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Sample records for 96-well plate formats

  1. HIGHLY SENSITIVE ASSAY FOR ANTICHOLINESTERASE COMPOUNDS USING 96 WELL PLATE FORMAT

    EPA Science Inventory

    The rapid and sensitive detection of organophosphate insecticides using a 96 well plate format is reported. Several features of this assay make it attractive for development as a laboratory-based or field screening assay. Acetylcholinesterase (AChE) was stabilized in a gelati...

  2. A Novel 96well-formatted Micro-gap Plate Enabling Drug Response Profiling on Primary Tumour Samples

    NASA Astrophysics Data System (ADS)

    Ma, Wei-Yuan; Hsiung, Lo-Chang; Wang, Chen-Ho; Chiang, Chi-Ling; Lin, Ching-Hung; Huang, Chiun-Sheng; Wo, Andrew M.

    2015-04-01

    Drug-based treatments are the most widely used interventions for cancer management. Personalized drug response profiling remains inherently challenging with low cell count harvested from tumour sample. We present a 96well-formatted microfluidic plate with built-in micro-gap that preserves up to 99.2% of cells during multiple assay/wash operation and only 9,000 cells needed for a single reagent test (i.e. 1,000 cells per test spot x 3 selected concentration x triplication), enabling drug screening and compatibility with conventional automated workstations. Results with MCF7 and MDA-MB-231 cell lines showed that no statistical significance was found in dose-response between the device and conventional 96-well plate control. Primary tumour samples from breast cancer patients tested in the device also showed good IC50 prediction. With drug screening of primary cancer cells must consider a wide range of scenarios, e.g. suspended/attached cell types and rare/abundant cell availability, the device enables high throughput screening even for suspended cells with low cell count since the signature microfluidic cell-trapping feature ensures cell preservation in a multiple solution exchange protocol.

  3. Electrothermal micromixing in 96 well plate

    NASA Astrophysics Data System (ADS)

    Kauffmann, Paul; Loire, Sophie; Mezic, Igor

    2011-11-01

    Diagnostic and pharmacology processes could be greatly accelerated by appropriate mixing. Here electrothermal flows are explored to provide mixing of conductive physiological solutions (=1.6 S/m) in a 96 well plate. Three interdigitated electrodes provide an electric field (< 15Vpp, 1MHz) beneath each well. Polarization and conduction phenomenon of the fluid in a well will be first modeled numerically and compared to an electrical circuit model. Due to high conductivity and permittivity of the fluid, the impedance of the array of filled wells collapse dramatically (96 wells: R = 1Ohm, C=250nF). The power supply challenges accordingly raised by arrays of electrothermal micromixers will be then analyzed. The efficiency of different methods of mixing in those wells will be also compared: the addition of low frequency signal leading to AC electro-osmotic perturbations, a blinking vortices method. The experimental results will be compared to simulations.

  4. Quantum dot immunoassays in renewable surface column and 96-well plate formats for the fluorescence detection of Botulinum neurotoxin using high-affinity antibodies

    PubMed Central

    Grate, Jay W.; Tyler, Abby; Ozanich, Richard M.; Miller, Keith D.; Lou, Jianlong; Marks, James D.; Bruckner-Lea, Cynthia J.

    2009-01-01

    A fluorescence sandwich immunoassay using high affinity antibodies and quantum dot (QD) reporters has been developed for detection of botulinum neurotoxin serotype A (BoNT/A) using a nontoxic recombinant fragment of the holotoxin (BoNT/A-HC-fragment) as a structurally valid simulant for the full toxin molecule. The antibodies used, AR4 and RAZ1, bind to nonoverlapping epitopes present on both the full toxin and on the recombinant fragment. In one format, the immunoassay is carried out in a 96-well plate with detection in a standard plate reader using AR4 as the capture antibody and QD-coupled RAZ1 as the reporter. Detection to 31 pM with a total incubation time of 3 hours was demonstrated. In a second format, the AR4 capture antibody was coupled to Sepharose beads, and the reactions were carried out in microcentrifuge tubes with an incubation time of 1 hour. The beads were subsequently captured and concentrated in a rotating rod “renewable surface” flow cell equipped with a fiber optic system for fluorescence measurements. In PBS buffer, the BoNT/A-HC-fragment was detected to concentrations as low as 5 pM using the fluidic measurement approach. PMID:19643593

  5. Quantum dot immunoassays in renewable surface column and 96-well plate formats for the fluorescence detection of Botulinum neurotoxin using high-affinity antibodies

    SciTech Connect

    Warner, Marvin G.; Grate, Jay W.; Tyler, Abby J.; Ozanich, Richard M.; Miller, Keith D.; Lou, Jianlong; Marks, James D.; Bruckner-Lea, Cindy J.

    2009-09-01

    A fluorescence sandwich immunoassay using high affinity antibodies and quantum dot (QD) reporters has been developed for detection of botulinum toxin serotype A (BoNT/A). For the development of the assay, a nontoxic recombinant fragment of the holotoxin (BoNT/A-HC-fragment) has been used as a structurally valid simulant for the full toxin molecule. The antibodies used, AR4 and RAZ1, bind to nonoverlapping epitopes present on both the full toxin and on the recombinant fragment. In one format, the immunoassay is carried out in a 96-well plate with detection in a standard plate reader. Detection down to 31 pM of the BoNT/Hc-fragment was demonstrated with a total incubation time of 3 hours, using AR4 as the capture antibody and QD-coupled RAZ1 as the reporter. In a second format, the AR4 capture antibody was coupled to Sepharose beads, and the immunochemical reactions were carried out in microcentrifuge tubes with an incubation time of 1 hour. These beads were subsequently captured and concentrated in a rotating rod “renewable surface” flow cell as part of a sequential injection fluidic system. This flow cell was equipped with a fiber optic system for fluorescence measurements. In PBS buffer solution matrix, the BoNT/A-HC-fragment was detected to concentrations as low as 5 pM using the fluidic measurement approach.

  6. Quantification of cells cultured on 96-well plates.

    PubMed

    Kueng, W; Silber, E; Eppenberger, U

    1989-10-01

    The method for cell number measurement in monolayer cultures by crystal violet staining published recently by Gillies et al. (R. G. Gillies, N. Didier, M. Denton (1986) Anal. Biochem. 159, 109-113) was modified and significantly improved. The procedure was adapted for use in 96-well plates since the method is inherently very sensitive. Modifications allowed fast and complete solubilization of dye adsorbed by cell nuclei during staining. Since light absorption of the unstained or destained cell layers is negligible, cell number measurements can be performed in the respective wells. Due to these features, multiple assays may be carried out rapidly using standard 96-well plate readers. In addition, it is shown that the sensitivity of the assay can be varied and easily controlled by choosing the appropriate pH during the staining procedure. This increases the flexibility of the method making it useful for determining cell density of a wide range of different cell types. PMID:2604040

  7. Lactobacillus casei microbiological assay of folic acid derivatives in 96-well microtiter plates.

    PubMed

    Horne, D W; Patterson, D

    1988-11-01

    Microbiological assay is still widely used for estimating folic acid derivatives in serum and other biological samples. We describe here a modification of this procedure involving use of 96-well microtiter plates. This procedure, used with modern, computer-interfaced microtiter-plate readers and data-reduction software, greatly shortens the time and minimizes reagent costs for this assay. Under the conditions of our assay procedures, all folic acid derivatives tested gave equal growth response for Lactobacillus casei. Results for assays of rat liver extracts showed excellent agreement between the standard bioassay and the 96-well procedure. PMID:3141087

  8. Toward Microbioreactor Arrays: A Slow-Responding Oxygen Sensor for Monitoring of Microbial Cultures in Standard 96-Well Plates.

    PubMed

    Glauche, Florian; John, Gernot T; Arain, Sarina; Knepper, Andreas; Neubauer, Antje; Goelling, Detlef; Lang, Christine; Violet, Norman; King, Rudibert; Neubauer, Peter

    2015-08-01

    In this study, a slow-responding chemo-optical sensor for dissolved oxygen (DO) integrated into a 96-well plate was developed. The slow response time ensures that the measured oxygen value does not change much during plate transport to the microplate reader. The sensor therefore permits at-line DO measurement of microbial cultures. Moreover, it eliminates the necessity of individual optical measurement systems for each culture plate, as many plates can be measured successively. Combined with the 96-well format, this increases the experimental throughput enormously. The novel sensor plate (Slow OxoPlate) consists of fluorophores suspended in a polymer matrix that were placed into u-bottom 96-well plates. Response time was measured using sodium sulfite, and a t90 value of 9.7 min was recorded. For application, DO values were then measured in Escherichia coli and Saccharomyces cerevisiae cultures grown under fed-batch-like conditions. Depending on the DO sensor's response time, different information on the oxygenation state of the culture plate was obtained: a fast sensor variant detects disturbance through sampling, whereas the slow sensor indicates oxygen limitation during incubation. A combination of the commercially available OxoPlate and the Slow OxoPlate enables operators of screening facilities to validate their cultivation procedures with regard to oxygen availability. PMID:25720599

  9. Establishment of ATP-based luciferase viability assay in 96-well plate for Trypanosoma congolense.

    PubMed

    Suganuma, Keisuke; Allamanda, Puttik; Hakimi, Hassan; Zhou, Mo; Angeles, Jose Ma; Kawazu, Shin-ichiro; Inoue, Noboru

    2014-11-01

    Animal African trypanosomosis (AAT), caused by Trypanosoma congolense, is widespread throughout sub-Saharan Africa. There are significant concerns related to the current drugs available for the treatment of AAT due to their limited effectiveness across species and their adverse effects. Moreover, drug resistant trypanosomes have recently been reported in the field. High throughput screening (HTS) of large chemical compound library collections is a promising approach for identifying novel drug candidates. While HTS for Trypanozoon trypanosomes, T. brucei sspp. and T. evansi is well established, no assays have been developed for T. congolense. In the present study, the authors developed an ATP-based luciferase viability assay for T. congolense in a 96-well plate format. The calculated 50% inhibitory concentration (IC50) values for pentamidine and diminazene were 10-100 times higher in T. congolense than in T. brucei. This result suggests that the transporters for the 2 tested compounds differ between T. congolense and T. brucei. This assay could further be applied to screen novel chemical compounds for the treatment of AAT caused by T. congolense. PMID:25056575

  10. Establishment of ATP-Based Luciferase Viability Assay in 96-Well Plate for Trypanosoma congolense

    PubMed Central

    SUGANUMA, Keisuke; ALLAMANDA, Puttik; HAKIMI, Hassan; ZHOU, Mo; ANGELES, Jose Ma.; KAWAZU, Shin-ichiro; INOUE, Noboru

    2014-01-01

    ABSTRACT Animal African trypanosomosis (AAT), caused by Trypanosoma congolense, is widespread throughout sub-Saharan Africa. There are significant concerns related to the current drugs available for the treatment of AAT due to their limited effectiveness across species and their adverse effects. Moreover, drug resistant trypanosomes have recently been reported in the field. High throughput screening (HTS) of large chemical compound library collections is a promising approach for identifying novel drug candidates. While HTS for Trypanozoon trypanosomes, T. brucei sspp. and T. evansi is well established, no assays have been developed for T. congolense. In the present study, the authors developed an ATP-based luciferase viability assay for T. congolense in a 96-well plate format. The calculated 50% inhibitory concentration (IC50) values for pentamidine and diminazene were 10–100 times higher in T. congolense than in T. brucei. This result suggests that the transporters for the 2 tested compounds differ between T. congolense and T. brucei. This assay could further be applied to screen novel chemical compounds for the treatment of AAT caused by T. congolense. PMID:25056575

  11. 96-Well Plate Colorimetric Assay for K(sub i) Determination of (plusmn)-2-Benzylsuccinic Acid, an Inhibitor of Carboxypeptidase A

    ERIC Educational Resources Information Center

    Wentland, Mark P.; Raza, Shaan; Yingtong Gao

    2004-01-01

    An appropriate assay to determine the inhibition potency of carboxypeptidase A (CPA) in 96-well format to illustrate how high throughput screening is used in modern drug discovery to identify bioactive molecules is developed. Efforts in developing a colorimetric 96-well plate assay for determination of the K(sub i) for inhibition of CPA by…

  12. Biofilm Localization in the Vertical Wall of Shaking 96-Well Plates

    PubMed Central

    Gomes, Luciana C.; Moreira, Joana M. R.; Simões, Manuel; Melo, Luís F.; Mergulhão, Filipe J.

    2014-01-01

    Microtiter plates with 96 wells are being increasingly used for biofilm studies due to their high throughput, low cost, easy handling, and easy application of several analytical methods to evaluate different biofilm parameters. These methods provide bulk information about the biofilm formed in each well but lack in detail, namely, regarding the spatial location of the biofilms. This location can be obtained by microscopy observation using optical and electron microscopes, but these techniques have lower throughput and higher cost and are subjected to equipment availability. This work describes a differential crystal violet (CV) staining method that enabled the determination of the spatial location of Escherichia coli biofilms formed in the vertical wall of shaking 96-well plates. It was shown that the biofilms were unevenly distributed on the wall with denser cell accumulation near the air-liquid interface. The results were corroborated by scanning electron microscopy and a correlation was found between biofilm accumulation and the wall shear strain rates determined by computational fluid dynamics. The developed method is quicker and less expensive and has a higher throughput than the existing methods available for spatial location of biofilms in microtiter plates. PMID:24834360

  13. Automation of cell-based drug absorption assays in 96-well format using permeable support systems.

    PubMed

    Larson, Brad; Banks, Peter; Sherman, Hilary; Rothenberg, Mark

    2012-06-01

    Cell-based drug absorption assays, such as Caco-2 and MDCK-MDR1, are an essential component of lead compound ADME/Tox testing. The permeability and transport data they provide can determine whether a compound continues in the drug discovery process. Current methods typically incorporate 24-well microplates and are performed manually. Yet the need to generate absorption data earlier in the drug discovery process, on an increasing number of compounds, is driving the use of higher density plates. A simple, more efficient process that incorporates 96-well permeable supports and proper instrumentation in an automated process provides more reproducible data compared to manual methods. Here we demonstrate the ability to perform drug permeability and transport assays using Caco-2 or MDCKII-MDR1 cells. The assay procedure was automated in a 96-well format, including cell seeding, media and buffer exchanges, compound dispense, and sample removal using simple robotic instrumentation. Cell monolayer integrity was confirmed via transepithelial electrical resistance and Lucifer yellow measurements. Proper cell function was validated by analyzing apical-to-basolateral and basolateral-to-apical movement of rhodamine 123, a known P-glycoprotein substrate. Apparent permeability and efflux data demonstrate how the automated procedure provides a less variable method than manual processing, and delivers a more accurate assessment of a compound's absorption characteristics. PMID:22357561

  14. Stability test for amorphous materials in humidity controlled 96-well plates by near-infrared spectroscopy.

    PubMed

    Otsuka, Makoto; Tanabe, Hideaki

    2012-03-01

    The purpose of this research is to apply near infrared spectrometry (NIR) with chemoinformetrics to predict the change of crystalline properties of indomethacin (IMC) amorphous under various levels of relative humidity storage conditions. Stability test for amorphous and meta-stable polymorphic forms was performed in humidity controlled the modified 96-well quartz plates containing various kinds of saturated salt solutions (0-100% of relative humidity (RH)) by NIR spectroscopy. Amorphous form was obtained melt product to pour into liquid nitrogen and after then ground. Samples were stored at 25°C in the 6-well plates at various levels of RH. The spectra of the powder samples were measured by the reflectance FT-NIR spectrometer. The second derivative spectra of form α showed specific absorption peaks at 4980, 6036, 7296 and 8616 cm-1 and that of form γ showed those at 5020, 5028, 7344, 7428 and 8436 cm-1. After storage at less than 50% RH, the peak intensities at 5020, 5028, 7344, 7428 and 8436 cm-1 of the amorphous solid increased with increasing of storage time. However, the peak intensity at 4980, 6036 and 7296 cm-1 increased at more than 50% RH Please check and confirm the edit. The results suggested that at lower humidity, the IMC amorphous solid transformed into form γ, but it transformed into form α at more than high humidity. It is possible that crystalline stability of the pharmaceutical preparations could be predicted by using humidity controlled 96-well plates and reflectance NIR-chemoinformetric methods. PMID:21942281

  15. Measuring oxidative stress resistance of Caenorhabditis elegans in 96-well microtiter plates.

    PubMed

    Possik, Elite; Pause, Arnim

    2015-01-01

    Oxidative stress, which is the result of an imbalance between production and detoxification of reactive oxygen species, is a major contributor to chronic human disorders, including cardiovascular and neurodegenerative diseases, diabetes, aging, and cancer. Therefore, it is important to study oxidative stress not only in cell systems but also using whole organisms. C. elegans is an attractive model organism to study the genetics of oxidative stress signal transduction pathways, which are highly evolutionarily conserved. Here, we provide a protocol to measure oxidative stress resistance in C. elegans in liquid. Briefly, ROS-inducing reagents such as paraquat (PQ) and H2O2 are dissolved in M9 buffer, and solutions are aliquoted in the wells of a 96 well microtiter plate. Synchronized L4/young adult C. elegans animals are transferred to the wells (5-8 animals/well) and survival is measured every hour until most worms are dead. When performing an oxidative stress resistance assay using a low concentration of stressors in plates, aging might influence the behavior of animals upon oxidative stress, which could lead to an incorrect interpretation of the data. However, in the assay described herein, this problem is unlikely to occur since only L4/young adult animals are being used. Moreover, this protocol is inexpensive and results are obtained in one day, which renders this technique attractive for genetic screens. Overall, this will help to understand oxidative stress signal transduction pathways, which could be translated into better characterization of oxidative stress-associated human disorders. PMID:25993260

  16. A rapid direct telomerase assay method using 96-well streptavidin plates.

    PubMed

    Francis, Rawle; Friedman, Simon H

    2002-05-01

    We have developed a high-throughput direct assay methodfor the assay of telomerase activity that improves on previous direct telomerase assays in two ways that allow larger numbers of samples to be conveniently processed: (i) 96-well streptavidin coated plates are used to bind and wash biotinylated primer extension products from the telomerase assay, as opposed to tubes containing streptavidin-coated magnetic beads; and (ii) storage phosphor-imagery is used instead of film autoradiography to detect telomerase products after being washed and released from the streptavidin-derivatized matrix. This method improves on previous direct assay methods using magnetic beads by allowing larger numbers of samples to be conveniently assayed. Also, the total activity of the radiolabeled nucleotides used in this procedure is significantly lower than that used in standard direct telomerase assays, lowering costs and exposure to radioactivity. We have validated the assay by repeating, in triplicate, the IC50 determination of rivanol, our previously identified telomerase inhibitor. PMID:12019789

  17. Urine sample preparation in 96-well filter plates for quantitative clinical proteomics.

    PubMed

    Yu, Yanbao; Suh, Moo-Jin; Sikorski, Patricia; Kwon, Keehwan; Nelson, Karen E; Pieper, Rembert

    2014-06-01

    Urine is an important, noninvasively collected body fluid source for the diagnosis and prognosis of human diseases. Liquid chromatography mass spectrometry (LC-MS) based shotgun proteomics has evolved as a sensitive and informative technique to discover candidate disease biomarkers from urine specimens. Filter-aided sample preparation (FASP) generates peptide samples from protein mixtures of cell lysate or body fluid origin. Here, we describe a FASP method adapted to 96-well filter plates, named 96FASP. Soluble urine concentrates containing ~10 μg of total protein were processed by 96FASP and LC-MS resulting in 700-900 protein identifications at a 1% false discovery rate (FDR). The experimental repeatability, as assessed by label-free quantification and Pearson correlation analysis for shared proteins among replicates, was high (R ≥ 0.97). Application to urinary pellet lysates which is of particular interest in the context of urinary tract infection analysis was also demonstrated. On average, 1700 proteins (±398) were identified in five experiments. In a pilot study using 96FASP for analysis of eight soluble urine samples, we demonstrated that protein profiles of technical replicates invariably clustered; the protein profiles for distinct urine donors were very different from each other. Robust, highly parallel methods to generate peptide mixtures from urine and other body fluids are critical to increase cost-effectiveness in clinical proteomics projects. This 96FASP method has potential to become a gold standard for high-throughput quantitative clinical proteomics. PMID:24797144

  18. SIMPLE DEVICE TO DELIVER BEADS TO 96-WELL PLATES FOR RAPID RESUSPENSION OF CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic sequencing involves sequence determination of inserts from a large numbers of plasmids of a genomic library. In high throughput DNA sequencing projects, cultures are grown in a 96-deep well plate format, centrifuged, and resuspended. Resuspension of cells was aided by use of a simple devic...

  19. IDENTIFICATION OF SALMONELLA-POSITIVE FECAL SAMPLES USING A 96-WELL MICROCULTURE PLATE TECHNIQUE (RX METHOD)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional Salmonella isolation involves multiple sample transfers to culture media performed by an experienced microbiologist. The modified semi-solid RV and XLT (RX) Plate method, a modification of the RX tube format designed by Gailey et al. (2004), consolidates pre-enrichment (buffered pepton...

  20. Human tear analysis with miniaturized multiplex cytokine assay on “wall-less” 96-well plate

    PubMed Central

    Quah, Joanne; Tong, Louis; Kim, Namyong

    2015-01-01

    Purpose Tears are a particularly limited body fluid and commonly used in the diagnosis of patients who have ocular diseases. A popular method for analysis of ocular inflammation in tears uses Luminex® bead multiplex technology to generate valuable multiple cytokine profile outputs with 25–50 µl tear sample volume. We propose a method for measuring tear cytokines with 5 μl tear sample volume and 80% reduced Luminex reagents compared to previous protocols. Methods Using human tears pooled from 1,000 participants, the DA-Bead-based method running at 5–20 µl volume, using manual pipetting, in conjunction with a magnetic Luminex cytokine (four-plex) panel assay in a 96-well format was performed and validated for tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-1β, and IL-6. Results Upon use of the DA-Bead method at the 5 μl volume with cytokine standards, the concentrations of each of the four cytokines were found to be linear over a range of 3.5–4 log pg/ml with an intra-assay coefficient of variation (CV) ≤5%, inter-assay %CV ≤10%, and accuracy within the 70–130% range. Upon use of a 5 µl healthy pooled tear sample, cytokine concentrations were detected with a precision intra-assay %CV ˂ 20% for IL-6, IFN-γ, or TNF-α or 30.37% with IL-1β. The inter-assay %CV with tears was ≤20.84% for all cytokines. Tear volumes run at 5 μl on DA-Bead produced a similar cytokine expression profile at a 1-month interval and were highly correlated with the larger 10 μl–based tear sample volume cytokine profile with R2 = 0.98. Conclusions DA-Bead assay is highly sensitive and reproducible and has a performance profile that is potentially suitable for use in standard clinical scenarios. Considering the use of as little as 5 µl of assay beads and 5 µl sample, this is also likely to reduce the assay cost significantly and ease diagnosis of patients with ocular diseases. PMID:26539027

  1. 96-well format-based microfluidic platform for parallel interconnection of multiple multicellular spheroids.

    PubMed

    Kim, Jin-Young; Fluri, David A; Kelm, Jens M; Hierlemann, Andreas; Frey, Olivier

    2015-06-01

    In this article, we present a microfluidic platform, compatible with conventional 96-well formats, that enables facile and parallelized culturing and testing of spherical microtissues in a standard incubator. The platform can accommodate multiple microtissues (up to 66) of different cell types, formed externally by using the hanging-drop method, and enables microtissue interconnection through microfluidic channels for continuous media perfusion or dosage of substances. The platform contains 11 separate channels, and each channel has six tissue compartments. Primary rat liver tissues were cultured over 8 days, and multiple tumor tissues (HCT116) were exposed to various concentrations of 5-fluorouracil for platform characterization. PMID:25524491

  2. Ice-Cap: a method for growing Arabidopsis and tomato plants in 96-well plates for high-throughput genotyping.

    PubMed

    Su, Shih-Heng; Clark, Katie A; Gibbs, Nicole M; Bush, Susan M; Krysan, Patrick J

    2011-01-01

    It is becoming common for plant scientists to develop projects that require the genotyping of large numbers of plants. The first step in any genotyping project is to collect a tissue sample from each individual plant. The traditional approach to this task is to sample plants one-at-a-time. If one wishes to genotype hundreds or thousands of individuals, however, using this strategy results in a significant bottleneck in the genotyping pipeline. The Ice-Cap method that we describe here provides a high-throughput solution to this challenge by allowing one scientist to collect tissue from several thousand seedlings in a single day (1,2). This level of throughput is made possible by the fact that tissue is harvested from plants 96-at-a-time, rather than one-at-a-time. The Ice-Cap method provides an integrated platform for performing seedling growth, tissue harvest, and DNA extraction. The basis for Ice-Cap is the growth of seedlings in a stacked pair of 96-well plates. The wells of the upper plate contain plugs of agar growth media on which individual seedlings germinate. The roots grow down through the agar media, exit the upper plate through a hole, and pass into a lower plate containing water. To harvest tissue for DNA extraction, the water in the lower plate containing root tissue is rapidly frozen while the seedlings in the upper plate remain at room temperature. The upper plate is then peeled away from the lower plate, yielding one plate with 96 root tissue samples frozen in ice and one plate with 96 viable seedlings. The technique is named "Ice-Cap" because it uses ice to capture the root tissue. The 96-well plate containing the seedlings can then wrapped in foil and transferred to low temperature. This process suspends further growth of the seedlings, but does not affect their viability. Once genotype analysis has been completed, seedlings with the desired genotype can be transferred from the 96-well plate to soil for further propagation. We have demonstrated

  3. High throughput preparation of fly genomic DNA in 96-well format using a paint-shaker

    PubMed Central

    Lang, Michael; Nagy, Olga; Lang, Claus; Orgogozo, Virginie

    2015-01-01

    Sample homogenization is an essential step for genomic DNA extraction, with multiple downstream applications in Molecular Biology. Genotyping hundreds or thousands of samples requires an automation of this homogenization step, and high throughput homogenizer equipment currently costs 7000 euros or more. We present an apparatus for homogenization of individual Drosophila adult flies in 96-well micro-titer dishes, which was built from a small portable paint-shaker (F5 portable paint-shaker, Ushake). Single flies are disrupted in each well that contains extraction buffer and a 4-mm metal ball. Our apparatus can hold up to five 96-well micro-titer plates. Construction of the homogenizer apparatus takes about 3–4 days, and all equipment can be obtained from a home improvement store. The total material cost is approximately 700 euros including the paint-shaker. We tested the performance of our apparatus using the ZR-96 Quick-gDNA™ kit (Zymo Research) homogenization buffer and achieved nearly complete tissue homogenization after 15 minutes of shaking. PCR tests did not detect any cross contamination between samples of neighboring wells. We obtained on average 138 ng of genomic DNA per fly, and DNA quality was adequate for standard PCR applications. In principle, our tissue homogenizer can be used for isolation of DNA suitable for library production and high throughput genotyping by Multiplexed Shotgun Genotyping (MSG), as well as RNA isolation from single flies. The sample adapter can also hold and shake other items, such as centrifuge tubes (15–50 mL) or small bottles. PMID:26818699

  4. High throughput preparation of fly genomic DNA in 96-well format using a paint-shaker.

    PubMed

    Lang, Michael; Nagy, Olga; Lang, Claus; Orgogozo, Virginie

    2015-01-01

    Sample homogenization is an essential step for genomic DNA extraction, with multiple downstream applications in Molecular Biology. Genotyping hundreds or thousands of samples requires an automation of this homogenization step, and high throughput homogenizer equipment currently costs 7000 euros or more. We present an apparatus for homogenization of individual Drosophila adult flies in 96-well micro-titer dishes, which was built from a small portable paint-shaker (F5 portable paint-shaker, Ushake). Single flies are disrupted in each well that contains extraction buffer and a 4-mm metal ball. Our apparatus can hold up to five 96-well micro-titer plates. Construction of the homogenizer apparatus takes about 3-4 days, and all equipment can be obtained from a home improvement store. The total material cost is approximately 700 euros including the paint-shaker. We tested the performance of our apparatus using the ZR-96 Quick-gDNA™ kit (Zymo Research) homogenization buffer and achieved nearly complete tissue homogenization after 15 minutes of shaking. PCR tests did not detect any cross contamination between samples of neighboring wells. We obtained on average 138 ng of genomic DNA per fly, and DNA quality was adequate for standard PCR applications. In principle, our tissue homogenizer can be used for isolation of DNA suitable for library production and high throughput genotyping by Multiplexed Shotgun Genotyping (MSG), as well as RNA isolation from single flies. The sample adapter can also hold and shake other items, such as centrifuge tubes (15-50 mL) or small bottles. PMID:26818699

  5. MStern Blotting-High Throughput Polyvinylidene Fluoride (PVDF) Membrane-Based Proteomic Sample Preparation for 96-Well Plates.

    PubMed

    Berger, Sebastian T; Ahmed, Saima; Muntel, Jan; Cuevas Polo, Nerea; Bachur, Richard; Kentsis, Alex; Steen, Judith; Steen, Hanno

    2015-10-01

    We describe a 96-well plate compatible membrane-based proteomic sample processing method, which enables the complete processing of 96 samples (or multiples thereof) within a single workday. This method uses a large-pore hydrophobic PVDF membrane that efficiently adsorbs proteins, resulting in fast liquid transfer through the membrane and significantly reduced sample processing times. Low liquid transfer speeds have prevented the useful 96-well plate implementation of FASP as a widely used membrane-based proteomic sample processing method. We validated our approach on whole-cell lysate and urine and cerebrospinal fluid as clinically relevant body fluids. Without compromising peptide and protein identification, our method uses a vacuum manifold and circumvents the need for digest desalting, making our processing method compatible with standard liquid handling robots. In summary, our new method maintains the strengths of FASP and simultaneously overcomes one of the major limitations of FASP without compromising protein identification and quantification. PMID:26223766

  6. Protocol: high throughput silica-based purification of RNA from Arabidopsis seedlings in a 96-well format

    PubMed Central

    2011-01-01

    The increasing popularity of systems-based approaches to plant research has resulted in a demand for high throughput (HTP) methods to be developed. RNA extraction from multiple samples in an experiment is a significant bottleneck in performing systems-level genomic studies. Therefore we have established a high throughput method of RNA extraction from Arabidopsis thaliana to facilitate gene expression studies in this widely used plant model. We present optimised manual and automated protocols for the extraction of total RNA from 9-day-old Arabidopsis seedlings in a 96 well plate format using silica membrane-based methodology. Consistent and reproducible yields of high quality RNA are isolated averaging 8.9 μg total RNA per sample (~20 mg plant tissue). The purified RNA is suitable for subsequent qPCR analysis of the expression of over 500 genes in triplicate from each sample. Using the automated procedure, 192 samples (2 × 96 well plates) can easily be fully processed (samples homogenised, RNA purified and quantified) in less than half a day. Additionally we demonstrate that plant samples can be stored in RNAlater at -20°C (but not 4°C) for 10 months prior to extraction with no significant effect on RNA yield or quality. Additionally, disrupted samples can be stored in the lysis buffer at -20°C for at least 6 months prior to completion of the extraction procedure providing a flexible sampling and storage scheme to facilitate complex time series experiments. PMID:22136293

  7. Is biofilm removal properly assessed? Comparison of different quantification methods in a 96-well plate system.

    PubMed

    Stiefel, Philipp; Rosenberg, Urs; Schneider, Jana; Mauerhofer, Stefan; Maniura-Weber, Katharina; Ren, Qun

    2016-05-01

    Various methods have been reported to quantify total biofilm or different components of biofilm; however, these methods are often confusedly used, leading to discrepancies and misleading results. In this study, different methods for quantification of biofilm, including those for total biomass, total amount of bacterial cells, viable cell number, and amount of extracellular polymeric substances, were systematically compared in microtiter plates. To evaluate which method is suitable for assessment of biofilm removal and for bacterial killing, biofilm samples were treated with various cleaners possessing removing and/or killing capacities. It was found that most of the methods tested in this study in general exhibited high reproducibility and repeatability. Crystal Violet staining was a simple but reliable method for total biomass quantification. Total bacteria cell numbers could be reliably quantified by the fluorescent DNA-binding dye Acridine Orange. Viable cells could be quantified by either an ATP-based assay or a proliferation assay. Both of these viability methods showed a broad detection range and led to precise measurement. For quantification of proteins in the biofilm, staining with fluorescein isothiocyanate was most suitable. Furthermore, it was revealed that a combination of different methods is required to determine if a cleaner kills or removes biofilm. PMID:26923144

  8. Development of a novel bead-based 96-well filtration plate competitive immunoassay for the detection of Gentamycin.

    PubMed

    Ho, Tien Yu Jessica; Chan, Chia-Chung; Chan, KinGho; Wang, Yu Chieh; Lin, Jing-Tang; Chang, Cheng-Ming; Chen, Chien-Sheng

    2013-11-15

    We developed a sensitive, simple, inexpensive and rapid bead-based immunoassay platform, composed of liposomal nanovesicle amplification system, Gentamycin sulfate beads and 96-well filtration plates. In the beginning of the assay, Gentamycin sulfate beads, Gentamycin sulfate and Gentamycin specific antibody were incubated in a bottom-sealed 96-well filtration plate. After incubation, washing was done by running washing buffer through the unsealed filtration plate with only gravity and the antibody-Gentamycin bead complexes were retained in the plate. Fluorescent dye-loaded protein G-liposomal nanovesicles were then added to specifically bind to antibodies on the retained beads. After washing unbound nanovesicles, millions of fluorescent dye molecules were released by adding a detergent solution to lyse liposomal nanovesicles. The limit of detection (LOD) of this novel detection platform in TBS and in skim milk were 52.65 ng/mL and 14.16 ng/mL, which are both sufficient for detecting the 200 ng/mL Codex maximum residual level (MRL). The dynamic ranges were both from each of their LODs to 100 μg/mL. The 50% inhibition concentrations (IC50) in TBS and skim milk were 199.66 ng/mL and 360.81 ng/mL, respectively. We also demonstrated the good specificity of this platform by comparing detection results between pure Gentamycin solution and a mixture solution of 6 different antibiotics including Gentamycin in skim milk. The entire assay with 60 samples was conducted within 2h. In sum, this novel biosensing platform not only fulfilled most benefits of magnetic bead-based assays, but also was inexpensive and convenient by replacing the magnetic separation with filtration plate separation. PMID:23728198

  9. Development of a fluorimetric multispecies 96-well micro-plate growth test for screening metal toxicity to phytoplankton

    SciTech Connect

    Peterson, H.G.; Ruecker, N.J.; Cantin, I.A.; Nyholm, N.; Dal-Jensen, S.

    1995-12-31

    The rapid and cost-effective screening of industrial waste is an ideal approach to regulations that offer true protection of aquatic habitats. For these tests to be ecologically important protection of large groups of organisms is also essential. This can best be done by testing batteries of species. Photosynthetic organisms compose 99.9% of habitats as well as providing food for higher trophic levels. A test was developed that can accommodate the testing of most phytoplanktonic species irrespective of morphology (unicellular, multicellular, colonial, filamentous). Forty eight to 72 h growth tests were carried out with green algae, diatoms, and cyanobacteria. The algae were incubated with different levels of toxicants in 96-well microplates which were read in a 96-well fluorometric plate reader. Phytoplankton emitting low levels of fluorescence can be incubated with DCMU, which can increase the fluorescent signal 2 to 4 times. The data from the plate reader is transferred to a computer spreadsheet and inhibition levels are automatically calculated. Eleven metal mining wastes from across Canada were tested against this method using the following phytoplanktonic species: Selenastrum, Nannochloris (green algae), Nitzschia (diatom), Microcystis, and Pseudoanabaena (cyanobacteria). These wastes were also screened against Microtox. All wastes were highly toxic to the tested phytoplankton, but only 4 were toxic to Microtox{trademark}.

