. The first method was direct IT injection. The second method used direct RWM visualization via tympanomeatal flap for IBCA-soaked absorbable gelatin pledget placement. In the third method, the middle ear was filled with contrast after flap elevation. Volume acquisition CT images were obtained immediately post-exposure, and at 1, 6, and 24 hour intervals. Post-processing was accomplished using color ramping and subtraction imaging. Results Following the third method, positive RWM and perilymphatic enhancement were seen with endolymph sparing. Gray scale and color ramp multiplanar reconstructions displayed increased signal within the cochlea compared to pre-contrast imaging. The cochlea was measured for attenuation differences compared to pure water, revealing a pre-injection average of −1,103 HU and a post-injection average of 338 HU. Subtraction imaging shows enhancement remaining within the cochlear space, Eustachian tube, middle ear epithelial lining, and mastoid. Conclusions Iohexol iodine contrast is able to diffuse across the RWM. Volume acquisition CT imaging was able to detect perilymphatic enhancement at 0.5mm slice thickness. The clinical application of IBCA IT injection appears promising but requires further safety studies. PMID:26859543

Increase of heat-shock protein and induction of gamma/delta T cells in peritoneal exudate of mice after injection of live Fusobacterium nucleatum.

PubMed Central

Saito, K; Katsuragi, H; Mikami, M; Kato, C; Miyamaru, M; Nagaso, K

1997-01-01

Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans are Gram-negative rod periodontal pathogens. The peritoneal cavity of Institute of Cancer Research (ICR) mice was used as the local infection model. In vivo production of heat-shock proteins (hsp) was studied by injection of 1/10 minimum lethal dose (MLD) of each live bacteria into mice. Heat-shock proteins 70 and 60 were examined in the extract of peritoneal exudate cells (PEC) from mice injected intraperitoneally with either F. nucleatum or A. actinomycetemcomitans by using sodium dodecylsulphate-polyacrylamide gel electrophoresis and immunoblotting analysis. Although hsp are present in PEC without injection of the bacteria, both hsp increased and reached a peak on day 3 after F. nucleatum injection but not after A. actinomycetemcomitans. Kinetic study of gamma/delta cells in PEC after injection of bacteria showed that the increase of gamma/delta T cells was observed only in the PEC from mice injected with F. nucleatum but not A. actinomycetemcomitans. The gamma/delta T cells in PEC were either CD3+ and CD4+ or CD3+ and CD8+. The differential cell count of PEC suggested that gamma/delta T-cell induction is related to the expansion of the macrophage population. The phagocytic and chemiluminescence responses of macrophages against the same bacteria were compared after intensive immunization with live F. nucleatum and A. actinomycetemcomitans. Elevations of chemiluminescence response and phagocytic function by immunization were observed in the macrophages of mice immunized with F. nucleatum. These results suggest the sequential appearance of hsp, gamma/delta T cells and macrophage activation after fusobacterial infection. Images Figure 2 PMID:9135551

Development of the precerebellar nuclei in the rat: IV. The anterior precerebellar extramural migratory stream and the nucleus reticularis tegmenti pontis and the basal pontine gray.

PubMed

Altman, J; Bayer, S A

1987-03-22

Sequential thymidine radiograms from rats injected on days E16, E17, E18, and E19 and killed 2 hours after injection and at daily intervals up to day E22 were used to establish the site of origin, migratory route, and settling patterns of neurons of the nucleus reticularis tegmenti pontis and basal pontine gray. The nucleus reticularis tegmenti pontis neurons, which are produced predominantly on days E15 and E16, derive from the primary precerebellar neuroepithelium. These cells, unlike those of the lateral reticular and external cuneate nuclei, take an anteroventral subpial route, forming the anterior precerebellar extramural migratory stream. This migratory stream reaches the anterior pole of the pons by day E18. In rats injected on day E16 and killed on day E18 some of the cells that reach the pons are unlabeled, indicating that they represent the early component of neurons generated on day E15. The cells labeled on day E16 begin to settle in the pons on day E19, 3 days after their production. These cells, migrating in an orderly temporal sequence, form a posterodorsal-to-anteroventral gradient in the nucleus reticularis tegmenti pontis. Unlike the neurons of all the other precerebellar nuclei, the basal pontine gray neurons derive from the secondary precerebellar neuroepithelium. The secondary precerebellar neuroepithelium forms on day E16 as an outgrowth of the primary precerebellar neuroepithelium, and it remains mitotically active through day E19, spanning the entire period of basal pontine gray neurogenesis. The secondary precerebellar neuroepithelium is surrounded by a horizontal layer of postmitotic cells, representing the head-waters of the anterior precerebellar extramural migratory stream. In rats injected on day E18 and killed on day E19 the cells are labeled in the proximal half of the stream around the medulla but those closer to the pons are unlabeled, indicating an orderly sequence of migration. In rats injected on day E18 and killed on day E20 the labeled cells reach the pole of the pons. In the basal pontine gray the sequentially generated neurons settle in a precise order. The neurons generated on day E16 form a small core posteriorly and the neurons generated on days E17, E18, and E19 form regular concentric rings around the core in an inside-out sequence.

Emergence of methadone as a street drug in St. Petersburg, Russia.

PubMed

Heimer, Robert; Lyubimova, Aleksandra; Barbour, Russell; Levina, Olga S

2016-01-01

The syndemic of opioid addiction, HIV, hepatitis, tuberculosis, imprisonment, and overdose in Russia has been worsened by the illegality of opioid substitution therapy. As part of on-going serial studies, we sought to explore the influence of opioid availability on aspects of the syndemic as it has affected the city of St. Petersburg. We employed a sequential approach in which quantitative data collection and statistical analysis were followed by a qualitative phase. Quantitative data were obtained in 2013-2014 from a respondent-driven sample (RDS) of people who inject drugs (PWID). Individuals recruited by RDS were tested for antibodies to HIV and interviewed about drug use and injection practices, sociodemographics, health status, and access to medical care. Subsequently, we collected in-depth qualitative data on methadone use, knowledge, and market availability from PWID recruited at nine different locations within St. Petersburg. Analysis of interview data from the sample revealed the percentage of PWID injecting methadone in the 30 days prior to interview increased from 3.6% in 2010 to 53.3% in 2012-2013. Injection of only methadone, as compared to injecting only heroin or both drugs, was associated with less frequent injection and reduced HIV-related injected risk, especially a lower rate of injecting with a previously used syringe. In-depth questioning of methadone injectors corroborated the finding from serial quantitative surveys of PWID that methadone's black market availability is a recent phenomenon. Spatial analysis revealed widespread methadone availability but no concentration in any specific districts of the city. Despite the prohibition of substitution therapy and demonization of methadone, the drug has emerged to rival heroin as the most commonly available opioid in St. Petersburg. Ironically, its use is associated with reduced injection-related HIV risk even when its use is illegal. Copyright © 2015 Elsevier B.V. All rights reserved.

Emergence of Methadone as a Street Drug in St. Petersburg, Russia

PubMed Central

Heimer, Robert; Lyubimova, Aleksandra; Barbour, Russell; Levina, Olga S.

2015-01-01

Background The syndemic of opioid addiction, HIV, hepatitis, tuberculosis, imprisonment, and overdose in Russia has been worsened by the illegality of opioid substitution therapy. As part of on-going serial studies, we sought to explore the influence of opioid availability on aspects of the syndemic as it has affected the city of St. Petersburg. Methods We employed a sequential approach in which quantitative data collection and statistical analysis were followed by a qualitative phase. Quantitative data were obtained from a respondent-driven sample (RDS) of people who inject drugs (PWID) obtained in 2012–13. Individuals recruited by RDS were tested for antibodies to HIV and interviewed about drug use and injection practices, sociodemographics, health status, and access to medical care. Subsequently, we collected in-depth qualitative data on methadone use, knowledge, and market availability from PWID recruited at nine different locations within St. Petersburg. Results Analysis of interview data from the sample revealed he percentage of PWID injecting methadone in the 30 days prior to interview increased from 3.6% in 2010 to 53.3% in 2012–13. Injection of only methadone, as compared to injecting only heroin or both drugs, was associated with less frequent injection and reduced HIV-related injected risk, especially a lower rate of injecting with a previously used syringe. In-depth questioning of methadone injectors corroborated the finding from serial quantitative surveys of PWID that methadone’s black market availability is a recent phenomenon. Spatial analysis revealed widespread methadone availability but no concentration in any specific districts of the city. Conclusion Despite the prohibition of substitution therapy and demonization of methadone, the drug has emerged to rival heroin as the most commonly available opioid in St. Petersburg. Ironically, its use is associated with reduced injection-related HIV risk even when its use is illegal. PMID:26573380

Factors influencing discomfort during anterior ultrasound-guided injection for hip arthrography.

PubMed

Hsu, Yi-Chih; Wu, Yu-Cheng; Kao, Hao-Lun; Pan, Ru-Yu; Lee, Meei-Shyuan; Huang, Guo-Shu

2013-09-01

Although ultrasound (US)-guided injection techniques for magnetic resonance arthrography of the hip have been used with increasing frequency to diagnose internal joint derangements, little is known about patient tolerance, which is relevant information for patients. The objective of this study was to evaluate prospectively the association between possible influencing factors and discomfort felt during the performance of anterior US-guided injection techniques targeting the femoral head-neck junction during hip arthrography. Forty-four consecutive patients (21 women and 23 men; mean age, 41 years) undergoing magnetic resonance hip arthrography were sequentially assigned to receive injection alternating between fixed and freehand US-guided injection. Discomfort was assessed using a visual analog scale and relative ratings. Patient body mass index, extra-articular contrast leakage, the duration of the procedure, the needle advancement distance, and the fixed trajectory of the needle were assessed. Pearson's correlation coefficients and multiple logistic regression analysis were used to determine the association. Puncture was successfully accomplished in all cases, and no relevant complications were reported. The only significant relationships were between discomfort and the time required for needle manipulation (r = 0.8) and fixed US-guided injection (r = 0.6; p < 0.001). Compared with the freehand technique, the fixed technique resulted in significantly less pain and took significantly less time to perform (p < 0.001). The procedure time during needle manipulation in the fixed US-guided injections (4.0 ± 0.9 seconds) was significantly less than that in the freehand US-guided injections (19.4 ± 17.6 seconds; p < 0.001). No significant relationships were found between discomfort and other parameters (r < 0.3, p > 0.05). The procedure time appears to be the most important factor influencing patient discomfort. Fixed US-guided injection is a time-saving technique that alleviates procedure-related discomfort. Copyright © 2013. Published by Elsevier B.V.

Evaluation of Silicone as an Artificial Lubricant in Osteoarthrotic Joints

PubMed Central

Wright, V.; Haslock, D. I.; Dowson, D.; Seller, P. C.; Reeves, B.

1971-01-01

Silicone 300 has been evaluated as an artificial lubricant in osteoarthrotic joints by means of a pilot study in five inpatients and a control trial of 25 outpatients with 40 osteoarthrotic knees. Sequential analysis showed a significant benefit from saline compared with silicone at one week follow-up and no significant difference at one month. Measurement of stiffness with a knee arthrograph showed no difference in reduction of stiffness between the two substances. In a study of 18 rabbits there was no evidence that silicone was retained in the joint cavity for longer than 48 hours. There was a failure of clearance of iodinated serum albumin for as long as three to four days after the injection of silicone, suggesting some obstruction to lymphatic outflow. Experimentally produced cartilaginous defects did not heal quicker with the injection of silicone into the joint. PMID:5575973

Speciation of chromium (VI) and total chromium determination in welding dust samples by flow-injection analysis coupled to atomic absorption spectrometry.

PubMed

Girard, L; Hubert, J

1996-11-01

We have studied the speciation of chromium (VI) in stainless-steel welding dusts. The approach used for the analysis of Cr(VI) and total Cr relies on a flow-injection analyzer (FIA) equipped with two different sequential detectors. The system measures Cr(VI). by colorimetry (with 1,5-diphenyl carbohydrazide) and total chromium content by flame atomic absorption spectroscopy (AAS). The extraction of the samples of welding-fume dusts is achieved in a buffer solution (acetic acid and sodium acetate at pH 4). This extraction procedure gives a 96% recovery of chromium (VI). The FIA-AAS system that has been described is also more sensitive, has a lower detection limit (0.005 mug ml(-1)) and gives a better precision (< 1%) than other equivalent systems that have been previously described.

Targeted Drug Delivery in the Suprachoroidal Space by Swollen Hydrogel Pushing

PubMed Central

Jung, Jae Hwan; Desit, Patcharin; Prausnitz, Mark R.

2018-01-01

Purpose The purpose is to target model drug particles to the posterior region of the suprachoroidal space (SCS) of the eye controlled via pushing by hydrogel swelling. Methods A particle formulation containing 1% hyaluronic acid (HA) with fluorescent polymer particles and a hydrogel formulation containing 4% HA were introduced in a single syringe as two layers without mixing, and injected sequentially into the SCS of the rabbit eye ex vivo and in vivo using a microneedle. Distribution of particles in the eye was determined by microscopy. Results During injection, the particle formulation was pushed toward the middle of the SCS by the viscous hydrogel formulation, but less than 12% of particles reached the posterior SCS. After injection, the particle formulation was pushed further toward the macula and optic nerve in the posterior SCS by hydrogel swelling and spreading. Heating the eye to 37°C, or injecting in vivo decreased viscosity and mechanical strength of the hydrogel, thereby allowing it to swell and flow further in the SCS. A high salt concentration (9% NaCl) in the hydrogel formulation further increased hydrogel swelling due to osmotic flow into the hydrogel. In this way, up to 76% of particles were delivered to the posterior SCS from an injection made near the limbus. Conclusions This study shows that model drug particles can be targeted to the posterior SCS by HA hydrogel swelling and pushing without particle functionalization or administering external driving forces. PMID:29677369

In situ bioremediation of uranium with emulsified vegetable oil as the electron donor.

PubMed

Watson, David B; Wu, Wei-Min; Mehlhorn, Tonia; Tang, Guoping; Earles, Jennifer; Lowe, Kenneth; Gihring, Thomas M; Zhang, Gengxin; Phillips, Jana; Boyanov, Maxim I; Spalding, Brian P; Schadt, Christopher; Kemner, Kenneth M; Criddle, Craig S; Jardine, Philip M; Brooks, Scott C

2013-06-18

A field test with a one-time emulsified vegetable oil (EVO) injection was conducted to assess the capacity of EVO to sustain uranium bioreduction in a high-permeability gravel layer with groundwater concentrations of (mM) U, 0.0055; Ca, 2.98; NO3(-), 0.11; HCO3(-), 5.07; and SO4(2-), 1.23. Comparison of bromide and EVO migration and distribution indicated that a majority of the injected EVO was retained in the subsurface from the injection wells to 50 m downgradient. Nitrate, uranium, and sulfate were sequentially removed from the groundwater within 1-2 weeks, accompanied by an increase in acetate, Mn, Fe, and methane concentrations. Due to the slow release and degradation of EVO with time, reducing conditions were sustained for approximately one year, and daily U discharge to a creek, located approximately 50 m from the injection wells, decreased by 80% within 100 days. Total U discharge was reduced by 50% over the one-year period. Reduction of U(VI) to U(IV) was confirmed by synchrotron analysis of recovered aquifer solids. Oxidants (e.g., dissolved oxygen, nitrate) flowing in from upgradient appeared to reoxidize and remobilize uranium after the EVO was exhausted as evidenced by a transient increase of U concentration above ambient values. Occasional (e.g., annual) EVO injection into a permeable Ca and bicarbonate-containing aquifer can sustain uranium bioreduction/immobilization and decrease U migration/discharge.

Microengineered open tubular columns for GC analysis

NASA Astrophysics Data System (ADS)

Wiranto, Goib; Haskard, Malcolm R.; Mulcahy, Dennis E.; Davey, David E.; Dawes, Ernest F.

1999-09-01

Microengineered open tubular (MOT) columns with semi rectangular cross-sections have been designed and fabricated using microengineering techniques. The creation of 100-micrometers wide, 20-micrometers deep, and 125-cm long columns employed isotropic etching on (100) silicon and anodic bonding with a Pyrex 7740 glass cover plate. Column geometry has been optimized to achieve maximum efficiency and allow extreme operating conditions. The walls of the microcolumns were coated with a non-polar liquid stationary phase. Performances of the MOT columns have been demonstrated by their ability to completely separate a series of hydrocarbon mixture in less than 1.25 min under isothermal condition of 150 degrees C. The achievable column efficiencies as measured in terms of theoretical plate height ranged from 0.57 to 1.45 mm, which agreed well with theoretical predictions.

Gas and liquid chromatography with inductively coupled plasma mass spectrometry detection for environmental speciation analysis — advances and limitations

NASA Astrophysics Data System (ADS)

Szpunar, Joanna; McSheehy, Shona; Połeć, Kasia; Vacchina, Véronique; Mounicou, Sandra; Rodriguez, Isaac; Łobiński, Ryszard

2000-07-01

Recent advances in the coupling of gas chromatography (GC) and high performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP MS) and their role in trace element speciation analysis of environmental materials are presented. The discussion is illustrated with three research examples concerning the following topics: (i) development and coupling of multicapillary microcolumn GC with ICP MS for speciation of organotin in sediment and biological tissue samples; (ii) speciation of arsenic in marine algae by size-exclusion-anion-exchange HPLC-ICP MS; and (iii) speciation of cadmium in plant cell cultures by size-exclusion HPLC-ICP MS. Particular attention is paid to the problem of signal identification in ICP MS chromatograms; the potential of electrospray MS/MS for this purpose is highlighted.

Preparation of superhydrophobic copper surface by a novel silk-screen printing aided electrochemical machining method

NASA Astrophysics Data System (ADS)

Yan, X. Y.; Chen, G. X.; Liu, J. W.

2018-03-01

A kind of superhydrophobic copper surface with micro-nanocomposite structure has been successfully fabricated by employing a silk-screen printing aided electrochemical machining method. At first silk-screen printing technology has been used to form a column point array mask, and then the microcolumn array would be fabricated by electrochemical machining (ECM) effect. In this study, the drop contact angles have been studied and scanning electron microscopy (SEM) has been used to study the surface characteristic of the workpiece. The experiment results show that the micro-nanocomposite structure with cylindrical array can be successfully fabricated on the metal surface. And the maximum contact angle is 151° when the fluoroalkylsilane ethanol solution was used to modify the machined surface in this study.

Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

PubMed Central

Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

2017-01-01

Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and recorded, and at the end of experiments, tumor xenografts were removed for Western blot and immunohistochemical analyses. Compared to control groups (negative control, regular-dose icotinib [IcoR], high-dose icotinib [IcoH], and docetaxel [DTX]) and regular icotinib dose (60 mg/kg) with docetaxel, treatment of mice with a high-dose (1200 mg/kg) of icotinib plus sequential docetaxel for 3 weeks (IcoH-DTX) had an additive effect on suppression of tumor xenograft size and volume (P < 0.05). Icotinib-containing treatments markedly reduced phosphorylation of EGFR, mitogen activated protein kinase (MAPK), and protein kinase B (Akt), but only the high-dose icotinib-containing treatments showed an additive effect on CD34 inhibition (P < 0.05), an indication of reduced microvessel density in tumor xenografts. Moreover, high-dose icotinib plus docetaxel had a similar effect on mouse weight loss (a common way to measure adverse reactions in mice), compared to the other treatment combinations. The study indicate that the high dose of icotinib plus sequential docetaxel (IcoH-DTX) have an additive effect on suppressing the growth of wild-type EGFR NSCLC cell nude mouse xenografts, possibly through microvessel density reduction. Future clinical trials are needed to confirm the findings of this study. PMID:27852073

Ratio of sequential chromatograms for quantitative analysis and peak deconvolution: Application to standard addition method and process monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Synovec, R.E.; Johnson, E.L.; Bahowick, T.J.

1990-08-01

This paper describes a new technique for data analysis in chromatography, based on taking the point-by-point ratio of sequential chromatograms that have been base line corrected. This ratio chromatogram provides a robust means for the identification and the quantitation of analytes. In addition, the appearance of an interferent is made highly visible, even when it coelutes with desired analytes. For quantitative analysis, the region of the ratio chromatogram corresponding to the pure elution of an analyte is identified and is used to calculate a ratio value equal to the ratio of concentrations of the analyte in sequential injections. For themore » ratio value calculation, a variance-weighted average is used, which compensates for the varying signal-to-noise ratio. This ratio value, or equivalently the percent change in concentration, is the basis of a chromatographic standard addition method and an algorithm to monitor analyte concentration in a process stream. In the case of overlapped peaks, a spiking procedure is used to calculate both the original concentration of an analyte and its signal contribution to the original chromatogram. Thus, quantitation and curve resolution may be performed simultaneously, without peak modeling or curve fitting. These concepts are demonstrated by using data from ion chromatography, but the technique should be applicable to all chromatographic techniques.« less

Treatment of menopausal symptoms with three low-dose continuous sequential 17β-estradiol/progesterone parenteral monthly formulations using novel non-polymeric microsphere technology

PubMed Central

Cortés-Bonilla, Manuel; Bernardo-Escudero, Roberto; Alonso-Campero, Rosalba; Francisco-Doce, María T.; Hernández-Valencia, Marcelino; Celis-González, Cuauhtémoc; Márquez-Oñate, Ricardo; Chedraui, Peter; Uribe, Juan A.

2015-01-01

Abstract Objective: To analyze the short-term efficacy and safety over menopausal symptoms of three low-dose continuous sequential 17β-estradiol (E)/progesterone (P) parental monthly formulations using novel non-polymeric microspheres. Methods: This was a multicenter, randomized, single blinded study in which peri- and postmenopausal women were assigned to receive a monthly intramuscular injection of 0.5 mg E + 15 mg P (Group A, n = 34), 1 mg E + 20 mg P (Group B, n = 24) or 1 mg E + 30 mg P (Group C, n = 26) for 6 months. Primary efficacy endpoints included mean change in the frequency and severity of hot flushes and the effect over urogenital atrophy symptoms at 3 and 6 months. Safety variables included changes in the rate of amenorrhea, endometrial thickness and histopathology, and local and systemic adverse events. Results: Compared to baseline at month 6, the three treatment schemes significantly decreased the rate of urogenital atrophy symptoms and the frequency (mean number per day) and severity (mean number graded as moderate and severe per month) of hot flushes. No differences in studied efficacy parameters were observed between studied groups at baseline or at the end of the study. For all groups the most frequent adverse event was pain at the injection site; however they were all rated as mild. At the end of the study peri- and postmenopausal women displayed no significant changes in endometrial thickness or histopathology in all treated groups. The rate of amenorrhea at the end of the study decreased for all studied groups yet was less evident among postmenopausal women as compared to perimenopausal ones. Conclusions: The three low-dose continuous sequential intramuscular monthly treatments of E/P using novel microsphere technology were effective at reducing menopausal symptoms at short-term with a low rate of adverse events. More long-term and comparative research is warranted to support our positive findings. PMID:26062108

Effects of Injected CO2 on Geomechanical Properties Due to Mineralogical Changes

NASA Astrophysics Data System (ADS)

Nguyen, B. N.; Hou, Z.; Bacon, D. H.; Murray, C. J.; White, J. A.

2013-12-01

Long-term injection and storage of CO2 in deep underground reservoirs may significantly modify the geomechanical behavior of rocks since CO2 can react with the constituent phases of reservoir rocks and modify their composition. This can lead to modifications of their geomechanical properties (i.e., elastic moduli, Biot's coefficients, and permeability). Modifications of rock geomechanical properties have important consequences as these directly control stress and strain distributions, affect conditions for fracture initiation and development and/or fault healing. This paper attempts to elucidate the geochemical effects of CO2 on geomechanical properties of typical reservoir rocks by means of numerical analyses using the STOMP-ABAQUS sequentially coupled simulator that includes the capability to handle geomechanics and the reactive transport of CO2 together with a module (EMTA) to compute the homogenized rock poroelastic properties as a function of composition changes. EMTA, a software module developed at PNNL, implements the standard and advanced Eshelby-Mori-Tanaka approaches to compute the thermoelastic properties of composite materials. In this work, EMTA will be implemented in the coupled STOMP-ABAQUS simulator as a user subroutine of ABAQUS and used to compute local elastic stiffness based on rock composition. Under the STOMP-ABAQUS approach, STOMP models are built to simulate aqueous and CO2 multiphase fluid flows, and relevant chemical reactions of pore fluids with minerals in the reservoirs. The ABAQUS models then read STOMP output data for cell center coordinates, gas pressures, aqueous pressures, temperatures, saturations, constituent volume fractions, as well as permeability and porosity that are affected by chemical reactions. These data are imported into ABAQUS meshes using a mapping procedure developed for the exchange of data between STOMP and ABAQUS. Constitutive models implemented in ABAQUS via user subroutines then compute stiffness, stresses, strains, pore pressure, permeability, porosity, and capillary pressure, and return updated permeability, porosity, and capillary pressure to STOMP at selected times. In preliminary work, the enhanced STOMP-ABAQUS sequentially coupled approach is validated and illustrated in an example analysis of a cylindrical rock specimen subjected to axial loading, confining pressure, and CO2 fluid injection. The geomechanical analysis accounting for CO2 reactions with rock constituents is compared to that without chemical reactions to elucidate the geochemical effects of injected CO2 on the response of the reservoir rock to stress.

Sequential injection analysis with chemiluminescence detection for rapid monitoring of commercial Calendula officinalis extractions.

PubMed

Hughes, Rachel R; Scown, David; Lenehan, Claire E

2015-01-01

Plant extracts containing high levels of antioxidants are desirable due to their reported health benefits. Most techniques capable of determining the antioxidant activity of plant extracts are unsuitable for rapid at-line analysis as they require extensive sample preparation and/or long analysis times. Therefore, analytical techniques capable of real-time or pseudo real-time at-line monitoring of plant extractions, and determination of extraction endpoints, would be useful to manufacturers of antioxidant-rich plant extracts. To develop a reliable method for the rapid at-line extraction monitoring of antioxidants in plant extracts. Calendula officinalis extracts were prepared from dried flowers and analysed for antioxidant activity using sequential injection analysis (SIA) with chemiluminescence (CL) detection. The intensity of CL emission from the reaction of acidic potassium permanganate with antioxidants within the extract was used as the analytical signal. The SIA-CL method was applied to monitor the extraction of C. officinalis over the course of a batch extraction to determine the extraction endpoint. Results were compared with those from ultra high performance liquid chromatography (UHPLC). Pseudo real-time, at-line monitoring showed the level of antioxidants in a batch extract of Calendula officinalis plateaued after 100 min of extraction. These results correlated well with those of an offline UHPLC study. SIA-CL was found to be a suitable method for pseudo real-time monitoring of plant extractions and determination of extraction endpoints with respect to antioxidant concentrations. The method was applied at-line in the manufacturing industry. Copyright © 2015 John Wiley & Sons, Ltd.

Synthetic progestins induce growth and metastasis of BT-474 human breast cancer xenografts in nude mice.

PubMed

Liang, Yayun; Benakanakere, Indira; Besch-Williford, Cynthia; Hyder, Ryyan S; Ellersieck, Mark R; Hyder, Salman M

2010-01-01

Previous studies have shown that sequential exposure to estrogen and progesterone or medroxyprogesterone acetate (MPA) stimulates vascularization and promotes the progression of BT-474 and T47-D human breast cancer cell xenografts in nude mice (Liang et al, Cancer Res 2007, 67:9929). In this follow-up study, the effects of progesterone, MPA, norgestrel (N-EL), and norethindrone (N-ONE) on BT-474 xenograft tumors were compared in the context of several different hormonal environments. N-EL and N-ONE were included in the study because synthetic progestins vary considerably in their biological effects and the effects of these two progestins on the growth of human tumor xenografts are not known. Estradiol-supplemented intact and ovariectomized immunodeficient mice were implanted with BT-474 cells. Progestin pellets were implanted simultaneously with estradiol pellets either 2 days before tumor cell injection (ie, combined) or 5 days after tumor cell injections (ie, sequentially). Progestins stimulated the growth of BT-474 xenograft tumors independent of exposure timing and protocol, MPA stimulated the growth of BT-474 xenograft tumors in ovariectomized mice, and progestins stimulated vascular endothelial growth factor elaboration and increased tumor vascularity. Progestins also increased lymph node metastasis of BT-474 cells. Therefore, progestins, including N-EL and N-ONE, induce the progression of breast cancer xenografts in nude mice and promote tumor metastasis. These observations suggest that women who ingest progestins for hormone therapy or oral contraception could be more at risk for developing breast cancer because of proliferation of existing latent tumor cells. Such risks should be considered in the clinical setting.

Method development for the determination of arsenic by sequential injection/anodic stripping voltammetry using long-lasting gold-modified screen-printed carbon electrode.

PubMed

Punrat, Eakkasit; Chuanuwatanakul, Suchada; Kaneta, Takashi; Motomizu, Shoji; Chailapakul, Orawon

2013-11-15

An automated method has been developed for determining the concentration of inorganic arsenic. The technique uses sequential injection/anodic stripping voltammetry with a long-lasting gold-modified screen-printed carbon electrode. The long-lasting gold electrode was electrochemically deposited onto a screen-printed carbon electrode at a potential of -0.5 V vs. Ag/AgCl in a supporting electrolyte solution of 1M hydrochloric acid. Under optimal conditions and the applied potentials, the electrode demonstrated that it can be used for a long time without a renewal process. The linear range for the determination of arsenic(III) was 1-100 μg L(-1), and the limit of detection (LOD) in standard solutions was as low as 0.03 μg L(-1) for a deposition time of 120 s and sample volume of 1 mL. This method was used to determine the concentration of arsenic(III) in water samples with satisfactory results. The LOD in real samples was found to be 0.5 μg L(-1). In addition, speciation between arsenic(III) and arsenic(V) has been achieved with the proposed method using deposition potentials of -0.5 V and -1.5 V for the determination of the arsenic(III) concentration and the total arsenic concentration, respectively; the results were acceptable. The proposed method is an automated system that offers a less expensive alternative for determining trace amounts of inorganic arsenic. © 2013 Elsevier B.V. All rights reserved.

Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype.

PubMed

Herbst, Daniel P

2014-09-01

Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient's systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26-33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique.

Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype

PubMed Central

Herbst, Daniel P.

2014-01-01

Abstract: Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient’s systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26–33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique. PMID:26357790

Expanding Lipidome Coverage Using LC-MS/MS Data-Dependent Acquisition with Automated Exclusion List Generation

NASA Astrophysics Data System (ADS)

Koelmel, Jeremy P.; Kroeger, Nicholas M.; Gill, Emily L.; Ulmer, Candice Z.; Bowden, John A.; Patterson, Rainey E.; Yost, Richard A.; Garrett, Timothy J.

2017-05-01

Untargeted omics analyses aim to comprehensively characterize biomolecules within a biological system. Changes in the presence or quantity of these biomolecules can indicate important biological perturbations, such as those caused by disease. With current technological advancements, the entire genome can now be sequenced; however, in the burgeoning fields of lipidomics, only a subset of lipids can be identified. The recent emergence of high resolution tandem mass spectrometry (HR-MS/MS), in combination with ultra-high performance liquid chromatography, has resulted in an increased coverage of the lipidome. Nevertheless, identifications from MS/MS are generally limited by the number of precursors that can be selected for fragmentation during chromatographic elution. Therefore, we developed the software IE-Omics to automate iterative exclusion (IE), where selected precursors using data-dependent topN analyses are excluded in sequential injections. In each sequential injection, unique precursors are fragmented until HR-MS/MS spectra of all ions above a user-defined intensity threshold are acquired. IE-Omics was applied to lipidomic analyses in Red Cross plasma and substantia nigra tissue. Coverage of the lipidome was drastically improved using IE. When applying IE-Omics to Red Cross plasma and substantia nigra lipid extracts in positive ion mode, 69% and 40% more molecular identifications were obtained, respectively. In addition, applying IE-Omics to a lipidomics workflow increased the coverage of trace species, including odd-chained and short-chained diacylglycerides and oxidized lipid species. By increasing the coverage of the lipidome, applying IE to a lipidomics workflow increases the probability of finding biomarkers and provides additional information for determining etiology of disease.

/sup 99m/Tc-fibrinogen scanning in adult respiratory distress syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quinn, D.A.; Carvalho, A.C.; Geller, E.

1987-01-01

Fibrin is often seen occluding the lung vessels of patients dying from ARDS and is surrounded by regions of lung necrosis. To learn if we could observe increased or focal fibrin deposition and assess the kinetics of plasma fibrinogen turnover during severe acute respiratory failure, we injected technetium 99m-labeled human purified fibrinogen (Tc-HF) and used gamma camera scanning for as long as 12 h in 13 sequential patients as soon as possible after ICU admission. The fibrinogen uptake rates were determined by calculating the lung:heart radioactivity ratios at each time point. Slopes of the lung:heart ratio versus time were comparedmore » between ARDS and mild acute respiratory failure (ARF). The slope of the lung:heart Tc-HF ratio of the 9 patients with ARDS (2.9 +/- 0.4 units) was markedly higher (p less than 0.02) than the slope of the 4 patients with mild ARF (1.1 +/- 0.4) and the 3 patients studied 5 to 9 months after recovery from respiratory failure (0.7 +/- 0.07). In the 1 patient with ARDS and the 2 patients with mild ARF studied both during acute lung injury and after recovery, the lung:heart Tc-HF ratio had decreased at recovery. To compare the pulmonary uptake of Tc-HF to /sup 99m/Tc-labeled human serum albumin (Tc-HSA), 5 patients were injected with 10 mCi of Tc-HSA, and scanning of the thorax was performed with a similar sequential imaging protocol 24 h after conclusion of the Tc-HF study.« less

Microcolumn studies of dye adsorption onto manganese oxides modified diatomite.

PubMed

Al-Ghouti, M A; Khraisheh, M A M; Ahmad, M N; Allen, S J

2007-07-19

The method described here cannot fully replace the analysis of large columns by small test columns (microcolumns). The procedure, however, is suitable for speeding up the determination of adsorption parameters of dye onto the adsorbent and for speeding up the initial screening of a large adsorbent collection that can be tedious if a several adsorbents and adsorption conditions must be tested. The performance of methylene blue (MB), a basic dye, Cibacron reactive black (RB) and Cibacron reactive yellow (RY) was predicted in this way and the influence of initial dye concentration and other adsorption conditions on the adsorption behaviour were demonstrated. On the basis of the experimental results, it can be concluded that the adsorption of RY onto manganese oxides modified diatomite (MOMD) exhibited a characteristic "S" shape and can be simulated effectively by the Thomas model. It is shown that the adsorption capacity increased as the initial dye concentration increased. The increase in the dye uptake capacity with the increase of the adsorbent mass in the column was due to the increase in the surface area of adsorbent, which provided more binding sites for the adsorption. It is shown that the use of high flow rates reduced the time that RY in the solution is in contact with the MOMD, thus allowing less time for adsorption to occur, leading to an early breakthrough of RY. A rapid decrease in the column adsorption capacity with an increase in particle size with an average 56% reduction in capacity resulting from an increase in the particle size from 106-250 microm to 250-500 microm. The experimental data correlated well with calculated data using the Thomas equation and the bed depth-service time (BDST) equation. Therefore, it might be concluded that the Thomas equation and the BDST equations can produce accurate predication for variation of dye concentration, mass of the adsorbent, flow rate and particle size. In general, the values of adsorption isotherm capacity obtained in a batch system show the maximum values and are considerably higher than those obtained in a fixed-bed.

Pharmacokinetics of 99mTc-MAA- and 99mTc-HSA-Microspheres Used in Preradioembolization Dosimetry: Influence on the Liver-Lung Shunt.

PubMed

Grosser, Oliver S; Ruf, Juri; Kupitz, Dennis; Pethe, Annette; Ulrich, Gerhard; Genseke, Philipp; Mohnike, Konrad; Pech, Maciej; Richter, Wolf S; Ricke, Jens; Amthauer, Holger

2016-06-01

Perfusion scintigraphy using (99m)Tc-labeled albumin aggregates is mandatory before hepatic radioembolization with (90)Y-microspheres. As part of a prospective trial, the intrahepatic and intrapulmonary stability of 2 albumin compounds, (99m)Tc-MAA (macroaggregated serum albumin [MAA]) and (99m)Tc-HSA (human serum albumin [HSA]), was assessed. In 24 patients with metastatic colorectal cancer, biodistribution (liver, lung) and liver-lung shunt (LLS) of both tracers (12 patients each) were assessed by sequential planar scintigraphy (1, 5, and 24 h after injection). Liver uptake of both albumin compounds decreased differently. Although initial LLSs at 1 h after injection were similar in both groups, MAA-LLS increased significantly from 1 (3.9%) to 5 h (7.7%) and 24 h (9.9%) after injection, respectively. HSA-LLS did not change significantly (1 to 5 h), indicating a steady state of pulmonary and intrahepatic degradation. Compared with (99m)Tc-MAA-microspheres, (99m)Tc-HSA-microspheres are likely more resistant to degradation over time, allowing a reliable LLS determination even at later time points. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Employment-based abstinence reinforcement promotes opiate and cocaine abstinence in out-of-treatment injection drug users.

PubMed

Holtyn, August F; Koffarnus, Mikhail N; DeFulio, Anthony; Sigurdsson, Sigurdur O; Strain, Eric C; Schwartz, Robert P; Silverman, Kenneth

2014-01-01

We examined the use of employment-based abstinence reinforcement in out-of-treatment injection drug users, in this secondary analysis of a previously reported trial. Participants (N = 33) could work in the therapeutic workplace, a model employment-based program for drug addiction, for 30 weeks and could earn approximately $10 per hr. During a 4-week induction, participants only had to work to earn pay. After induction, access to the workplace was contingent on enrollment in methadone treatment. After participants met the methadone contingency for 3 weeks, they had to provide opiate-negative urine samples to maintain maximum pay. After participants met those contingencies for 3 weeks, they had to provide opiate- and cocaine-negative urine samples to maintain maximum pay. The percentage of drug-negative urine samples remained stable until the abstinence reinforcement contingency for each drug was applied. The percentage of opiate- and cocaine-negative urine samples increased abruptly and significantly after the opiate- and cocaine-abstinence contingencies, respectively, were applied. These results demonstrate that the sequential administration of employment-based abstinence reinforcement can increase opiate and cocaine abstinence among out-of-treatment injection drug users. © Society for the Experimental Analysis of Behavior.

EMPLOYMENT-BASED ABSTINENCE REINFORCEMENT PROMOTES OPIATE AND COCAINE ABSTINENCE IN OUT-OF-TREATMENT INJECTION DRUG USERS

PubMed Central

Holtyn, August F.; Koffarnus, Mikhail N.; DeFulio, Anthony; Sigurdsson, Sigurdur O.; Strain, Eric C.; Schwartz, Robert P.; Silverman, Kenneth

2016-01-01

We examined the use of employment-based abstinence reinforcement in out-of-treatment injection drug users, in this secondary analysis of a previously reported trial. Participants (N = 33) could work in the therapeutic workplace, a model employment-based program for drug addiction, for 30 weeks and could earn approximately $10 per hr. During a 4-week induction, participants only had to work to earn pay. After induction, access to the workplace was contingent on enrollment in methadone treatment. After participants met the methadone contingency for 3 weeks, they had to provide opiate-negative urine samples to maintain maximum pay. After participants met those contingencies for 3 weeks, they had to provide opiate- and cocaine-negative urine samples to maintain maximum pay. The percentage of drug-negative urine samples remained stable until the abstinence reinforcement contingency for each drug was applied. The percentage of opiate- and cocaine-negative urine samples increased abruptly and significantly after the opiate- and cocaine-abstinence contingencies, respectively, were applied. These results demonstrate that the sequential administration of employment-based abstinence reinforcement can increase opiate and cocaine abstinence among out-of-treatment injection drug users. PMID:25292399

Vaccine allergy and pseudo-allergy.

PubMed

Ponvert, Claude; Scheinmann, Pierre

2003-01-01

Allergic and pseudo-allergic reactions to vaccines frequently involve the skin, and can be generalized systemic symptoms (urticaria/angioedema, serum sickness, flares of eczema) or localized at the sites of vaccination (persistent nodules, abcesses, granulomas). Diagnosis of Arthus-type reactions is based on clinical history and specific IgM/IgG anti-toxoid determination. For other local reactions, diagnostic value of non-immediate responses in skin tests varies with clinical symptoms and substances involved. Immediate responses in skin tests and specific IgE determination have good diagnostic and/or predictive value in anaphylaxis and immediate/accelerated urticaria/angioedema to toxoid-, pneumococcus-, and egg- and gelatin-containing vaccines. Diagnosis of reactions to dextran in BCG is based on specific IgM/IgG determination. Most non-immediate generalized reactions result from non-specific inflammation, except for gelatin-containing vaccines, but the diagnostic value of immuno-allergological tests with the vaccines and gelatin are controversial. Withholding booster injections is advised if specific IgM/IgG levels are high. If the levels are low, sequential injections of vaccines containing a single vaccinating agent are usually tolerated. However, injections of the vaccine should be performed using a " desensitization " procedure in patients reporting anaphylaxis and immediate/accelerated urticaria/angioedema.

What Effect Does Ethnicity Have on the Response to Ranibizumab in the Treatment of Wet Age-Related Macular Degeneration?

PubMed

Mohamed, Ryian; Gadhvi, Kunal; Mensah, Evelyn

2018-05-30

To compare, in a single urban population, the visual outcomes of ranibizumab monotherapy in "White" (W) and "Non-White" (NW) patients with wet age-related macular degeneration (AMD). Prospective data was collected from 434 eyes of 217 patients with wet AMD patients receiving intravitreal ranibizumab. Baseline and monthly LogMAR visual acuities were obtained. All patients received treatment under a "treat and extend policy" consisting of three monthly injections of ranibizumab, followed by individualised sequentially lengthening follow-up intervals when stable. At 24 months, the percentage of eyes that maintained or improved vision was 91% in W patients and 83% in NW patients. Correspondingly, at 24 months, the percentage of visual loss was 9% for W patients and 17% of NW patients. We found that whilst W patients required fewer overall injections (14.1) they gained an average 4 LogMAR letters of visual acuity. However, NW patients required more injections (14.6) to gain 0.5 LogMAR letters of visual acuity over the same 24 months of treatment. Individualised ranibizumab monotherapy is more effective in preserving vision for W compared to NW patients with wet AMD. © 2018 S. Karger AG, Basel.

Injecting 1000 centistoke liquid silicone with ease and precision.

PubMed

Benedetto, Anthony V; Lewis, Alan T

2003-03-01

Since the Food and Drug Administration approved the use of the 1000 centistoke liquid silicone, Silikon 1000, for intraocular injection, the off-label use of this injectable silicone oil as a permanent soft-tissue filler for facial rejuvenation has increased in the United States. Injecting liquid silicone by the microdroplet technique is the most important preventive measure that one can use to avoid the adverse sequelae of silicone migration and granuloma formation, especially when injecting silicone to improve small facial defects resulting from acne scars, surgical procedures, or photoaging. To introduce an easy method for injecting a viscous silicone oil by the microdroplet technique, using an inexpensive syringe and needle that currently is available from distributors of medical supplies in the United States. We suggest the use of a Becton Dickinson 3/10 cc insulin U-100 syringe to inject Silikon 1000. This syringe contains up to 0.3 mL of fluid, and its barrel is clearly marked with an easy-to-read scale of large cross-hatches. Each cross-hatch marking represents either a unit value of 0.01 mL or a half-unit value of 0.005 mL of fluid, which is the approximate volume preferred when injecting liquid silicone into facial defects. Because not enough negative pressure can be generated in this needle and syringe to draw up the viscous silicone oil, we describe a convenient and easy method for filling this 3/10 cc diabetic syringe with Silikon 1000. We have found that by using the Becton Dickinson 3/10 cc insulin U-100 syringe, our technique of injecting minute amounts of Silikon 1000 is facilitated because each widely spaced cross-hatch on the side of the syringe barrel is easy to read and measures exact amounts of the silicone oil. These lines of the scale on the syringe barrel are so large and clearly marked that it is virtually impossible to overinject the most minute amount of silicone. Sequential microdroplets of 0.01 cc or less of Silikon 1000 can be measured and injected with the greatest ease and precision so that inadvertent overdosing and complications can be avoided.

Dexamethasone levels and base to apex concentration gradients in scala tympani perilymph following intracochlear delivery in the guinea pig

PubMed Central

Hahn, Hartmut; Salt, Alec N.; Biegner, Thorsten; Kammerer, Bernd; Delabar, Ursular; Hartsock, Jared; Plontke, Stefan K.

2012-01-01

Hypothesis To determine whether intracochlearly applied dexamethasone will lead to better control of drug levels, higher peak concentrations and lower base-to apex concentration gradients in scala tympani (ST) of the guinea pig than after intratympanic (round window, RW) application. Background Local application of drugs to the RW results in substantial variation of intracochlear drug levels and significant base-to apex concentration gradients in ST. Methods Two μL of dexamethasone-phosphate (10 mg/mL) were injected into ST either through the RW membrane which was covered with 1% sodium hyaluronate gel or through a cochleostomy with a fluid tight seal of the micropipette. Perilymph was sequentially sampled from the apex at a single time point for each animal, at 20, 80, or 200 min after the injection ended. Results were mathematically interpreted by the means of an established computer model and compared with prior experiments performed by our group with the same experimental techniques but using intratympanic applications. Results Single intracochlear injections over 20 min resulted in approximately ten times higher peak concentrations (on average) than 2-3 hours of intratympanic application to the round window niche. Intracochlear drug levels were less variable and could be measured for at least up to 220 min. Concentration gradients along scala tympani were less pronounced. The remaining variability in intracochlear drug levels was attributable to perilymph and drug leak from the injection site. Conclusion With significantly higher, less variable drug levels and smaller base-to apex concentration gradients, intracochlear applications have advantages to intratympanic injections. For further development of this technique, it is of importance to control leaks of perilymph and drug from the injection site and to evaluate its clinical feasibility and associated risks. PMID:22588238

Dexamethasone levels and base-to-apex concentration gradients in the scala tympani perilymph after intracochlear delivery in the guinea pig.

PubMed

Hahn, Hartmut; Salt, Alec N; Biegner, Thorsten; Kammerer, Bernd; Delabar, Ursular; Hartsock, Jared J; Plontke, Stefan K

2012-06-01

To determine whether intracochlearly applied dexamethasone will lead to better control of drug levels, higher peak concentrations, and lower base-to-apex concentration gradients in the scala tympani (ST) of the guinea pig than after intratympanic (round window [RW]) application. Local application of drugs to the RW results in substantial variation of intracochlear drug levels and significant base-to-apex concentration gradients in ST. Two microliters of dexamethasone-phosphate (10 mg/ml) were injected into ST either through the RW membrane, which was covered with 1% sodium hyaluronate gel or through a cochleostomy with a fluid tight seal of the micropipette. Perilymph was sequentially sampled from the apex at a single time point for each animal, at 20, 80, or 200 min after the injection ended. Results were mathematically interpreted by means of an established computer model and compared with previous experiments performed by our group with the same experimental techniques but using intratympanic applications. Single intracochlear injections of 20 minutes resulted in approximately 10 times higher peak concentrations (on average) than 2 to 3 hours of intratympanic application to the RW niche. Intracochlear drug levels were less variable and could be measured for over 220 minutes. Concentration gradients along the scala tympani were less pronounced. The remaining variability in intracochlear drug levels was attributable to perilymph and drug leak from the injection site. With significantly higher, less variable drug levels and smaller base-to-apex concentration gradients, intracochlear applications have advantages to intratympanic injections. For further development of this technique, it is of importance to control leaks of perilymph and drug from the injection site and to evaluate its clinical feasibility and associated risks.

