Science.gov

Sample records for rapid one-step purification

  1. Rapid one-step purification of single-cells encapsulated in alginate microcapsules from oil to aqueous phase using a hydrophobic filter paper: implications for single-cell experiments.

    PubMed

    Lee, Do-Hyun; Jang, Miran; Park, Je-Kyun

    2014-10-01

    By virtue of the biocompatibility and physical properties of hydrogel, picoliter-sized hydrogel microcapsules have been considered to be a biometric signature containing several features similar to that of encapsulated single cells, including phenotype, viability, and intracellular content. To maximize the experimental potential of encapsulating cells in hydrogel microcapsules, a method that enables efficient hydrogel microcapsule purification from oil is necessary. Current methods based on centrifugation for the conventional stepwise rinsing of oil, are slow and laborious and decrease the monodispersity and yield of the recovered hydrogel microcapsules. To remedy these shortcomings we have developed a simple one-step method to purify alginate microcapsules, containing a single live cell, from oil to aqueous phase. This method employs oil impregnation using a commercially available hydrophobic filter paper without multistep centrifugal purification and complicated microchannel networks. The oil-suspended alginate microcapsules encapsulating single cells from mammalian cancer cell lines (MCF-7, HepG2, and U937) and microorganisms (Chlorella vulgaris) were successfully exchanged to cell culture media by quick (~10 min) depletion of the surrounding oil phase without coalescence of neighboring microcapsules. Cell proliferation and high integrity of the microcapsules were also demonstrated by long-term incubation of microcapsules containing a single live cell. We expect that this method for the simple and rapid purification of encapsulated single-cell microcapsules will attain widespread adoption, assisting cell biologists and clinicians in the development of single-cell experiments.

  2. Design of affinity tags for one-step protein purification from immobilized zinc columns

    SciTech Connect

    Pasquinelli, R.S.; Shepherd, R.E.; Koepsel, R.R.; Zhao, A.; Ataai, M.M.

    2000-02-01

    Affinity tags are often used to accomplish recombinant protein purification using immobilized metal affinity chromatography. Success of the tag depends on the chelated metal used and the elution profile of the host cell proteins. Zn(II)-iminodiacetic acid (Zn(II)-IDA) may prove to e superior to either immobilized copper or nickel as a result of its relatively low binding affinity for cellular proteins. for example, almost all Escherichia coli proteins elute from Zn(II)-IDA columns between pH 7.5 and 7.0 with very little cellular protein emerging at pH values lower than 7.0. Thus, a large portion of the Zn(II)-IDA elution profile may be free of contaminant proteins, which can be exploited for one-step purification of a target protein from raw cell extract. In this paper the authors have identified several fusion tags that can direct the elution of the target protein to the low background region of the Zn(II)-IDA elution profile. These tags allow targeting of proteins to different regions of the elution profile, facilitating purification under mild conditions.

  3. One-step chromatographic procedure for purification of B-phycoerythrin from Porphyridium cruentum.

    PubMed

    Tang, Zhihong; Jilu Zhao; Ju, Bao; Li, Wenjun; Wen, Shaohong; Pu, Yang; Qin, Song

    2016-07-01

    B-phycoerythrin (B-PE) was separated and purified from microalga Porphyridium cruentum using one-step chromatographic method. Phycobiliproteins in P. cruentum was extracted by osmotic shock and initially purified by ultrafiltration. Further purification was carried out with a SOURCE 15Q exchange column and analytical grade B-PE was obtained with a purity ratio (A545/A280) of 5.1 and a yield of 68.5%. It showed a double absorption peaks at 545 nm and 565 nm and a shoulder peak at 498 nm, and displayed a fluorescence emission maximum at 580 nm. The analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a bulky band between 18 and 20 kDa which could be assigned to subunits α and β and a low intensity band of 27 kDa assigned to γ subunit. Our protocol provides attractive alternative to consider for the purification procedure to obtain analytical grade B-PE at commercial level.

  4. One-step chromatographic procedure for purification of B-phycoerythrin from Porphyridium cruentum.

    PubMed

    Tang, Zhihong; Jilu Zhao; Ju, Bao; Li, Wenjun; Wen, Shaohong; Pu, Yang; Qin, Song

    2016-07-01

    B-phycoerythrin (B-PE) was separated and purified from microalga Porphyridium cruentum using one-step chromatographic method. Phycobiliproteins in P. cruentum was extracted by osmotic shock and initially purified by ultrafiltration. Further purification was carried out with a SOURCE 15Q exchange column and analytical grade B-PE was obtained with a purity ratio (A545/A280) of 5.1 and a yield of 68.5%. It showed a double absorption peaks at 545 nm and 565 nm and a shoulder peak at 498 nm, and displayed a fluorescence emission maximum at 580 nm. The analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a bulky band between 18 and 20 kDa which could be assigned to subunits α and β and a low intensity band of 27 kDa assigned to γ subunit. Our protocol provides attractive alternative to consider for the purification procedure to obtain analytical grade B-PE at commercial level. PMID:26851659

  5. One-Step Chromatographic Purification of Helicobacter pylori Neutrophil-Activating Protein Expressed in Bacillus subtilis

    PubMed Central

    Shih, Kuo-Shun; Lin, Chih-Chang; Hung, Hsiao-Fang; Yang, Yu-Chi; Wang, Chung-An; Jeng, Kee-Ching; Fu, Hua-Wen

    2013-01-01

    Helicobacter pylori neutrophil-activating protein (HP-NAP), a major virulence factor of Helicobacter pylori (H. pylori), is capable of activating human neutrophils to produce reactive oxygen species (ROS) and secrete inammatory mediators. HP-NAP is a vaccine candidate, a possible drug target, and a potential in vitro diagnostic marker for H. pylori infection. HP-NAP has also been shown to be a novel therapeutic agent for the treatment of allergic asthma and bladder cancer. Hence, an efficient way to obtain pure HP-NAP needs to be developed. In this study, one-step anion-exchange chromatography in negative mode was applied to purify the recombinant HP-NAP expressed in Bacillus subtilis (B. subtilis). This purification technique was based on the binding of host cell proteins and/or impurities other than HP-NAP to DEAE Sephadex resins. At pH 8.0, almost no other proteins except HP-NAP passed through the DEAE Sephadex column. More than 60% of the total HP-NAP with purity higher than 91% was recovered in the flow-through fraction from this single-step DEAE Sephadex chromatography. The purified recombinant HP-NAP was further demonstrated to be a multimeric protein with a secondary structure of α-helix and capable of activating human neutrophils to stimulate ROS production. Thus, this one-step negative chromatography using DEAE Sephadex resin can efficiently yield functional HP-NAP from B. subtilis in its native form with high purity. HP-NAP purified by this method could be further utilized for the development of new drugs, vaccines, and diagnostics for H. pylori infection. PMID:23577158

  6. One-step purification of R-phycoerythrin from the red edible seaweed Grateloupia turuturu.

    PubMed

    Munier, Mathilde; Morançais, Michèle; Dumay, Justine; Jaouen, Pascal; Fleurence, Joël

    2015-06-15

    A one-step chromatographic method for the purification of R-phycoerythrin (R-PE) of Grateloupia turuturu Yamada is described. Native R-PE was obtained with a purity index of 2.89 and a recovery yield of 27% using DEAE-Sepharose Fast Flow chromatography with a three-step increase in ionic strength. The analysis by SDS electrophoresis showed a broad band between 18 and 21kDa in size corresponding to subunits α and β and a low intensity band of 29kDa corresponding to the γ subunit. Two forms of R-PE were identified by gel filtration chromatography: a native form with a molecular weight of 260±5kDa and a dissociated form with a molecular weight of 60±2kDa. The native form presented the characteristic absorption spectrum of R-PE with three absorbance maxima at 498, 540 and 565nm, whereas the dissociated form presented only the 498 and 540nm peaks. Moreover, the two forms displayed two different fluorescence maxima. PMID:25939094

  7. One-step purification of phosphinothricin acetyltransferase using reactive dye-affinity chromatography.

    PubMed

    Wang, Cunxi; Lee, Thomas C; Crowley, Kathleen S; Bell, Erin

    2015-01-01

    Reactive dye purification is an affinity purification technique offering unique selectivity and high purification potential. Historically, purification of phosphinothricin acetyltransferase (PAT) has involved several steps of precipitation and column chromatography. Here, we describe a novel purification method that is simple, time-saving, inexpensive, and reproducible. The novel method employs a single chromatography step using a reactive dye resin, Reactive brown 10-agarose. Reactive brown 10 preferentially binds the PAT protein, which can then be specifically released by one of its substrates, acetyl-CoA. Using Reactive brown 10-agarose, PAT protein can be purified to homogeneity from E. coli or plant tissue with high recovery efficiency. PMID:25749943

  8. A rapid, one step molecular identification of Trichoderma citrinoviride and Trichoderma reesei.

    PubMed

    Saroj, Dina B; Dengeti, Shrinivas N; Aher, Supriya; Gupta, Anil K

    2015-06-01

    Trichoderma species are widely used as production hosts for industrial enzymes. Identification of Trichoderma species requires a complex molecular biology based identification involving amplification and sequencing of multiple genes. Industrial laboratories are required to run identification tests repeatedly in cell banking procedures and also to prove absence of production host in the product. Such demands can be fulfilled by a brief method which enables confirmation of strain identity. This communication describes one step identification method for two common Trichoderma species; T. citrinoviride and T. reesei, based on identification of polymorphic region in the nucleotide sequence of translation elongation factor 1 alpha. A unique forward primer and common reverse primer resulted in 153 and 139 bp amplicon for T. citrinoviride and T. reesei, respectively. Simplification was further introduced by using mycelium as template for PCR amplification. Method described in this communication allows rapid, one step identification of two Trichoderma species.

  9. Expression and one-step purification of Plasmodium proteins in dictyostelium.

    PubMed

    van Bemmelen, M X; Beghdadi-Rais, C; Desponds, C; Vargas, E; Herrera, S; Reymond, C D; Fasel, N

    2000-12-01

    Nearly full-length Circumsporozoite protein (CSP) from Plasmodium falciparum, the C-terminal fragments from both P. falciparm and P. yoelii CSP and a fragment comprising 351 amino acids of P.vivax MSPI were expressed in the slime mold Dictyostelium discoideum. Discoidin-tag expression vectors allowed both high yields of these proteins and their purification by a nearly single-step procedure. We exploited the galactose binding activity of Discoidin Ia to separate the fusion proteins by affinity chromatography on Sepharose-4B columns. Inclusion of a thrombin recognition site allowed cleavage of the Discoidin-tag from the fusion protein. Partial secretion of the protein was obtained via an ER independent pathway, whereas routing the recombinant proteins to the ER resulted in glycosylation and retention. Yields of proteins ranged from 0.08 to 3 mg l(-1) depending on the protein sequence and the purification conditions. The recognition of purified MSPI by sera from P. vivax malaria patients was used to confirm the native conformation of the protein expressed in Dictyostelium. The simple purification procedure described here, based on Sepharose-4B, should facilitate the expression and the large-scale purification of various Plasmodium polypeptides. PMID:11163444

  10. Intein-mediated one-step purification of Escherichia coli secreted human antibody fragments.

    SciTech Connect

    Wu, Wan-Yi; Miller, Keith D.; Coolbaugh, Michael; Wood, David W.

    2011-02-25

    In this work, we apply self-cleaving affinity tag technology to several target proteins secreted into the Escherichia coli periplasm, including two with disulfide bonds. The target proteins were genetically fused to a self-cleaving chitin-binding domain intein tag for purification via a chitin agarose affinity resin. By attaching the intein-tagged fusion genes to the PelB secretion leader sequence, the tagged target proteins were secreted to the periplasmic space and could be recovered in active form by simple osmotic shock. After chitin-affinity purification, the target proteins were released from the chitin-binding domain tag via intein self-cleaving. This was induced by a small change in pH from 8.5 to 6.5 at room temperature, allowing direct elution of the cleaved target protein from the chitin affinity resin. The target proteins include the E. coli maltose-binding protein and b-lactamase enzyme, as well as two human antibody fragments that contain disulfide bonds. In all cases, the target proteins were purified with good activity and yield, without the need for refolding. Overall, this work demonstrates the compatibility of the DI-CM intein with the PelB secretion system in E. coli, greatly expanding its potential to more complex proteins.

  11. Strategies for the one-step immobilization-purification of enzymes as industrial biocatalysts.

    PubMed

    Barbosa, Oveimar; Ortiz, Claudia; Berenguer-Murcia, Ángel; Torres, Rodrigo; Rodrigues, Rafael C; Fernandez-Lafuente, Roberto

    2015-01-01

    In this review, we detail the efforts performed to couple the purification and the immobilization of industrial enzymes in a single step. The use of antibodies, the development of specific domains with affinity for some specific supports will be revised. Moreover, we will discuss the use of domains that increase the affinity for standard matrices (ionic exchangers, silicates). We will show how the control of the immobilization conditions may convert some unspecific supports in largely specific ones. The development of tailor-made heterofunctional supports as a tool to immobilize-stabilize-purify some proteins will be discussed in deep, using low concentration of adsorbent groups and a dense layer of groups able to give an intense multipoint covalent attachment. The final coupling of mutagenesis and tailor made supports will be the last part of the review.

  12. Strategies for the one-step immobilization-purification of enzymes as industrial biocatalysts.

    PubMed

    Barbosa, Oveimar; Ortiz, Claudia; Berenguer-Murcia, Ángel; Torres, Rodrigo; Rodrigues, Rafael C; Fernandez-Lafuente, Roberto

    2015-01-01

    In this review, we detail the efforts performed to couple the purification and the immobilization of industrial enzymes in a single step. The use of antibodies, the development of specific domains with affinity for some specific supports will be revised. Moreover, we will discuss the use of domains that increase the affinity for standard matrices (ionic exchangers, silicates). We will show how the control of the immobilization conditions may convert some unspecific supports in largely specific ones. The development of tailor-made heterofunctional supports as a tool to immobilize-stabilize-purify some proteins will be discussed in deep, using low concentration of adsorbent groups and a dense layer of groups able to give an intense multipoint covalent attachment. The final coupling of mutagenesis and tailor made supports will be the last part of the review. PMID:25777494

  13. Evaluation of strategies to control Fab light chain dimer during mammalian expression and purification: A universal one-step process for purification of correctly assembled Fab.

    PubMed

    Spooner, Jennifer; Keen, Jenny; Nayyar, Kalpana; Birkett, Neil; Bond, Nicholas; Bannister, David; Tigue, Natalie; Higazi, Daniel; Kemp, Benjamin; Vaughan, Tristan; Kippen, Alistair; Buchanan, Andrew

    2015-07-01

    Fabs are an important class of antibody fragment as both research reagents and therapeutic agents. There are a plethora of methods described for their recombinant expression and purification. However, these do not address the issue of excessive light chain production that forms light chain dimers nor do they describe a universal purification strategy. Light chain dimer impurities and the absence of a universal Fab purification strategy present persistent challenges for biotechnology applications using Fabs, particularly around the need for bespoke purification strategies. This study describes methods to address light chain dimer formation during Fab expression and identifies a novel CH 1 affinity resin as a simple and efficient one-step purification for correctly assembled Fab.

  14. One-step purification of lactoperoxidase from bovine milk by affinity chromatography.

    PubMed

    Atasever, Ali; Ozdemir, Hasan; Gulcin, Ilhami; Irfan Kufrevioglu, O

    2013-01-15

    Sulphanilamide was determined to be a new inhibitor of lactoperoxidase (LPO) with an IC(50) of 0.848.10(-5)M. The K(i) for sulphanilamide was determined to be 3.57.10(-5)M and sulphanilamide showed competitive inhibition, which makes it a suitable ligand for constructing a Sepharose 4B-L-tyrosine affinity matrix. The affinity matrix was synthesised by coupling sulphanilamide as the ligand and L-tyrosine as the spacer arm to a cyanogen bromide (CNBr)-activated-Sepharose 4B matrix. Lactoperoxidase was purified 409-fold from the synthesized affinity matrix in a single step, with a yield of 62.3% and a specific activity of 40.9 EU/mg protein. The enzyme activity was measured using ABTS as a chromogenic substrate (pH 6.0). The degree of LPO purification was monitored by SDS-PAGE and its R(z) (A(412)/A(280)) value. The R(z) value for the purified LPO was found to be 0.7. Maximum binding was achieved and K(m) and V(max) values were determined.

  15. Renaturation and one step purification of the chicken GIIA secreted phospholipase A2 from inclusion bodies.

    PubMed

    Karray, Aida; Amara, Sawsan; Carrière, Frédéric; Gargouri, Youssef; Bezzine, Sofiane

    2014-06-01

    The cDNA coding for a mature protein of 123 amino acids, containing all of the structural features of catalytically active group IIA sPLA2, has been amplified from chicken intestine. The gene has been cloned into the bacterial expression vector pET-21a(+), which allows protein over-expression as inclusion bodies and enables about 3mg/l of pure refolded fully active enzyme to be obtained. Recombinant expression of chicken intestinal sPLA2-IIA (ChPLA2-IIA) in Escherichia coli shows that the enzyme is Ca(2+) dependent, maximally active at pH 8-9, and hydrolyses phosphatidylglycerol versus phosphatidylcholine with a 10-fold preference. Indeed, we report in this work, a comparative kinetic study between the wild type and the recombinant ChPLA2-IIA, on zwitterionic head group phospholipids (DDPC) and negatively charged phospholipids (POPG) using the monomolecular film technique. The ability to express reasonably large amounts of the sPLA2 Group IIA, compared to that obtained with the classical purification will provide a basis for future site directed mutagenesis studies of this important enzyme.

  16. Rapid one-step assays for on-site monitoring of mouse and rat urinary allergens.

    PubMed

    Koets, Marjo; Renström, Anne; Zahradnik, Eva; Bogdanovic, Jelena; Wouters, Inge M; van Amerongen, Aart

    2011-12-01

    Allergy to rodent proteins is common among laboratory animal workers. Sensitive methods to measure exposure to these allergens have been developed. These assays are, however, expensive, time-consuming, and require a laboratory facility and methodological expertise. A simple method to screen for allergen spread, or to test whether hygiene standards are maintained, would be useful. Lateral flow immunoassays (LFIAs) are especially suited for field settings; the tests are simple and results are visible within minutes. LFIAs were developed for detection of the rodent urinary allergens Mus m 1 and Rat n 1. Pilot studies were performed in animal facilities in three countries using both extracts from airborne dust samples and samples collected by wiping surfaces. For comparison and determination of sensitivity, the concentrations of rodent urinary allergens in the samples were also measured using enzyme immunoassays (EIAs). The LFIAs for rat and mouse urinary allergens had a detection limit of 31 pg allergen per mL in a buffer system with purified allergen standards. Results of environmental dust extracts tested in LFIAs correlated well with levels obtained using EIAs. Spread of rodent allergens, or non-adherence to hygiene around laboratory animal facilities, may aggravate rodent allergy. Using a simple, sensitive one-step assay, allergens can be detected to prevent allergen exposure. The results reveal that the rapid assays are suited for on-site demonstration of exposure to rodent allergens, and thus, useful in occupational hygiene practice.

  17. Self-Assembly of Synthetic Metabolons through Synthetic Protein Scaffolds: One-Step Purification, Co-immobilization, and Substrate Channeling

    SciTech Connect

    You, C; Zhang, YHP

    2013-02-01

    One-step purification of a multi-enzyme complex was developed based on a mixture of cell extracts containing three dockerin-containing enzymes and one family 3 cellulose-binding module (CBM3)-containing scaffoldin through high-affinity adsorption on low-cost solid regenerated amorphous cellulose (RAC). The three-enzyme complex, called synthetic metabolon, was self-assembled through the high-affinity interaction between the dockerin in each enzyme and three cohesins in the synthetic scaffoldin. The metabolons were either immobilized on the external surface of RAC or free when the scaffoldin contained an intein between the CBM3 and three cohesins. The immobilized and free metabolons containing triosephosphate isomerase, aldolase, and fructose 1,6-biphosphatase exhibited initial reaction rates 48 and 38 times, respectively, that of the non-complexed three-enzyme mixture at the same enzyme loading. Such reaction rate enhancements indicated strong substrate channeling among synthetic metabolons due to the close spatial organization among cascade enzymes. These results suggested that the construction of synthetic metabolons by using cohesins, dockerins, and cellulose-binding modules from cellulosomes not only decreased protein purification labor and cost for in vitro synthetic biology projects but also accelerated reaction rates by 1 order of magnitude compared to non-complexed enzymes. Synthetic metabolons would be an important biocatalytic module for in vitro and in vivo synthetic biology projects.

  18. Preparative isolation and purification of phlorotannins from Ecklonia cava using centrifugal partition chromatography by one-step.

    PubMed

    Lee, Ji-Hyeok; Ko, Ju-Young; Oh, Jae-Young; Kim, Chul-Young; Lee, Hee-Ju; Kim, Jaeil; Jeon, You-Jin

    2014-09-01

    Various bioactive phlorotannins of Ecklonia cava (e.g., dieckol, eckol, 6,6-bieckol, phloroglucinol, phloroeckol, and phlorofucofuroeckol-A) are reported. However, their isolation and purification are not easy. Centrifugal partition chromatography (CPC) can be used to efficiently purify the various bioactive-compounds efficiently from E. cava. Phlorotannins are successfully isolated from the ethyl acetate (EtOAc) fraction of E. cava by CPC with a two-phase solvent system comprising n-hexane:EtOAc:methanol:water (2:7:3:7, v/v) solution. The dieckol (fraction I, 40.2mg), phlorofucofuroeckol-A (fraction III, 31.1mg), and fraction II (34.1mg) with 2,7-phloroglucinol-6,6-bieckol and pyrogallol-phloroglucinol-6,6-bieckol are isolated from the crude extract (500 mg) by a one-step CPC system. The purities of the isolated dieckol and phlorofucofuroeckol-A are ⩾90% according to high performance liquid chromatography (HPLC) and electrospray ionization multi stage tandem mass spectrometry analyses. The purified 2,7-phloroglucinol-6,6-bieckol and pyrogallol-phloroglucinol-6,6-bieckol are collected from fraction II by recycle-HPLC. Thus, the CPC system is useful for easy and simple isolation of phlorotannins from E. cava.

  19. A One-Step, Real-Time PCR Assay for Rapid Detection of Rhinovirus

    PubMed Central

    Do, Duc H.; Laus, Stella; Leber, Amy; Marcon, Mario J.; Jordan, Jeanne A.; Martin, Judith M.; Wadowsky, Robert M.

    2010-01-01

    One-step, real-time PCR assays for rhinovirus have been developed for a limited number of PCR amplification platforms and chemistries, and some exhibit cross-reactivity with genetically similar enteroviruses. We developed a one-step, real-time PCR assay for rhinovirus by using a sequence detection system (Applied Biosystems; Foster City, CA). The primers were designed to amplify a 120-base target in the noncoding region of picornavirus RNA, and a TaqMan (Applied Biosystems) degenerate probe was designed for the specific detection of rhinovirus amplicons. The PCR assay had no cross-reactivity with a panel of 76 nontarget nucleic acids, which included RNAs from 43 enterovirus strains. Excellent lower limits of detection relative to viral culture were observed for the PCR assay by using 38 of 40 rhinovirus reference strains representing different serotypes, which could reproducibly detect rhinovirus serotype 2 in viral transport medium containing 10 to 10,000 TCID50 (50% tissue culture infectious dose endpoint) units/ml of the virus. However, for rhinovirus serotypes 59 and 69, the PCR assay was less sensitive than culture. Testing of 48 clinical specimens from children with cold-like illnesses for rhinovirus by the PCR and culture assays yielded detection rates of 16.7% and 6.3%, respectively. For a batch of 10 specimens, the entire assay was completed in 4.5 hours. This real-time PCR assay enables detection of many rhinovirus serotypes with the Applied Biosystems reagent-instrument platform. PMID:19948820

  20. Rapid and Efficient One-Step Metabolic Pathway Integration in E. coli.

    PubMed

    Bassalo, Marcelo C; Garst, Andrew D; Halweg-Edwards, Andrea L; Grau, William C; Domaille, Dylan W; Mutalik, Vivek K; Arkin, Adam P; Gill, Ryan T

    2016-07-15

    Methods for importing heterologous genes into genetically tractable hosts are among the most desired tools of synthetic biology. Easy plug-and-play construction methods to rapidly test genes and pathways stably in the host genome would expedite synthetic biology and metabolic engineering applications. Here, we describe a CRISPR-based strategy that allows highly efficient, single step integration of large pathways in Escherichia coli. This strategy allows high efficiency integration in a broad range of homology arm sizes and genomic positions, with efficiencies ranging from 70 to 100% in 7 distinct loci. To demonstrate the large size capability, we integrated a 10 kb construct to implement isobutanol production in a single day. The ability to efficiently integrate entire metabolic pathways in a rapid and markerless manner will facilitate testing and engineering of novel pathways using the E. coli genome as a stable testing platform. PMID:27072506

  1. Development of one-step quantitative reverse transcription PCR for the rapid detection of flaviviruses

    PubMed Central

    2013-01-01

    Background The genus Flavivirus includes several pathogenic agents that cause severe illness in humans. Re-emergence of West Nile virus in Europe and continuous spread of certain flaviviruses such as dengue, yellow fever and Japanese encephalitis viruses represent a global danger to public health. Therefore, a rapid and accurate molecular method is required for diagnostics and epidemiological surveillance of flaviviruses. Methods A Pan-Flavi quantitative RT-PCR assay using a Locked-Nucleic Acid probe targeting the flavivirus NS5 gene was developed and optimized to detect a wide range of flaviviruses simultaneously. The specificity and sensitivity of the Pan-Flavi assay were tested using RNA of different flaviviruses and non-flaviviruses. Furthermore, the assay was compared directly to flavivirus species-specific assays for the ability to detect flaviviruses sensitively. Results Two degenerate primers and one Locked-Nucleic Acids probe were designed to amplify most of the flaviviruses. To increase the specificity and fluorescence signal of the Pan-Flavi assay for detection of yellow fever virus and dengue virus 4, additional primers and probes were included. Viral RNA of thirty different flaviviruses was detected, verifying the broad range specificity. The testing of this assay was successful, using standard plasmid and RNA dilutions of yellow fever virus vaccine strain, dengue virus 1 and tick-borne encephalitis virus, with a sensitivity limit of 10–100 genome copies/reaction. Also comparatively good results were achieved for detecting different flaviviruses by the Pan-Flavi assay when compared to the flavivirus species-specific assays. Conclusion The assay is rapid, broad-range flavivirus-specific and highly sensitive making it a valuable tool for rapid detection of flaviviruses in livestock samples, epidemiological studies or as useful complement to single flavivirus-specific assays for clinical diagnosis. PMID:23410000

  2. A rapid one-step immunochromatographic assay for the detection of asiaticoside.

    PubMed

    Sritularak, Boonchoo; Juengwatanatrakul, Thaweesak; Putalun, Waraporn; Tanaka, Hiroyuki; Morimoto, Satoshi

    2012-04-01

    Asiaticoside has been identified as the most active compound in Centella asiatica. In order to screen a large number of plant samples for the presence of asiaticoside, a rapid and simple technique is required that utilizes small quantities for test samples. In this study, an immunochromatographic strip test has been developed for the detection of asiaticoside in plant samples that uses a monoclonal antibody against asiaticoside. The limit of detection for the strip test was 12.5 μg/ml. Immunoassay using monoclonal antibodies could be useful for the determination of small quantities of asiaticoside in plant extracts.

  3. One-step and rapid synthesis of porous Pd nanoparticles with superior catalytic activity toward ethanol/formic acid electrooxidation

    NASA Astrophysics Data System (ADS)

    Hong, Wei; Fang, Youxing; Wang, Jin; Wang, Erkang

    2014-02-01

    Porous Pd nanoparticles are successfully prepared by a rapid, one-step, and efficient route with high yield in aqueous solution. The developed method is very simple, just by mixing sodium tetrachloropalladate, polyvinylpyrrolidone and hydroquinone and heated at 70 °C for 15 min. The structure and composition are analyzed by transmission electron microscope, selected-area electron diffraction, inductively coupled plasma optical emission spectrometer, X-ray diffraction, energy dispersive X-ray spectrum and X-ray photoelectron spectroscopy. Electrochemical catalytic measurement results prove that the as synthesized porous Pd nanoparticles exhibit superior catalytic activity towards ethanol and formic acid electrooxidation.

  4. Ultrasensitive one-step rapid visual detection of bisphenol A in water samples by label-free aptasensor.

    PubMed

    Mei, Zhanlong; Chu, Huaqin; Chen, Wei; Xue, Feng; Liu, Jian; Xu, Huaneng; Zhang, Rui; Zheng, Lei

    2013-01-15

    A simple, one-step, rapid method to detect bisphenol A (BPA) using a label-free aptasensor is presented. A high selective anti-BPA aptamer was added to gold nanoparticles (GNPs) to prepare the label-free aptasensor for BPA, which maintains good tolerance of GNPs under aqueous conditions with high salt concentrations. With the presence of BPA in the aptasensor system, the GNPs would aggregate by competitive binding of BPA and aptamer. Detection results can be visualized by the aggregation-induced color change of GNPs without the use of any instrumentation. The limit of visual detection (LOD) was found to be 0.1ng/mL by naked-eye observation, which was competitive to some current rapid BPA detection methods, even some instrumental based methods. Besides the obvious advantages, including reduced detection time and operation procedures, the results of this method meet the various detection requirements for BPA and are comparable to the traditional ELISA and instrument-based methods. The proposed one-step, label-free method was successfully used to determine BPA in actual water samples. PMID:22794930

  5. Efficient and versatile one-step affinity purification of in vivo biotinylated proteins: Expression, characterization and structure analysis of recombinant human glutamate carboxypeptidase II

    SciTech Connect

    Tykvart, J.; Sacha, P.; Barinka, C.; Knedlik, T.; Starkova, J.; Lubkowski, J.; Konvalinka, J.