  10. Scalable 96-well Plate Based iPSC Culture and Production Using a Robotic Liquid Handling System.

    PubMed

    Conway, Michael K; Gerger, Michael J; Balay, Erin E; O'Connell, Rachel; Hanson, Seth; Daily, Neil J; Wakatsuki, Tetsuro

    2015-01-01

    Continued advancement in pluripotent stem cell culture is closing the gap between bench and bedside for using these cells in regenerative medicine, drug discovery and safety testing. In order to produce stem cell derived biopharmaceutics and cells for tissue engineering and transplantation, a cost-effective cell-manufacturing technology is essential. Maintenance of pluripotency and stable performance of cells in downstream applications (e.g., cell differentiation) over time is paramount to large scale cell production. Yet that can be difficult to achieve especially if cells are cultured manually where the operator can introduce significant variability as well as be prohibitively expensive to scale-up. To enable high-throughput, large-scale stem cell production and remove operator influence novel stem cell culture protocols using a bench-top multi-channel liquid handling robot were developed that require minimal technician involvement or experience. With these protocols human induced pluripotent stem cells (iPSCs) were cultured in feeder-free conditions directly from a frozen stock and maintained in 96-well plates. Depending on cell line and desired scale-up rate, the operator can easily determine when to passage based on a series of images showing the optimal colony densities for splitting. Then the necessary reagents are prepared to perform a colony split to new plates without a centrifugation step. After 20 passages (~3 months), two iPSC lines maintained stable karyotypes, expressed stem cell markers, and differentiated into cardiomyocytes with high efficiency. The system can perform subsequent high-throughput screening of new differentiation protocols or genetic manipulation designed for 96-well plates. This technology will reduce the labor and technical burden to produce large numbers of identical stem cells for a myriad of applications. PMID:26068617

  11. Scalable 96-well Plate Based iPSC Culture and Production Using a Robotic Liquid Handling System

    PubMed Central

    Conway, Michael K.; Gerger, Michael J.; Balay, Erin E.; O'Connell, Rachel; Hanson, Seth; Daily, Neil J.; Wakatsuki, Tetsuro

    2015-01-01

    Continued advancement in pluripotent stem cell culture is closing the gap between bench and bedside for using these cells in regenerative medicine, drug discovery and safety testing. In order to produce stem cell derived biopharmaceutics and cells for tissue engineering and transplantation, a cost-effective cell-manufacturing technology is essential. Maintenance of pluripotency and stable performance of cells in downstream applications (e.g., cell differentiation) over time is paramount to large scale cell production. Yet that can be difficult to achieve especially if cells are cultured manually where the operator can introduce significant variability as well as be prohibitively expensive to scale-up. To enable high-throughput, large-scale stem cell production and remove operator influence novel stem cell culture protocols using a bench-top multi-channel liquid handling robot were developed that require minimal technician involvement or experience. With these protocols human induced pluripotent stem cells (iPSCs) were cultured in feeder-free conditions directly from a frozen stock and maintained in 96-well plates. Depending on cell line and desired scale-up rate, the operator can easily determine when to passage based on a series of images showing the optimal colony densities for splitting. Then the necessary reagents are prepared to perform a colony split to new plates without a centrifugation step. After 20 passages (~3 months), two iPSC lines maintained stable karyotypes, expressed stem cell markers, and differentiated into cardiomyocytes with high efficiency. The system can perform subsequent high-throughput screening of new differentiation protocols or genetic manipulation designed for 96-well plates. This technology will reduce the labor and technical burden to produce large numbers of identical stem cells for a myriad of applications. PMID:26068617

  12. Protein farnesyltransferase: measurement of enzymatic activity in 96-well format using TopCount microplate scintillation counting technology.

    PubMed

    Harwood, H J

    1995-04-10

    Protein farnesyltransferase (PFT) catalyzes the transfer of the farnesyl group of farnesyl pyrophosphate (FPP) to proteins ending with a carboxy-terminal CAAX motif, forming a thioether linkage to the cysteine residue of the protein. A method is described herein for measurement of PFT activity in 96-well format using TopCount microplate scintillation counting technology. This method has the advantages of requiring only a single transfer from reaction vessels or wells of a 96-well reaction plate to the filtration wells of a 96-well Packard UniFilter GF/B filtration plate following acid precipitation and of allowing liquid scintillation counting to be conducted directly in the filtration plate without the need for either removal of the filter from the plate or transfer of the filter to liquid scintillation vials prior to radioactivity assessment. Using rat brain cytosol as the source of PFT, H-ras as the source of farnesyl acceptor protein, and [1-3H]FPP as the farnesyl donor, the incorporation of radiolabeled farnesyl residues into H-ras was found to be a linear function of both the time of incubation at 37 degrees C (up to 75 min) and the concentration of rat brain cytosolic protein present during incubation (up to 40 micrograms protein), and to be dependent on the concentration of H-ras (Km = 1.1 microM) and FPP (Km = 0.6 microM) present in the incubation reaction. In the presence of 4 microM H-ras, 0.5 microM FPP, 4 mM MgCl2, and 20 microM ZnCl2, the specific activity of rat brain cytosolic PFT measured using this methodology was 0.253 +/- 0.036 (SD; n = 30) pmol H-ras farnesylated per minute of incubation at 37 degrees C per milligram cytosolic protein. The signal-to-noise ratio for H-ras farnesylation using this methodology averaged 25 relative to incubation in the absence of H-ras (background farnesylation of cytosolic proteins) and 50 relative to incubation in the absence of both H-ras and rat brain cytosol (background filter associated radioactivity

  13. Facile preparation of a photoactivatable surface on a 96-well plate: a versatile and multiplex cell migration assay platform.

    PubMed

    Kamimura, Masao; Scheideler, Olivia; Shimizu, Yoshihisa; Yamamoto, Shota; Yamaguchi, Kazuo; Nakanishi, Jun

    2015-06-01

    Cell migration is an essential cellular activity in various physiological and pathological processes, such as wound healing and cancer metastasis. Therefore, in vitro cell migration assays are important not only for fundamental biological studies but also for evaluating potential drugs that control cell migration activity in medical applications. In this regard, robust control over cell migrating microenvironments is critical for reliable and quantitative analysis as cell migration is highly dependent upon the microenvironments. Here, we developed a facile method for making a commercial glass-bottom 96-well plate photoactivatable for cell adhesion, aiming to develop a versatile and multiplex cell migration assay platform. Cationic poly-d-lysine was adsorbed to the anionic glass surface via electrostatic interactions and, subsequently, functionalized with poly(ethylene glycol) (PEG) bearing a photocleavable reactive group. The initial PEGylated surface is non-cell-adhesive. However, upon near-ultraviolet (UV) irradiation, the photorelease of PEG switches the surface from non-biofouling to cell-adhesive. With this platform, we assayed cell migration in the following procedure: (1) create cell-attaching regions of precise geometries by controlled photoirradiation, (2) seed cells to allow them to attach selectively to the irradiated regions, (3) expose UV light to the remaining PEGylated regions to extend the cell-adhesive area, (4) analyse cell migration using microscopy. Surface modification of the glass surface was characterized by ζ-potential and contact angle measurements. The PEGylated surface showed cell-resistivity and became cell-adhesive upon releasing PEG by near-UV irradiation. The method was applied for parallelly evaluating the effect of model drugs on the migration of epithelial MDCK cells in the multiplexed platform. The dose-response relationship for cytochalasin D treatment on cell migration behavior was successfully evaluated with high

  14. Fast carbohydrate analysis via liquid chromatography coupled with ultra violet and electrospray ionization ion trap detection in 96-well format.

    PubMed

    Rühmann, Broder; Schmid, Jochen; Sieber, Volker

    2014-07-11

    A fast carbohydrate screening platform processible in 96-well format is described. The method is suitable for the determination of various carbohydrates out of complex mixtures as obtained by acidic hydrolysis of carbohydrates polymers. The chromatographic conditions for an efficient separation (12min) and the derivatization process with 1-phenyl-3-methyl-5-pyrazolone (PMP) were optimized for high resolution separation and simultaneous determination of deoxy-, amino-, anhydro-sugars as well as hexoses, pentoses, dimers, uronic acids and degradation products like furfural and hydroxymethylfurfural (HMF). The potential to quantify with UV- and MS-detector in the same range has been demonstrated for 20 different compounds. Finally, the matrix effects of the hydrolysis were positively evaluated. The micro scale hydrolysis and PMP-derivatization without any extraction or drying steps, both in 96-well format, result in a fast and intuitive sample preparation. In combination with a fast liquid chromatography coupled to UV and electrospray ionization ion trap detection (LC-UV-ESI-MS/MS) for the qualification and quantification of various sugars, dimers and degradation products, this method shows great performance in carbohydrate analysis. PMID:24861788

  15. Immobilization of saccharides and peptides on 96-well microtiter plates coated with methyl vinyl ether-maleic anhydride copolymer.

    PubMed

    Satoh, A; Kojima, K; Koyama, T; Ogawa, H; Matsumoto, I

    1998-06-15

    We have previously reported a method to immobilize protein ligands on microtiter plates coated with methyl vinyl ether-maleic anhydride copolymer (MMAC) [Isosaki, K., et al. (1992) J. Chromatogr. 597, 123-128]. In this study, we improved the MMAC method to efficiently immobilize not only small ligands such as peptides and oligosaccharides, which could not be efficiently immobilized previously, but also heparin via its reducing end. Amino and hydrazino groups were introduced to MMAC-coated microtiter plate wells by coupling to acid anhydride groups of MMAC with 1,6-hexamethylenediamine and adipic acid dihydrazide, respectively. The amino groups introduced were allowed to react with peptides by use of divalent cross-linkers. Hydrazino groups were allowed to react with formyl groups of saccharides by reductive amination. Peptides and oligosaccharides were immobilized in a dose-dependent manner by these methods. In the case of the angiotensin peptide thus immobilized, the detection limit by monoclonal antibodies was as low as 0.1-1 fmol peptide per well. Application of 20-200 nmol oligosaccharides to the well was sufficient to immobilize and subsequently detect lectins. Furthermore, heparin immobilized on the hydrazinocoated wells was successfully used for the binding assay of annexin IV. PMID:9648659

  16. Collection, storage, and filtration of in vivo study samples using 96-well filter plates to facilitate automated sample preparation and LC/MS/MS analysis.

    PubMed

    Berna, M; Murphy, A T; Wilken, B; Ackermann, B

    2002-03-01

    The benefits of high-throughput bioanalysis within the pharmaceutical industry are well established. One of the most significant bottlenecks in bioanalysis is transferring in vivo-generated study samples from their collection tubes during sample preparation and extraction. In most cases, the plasma samples must be stored frozen prior to analysis, and the freeze/thaw (F/T) process introduces thrombin clots that are capable of plugging pipets and automated liquid-transfer systems. A new approach to dealing with this problem involves the use of Ansys Captiva 96-well 20-microm polypropylene filter plates to collect, store frozen, and filter plasma samples prior to bioanalysis. The samples are collected from the test subjects, and the corresponding plasma samples are placed directly into the wells of the filter plate. Two Duoseal (patent pending) covers are used to seal the top and bottom of the plate, and the plate is stored at down to -70 degrees C. Prior to sample analysis, the seals are removed and the plate is placed in a 96-well SPE manifold. As the plasma thaws, it passes (by gravity or mild vacuum) through the polypropylene filter into a 96-well collection plate. A multichannel pipet or automated liquid-transfer system is used to transfer sample aliquots without fear of plugging. A significant advantage of this approach is that, unlike other methods, issues related to incomplete pipetting are virtually eliminated. The entire process is rapid since thawing and filtering take place simultaneously, and if a second F/T cycle is required for reanalysis, it is not necessary to refilter the samples (additional clotting was not observed after three F/T cycles). This technique was tested using monkey, rat, and dog plasma and sodium heparin and EDTA anticoagulants. To assess the possibility of nonspecific binding to the polypropylene filter, a variety of drug candidates from diverse drug classes were studied. Validation data generated for two Lilly compounds from distinct

  17. Identification of photosynthesis inhibitors of pelagic marine algae using 96-well plate microfractionation for enhanced throughput in effect-directed analysis.

    PubMed

    Booij, Petra; Vethaak, A Dick; Leonards, Pim E G; Sjollema, Sascha B; Kool, Jeroen; de Voogt, Pim; Lamoree, Marja H

    2014-07-15

    Because of large-scale production and use of an increasing diversity of chemicals in modern society, estuarine and coastal waters may be contaminated with numerous substances. Some of these compounds have the potential to affect microalgae at the base of the pelagic food chain. Therefore, we identified the main chemical stressors that negatively affect the effective photosystem II efficiency (ϕPSII) in marine microalgae of the Dutch estuarine and coastal waters. An enhanced effect-directed analysis (EDA) was carried out by combining reversed-phase ultra performance liquid chromatography fractionation of extracts from passive samplers, followed by effect assessment using the pulse amplitude modulation fluorometry assay and chemical analysis of biologically active fractions using high-resolution mass spectrometry. This study focuses on a novel microfractionation technique using 96-well plates to enhance throughput in EDA, structure elucidation, and the analytical and effect confirmation of the compounds that are identified. Although there are numerous unknown compounds present in estuarine and coastal waters, our EDA study shows that atrazine, diuron, irgarol, isoproturon, terbutryn, and terbutylazine are the main contributors to the observed effect on the ϕPSII of marine microalgae. PMID:24926900

  18. High throughput adjustable 96-well plate assay for androgen receptor binding: a practical approach for EDC screening using the chimpanzee AR.

    PubMed

    Hartig, P C; Cardon, M C; Blystone, C R; Gray, L E; Wilson, V S

    2008-09-26

    The issue as to whether natural and man-made chemicals interfere with endocrine function has raised concerns. This interference could be biologically significant even at very low doses if the chemicals interact deleteriously with hormone receptors at low concentrations. Therefore, the United States Environmental Protection Agency (USEPA) Office of Coordination and Policy (OSCP) requested that a nonhuman mammalian androgen receptor binding assay be developed for possible use in their Endocrine Disruptor Screening Program (EDSP). Ideally, this assay would be high throughput, not use animals as a source of receptor protein, easily deployed throughout the scientific community, utilize reagents available to both the public and private sector, and have the potential for future automation. We developed a highly modified 96-well plate assay which meets these criteria. It employs a baculovirus expressed recombinant primate androgen receptor which is publically available and exploits the unique ability of some mammalian androgen receptors to remain biologically active after guanidine hydrochloride (GdnHCl) solubilization. This GdnHCl treated receptor remains soluble and requires no additional purification prior to use. We provide a very detailed description of the assay protocol itself, and similarly detailed method for producing and solubilizing the receptor. PMID:18691642

  19. HIGHLY SENSITIVE ASSAY FOR ANTICHOLINESTERASE COMPOUNDS USING 96 WELL PLATE FORMAT

    EPA Science Inventory

    One of the approaches for reducing uncertainties in the assessment of human exposure is to better characterize concentrations of hazardous compounds that may be present in our immediate environment. A significant limitation to this approach, however, is that sampling and labora...

  20. Development of a novel 96-well format for liquid-liquid microextraction and its application in the HPLC analysis of biological samples.

    PubMed

    Borijihan, Guirong; Li, Youxin; Gao, Jianguo; Bao, James J

    2014-05-01

    A novel 96-well liquid-liquid microextraction system combined with modern HPLC was developed and used for the simultaneous analysis of 96 biological samples. The system made use of hollow fibers, a 96-well plate, and a plastic base with a center hole and a side hole. One end of the hollow fiber was sealed, while the other end was attached to one of the holes positioned at the center for the plastic base. The needle was inserted into the liquid from inside or outside of the hollow fiber through the center or the side holes, respectively. The system was tested with plasma samples containing three compounds, acidic indomethacin, neutral dexamethasone, and basic propafenone. Some parameters, such as the kind and dimension of hollow fiber, pH and salt concentration of the donor phase, the selection of organic solvent for the acceptor phase, and the extraction time were investigated. Under the optimization conditions, the Log D and drug concentration of indomethacin, dexamethasone, and propafenone in plasma and urine samples were analyzed. Then, the methodology was validated. The results demonstrated that ng/mL levels could be exactly and rapidly analyzed by our system, which was equipped with an auto-injection sampler, making sample analysis more convenient. PMID:24574156

  1. A novel colorimetric assay of β-D-glucans in basidiomycete strains by alcian blue dye in a 96-well microtiter plate.

    PubMed

    C Semedo, Magda; Karmali, Amin; Fonseca, Luís

    2015-01-01

    Basidiomycete strains synthesize several types of β-d-glucans, which play a major role in the medicinal properties of mushrooms. Therefore, the specific quantification of these β-d-glucans in mushroom strains is of great biochemical importance. Because published assay methods for these β-d-glucans present some disadvantages, a novel colorimetric assay method for β-d-glucan with alcian blue dye was developed. The complex formation was detected by following the decrease in absorbance in the range of 620 nm and by hypsochromic shift from 620 to 606 nm (∼14 nm) in UV-Vis spectrophotometer. Analysis of variance was used for optimization of the slope of the calibration curve by using the assay mixture containing 0.017% (w/v) alcian blue in 2% (v/v) acetic acid at pH 3.0. The high-throughput colorimetric assay method on microtiter plates was used for quantification of β-d-glucans in the range of 0-0.8 μg, with a slope of 44.15 × 10(-2) and a limit of detection of 0.017 μg/well. Recovery experiments were carried out by using a sample of Hericium erinaceus, which exhibited a recovery of 95.8% for β-1,3-d-glucan. The present assay method exhibited a 10-fold higher sensitivity and a 59-fold lower limit of detection compared with the published method with congo red. β-d-glucans of several mushrooms strains were isolated from fruiting bodies and mycelia, and they were quantified by this assay method. This assay method is fast, specific, simple, and it can be used to quantify β-d-glucans from other biological sources. PMID:26317582

  2. Soluble penicillin-binding protein 2a: beta-lactam binding and inhibition by non-beta-lactams using a 96-well format.

    PubMed

    Toney, J H; Hammond, G G; Leiting, B; Pryor, K D; Wu, J K; Cuca, G C; Pompliano, D L

    1998-01-01

    High level methicillin resistance in Staphylococcus aureus is dependent upon the acquisition of the mecA gene encoding penicillin-binding protein 2a (PBP2a). PBP2a is a member of a family of peptidoglycan biosynthetic enzymes involved in assembly of the cell wall in bacteria and is poorly inactivated by beta-lactam antibiotics. We describe a 96-well-filter binding assay using recombinant, soluble PBP2a which allows for kinetic measurement of penicillin binding. The deacylation rate constant for the PBP2a-penicillin G covalent complex was found to be 5.7 +/- 1.0 x 10(-5) s-1 at 30 degrees C (half-life of approximately 200 min). For the PBP2a acylation reaction, the value of K(m) (penicillin G) = 0.5 +/- 0.1 mM and kcat = 1 x 10(-3) s-1, which yields a second-order rate constant (kcat/K(m)) for inactivation of 2.0 M-1 s-1. Using this assay, several non-beta-lactam inhibitors including Cibacron blue have been found which exhibit IC50 values between 10 and 30 microM. The binding affinities of several carbapenems and beta-lactams correlated well between the filter binding assay described in this report and an electrophoretic assay for PBP2a using membranes prepared form methicillin-resistant S. aureus. PMID:9448849

  3. Development and application of a high-throughput sample cleanup process based on 96-well plate for simultaneous determination of 16 steroids in biological matrices using liquid chromatography-triple quadrupole mass spectrometry.

    PubMed

    Luo, Guanzhong; Li, Youxin; Bao, James J

    2016-02-01

    A novel high-throughput sample pretreatment system was developed by the integration of protein precipitation (PP), phospholipid removal (PPR), and hollow fiber liquid-phase microextraction (HF-LPME) into two simple 96-well plates and a matching 96-grid lid. With this system, 16 steroids were separated from biological matrices of plasma, milk, and urine and analyzed by liquid chromatography-triple quadrupole mass spectrometry. In the tandem sample cleanup process, the prepositive PP and PPR step preliminarily removed some of the interferences from the biological matrices. The following HF-LPME step kept the residual interference out of the hollow fiber and enriched the steroids in the hollow fiber to achieve high sensitivity. By a series of method optimizations, acetonitrile was chosen as the crash solvent for PP and PPR. A mixture of octanol and toluene (1:1 v/v) was used as the acceptor phase for HF-LPME. The extraction was conducted at 80 rpm for 50 min in a donor phase containing 1 mL 20% sodium chloride at 25 °C. Under these conditions, the limits of detection for the 16 steroids were 3.6-300.0 pg(.)mL(-1) in plasma, 3.0-270.0 pg·mL(-1) in milk, and 2.2-210.0 pg(.)mL(-1) in urine. The recoveries of the 16 steroids were 81.9-97.9% in plasma (relative standard deviation 1.0-8.0%), 80.6-97.7% in milk (relative standard deviation 0.8-5.4%), and 87.3-98.7% in urine (relative standard deviation 1.0-4.9%). Further, the integrated 96-well platform of PP, PPR, and HF-LPME enabled us to run this assay in an automatic and high-throughput fashion. The reliability of the method was further corroborated by evaluation of its applicability in plasma and urine samples from volunteers and fresh bovine milk from local dairy enterprises. PMID:26738495

  4. β-Cyclodextrin enhanced on-line organic solvent field-amplified sample stacking in capillary zone electrophoresis for analysis of ambroxol in human plasma, following liquid-liquid extraction in the 96-well format.

    PubMed

    Li, Ji; Bi, Youwei; Wang, Li; Sun, Fanlu; Chen, Zhao; Xu, Guili; Fan, Guorong

    2012-07-01

    A field-amplified sample stacking (FASS) and capillary zone electrophoresis (CZE) method is described for the quantification of ambroxol hydrochloride in human plasma, following liquid-liquid extraction in the 96-well format. The separation was carried out at 25 °C in a 31.2 cm × 75 μm fused-silica capillary with an applied voltage of 15 kV. The background electrolyte (BGE) was composed of 6.25 mM borate-25 mM phosphate (pH 3.0) and 1mM β-cyclodextrin. The detection wavelength was 210 nm. Clean-up and preconcentration of plasma biosamples were developed by 96-well format liquid-liquid extraction (LLE). In this study, FASS in combination with β-cyclodextrin enhanced the sensitivity about 60-70 fold in total. The method was suitably validated with respect to stability, specificity, linearity, lower limit of quantitation, accuracy, precision, extraction recovery and robustness. The calibration graph was linear for ambroxol hydrochloride from 2 to 500 ng/ml. The lower limit of quantification was 2 ng/ml. The intra- and inter-day precisions of lowest limit of quantification (LLOQ) were 9.61 and 11.80%, respectively. The method developed was successfully applied to the evaluation of clinical pharmacokinetic study of ambroxol hydrochloride tablet after oral administration to 12 healthy volunteers. PMID:22464560

  5. Location dependent biases in automatic 96-well microplate readers.

    PubMed

    Harrison, R O; Hammock, B D

    1988-01-01

    Procedures performed in 96-well microplates and quantitated by automatic readers assume instruments to be precise, accurate, and free of well location dependent bias. Instrument specifications generally focus on precision and accuracy without specifically addressing biases which are dependent on well location. These biases appear to be meniscus dependent and can be demonstrated in varying degrees in automatic readers of many designs by using a reverse plate wet test, which compares repeated readings of a dye loaded plate in normal and reversed positions. This test analyzes differences between readings and is, therefore, independent of pipetting error or other experimental variables such as protein binding or immunoassay variability. Different plates increased or decreased the magnitude of observed errors but did not themselves cause the errors measured by the reverse plate wet test. Error patterns were consistent for each reader and varied widely among the 16 instruments tested. Only 4 of 16 instruments passed an existing manufacturer's specification for precision, and only one of the 16 readers tested passed a similar specification for accuracy. The severest location dependent bias was found in an instrument which exhibited excellent repeatability and consistently passed its built-in diagnostic tests. One reader with significant bias was returned to the manufacturer for routine service and calibration, but it was not demonstrably improved. The reverse plate wet test is an extremely useful diagnostic tool for quality control at all stages of instrument manufacture and use. PMID:3069835

  6. A microassay for measuring glycogen in 96-well-cultured cells.

    PubMed

    Gómez-Lechón, M J; Ponsoda, X; Castell, J V

    1996-05-01

    This study describes a rapid, sensitive, and automated spectrophotometric enzymatic microassay that measures the intracellular glycogen of primary cultured hepatocytes and other cultured cells in 96-well plates and can be adapted for other samples that are transferred to these plates. The procedure involves in situ disruption of cells, followed by hydrolysis of glycogen into glucosyl units by fungal glucoamylase (exo-1.4-alpha-glucosidase, EC 3.2.1.3), and glucose determination with the glucose oxidase colorimetric method. The color intensity can be measured in conventional ELISA readers, and the data can be fed to an on-line computer for rapid processing. The advantages of this method are its simplicity and automation, the reduction in sample handling, and the small number of cells required compared to other conventional methods. PMID:8660508

  7. Optimizing Two-Color Semiconductor Nanocrystal Immunoassays in Single Well Microtiter Plate Formats

    PubMed Central

    Sapsford, Kim E.; Spindel, Samantha; Jennings, Travis; Tao, Guoliang; Triulzi, Robert C.; Algar, W. Russ; Medintz, Igor L.

    2011-01-01

    The simultaneous detection of two analytes, chicken IgY (IgG) and Staphylococcal enterotoxin B (SEB), in the single well of a 96-well plate is demonstrated using luminescent semiconductor quantum dot nanocrystal (NC) tracers. The NC-labeled antibodies were prepared via sulfhydryl-reactive chemistry using a facile protocol that took <3 h. Dose response curves for each target were evaluated in a single immunoassay format and compared to Cy5, a fluorophore commonly used in fluorescent immunoassays, and found to be equivalent. Immunoassays were then performed in a duplex format, demonstrating multiplex detection in a single well with limits of detection equivalent to the single assay format: 9.8 ng/mL chicken IgG and 7.8 ng/mL SEB. PMID:22164051

  8. Establishment and validation of a method for multi-dose irradiation of cells in 96-well microplates

    SciTech Connect

    Abatzoglou, Ioannis; Zois, Christos E.; Pouliliou, Stamatia

    2013-02-15

    Highlights: ► We established a method for multi-dose irradiation of cell cultures within a 96-well plate. ► Equations to adjust to preferable dose levels are produced and provided. ► Up to eight different dose levels can be tested in one microplate. ► This method results in fast and reliable estimation of radiation dose–response curves. -- Abstract: Microplates are useful tools in chemistry, biotechnology and molecular biology. In radiobiology research, these can be also applied to assess the effect of a certain radiation dose delivered to the whole microplate, to test radio-sensitivity, radio-sensitization or radio-protection. Whether different radiation doses can be accurately applied to a single 96-well plate to further facilitate and accelerated research by one hand and spare funds on the other, is a question dealt in the current paper. Following repeated ion-chamber, TLD and radiotherapy planning dosimetry we established a method for multi-dose irradiation of cell cultures within a 96-well plate, which allows an accurate delivery of desired doses in sequential columns of the microplate. Up to eight different dose levels can be tested in one microplate. This method results in fast and reliable estimation of radiation dose–response curves.

  9. Determining cereal starch amylose content using a dual wavelength iodine binding 96 well plate assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal starch amylose/amylopectin (AM/AP) ratios are critical in functional properties for food and industrial applications. Conventional determination of AM/AP of cereal starches are very time consuming and labor intensive making it very difficult to screen large sample sets. Studying these large...

  10. Development of a 96-well plate iodine binding assay for amylose content determination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal starch amylose/amylopectin (AM/AP) ratios are critical in functional properties for food and industrial applications. Conventional methods for the determination of AM/AP of cereal starches are very time consuming and labor intensive making it very difficult to screen large sample sets. Stud...

  11. Folate content in fresh-cut vegetable packed products by 96-well microtiter plate microbiological assay.

    PubMed

    Fajardo, Violeta; Alonso-Aperte, Elena; Varela-Moreiras, Gregorio

    2015-02-15

    Ready-to-eat foods have nowadays become a significant portion of the diet. Accordingly, nutritional composition of these food categories should be well-known, in particular its folate content. However, there is a broad lack of folate data in food composition tables and databases. A total of 21 fresh-cut vegetable and fruit packed products were analysed for total folate (TF) content using a validated method that relies on the folate-dependent growth of chloramphenicol-resistant Lactobacillus casei subspecies rhamnosus (NCIMB 10463). Mean TF content ranged from 10.0 to 140.9μg/100g for the different matrices on a fresh weight basis. Higher TF quantity, 140.9-70.1μg/100g, was found in spinach, rocket, watercress, chard and broccoli. Significant differences were observed between available data for fresh vegetables and fruits from food composition tables or databases and the analysed results for fresh-cut packed products. Supplied data support the potential of folate-rich fresh-cut ready-to-eat vegetables to increase folate intake significantly. PMID:25236228

  12. Aspects of lead/acid battery technology 4. Plate formation

    NASA Astrophysics Data System (ADS)

    Prout, L.

    By design there is usually an excess of positive over negative material in plates. This compensates to an extent the lesser formation charge input required by positive and renders the mismatch when forming positive plate against negative plate of minor importance. Open tank and container formations are described and the dangers of imcomplete formation when 'no-burn' connections are used. The mechanism of material conversation is illustrated from microsections taken from a traction negative. Variations of container formation to suit factory conditions are detailed and economies in electrolyte usage in open-tank formation. The benefit of rest periods during charge are examined particularly for traction. The drying of the positive plates after formation requires careful control; when used in dry-charged automotive batteries poor initial starting can occur if the drying temperature exceeds 70 °C and the moisture content is below 0.25 wt.%.

  13. Droplet formation under the effect of a flexible nozzle plate.

    PubMed

    Sangplung, S; Liburdy, J A

    2009-09-01

    Droplet formation from a flexible nozzle plate driven by a prescribed-waveform excitation of a piezoelectric is numerically investigated using a computational fluid dynamics (CFD) model with the volume of fluid (VOF) method. The droplet generator with a flexible nozzle plate, which is free to vibrate due to the pressure acting on the plate, is modeled in a CFD computational domain. The CFD analysis includes the fluid-structure interaction between fluid and a flexible plate using large deflection theory. The problem is characterized by the nondimensional variables based on the capillary parameters of time, velocity, and pressure. The CFD model is validated with the experiment results. This study examines the characteristics of the applied waveforms and nozzle plate material properties to change the vibrational characteristics of the nozzle plate. The effect of fluid properties on the droplet formation process is also investigated focusing on surface tension and viscous forces. Increasing the impulse of the piezoelectric can be used to cause a higher droplet velocity and it is shown that the vibration of the nozzle plate has a strong effect on the droplet velocity, shape, and volume. Surface tension has a strong influence on the droplet formation characteristics in contrast to viscous forces. For the combination of a fluid with high surface tension and the most flexible nozzle plate, this system cannot cause the droplet ejected out of the nozzle. PMID:19501837

  14. Periodic Microstructures Formation on Plastic Plate by Aerosol Beam Irradiation

    NASA Astrophysics Data System (ADS)

    Tsukamoto, Masahiro; Abe, Nobuyuki; Morimoto, Junji; Akedo, Jun

    Technology of periodic microstructures formation on plastic plate, the polyethylene terephthalate (PET) plate, was developed with an aerosol beam. The beam was composed of submicron-size anatase titania (TiO2) particles. Formation mechanism depended on an incident angle of the beam to the PET plate. At an incident angles in the range of 0 to 30°C, a TiO2 films were fabricated on the PET plate. Deposition rate of the film decreased as incident angle increased in the range of 0 to 30°C. The film was not produced at 40°C. At 50 and 60°C, the PET plate was etched by the beam irradiation. In the etching area, periodic microstructures were self-organized, whose grooves’ direction was perpendicular to the beam incidence direction.

  15. Multiwell cell culture plate format with integrated microfluidic perfusion system

    NASA Astrophysics Data System (ADS)

    Domansky, Karel; Inman, Walker; Serdy, Jim; Griffith, Linda G.

    2006-01-01

    A new cell culture analog has been developed. It is based on the standard multiwell cell culture plate format but it provides perfused three-dimensional cell culture capability. The new capability is achieved by integrating microfluidic valves and pumps into the plate. The system provides a means to conduct high throughput assays for target validation and predictive toxicology in the drug discovery and development process. It can be also used for evaluation of long-term exposure to drugs or environmental agents or as a model to study viral hepatitis, cancer metastasis, and other diseases and pathological conditions.

  16. Crust formation and plate motion in the early archean.

    PubMed

    Kröner, A; Layer, P W

    1992-06-01

    Mounting evidence for voluminous continental crust formation in the early Archean involving intracrustal melting and selective preservation of granitoid rocks suggests that initial crust formation crust formation and growth were predominantly by magmatic underplating in plumegenerated Iceland-type settings. Collision of these early islands to give rise to larger blocks is suggested by extensive horizontal shortening in both supracrustal and granitoid assemblages. Preservation of early Archean high-grade gneisses that were once at depths of 20 to 30 kilometers implies that these blocks developed thick, subcrustal roots despite high mantle heat flow. Rigid continental plates must have existed since at least 3.5 billion years ago, and greenstone belts (composed of mixed metavolcanic and metasedimentary sequences intruded by granitoid plutons) probably developed on or near these microcontinents. Paleomagnetic data with good age control from at least one ancient craton suggest that plate motion was at normal minimum average velocities of about 17 millimeters per year with respect to the poles during the period 3.5 billion to 2.4 billion years ago. If this is true on a global scale, Archean plate motion was not faster than in later geologic times. PMID:17791608

  17. High Speed Large Format Photon Counting Microchannel Plate Imaging Sensors

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Ertley, C.; Vallerga, J.

    The development of a new class of microchannel plate technology, using atomic layer deposition (ALD) techniques applied to a borosilicate microcapillary array is enabling the implementation of larger, more stable detectors for Astronomy and remote sensing. Sealed tubes with MCPs with SuperGenII, bialkali, GaAs and GaN photocathodes have been developed to cover a wide range of optical/UV sensing applications. Formats of 18mm and 25mm circular, and 50mm (Planacon) and 20cm square have been constructed for uses from night time remote reconnaissance and biological single-molecule fluorescence lifetime imaging microscopy, to large area focal plane imagers for Astronomy, neutron detection and ring imaging Cherenkov detection. The large focal plane areas were previously unattainable, but the new developments in construction of ALD microchannel plates allow implementation of formats of 20cm or more. Continuing developments in ALD microchannel plates offer improved overall sealed tube lifetime and gain stability, and furthermore show reduced levels of radiation induced background. High time resolution astronomical and remote sensing applications can be addressed with microchannel plate based imaging, photon time tagging detector sealed tube schemes. Photon counting imaging readouts for these devices vary from cross strip (XS), cross delay line (XDL), to stripline anodes, and pad arrays depending on the intended application. The XS and XDL readouts have been implemented in formats from 22mm, and 50mm to 20cm. Both use MCP charge signals detected on two orthogonal layers of conductive fingers to encode event X-Y positions. XDL readout uses signal propagation delay to encode positions while XS readout uses charge cloud centroiding. Spatial resolution readout of XS detectors can be better than 20 microns FWHM, with good image linearity while using low gain (<10^6), allowing high local counting rates and longer overall tube lifetime. XS tubes with electronics can encode event

  18. A 96-well electrochemical method for the screening of enzymatic activities.

    PubMed

    Abdellaoui, Sofiène; Noiriel, Alexandre; Henkens, Robert; Bonaventura, Celia; Blum, Loïc J; Doumèche, Bastien

    2013-04-01

    The rapid electrochemical screening of enzyme activities in bioelectronics is still a challenging issue. In order to solve this problem, we propose to use a 96-well electrochemical assay. This system is composed of 96 screen-printed electrodes on a printed circuit board adapted from a commercial system (carbon is used as the working electrode and silver chloride as the counter/reference electrode). The associated device allows for the measurements on the 96 electrodes to be performed within a few seconds. In this work, we demonstrate the validity of the screening method with the commercial laccase from the fungus Trametes versicolor. The signal-to-noise ratio (S/N) is found to be the best way to analyze the electrochemical signals. The S/N follows a saturation-like mechanism with a dynamic linear range of two decades ranging from 0.5 to 75 ng of laccase (corresponding to enzymatic activities from 62 × 10(-6) to 9.37 × 10(-3) μmol min(-1)) and a sensitivity of 3027 μg(-1) at +100 mV versus Ag/AgCl. Laccase inhibitors (azide and fluoride anions), pH optima, and interfering molecules could also be identified within a few minutes. PMID:23461701

  19. A novel 96-well gel-based assay for determining antifungal activity against filamentous fungi.

    PubMed

    Troskie, Anscha Mari; Vlok, Nicolas Maré; Rautenbach, Marina

    2012-12-01

    In recent years the global rise in antibiotic resistance and environmental consciousness lead to a renewed fervour to find and develop novel antibiotics, including antifungals. However, the influence of the environment on antifungal activity is often disregarded and many in vitro assays may cause the activity of certain antifungals to be overestimated or underestimated. The general antifungal test assays that are economically accessible to the majority of scientists primarily rely on visual examination or on spectrophotometric analysis. The effect of certain morphogenic antifungals, which may lead to hyperbranching of filamentous fungi, unfortunately renders these methods unreliable. To minimise the difficulties experienced as a result of hyperbranching, we developed a straightforward, economical 96-well gel-based method, independent of spectrophotometric analysis, for highly repeatable determination of antifungal activity. For the calculation of inhibition parameters, this method relies on the visualisation of assay results by digitisation. The antifungal activity results from our novel micro-gel dilution assay are comparable to that of the micro-broth dilution assay used as standard reference test of The Clinical and Laboratory Standard Institute. Furthermore, our economical assay is multifunctional as it permits microscopic analysis of the preserved assay results, as well as rendering highly reliable data. PMID:23089670

  20. Formation of plate boundaries: The role of mantle volatilization

    NASA Astrophysics Data System (ADS)

    Seno, Tetsuzo; Kirby, Stephen H.