Patterns of Drug Use, Risky Behavior, and Health Status Among Persons Who Inject Drugs Living in San Diego, California: A Latent Class Analysis

PubMed Central

Roth, Alexis M.; Armenta, Richard A.; Wagner, Karla D.; Roesch, Scott C.; Bluthenthal, Ricky N.; Cuevas-Mota, Jazmine; Garfein, Richard S.

2015-01-01

Background Among persons who inject drugs (PWID), polydrug use (the practice of mixing multiple drugs/alcohol sequentially or simultaneously) increases risk for HIV transmission and unintentional overdose deaths. Research has shown local drug markets influence drug use practices. However, little is known about the impact of drug mixing in markets dominated by black tar heroin and methamphetamine, such as the western United States. Methods Data were collected through an ongoing longitudinal study examining drug use, risk behavior, and health status among PWID. Latent class analysis (LCA) was used to identify patterns of substance use (heroin, methamphetamine, prescription drugs, alcohol, and marijuana) via multiple administration routes (injecting, smoking, and swallowing). Logistic regression was used to identify behaviors and health indicators associated with drug use class. Results The sample included 511 mostly white (51.5%) males (73.8%), with mean age of 43.5 years. Two distinct classes of drug users predominated: methamphetamine by multiple routes (51%) and heroin by injection (49%). In multivariable logistic regression, class membership was associated with age, race, and housing status. PWID who were HIV-seropositive and reported prior sexually transmitted infections had increased odds of belonging to the methamphetamine class. Those who were HCV positive and reported previous opioid overdose had an increased odds of being in the primarily heroin injection class (all P-values < .05). Conclusion Risk behaviors and health outcomes differed between PWID who primarily inject heroin vs. those who use methamphetamine. The findings suggest that in a region where PWID mainly use black tar heroin or methamphetamine, interventions tailored to sub-populations of PWID could improve effectiveness. PMID:25313832

Fuel mixture stratification as a method for improving homogeneous charge compression ignition engine operation

DOEpatents

Dec, John E [Livermore, CA; Sjoberg, Carl-Magnus G [Livermore, CA

2006-10-31

A method for slowing the heat-release rate in homogeneous charge compression ignition ("HCCI") engines that allows operation without excessive knock at higher engine loads than are possible with conventional HCCI. This method comprises injecting a fuel charge in a manner that creates a stratified fuel charge in the engine cylinder to provide a range of fuel concentrations in the in-cylinder gases (typically with enough oxygen for complete combustion) using a fuel with two-stage ignition fuel having appropriate cool-flame chemistry so that regions of different fuel concentrations autoignite sequentially.

Split Flow Online Solid-Phase Extraction Coupled with Inductively Coupled Plasma Mass Spectrometry System for One-Shot Data Acquisition of Quantification and Recovery Efficiency.

PubMed

Furukawa, Makoto; Takagai, Yoshitaka

2016-10-04

Online solid-phase extraction (SPE) coupled with inductively coupled plasma mass spectrometry (ICPMS) is a useful tool in automatic sequential analysis. However, it cannot simultaneously quantify the analytical targets and their recovery percentages (R%) in one-shot samples. We propose a system that simultaneously acquires both data in a single sample injection. The main flowline of the online solid-phase extraction is divided into main and split flows. The split flow line (i.e., bypass line), which circumvents the SPE column, was placed on the main flow line. Under program-controlled switching of the automatic valve, the ICPMS sequentially measures the targets in a sample before and after column preconcentration and determines the target concentrations and the R% on the SPE column. This paper describes the system development and two demonstrations to exhibit the analytical significance, i.e., the ultratrace amounts of radioactive strontium ( 90 Sr) using commercial Sr-trap resin and multielement adsorbability on the SPE column. This system is applicable to other flow analyses and detectors in online solid phase extraction.

Investigation of arsenic removal in batch wise water treatments by means of sequential hydride generation flow injection analysis.

PubMed

Toda, Kei; Takaki, Mari; Hashem, Md Abul

2008-08-01

Arsenic water pollution is a big issue worldwide. Determination of inorganic arsenic in each oxidation state is important because As(III) is much more toxic than As(V). An automated arsenic measurement system was developed based on complete vaporization of As by a sequential procedure and collection/preconcentration of the vaporized AsH(3), which was subsequently measured by a flow analysis. The automated sensitive method was applied to monitoring As(III) and As(V) concentrations in contaminated water standing overnight. Behaviors of arsenics were investigated in different conditions, and unique time dependence profiles were obtained. For example, in the standing of anaerobic water samples, the As(III) concentration immediately began decreasing whereas dead time was observed in the removal of As(V). In normal groundwater conditions, most arsenic was removed from the water simply by standing overnight. To obtain more effective removal, the addition of oxidants and use of steel wools were investigated. Simple batch wise treatments of arsenic contaminated water were demonstrated, and detail of the transitional changes in As(III) and As(V) were investigated.

Electrochemical immunoassay on a microfluidic device with sequential injection and flushing functions.

PubMed

Nashida, Norihiro; Satoh, Wataru; Fukuda, Junji; Suzuki, Hiroaki

2007-06-15

An integrated microfluidic device with injecting, flushing, and sensing functions was realized using valves that operate based on direct electrowetting. The device consisted of two substrates: a glass substrate with driving and sensing electrodes and a poly(dimethylsiloxane) (PDMS) substrate. Microfluidic transport was achieved using the spontaneous movement of solutions in hydrophilic flow channels formed with a dry-film photoresist layer. The injection and flushing of solutions were controlled by gold working electrodes, which functioned as valves. The valves were formed either in the channels or in a through-hole in the glass substrate. To demonstrate the system's applicability to an immunoassay, the detection of immobilized antigens was performed as a partial simulation of a sandwich immunoassay. Human alpha-fetoprotein (AFP) or an anti-human AFP antibody was immobilized on a platinum working electrode in the chamber using a plasma-polymerized film (PPF). By applying a potential to the injection valves, necessary solutions were injected one by one through the channels into a reaction chamber at the center of the chip and incubated for reasonable periods of time. The solutions were then flushed through the flushing valve and absorbed in a filter paper placed under the device. After incubation with the corresponding antibodies labeled with glucose oxidase (GOD), electrochemical detection was conducted. In both cases, the obtained current depended on the amount of immobilized antigen. The calibration curves were sigmoidal, and the detection limit was 0.1 ng. The developed microfluidic system could potentially be a fundamental component for a micro immunoassay of the next generation.

Intratympanic Iodine Contrast Injection Diffuses Across the Round Window Membrane Allowing for Perilymphatic CT Volume Acquisition Imaging.

PubMed

Abt, Nicholas B; Lehar, Mohamed; Guajardo, Carolina Trevino; Penninger, Richard T; Ward, Bryan K; Pearl, Monica S; Carey, John P

2016-04-01

Whether the round window membrane (RWM) is permeable to iodine-based contrast agents (IBCA) is unknown; therefore, our goal was to determine if IBCAs could diffuse through the RWM using CT volume acquisition imaging. Imaging of hydrops in the living human ear has attracted recent interest. Intratympanic (IT) injection has shown gadolinium's ability to diffuse through the RWM, enhancing the perilymphatic space. Four unfixed human cadaver temporal bones underwent intratympanic IBCA injection using three sequentially studied methods. The first method was direct IT injection. The second method used direct RWM visualization via tympanomeatal flap for IBCA-soaked absorbable gelatin pledget placement. In the third method, the middle ear was filled with contrast after flap elevation. Volume acquisition CT images were obtained immediately postexposure, and at 1-, 6-, and 24-hour intervals. Postprocessing was accomplished using color ramping and subtraction imaging. After the third method, positive RWM and perilymphatic enhancement were observed with endolymph sparing. Gray scale and color ramp multiplanar reconstructions displayed increased signal within the cochlea compared with precontrast imaging. The cochlea was measured for attenuation differences compared with pure water, revealing a preinjection average of -1,103 HU and a postinjection average of 338 HU. Subtraction imaging shows enhancement remaining within the cochlear space, Eustachian tube, middle ear epithelial lining, and mastoid. Iohexol iodine contrast is able to diffuse across the RWM. Volume acquisition CT imaging was able to detect perilymphatic enhancement at 0.5-mm slice thickness. The clinical application of IBCA IT injection seems promising but requires further safety studies.

Micro-separation toward systems biology.

PubMed

Liu, Bi-Feng; Xu, Bo; Zhang, Guisen; Du, Wei; Luo, Qingming

2006-02-17

Current biology is experiencing transformation in logic or philosophy that forces us to reevaluate the concept of cell, tissue or entire organism as a collection of individual components. Systems biology that aims at understanding biological system at the systems level is an emerging research area, which involves interdisciplinary collaborations of life sciences, computational and mathematical sciences, systems engineering, and analytical technology, etc. For analytical chemistry, developing innovative methods to meet the requirement of systems biology represents new challenges as also opportunities and responsibility. In this review, systems biology-oriented micro-separation technologies are introduced for comprehensive profiling of genome, proteome and metabolome, characterization of biomolecules interaction and single cell analysis such as capillary electrophoresis, ultra-thin layer gel electrophoresis, micro-column liquid chromatography, and their multidimensional combinations, parallel integrations, microfabricated formats, and nano technology involvement. Future challenges and directions are also suggested.

Method for the determination of organophosphate insecticides in water, sediment and biota.

PubMed

Tse, Hung; Comba, Michael; Alaee, Mehran

2004-01-01

A procedure for the determination of 13 organophosphate insecticides (OPs) in water, sediment and biota at low ppb levels is described. Samples were extracted with dichloromethane or acetone/hexane and cleaned up with micro-column silica gel chromatography. Measurements were made by dual capillary column gas chromatography using both nitrogen-phosphorus (NPD) and electron capture (ECD) detection. Recoveries from fortified water samples ranged from 76% to 102% for all sample types. Practical detection limits ranged between 0.003 and 0.029 microg/l in natural water samples, 0.0004-0.005 microg/g w.w. for sediments, and 0.001-0.005 microg/g w.w for biota using the NPD and ECD method. Losses in sediments were experienced when sulphur was removed. Precision and accuracy were not affected in sediment samples where sulphur was not removed.

Two-column sequential injection chromatography--new approach for fast and effective analysis and its comparison with gradient elution chromatography.

PubMed

Chocholous, Petr; Satínský, Dalibor; Sklenárová, Hana; Solich, Petr

2010-05-23

This work presents novel approach in low-pressure chromatography flow systems--two-column Sequential Injection Chromatography (2-C SIC) and its comparison with gradient elution chromatography on the same instrument. The system was equipped with two different chromatographic columns (connected to selection valve in parallel design) for isocratic separation and determination of all components in composed anti-inflammatory pharmaceutical preparation (tablets). The sample was first injected on the first column of length 30 mm where less retained analytes were separated and then the sample was injected on the second column of length 10 mm where more retained analytes were separated. The SIC system was based on a commercial SIChrom manifold (8-port high-pressure selection valve and medium-pressure syringe pump with 4 mL reservoir) (FIAlab, USA) with two commercially available monolithic columns the "first column" Chromolith Flash RP-18e (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.) and the "second column" Chromolith RP-18e (10 mm x 4.6 mm i.d.) and CCD UV-vis detector USB 4000 with micro-volume 1.0 cm Z flow cell. Two mobile phases were used for analysis (one for each column). The mobile phase 1 used for elution of paracetamol, caffeine and salicylic acid (internal standard) was acetonitrile/water (10:90, v/v, the water part of pH 3.5 adjusted with acetic acid), flow rate was 0.9 mL min(-1) (volume 3.0 mL of mobile phase per analysis). The mobile phase 2 used for elution of propyphenazone was acetonitrile/water (30:70, v/v); flow rate was 1.2 mL min(-1) (volume 1.5 mL of mobile phase per analysis). Absorbance was monitored at 210 nm. Samples were prepared by dissolving of one tablet in 30% acetonitrile and 10 microL of filtered supernatant was injected on each column (2 x 10 microL). The chromatographic resolution between all compounds was >1.45 and analysis time was 5.5 min under the optimal conditions. Limits of detection were determined at 0.4 microg mL(-1) for paracetamol, at 0.5 microg mL(-1) for caffeine and at 0.7 microg mL(-1) for propyphenazone. The new two-column chromatographic set-up developed as an alternative approach to gradient elution chromatography shows evident advantages (time and solvent reduction more than one-third) as compared with single-column gradient SIC method with Chromolith Flash RP-18 (25 mm x 4.6 mm i.d. with guard column 5 mm x 4.6 mm i.d.). Copyright 2010 Elsevier B.V. All rights reserved.

Human sympathetic and vagal baroreflex responses to sequential nitroprusside and phenylephrine

NASA Technical Reports Server (NTRS)

Rudas, L.; Crossman, A. A.; Morillo, C. A.; Halliwill, J. R.; Tahvanainen, K. U.; Kuusela, T. A.; Eckberg, D. L.

1999-01-01

We evaluated a method of baroreflex testing involving sequential intravenous bolus injections of nitroprusside followed by phenylephrine and phenylephrine followed by nitroprusside in 18 healthy men and women, and we drew inferences regarding human sympathetic and vagal baroreflex mechanisms. We recorded the electrocardiogram, photoplethysmographic finger arterial pressure, and peroneal nerve muscle sympathetic activity. We then contrasted least squares linear regression slopes derived from the depressor (nitroprusside) and pressor (phenylephrine) phases with 1) slopes derived from spontaneous fluctuations of systolic arterial pressures and R-R intervals, and 2) baroreflex gain derived from cross-spectral analyses of systolic pressures and R-R intervals. We calculated sympathetic baroreflex gain from integrated muscle sympathetic nerve activity and diastolic pressures. We found that vagal baroreflex slopes are less when arterial pressures are falling than when they are rising and that this hysteresis exists over pressure ranges both below and above baseline levels. Although pharmacological and spontaneous vagal baroreflex responses correlate closely, pharmacological baroreflex slopes tend to be lower than those derived from spontaneous fluctuations. Sympathetic baroreflex slopes are similar when arterial pressure is falling and rising; however, small pressure elevations above baseline silence sympathetic motoneurons. Vagal, but not sympathetic baroreflex gains vary inversely with subjects' ages and their baseline arterial pressures. There is no correlation between sympathetic and vagal baroreflex gains. We recommend repeated sequential nitroprusside followed by phenylephrine doses as a simple, efficientmeans to provoke and characterize human vagal and sympathetic baroreflex responses.

Intra-tumor distribution of PEGylated liposome upon repeated injection: No possession by prior dose.

PubMed

Nakamura, Hiroyuki; Abu Lila, Amr S; Nishio, Miho; Tanaka, Masao; Ando, Hidenori; Kiwada, Hiroshi; Ishida, Tatsuhiro

2015-12-28

Liposomes have proven to be a viable means for the delivery of chemotherapeutic agents to solid tumors. However, significant variability has been detected in their intra-tumor accumulation and distribution, resulting in compromised therapeutic outcomes. We recently examined the intra-tumor accumulation and distribution of weekly sequentially administered oxaliplatin (l-OHP)-containing PEGylated liposomes. In that study, the first and second doses of l-OHP-containing PEGylated liposomes were distributed diversely and broadly within tumor tissues, resulting in a potent anti-tumor efficacy. However, little is known about the mechanism underlying such a diverse and broad liposome distribution. Therefore, in the present study, we investigated the influence of dosage interval on the intra-tumor accumulation and distribution of "empty" PEGylated liposomes. Intra-tumor distribution of sequentially administered "empty" PEGylated liposomes was altered in a dosing interval-dependent manner. In addition, the intra-tumor distribution pattern was closely related to the chronological alteration of tumor blood flow as well as vascular permeability in the growing tumor tissue. These results suggest that the sequential administrations of PEGylated liposomes in well-spaced intervals might allow the distribution to different areas and enhance the total bulk accumulation within tumor tissue, resulting in better therapeutic efficacy of the encapsulated payload. This study may provide useful information for a better design of therapeutic regimens involving multiple administrations of nanocarrier drug delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Hydraulic Fracture Induced Seismicity During A Multi-Stage Pad Completion in Western Canada: Evidence of Activation of Multiple, Parallel Faults

NASA Astrophysics Data System (ADS)

Maxwell, S.; Garrett, D.; Huang, J.; Usher, P.; Mamer, P.

2017-12-01

Following reports of injection induced seismicity in the Western Canadian Sedimentary Basin, regulators have imposed seismic monitoring and traffic light protocols for fracturing operations in specific areas. Here we describe a case study in one of these reservoirs, the Montney Shale in NE British Columbia, where induced seismicity was monitored with a local array during multi-stage hydraulic fracture stimulations on several wells from a single drilling pad. Seismicity primarily occurred during the injection time periods, and correlated with periods of high injection rates and wellhead pressures above fracturing pressures. Sequential hydraulic fracture stages were found to progressively activate several parallel, critically-stressed faults, as illuminated by multiple linear hypocenter patterns in the range between Mw 1 and 3. Moment tensor inversion of larger events indicated a double-couple mechanism consistent with the regional strike-slip stress state and the hypocenter lineations. The critically-stressed faults obliquely cross the well paths which were purposely drilled parallel to the minimum principal stress direction. Seismicity on specific faults started and stopped when fracture initiation points of individual injection stages were proximal to the intersection of the fault and well. The distance ranges when the seismicity occurs is consistent with expected hydraulic fracture dimensions, suggesting that the induced fault slip only occurs when a hydraulic fracture grows directly into the fault and the faults are temporarily exposed to significantly elevated fracture pressures during the injection. Some faults crossed multiple wells and the seismicity was found to restart during injection of proximal stages on adjacent wells, progressively expanding the seismogenic zone of the fault. Progressive fault slip is therefore inferred from the seismicity migrating further along the faults during successive injection stages. An accelerometer was also deployed close to the pad operations providing information about the local ground motion at near offsets, although no ground motion was recorded that exceeds the minimum levels requiring mandatory reporting to the regulator.

Synthetic progestins induce growth and metastasis of BT-474 human breast cancer xenografts in nude mice

PubMed Central

Liang, Yayun; Benakanakere, Indira; Besch-Williford, Cynthia; Hyder, Ryyan S; Ellersieck, Mark R.; Hyder, Salman M

2010-01-01

Objective Previous studies showed that sequential exposure to estrogen and progesterone or medroxyprogesterone acetate (MPA) stimulates vascularization and promotes the progression of BT-474 and T47-D human breast cancer cell xenografts in nude mice (Liang et al, Cancer Res 2007, 67:9929). In this follow-up study, the effects of progesterone, MPA, norgestrel (N-EL) and norethindrone (N-ONE) on BT-474 xenograft tumors were compared in the context of several different hormonal environments. N-EL and N-ONE were included in the study since synthetic progestins vary considerably in their biological effects and the effects of these two progestins on the growth of human tumor xenografts are not known. Methods Estradiol-supplemented intact and ovariectomized Immunodeficient mice were implanted with BT-474 cells. Progestin pellets were implanted either simultaneously with estradiol pellets 2-days prior to tumor cell injection (i.e. combined), or 5-days following tumor cell injections (i.e. sequentially). Results Progestins stimulated the growth of BT-474 xenograft tumors independent of exposure timing and protocol, MPA stimulated the growth of BT-474 xenograft tumors in ovariectomized mice and progestins stimulated VEGF elaboration and increased tumor vascularity. Progestins also increased lymph node metastasis of BT-474 cells. Therefore, progestins, including N-EL and N-ONE, induce the progression of breast cancer xenografts in nude mice and promote tumor metastasis. Conclusions These observations suggests that women who ingest progestins for HT or oral contraception could be more at risk for developing breast cancer as a result of proliferation of existing latent tumor cells. Such risks should be considered in the clinical setting. PMID:20461021

On-line hyphenation of solid-phase extraction to chromatographic separation of sulfonamides with fused-core columns in sequential injection chromatography.

PubMed

Batista, Alex D; Chocholouš, Petr; Satínský, Dalibor; Solich, Petr; Rocha, Fábio R P

2015-02-01

On-line sample pretreatment (clean-up and analyte preconcentration) is for the first time coupled to sequential injection chromatography. The approach combines anion-exchange solid-phase extraction and the highly effective pentafluorophenylpropyl (F5) fused-core particle column for separation of eight sulfonamide antibiotics with similar structures (sulfathiazole, sulfanilamide, sulfacetamide, sulfadiazine, sulfamerazine, sulfadimidine, sulfamethoxazole and sulfadimethoxine). The stationary phase was selected after a critical comparison of the performance achieved by three fused-core reversed phase columns (Ascentis(®) Express RP-Amide, Phenyl-Hexyl, and F5) and two monolithic columns (Chromolith(®) High Resolution RP-18 and CN). Acetonitrile and acetate buffer pH 5.0 at 0.60 mL min(-1) were used as mobile phase to perform the separations before spectrophotometric detection. The first mobile phase was successfully used as eluent from SPE column ensuring transfer of a narrow zone to the chromatographic column. Enrichment factors up to 39.2 were achieved with a 500 µL sample volume. The developed procedure showed analysis time <10.5 min, resolutions >1.83 with peak symmetry ≤1.52, LODs between 4.9 and 27 µg L(-1), linear response ranges from 30.0 to 1000.0 µg L(-1) (r(2)>0.996) and RSDs of peak heights <2.9% (n=6) at a 100 µg L(-1) level and enabled the screening control of freshwater samples contaminated at the 100 µg L(-1) level. The proposed approach expanded the analytical potentiality of SIC and avoided the time-consuming batch sample pretreatment step, thus minimizing risks of sample contamination and analyte losses. Copyright © 2014 Elsevier B.V. All rights reserved.

Design, fabrication and test of a pneumatically controlled, renewable, microfluidic bead trapping device for sequential injection analysis applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Guocheng; Lu, Donglai; Fu, Zhifeng

This paper describes the design, fabrication, and testing of a pneumatically controlled,renewable, microfluidic device for conducting bead-based assays in an automated sequential injection analysis system. The device used a “brick wall”-like pillar array (pillar size: 20 μm length X 50 μm width X 45 μm height) with 5 μm gaps between the pillars serving as the micro filter. The flow channel where bead trapping occurred is 500 μm wide X 75 μm deep. An elastomeric membrane and an air chamber were located underneath the flow channel. By applying pressure to the air chamber, the membrane is deformed and pushed upwardmore » against the filter structure. This effectively traps beads larger than 5 μm and creates a “bed” or micro column of beads that can be perfused and washed with liquid samples and reagents. Upon completion of the assay process, the pressure is released and the beads are flushed out from underneath the filter structure to renew the device. Mouse IgG was used as a model analyte to test the feasibility of using the proposed device for immunoassay applications. Resulting microbeads from an on-chip fluorescent immunoassay were individually examined using flow cytometry. The results show that the fluorescence signal intensity distribution is fairly narrow indicating high chemical reaction uniformity among the beads population. Electrochemical onchip assay was also conducted. A detection limit of 0.1 ng/mL1 ppb was achieved and good device reliability and repeatability were demonstrated. The novel microfluidic-based beadstrapping device thus opens up a new pathway to design micro-bead based biosensor immunoassays for clinical and othervarious applications.« less

Monitoring glucose, calcium, and magnesium levels in saliva as a non-invasive analysis by sequential injection multi-parametric determination.

PubMed

Machado, Ana; Maneiras, Rui; Bordalo, Adriano A; Mesquita, Raquel B R

2018-08-15

The use of saliva for diagnose and surveillance of systemic illnesses, and general health has been arousing great interest worldwide, emerging as a highly desirable goal in healthcare. The collection is non-invasive, stress-free, inexpensive, and simple representing a major asset. Glucose, calcium, and magnesium concentration are three major parameters evaluated in clinical context due to their essential role in a wide range of biochemical reactions, and consequently many health disorders. In this work, a spectrophotometric sequential injection method is described for the fast screening of glucose, calcium, and magnesium in saliva samples. The glucose determination reaction involves the oxidation of the aldehyde functional group present in glucose with simultaneous reduction of 3,5-dinitrosalicylic acid (DNS) to 3-amino, 5-nitrosalicylic acid under alkaline conditions, followed by the development of colour. The determination of both metals is based on their reaction with cresolphtalein complexone (CPC), and the interference of calcium in the magnesium determination minimized by ethylene glycol-bis[β-aminoethyl ether]-N,N,N',N'-tetraacetic acid (EGTA). The developed multi-parametric method enabled dynamic ranges of 50 - 300 mg/dL for glucose, 0.1 - 2 mg/dL for calcium, and 0.1 - 0.5 mg/dL for magnesium. Determination rates of 28, 60, 52 h -1 were achieved for glucose, calcium, and magnesium, respectively. Less than 300 µL of saliva is required for the multi-parametric determination due to saliva viscosity and inherent necessity of dilution prior to analysis. RSDs lower than 5% were obtained, and the results agreed with those obtained by reference methods, while recovery tests confirmed its accuracy. Copyright © 2018 Elsevier B.V. All rights reserved.

Solid-phase based on-chip DNA purification through a valve-free stepwise injection of multiple reagents employing centrifugal force combined with a hydrophobic capillary barrier pressure.

PubMed

Zhang, Hainan; Tran, Hong Hanh; Chung, Bong Hyun; Lee, Nae Yoon

2013-03-21

In this paper, we demonstrate a simple technique for sequentially introducing multiple sample liquids into microchannels driven by centrifugal force combined with a hydrophobic barrier pressure and apply the technique for performing solid-phase based on-chip DNA purification. Three microchannels with varying widths, all equipped with independent sample reservoirs at the inlets, were fabricated on a hydrophobic elastomer, poly(dimethylsiloxane) (PDMS). First, glass beads were packed inside the reaction chamber, and a whole cell containing the DNA extract was introduced into the widest channel by applying centrifugal force for physical adsorption of the DNA onto the glass beads. Next, washing and elution solutions were sequentially introduced into the intermediate and narrowest microchannels, respectively, by gradually increasing the amount of centrifugal force. Through a precise manipulation of the centrifugal force, the DNA adsorbed onto the glass beads was successfully washed and eluted in a continuous manner without the need to introduce each solution manually. A stepwise injection of liquids was successfully demonstrated using multiple ink solutions, the results of which corresponded well with the theoretical analyses. As a practical application, the D1S80 locus of human genomic DNA, which is widely used for forensic purposes, was successfully purified using the microdevice introduced in this study, as demonstrated through successful target amplification. This will pave the way for the construction of a control-free valve system for realizing on-chip DNA purification, which is one of the most labor-intensive and hard-to-miniaturize components, on a greatly simplified and miniaturized platform employing hydrophobic PDMS.

Concomitant or sequential administration of live attenuated Japanese encephalitis chimeric virus vaccine and yellow fever 17D vaccine: randomized double-blind phase II evaluation of safety and immunogenicity.

PubMed

Nasveld, Peter E; Marjason, Joanne; Bennett, Sonya; Aaskov, John; Elliott, Suzanne; McCarthy, Karen; Kanesa-Thasan, Niranjan; Feroldi, Emmanuel; Reid, Mark

2010-11-01

A randomized, double-blind, study was conducted to evaluate the safety, tolerability and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) co-administered with live attenuated yellow fever vaccine (YF-17D strain; Stamaril®, Sanofi Pasteur) or administered successively. Participants (n = 108) were randomized to receive: YF followed by JE-CV 30 days later, JE followed by YF 30 days later, or the co-administration of JE and YF followed or preceded by placebo 30 days later or earlier. Placebo was used in a double-dummy fashion to ensure masking. Neutralizing antibody titers against JE-CV, YF-17D and selected wild-type JE strains was determined using a 50% serum-dilution plaque reduction neutralization test. Seroconversion was defined as the appearance of a neutralizing antibody titer above the assay cut-off post-immunization when not present pre-injection at day 0, or a least a four-fold rise in neutralizing antibody titer measured before the pre-injection day 0 and later post vaccination samples. There were no serious adverse events. Most adverse events (AEs) after JE vaccination were mild to moderate in intensity, and similar to those reported following YF vaccination. Seroconversion to JE-CV was 100% and 91% in the JE/YF and YF/JE sequential vaccination groups, respectively, compared with 96% in the co-administration group. All participants seroconverted to YF vaccine and retained neutralizing titers above the assay cut-off at month six. Neutralizing antibodies against JE vaccine were detected in 82-100% of participants at month six. These results suggest that both vaccines may be successfully co-administered simultaneously or 30 days apart.

Fully automated analytical procedure for propofol determination by sequential injection technique with spectrophotometric and fluorimetric detections.

PubMed

Šrámková, Ivana; Amorim, Célia G; Sklenářová, Hana; Montenegro, Maria C B M; Horstkotte, Burkhard; Araújo, Alberto N; Solich, Petr

2014-01-01

In this work, an application of an enzymatic reaction for the determination of the highly hydrophobic drug propofol in emulsion dosage form is presented. Emulsions represent a complex and therefore challenging matrix for analysis. Ethanol was used for breakage of a lipid emulsion, which enabled optical detection. A fully automated method based on Sequential Injection Analysis was developed, allowing propofol determination without the requirement of tedious sample pre-treatment. The method was based on spectrophotometric detection after the enzymatic oxidation catalysed by horseradish peroxidase and subsequent coupling with 4-aminoantipyrine leading to a coloured product with an absorbance maximum at 485 nm. This procedure was compared with a simple fluorimetric method, which was based on the direct selective fluorescence emission of propofol in ethanol at 347 nm. Both methods provide comparable validation parameters with linear working ranges of 0.005-0.100 mg mL(-1) and 0.004-0.243 mg mL(-1) for the spectrophotometric and fluorimetric methods, respectively. The detection and quantitation limits achieved with the spectrophotometric method were 0.0016 and 0.0053 mg mL(-1), respectively. The fluorimetric method provided the detection limit of 0.0013 mg mL(-1) and limit of quantitation of 0.0043 mg mL(-1). The RSD did not exceed 5% and 2% (n=10), correspondingly. A sample throughput of approx. 14 h(-1) for the spectrophotometric and 68 h(-1) for the fluorimetric detection was achieved. Both methods proved to be suitable for the determination of propofol in pharmaceutical formulation with average recovery values of 98.1 and 98.5%. © 2013 Elsevier B.V. All rights reserved.

Single peak parameters technique for simultaneous measurements: Spectrophotometric sequential injection determination of Fe(II) and Fe(III).

PubMed

Kozak, J; Paluch, J; Węgrzecka, A; Kozak, M; Wieczorek, M; Kochana, J; Kościelniak, P

2016-02-01

Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of a single peak. In the developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into a holding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming a more stable colorless compound with Fe(III), a complex signal is registered. Measurements are performed at wavelength 530 nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2 min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04-4.00 and 0.1-5.00 mg L(-1), with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09 mg L(-1) for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Combined Simultaneous and Sequential Endostar and Cisplatin Treatment in a Mice Model of Gastric Cancer Peritoneal Metastases.

PubMed

Jia, Lin; Ren, Shuguang; Li, Tao; Wu, Jianing; Zhou, Xinliang; Zhang, Yan; Wu, Jianhua; Liu, Wei

2017-01-01

Objective . Aimed to study the effects of endostar and cisplatin using an in vivo imaging system (IVIS) in a model of peritoneal metastasis of gastric cancer. Methods . NUGC-4 gastric cancer cells transfected with luciferase gene (NUGC-4-Luc) were injected i.p. into nude mice. One week later, mice were randomly injected i.p.: group 1, cisplatin (d1-3) + endostar (d4-7); group 2, endostar (d1-4) + cisplatin (d5-7); group 3, endostar + cisplatin d1, 4, and 7; group 4, saline for two weeks. One week after the final administration, mice were sacrificed. Bioluminescent data, microvessel density (MVD), and lymphatic vessel density (LVD) were analyzed. Results . Among the four groups, there were no significant differences in the weights and in the number of cancer cell photons on days 1 and 8 ( P > 0.05). On day 15, the numbers in groups 3 and 1 were less than that in group 2 ( P < 0.05). On day 21, group 3 was significantly less than group 2 ( P < 0.05). MVD of group 4 was less than that of groups 1 and 2 ( P < 0.01). There was no significant difference between groups 2 and 3 ( P > 0.05) or in LVD number among the four groups ( P > 0.05). Conclusions . IVIS® was more useful than weight, volume of ascites, and number of peritoneal nodules. The simultaneous group was superior to sequential groups in killing cancer cells and inhibiting vascular endothelium. Cisplatin-endostar was superior to endostar-cisplatin in killing cancer cells, while the latter in inhibiting peritoneal vascular endothelium.

A novel dual-valve sequential injection manifold (DV-SIA) for automated liquid-liquid extraction. Application for the determination of picric acid.

PubMed

Skrlíková, Jana; Andruch, Vasil; Sklenárová, Hana; Chocholous, Petr; Solich, Petr; Balogh, Ioseph S

2010-05-07

A novel dual-valve sequential injection system (DV-SIA) for online liquid-liquid extraction which resolves the main problems of LLE utilization in SIA has been designed. The main idea behind this new design was to construct an SIA system by connecting two independent units, one for aqueous-organic mixture flow and the second specifically for organic phase flow. As a result, the DV-SIA manifold consists of an Extraction unit and a Detection unit. Processing a mixture of aqueous-organic phase in the Extraction unit and a separated organic phase in the Detection unit solves the problems associated with the change of phases having different affinities to the walls of the Teflon tubing used in the SI-system. The developed manifold is a simple, user-friendly and universal system built entirely from commercially available components. The system can be used for a variety of samples and organic solvents and is simple enough to be easily handled by operators less familiar with flow systems. The efficiency of the DV-SIA system is demonstrated by the extraction of picric acid in the form of an ion associate with 2-[2-(4-methoxy-phenylamino)-vinyl]-1,3,3-trimethyl-3H-indolium reagent, with subsequent spectrophotometric detection. The suggested DV-SIA concept can be expected to stimulate new experiments in analytical laboratories and can be applied to the elaboration of procedures for the determination of other compounds extractable by organic solvents. It could thus form a basis for the design of simple, single-purpose commercial instruments used in LLE procedures. 2010 Elsevier B.V. All rights reserved.

The Dependency in the Elasticity of the Saccharomyces cerevisiae Cell Wall upon Cell Viability and Membrane Integrity

NASA Astrophysics Data System (ADS)

McPherson, Dacia; Zhu, Chenhui; Yi, Youngwoo; Clark, Noel

2007-03-01

In this study the elastic spring constant of the yeast cell wall is probed with the atomic force microscope (AFM) under variable conditions. Cells were sequentially analyzed in rich growth medium (YPD), a 0.8 M NaCl rich growth medium solution and an injection of 0.01% sodium azide solution. Cells in late log phase, which have variable diameters within three to five microns, were immobilized on a patterned silicon substrate with holes approximately 3.8um in diameter and 1.5um deep that was functionalized with polyethylenimine prior to cell application. Force curves were taken moving laterally across the cell in one dimension after exposure to each medium. Spring constants of the cells, calculated from force curves, displayed a positional dependency and marked differences in high osmolarity medium and after the injection of sodium azide. This study demonstrates the ability of the AFM to investigate changes in cell morphology and correlate those findings to underlying physiological processes.

EMC3-EIRENE modelling of toroidally-localized divertor gas injection experiments on Alcator C-Mod

DOE PAGES

Lore, Jeremy D.; Reinke, M. L.; LaBombard, Brian; ...

2014-09-30

Experiments on Alcator C-Mod with toroidally and poloidally localized divertor nitrogen injection have been modeled using the three-dimensional edge transport code EMC3-EIRENE to elucidate the mechanisms driving measured toroidal asymmetries. In these experiments five toroidally distributed gas injectors in the private flux region were sequentially activated in separate discharges resulting in clear evidence of toroidal asymmetries in radiated power and nitrogen line emission as well as a ~50% toroidal modulation in electron pressure at the divertor target. The pressure modulation is qualitatively reproduced by the modelling, with the simulation yielding a toroidal asymmetry in the heat flow to the outermore » strike point. Finally, toroidal variation in impurity line emission is qualitatively matched in the scrape-off layer above the strike point, however kinetic corrections and cross-field drifts are likely required to quantitatively reproduce impurity behavior in the private flux region and electron temperatures and densities directly in front of the target.« less

Dose-dependent biodistribution of prenatal exposure to rutile-type titanium dioxide nanoparticles on mouse testis

NASA Astrophysics Data System (ADS)

Kubo-Irie, Miyoko; Uchida, Hiroki; Mastuzawa, Shotaro; Yoshida, Yasuko; Shinkai, Yusuke; Suzuki, Kenichiro; Yokota, Satoshi; Oshio, Shigeru; Takeda, Ken

2014-02-01

Titanium dioxide nanoparticles (nano-TiO2), believed to be inert and safe, are used in many products especially rutile-type in cosmetics. Detection, localization, and count of nanoparticles in tissue sections are of considerable current interest. Here, we evaluate the dose-dependent biodistribution of rutile-type nano-TiO2 exposure during pregnancy on offspring testes. Pregnant mice were subcutaneously injected five times with 0.1 ml of sequentially diluted of nano-TiO2 powder, 35 nm with primary diameter, suspensions (1, 10, 100, or 1,000 μg/ml), and received total doses of 0.5, 5, 50, and 500 μg, respectively. Prior to injection, the size distribution of nano-TiO2 was analyzed by dynamic light scattering measurement. The average diameter was increased in a dose-dependent manner. The most diluted concentration, 1 μg/ml suspension, contained small agglomerates averaging 193.3 ± 5.4 nm in diameter. The offspring testes were examined at 12 weeks postpartum. Individual particle analysis in testicular sections under scanning and transmission electron microscopy enabled us to understand the biodistribution. The correlation between nano-TiO2 doses injected to pregnant mice, and the number of agglomerates in the offspring testes was demonstrated to be dose-dependent by semiquantitative evaluation. However, the agglomerate size was below 200 nm in the testicular sections of all recipient groups, independent from the injected dose during pregnancy.

Mathematical modeling heat and mass transfer processes in porous media

NASA Astrophysics Data System (ADS)

Akhmed-Zaki, Darkhan

2013-11-01

On late development stages of oil-fields appears a complex problem of oil-recovery reduction. One of solution approaches is injecting of surfactant together with water in the form of active impurities into the productive layer - for decreasing oil viscosity and capillary forces between ``oil-water'' phases system. In fluids flow the surfactant can be in three states: dissolved in water, dissolved in oil and adsorbed on pore channels' walls. The surfactant's invasion into the reservoir is tracked by its diffusion with reservoir liquid and mass-exchange with two phase (liquid and solid) components of porous structure. Additionally, in this case heat exchange between fluids (injected, residual) and framework of porous medium has practical importance for evaluating of temperature influences on enhancing oil recovery. Now, the problem of designing an adequate mathematical model for describing a simultaneous flowing heat and mass transfer processes in anisotropic heterogeneous porous medium -surfactant injection during at various temperature regimes has not been fully researched. In this work is presents a 2D mathematical model of surfactant injections into the oil reservoir. Description of heat- and mass transfer processes in a porous media is done through differential and kinetic equations. For designing a computational algorithm is used modify version of IMPES method. The sequential and parallel computational algorithms are developed using an adaptive curvilinear meshes which into account heterogeneous porous structures. In this case we can evaluate the boundaries of our process flows - fronts (``invasion'', ``heat'' and ``mass'' transfers), according to the pressure, temperature, and concentration gradient changes.

Superparamagnetic And Paramagnetic MRI Contrast Agents: Application Of Rapid Magnetic Resonance Imaging To Assess Renal Function

NASA Astrophysics Data System (ADS)

Carvlin, Mark J.; Renshaw, Perry F.; Arger, Peter; Kundel, Harold L.; Dougherty, Larry; Axel, Leon; Kassab, Eleanor; Moore, Bethanne

1988-06-01

The paramagnetic chelate complex, gadolinium-diethylene-triamine-pentaacetic acid, Gd-DTPA, and superparamagnetic particles, such as those composed of dextran coated magnetite, function as magnetic resonance contrast agents by changing the relaxation rates, 1/T1 and 1/T2. The effects that these agents have upon MR signal intensity are determined by: the inherent biophysical properties of the tissue being imaged, the concentration of the contrast agent and the data acquisition scheme (pulse sequence parameters) employed. Following the time course of MR signal change in the first minutes after the injection of contrast agent(s) allows a dynamic assessment of organ functions in a manner analogous to certain nuclear medicine studies. In order to study renal function, sequential MR fast scan images, gradient echo (TR=35/TE=7 msec, flip angle=25 degrees), were acquired, one every 12 seconds, after intravenous injection of Gd-DTPA and/or dextran-magnetite. Gd-DTPA, which is freely filtered at the glomerulus and is neither secreted nor reabsorbed, provides information concerning renal perfusion, glomerular filtration and tubular concentrating ability. Dextran-magnetite (200 A diameter), which is primarily contained within the intravascular space shortly after injection, provides information on blood flow to and distribution within the kidney. The MR signal change observed after administration of contrast agents varied dramatically depending upon the agents injected and the imaging parameters used. Hence a broad range of physiolgic processes may be described using these techniques, i.e. contrast agent enhanced functional MR examinations.

Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

PubMed

Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

2017-11-01

A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of severe scorpion envenoming following subcutaneous venom injection into dogs: Hemodynamic and concentration/effect analysis.

PubMed

Elatrous, Souheil; Ouanes-Besbes, Lamia; Ben Sik-Ali, Habiba; Hamouda, Zineb; BenAbdallah, Saoussen; Tilouche, Nejla; Jalloul, Faten; Fkih-Hassen, Mohamed; Dachraoui, Fahmi; Ouanes, Islem; Abroug, Fekri

2015-09-15

To evaluate the dose-effects of Androctonus australis hector (Aah) venom injected subcutaneously on hemodynamics and neurohormonal secretions, 10 anesthetized and ventilated mongrel dogs, were split in two groups (n = 5/group). Subcutaneous injection was done with either 0.2 mg/kg or 0.125 mg/kg of the purified G50 scorpion toxic fraction. Hemodynamic parameters using right heart catheter were recorded and plasma concentrations of catecholamine, troponin, and serum toxic fraction were measured sequentially from baseline to 120 min. We identified the dose of toxic fraction evoking characteristic hemodynamic perturbation of severe envenomation, the time-lapse to envenomation, and the associated plasma level. The injection of 0.125 mg/kg toxic fraction was not associated with significant variations in hemodynamic parameters, whereas the 0.2 mg/kg dose caused envenomation characterized by significant increase in plasma catecholamines, increased pulmonary artery occluded pressure, mean arterial pressure, and systemic vascular resistance (p < 0.05), in association with sustained decline in cardiac output (p < 0.001). Envenomation occurred by the 30th minute, and the corresponding concentration of toxic fraction was 1.14 ng/ml. The current experiment allowed the identification of the sub-lethal dose (0.2 mg/kg) of the toxic fraction of Aah administered by the subcutaneous route. Two parameters with potential clinical relevance were also uncovered: the time-lapse to envenomation and the corresponding concentration of toxic fraction. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Interactive Excel Program for Tracking a Single Droplet in Crossflow Computation

NASA Technical Reports Server (NTRS)

Urip, E.; Yang, S. L.; Marek, C. J.

2002-01-01

Spray jet in crossflow has been a subject of research because of its wide application in systems involving pollutant dispersion, jet mixing in the dilution zone of combustors, and fuel injection strategies. The focus of this work is to investigate dispersion of a 2-dimensional atomized spray jet into a 2-dimensional crossflow. A quick computational method is developed using available software. The spreadsheet can be used for any 2D droplet trajectory problem where the drop is injected into the free stream eventually coming to the free stream conditions. During the transverse injection of a spray into high velocity airflow, the droplets (carried along and deflected by a gaseous stream of co-flowing air) are subjected to forces that affect their motion in the flow field. Based on the Newton's Second Law of motion, four ordinary differential equations were used. These equations were then solved by a fourth-order Runge-Kutta method using Excel software. Visual basic programming and Excel macrocode to produce the data facilitate Excel software to plot graphs describing the droplet's motion in the flow field. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user's manual on how to use the program is also included in this report.

Automated tagging of pharmaceutically active thiols under flow conditions using monobromobimane.

PubMed

Tzanavaras, Paraskevas D; Karakosta, Theano D

2011-03-25

The thiol-specific derivatization reagent monobromobimane (MBB) is applied--for the first time--under flow conditions. Sequential injection analysis allows the handling of precise volumes of the reagent in the micro-liter range. The effect of the main chemical and instrumental variables was investigated using captopril (CAP), N-acetylcysteine (NAC) and penicillamine (PEN) as representative pharmaceutically active thiols. Previously reported hydrolysis of MBB due to interaction with nucleophilic components of the buffers was avoided kinetically under flow conditions. The proposed analytical scheme is suitable for the fluorimetric determination of thiols at a sampling rate of 36 h(-1). Copyright © 2010 Elsevier B.V. All rights reserved.

Procedural and Physical Interventions for Vaccine Injections: Systematic Review of Randomized Controlled Trials and Quasi-Randomized Controlled Trials.

PubMed

Taddio, Anna; Shah, Vibhuti; McMurtry, C Meghan; MacDonald, Noni E; Ipp, Moshe; Riddell, Rebecca Pillai; Noel, Melanie; Chambers, Christine T

2015-10-01

This systematic review evaluated the effectiveness of physical and procedural interventions for reducing pain and related outcomes during vaccination. Databases were searched using a broad search strategy to identify relevant randomized and quasi-randomized controlled trials. Data were extracted according to procedure phase (preprocedure, acute, recovery, and combinations of these) and pooled using established methods. A total of 31 studies were included. Acute infant distress was diminished during intramuscular injection without aspiration (n=313): standardized mean difference (SMD) -0.82 (95% confidence interval [CI]: -1.18, -0.46). Injecting the most painful vaccine last during vaccinations reduced acute infant distress (n=196): SMD -0.69 (95% CI: -0.98, -0.4). Simultaneous injections reduced acute infant distress compared with sequential injections (n=172): SMD -0.56 (95% CI: -0.87, -0.25). There was no benefit of simultaneous injections in children. Less infant distress during the acute and recovery phases combined occurred with vastus lateralis (vs. deltoid) injections (n=185): SMD -0.70 (95% CI: -1.00, -0.41). Skin-to-skin contact in neonates (n=736) reduced acute distress: SMD -0.65 (95% CI: -1.05, -0.25). Holding infants reduced acute distress after removal of the data from 1 methodologically diverse study (n=107): SMD -1.25 (95% CI: -2.05, -0.46). Holding after vaccination (n=417) reduced infant distress during the acute and recovery phases combined: SMD -0.65 (95% CI: -1.08, -0.22). Self-reported fear was reduced for children positioned upright (n=107): SMD -0.39 (95% CI: -0.77, -0.01). Non-nutritive sucking (n=186) reduced acute distress in infants: SMD -1.88 (95% CI: -2.57, -1.18). Manual tactile stimulation did not reduce pain across the lifespan. An external vibrating device and cold reduced pain in children (n=145): SMD -1.23 (95% CI: -1.58, -0.87). There was no benefit of warming the vaccine in adults. Muscle tension was beneficial in selected indices of fainting in adolescents and adults. Interventions with evidence of benefit in select populations include: no aspiration, injecting most painful vaccine last, simultaneous injections, vastus lateralis injection, positioning interventions, non-nutritive sucking, external vibrating device with cold, and muscle tension.

Stability of tacrolimus solutions in polyolefin containers.