    2012-02-07

    Affinity purification is a useful approach for purification of recombinant proteins. Eukaryotic expression systems have become more frequently used at the expense of prokaryotic systems since they afford recombinant eukaryotic proteins with post-translational modifications similar or identical to the native ones. Here, we present a one-step affinity purification set-up suitable for the purification of secreted proteins. The set-up is based on the interaction between biotin and mutated streptavidin. Drosophila Schneider 2 cells are chosen as the expression host, and a biotin acceptor peptide is used as an affinity tag. This tag is biotinylated by Escherichia coli biotin-protein ligase in vivo. We determined that localization of the ligase within the ER led to the most effective in vivo biotinylation of the secreted proteins. We optimized a protocol for large-scale expression and purification of AviTEV-tagged recombinant human glutamate carboxypeptidase II (Avi-GCPII) with milligram yields per liter of culture. We also determined the 3D structure of Avi-GCPII by X-ray crystallography and compared the enzymatic characteristics of the protein to those of its non-tagged variant. These experiments confirmed that AviTEV tag does not affect the biophysical properties of its fused partner. Purification approach, developed here, provides not only a sufficient amount of highly homogenous protein but also specifically and effectively biotinylates a target protein and thus enables its subsequent visualization or immobilization.

  6. Quantitative one-step RT-PCR assay for rapid and sensitive identification and titration of polioviruses in clinical specimens.

    PubMed

    Laassri, Majid; Dipiazza, Anthony; Bidzhieva, Bella; Zagorodnyaya, Tatiana; Chumakov, Konstantin

    2013-04-01

    Rapid identification and quantitation of polioviruses in clinical specimens is important for surveillance and analysis of virus shedding by vaccine recipients, which could be used to assess the level of mucosal immunity. A quantitative one step RT-PCR was developed for identification and titration of all three poliovirus serotypes. The assay could be an alternative to the traditional procedure based on cell culture isolation and subsequent determination of poliovirus serotype and virus titration. The method is based on quantitative PCR performed with reverse transcription reaction in the same tube. The multiplex assay that quantifies all three serotypes of poliovirus was found to be highly specific, sensitive, and takes only one day to complete.

  7. Expression and characterization of endochitinase C from Serratia marcescens BJL200 and its purification by a one-step general chitinase purification method.

    PubMed

    Synstad, Bjørnar; Vaaje-Kolstad, Gustav; Cederkvist, F Henning; Saua, Silje F; Horn, Svein J; Eijsink, Vincent G H; Sørlie, Morten

    2008-03-01

    In this study we cloned, expressed, purified, and charaterized chitinase C1 from Serratia marcescens strain BJL200. As expected, the BJL200-ChiC1 amino acid sequence of this strain was highly similar to sequences of ChiC1 identified in two other strains of S. marcescens. BJL200-ChiC1 was overproduced in E. coli by the T7 expression system, and purified by a one-step hydrophobic interaction chromatography (HIC) with phenyl-sepharose. BJL200-ChiA and BJL200-ChiB had an approximately 30-fold higher k(cat) and 15 fold-lower K(m) than BJL200-ChiC1 for the oligomeric substrate 4-methylumbelliferyl-beta-D-N-N'-N''-triacetylchitotrioside, while BJL200-ChiC1 was 10-15 times faster than BJL200-ChiB and BJL200-ChiA in degrading the polymeric substrate CM-chitin-RBV. BJL200-ChiC1 degradation of beta-chitin resulted in a range of different chito-oligosaccharides (GlcNAc)(2) (main product), GlcNAc, (GlcNAc)(3), (GlcNAc)(4), and (GlcNAc)(5), indicating endo activity. The purification method used for BJL200-ChiC1 in this study is generally applicable to family 18 chitinases and their mutants, including inactive mutants, some of which tend to bind almost irreversibly to chitin columns. The high specificity of the interaction with the (non-chitinous) column material is mediated by aromatic residues that occur in the substrate-binding clefts and surfaces of the enzymes.

  8. One step partial purification of beta-D-galactosidase from Kluyveromyces marxianus CDB 002 using STREAMLINE-DEAE.

    PubMed

    Artolozaga, M J; Jonas, R; Schneider, A L; Furlan, S A; Carvalho-Jonas, M de F

    1998-01-01

    The intracellular enzyme beta-D-galactosidase provides interesting applications in the dairy industry, which are able to solve problems related to product processing, or can alleviate lactose intolerance in some populations. In order to obtain a technical enzyme, yeast cells of Kluyveromyces marxianus CDB 002 were disrupted by high pressure homogenization and an innovative chromatographic technique was tested for the recovery of beta-D-galactosidase. A STREAMLINE 25 column, containing 65 ml STREAMLINE-DEAE was equilibrated with 50 mM potassium phosphate buffer pH 7.5 at an upward flow of 250 cmh-1. 100-200 ml cell homogenate were applied onto the expanded gel. After unbound proteins and cellular debris were washed out, the bed was allowed to sediment and beta-D-galactosidase was eluted with a downward flow of 0.2 M NaCl in the same buffer. A 6-fold purification factor was achieved with 63% activity recovery, while removing cell debris at a single step, thus avoiding a centrifugation step. Concentration and volume of the applied sample affected purification and gel performance. The results presented show STREAMLINE-DEAE chromatography to be an interesting method for the production of beta-D-galactosidase as a technical enzyme, since it can also be applied on a large scale without much modification.

  9. Rapid Stencil Mask Fabrication Enabled One-Step Polymer-Free Graphene Patterning and Direct Transfer for Flexible Graphene Devices.

    PubMed

    Yong, Keong; Ashraf, Ali; Kang, Pilgyu; Nam, SungWoo

    2016-01-01

    We report a one-step polymer-free approach to patterning graphene using a stencil mask and oxygen plasma reactive-ion etching, with a subsequent polymer-free direct transfer for flexible graphene devices. Our stencil mask is fabricated via a subtractive, laser cutting manufacturing technique, followed by lamination of stencil mask onto graphene grown on Cu foil for patterning. Subsequently, micro-sized graphene features of various shapes are patterned via reactive-ion etching. The integrity of our graphene after patterning is confirmed by Raman spectroscopy. We further demonstrate the rapid prototyping capability of a stretchable, crumpled graphene strain sensor and patterned graphene condensation channels for potential applications in sensing and heat transfer, respectively. We further demonstrate that the polymer-free approach for both patterning and transfer to flexible substrates allows the realization of cleaner graphene features as confirmed by water contact angle measurements. We believe that our new method promotes rapid, facile fabrication of cleaner graphene devices, and can be extended to other two dimensional materials in the future. PMID:27118249

  10. Rapid Stencil Mask Fabrication Enabled One-Step Polymer-Free Graphene Patterning and Direct Transfer for Flexible Graphene Devices

    PubMed Central

    Yong, Keong; Ashraf, Ali; Kang, Pilgyu; Nam, SungWoo

    2016-01-01

    We report a one-step polymer-free approach to patterning graphene using a stencil mask and oxygen plasma reactive-ion etching, with a subsequent polymer-free direct transfer for flexible graphene devices. Our stencil mask is fabricated via a subtractive, laser cutting manufacturing technique, followed by lamination of stencil mask onto graphene grown on Cu foil for patterning. Subsequently, micro-sized graphene features of various shapes are patterned via reactive-ion etching. The integrity of our graphene after patterning is confirmed by Raman spectroscopy. We further demonstrate the rapid prototyping capability of a stretchable, crumpled graphene strain sensor and patterned graphene condensation channels for potential applications in sensing and heat transfer, respectively. We further demonstrate that the polymer-free approach for both patterning and transfer to flexible substrates allows the realization of cleaner graphene features as confirmed by water contact angle measurements. We believe that our new method promotes rapid, facile fabrication of cleaner graphene devices, and can be extended to other two dimensional materials in the future. PMID:27118249

  11. A one step multiplex PCR assay for rapid screening of East Asian mtDNA haplogroups on forensic samples.

    PubMed

    Lee, Hwan Young; Yoon, Jung Ah; Yang, Woo Ick; Shin, Kyoung-Jin

    2013-01-01

    The mitochondrial DNA (mtDNA) haplogroup typing has become an essential tool to study human evolutionary history and to infer the matrilineal bio-geographic ancestry. In forensic field, the screening of mtDNA haplogroups by genotyping of mtDNA single nucleotide polymorphisms (SNPs) can help guarantee the quality of mtDNA sequence data as well as can reduce the need to sequence samples that do not match. Here, a multiplex mutagenically separated (MS) polymerase chain reaction (PCR) system was developed for simultaneous rapid detection of 14 coding region SNPs and one deletion motif representing common mtDNA haplogroups of East Asia. The multiplex MS PCR system we developed has the advantage of being a one step procedure that requires only a single PCR amplification with allele-specific primers and allowing straightforward designation of haplogroups along the branches of the phylogenetic tree. Therefore, it would be a simple, rapid, and reliable detection method useful for large-scale screening of mtDNA variations to determine East Asian mtDNA haplogroups.

  12. Rapid Stencil Mask Fabrication Enabled One-Step Polymer-Free Graphene Patterning and Direct Transfer for Flexible Graphene Devices

    NASA Astrophysics Data System (ADS)

    Yong, Keong; Ashraf, Ali; Kang, Pilgyu; Nam, Sungwoo

    2016-04-01

    We report a one-step polymer-free approach to patterning graphene using a stencil mask and oxygen plasma reactive-ion etching, with a subsequent polymer-free direct transfer for flexible graphene devices. Our stencil mask is fabricated via a subtractive, laser cutting manufacturing technique, followed by lamination of stencil mask onto graphene grown on Cu foil for patterning. Subsequently, micro-sized graphene features of various shapes are patterned via reactive-ion etching. The integrity of our graphene after patterning is confirmed by Raman spectroscopy. We further demonstrate the rapid prototyping capability of a stretchable, crumpled graphene strain sensor and patterned graphene condensation channels for potential applications in sensing and heat transfer, respectively. We further demonstrate that the polymer-free approach for both patterning and transfer to flexible substrates allows the realization of cleaner graphene features as confirmed by water contact angle measurements. We believe that our new method promotes rapid, facile fabrication of cleaner graphene devices, and can be extended to other two dimensional materials in the future.

  13. One-step reverse transcription loop-mediated isothermal amplification for the rapid detection of cucumber green mottle mosaic virus.

    PubMed

    Li, Jin-yu; Wei, Qi-wei; Liu, Yong; Tan, Xin-qiu; Zhang, Wen-na; Wu, Jian-yan; Charimbu, Miriam Karwitha; Hu, Bai-shi; Cheng, Zhao-bang; Yu, Cui; Tao, Xiao-rong

    2013-11-01

    Cucumber green mottle mosaic virus (CGMMV) has caused serious damage to Cucurbitaceae crops worldwide. The virus is considered one of the most serious Cucurbitaceae quarantine causes in many countries. In this study, a highly efficient and practical one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed for the detection of CGMMV. The total RNA or crude RNA extracted from watermelon plants or seeds could be detected easily by this RT-LAMP assay. The RT-LAMP assay was conducted in isothermal (63°C) conditions within 1h. The amplified products of CGMMV could be detected as ladder-like bands using agarose gel electrophoresis or visualized in-tube under UV light with the addition of a fluorescent dye. The RT-LAMP amplification was specific to CGMMV, as no cross-reaction was observed with other viruses. The RT-LAMP assay was 100-fold more sensitive than that of reverse-transcription polymerase chain reaction (RT-PCR). This is the first report of the application of the RT-LAMP assay to detect CGMMV. The sensitive, specific and rapid RT-LAMP assay developed in this study can be applied widely in laboratories, the field and quarantine surveillance of CGMMV. PMID:23933076

  14. An interference-free and rapid electrochemical lateral-flow immunoassay for one-step ultrasensitive detection with serum.

    PubMed

    Akanda, Md Rajibul; Joung, Hyou-Arm; Tamilavan, Vellaiappillai; Park, Seonhwa; Kim, Sinyoung; Hyun, Myung Ho; Kim, Min-Gon; Yang, Haesik

    2014-03-21

    Point-of-care testing (POCT) of biomarkers in clinical samples is of great importance for rapid and cost-effective diagnosis. However, it is extremely challenging to develop an electrochemical POCT technique retaining both ultrasensitivity and simplicity. We report an interference-free electrochemical lateral-flow immunoassay that enables one-step ultrasensitive detection with serum. The electrochemical-chemical-chemical (ECC) redox cycling combined with an enzymatic reaction of an enzyme label is used to obtain high signal amplification. The ECC redox cycling involving Ru(NH3)6(3+), enzyme product, and tris(3-carboxyethyl)phosphine (TCEP) depends on pH, because the formal potentials of an enzyme product and TCEP increase with decreasing pH although that of Ru(NH3)6(3+) is pH-independent. With consideration of the pH dependence of ECC redox cycling, a noble combination of enzyme label, substrate, and product [β-galactosidase, 4-amino-1-naphthyl β-D-galactopyranoside, and 4-amino-1-naphthol, respectively] is introduced to ensure fast and selective ECC redox cycling of the enzyme product along with a low background level. The selective ECC redox cycling at a low applied potential (0.05 V vs. Ag/AgCl) minimizes the interference effect of electroactive species (L-ascorbic acid, acetaminophen, and uric acid) in serum. A detection limit of 0.1 pg mL(-1) for troponin I is obtained only 11 min after serum dropping without the use of an additional solution. Moreover, the lateral-flow immunoassay is applicable to the analysis of real clinical samples.

  15. Application of stepwise gradients in counter-current chromatography: a rapid and economical strategy for the one-step separation of eight coumarins from Seseli resinosum.

    PubMed

    Shehzad, Omer; Khan, Salman; Ha, In Jin; Park, Youmie; Tosun, Alev; Kim, Yeong Shik

    2013-10-01

    The targeted purification of compounds with a broad polarity range from traditional medicinal plants is a big challenge for counter-current chromatography (CCC). Gradient elution was introduced in CCC to address this problem. However, once a suitable solvent system is selected, the separation process requires optimization of operational parameters. The present study was conducted to optimize various operational parameters to integrate the flow rate and solvent gradients for the rapid isolation of eight coumarins from Seseli resinosum in a single run. An increase in the system temperature from 15°C to 35°C increased the stationary phase retention and solubility of the sample, whereas the operation time and viscosity of the system were decreased. The high purity of each compound was ensured by collecting the fractions from the main peaks while all the shoulder peaks were mixed and separated under the same conditions with semi-preparative CCC. GC-FID was used to analyze the components of each phase, which was prepared without presaturation to save the time and solvent consumption. Finally, eight coumarins were purified, including (1) d-laserpitin, (2) (3'S,4'S)-3'-angeloyloxy-4'-hydroxy-3',4'-dihydroseselin, (3) (+)-samidin, (4) (3'S,4'S)-3'-acetoxy-4'-angeloyloxy-3',4'-dihydroseselin, (5) deltoin (6), calipteryxin, (7) (3'S,4'S)-3',4'-disenecioyloxy-3',4'-dihydroseselin, and (8) (-)-anomalin. The present technique has successfully accomplished the goal of one-step separation of these compounds with high purity and recovery in an economic and time efficient manner. PMID:23992840

  16. One-step refolding and purification of recombinant human tumor necrosis factor-α (rhTNF-α) using ion-exchange chromatography.

    PubMed

    Wang, Yan; Ren, Wenxuan; Gao, Dong; Wang, Lili; Yang, Ying; Bai, Quan

    2015-02-01

    Protein refolding is a key step for the production of recombinant proteins, especially at large scales, and usually their yields are very low. Chromatographic-based protein refolding techniques have proven to be superior to conventional dilution refolding methods. High refolding yield can be achieved using these methods compared with dilution refolding of proteins. In this work, recombinant human tumor necrosis factor-α (rhTNF-α) from inclusion bodies expressed in Escherichia coli was renatured with simultaneous purification by ion exchange chromatography with a DEAE Sepharose FF column. Several chromatographic parameters influencing the refolding yield of the denatured/reduced rhTNF-α, such as the urea concentration, pH value and concentration ratio of glutathione/oxidized glutathione in the mobile phase, were investigated in detail. Under optimal conditions, rhTNF-α can be renatured and purified simultaneously within 30 min by one step. Specific bioactivity of 2.18 × 10(8) IU/mg, purity of 95.2% and mass recovery of 76.8% of refolded rhTNF-α were achieved. Compared with the usual dilution method, the ion exchange chromatography method developed here is simple and more effective for rhTNF-α refolding in terms of specific bioactivity and mass recovery.

  17. FusX: A Rapid One-Step Transcription Activator-Like Effector Assembly System for Genome Science.

    PubMed

    Ma, Alvin C; McNulty, Melissa S; Poshusta, Tanya L; Campbell, Jarryd M; Martínez-Gálvez, Gabriel; Argue, David P; Lee, Han B; Urban, Mark D; Bullard, Cassandra E; Blackburn, Patrick R; Man, Toni K; Clark, Karl J; Ekker, Stephen C

    2016-06-01

    Transcription activator-like effectors (TALEs) are extremely effective, single-molecule DNA-targeting molecular cursors used for locus-specific genome science applications, including high-precision molecular medicine and other genome engineering applications. TALEs are used in genome engineering for locus-specific DNA editing and imaging, as artificial transcriptional activators and repressors, and for targeted epigenetic modification. TALEs as nucleases (TALENs) are effective editing tools and offer high binding specificity and fewer sequence constraints toward the targeted genome than other custom nuclease systems. One bottleneck of broader TALE use is reagent accessibility. For example, one commonly deployed method uses a multitube, 5-day assembly protocol. Here we describe FusX, a streamlined Golden Gate TALE assembly system that (1) is backward compatible with popular TALE backbones, (2) is functionalized as a single-tube 3-day TALE assembly process, (3) requires only commonly used basic molecular biology reagents, and (4) is cost-effective. More than 100 TALEN pairs have been successfully assembled using FusX, and 27 pairs were quantitatively tested in zebrafish, with each showing high somatic and germline activity. Furthermore, this assembly system is flexible and is compatible with standard molecular biology laboratory tools, but can be scaled with automated laboratory support. To demonstrate, we use a highly accessible and commercially available liquid-handling robot to rapidly and accurately assemble TALEs using the FusX TALE toolkit. Together, the FusX system accelerates TALE-based genomic science applications from basic science screening work for functional genomics testing and molecular medicine applications. PMID:26854857

  18. FusX: A Rapid One-Step Transcription Activator-Like Effector Assembly System for Genome Science

    PubMed Central

    Ma, Alvin C.; McNulty, Melissa S.; Poshusta, Tanya L.; Campbell, Jarryd M.; Martínez-Gálvez, Gabriel; Argue, David P.; Lee, Han B.; Urban, Mark D.; Bullard, Cassandra E.; Blackburn, Patrick R.; Man, Toni K.; Clark, Karl J.; Ekker, Stephen C.

    2016-01-01

    Transcription activator-like effectors (TALEs) are extremely effective, single-molecule DNA-targeting molecular cursors used for locus-specific genome science applications, including high-precision molecular medicine and other genome engineering applications. TALEs are used in genome engineering for locus-specific DNA editing and imaging, as artificial transcriptional activators and repressors, and for targeted epigenetic modification. TALEs as nucleases (TALENs) are effective editing tools and offer high binding specificity and fewer sequence constraints toward the targeted genome than other custom nuclease systems. One bottleneck of broader TALE use is reagent accessibility. For example, one commonly deployed method uses a multitube, 5-day assembly protocol. Here we describe FusX, a streamlined Golden Gate TALE assembly system that (1) is backward compatible with popular TALE backbones, (2) is functionalized as a single-tube 3-day TALE assembly process, (3) requires only commonly used basic molecular biology reagents, and (4) is cost-effective. More than 100 TALEN pairs have been successfully assembled using FusX, and 27 pairs were quantitatively tested in zebrafish, with each showing high somatic and germline activity. Furthermore, this assembly system is flexible and is compatible with standard molecular biology laboratory tools, but can be scaled with automated laboratory support. To demonstrate, we use a highly accessible and commercially available liquid-handling robot to rapidly and accurately assemble TALEs using the FusX TALE toolkit. Together, the FusX system accelerates TALE-based genomic science applications from basic science screening work for functional genomics testing and molecular medicine applications. PMID:26854857

  19. Rapid establishment of thermophilic anaerobic microbial community during the one-step startup of thermophilic anaerobic digestion from a mesophilic digester.

    PubMed

    Tian, Zhe; Zhang, Yu; Li, Yuyou; Chi, Yongzhi; Yang, Min

    2015-02-01

    The purpose of this study was to explore how fast the thermophilic anaerobic microbial community could be established during the one-step startup of thermophilic anaerobic digestion from a mesophilic digester. Stable thermophilic anaerobic digestion was achieved within 20 days from a mesophilic digester treating sewage sludge by adopting the one-step startup strategy. The succession of archaeal and bacterial populations over a period of 60 days after the temperature increment was followed by using 454-pyrosequencing and quantitative PCR. After the increase of temperature, thermophilic methanogenic community was established within 11 days, which was characterized by the fast colonization of Methanosarcina thermophila and two hydrogenotrophic methanogens (Methanothermobacter spp. and Methanoculleus spp.). At the same time, the bacterial community was dominated by Fervidobacterium, whose relative abundance rapidly increased from 0 to 28.52 % in 18 days, followed by other potential thermophilic genera, such as Clostridium, Coprothermobacter, Anaerobaculum and EM3. The above result demonstrated that the one-step startup strategy could allow the rapid establishment of the thermophilic anaerobic microbial community.

  20. Antibody-free magnetic cell sorting of genetically modified primary human CD4+ T cells by one-step streptavidin affinity purification.

    PubMed

    Matheson, Nicholas J; Peden, Andrew A; Lehner, Paul J

    2014-01-01

    Existing methods for phenotypic selection of genetically modified mammalian cells suffer disadvantages of time, cost and scalability and, where antibodies are used to bind exogenous cell surface markers for magnetic selection, typically yield cells coated with antibody-antigen complexes and beads. To overcome these limitations we have developed a method termed Antibody-Free Magnetic Cell Sorting in which the 38 amino acid Streptavidin Binding Peptide (SBP) is displayed at the cell surface by the truncated Low Affinity Nerve Growth Receptor (LNGFRF) and used as an affinity tag for one-step selection with streptavidin-conjugated magnetic beads. Cells are released through competition with the naturally occurring vitamin biotin, free of either beads or antibody-antigen complexes and ready for culture or use in downstream applications. Antibody-Free Magnetic Cell Sorting is a rapid, cost-effective, scalable method of magnetic selection applicable to either viral transduction or transient transfection of cell lines or primary cells. We have optimised the system for enrichment of primary human CD4+ T cells expressing shRNAs and exogenous genes of interest to purities of >99%, and used it to isolate cells following Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 genome editing.

  1. Development of a rapid DNA extraction method and one-step nested PCR for the detection of Naegleria fowleri from the environment.

    PubMed

    Ahmad, Arine Fadzlun; Lonnen, James; Andrew, Peter W; Kilvington, Simon

    2011-10-15

    Naegleria fowleri is a small free-living amoebo-flagellate found in natural and manmade thermal aquatic habitats worldwide. The organism is pathogenic to man causing fatal primary amoebic meningoencephalitis (PAM). Infection typically results from bathing in contaminated water and is usually fatal. It is, therefore, important to identify sites containing N. fowleri in the interests of preventive public health microbiology. Culture of environmental material is the conventional method for the isolation of N. fowleri but requires several days incubation and subsequent biochemical or molecular tests to confirm identification. Here, a nested one-step PCR test, in conjunction with a direct DNA extraction from water or sediment material, was developed for the rapid and reliable detection of N. fowleri from the environment. Here, the assay detected N, fowleri in 18/109 river water samples associated with a nuclear power plant in South West France and 0/10 from a similar site in the UK. Although culture of samples yielded numerous thermophilic free-living amoebae, none were N. fowleri or other thermophilic Naegleria spp. The availability of a rapid, reliable and sensitive one-step nested PCR method for the direct detection of N. fowleri from the environment may aid ecological studies and enable intervention to prevent PAM cases.

  2. Engineering foot-and-mouth disease virus serotype O IND R2/1975 for one-step purification by immobilized metal affinity chromatography.

    PubMed

    Biswal, Jitendra K; Bisht, Punam; Subramaniam, Saravanan; Ranjan, Rajeev; Sharma, Gaurav K; Pattnaik, Bramhadev

    2015-09-01

    Immobilized metal affinity chromatography (IMAC) allows for the efficient protein purification via metal affinity tag such as hexa-histidine (His6) sequence. To develop a new chromatography strategy for the purification and concentration of foot-and-mouth disease virus (FMDV) particles, we inserted the His6-tag at the earlier reported site in the VP1 G-H loop of the FMD virus serotype O vaccine strain IND R2/1975. Display of the His6-tag on the capsid surface, endowed the virus with an increased affinity for immobilized nickel ions. We demonstrated that the His6-tagged FMDV could be produced to high titre and purified from the infected BHK-21 cell lysates by IMAC efficiently. Further, a 1150-fold reduction in protein contaminant level and an 8400-fold reduction in DNA contaminant level were achieved in the IMAC purification of His6-tagged FMDV. Through various functional assays it has been found that the tagged virus retains its functionality and infectivity similar to the non-tagged virus. The affinity purification of the His6-tagged FMDV may offer a feasible, alternative approach to the current methods of FMDV antigen purification, concentration and process scalability. PMID:26123433

  3. One-step purification of twin-strep-tagged proteins and their complexes on strep-tactin resin cross-linked with bis(sulfosuccinimidyl) suberate (BS3).

    PubMed

    Ivanov, Konstantin I; Bašić, Marta; Varjosalo, Markku; Mäkinen, Kristiina

    2014-01-01

    Affinity purification of Strep-tagged fusion proteins on resins carrying an engineered streptavidin (Strep-Tactin) has become a widely used method for isolation of protein complexes under physiological conditions. Fusion proteins containing two copies of Strep-tag II, designated twin-Strep-tag or SIII-tag, have the advantage of higher affinity for Strep-Tactin compared to those containing only a single Strep-tag, thus allowing more efficient protein purification. However, this advantage is offset by the fact that elution of twin-Strep-tagged proteins with biotin may be incomplete, leading to low protein recovery. The recovery can be dramatically improved by using denaturing elution with sodium dodecyl sulfate (SDS), but this leads to sample contamination with Strep-Tactin released from the resin, making the assay incompatible with downstream proteomic analysis. To overcome this limitation, we have developed a method whereby resin-coupled tetramer of Strep-Tactin is first stabilized by covalent cross-linking with Bis(sulfosuccinimidyl) suberate (BS3) and the resulting cross-linked resin is then used to purify target protein complexes in a single batch purification step. Efficient elution with SDS ensures good protein recovery, while the absence of contaminating Strep-Tactin allows downstream protein analysis by mass spectrometry. As a proof of concept, we describe here a protocol for purification of SIII-tagged viral protein VPg-Pro from nuclei of virus-infected N. benthamiana plants using the Strep-Tactin polymethacrylate resin cross-linked with BS3. The same protocol can be used to purify any twin-Strep-tagged protein of interest and characterize its physiological binding partners. PMID:24796313

  4. Establishment of a novel one-step reverse transcription loop-mediated isothermal amplification assay for rapid identification of RNA from the severe fever with thrombocytopenia syndrome virus.

    PubMed

    Xu, Haihong; Zhang, Lei; Shen, Guangqiang; Feng, Cen; Wang, Xinying; Yan, Jie; Zhang, Yanjun

    2013-12-01

    As an emerging infectious disease, severe fever with thrombocytopenia syndrome virus (SFTSV) infection has been found in many areas of China. Suitable laboratory diagnostic method is urgently needed in clinical detections and epidemiological investigations. In this study, a modified, low-cost and rapid visualized one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of RNA from the SFTSV has been established. In order to avoid the risk of aerosol contamination and facilitate the naked eye to observe, a microcrystalline wax-dye capsule wrapping the highly sensitive DNA fluorescence dye SYBR Green I was added to the RT-LAMP reaction tube before the initiation of the assay. The detection limit of the established RT-LAMP assay was 10 fg template RNA per reaction mixture. The RT-LAMP assay was confirmed to be high specific to SFTSV, and no cross-reaction was found with the detection of the Chikungunya fever virus, Hemorrhagic Fever with Renal Syndrome virus (HFRSV), and Dengue fever virus. The assay was then applied for the detection of SFTSV RNA in 32 clinical serum samples and showed 94.4% consistence with the detection results of the real-time RT-PCR. The whole process, from sample preparation to result reporting, can be completed within 2h. This adapted, cost efficient and quick visualized RT-LAMP method is feasible for SFTSV field diagnosis in resource-limited field settings.

  5. Establishment of a novel one-step reverse transcription loop-mediated isothermal amplification assay for rapid identification of RNA from the severe fever with thrombocytopenia syndrome virus.

    PubMed

    Xu, Haihong; Zhang, Lei; Shen, Guangqiang; Feng, Cen; Wang, Xinying; Yan, Jie; Zhang, Yanjun

    2013-12-01

    As an emerging infectious disease, severe fever with thrombocytopenia syndrome virus (SFTSV) infection has been found in many areas of China. Suitable laboratory diagnostic method is urgently needed in clinical detections and epidemiological investigations. In this study, a modified, low-cost and rapid visualized one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of RNA from the SFTSV has been established. In order to avoid the risk of aerosol contamination and facilitate the naked eye to observe, a microcrystalline wax-dye capsule wrapping the highly sensitive DNA fluorescence dye SYBR Green I was added to the RT-LAMP reaction tube before the initiation of the assay. The detection limit of the established RT-LAMP assay was 10 fg template RNA per reaction mixture. The RT-LAMP assay was confirmed to be high specific to SFTSV, and no cross-reaction was found with the detection of the Chikungunya fever virus, Hemorrhagic Fever with Renal Syndrome virus (HFRSV), and Dengue fever virus. The assay was then applied for the detection of SFTSV RNA in 32 clinical serum samples and showed 94.4% consistence with the detection results of the real-time RT-PCR. The whole process, from sample preparation to result reporting, can be completed within 2h. This adapted, cost efficient and quick visualized RT-LAMP method is feasible for SFTSV field diagnosis in resource-limited field settings. PMID:23911296

  6. Rapid diagnosis of acute hemorrhagic conjunctivitis due to coxsackievirus A24 variant by real-time one-step RT-PCR.

    PubMed

    Lévêque, Nicolas; Lahlou Amine, Idriss; Tcheng, Remy; Falcon, Delphine; Rivat, Nathalie; Dussart, Philippe; Muyembe, Jean-Jacques; Chomel, Jean-Jacques; Norder, Helene; Eugene, Maxime; Lina, Bruno

    2007-06-01

    Coxsackievirus A24 variant is, together with enterovirus 70 and adenoviruses, the major etiological agent involved in acute hemorrhagic conjunctivitis outbreaks worldwide. However, the standard virus isolation method followed by serotyping or VP1 region sequencing is time-consuming. A rapid method for the detection of coxsackievirus A24 variant from conjunctival swab specimens would be useful in the context of explosive and extensive outbreaks. A one-step real-time RT-PCR assay based on TaqMan technology was thus developed and assessed on 36 conjunctival swabs from outbreaks of conjunctivitis in Morocco in 2004 due to a coxsackievirus A24 variant and in Corsica in 2006 due to adenovirus type 3, and 83 virus strains including 41 coxsackievirus A24 variant collected in French Guiana and Guadeloupe in 2003, in the Democratic Republic of the Congo in 2003, in Morocco in 2004 and 42 other virus species genetically close or known to be responsible for conjunctivitis. All the conjunctival swabs from coxsackievirus A24 variant related outbreak and the 41 coxsackievirus A24 variant strains were tested positive by the RT-PCR assay within 4h. This novel single-tube real-time RT-PCR assay is sensitive and specific, and consists in a reliable and faster alternative to the viral culture for recent and future acute hemorrhagic conjunctivitis outbreaks caused by coxsackievirus A24 variant.