    2014-02-01

    In the early Earth, convection occurred with the accumulation of thick crust over a weak boundary layer downwelling into the mantle (Davies, G.F., 1992. On the emergence of plate tectonics. Geology 20, 963-966.). This would have transitioned to stagnant-lid convection as the mantle cooled (Solomatov, V.S., Moresi, L.-N., 1997. Three regimes of mantle convection with non-Newtonian viscosity and stagnant lid convection on the terrestrial planets. Geophys. Res. Lett. 24, 1907-1910.) or back to a magma ocean as the mantle heated (Sleep, N., 2000. Evolution of the mode of convection within terrestrial planets. J. Geophys. Res. 105(E7): 17563-17578). Because plate tectonics began operating on the Earth, subduction must have been initiated, thus avoiding these shifts. Based on an analogy with the continental crust subducted beneath Hindu Kush and Burma, we propose that the lithosphere was hydrated and/or carbonated by H2O-CO2 vapors released from magmas generated in upwelling plumes and subsequently volatilized during underthrusting, resulting in lubrication of the thrust above, and subduction of the lithosphere along with the overlying thick crust. Once subduction had been initiated, serpentinized forearc mantle may have formed in a wedge-shaped body above a dehydrating slab. In relict arcs, suture zones, or rifted margins, any agent that warms and dehydrates the wedge would weaken the region surrounding it, and form various types of plate boundaries depending on the operating tectonic stress. Thus, once subduction is initiated, formation of plate boundaries might be facilitated by a major fundamental process: weakening due to the release of pressurized water from the warming serpentinized forearc mantle.

  1. Determination of suvorexant in human plasma using 96-well liquid-liquid extraction and HPLC with tandem mass spectrometric detection.

    PubMed

    Breidinger, S A; Simpson, R C; Mangin, E; Woolf, E J

    2015-10-01

    A method, using liquid chromatography with tandem mass spectrometric detection (LC-MS/MS), was developed for the determination of suvorexant (MK-4305, Belsomra(®)), a selective dual orexin receptor antagonist for the treatment insomnia, in human plasma over the concentration range of 1-1000ng/mL. Stable isotope labeled (13)C(2)H3-suvorexant was used as an internal standard. The sample preparation procedure utilized liquid-liquid extraction, in the 96-well format, of a 100μL plasma sample with methyl t-butyl ether. The compounds were chromatographed under isocratic conditions on a Waters dC18 (50×2.1mm, 3μm) column with a mobile phase consisting of 30/70 (v/v %) 10mM ammonium formate, pH3/acetonitrile at a flow rate of 0.3mL/min. Multiple reaction monitoring of the precursor-to-product ion pairs for suvorexant (m/z 451→186) and (13)C(2)H3-suvorexant (m/z 455→190) on an Applied Biosystems API 4000 tandem mass spectrometer was used for quantitation. Intraday assay precision, assessed in six different lots of control plasma, was within 10% CV at all concentrations, while assay accuracy ranged from 95.6 to 105.0% of nominal. Quality control (QC) samples in plasma were stored at -20°C. Initial within day analysis of QCs after one freeze-thaw cycle showed accuracy within 9.5% of nominal with precision (CV) of 6.7% or less. The plasma QC samples were demonstrated to be stable for up to 25 months at -20°C. The method described has been used to support clinical studies during Phase I through III of clinical development. PMID:26343269

  2. Formation of a vortex at the edge of a plate

    NASA Technical Reports Server (NTRS)

    Anton, Leo

    1956-01-01

    The flow about the plate of infinite width may be represented as a potential flow with discontinuity surfaces which extend from the plate edges. For prescribed form and vortex distribution of the discontinuity surfaces, the velocity field may be calculated by means of a conformal representation. One condition is that the velocity at the plate edges must be finite. However, it is not sufficient for determination of the form and vortex distribution of the surface. However, on the basis of a similitude requirement one succeeds in finding a solution of this problem for the plate of infinite width which is correct for the very beginning of the motion of the fluid. Starting from this solution, the further development of the vortex distribution and shape of the surface are observed in the case of a plate of finite width.

  3. A comparative study of pulsed current formation for positive plates of automotive lead acid batteries

    NASA Astrophysics Data System (ADS)

    Diniz, Flamarion B.; Borges, Lucila Ester P.; Neto, Benício de B.

    Positive plate formation with pulsed current is investigated under a wide range of pulse characteristics and compared with continuous current formation. The results indicate that pulsed current formation has a higher faradaic efficiency for conversion into lead dioxide than formation with continuous current. On the other hand, with pulsed current, there is always some residual tetrabasic lead sulfate, not observed on plates formed with continuous current. Pulsed current formation yields higher β-PbO 2/α-PbO 2 ratio than continuous current formation, and is more efficient at longer times of formation.

  4. Titer-plate formatted continuous flow thermal reactors: Design and performance of a nanoliter reactor

    PubMed Central

    Chen, Pin-Chuan; Park, Daniel S.; You, Byoung-Hee; Kim, Namwon; Park, Taehyun; Soper, Steven A.; Nikitopoulos, Dimitris E.; Murphy, Michael C.

    2010-01-01

    velocity, fragment length, and copy number. A 99 bp DNA fragment was successfully amplified at flow velocities from 1 mm/s to 3 mm/s, requiring from 8.16 minutes for 20 cycles (24.48 s/cycle) to 2.72 minutes for 20 cycles (8.16 s/cycle), respectively. Yield compared to the same amplification sequence performed using a bench top thermal cycler decreased nonlinearly from 73% (at 1 mm/s) to 13% (at 3 mm/s) with shorter residence time at the optimal temperatures for the reactions due to increased flow rate primarily responsible. Six different DNA fragments with lengths between 99 bp and 997 bp were successfully amplified at 1 mm/s. Repeatable, successful amplification of a 99 bp fragment was achieved with a minimum of 8000 copies of the DNA template. This is the first demonstration and characterization of continuous flow thermal reactors within the 8 mm × 8 mm footprint of a 96-well micro-titer plate and is the smallest continuous flow PCR to date. PMID:20871807

  5. Vortex Formation in the Starting Flow of Rotating Low-Aspect-Ratio Plates

    NASA Astrophysics Data System (ADS)

    Devoria, Adam; Ringuette, Matthew

    2010-11-01

    We investigate the unsteady flow of fish fin-like plates accelerating from rest through various angular velocity profiles. The objective is to gain an understanding of the connection among the prescribed kinematics and resulting vortex formation; a relationship which has not currently been thoroughly explored. The root-to-tip flow that is induced by the plate motion is expected to have significant effects on the vortex formation. Additionally, different plate shapes are studied to compare the effects of geometrical changes. The experiments are conducted in a water tank, and the plates have a fixed axis of rotation. Digital particle image velocimetry (DPIV) is used to measure the flow velocity in a symmetry plane through the plates. Vorticity and circulation are subsequently computed and vortices are distinguished from surrounding flow structures using vortex identification schemes. Carefully incorporating these techniques will aid the development of scaling laws to characterize the vortex formation with maximum attainable vortex strength.

  6. Single-step method for β-galactosidase assays in Escherichia coli using a 96-well microplate reader.

    PubMed

    Schaefer, Jorrit; Jovanovic, Goran; Kotta-Loizou, Ioly; Buck, Martin

    2016-06-15

    Historically, the lacZ gene is one of the most universally used reporters of gene expression in molecular biology. Its activity can be quantified using an artificial substrate, o-nitrophenyl-ß-d-galactopyranoside (ONPG). However, the traditional method for measuring LacZ activity (first described by J. H. Miller in 1972) can be challenging for a large number of samples, is prone to variability, and involves hazardous compounds for lysis (e.g., chloroform, toluene). Here we describe a single-step assay using a 96-well microplate reader with a proven alternative cell permeabilization method. This modified protocol reduces handling time by 90%. PMID:27036618

  7. Single-step method for β-galactosidase assays in Escherichia coli using a 96-well microplate reader

    PubMed Central

    Schaefer, Jorrit; Jovanovic, Goran; Kotta-Loizou, Ioly; Buck, Martin

    2016-01-01

    Historically, the lacZ gene is one of the most universally used reporters of gene expression in molecular biology. Its activity can be quantified using an artificial substrate, o-nitrophenyl-ß-d-galactopyranoside (ONPG). However, the traditional method for measuring LacZ activity (first described by J. H. Miller in 1972) can be challenging for a large number of samples, is prone to variability, and involves hazardous compounds for lysis (e.g., chloroform, toluene). Here we describe a single-step assay using a 96-well microplate reader with a proven alternative cell permeabilization method. This modified protocol reduces handling time by 90%. PMID:27036618

  8. Endocytosis of cell surface material mediates cell plate formation during plant cytokinesis.

    PubMed

    Dhonukshe, Pankaj; Baluska, Frantisek; Schlicht, Markus; Hlavacka, Andrej; Samaj, Jozef; Friml, Jirí; Gadella, Theodorus W J

    2006-01-01

    Dividing plant cells perform a remarkable task of building a new cell wall within the cytoplasm in a few minutes. A long-standing paradigm claims that this primordial cell wall, known as the cell plate, is generated by delivery of newly synthesized material from Golgi apparatus-originated secretory vesicles. Here, we show that, in diverse plant species, cell surface material, including plasma membrane proteins, cell wall components, and exogenously applied endocytic tracers, is rapidly delivered to the forming cell plate. Importantly, this occurs even when de novo protein synthesis is blocked. In addition, cytokinesis-specific syntaxin KNOLLE as well as plasma membrane (PM) resident proteins localize to endosomes that fuse to initiate the cell plate. The rate of endocytosis is strongly enhanced during cell plate formation, and its genetic or pharmacological inhibition leads to cytokinesis defects. Our results reveal that endocytic delivery of cell surface material significantly contributes to cell plate formation during plant cytokinesis. PMID:16399085

  9. Spray Formation during the Impact of a Flat Plate on Water Surface

    NASA Astrophysics Data System (ADS)

    Wang, An; Duncan, James H.

    2015-11-01

    Spray formation during the impact of a flat plate on a water surface is studied experimentally. The plate is mounted on a two-axis carriage that can slam the plate vertically into the water surface as the carriage moves horizontally along a towing tank. The plate is 122 cm by 38 cm and oriented with adjustable pitch and roll angle. The port (lower) edge of the plate is positioned with a 3-mm gap from one of the tank walls. A laser sheet is created in a plane oriented perpendicular to the axis of the horizontal motion of the carriage. The temporal evolution of the spray within the light sheet is measured with a cinematic laser induced fluorescence technique at a frame rate of 800 Hz. Experiments are performed with a fixed plate trajectory in a vertical plane, undertaken at various speeds. Two types of spray are found when the plate has nonzero pitch and roll angles. The first type is composed of a cloud of high-speed droplets and ligaments generated as the port edge of the plate hits the water surface during the initial impact. The second type is a thin sheet of water that grows from the starboard edge of the plate as it moves below the local water level. The geometrical features of the spray are found to be dramatically affected by the impact velocity. The support of the Office of Naval Research under grant N000141310587 is gratefully acknowledged.

  10. Characterization of multiple platelet activation pathways in patients with bleeding as a high-throughput screening option: use of 96-well Optimul assay

    PubMed Central

    Lordkipanidzé, Marie; Lowe, Gillian C.; Kirkby, Nicholas S.; Chan, Melissa V.; Lundberg, Martina H.; Morgan, Neil V.; Bem, Danai; Nisar, Shaista P.; Leo, Vincenzo C.; Jones, Matthew L.; Mundell, Stuart J.; Daly, Martina E.; Mumford, Andrew D.; Warner, Timothy D.; Watson, Steve P.; Watson, Steve P.; Mumford, Andrew D.; Mundell, Stuart J.; Gissen, Paul; Daly, Martina E.; Lester, Will; Clark, Justin; Williams, Mike; Motwani, Jayashree; Marshall, Dianne; Nyatanga, Priscilla; Mann, Pat; Kirwan, Julie; Wilde, Jonathan; Dunkley, Tracey; Greenway, April; Makris, Michael; Pavord, Sue; Dattani, Rashesh; Grimley, Gerry Dolan Charlotte; Stokley, Simone; Astwood, Emma; Chang, Cherry; Foros, Merri; Trower, Linda; Thachil, Jecko; Hay, Charlie; Pike, Gill; Will, Andrew; Grainger, John; Foulkes, Matt; Fareh, Mona; Talks, Kate; Biss, Tina; Kesteven, Patrick; Hanley, John; Vowles, Julie; Basey, Lesley; Barnes, Michelle; Collins, Peter; Rayment, Rachel; Alikhan, Raza; Morris, Ana Guerrero Rebecca; Mansell, Dianne; Toh, Cheng Hock; Martlew, Vanessa; Murphy, Elaine; Lachmann, Robin; Rose, Peter; Chapman, Oliver; Lokare, Anand; Marshall, Kathryn; Khan, Naseem; Keeling, David; Giangrande, Paul; Austin, Steve; Bevan, David; Alamelu, Jayanthi

    2014-01-01

    Up to 1% of the population have mild bleeding disorders, but these remain poorly characterized, particularly with regard to the roles of platelets. We have compared the usefulness of Optimul, a 96-well plate-based assay of 7 distinct pathways of platelet activation to characterize inherited platelet defects in comparison with light transmission aggregometry (LTA). Using Optimul and LTA, concentration-response curves were generated for arachidonic acid, ADP, collagen, epinephrine, Thrombin receptor activating-peptide, U46619, and ristocetin in samples from (1) healthy volunteers (n = 50), (2) healthy volunteers treated with antiplatelet agents in vitro (n = 10), and (3) patients with bleeding of unknown origin (n = 65). The assays gave concordant results in 82% of cases (κ = 0.62, P < .0001). Normal platelet function results were particularly predictive (sensitivity, 94%; negative predictive value, 91%), whereas a positive result was not always substantiated by LTA (specificity, 67%; positive predictive value, 77%). The Optimul assay was significantly more sensitive at characterizing defects in the thromboxane pathway, which presented with normal responses with LTA. The Optimul assay is sensitive to mild platelet defects, could be used as a rapid screening assay in patients presenting with bleeding symptoms, and detects changes in platelet function more readily than LTA. This trial was registered at www.isrctn.org as #ISRCTN 77951167. PMID:24408324

  11. Characterization of multiple platelet activation pathways in patients with bleeding as a high-throughput screening option: use of 96-well Optimul assay.

    PubMed

    Lordkipanidzé, Marie; Lowe, Gillian C; Kirkby, Nicholas S; Chan, Melissa V; Lundberg, Martina H; Morgan, Neil V; Bem, Danai; Nisar, Shaista P; Leo, Vincenzo C; Jones, Matthew L; Mundell, Stuart J; Daly, Martina E; Mumford, Andrew D; Warner, Timothy D; Watson, Steve P

    2014-02-20

    Up to 1% of the population have mild bleeding disorders, but these remain poorly characterized, particularly with regard to the roles of platelets. We have compared the usefulness of Optimul, a 96-well plate-based assay of 7 distinct pathways of platelet activation to characterize inherited platelet defects in comparison with light transmission aggregometry (LTA). Using Optimul and LTA, concentration-response curves were generated for arachidonic acid, ADP, collagen, epinephrine, Thrombin receptor activating-peptide, U46619, and ristocetin in samples from (1) healthy volunteers (n = 50), (2) healthy volunteers treated with antiplatelet agents in vitro (n = 10), and (3) patients with bleeding of unknown origin (n = 65). The assays gave concordant results in 82% of cases (κ = 0.62, P < .0001). Normal platelet function results were particularly predictive (sensitivity, 94%; negative predictive value, 91%), whereas a positive result was not always substantiated by LTA (specificity, 67%; positive predictive value, 77%). The Optimul assay was significantly more sensitive at characterizing defects in the thromboxane pathway, which presented with normal responses with LTA. The Optimul assay is sensitive to mild platelet defects, could be used as a rapid screening assay in patients presenting with bleeding symptoms, and detects changes in platelet function more readily than LTA. This trial was registered at www.isrctn.org as #ISRCTN 77951167. PMID:24408324

  12. Development and validation of a 96-well cellular assay for the discovery of ALDH1A1 inhibitors.

    PubMed

    Ming, Wenyu; Ma, Wenzhen; Chen, Lisa H; Volk, Catherine; Michael, Mervyn Dodson; Xu, Yanping; Zhang, Fang; Wang, Xiaojun

    2013-07-01

    Retinoic acid, the active metabolite of vitamin A, plays important roles in various physiological and pathological processes. The two-step production of retinoic acid from vitamin A (retinol) is catalyzed by alcohol dehydrogenases and aldehyde dehydrogenases, which are potential therapeutic targets for numerous diseases, such as obesity, diabetes, and cancer. Currently, the lack of a suitable high-throughput cellular assay hinders efforts to identify therapeutic small molecular inhibitors of aldehyde dehydrogenase, such as ALDH1A1. In this report, we utilized high-content imaging technology and a commercially available cell permeable ALDH substrate to develop a 96-well cellular ALDH1A1 assay. This assay has a robust and sensitive readout and is amenable to automation. With this cellular assay, we identified potent selective ALDH1A1 inhibitors to explore the role of retinoic acid production in various preclinical disease models. PMID:23957476

  13. Development of a new microtiter plate format for clinically relevant assays.

    PubMed

    Piletska, Elena V; Piletsky, Stanislav S; Whitcombe, Michael J; Chianella, Iva; Piletsky, Sergey A

    2012-02-21

    A new format for the microtiter plate-based assays was proposed. The novelty involves the use of disk-shaped inserts for immobilization of biological and chemical reagents. The internal opening of the disks allows measurements of the reactions by standard microtiter plate readers without any additional steps involving liquid handling. Ideally the plate end-users just have to add the sample and take the measurement without any need of multiple reagent additions or transfer of the liquid to a different plate. The novel assay format also allows handling of reagents which are not soluble in an aqueous environment. As a proof of concept we describe here several model reactions which are compatible with microtiter plate format, such as monitoring enzymatic reactions catalyzed by glucose oxidase (GOx) and urease, measurements of proteins by BCA assay, analysis of pH, and concentration of antioxidants. The "mix and match" approach in the disk-shape format allows multiplexing and could be particularly useful for high throughput screening. One of the potential application areas for this novel assay format could be in a multianalyte system for measurement of clinically relevant analytes in primary care. PMID:22264028

  14. The BUME method: a novel automated chloroform-free 96-well total lipid extraction method for blood plasma[S

    PubMed Central

    Löfgren, Lars; Ståhlman, Marcus; Forsberg, Gun-Britt; Saarinen, Sinikka; Nilsson, Ralf; Hansson, Göran I.

    2012-01-01

    Lipid extraction from biological samples is a critical and often tedious preanalytical step in lipid research. Primarily on the basis of automation criteria, we have developed the BUME method, a novel chloroform-free total lipid extraction method for blood plasma compatible with standard 96-well robots. In only 60 min, 96 samples can be automatically extracted with lipid profiles of commonly analyzed lipid classes almost identically and with absolute recoveries similar or better to what is obtained using the chloroform-based reference method. Lipid recoveries were linear from 10–100 µl plasma for all investigated lipids using the developed extraction protocol. The BUME protocol includes an initial one-phase extraction of plasma into 300 µl butanol:methanol (BUME) mixture (3:1) followed by two-phase extraction into 300 µl heptane:ethyl acetate (3:1) using 300 µl 1% acetic acid as buffer. The lipids investigated included the most abundant plasma lipid classes (e.g., cholesterol ester, free cholesterol, triacylglycerol, phosphatidylcholine, and sphingomyelin) as well as less abundant but biologically important lipid classes, including ceramide, diacylglycerol, and lyso-phospholipids. This novel method has been successfully implemented in our laboratory and is now used daily. We conclude that the fully automated, high-throughput BUME method can replace chloroform-based methods, saving both human and environmental resources. PMID:22645248

  15. Effect of the substrate orientation on the formation of He-plates in Si

    SciTech Connect

    Vallet, M.; Barbot, J. F.; Declémy, A.; Beaufort, M. F.; Reboh, S.

    2013-11-21

    The effect of the crystalline orientation on the implantation-induced strain/stress and on the formation of He-plates was studied by combining high-resolution X-ray scattering and transmission electron microscopy. The highest strains are obtained in (001)-oriented implanted substrates regardless of the fluence and of the channeling effects. The anisotropic properties of the silicon that generate an anisotropic elastic response of the substrate were taken into account to explain these different values of strain. Upon specific thermal annealing, it is shown that the formation of He-plates occurs only in the (001) habit planes regardless of the orientation of the substrates, non-tilted and tilted (001)-, (110)-, and (111)-substrates. Moreover, the distribution of He-plates in the (001) variants was found to be strongly dependent on the angle of the habit plane with the surface and on the intensity of the implantation-induced strain/stress. The implantation-induced stress thus favors the formation of He-plates in specific planes (of low angle with the surface) forming different defect configurations. The nucleation and growth of He-plates are thus discussed with regard to the implantation-induced stress.

  16. Vortex Formation, Shedding and Energy Harvesting from a Cyber-Physical Pitching Flat Plate

    NASA Astrophysics Data System (ADS)

    Onoue, Kyohei; Breuer, Kenneth

    2014-11-01

    We examine the dynamics and energy harvesting capabilities of an elastically mounted flat plate undergoing large amplitude limit cycle oscillations in a uniform flow. All experiments are performed using a cyber-physical system, wherein the structural inertia, stiffness and damping are numerically simulated using a position-following feedback algorithm. The cyber-physical system also allows for implementation of nonlinear spring and damping coefficients, which control the plate dynamics and subsequent energy harvesting characteristics. Analysis of the plate kinematics and the fluid flow over the plate and in the wake (measured using PIV) are used to understand the interplay between structural motion and vortex formation at the sharp leading and trailing edges of the plate. By varying the structural properties of the system we systematically analyze the formation, strength, stability and separation of the leading edge vortex, as well as the dependence on kinematic parameters and Reynolds number. Connections to previous results on vortex formation time and bluff body aerodynamics are discussed. This research is funded by the Air Force Office of Scientific Research (AFOSR).

  17. Study and application of several-step tank formation of lead/acid battery plates

    NASA Astrophysics Data System (ADS)

    Chen, Hongyu; Wei, Yongzhong; Luo, Yourong; Duan, Shuzhen

    A several-step tank formation method and related charging equipment have been developed for automotive lead/acid batteries. This process offers the advantages of reduced energy requirements, increased charging efficiency and reduced environmental problems. Results also suggest that several-step formation ameliorates the problem of premature capacity loss and extends the useful service-life of automotive batteries. This is thought to be due to the production of greater amounts of α-PbO 2 in the positive plates.

  18. Measuring Ca²⁺ changes in multiwell format using the Fluorometric Imaging Plate Reader (FLIPR(®)).

    PubMed

    Marshall, Ian C B; Owen, Davina E; McNulty, Shaun

    2013-01-01

    The Fluorometric Imaging Plate Reader (FLIPR) has made a significant contribution to drug discovery programs. The key advantage of FLIPR over conventional plate readers is the ability to measure fluorescence emission from multiple wells (96 wells or 384 wells) simultaneously and with high temporal resolution. Consequently, FLIPR has been used extensively to record dynamic intracellular processes such as changes in intracellular Ca(2+) ion concentration, membrane potential, and pH. Since FLIPR is used to measure a functional response in cells, it is rapidly able to distinguish full agonists, partial agonists, and antagonists at a target of interest, making the system a valuable screening tool for interrogation of compound libraries. Automated FLIPR systems for ultra high throughput have also become available that employ integrated plate stackers, washers and specialized stages to allow users to shuttle cell and compound plates from incubators or storage magazines onto the FLIPR system itself. In this chapter generic methods for assessing intracellular Ca(2+) on the FLIPR are described. PMID:23007581

  19. SOXC Transcription Factors Induce Cartilage Growth Plate Formation in Mouse Embryos by Promoting Noncanonical WNT Signaling.

    PubMed

    Kato, Kenji; Bhattaram, Pallavi; Penzo-Méndez, Alfredo; Gadi, Abhilash; Lefebvre, Véronique

    2015-09-01

    Growth plates are specialized cartilage structures that ensure the elongation of most skeletal primordia during vertebrate development. They are made by chondrocytes that proliferate in longitudinal columns and then progress in a staggered manner towards prehypertrophic, hypertrophic and terminal maturation. Complex molecular networks control the formation and activity of growth plates, but remain incompletely understood. We investigated here the importance of the SoxC genes, which encode the SOX4, SOX11 and SOX12 transcription factors, in growth plates. We show that the three genes are expressed robustly in perichondrocytes and weakly in growth plate chondrocytes. SoxC(Prx1Cre) mice, which deleted SoxC genes in limb bud skeletogenic mesenchyme, were born with tiny appendicular cartilage primordia because of failure to form growth plates. In contrast, SoxC(Col2Cre) and SoxC(ATC) mice, which deleted SoxC genes primarily in chondrocytes, were born with mild dwarfism and fair growth plates. Chondrocytes in the latter mutants matured normally, but formed irregular columns, proliferated slowly and died ectopically. Asymmetric distribution of VANGL2 was defective in both SoxC(Prx1Cre) and SoxC(ATC) chondrocytes, indicating impairment of planar cell polarity, a noncanonical WNT signaling pathway that controls growth plate chondrocyte alignment, proliferation and survival. Accordingly, SoxC genes were necessary in perichondrocytes for expression of Wnt5a, which encodes a noncanonical WNT ligand required for growth plate formation, and in chondrocytes and perichondrocytes for expression of Fzd3 and Csnk1e, which encode a WNT receptor and casein kinase-1 subunit mediating planar cell polarity, respectively. Reflecting the differential strengths of the SOXC protein transactivation domains, SOX11 was more powerful than SOX4, and SOX12 interfered with the activity of SOX4 and SOX11. Altogether, these findings provide novel insights into the molecular regulation of skeletal

  20. Protective nitride formation on stainless steel alloys for proton exchange membrane fuel cell bipolar plates

    NASA Astrophysics Data System (ADS)

    Yang, B.; Brady, M. P.; Wang, H.; Turner, J. A.; More, K. L.; Young, D. J.; Tortorelli, P. F.; Payzant, E. A.; Walker, L. R.

    Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr 2N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr-nitride surface layer was found to be the initial formation of oxide during nitridation, which prevented the internal nitridation typically observed for these alloys, and resulted in external Cr-nitride layer formation. The addition of V to the alloy, which resulted in the initial formation of V 2O 3-Cr 2O 3, was found to enhance this effect, by making the initially formed oxide more amenable to subsequent nitridation. The Cr-nitride surface layer formed on model V-modified Fe-27Cr alloys exhibited excellent corrosion resistance and low interfacial contact resistance under simulated PEMFC bipolar plate conditions.

  1. Determination of the HIV integrase inhibitor, MK-0518 (raltegravir), in human plasma using 96-well liquid-liquid extraction and HPLC-MS/MS.

    PubMed

    Merschman, S A; Vallano, P T; Wenning, L A; Matuszewski, B K; Woolf, E J

    2007-09-15

    An HPLC-MS/MS method was developed for the determination of MK-0518 (raltegravir), an HIV integrase inhibitor, in human plasma over the concentration range of 2-1000 ng/mL. Stable isotope labeled (13)C(6)-MK-0518 was used as an internal standard. The sample preparation procedure utilized liquid-liquid extraction with hexane:methylene chloride in the 96-well format with a 200 microL plasma sample size. The compounds were chromatographed on an Ace C(18) (50 x 3.0 mm, 3 microm, titanium frits) column with 42.5/57.5 (v/v %) 0.1mM EDTA in 0.1% formic acid/methanol mobile phase at a flow rate of 0.5 mL/min. Multiple reaction monitoring of the precursor-to-product ion pairs for MK-0518 (m/z 445-->109) and (13)C(6)-MK-0518 (m/z 451-->367) on an Applied Biosystem API 4000 HPLC-MS/MS was used for quantitation. Intraday precision of standard curve concentrations in five different lots of control plasma was within 3.2%, while accuracy ranged from 94.8 to 106.8%. The mean extraction recovery of spiked plasma samples was 87%. Quality control (QC) samples were stored at -20 degrees C. Initial within day analysis showed QC accuracy within 7.5% of nominal with precision of 3.1% or less. The plasma QC samples were demonstrated to be stable for up to 23 months at -20 degrees C. The method described has been used to support over 18 clinical studies during Phase I through III of clinical development. PMID:17644453

  2. An antibody microarray, in multiwell plate format, for multiplex screening of foodborne pathogenic bacteria and biomolecules

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intoxication and infection caused by foodborne pathogens are important problems in the United States, and screening tests for multiple pathogen detection have been developed because food producers are known reservoirs of multiple pathogens. We developed a 96-well microplate, multiplex antibody micr...

  3. Insight into characteristic features of cartilage growth plate as a physiological template for bone formation.

    PubMed

    Jaroszewicz, Jakub; Kosowska, Anna; Hutmacher, Dietmar; Swieszkowski, Wojciech; Moskalewski, Stanisław

    2016-02-01

    Cartilage growth plate is a natural template from both a biochemical and structural point of view and allows osteoblasts migration, proliferation, differentiation, and ultimately, bone formation. It is evolutionary adjusted to support bone formation within strictly defined spatial framework serving as an interesting model for studying more mechanistically aspects which might be important for specific scaffold-based bone tissue engineering strategies. Surprisingly little is known about the geometric features of this physiological template. To this purpose we analyzed cartilage growth plate from rat, mouse, and human costochondral junction and tibia. High-resolution X-ray tomography showed that pore size in the zone of provisional calcification was within 20 to 30 µm range and in the metaphysis in 35 to 50 µm range. The thickness of calcified longitudinal septa in zone of provisional calcification was 3 to 5 µm and in metaphysis 7 to 12 µm. The porosity varied from 84 to 88%. We observed that numerical values characteristic for cartilage growth plate were not significantly influenced by the species of origin, by the type of bone, or by age. In addition, electron microscopy of calcified fragments of longitudinal septa showed that the calcium aggregates were globular, connected with each other, and formed a shell covering cartilage matrix located within longitudinal septa. PMID:26453900

  4. Vortex formation and drag on low aspect ratio, normal flat plates

    NASA Astrophysics Data System (ADS)

    Ringuette, Matthew James

    Experiments were done to investigate the role of vortex formation in the drag force generation of low aspect ratio, normal flat plates starting from rest. This very simplified case is a first, fundamental step toward understanding the more complicated flow of hovering flight, which relies primarily on drag for propulsion. The relative importance of the plate's free end, or tip, with varying aspect ratio was also studied. Identifying the relationship among aspect ratio, vortex formation, and drag force can provide insight into the wing aspect ratios and kinematics found nature, with the eventual goal of designing man-made flapping wing micro air vehicles. The experiments were carried out using flat plate models in a towing tank at a moderate Reynolds number of 3000. Two aspect ratios, 6 and 2, were considered, the latter in order to have a highly tip-dominated case. A force balance measured the time-varying drag, and multiple, perpendicular sections of the flow velocity were measured quantitatively using digital particle image velocimetry. Vorticity fields were calculated from the velocity data, and features in the drag force for different aspect ratios were related to the vortex dynamics. Finally, since the flow is highly three-dimensional, dye flow visualization was done to characterize its structure and to augment the two-dimensional digital particle image velocimetry data.

  5. Calculating formation range of binary amorphous alloys fabricated by electroless plating

    NASA Astrophysics Data System (ADS)

    Zhang, Bangwei; Liao, Shuzhi; Shu, Xiaolin; Xie, Haowen

    2016-06-01

    A lot of amorphous alloy deposits in the binary (Ni, Co, Cu)-(P, B) alloy systems fabricated by electroless plating (EP) have been reported up to date. But no one reported their theoretical modeling of the amorphous formation and calculated their concentration range of amorphous formation (RAF). Using Miedema model and subregular model scheme, the RAFs for the six EP (Ni, Co, Cu)-(P, B) alloys and three Ni-Cu, Ni-Co and Co-Cu alloys have been calculated systematically for the first time. The calculated results are in agreement with experimental observations. Experiments and calculations for the RAFs in the latter three alloy systems reveal that not any RAF formed except crystalline states. The huge difference between the six metal-metalloid alloys and three metal-metal alloys in RAF has been discussed in detail in the paper.

  6. A transient analysis of frost formation on a parallel plate evaporator

    SciTech Connect

    Martinez-Frias, J.; Aceves, S.M.; Hernandez-Guerrero, A.

    1996-12-31

    This paper presents the development of a transient model for evaluating frost formation on a parallel plate evaporator for heat pump applications. The model treats the frost layer as a porous substance, and applies the equations of conservation of mass, momentum and energy to calculate the growth and densification of the frost layer. Empirical correlations for thermal conductivity and tortuosity as a function of density are incorporated from previous studies. Frost growth is calculated as a function of time, Reynolds number, longitudinal location, plate temperature, and ambient air temperature and humidity. The main assumptions are: ideal gas behavior for air and water vapor, uniform frost density and thermal conductivity across the thickness of the frost layer; and quasi-steady conditions during the whole process. The mathematical model is validated by comparing the predicted values of frost thickness and frost density with results obtained in recent experimental studies. A good agreement was obtained in the comparison. The frost formation model calculates pressure drop and heat transfer resistance that result from the existence of the frost layer, and it can therefore be incorporated into a heat pump model to evaluate performance losses due to frosting as a function of weather conditions and time of operation since the last evaporator defrost.

  7. Computational Analysis of Vortex Formation Over a Plunge Oscillating Flat Plate with Various Slip Conditions

    NASA Astrophysics Data System (ADS)

    Palmore, John; Sharif, Muhammad; Lang, Amy

    2010-11-01

    A thorough understanding of small scale aerodynamics is important for the design of micro air vehicles. Since they fly in the same Re regime as that of insects, these animals can provide biologically inspired designs. This study looks at how an alteration to the surface slip condition affects the aerodynamic flow over a wing at low Re. Butterflies have small scales (on the order of 100 microns in length) that line the surface of their wings, and it is hypothesized that these scales can affect the slip condition over their wings altering vortex formation and possibly leading to improved flight characteristics. As an initial test to this hypothesis, the flow over an infinitely thin, two-dimensional flat plate was studied using the CFD software FLUENT. The no-slip condition was modified by directly altering the shear stress distribution over the plate. In addition, the action of flapping was simulated by varying the angle of attack as a function of time between -60 and 60 degrees. Multiple shear stress distributions, varying from shear free to no-slip, and multiple flapping frequencies were tested to discern the effects on vortex formation; lift and drag were also analyzed.