PubMed

Lee, Jun H; Goldspiel, Barry R; Ryu, Sujung; Potti, Gopal K

2016-02-01

Results of a study to determine the stability of tacrolimus solutions stored in polyolefin containers under various temperature conditions are reported. Triplicate solutions of tacrolimus (0.001, 0.01, and 0.1 mg/mL) in 0.9% sodium chloride injection or 5% dextrose injection were prepared in polyolefin containers. Some samples were stored at room temperature (20-25 °C); others were refrigerated (2-8 °C) for 20 hours and then stored at room temperature for up to 28 hours. The solutions were analyzed by stability-indicating high-performance liquid chromatography (HPLC) assay at specified time points over 48 hours. Solution pH was measured and containers were visually inspected at each time point. Stability was defined as retention of at least 90% of the initial tacrolimus concentration. All tested solutions retained over 90% of the initial tacrolimus concentration at all time points, with the exception of the 0.001-mg/mL solution prepared in 0.9% sodium chloride injection, which was deemed unstable beyond 24 hours. At all evaluated concentrations, mean solution pH values did not change significantly over 48 hours; no particle formation was detected. During storage in polyolefin bags at room temperature, a 0.001-mg/mL solution of tacrolimus was stable for 24 hours when prepared in 0.9% sodium chloride injection and for at least 48 hours when prepared in 5% dextrose injection. Solutions of 0.01 and 0.1 mg/mL prepared in either diluent were stable for at least 48 hours, and the 0.01-mg/mL tacrolimus solution was also found to be stable throughout a sequential temperature protocol. Copyright © 2016 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Small-scale enzymatic digestion of glycoproteins and proteoglycans for analysis of oligosaccharides by LC-MS and FACE gel electrophoresis.

PubMed

Estrella, Ruby P; Whitelock, John M; Roubin, Rebecca H; Packer, Nicolle H; Karlsson, Niclas G

2009-01-01

Structural characterization of oligosaccharides from proteoglycans and other glycoproteins is greatly enhanced through the use of mass spectrometry and gel electrophoresis. Sample preparation for these sensitive techniques often requires enzymatic treatments to produce oligosaccharide sequences for subsequent analysis. This chapter describes several small-scale methods for in-gel, on-blot, and in-solution enzymatic digestions in preparation for graphitized carbon liquid chromatography-mass spectrometry (LC-MS) analysis, with specific applications indicated for glycosaminoglycans (GAGs) and N-linked oligosaccharides. In addition, accompanying procedures for oligosaccharide reduction by sodium borohydride, sample desalting via carbon microcolumn, desialylation by sialidase enzyme treatment, and small-scale oligosaccharide species fractionation are included. Fluorophore-assisted carbohydrate electrophoresis (FACE) is another useful method to isolate derivatized oligosaccharides. Overall, the modularity of these techniques provides ease and flexibility for use in conjunction with mass spectrometric and electrophoretic tools for glycomic research studies.

Activity-dependent stochastic resonance in recurrent neuronal networks

NASA Astrophysics Data System (ADS)

Volman, Vladislav

2009-03-01

An important source of noise for neuronal networks is that of the stochastic nature of synaptic transmission. In particular, there can occur spontaneous asynchronous release of neurotransmitter at a rate that is strongly dependent on the presynaptic Ca2+ concentration and hence strongly dependent on the rate of spike induced Ca2+. Here it is shown that this noise can lead to a new form of stochastic resonance for local circuits consisting of roughly 100 neurons - a ``microcolumn''- coupled via noisy plastic synapses. Furthermore, due to the plastic coupling and activity-dependent noise component, the detection of weak stimuli will also depend on the structure of the latter. In addition, the circuit can exhibit short-term memory, by which we mean that spiking will continue to occur for a transient period following removal of the stimulus. These results can be directly tested in experiments on cultured networks.

The controlled growth of GaN microrods on Si(111) substrates by MOCVD

NASA Astrophysics Data System (ADS)

Foltynski, Bartosz; Garro, Nuria; Vallo, Martin; Finken, Matthias; Giesen, Christoph; Kalisch, Holger; Vescan, Andrei; Cantarero, Andrés; Heuken, Michael

2015-03-01

In this paper, a selective area growth (SAG) approach for growing GaN microrods on patterned SiNx/Si(111) substrates by metal-organic chemical vapor deposition (MOCVD) is studied. The surface morphology, optical and structural properties of vertical GaN microrods terminated by pyramidal shaped facets (six { 10 1 bar 1} planes) were characterized using scanning electron microscopy (SEM), room temperature photoluminescence (PL) and Raman spectroscopy, respectively. Measurements revealed high-quality GaN microcolumns grown with silane support. Characterized structures were grown nearly strain-free (central frequency of Raman peak of 567±1 cm-1) with crystal quality comparable to bulk crystals (FWHM=4.2±1 cm-1). Such GaN microrods might be used as a next-generation device concept for solid-state lighting (SSL) applications by realizing core-shell InGaN/GaN multi-quantum wells (MQWs) on the n-GaN rod base.

A SEQUENTIAL, MULTIPLE-TREATMENT, TARGETED APPROACH TO REDUCE WOUND HEALING AND FAILURE OF GLAUCOMA FILTRATION SURGERY IN A RABBIT MODEL (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

PubMed Central

Sherwood, Mark Brian

2006-01-01

Purpose The purpose of this study was to evaluate the concept of targeting mediators of the scarring process at multiple points across the course of bleb failure, in order to prolong bleb survival. Methods There were three linked parts to the experiment. In the first part, a cannula glaucoma filtration surgery (GFS) was performed on 32 New Zealand White (NZW) rabbits, and bleb survival was assessed for six different regimens plus controls by grading bleb height and width. For the second part of the study, the same GFS surgery was performed on an additional 10 NZW rabbits. Two additional filtering blebs were treated with balanced saline solution (BSS), two received mitomycin-C (MMC) (0.4 mg/mL), and for the remaining six, a sequential regimen was given consisting of 200 mmol/L mannose-6-phosphate (M-6-P) solution at the time of surgery, followed by subconjunctival injections of antibody to connective tissue growth factor at days 2 and 4, and Ilomastat, a broad-spectrum matrix metalloproteinase inhibitor, at days 7, 12, and 20 postoperatively. Bleb survival was again assessed. In the final part of the experiment, blebs treated with either BSS, MMC, or the above sequential multitreatment regimen were examined histologically at 14 days postoperatively in three additional NZW rabbits. Results All six individual therapies selected resulted in some improvement of bleb survival compared to BSS control. Blebs treated with the new sequential, multitreatment protocol survived an average of 29 days (regression slope, P < .0001 compared to control), those receiving BSS an average of 17 days, and those treated with MMC (0.4 mg/mL) an average of 36 days. The sequential, multitreatment regimen was significantly superior to any of the six monotherapies for time to zero analysis (flattening) of the bleb (P < .002). Histologic examination of the bleb tissues showed a markedly less epithelial thinning, subepithelial collagen thinning, and goblet cell loss in the multitreatment group, when compared with the MMC blebs. Conclusions In a rabbit model of GFS, a sequential, targeted, multitreatment approach prolonged bleb survival compared to BSS controls and decreased bleb tissue morphological changes when compared to those treated with MMC. It is not known whether these findings can be reproduced in humans, and further work is needed to determine an optimum regimen and timing of therapeutic delivery. PMID:17471357

Monitoring variations of dimethyl sulfide and dimethylsulfoniopropionate in seawater and the atmosphere based on sequential vapor generation and ion molecule reaction mass spectrometry.

PubMed

Iyadomi, Satoshi; Ezoe, Kentaro; Ohira, Shin-Ichi; Toda, Kei

2016-04-01

To monitor the fluctuations of dimethyl sulfur compounds at the seawater/atmosphere interface, an automated system was developed based on sequential injection analysis coupled with vapor generation-ion molecule reaction mass spectrometry (SIA-VG-IMRMS). Using this analytical system, dissolved dimethyl sulfide (DMS(aq)) and dimethylsulfoniopropionate (DMSP), a precursor to DMS in seawater, were monitored together sequentially with atmospheric dimethyl sulfide (DMS(g)). A shift from the equilibrium point between DMS(aq) and DMS(g) results in the emission of DMS to the atmosphere. Atmospheric DMS emitted from seawater plays an important role as a source of cloud condensation nuclei, which influences the oceanic climate. Water samples were taken periodically and dissolved DMS(aq) was vaporized for analysis by IMRMS. After that, DMSP was hydrolyzed to DMS and acrylic acid, and analyzed in the same manner as DMS(aq). The vaporization behavior and hydrolysis of DMSP to DMS were investigated to optimize these conditions. Frequent (every 30 min) determination of the three components, DMS(aq)/DMSP (nanomolar) and DMS(g) (ppbv), was carried out by SIA-VG-IMRMS. Field analysis of the dimethyl sulfur compounds was undertaken at a coastal station, which succeeded in showing detailed variations of the compounds in a natural setting. Observed concentrations of the dimethyl sulfur compounds both in the atmosphere and seawater largely changed with time and similar variations were repeatedly observed over several days, suggesting diurnal variations in the DMS flux at the seawater/atmosphere interface.

Single-Cell Resolution Imaging of Retinal Ganglion Cell Apoptosis In Vivo Using a Cell-Penetrating Caspase-Activatable Peptide Probe

PubMed Central

Qiu, Xudong; Johnson, James R.; Wilson, Bradley S.; Gammon, Seth T.; Piwnica-Worms, David; Barnett, Edward M.

2014-01-01

Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models. PMID:24586415

Determination of essential elements in beverages, herbal infusions and dietary supplements using a new straightforward sequential approach based on flame atomic absorption spectrometry.

PubMed

Gómez-Nieto, Beatriz; Gismera, Mª Jesús; Sevilla, Mª Teresa; Procopio, Jesús R

2017-03-15

A simple method based on FAAS was developed for the sequential multi-element determination of Cu, Zn, Mn, Mg and Si in beverages and food supplements with successful results. The main absorption lines for Cu, Zn and Si and secondary lines for Mn and Mg were selected to carry out the measurements. The sample introduction was performed using a flow injection system. Using the choice of the absorption line wings, the upper limit of the linear range increased up to 110mgL -1 for Mg, 200mgL -1 for Si and 13mgL -1 for Zn. The determination of the five elements was carried out, in triplicate, without the need of additional sample dilutions and/or re-measurements, using less than 3.5mL of sample to perform the complete analysis. The LODs were 0.008mgL -1 for Cu, 0.017mgL -1 for Zn, 0.011mgL -1 for Mn, 0.16mgL -1 for Si and 0.11mgL -1 for Mg. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrologic and geochemical data assimilation at the Hanford 300 Area

NASA Astrophysics Data System (ADS)

Chen, X.; Hammond, G. E.; Murray, C. J.; Zachara, J. M.

2012-12-01

In modeling the uranium migration within the Integrated Field Research Challenge (IFRC) site at the Hanford 300 Area, uncertainties arise from both hydrologic and geochemical sources. The hydrologic uncertainty includes the transient flow boundary conditions induced by dynamic variations in Columbia River stage and the underlying heterogeneous hydraulic conductivity field, while the geochemical uncertainty is a result of limited knowledge of the geochemical reaction processes and parameters, as well as heterogeneity in uranium source terms. In this work, multiple types of data, including the results from constant-injection tests, borehole flowmeter profiling, and conservative tracer tests, are sequentially assimilated across scales within a Bayesian framework to reduce the hydrologic uncertainty. The hydrologic data assimilation is then followed by geochemical data assimilation, where the goal is to infer the heterogeneous distribution of uranium sources using uranium breakthrough curves from a desorption test that took place at high spring water table. We demonstrate in our study that Ensemble-based data assimilation techniques (Ensemble Kalman filter and smoother) are efficient in integrating multiple types of data sequentially for uncertainty reduction. The computational demand is managed by using the multi-realization capability within the parallel PFLOTRAN simulator.

Statistical physics approaches to Alzheimer's disease

NASA Astrophysics Data System (ADS)

Peng, Shouyong

Alzheimer's disease (AD) is the most common cause of late life dementia. In the brain of an AD patient, neurons are lost and spatial neuronal organizations (microcolumns) are disrupted. An adequate quantitative analysis of microcolumns requires that we automate the neuron recognition stage in the analysis of microscopic images of human brain tissue. We propose a recognition method based on statistical physics. Specifically, Monte Carlo simulations of an inhomogeneous Potts model are applied for image segmentation. Unlike most traditional methods, this method improves the recognition of overlapped neurons, and thus improves the overall recognition percentage. Although the exact causes of AD are unknown, as experimental advances have revealed the molecular origin of AD, they have continued to support the amyloid cascade hypothesis, which states that early stages of aggregation of amyloid beta (Abeta) peptides lead to neurodegeneration and death. X-ray diffraction studies reveal the common cross-beta structural features of the final stable aggregates-amyloid fibrils. Solid-state NMR studies also reveal structural features for some well-ordered fibrils. But currently there is no feasible experimental technique that can reveal the exact structure or the precise dynamics of assembly and thus help us understand the aggregation mechanism. Computer simulation offers a way to understand the aggregation mechanism on the molecular level. Because traditional all-atom continuous molecular dynamics simulations are not fast enough to investigate the whole aggregation process, we apply coarse-grained models and discrete molecular dynamics methods to increase the simulation speed. First we use a coarse-grained two-bead (two beads per amino acid) model. Simulations show that peptides can aggregate into multilayer beta-sheet structures, which agree with X-ray diffraction experiments. To better represent the secondary structure transition happening during aggregation, we refine the model to four beads per amino acid. Typical essential interactions, such as backbone hydrogen bond, hydrophobic and electrostatic interactions, are incorporated into our model. We study the aggregation of Abeta16-22, a peptide that can aggregate into a well-ordered fibrillar structure in experiments. Our results show that randomly-oriented monomers can aggregate into fibrillar subunits, which agree not only with X-ray diffraction experiments but also with solid-state NMR studies. Our findings demonstrate that coarse-grained models and discrete molecular dynamics simulations can help researchers understand the aggregation mechanism of amyloid peptides.

Coupled Reactive Transport Modeling of CO2 Injection in Mt. Simon Sandstone Formation, Midwest USA

NASA Astrophysics Data System (ADS)

Liu, F.; Lu, P.; Zhu, C.; Xiao, Y.

2009-12-01

CO2 sequestration in deep geological formations is one of the promising options for CO2 emission reduction. While several large scale CO2 injections in saline aquifers have shown to be successful for the short-term, there is still a lack of fundamental understanding on key issues such as CO2 storage capacity, injectivity, and security over multiple spatial and temporal scales that need to be addressed. To advance these understandings, we applied multi-phase coupled reactive mass transport modeling to investigate the fate of injected CO2 and reservoir responses to the injection into Mt. Simon Formation. We developed both 1-D and 2-D reactive transport models in a radial region of 10,000 m surrounding a CO2 injection well to represent the Mt. Simon sandstone formation, which is a major regional deep saline reservoir in the Midwest, USA. Supercritical CO2 is injected into the formation for 100 years, and the modeling continues till 10,000 years to monitor both short-term and long-term behavior of injected CO2 and the associated rock-fluid interactions. CO2 co-injection with H2S and SO2 is also simulated to represent the flue gases from coal gasification and combustion in the Illinois Basin. The injection of CO2 results in acidified zones (pH ~3 and 5) adjacent to the wellbore, causing progressive water-rock interactions in the surrounding region. In accordance with the extensive dissolution of authigenic K-feldspar, sequential precipitations of secondary carbonates and clay minerals are predicted in this zone. The vertical profiles of CO2 show fingering pattern from the top of the reservoir to the bottom due to the density variation of CO2-impregnated brine, which facilitate convection induced mixing and solubility trapping. Most of the injected CO2 remains within a radial distance of 2500 m at the end of 10,000 years and is sequestered and immobilized by solubility and residual trapping. Mineral trapping via secondary carbonates, including calcite, magnesite, ankerite and dawsonite, is predicted, but only constituting a minor component as compared to other trapping mechanisms. The mineral alteration induced by CO2 injection results in changes in porosity/permeability due to these complex mineral dissolution and precipitation reactions. Increases in porosity (from 15% to 16.2%) occur in the low-pH zones due to the acidic dissolution of minerals. However, within the carbonate mineral trapping zone, porosity reduction occurs. Co-injection of H2S causes relatively limited modification from the CO2 alone case while significantly higher water-rock reactivity is associated with the SO2 co-injection. Although co-injection of CO2 with H2S and SO2 could potentially reduce separation and injection cost, it may lead to some uncertainty and risks and therefore require further investigation.

A study of effects of electrode contacts on performance of organic-based light-emitting field-effect transistors

NASA Astrophysics Data System (ADS)

Kim, Dae-Kyu; Choi, Jong-Ho

2018-02-01

Herein is presented a comparative performance analysis of heterojunction organic-based light-emitting field-effect transistors (OLEFETs) with symmetric (Au only) and asymmetric (Au and LiF/Al) electrode contacts. The devices had a top source-drain contact with long-channel geometry and were produced by sequentially depositing p-type pentacene and n-type N,N‧-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13) using a neutral cluster beam deposition apparatus. The spectroscopic, structural and morphological properties of the organic thin films were examined using photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) method, laser scanning confocal and atomic force microscopy (LSCM, AFM). Based upon the growth of high-quality, well-packed crystalline thin films, the devices demonstrated ambipolar field-effect characteristics, stress-free operational stability, and light emission under ambient conditions. Various device parameters were derived from the fits of the observed characteristics. The hole mobilities were nearly equal irrespective of the electrode contacts, whereas the electron mobilities of the transistors with LiF/Al drain electrodes were higher due to the low injection barrier. For the OLEFETs with symmetric electrodes, electroluminescence (EL) occurred only in the vicinity of the hole-injecting electrode, whereas for the OLEFETs with asymmetric electrodes, the emission occurred in the vicinity of both hole- and electron-injecting electrodes. By tuning the carrier injection and transport through high- and low-work function metals, the hole-electron recombination sites could be controlled. The operating conduction and light emission mechanism are discussed with the aid of EL images obtained using a charge-coupled device (CCD) camera.

A Critical Review of the Impacts of Leaking CO 2 Gas and Brine on Groundwater Quality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qafoku, Nikolla; Zheng, Liange; Bacon, Diana H.

2015-09-30

Geological carbon sequestration (GCS) is a global carbon emission reduction strategy involving the capture of CO 2 emitted from fossil fuel burning power plants, as well as the subsequent injection of the captured CO 2 gas into deep saline aquifers or depleted oil and gas reservoirs. A critical question that arises from the proposed GCS is the potential impacts of CO 2 injection on the quality of drinking-water systems overlying CO 2 sequestration storage sites. Although storage reservoirs are evaluated and selected based on their ability to safely and securely store emplaced fluids, leakage of CO 2 from storage reservoirsmore » is a primary risk factor and potential barrier to the widespread acceptance of geologic CO 2 sequestration (OR Harvey et al. 2013; Y-S Jun et al. 2013; DOE 2007). Therefore, a systematic understanding of how CO 2 leakage would affect the geochemistry of potable aquifers, and subsequently control or affect elemental and contaminant release via sequential and/or simultaneous abiotic and biotic processes and reactions is vital.« less

Investigation of Multiphase Flow in a Packed Bed Reactor Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Lian, Yongsheng; Motil, Brian; Rame, Enrique

2016-01-01

In this paper we study the two-phase flow phenomena in a packed bed reactor using an integrated experimental and numerical method. The cylindrical bed is filled with uniformly sized spheres. In the experiment water and air are injected into the bed simultaneously. The pressure distribution along the bed will be measured. The numerical simulation is based on a two-phase flow solver which solves the Navier-Stokes equations on Cartesian grids. A novel coupled level set and moment of fluid method is used to construct the interface. A sequential method is used to position spheres in the cylinder. Preliminary experimental results showed that the tested flow rates resulted in pulse flow. The numerical simulation revealed that air bubbles could merge into larger bubbles and also could break up into smaller bubbles to pass through the pores in the bed. Preliminary results showed that flow passed through regions where the porosity is high. Comparison between the experimental and numerical results in terms of pressure distributions at different flow injection rates will be conducted. Comparison of flow phenomena under terrestrial gravity and microgravity will be made.

Stochastic Model of Fracture Frequency Heterogeneity in a Welded Tuff EGS reservoir, Snake River Plain, Idaho, USA

NASA Astrophysics Data System (ADS)

Moody, A.; Fairley, J. P., Jr.

2014-12-01

In light of recent advancements in reservoir enhancement and injection tests at active geothermal fields, there is interest in investigating the geothermal potential of widespread subsurface welded tuffs related to caldera collapse on the Snake River Plain (SRP). Before considering stimulation strategies, simulating heat extraction from the reservoir under in-situ fracture geometries will give a first-order estimation of extractable heat. With only limited deep boreholes drilled on the SRP, few analyses of the bulk hydrologic properties of the tuffs exist. Acknowledging the importance of the spatial heterogeneity of fractures to the permeability and injectivity of reservoirs hosted in impermeable volcanic units, we present fracture distributions from ICDP hole 5036-2A drilled as a part of Project HOTSPOT. The core documents more than 1200 m of largely homogeneous densely welded tuff hosting an isothermal warm-water reservoir at ~60˚ C. Multiple realizations of a hypothetical reservoir are created using sequential indicator algorithms that honor the observed vertical fracture frequency statistics. Results help form criteria for producing geothermal energy from the SRP.

Automatic instrument for chemical processing to detect microorganism in biological samples by measuring light reactions

NASA Technical Reports Server (NTRS)

Kelbaugh, B. N.; Picciolo, G. L.; Chappelle, E. W.; Colburn, M. E. (Inventor)

1973-01-01

An automated apparatus is reported for sequentially assaying urine samples for the presence of bacterial adenosine triphosphate (ATP) that comprises a rotary table which carries a plurality of sample containing vials and automatically dispenses fluid reagents into the vials preparatory to injecting a light producing luciferase-luciferin mixture into the samples. The device automatically measures the light produced in each urine sample by a bioluminescence reaction of the free bacterial adenosine triphosphate with the luciferase-luciferin mixture. The light measured is proportional to the concentration of bacterial adenosine triphosphate which, in turn, is proportional to the number of bacteria present in the respective urine sample.

Anterograde and retrograde tracing with high molecular weight biotinylated dextran amine through thalamocortical and corticothalamic pathways.

PubMed

Zhang, Wenjie; Xu, Dongsheng; Cui, Jingjing; Jing, Xianghong; Xu, Nenggui; Liu, Jianhua; Bai, Wanzhu

2017-02-01

Biotinylated dextran amine (BDA) has been used for neural pathway tracing in the central nervous system for many decades, in which high molecular weight BDA appeared to be transported predominantly in the anterograde direction and less in the retrograde direction. In the current study, we reexamined the properties of neural labeling with high molecular weight BDA through a reciprocal neural pathway between thalamus and somatosensory cortex. After injection of BDA into the ventral posteromedial nucleus of thalamus (VPM) in the rat, the BDA labeling was sequentially examined on somatosensory cortex at 3, 5, 7, 10, and 14 survival days. Both of anterogradely labeled axonal terminals and retrogradely labeled neuronal cell bodies were observed simultaneously on the somatosensory cortex. With the increasing of survival times after injection, morphological changes occurred on the labeled axonal arbors and neuronal dendrites, in which the high quality of BDA labeling appeared on the tenth survival day. These results indicate that high molecular weight BDA is not only a sensitive anterograde tracer but also an excellent retrograde marker to be used for tracing through thalamocortical and corticothalamic pathways. And the detailed structure of neural labeling with BDA similar to Golgi-like resolution can be obtained at optimal survival times of animals after the injection of high molecular weight BDA. © 2016 Wiley Periodicals, Inc.

A remediation performance model for enhanced metabolic reductive dechlorination of chloroethenes in fractured clay till

NASA Astrophysics Data System (ADS)

Manoli, Gabriele; Chambon, Julie C.; Bjerg, Poul L.; Scheutz, Charlotte; Binning, Philip J.; Broholm, Mette M.

2012-04-01

A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation efficiency and timeframe. A relatively simple approach is used to link the fermentation of the electron donor soybean oil to the sequential dechlorination of trichloroethene (TCE) while considering redox conditions and the heterogeneous clay till system (clay till matrix, fractures and sand stringers). The model is tested on lab batch experiments and applied to describe sediment core samples from a TCE-contaminated site. Model simulations compare favorably to field observations and demonstrate that dechlorination may be limited to narrow bioactive zones in the clay matrix around fractures and sand stringers. Field scale simulations show that the injected donor is expected to be depleted after 5 years, and that without donor re-injection contaminant rebound will occur in the high permeability zones and the mass removal will stall at 18%. Long remediation timeframes, if dechlorination is limited to narrow bioactive zones, and the need for additional donor injections to maintain dechlorination activity may limit the efficiency of ERD in low-permeability media. Future work should address the dynamics of the bioactive zones, which is essential to understand for predictions of long term mass removal.

Safety of three sequential whole bladder photodynamic therapy (WBPDT) treatments in the management of resistant bladder cancer

NASA Astrophysics Data System (ADS)

Mejia, Maria C.; Nseyo, Unyime O.

2009-02-01

INTRODUCTION: WBPDT has been used to treat resistant superficial bladder cancer, with clinical benefits and associated dose-dependent side effects. OBJECTIVE: The objective of this study was to assess the safety of three sequential WBPDT treatments in patients with resistant non-muscle invasive (NMI) bladder cancer. MATERIALS AND METHODS: 12 males and one female provided written informed consent in this Phase II study. Each patient received intravenous injection of Photofrin® (AXCAN Parma Inc, Canada) at 1.5 mg/kg two days prior to whole bladder laser (630nm) treatment. Assessment of safety and efficacy included weekly urinary symptoms; cystoscopy, biopsy and cytology; and measurement of bladder volume quarterly after each treatment at baseline, six and 12 months. Treatment #2 and/or #3 occurred only in the absence of bladder contracture, and/or disease progression. RESULTS: 13 patients: 12 males and one female have been enrolled and average age of enrollees is 67.1(52 - 87) years. Four patients had Ta-T1/Grade I-III tumors; two patients had CIS associated with T1/GI-III; and seven patients had carcinoma in situ (CIS) only. Three patients received 3/3 treatments, and are evaluable for toxicity; three patients received two treatments only; and seven patients received one treatment only. There was no bladder contracture; transient mild to moderate bladder irritative voiding symptoms of dysuria, urinary frequency, nocturia and urgency occurred in all patients. The three evaluable patients were without evidence of disease at average of 13.1 (7-20) months. CONCLUSION: Three sequential WBPDT treatments might have a favorable toxicity profile in the management of recurrent/ refractory non-muscle invasive bladder cancer.

Daily subcutaneous parecoxib injection for cancer pain: an open label pilot study.

PubMed

Kenner, David J; Bhagat, Sandeep; Fullerton, Sonia L

2015-04-01

Nonsteroidal anti-inflammatory analgesics (NSAIDs) are useful in cancer pain but the specific use of subcutaneous parecoxib has not been previously reported. This pilot study aimed to establish the efficacy and side effect profile of short-term sequential single daily dose subcutaneous parecoxib sodium in patients with severe cancer bone pain. Nineteen hospitalized patients with advanced cancer and uncontrolled malignant bone pain (9 males, 10 females) received 24 courses of one, two, or three days sequential therapy with 'off-label' daily subcutaneous parecoxib. All patients were receiving opioid therapy; the median baseline daily oral equivalent dose (OED) of morphine was 180 mg. Pain was assessed at baseline, 24 hours, 48 hours, and 72 hours. Pain scores as assessed on an 11-point numeric pain rating scale (NPRS), any side effects including subcutaneous site reactions, as well as patient satisfaction rating with analgesia were recorded. A clinically significant decrease in pain scores was defined as a reduction of two or more points on the NPRS. Median pain score of all patient treatments decreased from 7 to 4.5 at 24 hours (p<0.001) and 4.0 at 48 hours. A response was seen in 17 (71%) of the 24 treatments at 24 hours. There was no difference between median negative change in pain scores in 19 (79%) treatments where pain was either strongly movement related, or in 22 (94%) treatments where local bone tenderness was more pronounced. No major side effects were observed during treatment. One patient died from pulmonary embolism after cessation of concurrent prophylactic low molecular weight heparin prior to staging liver biopsy. Subcutaneous site reactions occurred in 2 (8%) treatments and were mild and self limiting. Short-term daily subcutaneous parecoxib injection was effective for malignant bone pain when added to existing analgesic therapy and was well tolerated. Further research is warranted into the short-term use of parecoxib in hospitalized patients with intractable malignant bone pain.

Rapid Intradeformational Emplacement of the Big Hole Canyon Pluton Into the Sevier Fold-Thrust Belt, Southwest Montana.

NASA Astrophysics Data System (ADS)

Hespenheide, M. A.

2002-12-01

The Big Hole Canyon pluton (BHCp) is a Late Cretaceous pluton emplaced within the Sevier fold-and-thrust belt of the western North American Cordillera. The pluton is exposed over 60km2 and a thickness of ~1400m. Combined anisotropy of magnetic susceptibility (AMS), structural, and field studies document a clear pattern of magmatic flow radiating from at least three subvertical conduits <100m wide and ~300 to ~800m long. Interpreted flow plunges change rapidly to subhorizontal fabrics across the rest of the pluton, matching the expected pattern for laccolithic emplacement. Ascent conduits within the Big Hole Canyon pluton are coincident with the fold axis of an anticline above a thrust ramp, suggesting that the magma ascended up the fault of the fault-bend-fold. Geobarometry and stratigraphic reconstructions indicate an emplacement depth of approximately ~3km. Preliminary thermal modeling indicates that the BHCp was emplaced in 250,000 years, likely between periods of regional shortening deformation. Rapid magma ascent rates calculated by dike flow modeling and implied by entrained wall-rock xenoliths may indicate sequential magma injection into the pluton; an absence of chill margins between phases within the pluton indicates that sequential injections must have taken place quickly enough that the magmas did not have time to cool below the solidus temperature. The geometry and location of the BHCp suggest that magma used a pre-existing fault as a mechanical discontinuity for both ascent and emplacement. Continued intrusion of magma had a sufficient amount of driving pressure to stretch, shear, and lift the roof of the pluton. Detailed field mapping, structural studies, AMS, and thermobarometry indicate that the Late Cretaceous Big Hole Canyon pluton was emplaced as a laccolith at the top of a pre-existing fault-bend-fold in the frontal portion of the Sevier fold-thrust belt.

Assessment of elemental mobility in soil using a fluidised bed approach with on-line ICP-MS analysis.

PubMed

Beeston, Michael Philip; Glass, Hylke Jan; van Elteren, Johannes Teun; Slejkovec, Zdenka

2007-09-19

A new method has been developed to analyse the mobility of elements within soils employing counter-current flow soil contacting in a fluidised bed (FB) column. This method alleviates the problem of irreproducible peaks suffered by state-of-the-art micro-column techniques as a result of particle compaction. Reproducible extraction profiles are produced through the leaching of soil with a linear gradient of 0.05 mol L(-1) ammonium sulphate to 0.11 mol L(-1) acetic acid using a high pressure liquid chromatography (HPLC) quaternary pump, and the continuous monitoring of the elements in the leachate with inductively coupled plasma mass spectrometry (ICP-MS). Quantification of the procedure is achieved with an external flow injection (FI) calibration method. Flow rate and FB column length were investigated as critical parameters to the efficiency of the extraction methodology. It was found that an increase in the column length from 10 to 20 cm using a flow rate of 0.15 mL min(-1) produced the same increase in extracted elemental concentration as an increase in flow rate from 0.15 to 0.30 mL min(-1). In both examples, the increase in the concentration of elements leached from the soil may be ascribed to the increase in the concentration gradient between the solid and liquid. The exhaustive nature of the technique defines the maximum leachable concentration within the operationally defined leaching parameters of the exchangeable phase, providing a more accurate assessment of the risk associated with the elements in the soil for the phase providing the greatest risk to the environment. The multi-elemental high sensitivity nature of the on-line detector provides an accurate determination of the associations present between the elements in the soil, and the identification of multiple phases within the exchangeable phase through the presence of multiple peaks in the extraction profiles. It is possible through the deconvolution of these extraction profiles that the concentration corresponding to the peaks identified can be defined.

Hypertension study in anaesthetized rabbits: protocol proposal for AT1 antagonists screening.

PubMed

Politi, Aggeliki P; Zervou, Maria V; Triantafyllidi, Helen; Zoumpoulakis, Panagiotis G; Mavromoustakos, Thomas M; Zoga, Anastasia A; Moutevelis-Minakakis, Panagiota; Kokotos, George; Iliodromitis, Efstathios K; Kremastinos, Dimitris Th

2010-06-01

The aim of this study was to establish an optimized fast and safe protocol for the pharmacological screening of AT(1) antagonists. The pharmaceutical prototype AT(1) antagonist losartan, its active metabolite EXP3174 and the synthetic compound MMK1 were analysed in order to validate the protocol. Ang II was continuously infused while the animals received the drugs in two procedures. In the post-treatment procedure drugs were administered either in a single bolus dose or in a sequential manner. When losartan was administered in a single bolus dose, efficacy was evident until the 7th min (p=0.012) whilst EXP3174 infusion extended the efficiency up to the end of the study (p=0.006). In addition, the sequential injections of losartan prolonged the inhibitory time interval until the end of the study (p=0.045). In the pre-treatment procedure, results suggested a dose-dependent inhibitory effect for both antagonists. The pressor response to Ang II was unchanged after MMK1 administration either in the post- or in the pre-treatment mode. The proposed protocol appears to be safe, simple and fast for the pharmacological screening of AT(1) antagonists and enables the evaluation of new antagonists using lower doses than any other reported in the literature.

Perilymph pharmacokinetics of marker applied through a cochlear implant in guinea pigs

PubMed Central

Hartsock, Jared; Gill, Ruth; Smyth, Daniel; Kirk, Jonathon; Verhoeven, Kristien

2017-01-01

Patients undergoing cochlear implantation could benefit from a simultaneous application of drugs into the ear, helping preserve residual low-frequency hearing and afferent nerve fiber populations. One way to apply drugs is to incorporate a cannula into the implant, through which drug solution is driven. For such an approach, perilymph concentrations achieved and the distribution in the ear over time have not previously been documented. We used FITC-labeled dextran as a marker, delivering it into perilymph of guinea pigs at 10 or 100 nL/min though a cannula incorporated into a cochlear implant with the outlet in the mid basal turn. After injections of varying duration (2 hours, 1 day or 7 days) perilymph was collected from the cochlear apex using a sequential sampling technique, allowing dextran levels and gradients along scala tympani to be quantified. Data were interpreted quantitatively using computer simulations of the experiments. For injections of 2 hours duration, dextran levels were critically influenced by the presence or absence of fluid leakage at the cochleostomy site. When the cochleostomy was fluid-tight, substantially higher perilymph levels were achieved at the injection site, with concentration declining along scala tympani towards the apex. Contrary to expectations, large dextran gradients along scala tympani persisted after 24 hours of sustained injection and were still present in some animals after 7 days injection. Functional changes associated with implantation and dextran delivery, and the histological state of the implant and cannula were also documented. The persistent longitudinal gradients of dextan along the ear were not readily explained by computer simulations of the experiments based on prior pharmacokinetic data. One explanation is that inner ear pharmacokinetics are altered in the period after cochlear implantation, possibly by a permeabilization of the blood-labyrinth barrier as part of the immune response to the implant. PMID:28817653

Simulating Bioremediation of Chloroethenes in a Fractured Rock Aquifer.

NASA Astrophysics Data System (ADS)

Curtis, G. P.

2016-12-01

Reactive transport simulations are being conducted to synthesize the results of a field experiment on the enhanced bioremediation of chloroethenes in a heterogeneous fractured-rock aquifer near West Trenton, NJ. The aquifer consists of a sequence of dipping mudstone beds, with water-conducting bedding-plane fractures separated by low-permeability rock where transport is diffusion-limited. The enhanced bioremediation experiment was conducted by injecting emulsified vegetable oil as an electron donor (EOS™) and a microbial consortium (KB1™) that contained dehalococcoides ethenogenes into a fracture zone that had maximum trichloroethene (TCE) concentrations of 84µM. TCE was significantly biodegraded to dichloroethene, chloroethene and ethene or CO2 at the injection well and at a downgradient well. The results also show the concomitant reduction of Fe(III) and S(6) and the production of methane . The results were used to calibrate transport models for quantifying the dominant mass-removal mechanisms. A nonreactive transport model was developed to simulate advection, dispersion and matrix diffusion of bromide and deuterium tracers present in the injection solution. This calibrated model matched tracer concentrations at the injection well and a downgradient observation well and demonstrated that matrix diffusion was a dominant control on tracer transport. A reactive transport model was developed to extend the nonreactive transport model to simulate the microbially mediated sequential dechlorination reactions, reduction of Fe(III) and S(6), and methanogenesis. The reactive transport model was calibrated to concentrations of chloride, chloroethenes, pH, alkalinity, redox-sensitive species and major ions, to estimate key biogeochemical kinetic parameters. The simulation results generally match the diverse set of observations at the injection and observation wells throughout the three year experiment. In addition, the observations and model simulations indicate that a significant pool of TCE that was initially sorbed to either the fracture surfaces or in the matrix was degraded during the field experiment. The calibrated reactive transport model will be used to quantify the extent of chloroethene mass removal from a range of hypothetical aquifers.

Comparison of pressure-controlled provocation discography using automated versus manual syringe pump manometry in patients with chronic low back pain.

PubMed

Derby, Richard; Lee, Sang Hoon; Lee, Jeong-Eun; Lee, Sang-Heon

2011-01-01

The study compares the rate of positive discograms using an automated versus a manual pressure-controlled injection devise and compares the pressure and volume values at various pressures and initial evoked pain and 6/10 or greater evoked pain. A retrospective study prospectively collected patient study data used in a prior prospective study and with prospectively collected data which is routinely collected per our institutional standardized audit protocol. Two custom-built disc manometers (automated injection speed control; manual injection speed control) were sequentially employed during provocation discography in 510 discs of 151 consecutive patients. Two hundred thirty-seven discs of 67 patients with chronic low back pain were evaluated using the automated manometer (automated group) and 273 discs of 84 patients were evaluated with a manual manometer (manual group). No significant differences in positive discogram rates were found between the automated and manual groups (32.1% vs 32.6% per disc, respectively, P>0.05). No significant differences in low-pressure positive discogram rates were found (16.0% vs 15.0% per disc, automated group versus manual group, respectively, P>0.05). However, there were significantly increased volumes and lower pressures at initial and "bad" pain provocation. The study results found equivalent positive discogram rates following a series of pressure-controlled discography using either an automated or manual pressure devise. There were, however significant increases in volume at both initial onset of evoked pain and at 6/10 pain when using the automated injection devise that may have caused the observed lower opening pressure and lower pressure values at initial evoked pain. Assuming increased volumes are innocuous, automated injection is inherently more controlled and may better reduce unintended and often unrecorded spurious high dynamic pressure peaks thereby reducing conscious and unconscious operator bias. Wiley Periodicals, Inc.

Fibrous membranes in diabetic retinopathy and bevacizumab.

PubMed

Pattwell, David M; Stappler, Theodor; Sheridan, Carl; Heimann, Heinrich; Gibran, Syed K; Wong, David; Hiscott, Paul

2010-01-01

The purpose of this study was to determine the histopathologic characteristics of bevacizumab-treated human proliferative diabetic retinopathy (PDR) membranes with particular regard to membrane vasculature as a step toward addressing the effects of the drug on PDR membranes. Intravitreous injection of bevacizumab, an antivascular endothelial growth factor monoclonal antibody, has recently been advocated as an adjunct in surgery for PDR. In this context, a clinically observed decrease in PDR epiretinal membrane vascularity (vascular regression) occurs from 24 hours to 48 hours after injection, but the exact mechanisms of drug action are unknown. A consecutive series of seven PDR membrane specimens that had been removed sequentially from seven bevacizumab-treated patients were studied retrospectively. The membrane specimens were examined using light microscopic methods, including immunohistochemistry. Five of the seven membranes were clinically avascular (one contained "ghost" vessels) and did not hemorrhage during excision. Of these 5 specimens, which included 1 removed 7 days after a total of 6 intravitreous injections of 1.25 mg bevacizumab, 4 contained histologically detectable capillaries (1 did not). These blood vessels were lined by endothelial cells as determined by immunohistochemistry for the endothelial markers CD31 and CD34. The two remaining membranes were clinically and histologically still vascularized despite bevacizumab treatment. All the specimens also contained smooth muscle actin-containing fibroblastic cells within the collagenous stroma. The findings do not support the concept that the clinical phenomenon of vascular regression in PDR membranes after bevacizumab injection in the vitreous is resulting from obliteration of the membrane blood vessels. Another mechanism appears to be involved in at least some patients, possibly a vasoconstrictive response. Such a mechanism might explain reversal of the effects of bevacizumab that has been reported after this treatment.

Multimodal fusion imaging ensemble for targeted sentinel lymph node management: initial results of an innovative promising approach for anatomically difficult lymphatic drainage in different tumour entities.

PubMed

Maza, Sofiane; Taupitz, Mathias; Taymoorian, Kasra; Winzer, Klaus Jürgen; Rückert, Jens; Paschen, Christian; Räber, Gert; Schneider, Sylke; Trefzer, Uwe; Munz, Dieter L

2007-03-01

There are situations where exact identification and localisation of sentinel lymph nodes (SLNs) are very difficult using lymphoscintigraphy, a hand-held gamma probe and vital dye, either a priori or a posteriori. We developed a new method using a simultaneous injection of two lymphotropic agents for exact topographical tomographic localisation and biopsy of draining SLNs. The purpose of this prospective pilot study was to investigate the feasibility and efficacy of this method ensemble. Fourteen patients with different tumour entities were enrolled. A mixture of (99m)Tc-nanocolloid and a dissolved superparamagnetic iron oxide was injected interstitially. Dynamic, sequential static lymphoscintigraphy and SPECT served as pathfinders. MR imaging was performed 2 h after injection. SPECT, contrast MRI and, if necessary, CT scan data sets were fused and evaluated with special regard to the topographical location of SLNs. The day after injection, nine patients underwent SLN biopsy and, in the presence of SLN metastasis, an elective lymph node dissection. Twenty-five SLNs were localised in the 14 patients examined. A 100% fusion correlation was achieved in all patients. The anatomical sites of SLNs detected during surgery showed 100% agreement with those localised on the multimodal fusion images. SLNs could be excised in 11/14 patients, six of whom had nodal metastasis. Our novel approach of multimodal fusion imaging for targeted SLN management in primary tumours with lymphatic drainage to anatomically difficult regions enables SLN biopsy even in patients with lymphatic drainage to obscure regions. Currently, we are testing its validity in larger patient groups and other tumour entities.

On the effect of injection timing on the ignition of lean PRF/air/EGR mixtures under direct dual fuel stratification conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luong, Minh Bau; Sankaran, Ramanan; Yu, Gwang Hyeon

2017-06-09

The ignition characteristics of lean primary reference fuel (PRF)/air/exhaust gas recirculation (EGR) mixture under reactivity-controlled compression ignition (RCCI) and direct duel fuel stratification (DDFS) conditions are investigated in this paper by 2-D direct numerical simulations (DNSs) with a 116-species reduced chemistry of the PRF oxidation. The 2-D DNSs of the DDFS combustion are performed by varying the injection timing of iso-octane (i-C 8H 18) with a pseudo-iso-octane (PC 8H 18) model together with a novel compression heating model to account for the compression heating and expansion cooling effects of the piston motion in an engine cylinder. The PC 8H 18more » model is newly developed to mimic the timing, duration, and cooling effects of the direct injection of i-C 8H 18 onto a premixed background charge of PRF/air/EGR mixture with composition inhomogeneities. It is found that the RCCI combustion exhibits a very high peak heat release rate (HRR) with a short combustion duration due to the predominance of the spontaneous ignition mode of combustion. However, the DDFS combustion has much lower peak HRR and longer combustion duration regardless of the fuel injection timing compared to those of the RCCI combustion, which is primarily attributed to the sequential injection of i-C 8H 18. It is also found that the ignition delay of the DDFS combustion features a non-monotonic behavior with increasing fuel-injection timing due to the different effect of fuel evaporation on the low-, intermediate-, and high-temperature chemistry of the PRF oxidation. The budget and Damköhler number analyses verify that although a mixed combustion mode of deflagration and spontaneous ignition exists during the early phase of the DDFS combustion, the spontaneous ignition becomes predominant during the main combustion, and hence, the spread-out of heat release rate in the DDFS combustion is mainly governed by the direct injection process of i-C 8H 18. Finally, a misfire is observed for the DDFS combustion when the direct injection of i-C 8H 18 occurs during the intermediate-temperature chemistry (ITC) regime between the first- and second-stage ignition. Finally, this is because the temperature drop induced by the direct injection of i-C 8H 18 impedes the main ITC reactions, and hence, the main combustion fails to occur.« less

Rapid, Sensitive Detection of Botulinum Toxin on a Flexible Microfluidics Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warner, Marvin G.; Dockendorff, Brian P.; Feldhaus, Michael J.

2004-10-30

In this paper we will describe how high affinity reagents and a sensor configuration enabling rapid mass transport can be combined for rapid, sensitive biodetection. The system that we have developed includes a renewable surface immunoassay, which involves on-column detection of a fluorescently labeled secondary antibody in a sandwich immunoassay. Yeast display and directed molecular evolution were used to create high affinity antibodies to the botulinum toxin heavy chain receptor binding domain, AR1 and 3D12. A rotating rod renewable surface microcolumn was used to form a microliter-sized column containing beads functionalized with the capture antibody (AR1). The column was perfusedmore » with sample, wash solutions, and a fluorescently labeled secondary antibody (3D12) while the on-column fluorescence was monitored. Detection was accomplished in less than 5 minutes, with a total processing time of about 10 minutes. On-column detection of botulinum toxin was more sensitive and much faster than flow cytometry analysis on microbeads using the same reagents.« less

Quantum cascade light emitting diodes based on type-2 quantum wells

NASA Technical Reports Server (NTRS)

Lin, C. H.; Yang, R. Q.; Zhang, D.; Murry, S. J.; Pei, S. S.; Allerman, A. A.; Kurtz, S. R.

1997-01-01

The authors have demonstrated room-temperature CW operation of type-2 quantum cascade (QC) light emitting diodes at 4.2 (micro)m using InAs/InGaSb/InAlSb type-2 quantum wells. The type-2 QC configuration utilizes sequential multiple photon emissions in a staircase of coupled type-2 quantum wells. The device was grown by molecular beam epitaxy on a p-type GaSb substrate and was compared of 20 periods of active regions separated by digitally graded quantum well injection regions. The maximum average output power is about 250 (micro)W at 80 K, and 140 (micro)W at 300 K at a repetition rate of 1 kHz with a duty cycle of 50%.

Automated thermometric enzyme immunoassay of human proinsulin produced by Escherichia coli.

PubMed

Birnbaum, S; Bülow, L; Hardy, K; Danielsson, B; Mosbach, K

1986-10-01

We have determined and monitored the production and release of human proinsulin by genetically engineered Escherichia coli cells. Several M9 media samples were analyzed sequentially after centrifugation with the aid of a rapid automated flow-through thermometric enzyme-linked immunosorbent assay (TELISA) system. The response time was 7 min after sample injection and a single assay was complete after 13 min. Insulin concentrations in the range of 0.1-50 micrograms/ml could be determined. The TELISA method correlated well with conventional radioimmunoassay determinations. Standard curves were reproducible over a period of several days even when the immobilized antibody column was stored at 25 degrees C in the enzyme thermistor unit. Thus, immediate assay start up was possible.

Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spino, M.; Chai, R.P.; Isles, A.F.

1985-07-01

A study was conducted to examine renal function in 10 healthy control subjects and eight patients with cystic fibrosis in stable condition. Sequential bolus injections of /sup 99m/Tc-DTPA and /sup 125/I-OIH were administered to assess glomerular filtration rate and effective renal plasma flow, respectively. Blood was subsequently collected for 3 hours, and urine for 24 hours. Renal clearances of both radioisotope markers were virtually identical in patients and controls. Inasmuch as neither glomerular filtration rate nor effective renal plasma flow was enhanced in patients with cystic fibrosis, increased clearance of drugs in these patients is unlikely to be the resultmore » of enhanced glomerular filtration or tubular secretion.« less

Method of deep drilling

DOEpatents

Colgate, Stirling A.