  7. Rapid Detection of Melamine in Tap Water and Milk Using Conjugated "One-Step" Molecularly Imprinted Polymers-Surface Enhanced Raman Spectroscopic Sensor.

    PubMed

    Hu, Yaxi; Lu, Xiaonan

    2016-05-01

    An innovative "one-step" sensor conjugating molecularly imprinted polymers and surface enhanced Raman spectroscopic-active substrate (MIPs-SERS) was investigated for simultaneous extraction and determination of melamine in tap water and milk. This sensor was fabricated by integrating silver nanoparticles (AgNPs) with MIPs synthesized by bulk polymerization of melamine (template), methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linking agent), and 2,2'-azobisisobutyronitrile (initiator). Static and kinetic adsorption tests validated the specific affinity of MIPs-AgNPs to melamine and the rapid adsorption equilibration rate. Principal component analysis segregated SERS spectral features of tap water and milk samples with different melamine concentrations. Partial least squares regression models correlated melamine concentrations in tap water and skim milk with SERS spectral features. The limit of detection (LOD) and limit of quantification (LOQ) of melamine in tap water were determined as 0.0019 and 0.0064 mmol/L, while the LOD and LOQ were 0.0165 and 0.055 mmol/L for the determination of melamine in skim milk. However, this sensor is not ideal to quantify melamine in tap water and skim milk. By conjugating MIPs with SERS-active substrate (that is, AgNPs), reproducibility of SERS spectral features was increased, resulting in more accurate detection. The time required to determine melamine in tap water and milk were 6 and 25 min, respectively. The low LOD, LOQ, and rapid detection confirm the potential of applying this sensor for accurate and high-throughput detection of melamine in tap water and milk. PMID:27061315

  8. High-Level Soluble Expression and One-step Purification of HTLV-I P19 Protein in Escherichia coli by Fusion Expression.

    PubMed

    Mosadeghi, Parvin; Zarnagh, Hafez Heydari; Mohammad-Zadeh, Mohammad; Salehi Moghaddam, Masoud

    2015-12-01

    Expression of HTLV-I p19 protein in an Escherichia coli expression system always leads to the formation of inclusion body. Solubilisation and refolding of the inclusion bodies is complex, time consuming and difficult during large-scale preparation. This study aimed to express and purify a soluble form of recombinant HTLV-I p19 protein in an E. coli expression system. The synthetic DNA encoding the p19 was subcloned into a pGS21a vector along with a His-GST solubility/purification tag. The recombinant pGS21a-p19 vector was then transformed into chemically competent E. coli BL21 (DE3) cells, and expression of the recombinant His-GST-p19 protein was induced by IPTG. Expression and distribution of the His-GST-p19 protein in soluble and insoluble fractions were evaluated using SDS-PAGE. Antigenicity of the His-GST-p19 protein was evaluated using ELISA after purifying the protein using Ni-NTA affinity chromatography, then compared to the results of synthetic immunodominant p19 peptide ELISA. The fusion His-GST-p19 protein accounted for 30% of the total cellular proteins. The SDS-PAGE results indicated that approximately 50% of the expressed His-GST-p19 proteins were soluble and accounted for 50% of the total soluble proteins. ELISA showed that the His-GST tag did not impair the antigenicity of the p19 protein and that the fusion protein reacted with HTLV-I antibodies in a concentration-dependent manner. The results of His-GST-p19 ELISA indicated that specificity of p19 reactivity was compatible to the results of p19 peptide ELISA. Combination of key strategies for the soluble expresion of proteins, like fusion with solubility/purification tags, low IPTG concentration and induction at low temperature, provide an efficient and facile platform for producing soluble  HTLV-I p19 protein.

  9. Uniform magnetic core/shell microspheres functionalized with Ni2+-iminodiacetic acid for one step purification and immobilization of his-tagged enzymes.

    PubMed

    Zhang, Yuting; Yang, Yongkun; Ma, Wanfu; Guo, Jia; Lin, Yao; Wang, Changchun

    2013-04-10

    A facile approach has been developed to synthesize Fe3O4/PMG (poly (N,N'-methylenebisacrylamide-co-glycidyl methacrylate)) core/shell microspheres using distillation-precipitation polymerization. Treating PMG shell with iminodiacetic acid (IDA) and Ni2+ yields composite microspheres of Fe3O4/PMG/IDA-Ni2+. The Ni2+ ions loaded on the surface of microspheres provide abundant docking sites for immobilization of histidine-tagged proteins. The high saturation magnetization of Fe3O4/PMG (23 emu/g), determined by vibrating sample magnetometer (VSM), allows an easy separation of the microspheres from solution under an external magnetic field. The composite microspheres were used to purify two His-tagged cellulolytic enzymes (Cel48F and Cel9G) directly from crude cell lysates with high binding affinity, capacity, and specificity. The microspheres can be recycled for many times without significant loss of binding capacity to enzymes. The immobilized enzymes on the surface of microspheres well retain their biological activities in degradation of cellulose. These materials show great potential in the biomedical and biotechnological applications that require low-cost purification of recombinant proteins and instant enzyme immobilization at an industrial scale. PMID:23470159

  10. Single-reagent one-step procedures for the purification of ovine IgG, F(ab')2 and Fab antivenoms by caprylic acid.

    PubMed

    Al-Abdulla, Ibrahim; Casewell, Nicholas R; Landon, John

    2014-01-15

    Antivenoms are typically produced in horses or sheep and often purified using salt precipitation of immunoglobulins or F(ab')2 fragments. Caprylic (octanoic) acid fractionation of antiserum has the advantage of not precipitating the desired antibodies, thereby avoiding potential degradation that can lead to the formation of aggregates, which may be the cause of some adverse reactions to antivenoms. Here we report that when optimising the purification of immunoglobulins from ovine antiserum raised against snake venom, caprylic acid was found to have no effect on the activity of the enzymes pepsin and papain, which are employed in antivenom manufacturing to digest immunoglobulins to obtain F(ab')2 and Fab fragments, respectively. A "single-reagent" method was developed for the production of F(ab')2 antivenom whereby whole ovine antiserum was mixed with both caprylic acid and pepsin and incubated for 4h at 37°C. For ovine Fab antivenom production from whole antiserum, the "single reagent" comprised of caprylic acid, papain and l-cysteine; after incubation at 37°C for 18-20h, iodoacetamide was added to stop the reaction. Caprylic acid facilitated the precipitation of albumin, resulting in a reduced protein load presented to the digestion enzymes, culminating in substantial reductions in processing time. The ovine IgG, F(ab')2 and Fab products obtained using these novel caprylic acid methods were comparable in terms of yield, purity and specific activity to those obtained by multi-step conventional salt fractionation with sodium sulphate.

  11. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo/cytochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  12. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo-cyctochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  13. Rapid synthesis of ZnO nano-rods by one-step, room-temperature, solid-state reaction and their gas-sensing properties

    NASA Astrophysics Data System (ADS)

    Sun, Zhi-Peng; Liu, Lang; Zhang, Li; Jia, Dian-Zeng

    2006-05-01

    ZnO nano-rods are prepared by one-step solid-state reaction of zinc acetate dihydrate, sodium hydroxide and cetyltrimethylammonium bromide (CTAB) at room temperature. The samples are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The gas-sensing properties of the prepared material have been investigated. The results indicate that the as-prepared ZnO nano-rods are uniform with diameters of 10-30 nm and lengths of about 150-250 nm. The relatively high sensor signal and stability of sensors made from ZnO nano-rods demonstrate the potential for developing a new class of sensitive sensors.

  14. Development of one-step real-time reverse transcriptase-PCR-based assays for the rapid and simultaneous detection of four viruses causing porcine diarrhea.

    PubMed

    Masuda, Tsuneyuki; Tsuchiaka, Shinobu; Ashiba, Tomoko; Yamasato, Hiroshi; Fukunari, Kazuhiro; Omatsu, Tsutomu; Furuya, Tetsuya; Shirai, Junsuke; Mizutani, Tetsuya; Nagai, Makoto

    2016-02-01

    Porcine diarrhea caused by viruses is a major problem of the pig farming industry and can result in substantial losses of revenue. Thus, diagnosing the infectious agents is important to prevent and control diseases in pigs. We developed novel one-step real-time quantitative RT-PCR (qPCR) assays that can detect four porcine diarrheal viruses simultaneously: porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), and porcine group A rotavirus (PRVA). The qPCR analysis takes only 75 minutes to detect the presence of the four viruses. The limits of detection of our new assays for PEDV, TGEV, PDCoV, and PRVA were 100, 10, 10 and 10 copies per reaction, respectively. The sensitivity of qPCR was 1-1000 times higher than that of published gel-based RT-PCR. We used our qPCR method to successfully diagnose clinical samples from infected pigs, and no false positive results were obtained. In conclusion, qPCR can drastically reduce the diagnostic time to detect viruses compared to currently employed methods. We predict that the qPCR assays will become a useful tool for detecting viral infections that cause diarrhea and other complications in pigs. PMID:27348884

  15. Development of novel AllGlo-probe-based one-step multiplex qRT-PCR assay for rapid identification of avian influenza virus H7N9.

    PubMed

    Zhang, Yanjun; Mao, Haiyan; Yan, Juying; Wang, Xinying; Zhang, Lei; Guus, Koch; Li, Hui; Li, Zhen; Chen, Yin; Gong, Liming; Chen, Zhiping; Xia, Shichang

    2014-07-01

    Recently, human deaths have resulted from infection with low-pathogenicity avian influenza virus H7N9 strains that have emerged recently in China. To strengthen H7N9 surveillance and outbreak control, rapid and reliable diagnostic methods are needed. To develop a sensitive quantitative real-time RT-PCR assay for rapid detection of H7N9 viral RNA, primers and AllGlo probes were designed to target the HA and NA genes of H7N9. Conserved sequences in the HA and NA genes were identified by phylogenic analysis and used as targets for H7N9 virus detection. The similarities of the targeted HA and NA gene sequences from different H7 and N9 influenza virus strains were 93.2-99.9 % and 96.0-99.6 %, respectively The specificity and sensitivity of the new multiplex real-time qRT-PCR was established. The test was used for the detection of viral RNA in human pharyngeal swabs and environmental samples. The detection limit of the multiplex qRT-PCR was estimated to be about 10(-1) TCID50/reaction. Finally, the diagnostic sensitivities of the multiplex qRT-PCR, virus isolation and TaqMan qRT-PCR were compared using pharyngeal swabs and environmental samples. These analyses yielded positive results in 46.7 %, 43.3 % and 20.0 % of the samples, respectively. The novel multiplex AllGlo qRT-PCR is a rapid and sensitive method to identify H7N9 virus in clinical and environmental samples and can be used to facilitate studies on the epidemiology of H7N9 virus.

  16. New Tris(hydroxypyridinone) Bifunctional Chelators Containing Isothiocyanate Groups Provide a Versatile Platform for Rapid One-Step Labeling and PET Imaging with 68Ga3+

    PubMed Central

    2015-01-01

    Two new bifunctional tris(hydroxypyridinone) (THP) chelators designed specifically for rapid labeling with 68Ga have been synthesized, each with pendant isothiocyanate groups and three 1,6-dimethyl-3-hydroxypyridin-4-one groups. Both compounds have been conjugated with the primary amine group of a cyclic integrin targeting peptide, RGD. Each conjugate can be radiolabeled and formulated by treatment with generator-produced 68Ga3+ in over 95% radiochemical yield under ambient conditions in less than 5 min, with specific activities of 60–80 MBq nmol–1. Competitive binding assays and in vivo biodistribution in mice bearing U87MG tumors demonstrate that the new 68Ga3+-labeled THP peptide conjugates retain affinity for the αvβ3 integrin receptor, clear within 1–2 h from circulation, and undergo receptor-mediated tumor uptake in vivo. We conclude that bifunctional THP chelators can be used for simple, efficient labeling of 68Ga biomolecules under mild conditions suitable for peptides and proteins. PMID:26286399

  17. Novel One-Tube-One-Step Real-Time Methodology for Rapid Transcriptomic Biomarker Detection: Signal Amplification by Ternary Initiation Complexes.

    PubMed

    Fujita, Hiroto; Kataoka, Yuka; Tobita, Seiji; Kuwahara, Masayasu; Sugimoto, Naoki

    2016-07-19

    We have developed a novel RNA detection method, termed signal amplification by ternary initiation complexes (SATIC), in which an analyte sample is simply mixed with the relevant reagents and allowed to stand for a short time under isothermal conditions (37 °C). The advantage of the technique is that there is no requirement for (i) heat annealing, (ii) thermal cycling during the reaction, (iii) a reverse transcription step, or (iv) enzymatic or mechanical fragmentation of the target RNA. SATIC involves the formation of a ternary initiation complex between the target RNA, a circular DNA template, and a DNA primer, followed by rolling circle amplification (RCA) to generate multiple copies of G-quadruplex (G4) on a long DNA strand like beads on a string. The G4s can be specifically fluorescence-stained with N(3)-hydroxyethyl thioflavin T (ThT-HE), which emits weakly with single- and double-stranded RNA/DNA but strongly with parallel G4s. An improved dual SATIC system, which involves the formation of two different ternary initiation complexes in the RCA process, exhibited a wide quantitative detection range of 1-5000 pM. Furthermore, this enabled visual observation-based RNA detection, which is more rapid and convenient than conventional isothermal methods, such as reverse transcription-loop-mediated isothermal amplification, signal mediated amplification of RNA technology, and RNA-primed rolling circle amplification. Thus, SATIC methodology may serve as an on-site and real-time measurement technique for transcriptomic biomarkers for various diseases.

  18. Novel One-Tube-One-Step Real-Time Methodology for Rapid Transcriptomic Biomarker Detection: Signal Amplification by Ternary Initiation Complexes.

    PubMed

    Fujita, Hiroto; Kataoka, Yuka; Tobita, Seiji; Kuwahara, Masayasu; Sugimoto, Naoki

    2016-07-19

    We have developed a novel RNA detection method, termed signal amplification by ternary initiation complexes (SATIC), in which an analyte sample is simply mixed with the relevant reagents and allowed to stand for a short time under isothermal conditions (37 °C). The advantage of the technique is that there is no requirement for (i) heat annealing, (ii) thermal cycling during the reaction, (iii) a reverse transcription step, or (iv) enzymatic or mechanical fragmentation of the target RNA. SATIC involves the formation of a ternary initiation complex between the target RNA, a circular DNA template, and a DNA primer, followed by rolling circle amplification (RCA) to generate multiple copies of G-quadruplex (G4) on a long DNA strand like beads on a string. The G4s can be specifically fluorescence-stained with N(3)-hydroxyethyl thioflavin T (ThT-HE), which emits weakly with single- and double-stranded RNA/DNA but strongly with parallel G4s. An improved dual SATIC system, which involves the formation of two different ternary initiation complexes in the RCA process, exhibited a wide quantitative detection range of 1-5000 pM. Furthermore, this enabled visual observation-based RNA detection, which is more rapid and convenient than conventional isothermal methods, such as reverse transcription-loop-mediated isothermal amplification, signal mediated amplification of RNA technology, and RNA-primed rolling circle amplification. Thus, SATIC methodology may serve as an on-site and real-time measurement technique for transcriptomic biomarkers for various diseases. PMID:27347743

  19. Evaluation of hybridization efficiencies of centromeric probes for chromosomes X, Y, 18 and 13/21 on uncultured amniocytes by a `rapid one-step` fluorescence in situ hybridization

    SciTech Connect

    Prashad, N.; Cubbage, M.; Weber, W.

    1994-09-01

    Aprogenex has developed a rapid one-step FISH assay, KaryoSite{trademark}, for the detection of chromosomes X, Y, 13, 18 and 21. The chromosome probes used are synthetic oligonucleotides with covalently attached chromosomes. In combination with a unique hybridization cocktail, these chromosomes are detected in a one-step hybridization. This method allows the detection of aneuploidy for these five chromosomes in uncultured amniocytes as well as metaphase chromosome preparations. Hybridization efficiency of dual probe combinations, X-Rhodamine plus Y-FITC and 18-FITC plus 13/21-Rhodamine, was determined on 50 amniocyte samples. Probes were added to the cells on slides and target cellular DNA was denatured at 90{degrees}C for 5 minutes followed by hybridization at 42{degrees}C for 30 minutes. Hybridization efficiency for SY probes was greater than 95% and for 18-13/21 probes was greater than 90%. Aneuploidy data from amniocyte samples will be presented. Aprogenex`s FISH technology is a reliable and rapid one-step method for prenatal diagnosis of aneuploidy for chromosome X, Y, 13, 18 and 21 in uncultured amniocytes.

  20. Simple, rapid and green one-step strategy to synthesis of graphene/carbon nanotubes/chitosan hybrid as solid-phase extraction for square-wave voltammetric detection of methyl parathion.

    PubMed

    Liu, Yan; Yang, Shanli; Niu, Weifen

    2013-08-01

    Simple, rapid, green and one-step electrodeposition strategy was first proposed to synthesis of graphene/carbon nanotubes/chitosan (GR/CNTs/CS) hybrid. The one-step electrodeposition approach for the construction of GR-based hybrid is green environmentally, which would not involve the chemical reduction of graphene oxide (GO) and therefore result in no further contamination. The whole procedure is simple and needs only several minutes. Combining the advantages of GR (large surface area, high conductivity and good adsorption ability), CNTs (high surface area, high enrichment capability and good adsorption ability) and CS (good adsorption and excellent film-forming ability), the obtained GR/CNTs/CS composite could be highly efficient to capture organophosphate pesticides (OPs) and used as solid phase extraction (SPE). The GR/CNTs/CS sensor is used for enzymeless detection of OPs, using methyl parathion (MP) as a model analyte. Significant redox response of MP on GR/CNTs/CS sensor is proved. The linear range is wide from 2.0ngmL(-1) to 500ngmL(-1), with a detection limit of 0.5ngmL(-1). Detection limit of the proposed sensor is much lower than those enzyme-based sensors and many other enzymeless sensors. Moreover, the proposed sensor exhibits high reproducibility, long-time storage stability and satisfactory anti-interference ability. This work provides a green and one-step route for the preparation of GR-based hybrid, and also offers a new promising protocol for OPs analysis.

  1. One-step purification and porin transport activity of the major outer membrane proteins P2 from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis.

    PubMed

    Kattner, Christof; Pfennig, Sabrina; Massari, Paola; Tanabe, Mikio

    2015-03-01

    Bacterial porins are major outer membrane proteins that function as essential solute transporters between the bacteria and the extracellular environment. Structural features of porins are also recognized by eukaryotic cell receptors involved in innate and adaptive immunity. To better investigate the function of porins, proper refolding is necessary following purification from inclusion bodies [1, 2]. Using a single-step size exclusion chromatographic method, we have purified three major porins from pathogenic bacteria, the OmpP2 (P2) from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis, at high yield and report their unique solute transport activity with size exclusion limit. Furthermore, we have optimized their purification method and achieved improvement of their thermostability for facilitating functional and structural analyses.

  2. Microchip capillary electrophoresis with laser-induced fluorescence combined with one-step duplex reverse-transcription polymerase chain reaction for the rapid detection of Enterovirus 71 and Coxsackievirus A16 in throat swab specimens.

    PubMed

    Jia, Ruan; Chengjun, Sun; Heng, Chen; Chen, Zhou; Yuanqian, Li; Yongxin, Li

    2015-07-01

    Enterovirus 71 and Coxsackievirus A16 are the main pathogens causing hand-foot-mouth disease. In this paper, microchip capillary electrophoresis with laser-induced fluorescence combined with one-step duplex reverse transcript-polymerase chain reaction has been developed for the detection of Enterovirus 71 and Coxsackievirus A16 in throat swab specimens. The specific reverse transcription-polymerase chain reaction amplicons labeled with SYBR Orange were separated by microchip capillary electrophoresis and detected by laser induced fluorescence detector within 7 min. The intraday and interday relative standard deviation of migration time for DNA Marker was in the range of 1.36-2.94 and 2.78-3.96%, respectively. The detection limits were as low as 2.06 × 10(3) copies/mL for Enterovirus 71 and 5 × 10(3) copies/mL for Coxsackievirus A16. No cross-reactivity was observed with rotavirus, astrovirus, norovirus, and adenovirus, which showed good specificity of the method. This assay was validated using 100 throat swab specimens that were detected by real-time reverse-transcript polymerase chain reaction in parallel and the two methods produced the same results. This study provided a rapid, sensitive and specific method for the detection of Enterovirus 71 and Coxsackievirus A16, which make a contribution to significant time and cost saving for the identification and treatment of patients. PMID:25953405

  3. Microchip capillary electrophoresis with laser-induced fluorescence combined with one-step duplex reverse-transcription polymerase chain reaction for the rapid detection of Enterovirus 71 and Coxsackievirus A16 in throat swab specimens.

    PubMed

    Jia, Ruan; Chengjun, Sun; Heng, Chen; Chen, Zhou; Yuanqian, Li; Yongxin, Li

    2015-07-01

    Enterovirus 71 and Coxsackievirus A16 are the main pathogens causing hand-foot-mouth disease. In this paper, microchip capillary electrophoresis with laser-induced fluorescence combined with one-step duplex reverse transcript-polymerase chain reaction has been developed for the detection of Enterovirus 71 and Coxsackievirus A16 in throat swab specimens. The specific reverse transcription-polymerase chain reaction amplicons labeled with SYBR Orange were separated by microchip capillary electrophoresis and detected by laser induced fluorescence detector within 7 min. The intraday and interday relative standard deviation of migration time for DNA Marker was in the range of 1.36-2.94 and 2.78-3.96%, respectively. The detection limits were as low as 2.06 × 10(3) copies/mL for Enterovirus 71 and 5 × 10(3) copies/mL for Coxsackievirus A16. No cross-reactivity was observed with rotavirus, astrovirus, norovirus, and adenovirus, which showed good specificity of the method. This assay was validated using 100 throat swab specimens that were detected by real-time reverse-transcript polymerase chain reaction in parallel and the two methods produced the same results. This study provided a rapid, sensitive and specific method for the detection of Enterovirus 71 and Coxsackievirus A16, which make a contribution to significant time and cost saving for the identification and treatment of patients.

  4. Target-triggered three-way junction structure and polymerase/nicking enzyme synergetic isothermal quadratic DNA machine for highly specific, one-step, and rapid microRNA detection at attomolar level.

    PubMed

    Zhang, Qing; Chen, Feng; Xu, Feng; Zhao, Yongxi; Fan, Chunhai

    2014-08-19

    MicroRNAs (miRNAs) play important roles in many biological processes and are regarded as promising cancer biomarkers. Herein, a highly specific, one-step, and rapid miRNAs detection strategy with attomolar sensitivity has been developed on the basis of a target-triggered three-way junction (3-WJ) structure and polymerase/nicking enzyme synergetic isothermal quadratic DNA machine (ESQM). To this end, 3-WJ probes (primer and template) are designed to selectively recognize target miRNA and form the stable 3-WJ structure to trigger ESQM, resulting in a high quadratic amplified signal. A high specificity is demonstrated by the excellent discrimination of even single-base mismatched homologous sequences with mismatched bases in varied locations (close to the 3'-end, the 5'-end, and the middle). In addition, a low detection limit down to 2 amol was achieved within 30 min. This sensitivity is much higher than those of most linear amplification-based approaches and is even comparable to those of some exponential amplification-based methods. Furthermore, the applicability of this method in complex samples was demonstrated by the analysis of cancer cell small RNA extracts, results of which were in good agreement with those obtained by a commercial miRNA kit and previously published data. The miRNA with a 3' end modification (2'-O-methylation), such as plant miRNA, was also successfully detected, confirming the good universality of the proposed strategy. It is worthwhile to point out that several well-established methods using miRNA as primer for polymerization reaction are of relatively poor performance in the analysis of these modified miRNA. Therefore, these merits endow the developed strategy with powerful implications for biological research and an effective diagnostic assay. PMID:25072308

  5. One-step error correction for multipartite polarization entanglement

    SciTech Connect

    Deng Fuguo

    2011-06-15

    We present two economical one-step error-correction protocols for multipartite polarization-entangled systems in a Greenberger-Horne-Zeilinger state. One uses spatial entanglement to correct errors in the polarization entanglement of an N-photon system, resorting to linear optical elements. The other uses frequency entanglement to correct errors in the polarization entanglement of an N-photon system. The parties in quantum communication can obtain a maximally entangled state from each N-photon system transmitted with one step in these two protocols, and both of their success probabilities are 100%, in principle. That is, they both work in a deterministic way, and they do not largely consume the less-entangled photon systems, which is far different from conventional multipartite entanglement purification schemes. These features may make these two protocols more useful for practical applications in long-distance quantum communication.

  6. ONE-STEP PURIFICATION OF ENTEROCYTOZOON BIENEUSI SPORES (R828043)

    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...

  7. Rapid Microscale Isolation and Purification of Yeast Alcohol Dehydrogenase Using Cibacron Blue Affinity Chromatography

    NASA Astrophysics Data System (ADS)

    Morgan, Chad; Moir, Neil

    1996-11-01

    A rapid microscale procedure has been developed for the isolation and purification of yeast alcohol dehydrogenase. Glass beads are used for cytolysis, PEG precipitation for partial purification and a cibacron blue affinity column for the final step. A 27.5 fold purification can be achieved in 2 - 3 hours.

  8. One-step fabrication of multifunctional micromotors

    NASA Astrophysics Data System (ADS)

    Gao, Wenlong; Liu, Mei; Liu, Limei; Zhang, Hui; Dong, Bin; Li, Christopher Y.