  8. Influences of surface hydrophilicity on frost formation on a vertical cold plate under natural convection conditions

    SciTech Connect

    Liu, Zhongliang; Zhang, Xinghua; Wang, Hongyan; Meng, Sheng; Cheng, Shuiyuan

    2007-07-15

    Surface hydrophilicity has a strong influence on frost nucleation according to phase transition theory. To study this effect, a close observation of frost formation and deposition processes on a vertical plate was made under free convection conditions. The formation and shape variation of frost crystals during the initial period are described and the frost thickness variation with time on both hydrophobic and plain copper cold surfaces are presented. The various influencing factors are discussed in depth. The mechanism of surface hydrophilicity influence on frost formation was analyzed theoretically. This revealed that increasing the contact angle can increase the potential barrier and restrain crystal nucleation and growth and thus frost deposition. The experimental results show that the initial water drops formed on a hydrophobic surface are smaller and remain in the liquid state for a longer time compared with ones formed on a plain copper surface. It is also observed that the frost layer deposited on a hydrophobic surface is loose and weak. Though the hydrophobic surface can retard frost formation to a certain extent and causes a looser frost layer, our experimental results show that it does not depress the growth of the frost layer. (author)

  9. The Pemali Formation of Central Java and equivalents: Indicators of sedimentation on an active plate margin

    NASA Astrophysics Data System (ADS)

    Lunt, Peter; Burgon, Gerald; Baky, Alaa

    2009-01-01

    The Pemali Formation is revised from being the oldest known sedimentary unit in north Central Java to being almost the youngest. This, and a new examination of its composition, has implications for regional geological models and petroleum geology. The Pemali Formation was originally interpreted as "early Miocene" but is now shown to be latest Miocene through Pliocene in age, and characterised by both very high rates of sedimentation and a particularly high degree of reworking. The mid-Late Miocene tectonic event that initiated deposition of this formation created a new series of basins that were filled by erosion of new structural highs. Continuing constriction of the basins resulted in the uplift of older Pemali sediments on the basin margins, being reworked into the youngest Pemali strata. Neither the Pemali Formation nor the associated uplift and erosion are seen in the basins in the Java Sea a short distance to the north. Both the severe effects of the mid-Late Miocene tectonism and the Pemali-type sediments are restricted to a particular geologic zone, which is roughly the same as the modern island of Java. This may be above lithosphere of mixed terranes that forms a rim to the sialic Sunda Plate. The onshore Java area has a history of severe tectonism through the Tertiary and consequently a stratigraphy that greatly contrasts with that of the present-day Java Sea. The localised and thick Pemali deposition affected the burial history and the generation of hydrocarbons around the mid-Late Miocene basins, whilst the uplifted areas may include hydrocarbon traps. If basement composition influenced the location and thickness of the Pemali Formation then it is also likely to have fundamentally controlled deposition of older formations, including the unknown source rock for surface oil seeps. Likewise, these controls appear to contrast strongly with the better known rift-sag basins of the Java Sea.

  10. Effect of formation temperature on properties of graphite/stannum composite for bipolar plate

    NASA Astrophysics Data System (ADS)

    Selamat, Mohd Zulkefli; Yusuf, Muhammad Yusri Md; Wer, Tio Kok; Sahadan, Siti Norbaya; Malingam, Sivakumar Dhar; Mohamad, Noraiham

    2016-03-01

    Bipolar plates are key components in Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In this research, the raw materials used to fabricate the high performance bipolar plate are Graphite (Gr), Stannum (Sn) and Polypropylene (PP). All materials used was in powder form and Gr and Sn act as fillers and the PP acts as binder. The ratio of fillers (Gr/Sn) and binder (PP) was fixed at 80:20. For the multi-conductive filler, small amount of Sn, which is 10 up to 20wt% (from the total weight of fillers 80%) have been added into Gr/Sn/PP composite. The fillers were mixed by using the ball mill machine. The second stage of mixing process between the mixer of fillers and binder is also carried out by using ball mill machine before the compaction process by the hot press machine. The effect of formation temperatures (160°C-170°C) on the properties of Gr/Sn/PP composite had been studied in detail, especially the electrical conductivity, bulk density, hardness and microstructure analysis of Gr/Sn/PP composite. The result shows that there are significant improvement in the electrical conductivity and bulk density, which are exceeding the US-DoE target with the maximum value of 265.35 S/cm and 1.682g/cm3 respectively.

  11. Enhancement of measurement sensitivity in the formation of shear interferograms of transparent plates with small residual wedging

    SciTech Connect

    But', A I; Lyalikov, A M

    2011-10-31

    We have proposed a method for increasing the sensitivity of measurements of the wedge angle in transparent plates. The method is based on formation of the holographic shear interferograms using a combination of 180 Degree-Sign rotation of the plate with byturn adjustment of interferograms in its images to an infinitely wide fringe. The sensitivity enhancement is due to the increased number of interference fringes in the observed images of the wedged plate, which favours the reduction of the measurement error during optical processing of the obtained interferograms. Data on the experimental validation of the proposed method are presented.

  12. Dynamics of intraoceanic subduction initiation: 2. Suprasubduction zone ophiolite formation and metamorphic sole exhumation in context of absolute plate motions

    NASA Astrophysics Data System (ADS)

    van Hinsbergen, Douwe J. J.; Peters, Kalijn; Maffione, Marco; Spakman, Wim; Guilmette, Carl; Thieulot, Cedric; Plümper, Oliver; Gürer, Derya; Brouwer, Fraukje M.; Aldanmaz, Ercan; Kaymakcı, Nuretdin

    2015-06-01

    Analyzing subduction initiation is key for understanding the coupling between plate tectonics and the underlying mantle. Here we focus on suprasubduction zone (SSZ) ophiolites and how their formation links to intraoceanic subduction initiation in an absolute plate motion frame. SSZ ophiolites form the majority of exposed oceanic lithosphere fragments and are widely recognized to have formed during intraoceanic subduction initiation. Structural, petrological, geochemical, and plate kinematic constraints on their kinematic evolution show that SSZ crust forms at fore-arc spreading centers at the expense of a mantle wedge, thereby flattening the nascent slab. This leads to the typical inverted pressure gradients found in metamorphic soles that form at the subduction plate contact below and during SSZ crust crystallization. Former spreading centers are preserved in forearcs when subduction initiates along transform faults or off-ridge oceanic detachments. We show how these are reactivated when subduction initiates in the absolute plate motion direction of the inverting weakness zone. Upon inception of slab pull due to, e.g., eclogitization, the sole is separated from the slab, remains welded to the thinned overriding plate lithosphere, and can become intruded by mafic dikes upon asthenospheric influx into the mantle wedge. We propound that most ophiolites thus formed under special geodynamic circumstances and may not be representative of normal oceanic crust. Our study highlights how far-field geodynamic processes and absolute plate motions may force intraoceanic subduction initiation as key toward advancing our understanding of the entire plate tectonic cycle.

  13. Rapid and efficient generation of neurons from human pluripotent stem cells in a multititre plate format.

    PubMed

    Zhang, Miao; Schöler, Hans R; Greber, Boris

    2013-01-01

    Existing protocols for the generation of neurons from human pluripotent stem cells (hPSCs) are often tedious in that they are multistep procedures involving the isolation and expansion of neural precursor cells, prior to terminal differentiation. In comparison to these time-consuming approaches, we have recently found that combined inhibition of three signaling pathways, TGFβ/SMAD2, BMP/SMAD1, and FGF/ERK, promotes rapid induction of neuroectoderm from hPSCs, followed by immediate differentiation into functional neurons. Here, we have adapted our procedure to a novel multititre plate format, to further enhance its reproducibility and to make it compatible with mid-throughput applications. It comprises four days of neuroectoderm formation in floating spheres (embryoid bodies), followed by a further four days of differentiation into neurons under adherent conditions. Most cells obtained with this protocol appear to be bipolar sensory neurons. Moreover, the procedure is highly efficient, does not require particular expert skills, and is based on a simple chemically defined medium with cost-efficient small molecules. Due to these features, the procedure may serve as a useful platform for further functional investigation as well as for cell-based screening approaches requiring human sensory neurons or neurons of any type. PMID:23486189

  14. FIPRONIL EFFECTS ON ESTUARINE COPEPOD (AMPHIASCUS TENUIREMIS) DEVELOPMENT, FERTILITY, AND REPRODUCTION: A RAPID LIFE-CYCLE ASSAY IN 96-WELL MICROPLATE FORMAT. (R827397)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. A practical method to follow the evolution of electrochemically active areas during plate formation processes in lead acid batteries

    NASA Astrophysics Data System (ADS)

    D'Alkaine, C. V.; de Andrade, J.; Impinnisi, P. R.

    A new method to follow the evolution of the plates of a battery during the formation processes is proposed and developed. The developed methodology can be used not only in research but also in the factory laboratories due to its simplicity. To exemplify the methodology, results for formation processes of tubular plates are presented using as precursor PbO or Pb 3O 4. The methodology gives access to the evolution, during its formation process, of the portions of the active material available for the discharge processes, the so called electrochemically active area. At the same time, the proposed technique permits the determination of the whole amount of PbO 2 during formation. Through the results it is pointed out what experimental conditions must be used during the application of the method and examples are given of the kinds of interpretation that can be made. Finally, information is presented which was deduced from the results presented.

  16. Paper microzone plates.

    PubMed

    Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

    2009-08-01

    This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader. PMID:19572563

  17. Vortex Formation on a Plunging Plate with Butterfly Inspired Surface Patterning

    NASA Astrophysics Data System (ADS)

    Powell, Preston; Lang, Amy; Bradshaw, Michael

    2013-11-01

    Previous research has shown that butterfly wings are covered in scales (100 microns in length) that are aligned in rows. When these scales are removed, butterflies require more energy and flaps per second to fly. These scales are pivotal to a butterfly's flying efficiency and are the inspiration for this study. This study examined whether improved efficiency is a result of the prolonged attachment of the leading-edge vortex (LEV) due to the arrangement of these rows. Efficiency is important for any system, however, this type of flight is quite similar to that of an MAV. A long flat plate was lifted at various Reynolds numbers to generate tip vortices on the bottom side. Three test plates were used: one flat plate as a control, one with length-wise ridges, and one with width-wise ridges. These ridges act as a simplistic model of butterfly scales while maintaining flow similarity. DPIV was used to measure the circulation and attachment of the leading-edge vortex for each plate. This experiment tested the hypothesis that the width-wise ridges will exhibit the longest attachment of the LEV which corresponds to increased lift. Also, the plate with length-wise ridges will have the quickest shedding of the LEV and decreased lift. Funding from NSF REU Grant #1062611 is gratefully acknowledged.

  18. Formation and Evaluation of Electroless-Plated Barrier Films for High-Aspect-Ratio Through-Si Vias

    NASA Astrophysics Data System (ADS)

    Miyake, Hiroshi; Inoue, Fumihiro; Yokoyama, Takumi; Shimizu, Tomohiro; Tanaka, Shukichi; Terui, Toshifumi; Shingubara, Shoso

    2011-05-01

    The formation of a diffusion barrier layer in a through-Si via (TSV) has been studied with a combination of nanoparticle catalyst and electroless plating (ELP). We used Au-nanoparticles (Au-NPs) or Pd-nanoparticles (Pd-NPs) as catalysts for ELP of Ni- and Co-alloy barrier layers. We studied deposition of Ni-B and Co-B films in high-aspect-ratio (AR) TSV. Then, we succeeded in controlling the deposition profile of Ni-B in a high-AR TSV by the addition of bis(3-sulfopropyl)-disulfide (SPS). SPS turned out to be an inhibitor of electroless plating of Ni-B. On the other hand, the Co-B film was deposited conformally without additive. The electrical resistivity of Cu after annealing Cu/barrier stacked structure suggests that Co-B has better thermal stability than Ni-B.

  19. Self-similar formation of an inverse cascade in vibrating elastic plates

    NASA Astrophysics Data System (ADS)

    Düring, Gustavo; Josserand, Christophe; Rica, Sergio

    2015-05-01

    The dynamics of random weakly nonlinear waves is studied in the framework of vibrating thin elastic plates. Although it has been previously predicted that no stationary inverse cascade of constant wave action flux could exist in the framework of wave turbulence for elastic plates, we present substantial evidence of the existence of a time-dependent inverse cascade, opening up the possibility of self-organization for a larger class of systems. This inverse cascade transports the spectral density of the amplitude of the waves from short up to large scales, increasing the distribution of long waves despite the short-wave fluctuations. This dynamics appears to be self-similar and possesses a power-law behavior in the short-wavelength limit which significantly differs from the exponent obtained via a Kolmogorov dimensional analysis argument. Finally, we show explicitly a tendency to build a long-wave coherent structure in finite time.

  20. Kinetics of the formation and structure of oligoperoxide nanolayers and grafted polymer brushes on glass plate surface

    NASA Astrophysics Data System (ADS)

    Kostruba, Andriy; Zaichenko, Alexander; Mitina, Natalya; Rayevska, Kateryna; Hertsyk, Kateryna

    2008-09-01

    Functional oligoperoxide surfactants and coordinating oligoperoxide metal complexes were studied as modifiers of glass flat plates to provide the localization of radical forming sites and other functional fragments in adsorbed polymeric layers of a nanoscale thickness. Both the kinetics of the coating formation and properties of the nanolayers witness the dependence of the packing density of oligoperoxide molecules in the coatings on the oligoperoxide natures, concentrations and conditions of the sorption modification. The availability of definite amount of peroxide groups in formed nanolayer provides the possibility of controlled radical graft polymerization initiated from modified surface leading to reliable surface protection, functionality and targeted surface hydrophilic-hydrophobic properties.

  1. Formation of the beam profile in a plate electrode HF laser

    SciTech Connect

    Andramanov, A V; Kabaev, S A; Lazhintsev, B V; Nor-Arevyan, V A; Pisetskaya, A V; Selemir, Victor D

    2005-04-30

    The near-field energy-density distribution of a beam from an HF electric-discharge laser with an inductively stabilised discharge, an SF{sub 6}- and H{sub 2}-based active medium, and interelectrode gaps of 34 and 52 mm is studied. Plates 1-mm thick and 60- or 120-mm wide oriented at an angle of 30{sup 0} to the optical axis serve as 60-mm-wide electrodes. Electrodes 30-mm wide are formed by 60-mm-wide plates also oriented at an angle of 30{sup 0} to the optical axis. The distributions of the laser-radiation density in a resonator with flat mirrors and the discharge-emission intensity over the resonator cross section are studied. The distributions of the laser-radiation density in the near-field zone and the discharge-emission intensity have similar profiles. The arrangement of the electrode plates at an angle of 30{sup 0} provided a considerable increase in the width of the lasing region. The FWHM of the laser-radiation distribution is {approx}80% of the electrode width for the both interelectrode gaps. (beams, modes)

  2. Measuring Ca²+ changes in multiwell format using the Fluorometric Imaging Plate Reader.

    PubMed

    Marshall, Ian C B; Owen, Davina E; McNulty, Shaun

    2005-01-01

    The Fluorometric Imaging Plate Reader (FLIPR®; Molecular Devices, Sunnyvale, CA) has made a significant contribution to drug discovery programs in the pharmaceutical industry since the first commercial instruments were introduced 9 yr ago. The key advantage of FLIPR over conventional plate readers is its ability to measure fluorescence emission from multiple wells (96- or 384-well) simultaneously and with high temporal resolution. Consequently, FLIPR has been used extensively to record dynamic intracellular processes such as changes in intracellular Ca(2+) ion concentration, membrane potential, and pH. Since FLIPR is used to measure a functional response in cells, it is rapidly able to distinguish full agonists, partial agonists, and antagonists at a target of interest, making the system a valuable screening tool for interrogation of compound libraries. Typically, FLIPR can be used to screen more than 150 compound plates per day in a high-throughput screening environment equating to more than 50,000 compounds at a single concentration in a 384-well system. PMID:21341095

  3. Touch-plate and statolith formation in graviceptors of ephyrae which developed while weightless in space

    NASA Technical Reports Server (NTRS)

    Spangenberg, D. B.; Coccaro, E.; Schwarte, R.; Lowe, B.

    1996-01-01

    Ultrastructural studies of the statocysts and touch-plates of graviceptors (rhopalia) of Aurelia ephyrae revealed that (1) touch-plate hair cells are present; and (2) cytoplasmic strands from the hair cell bases extend from the neurite plexus to touch similar strands from the lithocytes. This close association of hair cell neurites and statocysts may have important implications regarding the transmitting and processing of positional information with respect to the gravity vector. Graviceptors of ephyrae which developed while weightless in microgravity were compared with controls at the ultrastructural level. We found that hair cells of ephyrae which developed in microgravity had fewer lipid droplets in the large spaces near their bases as compared with 1 g controls. In the ephyrae from the first microgravity experiment, hair cells had more large apical vacuoles with filamentous content than were found in hair cells of ephyrae from the second experiment and controls. The neurite plexus and the network of cytoplasmic strands extending to the statocysts were not different in microgravity-developed ephyrae from controls. Behavioral differences in swimming and orienting in ephyrae in microgravity and controls (reported earlier) were not explained by morphological differences in the hair cells of the touch-plates or the statocysts, although functional differences apparently occurred.

  4. Fluorescent protein-based cellular assays analyzed by laser-scanning microplate cytometry in 1536-well plate format.

    PubMed

    Auld, Douglas S; Johnson, Ronald L; Zhang, Ya-qin; Veith, Henrike; Jadhav, Ajit; Yasgar, Adam; Simeonov, Anton; Zheng, Wei; Martinez, Elisabeth D; Westwick, John K; Austin, Christopher P; Inglese, James

    2006-01-01

    Microtiter plate readers have evolved from photomultiplier and charged-coupled device-based readers, where a population-averaged signal is detected from each well, to microscope-based imaging systems, where cellular characteristics from individual cells are measured. For these systems, speed and ease of data analysis are inversely proportional to the amount of data collected from each well. Microplate laser cytometry is a technology compatible with a 1536-well plate format and capable of population distribution analysis. Microplate cytometers such as the Acumen Explorer can monitor up to four fluorescent signals from single objects in microtiter plates with densities as high as 1536 wells. These instruments can measure changes in fluorescent protein expression, cell shape, or simple cellular redistribution events such as cytoplasmic to nuclear translocation. To develop high-throughput screening applications using laser-scanning microplate cytometry, we used green fluorescent protein- and yellow fluorescent protein-expressing cell lines designed to measure diverse biological functions such as nuclear translocation, epigenetic signaling, and G protein-coupled receptor activation. This chapter illustrates the application of microplate laser cytometry to these assays in a manner that is suitable for screening large compound collections in high throughput. PMID:17110211

  5. Alteration mineralogy of Home Plate and Columbia Hills—Formation conditions in context to impact, volcanism, and fluvial activity

    NASA Astrophysics Data System (ADS)

    Filiberto, Justin; Schwenzer, Susanne P.

    2013-10-01

    The Mars Exploration Rover Spirit investigated the igneous and alteration mineralogy and chemistry of Home Plate and its surrounding deposits. Here, we focus on using thermochemical modeling to understand the secondary alteration mineralogy at the Home Plate outcrop and surrounding Columbia Hills region in Gusev crater. At high temperatures (300 °C), magnetite occurs at very high W/R ratios, but the alteration assemblage is dominated by chlorite and serpentine over most of the W/R range. Quartz, epidote, and typical high-T phases such as feldspar, pyroxene, and garnet occur at low W/R. At epithermal temperatures (150 °C), hematite occurs at very high W/R. A range of phyllosilicates, including kaolinite, nontronite, chlorite, and serpentine are precipitated at specific W/R. Amphibole, with garnet, feldspar, and pyroxene occur at low W/R. If the CO2 content of the system is high, the assemblage is dominated by carbonate with increasing amounts of an SiO2-phase, kaolinite, carpholite, and chlorite with lower W/R. At temperatures of hydrous weathering (13 °C), the oxide phase is goethite, silicates are chlorite, nontronite, and talc, plus an SiO2-phase. In the presence of CO2, the mineral assemblage at high W/R remains the same, and only at low W/R, i.e., with increasing salinity, carbonate precipitates. The geochemical gradients observed at Home Plate are attributed to short-lived, initially high (300 °C) temperature, but fast cooling events, which are in agreement with our models and our interpretation of a multistage alteration scenario of Home Plate and Gusev in general. Alteration at various temperatures and during different geological processes within Gusev crater has two effects, both of which increase the habitability of the local environment: precipitation of hydrous sheet silicates, and formation of a brine, which might contain elements essential for life in diluted, easily accessible form.

  6. Precambrian Plate Tectonics and the Formation of the Canadian Shield: Seismic Evidence from Hudson Bay

    NASA Astrophysics Data System (ADS)

    Bastow, I. D.; Thompson, D. A.; Kendall, J. M.; Helffrich, G. R.; Wookey, J.; Snyder, D. B.; Eaton, D. W.; Darbyshire, F. A.

    2010-12-01

    The Canadian Shield is one of the largest exposures of Precambrian rocks on Earth. It is a mosaic of several Archean terranes that were brought together during a series of Paleoproterozoic orogens culminating in the so-called Trans-Hudson Orogen (THO), which is thought to have been similar to the Himalayan orogen in scale and nature. The tectonic evolution and lithospheric subdivisions of this region are poorly understood, but new seismic networks in northern Hudson Bay provide fresh information sources to place constraints on the Precambrian processes that formed and shaped it. Using data from a network of 12 broadband seismic stations in the northern part of Hudson Bay that complement existing POLARIS and CNSN networks in the region, we report on a combined study of seismic anisotropy, travel-time tomography, and receiver functions. While tomographic images reveal no clear seismological distinction between Archean and Proterozoic mantle, results from the study of seismic anisotropy show that much of the northern Hudson Bay region retains a strong signature of Archean-to-Paleoproterozoic tectonics - in particular the THO. The receiver function study also provides evidence in support of this 1.8 Ga orogenic event, but the simplicity of crustal structure in the oldest terranes as well as the scale of orogenic belts provides little evidence in support modern-day-style plate tectonics. When reviewed in light of age and compositional constraints from the geological record, our seismic observations point towards a secular change from non-plate tectonic deformation during the Paleo- to Mesoarchean evolving towards fully-developed modern-style plate tectonic interactions during the Paleoproterozoic.

  7. Simultaneous determination of a novel KDR kinase inhibitor and its N-oxide metabolite in human plasma using 96-well solid-phase extraction and liquid chromatography/tandem mass spectrometry.

    PubMed

    Xu, Yang; Du, Lihong; Soli, Eric D; Braun, Matthew P; Dean, Dennis C; Musson, Donald G

    2005-03-25

    To support pharmacokinetic studies, a selective and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous determination of a novel KDR kinase inhibitor (1) and its active metabolite (2) in human plasma. The method is fully automated using a Packard MultiPROBE II system and a TomTec Quadra 96 liquid handling workstation to perform sample preparation and solid-phase extraction (SPE). Following the extraction on a mixed-mode SPE using Oasis MCX 96-well plate, the analytes were separated on a Aquasil C18 column (50 mm x 2.1 mm, i.d., 3 microm) with a mobile phase consisting of acetonitrile/ammonium acetate buffer (5 mM, pH 5.0) (60/40, v/v). The run time for each injection was 4.5 min with the retention times of approximately 2.0 and 2.7 min for 1 and 2 respectively, at a flow rate of 0.25 mL/min. A tandem mass spectrometric detection was conducted using multiple reaction monitoring (MRM) under the positive ion mode with a turbo ion-spray interface. The linear ranges of the calibration curves were 0.05-400 ng/mL for 1 and 0.1-400 ng/mL for 2 on a PE Sciex API 4000 LC-MS/MS system. The lower limits of quantitation (LLOQ) of the assay were 0.05 and 0.1 ng/mL for 1 and 2 respectively, when 0.4 mL of plasma was processed. Intra-day assay precision (using five standard curves prepared by spiking compounds to five lots of plasma) was less than 4.9% for 1 and less than 9.6% for 2 on each concentration. Assay accuracy was found to be 95.1-104.6% of nominal for 1 standards and 93.5-105.6% for 2 standards. QC samples were stable when kept at room temperature for 4 h, at -70 degrees C for 10 days, and after three freeze-thaw cycles. The extraction recoveries were 80%, 83% and 84% for 1 and 2 and I.S. respectively, and no significant matrix effects were observed. The method was successfully applied to plasma samples from clinical studies after oral administration of compound 1. PMID:15686997

  8. Effect of Fe- and Si-Enriched Secondary Precipitates and Surface Roughness on Pore Formation on Aluminum Plate Surfaces During Anodizing

    NASA Astrophysics Data System (ADS)

    Zhu, Yuanzhi; Wang, Shizhi; Yang, Qingda; Zhou, Feng

    2014-09-01

    Two twin roll casts (TRCs) and one hot rolled (HR) AA 1235 aluminum alloy plates with different microstructures are prepared. The plates were electrolyzed in a 1.2 wt% HCl solution with a voltage of 21 V and a current of 1.9 mA. The shape, size, and number of pores formed on the surfaces of these plates were analyzed and correlated with the microstructures of the plates. It is found that pores are easier to form on the alloy plates containing subgrains with a lower dislocation density inside the subgrains, rather than along the grain boundaries. Furthermore, Fe- and Si-enriched particles in the AA1235 aluminum alloys lead to the formation of pores on the surface during electrolyzing; the average precipitate sizes of 4, 3.5, and 2 μm in Alloy 1#, Alloy 2# and Alloy 3# result in the average pore sizes of 3.78, 2.76, and 1.9 μm on the surfaces of the three alloys, respectively; The G.P zone in the alloy also facilitates the surface pore formation. High-surface roughness enhances the possibility of entrapping more lubricants into the plate surface, which eventually blocks the formation of the pores on the surface of the aluminum plates in the following electrolyzing process.

  9. Exhumation and Coupling at the Plate Interface: Large Tectonic Slices V. Melange Formation? Key Contexts and Possible Controlling Parameters

    NASA Astrophysics Data System (ADS)

    Agard, P.; Angiboust, S.; Guillot, S.; Garcia-Casco, A.

    2011-12-01

    Fragments of subducted oceanic lithosphere returned along the plate interface convey crucial information regarding the thermal and rheological conditions of convergent plate boundaries. Geological evidence indicate that, unlike subduction, exhumation is non-steady (Agard et al., Earth Sci. Rev. 2009). We herein focus on deep processes along the plate interface (40-80 km depth), for which there is no counterflow (unlike in accretionary prisms) and no other known mechanisms to return eclogites than interplate friction or buoyancy. These eclogites are of two major types: large scale (>km) slices with coherent PT estimates (W. Alps) versus isolated fragments (frequently m-hm) in a serpentinite- or sedimentary-rich matrix showing contrasting equilibration depths (with hints of punctuated exhumation and even reburial; Franciscan, Cuba, Sistan; e.g., Garcia-Casco et al., Geol. Acta 2006). This latter type tends to show warmer equilibration paths, whereas the larger tectonic slices from the former type remain systematically cold. Serpentinites are crucial for both in permitting decoupling and acting as a buoy, and fluid budget is important too in enhancing floatability and allowing large slices to survive (Angiboust and Agard, Lithos 2010). Numerical models implementing free migration of fluids in the subduction zone also show that the plate interface is strongly localized in the absence of fluids: mechanical decoupling efficiently occurs along the sediment veneer and/or at the top of the highly hydrothermalized crust. Whenever fluids are released in greater amounts (depending on initial fluid content and/or thermal structure), deformation becomes much more distributed and affects both the mantle wedge and the top of the downgoing lithosphere (crust and hydrated mantle top), thereby increasing mechanical coupling between the two plates. Based on natural data and numerical modelling we herein propose that rheological contrast chiefly controls mechanical decoupling. On a

  10. The formation of protective nitride surfaces for PEM fuel cell metallic bipolar plates

    NASA Astrophysics Data System (ADS)

    Brady, M. P.; Yang, B.; Wang, H.; Turner, J. A.; More, K. L.; Wilson, M.; Garzon, F.

    2006-08-01

    The selective gas nitridation of model nickel-based alloys was used to form dense, electrically conductive and corrosion-resistant nitride surface layers, including TiN, VN, CrN, Cr2N, as wellas a complex NiNbVN phase. Evaluation for use as a protective surface for metallic bipolar plates in proton exchange membrane fuel cells (PEMFC) indicated that CrN/Cr2N based surfaces holdpromise to meet U.S. Department of Energy (DOE) performance goals for automative applications. The thermally grown CrN/Cr2N surface formed on model Ni-Cr based alloys exhibited good stability and low electrical resistance in single-cell fuel cell testing under simulated drive-cycle conditions. Recent results indicate that similar protective chromium nitride surfaces can be formed on less expensive Fe-Cr based alloys potentially capable of meeting DOE cost goals.

  11. Antibody array in a multiwell plate format for the sensitive and multiplexed detection of important plant pathogens.

    PubMed

    Charlermroj, Ratthaphol; Himananto, Orawan; Seepiban, Channarong; Kumpoosiri, Mallika; Warin, Nuchnard; Gajanandana, Oraprapai; Elliott, Christopher T; Karoonuthaisiri, Nitsara

    2014-07-15

    The global seed market is considered to be an important industry with a total value of $10,543 million US dollars in 2012. Because plant pathogens such as bacteria and viruses cause a significant economic loss to both producers and exporters, the seed export industry urgently requires rapid, sensitive, and inexpensive testing for the pathogens to prevent disease spreading worldwide. This study developed an antibody array in a multiwell plate format to simultaneously detect four crucial plant pathogens, namely, a bacterial fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), Chilli veinal mottle virus (ChiVMV, potyvirus), Watermelon silver mottle virus (WSMoV, tospovirus serogroup IV), and Melon yellow spot virus (MYSV, tospovirus). The capture antibodies specific to the pathogens were immobilized on each well at preassigned positions by an automatic microarrayer. The antibodies on the arrays specifically captured the corresponding pathogens present in the sample extracts. The presence of pathogens bound on the capture antibodies was subsequently detected by a cocktail of fluorescently conjugated secondary antibodies. The limits of detection of the developed antibody array for the detection of Aac, ChiVMV, WSMoV, and MYSV were 5 × 10(5) CFU/mL, 30 ng/mL, 1000 ng/mL, and 160 ng/mL, respectively, which were very similar to those of the conventional ELISA method. The antibody array in a multiwell plate format accurately detected plant pathogens in single and multiple detections. Moreover, this format enables easy handling of the assay at a higher speed of operation. PMID:24945525

  12. Inhibition of Candida albicans CC biofilms formation in polystyrene plate surfaces by biosurfactant produced by Trichosporon montevideense CLOA72.

    PubMed

    Monteiro, Andrea S; Miranda, Tatiana T; Lula, Ivana; Denadai, Ângelo M L; Sinisterra, Rubén D; Santoro, Marcelo M; Santos, Vera L

    2011-06-01

    This study evaluated the effects of glycolipid-type biosurfactant produced by Trichosporon montevideense CLOA72 in the formation of biofilms in polystyrene plate surfaces by Candida albicans CC isolated from the apical tooth canal. Biofilm formation was reduced up to 87.4% with use of biosurfactant at 16 mg/ml concentration. It has been suggested that the interaction with the cell or polystyrene plate surface could ultimately be responsible for these actions. Therefore, the interaction of C. albicans CC cells with the biosurfactant, as well as the corresponding thermodynamic parameters, have been determined by isothermal titration calorimetry and zeta potential measurements. This process is endothermic (((int)H°=+1284±5 cal/mg OD(600)) occurring with a high increase of entropy (T((int)S°=+10635 cal/mg OD(600)). The caloric energy rate data released during the titulation indicates saturation of the cell-biosurfactant at 1.28 mg/ml OD(600). Also, the zeta potential of the cell surface was monitored as a function of the biosurfactant concentration added to cell suspension showing partial neutralization of net surface charge, since the value of zeta potential ranged from -16 mV to -6 mV during the titration. The changes of cell surface characteristics can contribute to the inhibition of initial adherence of cells of C. albicans in surface. The CMC of the purified biosurfactant produced from T. montevideense CLOA72 is 2.2 mg/ml, as determined both by ITC dilution experiments and by surface tension measurements. This biomolecule did not presented any cytotoxic effect in HEK 293A cell line at concentrations of 0.25-1 mg/ml. This study suggests a possible application of the referred biosurfactant in inhibiting the formation of biofilms on plastic surfaces by C. albicans. PMID:21376544

  13. A Cell-based PDE4 Assay in 1536-well Plate format for High Throughput Screening

    PubMed Central

    Titus, Steven A.; Li, Xiao; Southall, Noel; Lu, Jianming; Inglese, James; Brasch, Michael; Austin, Christopher P.; Zheng, Wei

    2009-01-01

    The cyclic nucleotide phosphodiesterases (PDEs) are intracellular enzymes that catalyze the hydrolysis of 3', 5'-cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), to their corresponding 5'-nucleotide monophosphates. These enzymes play an important role in controlling cellular concentrations of cyclic nucleotides and thus regulate a variety of cellular signaling events. PDEs are emerging as drug targets for several diseases including asthma, cardiovascular disease, ADHD, Parkinson’s disease, and Alzheimer’s disease. Though biochemical assays with purified recombinant PDE enzymes and cAMP or cGMP substrate are commonly used for compound screening, cell-based assays would provide a better assessment of compound activity in a more physiological context. Here we report the development and validation of a new cell-based PDE4 assay using a constitutively active GPCR as a driving force for cAMP production and a cyclic nucleotide gated (CNG) cation channel as a biosensor in 1536-well plates. PMID:18591513

  14. Arabidopsis CSLD5 Functions in Cell Plate Formation in a Cell Cycle-Dependent Manner.

    PubMed

    Gu, Fangwei; Bringmann, Martin; Combs, Jonathon R; Yang, Jiyuan; Bergmann, Dominique C; Nielsen, Erik

    2016-07-01

    In plants, the presence of a load-bearing cell wall presents unique challenges during cell division. Unlike other eukaryotes, which undergo contractile cytokinesis upon completion of mitosis, plants instead synthesize and assemble a new dividing cell wall to separate newly formed daughter cells. Here, we mine transcriptome data from individual cell types in the Arabidopsis thaliana stomatal lineage and identify CSLD5, a member of the Cellulose Synthase Like-D family, as a cell wall biosynthesis enzyme uniquely enriched in rapidly dividing cell populations. We further show that CSLD5 is a direct target of SPEECHLESS, the master transcriptional regulator of these divisions during stomatal development. Using a combination of genetic analysis and in vivo localization of fluorescently tagged fusion proteins, we show that CSLD5 preferentially accumulates in dividing plant cells where it participates in the construction of newly forming cell plates. We show that CSLD5 is an unstable protein that is rapidly degraded upon completion of cell division and that the protein turnover characteristics of CSLD5 are altered in ccs52a2 mutants, indicating that CSLD5 turnover may be regulated by a cell cycle-associated E3-ubiquitin ligase, the anaphase-promoting complex. PMID:27354558

  15. Formation Process of Intermittent Molten Bridge Between Au-Plated Contacts at Super Low Breaking Velocity

    NASA Astrophysics Data System (ADS)

    Ren, Wanbin; Chang, Cheng; Chen, Yu

    2016-03-01

    This paper presents the molten bridge behaviors of Au-plated material at super low breaking velocity conditions by introducing our new designed test rig. The typical waveforms of the contact voltage and contact force during breaking are investigated under the load of 5-25 V/0.2-1 A and velocity of 25-150 nm/s. It is shown that the intermittent molten bridge is formed from the competition of multitude contact a-spots for current distribution and the solid-liquid mixing characteristics of a molten bridge. Also, it is proved that the bridge is not composed by the completed melted metal by using FEM thermal simulation and the voltage-temperature relation. The observed surface morphology reveals that the scattered and stacked melted regions are attributed to the intermittent bridge. Finally, the effects of breaking velocity and electrical load on bridge length and duration are also analyzed. supported by National Natural Science Foundation of China (Nos. 51007010 and 51377029)

  16. Early biofilm formation and the effects of antimicrobial agents on orthodontic bonding materials in a parallel plate flow chamber.