1984-01-01

Deep drilling is facilitated by the following steps practiced separately or in any combination: (1) Periodically and sequentially fracturing zones adjacent the bottom of the bore hole with a thixotropic fastsetting fluid that is accepted into the fracture to overstress the zone, such fracturing and injection being periodic as a function of the progression of the drill. (2) Casing the bore hole with ductile, pre-annealed casing sections, each of which is run down through the previously set casing and swaged in situ to a diameter large enough to allow the next section to run down through it. (3) Drilling the bore hole using a drill string of a low density alloy and a high density drilling mud so that the drill string is partially floated.

New insights on SOI Tunnel FETs with low-temperature process flow for CoolCube™ integration

NASA Astrophysics Data System (ADS)

Diaz Llorente, C.; Le Royer, C.; Batude, P.; Fenouillet-Beranger, C.; Martinie, S.; Lu, C.-M. V.; Allain, F.; Colinge, J.-P.; Cristoloveanu, S.; Ghibaudo, G.; Vinet, M.

2018-06-01

This paper reports the fabrication and electrical characterization of planar SOI Tunnel FETs (TFETs) made using a Low-Temperature (LT) process designed for 3D sequential integration. These proof-of-concept TFETs feature junctions obtained by Solid Phase Epitaxy Regrowth (SPER). Their electrical behavior is analyzed and compared to reference samples (regular process using High-Temperature junction formation, HT). Dual ID-VDS measurements verify that the TFET structures present Band-to-Band tunnelling (BTBT) carrier injection and not Schottky Barrier tunnelling. P-mode operating LT TFETs deliver an ON state current similar to that of the HT reference, opening the door towards optimized devices operating with very low threshold voltage VTH and low supply voltage VDD.

Fast BIA-amperometric determination of isoniazid in tablets.

PubMed

Quintino, Maria S M; Angnes, Lúcio

2006-09-26

This paper proposes a new, fast and precise method to analyze isoniazid based on the electrochemical oxidation of the analyte at a glassy carbon electrode in 0.1M NaOH. The quantification was performed utilizing amperometry associated with batch injection analysis (BIA) technique. Fast sequential analysis (60 determinations h(-1)) in an unusually wide linear dynamic range (from 2.5 x 10(-8) to 1.0 x 10(-3)M), with high sensitivity and low limits of detection (4.1 x 10(-9)M) and quantification (1.4 x 10(-8)M), was achieved. Such characteristics allied to a good repeatability of the current responses (relative standard deviation of 0.79% for 30 measurements), were explored for the specific determination of isoniazid in isoniazid-rifampin tablet.

Nanotune: A Novel Approach to Control the Deposition and Fate of Particles in Porous Media

NASA Astrophysics Data System (ADS)

Sethi, R.; Bianco, C.; Tosco, T.; Tiraferri, A.; Patiño Higuita, J. E.

2017-12-01

Nanoremediation is an innovative environmental nanotechnology aimed at reclaiming contaminated aquifers. It consists in the subsurface injection of a reactive colloidal suspension for the in-situ treatment of pollutants. The greatest challenges faced by engineers to advance nanoremediation are the effective delivery and the appropriate dosing of the nanoparticles into the subsoil. These are necessary for the correct emplacement of the in situ reactive zone and to minimize the overall cost of the reclamation and the potential secondary risks associated to the uncontrolled migration of the injected particles. In this study, a model assisted strategy, NanoTune, is developed to control the distribution of colloids in porous media. The proposed approach consists in the sequential injection of a stable suspension of reactive nanoparticles and of a destabilizing agent with the aim of creating a reactive zone within a targeted portion of the contaminated aquifer. The controlled and irreversible deposition of the particles is achieved by inducing the mixing of the two fluids in the desired portion of the aquifer. This approach is here exemplified by the delivery of humic acid-stabilized iron oxide nanoparticles (FeOx), a typical reagent for in situ immobilization of heavy metals. Divalent cations, which are known to cause rapid aggregation of the suspension because of their strong interaction with the humic acid coating, are used as destabilizing agents. The injection strategy is here applied in 1D columns to create a reactive zone for heavy metal removal in the central region of the sandy bed. The software MNMs was used to assess the correct sequence and duration of the injection of the different solutions in the 1D medium. Moreover, the numerical code MNM3D (MNM3D - Micro and Nanoparticle transport Model in 3D geometries) was developed by the authors of this work to support the case-specific design of the injection strategy during field scale applications. The NanoTune approach represents an advancement in the control of the fate of nanomaterials in the environment, and could enhance nanoremediation making it an effective alternative to more conventional techniques.

Determination of head conductivity frequency response in vivo with optimized EIT-EEG.

PubMed

Dabek, Juhani; Kalogianni, Konstantina; Rotgans, Edwin; van der Helm, Frans C T; Kwakkel, Gert; van Wegen, Erwin E H; Daffertshofer, Andreas; de Munck, Jan C

2016-02-15

Electroencephalography (EEG) benefits from accurate head models. Dipole source modelling errors can be reduced from over 1cm to a few millimetres by replacing generic head geometry and conductivity with tailored ones. When adequate head geometry is available, electrical impedance tomography (EIT) can be used to infer the conductivities of head tissues. In this study, the boundary element method (BEM) is applied with three-compartment (scalp, skull and brain) subject-specific head models. The optimal injection of small currents to the head with a modular EIT current injector, and voltage measurement by an EEG amplifier is first sought by simulations. The measurement with a 64-electrode EEG layout is studied with respect to three noise sources affecting EIT: background EEG, deviations from the fitting assumption of equal scalp and brain conductivities, and smooth model geometry deviations from the true head geometry. The noise source effects were investigated depending on the positioning of the injection and extraction electrode and the number of their combinations used sequentially. The deviation from equal scalp and brain conductivities produces rather deterministic errors in the three conductivities irrespective of the current injection locations. With a realistic measurement of around 2 min and around 8 distant distinct current injection pairs, the error from the other noise sources is reduced to around 10% or less in the skull conductivity. The analysis of subsequent real measurements, however, suggests that there could be subject-specific local thinnings in the skull, which could amplify the conductivity fitting errors. With proper analysis of multiplexed sinusoidal EIT current injections, the measurements on average yielded conductivities of 340 mS/m (scalp and brain) and 6.6 mS/m (skull) at 2 Hz. From 11 to 127 Hz, the conductivities increased by 1.6% (scalp and brain) and 6.7% (skull) on the average. The proper analysis was ensured by using recombination of the current injections into virtual ones, avoiding problems in location-specific skull morphology variations. The observed large intersubject variations support the need for in vivo measurement of skull conductivity, resulting in calibrated subject-specific head models. Copyright © 2015 Elsevier Inc. All rights reserved.

Visualization and in vivo tracking of the exosomes of murine melanoma B16-BL6 cells in mice after intravenous injection.

PubMed

Takahashi, Yuki; Nishikawa, Makiya; Shinotsuka, Haruka; Matsui, Yuriko; Ohara, Saori; Imai, Takafumi; Takakura, Yoshinobu

2013-05-20

The development of exosomes as delivery vehicles requires understanding how and where exogenously administered exosomes are distributed in vivo. In the present study, we designed a fusion protein consisting of Gaussia luciferase and a truncated lactadherin, gLuc-lactadherin, and constructed a plasmid expressing the fusion protein. B16-BL6 murine melanoma cells were transfected with the plasmid, and exosomes released from the cells were collected by ultracentrifugation. Strong luciferase activity was detected in the fraction containing exosomes, indicating their efficient labeling with gLuc-lactadherin. Then, the labeled B16-BL6 exosomes were intravenously injected into mice, and their tissue distribution was evaluated. Pharmacokinetic analysis of the exosome blood concentration-time profile revealed that B16-BL6 exosomes disappeared very quickly from the blood circulation with a half-life of approximately 2min. Little luciferase activity was detected in the serum at 4h after exosome injection, suggesting rapid clearance of B16-BL6 exosomes in vivo. Moreover, sequential in vivo imaging revealed that the B16-BL6 exosome-derived signals distributed first to the liver and then to the lungs. These results indicate that gLuc-lactadherin labeling is useful for tracing exosomes in vivo and that B16-BL6 exosomes are rapidly cleared from the blood circulation after systemic administration. Copyright © 2013 Elsevier B.V. All rights reserved.

An Immunoglobulin G1 Monoclonal Antibody Highly Specific to the Wall of Cryptosporidium Oocysts

PubMed Central

Weir, C.; Vesey, G.; Slade, M.; Ferrari, B.; Veal, D. A.; Williams, K.

2000-01-01

The detection of Cryptosporidium oocysts in drinking water is critically dependent on the quality of immunofluorescent reagents. Experiments were performed to develop a method for producing highly specific antibodies to Cryptosporidium oocysts that can be used for water testing. BALB/c mice were immunized with six different antigen preparations and monitored for immunoglobulin G (IgG) and IgM responses to the surface of Cryptosporidium oocysts. One group of mice received purified oocyst walls, a second group received a soluble protein preparation extracted from the outside of the oocyst wall, and the third group received whole inactivated oocysts. Three additional groups were immunized with sequentially prepared oocyst extracts to provide for a comparison of the immune response. Mice injected with the soluble protein extract demonstrated an IgG response to oocysts surface that was not seen in the whole-oocyst group. Mice injected with whole oocysts showed an IgM response only, while mice injected with purified oocyst walls showed little increase in IgM or IgG levels. Of the additional reported preparations only one, BME (2-mercaptoethanol treated), produced a weak IgM response to the oocyst wall. A mouse from the soluble oocyst extract group yielding a high IgG response was utilized to produce a highly specific IgG1 monoclonal antibody (Cry104) specific to the oocyst surface. Comparative flow cytometric analysis indicated that Cry104 has a higher avidity and specificity to oocysts in water concentrates than other commercially available antibodies. PMID:10973448

Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Xingcai; Ji, Libin; Ma, Junjun

2011-02-15

This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively accordingmore » to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)« less

Geochemical and microbiological characteristics during in situ chemical oxidation and in situ bioremediation at a diesel contaminated site.

PubMed

Sutton, Nora B; Kalisz, Mariusz; Krupanek, Janusz; Marek, Jan; Grotenhuis, Tim; Smidt, Hauke; de Weert, Jasperien; Rijnaarts, Huub H M; van Gaans, Pauline; Keijzer, Thomas

2014-02-18

While in situ chemical oxidation with persulfate has seen wide commercial application, investigations into the impacts on groundwater characteristics, microbial communities and soil structure are limited. To better understand the interactions of persulfate with the subsurface and to determine the compatibility with further bioremediation, a pilot scale treatment at a diesel-contaminated location was performed consisting of two persulfate injection events followed by a single nutrient amendment. Groundwater parameters measured throughout the 225 day experiment showed a significant decrease in pH and an increase in dissolved diesel and organic carbon within the treatment area. Molecular analysis of the microbial community size (16S rRNA gene) and alkane degradation capacity (alkB gene) by qPCR indicated a significant, yet temporary impact; while gene copy numbers initially decreased 1-2 orders of magnitude, they returned to baseline levels within 3 months of the first injection for both targets. Analysis of soil samples with sequential extraction showed irreversible oxidation of metal sulfides, thereby changing subsurface mineralogy and potentially mobilizing Fe, Cu, Pb, and Zn. Together, these results give insight into persulfate application in terms of risks and effective coupling with bioremediation.

Positive predictive value of cholescintigraphy in common bile duct obstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lecklitner, M.L.; Austin, A.R.; Benedetto, A.R.

1986-09-01

Technetium-99m DISIDA imaging was employed in 400 patients to differentiate obstruction of the common bile duct from medical and other surgical causes of hyperbilirubinemia. Sequential anterior images demonstrated variable degrees of liver uptake, yet there was no evidence of intrabiliary or extrabiliary radioactivity for at least 4 hr after injection in 25 patients. Twenty-three patients were surgically documented to have complete obstruction of the common bile duct. One patient had hepatitis, and another had sickle cell crisis without bile duct obstruction. The remaining patients had either partial or no obstruction of the common bile duct. We conclude that the presencemore » of liver uptake without evident biliary excretion by 4 hr on cholescintigraphy is highly sensitive and predictive of total obstruction of the common bile duct.« less

Application of Geochemical Parameters for the Early Detection of CO2 Leakage from Sequestration Sites into Groundwater

NASA Astrophysics Data System (ADS)

Kharaka, Y. K.; Beers, S.; Thordsen, J.; Thomas, B.; Campbell, P.; Herkelrath, W. N.; Abedini, A. A.

2011-12-01

Geologically sequestered CO2 is buoyant, has a low viscosity and, when dissolved in brine, becomes reactive to minerals and well pipes. These properties of CO2 may cause it to leak upward, possibly contaminating underground sources of drinking water. We have participated in several multi-laboratory field experiments to investigate the chemical and isotopic parameters that are applicable to monitoring the flow of injected CO2 into deep saline aquifers and into potable shallow groundwater. Geochemical results from the deep SECARB Phase III tests at Cranfield oil field, Mississippi, and from the Frio Brine I and II pilots located in the S. Liberty oil field, Dayton, Texas, proved powerful tools in: 1- Tracking the successful injection and flow of CO2 into the injection sandstones; 2- showing major changes in the chemical (pH, alkalinity, and major divalent cations) and isotopic (δ13C values of CO2, and δ18O values of CO2 and brine) compositions of formation water; 3-. showing mobilization of metals, including Fe Mn and Pb, and organic compounds , including DOC, BTEX, PAHs, and phenols following CO2 injection; and 4- showing that some of the CO2 injected into the Frio "C" sandstone was detected in the overlying "B" sandstone that is separated from it by 15 m of shale and siltstone. Rapid, significant and systematic changes were also observed in the isotopic and chemical compositions of shallow groundwater at the Zero Emissions Research and Technology (ZERT) site located in Bozeman, Montana, in response to four yearly injections of variable amounts of CO2 gas through a slotted pipe placed horizontally at a depth of ~2 m below ground level. The observed changes, included the lowering of groundwater pH from ~7.0 to values as low as 5.6, increases in the alkalinity from about 400 mg/L as HCO3 to values of up to 1330 mg/L, increases in the electrical conductance from ~600 μS/cm to up to 1800 μS/cm, as well as increases in the concentrations of cations and metals following CO2 injection. Geochemical modeling, sequential extractions of cations from the ZERT-aquifer sediments, and controlled laboratory CO2-groundwater-sediment interactions demonstrated that calcite dissolution and ion exchange on organic material and inorganic mineral surfaces are responsible for the observed chemical changes. Results from both the deep and shallow field tests show that geochemical methods have highly sensitive chemical and isotopic tracers that are needed at CO2 injection sites to monitor injection performance and for early detection of any CO2 and brine leakages.

Hyperbaric bupivacaine 2.5 mg prolongs analgesia compared with plain bupivacaine when added to intrathecal fentanyl 25 microg in advanced labor.

PubMed

Teoh, Wendy H L; Sia, Alex T H

2003-09-01

We investigated the effect of sequential administration of intrathecal (IT) hyperbaric bupivacaine (after the initial administration of IT hypobaric fentanyl) on the duration of spinal analgesia. Thirty-seven nulliparous parturients with a cervical dilation >/= 5 cm were randomized to receive either IT fentanyl 25 micro g and plain bupivacaine 2.5 mg (group P; n = 19) or IT fentanyl 25 micro g and hyperbaric (with 8% glucose) bupivacaine 2.5 mg (group H; n = 18). The two components of the IT injectate were administered sequentially (fentanyl 25 micro g diluted in 2 mL of normal saline, immediately followed by 0.5 mL of 0.5% bupivacaine). Patients were then positioned with their torso elevated at 30 degrees for 30 min. Pain scores using 0-100 visual analog scales were collected before combined spinal/epidural analgesia and at 5, 15, and 30 min after the block. Patients in Group H had a longer median duration of analgesia (122 min; range, 80-210 min) than Group P (95 min; range, 75-125 min) (P < 0.01). Group H also had a more limited dermatomal spread (median highest sensory level of T8 versus T4 in group P; P < 0.05). The side-effect profile was similar. Under these circumstances, hyperbaric bupivacaine conferred an increased duration of IT analgesia compared with plain bupivacaine.

A 1000+ channel bionic communication system.

PubMed

Schulman, Joseph H; Mobley, J Phil; Wolfe, James; Stover, Howard; Krag, Adrian

2006-01-01

The wireless electronic nervous system interface known as the functional electrical stimulation-battery powered bion system is being developed at the Alfred Mann Foundation. It contains a real-time propagated wave micro-powered multichannel communication system. This system is designed to send bi-directional messages between an external master controller unit (MCU), and each one of a group of injectable stimulator-sensor battery powered bion implants (BPB). The system is capable of communicating in each direction about 90 times per second using a structure of 850 time slots within a repeating 11 millisecond time window. The system's total Time Division Multiple Access (TDMA) communication capability is about 77,000 two-way communications per second on a single 5 MHz wide radio channel. Each time slot can be used by one BPB, or shared alternately by two or more BPBs. Each bidirectional communication consists of a 15 data bit message sent from the MCU sequentially to each BPB and 10 data bit message sent sequentially from each BPB to the MCU. Redundancy bits are included to provide error detection and correction. This communication system is designed to draw only a few microamps from the 3.6 volt, 3.0 mAHr lithium ion (LiIon) battery contained in each BPB, and the majority of the communications circuitry is contained within a 1.4x5 mm integrated circuit.

Utility of a human-mouse xenograft model and in vivo near-infrared fluorescent imaging for studying wound healing.

PubMed

Shanmugam, Victoria K; Tassi, Elena; Schmidt, Marcel O; McNish, Sean; Baker, Stephen; Attinger, Christopher; Wang, Hong; Shara, Nawar; Wellstein, Anton

2015-12-01

To study the complex cellular interactions involved in wound healing, it is essential to have an animal model that adequately mimics the human wound microenvironment. Currently available murine models are limited because wound contraction introduces bias into wound surface area measurements. The purpose of this study was to demonstrate utility of a human-mouse xenograft model for studying human wound healing. Normal human skin was harvested from elective abdominoplasty surgery, xenografted onto athymic nude (nu/nu) mice, and allowed to engraft for 3 months. The graft was then wounded using a 2-mm punch biopsy. Wounds were harvested on sequential days to allow tissue-based markers of wound healing to be followed sequentially. On the day of wound harvest, mice were injected with XenoLight RediJect cyclooxygenase-2 (COX-2) probe and imaged according to package instructions. Immunohistochemistry confirms that this human-mouse xenograft model is effective for studying human wound healing in vivo. Additionally, in vivo fluorescent imaging for inducible COX-2 demonstrated upregulation from baseline to day 4 (P = 0·03) with return to baseline levels by day 10, paralleling the reepithelialisation of the wound. This human-mouse xenograft model, combined with in vivo fluorescent imaging provides a useful mechanism for studying molecular pathways of human wound healing. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Besemer, A; Marsh, I; Bednarz, B

Purpose: The calculation of 3D internal dose calculations in targeted radionuclide therapy requires the acquisition and temporal coregistration of a serial PET/CT or SPECT/CT images. This work investigates the dosimetric impact of different temporal coregistration methods commonly used for 3D internal dosimetry. Methods: PET/CT images of four mice were acquired at 1, 24, 48, 72, 96, 144 hrs post-injection of {sup 124}I-CLR1404. The therapeutic {sup 131}I-CLR1404 absorbed dose rate (ADR) was calculated at each time point using a Geant4-based MC dosimetry platform using three temporal image coregistration Methods: (1) no coregistration (NC), whole body sequential CT-CT affine coregistration (WBAC), andmore » individual sequential ROI-ROI affine coregistration (IRAC). For NC, only the ROI mean ADR was integrated to obtain ROI mean doses. For WBAC, the CT at each time point was coregistered to a single reference CT. The CT transformations were applied to the corresponding ADR images and the dose was calculated on a voxel-basis within the whole CT volume. For IRAC, each individual ROI was isolated and sequentially coregistered to a single reference ROI. The ROI transformations were applied to the corresponding ADR images and the dose was calculated on a voxel-basis within the ROI volumes. Results: The percent differences in the ROI mean doses were as large as 109%, 88%, and 32%, comparing the WBAC vs. IRAC, NC vs. IRAC, and NC vs. WBAC methods, respectively. The CoV in the mean dose between the all three methods ranged from 2–36%. The pronounced curvature of the spinal cord was not adequately coregistered using WBAC which resulted in large difference between the WBAC and IRAC. Conclusion: The method used for temporal image coregistration can result in large differences in 3D internal dosimetry calculations. Care must be taken to choose the most appropriate method depending on the imaging conditions, clinical site, and specific application. This work is partially funded by NIH Grant R21 CA198392-01.« less

Simulation of in situ uranium bioremediation with slow-release organic amendment injection

NASA Astrophysics Data System (ADS)

Zhang, F.; Parker, J.; Ye, M.; Tang, G.; Wu, W.; Mehlhorn, T.; Gihring, T. M.; Schadt, C.; Watson, D. B.; Brooks, S. C.

2010-12-01

In situ bioremediation of a highly uranium-contaminated gravel aquifer with a slow-release electron donor (emulsified edible oil) has been investigated at the US DOE Oak Ridge Integrated Field Research Challenge (ORIFRC) site in east Tennessee. Groundwater at the study location has pH ~6.7 and contains high concentrations of U (5-6 μM), sulfate (1.0-1.2) mM and Ca (3-4 mM). Diluted emulsified oil (20% solution) was injected into three injection wells within 1.5 hrs. Geochemical analysis of site groundwater demonstrated the sequential reduction of nitrate, Mn, Fe(III) and sulfate. The oil was degraded by indigenous microorganisms with acetate as a major product. Rapid removal of U(VI) from the aqueous phase occurred concurrently with acetate production and sulfate reduction. The field test data were analyzed using a reaction network with a kinetic model for lipid hydrolysis and glycerol fermentation and equilibrium reactions representing microbial reduction of sulfate, nitrate, iron, uranium, manganese and carbon dioxide based on the thermodynamic approach of Istok et al. (2010) using the parallelized HGC5 code. Model-simulated chemical concentrations and relative abundance of functional microbial populations are compared with field measurements. Application of the thermodynamically-based modeling approach instead of the widely used multi-Monod kinetic rate law to formulate bioreduction reactions substantially reduces the number of reaction parameters that need to be calibrated thus facilitating a more comprehensive representation of microbial community dynamics. The model developed through this study is expected to aid the design of future bioremediation strategies for the site.

The Art and Science of Using Diuretics in the Treatment of Heart Failure in Diverse Clinical Settings.

PubMed

Islam, Md Shahidul

2018-01-01

It is important to understand the rationale for appropriate use of different diuretics, alone or in combination, in different heart failure patients, under diverse clinical settings. Clinicians and nurses engaged in heart failure care, must be familiar with different diuretics, their appropriate doses, methods of administration, monitoring of the responses, and the side-effects. Inappropriate use of diuretics, both under-treatment and overtreatment, and poor follow-up can lead to failures, and adverse outcomes. Adequate treatment of congestion, with rather aggressive use of diuretics, is necessary, even if that may worsen renal function temporarily in some patients. Diuretic treatment should later be titrated down, by early recognition of the euvolemic sate, which can be assessed by clinical examination, measurement of the natriuretic peptides, and when possible, echocardiographic estimation of the left ventricular filling pressure. You need to treat patients, who are truly resistant to the loop diuretics, by administering the diuretics as intravenous bolus injection followed by continuous infusion, and/or by sequential nephron blockade by adding the thiazide diuretics. You need to use the diuretics based on a sound understanding of the pathophysiology of the disease process, the pharmacokinetics and pharmacodynamics of the diuretics, even when strong evidences for your choices might be lacking. Some patients may benefit from injection of loop diuretics together with hypertonic saline, and others from injection of loop diuretics with albumin. Patient education, and regular follow up of the treatment of heart failure patients, in out-patient settings are important for reducing the rates of complications, and for reducing the needs for urgent hospitalizations.

Novel Indocyanine Green-Phytate Colloid Technique for Sentinel Node Detection in Head and Neck: Mouse Study.

PubMed

Araki, Koji; Mizokami, Daisuke; Tomifuji, Masayuki; Yamashita, Taku; Ohnuki, Kazunobu; Umeda, Izumi O; Fujii, Hirofumi; Kosuda, Shigeru; Shiotani, Akihiro

2014-08-01

Sentinel node navigation surgery using real-time, near-infrared imaging with indocyanine green is becoming popular by allowing head and neck surgeons to avoid unnecessary neck dissection. The major drawback of this method is its quick migration through the lymphatics, limiting the diagnostic time window and undesirable detection of downstream nodes. We resolved this problem by mixing indocyanine green (ICG) with phytate colloid to retard its migration and demonstrated its feasibility in a nude mouse study. Experimental prospective animal study. Animal laboratory. Indocyanine green at 3 concentrations was tested to determine the optimal concentration for sentinel lymph node detection in a mouse model. Effect of indocyanine green with phytate colloid mixture solutions was also analyzed. Indocyanine green or mixture solution at different mixing ratios were injected into the tongue of nude mice and near-infrared fluorescence images were captured sequentially for up to 48 hours. The brightness of fluorescence in the sentinel lymph node and lymph nodes further downstream were assessed. Indocyanine green concentration >50 μg/mL did not improve sentinel lymph node detection. The addition of phytate colloid to indocyanine green extended the period when sentinel lymph node was detectable. Second echelon lymph nodes were not imaged in mice injected with the mixture, while these were visualized in mice injected with indocyanine green alone. This novel technique of ICG-phytate colloid mixture allows prolonged diagnostic time window, prevention of downstream subsequent nodes detection, and improved accuracy for the detection of true sentinel lymph nodes. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

High-performance serial block-face SEM of nonconductive biological samples enabled by focal gas injection-based charge compensation.

PubMed

Deerinck, T J; Shone, T M; Bushong, E A; Ramachandra, R; Peltier, S T; Ellisman, M H

2018-05-01

A longstanding limitation of imaging with serial block-face scanning electron microscopy is specimen surface charging. This charging is largely due to the difficulties in making biological specimens and the resins in which they are embedded sufficiently conductive. Local accumulation of charge on the specimen surface can result in poor image quality and distortions. Even minor charging can lead to misalignments between sequential images of the block-face due to image jitter. Typically, variable-pressure SEM is used to reduce specimen charging, but this results in a significant reduction to spatial resolution, signal-to-noise ratio and overall image quality. Here we show the development and application of a simple system that effectively mitigates specimen charging by using focal gas injection of nitrogen over the sample block-face during imaging. A standard gas injection valve is paired with a precisely positioned but retractable application nozzle, which is mechanically coupled to the reciprocating action of the serial block-face ultramicrotome. This system enables the application of nitrogen gas precisely over the block-face during imaging while allowing the specimen chamber to be maintained under high vacuum to maximise achievable SEM image resolution. The action of the ultramicrotome drives the nozzle retraction, automatically moving it away from the specimen area during the cutting cycle of the knife. The device described was added to a Gatan 3View system with minimal modifications, allowing high-resolution block-face imaging of even the most charge prone of epoxy-embedded biological samples. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Evaluation of safety in clinical use of generic paclitaxel [NK] for injection.

PubMed

Tsukiyama, Ikuto; Hotta, Kazuo; Takeuchi, Masayuki; Onishi, Masahumi; Toyama, Yukio; Saito, Hiroko; Sai, Yoshimichi; Miyamoto, Ken-Ichi; Hasegawa, Takaaki

2012-04-01

The introduction of generic drugs is a favored strategy in reducing medical costs, but some clinicians are often reluctant to use them because of lack of information with regard to their side effects. Generic paclitaxel [NK] differs from the proprietary version, Taxol®, in containing added citric acid and a more pure form of castor oil. However, little information exists regarding the effects of these additives on adverse events such as vascular pain, phlebitis, hypersensitivity and hepatic dysfunction. To compensate for this lack of information and to validate the safety of using generic paclitaxel, we investigated adverse events in response to generic paclitaxel [NK]. Our investigation focused on patients treated with both the proprietary formulation (Taxol® for injection) and the generic version(paclitaxel [NK] for injection)sequentially from April 2008 to March 2009. Adverse events were investigated retrospectively. Incidence of vascular pain, phlebitis and hypersensitivity was similar to that with the original product. Although the expression of some liver enzymes was slightly increased and some gastrointestinal events were reduced following generic paclitaxel [NK] treatment there was no statistically significant difference. The profiles of other adverse events were not significantly different. Increased vascular pain and phlebitis, predicted due to low pH conditions caused by citric acid, were not observed. Similarly, the pure castor oil included in generic paclitaxel [NK] did not influence hypersensitivity and hepatic function. We found no significant differences in our study of proprietary and generic paclitaxel [NK]. Thus, clinicians have no reason for prejudice against using generic paclitaxel [NK] on the basis of increased risk of side effects.

An integrated bioremediation process for petroleum hydrocarbons removal and odor mitigation from contaminated marine sediment.

PubMed

Zhang, Zhen; Lo, Irene M C; Yan, Dickson Y S

2015-10-15

This study developed a novel integrated bioremediation process for the removal of petroleum hydrocarbons and the mitigation of odor induced by reduced sulfur from contaminated marine sediment. The bioremediation process consisted of two phases. In Phase I, acetate was dosed into the sediment as co-substrate to facilitate the sulfate reduction process. Meanwhile, akaganeite (β-FeOOH) was dosed in the surface layer of the sediment to prevent S(2-) release into the overlying seawater. In Phase II, NO3(-) was injected into the sediment as an electron acceptor to facilitate the denitrification process. After 20 weeks of treatment, the sequential integration of the sulfate reduction and denitrification processes led to effective biodegradation of total petroleum hydrocarbons (TPH), in which about 72% of TPH was removed. In Phase I, the release of S(2-) was effectively controlled by the addition of akaganeite. The oxidation of S(2-) by Fe(3+) and the precipitation of S(2-) by Fe(2+) were the main mechanisms for S(2-) removal. In Phase II, the injection of NO3(-) completely inhibited the sulfate reduction process. Most of residual AVS and S(0) were removed within 4 weeks after NO3(-) injection. The 16S rRNA clone library-based analysis revealed a distinct shift of bacterial community structure in the sediment over different treatment phases. The clones affiliated with Desulfobacterales and Desulfuromonadales were the most abundant in Phase I, while the clones related to Thioalkalivibrio sulfidophilus, Thiohalomonas nitratireducens and Sulfurimonas denitrificans predominated in Phase II. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simple systems for treating pumped, turbid water with flocculants and a geotextile dewatering bag.

PubMed

Kang, Jihoon; McLaughlin, Richard A

2016-11-01

Pumping sediment-laden water from excavations is often necessary on construction sites. This water is often treated by pumping it through geotextile dewatering bags. The bags are not designed to filter the fine sediments that create high turbidity, but dosing with a flocculant prior to the bag could result in greater turbidity control. This study compared two systems for introducing flocculant: passive dosing of commercial solid biopolymer (chitosan) and injection of dissolved polyacrylamide (PAM) in a length of corrugated pipe connected to the bag. The biopolymer system consisted of sequential porous socks containing a "charging agent" followed by chitosan in the corrugated pipe with two levels of dosing. The dissolved PAM was injected into turbid water at a flow-weighted concentration at 1 mg L(-1). For each treatment, sediment-laden turbid water in the range of 2000 to 3500 nephelometric turbidity units (NTU) was pumped into the upstream of corrugated pipe and samples were taken from pipe entrance, pipe exit, and dewatering bag exit. Without flocculant treatment, the dewatering bag reduced turbidity by 70% but the addition of flocculant increased the turbidity reduction up to 97% relative to influent. At the pipe exit, the low-dose biopolymer was less effective in reducing turbidity (37%) but it was equally effective as the high-dose biopolymer or PAM injection after the bag. Our results suggest that a relatively simple treatment with flocculants, either passively or actively, can be very effective in reducing turbidity for pumped water on construction sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arthroscopic, histological and MRI analyses of cartilage repair after a minimally invasive method of transplantation of allogeneic synovial mesenchymal stromal cells into cartilage defects in pigs.

PubMed

Nakamura, Tomomasa; Sekiya, Ichiro; Muneta, Takeshi; Hatsushika, Daisuke; Horie, Masafumi; Tsuji, Kunikazu; Kawarasaki, Tatsuo; Watanabe, Atsuya; Hishikawa, Shuji; Fujimoto, Yasuhiro; Tanaka, Hozumi; Kobayashi, Eiji

2012-03-01

Transplantation of synovial mesenchymal stromal cells (MSCs) may induce repair of cartilage defects. We transplanted synovial MSCs into cartilage defects using a simple method and investigated its usefulness and repair process in a pig model. The chondrogenic potential of the porcine MSCs was compared in vitro. Cartilage defects were created in both knees of seven pigs, and divided into MSCs treated and non-treated control knees. Synovial MSCs were injected into the defect, and the knee was kept immobilized for 10 min before wound closure. To visualize the actual delivery and adhesion of the cells, fluorescence-labeled synovial MSCs from transgenic green fluorescent protein (GFP) pig were injected into the defect in a subgroup of two pigs. In these two animals, the wounds were closed before MSCs were injected and observed for 10 min under arthroscopic control. The defects were analyzed sequentially arthroscopically, histologically and by magnetic resonance imaging (MRI) for 3 months. Synovial MSCs had a higher chondrogenic potential in vitro than the other MSCs examined. Arthroscopic observations showed adhesion of synovial MSCs and membrane formation on the cartilage defects before cartilage repair. Quantification analyses for arthroscopy, histology and MRI revealed a better outcome in the MSC-treated knees than in the non-treated control knees. Leaving a synovial MSC suspension in cartilage defects for 10 min made it possible for cells to adhere in the defect in a porcine cartilage defect model. The cartilage defect was first covered with membrane, then the cartilage matrix emerged after transplantation of synovial MSCs.

Ultrafast electron and hole transfer dynamics of a solar cell dye containing hole acceptors on mesoporous TiO2 and Al2O3.

PubMed

Scholz, Mirko; Flender, Oliver; Boschloo, Gerrit; Oum, Kawon; Lenzer, Thomas

2017-03-08

The stability of dye cations against recombination with conduction band electrons in mesoporous TiO 2 electrodes is a key property for improving light harvesting in dye-sensitised solar cells. Using ultrafast transient broadband absorption spectroscopy, we monitor efficient intramolecular hole transfer in the solar cell dye E6 having two peripheral triarylamine acceptors. After photoexcitation, two hole transfer mechanisms are identified: a concerted mechanism for electron injection and hole transfer (2.4 ps) and a sequential mechanism with time constants of 3.9 ps and 30 ps. This way the dye retards unwanted recombination with a TiO 2 conduction band electron by quickly moving the hole further away from the surface. Contact of the E6/TiO 2 surface with the solvent acetonitrile has almost no influence on the electron injection and hole transfer kinetics. Fast hole transfer (2.8 ps) is also observed on a "non-injecting" Al 2 O 3 surface generating a radical cation-radical anion species with a lifetime of 530 ps. The findings confirm the good intramolecular hole transfer properties of this dye on both thin films. In contrast, intramolecular hole transfer does not occur in the mid-polar organic solvent methyl acetate. This is confirmed by TDDFT calculations suggesting a polarity-induced reduction of the driving force for hole transfer. In methyl acetate, only the relaxation of the initially photoexcited core chromophore is observed including solvent relaxation processes of the electronically excited state S 1 /ICT.

The effectiveness of Hering's nerve stimulation in controlling penicillin-induced seizures in the rat is dependent on the amygdala.

PubMed

Tubbs, R Shane; Wellons, John C; Patwardhan, Ravish V; Oakes, W Jerry; Wyss, J Michael

2002-11-01

This study tests the hypothesis that the ability of Hering's nerve stimulation (HNS) to blunt seizure activity is dependent on the availability of dopamine in the amygdala. In 10 rats, Hering's nerve (HN) on the right side was isolated and placed on an electrode and penicillin was locally placed on each rat's left frontoparietal region to induce seizures. After the initiation of seizures, HN was stimulated. After the recurrence of seizure activity, the left basolateral amygdala was injected with 1.0 microl of normal saline, dopamine, haloperidol or 1% lidocaine in sequential tests. HN was stimulated after each injection and the latency and amplitude of the seizure activity were assessed. Focal cortical penicillin induced seizures that resulted in tonic-clonic movement of the limbs and face that lasted 35-45 min. Tonic-clonic movements of the limbs and face of similar latency and amplitude were induced by repeated reapplication of penicillin in untreated rats. HNS decreased seizure activity, but infusion of haloperidol or lidocaine into the basolateral amygdala blocked this antiseizure effect of HNS. In contrast, infusion of saline or dopamine had no effect on the ability of HNS to blunt seizure activity. None of the amygdala injections altered the latency or amplitude of seizure activity. These results demonstrate that the ability of HNS to blunt seizure activity in the rat is dependent on an intact dopamine system in the basolateral amygdala. These data will hopefully be useful in furthering our understanding of the circuitry that allows peripheral nerve stimulation to alter seizure activity. Copyright 2002 S. Karger AG, Basel

Neutrophil alveolitis following endotoxemia. Enhancement by previous exposure to hyperoxia.

PubMed

Rinaldo, J E; Dauber, J H; Christman, J; Rogers, R M

1984-12-01

We injected Escherichia coli endotoxin, 2.5 mg/kg, intraperitoneally in rats, sequentially quantified alveolar inflammation during a 6-day period by several techniques, and observed the effect of previous exposure to hyperoxia on the intensity of alveolitis in this model. As noted in other models of endotoxemia, we found intravascular sequestration of leukocytes and an increase in the retention of 125I albumin in the lung 4 to 6 h after the injection of endotoxin. Bronchoalveolar lavage fluid (BALF) obtained at this time only slightly stimulated the migration of neutrophils in vitro, and the numbers and types of cells recovered by lavage were normal. Fifteen h after the injection of endotoxin, however, bronchoalveolar lavage fluid stimulated both random and directed migration of neutrophils in vitro, although recovery of neutrophils by lavage was increased only slightly. By 24 h, 125I albumin retention had returned to normal levels, but the chemotactic activity of BALF remained high, and the percentage and absolute number of neutrophils recovered by lung lavage were increased markedly. The recovery of neutrophils remained significantly elevated for 3 days but declined to control levels by 6 days, whereas the recovery of alveolar macrophages was increased at this time. Exposure to 100% O2 for 36 h prior to endotoxemia accelerated and intensified neutrophil influx into the lung and increased the stimulatory effect of BALF on neutrophil migration in vitro. We conclude that a single episode of endotoxemia in the rat causes a multi-phasic alveolar inflammatory response, and that this response is accelerated and intensified by prior, mild exposure to hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Markovian Analysis of the Sequential Behavior of the Spontaneous Spinal Cord Dorsum Potentials Induced by Acute Nociceptive Stimulation in the Anesthetized Cat.

PubMed

Martin, Mario; Béjar, Javier; Esposito, Gennaro; Chávez, Diógenes; Contreras-Hernández, Enrique; Glusman, Silvio; Cortés, Ulises; Rudomín, Pablo

2017-01-01

In a previous study we developed a Machine Learning procedure for the automatic identification and classification of spontaneous cord dorsum potentials ( CDPs ). This study further supported the proposal that in the anesthetized cat, the spontaneous CDPs recorded from different lumbar spinal segments are generated by a distributed network of dorsal horn neurons with structured (non-random) patterns of functional connectivity and that these configurations can be changed to other non-random and stable configurations after the noceptive stimulation produced by the intradermic injection of capsaicin in the anesthetized cat. Here we present a study showing that the sequence of identified forms of the spontaneous CDPs follows a Markov chain of at least order one. That is, the system has memory in the sense that the spontaneous activation of dorsal horn neuronal ensembles producing the CDPs is not independent of the most recent activity. We used this markovian property to build a procedure to identify portions of signals as belonging to a specific functional state of connectivity among the neuronal networks involved in the generation of the CDPs . We have tested this procedure during acute nociceptive stimulation produced by the intradermic injection of capsaicin in intact as well as spinalized preparations. Altogether, our results indicate that CDP sequences cannot be generated by a renewal stochastic process. Moreover, it is possible to describe some functional features of activity in the cord dorsum by modeling the CDP sequences as generated by a Markov order one stochastic process. Finally, these Markov models make possible to determine the functional state which produced a CDP sequence. The proposed identification procedures appear to be useful for the analysis of the sequential behavior of the ongoing CDPs recorded from different spinal segments in response to a variety of experimental procedures including the changes produced by acute nociceptive stimulation. They are envisaged as a useful tool to examine alterations of the patterns of functional connectivity between dorsal horn neurons under normal and different pathological conditions, an issue of potential clinical concern.

Synovial and systemic pharmacokinetics (PK) of triamcinolone acetonide (TA) following intra-articular (IA) injection of an extended-release microsphere-based formulation (FX006) or standard crystalline suspension in patients with knee osteoarthritis (OA).

PubMed

Kraus, V B; Conaghan, P G; Aazami, H A; Mehra, P; Kivitz, A J; Lufkin, J; Hauben, J; Johnson, J R; Bodick, N

2018-01-01

Intra-articular (IA) corticosteroids relieve osteoarthritis (OA) pain, but rapid absorption into systemic circulation may limit efficacy and produce untoward effects. We compared the pharmacokinetics (PK) of IA triamcinolone acetonide (TA) delivered as an extended-release, microsphere-based formulation (FX006) vs a crystalline suspension (TAcs) in knee OA patients. This Phase 2 open-label study sequentially enrolled 81 patients who received a single IA injection of FX006 (5 mL, 32 mg delivered dose, N = 63) or TAcs (1 mL, 40 mg, N = 18). Synovial fluid (SF) aspiration was attempted in each patient at baseline and one post-IA-injection visit (FX006: Week 1, Week 6, Week 12, Week 16 or Week 20; TAcs: Week 6). Blood was collected at baseline and multiple post-injection times. TA concentrations (validated LC-MS/MS, geometric means (GMs)), PK (non-compartmental analysis models), and adverse events (AEs) were assessed. SF TA concentrations following FX006 were quantifiable through Week 12 (pg/mL: 231,328.9 at Week 1; 3590.0 at Week 6; 290.6 at Week 12); post-TAcs, only two of eight patients had quantifiable SF TA at Week 6 (7.7 pg/mL). Following FX006, plasma TA gradually increased to peak (836.4 pg/mL) over 24 h and slowly declined to <110 pg/mL over Weeks 12-20; following TAcs, plasma TA peaked at 4 h (9628.8 pg/mL), decreased to 4991.1 pg/mL at 24 h, and was 149.4 pg/mL at Week 6, the last post-treatment time point assessed. AEs were similar between groups. In knee OA patients, microsphere-based TA delivery via a single IA injection prolonged SF joint residency, diminished peak plasma levels, and thus reduced systemic TA exposure relative to TAcs. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Three-dimensional rotational angiography fused with multimodal imaging modalities for targeted endomyocardial injections in the ischaemic heart.

PubMed

Dauwe, Dieter Frans; Nuyens, Dieter; De Buck, Stijn; Claus, Piet; Gheysens, Olivier; Koole, Michel; Coudyzer, Walter; Vanden Driessche, Nina; Janssens, Laurens; Ector, Joris; Dymarkowski, Steven; Bogaert, Jan; Heidbuchel, Hein; Janssens, Stefan

2014-08-01

Biological therapies for ischaemic heart disease require efficient, safe, and affordable intramyocardial delivery. Integration of multiple imaging modalities within the fluoroscopy framework can provide valuable information to guide these procedures. We compared an anatomo-electric method (LARCA) with a non-fluoroscopic electromechanical mapping system (NOGA(®)). LARCA integrates selective three-dimensional-rotational angiograms with biplane fluoroscopy. To identify the infarct region, we studied LARCA-fusion with pre-procedural magnetic resonance imaging (MRI), dedicated CT, or (18)F-FDG-PET/CT. We induced myocardial infarction in 20 pigs by 90-min LAD occlusion. Six weeks later, we compared peri-infarct delivery accuracy of coloured fluospheres using sequential NOGA(®)- and LARCA-MRI-guided vs. LARCA-CT- and LARCA-(18)F-FDG-PET/CT-guided intramyocardial injections. MRI after 6 weeks revealed significant left ventricular (LV) functional impairment and remodelling (LVEF 31 ± 3%, LVEDV 178 ± 15 mL, infarct size 17 ± 2% LV mass). During NOGA(®)-procedures, three of five animals required DC-shock for major ventricular arrhythmias vs. one of ten during LARCA-procedures. Online procedure time was shorter for LARCA than NOGA(®) (77 ± 6 vs. 130 ± 3 min, P < 0.0001). Absolute distance of injection spots to the infarct border was similar for LARCA-MRI (4.8 ± 0.5 mm) and NOGA(®) (5.4 ± 0.5 mm). LARCA-CT-integration allowed closer approximation of the targeted border zone than LARCA-PET (4.0 ± 0.5 mm vs. 6.2 ± 0.6 mm, P < 0.05). Three-dimensional -rotational angiography fused with multimodal imaging offers a new, cost-effective, and safe strategy to guide intramyocardial injections. Endoventricular procedure times and arrhythmias compare favourably to NOGA(®), without compromising injection accuracy. LARCA-based fusion imaging is a promising enabling technology for cardiac biological therapies. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Laboratory Seismic Monitoring and X-ray CT imaging of Supercritical CO2 Injection in Reservoir Sand: WESTCAB King Island Project

NASA Astrophysics Data System (ADS)

Nakashima, S.; Kneafsey, T. J.; Nakagawa, S.; Harper, E. J.

2013-12-01

The Central Valley of California contains promising locations for on-shore geologic CO2 storage. DOE's WESTCARB (West Coast Regional Carbon Sequestration Partnership) project drilled and cored a borehole (Citizen Green Well) at King Island (near Stockton, CA) to study the CO2 storage capability of saline and gas-bearing formations in the southwestern Sacramento Basin. Potential reservoirs encountered in the borehole include Domengine, Mokelumne River (primary target), and Top Starkey formations. In anticipation of geophysical monitoring of possible CO2 injection into this particular borehole and of the long-term migration of the CO2, we conducted small-scale CO2 injection experiments on three core samples retrieved from the well (Mokelumne River sand A and B) and from a mine outcrop (Domengine sandstone). During the experiment, a jacketed core sample (diameter 1.5 inches, length 4.0-6.0 inches) saturated with brine- (1% NaCl aq.) was confined within a pressure vessel via compressed nitrogen to 3,500-4,000psi, and supercritical CO2 was injected into the core at 2,000-2,500psi and 45-60 degrees C. The CO2 pressure and temperature were adjusted so that the bulk elastic modulus of the CO2 was close to the expected in-situ modulus--which affects the seismic properties most--while keeping the confining stress within our experimental capabilities. After the CO2 broke through the core, fresh brine was re-injected to remove the CO2 by both displacement and dissolution. Throughout the experiment, seismic velocity and attenuation of the core sample were measured using the Split Hopkinson Resonant Bar method (Nakagawa, 2012, Rev. Sci. Instr.) at near 1 kHz (500Hz--1.5 kHz), and the CO2 distribution determined via x-ray CT imaging. In contrast to relatively isotropic Mokelumne sand A, Domengine sandstone and Mokelumne sand B cores exhibited CO2 distributions strongly controlled by the bedding planes. During the CO2 injection, P-wave velocity and attenuation of the layered samples changed irregularly, roughly corresponding to the sequential invasion of the compliant fluid in the sedimentary layers revealed by the CT images. The overall behavior the seismic waves and the final CO2 saturation of the cores, however, were similar for all three cores used in this experiment.

Assessment of effectiveness of percutaneous adhesiolysis in managing chronic low back pain secondary to lumbar central spinal canal stenosis.