    2015-08-01

    Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications.Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications. Electronic supplementary information (ESI) available: Videos S1-S4 and Fig. S1-S3. See DOI: 10.1039/c5nr03574k

  9. One-step (18)F labeling of biomolecules using organotrifluoroborates.

    PubMed

    Liu, Zhibo; Lin, Kuo-Shyan; Bénard, François; Pourghiasian, Maral; Kiesewetter, Dale O; Perrin, David M; Chen, Xiaoyuan

    2015-09-01

    Herein we present a general protocol for the functionalization of biomolecules with an organotrifluoroborate moiety so that they can be radiolabeled with aqueous (18)F fluoride ((18)F(-)) and used for positron emission tomography (PET) imaging. Among the β(+)-emitting radionuclides, fluorine-18 ((18)F) is the isotope of choice for PET, and it is produced, on-demand, in many hospitals worldwide. Organotrifluoroborates can be (18)F-labeled in one step in aqueous conditions via (18)F-(19)F isotope exchange. This protocol features a recently designed ammoniomethyltrifluoroborate, and it describes the following: (i) a synthetic strategy that affords modular synthesis of radiolabeling precursors via a copper-catalyzed 'click' reaction; and (ii) a one-step (18)F-labeling method that obviates the need for HPLC purification. Within 30 min, (18)F-labeled PET imaging probes, such as peptides, can be synthesized in good chemical and radiochemical purity (>98%), satisfactory radiochemical yield of 20-35% (n > 20, non-decay corrected) and high specific activity of 40-111 GBq/μmol (1.1-3.0 Ci/μmol). The entire procedure, including the precursor preparation and (18)F radiolabeling, takes 7-10 d. PMID:26313478

  10. Purify First: rapid expression and purification of proteins from XMRV.

    PubMed

    Gillette, William K; Esposito, Dominic; Taylor, Troy E; Hopkins, Ralph F; Bagni, Rachel K; Hartley, James L

    2011-04-01

    Purifying proteins from recombinant sources is often difficult, time-consuming, and costly. We have recently instituted a series of improvements in our protein purification pipeline that allows much more accurate choice of expression host and conditions and purification protocols. The key elements are parallel cloning, small scale parallel expression and lysate preparation, and small scale parallel protein purification. Compared to analyzing expression data only, results from multiple small scale protein purifications predict success at scale-up with greatly improved reliability. Using these new procedures we purified eight of nine proteins from xenotropic murine leukemia virus-related virus (XMRV) on the first attempt at large scale. PMID:21146612

  11. One-step preparation of [(18)F]FPBM for PET imaging of serotonin transporter (SERT) in the brain.

    PubMed

    Qiao, Hongwen; Zhang, Yan; Wu, Zehui; Zhu, Lin; Choi, Seok Rye; Ploessl, Karl; Kung, Hank F

    2016-08-01

    Serotonin transporters (SERT) in the brain play an important role in normal brain function. Selective serotonin reuptake inhibitors such as fluoxetine, sertraline, paroxetine, escitalopram, etc., specifically target SERT binding in the brain. Development of SERT imaging agents may be useful for studying the function of SERT by in vivo imaging. A one-step preparation of [(18)F]FPBM, 2-(2'-(dimethylamino)methyl)-4'-(3-([(18)F]fluoropropoxy)phenylthio)benzenamine, for positron emission tomography (PET) imaging of SERT binding in the brain was achieved. An active OTs intermediate, 9, was reacted with [(18)F]F(-)/K222 to produce [(18)F]FPBM in one step and in high radiochemical yield. This labeling reaction was evaluated and optimized under different temperatures, bases, solvents, and varying amounts of precursor 9. The radiolabeling reaction led to the desired [(18)F]FPBM in one step and the crude product was purified by HPLC purification to give no-carrier-added [(18)F]FPBM (radiochemical yield, 24-33%, decay corrected; radiochemical purity >99%). PET imaging studies in normal monkeys (n=4) showed fast, pronounced uptakes in the midbrain and thalamus, regions known to be rich in SERT binding sites. A displacement experiment with escitalopram (5mg/kg iv injection at 30min after [(18)F]FPBM injection) showed a rapid and complete reversal of SERT binding, suggesting that binding by [(18)F]FPBM was highly specific and reversible. A one-step radiolabeling method coupled with HPLC purification for preparation of [(18)F]FPBM was developed. Imaging studies suggest that it is feasible to use this method to prepare [(18)F]FPBM for in vivo PET imaging of SERT binding in the brain. PMID:27236282

  12. One-step preparation of [(18)F]FPBM for PET imaging of serotonin transporter (SERT) in the brain.

    PubMed

    Qiao, Hongwen; Zhang, Yan; Wu, Zehui; Zhu, Lin; Choi, Seok Rye; Ploessl, Karl; Kung, Hank F

    2016-08-01

    Serotonin transporters (SERT) in the brain play an important role in normal brain function. Selective serotonin reuptake inhibitors such as fluoxetine, sertraline, paroxetine, escitalopram, etc., specifically target SERT binding in the brain. Development of SERT imaging agents may be useful for studying the function of SERT by in vivo imaging. A one-step preparation of [(18)F]FPBM, 2-(2'-(dimethylamino)methyl)-4'-(3-([(18)F]fluoropropoxy)phenylthio)benzenamine, for positron emission tomography (PET) imaging of SERT binding in the brain was achieved. An active OTs intermediate, 9, was reacted with [(18)F]F(-)/K222 to produce [(18)F]FPBM in one step and in high radiochemical yield. This labeling reaction was evaluated and optimized under different temperatures, bases, solvents, and varying amounts of precursor 9. The radiolabeling reaction led to the desired [(18)F]FPBM in one step and the crude product was purified by HPLC purification to give no-carrier-added [(18)F]FPBM (radiochemical yield, 24-33%, decay corrected; radiochemical purity >99%). PET imaging studies in normal monkeys (n=4) showed fast, pronounced uptakes in the midbrain and thalamus, regions known to be rich in SERT binding sites. A displacement experiment with escitalopram (5mg/kg iv injection at 30min after [(18)F]FPBM injection) showed a rapid and complete reversal of SERT binding, suggesting that binding by [(18)F]FPBM was highly specific and reversible. A one-step radiolabeling method coupled with HPLC purification for preparation of [(18)F]FPBM was developed. Imaging studies suggest that it is feasible to use this method to prepare [(18)F]FPBM for in vivo PET imaging of SERT binding in the brain.

  13. Rapid and mild purification method for nanoparticles from a dispersed solution using a monolithic silica disk.

    PubMed

    Itoh, Naoki; Santa, Tomofumi; Kato, Masaru

    2015-07-24

    A rapid and mild purification method for nanoparticles using the commercially available monolithic silica disk, MonoSpin(®), was developed. The nanoparticles were purified from a dispersed solution by filtration with the aid of centrifugation at 2290×g for 2min. The purification conditions were rapid, mild, and simple compared with those of the conventional purification methods such as ultracentrifugation, dialysis, size exclusion chromatography, and ultrafiltration. The method was shown to be applicable for the purification of various nanoparticles, regardless of their size (from 21 to 100nm), composition material (silica, polyethylene glycol, and pegylated liposome), and encapsulated molecule (rhodamine 110 and doxorubicin). It was shown that this method is applicable to the purification of a wide range of nanoparticles in many different fields.

  14. One-step electrodeposition process to fabricate cathodic superhydrophobic surface

    NASA Astrophysics Data System (ADS)

    Chen, Zhi; Li, Feng; Hao, Limei; Chen, Anqi; Kong, Youchao

    2011-12-01

    In this work, a rapid one-step process is developed to fabricate superhydrophobic cathodic surface by electrodepositing copper plate in an electrolyte solution containing manganese chloride (MnCl2·4H2O), myristic acid (CH3(CH2)12COOH) and ethanol. The superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The shortest electrolysis time for fabricating a superhydrophobic surface is about 1 min, the measured maximum contact angle is 163° and rolling angle is less than 3°. Furthermore, this method can be easily extended to other conductive materials. The approach is time-saving and cheap, and it is supposed to have a promising future in industrial fields.

  15. One Step Forward, One Step Beck: A Contribution to the Ongoing Conceptual Debate in Youth Studies

    ERIC Educational Resources Information Center

    Roberts, Steven

    2012-01-01

    In a time of rapid and unprecedented social change, the concepts we use to make sense of the ways in which young people understand and interact with the world are very much under the microscope. Some researchers argue that we need to reinvigorate our conceptual repertoire, while others argue that our theoretical tool box still has the capacity to…

  16. One-step PCR amplification of complete arthropod mitochondrial genomes.

    PubMed

    Hwang, U W; Park, C J; Yong, T S; Kim, W

    2001-06-01

    A new PCR primer set which enables one-step amplification of complete arthropod mitochondrial genomes was designed from two conserved 16S rDNA regions for the long PCR technique. For this purpose, partial 16S rDNAs amplified with universal primers 16SA and 16SB were newly sequenced from six representative arthropods: Armadillidium vulgare and Macrobrachium nipponense (Crustacea), Anopheles sinensis (Insecta), Lithobius forficatus and Megaphyllum sp. (Myriapoda), and Limulus polyphemus (Chelicerata). The genomic locations of two new primers, HPK16Saa and HPK16Sbb, correspond to positions 13314-13345 and 12951-12984, respectively, in the Drosophila yakuba mitochondrial genome. The usefulness of the primer set was experimentally examined and confirmed with five of the representative arthropods, except for A. vulgare, which has a linearized mitochondrial genome. With this set, therefore, we could easily and rapidly amplify complete mitochondrial genomes with small amounts of arthropod DNA. Although the primers suggested here were examined only with arthropod groups, a possibility of successful application to other invertebrates is very high, since the high degree of sequence conservation is shown on the primer sites in other invertebrates. Thus, this primer set can serve various research fields, such as molecular evolution, population genetics, and molecular phylogenetics based on DNA sequences, RFLP, and gene rearrangement of mitochondrial genomes in arthropods and other invertebrates. PMID:11399145

  17. Evaluation of one-step luminescent cyanoacrylate fuming.

    PubMed

    Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

    2016-06-01

    One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples. PMID:27105155

  18. Evaluation of one-step luminescent cyanoacrylate fuming.

    PubMed

    Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

    2016-06-01

    One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples.

  19. One-step continuous synthesis of functionalized magnetite nanoflowers

    NASA Astrophysics Data System (ADS)

    Thomas, G.; Demoisson, F.; Chassagnon, R.; Popova, E.; Millot, N.

    2016-04-01

    For the first time, functionalized magnetite nanoparticles (Fe3O4 NPs) that form aggregates with a nanoflower morphology were synthesized using a rapid (11 s) one-step continuous hydrothermal process, which was recently modified, and their application as a T 2 magnetic resonance imaging (MRI) contrast agent was evaluated. The nanoparticles functionalized with 3,4-dihydroxy-L-phenylalanine (LDOPA) or 3,4-dihydroxyhydrocinnamic acid (DHCA) consisted of small crystallites of approximately 15 nm of diameter that assembled to form flower-shaped aggregate structures. The Fe3O4-LDOPA nanoflowers exhibited a high transverse relaxivity, r 2 of 418 ± 10 l mmolFe -1 s-1 at 3 T owing to magnetic dipolar interactions, which is twice as that of the commercial Feridex®/Endorem®. The prepared nanostructures were compared with bare Fe3O4 NPs and citrated Fe3O4 NPs. DHCA, LDOPA, and citric acid (CA) were found to have an anti-oxidizing effect and to influence the crystallite size and the lattice parameter of the NPs. DHCA and LDOPA increased the crystallite size, whereas CA decreased it. Surface modification increased the colloidal stability of NPs as compared to bare NPs. Nanoflower suspensions of Fe3O4-LDOPA NPs were found to be stable in the phosphate-buffered saline, saline medium, and minimal essential medium and formed aggregates of sizes smaller than 120 nm. All samples were found to be superparamagnetic in nature and the highest saturation magnetization was obtained for the Fe3O4-LDOPA samples. These NPs can bind to polymers such as PEG, and to fluorescent and chelating agents owing to the presence of free -NH2 or -COOH groups on the surface of NPs, allowing their use in dual imaging applications.

  20. Rapid purification of gram quantities of β-sitosterol from a commercial phytosterol mixture

    PubMed Central

    2014-01-01

    Background β-Sitosterol, a plant sterol or phytosterol, has commercial uses in the nutraceutical and pharmaceutical industries, but is also employed frequently in biological research. Phytosterols always accumulate as mixtures, and obtaining highly pure β-sitosterol in larger quantities for biological assays has been a challenge. Findings An improved method for the rapid purification of β-sitosterol from a commercial phytosterol extract is presented. Fractional crystallization of soybean oil yielded a soluble and an insoluble fraction. β-Sitosterol was purified by silica gel and Na-Y zeolite chromatography. Conclusion The rapid and cost effective three-step purification described here afforded β-sitosterol in gram quantities with high purity (>92%) and yield (>22%). PMID:24674386

  1. Rapid Purification and Characterization of Mutant Origin Recognition Complexes in Saccharomyces cerevisiae

    PubMed Central

    Kawakami, Hironori; Ohashi, Eiji; Tsurimoto, Toshiki; Katayama, Tsutomu

    2016-01-01

    Purification of the origin recognition complex (ORC) from wild-type budding yeast cells more than two decades ago opened up doors to analyze the initiation of eukaryotic chromosomal DNA replication biochemically. Although revised methods to purify ORC from overproducing cells were reported later, purification of mutant proteins using these systems still depends on time-consuming processes including genetic manipulation to construct and amplify mutant baculoviruses or yeast strains as well as several canonical protein fractionations. Here, we present a streamlined method to construct mutant overproducers, followed by purification of mutant ORCs. Use of mammalian cells co-transfected with conveniently mutagenized plasmids bearing a His tag excludes many of the construction and fractionation steps. Transfection is highly efficient. All the six subunits of ORC are overexpressed at a considerable level and isolated as a functional heterohexameric complex. Furthermore, use of mammalian cells prevents contamination of wild-type ORC from yeast cells. The method is applicable to wild-type and at least three mutant ORCs, and the resultant purified complexes show expected biochemical activities. The rapid acquisition of mutant ORCs using this system will boost systematic biochemical dissection of ORC and can be even applied to the purification of protein complexes other than ORC. PMID:27148210

  2. One-step Sparse Estimates in Nonconcave Penalized Likelihood Models.

    PubMed

    Zou, Hui; Li, Runze

    2008-08-01

    Fan & Li (2001) propose a family of variable selection methods via penalized likelihood using concave penalty functions. The nonconcave penalized likelihood estimators enjoy the oracle properties, but maximizing the penalized likelihood function is computationally challenging, because the objective function is nondifferentiable and nonconcave. In this article we propose a new unified algorithm based on the local linear approximation (LLA) for maximizing the penalized likelihood for a broad class of concave penalty functions. Convergence and other theoretical properties of the LLA algorithm are established. A distinguished feature of the LLA algorithm is that at each LLA step, the LLA estimator can naturally adopt a sparse representation. Thus we suggest using the one-step LLA estimator from the LLA algorithm as the final estimates. Statistically, we show that if the regularization parameter is appropriately chosen, the one-step LLA estimates enjoy the oracle properties with good initial estimators. Computationally, the one-step LLA estimation methods dramatically reduce the computational cost in maximizing the nonconcave penalized likelihood. We conduct some Monte Carlo simulation to assess the finite sample performance of the one-step sparse estimation methods. The results are very encouraging.

  3. Modified drill permits one-step drilling operation

    NASA Technical Reports Server (NTRS)

    Libertone, C.

    1966-01-01

    Drill with modified cutting faces permits one-step drilling operation without chatter upon contact and premature wear. The modification of the drill, which has the same diameter as that of the desired hole, consists of a groove across the bottom of each of the cutting faces of the drill flutes.

  4. An efficient and more sustainable one-step continuous-flow multicomponent synthesis approach to chromene derivatives

    EPA Science Inventory

    A simple and rapid one-step continuous-flow synthesis route has been developed for the preparation of chromene derivatives from the reaction of aromatic aldehydes, α-cyanomethylene compounds and naphthols. In this contribution, a one-step continuous-flow protocol in a continuous ...

  5. Recombinant single-chain Fv antibody fragment-alkaline phosphatase conjugate for one-step immunodetection in molecular hybridization.

    PubMed

    Muller, B H; Chevrier, D; Boulain, J C; Guesdon, J L

    1999-07-30

    Using phage-display technology, a recombinant single-chain Fv antibody fragment (scFv) was rapidly generated from the K16-16 hybridoma secreting mouse monoclonal antibody (MAb) that binds to acetylaminofluorene-labeled DNA (AAF-DNA). The selected A4 phage-scFv specifically bound to AAF-DNA. The anti-AAF scFv gene was then recloned into a fusion vector for the production of a hybrid protein comprising the antibody fragment fused to a potent bacterial alkaline phosphatase variant (PhoAv). The anti-AAF scFv-PhoAv hybrid protein was bifunctional and possessed both antigen binding capacity and PhoA activity. The recombinant conjugate was directly used, without further purification, for one-step immunodetection in dot-blot hybridization. The detection limit was identical and the test was quicker than the conventional two-step procedure with the purified anti-AAF MAb revealed with a secondary enzyme-labeled antibody. To assess the value of this new reagent for the immunodetection of genomic nucleic acids, genomic DNAs of Campylobacter jejuni and Campylobacter coli were then one-step immunodetected with non-purified recombinant scFv-PhoAv conjugate in a Southern-blot hybridization experiment. The present study shows that the genetic fusion with PhoAv provides a new tool for immunodetection which presents easier and quicker production and use with the same sensitivity and specificity as classical reagents. The recombinant anti-AAF scFv-PhoAv conjugate is a promising alternative reagent for applications involving the immunodetection of specific DNA or RNA sequences, such as the detection and characterization of microorganisms.

  6. One-Step Model of Photoemission for Nonlocal Potentials

    NASA Astrophysics Data System (ADS)

    Potthoff, M.; Lachnitt, J.; Nolting, W.; Braun, J.

    1997-10-01

    The one-step model of valence-band photoemission and inverse photoemission from single-crystal surfaces is reformulated for generalized (nonlocal, complex and energy-dependent) potentials. Thereby, it becomes possible to account for self-energy corrections taken from many-body electronic-structure calculations. The original formulation due to Pendry and coworkers employs the KKR multiple-scattering theory for the calculation of the initial state. This prevents a straightforward generalization of the one-step model to nonlocal potentials. We therefore consider the Dyson equation which is set up within a muffin-tin-orbital representation as an alternative to obtain the initial-state Green function. This approach requires a revision of the transition-matrix elements which is carried out in detail. The final state is considered as a time-reversed LEED state as usual. The proposed generalization of the one-step model allows to distinguish between the bare photocurrent reflecting the (quasi-particle) band structure and the secondary effects due to the (dipole) selection rules and due to the wave-vector and energy dependence of the transition-matrix elements.

  7. Recombinant Passenger Proteins Can Be Conveniently Purified by One-Step Affinity Chromatography.

    PubMed

    Wang, Hua-zhen; Chu, Zhi-zhan; Chen, Chang-chao; Cao, Ao-cheng; Tong, Xin; Ouyang, Can-bin; Yuan, Qi-hang; Wang, Mi-nan; Wu, Zhong-kun; Wang, Hai-hong; Wang, Sheng-bin

    2015-01-01

    Fusion tag is one of the best available tools to date for enhancement of the solubility or improvement of the expression level of recombinant proteins in Escherichia coli. Typically, two consecutive affinity purification steps are often necessitated for the purification of passenger proteins. As a fusion tag, acyl carrier protein (ACP) could greatly increase the soluble expression level of Glucokinase (GlcK), α-Amylase (Amy) and GFP. When fusion protein ACP-G2-GlcK-Histag and ACP-G2-Amy-Histag, in which a protease TEV recognition site was inserted between the fusion tag and passenger protein, were coexpressed with protease TEV respectively in E. coli, the efficient intracellular processing of fusion proteins was achieved. The resulting passenger protein GlcK-Histag and Amy-Histag accumulated predominantly in a soluble form, and could be conveniently purified by one-step Ni-chelating chromatography. However, the fusion protein ACP-GFP-Histag was processed incompletely by the protease TEV coexpressed in vivo, and a large portion of the resulting target protein GFP-Histag aggregated in insoluble form, indicating that the intracellular processing may affect the solubility of cleaved passenger protein. In this context, the soluble fusion protein ACP-GFP-Histag, contained in the supernatant of E. coli cell lysate, was directly subjected to cleavage in vitro by mixing it with the clarified cell lysate of E. coli overexpressing protease TEV. Consequently, the resulting target protein GFP-Histag could accumulate predominantly in a soluble form, and be purified conveniently by one-step Ni-chelating chromatography. The approaches presented here greatly simplify the purification process of passenger proteins, and eliminate the use of large amounts of pure site-specific proteases. PMID:26641240

  8. Recombinant Passenger Proteins Can Be Conveniently Purified by One-Step Affinity Chromatography

    PubMed Central

    Wang, Hua-zhen; Chu, Zhi-zhan; Chen, Chang-chao; Cao, Ao-cheng; Tong, Xin; Ouyang, Can-bin; Yuan, Qi-hang; Wang, Mi-nan; Wu, Zhong-kun; Wang, Hai-hong; Wang, Sheng-bin

    2015-01-01

    Fusion tag is one of the best available tools to date for enhancement of the solubility or improvement of the expression level of recombinant proteins in Escherichia coli. Typically, two consecutive affinity purification steps are often necessitated for the purification of passenger proteins. As a fusion tag, acyl carrier protein (ACP) could greatly increase the soluble expression level of Glucokinase (GlcK), α-Amylase (Amy) and GFP. When fusion protein ACP-G2-GlcK-Histag and ACP-G2-Amy-Histag, in which a protease TEV recognition site was inserted between the fusion tag and passenger protein, were coexpressed with protease TEV respectively in E. coli, the efficient intracellular processing of fusion proteins was achieved. The resulting passenger protein GlcK-Histag and Amy-Histag accumulated predominantly in a soluble form, and could be conveniently purified by one-step Ni-chelating chromatography. However, the fusion protein ACP-GFP-Histag was processed incompletely by the protease TEV coexpressed in vivo, and a large portion of the resulting target protein GFP-Histag aggregated in insoluble form, indicating that the intracellular processing may affect the solubility of cleaved passenger protein. In this context, the soluble fusion protein ACP-GFP-Histag, contained in the supernatant of E. coli cell lysate, was directly subjected to cleavage in vitro by mixing it with the clarified cell lysate of E. coli overexpressing protease TEV. Consequently, the resulting target protein GFP-Histag could accumulate predominantly in a soluble form, and be purified conveniently by one-step Ni-chelating chromatography. The approaches presented here greatly simplify the purification process of passenger proteins, and eliminate the use of large amounts of pure site-specific proteases. PMID:26641240

  9. One Step Quantum Key Distribution Based on EPR Entanglement.

    PubMed

    Li, Jian; Li, Na; Li, Lei-Lei; Wang, Tao

    2016-01-01

    A novel quantum key distribution protocol is presented, based on entanglement and dense coding and allowing asymptotically secure key distribution. Considering the storage time limit of quantum bits, a grouping quantum key distribution protocol is proposed, which overcomes the vulnerability of first protocol and improves the maneuverability. Moreover, a security analysis is given and a simple type of eavesdropper's attack would introduce at least an error rate of 46.875%. Compared with the "Ping-pong" protocol involving two steps, the proposed protocol does not need to store the qubit and only involves one step. PMID:27357865

  10. One step geometrical calibration method for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Díaz Díaz, Jesús; Stritzel, Jenny; Rahlves, Maik; Majdani, Omid; Reithmeier, Eduard; Ortmaier, Tobias; Roth, Bernhard

    2016-01-01

    We present a novel one-step calibration methodology for geometrical distortion correction for optical coherence tomography (OCT). A calibration standard especially designed for OCT is introduced, which consists of an array of inverse pyramidal structures. The use of multiple landmarks situated on four different height levels on the pyramids allow performing a 3D geometrical calibration. The calibration procedure itself is based on a parametric model of the OCT beam propagation. It is validated by experimental results and enables the reduction of systematic errors by more than one order of magnitude. In future, our results can improve OCT image reconstruction and interpretation for medical applications such as real time monitoring of surgery.

  11. Effect of Simplified One-Step Drilling Protocol on Osseointegration.

    PubMed

    Patel, Arpita; Gil, Luiz F; Castellano, Arthur; Freitas, Gileade; Navarro, Daniel; Peredo, Ana P; Tovar, Nick; Coelho, Paulo

    2016-01-01

    This study was designed to compare the combined effect of two different drilling techniques (conventional expansion and one-step) and four different implant geometries in a beagle dog model. The nondecalcified bone-implant samples underwent histologic/metric analysis at 2 and 6 weeks. Morphologic analysis showed similarities between different drilling technique groups and implant geometries. Histomorphometric parameters, bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) were analyzed, and no statistical difference between drilling groups and/or implant geometry was found. Time was the only variable that affected BIC and BAFO, suggesting that the two protocols are equally biocompatible and osseoconductive. PMID:27560682

  12. One step high quality poly(dimethylsiloxane)-hydrocarbon plastics bonding.

    PubMed

    Xu, Bi-Yi; Yan, Xiao-Na; Xu, Jing-Juan; Chen, Hong-Yuan

    2012-03-01

    In this paper, one-step air plasma treatment is successfully used for poly(dimethylsiloxane)(PDMS)-plastic chip bonding. The technique is green, cheap, and requires no other reagent other than air. Hydrocarbon plastics: polystyrene (PS), cyclic olefin copolymer (COC), and polypropylene (PP) have all been successfully bonded to PDMS irreversibly. The corresponding compressed air resistances are measured to be around 500 kPa for PDMS-PS, PDMS-COC, and PDMS-PP hybrid chips. The bondings are also of good quality even after storage under different temperatures and subject to solutions from acid to base.

  13. One Step Quantum Key Distribution Based on EPR Entanglement

    PubMed Central

    Li, Jian; Li, Na; Li, Lei-Lei; Wang, Tao

    2016-01-01

    A novel quantum key distribution protocol is presented, based on entanglement and dense coding and allowing asymptotically secure key distribution. Considering the storage time limit of quantum bits, a grouping quantum key distribution protocol is proposed, which overcomes the vulnerability of first protocol and improves the maneuverability. Moreover, a security analysis is given and a simple type of eavesdropper’s attack would introduce at least an error rate of 46.875%. Compared with the “Ping-pong” protocol involving two steps, the proposed protocol does not need to store the qubit and only involves one step. PMID:27357865

  14. One-step reconstruction of assembled 3D holographic scenes

    NASA Astrophysics Data System (ADS)

    Velez Zea, Alejandro; Barrera-Ramírez, John Fredy; Torroba, Roberto

    2015-12-01

    We present a new experimental approach for reconstructing in one step 3D scenes otherwise not feasible in a single snapshot from standard off-axis digital hologram architecture, due to a lack of illuminating resources or a limited setup size. Consequently, whenever a scene could not be wholly illuminated or the size of the scene surpasses the available setup disposition, this protocol can be implemented to solve these issues. We need neither to alter the original setup in every step nor to cover the whole scene by the illuminating source, thus saving resources. With this technique we multiplex the processed holograms of actual diffuse objects composing a scene using a two-beam off-axis holographic setup in a Fresnel approach. By registering individually the holograms of several objects and applying a spatial filtering technique, the filtered Fresnel holograms can then be added to produce a compound hologram. The simultaneous reconstruction of all objects is performed in one step using the same recovering procedure employed for single holograms. Using this technique, we were able to reconstruct, for the first time to our knowledge, a scene by multiplexing off-axis holograms of the 3D objects without cross talk. This technique is important for quantitative visualization of optically packaged multiple images and is useful for a wide range of applications. We present experimental results to support the method.

  15. One-step synthesis of lignosulfonate-stabilized silver nanoparticles.

    PubMed

    Milczarek, Grzegorz; Rebis, Tomasz; Fabianska, Justyna

    2013-05-01

    Softwood lignosulfonate (SLS) was used as a reducing agent for one-step synthesis of silver nanoparticles (SLS-AgNPs) in an aqueous solution at room temperature. In this reaction SLS acts also as a stabilizing agent and as a result, stable colloids of silver nanoparticles are formed during the reaction with the average particle size of 41 nm. The obtained SLS-AgNPs were characterized by UV-vis spectrophotometry, size distribution and AFM imaging after casting on mica. Due to metal ion complexing capability of lignosulfonates, the SLS-AgNPs appeared to be capable of colorimetric detection of metal ions (especially nickel). Additionally, the SLS-AgNPs could be assembled into thin films on conducting substrates (ITO glass) using electrophoretic deposition. XPS spectroscopy was used to characterize such films and revealed a strong interaction of silver atoms with some carbon atoms of the SLS.

  16. One-step method for the production of nanofluids

    DOEpatents

    Kostic, Milivoje; Golubovic, Mihajlo; Hull, John; Choi, Stephen U. S.

    2011-08-16

    A one step method and system for producing nanofluids by a nanoparticle-source evaporation and deposition of the evaporant into a base fluid. The base fluid such oil or ethylene glycol is placed in a rotating cylindrical drum having an adjustable heater-boat-evaporator and heat exchanger-cooler apparatus. As the drum rotates, a thin liquid layer is formed on the inside surface of the drum. An insulated heater-boat-evaporator having an evaporant material (nanoparticle-source) placed within its boat evaporator is adjustably positioned near a portion of the rotating thin liquid layer, the evaporant material being heated thereby evaporating a portion of the evaporant material and forming nanoparticles, the nanoparticles absorbed by the liquid film to form nanofluid.

  17. One-step method for the production of nanofluids

    DOEpatents

    Kostic, Milivoje; Golubovic, Mihajlo; Hull, John R.; Choi, Stephen U. S.

    2010-05-18

    A one step method and system for producing nanofluids by a particle-source evaporation and deposition of the evaporant into a base fluid. The base fluid such (i.e. ethylene glycol) is placed in a rotating cylindrical drum having an adjustable heater-boat-evaporator and heat exchanger-cooler apparatus. As the drum rotates, a thin liquid layer is formed on the inside surface of the drum. A heater-boat-evaporator having an evaporant material (particle-source) placed within its boat evaporator is adjustably positioned near a portion of the rotating thin liquid layer, the evaporant material being heated thereby evaporating a portion of the evaporant material, the evaporated material absorbed by the liquid film to form nanofluid.

  18. One-step separation of four flavonoids from Herba Salviae Plbeiae by HSCCC.

    PubMed

    Li, Jia; Zhang, Xiaoyong; Yu, Qi; Fu, Xiaohui; Wang, Weina

    2014-01-01

    High-speed countercurrent chromatography (HSCCC) was successfully applied to the isolation and purification of four flavonoids from Herba Salviae Plbeiae using stepwise and dual-mode elution with a pair of two-phase solvent systems. The systems composed of n-hexane-chloroform-methanol-water (0.5 : 4 : 3 : 2, v/v/v/v) and chloroform-methanol-water (4 : 3 : 2, v/v/v). Analytical HSCCC was used for the preliminary selection of a suitable system, and a linear scale-step procedure was performed at a preparative grade. Hispidulin (91 mg), nepetin (148 mg), homoplantaginin (405 mg) and nepetin-7-glucoside (192 mg) could be obtained from 1,500-mg crude sample in a one-step separation, with purities >95% as determined by high-performance liquid chromatography. Their chemical structures were identified by (1)H nuclear magnetic resonance (NMR) and (13)C NMR.

  19. One Step Synthesis of Inverted Aspartame Type Sweetener, Ac-Phe-Lys, Using Chemically Modified Chymotrypsin.

    PubMed

    Oaki, J; Nakahara, K; Tamura, M; Okai, H

    1999-01-01

    To search for techniques of simplified peptide synthesis, benzyloxycarbonyl chymotrypsin was prepared by a water-soluble acylating reagent and used to make Ac-Phe-Lys, an artificial peptide sweetener, which was selected as a target compound. As a result of using chemically modified chymotrypsin, Lys can be coupled directly with Ac-Phe and Ac-Phe-Lys made virtually in one step. Moreover, the total yield from preparation and purification steps for Ac-Phe-Lys was 13%. The value corresponds to that of the chemical synthesis method. On the contrary, enzymatic synthesis using native chymotrypsin cannot reach the level of the new method. It is expected that the method is more effective for simplified peptide synthesis as compared with other methods, especially on a large scale.