    PubMed

    Chin, Mervyn Y H; Busscher, Henk J; Evans, Robert; Noar, Joseph; Pratten, Jonathan

    2006-02-01

    Decalcification is a commonly recognized complication of orthodontic treatment with fixed appliances. A technology, based on a parallel plate flow chamber, was developed to investigate early biofilm formation of a strain of Streptococcus sanguis on the surface of four orthodontic bonding materials: glass ionomer cement (Ketac Cem), resin-modified glass ionomer cement (Fuji Ortho LC), chemically-cured composite resin (Concise) and light-cured composite resin (Transbond XT). S. sanguis was used as it is one of the primary colonizers of dental hard surfaces. Artificial saliva was supplied as a source of nutrients for the biofilms. The effects of two commercially available mouthrinses (i.e. a fluoride containing rinse and chlorhexidine) were evaluated. Initial colonization of the bacterium was assessed after 6 hours of growth by the percentage surface coverage (PSC) of the biofilm on the disc surfaces. There were statistically significant differences in bacterial accumulation between different bonding materials (P < 0.05), Concise being the least colonized and Transbond XT being the most colonized by S. sanguis biofilms. All materials pre-treated with 0.05 per cent sodium fluoride mouthrinse showed more than 50 per cent reduction in biofilm formation. The 0.2 per cent chlorhexidine gluconate mouthrinse caused significant reduction of biofilm formation on all materials except Ketac Cem. This in vitro study showed that the use of a chemically-cured composite resin (Concise) reduced early S. sanguis biofilm formation. Also, fluoride had a greater effect in reducing the PSC by S. sanguis biofilms than chlorhexidine. Rinsing with 0.05 per cent sodium fluoride prior to placement of orthodontic appliances is effective in reducing early biofilm formation. PMID:16373451

  17. Formation of Australian continental margin highlands driven by plate-mantle interaction

    NASA Astrophysics Data System (ADS)

    Müller, R. Dietmar; Flament, Nicolas; Matthews, Kara J.; Williams, Simon E.; Gurnis, Michael

    2016-05-01

    Passive margin highlands occur on most continents on Earth and play a critical role in the cycle of weathering, erosion, and atmospheric circulation. Yet, in contrast to the well-developed understanding of collisional mountain belts, such as the Alps and Himalayas, the origin of less elevated (1-2 km) passive margin highlands is still unknown. The eastern Australian highlands are a prime example of these plateaus, but compared to others they have a well-documented episodic uplift history spanning 120 million years. We use a series of mantle convection models to show that the time-dependent interaction of plate motion with mantle downwellings and upwellings accounts for the broad pattern of margin uplift phases. Initial dynamic uplift of 400-600 m from 120-80 Ma was driven by the eastward motion of eastern Australia's margin away from the sinking eastern Gondwana slab, followed by tectonic quiescence to about 60 Ma in the south (Snowy Mountains). Renewed uplift of ∼700 m in the Snowy Mountains is propelled by the gradual motion of the margin over the edge of the large Pacific mantle upwelling. In contrast the northernmost portion of the highlands records continuous uplift from 120 Ma to present-day totalling about 800 m. The northern highlands experienced a continuous history of dynamic uplift, first due to the end of subduction to the east of Australia, then due to moving over a large passive mantle upwelling. In contrast, the southern highlands started interacting with the edge of the large Pacific mantle upwelling ∼ 40- 50 million years later, resulting in a two-phase uplift history. Our results are in agreement with published uplift models derived from river profiles and the Cretaceous sediment influx into the Ceduna sub-basin offshore southeast Australia, reflecting the fundamental link between dynamic uplift, fluvial erosion and depositional pulses in basins distal to passive margin highlands.

  18. Thermochemical Constraints For the Formation Conditions of the Hydrothermal Alteration Mineralogy of Home Plate and Columbia Hills

    NASA Astrophysics Data System (ADS)

    Filiberto, J.; Schwenzer, S. P.

    2012-12-01

    Home Plate is a plateau in the Columbia Hills of Gusev Crater. It is dominated by igneous minerals (olivine, pyroxene, and magnetite) with small amounts of alteration minerals (hematite and nanophase oxides). Surrounding Home Plate are deposits containing diverse secondary mineral assemblages: Fe3+-sulfates deposits at Paso Robles, Dead Sea, Shredded, Arad, Tyrone, and Troy; Hematite-rich outcrops between Home Plate and Tyrone; SiO2-rich deposits possibly containing pyrite and/or marcasite at Fuzzy Smith; SiO2-rich, possibly opaline silica, deposits at Northern Valley, Eastern Valley, and Tyrone; and Mg-Fe-carbonate outcrops at Comanche in the Columbia Hills [1-4]. Here, we focus on using thermochemical modeling to understand the secondary alteration mineralogy at the Home Plate outcrop and surrounding Columbia Hills region in Gusev Crater. We use CHILLER [5] to evaluate mineral assemblages that are likely to form from the Martian Home Plate, Barn-Hill class rock Fastball in contact with a dilute fluid at various pressures, temperatures, and water-rock ratios. For details see [6]. In our models, hematite dominates the alteration assemblage at high W/R at 150°C, but is generally produced at W/R above 10. Goethite only forms at low temperature and W/R above 40 with a maximum around 100 and again around 100,000. Pyrite is produced at all temperatures but only at relatively high W/R. These results imply intermediate to high W/R and low to intermediate temperatures during alteration of the Home Plate region. Additional acidic brine, while not strictly excluded, is not required to form many of the observed phases. In contrast, the phyllosilicates recently invoked from orbital observations [4] indicate neutral to alkaline conditions - either accompanying the silica precipitation or as a separate event. For future exploration, our results emphasize that the observation of assemblages is critically important to understand mineral formation conditions and that minor phases

  19. IGF-I Signaling in Osterix-Expressing Cells Regulates Secondary Ossification Center Formation, Growth Plate Maturation, and Metaphyseal Formation During Postnatal Bone Development.

    PubMed

    Wang, Yongmei; Menendez, Alicia; Fong, Chak; ElAlieh, Hashem Z; Kubota, Takuo; Long, Roger; Bikle, Daniel D

    2015-12-01

    To investigate the role of IGF-I signaling in osterix (OSX)-expressing cells in the skeleton, we generated IGF-I receptor (IGF-IR) knockout mice ((OSX)IGF-IRKO) (floxed-IGF-IR mice × OSX promoter-driven GFP-labeled cre-recombinase [(OSX)GFPcre]), and monitored postnatal bone development. At day 2 after birth (P2), (OSX)GFP-cre was highly expressed in the osteoblasts in the bone surface of the metaphysis and in the prehypertrophic chondrocytes (PHCs) and inner layer of perichondral cells (IPCs). From P7, (OSX)GFP-cre was highly expressed in PHCs, IPCs, cartilage canals (CCs), and osteoblasts (OBs) in the epiphyseal secondary ossification center (SOC), but was only slightly expressed in the OBs in the metaphysis. Compared with the control mice, the IPC proliferation was decreased in the (OSX)IGF-IRKOs. In these mice, fewer IPCs invaded into the cartilage, resulting in delayed formation of the CC and SOC. Immunohistochemistry indicated a reduction of vessel number and lower expression of VEGF and ephrin B2 in the IPCs and SOC of (OSX)IGF-IRKOs. Quantitative real-time PCR revealed that the mRNA levels of the matrix degradation markers, MMP-9, 13 and 14, were decreased in the (OSX)IGF-IRKOs compared with the controls. The (OSX)IGF-IRKO also showed irregular morphology of the growth plate and less trabecular bone in the tibia and femur from P7 to 7 weeks, accompanied by decreased chondrocyte proliferation, altered chondrocyte differentiation, and decreased osteoblast differentiation. Our data indicate that during postnatal bone development, IGF-I signaling in OSX-expressing IPCs promotes IPC proliferation and cartilage matrix degradation and increases ephrin B2 production to stimulate vascular endothelial growth factor (VEGF) expression and vascularization. These processes are required for normal CC formation in the establishment of the SOC. Moreover, IGF-I signaling in the OSX-expressing PHC is required for growth plate maturation and osteoblast differentiation in

  20. Metamorphic sole formation and early plate interface rheology: Insights from Griggs apparatus experiments

    NASA Astrophysics Data System (ADS)

    Soret, Mathieu; Agard, Philippe; Dubacq, Benoît; Hirth, Greg; Yamato, Philippe; Ildefonse, Benoît; Prigent, Cécile

    2016-04-01

    800°C with confining pressure of 2 GPa. Another simple-shear experiment has been carried out at 800°C and 1 GPa with fined-grained natural garnet. With the aim of mimicking the early slab interface (between the metamorphic sole and banded peridotites at the base of the ophiolite), 2 simple-shear deformation experiments with 2 layers have been carried out at 800°C and confining pressure of 1 GPa. The bottom layer was made of hydrated basalt powder and the top layer was made of olivine. Fined-grained garnet-free amphibolite is significantly weaker than dunite but the appearance of harder minerals in the amphibolite (garnet and clinopyroxene) has major implications on its rheological evolution. These results allow liking field observations of strain localization at the interface to the metamorphic sole formation.

  1. A kinematic model for the formation of the Siletz terrane by capture of coherent fragments of the Farallon and Resurrection plates (Invited)

    NASA Astrophysics Data System (ADS)

    Wilson, D. S.; McCrory, P. A.

    2010-12-01

    The details of the formation of the mostly Eocene basaltic Siletz terrane in the coast ranges of Oregon and Washington have remained enigmatic. Early models [e.g. Duncan, 1982 JGR], noting younger ages for basalts and overlying foramifera in the center of the terrane near the Columbia River and older ages to the north and south, called for an interpretation of a captured fossil spreading ridge between the Kula and Farallon plates. However, later work showed two problems with this simple model [Wells et al., 1984 Tectonics]. First, the difference between old and young ages was larger than predicted by the relatively fast spreading rate. Second, the presence of proximal continental sediments interbedded with some of the older basalts conflicted with the large amounts of convergence predicted by the generally used models for motion of the Kula and Farallon plates relative to North America. The recent suggestion that an additional oceanic plate, the Resurrection plate, was present between the Kula and Farallon plates and subducting beneath eastern Alaska and western Canada during the early Cenozoic [Haeussler et al., 2003 GSAB] permits important revisions to the interpretation of regional tectonic history. We propose a model in which the older (~55 Ma) parts of the Siletz terrane formed at the Resurrection-Farallon ridge, not far offshore from the Klamath Mountains. Proximity to the Yellowstone hotspot could have generated thick oceanic crust in a setting analogous to Iceland. When the Juan de Fuca (Vancouver) plate separated from the Farallon plate at ~52 Ma, we propose that a small Siletz plate also separated from the northern Juan de Fuca plate, eventually to be captured in the Oregon coast range. A fragment of the Resurrection plate may have separated later (~48 Ma), eventually captured in the Washington coast range and constituting the southward-younging part of the terrane. Cessation of motion of these fragments relative to adjacent parts of North America may

  2. Study on multiple ring-like vortex formation and small vortex generation in late flow transition on a flat plate

    NASA Astrophysics Data System (ADS)

    Liu, Chaoqun; Chen, Lin; Lu, Ping; Liu, Xiaobing

    2013-02-01

    A high-order direct numerical simulation (DNS) of flow transition over a flat plate at a free stream Mach number 0.5 has been carried out. During the simulation, we cannot find, according to the classical theory of boundary layer transition, the "hairpin vortex breakdown to smaller structures" in the last stage of flow transition on a flat plate. However, we did discover the so-called spikes as a result of a multibridge or multiring formation. This indicated a large and stable vortex structure which can travel for a long distance. We believe that this is a result of ring heads that are located in an inviscid region. These heads of the "turbulence spot" never seem to break down and persist as a stable structure. In addition, we discovered that the U-shaped vortex is a part of an existing coherent structure instead of a newly generated one. The U-shaped vortex also provides an additional channel to transfer vorticity to the ring from the wall. During travel, the leading primary ring in the front of the spot is sloped and skewed, causing disappearance of the second sweep. As a consequence, no energy is brought down to the lower boundary layer near the vortex ring head of the spot. Thus, the small length scale structures become damped and the existing U-shaped vortex structure becomes distinguishable. So, the question is where do the turbulent small length scale vortices come from? We will address this with a new theory which states that all of small length scales (turbulence) are generated by high-shear (HS) layers rather than being produced by "vortex breakdown." The new DNS shows that the HS layers are produced by strong positive spikes surrounded by low-speed fluids and by the interaction between the secondary and higher-level vortices and the wall surface especially near the ring neck. This multiple ring-like vortex generation also follows the first Helmholtz vortex conservation law. Furthermore, the Λ-shaped vortex is formed and rolling up, and the Λ-vortex is

  3. Fuel swelling and interaction layer formation in the SELENIUM Si and ZrN coated U(Mo) dispersion fuel plates irradiated at high power in BR2

    NASA Astrophysics Data System (ADS)

    Leenaers, A.; Van den Berghe, S.; Koonen, E.; Kuzminov, V.; Detavernier, C.

    2015-03-01

    In the framework of the SELENIUM project two full size flat fuel plates were produced with respectively Si and ZrN coated U(Mo) particles and irradiated in the BR2 reactor at SCK•CEN. Non-destructive analysis of the plates showed that the fuel swelling profiles of both SELENIUM plates were very similar to each other and none of the plates showed signs of pillowing or excessive swelling at the end of irradiation at the highest power position (local maximum 70% 235U). The microstructural analysis showed that the Si coated fuel has less interaction phase formation at low burn-up but at the highest burn-ups, defects start to develop on the IL-matrix interface. The ZrN coated fuel, shows a virtual absence of reaction between the U(Mo) and the Al, up to high fission densities after which the interaction layer formation starts and defects develop in the matrix near the U(Mo) particles. It was found and is confirmed by the SELENIUM (Surface Engineering of Low ENrIched Uranium-Molybdenum) experiment that there are two phenomena at play that need to be controlled: the formation of an interaction layer and swelling of the fuel. As the interaction layer formation occurs at the U(Mo)-matrix interface, applying a diffusion barrier (coating) at that interface should prevent the interaction between U(Mo) and the matrix. The U(Mo) swelling, observed to proceed at an accelerating rate with respect to fission density accumulation, is governed by linear solid state swelling and fission gas bubble swelling due to recrystallization of the fuel. The examination of the SELENIUM fuel plates clearly show that for the U(Mo) dispersion fuel to be qualified, the swelling rate at high burn-up needs to be reduced.

  4. Current and potential distributions on positive plates with conductive Pb 3O 4 and BaPbO 3 in their formation and discharge

    NASA Astrophysics Data System (ADS)

    Guo, Yonglang; Liu, Huan

    The positive plates with conductive materials, Pb 3O 4 and BaPbO 3, in automotive lead-acid batteries were investigated by measuring their current and potential distributions in the course of formation and discharge. It is found that these two conductive materials, especially Pb 3O 4, enhance the formation in the initial stage greatly and that they make the current and potential distributions more uniform. In the discharge, the addition of Pb 3O 4 increases the capacity of the positive plate, but it is unfavorable to the paste curing and causes poor contact between active mass (AM) particles so that the polarization increases greatly at 3 C discharge rate. The BaPbO 3 additive improves not only the formation but also the discharge performance because of its stability in acidic media and at high polarization. The violent charge at high polarization around the plates in the initial formation can lead to poor AM contact and high polarization resistance.

  5. Microtiter plate-based antibody microarrays for bacteria and toxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has focused on the development of rapid biosensor-based, high-throughput, and multiplexed detection of pathogenic bacteria in foods. Specifically, antibody microarrays in 96-well microtiter plates have been generated for the purpose of selective detection of Shiga toxin-producing E. coli (...

  6. Development of resazurin-based assay in 384-well format for high throughput whole cell screening of Trypanosoma brucei rhodesiense strain STIB 900 for the identification of potential anti-trypanosomal agents.

    PubMed

    Lim, Kah Tee; Zahari, Zuriati; Amanah, Azimah; Zainuddin, Zafarina; Adenan, Mohd Ilham

    2016-03-01

    To accelerate the discovery of novel leads for the treatment of Human African Trypanosomiasis (HAT), it is necessary to have a simple, robust and cost-effective assay to identify positive hits by high throughput whole cell screening. Most of the fluorescence assay was made in black plate however in this study the HTS assay developed in 384-well format using clear plate and black plate, for comparison. The HTS assay developed is simple, sensitive, reliable and reproducible in both types of plates. Assay robustness and reproducibility were determined under the optimized conditions in 384-well plate was well tolerated in the HTS assay, including percentage of coefficient of variation (% CV) of 4.68% and 4.74% in clear and black 384-well plate, signal-to-background ratio (S/B) of 12.75 in clear 384-well plate and 12.07 in black 384-well plate, Z' factor of 0.79 and 0.82 in clear 384-well plate and black 384-well plate, respectively and final concentration of 0.30% dimethylsulfoxide (DMSO) in both types of plate. Drug sensitivity was found to be comparable to the reported anti-trypanosomal assay in 96-well format. The reproducibility and sensitivity of this assay make it compliant to automated liquid handler use in HTS applications. PMID:26772786

  7. Studies of the current and potential distributions on lead-acid batteries. III. Formation of the single-side pasted automotive positive plate

    NASA Astrophysics Data System (ADS)

    Guo, Yonglang; Zhou, Xuechou; Huang, Mingxiang; Liu, Huiyong

    The formation processes of the single-side pasted automotive positive plate have been studied by an in situ electrochemical scan technique. On the pasted side of the positive plate, its polarization is very high and its charge current is very low at the beginning of the formation, compared with those on the non-pasted side. Then, their difference becomes smaller and smaller with the formation. Moreover, the distributions of the current density and the polarization resistance are quite uneven on the pasted side at the initial stage of the formation. The lowest current density and the highest polarization resistance are located in the middle. At the later stage, the charge current on the pasted side becomes a little higher, but its charge amount is still lower than that on the non-pasted side. Although the conductivity of PbO 2 zones is very good, the violent charge at the high polarization will lead to the increase of the contact resistance between the active mass particles at the beginning of the formation.

  8. Innovative design of composite structures: The use of curvilinear fiber format to improve buckling resistance of composite plates with central circular holes

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Lee, H. H.

    1990-01-01

    The gains in buckling performance are explored that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point. The particular situation studied is a simply supported square plate with a centrally located hole loaded in compression. By using both a sensitivity analysis and a gradient-search technique, fiber orientation in a number of regions of the plate are selected so as to increase the buckling load relative to baseline straightline designs. The sensitivity analysis is used to determine which regions of the plate have the most influence on buckling load, and the gradient search is used to find the design that is believed to represent the absolute maximum buckling load for the conditions prescribed. Convergence studies and sensitivity of the final design are discussed. By examining the stress resultant contours, it is shown how the curvilinear fibers move the load away from the unsupported hole region of the plate to the supported edges, thus increasing the buckling capacity. The tensile capacity of the improved buckling design is investigated, and it is shown that both tensile capacity and buckling capacity can be improved with the curvilinear fiber concept.

  9. The effect of aluminium on the formation of orthorhombic plates in the Nb-Ti-Al ternary system

    SciTech Connect

    Hoelzer, D.T.; Ebrahimi, F.

    1997-12-31

    Transmission electron microscopy (TEM) was used to study the phase transformation in an alloy containing 33Ti-27Nb-40Al (at.%). The results showed that the BCC {beta} phase was present at high temperatures, which ordered to the B 2 phase, and finally was martensitically transformed to a plate microstructure during quenching. The plates possessed an orthorhombic crystal structure and a substructure that consisted of both coarse and fine anti-phase domain boundaries (APDBs). These APDBs were consistent with three sublattices that were derived from the inherited site occupancy of the B2 matrix and a subsequent disorder to order transition. The CBED analysis of the plates showed that the site occupancy of this orthorhombic phase was consistent with the Al{sub 2}NbTi stoichiometry with Al occupying the 8g, Nb the 4cl, and Ti the 4c2 Wyckoff sites.

  10. Conditional Deletion of Indian Hedgehog in Limb Mesenchyme Results in Complete Loss of Growth Plate Formation but Allows Mature Osteoblast Differentiation.

    PubMed

    Amano, Katsuhiko; Densmore, Michael J; Lanske, Beate

    2015-12-01

    Indian hedgehog (Ihh) is widely recognized as an essential factor for proper skeletal development. Previous in vivo studies using mutant Ihh mouse models were limited by perinatal lethality or carried out after a growth plate formed. Thus the important role of Ihh in mesenchymal cell differentiation has not been investigated. In this study, we established Prx1-Cre;Ihh(fl/fl) mice to ablate Ihh specifically in limb mesenchyme to allow us to observe the phenotype continuously from prenatal development to 3 weeks of age. Mutant mice displayed severe limb abnormalities characterized by complete lack of secondary ossification center and growth plate, indicating an essential role for Ihh in the development of these structures. Interestingly, we discovered that osteoblast differentiation and bone formation could occur in conditions of deficient Ihh. This is a novel finding that has not been observed because of the early lethality of previous Ihh mutants. Mature osteoblasts expressing osteocalcin could be detected in the center of mutant bones at postnatal day 10 (P10). Osteoclasts and blood vessel formation were also present, suggesting active bone remodeling. Histomorphometric analyses show a significant increase in osteoclast number with no major changes in bone formation rate at 3 weeks of age. Mutant long bones in the limbs were deformed, with cortices comprised of irregular woven bone. Also, there was a marked decrease in gene expression of osteoblastic and osteocytic markers. Moreover, mutant long bones displayed bone dysplasia in which we observed increased osteoclast activity and partially reduced osteoblastic and osteocytic differentiation that lead ultimately to loss of bone structures at 3 weeks of age. In summary, our data show for the first time, the presence of mature osteoblasts in long bones of the limbs despite the complete loss of growth plate formation due to Ihh deficiency. These data indicate an important function for Ihh in regulating limb

  11. SNW1 is a critical regulator of spatial BMP activity, neural plate border formation, and neural crest specification in vertebrate embryos.

    PubMed

    Wu, Mary Y; Ramel, Marie-Christine; Howell, Michael; Hill, Caroline S

    2011-01-01

    Bone morphogenetic protein (BMP) gradients provide positional information to direct cell fate specification, such as patterning of the vertebrate ectoderm into neural, neural crest, and epidermal tissues, with precise borders segregating these domains. However, little is known about how BMP activity is regulated spatially and temporally during vertebrate development to contribute to embryonic patterning, and more specifically to neural crest formation. Through a large-scale in vivo functional screen in Xenopus for neural crest fate, we identified an essential regulator of BMP activity, SNW1. SNW1 is a nuclear protein known to regulate gene expression. Using antisense morpholinos to deplete SNW1 protein in both Xenopus and zebrafish embryos, we demonstrate that dorsally expressed SNW1 is required for neural crest specification, and this is independent of mesoderm formation and gastrulation morphogenetic movements. By exploiting a combination of immunostaining for phosphorylated Smad1 in Xenopus embryos and a BMP-dependent reporter transgenic zebrafish line, we show that SNW1 regulates a specific domain of BMP activity in the dorsal ectoderm at the neural plate border at post-gastrula stages. We use double in situ hybridizations and immunofluorescence to show how this domain of BMP activity is spatially positioned relative to the neural crest domain and that of SNW1 expression. Further in vivo and in vitro assays using cell culture and tissue explants allow us to conclude that SNW1 acts upstream of the BMP receptors. Finally, we show that the requirement of SNW1 for neural crest specification is through its ability to regulate BMP activity, as we demonstrate that targeted overexpression of BMP to the neural plate border is sufficient to restore neural crest formation in Xenopus SNW1 morphants. We conclude that through its ability to regulate a specific domain of BMP activity in the vertebrate embryo, SNW1 is a critical regulator of neural plate border formation and

  12. Optimization of Salmonella Typhi biofilm assay on polypropylene microtiter plates using response surface methodology.

    PubMed

    Ganjali Dashti, M; Abdeshahian, P; Sudesh, K; Phua, K K

    2016-04-01

    The objective of this study was to develop an optimized assay for Salmonella Typhi biofilm that mimics the environment of the gallbladder as an experimental model for chronic typhoid fever. Multi-factorial assays are difficult to optimize using traditional one-factor-at-a-time optimization methods. Response surface methodology (RSM) was used to optimize six key variables involved in S. Typhi biofilm formation on cholesterol-coated polypropylene 96-well microtiter plates. The results showed that bile (1.22%), glucose (2%), cholesterol (0.05%) and potassium chloride (0.25%) were critical factors affecting the amount of biofilm produced, but agitation (275 rpm) and sodium chloride (0.5%) had antagonistic effects on each other. Under these optimum conditions the maximum OD reading for biofilm formation was 3.4 (λ600 nm), and the coefficients of variation for intra-plate and inter-plate assays were 3% (n = 20) and 5% (n = 8), respectively. These results showed that RSM is an effective approach for biofilm assay optimization. PMID:26963754

  13. Analysis of the effect of transverse power distribution in an involute fuel plate with and without oxide film formation.

    SciTech Connect

    Smith, R. S.

    1998-10-27

    Existing thermal hydraulics computer codes can account for variations in power and temperature in the axial and thickness directions but variations across the width of the plate cannot be accounted for. In the case of fuel plates in an annular core this can lead to significant errors which are accentuated by the presence of an oxide layer that builds up on the aluminum cladding with burnup. This paper uses a three dimensional SINDA model to account for the transverse variations in power. The effect of oxide thickness on these differences is studied in detail. Power distribution and fuel conductivity are also considered. The lower temperatures predicted with the SINDA model result in a greater margin to clad and fuel damage.

  14. An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS

    PubMed Central

    Wang, Wan; Qin, Suzi; Li, Linsen; Chen, Xiaohua; Wang, Qunjie; Wei, Junfu

    2015-01-01

    A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile phase of acetonitrile/water (70 : 30, v/v) and detected by LC-MS/MS coupled with electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curve ranged from 10 to 2500 ng/mL with sufficient linearity (r2 = 0.9999). The recoveries were in the range of 99.38% to 103.21% with RSD less than 6%. The limit of detection is 3 ng/mL. PMID:25873969

  15. Validation of a sensitive and automated 96-well solid-phase extraction liquid chromatography-tandem mass spectrometry method for the determination of desloratadine and 3-hydroxydesloratadine in human plasma.

    PubMed

    Yang, Liyu; Clement, Robert P; Kantesaria, Bhavna; Reyderman, Larisa; Beaudry, Francis; Grandmaison, Charles; Di Donato, Lorella; Masse, Robert; Rudewicz, Patrick J

    2003-07-25

    To support clinical development, a liquid chromatographic-tandem mass spectrometric (LC-MS-MS) method was developed and validated for the determination of desloratadine (descarboethoxyloratadine) and 3-OH desloratadine (3-hydroxydescarboethoxyloratadine) concentrations in human plasma. The method consisted of automated 96-well solid-phase extraction for sample preparation and liquid chromatography/turbo ionspray tandem mass spectrometry for analysis. [2H(4)]Desloratadine and [2H(4)]3-OH desloratadine were used as internal standards (I.S.). A quadratic regression (weighted 1/concentration(2)) gave the best fit for calibration curves over the concentration range of 25-10000 pg/ml for both desloratadine and 3-OH desloratadine. There was no interference from endogenous components in the blank plasma tested. The accuracy (%bias) at the lower limit of quantitation (LLOQ) was -12.8 and +3.4% for desloratadine and 3-OH desloratadine, respectively. The precision (%CV) for samples at the LLOQ was 15.1 and 10.9% for desloratadine and 3-OH desloratadine, respectively. For quality control samples at 75, 1000 and 7500 pg/ml, the between run %CV was

  16. Formation of {beta}-nickel hydroxide plate-like structures under mild conditions and their optical properties

    SciTech Connect

    Moura, A.P. de; Lima, R.C.; Paris, E.C.; Li, M.S.; Varela, J.A.; Longo, E.

    2011-10-15

    Nanostructural {beta}-nickel hydroxide ({beta}-Ni(OH){sub 2}) plates were prepared using the microwave-hydrothermal (MH) method at a low temperature and short reaction times. An ammonia solution was employed as the coordinating agent, which reacts with [Ni(H{sub 2}O){sub 6}]{sup 2+} to control the growth of {beta}-Ni(OH){sub 2} nuclei. A trigonal {beta}-Ni(OH){sub 2} single phase was observed by X-ray diffraction (XRD) analyses, and the crystal cell was constructed with structural parameters and atomic coordinates obtained from Rietveld refinement. Field emission scanning electron microscopy (FE-SEM) images revealed that the samples consisted of hexagonal-shaped nanoplates with a different particle size distribution. Broad absorption bands assigned as transitions of Ni{sup 2+} in oxygen octahedral sites were revealed by UV-vis spectra. Photoluminescence (PL) properties observed with a maximum peak centered in the blue-green region were attributed to different defects, which were produced during the nucleation process. We present a growth process scheme of the {beta}-Ni(OH){sub 2} nanoplates. - Graphical abstract: Nanostructural {beta}-Ni(OH){sub 2} crystalline powders were prepared by rapid microwave-hydrothermal method for 1, 8 and 32 min. The hexagonal-shaped nanoplates obtained presented PL emission in the blue-green region and each decomposed component represents a different type of electronic transition, which can be linked to the structural arrangement or surface defects. Highlights: > Ammonia solution to control the growth of {beta}-Ni(OH){sub 2} nuclei. > Regular plates-shape related to crystallization-dissolution-recrystallization. > The surface states and lattice defects generated in growth mechanism of crystals. > Different defects produced in the growth process responsible by photoluminescence. > Each component of photoluminescence curve linked to structural arrangement or surface defects.

  17. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  18. On the actual variety of plate dynamical mechanisms and how mantle evolution affected them through time, from core formation to the Indian collision

    NASA Astrophysics Data System (ADS)

    Osmaston, Miles

    2010-05-01

    If horizontal plate motions were driven by thermal convection of the mantle, they would display the action of slow-to-change body forces. Yet rapid changes of spreading rate and direction, and ridge jumps, are well-documented for the past 130Ma. Also convection cannot readily cause rotations of a plate (e.g. Africa) about a pole within the plate or near it. And plate motions, especially that of India, scarcely fit a convective pattern. To address these problems we look first at mantle motivation at both ends of earth history, beginning with core formation. I then introduce 3 important properties of mantle materials, whose neglect by mantle modellers has surely impaired the value of their work, but whose recognition illuminates the present plate dynamical situation and provides the Earth with a heat engine that is not thermal convection. Finally I sketch the intervening changes in behaviour over time, the sharpest of which brought about the rise of atmospheric oxygen at ~2.25Ga. Core formation. As the very high specific angular momentum of mean planetary material (>105-fold relative to solar) can only be achieved if the planets were wholly accreted in presence of the nebula [1], the iron percolation model is ruled out, because it takes too long. This validates the A.E.Ringwood model (1960-1978) involving nebular H reaction with erupting FeO. The iron then loads the downgoing limb of what is then not a truly thermal convection system. Huge volumes of reaction water were produced, giving the early Earth a wet mantle, a (diminishing) feature that we'll see has constrained mantle behaviour ever since. Plate dynamics since 150Ma. Multiple plate dynamical evidence [2], which will be rapidly re-presented here, shows that currently (a) the Earth has a 2-layer mantle system with a boundary at ~660km and (b) that most cratons have tectospheric keels that reach right to that boundary, or nearly so. The argument is the simple and persuasive one (even to seismologists) of mantle

  19. The Formation of the Betic-Alboran System in the Iberia-Africa Plate Boundary: a New Kinematic Evolution Model

    NASA Astrophysics Data System (ADS)

    Fernandez, M.; Verges, J.

    2013-12-01

    Several geodynamic models have been proposed so far to explain the origin and evolution of the Betic-Rif arcuate orogeny and the inner Alboran back-arc basin. Many of these models propose that the Alboran domain underwent a large westward drifting (> 600 km) driven by a subduction rollback, eventually resulting in a symmetric configuration in both the S-Iberia and N-African margins. Alternative models with a more autochthonous component assume that the Oligocene subduction trench extended continuously along the whole Iberian Mediterranean margin from the present Gibraltar arc to the Alps. Common assumptions to all these models are: i) the initial time is about 35 Ma (Eocene-Oligocene), ii) the plate boundary is continuous and non-segmented, iii) the initial subduction polarity is NW-dipping, and iv) the slab must underwent a twisted roll-back to explain the present position of the HP-LT metamorphic rocks involving slab rupture, detachment and tearing. Recent geophysical models based on seismic data, tomography and potential fields draw an arcuate mantle slab restricted below the Betic-Rif orogen, dipping towards the E below the Gibraltar Strait and turning to the SE and S beneath the Betics. In addition, the crust beneath the northern Moroccan margin shows a smooth thinning toward the Alboran basin whereas the southern Iberian margin presents a much sharper thinning. These findings put severe limitations to some of the proposed models and open room for new kinematic proposals. One of the most recent models is based on the following considerations: i) the reconstruction starts in Late Cretaceous times at the onset of northern Africa convergence, ii) displacements and initial configuration are based on plate reconstructions of the Atlantic-Ligurian-Tethys region, and iii) the model assumes that subduction polarity changes laterally from NW-dipping in the Algerian segment to SE-dipping in the Betic-Rif segment. Apart from its simplicity, this model requires a moderate

  20. Arabidopsis CSLD5 Functions in Cell Plate Formation in a Cell Cycle-Dependent Manner[OPEN

    PubMed Central

    2016-01-01

    In plants, the presence of a load-bearing cell wall presents unique challenges during cell division. Unlike other eukaryotes, which undergo contractile cytokinesis upon completion of mitosis, plants instead synthesize and assemble a new dividing cell wall to separate newly formed daughter cells. Here, we mine transcriptome data from individual cell types in the Arabidopsis thaliana stomatal lineage and identify CSLD5, a member of the Cellulose Synthase Like-D family, as a cell wall biosynthesis enzyme uniquely enriched in rapidly dividing cell populations. We further show that CSLD5 is a direct target of SPEECHLESS, the master transcriptional regulator of these divisions during stomatal development. Using a combination of genetic analysis and in vivo localization of fluorescently tagged fusion proteins, we show that CSLD5 preferentially accumulates in dividing plant cells where it participates in the construction of newly forming cell plates. We show that CSLD5 is an unstable protein that is rapidly degraded upon completion of cell division and that the protein turnover characteristics of CSLD5 are altered in ccs52a2 mutants, indicating that CSLD5 turnover may be regulated by a cell cycle-associated E3-ubiquitin ligase, the anaphase-promoting complex. PMID:27354558

  1. The formation of a hybrid structure from tungsten selenide and oxide plates for a hydrogen-evolution electrocatalyst

    NASA Astrophysics Data System (ADS)

    Fominski, V. Yu.; Grigoriev, S. N.; Romanov, R. I.; Volosova, M. A.; Grunin, A. I.; Teterina, G. D.

    2016-06-01

    It has been found that the pulsed laser deposition of a thin tungsten selenide film, followed by thermal treatment at 550°C in an Ar + O2 mixture of gases, results in the formation of a hybrid structure that is made up of ultrathin WSe2 and WO3- y platelets. The structural and size characteristics of the nanoplatelets deposited on microcrystalline graphite provide the effective hydrogen evolution reaction in a 0.5 M H2SO4 solution, with the cathode current made about seven times higher at a potential of-100 mV and the slope of the Tafel characteristic reduced from 340 to 90 mV/dec.

  2. The Relationships of Plate Triple-junction Evolution, Trench-Arc Lengthening, Boninite Generation, and SSZ Spreading Centers to Ophiolite Formation, High-Temperature Soles, and Obduction

    NASA Astrophysics Data System (ADS)

    Casey, J.; Dewey, J. F.