PubMed

Manchikanti, Laxmaiah; Cash, Kimberly A; McManus, Carla D; Pampati, Vidyasagar

2013-01-01

Chronic persistent low back and lower extremity pain secondary to central spinal stenosis is common and disabling. Lumbar surgical interventions with decompression or fusion are most commonly performed to manage severe spinal stenosis. However, epidural injections are also frequently performed in managing central spinal stenosis. After failure of epidural steroid injections, the next sequential step is percutaneous adhesiolysis and hypertonic saline neurolysis with a targeted delivery. The literature on the effectiveness of percutaneous adhesiolysis in managing central spinal stenosis after failure of epidural injections has not been widely studied. A prospective evaluation. An interventional pain management practice, a specialty referral center, a private practice setting in the United States. To evaluate the effectiveness of percutaneous epidural adhesiolysis in patients with chronic low back and lower extremity pain with lumbar central spinal stenosis. Seventy patients were recruited. The initial phase of the study was randomized, double-blind with a comparison of percutaneous adhesiolysis with caudal epidural injections. The 25 patients from the adhesiolysis group continued with follow-up, along with 45 additional patients, leading to a total of 70 patients. All patients received percutaneous adhesiolysis and appropriate placement of the Racz catheter, followed by an injection of 5 mL of 2% preservative-free lidocaine with subsequent monitoring in the recovery room. In the recovery room, each patient also received 6 mL of 10% hypertonic sodium chloride solution, and 6 mg of non-particulate betamethasone, followed by an injection of 1 mL of sodium chloride solution and removal of the catheter. Multiple outcome measures were utilized including the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3, 6, and 12, 18 and 24 months post treatment. The primary outcome measure was 50% or more improvement in pain scores and ODI scores. Overall, a primary outcome or significant pain relief and functional status improvement of 50% or more was seen in 71% of patients at the end of 2 years. The overall number of procedures over a period of 2 years were 5.7 ± 2.73. The lack of a control group and a prospective design. Significant relief and functional status improvement as seen in 71% of the 70 patients with percutaneous adhesiolysis utilizing local anesthetic steroids and hypertonic sodium chloride solution may be an effective management strategy in patients with chronic function limiting low back and lower extremity pain with central spinal stenosis after failure of conservatie management and fluoroscopically directed epidural injections.

Molecularly imprinted polymers as the extracted sorbents of clenbuterol ahead of liquid chromatographic determination*

PubMed Central

Lay, Sovichea; Yu, Hai-ning; Hu, Bao-xiang; Shen, Sheng-rong

2016-01-01

A pre-treatment methodology for clenbuterol hydrochloride (CLEN) isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers (MIPs). CLEN-imprinted polymers were synthesized by the combined use of ally-β-cyclodextrin (ally-β-CD) and methacrylic acid (MAA), allyl-β-CD and acrylonitrile (AN), and allyl-β-CD and methyl methacrylate (MMA) as the binary functional monomers. MAA-linked allyl-β-CD MIPs (M-MAA) were characterized by Fourier transform-infrared (FT-IR) spectroscopy and a scanning electron microscope (SEM). Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references: AN-linked allyl-β-CD MIPs (M-AN) and MMA-linked allyl-β-CD MIPs (M-MMA). M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction (MISPE) micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation (RSD) ≤4.45%. PMID:27256680

High-throughput NGL electron-beam direct-write lithography system

NASA Astrophysics Data System (ADS)

Parker, N. William; Brodie, Alan D.; McCoy, John H.

2000-07-01

Electron beam lithography systems have historically had low throughput. The only practical solution to this limitation is an approach using many beams writing simultaneously. For single-column multi-beam systems, including projection optics (SCALPELR and PREVAIL) and blanked aperture arrays, throughput and resolution are limited by space-charge effects. Multibeam micro-column (one beam per column) systems are limited by the need for low voltage operation, electrical connection density and fabrication complexities. In this paper, we discuss a new multi-beam concept employing multiple columns each with multiple beams to generate a very large total number of parallel writing beams. This overcomes the limitations of space-charge interactions and low voltage operation. We also discuss a rationale leading to the optimum number of columns and beams per column. Using this approach we show how production throughputs >= 60 wafers per hour can be achieved at CDs

Liquid chromatographic determination of urinary 5-methyl-2'-deoxycytidine and pseudouridine as potential biological markers for leukaemia.

PubMed

Zambonin, C G; Aresta, A; Palmisano, F; Specchia, G; Liso, V

1999-12-01

A simple reversed-phase liquid chromatographic (LC) method for the determination of urinary 5-methyl-2'-deoxycytidine (m5dCyd), recently claimed (on the basis of an imuno-technique) to be a potential marker for leukaemia, has been developed. Sample pre-treatment is based on a microcolumn clean-up step with an average recovery of 79% and a RSD of 3%. Detection limit was 0.2 microg/ml which is about tenfold lower than levels previously measured by an ELISA method in urine of healthy individuals. The creatinine (Cre) excretion, necessary for normalising the m5dCyd excretion, was evaluated by ion-pair liquid chromatography which permitted the simultaneous determination of pseudouridine (psi), a modified nucleoside also potentially useful as a marker for leukaemia. The described LC procedures were applied to the analysis of urine samples from healthy individuals and leukaemia patients. While the urinary psi/Cre ratio was found significantly increased for leukaemia patients, the urinary m5dCyd levels in healthy individuals were below the detection limits and did not increase in presence of the malignant disease.

Ground-water contamination by organic bases derived from coal-tar wastes

USGS Publications Warehouse

Pereira, Wilfred E.; Rostad, Colleen E.; Garbarino, John R.; Hult, Marc F.

1983-01-01

A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed.

Groundwater contamination by organic bases derived from coal-tar wastes

USGS Publications Warehouse

Pereira, W.E.; Rostad, C.E.; Garbarino, J.R.; Hult, M.F.

1983-01-01

A fluid sample from a shallow aquifer contaminated by coal-tar wastes was analyzed for organic bases. The sample consisted of a mixture of aqueous and oily-tar phases. The phases were separated by centrifugation and filtration. Organic bases were isolated from each phase by pH adjustment and solvent extraction. Organic bases in the oily-tar phase were further purified by neutral-alumina, micro-column adsorption chromatography. Separation and identification of the organic bases in each phase were achieved by using capillary gas chromatography-mass spectrometry-computer (GC-MS-COM) and probe distillation-high resolution mass spectrometry (PD-HRMS) techniques. Organic bases present in the aqueous phase included primary aromatic amines (such as aniline, alkylated anilines, and naphthylamines) as well as azaarenes (such as alkylated pyridines, quinolines, acridine, and benzoquinolines). The oily-tar phase contained acridine, benzacridines, dibenzacridines, and numerous other azaarenes, the elemental compositions of which were determined by PD-HRMS. Azaarenes in the oily-tar phase, varying in size from 6 to 12 rings, are reported for the first time. The origin and environmental significance of these compounds are discussed. ?? 1983.

Design of collimating and rearrangement systems of laser diode array beam

NASA Astrophysics Data System (ADS)

Gao, Runmei; Fang, Tao; Fu, Rulian; Yao, Jianquan

2015-10-01

To improve the laser diode output beam quality, micro-cylindrical lens and the step-type lens combination are designed. The former is used to collimate beam in fast-axis direction, while the latter plays a role in the slow-axis of splitting and the rearrangement. The micro-column semi-elliptical lens is made with the drops of spherical zoom lensin electric field and with the help of the material properties of light-cured production, which can reduce the reflection of the front surface and total reflection loss of the after. The divergence angle in the fast axis is compressed to roughly the same as that in the slow-axis direction; Stepped lens splits compressed long strip beam in the slow axis, with parallelogram style of level equidistant and rearrange in the fast axis direction. The spot in the slow axis gets smaller and the spot becomes larger in the fast axis. At last divergence angle and the beam spot achieve balanced in the fast axis and slow axis, optical parameters BPP integrates approximate the same, and beam quality can be improved.

Subsurface Characterization and Seismic Monitoring for the Southwest Partnerships Phase III Demonstration Project at Farnsworth Field, TX

NASA Astrophysics Data System (ADS)

Will, R. A.; Balch, R. S.

2015-12-01

The Southwest Partnership on Carbon Sequestration is performing seismic based characterization and monitoring activities at an active CO2 EOR project at Farnsworth Field, Texas. CO2 is anthropogenically sourced from a fertilizer and an ethanol plant. The field has 13 CO2 injectors and has sequestered 302,982 metric tonnes of CO2 since October 2013. The field site provides an excellent laboratory for testing a range of monitoring technologies in an operating CO2 flood since planned development is sequential and allows for multiple opportunities to record zero CO2 baseline data, mid-flood data, and fully flooded data. The project is comparing and contrasting several scales of seismic technologies in order to determine best practices for large scale commercial sequestration projects. Characterization efforts include an 85 km2 3D surface seismic survey, baseline and repeat 3D VSP surveys centered on injection wells, cross-well tomography baseline and repeat surveys between injector/producer pairs, and a borehole passive seismic array to monitor induced seismicity. All surveys have contributed to detailed geologic models which were then used for fluid flow and risk assessment simulations. 3D VSP and cross-well data with repeat surveys have allowed for direct comparisons of the reservoir prior to CO2 injection and at eight months into injection, with a goal of imaging the CO2 plume as it moves away from injection wells. Additional repeat surveys at regular intervals will continue to refine the plume. The goal of this work is to demonstrate seismic based technologies to monitor CO2 sequestration projects, and to contribute to best practices manuals for commercial scale CO2 sequestration projects. In this talk the seismic plan will be outlined, progress towards goals enumerated, and preliminary results from baseline and repeat seismic data will be discussed. Funding for this project is provided by the U.S. Department of Energy under Award No. DE-FC26-05NT42591.

Biodistribution and pharmacokinetics of In-111-labeled Stealth{reg_sign} liposomes in patients with solid tumours

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrington, K.J.; Peters, A.M.; Mohammadtaghi, S.

1996-05-01

The use of liposomal doxorubicin yields response rates of up to 70-80% in patients with AIDS-related Kaposi`s sarcoma with favourable alteration of the toxicity profile of the drug. Liposomal delivery of therapy in patients with solid cancers is currently under investigation. Our aim is to determine the biodistribution and pharmacokinetics of In-111-labeled Stealth{reg_sign} liposomes (SEQUUS{trademark}) liposomes (SEQUUS{trademark} Pharmaceuticals Inc., Menlo Park, USA) in patients with advanced solid malignant tumours. Ten patients (4 male, 6 female) with a median age of 59 (range 43 - 75) received 100 MBq of In-111-labeled Stealth{reg_sign} liposomes. Four had breast cancer, 3 head and neckmore » tumours, 2 lung and 1 cervical cancer. Blood samples and whole body gamma camera images were obtained at 0.5, 4, 24, 48, 72, 96 and 240 hours after injection and sequential 24 hour urine collections were performed for the first 96 h. SPECT imaging was performed when indicated. High definition images of tumours were obtained in 9 patients (3/4 breast, 3/3 head and neck, 2/2 lung and 1/1 cervix cancers). One patient (breast cancer) had negative images. The median cumulative urinary excretion of In-111 over the first 96 h was 17.8 (range 3.5-21.3) % of the injected dose. The uptake of liposomes in various tissues was estimated from regions of interest on the whole body images. Prominent uptake was seen in the liver (10-15% of injected dose), lungs (4-9%) and spleen (2-8%). Tumour uptake in the first 96 h varied form 0.5-4% of the injected dose. This is approximately 10 fold higher than might be expected from experience with other targeting methods (eg monoclonal antibodies). These data confirm that Stealth liposomes have a prolonged circulation half-life and localise to solid tumour tissue.« less

Rheological study of copper and copper grapheme feedstock for powder injection molding

NASA Astrophysics Data System (ADS)

Azaman, N. Emira Binti; Rafi Raza, M.; Muhamad, N.; Niaz Akhtar, M.; Bakar Sulong, A.

2017-01-01

Heatsink is one of the solution to optimize the performance of smart electronic devices. Copper and its composites are helping the electronic industry to solve the heating problem. Copper-graphene heat sink material with enhanced thermal conductivity is the ultimate goal.Powder injection molding (PIM) has advantages of high precision and production rate, complex shape, low cost and suitabality for metal and cremics.PIM consists of four sub sequential steps; feedstock preparation, molding, debinding and sintering. Feedstock preparation is a critical step in PIM process. Any deficiency at this stage cannot be recovered at latter stages. Therefore, this research was carried out to investigate the injectability of copper and copper graphene composite using PIM. PEG based multicomponent binder system was used and the powder loading was upto 7vol.% less than the critical powder loading was used to provide the wettability of the copper powder and graphene nanoplatelets (GNps). Corpper-graphene feedstock contained 0.5vol.% of GNps . To ensure the homogeneity of GNps within feedstock a unique technique was addopted. The microscopic results showed that the feedstock is homogeneous and ready for injection. The viscosity-shear rate relationship was determined and results showed that the addition of 0.5vol.% of GNps in copper has increased the viscosity upto 64.9% at 140˚C than that of pure copper feedstock. This attribute may be due to the large surface area of GNps. On the other hand, by increasing the temperature, viscosity of the feedstock was decreased, which was recommended for PIM. The overall viscosity and share rate lies within the range recommended for PIM process. It is clear that both feedstocks showed pseudo plastic behaviour which is suitable for PIM process. In the pseudo plastic behaviour, the viscosity decreases with the shear rate. It may be due to change in the structure of the solid particles or the binder. The molding results showed that both copper feedstocks were successfully molded and free from the physical defects.

EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

PubMed Central

Andreyev, Andriy; Sitek, Arkadiusz; Celler, Anna

2014-01-01

Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracer A which is a pure positron emitter (such as 18F or 11C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as 38K or 60Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and staggered injections improves the accuracy of DIPET reconstructions for static acquisitions so they reach almost the benchmark level calculated for perfectly separated tracers. PMID:24506645

Fuel system for rotary distributor fuel injection pump

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klopfer, K.H.; Kelly, W.W.

1993-06-01

In a fuel injection pump having a drive shaft, a pump rotor driven by the drive shaft, reciprocating pumping means with periodic intake and pumping strokes to periodically receive an intake charge of fuel and deliver fuel at high pressure for fuel injection is described; a distributor head with a plurality of angularly spaced distributor outlets, the pump rotor providing a distributor rotor with a distributor port connected to the pumping means, the distributor rotor being rotatably mounted in the distributor head for sequential registration of the distributor port with the distributor outlets for distributing said high pressure delivery ofmore » fuel thereto; a fuel system for supplying fuel to the pumping means, having an end chamber at one end of the pump rotor and a fuel supply pump driven by the drive shaft and having an inlet and outlet, the supply pump outlet being connected to the end chamber for supplying fuel thereto, and a pressure regulator for regulating the fuel pressure in the end chamber; and a control valve connected between the pumping means and the end chamber and selectively opened during the intake strokes to supply fuel to the pumping means from the end chamber and during the pumping strokes to spill fuel from the pumping means into the end chamber to terminate said high pressure delivery of fuel; the improvement wherein the fuel system comprises a fuel return passage connected in series with the end chamber downstream thereof, wherein the pressure regulator is mounted in the return passage for regulating the upstream fuel pressure, including the upstream fuel pressure within the end chamber, and is connected for conducting excess fuel for return to the supply pump inlet, and wherein the supply pump is driven by the drive shaft to supply fuel at a rate exceeding the rate of said high pressure delivery of fuel for fuel injection and to provide excess fuel flow continuously through the end chamber and return passage to the pressure regulator.« less

Immunogenicity and safety of zoster vaccine live administered with quadrivalent influenza virus vaccine.

PubMed

Levin, Myron J; Buchwald, Ulrike K; Gardner, Julie; Martin, Jason; Stek, Jon E; Brown, Elizabeth; Popmihajlov, Zoran

2018-01-02

Randomized, blinded, placebo-controlled trial to evaluate the safety and immunogenicity of ZOSTAVAX™ (ZV) administered concomitantly with quadrivalent inactivated influenza vaccine (IIV4) in adults≥50years of age (NCT02519855). Overall, 440 participants were randomized into the Concomitant Group (CG) and 442 into the Sequential Group (SG). The CG received ZV and IIV4 at separate injection sites on Day 1 and matching placebo at Week 4. The SG received placebo and IIV4 (2015-2016 influenza season) at separate injection sites on Day 1 and ZV at Week 4. Varicella-zoster virus (VZV) antibody geometric mean titer (GMT) and geometric mean fold-rise (GMFR) from baseline to 4weeks postvaccination, measured by glycoprotein enzyme-linked immunosorbent assay (gpELISA) and adjusted for age and prevaccination titer. Influenza strain-specific GMT at baseline and 4weeks postvaccination was measured by hemagglutination inhibition (HAI) assay. Injection-site and systemic adverse experiences (AEs) within 28days following any vaccination and serious AEs throughout the study. The adjusted VZV antibody GMT ratio (CG/SG) was 0.87 (95%CI: 0.80, 0.95), meeting the prespecified noninferiority criterion. The VZV antibody GMFR in the CG was 1.9 (95%CI: 1.76, 2.05), meeting the acceptability criterion. Influenza antibody GMT ratios for A/H1N1, A/H3N2, B/Yamagata and B/Victoria were 1.02 (95%CI: 0.88, 1.18), 1.10 (95%CI: 0.94, 1.29), 1.00 (95%CI: 0.88, 1.14), and 0.99 (95%CI: 0.87, 1.13), respectively. The frequency of vaccine-related injection-site and systemic AEs was comparable between groups. No vaccine-related serious AE was observed. The concomitant administration of ZV and IIV4 to adults≥50years of age induced VZV-specific and influenza-specific antibody responses that were comparable to those following administration of either vaccine alone, and was generally well tolerated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eco-friendly synthesis of gelatin-capped bimetallic Au-Ag nanoparticles for chemiluminescence detection of anticancer raloxifene hydrochloride.

PubMed

Alarfaj, Nawal A; El-Tohamy, Maha F

2016-09-01

This study described the utility of green analytical chemistry in the synthesis of gelatin-capped silver, gold and bimetallic gold-silver nanoparticles (NPs). The preparation of nanoparticles was based on the reaction of silver nitrate or chlorauric acid with a 1.0 wt% aqueous gelatin solution at 50°C. The gelatin-capped silver, gold and bimetallic NPs were characterized using transmission electron microscopy, UV-vis, X-ray diffraction and Fourier transform infrared spectroscopy, and were used to enhance a sensitive sequential injection chemiluminescence luminol-potassium ferricyanide system for determination of the anticancer drug raloxifene hydrochloride. The developed method is eco-friendly and sensitive for chemiluminescence detection of the selected drug in its bulk powder, pharmaceutical injections and biosamples. After optimizing the conditions, a linear relationship in the range of 1.0 × 10(-9) to 1.0 × 10(-1)  mol/L was obtained with a limit of detection of 5.0 × 10(-10)  mol/L and a limit of quantification of 1.0 × 10(-9)  mol/L. Statistical treatment and method validation were performed based on ICH guidelines. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Feedback from visual cortical area 7 to areas 17 and 18 in cats: How neural web is woven during feedback.

PubMed

Yang, X; Ding, H; Lu, J

2016-01-15

To investigate the feedback effect from area 7 to areas 17 and 18, intrinsic signal optical imaging combined with pharmacological, morphological methods and functional magnetic resonance imaging (fMRI) was employed. A spatial frequency-dependent decrease in response amplitude of orientation maps was observed in areas 17 and 18 when area 7 was inactivated by a local injection of GABA, or by a lesion induced by liquid nitrogen freezing. The pattern of orientation maps of areas 17 and 18 after the inactivation of area 7, if they were not totally blurred, paralleled the normal one. In morphological experiments, after one point at the shallow layers within the center of the cat's orientation column of area 17 was injected electrophoretically with HRP (horseradish peroxidase), three sequential patches in layers 1, 2 and 3 of area 7 were observed. Employing fMRI it was found that area 7 feedbacks mainly to areas 17 and 18 on ipsilateral hemisphere. Therefore, our conclusions are: (1) feedback from area 7 to areas 17 and 18 is spatial frequency modulated; (2) feedback from area 7 to areas 17 and 18 occurs mainly ipsilaterally; (3) histological feedback pattern from area 7 to area 17 is weblike. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Simultaneous detection of assembly and disassembly of multivalent HA tag and anti-HA antibody in single in-capillary assay.

PubMed

Wang, Jianhao; Qin, Yuqin; Qin, Haifang; Liu, Li; Ding, Shumin; Teng, Yiwan; Ji, Junling; Qiu, Lin; Jiang, Pengju

2016-08-01

Herein, we have developed an in-capillary assay for simultaneous detection of the assembly and disassembly of the multivalent HA tag peptide and antibody. HA tag with hexahistidine at C terminus (YPYDVPDYAG4 H6 , termed YPYDH6 ) was conjugated with quantum dots (QDs) by metal-affinity force to form a multivalent HA tag (QD-YPYDH6 ). QD-YPYDH6 and monoclonal anti-HA antibody (anti-HA) were sequentially injected into the capillary. They were mixed and assembled inside the capillary. The reaction products were online discriminated and detected by fluorescence coupled capillary electrophoresis (CE-FL). For the in-capillary assay, the binding efficiency of the multivalent HA tag and antibody on was influenced by the molar ratio and injection time. Such novel assay could even give out the self-assembly kinetic constant of QDs and YPYDH6 as KD of 34.1 μM with n (binding cooperativeness) of 2.2 by Hill equation. More importantly, the simultaneous detection of the assembly and imidazole (Im) induced disassembly of the QD-YPYDH6 -anti-HA complex was achieved in a single in-capillary assay. Our study demonstrated a new method for the online detection of antigen-antibody interactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

pH-based fiber optic biosensors for use in clinical and biotechnological applications

NASA Astrophysics Data System (ADS)

Mueller, Cord; Hitzmann, Bernd; Schubert, Florian; Scheper, Thomas

1995-05-01

The development of pH-based fiber optic biosensors and their uses in clinical and biotechnological applications are described. Based on a pH-sensitive optode, different biosensors for urea, penicillin, glucose and creatinine were developed. A multichannel modular fluorimeter was used to measure signals from up to three optodes simultaneously. The pH value and the buffer capacity are critical factors for biosensors based on pH probes and influence the biosensor signal. A flow injection analysis (FIA) system is used to eliminate the latter influences. With this integrated system, samples can be analyzed sequentially by the injection of a defined volume of each sample into a continuously flowing buffer stream that transports the samples to the sensors. The complex signal is transformed and analyzed by a computer system. Characteristic features of the FIA peak give information about the buffer capacity in the solution. With the help of intelligent computing (neural networks) it is possible to recognize these features and relate them to the respective buffer capacity to obtain more accurate values. Various applications of these biosensors are discussed. The pH optode is also used to monitor enzymatic reactions in non aqueous solvents. In this case the production of acetic acid can be detected on line.

Scintigraphic evaluation of digital circulation during the developmental and acute phases of equine laminitis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trout, D.R.

1987-01-01

Using nuclear isotopic imaging, digital circulation was sequentially evaluated at 24-hour intervals in 11 control horses and in 9 horses affected with acute laminitis, created by administration of a high-starch ration. Following intra-arterial injection of /sup 99m/Tc macroaggregated albumin into the brachiocephalic trunk, a gamma camera and dedicated nuclear medicine computer were used to acquire static images of the right front foot. Dynamic vascular-phase and static interstitial-phase images were also obtained after jugular vein injection of /sup 99m/Tc diethylenetriamine pentaacetic acid. These procedures were performed on standing horses, using either minimal or no tranquilization. The images were quantitatively analyzed formore » parameters indicative of circulation to the foot as a whole and to specific regions of interest within the foot. There was no evidence of reduced total blood flow to the lamellae during either the developmental or acute phases of laminitis. Although total flow tended to increase throughout the peripheral/external regions of the foot, statistically significant elevations were consistently present only within the lamellae. Changes indicative of decreased total blood flow were noted in the central/internal regions of the foot. These alterations usually occurred coincident with or after the onset of clinical lameness.« less

Inactivated poliovirus type 2 vaccine delivered to rat skin via high density microprojection array elicits potent neutralising antibody responses.

PubMed

Muller, David A; Pearson, Frances E; Fernando, Germain J P; Agyei-Yeboah, Christiana; Owens, Nick S; Corrie, Simon R; Crichton, Michael L; Wei, Jonathan C J; Weldon, William C; Oberste, M Steven; Young, Paul R; Kendall, Mark A F

2016-02-25

Polio eradication is progressing rapidly, and the live attenuated Sabin strains in the oral poliovirus vaccine (OPV) are being removed sequentially, starting with type 2 in April 2016. For risk mitigation, countries are introducing inactivated poliovirus vaccine (IPV) into routine vaccination programs. After April 2016, monovalent type 2 OPV will be available for type 2 outbreak control. Because the current IPV is not suitable for house-to-house vaccination campaigns (the intramuscular injections require health professionals), we developed a high-density microprojection array, the Nanopatch, delivered monovalent type 2 IPV (IPV2) vaccine to the skin. To assess the immunogenicity of the Nanopatch, we performed a dose-matched study in rats, comparing the immunogenicity of IPV2 delivered by intramuscular injection or Nanopatch immunisation. A single dose of 0.2 D-antigen units of IPV2 elicited protective levels of poliovirus antibodies in 100% of animals. However, animals receiving IPV2 by IM required at least 3 immunisations to reach the same neutralising antibody titres. This level of dose reduction (1/40th of a full dose) is unprecedented for poliovirus vaccine delivery. The ease of administration coupled with the dose reduction observed in this study points to the Nanopatch as a potential tool for facilitating inexpensive IPV for mass vaccination campaigns.

Pilot study of combination transcriptional modulation therapy with sodium phenylbutyrate and 5-azacytidine in patients with acute myeloid leukemia or myelodysplastic syndrome.

PubMed

Maslak, P; Chanel, S; Camacho, L H; Soignet, S; Pandolfi, P P; Guernah, I; Warrell, R; Nimer, S

2006-02-01

Epigenetic mechanisms underlying tumorigenesis have recently received much attention as potential therapeutic targets of human cancer. We designed a pilot study to target DNA methylation and histone deacetylation through the sequential administration of 5-azacytidine followed by sodium phenylbutyrate (PB) in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Ten evaluable patients (eight AML, two MDS) were treated with seven consecutive daily subcutaneous injections of 5-azacytidine at 75 mg/m2 followed by 5 days of sodium PB given intravenously at a dose of 200 mg/kg. Five patients (50%) were able to achieve a beneficial clinical response (partial remission or stable disease). One patient with MDS proceeded to allogeneic stem cell transplantation and is alive without evidence of disease 39 months later. The combination regimen was well tolerated with common toxicities of injection site skin reaction (90% of the patients) from 5-azacytidine, and somnolence/fatigue from the sodium PB infusion (80% of the patients). Correlative laboratory studies demonstrated the consistent reacetylation of histone H4, although no relationship with the clinical response could be demonstrated. Results from this pilot study demonstrate that a combination approach targeting different mechanisms of transcriptional modulation is clinically feasible with acceptable toxicity and measurable biologic and clinical outcomes.

High-throughput flow injection analysis mass spectroscopy with networked delivery of color-rendered results. 2. Three-dimensional spectral mapping of 96-well combinatorial chemistry racks.

PubMed

Görlach, E; Richmond, R; Lewis, I

1998-08-01

For the last two years, the mass spectroscopy section of the Novartis Pharma Research Core Technology group has analyzed tens of thousands of multiple parallel synthesis samples from the Novartis Pharma Combinatorial Chemistry program, using an in-house developed automated high-throughput flow injection analysis electrospray ionization mass spectroscopy system. The electrospray spectra of these samples reflect the many structures present after the cleavage step from the solid support. The overall success of the sequential synthesis is mirrored in the purity of the expected end product, but the partial success of individual synthesis steps is evident in the impurities in the mass spectrum. However this latter reaction information, which is of considerable utility to the combinatorial chemist, is effectively hidden from view by the very large number of analyzed samples. This information is now revealed at the workbench of the combinatorial chemist by a novel three-dimensional display of each rack's complete mass spectral ion current using the in-house RackViewer Visual Basic application. Colorization of "forbidden loss" and "forbidden gas-adduct" zones, normalization to expected monoisotopic molecular weight, colorization of ionization intensity, and sorting by row or column were used in combination to highlight systematic patterns in the mass spectroscopy data.

Interkinetic and migratory behavior of a cohort of neocortical neurons arising in the early embryonic murine cerebral wall

NASA Technical Reports Server (NTRS)

Takahashi, T.; Nowakowski, R. S.; Caviness, V. S. Jr

1996-01-01

Neocortical neuronogenesis occurs in the pseudostratified ventricular epithelium (PVE) where nuclei of proliferative cells undergo interkinetic nuclear movement. A fraction of daughter cells exits the cell cycle as neurons (the quiescent, or Q, fraction), whereas a complementary fraction remains in the cell cycle (the proliferative, or P, fraction). By means of sequential thymidine and bromodeoxyuridine injections in mouse on embryonic day 14, we have monitored the proliferative and post-mitotic migratory behaviors of 1 and 2 hr cohorts of PVE cells defined by the injection protocols. Soon after mitosis, the Q fraction partitions into a rapidly exiting (up to 50 microns/hr) subpopulation (Qr) and a more slowly exiting (6 microns/hr) subpopulation (Qs). Qr and Qs are separated as two distributions on exit from the ventricular zone with an interpeak distance of approximately 40 microns. Cells in Qr and Qs migrate through the intermediate zone with no significant change in the interpeak distance, suggesting that they migrate at approximately the same velocities. The rate of migration increases with ascent through the intermediate zone (average 2-6.4 microns/hr) slowing only transiently on entry into the developing cortex. Within the cortex, Qr and Qs merge to form a single distribution most concentrated over layer V.

Metabolism of glucose, fructose and lactate in vivo in chronically cannulated foetuses and in suckling lambs.

PubMed Central

Warnes, D M; Seamark, R F; Ballard, F J

1977-01-01

1. Chronically cannulated sheep foetuses and suckling lambs were injected with 14C-labelled glucose, fructose or lactate, and sequential blood samples taken under conditions of minimal stress and without anaesthesia. 2. Gluconeogenesis from lactate was not detectable in foetal sheep, but the pathway was active in suckling lambs. 3. Fructose utilization rates were low in foetal sheep, with no measurable conversion into glucose or lactate. 4. The high rates of irreversible loss of both glucose and lactate in the foetus were decreased in suckling lambs. Radioactivity from labelled glucose entered both the lactate and fructose pools in foetal sheep, and entered the lactate pool in suckling lambs. 5. A model is proposed in which carbon flow between glucose, fructose and lactate has been quantified in foetal sheep. PMID:869907

Spontaneous Reperfusion after In Situ Thromboembolic Stroke in Mice

PubMed Central

Cho, Tae-Hee; Bolbos, Radu; Langlois, Jean-Baptiste; Hermitte, Laure; Wiart, Marlène; Berthezène, Yves; Nighoghossian, Norbert

2012-01-01

Injection of thrombin into the middle cerebral artery (MCA) of mice has been proposed as a new model of thromboembolic stroke. The present study used sequential multiparametric Magnetic Resonance Imaging (MRI), including Magnetic Resonance Angiography (MRA), Diffusion-Weighted Imaging (DWI) and Perfusion-Weighted Imaging (PWI), to document MCA occlusion, PWI-DWI mismatch, and lesion development. In the first experiment, complete MCA occlusion and reproducible hypoperfusion were obtained in 85% of animals during the first hour after stroke onset. In the second experiment, 80% of animals showed partial to complete reperfusion during a three-hour follow-up. Spontaneous reperfusion thus contributed to the variability in ischemic volume in this model. The study confirmed the value of the model for evaluating new thrombolytic treatments, but calls for extended MRI follow-up at the acute stage in therapeutic studies. PMID:23166825

The effect of a sequential structure of practice for the training of perceptual-cognitive skills in tennis

PubMed Central

2017-01-01

Objective Anticipation of opponent actions, through the use of advanced (i.e., pre-event) kinematic information, can be trained using video-based temporal occlusion. Typically, this involves isolated opponent skills/shots presented as trials in a random order. However, two different areas of research concerning representative task design and contextual (non-kinematic) information, suggest this structure of practice restricts expert performance. The aim of this study was to examine the effect of a sequential structure of practice during video-based training of anticipatory behavior in tennis, as well as the transfer of these skills to the performance environment. Methods In a pre-practice-retention-transfer design, participants viewed life-sized video of tennis rallies across practice in either a sequential order (sequential group), in which participants were exposed to opponent skills/shots in the order they occur in the sport, or a non-sequential (non-sequential group) random order. Results In the video-based retention test, the sequential group was significantly more accurate in their anticipatory judgments when the retention condition replicated the sequential structure compared to the non-sequential group. In the non-sequential retention condition, the non-sequential group was more accurate than the sequential group. In the field-based transfer test, overall decision time was significantly faster in the sequential group compared to the non-sequential group. Conclusion Findings highlight the benefits of a sequential structure of practice for the transfer of anticipatory behavior in tennis. We discuss the role of contextual information, and the importance of representative task design, for the testing and training of perceptual-cognitive skills in sport. PMID:28355263

Extending the upper temperature range of gas chromatography with all-silicon microchip columns using a heater/clamp assembly.

PubMed

Ghosh, Abhijit; Johnson, Jacob E; Nuss, Johnathan G; Stark, Brittany A; Hawkins, Aaron R; Tolley, Luke T; Iverson, Brian D; Tolley, H Dennis; Lee, Milton L

2017-09-29

Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in GC with columns fabricated in microchips (referred to in this paper as "microchip columns"), the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector. In this work, a GC system utilizing microchip columns was developed that solves the latter challenge, i.e., microchip interfacing to injector and detector. A microchip compression clamp was constructed to heat the microchip (i.e., primary heater), and seal the injector and detector fused silica interface tubing to the inlet and outlet ports of the microchip channels with minimum extra-column dead volume. This clamp allowed occasional operation up to 375°C and routine operation up to 300°C. The compression clamp was constructed of a low expansion alloy, Kovar™, to minimize leaking due to thermal expansion mismatch at the interface during repeated thermal cycling, and it was tested over several months for more than one hundred injections without forming leaks. A 5.9m long microcolumn with rectangular cross section of 158μm×80μm, which approximately matches a 100μm i.d. cylindrical fused silica column, was fabricated in a silicon wafer using deep reactive ion etching (DRIE) and high temperature fusion bonding; finally, the channel was coated statically with a 1% vinyl, 5% phenyl, 94% methylpolysiloxane stationary phase. High temperature separations of C10-C40 n-alkanes and a commercial diesel sample were demonstrated using the system under both temperature programmed GC (TPGC) and thermal gradient GC (TGGC) conditions. TGGC analysis of a complex essential oil sample was also demonstrated. Addition of a secondary heater and polyimide insulation proved to be helpful in achieving the desired elution temperature without having to raise the primary heater temperature above 300°C for high boiling point compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Advantages of core-shell particle columns in Sequential Injection Chromatography for determination of phenolic acids.

PubMed

Chocholouš, Petr; Vacková, Jana; Srámková, Ivana; Satínský, Dalibor; Solich, Petr

2013-01-15

Currently, for Sequential Injection Chromatography (SIC), only reversed phase C18 columns have been used for chromatographic separations. This article presents the first use of three different stationary phases: three core-shell particle-packed reversed phase columns in flow systems. The aim of this work was to extend the chromatographic capabilities of the SIC system. Despite the particle-packed columns reaching system pressures of ≤ 610 PSI, their conditions matched those of a commercially produced and optimised SIC system (SIChrom™ (FIAlab(®), USA)) with a 8-port high-pressure selection valve and medium-pressure Sapphire™ syringe pump with a 4 mL reservoir and maximum system pressure of ≤ 1000 PSI. The selectivity of each of the tested columns, Ascentis(®) Express RP-Amide, Ascentis(®) Express Phenyl-Hexyl and Ascentis(®) Express C18 (30 mm × 4.6mm, core-shell particle size 2.7 μm), was compared by their ability to separate seven phenolic acids that are secondary metabolite substances widely distributed in plants. The separations of all of the components were performed by isocratic elution using binary mobile phases composed of acetonitrile and 0.065% phosphoric acid at pH 2.4 (a specific ratio was used for each column) at a flow-rate of 0.60 mL/min. The volume of the mobile phase was 3.8 mL for each separation. The injection volume of the sample was 10 μL for each separation. The UV detection wavelengths were set to 250, 280 and 325 nm. The RP-Amide column provided the highest chromatographic resolution and allowed for complete baseline separation of protocatechuic, syringic, vanillic, ferulic, sinapinic, p-coumaric and o-coumaric acids. The Phenyl-Hexyl and C18 columns were unable to completely separate the tested mixture, syringic and vanillic acid and ferulic and sinapinic acids could not be separated from one another. The analytical parameters were a LOD of 0.3 mg L(-1), a LOQ of 1.0 mg L(-1), a calibration range of 1.0-50.0 (100.0) mg L(-1) (r>0.997) and a system precision of 10 mg L(-1) with a RSD ≤ 1.65%. The high performance of the chromatography process with the RP-Amide column under optimised conditions was highlighted and well documented (HETP values ≤ 10 μm, peak symmetry ≤ 1.33, resolution ≥ 1.87 and time for one analysis <8.0 min). The results of these experiments confirmed the benefits of extending chromatographic selectivity using core-shell particle column technology in a SIC manifold. Copyright © 2012 Elsevier B.V. All rights reserved.

Bioinspired Nanocomplex for Spatiotemporal Imaging of Sequential mRNA Expression in Differentiating Neural Stem Cells

PubMed Central

2015-01-01

Messenger RNA plays a pivotal role in regulating cellular activities. The expression dynamics of specific mRNA contains substantial information on the intracellular milieu. Unlike the imaging of stationary mRNAs, real-time intracellular imaging of the dynamics of mRNA expression is of great value for investigating mRNA biology and exploring specific cellular cascades. In addition to advanced imaging methods, timely extracellular stimulation is another key factor in regulating the mRNA expression repertoire. The integration of effective stimulation and imaging into a single robust system would significantly improve stimulation efficiency and imaging accuracy, producing fewer unwanted artifacts. In this study, we developed a multifunctional nanocomplex to enable self-activating and spatiotemporal imaging of the dynamics of mRNA sequential expression during the neural stem cell differentiation process. This nanocomplex showed improved enzymatic stability, fast recognition kinetics, and high specificity. With a mechanism regulated by endogenous cell machinery, this nanocomplex realized the successive stimulating motif release and the dynamic imaging of chronological mRNA expression during neural stem cell differentiation without the use of transgenetic manipulation. The dynamic imaging montage of mRNA expression ultimately facilitated genetic heterogeneity analysis. In vivo lateral ventricle injection of this nanocomplex enabled endogenous neural stem cell activation and labeling at their specific differentiation stages. This nanocomplex is highly amenable as an alternative tool to explore the dynamics of intricate mRNA activities in various physiological and pathological conditions. PMID:25494492

Bioinspired nanocomplex for spatiotemporal imaging of sequential mRNA expression in differentiating neural stem cells.

PubMed

Wang, Zhe; Zhang, Ruili; Wang, Zhongliang; Wang, He-Fang; Wang, Yu; Zhao, Jun; Wang, Fu; Li, Weitao; Niu, Gang; Kiesewetter, Dale O; Chen, Xiaoyuan

2014-12-23

Messenger RNA plays a pivotal role in regulating cellular activities. The expression dynamics of specific mRNA contains substantial information on the intracellular milieu. Unlike the imaging of stationary mRNAs, real-time intracellular imaging of the dynamics of mRNA expression is of great value for investigating mRNA biology and exploring specific cellular cascades. In addition to advanced imaging methods, timely extracellular stimulation is another key factor in regulating the mRNA expression repertoire. The integration of effective stimulation and imaging into a single robust system would significantly improve stimulation efficiency and imaging accuracy, producing fewer unwanted artifacts. In this study, we developed a multifunctional nanocomplex to enable self-activating and spatiotemporal imaging of the dynamics of mRNA sequential expression during the neural stem cell differentiation process. This nanocomplex showed improved enzymatic stability, fast recognition kinetics, and high specificity. With a mechanism regulated by endogenous cell machinery, this nanocomplex realized the successive stimulating motif release and the dynamic imaging of chronological mRNA expression during neural stem cell differentiation without the use of transgenetic manipulation. The dynamic imaging montage of mRNA expression ultimately facilitated genetic heterogeneity analysis. In vivo lateral ventricle injection of this nanocomplex enabled endogenous neural stem cell activation and labeling at their specific differentiation stages. This nanocomplex is highly amenable as an alternative tool to explore the dynamics of intricate mRNA activities in various physiological and pathological conditions.

Dissociation of metabolic and hemodynamic levodopa responses in the 6-hydroxydopamine rat model.

PubMed

Lerner, Renata P; Bimpisidis, Zisis; Agorastos, Stergiani; Scherrer, Sandra; Dewey, Stephen L; Cenci, M Angela; Eidelberg, David

2016-12-01

Dissociation of vasomotor and metabolic responses to levodopa has been observed in human subjects with Parkinson's disease (PD) studied with PET and in autoradiograms from 6-hydroxydopamine (6-OHDA) rat. In both species, acute levodopa administration was associated with increases in basal ganglia cerebral blood flow (CBF) with concurrent reductions in cerebral metabolic rate (CMR) for glucose in the same brain regions. In this study, we used a novel dual-tracer microPET technique to measure CBF and CMR levodopa responses in the same animal. Rats with unilateral 6-OHDA or sham lesion underwent sequential 15 O-water (H 2 15 O) and 18 F-fluorodeoxyglucose (FDG) microPET to map CBF and CMR following the injection of levodopa or saline. A subset of animals was separately scanned under ketamine/xylazine and isoflurane to compare the effects of these anesthetics. Regardless of anesthetic agent, 6-OHDA animals exhibited significant dissociation of vasomotor (ΔCBF) and metabolic (ΔCMR) responses to levodopa, with stereotyped increases in CBF and reductions in CMR in the basal ganglia ipsilateral to the dopamine lesion. No significant changes were seen in sham-lesioned animals. These data faithfully recapitulate analogous dissociation effects observed previously in human PD subjects scanned sequentially during levodopa infusion. This approach may have utility in the assessment of new drugs targeting the exaggerated regional vasomotor responses seen in human PD and in experimental models of levodopa-induced dyskinesia. Copyright © 2016 Elsevier Inc. All rights reserved.

Sequential Syndrome Decoding of Convolutional Codes

NASA Technical Reports Server (NTRS)

Reed, I. S.; Truong, T. K.

1984-01-01

The algebraic structure of convolutional codes are reviewed and sequential syndrome decoding is applied to those codes. These concepts are then used to realize by example actual sequential decoding, using the stack algorithm. The Fano metric for use in sequential decoding is modified so that it can be utilized to sequentially find the minimum weight error sequence.

Robustness of the sequential lineup advantage.

PubMed

Gronlund, Scott D; Carlson, Curt A; Dailey, Sarah B; Goodsell, Charles A

2009-06-01

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Intraocular Pressure Increases After Intraarticular Knee Injection With Triamcinolone but Not Hyaluronic Acid.

PubMed

Taliaferro, Kevin; Crawford, Alexander; Jabara, Justin; Lynch, Jonathan; Jung, Edward; Zvirbulis, Raimonds; Banka, Trevor

2018-07-01

Intraarticular steroid injections are a common first-line therapy for severe osteoarthritis, which affects an estimated 27 million people in the United States. Although topical, oral, intranasal, and inhalational steroids are known to increase intraocular pressure in some patients, the effect of intraarticular steroid injections on intraocular pressure has not been investigated, to the best of our knowledge. If elevated intraocular pressure is sustained for long periods of time or is of sufficient magnitude acutely, permanent loss of the visual field can occur. How does intraocular pressure change 1 week after an intraarticular knee injection either with triamcinolone acetonide or hyaluronic acid? A nonrandomized, nonblinded prospective cohort study was conducted at an outpatient, ambulatory orthopaedic clinic. This study compared intraocular pressure elevation before and 1 week after intraarticular knee injection of triamcinolone acetonide versus hyaluronic acid for management of primary osteoarthritis of the knee. Patients self-selected to be injected in their knee with either triamcinolone acetonide or hyaluronic acid before being informed of the study. The primary endpoint was intraocular pressure elevation of ≥ 7 mm Hg 1 week after injection. This cutoff is determined as the minimum significant pressure change in the ophthalmology literature recognized as an intermediate responder to steroids. Intraocular pressure was measured using a handheld Tono-Pen® applanation device. This device is frequently used in intraocular pressure measurement in clinical and research settings; 10 sequential measurements are obtained and averaged with a confidence interval. Only measurements with a 95% confidence interval were used. Over a 6-month period, a total of 96 patients were approached to enroll in the study. Sixty-two patients out of 96 approached (65%) agreed. Thirty-one (50%) were injected with triamcinolone and 31 (50%) were injected with hyaluronic acid. Patients with osteoarthritis of the knee who were suitable candidates for either a steroid injection or hyaluronic acid injection were included in the study. Exclusion criteria included previous glaucoma surgery, previous corneal injury precluding use of a Tono-Pen, current acute or chronic steroid use, and diagnosis of glaucoma other than primary open-angle. Patients with elevated intraocular pressure at the 1-week timepoint were invited to return at 1 month for repeat measurement; however, only five of nine (55.6%) were able to do so. The mean age of the total population was 64.1 ± 11.65 years. There were 46 (74%) women and 16 men. Patient in the hyaluronic acid injection group were younger than the triamcinolone group, 59.5 ± 11.7 versus 68.7 ± 9.7 years of age (p < 0.003). The mean intraocular pressure increased by 2.79 mm Hg 1 week after treatment with triamcinolone, but it did not change among those patients treated with hyaluronic acid (2.79 ± 9.9 mm Hg versus -0.14 ± 2.96 mm Hg; mean difference 2.93 mm Hg; 95% confidence interval, -0.71 to 6.57 mm Hg; p = 0.12). More patients who received triamcinolone injections developed an increase in intraocular pressure > 7 mm than did those who received hyaluronic acid (29% [nine of 29] versus 0% [zero of 31]; p = 0.002). Of the nine patients who developed elevated intraocular pressure after a triamcinolone injection, five returned for reevaluation 1 month later, and four of them had pressures that remained elevated > 7 mm Hg from baseline. There appears to be an associated intraocular pressure elevation found in patients who have undergone a triamcinolone injection of the knee. Further larger scale randomized investigations are warranted to determine the longevity of this pressure elevation as well as long-term clinical implications, including optic nerve damage and visual field loss. Level II, therapeutic study.

Comparison of Gadofluorine-M and Gd-DTPA for Non-Invasive Staging of Atherosclerotic Plaque Stability Using MRI

PubMed Central

Ronald, John A.; Chen, Yuanxin; Belisle, Andre J.-L.; Hamilton, Amanda M.; Rogers, Kem A.; Hegele, Robert A.; Misselwitz, Bernd; Rutt, Brian K.

2009-01-01

Background Inflammation and neovascularization play critical roles in the stability of atherosclerotic plaques. Whole-body quantitative assessment of these plaque features may improve patient risk-stratification for life-threatening thromboembolic events and direct appropriate intervention. Here we determined the utility of the MR contrast agent Gadofluorine-M (GdF) for staging plaque stability and compared this to the conventional agent Gd-DTPA. Methods and Results 5 control and 7 atherosclerotic rabbits were sequentially imaged following administration of Gd-DTPA (0.2 mmol/kg) and GdF (0.1 mmol/kg) using a T1-weighted pulse sequence on a 3T MRI scanner. Diseased aortic wall could be distinguished from normal wall based on wall-to-muscle contrast-to-noise values following GdF administration. RAM-11 (macrophages) and CD-31 (endothelial cells) immunostaining of MR-matched histological sections revealed that GdF accumulation was related to the degree of inflammation at the surface of plaques and the extent of core neovascularization. Importantly, an MR measure of GdF accumulation at both 1 and 24 hours post-injection, but not Gd-DTPA at peak enhancement, was shown to correlate with a quantitative histological morphology index related to these two plaque features. Conclusions GdF-enhanced MRI of atherosclerotic plaques allows non-invasive quantitative information about plaque composition to be acquired at multiple time points post-injection (within 1 and up to 24 hours post-injection). This dramatically widens the imaging window for assessing plaque stability that is currently attainable with clinically approved MR agents, therefore opening the possibility of whole-body (including coronary) detection of unstable plaques in the future and potentially improved mitigation of cataclysmic cardiovascular events. PMID:19808597

Long-term, repeated measurements of mouse cortical microflow at the same region of interest with high spatial resolution.