  20. Rapid and efficient purification of native histidine-tagged protein expressed by recombinant vaccinia virus.

    PubMed Central

    Janknecht, R; de Martynoff, G; Lou, J; Hipskind, R A; Nordheim, A; Stunnenberg, H G

    1991-01-01

    Vaccinia virus has been used as a vector to express foreign genes for the production of functional and posttranslationally modified proteins. A procedure is described here that allows the rapid native purification of vaccinia-expressed proteins fused to an amino-terminal tag of six histidines. Extracts from cells infected with recombinant vaccinia virus are loaded onto Ni2+.nitrilotriacetic acid (Ni2+.NTA)-agarose and histidine-tagged proteins are selectively eluted with imidazole-containing buffers. In the case of the human serum response factor (SRF), a transcription factor involved in the regulation of the c-fos protooncogene, the vaccinia-expressed histidine-tagged SRF (SRF-6His) could be purified solely by this step to greater than 95% purity. SRF-6His was shown to resemble authentic SRF by functional criteria: it was transported to the nucleus, bound specifically the c-fos serum response element, interacted with the p62TCF protein to form a ternary complex, and stimulated in vitro transcription from the serum response element. Thus, the combination of vaccinia virus expression and affinity purification by Ni2+.NTA chromatography promises to be useful for the production of proteins in a functional and posttranslationally modified form. Images PMID:1924358

  1. Rapid two-step purification of a recombinant mouse Fab fragment expressed in Escherichia coli.

    PubMed

    Wlad, H; Ballagi, A; Bouakaz, L; Gu, Z; Janson, J C

    2001-07-01

    We report a rapid, large-scale process for the purification of a recombinant Fab fragment specific for the tobacco mosaic virus coat protein (Fab57P). The fragment is expressed periplasmically in Escherichia coli. The expression level was optimized in 0.3-L fermentors. The highest levels were obtained using the following conditions: (1) low postinduction temperature (21 degrees C), (2) combined use of two beta-lactam antibiotics (carbenicillin and ampicillin), (3) IPTG concentration 0.1 mM, (4) regulated pH 7.2, (5) 17-h induction time, and (6) conditions that reduce mechanical stress. Optimized large-scale fermentations were done in 15- and 300-L capacity fermentors. The recombinant Fab fragment was purified by two chromatographic steps. After disruption of the bacteria using an APV Gaulin homogenizer, the crude E. coli homogenate was directly applied, without centrifugation, to an SP Sepharose Big Beads column. The recombinant Fab fragment was eluted as a single peak in a sodium chloride gradient. The fragment was further purified by affinity adsorption to a column packed with Epoxy-activated Sepharose 6B to which the antigen peptide NH(2)-CGS YNR GSF SQS SGLV-CONH(2) had been coupled through its N-terminal cysteine. The purified Fab57P fragment showed one band in SDS-PAGE. The overall purification yield was 35%.

  2. Rapid and efficient purification of ficolin-2 using a disposable CELLine bioreactor

    PubMed Central

    Geno, K. Aaron; Spencer, Brady L.; Nahm, Moon H.

    2015-01-01

    The human opsonin ficolin-2 (L-ficolin) is an innate pattern-recognizing molecule that binds to acetylated moieties. Upon binding, ficolin-2 activates complement through the lectin pathway, opsonizing the target to promote phagocytic clearance. Ficolin-2 has been found to interact with a growing number of pathogenic bacteria, fungi, and viruses. Ficolin-2 also has proposed roles in host homeostasis, including the clearance of apoptotic cells. Consequently, there is an increased interest in studying ficolin-2, and access to purified ficolin-2 is necessary for these studies. Ficolin-2 purified from serum, plasma, or cell culture supernatants has been a useful tool in the characterization of ficolin-2 function; however, available protocols are laborious and inefficient, requiring additional processing of starting materials (e.g., polyethylene glycol precipitation or dialysis) and multiple steps of purification. Here, we investigated a simple solution to the problem: use of a simple, disposable bioreactor requiring only standard tissue culture equipment. Using this system, we generated cell culture supernatants containing high concentrations of recombinant ficolin-2, which permitted rapid purification of high-purity recombinant ficolin-2 without processing the supernatants. Purified recombinant ficolin-2 retained its binding capacity and supported complement activation in vitro. Bioreactor cultivation will likely be generally useful in the production of other recombinant proteins in the study of the complement system. PMID:26021447

  3. One-step electrospinning of cross-linked chitosan fibers.

    PubMed

    Schiffman, Jessica D; Schauer, Caroline L

    2007-09-01

    Chitin is a nitrogen-rich polysaccharide that is abundant in crustaceans, mollusks, insects, and fungi and is the second most abundant organic material found in nature next to cellulose. Chitosan, the N-deacetylated derivative of chitin, is environmentally friendly, nontoxic, biodegradable, and antibacterial. Fibrous mats are typically used in industries for filter media, catalysis, and sensors. Decreasing fiber diameters within these mats causes many beneficial effects such as increased specific surface area to volume ratios. When the intrinsically beneficial effects of chitosan are combined with the enhanced properties of nanofibrous mats, applications arise in a wide range of fields, including medical, packaging, agricultural, and automotive. This is particularly important as innovative technologies that focus around bio-based materials are currently of high urgency, as they can decrease dependencies on fossil fuels. We have demonstrated that Schiff base cross-linked chitosan fibrous mats can be produced utilizing a one-step electrospinning process that is 25 times faster and, therefore, more economical than a previously reported two-step vapor-cross-linking method. These fibrous mats are insoluble in acidic, basic, and aqueous solutions for 72 h. Additionally, this improved production method results in a decreased average fiber diameter, which measures 128 +/- 40 nm. Chemical and structural analyses were conducted utilizing Fourier transform infrared spectroscopy, solubility studies, and scanning electron microscopy. PMID:17696400

  4. One-step synthesis of magnetic chitosan polymer composite films

    NASA Astrophysics Data System (ADS)

    Cesano, Federico; Fenoglio, Gaia; Carlos, Luciano; Nisticò, Roberto

    2015-08-01

    In this study, a magnetic iron oxide-chitosan composite film is synthesized by one-step method and thoroughly investigated in order to better understand its inorganic/organic properties. A deep physico-chemical characterization of the magnetic films has been performed. In particular, the material composition was evaluated by means of XRD and ATR-FTIR spectroscopy, whereas the thermal stability and the subsequent inorganic phase transitions involving iron oxide species were followed by TGA analyses carried out at different experimental conditions (i.e. inert and oxidative atmosphere). The magnetic properties of the films were tested at the bulk and at the surface level, performing respectively magnetization hysteresis curve and magnetic force microscopy (MFM) surface mapping. Results indicate that the synthesized material can be prepared through a very simple synthetic procedure and suggests that it can be successfully applied for instance to environmental applications, such as the adsorption of contaminants from solid and liquid media thanks to its pronounced magnetic properties, which favour its recover.

  5. One step facile synthesis of ferromagnetic magnetite nanoparticles

    NASA Astrophysics Data System (ADS)

    Suppiah, Durga Devi; Abd Hamid, Sharifah Bee

    2016-09-01

    The ferromagnetic properties of magnetite (Fe3O4) were influenced by the nanoparticle size, hence importance were given to the synthesis method. This paper clearly shows that magnetite nanoparticles were successfully synthesized by employing one step controlled precipitation method using a single salt (Iron(II) sulfate) iron precursor. The acquired titration curve from this method provides vital information on the possible reaction mechanism leading to the magnetite (Fe3O4) nanoparticles formation. Goethite (α-FeOOH) was obtained at pH 4, while the continuous addition of hydroxyl ions (OH-) forms iron hydroxides (Fe(OH)2). This subsequently reacts with the goethite, producing magnetite (Fe3O4) at pH 10. Spectroscopy studies validate the magnetite phase existence while structural and morphology analysis illustrates cubic shaped magnetite with an average size of 35 nm was obtained. The synthesized magnetite might be superparamagnetic though lower saturation magnetization (67.5 emu/g) measured at room temperature as compared to bulk magnetite. However the nanoparticles surface anisotropy leads to higher remanence (12 emu/g) and coercivity (117.7 G) making the synthesized magnetite an excellent candidate to be utilized in recording devices. The understanding of the magnetite synthesis mechanism can not only be used to achieve even smaller magnetite nanoparticles but also to prepare different types of iron oxides hydroxides using different iron precursor source.

  6. Rapid purification of the gastric H+/K(+)-ATPase complex by tomato-lectin affinity chromatography.

    PubMed Central

    Callaghan, J M; Toh, B H; Simpson, R J; Baldwin, G S; Gleeson, P A

    1992-01-01

    We have previously shown that tomato lectin binds specifically to the 60-90 kDa membrane glycoprotein of parietal cell tubulovesicles, the beta-subunit of the gastric H+/K(+)-ATPase (proton pump) [Callaghan, Toh, Pettitt, Humphris & Gleeson (1990) J. Cell Sci. 95, 563-576; Toh, Gleeson, Simpson, Mortiz, Callaghan, Goldkorn, Jones, Martinelli, Mu, Humphris, Pettitt, Mori, Masuda, Sobieszczuk, Weinstock, Mantamadiotis & Baldwin (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 6418-6422]. Here we have exploited this interaction for the development of a rapid single-step chromatography procedure for the purification of an active pig gastric proton pump complex. Initially, H+/K(+)-ATPase-enriched membranes, prepared from pig gastric microsomes by density-gradient centrifugation, were extracted in 1% Triton X-100 and passed through a 1 ml tomato lectin-Sepharose 4B column. The bound material, eluted with 20 mM-chitotriose, showed a major band with an apparent molecular mass of 95 kDa, and a faint broad band of 60-90 kDa, by SDS/PAGE. N-Glycanase treatment of the bound material resulted in the appearance of a 35 kDa band, the size of the protein core of the 60-90 kDa glycoprotein beta-subunit. The two components were identified as the 95 kDa alpha-subunit and the 60-90 kDa beta-subunit of the gastric H+/K(+)-ATPase, by immunoreactivity with monospecific antibodies, and by tryptic peptide sequences of the tomato-lectin-bound material. The beta-subunit was present in approximately equimolar amounts to the catalytic alpha-subunit. Whereas the gastric H+/K(+)-ATPase was not active after solubilization in 1% Triton X-100, solubilization of density-gradient-purified membranes in the non-ionic detergent, C12E8, followed by chromatography of the extract on tomato lectin-Sepharose 4B, resulted in the purification of the gastric H+/K(+)-ATPase complex which exhibited K(+)-dependent phosphatase activity. This is the first report of a rapid purification of a partially active solubilized

  7. One-step immunoaffinity purification of complex I subunits from beef heart mitochondria.

    PubMed

    Haines, A M; Cooper, J M; Morgan-Hughes, J A; Clark, J B; Schapira, A H

    1992-06-01

    Polypeptides of beef heart mitochondrial complex I were isolated from 15 mg of solubilized beef heart mitochondria using antibodies immobilized on an agarose chromatography column. The preparation was examined by SDS electrophoresis and Western blotting using affinity-purified antibodies to complex I and compared to beef heart complex I purified according to the conventional method of Hatefi and Rieske. There was a high degree of homology between the two preparations as judged by SDS-polyacrylamide electrophoresis and by immunoblotting with seven affinity-purified antibodies to various complex I subunits. This method could be applied to the preparation of complex I subunits from small samples such as human muscle biopsy specimens.

  8. A cell-free expression and purification process for rapid production of protein biologics.

    PubMed

    Sullivan, Challise J; Pendleton, Erik D; Sasmor, Henri H; Hicks, William L; Farnum, John B; Muto, Machiko; Amendt, Eric M; Schoborg, Jennifer A; Martin, Rey W; Clark, Lauren G; Anderson, Mark J; Choudhury, Alaksh; Fior, Raffaella; Lo, Yu-Hwa; Griffey, Richard H; Chappell, Stephen A; Jewett, Michael C; Mauro, Vincent P; Dresios, John

    2016-02-01

    Cell-free protein synthesis has emerged as a powerful technology for rapid and efficient protein production. Cell-free methods are also amenable to automation and such systems have been extensively used for high-throughput protein production and screening; however, current fluidic systems are not adequate for manufacturing protein biopharmaceuticals. In this work, we report on the initial development of a fluidic process for rapid end-to-end production of recombinant protein biologics. This process incorporates a bioreactor module that can be used with eukaryotic or prokaryotic lysates that are programmed for combined transcription/translation of an engineered DNA template encoding for specific protein targets. Purification of the cell-free expressed product occurs through a series of protein separation modules that are configurable for process-specific isolation of different proteins. Using this approach, we demonstrate production of two bioactive human protein therapeutics, erythropoietin and granulocyte-macrophage colony-stimulating factor, in yeast and bacterial extracts, respectively, each within 24 hours. This process is flexible, scalable and amenable to automation for rapid production at the point-of-need of proteins with significant pharmaceutical, medical, or biotechnological value.

  9. Drilling with a one-step solids-control technique

    SciTech Connect

    Hayatdavoudi, A.

    1989-03-01

    The objectives of this paper are to report a new philosophy in solids control and field practice, referred to as fluid conditioning, to make a comparative evaluation of surface solids-control equipment, and to show details of a comprehensive mineralogical and physiochemical analysis of removed solids. For brevity, only a few field results are emphasized. For example, in a weighted mud system of 15.2 lbm/gal (18.2 X 10/sup 2/ kg/cm/sup 3/), the adjustable concentric device of fluid condition rejects a greater percentage of 0.5- to 1.0-..mu..m solids than a centrifuge. In an unweighted mud system of 9.5 lbm/gal (11.4 X 10/sup 2/ kg/m/sup 3/), fluid contaminants such as calcite, dolomite, and salt are rejected through underflow. Another field example based on microscopic and scanning electron microscopic (SEM) size analysis showed that in a 12-lbm/gal (14.4 X 10/sup 2/-kg/m/sup 3/) mud system, it is necessary to increase the operating pressure by a few psi to reduce the amount of 6-..mu..m material. The authors research in the area of particle size analysis of small, oilfield particles--e.g., smectite, sepiolite, Wyoming bentonite, and barite from bags of dust collectors--reveals that a quick-fix Fraunhofer diffraction analysis in the range of 10 ..mu..m and less is totally invalid in quantitative works. Finally, through the analysis of fluid rejects, they concluded that after the rig shaker (assuming that the rig shaker performs well), the one-step solids-control fluid conditioning can deliver desirable rheological properties and a reasonable size range for the suspended material.

  10. Rapid Purification and Procoagulant and Platelet Aggregating Activities of Rhombeobin: A Thrombin-Like/Gyroxin-Like Enzyme from Lachesis muta rhombeata Snake Venom

    PubMed Central

    Torres-Huaco, Frank Denis; Werneck, Cláudio C.; Vicente, Cristina Pontes; Vassequi-Silva, Talita; Nery-Diez, Ana Cláudia Coelho; Mendes, Camila B.; Antunes, Edson; Marangoni, Sérgio; Damico, Daniela C. S.

    2013-01-01

    We report a rapid purification method using one-step chromatography of SVSP Rhombeobin (LMR-47) from Lachesis muta rhombeata venom and its procoagulant activities and effects on platelet aggregation. The venom was fractionated by a single chromatographic step in RP-HPLC on a C8 Discovery BIO Wide Pore, showing high degree of molecular homogeneity with molecular mass of 47035.49 Da. Rhombeobin showed amidolytic activity upon BAρNA, with a broad optimum pH (7–10) and was stable in solution up to 60°C. The amidolytic activity was inhibited by serine proteinase inhibitors and reducing agents, but not chelating agents. Rhombeobin showed high coagulant activity on mice plasma and bovine fibrinogen. The deduced amino acid sequence of Rhombeobin showed homology with other SVSPs, especially with LM-TL (L. m. muta) and Gyroxin (C. d. terrificus). Rhombeobin acts, in vitro, as a strong procoagulant enzyme on mice citrated plasma, shortening the APTT and PT tests in adose-dependent manner. The protein showed, “ex vivo”, a strong defibrinogenating effect with 1 µg/animal. Lower doses activated the intrinsic and extrinsic coagulation pathways and impaired the platelet aggregation induced by ADP. Thus, this is the first report of a venom component that produces a venom-induced consumptive coagulopathy (VICC). PMID:24058917

  11. Rapid separation and purification of uranium and plutonium from dilute-matrix samples

    SciTech Connect

    Armstrong, Christopher R.; Ticknor, Brian W.; Hall, Gregory; Cadieux, James R.

    2014-03-11

    This work presents a streamlined separation and purification approach for trace uranium and plutonium from dilute (carrier-free) matrices. The method, effective for nanogram quantities of U and femtogram to picogram quantities of Pu, is ideally suited for environmental swipe samples that contain a small amount of collected bulk material. As such, it may be applicable for processing swipe samples such as those collected in IAEA inspection activities as well as swipes that are loaded with unknown analytes, such as those implemented in interlaboratory round-robin or proficiency tests. Additionally, the simplified actinide separation could find use in internal laboratory monitoring of clean room conditions prior to or following more extensive chemical processing. We describe key modifications to conventional techniques that result in a relatively rapid, cost-effective, and efficient U and Pu separation process. We demonstrate the efficacy of implementing anion exchange chromatography in a single column approach. We also show that hydrobromic acid is an effective substitute in lieu of hydroiodoic acid for eluting Pu. Lastly, we show that nitric acid is an effective digestion agent in lieu of perchloric acid and/or hydrofluoric acid. A step by step procedure of this process is detailed.

  12. Rapid separation and purification of uranium and plutonium from dilute-matrix samples

    DOE PAGES

    Armstrong, Christopher R.; Ticknor, Brian W.; Hall, Gregory; Cadieux, James R.

    2014-03-11

    This work presents a streamlined separation and purification approach for trace uranium and plutonium from dilute (carrier-free) matrices. The method, effective for nanogram quantities of U and femtogram to picogram quantities of Pu, is ideally suited for environmental swipe samples that contain a small amount of collected bulk material. As such, it may be applicable for processing swipe samples such as those collected in IAEA inspection activities as well as swipes that are loaded with unknown analytes, such as those implemented in interlaboratory round-robin or proficiency tests. Additionally, the simplified actinide separation could find use in internal laboratory monitoring ofmore » clean room conditions prior to or following more extensive chemical processing. We describe key modifications to conventional techniques that result in a relatively rapid, cost-effective, and efficient U and Pu separation process. We demonstrate the efficacy of implementing anion exchange chromatography in a single column approach. We also show that hydrobromic acid is an effective substitute in lieu of hydroiodoic acid for eluting Pu. Lastly, we show that nitric acid is an effective digestion agent in lieu of perchloric acid and/or hydrofluoric acid. A step by step procedure of this process is detailed.« less

  13. Viral DNA Packaging: One Step at a Time

    NASA Astrophysics Data System (ADS)

    Bustamante, Carlos; Moffitt, Jeffrey R.

    During its life-cycle the bacteriophage φ29 actively packages its dsDNA genome into a proteinacious capsid, compressing its genome to near crystalline densities against large electrostatic, elastic, and entropic forces. This remarkable process is accomplished by a nano-scale, molecular DNA pump - a complex assembly of three protein and nucleic acid rings which utilizes the free energy released in ATP hydrolysis to perform the mechanical work necessary to overcome these large energetic barriers. We have developed a single molecule optical tweezers assay which has allowed us to probe the detailed mechanism of this packaging motor. By following the rate of packaging of a single bacteriophage as the capsid is filled with genome and as a function of optically applied load, we find that the compression of the genome results in the build-up of an internal force, on the order of ˜ 55 pN, due to the compressed genome. The ability to work against such large forces makes the packaging motor one of the strongest known molecular motors. By titrating the concentration of ATP, ADP, and inorganic phosphate at different opposing load, we are able to determine features of the mechanochemistry of this motor - the coupling between the mechanical and chemical cycles. We find that force is generated not upon binding of ATP, but rather upon release of hydrolysis products. Finally, by improving the resolution of the optical tweezers assay, we are able to observe the discrete increments of DNA encapsidated each cycle of the packaging motor. We find that DNA is packaged in 10-bp increments preceded by the binding of multiple ATPs. The application of large external forces slows the packaging rate of the motor, revealing that the 10-bp steps are actually composed of four 2.5-bp steps which occur in rapid succession. These data show that the individual subunits of the pentameric ring-ATPase at the core of the packaging motor are highly coordinated, with the binding of ATP and the

  14. Fabrication of efficient planar perovskite solar cells using a one-step chemical vapor deposition method

    PubMed Central

    Tavakoli, Mohammad Mahdi; Gu, Leilei; Gao, Yuan; Reckmeier, Claas; He, Jin; Rogach, Andrey L.; Yao, Yan; Fan, Zhiyong

    2015-01-01

    Organometallic trihalide perovskites are promising materials for photovoltaic applications, which have demonstrated a rapid rise in photovoltaic performance in a short period of time. We report a facile one-step method to fabricate planar heterojunction perovskite solar cells by chemical vapor deposition (CVD), with a solar power conversion efficiency of up to 11.1%. We performed a systematic optimization of CVD parameters such as temperature and growth time to obtain high quality films of CH3NH3PbI3 and CH3NH3PbI3-xClx perovskite. Scanning electron microscopy and time resolved photoluminescence data showed that the perovskite films have a large grain size of more than 1 micrometer, and carrier life-times of 10 ns and 120 ns for CH3NH3PbI3 and CH3NH3PbI3-xClx, respectively. This is the first demonstration of a highly efficient perovskite solar cell using one step CVD and there is likely room for significant improvement of device efficiency. PMID:26392200

  15. An integrated microfluidic device for rapid cell lysis and DNA purification of epithelial cell samples.

    PubMed

    Ha, Seung-Mo; Cho, Woong; Ahn, Yoomin; Hwang, Seung Yong

    2011-05-01

    In this paper, we describe the design and fabrication of a microfluidic device for cell lysis and DNA purification, and the results of device tests using a real sample of buccal cells. Cell lysis was thermally executed for two minutes at 80 degrees C in a serpentine type microreactor (20 microL) using an Au microheater with a microsensor. The DNA was then mixed with other residual products and purified by a new filtration process involving micropillars and 50-80 microm microbeads. The entire process of sample loading, cell lysis, DNA purification, and sample extraction was successfully completed in the microchip within five minutes. Sample preparation within the microchip was verified by performing a SY158 gene PCR analysis and gel electrophoresis on the products obtained from the chip. The new purification method enhanced DNA purity from 0.93 to 1.62 after purification. PMID:21780436

  16. A rapid and efficient two-step gel electrophoresis method for the purification of major rye grass pollen allergens.

    PubMed

    Levy, D; Davies, J; O'Hehir, R; Suphioglu, C

    2001-06-01

    Purified proteins are mandatory for molecular, immunological and cellular studies. However, purification of proteins from complex mixtures requires specialised chromatography methods (i.e., gel filtration, ion exchange, etc.) using fast protein liquid chromatography (FPLC) or high-performance liquid chromatography (HPLC) systems. Such systems are expensive and certain proteins require two or more different steps for sufficient purity and generally result in low recovery. The aim of this study was to develop a rapid, inexpensive and efficient gel-electrophoresis-based protein purification method using basic and readily available laboratory equipment. We have used crude rye grass pollen extract to purify the major allergens Lol p 1 and Lol p 5 as the model protein candidates. Total proteins were resolved on large primary gel and Coomassie Brilliant Blue (CBB)-stained Lol p 1/5 allergens were excised and purified on a secondary "mini"-gel. Purified proteins were extracted from unstained separating gels and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analyses. Silver-stained SDS-PAGE gels resolved pure proteins (i.e., 875 microg of Lol p 1 recovered from a 8 mg crude starting material) while immunoblot analysis confirmed immunological reactivity of the purified proteins. Such a purification method is rapid, inexpensive, and efficient in generating proteins of sufficient purity for use in monoclonal antibody (mAb) production, protein sequencing and general molecular, immunological, and cellular studies.

  17. Facile One-step Micropatterning Using Photodegradable Methacrylated Gelatin Hydrogels for Improved Cardiomyocyte Organization and Alignment

    PubMed Central

    Tsang, Kelly M.C.; Annabi, Nasim; Ercole, Francesca; Zhou, Kun; Karst, Daniel; Li, Fanyi; Haynes, John M.; Evans, Richard A.; Thissen, Helmut

    2015-01-01

    Hydrogels are often employed as temporary platforms for cell proliferation and tissue organization in vitro. Researchers have incorporated photodegradable moieties into synthetic polymeric hydrogels as a means of achieving spatiotemporal control over material properties. In this study protein-based photodegradable hydrogels composed of methacrylated gelatin (GelMA) and a crosslinker containing o-nitrobenzyl ester groups have been developed. The hydrogels are able to degrade rapidly and specifically in response to UV light and can be photopatterned to a variety of shapes and dimensions in a one-step process. Micropatterned photodegradable hydrogels are shown to improve cell distribution, alignment and beating regularity of cultured neonatal rat cardiomyocytes. Overall this work introduces a new class of photodegradable hydrogel based on natural and biofunctional polymers as cell culture substrates for improving cellular organization and function. PMID:26327819

  18. One-step tumor detection from dynamic morphology tracking on aptamer-grafted surfaces

    PubMed Central

    Mahmood, Mohammed Arif I.; Hasan, Mohammad Raziul; Khan, Umair J. M.; Allen, Peter B.; Kim, Young-tae; Ellington, Andrew D.; Iqbal, Samir M.

    2015-01-01

    In this paper, we report a one-step tumor cell detection approach based on the dynamic morphological behavior tracking of cancer cells on a ligand modified surface. Every cell on the surface was tracked in real time for several minutes immediately after seeding until these were finally attached. Cancer cells were found to be very active in the aptamer microenvironment, changing their shapes rapidly from spherical to semi-elliptical, with much flatter spread and extending pseudopods at regular intervals. When incubated on a functionalized surface, the balancing forces between cell surface molecules and the surface-bound aptamers, together with the flexibility of the membranes, caused cells to show these distinct dynamic activities and variations in their morphologies. On the other hand, healthy cells remained distinguishingly inactive on the surface over the same period. The quantitative image analysis of cell morphologies provided feature vectors that were statistically distinct between normal and cancer cells. PMID:26753172

  19. One-Step Assembly of Phytic Acid Metal Complexes for Superhydrophilic Coatings.

    PubMed

    Li, Longbiao; Zhang, Guangyu; Su, Zhaohui

    2016-07-25

    While of immense scientific interest, superhydrophilic surfaces are usually difficult to prepare, and preparation methods are typically substrate specific. Herein, a one-step coating method is described that can endow superhydrophilicity to a variety of substrates, both inorganic and organic, using the coordination complexes of natural phytic acid and Fe(III) ions. Coating deposition occurs in minutes, and coatings are ultrathin, colorless, and transparent. Superhydrophilicity is attributed, in part, to the high density of phosphonic acid groups. The ease, rapidness, and mildness of the assembly process, which is also cost-effective and environmental-friendly, points towards potential applications, such as self-cleaning, oil/water separation, antifogging. PMID:27377349

  20. Detection of Zika virus by SYBR green one-step real-time RT-PCR.

    PubMed

    Xu, Ming-Yue; Liu, Si-Qing; Deng, Cheng-Lin; Zhang, Qiu-Yan; Zhang, Bo

    2016-10-01

    The ongoing Zika virus (ZIKV) outbreak has rapidly spread to new areas of Americas, which were the first transmissions outside its traditional endemic areas in Africa and Asia. Due to the link with newborn defects and neurological disorder, numerous infected cases throughout the world and various mosquito vectors, the virus has been considered to be an international public health emergency. In the present study, we developed a SYBR Green based one-step real-time RT-PCR assay for rapid detection of ZIKV. Our results revealed that the real-time assay is highly specific and sensitive in detection of ZIKV in cell samples. Importantly, the replication of ZIKV at different time points in infected cells could be rapidly monitored by the real-time RT-PCR assay. Specifically, the real-time RT-PCR showed acceptable performance in measurement of infectious ZIKV RNA. This assay could detect ZIKV at a titer as low as 1PFU/mL. The real-time RT-PCR assay could be a useful tool for further virology surveillance and diagnosis of ZIKV. PMID:27444120

  1. Detection of Zika virus by SYBR green one-step real-time RT-PCR.

    PubMed

    Xu, Ming-Yue; Liu, Si-Qing; Deng, Cheng-Lin; Zhang, Qiu-Yan; Zhang, Bo

    2016-10-01

    The ongoing Zika virus (ZIKV) outbreak has rapidly spread to new areas of Americas, which were the first transmissions outside its traditional endemic areas in Africa and Asia. Due to the link with newborn defects and neurological disorder, numerous infected cases throughout the world and various mosquito vectors, the virus has been considered to be an international public health emergency. In the present study, we developed a SYBR Green based one-step real-time RT-PCR assay for rapid detection of ZIKV. Our results revealed that the real-time assay is highly specific and sensitive in detection of ZIKV in cell samples. Importantly, the replication of ZIKV at different time points in infected cells could be rapidly monitored by the real-time RT-PCR assay. Specifically, the real-time RT-PCR showed acceptable performance in measurement of infectious ZIKV RNA. This assay could detect ZIKV at a titer as low as 1PFU/mL. The real-time RT-PCR assay could be a useful tool for further virology surveillance and diagnosis of ZIKV.

  2. A rapid one-step fabrication of patternable superhydrophobic surfaces driven by Marangoni instability.

    PubMed

    Kang, Sung-Min; Hwang, Sora; Jin, Si-Hyung; Choi, Chang-Hyung; Kim, Jongmin; Park, Bum Jun; Lee, Daeyeon; Lee, Chang-Soo

    2014-03-18

    We present a facile and inexpensive approach without any fluorinated chemistry to create superhydrophobic surface with exceptional liquid repellency, transportation of oil, selective capture of oil, optical bar code, and self-cleaning. Here we show experimentally that the control of evaporation is important and can be used to form superhydrophobic surface driven by Marangoni instability: the method involves in-situ photopolymerization in the presence of a volatile solvent and porous PDMS cover to afford superhydrophobic surfaces with the desired combination of micro- and nanoscale roughness. The porous PDMS cover significantly affects Marangoni convection of coating fluid, inducing composition gradients at the same time. In addition, the change of concentration of ethanol is able to produce versatile surfaces from hydrophilic to superhydrophobic and as a consequence to determine contact angles as well as roughness factors. In conclusion, the control of evaporation under the polymerization provides a convenient parameter to fabricate the superhydrophobic surface, without application of fluorinated chemistry and the elegant nanofabrication technique.