    2014-12-01

    A review of modern-day island arcs, the locations of boninite eruptions, the conditions necessary for hot upper plate spreading, potential regions of shallow SSZ flux melting, and formation of high-temperature metamorphic soles along the subduction channels indicates that many future, recent and ancient large slab ophiolite obduction events can be related to triple junctions that link SSZ spreading centers with trenches. These subduction systems leading to large slab ophiolite obduction events typically face stable continental margins. Boninitic melt generation requires hydrous melting of refractory mantle peridotite under an extremely high-temperature and low-pressure condition. This condition is generally explained by the addition of slab-derived fluids into a hot young oceanic mantle asthenosphere and lithosphere, which previously likely experienced melt extraction. Metamorphic conditions associated with metamorphic soles formation likewise require a hot upper plate lithosphere that, based on sole protolith, geochronologic and thermochronologic data, rapidly heats and then refrigerates and decompresses MORB-OIB type subcreted lithosphere. Numerous examples of present-day and recent SSZ spreading centers that link with two trenches or a trench and transform are considered ideal sites for ophiolite and boninite generation. The SZZ fore-arc spreading centers that link to the trench lines and triple junctions at the front of the arc may also continue towards the arc and back arc, creating no distinction between fore-arc and back-arc spreading episodes or to the transform-linked spreading centers from fore-arc to back arc. These SSZ spreading centers, which may be transiently produced during arc evolution over short or protracted time periods, act to open gaps in the arc massif and lengthen the trench, fore-arc and the arc crustal massif. They lead to an evolving arc magmatic front that begins in the infant fore-arc where ophiolite generation occurs at, near or in

  3. Formation and metasomatism of continental lithospheric mantle in intra-plate and subduction-related tectonic settings

    NASA Astrophysics Data System (ADS)

    Ionov, Dmitri

    2010-05-01

    , major and trace element and isotope compositions of fertile lherzolites and thus cannot provide viable alternatives to the concept of melt extraction from pristine mantle as the major mechanism of CLM formation. Published data on xenoliths from andesitic volcanoes and on supra-subduction oceanic peridotites [4] show that the most common rocks in mantle wedge lithosphere are highly refractory harzburgites characterized by a combination of variable but generally high modal opx (18-30%) with very low modal cpx (1.5-3%). At a given olivine (or MgO) content, they have higher opx and silica, and lower cpx, Al and Ca contents than normal refractory peridotite xenoliths in continental basalts; the Mg-Si and Al-Si trends in those rocks resemble those in cratonic peridotites. These features may indicate either fluid fluxing during melting in the mantle wedge or selective post-melting metasomatic enrichments in silica to transform some olivine to opx. High oxygen fugacities and radiogenic Os-isotope compositions in those rocks may be related to enrichments by slab-derived fluids, but these features are not always coupled with trace element enrichments or patterns commonly attributed to "subduction zone metasomatism" deduced from studies of arc volcanic rocks and experiments. The valuable insights provided by experimental work and xenolith case studies are difficult to apply to many natural peridotite series because late-stage processes commonly overlap the evidence for initial melting. References: [1] Herzberg C., J. Petrol. 45: 2507 (2004). [2] Ionov D. & Sobolev A., GCA 72 (S1): A410 (2008). [3] Ionov D., Contrib. Miner. Petrol. (2007) [4] Ionov D., J. Petrol. doi: 10.1093/petrology/egp090 (2010)

  4. Broken formations, melanges and olistostromes in Puerto Plata area (Northern Dominican Republic) as a record of subduction and collisional processes between the Caribbean and North-American plates

    NASA Astrophysics Data System (ADS)

    Hernaiz Huerta, Pedro Pablo; Valera Fernando, Pérez; de Los Santos Manuel, Abad; Jacques, Monthel; de Neira Alberto, Díaz

    2010-05-01

    The Northern Cordillera of the Dominican Republic records the (oblique) subduction and collisional processes occurred between the Caribbean and North-American plates during Upper Cretaceous to Lower Paleogene times. The boundary between these two plates can be traced within this range disrupted by an Upper Paleogene to present intense left-lateral strike-slip tectonism, onset after collision. In the western part of the range this boundary might be defined by the Camu fault. In the coastal area of Puerto Plata, located on the northern block of the Camu fault, basement rocks belonging to the subducting plate (the Puerto Plata Basement Complex) and several related units probably formed in an accretionary prism, preserve in a large (300 km2) outcrop of chaotic formations presumably formed (and exhumed) during collision. They include from broken formations and tectonic melanges to olistostromes and other coeval sedimentary deposits. The Puerto Plata Basement Complex (PPBC) consists of highly faulted and dismembered blocks formed by discontinuous but sometimes coherent outcrops of serpentinized or massive peridotite, pods of ultramafic cumulates, massive or banded gabbros and Los Caños Fm, a thick sequence of gross bedded volcaniclastic material with interbedded basaltic (sometimes pillowed) or andesitic flows. All these rocks bear low grade metamorphism and lack a general deformation fabric apart from occasional transformation to mylonites due to localized shearing. The PPBC has been interpreted as a fragment of oceanic crust, belonging to the subducting (North-American) slab that has been exhumed as a tectonic melange or a broken complex. The Imbert Fm, of Palaeocene-Eocene age, is formed by a well bedded succession of white very fine grained porcelaneous tuffs, with eventual intercalations of cherts, limestones and marls that, towards the lower part, is interbedded with volcanic-derived graywackes and limolites, and more occasionally, thick beds of conglomerates and

  5. The formation of nano-size SiO2 thin film on an aluminum plate with hexamethyldisilazane (HMDSA) and hexamethyldisiloxane (HMDSO)

    NASA Astrophysics Data System (ADS)

    Ma, H. K.; Zhao, E.; Yeh, C. L.; Chung, K. M.

    2003-02-01

    This study is using HMDSA (C6H19NSi2) or HMDSO (C6H18OSi2) vapor into C3H8/air premixed flames to form SiO2 thin film on the surface of an aluminum plate. With the addition of HMDSO or HMDSA to premixed flames, an orange secondary flame or a flame brush appeared and was contributed to the formation of SiO2 particles. Based upon the EDS, XPS and FTIR analysis, it is believed that the synthesized products consist of mainly SiO2 and a small amount of SiO. The pure SiO2 crystal structure, was proved by XRD analysis, which may form from the SiO2 amorphous structure after high temperature (1300°C) thermal treatment. The nano-size SiO2 particles, which ranged from 2.5-25 nm, are proved by analysis of the BET and TEM. A 2-D CFD-RC code with 12 reduced chemical reaction mechanism, based upon the SIMPLER procedure, was successfully employed to predict the flame temperature and both of the SiO2 and SiO concentration profiles. Compared with the experimental results, the calculated temperature profiles in the post-flame region are in good agreement with the measured data and observation phenomena.

  6. Miniaturized plate readers for low-cost, high-throughput phenotypic screening.

    PubMed

    Jensen, Paul A; Dougherty, Bonnie V; Moutinho, Thomas J; Papin, Jason A

    2015-02-01

    We present a miniaturized plate reader for measuring optical density in 96-well plates. Our standalone reader fits in most incubators, environmental chambers, or biological containment suites, allowing users to leverage their existing laboratory infrastructure. The device contains no moving parts, allowing an entire 96-well plate to be read several times per second. We demonstrate how the fast sampling rate allows our reader to detect small changes in optical density, even when the device is placed in a shaking incubator. A wireless communication module allows remote monitoring of multiple devices in real time. These features allow easy assembly of multiple readers to create a scalable, accurate solution for high-throughput phenotypic screening. PMID:25366331

  7. Miniaturized Plate Readers for Low-Cost, High-Throughput Phenotypic Screening

    PubMed Central

    Jensen, Paul A.; Dougherty, Bonnie V.; Moutinho, Thomas J.

    2015-01-01

    We present a miniaturized plate reader for measuring optical density in 96-well plates. Our standalone reader fits in most incubators, environmental chambers, or biological containment suites, allowing users to leverage their existing laboratory infrastructure. The device contains no moving parts, allowing an entire 96-well plate to be read several times per second. We demonstrate how the fast sampling rate allows our reader to detect small changes in optical density, even when the device is placed in a shaking incubator. A wireless communication module allows remote monitoring of multiple devices in real time. These features allow easy assembly of multiple readers to create a scalable, accurate solution for high-throughput phenotypic screening. PMID:25366331

  8. Use of a Fluorometric Imaging Plate Reader in high-throughput screening

    NASA Astrophysics Data System (ADS)

    Groebe, Duncan R.; Gopalakrishnan, Sujatha; Hahn, Holly; Warrior, Usha; Traphagen, Linda; Burns, David J.

    1999-04-01

    High-throughput screening (HTS) efforts at Abbott Laboratories have been greatly facilitated by the use of a Fluorometric Imaging Plate Reader. The FLIPR consists of an incubated cabinet with integrated 96-channel pipettor and fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorometer. An argon laser is used to excite fluorophores in a 96-well microtiter plate and the emitted fluorescence is imaged by a cooled CCD camera. The image data is downloaded from the camera and processed to average the signal form each well of the microtiter pate for each time point. The data is presented in real time on the computer screen, facilitating interpretation and trouble-shooting. In addition to fluorescence, the camera can also detect luminescence form firefly luciferase.

  9. A kinematic model for the formation of the Siletz-Crescent forearc terrane by capture of coherent fragments of the Farallon and Resurrection plates

    USGS Publications Warehouse

    McCrory, Patricia A.; Wilson, Douglas S.

    2013-01-01

    The volcanic basement of the Oregon and Washington Coast ranges has been proposed to represent a pair of tracks of the Yellowstone hotspot formed at a mid-ocean ridge during the early Cenozoic. This interpretation has been questioned on many grounds, especially that the range of ages does not match the offshore spreading rates and that the presence of continental coarse clastic sediments is difficult to reconcile with fast convergence rates between the oceanic plates and North America. Updates to basement geochronology and plate motion history reveal that these objections are much less serious than when they were first raised. Forward plate kinematic modeling reveals that predicted basement ages can be consistent with the observed range of about 55–49 Ma, and that the entire basement terrane can form within about 300 km of continental sources for clastic sediments. This kinematic model indicates that there is no firm reason to reject the near-ridge hotspot hypothesis on the basis of plate motions. A novel element of the model is the Resurrection plate, previously proposed to exist between the Farallon and Kula plates. By including the defunct Resurrection plate in our reconstruction, we are able to model the Farallon hotspot track as docking against the Oregon subduction margin starting about 53 Ma, followed by docking of the Resurrection track to the north starting about 48 Ma. Accretion of the Farallon plate fragment and partial subduction of the Resurrection fragment complicates the three-dimensional structure of the modern Cascadia forearc. We interpret the so-called “E” layer beneath Vancouver Island to be part of the Resurrection fragment. Our new kinematic model of mobile terranes within the Paleogene North American plate boundary allows reinterpretation of the three-dimensional structure of the Cascadia forearc and its relationship to ongoing seismotectonic processes.

  10. Peen plating

    NASA Technical Reports Server (NTRS)

    Babecki, A. J. (Inventor); Haehner, C. L.

    1973-01-01

    A process for metal plating which comprises spraying a mixture of metallic powder and small peening particles at high velocity against a surface is described. The velocity must be sufficient to impact and bond metallic powder onto the surface. In the case of metal surfaces, the process has as one of its advantages providing mechanical working (hardening) of the surface simultaneously with the metal plating.

  11. Evidence for Sexual Dimorphism in the Plated Dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA

    PubMed Central

    Saitta, Evan Thomas

    2015-01-01

    Conclusive evidence for sexual dimorphism in non-avian dinosaurs has been elusive. Here it is shown that dimorphism in the shape of the dermal plates of Stegosaurus mjosi (Upper Jurassic, western USA) does not result from non-sex-related individual, interspecific, or ontogenetic variation and is most likely a sexually dimorphic feature. One morph possessed wide, oval plates 45% larger in surface area than the tall, narrow plates of the other morph. Intermediate morphologies are lacking as principal component analysis supports marked size- and shape-based dimorphism. In contrast, many non-sex-related individual variations are expected to show intermediate morphologies. Taphonomy of a new quarry in Montana (JRDI 5ES Quarry) shows that at least five individuals were buried in a single horizon and were not brought together by water or scavenger transportation. This new site demonstrates co-existence, and possibly suggests sociality, between two morphs that only show dimorphism in their plates. Without evidence for niche partitioning, it is unlikely that the two morphs represent different species. Histology of the new specimens in combination with studies on previous specimens indicates that both morphs occur in fully-grown individuals. Therefore, the dimorphism is not a result of ontogenetic change. Furthermore, the two morphs of plates do not simply come from different positions on the back of a single individual. Plates from all positions on the body can be classified as one of the two morphs, and previously discovered, isolated specimens possess only one morph of plates. Based on the seemingly display-oriented morphology of plates, female mate choice was likely the driving evolutionary mechanism rather than male-male competition. Dinosaur ornamentation possibly served similar functions to the ornamentation of modern species. Comparisons to ornamentation involved in sexual selection of extant species, such as the horns of bovids, may be appropriate in predicting the

  12. Tectonics of the Easter plate

    NASA Technical Reports Server (NTRS)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  13. Nitrided Metallic Bipolar Plates

    SciTech Connect

    Brady, Michael P; Tortorelli, Peter F; Pihl, Josh A; Toops, Todd J; More, Karren Leslie; Meyer III, Harry M; Vitek, John Michael; Wang, Heli; Turner, John; Wilson, Mahlon; Garzon, Fernando; Rockward, Tommy; Connors, Dan; Rakowski, Jim; Gervasio, Don

    2008-01-01

    The objectives are: (1) Develop and optimize stainless steel alloys amenable to formation of a protective Cr-nitride surface by gas nitridation, at a sufficiently low cost to meet DOE targets and with sufficient ductility to permit manufacture by stamping. (2) Demonstrate capability of nitridation to yield high-quality stainless steel bipolar plates from thin stamped alloy foils (no significant stamped foil warping or embrittlement). (3) Demonstrate single-cell fuel cell performance of stamped and nitrided alloy foils equivalent to that of machined graphite plates of the same flow-field design ({approx}750-1,000 h, cyclic conditions, to include quantification of metal ion contamination of the membrane electrode assembly [MEA] and contact resistance increase attributable to the bipolar plates). (4) Demonstrate potential for adoption in automotive fuel cell stacks. Thin stamped metallic bipolar plates offer the potential for (1) significantly lower cost than currently-used machined graphite bipolar plates, (2) reduced weight/volume, and (3) better performance and amenability to high volume manufacture than developmental polymer/carbon fiber and graphite composite bipolar plates. However, most metals exhibit inadequate corrosion resistance in proton exchange membrane fuel cell (PEMFC) environments. This behavior leads to high electrical resistance due to the formation of surface oxides and/or contamination of the MEA by metallic ions, both of which can significantly degrade fuel cell performance. Metal nitrides offer electrical conductivities up to an order of magnitude greater than that of graphite and are highly corrosion resistant. Unfortunately, most conventional coating methods (for metal nitrides) are too expensive for PEMFC stack commercialization or tend to leave pinhole defects, which result in accelerated local corrosion and unacceptable performance.

  14. Importance of the Small-Scale Processes Melting, Plate Boundary Formation and Mineralogy on the Large-Scale, Long-Term Thermo-Chemical Evolution of Earth's Mantle-Plate System

    NASA Astrophysics Data System (ADS)

    Tackley, P.

    2015-12-01

    Seismic observations of the deep Earth reveal the presence of two large low shear velocity provinces (LLSVPs) that are typically inferred to be dense chemically-distinct material, as well as discontinuities that are typically linked to the post-perovskite (pPv) phase transition. Several possible origins of chemically-dense material have been proposed, including recycling of mid-ocean ridge basalt (MORB), primordial differentiation events, crystallisation of a basal magma ocean, or some combination of these creating a basal melange (BAM; Tackley 2012 Earth Sci. Rev.). Each of these possibilities would result in a different composition hence different mineralogy. In order to constrain this we have been running calculations of thermo-chemical mantle evolution over 4.5 billion years that include melting-induced differentiation, plate tectonics induced by strongly temperature-dependent viscosity and plastic yielding, core cooling and compressibility with reasonable assumptions about the pressure-dependence of other material properties. Some of our simulations start from a magma ocean state so initial layering is developed self-consistently. Already-published results (Nakagawa et al., 2009 GCubed, 2010 PEPI, 2012 GCubed) already indicate the importance of exact MORB composition on the amount of MORB segregating above the CMB, which in turn influences mantle thermal structure and the evolution of the core and geodynamo. In more recent results we have been additionally including primordial material. We find that melting-induced differentiation has several first-order effects on the dynamics, including (i) making plate tectonics easier (through stresses associated with lateral variations in crustal thickness) and (ii) reducing heat flux through the CMB (due to the build-up of dense material above the CMB); also (iii) tectonic mode (continuous plate tectonics, episodic lid or stagnant lid) also makes a first-order difference to mantle structure and dynamics. This emphasises

  15. Effect of Lactobacillus species on Streptococcus mutans biofilm formation.

    PubMed

    Ahmed, Ayaz; Dachang, Wu; Lei, Zhou; Jianjun, Liu; Juanjuan, Qiu; Yi, Xin

    2014-09-01

    Streptococcus mutans is the primary pathogen responsible for initiating dental caries and decay. The presence of sucrose, stimulates S. mutans to produce insoluble glucans to form oral biofilm also known as dental plaque to initiate caries lesion. The GtfB and LuxS genes of S. mutans are responsible for formation and maturation of biofilm. Lactobacillus species as probiotic can reduces the count of S. mutans. In this study effect of different Lactobacillus species against the formation of S. mutans biofilm was observed. Growing biofilm in the presence of sucrose was detected using 96 well microtiter plate crystal violet assay and biofilm formation by S. mutans in the presence of Lactobacillus was detected. Gene expression of biofilm forming genes (GtfB and LuxS) was quantified through Real-time PCR. All strains of Lactobacillus potently reduced the formation of S. mutans biofilm whereas Lactobacillus acidophilus reduced the genetic expression by 60-80%. Therefore, probiotic Lactobacillus species can be used as an alternative instead of antibiotics to decrease the chance of dental caries by reducing the count of S. mutans and their gene expression to maintain good oral health. PMID:25176247

  16. Effect of Honey on Streptococcus mutans Growth and Biofilm Formation

    PubMed Central

    Li, Mingyun

    2012-01-01

    Because of the tradition of using honey as an antimicrobial medicament, we investigated the effect of natural honey (NH) on Streptococcus mutans growth, viability, and biofilm formation compared to that of an artificial honey (AH). AH contained the sugars at the concentrations reported for NH. NH and AH concentrations were obtained by serial dilution with tryptic soy broth (TSB). Several concentrations of NH and AH were tested for inhibition of bacterial growth, viability, and biofilm formation after inoculation with S. mutans UA159 in 96-well microtiter plates to obtain absorbance and CFU values. Overall, NH supported significantly less (P < 0.05) bacterial growth than AH at 25 and 12.5% concentrations. At 50 and 25% concentrations, both honey groups provided significantly less bacterial growth and biofilm formation than the TSB control. For bacterial viability, the results for all honey concentrations except 50% NH were not significantly different from those for the TSB control. NH was able to decrease the maximum velocity of S. mutans growth compared to AH. In summary, NH demonstrated more inhibition of bacterial growth, viability, and biofilm formation than AH. This study highlights the potential antibacterial properties of NH and could suggest that the antimicrobial mechanism of NH is not solely due to its high sugar content. PMID:22038612

  17. A Compact Immunoassay Platform Based on a Multicapillary Glass Plate

    PubMed Central

    Xue, Shuhua; Zeng, Hulie; Yang, Jianmin; Nakajima, Hizuru; Uchiyama, Katsumi

    2014-01-01

    A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased and the reaction efficiency to be increased. To confirm the concept of the method, human immunoglobulin A (h-IgA) was measured using both the proposed immunoassay system and the traditional 96-well plate method. The proposed method resulted in a 1/5-fold decrease of immunoassay time, and a 1/56-fold cut in reagent consumption with a 0.05 ng/mL of limit of detection (LOD) for IgA. The method was also applied to saliva samples obtained from healthy volunteers. The results correlated well to those obtained by the 96-well plate method. The method has the potential for use in disease diagnostic or on-site immunoassays. PMID:24859022

  18. One plate, two plates, a thousand plates. How crystallisation changes with large numbers of samples.

    PubMed

    Newman, Janet

    2011-09-01

    Turning commercial lab automation into a high-throughput centre requires an underlying process, and implementing checks to ensure that the process is working as it should. At the Collaborative Crystallisation Centre (C3), protein samples from local, national and international groups are set up in crystallisation screening and optimisation experiments with two thousand 96 well plates being set up each year. During its five years of operation, the C3 has implemented a series of enabling protocols - from simple 'reality checks' to determine if a screen has evaporated during storage to more sophisticated systems such as a sample labelling and tracking system. The most important - and perhaps surprising - lesson has been how much effort is required to effectively communicate between the centre and its clients, as well as between the centre's staff members. It is easy to confuse the concept of 'high throughput' in any field with the idea of setting up an experiment quickly. Although automation can be used to set up a single experiment more rapidly than can be done by hand, the distinguishing feature of a high throughput technology is the sustainability of the increased rate. PMID:21571072

  19. Formation of III–V ternary solid solutions on GaAs and GaSb plates via solid-phase substitution reactions

    SciTech Connect

    Vasil’ev, V. I.; Gagis, G. S. Kuchinskii, V. I.; Danil’chenko, V. G.

    2015-07-15

    Processes are considered in which ultrathin layers of III–V ternary solid solutions are formed via the delivery of Group-V element vapors to GaAs and GaSb semiconductor plates, with solid-phase substitution reactions occurring in the surface layers of these plates. This method can form defect-free GaAs{sup 1–x}P{sup x}, GaAs{sup x}Sb{sup 1–x}, and GaP{sup x}Sb{sup 1–x} layers with thicknesses of 10–20 nm and a content x of the embedded components of up to 0.04.

  20. The Hydrothermal System at Home Plate in Gusev Crater, Mars: Formation of High Silica Material by Acid-Sulfate Alteration of Basalt

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Ming, D. W.; Gellert, R.; Yen, A.; Clark, B. C.; Gnaff, T. G.; Arvidson, R. E.; Squyres, S. W.

    2008-01-01

    The Alpha Particle X-ray Spectrometer (APXS) instrument on the Mars Exploration Rover (MER) Spirit measured three targets on or adjacent to Home Plate in Gusev Crater that have unusually high SiO2 concentrations (68% to 91%), unusually low FeO concentrations (1% to 7%, with total Fe as FeO), and unusually high TiO2/FeO ratios (0.2 to 1.2 by weight) [1]. Two targets (Kenosha Comets and Lefty Ganote) are located on high albedo soil (Gertrude Weise) that was exposed by the rover wheels, and one target is a float rock called Fuzzy Smith. Kenosha Comets has the highest SiO2 concentration, lowest FeO concentration, and highest TiO2/FeO ratio. Mineralogical evidence from the MER Miniature Thermal Emission Spectrometer (Mini-TES) suggests that the SiO2 is present as amorphous (noncrystalline) SiO2 at Gertrude Weise and nearby targets [2,3]. Mini-TES data were not acquired for Fuzzy Smith. Home Plate is considered to have an explosive volcanic origin, resulting when basaltic magma came into contact with ground water or ice [4]. Within 50 m to 1 km of Home Plate are sulfate rich soil deposits (Paso Robles class soils with 22-35% SO3) which are considered to be probable fumarolic and/or hydrothermal deposits associated with the volcanism [5]. We develop the model here, suggested by [5], that the high-silica materials are another manifestation of acid-sulfate processes associated with fumarolic and hydrothermal activity at Home Plate. This is done by analogy with basaltic materials altered by acid sulfate processes on the Island of Hawaii.

  1. The Golosyiv plate archive digitisation

    NASA Astrophysics Data System (ADS)

    Sergeeva, T. P.; Sergeev, A. V.; Pakuliak, L. K.; Yatsenko, A. I.

    2007-08-01

    The plate archive of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (Golosyiv, Kyiv) includes about 85 000 plates which have been taken in various observational projects during 1950-2005. Among them are about 25 000 of direct northern sky area plates and more than 600 000 plates containing stellar, planetary and active solar formations spectra. Direct plates have a limiting magnitude of 14.0-16.0 mag. Since 2002 we have been organising the storage, safeguarding, cataloguing and digitization of the plate archive. The very initial task was to create the automated system for detection of astronomical objects and phenomena, search of optical counterparts in the directions of gamma-ray bursts, research of long period, flare and other variable stars, search and rediscovery of asteroids, comets and other Solar System bodies to improve the elements of their orbits, informational support of CCD observations and space projects, etc. To provide higher efficiency of this work we have prepared computer readable catalogues and database for 250 000 direct wide field plates. Now the catalogues have been adapted to Wide Field Plate Database (WFPDB) format and integrated into this world database. The next step will be adaptation of our catalogues, database and images to standards of the IVOA. Some magnitude and positional accuracy estimations for Golosyiv archive plates have been done. The photometric characteristics of the images of NGC 6913 cluster stars on two plates of the Golosyiv's double wide angle astrograph have been determined. Very good conformity of the photometric characteristics obtained with external accuracies of 0.13 and 0.15 mag. has been found. The investigation of positional accuracy have been made with A3± format fixed bed scanner (Microtek ScanMaker 9800XL TMA). It shows that the scanner has non-detectable systematic errors on the X-axis, and errors of ± 15 μm on the Y-axis. The final positional errors are about ± 2 μm (

  2. Timing and Location of the Collision between North China Craton and Siberian Plate: New Evidence of Zircon U-Pb ages of Linxi Formation and its intrusion in Linxi region, Inner Mongolia

    NASA Astrophysics Data System (ADS)

    Shi, L.; Zheng, C.; Yao, W.; Xu, X.; Li, J.; Cui, F.; Wang, H.

    2013-12-01

    The amalgamation of Siberian Plate with North China Craton (NCC) is an important issue on study of tectonic frame of China and the whole eastern Asia. Different researchers have different understanding about the timing and location for the collision and final closure of Siberian Plate and NCC. Some researchers believe that Hegenshan-Sunitzuoqi-Soren Obo line in the northern Inner Mongolia is the final suture zone, but the timing for final closure has been in debating. Some other researchers believe that the Xar Moron River-Changchun-Yanji fault is the final suture, however they failed to reach a consensus regarding the suture time. To solve this problem, based on field studies, we collected detrital zircons in argillaceous rocks and magmatic zircons in granodiorite intrusions from the dynamic metamorphic belt to carry out LA-ICP-MS U-Pb dating in the northern side of Tongbu County, Linxi region, Inner Mongolia, where is tectonically located between the Xar Moron River suture belt and Erenhot-Hegenshan suture belt. LA-ICP-MS study on 40 detrital zircons in the dynamically metamophosed biotite schists in the Linxi Formation from Linxi region suggests that their U-Pb ages can be roughly divided into two groups; Group-I in the range of 397-482 Ma with the peak at 424 × 4 Ma and Group-II in the range of 261-358 Ma with the peak at 313.2 × 3.7 Ma. The youngest age, 261 × 3Ma, is interpreted to maximum depositional age of the protoliths of these schists and has limited the Linxi Formation to be formed at Late Permian. The age distribution patterns for detrital zircons in Linxin Formation suggest that the sedimentary materials are mainly from the NE China block rather than NCC, which has thus put constraint on the final collision location of Siberian plate with NCC to be at the Xar Moron River-Changchun suture belt, south of Linxi area, and on the timing for collision after the sedimentation of Linxi Formation sequences. The veined granodiorite that intruded into Linxi

  3. The radiolarian evidence for the accretion of the Fu-saki Formation with the inferred oceanic plate stratigraphy: A case of weakly-metamorphosed accretionary complex in Ishigaki Jima, southern Ryukyu Arc, Japan

    NASA Astrophysics Data System (ADS)

    Nakae, Satoshi

    2013-09-01

    The island of Ishigaki Jima, located in the western part of the southern Ryukyu Arc, Japan, is underlain by a basement comprising the Tumuru and Fu-saki formations. The former is a pelitic glaucophane schist with a metamorphic age of 220-190 Ma, and the latter is a weakly metamorphosed accretionary complex, composed mainly of chert, mudstone and sandstone with minor amounts of limestone and mafic rocks. The Fu-saki Formation was weakly metamorphosed at ∼140 Ma. Latest Carboniferous-Early Jurassic microfossils have been obtained from the limestones, cherts and siliceous mudstones of this formation, but no fossils have been collected from the phyllitic mudstones. The radiolarian fauna of the phyllitic mudstones described herein indicates a late Pliensbachian-early Toarcian (Early Jurassic) age. This result, when combined with existing data, enables the reconstruction of an oceanic plate stratigraphy, showing a succession of (in ascending order) Upper Carboniferous-Triassic cherts, Sinemurian-lower Pliensbachian siliceous mudstones and upper Pliensbachian-lower Toarcian phyllitic mudstones and sandstones. The radiolarians from the phyllitic mudstones are important in constraining the timing of the accretion of the Fu-saki Formation to the base of the Tumuru Formation.

  4. Multiplexed chemiluminescent assays in ArrayPlates for high-throughput measurement of gene expression

    NASA Astrophysics Data System (ADS)

    Martel, Ralph R.; Rounseville, Matthew P.; Botros, Ihab W.; Seligmann, Bruce E.

    2002-06-01

    Multiplexed Molecular Profiling (MMP) assays for drug discovery are performed in ArrayPlates. ArrayPlates are 96- well microtiter plates that contain a 16-element array at the bottom of each well. Each element within an array measures one analyte in a sample. A CCD imager records the quantitative chemiluminescent readout of all 1,536 elements in a 96-well plate simultaneously. Since array elements are reagent modifiable by the end-user, ArrayPlates can be adapted to a broad range of nucleic acid- and protein-based assays. Such multiplexed assays are rapidly established, flexible, robust, automation-friendly and cost-effective. Nucleic acid assays in ArrayPlates can detect DNA and RNA, including SNPs and ESTs. A multiplexed mRNA assay to measure the expression of 16 genes is described. The assay combines a homogeneous nuclease protection assay with subsequent probe immobilization to the array by means of a sandwich hybridization followed with chemiluminescent detection. This assay was used to examine cells grown and treated in microplates and avoided cloning, transfection, RNA insolation, reverse transcription, amplification and fluorochrome labeling. Standard deviations for the measurement of 16 genes ranged from 3 percent to 13 percent in samples of 30,000 cells. Such ArrayPlates transcription assays are useful in drug discovery and development for target validation, screening, lead optimization, metabolism and toxicity profiling. Chemiluminescent detection provides ArrayPlates assays with high signal-to-noise readout and simplifies imager requirements. Imaging a 2D surface that contains arrays simplifies lens requirements relative to imaging columns of liquid in microtiter plate wells. The Omix imager for ArrayPlates is described.

  5. MICROTUBULE-ASSOCIATED PROTEIN65 is essential for maintenance of phragmoplast bipolarity and formation of the cell plate in Physcomitrella patens.

    PubMed

    Kosetsu, Ken; de Keijzer, Jeroen; Janson, Marcel E; Goshima, Gohta

    2013-11-01

    The phragmoplast, a plant-specific apparatus that mediates cytokinesis, mainly consists of microtubules (MTs) arranged in a bipolar fashion, such that their plus ends interdigitate at the equator. Membrane vesicles are thought to move along the MTs toward the equator and fuse to form the cell plate. Although several genes required for phragmoplast MT organization have been identified, the mechanisms that maintain the bipolarity of phragmoplasts remain poorly understood. Here, we show that engaging phragmoplast MTs in a bipolar fashion in protonemal cells of the moss Physcomitrella patens requires the conserved MT cross-linking protein MICROTUBULE-ASSOCIATED PROTEIN65 (MAP65). Simultaneous knockdown of the three MAP65s expressed in those cells severely compromised MT interdigitation at the phragmoplast equator after anaphase onset, resulting in the collapse of the phragmoplast in telophase. Cytokinetic vesicles initially localized to the anaphase midzone as normal but failed to further accumulate in the next several minutes, although the bipolarity of the MT array was preserved. Our data indicate that the presence of bipolar MT arrays is insufficient for vesicle accumulation at the equator and further suggest that MAP65-mediated MT interdigitation is a prerequisite for maintenance of bipolarity of the phragmoplast and accumulation and/or fusion of cell plate-destined vesicles at the equatorial plane. PMID:24272487

  6. Cenozoic deep-water sedimentary basin formation at the Australia-Pacific plate boundary, southern New Caledonia Trough and Taranaki Basin, New Zealand

    NASA Astrophysics Data System (ADS)

    Baur, J. R.; Sutherland, R.; Stern, T. A.

    2010-12-01

    Investigation of four petroleum exploration wells and seismic-reflection interpretation reveal >2 km of tectonic subsidence related to Cretaceous rift structures, and 2-3km of Cenozoic subsidence with little faulting of the upper crust. Comparisons to thermal cooling models require stretching factors that are incompatible with the continental foundations of the basin. In addition, up to 50 % of the subsidence signal occurred in the Mid-Cenozoic, hundreds of kilometres from potential contemporary plate boundaries. Thus, upper crustal faulting, thermal relaxation or flexure cannot explain the 300-500 km wide and 2000 km long sedimentary basin system. We suggest that not all deep-water basins are the evolved products of processes that form shallow-water sedimentary basins, but instead they may be influenced by different processes such as convection in the asthenospheric mantle, instabilities in the mantle lithosphere and/or detachment fault zones that inevitably lead to deeper water.

  7. Petroleum occurrences and plate tectonics

    SciTech Connect

    Olenin, V.B.; Sokolov, B.A.

    1983-01-01

    This paper analyzes the mechanisms of petroleum formation and petroleum accumulation proposed in recent years by some Russian and foreign investigators from the viewpoint of the new global or plate tectonics. On the basis of discussion and the facts, the authors conclude that the mechanisms proposed are in contradiction to reality and their use in practical application is at least premature.

  8. Plate Tectonic Cycle. K-6 Science Curriculum.

    ERIC Educational Resources Information Center

    Blueford, J. R.; And Others

    Plate Tectonics Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) volcanoes (covering formation, distribution, and major volcanic groups); (2) earthquakes (with investigations on wave movements, seismograms and sub-suface earth currents); (3) plate tectonics (providing maps…

  9. Cross strip anode readouts for large format, photon counting microchannel plate detectors: developing flight qualified prototypes of the detector and electronics

    NASA Astrophysics Data System (ADS)

    Vallerga, John; Raffanti, Rick; Cooney, Michael; Cumming, Harley; Varner, Gary; Seljak, Andrej

    2014-07-01

    Photon counting microchannel plate (MCP) imagers have been the detector of choice for most UV astronomical missions over the last two decades (e.g. EUVE, FUSE, COS on Hubble etc.). Over this duration, improvements in the MCP laboratory readout technology have resulted in better spatial resolution (x10), temporal resolution (x1000) and output event rate (x100), all the while operating at lower gain (x 10) resulting in lower high voltage requirements and longer MCP lifetimes. One such technology is the parallel cross strip (PXS) readout. Laboratory versions of PXS electronics have demonstrated < 20 μm FWHM spatial resolution, count rates on the order of 2 MHz, and temporal resolution of ~ 1ns. In 2012 our group at U.C. Berkeley, along with our partners at the U. Hawaii, received a Strategic Astrophysics Technology grant to raise the TRL of the PXS detector and electronics from 4 to 6 by replacing most of the high powered electronics with application specific integrated circuits (ASICs) which will lower the power, mass and volume requirements of the PXS detector. We were also tasked to design and fabricate a "standard" 50mm square active area MCP detector incorporating these electronics that can be environmentally qualified for flight (temperature, vacuum, vibration). The first ASICs designed for this program have been fabricated and are undergoing testing. We present the latest progress on these ASIC designs and performance and show imaging results from the new 50 x 50 mm XS detector.

  10. The Critical Effect of Niobium Doping on the Formation of Mesostructured TiO2 : Single-Crystalline Ordered Mesoporous Nb-TiO2 and Plate-like Nb-TiO2 with Ordered Mesoscale Dimples.