PubMed

Tomita, Yutaka; Pinard, Elisabeth; Tran-Dinh, Alexy; Schiszler, Istvan; Kubis, Nathalie; Tomita, Minoru; Suzuki, Norihiro; Seylaz, Jacques

2011-02-04

A method for long-term, repeated, semi-quantitative measurements of cerebral microflow at the same region of interest (ROI) with high spatial resolution was developed and applied to mice subjected to focal arterial occlusion. A closed cranial window was chronically implanted over the left parieto-occipital cortex. The anesthetized mouse was placed several times, e.g., weekly, under a dynamic confocal microscope, and Rhodamine B-isothiocyanate-dextran was each time intravenously injected as a bolus, while microflow images were video recorded. Left and right tail veins were sequentially catheterized in a mouse three times at maximum over a 1.5 months' observation period. Smearing of the input function resulting from the use of intravenous injection was shown to be sufficiently small. The distal middle cerebral artery (MCA) was thermocoagulated through the cranial window in six mice, and five sham-operated mice were studied in parallel. Dye injection and video recording were conducted four times in this series, i.e., before and at 10 min, 7 and 30 days after sham operation or MCA occlusion. Pixelar microflow values (1/MTT) in a matrix of approximately 50×50 pixels were displayed on a two-dimensional (2-D) map, and the frequency distribution of the flow values was also calculated. No significant changes in microflow values over time were detected in sham-operated mice, while the time course of flow changes in the ischemic penumbral area in operated mice was similar to those reported in the literature. This method provides a powerful tool to investigate long-term changes in mouse cortical microflow under physiological and pathological conditions. Copyright © 2010 Elsevier B.V. All rights reserved.

Establishment of a canine model of acute pulmonary embolism with definite right ventricular dysfunction through introduced autologous blood clots.

PubMed

Zhao, Lin-Bo; Jia, Zhen-Yu; Lu, Guang-Dong; Zhu, Yin-Su; Jing, Lei; Shi, Hai-Bin

2015-04-01

To establish a canine model of acute pulmonary embolism (PE) with right ventricular (RV) dysfunction using autologous blood clots and evaluate by echocardiography and contrast-enhanced Computed Tomography (CT). Autologous blood clots formed in vitro were introduced sequentially into the pulmonary arteries of eight healthy mixed-breed dogs while monitoring pulmonary and systemic hemodynamic function. Blood clots were injected until the mean pulmonary artery pressure (MPAP) reached two-three times the baseline pressure, which was maintained up to 1 hour. The RV function was assessed by echocardiography and ECG-gated dual-source contrast CT. All animals survived the imaging procedure. The post-injection pulmonary angiograms showed extensive PE, and MPAP increased from 16.50±2.45 mmHg to 43.13±4.91 mmHg (P<0.001). On echocardiography, the RV fractional area change decreased from 42.06±3.36 to 27.96±3.54 (P<0.001), and the RV myocardial performance increased from 0.20±0.05 to 0.63±0.16 (P<0.001). On CT, the RV end-systolic volume increased from 11.11±1.81 ml to 24.71±4.60 ml (P<0.001), RV end-diastolic volume from 20.73±2.83 ml to 34.63±5.76 ml (P<0.001), and the four-chamber RV/left ventricular diameter ratio from 0.38±0.07 to 0.81±0.14 (P<0.001). Acute PE with RV dysfunction was established in a large animal model through controlled injection of autologous blood clots, which may be useful for developing and evaluating new therapeutic approaches for acute PE with RV dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Arthroscopic, histological and MRI analyses of cartilage repair after a minimally invasive method of transplantation of allogeneic synovial mesenchymal stromal cells into cartilage defects in pigs

PubMed Central

Nakamura, Tomomasa; Sekiya, Ichiro; Muneta, Takeshi; Hatsushika, Daisuke; Horie, Masafumi; Tsuji, Kunikazu; Kawarasaki, Tatsuo; Watanabe, Atsuya; Hishikawa, Shuji; Fujimoto, Yasuhiro; Tanaka, Hozumi; Kobayashi, Eiji

2012-01-01

Background aims Transplantation of synovial mesenchymal stromal cells (MSCs) may induce repair of cartilage defects. We transplanted synovial MSCs into cartilage defects using a simple method and investigated its usefulness and repair process in a pig model. Methods The chondrogenic potential of the porcine MSCs was compared in vitro. Cartilage defects were created in both knees of seven pigs, and divided into MSCs treated and non-treated control knees. Synovial MSCs were injected into the defect, and the knee was kept immobilized for 10 min before wound closure. To visualize the actual delivery and adhesion of the cells, fluorescence-labeled synovial MSCs from transgenic green fluorescent protein (GFP) pig were injected into the defect in a subgroup of two pigs. In these two animals, the wounds were closed before MSCs were injected and observed for 10 min under arthroscopic control. The defects were analyzed sequentially arthroscopically, histologically and by magnetic resonance imaging (MRI) for 3 months. Results Synovial MSCs had a higher chondrogenic potential in vitro than the other MSCs examined. Arthroscopic observations showed adhesion of synovial MSCs and membrane formation on the cartilage defects before cartilage repair. Quantification analyses for arthroscopy, histology and MRI revealed a better outcome in the MSC-treated knees than in the non-treated control knees. Conclusions Leaving a synovial MSC suspension in cartilage defects for 10 min made it possible for cells to adhere in the defect in a porcine cartilage defect model. The cartilage defect was first covered with membrane, then the cartilage matrix emerged after transplantation of synovial MSCs. PMID:22309371

Comparison of different local anesthesia techniques during TRUS-guided biopsies: a prospective pilot study.

PubMed

Kravchick, Sergey; Peled, Ronit; Ben-Dor, David; Dorfman, Dov; Kesari, David; Cytron, Shmuel

2005-01-01

To introduce two forms of anesthesia and compare them with standard local anesthesia techniques. A total of 114 consecutive patients underwent prostate needle biopsy. The patients were sequentially randomized to receive different kinds of anesthesia: 2% rectal lidocaine gel, 40% dimethyl sulfoxide (DMSO) with lidocaine, perianal injection of 1% lidocaine, or periprostatic nerve block. Pain perception was separately assessed for probe insertion and biopsies using a visual pain analog score. One-way analysis of variance was used to compare the data scale among the four groups. A linear regression model was used to define the independent variables that predicted the level of pain. The groups were similar in terms of age, prostate-specific antigen levels, digital rectal examination findings, prostate volume, pain tolerance, biopsy time, and number of cores taken. The lowest pain scores for probe insertion were for the perianal injection and DMSO/lidocaine groups (0.89 and 1.38, respectively). The difference between these scores and those for the other two groups was statistically significant (P <0.001). Pain perception during biopsy did not differ significantly among the DMSO/lidocaine, perianal, or periprostatic groups and was greatest in the lidocaine gel group (4.147; P <0.001). We did not observe any statistically significant correlation between the pain level during probe insertion and biopsy and pain tolerance (P = 0.514 and P = 0.788, respectively). The anesthesia type was the strongest single predictor of the pain level during biopsy (P <0.001). The use of 40% DMSO with lidocaine instilled into the rectal vault for 10 minutes avoids any need for injection and is capable of decreasing the discomfort or pain experienced during probe insertion and prostate biopsy comparable to the perianal and periprostatic protocols.

Perilymph Kinetics of FITC-Dextran Reveals Homeostasis Dominated by the Cochlear Aqueduct and Cerebrospinal Fluid.

PubMed

Salt, A N; Gill, R M; Hartsock, J J

2015-06-01

Understanding how drugs are distributed in perilymph following local applications is important as local drug therapies are increasingly used to treat disorders of the inner ear. The potential contribution of cerebrospinal fluid (CSF) entry to perilymph homeostasis has been controversial for over half a century, largely due to artifactual contamination of collected perilymph samples with CSF. Measures of perilymph flow and of drug distribution following round window niche applications have both suggested a slow, apically directed flow occurs along scala tympani (ST) in the normal, sealed cochlea. In the present study, we have used fluorescein isothiocyanate-dextran as a marker to study perilymph kinetics in guinea pigs. Dextran is lost from perilymph more slowly than other substances so far quantified. Dextran solutions were injected from pipettes sealed into the lateral semicircular canal (SCC), the cochlear apex, or the basal turn of ST. After varying delays, sequential perilymph samples were taken from the cochlear apex or lateral SCC, allowing dextran distribution along the perilymphatic spaces to be quantified. Variability was low and findings were consistent with the injection procedure driving volume flow towards the cochlear aqueduct, and with volume flow during perilymph sampling driven by CSF entry at the aqueduct. The decline of dextran with time in the period between injection and sampling was consistent with both a slow volume influx of CSF (~30 nL/min) entering the basal turn of ST at the cochlear aqueduct and a CSF-perilymph exchange driven by pressure-driven fluid oscillation across the cochlear aqueduct. Sample data also allowed contributions of other processes, such as communications with adjacent compartments, to be quantified. The study demonstrates that drug kinetics in the basal turn of ST is complex and is influenced by a considerable number of interacting processes.

Perilymph pharmacokinetics of markers and dexamethasone applied and sampled at the lateral semi-circular canal.

PubMed

Salt, Alec N; Hartsock, Jared J; Gill, Ruth M; Piu, Fabrice; Plontke, Stefan K

2012-12-01

Perilymph pharmacokinetics was investigated by a novel approach, in which solutions containing drug or marker were injected from a pipette sealed into the perilymphatic space of the lateral semi-circular canal (LSCC). The cochlear aqueduct provides the outlet for fluid flow so this procedure allows almost the entire perilymph to be exchanged. After wait times of up to 4 h the injection pipette was removed and multiple, sequential samples of perilymph were collected from the LSCC. Fluid efflux at this site results from cerebrospinal fluid (CSF) entry into the basal turn of scala tympani (ST) so the samples allow drug levels from different locations in the ear to be defined. This method allows the rate of elimination of substances from the inner ear to be determined more reliably than with other delivery methods in which drug may only be applied to part of the ear. Results were compared for the markers trimethylphenylammonium (TMPA) and fluorescein and for the drug dexamethasone (Dex). For each substance, the concentration in fluid samples showed a progressive decrease as the delay time between injection and sampling was increased. This is consistent with the elimination of substance from the ear with time. The decline with time was slowest for fluorescein, was fastest for Dex, with TMPA at an intermediate rate. Simulations of the experiments showed that elimination occurred more rapidly from scala tympani (ST) than from scala vestibuli (SV). Calculated elimination half-times from ST averaged 54.1, 24.5 and 22.5 min for fluorescein, TMPA and Dex respectively and from SV 1730, 229 and 111 min respectively. The elimination of Dex from ST occurred considerably faster than previously appreciated. These pharmacokinetic parameters provide an important foundation for understanding of drug treatments of the inner ear.

Selective sequential precipitation of dissolved metals in mine drainage from coal mine

NASA Astrophysics Data System (ADS)

Yim, Giljae; Bok, Songmin; Ji, Sangwoo; Oh, Chamteut; Cheong, Youngwook; Han, Youngsoo; Ahn, Joosung

2017-04-01

In abandoned mines in Korea, a large amount of mine drainage continues to flow out and spread pollution. In purification of the mine drainage a massive amount of sludge is generated as waste. Since this metal sludge contains high Fe, Al and Mn oxides, developing the treatment method to recover homogeneous individual metal with high purity may beneficial to recycle waste metals as useful resources and reduce the amount of sludge production. In this regard, we established a dissolved metals selective precipitation process to treat Waryong Industry's mine drainage. The process that selectively precipitates metals dissolved in mine drainage is a continuous Fe-buffer-Al process, and each process consists of the neutralization tank, the coagulation tank, and the settling tank. Based on this process, this study verified the operational applicability of the Fe and Al selective precipitation. Our previous study revealed that high-purity Fe and Al precipitates could be recovered at a flow rate of 1.5 ton/day, while the lower purity was achieved when the rate was increased to about 3 ton/day due to the difficulty in reagent dosage control. In the current study was conducted to increase the capacity of the system to recover Fe and Al as high-purity precipitates at a flow rate of 10 ton/day with the ensured continuous operations by introducing an automatic reagent injection system. The previous study had a difficulty in controlling the pH and operating system continuously due to the manually controlled reagent injection system. To upgrade this and ensure the optimal pH in a stable way, a continuous reagent injection system was installed. The result of operation of the 10 ton/day system confirmed that the scaled-up process could maintain the stable recovery rates and purities of precipitates on site.

Delay test generation for synchronous sequential circuits

NASA Astrophysics Data System (ADS)

Devadas, Srinivas

1989-05-01

We address the problem of generating tests for delay faults in non-scan synchronous sequential circuits. Delay test generation for sequential circuits is a considerably more difficult problem than delay testing of combinational circuits and has received much less attention. In this paper, we present a method for generating test sequences to detect delay faults in sequential circuits using the stuck-at fault sequential test generator STALLION. The method is complete in that it will generate a delay test sequence for a targeted fault given sufficient CPU time, if such a sequence exists. We term faults for which no delay test sequence exists, under out test methodology, sequentially delay redundant. We describe means of eliminating sequential delay redundancies in logic circuits. We present a partial-scan methodology for enhancing the testability of difficult-to-test of untestable sequential circuits, wherein a small number of flip-flops are selected and made controllable/observable. The selection process guarantees the elimination of all sequential delay redundancies. We show that an intimate relationship exists between state assignment and delay testability of a sequential machine. We describe a state assignment algorithm for the synthesis of sequential machines with maximal delay fault testability. Preliminary experimental results using the test generation, partial-scan and synthesis algorithm are presented.

Lineup composition, suspect position, and the sequential lineup advantage.

PubMed

Carlson, Curt A; Gronlund, Scott D; Clark, Steven E

2008-06-01

N. M. Steblay, J. Dysart, S. Fulero, and R. C. L. Lindsay (2001) argued that sequential lineups reduce the likelihood of mistaken eyewitness identification. Experiment 1 replicated the design of R. C. L. Lindsay and G. L. Wells (1985), the first study to show the sequential lineup advantage. However, the innocent suspect was chosen at a lower rate in the simultaneous lineup, and no sequential lineup advantage was found. This led the authors to hypothesize that protection from a sequential lineup might emerge only when an innocent suspect stands out from the other lineup members. In Experiment 2, participants viewed a simultaneous or sequential lineup with either the guilty suspect or 1 of 3 innocent suspects. Lineup fairness was varied to influence the degree to which a suspect stood out. A sequential lineup advantage was found only for the unfair lineups. Additional analyses of suspect position in the sequential lineups showed an increase in the diagnosticity of suspect identifications as the suspect was placed later in the sequential lineup. These results suggest that the sequential lineup advantage is dependent on lineup composition and suspect position. (c) 2008 APA, all rights reserved

Comparison of efficacy and safety of levofloxacin-containing versus standard sequential therapy in eradication of Helicobacter pylori infection in Korea.

PubMed

Lee, Hyuk; Hong, Sung Noh; Min, Byung-Hoon; Lee, Jun Haeng; Rhee, Poong-Lyul; Lee, Yong Chan; Kim, Jae J

2015-02-01

Declining of eradication rates for Helicobacter pylori in Korea may be partly from the increasing prevalence of antibiotic resistance, especially clarithromycin resistance. To compare the efficacy and the safety of using 10-day standard sequential therapy and levofloxacin-containing sequential therapy as a first-line treatment for Helicobacter pylori eradication in Korea. A total of 200 patients with proven Helicobacter pylori infection randomly received 10-day standard sequential therapy (n = 100) or levofloxacin-containing sequential therapy (n = 100). The standard sequential therapy group received rabeprazole and amoxicillin for 5 days, followed by rabeprazole, clarithromycin, and metronidazole for 5 more days. The levofloxacin-containing sequential therapy group was treated with rabeprazole and amoxicillin for 5 days, followed by rabeprazole, levofloxacin, and metronidazole for 5 more days. Intention-to-treat eradication rates were 79.0% and 78.0% for groups of standard sequential and levofloxacin-containing sequential therapy, respectively (P = 0.863). Per-protocol eradication rates were 84.9% and 81.3%, respectively, for these two therapies (P = 0.498). There were no significant differences between the groups in regard to the eradication rates and adverse events. The 10-day levofloxacin-containing sequential regimen and the standard sequential regimen showed the similar eradication rates of Helicobacter pylori in Korea. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Double-blind photo lineups using actual eyewitnesses: an experimental test of a sequential versus simultaneous lineup procedure.

PubMed

Wells, Gary L; Steblay, Nancy K; Dysart, Jennifer E

2015-02-01

Eyewitnesses (494) to actual crimes in 4 police jurisdictions were randomly assigned to view simultaneous or sequential photo lineups using laptop computers and double-blind administration. The sequential procedure used in the field experiment mimicked how it is conducted in actual practice (e.g., using a continuation rule, witness does not know how many photos are to be viewed, witnesses resolve any multiple identifications), which is not how most lab experiments have tested the sequential lineup. No significant differences emerged in rates of identifying lineup suspects (25% overall) but the sequential procedure produced a significantly lower rate (11%) of identifying known-innocent lineup fillers than did the simultaneous procedure (18%). The simultaneous/sequential pattern did not significantly interact with estimator variables and no lineup-position effects were observed for either the simultaneous or sequential procedures. Rates of nonidentification were not significantly different for simultaneous and sequential but nonidentifiers from the sequential procedure were more likely to use the "not sure" response option than were nonidentifiers from the simultaneous procedure. Among witnesses who made an identification, 36% (41% of simultaneous and 32% of sequential) identified a known-innocent filler rather than a suspect, indicating that eyewitness performance overall was very poor. The results suggest that the sequential procedure that is used in the field reduces the identification of known-innocent fillers, but the differences are relatively small.

Treatment of Cerebral Palsy with Stem Cells: A Report of 17 Cases.

PubMed

Abi Chahine, Nassim H; Wehbe, Tarek W; Hilal, Ramzi A; Zoghbi, Victoria V; Melki, Alia E; Habib, Emil B Bou

2016-05-30

Cerebral Palsy (CP) is a disabling condition that affects a child's life and his/her family irreversibly. It is usually a non-progressive condition but improvement over time is rarely seen. The condition can be due to prenatal hypoxia, metabolic, genetic, infectious, traumatic or other causes. It is therefore a heterogeneous group that results in functional motor disability associated with different degrees of cognitive abnormalities. There are no treatments that can cure or even improve CP and the best available approach aims at functional, social and nutritional supportive care and counseling. In this paper, we report 17 sequential patients with CP treated with intrathecal administration of Bone Marrow Mononuclear Cells (BMMC). All patients had an uneventful post-injection course with 73% of the evaluable patients treated having a good response using the Gross Motor Function Classification System (GMFCS). The average improvement was 1.3 levels on the GMFCS with cognitive improvements as well.

Determination of the titratable acidity and the pH of wine based on potentiometric flow injection analysis.

PubMed

Vahl, Katja; Kahlert, Heike; von Mühlen, Lisandro; Albrecht, Anja; Meyer, Gabriele; Behnert, Jürgen

2013-07-15

A FIA system using a pH-sensitive detector based on a graphite/quinhydrone/silicone composite electrode was applied to determine sequentially the titratable acidity and the pH of wine, as well as the sum of calcium and magnesium ions. For all measurements the same FIA configuration was used employing different carrier solutions. The results for the determination of acidity and pH are in good agreement with those obtained by classical potentiometric titrations and by pH measurements using a conventional glass electrode. The standard deviation was less than 1.5% for both kinds of measurements and the sample volume was 150 μL. The method allows about 40 determinations of titratable acidity per hour and 30 pH measurements per hour. The titration method can be adjusted to the legal requirements in USA and Europe. Copyright © 2013 Elsevier B.V. All rights reserved.

On-chip liquid storage and dispensing for lab-on-a-chip applications

NASA Astrophysics Data System (ADS)

Bodén, Roger; Lehto, Marcus; Margell, Joakim; Hjort, Klas; Schweitz, Jan-Åke

2008-07-01

This work presents novel components for on-chip storage and dispensing inside a lab-on-a-chip (LOC) for applications in immunoassay point-of-care testing (POCT), where incubation and washing steps are essential. It involves easy-to-use on-chip solutions for the sequential thermo-hydraulic actuation of liquids. The novel concept of combining the use of a rubber plug, both as a non-return valve cap and as a liquid injection interface of a sealed reservoir, allows simple filling of a sterilized cavity, as well as the storage and dispensing of reagent and washing buffer liquids. Segmenting the flow with air spacers enables effective rinsing and the use of small volumes of on-chip stored liquids. The chip uses low-resistance resistors as heaters in the paraffin actuator, providing the low-voltage actuation that is preferred for handheld battery driven instruments.

Automatic weld torch guidance control system

NASA Technical Reports Server (NTRS)

Smaith, H. E.; Wall, W. A.; Burns, M. R., Jr.

1982-01-01

A highly reliable, fully digital, closed circuit television optical, type automatic weld seam tracking control system was developed. This automatic tracking equipment is used to reduce weld tooling costs and increase overall automatic welding reliability. The system utilizes a charge injection device digital camera which as 60,512 inidividual pixels as the light sensing elements. Through conventional scanning means, each pixel in the focal plane is sequentially scanned, the light level signal digitized, and an 8-bit word transmitted to scratch pad memory. From memory, the microprocessor performs an analysis of the digital signal and computes the tracking error. Lastly, the corrective signal is transmitted to a cross seam actuator digital drive motor controller to complete the closed loop, feedback, tracking system. This weld seam tracking control system is capable of a tracking accuracy of + or - 0.2 mm, or better. As configured, the system is applicable to square butt, V-groove, and lap joint weldments.

Electrical properties of MOS devices fabricated on the 4H-SiC C-face.

NASA Astrophysics Data System (ADS)

Chen, Zengjun; Ahyi, A. C.; Williams, J. R.

2007-11-01

The electrical characteristics of MOS devices fabricated on the carbon face of 4H-SiC will be described. The C-face has a higher oxidation rate and a higher interface trap density compared to the Si-face. The thermal oxidation rate and the distribution of interface traps under different oxidation conditions will be discussed in this presentation. Sequential post-oxidation anneals in nitric oxide and hydrogen effectively reduces the interface density (Dit) near the conduction band edge. However, deeper in the band gap, the trap density remains higher compared to the Si-face. Time-dependent dielectric breakdown (TDDB) studies have also been performed to investigate oxide reliability on the C-face, and current-voltage measurements show that a low barrier height against carrier injection likely contributes to oxide degradation. Nevertheless, the effective channel mobility and threshold voltage for n-channel C-face lateral MOSFETs compare favorably with similar Si-face devices.

Automated measurement and monitoring of bioprocesses: key elements of the M(3)C strategy.

PubMed

Sonnleitner, Bernhard

2013-01-01

The state-of-routine monitoring items established in the bioprocess industry as well as some important state-of-the-art methods are briefly described and the potential pitfalls discussed. Among those are physical and chemical variables such as temperature, pressure, weight, volume, mass and volumetric flow rates, pH, redox potential, gas partial pressures in the liquid and molar fractions in the gas phase, infrared spectral analysis of the liquid phase, and calorimetry over an entire reactor. Classical as well as new optical versions are addressed. Biomass and bio-activity monitoring (as opposed to "measurement") via turbidity, permittivity, in situ microscopy, and fluorescence are critically analyzed. Some new(er) instrumental analytical tools, interfaced to bioprocesses, are explained. Among those are chromatographic methods, mass spectrometry, flow and sequential injection analyses, field flow fractionation, capillary electrophoresis, and flow cytometry. This chapter surveys the principles of monitoring rather than compiling instruments.

CFD simulation of vertical linear motion mixing in anaerobic digester tanks.

PubMed

Meroney, Robert N; Sheker, Robert E

2014-09-01

Computational fluid dynamics (CFD) was used to simulate the mixing characteristics of a small circular anaerobic digester tank (diameter 6 m) equipped sequentially with 13 different plunger type vertical linear motion mixers and two different type internal draft-tube mixers. Rates of mixing of step injection of tracers were calculated from which active volume (AV) and hydraulic retention time (HRT) could be calculated. Washout characteristics were compared to analytic formulae to estimate any presence of partial mixing, dead volume, short-circuiting, or piston flow. Active volumes were also estimated based on tank regions that exceeded minimum velocity criteria. The mixers were ranked based on an ad hoc criteria related to the ratio of AV to unit power (UP) or AV/UP. The best plunger mixers were found to behave about the same as the conventional draft-tube mixers of similar UP.

Rapid CE-UV binding tests of environmentally hazardous compounds with polymer-modified magnetic nanoparticles.

PubMed

Iqbal, Zafar; Alsudir, Samar; Miah, Musharraf; Lai, Edward P C

2011-08-01

Hazardous compounds and bacteria in water have an adverse impact on human health and environmental ecology. Polydopamine (or polypyrrole)-coated magnetic nanoparticles and polymethacrylic acid-co-ethylene glycol dimethacrylate submicron particles were investigated for their fast binding kinetics with bisphenol A, proflavine, naphthalene acetic acid, and Escherichia coli. A new method was developed for the rapid determination of % binding by sequential injection of particles first and compounds (or E. coli) next into a fused-silica capillary for overlap binding during electrophoretic migration. Only nanolitre volumes of compounds and particles were sufficient to complete a rapid binding test. After heterogeneous binding, separation of the compounds from the particles was afforded by capillary electrophoresis. % binding was influenced by applied voltage but not current flow. In-capillary coating of particles affected the % binding of compounds. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A rapid method for the simultaneous quantification of the major tocopherols, carotenoids, free and esterified sterols in canola (Brassica napus) oil using normal phase liquid chromatography.

PubMed

Flakelar, Clare L; Prenzler, Paul D; Luckett, David J; Howitt, Julia A; Doran, Gregory

2017-01-01

A normal phase high performance liquid chromatography (HPLC) method was developed to simultaneously quantify several prominent bioactive compounds in canola oil vis. α-tocopherol, γ-tocopherol, δ-tocopherol, β-carotene, lutein, β-sitosterol, campesterol and brassicasterol. The use of sequential diode array detection (DAD) and tandem mass spectrometry (MS/MS) allowed direct injection of oils, diluted in hexane without derivatisation or saponification, greatly reducing sample preparation time, and permitting the quantification of both free sterols and intact sterol esters. Further advantages over existing methods included increased analytical selectivity, and a chromatographic run time substantially less than other reported normal phase methods. The HPLC-DAD-MS/MS method was applied to freshly extracted canola oil samples as well as commercially available canola, palm fruit, sunflower and olive oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tag retention, growth, and survival of red swamp crayfish marked with a visible implant tag

USGS Publications Warehouse

Isely, J.J.; Stockett, P.E.

2001-01-01

Eighty juvenile (means: 42.4 mm total length, 1.6 g) red swamp crayfish Procambarus clarkii were implanted with sequentially numbered visible implant tags and held in the laboratory. Tags were injected transversely into the musculature just beneath the exoskeleton of the third abdominal segment from the cephalothorax; tags were visible upon inspection. An additional 20 crayfish were left untagged and served as controls. After 150 d, tag retention was 80% and all tags were readable. No tagged crayfish died during the study, and no differences in total length or weight were detected between tagged and control crayfish. All individuals molted at least three times during the 150-d study, and some individuals molted up to six times, suggesting that most tags would be permanently retained. The readability in the field without specialized equipment makes the visible implant tag ideal for studies of crayfish ecology, management, and culture.

Effects of ammonium on uranium partitioning and kaolinite mineral dissolution.

PubMed

Emerson, Hilary P; Di Pietro, Silvina; Katsenovich, Yelena; Szecsody, Jim

2017-02-01

Ammonia gas injection is a promising technique for the remediation of uranium within the vadose zone. It can be used to manipulate the pH of a system and cause co-precipitation processes that are expected to remove uranium from the aqueous phase and decrease leaching from the solid phase. The work presented in this paper explores the effects of ammonium and sodium hydroxide on the partitioning of uranium and dissolution of the kaolinite mineral in simplified synthetic groundwaters using equilibrium batch sorption and sequential extraction experiments. It shows that there is a significant increase in uranium removal in systems with divalent cations present in the aqueous phase but not in sodium chloride synthetic groundwaters. Further, the initial conditions of the aqueous phase do not affect the dissolution of kaolinite. However, the type of base treatment does have an effect on mineral dissolution. Published by Elsevier Ltd.

Sequential Testing: Basics and Benefits

DTIC Science & Technology

1978-03-01

Eii~TARADC6M and x _..TECHNICAL REPORT NO. 12325 SEQUENTIAL TESTING: BASICS AND BENEFITS / i * p iREFERENCE CP...Sequential Testing: Basics and Benefits Contents Page I. Introduction and Summary II. Sequential Analysis 2 III. Mathematics of Sequential Testing 4 IV...testing. The added benefit of reduced energy needs are inherent in this testing method. The text was originally released by the authors in 1972. The text

Sequential search leads to faster, more efficient fragment-based de novo protein structure prediction.

PubMed

de Oliveira, Saulo H P; Law, Eleanor C; Shi, Jiye; Deane, Charlotte M

2018-04-01

Most current de novo structure prediction methods randomly sample protein conformations and thus require large amounts of computational resource. Here, we consider a sequential sampling strategy, building on ideas from recent experimental work which shows that many proteins fold cotranslationally. We have investigated whether a pseudo-greedy search approach, which begins sequentially from one of the termini, can improve the performance and accuracy of de novo protein structure prediction. We observed that our sequential approach converges when fewer than 20 000 decoys have been produced, fewer than commonly expected. Using our software, SAINT2, we also compared the run time and quality of models produced in a sequential fashion against a standard, non-sequential approach. Sequential prediction produces an individual decoy 1.5-2.5 times faster than non-sequential prediction. When considering the quality of the best model, sequential prediction led to a better model being produced for 31 out of 41 soluble protein validation cases and for 18 out of 24 transmembrane protein cases. Correct models (TM-Score > 0.5) were produced for 29 of these cases by the sequential mode and for only 22 by the non-sequential mode. Our comparison reveals that a sequential search strategy can be used to drastically reduce computational time of de novo protein structure prediction and improve accuracy. Data are available for download from: http://opig.stats.ox.ac.uk/resources. SAINT2 is available for download from: https://github.com/sauloho/SAINT2. saulo.deoliveira@dtc.ox.ac.uk. Supplementary data are available at Bioinformatics online.

Assessment of Effectiveness of Percutaneous Adhesiolysis in Managing Chronic Low Back Pain Secondary to Lumbar Central Spinal Canal Stenosis

PubMed Central

Manchikanti, Laxmaiah; Cash, Kimberly A.; McManus, Carla D.; Pampati, Vidyasagar

2013-01-01

Background: Chronic persistent low back and lower extremity pain secondary to central spinal stenosis is common and disabling. Lumbar surgical interventions with decompression or fusion are most commonly performed to manage severe spinal stenosis. However, epidural injections are also frequently performed in managing central spinal stenosis. After failure of epidural steroid injections, the next sequential step is percutaneous adhesiolysis and hypertonic saline neurolysis with a targeted delivery. The literature on the effectiveness of percutaneous adhesiolysis in managing central spinal stenosis after failure of epidural injections has not been widely studied. Study Design: A prospective evaluation. Setting: An interventional pain management practice, a specialty referral center, a private practice setting in the United States. Objective: To evaluate the effectiveness of percutaneous epidural adhesiolysis in patients with chronic low back and lower extremity pain with lumbar central spinal stenosis. Methods: Seventy patients were recruited. The initial phase of the study was randomized, double-blind with a comparison of percutaneous adhesiolysis with caudal epidural injections. The 25 patients from the adhesiolysis group continued with follow-up, along with 45 additional patients, leading to a total of 70 patients. All patients received percutaneous adhesiolysis and appropriate placement of the Racz catheter, followed by an injection of 5 mL of 2% preservative-free lidocaine with subsequent monitoring in the recovery room. In the recovery room, each patient also received 6 mL of 10% hypertonic sodium chloride solution, and 6 mg of non-particulate betamethasone, followed by an injection of 1 mL of sodium chloride solution and removal of the catheter. Outcomes Assessment: Multiple outcome measures were utilized including the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3, 6, and 12, 18 and 24 months post treatment. The primary outcome measure was 50% or more improvement in pain scores and ODI scores. Results: Overall, a primary outcome or significant pain relief and functional status improvement of 50% or more was seen in 71% of patients at the end of 2 years. The overall number of procedures over a period of 2 years were 5.7 ± 2.73. Limitations: The lack of a control group and a prospective design. Conclusions: Significant relief and functional status improvement as seen in 71% of the 70 patients with percutaneous adhesiolysis utilizing local anesthetic steroids and hypertonic sodium chloride solution may be an effective management strategy in patients with chronic function limiting low back and lower extremity pain with central spinal stenosis after failure of conservatie management and fluoroscopically directed epidural injections. PMID:23289005

Discrimination between sequential and simultaneous virtual channels with electrical hearing

PubMed Central

Landsberger, David; Galvin, John J.

2011-01-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects’ discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. PMID:21895094

Discrimination between sequential and simultaneous virtual channels with electrical hearing.

PubMed

Landsberger, David; Galvin, John J

2011-09-01

In cochlear implants (CIs), simultaneous or sequential stimulation of adjacent electrodes can produce intermediate pitch percepts between those of the component electrodes. However, it is unclear whether simultaneous and sequential virtual channels (VCs) can be discriminated. In this study, CI users were asked to discriminate simultaneous and sequential VCs; discrimination was measured for monopolar (MP) and bipolar + 1 stimulation (BP + 1), i.e., relatively broad and focused stimulation modes. For sequential VCs, the interpulse interval (IPI) varied between 0.0 and 1.8 ms. All stimuli were presented at comfortably loud, loudness-balanced levels at a 250 pulse per second per electrode (ppse) stimulation rate. On average, CI subjects were able to reliably discriminate between sequential and simultaneous VCs. While there was no significant effect of IPI or stimulation mode on VC discrimination, some subjects exhibited better VC discrimination with BP + 1 stimulation. Subjects' discrimination between sequential and simultaneous VCs was correlated with electrode discrimination, suggesting that spatial selectivity may influence perception of sequential VCs. To maintain equal loudness, sequential VC amplitudes were nearly double those of simultaneous VCs, presumably resulting in a broader spread of excitation. These results suggest that perceptual differences between simultaneous and sequential VCs might be explained by differences in the spread of excitation. © 2011 Acoustical Society of America

Design requirements for ERD in diffusion-dominated media: how do injection interval, bioactive zones and reaction kinetics affect remediation performance?

NASA Astrophysics Data System (ADS)

Chambon, J.; Lemming, G.; Manoli, G.; Broholm, M. M.; Bjerg, P.; Binning, P. J.

2011-12-01

Enhanced Reductive Dechlorination (ERD) has been successfully used in high permeability media, such as sand aquifers, and is considered to be a promising technology for low permeability settings. Pilot and full-scale applications of ERD at several sites in Denmark have shown that the main challenge is to get contact between the injected bacteria and electron donor and the contaminants trapped in the low-permeability matrix. Sampling of intact cores from the low-permeability matrix has shown that the bioactive zones (where degradation occurs) are limited in the matrix, due to the slow diffusion transport processes, and this affects the timeframes for the remediation. Due to the limited ERD applications and the complex transport and reactive processes occurring in low-permeability media, design guidelines are currently not available for ERD in such settings, and remediation performance assessments are limited. The objective of this study is to combine existing knowledge from several sites with numerical modeling to assess the effect of the injection interval, development of bioactive zones and reaction kinetics on the remediation efficiency for ERD in diffusion-dominated media. A numerical model is developed to simulate ERD at a contaminated site, where the source area (mainly TCE) is located in a clayey till with fractures and interbedded sand lenses. Such contaminated sites are common in North America and Europe. Hydro-geological characterization provided information on geological heterogeneities and hydraulic parameters, which are relevant for clay till sites in general. The numerical model couples flow and transport in the fracture network and low-permeability matrix. Sequential degradation of TCE to ethene is modeled using Monod kinetics, and the kinetic parameters are obtained from laboratory experiments. The influence of the reaction kinetics on remediation efficiency is assessed by varying the biomass concentration of the specific degraders. The injected reactants (donor and bacteria) are assumed to spread in horizontal injection zones of various widths, depending on the development of bioactive zones. These injection zones are spaced at various intervals over depth, corresponding to the injection interval chosen. The results from the numerical model show that remediation timeframes can be reduced significantly by using closely spaced injection intervals and by ensuring the efficient spreading of the reactants into the clay till matrix. In contrast the reaction kinetics affect mass removal only up to a point where diffusive transport becomes limiting. Based on these results, guidelines on when ERD can be an effective remediation strategy in practice are provided. These take the form of dimensionless groupings (such as the Damkohler number), which combine site specific (physical and biogeochemical) and design parameters, and graphs showing how the main parameters affect remediation timeframes. Finally it is shown how model results can be used as input to other decision making tools such as life cycle assessment to guide remedial choices.

Life cycle of Hepatozoon canis (Apicomplexa: Adeleorina: Hepatozoidae) in the tick Rhipicephalus sanguineus and domestic dog (Canis familiaris).

PubMed

Baneth, Gad; Samish, Michael; Shkap, Varda

2007-04-01

The life cycle of the apicomplexan protozoon Hepatozoon canis in its natural hosts Rhipicephalus sanguineus (tick) and Canis familiaris (domestic dog) was studied in an experimental infection. Tick nymphs were fed on a naturally infected dog, or they were infected by percutaneous injection of blood. Dogs were inoculated by ingestion of adult ticks containing mature oocysts. Gamonts were in syzygy 24 hr after percutaneous injection of ticks. Early oocysts were detected 96 hr after nymph repletion, and mature oocysts in adult ticks were infective to dogs 40 days postmolt. Merogony was detected in dog bone marrow from 13 days postinoculation (PI) and included meronts containing 20-30 micromerozoites, and a second type with 2-4 macromerozoites. Monozoic cysts were observed in the spleen in conjunction with merogony. Gamontogony with infection of leukocytes by micromerozoites occurred from 26 days PI, and gamont parasitemia, which completed the life cycle, was detected 28 days PI. The length of the life cycle from nymphal attachment to parasitemia in dogs was 81 days. Increased body temperatures were evident from 16 to 27 days PI and paralleled the time of intensive bone marrow merogony. Skeletal pain and recumbency were manifested in 2 dogs. This study further elucidates the life cycle of H. canis and provides a sequential morphologic description of H. canis merogony, gamontogony, and sporogony.

Preparation and Biological Study of 68Ga-DOTA-alendronate

PubMed Central

Fakhari, Ashraf; Jalilian, Amir R.; Johari-Daha, Fariba; Shafiee-Ardestani, Mehdi; Khalaj, Ali

2016-01-01

Objective(s): In line with previous research on the development of conjugated bisphosphonate ligands as new bone-avid agents, in this study, DOTA-conjugated alendronate (DOTA-ALN) was synthesized and evaluated after labeling with gallium-68 (68Ga). Methods: DOTA-ALN was synthesized and characterized, followed by 68Ga-DOTA-ALN preparation, using DOTA-ALN and 68GaCl3 (pH: 4-5) at 92-95° C for 10 min. Stability tests, hydroxyapatite assay, partition coefficient calculation, biodistribution studies, and imaging were performed on the developed agent in normal rats. Results: The complex was prepared with high radiochemical purity (>99% as depicted by radio thin-layer chromatography; specific activity: 310-320 GBq/mmol) after solid phase purification and was stabilized for up to 90 min with a log P value of -2.91. Maximum ligand binding (65%) was observed in the presence of 50 mg of hydroxyapatite; a major portion of the activity was excreted through the kidneys. With the exception of excretory organs, gastrointestinal tract organs, including the liver, intestine, and colon, showed significant uptake; however, the bone uptake was low (<1%) at 30 min after the injection. The data were also confirmed by sequential imaging at 30-90 min following the intravenous injection. Conclusion: The high solubility and anionic properties of the complex led to major renal excretion and low hydroxyapatite uptake; therefore, the complex failed to demonstrate bone imaging behaviors. PMID:27408898

Preferential heating of light ions during an ionospheric Ar(+) injection experiment

NASA Technical Reports Server (NTRS)

Pollock, C. J.; Chandler, M. O.; Moore, T. E.; Arnoldy, R. L.; Kintner, P. M.; Chesney, S.; Cahill, L. J., Jr.

1995-01-01

The Argon Release for Controlled Studies (ARCS) 4 sounding rocket was launched northward into high altitude from Poker Flat Research Range on February 23, 1990. The vehicle crossed geomagnetic field lines containing discrete auroral activity. An instrumented subpayload released 100-eV and 200-eV Ar(+) ion beams sequentially, in a direction largely perpendicular to both the local geomagnetic field and the subpayload spin axis. The instrumented main payload was separated along field lines from the beam emitting subpayload by a distance which increased at a steady rate of approximately 2.4 m/s. Three dimensional mass spectrometric ion observations of ambient H(+) and O(+) ions, obtained on board the main payload, are presented. Main payload electric field observations in the frequency range 0-16 kHz, are also presented. These observations are presented to demonstrate the operation of transverse ion acceleration, which was differential with respect to ion mass, primarily during 100-eV beam operations. The preferential transverse acceleration of ambient H(+) ions, as compared with ambient O(+) ions, during the second, third, fourth, and fifth 100-eV beam operations, is attributed to a resonance among the injected Ar(+) ions, beam-generated lower hybrid waves, and H(+) ions in the tail of the ambient thermal distribution. This work provides experimental support of processes predicted by previously published theory and simulations.

Repeated diazepam administration reversed working memory impairments and glucocorticoid alterations in the prefrontal cortex after short but not long alcohol-withdrawal periods.

PubMed

Dominguez, G; Henkous, N; Pierard, C; Belzung, C; Mons, N; Beracochea, Daniel

2018-04-30

The study was designed to assess whether repeated administration of diazepam (Valium®, Roche)-a benzodiazepine exerting an agonist action on GABA A receptors-may alleviate both the short (1 week, 1W) and long-term (6 weeks, 6W) deleterious effects of alcohol withdrawal occurring after chronic alcohol consumption (6 months; 12% v/v) in C57/BL6 male mice. More pointedly, we first evidenced that 1W and 6W alcohol-withdrawn mice exhibited working memory deficits in a sequential alternation task, associated with sustained exaggerated corticosterone rise and decreased pCREB levels in the prefrontal cortex (PFC). In a subsequent experiment, diazepam was administered i.p. for 9 consecutive days (1 injection/day) during the alcohol withdrawal period at decreasing doses ranging from 1.0 mg/kg to 0.25 mg/kg. Diazepam was not detected in the blood of withdrawn mice at the time of memory testing, occurring 24 hours after the last diazepam injection. Repeated diazepam administration significantly improved alternation rates and normalized levels of glucocorticoids and pCREB activity in the PFC in 1W but not in 6W withdrawn mice. Thus, repeated diazepam administration during the alcohol-withdrawal period only transitorily canceled out the working memory impairments and glucocorticoid alterations in the PFC of alcohol-withdrawn animals.

Localized sequence-specific release of a chemopreventive agent and an anticancer drug in a time-controllable manner to enhance therapeutic efficacy.

PubMed

Pan, Wen-Yu; Lin, Kun-Ju; Huang, Chieh-Cheng; Chiang, Wei-Lun; Lin, Yu-Jung; Lin, Wei-Chih; Chuang, Er-Yuan; Chang, Yen; Sung, Hsing-Wen

2016-09-01

Combination chemotherapy with multiple drugs commonly requires several injections on various schedules, and the probability that the drug molecules reach the diseased tissues at the proper time and effective therapeutic concentrations is very low. This work elucidates an injectable co-delivery system that is based on cationic liposomes that are adsorbed on anionic hollow microspheres (Lipos-HMs) via electrostatic interaction, from which the localized sequence-specific release of a chemopreventive agent (1,25(OH)2D3) and an anticancer drug (doxorubicin; DOX) can be thermally driven in a time-controllable manner by an externally applied high-frequency magnetic field (HFMF). Lipos-HMs can greatly promote the accumulation of reactive oxygen species (ROS) in tumor cells by reducing their cytoplasmic expression of an antioxidant enzyme (superoxide dismutase) by 1,25(OH)2D3, increasing the susceptibility of cancer cells to the cytotoxic action of DOX. In nude mice that bear xenograft tumors, treatment with Lipos-HMs under exposure to HFMF effectively inhibits tumor growth and is the most effective therapeutic intervention among all the investigated. These empirical results demonstrate that the synergistic anticancer effects of sequential release of 1,25(OH)2D3 and DOX from the Lipos-HMs may have potential for maximizing DOX cytotoxicity, supporting more effective cancer treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

On-board measurement of emissions from liquefied petroleum gas, gasoline and diesel powered passenger cars in Algeria.

PubMed

Chikhi, Saâdane; Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2014-08-01

On-board measurements of unit emissions of CO, HC, NOx and CO₂ were conducted on 17 private cars powered by different types of fuels including gasoline, dual gasoline-liquefied petroleum gas (LPG), gasoline, and diesel. The tests performed revealed the effect of LPG injection technology on unit emissions and made it possible to compare the measured emissions to the European Artemis emission model. A sequential multipoint injection LPG kit with no catalyst installed was found to be the most efficient pollutant reduction device for all of the pollutants, with the exception of the NOx. Specific test results for a sub-group of LPG vehicles revealed that LPG-fueled engines with no catalyst cannot compete with catalyzed gasoline and diesel engines. Vehicle age does not appear to be a determining parameter with regard to vehicle pollutant emissions. A fuel switch to LPG offers many advantages as far as pollutant emissions are concerned, due to LPG's intrinsic characteristics. However, these advantages are being rapidly offset by the strong development of both gasoline and diesel engine technologies and catalyst converters. The LPG's performance on a chassis dynamometer under real driving conditions was better than expected. The enforcement of pollutant emission standards in developing countries is an important step towards introducing clean technology and reducing vehicle emissions. Copyright © 2014. Published by Elsevier B.V.

Preparation and Biological Study of (68)Ga-DOTA-alendronate.

PubMed

Fakhari, Ashraf; Jalilian, Amir R; Johari-Daha, Fariba; Shafiee-Ardestani, Mehdi; Khalaj, Ali

2016-01-01

In line with previous research on the development of conjugated bisphosphonate ligands as new bone-avid agents, in this study, DOTA-conjugated alendronate (DOTA-ALN) was synthesized and evaluated after labeling with gallium-68 ((68)Ga). DOTA-ALN was synthesized and characterized, followed by (68)Ga-DOTA-ALN preparation, using DOTA-ALN and (68)GaCl3 (pH: 4-5) at 92-95° C for 10 min. Stability tests, hydroxyapatite assay, partition coefficient calculation, biodistribution studies, and imaging were performed on the developed agent in normal rats. The complex was prepared with high radiochemical purity (>99% as depicted by radio thin-layer chromatography; specific activity: 310-320 GBq/mmol) after solid phase purification and was stabilized for up to 90 min with a log P value of -2.91. Maximum ligand binding (65%) was observed in the presence of 50 mg of hydroxyapatite; a major portion of the activity was excreted through the kidneys. With the exception of excretory organs, gastrointestinal tract organs, including the liver, intestine, and colon, showed significant uptake; however, the bone uptake was low (<1%) at 30 min after the injection. The data were also confirmed by sequential imaging at 30-90 min following the intravenous injection. The high solubility and anionic properties of the complex led to major renal excretion and low hydroxyapatite uptake; therefore, the complex failed to demonstrate bone imaging behaviors.

An effector role for platelets in systemic and local lipopolysaccharide-induced toxicity in mice, mediated by a CD11a- and CD54-dependent interaction with endothelium.