  3. One-step cell lysis suitable for quantitative bacteria detection in inhibitor-laden sands

    NASA Astrophysics Data System (ADS)

    Lim, Hyun Jeong; Choi, Jung-Hyun; Son, Ahjeong

    2015-04-01

    Complexity and heterogeneity of soils often hinder effective DNA extraction from the soil matrix. In particular, conventional DNA extraction techniques require extensive purification which makes DNA extraction time-consuming and labor-intensive. Other drawbacks include lower recovery yield, degradation, and damage of DNA, which are also caused by intensive purifications during DNA extraction. Therefore a rapid and simple and yet effective DNA pretreatment method is preferred for environmental monitoring and screening. This study has evaluated the feasibility of simple physical pretreatment for effective cell lysis of bacteria in sands. Bead beating method was selected as an effective physical cell lysis method in this study. We examined the capability of this physical lysis for Pseudomonas putida seeded sands without additional chemical purification steps. The lysate from the method was analysed by the quantitative polymerase chain reaction (qPCR) assay and subsequently compared to that by commercial DNA extraction kit. The best lysis condition (treatment with 0.1 mm glass beads at 3000 rpm for 3 minutes) was selected. The qPCR results of bead beating treated samples showed the better performance than that of conventional DNA extraction kit. Moreover, the qPCR assay was performed to the sands laden with qPCR inhibitors (humic acids, clay, and magnesium), which generally present in environmental samples. Further experiments with the sands containing less than 10 μg/g of humic acids and 70% of clay showed successful quantification results of qPCR assay. In conclusion, the bead beating method is useful for simplified DNA extraction prior to qPCR analysis for sand samples of particular composition. It is expected that this approach will be beneficial for environmental in-situ analysis or immediate pre-screening. It also provides the groundwork for future studies with real soil samples that have various physico-chemical properties.

  4. One-step detection of circulating tumor cells in ovarian cancer using enhanced fluorescent silica nanoparticles

    PubMed Central

    Kim, Jin Hyun; Chung, Hyun Hoon; Jeong, Min Sook; Song, Mi Ryoung; Kang, Keon Wook; Kim, Jun Sung

    2013-01-01

    Ovarian cancer is the fifth-leading cause of cancer-related deaths among women as a result of late diagnosis. For survival rates to improve, more sensitive and specific methods for earlier detection of ovarian cancer are needed. This study presents the development of rapid and specific one-step circulating tumor cell (CTC) detection using flow cytometry in a whole-blood sample with fluorescent silica nanoparticles. We prepared magnetic nanoparticle (MNP)-SiO2(rhodamine B isothiocyanate [RITC]) (MNP-SiO2[RITC] incorporating organic dyes [RITC, ëmax(ex/em) = 543/580 nm]) in the silica shell. We then controlled the amount of organic dye in the silica shell of MNP-SiO2(RITC) for increased fluorescence intensity to overcome the autofluorescence of whole blood and increase the sensitivity of CTC detection in whole blood. Next, we modified the surface function group of MNP-SiO2(RITC) from -OH to polyethylene glycol (PEG)/COOH and conjugated a mucin 1 cell surface-associated (MUC1) antibody on the surface of MNP-SiO2(RITC) for CTC detection. To study the specific targeting efficiency of MUC1-MNP-SiO2(RITC), we used immunocytochemistry with a MUC1-positive human ovarian cancer cell line and a negative human embryonic kidney cell line. This technology was capable of detecting 100 ovarian cancer cells in 50 μL of whole blood. In conclusion, we developed a one-step CTC detection technology in ovarian cancer based on multifunctional silica nanoparticles and the use of flow cytometry. PMID:23818781

  5. Optimization of a one-step heat-inducible in vivo mini DNA vector production system.

    PubMed

    Nafissi, Nafiseh; Sum, Chi Hong; Wettig, Shawn; Slavcev, Roderick A

    2014-01-01

    , achieving an overall LCC DNA minivector production efficiency of ∼ 90%.We optimized a robust technology conferring rapid, scalable, one-step in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics.

  6. One-step detection of pathogens and cancer biomarkers by the naked eye based on aggregation of immunomagnetic beads

    NASA Astrophysics Data System (ADS)

    Chen, Yiping; Xianyu, Yunlei; Sun, Jiashu; Niu, Yajing; Wang, Yu; Jiang, Xingyu

    2015-12-01

    This report shows that immunomagnetic beads (IMBs) can act as the optical readout for assays, in addition to serving as the carrier for purification/separation. Under the influence of an external magnet, IMBs are attracted to coat one side of a test tube. IMBs specifically bound to targets can form a narrow brown stripe, whereas free IMBs will form a diffuse, yellow coating on the side of the test tube. Target analytes can aggregate initially dispersed IMBs in a sample concentration-dependent manner, yielding a color change from yellow to brown that can be seen with the naked eye. This assay combines the convenience of a lateral flow assay, allowing a one-step assay to finish within 15 min, with the sensitivity of an enzyme-linked immonosorbent assay.This report shows that immunomagnetic beads (IMBs) can act as the optical readout for assays, in addition to serving as the carrier for purification/separation. Under the influence of an external magnet, IMBs are attracted to coat one side of a test tube. IMBs specifically bound to targets can form a narrow brown stripe, whereas free IMBs will form a diffuse, yellow coating on the side of the test tube. Target analytes can aggregate initially dispersed IMBs in a sample concentration-dependent manner, yielding a color change from yellow to brown that can be seen with the naked eye. This assay combines the convenience of a lateral flow assay, allowing a one-step assay to finish within 15 min, with the sensitivity of an enzyme-linked immonosorbent assay. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07044a

  7. A cleavable silica-binding affinity tag for rapid and inexpensive protein purification.

    PubMed

    Coyle, Brandon L; Baneyx, François

    2014-10-01

    We describe a new affinity purification tag called Car9 that confers proteins to which it is fused micromolar affinity for unmodified silica. When appended to the C-terminus of GFPmut2 through a flexible linker, Car9 promotes efficient adsorption to silica gel and the fusion protein can be released from the particles by incubation with L-lysine. Using a silica gel column and the lysine elution approach in fast protein liquid chromatography (FPLC) mode, Car9-tagged versions of GFPmut2, mCherry and maltose binding protein (MBP) can be recovered from clarified lysates with a purity of 80-90%. Capitalizing on silica's ability to handle large pressure drops, we further show that it is possible to go from cell lysates to purified protein in less than 15 min using a fully disposable device. Finally, we demonstrate that the linker-Car9 region is susceptible to proteolysis by E. coli OmpT and take advantage of this observation to excise the C-terminal extension of GFPmut2-Car9 by incubating purified fusion protein with cells that overproduce the outer membrane protease OmpT. The set of strategies described herein, should reduce the cost of affinity purification by at least 10-fold, cut down purification times to minutes, and allow for the production of proteins with native (or nearly native) termini from their C-terminally-tagged versions.

  8. A one-step bioprocess for production of high-content fructo-oligosaccharides from inulin by yeast.

    PubMed

    Wang, Da; Li, Fu-Li; Wang, Shi-An

    2016-10-20

    Commercial fructo-oligosaccharides (FOS) are predominantly produced from sucrose by transfructosylation process that presents a maximum theoretical yield below 0.60gFOSgSucrose(-1). To obtain high-content FOS, costly purification is generally employed. Additionally, high-content FOS can be produced from inulin by using endo-inulinases. However, commercial endo-inulinases have not been extensively used in scale-up production of FOS. In the present study, a one-step bioprocess that integrated endo-inulinase production, FOS fermentation, and non-FOS sugars removal into one reactor was proposed to produce high-content FOS from inulin. The bioprocess was implemented by a recombinant yeast strain JZHΔS-TSC, in which a heterologous endo-inulinase gene was expressed and the inherent invertase gene SUC2 was disrupted. FOS fermentation at 40°C from 200g/L chicory inulin presented the maximun titer, yield, and productivity of 180.2±0.8g/L, 0.9gFOSgInulin(-1), and 7.51±0.03g/L/h, respectively. This study demonstrated that the one-step bioprocess was simple and highly efficient. PMID:27474673

  9. A one-step bioprocess for production of high-content fructo-oligosaccharides from inulin by yeast.

    PubMed

    Wang, Da; Li, Fu-Li; Wang, Shi-An

    2016-10-20

    Commercial fructo-oligosaccharides (FOS) are predominantly produced from sucrose by transfructosylation process that presents a maximum theoretical yield below 0.60gFOSgSucrose(-1). To obtain high-content FOS, costly purification is generally employed. Additionally, high-content FOS can be produced from inulin by using endo-inulinases. However, commercial endo-inulinases have not been extensively used in scale-up production of FOS. In the present study, a one-step bioprocess that integrated endo-inulinase production, FOS fermentation, and non-FOS sugars removal into one reactor was proposed to produce high-content FOS from inulin. The bioprocess was implemented by a recombinant yeast strain JZHΔS-TSC, in which a heterologous endo-inulinase gene was expressed and the inherent invertase gene SUC2 was disrupted. FOS fermentation at 40°C from 200g/L chicory inulin presented the maximun titer, yield, and productivity of 180.2±0.8g/L, 0.9gFOSgInulin(-1), and 7.51±0.03g/L/h, respectively. This study demonstrated that the one-step bioprocess was simple and highly efficient.

  10. One-step multiplex reverse transcription-polymerase chain reaction for the simultaneous detection of three rice viruses.

    PubMed

    Cho, Sang-Yun; Jeong, Rae-Dong; Yoon, Young-Nam; Lee, Su-Heon; Shin, Dong Bum; Kang, Hang-Won; Lee, Bong Choon

    2013-11-01

    Rice stripe virus (RSV), Rice black-streaked dwarf virus (RBSDV), and Rice dwarf virus (RDV) are major rice-infecting viruses in Korea that can cause serious crop losses. A one-step multiplex reverse transcription-polymerase chain reaction (mRT-PCR) was developed for the simultaneous detection of these rice viruses. Three sets of specific primers targeted to the capsid protein coding genes of RSV, RBSDV, and RDV were used to amplify fragments that were 703 bp, 485 bp, and 252 bp, respectively. The one-step mRT-PCR assay proved to be a sensitive and rapid method for detecting the three rice viruses. This method could be used to facilitate better control of rice viruses.

  11. One-Step Reverse-Transcription FRET-PCR for Differential Detection of Five Ebolavirus Species

    PubMed Central

    Lu, Guangwu; Zhang, Jilei; Zhang, Chuntao; Li, Xiaolu; Shi, Dawei; Yang, Zhaopeng; Wang, Chengming

    2015-01-01

    Ebola is an emerging infectious disease caused by a deadly virus belonging to the family Filoviridae, genus Ebolavirus. Based on their geographical distribution, Ebolavirus has been classified into total five species so far, mainly Zaire, Sudan, Taï Forest, Bundibugyo and Reston. It is important to be able to differentiate the Ebolavirus species as they significantly differ in pathogenicity and more than one species can be present in an area. We have developed a one-step step-down RT-PCR detecting all five Ebolavirus species with high sensitivity (1 copy of Ebolavirus DNA, 10 copies of RNA and 320 copies of RNA spiked in 1 ml whole blood). The primers and FRET-probes we designed enabled us to differentiate five Ebolavirus species by distinct Tm (Zaire: flat peaks between 53.0°C and 56.9°C; Sudan: 51.6°C; Reston: flat peaks between 47.5°C and 54.9°C; Tai Forest: 52.8°C; Bundibugyo: dual peaks at 48.9°C and 53.5°C), and by different amplicon sizes (Zaire 255bp, Sudan 211bp, Reston 192bp, Taï Forest 166bp, Bundibugyo 146bp). This one-size-fit-all assay enables the rapid detection and discrimination of the five Ebolavirus species in a single reaction. PMID:26017916

  12. One-step formation of oligopeptide-like molecules from Glu and Asp in hydrothermal environments.

    PubMed

    Kawamura, Kunio; Shimahashi, Masanori

    2008-05-01

    Biopolymer accumulation in the absence of enzymes is an essential step for the chemical evolution of primitive life-like systems, and successful simulation experiments of prebiotic biopolymer formation have suggested that oligopeptides could have formed near submarine hydrothermal vent environments on primitive earth. However, the yield and length of oligopeptides -- typically limited to 6-mers -- seems to be inadequate. One reason is the rapid formation of diketopiperazines (DKPs) from dipeptides. In this study, using a hydrothermal microflow reactor, we show that the one-step synthesis of oligopeptide-like molecules of length up to 20-mers proceeds from Glu and Asp. Yields of up to 0.17-0.57% were obtained in an acidic solution within 183 s at 250-310 degrees C, as evaluated by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis and different types of high-performance liquid chromatography (HPLC) analyses. The present study indicates that Glu and Asp may have played important roles in the chemical evolution of oligopeptide-like molecules in hydrothermal vent environments on primitive earth. PMID:18253712

  13. One-step sol-gel imprint lithography for guided-mode resonance structures.

    PubMed

    Huang, Yin; Liu, Longju; Johnson, Michael; C Hillier, Andrew; Lu, Meng

    2016-03-01

    Guided-mode resonance (GMR) structures consisting of sub-wavelength periodic gratings are capable of producing narrow-linewidth optical resonances. This paper describes a sol-gel-based imprint lithography method for the fabrication of submicron 1D and 2D GMR structures. This method utilizes a patterned polydimethylsiloxane (PDMS) mold to fabricate the grating coupler and waveguide for a GMR device using a sol-gel thin film in a single step. An organic-inorganic hybrid sol-gel film was selected as the imprint material because of its relatively high refractive index. The optical responses of several sol-gel GMR devices were characterized, and the experimental results were in good agreement with the results of electromagnetic simulations. The influence of processing parameters was investigated in order to determine how finely the spectral response and resonant wavelength of the GMR devices could be tuned. As an example potential application, refractometric sensing experiments were performed using a 1D sol-gel device. The results demonstrated a refractive index sensitivity of 50 nm/refractive index unit. This one-step fabrication process offers a simple, rapid, and low-cost means of fabricating GMR structures. We anticipate that this method can be valuable in the development of various GMR-based devices as it can readily enable the fabrication of complex shapes and allow the doping of optically active materials into sol-gel thin film.

  14. One-step electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on magnesium alloy.

    PubMed

    Liu, Qin; Chen, Dexin; Kang, Zhixin

    2015-01-28

    A simple, one-step method has been developed to construct a superhydrophobic surface by electrodepositing Mg-Mn-Ce magnesium plate in an ethanol solution containing cerium nitrate hexahydrate and myristic acid. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were employed to characterize the surfaces. The shortest electrodeposition time to obtain a superhydrophobic surface was about 1 min, and the as-prepared superhydrophobic surfaces had a maximum contact angle of 159.8° and a sliding angle of less than 2°. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements demonstrated that the superhydrophobic surface greatly improved the corrosion properties of magnesium alloy in 3.5 wt % aqueous solutions of NaCl, Na2SO4, NaClO3, and NaNO3. Besides, the chemical stability and mechanical durability of the as-prepared superhydrophobic surface were also examined. The presented method is rapid, low-cost, and environmentally friendly and thus should be of significant value for the industrial fabrication of anticorrosive superhydrophobic surfaces and should have a promising future in expanding the applications of magnesium alloys.

  15. One step synthesis of polyacrylamide functionalized graphene and its application in Pb(II) removal

    NASA Astrophysics Data System (ADS)

    Xu, Zhiwei; Zhang, Yaoyao; Qian, Xiaoming; Shi, Jie; Chen, Lei; Li, Baodong; Niu, Jiarong; Liu, Liangsen

    2014-10-01

    Polyacrylamide grafted graphene (PAM-g-graphene) from graphite oxide (GO) was successfully prepared by γ-ray irradiation with acrylamide monomers in aqueous at room temperature in this paper. Our strategy involves the PAM chains graft on the surface and between the layers of GO by in situ radical polymerization which led to the exfoliation of GO into individual sheets. Results show that the degree of grafting of PAM-g-graphene samples is 24.2%, and the thickness is measured to be 2.59 nm. Moreover, the as-prepared PAM-g-graphene with some amino from PAM and little oxygen functional groups exhibit superior adsorption of Pb(II) ions. The adsorption processes reach equilibrium in just 30 min and the adsorption isotherms are described well by Langmuir and Freundlich classical isotherms models. The determined adsorption capacity of PAM-g-graphene is 819.67 mg g-1 (pH 6) for Pb(II), which is 20 times and 8 times capacities of that for graphene nanosheets and carbon nanotubes according to reports, respectively. This chemically modified graphene synthesized by this fast one-step approach, featuring a good versatility and adaptability, excellent adsorption capacity and rapid extraction, may provide a new idea for the global problem of heavy metal pollutants' removal in water.

  16. One-step electrodeposition process to fabricate corrosion-resistant superhydrophobic surface on magnesium alloy.

    PubMed

    Liu, Qin; Chen, Dexin; Kang, Zhixin

    2015-01-28

    A simple, one-step method has been developed to construct a superhydrophobic surface by electrodepositing Mg-Mn-Ce magnesium plate in an ethanol solution containing cerium nitrate hexahydrate and myristic acid. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were employed to characterize the surfaces. The shortest electrodeposition time to obtain a superhydrophobic surface was about 1 min, and the as-prepared superhydrophobic surfaces had a maximum contact angle of 159.8° and a sliding angle of less than 2°. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements demonstrated that the superhydrophobic surface greatly improved the corrosion properties of magnesium alloy in 3.5 wt % aqueous solutions of NaCl, Na2SO4, NaClO3, and NaNO3. Besides, the chemical stability and mechanical durability of the as-prepared superhydrophobic surface were also examined. The presented method is rapid, low-cost, and environmentally friendly and thus should be of significant value for the industrial fabrication of anticorrosive superhydrophobic surfaces and should have a promising future in expanding the applications of magnesium alloys. PMID:25559356

  17. One-Step Reverse-Transcription FRET-PCR for Differential Detection of Five Ebolavirus Species.

    PubMed

    Lu, Guangwu; Zhang, Jilei; Zhang, Chuntao; Li, Xiaolu; Shi, Dawei; Yang, Zhaopeng; Wang, Chengming

    2015-01-01

    Ebola is an emerging infectious disease caused by a deadly virus belonging to the family Filoviridae, genus Ebolavirus. Based on their geographical distribution, Ebolavirus has been classified into total five species so far, mainly Zaire, Sudan, Taï Forest, Bundibugyo and Reston. It is important to be able to differentiate the Ebolavirus species as they significantly differ in pathogenicity and more than one species can be present in an area. We have developed a one-step step-down RT-PCR detecting all five Ebolavirus species with high sensitivity (1 copy of Ebolavirus DNA, 10 copies of RNA and 320 copies of RNA spiked in 1 ml whole blood). The primers and FRET-probes we designed enabled us to differentiate five Ebolavirus species by distinct Tm (Zaire: flat peaks between 53.0°C and 56.9°C; Sudan: 51.6°C; Reston: flat peaks between 47.5°C and 54.9°C; Tai Forest: 52.8°C; Bundibugyo: dual peaks at 48.9°C and 53.5°C), and by different amplicon sizes (Zaire 255 bp, Sudan 211 bp, Reston 192 bp, Taï Forest 166 bp, Bundibugyo 146 bp). This one-size-fit-all assay enables the rapid detection and discrimination of the five Ebolavirus species in a single reaction. PMID:26017916

  18. Rapid purification of circular DNA by triplex-mediated affinity capture

    DOEpatents

    Ji, H.; Smith, L.M.

    1997-01-07

    A single-step capture of a target supercoiled double-stranded DNA molecule is accomplished by forming a local triple-helix among two strands of the supercoiled circular DNA and an oligonucleotide probe. The oligonucleotide is bound to an immobilizing support which facilitates the immobilization and purification of target DNA molecules. Non-target DNA molecules and other contaminating cellular material are easily removed by washing. The triple-helical structure is destabilized by raising the pH, leaving purified target DNA in the supernatant and reusable affinity capture oligonucleotide secured to the immobilizing support. 3 figs.

  19. Rapid purification of circular DNA by triplex-mediated affinity capture

    DOEpatents

    Ji, Huamin; Smith, Lloyd M.

    1997-01-01

    A single-step capture of a target supercoiled double-stranded DNA molecule is accomplished by forming a local triple-helix among two strands of the supercoiled circular DNA and an oligonucleotide probe. The oligonucleotide is bound to an immobilizing support which facilitates the immobilization and purification of target DNA molecules. Non-target DNA molecules and other contaminating cellular material are easily removed by washing. The triple-helical structure is destabilized by raising the pH, leaving purified target DNA in the supernatant and reusable affinity capture oligonucleotide secured to the immobilizing support.

  20. Rapid purification of recombinant dengue and West Nile virus envelope Domain III proteins by metal affinity membrane chromatography.

    PubMed

    Tan, Lik Chern Melvin; Chua, Anthony Jin Shun; Goh, Li Shan Liza; Pua, Shu Min; Cheong, Yuen Kuen; Ng, Mah Lee

    2010-11-01

    Arthropod-borne flaviviruses such as dengue virus (DENV) and West Nile virus (WNV) pose significant health threats to the global community. Due to escalating numbers of DENV and WNV infections worldwide, development of an effective vaccine remains a global health priority. As flavivirus envelope Domain III (DIII) protein is highly immunogenic and capable of inducing neutralizing antibodies against wild-type virus, it is both a potential protein subunit vaccine candidate and a suitable diagnostic reagent. Here, we describe the use of metal affinity membrane chromatography as a rapid and improved alternative for the purification of recombinant DIII (rDIII) antigens from DENV serotypes 1-4 and WNV - New York, Sarafend, Wengler and Kunjin strains. Optimum conditions for the expression, solubilization, renaturation and purification of these proteins were established. The purified proteins were confirmed by MALDI-TOF mass spectrometry and ELISA using antibodies raised against the respective viruses. Biological function of the purified rDIII proteins was confirmed by their ability to generate DIII-specific antibodies in mice that could neutralize the virus.

  1. Recyclable Crosslinked Polymer Networks via One-Step Controlled Radical Polymerization.

    PubMed

    Jin, Kailong; Li, Lingqiao; Torkelson, John M

    2016-08-01

    A nitroxide-mediated polymerization strategy allows one-step synthesis of recyclable crosslinked polymeric materials from any monomers or polymers that contain carbon-carbon double bonds amenable to radical polymerization. The resulting materials with dynamic covalent bonds can show full property recovery after multiple melt-reprocessing recycles. This one-step strategy provides for both robust, relatively sustainable recyclability of crosslinked polymers and design of networks for advanced technologies.

  2. Human caspase-4 and caspase-5 regulate the one-step non-canonical inflammasome activation in monocytes.

    PubMed

    Viganò, Elena; Diamond, Catherine Emma; Spreafico, Roberto; Balachander, Akhila; Sobota, Radoslaw M; Mortellaro, Alessandra

    2015-01-01

    Monocytes promote the early host response to infection releasing key pro-inflammatory cytokines, such as IL-1β. The biologically inactive IL-1β precursor is processed to active form by inflammasomes, multi-protein complexes activating caspase-1. Human monocytes exhibit an unconventional one-step pathway of inflammasome activation in response to lipopolysaccharide (LPS) alone. Although this lineage-restricted mechanism is likely to contribute to the pathology of endotoxin shock, signalling pathways regulating this mechanism are currently unknown. Here we report that caspase-4 and caspase-5 mediate IL-1α and IL-1β release from human monocytes after LPS stimulation. Although caspase-4 remains uncleaved, caspase-5 undergoes rapid processing upon LPS treatment. We also identify an additional caspase-5 cleavage product in LPS-stimulated monocytes, which correlates with IL-1 secretion. This one-step pathway requires Syk activity and Ca(2+) flux instigated by CD14/TLR4-mediated LPS internalization. Identification of caspase-4/5 as the key determinants of one-step inflammasome activation in human monocytes provides potential targets for therapeutic intervention in endotoxin shock. PMID:26508369

  3. Development of supercritical fluid extraction and supercritical fluid chromatography purification methods using rapid solubility screening with multiple solubility chambers.

    PubMed

    Gahm, Kyung H; Huang, Ke; Barnhart, Wesley W; Goetzinger, Wolfgang

    2011-01-01

    Rapid solubility screening in diverse supercritical fluids (SCFs) was carried out via multiple solubility chambers with a trapping device and online ultraviolet (UV) detection. With this device, it was possible to rapidly study the solubility variations of multiple components in a mixture. Results from solubility studies have been used to develop efficient supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) methods. After the investigation of solubilities of theophylline and caffeine in several neat organic solvents and SCFs, advantages of SFE over conventional organic solvent extraction were demonstrated with a model mixture of theophylline and caffeine. The highest solubility ratio of 1:40 (theophylline:caffeine) was observed in the SCF with 20% acetonitrile (MeCN), where a ratio of 1:11 was the highest in the neat organic solvents. A model mixture of theophylline:caffeine (85:15 w/w, caffeine as an impurity) was successfully purified by SFE by leveraging the highest solubility difference. The SCF with 20% MeCN selectively removed caffeine and left theophylline largely intact. Rapid SCF solubility screening was applied to development of SFE and SFC methods in a drug discovery environment. Two successful applications were demonstrated with proprietary Amgen compounds to either remove an achiral impurity before chiral purification or enhance chiral chromatographic throughput.

  4. Comparison one-step procedure with two-step procedure in percutaneous nephrolithotomy.

    PubMed

    Chen, Szu-Han; Wu, Wen-Jeng; Chou, Yii-Her; Yeh, Hsin-Chih; Tsai, Chia-Chun; Chueh, Kuang-Shun; Hou, Nien-Ting; Chiu, Siou-Jin; Tu, Hung-Pin; Li, Ching-Chia

    2014-04-01

    The aim of this study was to compare the effects of one-step percutaneous nephrolithotomy (PCNL) by the urologist alone and two-step PCNL by cooperating with the radiologist. We included 168 patients who underwent surgery by the same surgeon, 83 who underwent two-step PCNL, in which percutaneous nephrostomy insertion was performed by the radiologists on the day before endo-surgery, and 85 who underwent one-step PCNL, which involved the creation of a nephrostomy tract and performing the PCNL at the same time in the operating room, by a urologist. We compared the perioperative and postoperative parameters between these two groups. The result revealed that there were no significant differences between one-step and two-step PCNL in the decreases in haemoglobin level and blood transfusion volume, and the hospital stay was shorter in the one-step PCNL group. In addition, the one-step PCNL group was associated with significantly lower visual analogue score (VAS), which were 2.3, 1.1, and 0.4 on the post-operative days 1, 2, and 3, respectively, compared with 3.2, 1.7, and 1.0 in the two-step PCNL group. The number of parenteral analgesic prescriptions was fewer in the one-step PCNL group (0.8 ± 1.1 amps/vials) than in the two-step PCNL group (4.1 ± 2.4 amps/vials). Furthermore, different stone locations barely affected VAS and analgesic administrations. The results indicate that the one-step PCNL by the urologist alone, compared to two-step PCNL with the radiologist, has better wound pain outcome and shorter hospital stay with comparable successful rate and complication grade.

  5. Rapid and simplified procedure for purification of a cellulase from Fusarium lini

    SciTech Connect

    Vaidya, M.; Seeta, R.; Mishra, C.; Deshpande, V.; Rao, M.

    1984-01-01

    An endo-..beta..-1,4-glucanase (EC3.2.1.4) was obtained in high yields in purified form from a culture filtrate of Fusarium lini by an extremely simple method. The method consists of precipitation of the culture filtrate with ammonium sulphate (290 g/L), followed by chromatography of the precipitated fraction on Biogel P-150. The purification is based on the unusual property of the enzyme being eluted after cytochrome C, even though its molecular weight is 2.8 x 10/sup 4/ (by SDS PAGE). The yield of pure enzyme was 6.8 mg/L culture broth. The homogeneity of the enzyme was established by ultracentrifugation, isoelectric focusing, and electrophoresis in polyacrylamide gels containing SDS. The enzyme was isoelectric at pH 8.3 and contained 2.9% carbohydrate. The K/sub M/ value for carboxymethyl (CM) cellulose was 11.6 mg/mL. The enzyme showed high viscosity reducing activity towards CM cellulose but very low activity with Walseth cellulose and crystalline celluloses such as Avicel and cotton. The purified enzyme has activity towards xylan. The amino acid analysis showed a predominance of acidic and neutral amino acids and low contents of histidine, arginine, and methionine. One-half of the cysteine content was 11 residues/mol enzyme, and no free-SH group was detectable.

  6. A rapid and versatile method for the isolation, purification and cryogenic storage of Schwann cells from adult rodent nerves

    PubMed Central

    Andersen, Natalia D.; Srinivas, Shruthi; Piñero, Gonzalo; Monje, Paula V.

    2016-01-01

    We herein developed a protocol for the rapid procurement of adult nerve-derived Schwann cells (SCs) that was optimized to implement an immediate enzymatic dissociation of fresh nerve tissue while maintaining high cell viability, improving yields and minimizing fibroblast and myelin contamination. This protocol introduces: (1) an efficient method for enzymatic cell release immediately after removal of the epineurium and extensive teasing of the nerve fibers; (2) an adaptable drop-plating method for selective cell attachment, removal of myelin debris, and expansion of the initial SC population in chemically defined medium; (3) a magnetic-activated cell sorting purification protocol for rapid and effective fibroblast elimination; and (4) an optional step of cryopreservation for the storage of the excess of cells. Highly proliferative SC cultures devoid of myelin and fibroblast growth were obtained within three days of nerve processing. Characterization of the initial, expanded, and cryopreserved cell products confirmed maintenance of SC identity, viability and growth rates throughout the process. Most importantly, SCs retained their sensitivity to mitogens and potential for differentiation even after cryopreservation. To conclude, this easy-to-implement and clinically relevant protocol allows for the preparation of expandable homogeneous SC cultures while minimizing time, manipulation of the cells, and exposure to culture variables. PMID:27549422

  7. A rapid and versatile method for the isolation, purification and cryogenic storage of Schwann cells from adult rodent nerves.

    PubMed

    Andersen, Natalia D; Srinivas, Shruthi; Piñero, Gonzalo; Monje, Paula V

    2016-08-23

    We herein developed a protocol for the rapid procurement of adult nerve-derived Schwann cells (SCs) that was optimized to implement an immediate enzymatic dissociation of fresh nerve tissue while maintaining high cell viability, improving yields and minimizing fibroblast and myelin contamination. This protocol introduces: (1) an efficient method for enzymatic cell release immediately after removal of the epineurium and extensive teasing of the nerve fibers; (2) an adaptable drop-plating method for selective cell attachment, removal of myelin debris, and expansion of the initial SC population in chemically defined medium; (3) a magnetic-activated cell sorting purification protocol for rapid and effective fibroblast elimination; and (4) an optional step of cryopreservation for the storage of the excess of cells. Highly proliferative SC cultures devoid of myelin and fibroblast growth were obtained within three days of nerve processing. Characterization of the initial, expanded, and cryopreserved cell products confirmed maintenance of SC identity, viability and growth rates throughout the process. Most importantly, SCs retained their sensitivity to mitogens and potential for differentiation even after cryopreservation. To conclude, this easy-to-implement and clinically relevant protocol allows for the preparation of expandable homogeneous SC cultures while minimizing time, manipulation of the cells, and exposure to culture variables.