    PubMed

    Kitahara, Masaki; Shimasaki, Yuta; Matsuno, Takamichi; Kuroda, Yoshiyuki; Shimojima, Atsushi; Wada, Hiroaki; Kuroda, Kazuyuki

    2015-09-01

    Highly ordered mesoporous niobium-doped TiO2 with a single-crystalline framework was prepared by using silica colloidal crystals with ca. 30 nm in diameter as templates. The preparation of colloidal crystals composed of uniform silica nanoparticles is a key to obtain highly ordered mesoporous Nb-doped TiO2 . The XPS measurements of Nb-doped TiO2 showed the presence of Nb(5+) and correspondingly Ti(3+) . With the increase in the amount of doped Nb, the crystalline phase of the product was converted from rutile into anatase, and the lattice spacings of both rutile and anatase phases increased. Surprisingly, the increase in the amount of Nb led to the formation of plate-like TiO2 with dimpled surfaces on one side, which was directly replicated from the surfaces of the colloidal silica crystals. PMID:26216465

  11. Formation and evolution of a metasomatized lithospheric root at the motionless Antarctic plate: the case of East Island, Crozet Archipelago (Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Meyzen, Christine; Marzoli, Andrea; Bellieni, Giuliano; Levresse, Gilles

    2016-04-01

    Sitting atop the nearly stagnant Antarctic plate (ca. 6.46 mm/yr), the Crozet archipelago midway between Madagascar and Antarctica constitutes a region of unusually shallow (1543-1756 m below sea level) and thickened oceanic crust (10-16.5 km), high geoid height, and deep low-velocity zone, which may reflect the surface expression of a mantle plume. Here, we present new major and trace element data for Quaternary sub-aerial alkali basalts from East Island, the easterly and oldest island (ca. 9 Ma) of the Crozet archipelago. Crystallization at uppermost mantle depth and phenocryst accumulation have strongly affected their parental magma compositions. Their trace element patterns show a large negative K anomaly relative to Ta-La, moderate depletions in Rb and Ba with respect to Th-U, and heavy rare earth element (HREE) depletions relative to light REE. These characteristics allow limits to be placed upon the composition and mineralogy of their mantle source. The average trace element spectrum of East Island basalts can be matched by melting of about 2 % of a garnet-phlogopite-bearing peridotite source. The stability field of phlogopite restricts melting depth to lithospheric levels. The modelled source composition requires a multistage evolution, where the mantle has been depleted by melt extraction before having been metasomatized by alkali-rich plume melts. The depleted mantle component may be sourced by residual mantle plume remnants stagnated at the melting locus due to a weak lateral flow velocity inside the melting regime, whose accumulation progressively edifies a depleted lithospheric root above the plume core. Low-degree alkali-rich melts are likely derived from the plume source. Such a mantle source evolution may be general to both terrestrial and extraterrestrial environments where the lateral component velocity of the mantle flow field is extremely slow.

  12. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  13. Direct comparison of the Ames microplate format (MPF) test in liquid medium with the standard Ames pre-incubation assay on agar plates by use of equivocal to weakly positive test compounds.

    PubMed

    Flückiger-Isler, Sini; Kamber, Markus

    2012-08-30

    The Ames microplate format (MPF™) test, which uses liquid media and in 384-well microplates with a readout based on a colour-change, has been used for over 10 years at several major pharmaceutical companies for screening the genotoxic potential of early drug candidates when compound supply is minimal. Meanwhile, Xenometrix has adapted this screen from the two-strain Ames II test for use with five tester strains, in compliance with OECD Guideline 471. A set of 15 equivocal to weakly positive chemicals selected from the National Toxicology Program (NTP) database was tested simultaneously in the Ames microplate format (MPF) and the standard Ames pre-incubation method on agar plates. Such a direct comparison of the two test methods with the same overnight culture(s), chemicals and S9-mix preparation should exclude external variability factors. Thirteen of the 15 chemicals showed concordant results in both tests despite the choice of chemicals that showed varying inter- and even intra-laboratory results in the NTP studies. These results indicate that the Ames MPF™ assay is a reliable predictive tool that can be used like the regular Ames test to evaluate compounds for mutagenicity. PMID:22579797

  14. The Postcranial Skeleton of an Exceptionally Complete Individual of the Plated Dinosaur Stegosaurus stenops (Dinosauria: Thyreophora) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A.

    PubMed Central

    Maidment, Susannah Catherine Rose; Brassey, Charlotte; Barrett, Paul Michael

    2015-01-01

    Although Stegosaurus is one of the most iconic dinosaurs, well-preserved fossils are rare and as a consequence there is still much that remains unknown about the taxon. A new, exceptionally complete individual affords the opportunity to describe the anatomy of Stegosaurus in detail for the first time in over a century, and enables additional comparisons with other stegosaurian dinosaurs. The new specimen is from the Red Canyon Ranch Quarry, near Shell Wyoming, and appears to have been so well preserved because it was buried rapidly in a pond or body of standing water immediately after death. The quarry is probably located in the middle part of the Morrison Formation, which is believed to be Tithonian in age in this area. The specimen is referable to Stegosaurus stenops based on the possession of an edentulous anterior portion of the dentary and elevated postzygapophyses on the cervical vertebrae. New information provided by the specimen concerns the morphology of the vertebrae, the iliosacral block and dermal armor. Several aspects of its morphology indicate the individual was not fully skeletally mature at the time of death, corroborating a previous histological study. PMID:26466098

  15. The cytological changes of tobacco zygote and proembryo cells induced by beta-glucosyl Yariv reagent suggest the involvement of arabinogalactan proteins in cell division and cell plate formation

    PubMed Central

    2012-01-01

    Background In dicotyledonous plant, the first asymmetric zygotic division and subsequent several cell divisions are crucial for proembryo pattern formation and later embryo development. Arabinogalactan proteins (AGPs) are a family of extensively glycosylated cell surface proteins that are thought to have important roles in various aspects of plant growth and development, including embryogenesis. Previous results from our laboratory show that AGPs are concerned with tobacco egg cell fertilization and zygotic division. However, how AGPs interact with other factors involved in zygotic division and proembryo development remains unknown. Results In this study, we used the tobacco in vitro zygote culture system and series of meticulous cell biology techniques to investigate the roles of AGPs in zygote and proembryo cell division. For the first time, we examined tobacco proembryo division patterns detailed to every cell division. The bright-field images and statistical results both revealed that with the addition of an exogenous AGPs inhibitor, beta-glucosyl Yariv (beta-GlcY) reagent, the frequency of aberrant division increased remarkably in cultured tobacco zygotes and proembryos, and the cell plate specific locations of AGPs were greatly reduced after beta-GlcY treatment. In addition, the accumulations of new cell wall materials were also significantly affected by treating with beta-GlcY. Detection of cellulose components by Calcofluor white stain showed that strong fluorescence was located in the newly formed wall of daughter cells after the zygotic division of in vivo samples and the control samples from in vitro culture without beta-GlcY treatment; while there was only weak fluorescence in the newly formed cell walls with beta-GlcY treatment. Immunocytochemistry examination with JIM5 and JIM7 respectively against the low- and high-esterified pectins displayed that these two pectins located in opposite positions of zygotes and proembryos in vivo and the polarity was

  16. Inhibitory effect of gels loaded with a low concentration of antibiotics against biofilm formation by Enterococcus faecalis and Porphyromonas gingivalis.

    PubMed

    A Algarni, Amnah; H Yassen, Ghaeth; L Gregory, Richard

    2015-09-01

    We explored longitudinally the inhibitory effect of gels loaded with 1 mg/mL modified triple antibiotic paste (MTAP) or double antibiotic paste (DAP) against biofilm formation by Enterococcus faecalis and Porphyromonas gingivalis. Methylcellulose-based antibiotic gels of MTAP (ciprofloxacin, metronidazole and clindamycin) and DAP (ciprofloxacin and metronidazole) were prepared at a concentration of 1 mg/mL. Individually cultured E. faecalis and P. gingivalis bacterial suspensions were treated with MTAP, DAP, or placebo (vehicle only) gels at different dilutions and allowed to grow in 96-well microtiter plates. Untreated bacterial suspensions served as a negative control. Crystal violet assays were used to evaluate biofilm formation after 48 h. The ability of the gels to inhibit biofilm formation was determined immediately, and at 1 month and 3 months after the gels had been prepared. Data were analyzed using a mixed-model ANOVA. The MTAP and DAP gels significantly reduced biofilm formation by both bacterial species at all time points, regardless of the tested dilution. No-significant differences in biofilm-inhibitory effects between MTAP and DAP gels were observed at the majority of the tested dilutions through various time points. Gels loaded with 1 mg/mL MTAP and DAP demonstrated a significant antibiofilm effect against E.faecalis and P. gingivalis. PMID:26369485

  17. MAO NAS of Ukraine Plate Archives: Towards the WFPDB Integration

    NASA Astrophysics Data System (ADS)

    Sergeeva, T. P.; Golovnya, V. V.; Yizhakevych, E. M.; Kizyun, L. N.; Pakuliak, L. K.; Shatokhina, S. V.; Tsvetkov, M. K.; Tsvetkova, K. P.; Sergeev, A. V.

    2006-04-01

    The plate archives of the Main Astronomical Observatory (Golosyiv, Kyiv) includes about 85 000 plates which were taken for various astronomical projects in the period 1950-2005. Among them there are more than 60 000 plates containing stellar, planetary and active solar formations spectra and more than 20 000 of direct northern sky area plates (mostly with wide-field). The catalogues of these direct wide-field plates have been prepared in computer-readable form. Now they are reduced in the WFPDB format and included into the database.

  18. MerMade: An Oligodeoxyribonucleotide Synthesizer for High Throughput Oligonucleotide Production in Dual 96-Well Plates

    PubMed Central

    Rayner, Simon; Brignac, Stafford; Bumeister, Ron; Belosludtsev, Yuri; Ward, Travis; Grant, O’dell; O’Brien, Kevin; Evans, Glen A.; Garner, Harold R.

    1998-01-01

    We have designed and constructed a machine that synthesizes two standard 96-well plates of oligonucleotides in a single run using standard phosphoramidite chemistry. The machine is capable of making a combination of standard, degenerate, or modified oligos in a single plate. The run time is typically 17 hr for two plates of 20-mers and a reaction scale of 40 nm. The reaction vessel is a standard polypropylene 96-well plate with a hole drilled in the bottom of each well. The two plates are placed in separate vacuum chucks and mounted on an xy table. Each well in turn is positioned under the appropriate reagent injection line and the reagent is injected by switching a dedicated valve. All aspects of machine operation are controlled by a Macintosh computer, which also guides the user through the startup and shutdown procedures, provides a continuous update on the status of the run, and facilitates a number of service procedures that need to be carried out periodically. Over 25,000 oligos have been synthesized for use in dye terminator sequencing reactions, polymerase chain reactions (PCRs), hybridization, and RT–PCR. Oligos up to 100 bases in length have been made with a coupling efficiency in excess of 99%. These machines, working in conjunction with our oligo prediction code are particularly well suited to application in automated high throughput genomic sequencing. PMID:9685322

  19. Failure analysis of stainless steel femur fixation plate.

    PubMed

    Hussain, P B; Mohammad, M

    2004-05-01

    Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed. PMID:15468877

  20. Efficient DNA sequencing on microtiter plates using dried reagents and Bst DNA polymerase.

    PubMed

    Earley, J J; Kuivaniemi, H; Prockop, D J; Tromp, G

    1993-01-01

    Sequenase, Taq DNA polymerase and Bst DNA polymerase were tested for sequencing of DNA on microtiter plates using dried down reagents. Several parameters were investigated to expedite the drying process while minimizing damage to the enzyme. Sequenase did not tolerate drying very well, and frequently generated sequences with weak signals and many sites of premature termination. With Taq DNA polymerase it was possible to obtain sequences of good quality. However, there was considerable variation of results between experiments and between batches of microtiter plates. Bst DNA polymerase generated sequences of excellent quality. It was stable for more than a week in dried-down state at -20 degrees C and at least overnight at room temperature. The method described here using Bst DNA polymerase is well suited for laboratory robots and workstations that typically employ 96-well microtiter plates. PMID:8173079

  1. Relationship of biofilm formation and different virulence genes in uropathogenic Escherichia coli isolates from Northwest Iran

    PubMed Central

    Fattahi, Sargol; Kafil, Hossein Samadi; Nahai, Mohammad Reza; Asgharzadeh, Mohammad; Nori, Roghaya; Aghazadeh, Mohammad

    2015-01-01

    Background and objectives: The Escherichia coli (E. coli) bacterium is one of the main causative agents of urinary tract infections (UTI) worldwide. The ability of this bacterium to form biofilms on medical devices such as catheters plays an important role in the development of UTI. The aim of the present study was to investigate the possible relationship between virulence factors and biofilm formation of E. coli isolates responsible for urinary tract infection. Materials and methods: A total of 100 E. coli isolates isolated from patients with UTI were collected and characterized by routine bacteriological methods. In vitro biofilm formation by these isolates was determined using the 96-well microtiter-plate test, and the presence of fimA, papC, and hly virulence genes was examined by PCR assay. Data analysis was performed using SPSS 16.0 software. Results: From 100 E. coli isolates isolated from UTIs, 92% were shown to be biofilm positive. The genes papC, fimA, and hly were detected in 43%, 94% and 26% of isolates, respectively. Biofilm formation in isolates that expressed papC, fimA, and hly genes was 100%, 93%, and 100%, respectively. A significant relationship was found between presence of the papC gene and biofilm formation in E. coli isolates isolated from UTI (P<0.01), but there was no statistically significant correlation between presence of fimA and hly genes with biofilm formation (P<0.072, P<0.104). Conclusion: Results showed that fimA and hly genes do not seem to be necessary or sufficient for the production of biofilm in E. coli, but the presence of papC correlates with increased biofilm formation of urinary tract isolates. Overall, the presence of fimA, papC, and hly virulence genes coincides with in vitro biofilm formation in uropathogenic E. coli isolates. PMID:26213679

  2. A sensitive and simple plaque formation method for the Stx2 phage of Escherichia coli O157:H7, which does not form plaques in the standard plating procedure.

    PubMed

    Islam, Md Rakibul; Ogura, Yoshitoshi; Asadulghani, Md; Ooka, Tadasuke; Murase, Kazunori; Gotoh, Yasuhiro; Hayashi, Tetsuya

    2012-05-01

    Bacteriophages are fascinating genetic elements that play key roles in the evolution and diversification of bacterial genomes. Shiga toxin (Stx)-transducing phages are important genetic elements that disseminate the stx genes among enterohemorrhagic Escherichia coli (EHEC). They are generally regarded as lambda-like phages, but their biological and genetic properties have not been fully elucidated. This is partly due to a serious obstacle in obtaining visible plaques. Here, we describe a modified double agar overlay method that allows us to easily detect and accurately enumerate plaques of Sp5, the Stx2 phage of the EHEC O157 Sakai strain, which otherwise does not produce plaques in the standard plating procedure. In the modified method, the top agar was supplemented with mitomycin C (MMC) and Ca(2+) (or Mg(2+)). MMC appears to prevent the lysogenization of Sp5 and/or compel Sp5 to follow the lytic cycle by inducing the SOS response in the host cells. The divalent cations significantly improve phage adsorption to the host cells and thus yield a synergistic effect in combination with MMC. We further applied this method to a receptor analysis of Sp5 and obtained findings that suggest that the YaeT (BamA) protein serves as the receptor of Sp5. This method would be a very useful tool in studies of Stx2 phages and studies of other phages from various bacteria, in which researchers often encounter problems with plaque formation. PMID:22186359

  3. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  4. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

  5. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  6. Plating Tank Control Software

    Energy Science and Technology Software Center (ESTSC)

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  7. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  8. Quorum quenching bacteria isolated from the sludge of a wastewater treatment plant and their application for controlling biofilm formation.

    PubMed

    Kim, A-Leum; Park, Son-Young; Lee, Chi-Ho; Lee, Chung-Hak; Lee, Jung-Kee

    2014-11-28

    Bacteria recognize changes in their population density by sensing the concentration of signal molecules, N-acyl-homoserine lactones (AHLs). AHL-mediated quorum sensing (QS) plays a key role in biofilm formation, so the interference of QS, referred to as quorum quenching (QQ), has received a great deal of attention. A QQ strategy can be applied to membrane bioreactors (MBRs) for advanced wastewater treatment to control biofouling. To isolate QQ bacteria that can inhibit biofilm formation, we isolated diverse AHL-degrading bacteria from a laboratory-scale MBR and sludge from real wastewater treatment plants. A total of 225 AHLdegrading bacteria were isolated from the sludge sample by enrichment culture. To identify the enzyme responsible for AHL degradation in QQ bacteria, AHL-degrading activities were analyzed using cell-free lysate, culture supernatant, and whole cells. Afipia sp. and Acinetobacter sp. strains produced the intracellular QQ enzyme, whereas Pseudomonas sp. and Micrococcus sp. produced the extracellular QQ enzyme that was most likely to produce AHLacylase. AHL-degrading activity was observed in whole-cell assay with the Microbacterium sp. and Rhodococcus sp. strains. There has been no report for AHL-degrading capability in the case of Streptococcus sp. and Afipia sp. strains. Finally, inhibition of biofilm formation by isolated QQ bacteria or enzymes was observed on glass slides and 96-well microtiter plates using crystal violet staining. QQ strains or enzymes not only inhibited initial biofilm development but also reduced established biofilms. PMID:25112313

  9. Plate Tectonics, Geographical Information System, paleogeography

    SciTech Connect

    Moore, Thomas L.; Scotese, Christopher

    2002-05-24

    The PaleoX.framwork is a dynamically linked/loaded framework for Cocoa applications. The primary goal of this library is to standardize several elements used for working with paleogeographic data. This includes objects designed to organize information for tectonic plates, including maps, rotation objects, plate names, and designations. In addition, PaleoX provides object-oriented solutions for handling standard paleogeographic file formats from the PALEOMAP Project.

  10. Plate-induced Miocene extension in southern California

    SciTech Connect

    Stuart, W.D. Univ. of California, Santa Barbara, CA )

    1992-01-01

    Miocene crustal extension in southern California can be explained by the interaction of tectonic plates in relative motion. The Pacific, Juan de Fuca, and Farallon (Guadalupe) plates are represented by flat elastic plates surrounded by an infinite elastic plate, the eastern part of which represents the North America plate. Forcing is by assigned subduction pull, and tractions at all plate boundaries satisfy a viscous constitutive law. Plate bottoms are stress-free. In the first part of the solution plate velocities and boundary tractions are found from static equilibrium. Then principal horizontal stresses and strains in plate interiors caused by tractions and subduction pull are found by a boundary element procedure. Using plate boundary geometry from Stock and Hodges for early- and mid-Miocene times, it is found that the portion of the North America plate margin between the Mendocino and Rivera triple junctions has maximum extensional strain directed westward. This result is generally consistent with directions associated with metamorphic core complex formation in southern California. The model is also consistent with extensional strain and rotation sense of crustal blocks in the vicinity of Los Angeles, as inferred by Luyendyk and others from paleomagnetic data. In the model the greatest extensional strain of the North America plate occurs near the Pacific-North America transform, in the area above the absent Farallon slab. Extension direction varies from northwest to southwest according to plate geometry, subduction pull (Juan de Fuca and Guadalupe), and plate boundary tractions.

  11. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  12. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  13. Inhibitory effects of the κ-casein macropeptide isolated from milk protein on the biofilm formation and virulence of Listeria monocytogenes.

    PubMed

    Yun, Hyun Sun; Kim, Younghoon; Park, Mi Ri; Kim, Sae Hun; Oh, Sejong

    2014-01-01

    We demonstrate the inhibitory effects of κ-casein macropeptide (CMP) on the biofilm formation and virulence of Listeria monocytogenes Scott A. The inhibition of biofilm formation by CMP was initially investigated by using the protocol applied for the 96-well microtiter plate assay. Low concentrations of CMP (0.1, 0.2, 0.3, 0.4, and 0.5 mg/mL) that were tested resulted in a profound inhibitory effect on biofilm formation at a concentration of 0.4 mg/mL. CMP also significantly repressed the transcription of inlA (encoding internalin A) that was responsible for the initial adhesion and invasion event, and prolonged the survival of Caenorhabditis elegans infected by L. monocytogenes. Two-dimensional gel electrophoresis showed that newly identified proteins in the presence of CMP were involved in the stress response and metabolic processes that have important roles in developing listerial biofilms. Our results suggest that CMP from milk protein would be capable of eliminating biofilm formation and virulence by L. monocytogenes in the food industry. PMID:25036840

  14. WFPDB: European Plate Archives

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Milcho

    2007-08-01

    The Wide-Field Plate Database (WFPDB) gives an inventory of all wide-field (>~ 1 sq. deg) photographic observations archived in astronomical institutions over the world. So it facilitates and stimulates their use and preservation as a valuable source of information for future investigations in astronomy. At present WFPDB manages plate-index information for 25% of all existing plates providing on-line access from Sofia (http://www.skyarchive.org/search) and in CDS, Strasbourg. Here we present the new development of WFPDB as an instrument for searching of long term brightness variations of different sky objects stressing on the European photographic plate collections (from existing 2 million wide-field plates more than 55% are in Europe: Germany, Russia, Ukraine, Italy, Czech Republic, etc.). We comment examples of digitization (with flatbed scanners) of the European plate archives in Sonneberg, Pulkovo, Asiago, Byurakan, Bamberg, etc. and virtual links of WFPDB with European AVO, ADS, IBVS.

  15. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  16. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  17. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  18. Effects of short-chain fatty acids on Actinomyces naeslundii biofilm formation.

    PubMed

    Yoneda, S; Kawarai, T; Narisawa, N; Tuna, E B; Sato, N; Tsugane, T; Saeki, Y; Ochiai, K; Senpuku, H

    2013-10-01

    Actinomyces naeslundii is an early colonizer and has important roles in the development of the oral biofilm. Short-chain fatty acids (SCFA) are secreted extracellularly as a product of metabolism by gram-negative anaerobes, e.g. Porphyromonas gingivalis and Fusobacterium nucleatum; and the SCFA may affect biofilm development with interaction between A. naeslundii and gram-negative bacteria. Our aim was to investigate the effects of SCFA on biofilm formation by A. naeslundii and to determine the mechanism. We used the biofilm formation assay in 96-well microtiter plates in tryptic soy broth without dextrose and with 0.25% sucrose using safranin stain of the biofilm monitoring 492 nm absorbance. To determine the mechanism by SCFA, the production of chaperones and stress-response proteins (GrpE and GroEL) in biofilm formation was examined using Western blot fluorescence activity with GrpE and GroEL antibodies. Adding butyric acid (6.25 mm) 0, 6 and 10 h after beginning culture significantly increased biofilm formation by A. naeslundii, and upregulation was observed at 16 h. Upregulation was also observed using appropriate concentrations of other SCFA. In the upregulated biofilm, production of GrpE and GroEL was higher where membrane-damaged or dead cells were also observed. The upregulated biofilm was significantly reduced by addition of anti-GroEL antibody. The data suggest biofilm formation by A. naeslundii was upregulated dependent on the production of stress proteins, and addition of SCFA increased membrane-damaged or dead cells. Production of GroEL may physically play an important role in biofilm development. PMID:23731652

  19. Tectonic Evolution of the Jurassic Pacific Plate

    NASA Astrophysics Data System (ADS)

    Nakanishi, M.; Ishihara, T.

    2015-12-01

    We present the tectonic evolution of the Jurassic Pacific plate based on magnetic anomly lineations and abyssal hills. The Pacific plate is the largest oceanic plate on Earth. It was born as a microplate aroud the Izanagi-Farallon-Phoenix triple junction about 192 Ma, Early Jurassic [Nakanishi et al., 1992]. The size of the Pacific plate at 190 Ma was nearly half that of the present Easter or Juan Fernandez microplates in the East Pacific Rise [Martinez et at, 1991; Larson et al., 1992]. The plate boundary surrounding the Pacific plate from Early Jurassic to Early Cretaceous involved the four triple junctions among Pacific, Izanagi, Farallon, and Phoenix plates. The major tectonic events as the formation of oceanic plateaus and microplates during the period occurred in the vicinity of the triple junctions [e.g., Nakanishi and Winterer, 1998; Nakanishi et al., 1999], implying that the study of the triple junctions is indispensable for understanding the tectonic evolution of the Pacific plate. Previous studies indicate instability of the configuration of the triple junctions from Late Jurassic to Early Cretaceous (155-125 Ma). On the other hand, the age of the birth of the Pacific plate was determined assuming that all triple junctions had kept their configurations for about 30 m.y. [Nakanishi et al., 1992] because of insufficient information of the tectonic history of the Pacific plate before Late Jurassic.Increase in the bathymetric and geomagnetic data over the past two decades enables us to reveal the tectonic evolution of the Pacific-Izanagi-Farallon triple junction before Late Jurassic. Our detailed identication of magnetic anomaly lineations exposes magnetic bights before anomaly M25. We found the curved abyssal hills originated near the triple junction, which trend is parallel to magnetic anomaly lineations. These results imply that the configuration of the Pacific-Izanagi-Farallon triple junction had been RRR before Late Jurassic.

  20. PLATES WITH OXIDE INSERTS

    DOEpatents

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  1. CALUTRON FACE PLATE

    DOEpatents

    Brobeck, W.M.

    1959-08-25

    The construction of a removable cover plate for a calutron tank is described. The plate is fabricated of a rectangular frame member to which is welded a bowed or dished plate of thin steel, reinforced with transverse stiffening ribs. When the tank is placed between the poles of a magnet, the plate may be pivoted away from the tank and magnet and is adapted to support the ion separation mechanism secured to its inner side as well as the vacuum load within the tank.

  2. Nitric oxide regulates neutrophil migration through microparticle formation.

    PubMed

    Nolan, Sarah; Dixon, Rachel; Norman, Keith; Hellewell, Paul; Ridger, Victoria

    2008-01-01

    The role of nitric oxide (NO) in regulating neutrophil migration has been investigated. Human neutrophil migration to interleukin (IL)-8 (1 nmol/L) was measured after a 1-hour incubation using a 96-well chemotaxis plate assay. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) significantly (P < 0.001) enhanced IL-8-induced migration by up to 45%. Anti-CD18 significantly (P < 0.001) inhibited both IL-8-induced and L-NAME enhanced migration. Antibodies to L-selectin or PSGL-1 had no effect on IL-8-induced migration but prevented the increased migration to IL-8 induced by L-NAME. L-NAME induced generation of neutrophil-derived microparticles that was significantly (P < 0.01) greater than untreated neutrophils or D-NAME. This microparticle formation was dependent on calpain activity and superoxide production. Only microparticles from L-NAME and not untreated or D-NAME-treated neutrophils induced a significant (P < 0.01) increase in IL-8-induced migration and transendothelial migration. Pretreatment of microparticles with antibodies to L-selectin (DREG-200) or PSGL-1 (PL-1) significantly (P < 0.001) inhibited this effect. The ability of L-NAME-induced microparticles to enhance migration was found to be dependent on the number of microparticles produced and not an increase in microparticle surface L-selectin or PSGL-1 expression. These data show that NO can modulate neutrophil migration by regulating microparticle formation. PMID:18079439

  3. Alteration of the aPA ELISA by UV exposure of polystyrene microtiter plates.

    PubMed

    Goldberg, J S; Wagenknecht, D R; McIntyre, J A

    1996-01-01

    Interlaboratory inconsistencies in antiphospholipid antibody (aPA) solid phase assays have prompted controversy in clinical laboratory testing for aPA. We found that the aPA ELISA can be influenced by the type of microtiter plate utilized and by the conditions in which the plates are stored. By exposing 96-well, flat-bottom polystyrene microtiter plates to short wave UV light (254 nm), the aPA ELISA signal decreased in a UV dose-dependent manner. No effect was seen with long wave UV light (366 nm). These results were independent of the antibody isotype under study or the phospholipid (PL) antigen used: anionic phosphatidylserine (PS) and cardiolipin (CL), or zwitterionic phosphatidylethanolamine (PE). Purified human beta 2-glycoprotein I (beta 2 GPI), a known cofactor for anionic PL, and rabbit anti-beta 2 GPI antisera were used to demonstrate that beta 2 GPI bound equally to UV treated and untreated microtiter plates. In contrast, recognition of beta 2 GPI on an anionic PL surface was decreased on UV treated plates, suggesting that UV exposure alters the lipid binding properties of the microliter plate. To determine whether UV exposure inhibited PL binding directly or caused a change in the way the PL was bound, the amount of PL bound to UV treated and untreated plates was measured by using fluorescent labeled PS and a fluorimeter. PS binding was decreased by 53% in UV treated wells as compared to untreated wells. These data show that short wave UV exposure reduces PL binding to polystyrene microtiter plates, thereby reducing the amount of beta 2 GPI bound to PL coated ELISA plates. Thus by using UV exposed microtiter plates, decreased or false-negative a PA ELISA results may be obtained for aPA positive plasmas. PMID:8887002

  4. 4-D Subduction Models Incorporating an Upper Plate

    NASA Astrophysics Data System (ADS)

    Stegman, D.; Capitanio, F. A.; Moresi, L.; Mueller, D.; Clark, S.

    2007-12-01

    Thus far, relatively simplistic models of free subduction have been employed in which the trench and plate kinematics are emergent features completely driven by the negative buoyancy of the slab. This has allowed us to build a fundamental understanding of subduction processes such as the kinematics of subduction zones, the strength of slabs, and mantle flow-plate coupling. Additionaly, these efforts have helped to develop appreciable insight into subduction processes when considering the energetics of subduction, in particular how energy is dissipated in various parts of the system such as generating mantle flow and bending the plate. We are now in a position to build upon this knowledge and shift our focus towards the dynamic controls of deformation in the upper plate (vertical motions, extension, shortening, and dynamic topography). Here, the state of stress in the overriding plate is the product of the delicate balance of large tectonic forces in a highly-coupled system, and must therefore include all components of the system: the subducting plate, the overriding plate, and the underlying mantle flow which couples everything together. We will present some initial results of the fully dynamic 3-D models of free subduction which incorporate an overriding plate and systematically investigate how variations in the style and strength of subduction are expressed by the tectonics of the overriding plate. Deformation is driven in the overriding plate by the forces generated from the subducting plate and the type of boundary condition on the non-subducting side of the overriding plate (either fixed or free). Ultimately, these new models will help to address a range of issues: how the overriding plate influences the plate and trench kinematics; the formation and evolution of back-arc basins; the variation of tractions on the base of the overriding plate; the nature of forces which drive plates; and the dynamics controls on seismic coupling at the plate boundary.

  5. Performance evaluation of the R6R018 fuel plate using PLATE code

    SciTech Connect

    Pavel G. Medvedev; Hakan Ozaltun

    2010-03-01

    The paper presents results of performance evaluation of the R6R018 fuel plate using PLATE code. R6R018 is a U-7Mo dispersion type mini-plate with Al-3.5Si matrix irradiated in the RERTR-9B experiment. The design of this plate is prototypical of the planned LEONIDAS irradiation test. Therefore, a detailed performance analysis of this plate is important to confirm acceptable behavior in pile, and to provide baseline and justification for further analysis and testing. Specific results presented in the paper include fuel temperature history, growth of the interaction layer between the U-Mo and the matrix, swelling, growth of the corrosion layer, and degradation of thermal conductivity. The methodology of the analysis will be discussed including the newly developed capability to account for the formation of the interaction layer during fuel fabrication.

  6. Earthquakes and plate tectonics

    USGS Publications Warehouse

    Spall, H.

    1977-01-01

    An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

  7. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  8. Turbine vane plate assembly

    DOEpatents

    Schiavo Jr., Anthony L.

    2006-01-10

    A turbine vane assembly includes a turbine vane having first and second shrouds with an elongated airfoil extending between. Each end of the airfoil transitions into a shroud at a respective junction. Each of the shrouds has a plurality of cooling passages, and the airfoil has a plurality of cooling passages extending between the first and second shrouds. A substantially flat inner plate and an outer plate are coupled to each of the first and second shrouds so as to form inner and outer plenums. Each inner plenum is defined between at least the junction and the substantially flat inner plate; each outer plenum is defined between at least the substantially flat inner plate and the outer plate. Each inner plenum is in fluid communication with a respective outer plenum through at least one of the cooling passages in the respective shroud.

  9. Rapid LC-MS Drug Metabolite Profiling Using Microsomal Enzyme Bioreactors in a Parallel Processing Format

    PubMed Central

    Bajrami, Besnik; Zhao, Linlin; Schenkman, John B.; Rusling, James F.

    2009-01-01

    Silica nanoparticle bioreactors featuring thin films of enzymes and polyions were utilized in a novel high-throughput 96-well plate format for drug metabolism profiling. The utility of the approach was illustrated by investigating the metabolism of the drugs diclofenac (DCF), troglitazone (TGZ) and raloxifene, for which we observed known metabolic oxidation and bioconjugation pathways and turnover rates. A broad range of enzymes was included by utilizing human liver (HLM), rat liver (RLM) and bicistronic human-cyt P450 3A4 (bicis.-3A4) microsomes as enzyme sources. This parallel approach significantly shortens sample preparation steps compared to an earlier manual processing with nanoparticle bioreactors, allowing a range of significant enzyme reactions to be processed simultaneously. Enzyme turnover rates using the microsomal bioreactors were 2-3 fold larger compared to using conventional microsomal dispersions, most likely because of better accessibility of the enzymes. Ketoconazole (KET) and quinidine (QIN), substrates specific to cyt P450 3A enzymes, were used to demonstrate applicability to establish potentially toxic drug-drug interactions involving enzyme inhibition and acceleration. PMID:19904994

  10. Syncytial-Type Cell Plates

    PubMed Central

    Otegui, Marisa; Staehelin, L. Andrew

    2000-01-01

    Cell wall formation in the syncytial endosperm of Arabidopsis was studied by using high-pressure-frozen/freeze-substituted developing seeds and immunocytochemical techniques. The endosperm cellularization process begins at the late globular embryo stage with the synchronous organization of small clusters of oppositely oriented microtubules (∼10 microtubules in each set) into phragmoplast-like structures termed mini-phragmoplasts between both sister and nonsister nuclei. These mini-phragmoplasts produce a novel kind of cell plate, the syncytial-type cell plate, from Golgi-derived vesicles ∼63 nm in diameter, which fuse by way of hourglass-shaped intermediates into wide (∼45 nm in diameter) tubules. These wide tubules quickly become coated and surrounded by a ribosome-excluding matrix; as they grow, they branch and fuse with each other to form wide tubular networks. The mini-phragmoplasts formed between a given pair of nuclei produce aligned tubular networks that grow centrifugally until they merge into a coherent wide tubular network with the mini-phragmoplasts positioned along the network margins. The individual wide tubular networks expand laterally until they meet and eventually fuse with each other at the sites of the future cell corners. Transformation of the wide tubular networks into noncoated, thin (∼27 nm in diameter) tubular networks begins at multiple sites and coincides with the appearance of clathrin-coated budding structures. After fusion with the syncytial cell wall, the thin tubular networks are converted into fenestrated sheets and cell walls. Immunolabeling experiments show that the cell plates and cell walls of the endosperm differ from those of the embryo and maternal tissue in two features: their xyloglucans lack terminal fucose residues on the side chain, and callose persists in the cell walls after the cell plates fuse with the parental plasma membrane. The lack of terminal fucose residues on xyloglucans suggests that these cell wall

  11. Calcium Increases Xylella fastidiosa Surface Attachment, Biofilm Formation, and Twitching Motility

    PubMed Central

    Cruz, Luisa F.; Cobine, Paul A.