PubMed Central

Piguet, P F; Vesin, C; Ryser, J E; Senaldi, G; Grau, G E; Tacchini-Cottier, F

1993-01-01

The role of platelets was investigated in two models of lipopolysaccharide (LPS)-induced toxicity in mice: the systemic reaction, provoked by intravenous LPS injection in D-galactosamine-sensitized recipients, which results in host death, and the local reaction, elicited in the skin by sequential injections of LPS and tumor necrosis factor alpha at 24-h intervals, which results in hemorrhagic necrosis. In both models, the depletion of platelets with a rabbit polyclonal or a mouse monoclonal antiplatelet immunoglobulin G afforded significant protection. In the local reaction, studies of the distribution of 111In-labelled platelets as well as optical and electron microscopy showed that platelets are localized in the dermal venules before hemorrhage occurs. Anti-CD11a (LFA-1) and anti-CD54 (ICAM-1) monoclonal antibodies prevented both platelet localization and hemorrhagic necrosis, and these determinants were detected on mouse platelets by immunofluorescence. The antiplatelet monoclonal antibody did not reduce the localization of polymorphonuclear leukocytes in the dermal venules, as shown by histological sections. Thus, in the local reaction, the stimulation with LPS and tumor necrosis factor alpha leads to a binding of platelets to the endothelium of venules by their beta 2 integrins, which seems necessary for the development of the hemorrhagic necrosis. Images PMID:8104895

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morishita, Sadaharu; Goto, Tetsuya; Nagase, Masaaki

Multiprocesses in a single plasma process chamber with high throughput require precise, sequential, high-speed alteration of partial pressures of multiple gas species. A conventional gas-distribution system cannot realize this because the system seriously overshoots gas pressure immediately following valve operation. Furthermore, chamber volume and conductance of gas piping between the system and chamber should both be considered because they delay the stabilizing time of gas pressure. Therefore, the authors proposed a new gas-distribution system without overshoot by controlling gas flow rate based on pressure measurement, as well as a method of pulse-controlled gas injection immediately following valve operation. Time variationmore » of measured partial pressure agrees well with a calculation based on an equivalent-circuit model that represents the chamber and gas piping between the system and chamber. Using pulse-controlled gas injection, the stabilizing time can be reduced drastically to 0.6 s for HBr added to pure Ar plasma, and 0.7 s for O{sub 2} added to Ar/HBr plasma; without the pulse control, the stabilizing times are 3 and 7 s, respectively. In the O{sub 2} addition case, rapid stabilization can be achieved during the period of line/space pattern etching of poly-Si on a thin SiO{sub 2} film. This occurs without anomalous etching of the underlying SiO{sub 2} film or the Si substrate near the sidewall, thus obtaining a wide process margin with high throughput.« less

Inactivated poliovirus type 2 vaccine delivered to rat skin via high density microprojection array elicits potent neutralising antibody responses

PubMed Central

Muller, David A.; Pearson, Frances E.; Fernando, Germain J.P.; Agyei-Yeboah, Christiana; Owens, Nick S.; Corrie, Simon R.; Crichton, Michael L.; Wei, Jonathan C.J.; Weldon, William C.; Oberste, M. Steven; Young, Paul R.; Kendall, Mark A. F.

2016-01-01

Polio eradication is progressing rapidly, and the live attenuated Sabin strains in the oral poliovirus vaccine (OPV) are being removed sequentially, starting with type 2 in April 2016. For risk mitigation, countries are introducing inactivated poliovirus vaccine (IPV) into routine vaccination programs. After April 2016, monovalent type 2 OPV will be available for type 2 outbreak control. Because the current IPV is not suitable for house-to-house vaccination campaigns (the intramuscular injections require health professionals), we developed a high-density microprojection array, the Nanopatch, delivered monovalent type 2 IPV (IPV2) vaccine to the skin. To assess the immunogenicity of the Nanopatch, we performed a dose-matched study in rats, comparing the immunogenicity of IPV2 delivered by intramuscular injection or Nanopatch immunisation. A single dose of 0.2 D-antigen units of IPV2 elicited protective levels of poliovirus antibodies in 100% of animals. However, animals receiving IPV2 by IM required at least 3 immunisations to reach the same neutralising antibody titres. This level of dose reduction (1/40th of a full dose) is unprecedented for poliovirus vaccine delivery. The ease of administration coupled with the dose reduction observed in this study points to the Nanopatch as a potential tool for facilitating inexpensive IPV for mass vaccination campaigns. PMID:26911254

Determination of technetium-99 in environmental samples: a review.

PubMed

Shi, Keliang; Hou, Xiaolin; Roos, Per; Wu, Wangsuo

2012-01-04

Due to the lack of a stable technetium isotope, and the high mobility and long half-life, (99)Tc is considered to be one of the most important radionuclides in safety assessment of environmental radioactivity as well as nuclear waste management. (99)Tc is also an important tracer for oceanographic research due to the high technetium solubility in seawater as TcO(4)(-). A number of analytical methods, using chemical separation combined with radiometric and mass spectrometric measurement techniques, have been developed over the past decades for determination of (99)Tc in different environmental samples. This article summarizes and compares recently reported chemical separation procedures and measurement methods for determination of (99)Tc. Due to the extremely low concentration of (99)Tc in environmental samples, the sample preparation, pre-concentration, chemical separation and purification for removal of the interferences for detection of (99)Tc are the most important issues governing the accurate determination of (99)Tc. These aspects are discussed in detail in this article. Meanwhile, the different measurement techniques for (99)Tc are also compared with respect to advantages and drawbacks. Novel automated analytical methods for rapid determination of (99)Tc using solid extraction or ion exchange chromatography for separation of (99)Tc, employing flow injection or sequential injection approaches are also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Direct and Retrograde Transduction of Nigral Neurons with AAV6, 8, and 9 and Intraneuronal Persistence of Viral Particles

PubMed Central

Aebischer, Patrick

2013-01-01

Abstract Recombinant adeno-associated viral (AAV) vectors of serotypes 6, 8, and 9 were characterized as tools for gene delivery to dopaminergic neurons in the substantia nigra for future gene therapeutic applications in Parkinson's disease. While vectors of all three serotypes transduced nigral dopaminergic neurons with equal efficiency when directly injected to the substantia nigra, AAV6 was clearly superior to AAV8 and AAV9 for retrograde transduction of nigral neurons after striatal delivery. For sequential transduction of nigral dopaminergic neurons, the combination of AAV9 with AAV6 proved to be more powerful than AAV8 with AAV6 or repeated AAV6 administration. Surprisingly, single-stranded viral genomes persisted in nigral dopaminergic neurons within cell bodies and axon terminals in the striatum, and intact assembled AAV capsid was enriched in nuclei of nigral neurons, 4 weeks after virus injections to the substantia nigra. 6-Hydroxydopamine (6-OHDA)–induced degeneration of dopaminergic neurons in the substantia nigra reduced the number of viral genomes in the striatum, in line with viral genome persistence in axon terminals. However, 6-OHDA–induced axonal degeneration did not induce any transsynaptic spread of AAV infection in the striatum. Therefore, the potential presence of viral particles in axons may not represent an important safety issue for AAV gene therapy applications in neurodegenerative diseases. PMID:23600720

Exploring the sequential lineup advantage using WITNESS.

PubMed

Goodsell, Charles A; Gronlund, Scott D; Carlson, Curt A

2010-12-01

Advocates claim that the sequential lineup is an improvement over simultaneous lineup procedures, but no formal (quantitatively specified) explanation exists for why it is better. The computational model WITNESS (Clark, Appl Cogn Psychol 17:629-654, 2003) was used to develop theoretical explanations for the sequential lineup advantage. In its current form, WITNESS produced a sequential advantage only by pairing conservative sequential choosing with liberal simultaneous choosing. However, this combination failed to approximate four extant experiments that exhibited large sequential advantages. Two of these experiments became the focus of our efforts because the data were uncontaminated by likely suspect position effects. Decision-based and memory-based modifications to WITNESS approximated the data and produced a sequential advantage. The next step is to evaluate the proposed explanations and modify public policy recommendations accordingly.

Optimal Sequential Rules for Computer-Based Instruction.

ERIC Educational Resources Information Center

Vos, Hans J.

1998-01-01

Formulates sequential rules for adapting the appropriate amount of instruction to learning needs in the context of computer-based instruction. Topics include Bayesian decision theory, threshold and linear-utility structure, psychometric model, optimal sequential number of test questions, and an empirical example of sequential instructional…

Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling.

PubMed

Koopmeiners, Joseph S; Feng, Ziding

2011-01-01

The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves.

Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling

PubMed Central

Koopmeiners, Joseph S.; Feng, Ziding

2013-01-01

The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves. PMID:24039313

Single-step inline hydroxyapatite enrichment facilitates identification and quantitation of phosphopeptides from mass-limited proteomes with MudPIT

PubMed Central

Fonslow, Bryan R.; Niessen, Sherry M.; Singh, Meha; Wong, Catherine C.; Xu, Tao; Carvalho, Paulo C.; Choi, Jeong; Park, Sung Kyu; Yates, John R.

2012-01-01

Herein we report the characterization and optimization of single-step inline enrichment of phosphopeptides directly from small amounts of whole cell and tissue lysates (100 – 500 μg) using a hydroxyapatite (HAP) microcolumn and Multidimensional Protein Identification Technology (MudPIT). In comparison to a triplicate HILIC-IMAC phosphopeptide enrichment study, ~80% of the phosphopeptides identified using HAP-MudPIT were unique. Similarly, analysis of the consensus phosphorylation motifs between the two enrichment methods illustrates the complementarity of calcium-and iron-based enrichment methods and the higher sensitivity and selectivity of HAP-MudPIT for acidic motifs. We demonstrate how the identification of more multiply phosphorylated peptides from HAP-MudPIT can be used to quantify phosphorylation cooperativity. Through optimization of HAP-MudPIT on a whole cell lysate we routinely achieved identification and quantification of ca. 1000 phosphopeptides from a ~1 hr enrichment and 12 hr MudPIT analysis on small quantities of material. Finally, we applied this optimized method to identify phosphorylation sites from a mass-limited mouse brain region, the amygdala (200 – 500 μg), identifying up to 4000 phosphopeptides per run. PMID:22509746

Porous Silicon Gradient Refractive Index Micro-Optics.

PubMed

Krueger, Neil A; Holsteen, Aaron L; Kang, Seung-Kyun; Ocier, Christian R; Zhou, Weijun; Mensing, Glennys; Rogers, John A; Brongersma, Mark L; Braun, Paul V

2016-12-14

The emergence and growth of transformation optics over the past decade has revitalized interest in how a gradient refractive index (GRIN) can be used to control light propagation. Two-dimensional demonstrations with lithographically defined silicon (Si) have displayed the power of GRIN optics and also represent a promising opportunity for integrating compact optical elements within Si photonic integrated circuits. Here, we demonstrate the fabrication of three-dimensional Si-based GRIN micro-optics through the shape-defined formation of porous Si (PSi). Conventional microfabrication creates Si square microcolumns (SMCs) that can be electrochemically etched into PSi elements with nanoscale porosity along the shape-defined etching pathway, which imparts the geometry with structural birefringence. Free-space characterization of the transmitted intensity distribution through a homogeneously etched PSi SMC exhibits polarization splitting behavior resembling that of dielectric metasurfaces that require considerably more laborious fabrication. Coupled birefringence/GRIN effects are studied by way of PSi SMCs etched with a linear (increasing from edge to center) GRIN profile. The transmitted intensity distribution shows polarization-selective focusing behavior with one polarization focused to a diffraction-limited spot and the orthogonal polarization focused into two laterally displaced foci. Optical thickness-based analysis readily predicts the experimentally observed phenomena, which strongly match finite-element electromagnetic simulations.

Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

PubMed Central

Mahmoud, Mohamed E.; Osman, Maher M.; Ahmed, Somia B.; Abdel-Fattah, Tarek M.

2012-01-01

Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker's yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II) sorption compared to blank active carbon providing a maximum sorption capacity of lead(II) ion as 500 μmol g−1. Sorption processes of lead(II) by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II) concentration, and foreign ions. Lead(II) sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0 ± 3.0–5.0%) by various carbonaceous-modified-bakers yeast biosorbents. PMID:22629157

Affinity monolith chromatography: A review of principles and recent analytical applications

PubMed Central

Pfaunmiller, Erika L.; Paulemond, Marie Laura; Dupper, Courtney M.; Hage, David S.

2012-01-01

Affinity monolith chromatography (AMC) is a type of liquid chromatography that uses a monolithic support and a biologically-related binding agent as a stationary phase. AMC is a powerful method for the selective separation, analysis or studies of specific target compounds in a sample. This review discusses the basic principles of AMC and recent developments or applications of this method, with particular emphasis being given to work that has appeared in the last five years. Various materials that have been used to prepare columns for AMC are examined, including organic monoliths, silica monoliths, agarose monoliths and cryogels. These supports have been used in AMC for formats that have ranged from traditional columns to disks, microcolumns and capillaries. Many binding agents have also been employed in AMC, such as antibodies, enzymes, proteins, lectins, immobilized metal-ions and dyes. Some applications that have been reported with these binding agents in AMC are bioaffinity chromatography, immunoaffinity chromatography or immunoextraction, immobilized metal-ion affinity chromatography, dye-ligand affinity chromatography, chiral separations and biointeraction studies. Examples are presented from fields that include analytical chemistry, pharmaceutical analysis, clinical testing and biotechnology. Current trends and possible future directions in AMC are also discussed. PMID:23187827

Development of a temperature gradient focusing method for in situ extraterrestrial biomarker analysis.

PubMed

Danger, Grégoire; Ross, David

2008-08-01

Scanning temperature gradient focusing (TGF) is a recently described technique for the simultaneous concentration and separation of charged analytes. It allows for high analyte peak capacities and low LODs in microcolumn electrophoretic separations. In this paper, we present the application of scanning TGF for chiral separations of amino acids. Using a mixture of seven carboxyfluorescein succinimidyl ester-labeled amino acids (including five chiral amino acids) which constitute the Mars7 standard, we show that scanning TGF is a very simple and efficient method for chiral separations. The modulation of TGF separation parameters (temperature window, pressure scan rate, temperature range, and chiral selector concentration) allows optimization of peak efficiencies and analyte resolutions. The use of hydroxypropyl-beta-CD at low concentration (1-5 mmol/L) as a chiral selector, with an appropriate pressure scan rate ( -0.25 Pa/s) and with a low temperature range (3-25 degrees C over 1 cm) provided high resolution between enantiomers (Rs >1.5 for each pair of enantiomers) using a short, 4 cm long capillary. With these new results, the scanning TGF method appears to be a viable method for in situ trace biomarker analysis for future missions to Mars or other solar system bodies.

G-sequentially connectedness for topological groups with operations

NASA Astrophysics Data System (ADS)

Mucuk, Osman; Cakalli, Huseyin

2016-08-01

It is a well-known fact that for a Hausdorff topological group X, the limits of convergent sequences in X define a function denoted by lim from the set of all convergent sequences in X to X. This notion has been modified by Connor and Grosse-Erdmann for real functions by replacing lim with an arbitrary linear functional G defined on a linear subspace of the vector space of all real sequences. Recently some authors have extended the concept to the topological group setting and introduced the concepts of G-sequential continuity, G-sequential compactness and G-sequential connectedness. In this work, we present some results about G-sequentially closures, G-sequentially connectedness and fundamental system of G-sequentially open neighbourhoods for topological group with operations which include topological groups, topological rings without identity, R-modules, Lie algebras, Jordan algebras, and many others.

Eyewitness confidence in simultaneous and sequential lineups: a criterion shift account for sequential mistaken identification overconfidence.

PubMed

Dobolyi, David G; Dodson, Chad S

2013-12-01

Confidence judgments for eyewitness identifications play an integral role in determining guilt during legal proceedings. Past research has shown that confidence in positive identifications is strongly associated with accuracy. Using a standard lineup recognition paradigm, we investigated accuracy using signal detection and ROC analyses, along with the tendency to choose a face with both simultaneous and sequential lineups. We replicated past findings of reduced rates of choosing with sequential as compared to simultaneous lineups, but notably found an accuracy advantage in favor of simultaneous lineups. Moreover, our analysis of the confidence-accuracy relationship revealed two key findings. First, we observed a sequential mistaken identification overconfidence effect: despite an overall reduction in false alarms, confidence for false alarms that did occur was higher with sequential lineups than with simultaneous lineups, with no differences in confidence for correct identifications. This sequential mistaken identification overconfidence effect is an expected byproduct of the use of a more conservative identification criterion with sequential than with simultaneous lineups. Second, we found a steady drop in confidence for mistaken identifications (i.e., foil identifications and false alarms) from the first to the last face in sequential lineups, whereas confidence in and accuracy of correct identifications remained relatively stable. Overall, we observed that sequential lineups are both less accurate and produce higher confidence false identifications than do simultaneous lineups. Given the increasing prominence of sequential lineups in our legal system, our data argue for increased scrutiny and possibly a wholesale reevaluation of this lineup format. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Robustness of the Sequential Lineup Advantage

ERIC Educational Resources Information Center

Gronlund, Scott D.; Carlson, Curt A.; Dailey, Sarah B.; Goodsell, Charles A.

2009-01-01

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup…

Lung Volume Measured during Sequential Swallowing in Healthy Young Adults

ERIC Educational Resources Information Center

Hegland, Karen Wheeler; Huber, Jessica E.; Pitts, Teresa; Davenport, Paul W.; Sapienza, Christine M.

2011-01-01

Purpose: Outcomes from studying the coordinative relationship between respiratory and swallow subsystems are inconsistent for sequential swallows, and the lung volume at the initiation of sequential swallowing remains undefined. The first goal of this study was to quantify the lung volume at initiation of sequential swallowing ingestion cycles and…

The use of injectable sonication-induced silk hydrogel for VEGF165 and BMP-2 delivery for elevation of the maxillary sinus floor

PubMed Central

Zhang, Wenjie; Wang, Xiuli; Wang, Shaoyi; Zhao, Jun; Xu, Lianyi; Zhu, Chao; Zeng, Deliang; Chen, Jake; Zhang, Zhiyuan; Kaplan, David L.; Jiang, Xinquan

2011-01-01

Sonication-induced silk hydrogels were previously prepared as an injectable bone replacement biomaterial, with a need to improve osteogenic features. Vascular endothelial growth factor (VEGF165) and bone morphogenic protein-2 (BMP-2) are key regulators of angiogenesis and osteogenesis, respectively, during bone regeneration. Therefore, the present study aimed at evaluating in situ forming silk hydrogels as a vehicle to encapsulate dual factors for rabbit maxillary sinus floor augmentation. Sonication-induced silk hydrogels were prepared in vitro and the slow release of VEGF165 and BMP-2 from these silk gels was evaluated by ELISA. For in vivo studies for each time point (4 and 12 weeks), 24 sinus floors elevation surgeries were made bilaterally in 12 rabbits for the following four treatment groups: silk gel (group Silk gel), silk gel/VEGF165 (group VEGF), silk gel/BMP-2 (group BMP-2), silk gel/VEGF165/BMP-2 (group V+B) (n=6 per group). Sequential florescent labeling and radiographic observations were used to record new bone formation and mineralization, along with histological and histomorphometric analysis. At week 4, VEGF165 promoted more tissue infiltration into the gel and accelerated the degradation of the gel material. At this time point, the bone area in group V+B was significantly larger than those in the other three groups. At week 12, elevated sinus floor heights of groups BMP-2 and V+B were larger than those of the Silk gel and VEGF groups, and the V+B group had the largest new bone area among all groups. In addition, a larger blood vessel area formed in the remaining gel areas in groups VEGF and V+B. In conclusion, VEGF165 and BMP-2 released from injectable and biodegradable silk gels promoted angiogenesis and new bone formation, with the two factors demonstrating an additive effect on bone regeneration. These results indicate that silk hydrogels can be used as an injectable vehicle to deliver multiple growth factors in a minimally invasive approach to regenerate irregular bony cavities. PMID:21889205

Adult human mesenchymal stem cells delivered via intra-articular injection to the knee following partial medial meniscectomy: a randomized, double-blind, controlled study.

PubMed

Vangsness, C Thomas; Farr, Jack; Boyd, Joel; Dellaero, David T; Mills, C Randal; LeRoux-Williams, Michelle

2014-01-15

There are limited treatment options for tissue restoration and the prevention of degenerative changes in the knee. Stem cells have been a focus of intense preclinical research into tissue regeneration but limited clinical investigation. In a randomized, double-blind, controlled study, the safety of the intra-articular injection of human mesenchymal stem cells into the knee, the ability of mesenchymal stem cells to promote meniscus regeneration following partial meniscectomy, and the effects of mesenchymal stem cells on osteoarthritic changes in the knee were investigated. A total of fifty-five patients at seven institutions underwent a partial medial meniscectomy. A single superolateral knee injection was given within seven to ten days after the meniscectomy. Patients were randomized to one of three treatment groups: Group A, in which patients received an injection of 50 × 10⁶ allogeneic mesenchymal stem cells; Group B, 150 × 10⁶ allogeneic mesenchymal stem cells; and the control group, a sodium hyaluronate (hyaluronic acid/hyaluronan) vehicle control. Patients were followed to evaluate safety, meniscus regeneration, the overall condition of the knee joint, and clinical outcomes at intervals through two years. Evaluations included sequential magnetic resonance imaging (MRI). No ectopic tissue formation or clinically important safety issues were identified. There was significantly increased meniscal volume (defined a priori as a 15% threshold) determined by quantitative MRI in 24% of patients in Group A and 6% in Group B at twelve months post meniscectomy (p = 0.022). No patients in the control group met the 15% threshold for increased meniscal volume. Patients with osteoarthritic changes who received mesenchymal stem cells experienced a significant reduction in pain compared with those who received the control, on the basis of visual analog scale assessments. There was evidence of meniscus regeneration and improvement in knee pain following treatment with allogeneic human mesenchymal stem cells. These results support the study of human mesenchymal stem cells for the apparent knee-tissue regeneration and protective effects.

EM reconstruction of dual isotope PET using staggered injections and prompt gamma positron emitters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andreyev, Andriy, E-mail: andriy.andreyev-1@philips.com; Sitek, Arkadiusz; Celler, Anna

2014-02-15

Purpose: The aim of dual isotope positron emission tomography (DIPET) is to create two separate images of two coinjected PET radiotracers. DIPET shortens the duration of the study, reduces patient discomfort, and produces perfectly coregistered images compared to the case when two radiotracers would be imaged independently (sequential PET studies). Reconstruction of data from such simultaneous acquisition of two PET radiotracers is difficult because positron decay of any isotope creates only 511 keV photons; therefore, the isotopes cannot be differentiated based on the detected energy. Methods: Recently, the authors have proposed a DIPET technique that uses a combination of radiotracermore » A which is a pure positron emitter (such as{sup 18}F or {sup 11}C) and radiotracer B in which positron decay is accompanied by the emission of a high-energy (HE) prompt gamma (such as {sup 38}K or {sup 60}Cu). Events that are detected as triple coincidences of HE gammas with the corresponding two 511 keV photons allow the authors to identify the lines-of-response (LORs) of isotope B. These LORs are used to separate the two intertwined distributions, using a dedicated image reconstruction algorithm. In this work the authors propose a new version of the DIPET EM-based reconstruction algorithm that allows the authors to include an additional, independent estimate of radiotracer A distribution which may be obtained if radioisotopes are administered using a staggered injections method. In this work the method is tested on simple simulations of static PET acquisitions. Results: The authors’ experiments performed using Monte-Carlo simulations with static acquisitions demonstrate that the combined method provides better results (crosstalk errors decrease by up to 50%) than the positron-gamma DIPET method or staggered injections alone. Conclusions: The authors demonstrate that the authors’ new EM algorithm which combines information from triple coincidences with prompt gammas and staggered injections improves the accuracy of DIPET reconstructions for static acquisitions so they reach almost the benchmark level calculated for perfectly separated tracers.« less

A gas-phase chemiluminescence-based analyzer for waterborne arsenic

USGS Publications Warehouse

Idowu, A.D.; Dasgupta, P.K.; Genfa, Z.; Toda, K.; Garbarino, J.R.

2006-01-01

We show a practical sequential injection/zone fluidics-based analyzer that measures waterborne arsenic. The approach is capable of differentiating between inorganic As(III) and As(V). The principle is based on generating AsH 3 from the sample in a confined chamber by borohydride reduction at controlled pH, sparging the chamber to drive the AsH3 to a small reflective cell located atop a photomultiplier tube, allowing it to react with ozone generated from ambient air, and measuring the intense chemiluminescence that results. Arsine generation and removal from solution results in isolation from the sample matrix, avoiding the pitfalls encountered in some solution-based analysis techniques. The differential determination of As(III) and As(V) is based on the different pH dependence of the reducibility of these species to AsH3. At pH ???1, both As(III) and As(V) are quantitatively converted to arsine in the presence of NaBH4. At a pH of 4-5, only As(III) is converted to arsine. In the present form, the limit of detection (S/N = 3) is 0.05 ??g/L As at pH ???1 and 0.09 ??g/L As(III) at pH ???4-5 for a 3-mL sample. The analyzer is intrinsically automated and requires 4 min per determination. It is also possible to determine As(III) first at pH 4.5 and then determine the remaining As in a sequential manner; this requires 6 min. There are no significant practical interferences. A new borohydride solution formulation permits month-long reagent stability. ?? 2006 American Chemical Society.

Determination of dextromethorphan in human plasma using pipette tip solid-phase extraction and gas chromatography-mass spectrometry.

PubMed

Hasegawa, Chika; Kumazawa, Takeshi; Uchigasaki, Seisaku; Lee, Xiao-Pen; Sato, Keizo; Terada, Masaru; Kurosaki, Kunihiko

2011-10-01

Dextromethorphan was extracted from human plasma samples (100 μL) using MonoTip C(18) tips, which are packed with C(18)-bonded monolithic silica gel that is attached to the inside of the tip. The samples, which contained dextromethorphan and trimeprazine as an internal standard (IS), were mixed with 200 μL of distilled water and 50 μL of 1 mol/L glycine-sodium hydroxide buffer (pH 10). The mixture was extracted to the C(18) phase of the tip by 20 sequential aspirating/dispensing cycles using a manual micropipettor. The analytes retained on the C(18) phase were then eluted with methanol by five sequential aspirating/dispensing cycles. The eluate was injected directly into a gas chromatograph and detected by a mass spectrometer with selected ion monitoring in positive electron ionization mode. An Equity-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.5 μm) gave adequate separation of the dextromethorphan, IS, and impurities. The recoveries of dextromethorphan and the IS spiked into plasma were >87.4%. The regression equation for dextromethorphan showed excellent linearity from 2.5 to 320 ng/mL of plasma, and the limit of detection was 1.25 ng/mL of plasma. The intraday and interday coefficients of variation were less than 10.5% and 14.7%, respectively. The accuracy ranged from 91.9% to 107%. The validated method was successfully used to quantify the plasma concentration of dextromethorphan in a human subject after oral administration of the drug. © Springer-Verlag 2011

Small Molecule Sequential Dual-Targeting Theragnostic Strategy (SMSDTTS): from Preclinical Experiments towards Possible Clinical Anticancer Applications

PubMed Central

Li, Junjie; Oyen, Raymond; Verbruggen, Alfons; Ni, Yicheng

2013-01-01

Hitting the evasive tumor cells proves challenging in targeted cancer therapies. A general and unconventional anticancer approach namely small molecule sequential dual-targeting theragnostic strategy (SMSDTTS) has recently been introduced with the aims to target and debulk the tumor mass, wipe out the residual tumor cells, and meanwhile enable cancer detectability. This dual targeting approach works in two steps for systemic delivery of two naturally derived drugs. First, an anti-tubulin vascular disrupting agent, e.g., combretastatin A4 phosphate (CA4P), is injected to selectively cut off tumor blood supply and to cause massive necrosis, which nevertheless always leaves peripheral tumor residues. Secondly, a necrosis-avid radiopharmaceutical, namely 131I-hypericin (131I-Hyp), is administered the next day, which accumulates in intratumoral necrosis and irradiates the residual cancer cells with beta particles. Theoretically, this complementary targeted approach may biologically and radioactively ablate solid tumors and reduce the risk of local recurrence, remote metastases, and thus cancer mortality. Meanwhile, the emitted gamma rays facilitate radio-scintigraphy to detect tumors and follow up the therapy, hence a simultaneous theragnostic approach. SMSDTTS has now shown promise from multicenter animal experiments and may demonstrate unique anticancer efficacy in upcoming preliminary clinical trials. In this short review article, information about the two involved agents, the rationale of SMSDTTS, its preclinical antitumor efficacy, multifocal targetability, simultaneous theragnostic property, and toxicities of the dose regimens are summarized. Meanwhile, possible drawbacks, practical challenges and future improvement with SMSDTTS are discussed, which hopefully may help to push forward this strategy from preclinical experiments towards possible clinical applications. PMID:23412554

Small Molecule Sequential Dual-Targeting Theragnostic Strategy (SMSDTTS): from Preclinical Experiments towards Possible Clinical Anticancer Applications.

PubMed

Li, Junjie; Oyen, Raymond; Verbruggen, Alfons; Ni, Yicheng

2013-01-01

Hitting the evasive tumor cells proves challenging in targeted cancer therapies. A general and unconventional anticancer approach namely small molecule sequential dual-targeting theragnostic strategy (SMSDTTS) has recently been introduced with the aims to target and debulk the tumor mass, wipe out the residual tumor cells, and meanwhile enable cancer detectability. This dual targeting approach works in two steps for systemic delivery of two naturally derived drugs. First, an anti-tubulin vascular disrupting agent, e.g., combretastatin A4 phosphate (CA4P), is injected to selectively cut off tumor blood supply and to cause massive necrosis, which nevertheless always leaves peripheral tumor residues. Secondly, a necrosis-avid radiopharmaceutical, namely (131)I-hypericin ((131)I-Hyp), is administered the next day, which accumulates in intratumoral necrosis and irradiates the residual cancer cells with beta particles. Theoretically, this complementary targeted approach may biologically and radioactively ablate solid tumors and reduce the risk of local recurrence, remote metastases, and thus cancer mortality. Meanwhile, the emitted gamma rays facilitate radio-scintigraphy to detect tumors and follow up the therapy, hence a simultaneous theragnostic approach. SMSDTTS has now shown promise from multicenter animal experiments and may demonstrate unique anticancer efficacy in upcoming preliminary clinical trials. In this short review article, information about the two involved agents, the rationale of SMSDTTS, its preclinical antitumor efficacy, multifocal targetability, simultaneous theragnostic property, and toxicities of the dose regimens are summarized. Meanwhile, possible drawbacks, practical challenges and future improvement with SMSDTTS are discussed, which hopefully may help to push forward this strategy from preclinical experiments towards possible clinical applications.

Effects of multiple collections on spermatozoa quality of Persian sturgeon, Acipenser persicus: motility, density and seminal plasma composition.

PubMed

Aramli, M S; Kalbassi, M R; Gharibi, M R

2015-02-01

In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH-A2, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p < 0.05) after the second and third collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl(-) ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p < 0.05) of seminal plasma was observed. This study provides new data on the effects of multiple collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Safety and Immune Responses in Children After Concurrent or Sequential 2009 H1N1 and 2009–2010 Seasonal Trivalent Influenza Vaccinations

PubMed Central

Frey, Sharon E.; Bernstein, David I.; Gerber, Michael A.; Keyserling, Harry L.; Munoz, Flor M.; Winokur, Patricia L.; Turley, Christine B.; Rupp, Richard E.; Hill, Heather; Wolff, Mark; Noah, Diana L.; Ross, Allison C.; Cress, Gretchen; Belshe, Robert B.

2012-01-01

Background. Administering 2 separate vaccines for seasonal and pandemic influenza was necessary in 2009. Therefore, we conducted a randomized trial of monovalent 2009 H1N1 influenza vaccine (2009 H1N1 vaccine) and seasonal trivalent inactivated influenza vaccine (TIV; split virion) given sequentially or concurrently in previously vaccinated children. Methods. Children randomized to 4 study groups and stratified by age received 1 dose of seasonal TIV and 2 doses of 2009 H1N1 vaccine in 1 of 4 combinations. Injections were given at 21-day intervals and serum samples for hemagglutination inhibition antibody responses were obtained prior to and 21 days after each vaccination. Reactogenicity and adverse events were monitored. Results. All combinations of vaccines were safe in the 531 children enrolled. Generally, 1 dose of 2009 H1N1 vaccine and 1 dose of TIV, regardless of sequence or concurrency of administration, was immunogenic in children ≥10 years of age; children <10 years of age required 2 doses of 2009 H1N1 vaccine. Conclusions. Vaccines were generally well tolerated. The immune responses to 2009 H1N1 vaccine were adequate regardless of the sequence of vaccination in all age groups but the sequence affected titers to TIV antigens. Two doses of 2009 H1N1 vaccine were required to achieve a protective immune response in children <10 years of age. Clinical Trials Registration. NCT00943202. PMID:22802432

Sequential Pumping and Tracing Experiments Using Packer Systems in a Chalk Aquifer

NASA Astrophysics Data System (ADS)

Goderniaux, P.; Poulain, A.

2016-12-01

The hydraulic characterization of subsurface geological unit is crucial for many hydrogeological applications. The quantification and the spatial distribution of the related parameters is however not always straightforward. As a consequence, parameters values are often considered as homogeneous over the thickness of an aquifer unit. To try to catch the possible heterogeneity, sequential tracer and pumping tests have been performed between two piezometers, using inflatable packer systems to isolate and study specific sections of the boreholes. The experimental site is composed of two 50m-deep piezometers located in a chalk aquifer, in South-West Belgium. The boreholes are not equipped with any casing or screen, to allow the use of the packers. The chalk is characterized by a high porosity, which enables the storage of large quantities of groundwater, and by fractures where fast preferential flow occurs. Recordings made with a borehole camera system has evidenced the presence of many fractures along the borehole, with a mean density of 2 fractures by meter. The frequency of fracture occurrences is however variable along the borehole. Pumping and tracer tests have been performed (1) using the whole borehole depth, and (2) over specific 1-meter sections, isolated with packers. Results confirm that flow and transport parameters are heterogeneous within the chalk aquifer unit. Groundwater head variations, induced by water pumping or injection, and tracer transfer times are variable according to the studied borehole section. Tests are still going on, and the objective is to have measurements over the whole borehole, to be used for numerical interpretation.

Replay of Episodic Memories in the Rat.

PubMed

Panoz-Brown, Danielle; Iyer, Vishakh; Carey, Lawrence M; Sluka, Christina M; Rajic, Gabriela; Kestenman, Jesse; Gentry, Meredith; Brotheridge, Sydney; Somekh, Isaac; Corbin, Hannah E; Tucker, Kjersten G; Almeida, Bianca; Hex, Severine B; Garcia, Krysten D; Hohmann, Andrea G; Crystal, Jonathon D

2018-05-21

Vivid episodic memories in people have been characterized as the replay of multiple unique events in sequential order [1-3]. The hippocampus plays a critical role in episodic memories in both people and rodents [2, 4-6]. Although rats remember multiple unique episodes [7, 8], it is currently unknown if animals "replay" episodic memories. Therefore, we developed an animal model of episodic memory replay. Here, we show that rats can remember a trial-unique stream of multiple episodes and the order in which these events occurred by engaging hippocampal-dependent episodic memory replay. We document that rats rely on episodic memory replay to remember the order of events rather than relying on non-episodic memories. Replay of episodic memories survives a long retention-interval challenge and interference from the memory of other events, which documents that replay is part of long-term episodic memory. The chemogenetic activating drug clozapine N-oxide (CNO), but not vehicle, reversibly impairs episodic memory replay in rats previously injected bilaterally in the hippocampus with a recombinant viral vector containing an inhibitory designer receptor exclusively activated by a designer drug (DREADD; AAV8-hSyn-hM4Di-mCherry). By contrast, two non-episodic memory assessments are unaffected by CNO, showing selectivity of this hippocampal-dependent impairment. Our approach provides an animal model of episodic memory replay, a process by which the rat searches its representations in episodic memory in sequential order to find information. Our findings using rats suggest that the ability to replay a stream of episodic memories is quite old in the evolutionary timescale. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sequential lineup laps and eyewitness accuracy.

PubMed

Steblay, Nancy K; Dietrich, Hannah L; Ryan, Shannon L; Raczynski, Jeanette L; James, Kali A

2011-08-01

Police practice of double-blind sequential lineups prompts a question about the efficacy of repeated viewings (laps) of the sequential lineup. Two laboratory experiments confirmed the presence of a sequential lap effect: an increase in witness lineup picks from first to second lap, when the culprit was a stranger. The second lap produced more errors than correct identifications. In Experiment 2, lineup diagnosticity was significantly higher for sequential lineup procedures that employed a single versus double laps. Witnesses who elected to view a second lap made significantly more errors than witnesses who chose to stop after one lap or those who were required to view two laps. Witnesses with prior exposure to the culprit did not exhibit a sequential lap effect.

Simultaneous control of microorganisms and disinfection by-products by sequential chlorination.

PubMed

Chen, Chao; Zhang, Xiao-Jian; He, Wen-Jie; Han, Hong-Da

2007-04-01

To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Pilot tests of this sequential chlorination were carried out in a drinking water plant. The sequential chlorination disinfection process had the same or better efficiency on microbe (including virus) inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process. The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination. This process takes advantages of free chlorine's quick inactivation of microorganisms and chloramine's low disinfection by-product (DBP) yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.

A Novel Method for Discovering Fuzzy Sequential Patterns Using the Simple Fuzzy Partition Method.

ERIC Educational Resources Information Center

Chen, Ruey-Shun; Hu, Yi-Chung

2003-01-01

Discusses sequential patterns, data mining, knowledge acquisition, and fuzzy sequential patterns described by natural language. Proposes a fuzzy data mining technique to discover fuzzy sequential patterns by using the simple partition method which allows the linguistic interpretation of each fuzzy set to be easily obtained. (Author/LRW)

SPMBR: a scalable algorithm for mining sequential patterns based on bitmaps

NASA Astrophysics Data System (ADS)

Xu, Xiwei; Zhang, Changhai

2013-12-01

Now some sequential patterns mining algorithms generate too many candidate sequences, and increase the processing cost of support counting. Therefore, we present an effective and scalable algorithm called SPMBR (Sequential Patterns Mining based on Bitmap Representation) to solve the problem of mining the sequential patterns for large databases. Our method differs from previous related works of mining sequential patterns. The main difference is that the database of sequential patterns is represented by bitmaps, and a simplified bitmap structure is presented firstly. In this paper, First the algorithm generate candidate sequences by SE(Sequence Extension) and IE(Item Extension), and then obtain all frequent sequences by comparing the original bitmap and the extended item bitmap .This method could simplify the problem of mining the sequential patterns and avoid the high processing cost of support counting. Both theories and experiments indicate that the performance of SPMBR is predominant for large transaction databases, the required memory size for storing temporal data is much less during mining process, and all sequential patterns can be mined with feasibility.

A weight modification sequential method for VSC-MTDC power system state estimation

NASA Astrophysics Data System (ADS)

Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

2017-06-01

This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

Continuity of the sequential product of sequential quantum effect algebras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lei, Qiang, E-mail: leiqiang@hit.edu.cn; Su, Xiaochao, E-mail: hitswh@163.com; Wu, Junde, E-mail: wjd@zju.edu.cn

In order to study quantum measurement theory, sequential product defined by A∘B = A{sup 1/2}BA{sup 1/2} for any two quantum effects A, B has been introduced. Physically motivated conditions ask the sequential product to be continuous with respect to the strong operator topology. In this paper, we study the continuity problems of the sequential product A∘B = A{sup 1/2}BA{sup 1/2} with respect to other important topologies, such as norm topology, weak operator topology, order topology, and interval topology.

A Rejection Principle for Sequential Tests of Multiple Hypotheses Controlling Familywise Error Rates

PubMed Central

BARTROFF, JAY; SONG, JINLIN

2015-01-01

We present a unifying approach to multiple testing procedures for sequential (or streaming) data by giving sufficient conditions for a sequential multiple testing procedure to control the familywise error rate (FWER). Together we call these conditions a “rejection principle for sequential tests,” which we then apply to some existing sequential multiple testing procedures to give simplified understanding of their FWER control. Next the principle is applied to derive two new sequential multiple testing procedures with provable FWER control, one for testing hypotheses in order and another for closed testing. Examples of these new procedures are given by applying them to a chromosome aberration data set and to finding the maximum safe dose of a treatment. PMID:26985125

Comparative efficacy of simultaneous versus sequential multiple health behavior change interventions among adults: A systematic review of randomised trials.

PubMed

James, Erica; Freund, Megan; Booth, Angela; Duncan, Mitch J; Johnson, Natalie; Short, Camille E; Wolfenden, Luke; Stacey, Fiona G; Kay-Lambkin, Frances; Vandelanotte, Corneel

2016-08-01

Growing evidence points to the benefits of addressing multiple health behaviors rather than single behaviors. This review evaluates the relative effectiveness of simultaneous and sequentially delivered multiple health behavior change (MHBC) interventions. Secondary aims were to identify: a) the most effective spacing of sequentially delivered components; b) differences in efficacy of MHBC interventions for adoption/cessation behaviors and lifestyle/addictive behaviors, and; c) differences in trial retention between simultaneously and sequentially delivered interventions. MHBC intervention trials published up to October 2015 were identified through a systematic search. Eligible trials were randomised controlled trials that directly compared simultaneous and sequential delivery of a MHBC intervention. A narrative synthesis was undertaken. Six trials met the inclusion criteria and across these trials the behaviors targeted were smoking, diet, physical activity, and alcohol consumption. Three trials reported a difference in intervention effect between a sequential and simultaneous approach in at least one behavioral outcome. Of these, two trials favoured a sequential approach on smoking. One trial favoured a simultaneous approach on fat intake. There was no difference in retention between sequential and simultaneous approaches. There is limited evidence regarding the relative effectiveness of sequential and simultaneous approaches. Given only three of the six trials observed a difference in intervention effectiveness for one health behavior outcome, and the relatively consistent finding that the sequential and simultaneous approaches were more effective than a usual/minimal care control condition, it appears that both approaches should be considered equally efficacious. PROSPERO registration number: CRD42015027876. Copyright © 2016 Elsevier Inc. All rights reserved.

Group Sequential Testing of the Predictive Accuracy of a Continuous Biomarker with Unknown Prevalence

PubMed Central

Koopmeiners, Joseph S.; Feng, Ziding

2015-01-01

Group sequential testing procedures have been proposed as an approach to conserving resources in biomarker validation studies. Previously, Koopmeiners and Feng (2011) derived the asymptotic properties of the sequential empirical positive predictive value (PPV) and negative predictive value curves, which summarize the predictive accuracy of a continuous marker, under case-control sampling. A limitation of their approach is that the prevalence can not be estimated from a case-control study and must be assumed known. In this manuscript, we consider group sequential testing of the predictive accuracy of a continuous biomarker with unknown prevalence. First, we develop asymptotic theory for the sequential empirical PPV and NPV curves when the prevalence must be estimated, rather than assumed known in a case-control study. We then discuss how our results can be combined with standard group sequential methods to develop group sequential testing procedures and bias-adjusted estimators for the PPV and NPV curve. The small sample properties of the proposed group sequential testing procedures and estimators are evaluated by simulation and we illustrate our approach in the context of a study to validate a novel biomarker for prostate cancer. PMID:26537180

A Sequential Multiplicative Extended Kalman Filter for Attitude Estimation Using Vector Observations.

PubMed

Qin, Fangjun; Chang, Lubin; Jiang, Sai; Zha, Feng

2018-05-03

In this paper, a sequential multiplicative extended Kalman filter (SMEKF) is proposed for attitude estimation using vector observations. In the proposed SMEKF, each of the vector observations is processed sequentially to update the attitude, which can make the measurement model linearization more accurate for the next vector observation. This is the main difference to Murrell’s variation of the MEKF, which does not update the attitude estimate during the sequential procedure. Meanwhile, the covariance is updated after all the vector observations have been processed, which is used to account for the special characteristics of the reset operation necessary for the attitude update. This is the main difference to the traditional sequential EKF, which updates the state covariance at each step of the sequential procedure. The numerical simulation study demonstrates that the proposed SMEKF has more consistent and accurate performance in a wide range of initial estimate errors compared to the MEKF and its traditional sequential forms.

RACE/A: an architectural account of the interactions between learning, task control, and retrieval dynamics.

PubMed

van Maanen, Leendert; van Rijn, Hedderik; Taatgen, Niels

2012-01-01

This article discusses how sequential sampling models can be integrated in a cognitive architecture. The new theory Retrieval by Accumulating Evidence in an Architecture (RACE/A) combines the level of detail typically provided by sequential sampling models with the level of task complexity typically provided by cognitive architectures. We will use RACE/A to model data from two variants of a picture-word interference task in a psychological refractory period design. These models will demonstrate how RACE/A enables interactions between sequential sampling and long-term declarative learning, and between sequential sampling and task control. In a traditional sequential sampling model, the onset of the process within the task is unclear, as is the number of sampling processes. RACE/A provides a theoretical basis for estimating the onset of sequential sampling processes during task execution and allows for easy modeling of multiple sequential sampling processes within a task. Copyright © 2011 Cognitive Science Society, Inc.

A Sequential Multiplicative Extended Kalman Filter for Attitude Estimation Using Vector Observations

PubMed Central

Qin, Fangjun; Jiang, Sai; Zha, Feng

2018-01-01

In this paper, a sequential multiplicative extended Kalman filter (SMEKF) is proposed for attitude estimation using vector observations. In the proposed SMEKF, each of the vector observations is processed sequentially to update the attitude, which can make the measurement model linearization more accurate for the next vector observation. This is the main difference to Murrell’s variation of the MEKF, which does not update the attitude estimate during the sequential procedure. Meanwhile, the covariance is updated after all the vector observations have been processed, which is used to account for the special characteristics of the reset operation necessary for the attitude update. This is the main difference to the traditional sequential EKF, which updates the state covariance at each step of the sequential procedure. The numerical simulation study demonstrates that the proposed SMEKF has more consistent and accurate performance in a wide range of initial estimate errors compared to the MEKF and its traditional sequential forms. PMID:29751538

Multiuser signal detection using sequential decoding

NASA Astrophysics Data System (ADS)

Xie, Zhenhua; Rushforth, Craig K.; Short, Robert T.

1990-05-01

The application of sequential decoding to the detection of data transmitted over the additive white Gaussian noise channel by K asynchronous transmitters using direct-sequence spread-spectrum multiple access is considered. A modification of Fano's (1963) sequential-decoding metric, allowing the messages from a given user to be safely decoded if its Eb/N0 exceeds -1.6 dB, is presented. Computer simulation is used to evaluate the performance of a sequential decoder that uses this metric in conjunction with the stack algorithm. In many circumstances, the sequential decoder achieves results comparable to those obtained using the much more complicated optimal receiver.

Injection of Emulsified Vegetable Oil for Long-Term Bioreduction of Uranium

NASA Astrophysics Data System (ADS)

Brooks, S. C.; Watson, D. B.; Schadt, C. W.; Jardine, P. M.; Gihring, T. M.; Zhang, G.; Mehlhorn, T.; Lowe, K.; Phillips, J.; Earles, J.; Wu, W.; Criddle, C. S.; Kemner, K. M.; Boyanov, M.