  8. One-step Conversion of Furfural into 2-Methyltetrahydrofuran under Mild Conditions.

    PubMed

    Dong, Fang; Zhu, Yulei; Ding, Guoqiang; Cui, Jinglei; Li, Xianqing; Li, Yongwang

    2015-05-11

    One-step direct conversion of biomass-derived furfural to 2-methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two-stage-packed Cu-Pd in a reactor; this is the first report that one-step conversion of furfural resulted in high yield of 2-methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product-separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield. PMID:25873007

  9. An algorithm for constrained one-step inversion of spectral CT data.

    PubMed

    Foygel Barber, Rina; Sidky, Emil Y; Gilat Schmidt, Taly; Pan, Xiaochuan

    2016-05-21

    We develop a primal-dual algorithm that allows for one-step inversion of spectral CT transmission photon counts data to a basis map decomposition. The algorithm allows for image constraints to be enforced on the basis maps during the inversion. The derivation of the algorithm makes use of a local upper bounding quadratic approximation to generate descent steps for non-convex spectral CT data discrepancy terms, combined with a new convex-concave optimization algorithm. Convergence of the algorithm is demonstrated on simulated spectral CT data. Simulations with noise and anthropomorphic phantoms show examples of how to employ the constrained one-step algorithm for spectral CT data.

  10. One-step nanopatterning of conjugated polymers by electron-beam-assisted electropolymerization

    PubMed Central

    Higuchi, Takeshi; Nishiyama, Hidetoshi; Suga, Mitsuo; Watanabe, Hirohmi; Takahara, Atsushi; Jinnai, Hiroshi

    2015-01-01

    We propose a one-step nanopatterning method where liquid monomers are polymerized directly with an electron beam under an atmospheric pressure. The method allows precise positional control of an electron beam that induces electropolymerization based on an anodic oxidation only in the irradiated areas. Various versatile conjugated polymers, including polypyrrole, polyaniline and poly(3-hexylthiophene), have been directly polymerized from monomers without solvents and patterned by our one-step nanopatterning method. Vertically oriented arrays of nanorods several hundred nanometers in diameter with an aspect ratio (height to diameter) of around two were fabricated. PMID:25825510

  11. One-step Conversion of Furfural into 2-Methyltetrahydrofuran under Mild Conditions.

    PubMed

    Dong, Fang; Zhu, Yulei; Ding, Guoqiang; Cui, Jinglei; Li, Xianqing; Li, Yongwang

    2015-05-11

    One-step direct conversion of biomass-derived furfural to 2-methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two-stage-packed Cu-Pd in a reactor; this is the first report that one-step conversion of furfural resulted in high yield of 2-methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product-separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield.

  12. The symmetric MSD encoder for one-step adder of ternary optical computer

    NASA Astrophysics Data System (ADS)

    Kai, Song; LiPing, Yan

    2016-08-01

    The symmetric Modified Signed-Digit (MSD) encoding is important for achieving the one-step MSD adder of Ternary Optical Computer (TOC). The paper described the symmetric MSD encoding algorithm in detail, and developed its truth table which has nine rows and nine columns. According to the truth table, the state table was developed, and the optical-path structure and circuit-implementation scheme of the symmetric MSD encoder (SME) for one-step adder of TOC were proposed. Finally, a series of experiments were designed and performed. The observed results of the experiments showed that the scheme to implement SME was correct, feasible and efficient.

  13. Methods for separation/purification utilizing rapidly cycled thermal swing sorption

    DOEpatents

    Tonkovich, Anna Lee Y.; Monzyk, Bruce F.; Wang, Yong; VanderWiel, David P.; Perry, Steven T.; Fitzgerald, Sean P.; Simmons, Wayne W.; McDaniel, Jeffrey S.; Weller, Jr., Albert E.

    2004-11-09

    The present invention provides apparatus and methods for separating fluid components. In preferred embodiments, the apparatus and methods utilize microchannel devices with small distances for heat and mass transfer to achieve rapid cycle times and surprisingly large volumes of fluid components separated in short times using relatively compact hardware.

  14. Detection of cucumber mosaic virus isolates from banana by one-step reverse transcription loop-mediated isothermal amplification.

    PubMed

    Peng, Jun; Shi, Minjing; Xia, Zihao; Huang, Junsheng; Fan, Zaifeng

    2012-11-01

    Cucumber mosaic virus (CMV) is one of the most devastating threats to the banana industry. A single-tube, one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the rapid detection of CMV-infected banana and plantain (Musa spp.). The reaction was performed in a single tube at 63 °C for 90 min using a real-time turbidimeter, with an improved closed-tube visual detection system in which fluorescent dye was added to the inside of the lid prior to amplification. This RT-LAMP assay is an alternative method for the rapid detection of CMV in banana plants and tissue culture materials. PMID:22782136

  15. Detection of cucumber mosaic virus isolates from banana by one-step reverse transcription loop-mediated isothermal amplification.

    PubMed

    Peng, Jun; Shi, Minjing; Xia, Zihao; Huang, Junsheng; Fan, Zaifeng

    2012-11-01

    Cucumber mosaic virus (CMV) is one of the most devastating threats to the banana industry. A single-tube, one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the rapid detection of CMV-infected banana and plantain (Musa spp.). The reaction was performed in a single tube at 63 °C for 90 min using a real-time turbidimeter, with an improved closed-tube visual detection system in which fluorescent dye was added to the inside of the lid prior to amplification. This RT-LAMP assay is an alternative method for the rapid detection of CMV in banana plants and tissue culture materials.

  16. One-step synthesis of fluorescently labelled, single-walled carbon nanotubes.

    PubMed

    Guaragno, Michelle L; Gottardi, Riccardo; Fedorchak, Morgan V; Roy, Abhijit; Kumta, Prashant N; Little, Steven R

    2015-12-18

    Single-walled carbon nanotubes (SWNTs) can be labelled with functional moieties that endow them with a number of unique characteristics, which can be applicable to biomedical applications such as imaging. Herein we describe a facile, one-step esterification process to functionalize SWNT with fluorescein. PMID:26458421

  17. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J. Birch; Kingman, Donald D.; Bianchini, Gregory M.

    1989-01-01

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  18. One step process for producing dense aluminum nitride and composites thereof

    DOEpatents

    Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

    1989-10-31

    A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1,000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  19. Magnetic controlling of migration of DNA and proteins using one-step modified gold nanoparticles.

    PubMed

    Xu, Lu; Feng, Lei; Dong, Shuli; Hao, Jingcheng

    2015-06-01

    A protocol was developed for preparing magnetic gold nanoparticles via one-step modification with a paramagnetic cationic surfactant. These magnetic gold nanoparticles can bind to and manipulate a low strength magnetic field-based delivery of DNA and proteins powerfully and non-invasively. PMID:25847127

  20. Two Steps Forward, One Step Backward: Must This Be the Future of Diversity?

    ERIC Educational Resources Information Center

    Butler, Johnnella E.

    2013-01-01

    Johnnella Butler writes here that the title of this article "Two Steps Forward, One Step Backward," expresses the "wicked problem" of diversity as a concrete goal in higher education. The concept of the "wicked problem," is a term coined in the late 1960s by social planners. Consulting Wikipedia, as so many of our…

  1. One step continuous hydrothermal synthesis of very fine stabilized superparamagnetic nanoparticles of magnetite.

    PubMed

    Maurizi, Lionel; Bouyer, Frédéric; Paris, Jérémy; Demoisson, Frédéric; Saviot, Lucien; Millot, Nadine

    2011-11-14

    Stable suspensions of citrated SPIO nanoparticles were synthesised in one step using a hydrothermal continuous process. Citrates control the crystallite size and the oxidation degree of metallic ions despite the very short reaction time (4 s). Magnetite particles, Fe(2.94)O(4), with an average size of 4 nm and good monodispersity were obtained.

  2. One-step Multiplex Transgenesis via Sleeping Beauty Transposition in Cattle.

    PubMed

    Garrels, Wiebke; Talluri, Thirumala R; Apfelbaum, Ronja; Carratalá, Yanet P; Bosch, Pablo; Pötzsch, Kerstin; Grueso, Esther; Ivics, Zoltán; Kues, Wilfried A

    2016-02-24

    Genetically modified cattle are important for developing new biomedical models and for an improved understanding of the pathophysiology of zoonotic diseases. However, genome editing and genetic engineering based on somatic cell nuclear transfer suffer from a low overall efficiency. Here, we established a highly efficient one-step multiplex gene transfer system into the bovine genome.

  3. One-step Multiplex Transgenesis via Sleeping Beauty Transposition in Cattle

    PubMed Central

    Garrels, Wiebke; Talluri, Thirumala R.; Apfelbaum, Ronja; Carratalá, Yanet P.; Bosch, Pablo; Pötzsch, Kerstin; Grueso, Esther; Ivics, Zoltán; Kues, Wilfried A.

    2016-01-01

    Genetically modified cattle are important for developing new biomedical models and for an improved understanding of the pathophysiology of zoonotic diseases. However, genome editing and genetic engineering based on somatic cell nuclear transfer suffer from a low overall efficiency. Here, we established a highly efficient one-step multiplex gene transfer system into the bovine genome. PMID:26905416

  4. Electrochemical synthesis and one step modification of PMProDot nanotubes and their enhanced electrochemical properties.

    PubMed

    Nguyen, Thao M; Cho, Seungil; Varongchayakul, Nitinun; Yoon, Daehyun; Seog, Joonil; Zong, Kyukwan; Lee, Sang Bok

    2012-03-11

    Poly (3,4-(2-methylene)propylenedioxythiophene) (PMProDot) nanotubes were synthesized within the pores of polycarbonate and were further modified with styrene and vinylcarbazole by a one step electrochemical method through the methylene functional group. The enhanced electrochemical and electrochromic properties of composite nanotubes were investigated using FTIR, UV/Vis absorbance spectroscopy, and AFM.

  5. One step combustion synthesis and thermoluminescence in Y3Al5O12:Ce3+

    NASA Astrophysics Data System (ADS)

    Dhadade, I. H.; Moharil, S. V.; Dhoble, S. J.; Rahangdale, S. R.

    2016-05-01

    In the present paper one step combustion synthesis of compound Y3Al5O12:Ce3+ is reported using a modified procedure and employing mixed (Urea + Glycine) as fuel. Powder X-ray diffraction confirms the formation of said compound. Thermoluminescence study over the wide gamma exposure (1KGy - 13 KGy) Suggests the possible use of the phosphor in dosimetric application.

  6. One-step Multiplex Transgenesis via Sleeping Beauty Transposition in Cattle.

    PubMed

    Garrels, Wiebke; Talluri, Thirumala R; Apfelbaum, Ronja; Carratalá, Yanet P; Bosch, Pablo; Pötzsch, Kerstin; Grueso, Esther; Ivics, Zoltán; Kues, Wilfried A

    2016-01-01

    Genetically modified cattle are important for developing new biomedical models and for an improved understanding of the pathophysiology of zoonotic diseases. However, genome editing and genetic engineering based on somatic cell nuclear transfer suffer from a low overall efficiency. Here, we established a highly efficient one-step multiplex gene transfer system into the bovine genome. PMID:26905416

  7. Towards "Inverse" Character Tables? A One-Step Method for Decomposing Reducible Representations

    ERIC Educational Resources Information Center

    Piquemal, J.-Y.; Losno, R.; Ancian, B.

    2009-01-01

    In the framework of group theory, a new procedure is described for a one-step automated reduction of reducible representations. The matrix inversion tool, provided by standard spreadsheet software, is applied to the central part of the character table that contains the characters of the irreducible representation. This method is not restricted to…

  8. One-step synthesis of silver nanoparticle-filled Nylon 6 nanofibers and their antibacterial properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel and facile one-step approach to in situ synthesize silver nanoparticle-filled nylon 6 nanofibers by electrospinning is reported. The method does not need post-treatments and can be carried out at ambient conditions without using additional chemicals. It employs the electrospinning solvent as...

  9. Purification and characterization of Fab fragments with rapid reaction kinetics against myoglobin.

    PubMed

    Song, Hyung-Nam; Kim, Dong-Hyung; Park, Sung-Goo; Lee, Myung Kyu; Paek, Se-Hwan; Woo, Eui-Jeon

    2015-01-01

    Myoglobin is an early biomarker for acute myocardial infarction. Recently, we isolated the antibody IgG-Myo2-7ds, which exhibits unique rapid reaction kinetics toward human myoglobin antigen. Antibodies with rapid dissociation kinetics are thought to be premature IgG forms that are produced during the early stage of in vivo immunization. In the present study, we identified the epitope region of the IgG-Myo2-7ds antibody to be the C-terminal region of myoglobin, which corresponds to 144-154 aa. The Fab fragment was directly purified by papain cleavage and protein G affinity chromatography and demonstrated kinetics of an association constant of 4.02 × 10(4) M(-1) s(-1) and a dissociation constant of 2.28 × 10(-2) s(-1), which retained the unique reaction kinetics of intact IgG-Myo2-7ds antibodies. Because a rapid dissociation antibody can be utilized for antibody recycling, the results from this study would provide a platform for the development of antibody engineering in potential diagnostic areas such as a continuous monitoring system for heart disease.

  10. Rapid, scalable, and low-cost purification of recombinant adeno-associated virus produced by baculovirus expression vector system

    PubMed Central

    Buclez, Pierre-Olivier; Dias Florencio, Gabriella; Relizani, Karima; Beley, Cyriaque; Garcia, Luis; Benchaouir, Rachid

    2016-01-01

    Recombinant adeno-associated viruses (rAAV) are largely used for gene transfer in research, preclinical developments, and clinical trials. Their broad in vivo biodistribution and long-term efficacy in postmitotic tissues make them good candidates for numerous gene transfer applications. Upstream processes able to produce large amounts of rAAV were developed, particularly those using baculovirus expression vector system. In parallel, downstream processes present a large panel of purification methods, often including multiple and time consuming steps. Here, we show that simple tangential flow filtration, coupled with an optimized iodixanol-based isopycnic density gradient, is sufficient to purify several liters of crude lysate produced by baculovirus expression vector system in only one working day, leading to high titers and good purity of rAAV products. Moreover, we show that the viral vectors retain their in vitro and in vivo functionalities. Our results demonstrate that simple, rapid, and relatively low-cost methods can easily be implemented for obtaining a high-quality grade of gene therapy products based on rAAV technology. PMID:27226971

  11. Preparation of monomeric and polymeric β-cyclodextrin functionalized monoliths for rapid isolation and purification of puerarin from Radix puerariae.

    PubMed

    Lv, Yongqin; Hughes, Timothy C; Hao, Xiaojuan; Mei, Danping; Tan, Tianwei

    2011-08-01

    Monomeric and epichlorohydrin polymerized β-CD functionalized monoliths were prepared for the rapid isolation and purification of the isoflavonoid puerarin, a well-known traditional Chinese drug, from a crude extract of Radix puerariae (root of the plant Pueraria lobata). Two copolymers poly(isocyanatoethyl methacrylate-co-methyl methacrylate-co-ethylene dimethacrylate) (poly(IEM-co-MMA-co-EDMA)) and poly(glycidyl methacrylate-co-EDMA) (poly(GMA-co-EDMA)) were developed as facile, highly reactive and versatile monolithic matrix. SEM characterization demonstrated that the modified monoliths had homogenous porous structure and morphology. The success of the chemical modification of the monolithic matrix was confirmed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), solid-state (13) C NMR and elemental analysis. It was demonstrated that polymeric β-CD modified monoliths had better separation and selectivity for puerarin, recovering puerarin with a purity of 96% (m%) and a yield of 93% (m%). Compared with poly(glycidyl methacrylate-co-EDMA), poly(isocyanatoethyl methacrylate-co-methyl methacrylate-co-EDMA) monolithic matrix had higher reactivity, which significantly improved the β-CD ligand density and thus the selectivity of the monoliths. Puerarin with a purity of 96% (m%) and with a yield of 89% (m%) was recovered on the monolith.

  12. Facile and rapid DNA extraction and purification from food matrices using IFAST (immiscible filtration assisted by surface tension).

    PubMed

    Strotman, Lindsay N; Lin, Guangyun; Berry, Scott M; Johnson, Eric A; Beebe, David J

    2012-09-01

    Extraction and purification of DNA is a prerequisite to detection and analytical techniques. While DNA sample preparation methods have improved over the last few decades, current methods are still time consuming and labor intensive. Here we demonstrate a technology termed IFAST (Immiscible Filtration Assisted by Surface Tension), that relies on immiscible phase filtration to reduce the time and effort required to purify DNA. IFAST replaces the multiple wash and centrifugation steps required by traditional DNA sample preparation methods with a single step. To operate, DNA from lysed cells is bound to paramagnetic particles (PMPs) and drawn through an immiscible fluid phase barrier (i.e. oil) by an external handheld magnet. Purified DNA is then eluted from the PMPs. Here, detection of Clostridium botulinum type A (BoNT/A) in food matrices (milk, orange juice), a bioterrorism concern, was used as a model system to establish IFAST's utility in detection assays. Data validated that the DNA purified by IFAST was functional as a qPCR template to amplify the bont/A gene. The sensitivity limit of IFAST was comparable to the commercially available Invitrogen ChargeSwitch® method. Notably, pathogen detection via IFAST required only 8.5 μL of sample and was accomplished in five-fold less time. The simplicity, rapidity and portability of IFAST offer significant advantages when compared to existing DNA sample preparation methods. PMID:22814365

  13. Rapid purification of the over-expressed membrane 3 β-hydroxysteroid dehydrogenase in the presence of detergents

    NASA Astrophysics Data System (ADS)

    Zhou, Ming; Breton, Rock; Azzi, Arezki; Lin, Sheng-Xiang

    1996-10-01

    Three-beta hydroxysteroid dehydrogenase / Δ 5-Δ 4 isomerase catalyses a key step in the transformation of all 5-prognen-3β-ol and 5-androsten-3β-ol steroids into the corresponding Δ 4-3-keto-steroids. Human type I 3β-HSD can be found in the subcellular fractions of mitochondria and microsome. A 1.5 kbp cDNA encoding human type I 3β-HSD was inserted into the transfer vector pBlueBac to form plasmid pBB / 3β-HSD. The recombinant baculovirus was obtained by co-transfection of wild type AcNPV genomic DNA and PBB / 3β-HSD in Sf9 cells, then used to infect Sf9 cells to over-express human 3β-HSD protein. The 3β-HSD sample was purified to homogeneity by a rapid procedure, consisting of an anion-exchange and an adsorbance chromatographies, based on FPLC and some detergents application. The whole process was successful with a purification rate of 90 fold and a high recovery (70%). The kinetic study showed a Vmax of 500 nmol/min · mg and a Km of 2.8 μM, being much more active than those reported.

  14. Coupling Isotachophoresis with Affinity Chromatography for Rapid and Selective Purification with High Column Utilization, Part 1: Theory

    PubMed Central

    2015-01-01

    We present a novel technique that couples isotachophoresis (ITP) with affinity chromatography (AC) to achieve rapid, selective purification with high column utilization. ITP simultaneously preconcentrates an analyte and purifies it, based on differences in mobility of sample components, excluding species that may foul or compete with the target at the affinity substrate. ITP preconcentration accelerates the affinity reaction, reducing assay time, improving column utilization, and allowing for capture of targets with higher dissociation constants. Furthermore, ITP-AC separates the target and contaminants into nondiffusing zones, thus achieving high resolution in a short distance and time. We present an analytical model for spatiotemporal dynamics of ITP-AC. We identify and explore the effect of key process parameters, including target distribution width and height, ITP zone velocity, forward and reverse reaction constants, and probe concentration on necessary affinity region length, assay time, and capture efficiency. Our analytical approach shows collapse of these variables to three nondimensional parameters. The analysis yields simple analytical relations for capture length and capture time in relevant ITP-AC regimes, and it demonstrates how ITP greatly reduces assay time and improves column utilization. In the second part of this two-part series, we will present experimental validation of our model and demonstrate ITP-AC separation of the target from 10,000-fold more-abundant contaminants. PMID:24937679

  15. Rapid and label-free microfluidic neutrophil purification and phenotyping in diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Hou, Han Wei; Petchakup, Chayakorn; Tay, Hui Min; Tam, Zhi Yang; Dalan, Rinkoo; Chew, Daniel Ek Kwang; Li, King Ho Holden; Boehm, Bernhard O.

    2016-07-01

    Advanced management of dysmetabolic syndromes such as diabetes will benefit from a timely mechanistic insight enabling personalized medicine approaches. Herein, we present a rapid microfluidic neutrophil sorting and functional phenotyping strategy for type 2 diabetes mellitus (T2DM) patients using small blood volumes (fingerprick ~100 μL). The developed inertial microfluidics technology enables single-step neutrophil isolation (>90% purity) without immuno-labeling and sorted neutrophils are used to characterize their rolling behavior on E-selectin, a critical step in leukocyte recruitment during inflammation. The integrated microfluidics testing methodology facilitates high throughput single-cell quantification of neutrophil rolling to detect subtle differences in speed distribution. Higher rolling speed was observed in T2DM patients (P < 0.01) which strongly correlated with neutrophil activation, rolling ligand P-selectin glycoprotein ligand 1 (PSGL-1) expression, as well as established cardiovascular risk factors (cholesterol, high-sensitive C-reactive protein (CRP) and HbA1c). Rolling phenotype can be modulated by common disease risk modifiers (metformin and pravastatin). Receiver operating characteristics (ROC) and principal component analysis (PCA) revealed neutrophil rolling as an important functional phenotype in T2DM diagnostics. These results suggest a new point-of-care testing methodology, and neutrophil rolling speed as a functional biomarker for rapid profiling of dysmetabolic subjects in clinical and patient-oriented settings.

  16. Rapid and label-free microfluidic neutrophil purification and phenotyping in diabetes mellitus

    PubMed Central

    Hou, Han Wei; Petchakup, Chayakorn; Tay, Hui Min; Tam, Zhi Yang; Dalan, Rinkoo; Chew, Daniel Ek Kwang; Li, King Ho Holden; Boehm, Bernhard O.

    2016-01-01

    Advanced management of dysmetabolic syndromes such as diabetes will benefit from a timely mechanistic insight enabling personalized medicine approaches. Herein, we present a rapid microfluidic neutrophil sorting and functional phenotyping strategy for type 2 diabetes mellitus (T2DM) patients using small blood volumes (fingerprick ~100 μL). The developed inertial microfluidics technology enables single-step neutrophil isolation (>90% purity) without immuno-labeling and sorted neutrophils are used to characterize their rolling behavior on E-selectin, a critical step in leukocyte recruitment during inflammation. The integrated microfluidics testing methodology facilitates high throughput single-cell quantification of neutrophil rolling to detect subtle differences in speed distribution. Higher rolling speed was observed in T2DM patients (P < 0.01) which strongly correlated with neutrophil activation, rolling ligand P-selectin glycoprotein ligand 1 (PSGL-1) expression, as well as established cardiovascular risk factors (cholesterol, high-sensitive C-reactive protein (CRP) and HbA1c). Rolling phenotype can be modulated by common disease risk modifiers (metformin and pravastatin). Receiver operating characteristics (ROC) and principal component analysis (PCA) revealed neutrophil rolling as an important functional phenotype in T2DM diagnostics. These results suggest a new point-of-care testing methodology, and neutrophil rolling speed as a functional biomarker for rapid profiling of dysmetabolic subjects in clinical and patient-oriented settings. PMID:27381673

  17. Rapid Isolation And Purification Of Mitochondria For Transplantation By Tissue Dissociation And Differential Filtration

    PubMed Central

    Preble, Janine M.; Pacak, Christina A.; Kondo, Hiroshi; MacKay, Allison A.; Cowan, Douglas B.; McCully, James D.

    2014-01-01

    Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to complete. We describe a method for the rapid isolation of mitochondria from mammalian biopsies using a commercial tissue dissociator and differential filtration. In this protocol, manual homogenization is replaced with the tissue dissociator’s standardized homogenization cycle. This allows for uniform and consistent homogenization of tissue that is not easily achieved with manual homogenization. Following tissue dissociation, the homogenate is filtered through nylon mesh filters, which eliminate repetitive centrifugation steps. As a result, mitochondrial isolation can be performed in less than 30 min. This isolation protocol yields approximately 2 x 1010 viable and respiration competent mitochondria from 0.18 ± 0.04 g (wet weight) tissue sample. PMID:25225817

  18. Rapid isolation and purification of mitochondria for transplantation by tissue dissociation and differential filtration.

    PubMed

    Preble, Janine M; Pacak, Christina A; Kondo, Hiroshi; MacKay, Allison A; Cowan, Douglas B; McCully, James D

    2014-09-06

    Previously described mitochondrial isolation methods using differential centrifugation and/or Ficoll gradient centrifugation require 60 to 100 min to complete. We describe a method for the rapid isolation of mitochondria from mammalian biopsies using a commercial tissue dissociator and differential filtration. In this protocol, manual homogenization is replaced with the tissue dissociator's standardized homogenization cycle. This allows for uniform and consistent homogenization of tissue that is not easily achieved with manual homogenization. Following tissue dissociation, the homogenate is filtered through nylon mesh filters, which eliminate repetitive centrifugation steps. As a result, mitochondrial isolation can be performed in less than 30 min. This isolation protocol yields approximately 2 x 10(10) viable and respiration competent mitochondria from 0.18 ± 0.04 g (wet weight) tissue sample.

  19. One-step synthesis of 2-keto-3-deoxy-d-gluconate by biocatalytic dehydration of d-gluconate.

    PubMed

    Matsubara, Kohei; Köhling, Rudi; Schönenberger, Bernhard; Kouril, Theresa; Esser, Dominik; Bräsen, Christopher; Siebers, Bettina; Wohlgemuth, Roland

    2014-12-10

    2-Keto-3-deoxy-sugar acids are key intermediates of central metabolism and integral constituents of bacterial (lipo)polysaccharides and cell wall components and are therefore continuously and highly demanded in related research fields. The stereospecific chemical synthesis of chiral 2-keto-deoxy-sugar acids involves a multitude of reaction steps, while in metabolic pathways only few conversions lead to the same 2-keto-3-deoxy sugar acids from easily available carbohydrate precursors. Here we present a straightforward and highly economic one-step biocatalytic synthesis procedure of 2-keto-3-deoxy-d-gluconate (KDG) from d-gluconate using recombinant gluconate dehydratase (GAD) from the hyperthermophilic crenarchaeon Thermoproteus tenax. This method is highly advantageous to KDG production schemes described so far for several reasons: (i) the d-gluconate is completely converted to stereochemically pure D-KDG without side-product formation, (ii) the final KDG yield is approximately 90%, (iii) the newly developed quantitative and qualitative LC-MS analysis method enabled the simultaneous detection of d-gluconate and KDG and (iv) the T. tenax GAD as biocatalyst can be provided by a simple and rapid procedure involving only two precipitation steps. The described utilization of dehydratases for 2-keto-3-deoxy sugar acid syntheses represents a highly resource-efficient one-step preparation and offers potential short synthetic routes toward a broad range of 2-keto-3-deoxy sugar acids and their derivatives.

  20. Properties of a Ni-FUSI gate formed by the EBV method and one-step RTA

    NASA Astrophysics Data System (ADS)

    Youwei, Zhang; Dawei, Xu; Li, Wan; Zhongjian, Wang; Chao, Xia; Xinhong, Cheng; Yuehui, Yu

    2012-03-01

    Nickel fully silicided (Ni-FUSI) gate material has been fabricated on a HfO2 surface to form a Ni-FUSI gate/HfO2/Si/Al (MIS) structure by using an ultra-high vacuum e-beam evaporation (EBV) method followed by a one step rapid thermal annealing (RTA) treatment. X-ray diffraction (XRD) and Raman spectroscopy were used to reveal the microstructures and electrical properties of the MIS structure. Results show that a one step post RTA treatment is enough to promote the full reaction of nickel silicide, compared with multiple RTA treatments. Furthermore, the HfO2 gate dielectric film is sensitive to heat treatment, and multiple RTA treatments can damage the electrical properties of the HfO2 film rather than improve them. By optimization of the sample fabrication technique, the MIS capacitor produces good high-frequency capacitance-voltage curves with a hysteresis of 30 mV, a work function of about 5.44-5.53 eV and leakage current density of only 1.45 × 10-8 A/cm2 at -1 V gate bias.

  1. One-step synthesis of dispersed bimetallic carbides and nitrides from transition metals hexamethylenetetramine complexes

    SciTech Connect

    Chouzier, Sandra; Afanasiev, Pavel . E-mail: Pavel.Afanasiev@catalyse.cnrs.fr; Vrinat, Michel; Cseri, Tivadar; Roy-Auberger, Magalie

    2006-11-15

    Bimetallic nitrides and carbides Co(Ni)-Mo were obtained from the decomposition of transition metals complexes with hexamethylenetetramine (HMTA) under inert atmosphere. The precursor complexes were prepared by means of aqueous precipitation of ammonium molybdate with cobalt nitrate or nickel nitrate and HMTA. During the decomposition, HMTA acts at once as a reducing agent and as a source of carbon and nitrogen. The precursor's composition and the decomposition conditions are the key parameters to influence the nature of the obtained phases. The method developed provides a simple one-step way to highly divided bimetallic nitrides and carbides. -- Graphical abstract: Bimetallic nitrides and carbides Co(Ni)-Mo were obtained from the decomposition of metals complexes with hexamethylenetetramine (HMTA) under inert atmosphere. During the decomposition, HMTA acts at once as a reducing agent and as a source of carbon and nitrogen. The method provides a simple one-step way to highly divided nitrides and carbides. Display Omitted.