    2012-01-01

    Xylella fastidiosa is a plant-pathogenic bacterium that forms biofilms inside xylem vessels, a process thought to be influenced by the chemical composition of xylem sap. In this work, the effect of calcium on the production of X. fastidiosa biofilm and movement was analyzed under in vitro conditions. After a dose-response study with 96-well plates using eight metals, the strongest increase of biofilm formation was observed when medium was supplemented with at least 1.0 mM CaCl2. The removal of Ca by extracellular (EGTA, 1.5 mM) and intracellular [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA/AM), 75 μM] chelators reduced biofilm formation without compromising planktonic growth. The concentration of Ca influenced the force of adhesion to the substrate, biofilm thickness, cell-to-cell aggregation, and twitching motility, as shown by assays with microfluidic chambers and other assays. The effect of Ca on attachment was lost when cells were treated with tetracycline, suggesting that Ca has a metabolic or regulatory role in cell adhesion. A double mutant (fimA pilO) lacking type I and type IV pili did not improve biofilm formation or attachment when Ca was added to the medium, while single mutants of type I (fimA) or type IV (pilB) pili formed more biofilm under conditions of higher Ca concentrations. The concentration of Ca in the medium did not significantly influence the levels of exopolysaccharide produced. Our findings indicate that the role of Ca in biofilm formation may be related to the initial surface and cell-to-cell attachment and colonization stages of biofilm establishment, which rely on critical functions by fimbrial structures. PMID:22194297

  12. Lohse's historic plate archive

    NASA Astrophysics Data System (ADS)

    Tsvetkov, M.; Tsvetkova, K.; Richter, G.; Scholz, G.; Böhm, P.

    The description and the analysis of Oswald Lohse's astrophotographic plates, collected at the Astrophysical Observatory Potsdam in the period 1879 - 1889, are presented. 67 plates of the archive, taken with the greatest instrument of the observatory at that time - the refractor (D = 0.30 m, F = 5.40 m, scale = 38''/mm) and with the second heliographic objective (D = 0.13 m, F = 1.36 m, scale = 152''/mm) - - survived two world wars in relative good condition. The plate emulsions are from different manufacturers in the beginning of astrophotography (Gädicke, Schleussner, Beernaert, etc.). The sizes of the plates are usually 9x12 cm2, which corresponds to fields of 1.2deg and 5deg respectively for each instrument mentioned above. The average limiting magnitude is 13.0(pg). Besides of the plates received for technical experiments (work on photographic processes, testing of new instruments and methods of observations), the scientific observations follow programs for studies of planet surfaces, bright stars, some double stars, stellar clusters and nebulous objects. Lohse's archive is included into the Wide Field Plate Database (http://www.skyarchive.org) as the oldest systematic one, covering the fields of Orion (M42/43), Pleiades, h & chi Persei, M37, M3, M11, M13, M92, M31, etc. With the PDS 2020 GM+ microdensitometer of Münster University 10 archive plates were digitized.

  13. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  14. Cavity-Enhanced Immunoassay Measurements in Microtiter Plates Using BBCEAS.

    PubMed

    Bajuszova, Zuzana; Ali, Zulfiqur; Scott, Simon; Seetohul, L Nitin; Islam, Meez

    2016-05-17

    We report on the first detailed use of broadband cavity enhanced absorption spectroscopy (BBCEAS) as a detection system for immunoassay. A vertical R ≥ 0.99 optical cavity was integrated with a motorized XY stage, which functioned as a receptacle for 96-well microtiter plates. The custom-built cavity enhanced microplate reader was used to make measurements on a commercially available osteocalcin sandwich ELISA kit. A 30-fold increase in path length was obtained with a minimum detectable change in the absorption coefficient, αmin(t), of 5.3 × 10(-5) cm(-1) Hz(-1/2). This corresponded to a 39-fold increase in the sensitivity of measurement when directly compared to measurements in a conventional microplate reader. Separate measurements of a standard STREP-HRP colorimetric reaction in microtiter plates of differing optical quality produced an increase in sensitivity of up to 115-fold compared to a conventional microplate reader. The sensitivity of the developed setup compared favorably with previous liquid-phase cavity enhanced studies and approaches the sensitivity of typical fluorometric ELISAs. It could benefit any biochemical test which uses single pass absorption as a detection method, through either the label free detection of biologically important molecules at lower concentrations or the reduction in the amount of expensive biochemicals needed for a particular test, leading to cheaper tests. PMID:27089516

  15. Plate tectonics, habitability and life

    NASA Astrophysics Data System (ADS)

    Spohn, Tilman; Breuer, Doris

    2016-04-01

    The role of plate tectonics in defining habitability of terrestrial planets is being increasingly discussed (e.g., Elkins-Tanton, 2015). Plate tectonics is a significantly evolved concept with a large variety of aspects. In the present context, cycling of material between near surface and mantle reservoirs is most important. But increased heat transport through mixing of cold lithosphere with the deep interior and formation of continental crust may also matter. An alternative mechanism of material cycling between these reservoirs is hot-spot volcanism combined with crust delamination. Hot-spot volcanism will transport volatiles to the atmosphere while delamination will mix crust, possibly altered by sedimentation and chemical reactions, with the mantle. The mechanism works as long as the stagnant lithosphere plate has not grown thicker than the crust and as long as volcanic material is added onto the crust. Thermal evolution studies suggest that the mechanism could work for the first 1-2 Ga of planetary evolution. The efficiency of the mechanism is limited by the ratio of extrusive to intrusive volcanism, which is thought to be less than 0.25. Plate tectonics would certainly have an advantage by working even for more evolved planets. A simple, most-used concept of habitability requires the thermodynamic stability of liquid water on the surface of a planet. Cycling of CO2between the atmosphere, oceans and interior through subduction and surface volcanism is an important element of the carbonate-silicate cycle, a thermostat feedback cycle that will keep the atmosphere from entering into a runaway greenhouse. Calculations for a model Earth lacking plate tectonics but degassing CO2, N, and H2O to form a surface ocean and a secondary atmosphere (Tosi et al, 2016) suggest that liquid water can be maintained on the surface for 4.5Ga. The model planet would then qualify as habitable. It is conceivable that the CO2 buffering capability of its ocean together with silicate

  16. Plate tectonics: Metamorphic myth

    NASA Astrophysics Data System (ADS)

    Korenaga, Jun

    2016-01-01

    Clear evidence for subduction-induced metamorphism, and thus the operation of plate tectonics on the ancient Earth has been lacking. Theoretical calculations indicate that we may have been looking for something that cannot exist.

  17. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  18. Flat plate solar oven

    SciTech Connect

    Parikh, M.

    1981-01-01

    The construction of an Indian Rs. 186 (US $20.33) flat-plate solar oven is described. Detailed drawings are provided and relevant information on cooking times and temperature for different foods is given.

  19. Violin plate modes.

    PubMed

    Gough, Colin

    2015-01-01

    As the first step toward developing a generic model for the acoustically radiating vibrational modes of the violin and related instruments, the modes of both freely supported and edge-constrained top and back plates have been investigated as functions of shape, arching height, elastic anisotropy, the f-holes and associated island area, thickness graduations, and the additional boundary constraints of the ribs, soundpost, and bass-bar present in the assembled instrument. Comsol shell structure finite element software has been used as a quasi-experimental tool, with physical and geometric properties varied smoothly, often over several orders of magnitude, allowing the development of the plate modes to be followed continuously from those of an initially square plate to those of doubly-arched, guitar-shaped, orthotropic plates and their dependence on all the above factors. PMID:25618046

  20. Positive battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John R. (Inventor)

    1985-01-01

    The power characteristics of a lead acid battery are improved by incorporating a dispersion of 1 to 10% by weight of a thermodynamically stable conductivity additive, such as conductive tin oxide coated glass fibers (34) of filamentary glass wool (42) in the positive active layer (32) carried on the grid (30) of the positive plate (16). Positive plate potential must be kept high enough to prevent reduction of the tin oxide to tin by utilizing an oversized, precharged positive paste.

  1. Fractal multifiber microchannel plates

    NASA Technical Reports Server (NTRS)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  2. Phononic plate waves.

    PubMed

    Wu, Tsung-Tsong; Hsu, Jin-Chen; Sun, Jia-Hong

    2011-10-01

    In the past two decades, phononic crystals (PCs) which consist of periodically arranged media have attracted considerable interest because of the existence of complete frequency band gaps and maneuverable band structures. Recently, Lamb waves in thin plates with PC structures have started to receive increasing attention for their potential applications in filters, resonators, and waveguides. This paper presents a review of recent works related to phononic plate waves which have recently been published by the authors and coworkers. Theoretical and experimental studies of Lamb waves in 2-D PC plate structures are covered. On the theoretical side, analyses of Lamb waves in 2-D PC plates using the plane wave expansion (PWE) method, finite-difference time-domain (FDTD) method, and finite-element (FE) method are addressed. These methods were applied to study the complete band gaps of Lamb waves, characteristics of the propagating and localized wave modes, and behavior of anomalous refraction, called negative refraction, in the PC plates. The theoretical analyses demonstrated the effects of PC-based negative refraction, lens, waveguides, and resonant cavities. We also discuss the influences of geometrical parameters on the guiding and resonance efficiency and on the frequencies of waveguide and cavity modes. On the experimental side, the design and fabrication of a silicon-based Lamb wave resonator which utilizes PC plates as reflective gratings to form the resonant cavity are discussed. The measured results showed significant improvement of the insertion losses and quality factors of the resonators when the PCs were applied. PMID:21989878

  3. Biofilm formation and sanitizer resistance of Escherichia coli O157:H7 strains isolated from "high event period" meat contamination.

    PubMed

    Wang, Rong; Kalchayanand, Norasak; King, David A; Luedtke, Brandon E; Bosilevac, Joseph M; Arthur, Terrance M

    2014-11-01

    In the meat industry, a "high event period" (HEP) is defined as a time period during which commercial meat plants experience a higher than usual rate of Escherichia coli O157:H7 contamination. Genetic analysis indicated that within a HEP, most of the E. coli O157:H7 strains belong to a singular dominant strain type. This was in disagreement with the current beef contamination model stating that contamination occurs when incoming pathogen load on animal hides, which consists of diverse strain types of E. coli O157:H7, exceeds the intervention capacity. Thus, we hypothesize that the HEP contamination may be due to certain in-plant colonized E. coli O157:H7 strains that are better able to survive sanitization through biofilm formation. To test our hypothesis, a collection of 45 E. coli O157:H7 strains isolated from HEP beef contamination incidents and a panel of 47 E. coli O157:H7 strains of diverse genetic backgrounds were compared for biofilm formation and sanitizer resistance. Biofilm formation was tested on 96-well polystyrene plates for 1 to 6 days. Biofilm cell survival and recovery growth after sanitization were compared between the two strain collections using common sanitizers, including quaternary ammonium chloride, chlorine, and sodium chlorite. No difference in "early stage" biofilms was observed between the two strain collections after incubation at 22 to 25°C for 1 or 2 days. However, the HEP strains demonstrated significantly higher potency of "mature" biofilm formation after incubation for 4 to 6 days. Biofilms of the HEP strains also exhibited significantly stronger resistance to sanitization. These data suggest that biofilm formation and sanitization resistance could have a role in HEP beef contamination by E. coli O157:H7, which highlights the importance of proper and complete sanitization of food contact surfaces and food processing equipment in commercial meat plants. PMID:25364934

  4. Formation of the giant Chalukou porphyry Mo deposit in northern Great Xing'an Range, NE China: Partial melting of the juvenile lower crust in intra-plate extensional environment

    NASA Astrophysics Data System (ADS)

    Li, Zhen-Zhen; Qin, Ke-Zhang; Li, Guang-Ming; Ishihara, Shunso; Jin, Lu-Ying; Song, Guo-Xue; Meng, Zhao-Jun

    2014-08-01

    The Chalukou porphyry Mo deposit (2.46 Mt @ 0.087% Mo), located in the northern Great Xing'an Range, NE China, is the largest Mo deposit discovered in China so far. The host rocks consist of aplite porphyry, granite porphyry and quartz porphyry, and are intruded into Lower Ordovician intermediate-felsic volcanic-sedimentary rocks and pre-ore monzogranite and are cut by post-ore feldspar porphyry, diorite porphyry and quartz monzonite porphyry. Here, we present the zircon U-Pb ages, whole-rock geochemistry, Sr-Nd isotopic and zircon Hf isotopic data for the pre-ore, syn-ore and post-ore intrusive rocks. The Chalukou ore-forming porphyries intruded during 147-148 Ma and have high-silica, alkali-rich, metaluminous to slightly peraluminous compositions and are oxidized. They are enriched in large ion lithophile elements (e.g. K, Rb, U and Th), light REE and depleted in high-field strength elements (e.g. Nb, P and Ti). Depletions in Eu, Ba, Sr, Nb, Ta, P and Ti suggest that they have experienced strong fractional crystallization of plagioclase, biotite, hornblende and accessory minerals. The pre-ore monzogranite (~ 172 Ma) also belongs to the high-K calc-alkaline series. Highly fractionated REE patterns ((La/Yb) N = 19.6-21.7), high values of Sr/Y (54-69) and La/Yb (29-32), are adakite-like geochemical features. The post-ore rocks (~ 141-128 Ma) have similar geochemical characteristics with ore-forming porphyries except that quartz monzonite porphyry shows no Ba-Sr negative anomaly. All intrusive rocks have relative low initial 87Sr/86Sr (0.705413-0.707889) and εNd (t) values (- 1.28 to + 0.92), positive εHf (t) values (+ 2.4 to + 10.1) and young two-stage Nd and Hf model ages (TDM2 (Nd) = 863-977 Ma, TDM2 (Hf) = 552-976 Ma). These geochemical and isotopic data are interpreted to demonstrate that the ore-forming porphyries formed by partial melting of the juvenile lower crust caused by underplating of mafic magmas in an intra-plate extensional setting. The pre

  5. Relationship between plume and plate tectonics

    NASA Astrophysics Data System (ADS)

    Puchkov, V. N.

    2016-07-01

    The relationship between plate- and plume-tectonics is considered in view of the growth and breakdown of supercontinents, active rifting, the formation of passive volcanic-type continental margins, and the origin of time-progressive volcanic chains on oceanic and continental plates. The mantle wind phenomenon is described, as well as its effect on plume morphology and anisotropy of the ambient mantle. The interaction of plumes and mid-ocean ridges is discussed. The principles and problems of plume activity analysis in subduction- and collision-related foldbelts are considered and illustrated with examples.

  6. Distinct modes of floor plate induction in the chick embryo.

    PubMed

    Patten, Iain; Kulesa, Paul; Shen, Michael M; Fraser, Scott; Placzek, Marysia

    2003-10-01

    To begin to reconcile models of floor plate formation in the vertebrate neural tube, we have performed experiments aimed at understanding the development of the early floor plate in the chick embryo. Using real-time analyses of cell behaviour, we provide evidence that the principal contributor to the early neural midline, the future anterior floor plate, exists as a separate population of floor plate precursor cells in the epiblast of the gastrula stage embryo, and does not share a lineage with axial mesoderm. Analysis of the tissue interactions associated with differentiation of these cells to a floor plate fate reveals a role for the nascent prechordal mesoderm, indicating that more than one inductive event is associated with floor plate formation along the length of the neuraxis. We show that Nr1, a chick nodal homologue, is expressed in the nascent prechordal mesoderm and we provide evidence that Nodal signalling can cooperate with Shh to induce the epiblast precursors to a floor-plate fate. These results indicate that a shared lineage with axial mesoderm cells is not a pre-requisite for floor plate differentiation and suggest parallels between the development of the floor plate in amniote and anamniote embryos. PMID:12917296

  7. Caribbean plate interactions

    SciTech Connect

    Ball, M. )

    1993-02-01

    Vector analysis of plate motions, derived from studies of Atlantic magnetic lineations and fracture zone trends, indicates the following relative movements between the Caribbean, North American, and South American Plates. (1) During Early Jurassic to Early Cretaceous, the North American Plate moved 1900 km westward and 900 km northward relative to the South American Plate. A broad zone including the Caribbean region, i.e., the zone between the North and South America Plates, was a site of left-lateral shear and north-south extension. (2) During Early Cretaceous to Late Cretaceous, the North American Mate moved an additional 1200 km westward relative to South America across this zone. (3) During Late Cretaceous to the end of the Eocene, the North American Plate moved 200 km westward and 400 km northward relative to the South American Plate. (4) From the end of the Eocene to near the end of the Miocene, North America converged on South America some 200 km and moved 100 km eastward relative to it. Through the Mesozoic and earliest Tertiary history of the Caribbean, the region was a shear zone within which left-lateral displacement exceeded 3000 km and north-south extension exceeded 1300 km. In regard to time, 80% of the history of the Caribbean region is one of north-south extension and left-lateral shear. In terms of space, 97% of the shear is left-lateral and the ratio of divergence versus convergence is 7 to 1. Thus, characterizing the Caribbean region, and the Atlantic to its east, as a zone of north-south extension and left-lateral shear, is a fair generalization.

  8. Inhibition of Serratia marcescens Smj-11 biofilm formation by Alcaligenes faecalis STN17 crude extract

    NASA Astrophysics Data System (ADS)

    Lutfi, Zainal; Usup, Gires; Ahmad, Asmat

    2014-09-01

    Serratia marcescens biofilms are formed when they are bound to surfaces in aqueous environments. S. marcescens utilizes N-acylhomoserine lactone (AHL) as its quorum sensing signal molecule. The accumulation of AHL indicates the bacteria to produce matrices to form biofilms. Prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosin), which causes red pigmentation in the colonies, are also produced when the AHL reaches a certain threshold. The Alcaligenes faecalis STN17 crude extract is believed to inhibit quorum sensing in the S. marcescens Smj-11 and, thus, impedes its biofilm formation ability. A. faecalis STN17 was grown in marine broth, and ethyl acetate extraction was carried out. The crude compound of A. faecalis STN17 was diluted at high concentration (0.2-6.4 mg/mL) and was taken to confirm anti-biofilm activity through the crystal violet method in 96-wells plate. Then, the crude extract underwent purification using simple solvents partitioning test to discern the respective compounds that had the anti-biofilm activity under the crystal violet method. The crystal violet test showed that the crude did have anti-biofilm activity on S. marcescens Smj-11, but did not kill the cells. This finding signifies that the suppression of biofilm formation in S. marcescens by A. faecalis STN17 has a strong correlation. The partitioning test showed that A. faecalis STN17 crude extract has several compounds and only the compound(s) in chloroform showed activities. In conclusion, the crude extract of A. faecalis STN17 has the ability to inhibit S. marcescens Smj-11 biofilm formation.

  9. Inhibition of Serratia marcescens Smj-11 biofilm formation by Alcaligenes faecalis STN17 crude extract

    SciTech Connect

    Lutfi, Zainal; Ahmad, Asmat; Usup, Gires

    2014-09-03

    Serratia marcescens biofilms are formed when they are bound to surfaces in aqueous environments. S. marcescens utilizes N-acylhomoserine lactone (AHL) as its quorum sensing signal molecule. The accumulation of AHL indicates the bacteria to produce matrices to form biofilms. Prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosin), which causes red pigmentation in the colonies, are also produced when the AHL reaches a certain threshold. The Alcaligenes faecalis STN17 crude extract is believed to inhibit quorum sensing in the S. marcescens Smj-11 and, thus, impedes its biofilm formation ability. A. faecalis STN17 was grown in marine broth, and ethyl acetate extraction was carried out. The crude compound of A. faecalis STN17 was diluted at high concentration (0.2-6.4 mg/mL) and was taken to confirm anti-biofilm activity through the crystal violet method in 96-wells plate. Then, the crude extract underwent purification using simple solvents partitioning test to discern the respective compounds that had the anti-biofilm activity under the crystal violet method. The crystal violet test showed that the crude did have anti-biofilm activity on S. marcescens Smj-11, but did not kill the cells. This finding signifies that the suppression of biofilm formation in S. marcescens by A. faecalis STN17 has a strong correlation. The partitioning test showed that A. faecalis STN17 crude extract has several compounds and only the compound(s) in chloroform showed activities. In conclusion, the crude extract of A. faecalis STN17 has the ability to inhibit S. marcescens Smj-11 biofilm formation.

  10. Using Plate Mapping to Examine Portion Size and Plate Composition for Large and Small Divided Plates

    PubMed Central

    Sharp, David E.; Sobal, Jeffery; Wansink, Brian

    2015-01-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods – such as meat versus starch versus vegetables – very differently? To examine this, we utilize a promising new plate mapping method where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, that is, the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are discussed. PMID:25280373

  11. Optimization of device geometry in single-plate digital microfluidics

    NASA Astrophysics Data System (ADS)

    Abdelgawad, Mohamed; Park, Philip; Wheeler, Aaron R.

    2009-05-01

    Digital microfluidics is a popular tool for lab-on-a-chip applications and is typically implemented in one of two formats: single-plate ("open") devices or two-plate ("closed") devices. Single-plate devices have some advantages relative to the more common two-plate format such as faster mixing, the capacity to move larger volumes on a given footprint, and easier access to droplets for handling or optical detection. In contrast with the two-plate format, in which ground potential is generally supplied via a top electrode, in the single-plate format, many different geometries of ground wires/electrodes have been used. Until the present study, there has been no metric to determine which of these geometries is best suited for droplet actuation. Here, we present a combination of numerical simulations and experimental tests to compare six different single-plate designs. We applied finite element analysis, using the commercially available COMSOL software package to calculate the electrodynamic actuation forces in each of the different designs and used the results to optimize device design. Forces predicted by the electrodynamic model were in agreement with forces predicted using electromechanical models. More importantly, results were verified experimentally using a unique technique that permits indirect estimation of actuation forces on digital microfluidic devices. This work illustrates the promise of using numerical modeling to enhance the design and performance of digital microfluidic devices.

  12. When Did Plate Tectonics Begin

    NASA Astrophysics Data System (ADS)

    Brown, M.

    2015-12-01

    Present-day plate tectonics on Earth is characterized by asymmetric (one-sided) subduction, but how do we recognize the imprint of subduction in the geologic record? How do we weigh global (commonly younger) vs local (commonly older) datasets or distinguish initiation from episodic from continuous subduction? How reliable are data gaps? Characteristics of the Paleozoic record of subduction include calc-alkaline magmatism, blueschist/UHP metamorphism and collisional orogenesis, and ophiolites as representatives of former ocean lithosphere. Are these characteristic rocks preserved in Proterozoic, Archean and Hadean crust? Does a hotter mantle, higher heat production and weaker lithosphere modify or eliminate these features? What preceded subduction and how do we recognize that regime? Are rock associations or geochemical fingerprints reliable? Does reworking and overprinting modify geochemical fingerprints? Proposals for the start of plate tectonics have been based on: persistence of isotope anomalies/fractionated chemical domains in the mantle; changes in chemistry of magmatic rocks, rates of crustal growth vs reworking, and sites of growth; the metamorphic record, particularly the first appearance of contrasting thermal gradients or eclogite (including evidence from mineral inclusions in diamonds) or UHP metamorphic rocks; stabilization of cratonic lithosphere and formation of supercratons, and the beginning of the Proterozoic supercontinent cycle; the end of the flat Earth, emergence of continents, development of significant topography, changes in the style of orogeny and the rise in atmospheric oxygen; and, the appearance of passive margins and changes in the style of sedimentation. Estimates of the timing have varied from the Hadean to Neoproterozoic. I will summarize evidence for a growing consensus that the late Mesoarchean to early Paleoproterozoic was a 700 Myr long period of transition to continuous (?) subduction and global (?) mobile-lid plate tectonics.

  13. Cadmium plating replacements

    NASA Technical Reports Server (NTRS)

    Nelson, Mary J.; Groshart, Earl C.

    1995-01-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  14. Cadmium plating replacements

    SciTech Connect

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  15. Effects of the microstructure of twin roll cast and hot rolled plates on the surface quality of presensitized plates

    NASA Astrophysics Data System (ADS)

    Zhu, Yuan-Zhi; Zhang, Ya-Feng; Zhao, Chao-Qi; Zhou, Feng

    2014-09-01

    The effect of the microstructure of plates fabricated both in the traditional process, involving casting, hot rolling and cold rolling (HR), and in the novel twin roll casting + cold rolling (TRC) process on the surface quality of presensitized (PS) plates was analyzed by optical microscopy (OM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDXS). The formation of pores on the surface of the electrolyzed HR plate could be attributed to the presence of approximately 1-μm-sized large Al-Fe precipitates in the HR plate compared to the smaller precipitates in the TRC plate. Moreover, residual graphite lubricants used during the TRC process were entrapped on the surface of the TRC plate during the subsequent rolling process. The entrapped pollutants tended to further deteriorate the formation of pores on the surface of the TRC plate, and no residual carbon was detected on the surface of the HR plate. Furthermore, the surface quality of the TRC plate can be improved by surface cleaning before the cold rolling process, which could dramatically lower the residual graphite on the surface.

  16. Polar Plate Theory for Orthogonal Anisotropy

    NASA Technical Reports Server (NTRS)

    Bailey, Michelle D.; Bower, Mark V.

    2000-01-01

    evaluate out-of-plane displacements for given load conditions in design of composite Structures. Without the formation of these unique plate equations, design of such structures is not a precise engineering accomplishment due to the lack of precise design tools. Such structures are over designed to compensate and costly tests need to be performed after production to validate safety. Though impossible to present the mathematical solution within the limits of this paper, the application of the newly derived plate equation in its orthotropic form for a balanced symmetric laminate compared favorably with test results and surpassed the results of standard numerical methods. Within the limitations of the problem foundation the predictive model provides a mechanism for establishing out-of-plane deflection levels for a circular composite plate. Future work in this area should include incorporating the circular composite plate equations in Finite Element Models. The new anisotropic polar plate equations call be utilized as a design tool so that the design more accurately meets the requirements, thus taking full advantage of the weight savings of composites. These accomplishments have not previously been presented to the engineering community nor ever proposed to the IAF. Should the proposed paper be accepted for presentation, attendance is assured.

  17. Development of electrolyte plate for molten carbonate fuel cell

    SciTech Connect

    Shoji, C.; Matsuo, T.; Suzuki, A.; Yamamasu, Y.

    1998-07-01

    It is important for the commercialization of molten carbonate fuel cell (MCFC) to improve the endurance and the reliability of the electrolyte plate. The electrolyte-loss in the electrolyte plate increases the cell resistance and deteriorates the cell voltage. The formulation of cracks in the electrolyte plate causes a gas cross leakage between the fuel gas and the oxidizer gas. The pore structure of electrolyte plate must be stable and fine to support liquid electrolyte under MCFC operation. It is necessary to prevent the formation of cracks in electrolyte plate during thermal cycling. The authors have improved the stability of electrolyte plate using advanced LiAlO{sub 2} powder and improved the durability of electrolyte plate for thermal cycling by the addition of the ceramic fiber. The initial cell voltage using electrolyte plate with advanced LiAlO{sub 2} powder was 820 mV at current density 150mA/cm{sup 2} and the decay rate of cell voltage was under 0.5%/1,000h for 8,800h. According to the post analyses, the pore structure of the electrolyte plate did not change. The stability of advanced LiAlO{sub 2} powder was confirmed. It was proved that the electrolyte plate reinforced with ceramic fiber is effective for thermal cycling.

  18. Bipolar battery plate

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1987-01-01

    A liquid-impermeable plate (10) having through-plate conductivity with essentially zero resistance comprises an insulator sheet (12) having a series of spaced perforations (14) each of which contains a metal element (16) sealingly received into the perforation (14). A low-cost plate can readily be manufactured by punching a thermoplastic sheet (40) such as polypropylene with a punching tool (52), filling the apertures with led spheres (63) having a diameter smaller than the holes (50) but larger than the thickness of the sheet, sweeping excess spheres (62) off the sheet with a doctor blade (60) and then pressing a heated platen (74) onto the sheet to swage the spheres into a cylindrical shape and melt the surrounding resin to form a liquid-impermeable collar (4) sealing the metal into the sheet.

  19. Enzyme activity deviates due to spatial and temporal temperature profiles in commercial microtiter plate readers.

    PubMed

    Grosch, Jan-Hendrik; Sieben, Michaela; Lattermann, Clemens; Kauffmann, Kira; Büchs, Jochen; Spieß, Antje C

    2016-03-01

    Microtiter plates (MTP) and automatized techniques are increasingly applied in the field of biotechnology. However, the susceptibility of MTPs to edge effects such as thermal gradients can lead to high variation of measured enzyme activities. In an effort to enhance experimental reliability, to quantify, and to minimize instrument-caused deviations in enzyme kinetics between two MTP-readers, we comprehensively quantified temperature distribution in 96-well MTPs. We demonstrated the robust application of the absorbance dye cresol red as easily applicable temperature indicator in cuvettes and MTPs and determined its accuracy to ±0.16°C. We then quantified temperature distributions in 96-well MTPs revealing temperature deviations over single MTP of up to 2.2°C and different patterns in two commercial devices (BioTek Synergy 4 and Synergy Mx). The obtained liquid temperature was shown to be substantially controlled by evaporation. The temperature-induced enzyme activity variation within MTPs amounted to about 20 %. Activity deviations between MTPs and to those in cuvettes were determined to 40 % due to deviations from the set temperature in MTPs. In conclusion, we propose a better control of experimental conditions in MTPs or alternative experimental systems for reliable determination of kinetic parameters for bioprocess development. PMID:26709721

  20. Plate-mantle coupling from post-Pangea plate kinematics

    NASA Astrophysics Data System (ADS)

    Zahirovic, Sabin; Dietmar Müller, R.; Seton, Maria; Flament, Nicolas

    2015-04-01

    Convection in the Earth's mantle that involves plates at the surfaces gives rise to plate velocities that vary through time and depend on the balance of plate boundary forces, with the present-day providing a snapshot of this ongoing process. However, present-day plate velocities do not capture plate behaviour over geologically representative timeframes and thus cannot be used to evaluate factors limiting plate velocities. Previous studies investigated the effects of continental keels on plate speeds by either using the present-day snapshot or a limited number of reconstructed plate configurations, often leading to conflicting results. For example, an early assumption was that continental keels (especially cratons) were unlikely to impede fast plate motions because India's velocity approached ~20 cm/yr in the Eocene prior to the collision with Eurasia. We employ a modern plate reconstruction approach with evolving global topological plate boundaries for the post-Pangea timeframe (since 200 Ma) to evaluate factors controlling plate velocities. Plate boundary configurations and plate velocities are extracted from the open-source and cross-platform plate reconstruction package GPlates (www.gplates.org) at 1 Myr intervals. For each plate, at each timestep, the area of continental and cratonic lithosphere is calculated to evaluate the effect on plate velocities. Our results support that oceanic plates tend to be 2-3 times faster than plates with large portion of continental plate area, consistent with predictions of numerical models of mantle convection. The fastest plates (~8.5 cm/yr RMS) are dominated by oceanic plate area and high subducting portion of plate perimeter, while the slowest plates (~2.6-2.8 cm/yr RMS) are dominated by continental plate area and bounded by transforms and mid-oceanic ridge segments. Importantly, increasing cratonic fractions (both Proterozoic and Archean lithosphere) significantly impede plate velocities, suggesting that deep continental

  1. NICKEL PLATING PROCESS

    DOEpatents

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  2. Reduced Plating Ignitron

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A (Inventor); Pearson, J Boise (Inventor)

    2014-01-01

    An ignitron apparatus has an airtight tubular housing having a first sealed end and a second sealed end. An anode is connected at the first sealed end, projecting into the housing, and a recess at the second sealed and forms a well which contains a quantity of liquid gallium or gallium alloy making up the cathode. An ignitor projects through the liquid metal and into the housing. The inner surface of the housing includes at least one plating-reduction structure to prevent electrical shorting of the apparatus caused by plating of the liquid metal.

  3. Preserving and Archiving Astronomical Photographic Plates

    NASA Astrophysics Data System (ADS)

    Castelaz, M. W.; Cline, J. D.

    2005-05-01

    Astronomical objects change with time. New observations complement past observations recorded on photographic plates. Analyses of changes provide essential routes to information about an object's formation, constitution and evolution. Preserving a century of photographic plate observations is thus of paramount importance. Plate collections are presently widely dispersed; plates may be stored in poor conditions, and are effectively inaccessible to both researchers and historians. We describe a planned project at Pisgah Astronomical Research Institute to preserve the collections of astronomical plates in the United States by gathering them into a single storage location. Collections will be sorted, cleaned, and cataloged on-line so as to provide access to researchers. Full scientific and historic use of the material then requires the observations themselves to be accessible digitally. The project's goal will be the availability of these data as a unique, fully-maintained scientific and educational resource. The new archive will support trans-disciplinary research such as the chemistry of the Earth's atmosphere, library information science, trends in local weather patterns, and impacts of urbanization on telescope use, while the hand-written observatory logs will be a valuable resource for science historians and biographers.

  4. Elastocapillary coalescence of plates and pillars

    PubMed Central

    Wei, Z.; Schneider, T. M.; Kim, J.; Kim, H.-Y.; Aizenberg, J.; Mahadevan, L.

    2015-01-01

    When a fluid-immersed array of supported plates or pillars is dried, evaporation leads to the formation of menisci on the tips of the plates or pillars that bring them together to form complex patterns. Building on prior experimental observations, we use a combination of theory and computation to understand the nature of this instability and its evolution in both the two- and three-dimensional setting of the problem. For the case of plates, we explicitly derive the interaction torques based on the relevant physical parameters associated with pillar deformation, contact-line pinning/depinning and fluid volume changes. A Bloch-wave analysis for our periodic mechanical system captures the window of volumes where the two-plate eigenvalue characterizes the onset of the coalescence instability. We then study the evolution of these binary clusters and their eventual elastic arrest using numerical simulations that account for evaporative dynamics coupled to capillary coalescence. This explains both the formation of hierarchical clusters and the sensitive dependence of the final structures on initial perturbations, as seen in our experiments. We then generalize our analysis to treat the problem of pillar collapse in three dimensions, where the fluid domain is completely connected and the interface is a minimal surface with the uniform mean curvature. Our theory and simulations capture the salient features of experimental observations in a range of different situations and may thus be useful in controlling the ensuing patterns. PMID:25792949

  5. Nuclear reactor alignment plate configuration

    DOEpatents

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  6. INL HIP Plate Fabrication

    SciTech Connect

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  7. Unitary plate electrode

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor); Clough, Thomas J. (Inventor); Josefowicz, Jack Y. (Inventor); Sibert, John W. (Inventor)

    1985-01-01

    The unitary electrode (10) comprises a porous sheet (12) of fiberglass the strands (14) of which contain a coating (16) of conductive tin oxide. The lower portion of the sheet contains a layer (18) of resin and the upper layer (20) contains lead dioxide forming a positive active electrode on an electrolyte-impervious layer. The strands (14) form a continuous conduction path through both layers (16, 18). Tin oxide is prevented from reduction by coating the surface of the plate facing the negative electrode with a conductive, impervious layer resistant to reduction such as a thin film (130) of lead or graphite filled resin adhered to the plate with a layer (31) of conductive adhesive. The plate (10) can be formed by casting a molten resin from kettle (60) onto a sheet of glass wool (56) overlying a sheet of lead foil and then applying positive active paste from hopper (64) into the upper layer (68). The plate can also be formed by passing an assembly of a sheet ( 80) of resin, a sheet (86) of sintered glass and a sheet (90) of lead between the nip (92) of heated rollers (93, 95) and then filling lead oxide into the pores (116) of the upper layer (118).

  8. Growth Plate Injuries

    MedlinePlus

    ... or crushed, the growth plate may close prematurely, forming a bony bridge or “bar.” The risk of ... this publication: James S. Panagis, M.D., M.P.H., NIAMS/NIH; R. Tracy Ballock, M.D., Case ...

  9. The Plate Tectonics Project

    ERIC Educational Resources Information Center

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  10. Geology and plate-tectonic development

    SciTech Connect

    Irwin, W.P.

    1990-01-01

    The San Andreas fault is a transform fault along the boundary between the Pacific and North American plates. Bedrock along the fault includes various lithologic units that range in age from Precambrian to Tertiary and younger. Some bedrock units that can be matched across the fault suggest strike-slip displacement of as much as 560 km. This chapter describes geologic formations of northern and central California, including Franciscan rocks, Coast Range ophiolite, Great Valley sequence, Coast Range thrust, Salinian block, displacement of pre-Quaternary rocks by the San Andreas fault, and the relation of geologic structure to seismic behavior. Formations of southern California which are described are the Transverse Ranges and the Salton Trough and displacement of basement rocks by the San Andreas fault. Plate-tectonic development of the San Andreas fault is also discussed.