2011-12-01

In situ bioremediation of a uranium and nitrate-contaminated aquifer with the slow-release electron donor, emulsified vegetable oil (EVO), was tested at the US DOE Subsurface Biogeochemical Research Program (SBR) Integrated Field Research Challenge (IFRC) site, in Oak Ridge, TN. The EVO injection took place in Area 2 of the IFRC located about 300 m downgradient of the former S-3 disposal ponds. Liquid wastes, disposed in the ponds from 1951 to 1983, were primarily composed of nitric acid, plating wastes containing various metals (Cr, Ni) radionuclides (U, Tc), inorganics (nitrate, sulfate) and organic contaminants (tetrachloroethylene, acetone). Prior pond closure in 1987, large volumes of waste fluids migrated into the subsurface, down Bear Creek Valley and into Bear Creek. Contaminants detected at Area 2 were transported through a high permeability gravelly fill that is considered a preferred transport pathway for U to Bear Creek. Groundwater in the gravelly fill is contaminated with U (1-3 mg/L), sulfate (95-130 mg/L), and nitrate (20-40 mg/L) and 500 mg/kg or higher U has been detected on the solid phase of the fill material. The objective of this study is to investigate the feasibility and long-term sustainability of U(VI) reduction and immobilization, and nitrate degradation in the high permeability, high flow gravel fill using EVO as the electron donor. A one-time EVO injection was conducted over a 2 hour period in the highly permeable gravel (hydraulic conductivity 0.08 cm/sec) in the well instrumented IFRC Area 2 field plot. Extensive monitoring of geochemical parameters, dissolved gases and microbial populations were conducted during the test. A bromide tracer test was conducted prior to the injection of the EVO to assess transport pathways and rates. Geochemical analysis of site groundwater demonstrated the sequential bioreduction of oxygen, nitrate, Mn(IV), Fe(III) and sulfate. Transient accumulation of acetate was observed as an intermediate in the oil degradation. Reduction and removal of U and nitrate from groundwater was observed in all wells in hydraulic connection to the injection wells after 2-4 weeks. U concentrations in groundwater were reduced to below 30 ppb (US EPA drinking water standard) at some well locations and nitrate was reduced to below detectable levels. Rebound of U in groundwater was observed together with the rebound of sulfate concentrations as the EVO was consumed. The flux of U and nitrate contamination from groundwater to the surface water receptor (Bear Creek) was significantly reduced by the EVO injection over a one year period. Uranium (VI) reduction to U(IV) in the field tests was confirmed by X-ray absorption near-edge spectroscopy (XANES) analysis. The reduced U(IV) was determined by X-ray absorption fine structure (XAFS) to be in an Fe-U complex, not uraninite. The activities of major Fe(III)- and sulfate-reducing bacteria with U(VI)-reducing capability as well as methanogens was stimulated after injection of the oil.

Comparison of ablation centration after bilateral sequential versus simultaneous LASIK.

PubMed

Lin, Jane-Ming; Tsai, Yi-Yu

2005-01-01

To compare ablation centration after bilateral sequential and simultaneous myopic LASIK. A retrospective randomized case series was performed of 670 eyes of 335 consecutive patients who had undergone either bilateral sequential (group 1) or simultaneous (group 2) myopic LASIK between July 2000 and July 2001 at the China Medical University Hospital, Taichung, Taiwan. The ablation centrations of the first and second eyes in the two groups were compared 3 months postoperatively. Of 670 eyes, 274 eyes (137 patients) comprised the sequential group and 396 eyes (198 patients) comprised the simultaneous group. Three months post-operatively, 220 eyes of 110 patients (80%) in the sequential group and 236 eyes of 118 patients (60%) in the simultaneous group provided topographic data for centration analysis. For the first eyes, mean decentration was 0.39 +/- 0.26 mm in the sequential group and 0.41 +/- 0.19 mm in the simultaneous group (P = .30). For the second eyes, mean decentration was 0.28 +/- 0.23 mm in the sequential group and 0.30 +/- 0.21 mm in the simultaneous group (P = .36). Decentration in the second eyes significantly improved in both groups (group 1, P = .02; group 2, P < .01). The mean distance between the first and second eyes was 0.31 +/- 0.25 mm in the sequential group and 0.32 +/- 0.18 mm in the simultaneous group (P = .33). The difference of ablation center angles between the first and second eyes was 43.2 < or = 48.3 degrees in the sequential group and 45.1 +/- 50.8 degrees in the simultaneous group (P = .42). Simultaneous bilateral LASIK is comparable to sequential surgery in ablation centration.

Simultaneous versus sequential penetrating keratoplasty and cataract surgery.

PubMed

Hayashi, Ken; Hayashi, Hideyuki

2006-10-01

To compare the surgical outcomes of simultaneous penetrating keratoplasty and cataract surgery with those of sequential surgery. Thirty-nine eyes of 39 patients scheduled for simultaneous keratoplasty and cataract surgery and 23 eyes of 23 patients scheduled for sequential keratoplasty and secondary phacoemulsification surgery were recruited. Refractive error, regular and irregular corneal astigmatism determined by Fourier analysis, and endothelial cell loss were studied at 1 week and 3, 6, and 12 months after combined surgery in the simultaneous surgery group or after subsequent phacoemulsification surgery in the sequential surgery group. At 3 and more months after surgery, mean refractive error was significantly greater in the simultaneous surgery group than in the sequential surgery group, although no difference was seen at 1 week. The refractive error at 12 months was within 2 D of that targeted in 15 eyes (39%) in the simultaneous surgery group and within 2 D in 16 eyes (70%) in the sequential surgery group; the incidence was significantly greater in the sequential group (P = 0.0344). The regular and irregular astigmatism was not significantly different between the groups at 3 and more months after surgery. No significant difference was also found in the percentage of endothelial cell loss between the groups. Although corneal astigmatism and endothelial cell loss were not different, refractive error from target refraction was greater after simultaneous keratoplasty and cataract surgery than after sequential surgery, indicating a better outcome after sequential surgery than after simultaneous surgery.

Induction of simultaneous and sequential malolactic fermentation in durian wine.

PubMed

Taniasuri, Fransisca; Lee, Pin-Rou; Liu, Shao-Quan

2016-08-02

This study represented for the first time the impact of malolactic fermentation (MLF) induced by Oenococcus oeni and its inoculation strategies (simultaneous vs. sequential) on the fermentation performance as well as aroma compound profile of durian wine. There was no negative impact of simultaneous inoculation of O. oeni and Saccharomyces cerevisiae on the growth and fermentation kinetics of S. cerevisiae as compared to sequential fermentation. Simultaneous MLF did not lead to an excessive increase in volatile acidity as compared to sequential MLF. The kinetic changes of organic acids (i.e. malic, lactic, succinic, acetic and α-ketoglutaric acids) varied with simultaneous and sequential MLF relative to yeast alone. MLF, regardless of inoculation mode, resulted in higher production of fermentation-derived volatiles as compared to control (alcoholic fermentation only), including esters, volatile fatty acids, and terpenes, except for higher alcohols. Most indigenous volatile sulphur compounds in durian were decreased to trace levels with little differences among the control, simultaneous and sequential MLF. Among the different wines, the wine with simultaneous MLF had higher concentrations of terpenes and acetate esters while sequential MLF had increased concentrations of medium- and long-chain ethyl esters. Relative to alcoholic fermentation only, both simultaneous and sequential MLF reduced acetaldehyde substantially with sequential MLF being more effective. These findings illustrate that MLF is an effective and novel way of modulating the volatile and aroma compound profile of durian wine. Copyright © 2016 Elsevier B.V. All rights reserved.

An anthocyanin-rich extract from Hibiscus sabdariffa linnaeus inhibits N-nitrosomethylurea-induced leukemia in rats.

PubMed

Tsai, Tsung-Chang; Huang, Hui-Pei; Chang, Yun-Ching; Wang, Chau-Jong

2014-02-19

A previous study reported that anthocyanins from roselle (Hibiscus sabdariffa L.) showed significant anticancer activity in human promyelocytic leukemia cells. To explore the antitumor effect of anthocyanin, a roselle bioactive polyphenol in a rat model of chemical-induced leukemia was assayed. Anthocyanin extract of roselle (Hibiscus anthocyanins, HAs) was supplemented in the diet (0.1 and 0.2%). This study was carried out to evaluate the protective effect of HAs on N-nitrosomethylurea (NMU)-induced leukemia of rats. The study employed male Sprague-Dawley rats (n = 48), and leukemia was induced by intravenous injection of 35 mg kg(-1) body weight of NMU dissolved in physiologic saline solution. The rats were divided into four groups (n = 12): control, NMU only, and HAs groups that received different doses of HAs (0.1 and 0.2%) daily, orally, after NMU injection. After 220 days, the animals were killed, and the following parameters were assessed: morphological observation, hematology examination, histopathological assessment, and biochemical assay. When compared with the NMU-only group, HAs significantly prevented loss of organ weight and ameliorated the impairment of morphology, hematology, and histopathology. Treatment with HAs caused reduction in the levels of AST, ALT, uric acid, and MPO. Also, the results showed that oral administration of HAs (0.2%) remarkably inhibited progression of NMU-induced leukemia by approximately 33.3% in rats. This is the first report to demonstrate that the sequential administration of HAs followed by NMU resulted in an antileukemic activity in vivo.

Molten salt electrodeposition of high temperature superconductors. Final report, 7 September 1990-30 November 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tench, D.M.; Kendig, M.W.; Jeanjaquet, S.

1993-06-01

The overall objective of this project was to develop a process for direct electrodeposition of Y-Ba-Cu superconducting oxides from a molten salt at relatively low temperatures (300-550 deg C). An important finding was that cathodic deposition of metallic oxides, rather than free metals, generally occurs from nitrate melts, apparently via reduction of metal nitrato complexes. Oxide deposition was confirmed for Cu as CuO, Y as Y2O3, and Co as Co3O4, and apparently also occurs for Ba. Deposition of mixed Ba-Y-Cu oxides was demonstrated on both Cu and Pt substrates. Data were compiled that provide a good basis for designing schemesmore » for deposition of various mixed oxides from nitrate melts. A sequential anodic injection method was conceived for depositing ultrathin mixed oxide layers, which can be viewed as an analog of molecular beam epitaxy. Results obtained with this approach were encouraging but were inconclusive because of contamination with Gd from the Y injection anode. Based on the results of this program and literature studies, cathodic metal oxide deposition from nitrate melts is a general phenomenon that could ultimately prove to be a practical means of preparing a variety of single and mixed anhydrous metal oxide films. It is recommended that future work focus initially on deposition of perovskite materials, which are of considerable practical interest and involve only two metallic components so that the required deposition schemes are inherently simpler.« less

A Computational Model of Coupled Multiphase Flow and Geomechanics to Study Fault Slip and Induced Seismicity

NASA Astrophysics Data System (ADS)

Juanes, R.; Jha, B.

2014-12-01

The coupling between subsurface flow and geomechanical deformation is critical in the assessment of the environmental impacts of groundwater use, underground liquid waste disposal, geologic storage of carbon dioxide, and exploitation of shale gas reserves. In particular, seismicity induced by fluid injection and withdrawal has emerged as a central element of the scientific discussion around subsurface technologies that tap into water and energy resources. Here we present a new computational approach to model coupled multiphase flow and geomechanics of faulted reservoirs. We represent faults as surfaces embedded in a three-dimensional medium by using zero-thickness interface elements to accurately model fault slip under dynamically evolving fluid pressure and fault strength. We incorporate the effect of fluid pressures from multiphase flow in the mechanical stability of faults and employ a rigorous formulation of nonlinear multiphase geomechanics that is capable of handling strong capillary effects. We develop a numerical simulation tool by coupling a multiphase flow simulator with a mechanics simulator, using the unconditionally stable fixed-stress scheme for the sequential solution of two-way coupling between flow and geomechanics. We validate our modeling approach using several synthetic, but realistic, test cases that illustrate the onset and evolution of earthquakes from fluid injection and withdrawal. We also present the application of the coupled flow-geomechanics simulation technology to the post mortem analysis of the Mw=5.1, May 2011 Lorca earthquake in south-east Spain, and assess the potential that the earthquake was induced by groundwater extraction.

Tolerability and immunogenicity of an inactivated enterovirus 71 vaccine in Chinese healthy adults and children: an open label, phase 1 clinical trial.

PubMed

Meng, Fan-Yue; Li, Jing-Xin; Li, Xiu-Ling; Chu, Kai; Zhang, Yun-Tao; Ji, Hong; Li, Liang; Liang, Zheng-Lun; Zhu, Feng-Cai

2012-05-01

In this open labeled phase 1 clinical trial with enterovirus 71 (EV71) vaccine (ClinicalTrials.gov number: NCT01267903) performed in Donghai County, Jiangsu Province, China, in January 2011. A total of 100 healthy participants, stratified by age (40 adults aged 16-22 y and 60 children aged 6-15 y), were enrolled from volunteers and sequentially received EV71 vaccines of 160U (only for children), 320U, or 640U on day 0 and 28, in a manner of dose escalation. All the participants were followed for 28 d after each shot. During the study period, 37 participants reported at least one injection-site or systemic adverse reaction. No case of grade 3 adverse reaction or serious adverse event (SAE) was observed. Also no dose-related increase in reaction rate was noticed. Pain at injection-site and fever were the most frequently reported local and systematic reaction, respectively. The studied EV71 vaccines demonstrated acceptable tolerability and no anti-nuclear antibody (ANA) seropositive was detected pre or post vaccinations in participants. Also, no clinically significant abnormal change for the liver or kidney function indexes was found. In the according-to-protocol cohort for immunogenicity, it was observed one dose of EV71 vaccine elicited good immune response in the participants, especially for the ones with sero-positive baseline. No obvious dose-response relationship for immunogenicity was found.

Recombinant Temporal Aberration Detection Algorithms for Enhanced Biosurveillance

PubMed Central

Murphy, Sean Patrick; Burkom, Howard

2008-01-01

Objective Broadly, this research aims to improve the outbreak detection performance and, therefore, the cost effectiveness of automated syndromic surveillance systems by building novel, recombinant temporal aberration detection algorithms from components of previously developed detectors. Methods This study decomposes existing temporal aberration detection algorithms into two sequential stages and investigates the individual impact of each stage on outbreak detection performance. The data forecasting stage (Stage 1) generates predictions of time series values a certain number of time steps in the future based on historical data. The anomaly measure stage (Stage 2) compares features of this prediction to corresponding features of the actual time series to compute a statistical anomaly measure. A Monte Carlo simulation procedure is then used to examine the recombinant algorithms’ ability to detect synthetic aberrations injected into authentic syndromic time series. Results New methods obtained with procedural components of published, sometimes widely used, algorithms were compared to the known methods using authentic datasets with plausible stochastic injected signals. Performance improvements were found for some of the recombinant methods, and these improvements were consistent over a range of data types, outbreak types, and outbreak sizes. For gradual outbreaks, the WEWD MovAvg7+WEWD Z-Score recombinant algorithm performed best; for sudden outbreaks, the HW+WEWD Z-Score performed best. Conclusion This decomposition was found not only to yield valuable insight into the effects of the aberration detection algorithms but also to produce novel combinations of data forecasters and anomaly measures with enhanced detection performance. PMID:17947614

Comprehensive analysis of pharmaceutical products using simultaneous mixed-mode (ion-exchange/reversed-phase) and hydrophilic interaction liquid chromatography.

PubMed

Kazarian, Artaches A; Nesterenko, Pavel N; Soisungnoen, Phimpha; Burakham, Rodjana; Srijaranai, Supalax; Paull, Brett

2014-08-01

Liquid chromatographic assays were developed using a mixed-mode column coupled in sequence with a hydrophilic interaction liquid chromatography column to allow the simultaneous comprehensive analysis of inorganic/organic anions and cations, active pharmaceutical ingredients, and excipients (carbohydrates). The approach utilized dual sample injection and valve-mediated column switching and was based upon a single high-performance liquid chromatography gradient pump. The separation consisted of three distinct sequential separation mechanisms, namely, (i) ion-exchange, (ii) mixed-mode interactions under an applied dual gradient (reversed-phase/ion-exchange), and (iii) hydrophilic interaction chromatography. Upon first injection, the Scherzo SS C18 column (Imtakt) provided resolution of inorganic anions and cations under isocratic conditions, followed by a dual organic/salt gradient to elute active pharmaceutical ingredients and their respective organic counterions and potential degradants. At the top of the mixed-mode gradient (high acetonitrile content), the mobile phase flow was switched to a preconditioned hydrophilic interaction liquid chromatography column, and the standard/sample was reinjected for the separation of hydrophilic carbohydrates, some of which are commonly known excipients in drug formulations. The approach afforded reproducible separation and resolution of up to 23 chemically diverse solutes in a single run. The method was applied to investigate the composition of commercial cough syrups (Robitussin®), allowing resolution and determination of inorganic ions, active pharmaceutical ingredients, excipients, and numerous well-resolved unknown peaks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Remifentanil maintains lower initial delayed nonmatching-to-sample accuracy compared to food pellets in male rhesus monkeys.

PubMed

Hutsell, Blake A; Banks, Matthew L

2017-12-01

Emerging human laboratory and preclinical drug self-administration data suggest that a history of contingent abused drug exposure impairs performance in operant discrimination procedures, such as delayed nonmatching-to-sample (DNMTS), that are hypothesized to assess components of executive function. However, these preclinical discrimination studies have exclusively used food as the reinforcer and the effects of drugs as reinforcers in these operant procedures are unknown. The present study determined effects of contingent intravenous remifentanil injections on DNMTS performance hypothesized to assess 1 aspect of executive function, working memory. Daily behavioral sessions consisted of 2 components with sequential intravenous remifentanil (0, 0.01-1.0 μg/kg/injection) or food (0, 1-10 pellets) availability in nonopioid dependent male rhesus monkeys (n = 3). Remifentanil functioned as a reinforcer in the DNMTS procedure. Similar delay-dependent DNMTS accuracy was observed under both remifentanil- and food-maintained components, such that higher accuracies were maintained at shorter (0.1-1.0 s) delays and lower accuracies approaching chance performance were maintained at longer (10-32 s) delays. Remifentanil maintained significantly lower initial DNMTS accuracy compared to food. Reinforcer magnitude was not an important determinant of DNMTS accuracy for either remifentanil or food. These results extend the range of experimental procedures under which drugs function as reinforcers. Furthermore, the selective remifentanil-induced decrease in initial DNMTS accuracy is consistent with a selective impairment of attentional, but not memorial, processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Performance review using sequential sampling and a practice computer.

PubMed

Difford, F

1988-06-01

The use of sequential sample analysis for repeated performance review is described with examples from several areas of practice. The value of a practice computer in providing a random sample from a complete population, evaluating the parameters of a sequential procedure, and producing a structured worksheet is discussed. It is suggested that sequential analysis has advantages over conventional sampling in the area of performance review in general practice.

A cost and policy analysis comparing immediate sequential cataract surgery and delayed sequential cataract surgery from the physician perspective in the United States.

PubMed

Neel, Sean T

2014-11-01

A cost analysis was performed to evaluate the effect on physicians in the United States of a transition from delayed sequential cataract surgery to immediate sequential cataract surgery. Financial and efficiency impacts of this change were evaluated to determine whether efficiency gains could offset potential reduced revenue. A cost analysis using Medicare cataract surgery volume estimates, Medicare 2012 physician cataract surgery reimbursement schedules, and estimates of potential additional office visit revenue comparing immediate sequential cataract surgery with delayed sequential cataract surgery for a single specialty ophthalmology practice in West Tennessee. This model should give an indication of the effect on physicians on a national basis. A single specialty ophthalmology practice in West Tennessee was found to have a cataract surgery revenue loss of $126,000, increased revenue from office visits of $34,449 to $106,271 (minimum and maximum offset methods), and a net loss of $19,900 to $91,700 (base case) with the conversion to immediate sequential cataract surgery. Physicians likely stand to lose financially, and this loss cannot be offset by increased patient visits under the current reimbursement system. This may result in physician resistance to converting to immediate sequential cataract surgery, gaming, and supplier-induced demand.

Sequential biases in accumulating evidence

PubMed Central

Huggins, Richard; Dogo, Samson Henry

2015-01-01

Whilst it is common in clinical trials to use the results of tests at one phase to decide whether to continue to the next phase and to subsequently design the next phase, we show that this can lead to biased results in evidence synthesis. Two new kinds of bias associated with accumulating evidence, termed ‘sequential decision bias’ and ‘sequential design bias’, are identified. Both kinds of bias are the result of making decisions on the usefulness of a new study, or its design, based on the previous studies. Sequential decision bias is determined by the correlation between the value of the current estimated effect and the probability of conducting an additional study. Sequential design bias arises from using the estimated value instead of the clinically relevant value of an effect in sample size calculations. We considered both the fixed‐effect and the random‐effects models of meta‐analysis and demonstrated analytically and by simulations that in both settings the problems due to sequential biases are apparent. According to our simulations, the sequential biases increase with increased heterogeneity. Minimisation of sequential biases arises as a new and important research area necessary for successful evidence‐based approaches to the development of science. © 2015 The Authors. Research Synthesis Methods Published by John Wiley & Sons Ltd. PMID:26626562

Multi-Level Sequential Pattern Mining Based on Prime Encoding

NASA Astrophysics Data System (ADS)

Lianglei, Sun; Yun, Li; Jiang, Yin

Encoding is not only to express the hierarchical relationship, but also to facilitate the identification of the relationship between different levels, which will directly affect the efficiency of the algorithm in the area of mining the multi-level sequential pattern. In this paper, we prove that one step of division operation can decide the parent-child relationship between different levels by using prime encoding and present PMSM algorithm and CROSS-PMSM algorithm which are based on prime encoding for mining multi-level sequential pattern and cross-level sequential pattern respectively. Experimental results show that the algorithm can effectively extract multi-level and cross-level sequential pattern from the sequence database.

Biased lineups: sequential presentation reduces the problem.

PubMed

Lindsay, R C; Lea, J A; Nosworthy, G J; Fulford, J A; Hector, J; LeVan, V; Seabrook, C

1991-12-01

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.

Eyewitness identification in simultaneous and sequential lineups: an investigation of position effects using receiver operating characteristics.

PubMed

Meisters, Julia; Diedenhofen, Birk; Musch, Jochen

2018-04-20

For decades, sequential lineups have been considered superior to simultaneous lineups in the context of eyewitness identification. However, most of the research leading to this conclusion was based on the analysis of diagnosticity ratios that do not control for the respondent's response criterion. Recent research based on the analysis of ROC curves has found either equal discriminability for sequential and simultaneous lineups, or higher discriminability for simultaneous lineups. Some evidence for potential position effects and for criterion shifts in sequential lineups has also been reported. Using ROC curve analysis, we investigated the effects of the suspect's position on discriminability and response criteria in both simultaneous and sequential lineups. We found that sequential lineups suffered from an unwanted position effect. Respondents employed a strict criterion for the earliest lineup positions, and shifted to a more liberal criterion for later positions. No position effects and no criterion shifts were observed in simultaneous lineups. This result suggests that sequential lineups are not superior to simultaneous lineups, and may give rise to unwanted position effects that have to be considered when conducting police lineups.

Cost-effectiveness of simultaneous versus sequential surgery in head and neck reconstruction.

PubMed

Wong, Kevin K; Enepekides, Danny J; Higgins, Kevin M

2011-02-01

To determine whether simultaneous (ablation and reconstruction overlaps by two teams) head and neck reconstruction is cost effective compared to sequentially (ablation followed by reconstruction) performed surgery. Case-controlled study. Tertiary care hospital. Oncology patients undergoing free flap reconstruction of the head and neck. A match paired comparison study was performed with a retrospective chart review examining the total time of surgery for sequential and simultaneous surgery. Nine patients were selected for both the sequential and simultaneous groups. Sequential head and neck reconstruction patients were pair matched with patients who had undergone similar oncologic ablative or reconstructive procedures performed in a simultaneous fashion. A detailed cost analysis using the microcosting method was then undertaken looking at the direct costs of the surgeons, anesthesiologist, operating room, and nursing. On average, simultaneous surgery required 3 hours 15 minutes less operating time, leading to a cost savings of approximately $1200/case when compared to sequential surgery. This represents approximately a 15% reduction in the cost of the entire operation. Simultaneous head and neck reconstruction is more cost effective when compared to sequential surgery.

Sequential Tests of Multiple Hypotheses Controlling Type I and II Familywise Error Rates

PubMed Central

Bartroff, Jay; Song, Jinlin

2014-01-01

This paper addresses the following general scenario: A scientist wishes to perform a battery of experiments, each generating a sequential stream of data, to investigate some phenomenon. The scientist would like to control the overall error rate in order to draw statistically-valid conclusions from each experiment, while being as efficient as possible. The between-stream data may differ in distribution and dimension but also may be highly correlated, even duplicated exactly in some cases. Treating each experiment as a hypothesis test and adopting the familywise error rate (FWER) metric, we give a procedure that sequentially tests each hypothesis while controlling both the type I and II FWERs regardless of the between-stream correlation, and only requires arbitrary sequential test statistics that control the error rates for a given stream in isolation. The proposed procedure, which we call the sequential Holm procedure because of its inspiration from Holm’s (1979) seminal fixed-sample procedure, shows simultaneous savings in expected sample size and less conservative error control relative to fixed sample, sequential Bonferroni, and other recently proposed sequential procedures in a simulation study. PMID:25092948

Transgenerational effects of adolescent nicotine exposure in rats: Evidence for cognitive deficits in adult female offspring.

PubMed

Renaud, Samantha M; Fountain, Stephen B

2016-01-01

This study investigated whether adolescent nicotine exposure in one generation of rats would impair the cognitive capacity of a subsequent generation. Male and female rats in the parental F0 generation were given twice-daily i.p. injections of either 1.0mg/kg nicotine or an equivalent volume of saline for 35days during adolescence on postnatal days 25-59 (P25-59). After reaching adulthood, male and female nicotine-exposed rats were paired for breeding as were male and female saline control rats. Only female offspring were used in this experiment. Half of the offspring of F0 nicotine-exposed breeders and half of the offspring of F0 saline control rats received twice-daily i.p. injections of 1.0mg/kg nicotine during adolescence on P25-59. The remainder of the rats received twice-daily saline injections for the same period. To evaluate transgenerational effects of nicotine exposure on complex cognitive learning abilities, F1 generation rats were trained to perform a highly structured serial pattern in a serial multiple choice (SMC) task. Beginning on P95, rats in the F1 generation were given either 4days of massed training (20patterns/day) followed by spaced training (10 patterns/day) or only spaced training. Transgenerational effects of adolescent nicotine exposure were observed as greater difficulty in learning a "violation element" of the pattern, which indicated that rats were impaired in the ability to encode and remember multiple sequential elements as compound or configural cues. The results indicated that for rats that received massed training, F1 generation rats with adolescent nicotine exposure whose F0 generation parents also experienced adolescent nicotine exposure showed poorer learning of the violation element than rats that experienced adolescent nicotine exposure only in the F1 generation. Thus, adolescent nicotine exposure in one generation of rats produced a cognitive impairment in the next generation. Copyright © 2016 Elsevier Inc. All rights reserved.

Corticosterone and exogenous glucose alter blood glucose levels, neurotoxicity, and vascular toxicity produced by methamphetamine.

PubMed

Bowyer, John F; Tranter, Karen M; Sarkar, Sumit; George, Nysia I; Hanig, Joseph P; Kelly, Kimberly A; Michalovicz, Lindsay T; Miller, Diane B; O'Callaghan, James P

2017-10-01

Our previous studies have raised the possibility that altered blood glucose levels may influence and/or be predictive of methamphetamine (METH) neurotoxicity. This study evaluated the effects of exogenous glucose and corticosterone (CORT) pretreatment alone or in combination with METH on blood glucose levels and the neural and vascular toxicity produced. METH exposure consisted of four sequential injections of 5, 7.5, 10, and 10 mg/kg (2 h between injections) D-METH. The three groups given METH in combination with saline, glucose (METH+Glucose), or CORT (METH+CORT) had significantly higher glucose levels compared to the corresponding treatment groups without METH except at 3 h after the last injection. At this last time point, the METH and METH+Glucose groups had lower levels than the non-METH groups, while the METH+CORT group did not. CORT alone or glucose alone did not significantly increase blood glucose. Mortality rates for the METH+CORT (40%) and METH+Glucose (44%) groups were substantially higher than the METH (< 10%) group. Additionally, METH+CORT significantly increased neurodegeneration above the other three METH treatment groups (≈ 2.5-fold in the parietal cortex). Thus, maintaining elevated levels of glucose during METH exposure increases lethality and may exacerbate neurodegeneration. Neuroinflammation, specifically microglial activation, was associated with degenerating neurons in the parietal cortex and thalamus after METH exposure. The activated microglia in the parietal cortex were surrounding vasculature in most cases and the extent of microglial activation was exacerbated by CORT pretreatment. Our findings show that acute CORT exposure and elevated blood glucose levels can exacerbate METH-induced vascular damage, neuroinflammation, neurodegeneration and lethality. Cover Image for this issue: doi. 10.1111/jnc.13819. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

High-resolution reflection seismic survey at a CCS site, Taiwan

NASA Astrophysics Data System (ADS)

Wang, Chien-Ying; Chung, Chen-Tung; Kuo, Hsuan-Yu; Wu, Ming-shyan; Kuo-Chen, Hao

2017-04-01

To control the effect of greenhouse gas on global warming, the reduction of carbon dioxide emission has become a significant international issue in recent years. The capture of carbon dioxide during its manufacturing and storing in adjacent areas are the most economical way. This research uses high-resolution seismic reflection survey to investigate the region around the world's largest coal-fired power plant at Taichung Port, Taiwan. We aim to detect proper geological structures and to evaluate the possible way to store carbon dioxide. This research uses reflection seismic survey with two mini-vibrators and 240 channels to investigate detailed underground structures. The total length of seismic lines is more than 20 kilometers. By aligning sequential seismic lines, we are able to correlate stratigraphic layers over a wide area. Two adjacent wells along the seismic line are used to identified possible formations. The TaiChung Power Plant (TCPP) at Taichung Port is our target which has more cross-tied seismic lines and a seismic line even extending into the sea water. We analyze these seismic profiles to establish the geological model for carbon dioxide storage and evaluate the possibility of storage systems. Furthermore, this research may prepare some baseline data for the future carbon dioxide injection monitoring. The result shows that the geological structures striking 8 degrees east of north and dipping 2.8 degrees to the east. This means that carbon dioxide will migrate toward the sea direction after injection. The structural layers are relatively flat without any sign of faults. Three carbon dioxide storage systems : Mushan Wuchihshan—Paling(bottom), Peiliao—Talu(middle) and Kueichulin—Chinshui(upper) system are identified. All has the proper reservoir with high porosity and capable caprocks more than 100 meters thick. The geological storage of carbon dioxide injected into TCPP site is a feasible, commercial and safe way to reduce the emission of carbon dioxide from TCPP.

Exosomes from embryonic mesenchymal stem cells alleviate osteoarthritis through balancing synthesis and degradation of cartilage extracellular matrix.

PubMed

Wang, Yafei; Yu, Dongsheng; Liu, Zhiming; Zhou, Fang; Dai, Jun; Wu, Bingbing; Zhou, Jing; Heng, Boon Chin; Zou, Xiao Hui; Ouyang, Hongwei; Liu, Hua

2017-08-14

Mesenchymal stem cell therapy for osteoarthritis (OA) has been widely investigated, but the mechanisms are still unclear. Exosomes that serve as carriers of genetic information have been implicated in many diseases and are known to participate in many physiological processes. Here, we investigate the therapeutic potential of exosomes from human embryonic stem cell-induced mesenchymal stem cells (ESC-MSCs) in alleviating osteoarthritis (OA). Exosomes were harvested from conditioned culture media of ESC-MSCs by a sequential centrifugation process. Primary mouse chondrocytes treated with interleukin 1 beta (IL-1β) were used as an in vitro model to evaluate the effects of the conditioned medium with or without exosomes and titrated doses of isolated exosomes for 48 hours, prior to immunocytochemistry or western blot analysis. Destabilization of the medial meniscus (DMM) surgery was performed on the knee joints of C57BL/6 J mice as an OA model. This was followed by intra-articular injection of either ESC-MSCs or their exosomes. Cartilage destruction and matrix degradation were evaluated with histological staining and OARSI scores at the post-surgery 8 weeks. We found that intra-articular injection of ESC-MSCs alleviated cartilage destruction and matrix degradation in the DMM model. Further in vitro studies illustrated that this effect was exerted through ESC-MSC-derived exosomes. These exosomes maintained the chondrocyte phenotype by increasing collagen type II synthesis and decreasing ADAMTS5 expression in the presence of IL-1β. Immunocytochemistry revealed colocalization of the exosomes and collagen type II-positive chondrocytes. Subsequent intra-articular injection of exosomes derived from ESC-MSCs successfully impeded cartilage destruction in the DMM model. The exosomes from ESC-MSCs exert a beneficial therapeutic effect on OA by balancing the synthesis and degradation of chondrocyte extracellular matrix (ECM), which in turn provides a new target for OA drug and drug-delivery system development.

Study on 41Ca-AMS for diagnosis and assessment of cancer bone metastasis in rats

NASA Astrophysics Data System (ADS)

Shen, Hongtao; Pang, Fangfang; Jiang, Shan; He, Ming; Dong, Kejun; Dou, Liang; Pang, Yijun; Yang, Xianlin; Ruan, Xiangdong; Liu, Manjun; Xia, Chunbo

2015-10-01

The annual incidence of new cancer patients in China is about 2 million, 30-40% of which will end up with bone metastasis. Profound study on the preclinical model and early diagnosis of cancer bone metastasis in rats are very significant for the drug development, better understanding and treatment of bone metastases. In order to monitor the process of bone metabolism and early detection of bone metastasis of cancer cells, a technique of 41Ca isotope tracer combined with AMS has been developed and applied in the study on the bone metastasis of cancer cells by rat model. In this work, 3-month-old female Sprague-Dawley (SD) rats were randomly divided into different groups, and tumor cells injected respectively into the tail vein, femoral artery, femoral cavity and the thigh muscle to establish the rat models for bone metastases. The most appropriate model, i.e., the thigh muscle group, was finally adopted in our real metastases experiment. Each rat in this group was intramuscularly (i.m.) injected with 250 μl CaCl2 solution (containing 1.4 mg Ca and 5nCi 41Ca). About 40 days later, the rat mammary gland carcinoma cells (Walker 256) were injected into these rats following the established protocol. After bone metastasis, medicine interventions were performed. The sequential urine and blood samples were collected and analyzed for 41Ca (by AMS) and N-terminal telopeptide (Ntx), respectively. Bone Mineral Density (BMD) values in the femur and the tibia were measured by CT scan. The results of 41Ca/Ca in longitudinal urinary samples can sensitively reveal the skeletal perturbations caused by bone metastasis of rats, suggests that 41Ca might be similarly developed for human use and improve clinical management through the assessment of the curative effect and non-invasive detection of the earliest stages of cancer growth in bone.

Three-Dimensional Modeling of the Reactive Transport of CO2 and Its Impact on Geomechanical Properties of Reservoir Rocks and Seals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Hou, Zhangshuan; Bacon, Diana H.

This article develops a novel multiscale modeling approach to analyze CO2 reservoirs using Pacific Northwest National Laboratory’s STOMP-CO2-R code that is interfaced with the ABAQUS® finite element package. The STOMP-CO2-R/ABAQUS® sequentially coupled simulator accounts for the reactive transport of CO2 causing mineral composition changes that modify the geomechanical properties of reservoir rocks and seals. Formation rocks’ elastic properties that vary during CO2 injection and govern the poroelastic behavior of rocks are modeled by an Eshelby-Mori-Tanka approach (EMTA) implemented in ABAQUS® via user-subroutines. The computational tool incorporates the change in rock permeability due to both geochemistry and geomechanics. A three-dimensional (3D)more » STOMP-CO2-R model for a model CO2 reservoir containing a vertical fault is built to analyze a formation containing a realistic geochemical reaction network with 5 minerals: albite, anorthite, calcite, kaolinite and quartz. A 3D ABAQUS® model that maps the above STOMP-CO2-R model is built for the analysis using STOMP-CO2-R/ABAQUS®. The results show that the changes in volume fraction of minerals include dissolution of anorthite, precipitation of calcite and kaolinite, with little change in the albite volume fraction. After a long period of CO2 injection the mineralogical and geomechanical changes significantly reduced the permeability and elastic modulus of the reservoir (between the base and caprock) in front of the fault leading to a reduction of the pressure margin to fracture at and beyond the injection location. The impact of reactive transport of CO2 on the geomechanical properties of reservoir rocks and seals are studied in terms of mineral composition changes that directly affect the rock stiffness, stress and strain distributions as well as the pressure margin to fracture.« less

Similar Neural Correlates for Language and Sequential Learning: Evidence from Event-Related Brain Potentials

PubMed Central

Christiansen, Morten H.; Conway, Christopher M.; Onnis, Luca

2011-01-01

We used event-related potentials (ERPs) to investigate the time course and distribution of brain activity while adults performed (a) a sequential learning task involving complex structured sequences, and (b) a language processing task. The same positive ERP deflection, the P600 effect, typically linked to difficult or ungrammatical syntactic processing, was found for structural incongruencies in both sequential learning as well as natural language, and with similar topographical distributions. Additionally, a left anterior negativity (LAN) was observed for language but not for sequential learning. These results are interpreted as an indication that the P600 provides an index of violations and the cost of integration of expectations for upcoming material when processing complex sequential structure. We conclude that the same neural mechanisms may be recruited for both syntactic processing of linguistic stimuli and sequential learning of structured sequence patterns more generally. PMID:23678205

Treatment of Cerebral Palsy with Stem Cells: A Report of 17 Cases

PubMed Central

Abi Chahine, Nassim H.; Wehbe, Tarek W.; Hilal, Ramzi A.; Zoghbi, Victoria V.; Melki, Alia E.; Bou Habib, Emil B.

2016-01-01

Cerebral Palsy (CP) is a disabling condition that affects a child’s life and his/her family irreversibly. It is usually a non-progressive condition but improvement over time is rarely seen. The condition can be due to prenatal hypoxia, metabolic, genetic, infectious, traumatic or other causes. It is therefore a heterogeneous group that results in functional motor disability associated with different degrees of cognitive abnormalities. There are no treatments that can cure or even improve CP and the best available approach aims at functional, social and nutritional supportive care and counseling. In this paper, we report 17 sequential patients with CP treated with intrathecal administration of Bone Marrow Mononuclear Cells (BMMC). All patients had an uneventful post-injection course with 73% of the evaluable patients treated having a good response using the Gross Motor Function Classification System (GMFCS). The average improvement was 1.3 levels on the GMFCS with cognitive improvements as well. PMID:27426090

ATR-FTIR membrane-based sensor for the simultaneous determination of surfactant and oil total indices in industrial degreasing baths.

PubMed

Lucena, Rafael; Cárdenas, Soledad; Gallego, Mercedes; Valcárcel, Miguel

2006-03-01

Monitoring the exhaustion of alkaline degreasing baths is one of the main aspects in metal mechanizing industrial process control. The global level of surfactant, and mainly grease, can be used as ageing indicators. In this paper, an attenuated total reflection-Fourier transform infrared (ATR-FTIR) membrane-based sensor is presented for the determination of these parameters. The system is based on a micro-liquid-liquid extraction of the analytes through a polymeric membrane from the aqueous to the organic solvent layer which is in close contact with the internal reflection element and continuously monitored. Samples are automatically processed using a simple, robust sequential injection analysis (SIA) configuration, on-line coupled to the instrument. The global signal obtained for both families of compounds are processed via a multivariate calibration technique (partial least squares, PLS). Excellent correlation was obtained for the values given by the proposed method compared to those of the gravimetric reference one with very low error values for both calibration and validation.

Determination of the total acidity in soft drinks using potentiometric sequential injection titration.

PubMed

van Staden, J Koos F; Mashamba, M Mulalo G; Stefan, R Raluca I

2002-12-06

A potentiometric SI titration system for the determination of total acidity in soft drinks is proposed. The concept is based on the aspiration of the acid soft drink sample between two base zones into a holding coil with the volume of the first base zone twice to that of the second one and channelled by flow reversal through a reaction coil to a potentiometric sensor. A solution of 0.1 mol l(-1) sodium chloride is used as ionic strength adjustment buffer in the carrier stream. The system has been applied to the analysis of some South African soft drinks having a total acidity level of about 0.2-0.3% (w/v). The method has a sample frequency of 45 samples per h with a linear range of 0.1 and 0.6% (w/v). It is easy to use, fully computerised, and gives the results that are comparable to both automated batch titration and manual titration.

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link

PubMed Central

Lee, Hyung-Min; Ghovanloo, Maysam

2014-01-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35-μm 4-metal 2-poly standard CMOS process in 2.1 mm2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μF capacitors up to ±2 V in 420 μs, achieving a high measured charging efficiency of 82%. PMID:24678284

Microbial detection in microfluidic devices through dual staining of quantum dots-labeled immunoassay and RNA hybridization.

PubMed

Zhang, Qing; Zhu, Liang; Feng, Hanhua; Ang, Simon; Chau, Fook Siong; Liu, Wen-Tso

2006-01-18

This paper reported the development of a microfludic device for the rapid detection of viable and nonviable microbial cells through dual labeling by fluorescent in situ hybridization (FISH) and quantum dots (QDs)-labeled immunofluorescent assay (IFA). The coin sized device consists of a microchannel and filtering pillars (gap=1-2 microm) and was demonstrated to effectively trap and concentrate microbial cells (i.e. Giardia lamblia). After sample injection, FISH probe solution and QDs-labeled antibody solution were sequentially pumped into the device to accelerate the fluorescent labeling reactions at optimized flow rates (i.e. 1 and 20 microL/min, respectively). After 2 min washing for each assay, the whole process could be finished within 30 min, with minimum consumption of labeling reagents and superior fluorescent signal intensity. The choice of QDs 525 for IFA resulted in bright and stable fluorescent signal, with minimum interference with the Cy3 signal from FISH detection.

Biphasic magnetic nanoparticles-nanovesicle hybrids for chemotherapy and self-controlled hyperthermia.

PubMed

Gogoi, Manashjit; Sarma, Haladhar D; Bahadur, Dhirendra; Banerjee, Rinti

2014-05-01

The aim was to develop magnetic nanovesicles for chemotherapy and self-controlled hyperthermia that prevent overheating of tissues. Magnetic nanovesicles containing paclitaxel and a dextran-coated biphasic suspension of La0.75Sr0.25MnO3 and Fe3O4 nanoparticles (magnetic nanoparticles) were developed. Encapsulation efficiencies of magnetic nanoparticles and paclitaxel were 67 ± 5 and 83 ± 3%, respectively. Sequential release performed at 37°C for 1 h followed by 44°C for another 1 h (as expected for intratumoral injection), showed a cumulative release of 6.6% (109.6 µg), which was above the IC50 of the drug. In an alternating current magnetic field, the temperature remained controlled at 44°C and a synergistic cytotoxicity of paclitaxel and hyperthermia was observed in MCF-7 cells. Magnetic nanovesicles containing biphasic suspensions La0.75Sr0.25MnO3 and Fe3O4 nanoparticles encapsulating paclitaxel have potential for combined self-controlled hyperthermia and chemotherapy.

Microbial enhanced oil recovery research. Annex 5, Summary annual report 1990--1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, M.M.; Georgiou, G.

1991-12-31

The objective of this work is to develop an engineering framework for the exploitation of microorganisms to enhance oil recovery. Specific goals include: (1) the production, isolation, chemical characterization and study of the physical properties of microbially produced surfactants; (2) development of simulators for MEOR; (3) model studies in sandstone cores for the characterization of the interactions between growing microbially cultures and oil reservoirs,; (4) design of operation strategies for the sequential injection of microorganisms and nutrient in reservoirs. Accomplishments are: (1) ultra low interfacial tensions (0.003 mN/M) were obtained between decane and 5% NaCl brine using biosurfactants obtained frommore » Bacillus Licheniformis, JF-2 which is the lowest IFT ever reported for biosurfactants; (2) a method to was developed isolate the biosurfactant from the growth medium; (3) the structure of the isolated biosurfactant has been determined; (4) several techniques have been proposed to increase the yield of the surfactant; and (5) an MEOR simulator has been completed.« less

Automated electronic tongue based on potentiometric sensors for the determination of a trinary anionic surfactant mixture.

PubMed

Cortina, Montserrat; Ecker, Christina; Calvo, Daniel; del Valle, Manuel

2008-01-22

An automated electronic tongue consisting of an array of potentiometric sensors and an artificial neural network (ANN) has been developed to resolve mixtures of anionic surfactants. The sensor array was formed by five different flow-through sensors for anionic surfactants, based on poly(vinyl chloride) membranes having cross-sensitivity features. Feedforward multilayer neural networks were used to predict surfactant concentrations. As a great amount of information is required for the correct modelling of the sensors response, a sequential injection analysis (SIA) system was used to automatically provide it. Dodecylsulfate (DS(-)), dodecylbenzenesulfonate (DBS(-)) and alpha-alkene sulfonate (ALF(-)) formed the three-analyte study case resolved in this work. Their concentrations varied from 0.2 to 4mM for ALF(-) and DBS(-) and from 0.2 to 5mM for DS(-). Good prediction ability was obtained with correlation coefficients better than 0.933 when the obtained values were compared with those expected for a set of 16 external test samples not used for training.

A Power-Efficient Wireless Capacitor Charging System Through an Inductive Link.

PubMed

Lee, Hyung-Min; Ghovanloo, Maysam

2013-10-01

A power-efficient wireless capacitor charging system for inductively powered applications has been presented. A bank of capacitors can be directly charged from an ac source by generating a current through a series charge injection capacitor and a capacitor charger circuit. The fixed charging current reduces energy loss in switches, while maximizing the charging efficiency. An adaptive capacitor tuner compensates for the resonant capacitance variations during charging to keep the amplitude of the ac input voltage at its peak. We have fabricated the capacitor charging system prototype in a 0.35- μ m 4-metal 2-poly standard CMOS process in 2.1 mm 2 of chip area. It can charge four pairs of capacitors sequentially. While receiving 2.7-V peak ac input through a 2-MHz inductive link, the capacitor charging system can charge each pair of 1 μ F capacitors up to ±2 V in 420 μ s, achieving a high measured charging efficiency of 82%.

Human factors in equipment development for the Space Shuttle - A study of the general purpose work station

NASA Technical Reports Server (NTRS)

Junge, M. K.; Giacomi, M. J.

1981-01-01

The results of a human factors test to assay the suitability of a prototype general purpose work station (GPWS) for biosciences experiments on the fourth Spacelab mission are reported. The evaluation was performed to verify that users of the GPWS would optimally interact with the GPWS configuration and instrumentation. Six male subjects sat on stools positioned to allow assimilation of the zero-g body posture. Trials were run concerning the operator viewing angles facing the console, the console color, procedures for injecting rates with dye, a rat blood cell count, mouse dissection, squirrel monkey transfer, and plant fixation. The trials were run for several days in order to gage improvement or poor performance conditions. Better access to the work surface was found necessary, together with more distinct and better located LEDs, better access window latches, clearer sequences on control buttons, color-coded sequential buttons, and provisions made for an intercom system when operators of the GPWS work in tandem.

Kinetic and Structural Insights into the Mechanism of AMPylation by VopS Fic Domain*

PubMed Central

Luong, Phi; Kinch, Lisa N.; Brautigam, Chad A.; Grishin, Nick V.; Tomchick, Diana R.; Orth, Kim

2010-01-01

The bacterial pathogen Vibrio parahemeolyticus manipulates host signaling pathways during infections by injecting type III effectors into the cytoplasm of the target cell. One of these effectors, VopS, blocks actin assembly by AMPylation of a conserved threonine residue in the switch 1 region of Rho GTPases. The modified GTPases are no longer able to interact with downstream effectors due to steric hindrance by the covalently linked AMP moiety. Herein we analyze the structure of VopS and its evolutionarily conserved catalytic residues. Steady-state analysis of VopS mutants provides kinetic understanding on the functional role of each residue for AMPylation activity by the Fic domain. Further mechanistic analysis of VopS with its two substrates, ATP and Cdc42, demonstrates that VopS utilizes a sequential mechanism to AMPylate Rho GTPases. Discovery of a ternary reaction mechanism along with structural insight provides critical groundwork for future studies for the family of AMPylators that modify hydroxyl-containing residues with AMP. PMID:20410310