  2. One-step detection of pathogens and viruses: combining magnetic relaxation switching and magnetic separation.

    PubMed

    Chen, Yiping; Xianyu, Yunlei; Wang, Yu; Zhang, Xiaoqing; Cha, Ruitao; Sun, Jiashu; Jiang, Xingyu

    2015-03-24

    We report a sensing methodology that combines magnetic separation (MS) and magnetic relaxation switching (MS-MRS) for one-step detection of bacteria and viruses with high sensitivity and reproducibility. We first employ a magnetic field of 0.01 T to separate the magnetic beads of large size (250 nm in diameter) from those of small size (30 nm in diameter) and use the transverse relaxation time (T2) of the water molecules around the 30 nm magnetic beads (MB30) as the signal readout of the immunoassay. An MS-MRS sensor integrates target enrichment, extraction, and detection into one step, and the entire immunoassay can be completed within 30 min. Compared with a traditional MRS sensor, an MS-MRS sensor shows enhanced sensitivity, better reproducibility, and convenient operation, thus providing a promising platform for point-of-care testing.

  3. One-step aluminium-assisted crystallization of Ge epitaxy on Si by magnetron sputtering

    SciTech Connect

    Liu, Ziheng Hao, Xiaojing; Ho-Baillie, Anita; Green, Martin A.

    2014-02-03

    In this work, one-step aluminium-assisted crystallization of Ge on Si is achieved via magnetron sputtering by applying an in-situ low temperature (50 °C to 150 °C) heat treatment in between Al and Ge depositions. The effect of heat treatment on film properties and the growth mechanism of Ge epitaxy on Si are studied via X-ray diffraction, Raman and transmission electron microscopy analyses. Compared with the conventional two-step process, the one-step aluminium-assisted crystallization requires much lower thermal budget and results in pure Ge epitaxial layer, which may be suitable for use as a virtual substrate for the fabrication of III-V solar cells.

  4. One-step synthesis of chlorinated graphene by plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Fan, Liwei; Zhang, Hui; Zhang, Pingping; Sun, Xuhui

    2015-08-01

    We developed an approach to synthesize the chlorinated single layer graphene (Cl-G) by one-step plasma enhanced chemical vapor deposition. Copper foil was simply treated with hydrochloric acid and then CuCl2 formed on the surface was used as Cl source under the assistance of plasma treatment. Compared with other two-step methods by post plasma/photochemical treatment of CVD-grown single layer graphene (SLG), one-step Cl-G synthesis approach is quite straightforward and effective. X-ray photoelectron spectroscopy (XPS) revealed that ∼2.45 atom% Cl remained in SLG. Compared with the pristine SLG, the obvious blue shifts of G band and 2D band along with the appearance of D' band and D + G band in the Raman spectra indicate p-type doping of Cl-G.

  5. One-step synthesis of novel biacidic carbon via hydrothermal carbonization

    SciTech Connect

    Xiao Huiquan; Guo Yingxue; Liang Xuezheng; Qi Chenze

    2010-07-15

    The novel biacidic carbon has been synthesized via one-step hydrothermal carbonization of glucose, citric acid, and hydroxyethylsulfonic acid at 180 {sup o}C for only 4 h. The novel carbon had an acidity of 1.7 mmol/g with the carbonyl to sulfonic acid groups molar ratio of 1:3, which was confirmed by IR, XPS, TPD, SEM, and BET analyses. The catalytic activities of the carbon were investigated through esterification and oxathioketalization. The results showed that the carbon owned the comparable activities to sulfuric acid, which indicated that the carbon holds great potential for the green processes. - Graphical abstract: The novel biacidic carbon has been synthesized via one-step hydrothermal carbonization. Both the sulfonic and carbonyl acid groups were introduced to the carbon during the carbonization processes.

  6. One Step Combustion Synthesis Of YAG:Ce Phosphor For Solid State Lighting

    NASA Astrophysics Data System (ADS)

    Yadav, Pooja; Gupta, K. Vijay Kumar; Muley, Aarti; Joshi, C. P.; Moharil, S. V.

    2011-10-01

    YAG:Ce is an important phosphor having applications in various fields ranging from solid state lighting to scintillation detectors. YAG phosphors doped with activators are mainly synthesized by solid state reaction techniques that require high sintering temperatures (above 1500°C) to eliminate YAM and YAP phases. Though several soft chemical routes have been explored for synthesis of YAG, most of these methods are complex and phase pure materials are not obtained in one step, but prolonged annealing at temperatures around 1000 C or above becomes necessary. One step combustion synthesis of YAG:Ce3+ and related phosphors carried out at 500 C furnace temperature is reported here. Activation with Ce3+ could be achieved during the synthesis without taking recourse to any post-combustion thermal treatment. LEDs prepared from the combustion synthesized YAG:Ce3+, exhibited properties comparable to those produced from the commercial phosphor.

  7. A general one-step method for the cloning of PCR products.

    PubMed

    Bolchi, Angelo; Ottonello, Simone; Petrucco, Stefania

    2005-12-01

    A very fast, highly efficient, versatile and low-cost cloning of PCR products is described. PCR amplicons, obtained with any set of primers, is directly integrated into circular plasmid vectors by means of a one-step restriction-ligation procedure. When using proof-reading DNA polymerases, 100% cloning efficiency is easily achieved, implying that direct cloning into 'final-use' vectors (i.e. avoiding any intermediate cloning step) is a feasible task. Albeit with a lower efficiency, the same procedure is also suitable for the cloning of PCR products generated by 'non-proof-reading' DNA polymerases. Furthermore, with a simple modification of the vector polylinker site, the present method can be easily adapted to the directional cloning of open-reading-frame-encoding amplicons. This one-step procedure thus couples high efficiency with high reliability and versatility, and lends itself as the method of choice for routine cloning of PCR products.

  8. A general one-step method for the cloning of PCR products.

    PubMed

    Bolchi, Angelo; Ottonello, Simone; Petrucco, Stefania

    2005-12-01

    A very fast, highly efficient, versatile and low-cost cloning of PCR products is described. PCR amplicons, obtained with any set of primers, is directly integrated into circular plasmid vectors by means of a one-step restriction-ligation procedure. When using proof-reading DNA polymerases, 100% cloning efficiency is easily achieved, implying that direct cloning into 'final-use' vectors (i.e. avoiding any intermediate cloning step) is a feasible task. Albeit with a lower efficiency, the same procedure is also suitable for the cloning of PCR products generated by 'non-proof-reading' DNA polymerases. Furthermore, with a simple modification of the vector polylinker site, the present method can be easily adapted to the directional cloning of open-reading-frame-encoding amplicons. This one-step procedure thus couples high efficiency with high reliability and versatility, and lends itself as the method of choice for routine cloning of PCR products. PMID:15992357

  9. One-step electrochemical synthesis of a graphene–ZnO hybrid for improved photocatalytic activity

    SciTech Connect

    Wei, Ang; Xiong, Li; Sun, Li; Liu, Yanjun; Li, Weiwei; Lai, Wenyong; Liu, Xiangmei; Wang, Lianhui; Huang, Wei; Dong, Xiaochen

    2013-08-01

    Graphical abstract: - Highlights: • Graphene–ZnO hybrid was synthesized by one-step electrochemical deposition. • Graphene–ZnO hybrid presents a special structure and wide UV–vis absorption spectra. • Graphene–ZnO hybrid exhibits an exceptionally higher photocatalytic activity for the degradation of dye methylene blue. - Abstract: A graphene–ZnO (G-ZnO) hybrid was synthesized by one-step electrochemical deposition. During the formation of ZnO nanostructure by cathodic electrochemical deposition, the graphene oxide was electrochemically reduced to graphene simultaneously. Scanning electron microscope images, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectra, and UV–vis absorption spectra indicate the resulting G-ZnO hybrid presents a special structure and wide UV–vis absorption spectra. More importantly, it exhibits an exceptionally higher photocatalytic activity for the degradation of dye methylene blue than that of pure ZnO nanostructure under both ultraviolet and sunlight irradiation.

  10. Fast-ion energy resolution by one-step reaction gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Salewski, M.; Nocente, M.; Gorini, G.; Jacobsen, A. S.; Kiptily, V. G.; Korsholm, S. B.; Leipold, F.; Madsen, J.; Moseev, D.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Tardocchi, M.; Contributors, JET

    2016-04-01

    The spectral broadening of γ-rays from fusion plasmas can be measured in high-resolution gamma-ray spectrometry (GRS). We derive weight functions that determine the observable velocity space and quantify the velocity-space sensitivity of one-step reaction high-resolution GRS measurements in magnetized fusion plasmas. The weight functions suggest that GRS resolves the energies of fast ions directly without the need for tomographic inversion for selected one-step reactions at moderate plasma temperatures. The D(p,γ)3He reaction allows the best direct fast-ion energy resolution. We illustrate our general formalism using reactions with and without intrinsic broadening of the γ-rays for the GRS diagnostic at JET.

  11. Detection of BCR-ABL using one step reverse transcriptase- polymerase chain reaction and microchip electrophoresis.

    PubMed

    Lin, Xuexia; Wu, Jing; Liu, Wu; Li, Haifang; Wang, Zhihua; Lin, Jin-Ming

    2013-12-15

    One-step reverse transcriptase polymerase chain reaction (RT-PCR) coupled with microchip electrophoresis (MCE) was established to analyze BCR-ABL fusion gene. The use of one-step RT-PCR could simplify the RT-PCR procedure and thus reduced the risk of contamination and sample consumption. This method also enhanced the sensitivity for amplified target DNA and dramatically shorted the analysis time. Moreover, this assay can simultaneously identify b2a2 and b3a2. Orthogonal array design, which can investigated mutual effects of PCR parameters, was used to optimize the reaction system. This approach was highly effective, reproducible and sensitive, and would be suitable for the determination of BCR-ABL in clinic diagnosis.

  12. One-step synthesis and luminescence properties of tetragonal double tungstates nanocrystals.

    PubMed

    Wang, Z J; Zhang, Y L; Zhong, J P; Yao, H H; Wang, J; Wu, M M; Meijerink, A

    2016-08-25

    A versatile one-step thermolysis protocol is demonstrated to produce a uniform dispersion of tetragonal double tungstates NaRE(WO4)2 (RE = rare earth) nanocrystals (NCs). Oriented attachment in the [001] direction occurred. Doping with luminescent RE(3+) ions resulted in highly luminescent NCs showing characteristic line emission of the dopant as well as a blue emission assigned to surface adsorbed organic species. PMID:27524472

  13. On one-step worst-case optimal trisection in univariate bi-objective Lipschitz optimization

    NASA Astrophysics Data System (ADS)

    Žilinskas, Antanas; Gimbutienė, Gražina

    2016-06-01

    The bi-objective Lipschitz optimization with univariate objectives is considered. The concept of the tolerance of the lower Lipschitz bound over an interval is generalized to arbitrary subintervals of the search region. The one-step worst-case optimality of trisecting an interval with respect to the resulting tolerance is established. The theoretical investigation supports the previous usage of trisection in other algorithms. The trisection-based algorithm is introduced. Some numerical examples illustrating the performance of the algorithm are provided.

  14. Autologous matrix-induced chondrogenesis (AMIC). A one-step procedure for retropatellar articular resurfacing.

    PubMed

    Benthien, Jan Philipp; Behrens, Peter

    2010-04-01

    The objective of this technical note is to describe the autologous matrix induced chondrogenesis (AMIC) procedure and to evaluate its possible role for resurfacing of retropatellar cartilage defects. AMIC is a one-step procedure combining microfracturing with application of a collagen I/III membrane to protect the initial blood clot and to serve as a scaffold for the developing chondrocytes. A retrospective analysis of our experience in three patients followed for 18 months is presented.

  15. Low-cost one-step fabrication of superhydrophobic surface on Al alloy

    NASA Astrophysics Data System (ADS)

    Zhang, Youfa; Wu, Jie; Yu, Xinquan; Wu, Hao

    2011-07-01

    A stable superhydrophobicity on aluminum alloy has been rendered by a low-cost one-step method, simply immersing the substrates in a solution containing hydrochloric acid and fatty acid molecules. The formation mechanism of such a surface was proposed by SEM morphology and EDS results. The resulting surface shows superhydrophobicity and low adhesion. This low cost and facile process provides a real feasible avenue for large-scale production of superhydrophobic surfaces.

  16. One-step two-dimensional microfluidics-based synthesis of three-dimensional particles.

    PubMed

    Hakimi, Navid; Tsai, Scott S H; Cheng, Chil-Hung; Hwang, Dae Kun

    2014-03-01

    Synthesis of three-dimensional anisotropic microparticles using a simple one-step microfluidic-based method is described. The method exploits the nonuniformity of the polymerizing UV light, UV absorption by opaque nanoparticles in the precursor solution, and discontinuous photomask patterns to make magnetic and non-magnetic microparticles in a twodimensional microchannel. Numerical simulations of monomer conversion in the microfluidic channel are performed to predict the manufactured particle shape. PMID:24327458

  17. On one-step replica symmetry breaking in the Edwards–Anderson spin glass model

    NASA Astrophysics Data System (ADS)

    Del Ferraro, Gino; Wang, Chuang; Zhou, Hai-Jun; Aurell, Erik

    2016-07-01

    We consider a one-step replica symmetry breaking description of the Edwards–Anderson spin glass model in 2D. The ingredients of this description are a Kikuchi approximation to the free energy and a second-level statistical model built on the extremal points of the Kikuchi approximation, which are also fixed points of a generalized belief propagation (GBP) scheme. We show that a generalized free energy can be constructed where these extremal points are exponentially weighted by their Kikuchi free energy and a Parisi parameter y, and that the Kikuchi approximation of this generalized free energy leads to second-level, one-step replica symmetry breaking (1RSB), GBP equations. We then proceed analogously to the Bethe approximation case for tree-like graphs, where it has been shown that 1RSB belief propagation equations admit a survey propagation solution. We discuss when and how the one-step-replica symmetry breaking GBP equations that we obtain also allow a simpler class of solutions which can be interpreted as a class of generalized survey propagation equations for the single instance graph case.

  18. One-step graphene coating of heteroepitaxial GaN films.

    PubMed

    Choi, Jae-Kyung; Huh, Jae-Hoon; Kim, Sung-Dae; Moon, Daeyoung; Yoon, Duhee; Joo, Kisu; Kwak, Jinsung; Chu, Jae Hwan; Kim, Sung Youb; Park, Kibog; Kim, Young-Woon; Yoon, Euijoon; Cheong, Hyeonsik; Kwon, Soon-Yong

    2012-11-01

    Today, state-of-the-art III-Ns technology has been focused on the growth of c-plane nitrides by metal-organic chemical vapor deposition (MOCVD) using a conventional two-step growth process. Here we show that the use of graphene as a coating layer allows the one-step growth of heteroepitaxial GaN films on sapphire in a MOCVD reactor, simplifying the GaN growth process. It is found that the graphene coating improves the wetting between GaN and sapphire, and, with as little as ~0.6 nm of graphene coating, the overgrown GaN layer on sapphire becomes continuous and flat. With increasing thickness of the graphene coating, the structural and optical properties of one-step grown GaN films gradually transition towards those of GaN films grown by a conventional two-step growth method. The InGaN/GaN multiple quantum well structure grown on a GaN/graphene/sapphire heterosystem shows a high internal quantum efficiency, allowing the use of one-step grown GaN films as 'pseudo-substrates' in optoelectronic devices. The introduction of graphene as a coating layer provides an atomic playground for metal adatoms and simplifies the III-Ns growth process, making it potentially very useful as a means to grow other heteroepitaxial films on arbitrary substrates with lattice and thermal mismatch.

  19. Evaluating formability of LCP plate for sacral fractures with one step inverse forming finite element analysis.

    PubMed

    Li, Xiaoda; Zhang, Xiangkui; Hu, Ping; Liu, Weijie; Shen, Guozhe; Zhan, Xianghui

    2015-01-01

    The locking compression plate fixation treatment for the unstable sacral fractures is simple and effective, with less trauma and complications. Some locking compression plate parts have been made of high-strength Plate manufactured by hot stamping process since the demand for lightweight biomedical materials. Finite Element (FE) method of One-Step inverse forming based on deformation theory is the tool to evaluate the formability of locking compression plate panel quickly in initial design for reducing costs and development cycle of Plate. But current one-step inverse forming methods are all suitable for cold stamping, not hot-stamping. This paper proposed one-step inverse forming method and workflow for hot-stamping of locking compression Plate. And the B pillar of a sacral bone was simulated and its computing result was compared with experimental value. The result shows that the proposed method in this paper can quickly evaluate high temperature formability of high-strength Plate. And the method is proposed to be used in initial design. PMID:26405951

  20. Graphitic carbon nitride nanosheets: one-step, high-yield synthesis and application for Cu2+ detection.

    PubMed

    Cheng, Ningyan; Jiang, Ping; Liu, Qian; Tian, Jingqi; Asiri, Abdullah M; Sun, Xuping

    2014-10-21

    In this article we report on the one-step, rapid, high-yield synthesis of graphitic carbon nitride (g-C3N4) nanosheets for the first time. The nanosheets were obtained by pyrolyzing a melamine-KBH4 mixture under Ar. As a fluorosensor for Cu(2+), the g-C3N4 nanosheets exhibit a detection limit as low as 0.5 nM and high selectivity in buffer solutions, and this sensor was applied to the analysis of lake water samples. The electrogenerated chemiluminescence (ECL) behavior of the g-C3N4 nanosheets using Na2S2O8 as the coreactant was also studied. Results suggest that the ECL intensity of the g-C3N4 nanosheets was linear over concentrations of 0-45 nM, with a detection limit of 1.2 nM for Cu(2+). PMID:25134657

  1. One-step bulk synthesis of stable, near unit-cell sized oxide nanoparticles and nanoparticle blends using KO2.

    PubMed

    Sutto, Thomas E

    2014-05-01

    Presented here is a novel one-step synthesis of oxide or hydroxide nanoparticles using, for the first time, potassium superoxide (KO2). This work demonstrates that the reaction of KO2 with different salt solutions produces grams of stable, near unit-cell sized nanoparticles. This new synthetic technique is applied to representative elements from across the periodic table to rapidly produce nanometer sized oxides or hydroxides of Mg, Al, Y, Ti, Mn, Fe, Co, Ni, Cu, Zn, Sn, Tl, Pb, and Ce. This technique is also used to produce blends of nanoparticles, demonstrating the ability to prepare complex materials such as nanoparticulate blends of a lithium cathode material (LiCoO2), the multiferroic compound (BiMnO(3+δ)), and the superconducting YBa2Cu3O(7-γ). PMID:24724979

  2. Coupling Isotachophoresis with Affinity Chromatography for Rapid and Selective Purification with High Column Utilization, Part 2: Experimental Study

    PubMed Central

    2015-01-01

    We present an experimental study of coupling of isotachophoresis (ITP) and affinity chromatography (AC) to effect rapid, selective purification with high column utilization and high resolution. We provide a detailed protocol for performing ITP-AC and describe the design of a buffer system to perform sequence specific separation of nucleic acids. We describe the synthesis and functionalization of our affinity substrate, poly(glycidyl methacrylate-co-ethylene dimethacrylate) porous polymer monolith (GMA-EDMA PPM). This substrate allows easy immobilization of affinity probes, is nonsieving (even to macromolecules), and exhibits negligible nonspecific binding. We demonstrate ITP-AC with 25 nt, Cy5 labeled DNA target and a DNA probe and study the spatiotemporal dynamics using epifluorescence imaging. We make qualitative and quantitative comparisons between these data and the model presented in the first part of this two-paper series. We vary the target concentration from 1 pg μL–1 to 100 pg μL–1 and ITP velocity over the range of 10–50 μm s–1, and thereby explore over 4 orders of magnitude of scaled target amount. We observe very good agreement between predictions and experimental data for the spatiotemporal behavior of the coupled ITP and affinity process, and for key figures of merit, including scaled capture length and maximum capture efficiency. Lastly, we demonstrate that the resolution of ITP-AC increases linearly with time and purify 25 nt target DNA from 10 000-fold higher abundance background (contaminating) genomic fish sperm DNA. We perform this capture from 200 μL of sample in under 1 mm column length and within <10 min. PMID:24937777

  3. One step synthesis of 6-oxo-cholestan-3β,5α-diol

    SciTech Connect

    Voisin, Maud; Silvente-Poirot, Sandrine; Poirot, Marc

    2014-04-11

    Highlights: • Cholesterol-5,6-epoxides are metabolized into cholestane-3β,5α,6β-triol (CT) in cancer cells. • 6-Oxo-cholestan-3β,5α-diol (OCDO) is a putative metabolite of CT. • The one step syntheses of CT and OCDO from cholesterol are reported. • The one step syntheses of labelled CT and OCDO are reported. - Abstract: Cholesterol metabolism has been recently linked to cancer, highlighting the importance of the characterization of new metabolic pathways in the sterol series. One of these pathways is centered on cholesterol-5,6-epoxides (5,6-ECs). 5,6-ECs can either generate dendrogenin A, a tumor suppressor present in healthy mammalian tissues, or the carcinogenic cholestane-3β,5α,6β-triol (CT) and its putative metabolite 6-oxo-cholestan-3β,5α-diol (OCDO) in tumor cells. We are currently investigating the identification of the enzyme involved in OCDO biosynthesis, which would be highly facilitated by the use of commercially unavailable [{sup 14}C]-cholestane-3β,5α,6β-triol and [{sup 14}C]-6-oxo-cholestan-3β,5α-diol. In the present study we report the one-step synthesis of [{sup 14}C]-cholestane-3β,5α,6β-triol and [{sup 14}C]-6-oxo-cholestan-3β,5α-diol by oxidation of [{sup 14}C]-cholesterol with iodide metaperiodate (HIO{sub 4})

  4. One-Step Direct Aeroacoustic Simulation Using Space-Time Conservation Element and Solution Element Method

    NASA Astrophysics Data System (ADS)

    Ho, C. Y.; Leung, R. C. K.; Zhou, K.; Lam, G. C. Y.; Jiang, Z.

    2011-09-01

    One-step direct aeroacoustic simulation (DAS) has received attention from aerospace and mechanical high-pressure fluid-moving system manufacturers for quite some time. They aim to simulate the unsteady flow and acoustic field in the duct simultaneously in order to investigate the aeroacoustic generation mechanisms. Because of the large length and energy scale disparities between the acoustic far field and the aerodynamic near field, highly accurate and high-resolution simulation scheme is required. This involves the use of high order compact finite difference and time advancement schemes in simulation. However, in this situation, large buffer zones are always needed to suppress the spurious numerical waves emanating from computational boundaries. This further increases the computational resources to yield accurate results. On the other hand, for such problem as supersonic jet noise, the numerical scheme should be able to resolve both strong shock waves and weak acoustic waves simultaneously. Usually numerical aeroa-coustic scheme that is good for low Mach number flow is not able to give satisfactory simulation results for shock wave. Therefore, the aeroacoustic research community has been looking for a more efficient one-step DAS scheme that has the comparable accuracy to the finite-difference approach with smaller buffer regions, yet is able to give accurate solutions from subsonic to supersonic flows. The conservation element and solution element (CE/SE) scheme is one of the possible schemes satisfying the above requirements. This paper aims to report the development of a CE/SE scheme for one-step DAS and illustrate its robustness and effectiveness with two selected benchmark problems.

  5. A reagent for the one-step preparation of potassium acyltrifluoroborates (KATs) from aryl- and heteroarylhalides.

    PubMed

    Erős, Gábor; Kushida, Yo; Bode, Jeffrey W

    2014-07-14

    Potassium acyltrifluoroborates (KATs) are fascinating functional groups whose further exploration is limited by poor synthetic access. Documented herein is the design and synthesis of a new reagent for their one-step preparation from aryl- and heteroarylhalides. The reagent is a stable, soluble zwitterion prepared by S-alkylation of a novel thioformamide trifluoroboronate. The KATs are prepared by adding one equivalent of nBuLi to a mixture of the aryl halide and the reagent at -78 °C. This protocol is suitable for the preparation of KATs containing pyridines, esters, nitro groups, and halides. PMID:24888578

  6. One-step Entanglement Generation Between Separated Nitrogen-vacancy Centers Embedded in Photonic Crystal Cavities

    NASA Astrophysics Data System (ADS)

    Santos, A. F.; Khanna, Faqir C.

    2016-09-01

    We propose a one-step scheme for creating entanglement between two distant nitrogen-vacancy (NV) centers, which are placed in separate single-mode nanocavities in a planar photonic crystal (PC). With a laser-driven, the decoherence from the excited states of the NV centers can be effectively suppressed by virtue of the Raman transition in the dispersive regime. With the assistant of a strong classical field, fast operation can be achieved. The experimental feasibility of the scheme is discussed based on currently available technology.

  7. One-step synthesis of novel biacidic carbon via hydrothermal carbonization

    NASA Astrophysics Data System (ADS)

    Xiao, Huiquan; Guo, Yingxue; Liang, Xuezheng; Qi, Chenze

    2010-07-01

    The novel biacidic carbon has been synthesized via one-step hydrothermal carbonization of glucose, citric acid, and hydroxyethylsulfonic acid at 180 °C for only 4 h. The novel carbon had an acidity of 1.7 mmol/g with the carbonyl to sulfonic acid groups molar ratio of 1:3, which was confirmed by IR, XPS, TPD, SEM, and BET analyses. The catalytic activities of the carbon were investigated through esterification and oxathioketalization. The results showed that the carbon owned the comparable activities to sulfuric acid, which indicated that the carbon holds great potential for the green processes.

  8. Template-directed synthesis of flexible porphyrin nanocage and nanorings via one-step olefin metathesis.

    PubMed

    Zhu, Bin; Chen, Huanxin; Lin, Wei; Ye, Yang; Wu, Jing; Li, Shijun

    2014-10-29

    We describe the fabrication of a suite of flexible porphyrin cages and nanorings from a simple tetraalkene-derived zinc porphyrin monomer via a highly efficient template-directed strategy. The zinc porphyrin monomers were preorganized together by coordination with N atoms of multidentate ligands. Subsequent one-step olefin metathesis furnished a bisporphyrin cage, a triporphyrin nanoring, and a hexaporphyrin nanoring. In the case of the hexaporphyrin nanoring, 24 terminal olefins from six porphyrin monomers reacted with each other to form 12 new double bonds, delivering the final product. The triporphyrin and hexaporphyrin nanorings were further employed as hosts to encapsulate C60 and C70. PMID:25303609

  9. Corrosion resistance properties of superhydrophobic copper surfaces fabricated by one-step electrochemical modification process

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Sarkar, D. K.; Gallant, Danick; Chen, X.-Grant

    2013-10-01

    Superhydrophobic copper surfaces have been prepared by a one-step electrochemical modification process in an ethanolic stearic acid solution. In this work, the corrosion properties of hydrophobic copper surface and superhydrophobic copper surfaces were analyzed by means of electrochemical analyses and compared with that of as-received bare copper substrate. The decrease of corrosion current density (icorr) as well as the increase of polarization resistance (Rp) obtained from potentiodynamic polarization curves revealed that the superhydrophobic film on the copper surfaces improved the corrosion resistance performance of the copper substrate.

  10. Superhydrophobic aluminum alloy surfaces by a novel one-step process.

    PubMed

    Saleema, N; Sarkar, D K; Paynter, R W; Chen, X-G

    2010-09-01

    A simple one-step process has been developed to render aluminum alloy surfaces superhydrophobic by immersing the aluminum alloy substrates in a solution containing NaOH and fluoroalkyl-silane (FAS-17) molecules. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements have been performed to characterize the morphological features, chemical composition and superhydrophobicity of the surfaces. The resulting surfaces provided a water contact angle as high as ∼162° and a contact angle hysteresis as low as ∼4°. The study indicates that it is possible to fabricate superhydrophobic aluminum surfaces easily and effectively without involving the traditional two-step processes.

  11. One-step green synthesis of gold nanoparticles by mesophilic filamentous fungi

    NASA Astrophysics Data System (ADS)

    Vágó, Adél; Szakacs, George; Sáfrán, György; Horvath, Robert; Pécz, Béla; Lagzi, István

    2016-02-01

    We report a one-step and green method for the synthesis of gold nanoparticles by randomly selected 21 types of microscopic fungi. Depending on the exact type of microorganisms and experimental parameters (such as fermentation conditions) highly stable particles with various shapes and sizes were obtained from the cell-free extracts of fungi, as revealed by spectroscopic and electron microscopic measurements. The active compound in the fungal extracellular supernatants which is responsible for the bioreduction was found to be less than 3000 Da in molecular weight determined by molecular sieves.

  12. Template-directed synthesis of flexible porphyrin nanocage and nanorings via one-step olefin metathesis.

    PubMed

    Zhu, Bin; Chen, Huanxin; Lin, Wei; Ye, Yang; Wu, Jing; Li, Shijun

    2014-10-29

    We describe the fabrication of a suite of flexible porphyrin cages and nanorings from a simple tetraalkene-derived zinc porphyrin monomer via a highly efficient template-directed strategy. The zinc porphyrin monomers were preorganized together by coordination with N atoms of multidentate ligands. Subsequent one-step olefin metathesis furnished a bisporphyrin cage, a triporphyrin nanoring, and a hexaporphyrin nanoring. In the case of the hexaporphyrin nanoring, 24 terminal olefins from six porphyrin monomers reacted with each other to form 12 new double bonds, delivering the final product. The triporphyrin and hexaporphyrin nanorings were further employed as hosts to encapsulate C60 and C70.

  13. Synthesis of fluorescent carbon nanoparticles directly from active carbon via a one-step ultrasonic treatment

    SciTech Connect

    Li, Haitao; He, Xiaodie; Liu, Yang; Yu, Hang; Kang, Zhenhui; Lee, Shuit-Tong

    2011-01-15

    Water-soluble fluorescent carbon nanoparticles were synthesized directly from active carbon by a one-step hydrogen peroxide-assisted ultrasonic treatment. The carbon nanoparticles were characterized by transmission electron microscopy, optical fluorescent microscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy and ultraviolet-visible spectrophotometer. The results showed that the surface of carbon nanoparticles was rich of hydroxyl groups resulting in high hydrophilicity. The carbon nanoparticles could emit bright and colorful photoluminescence covering the entire visible-to-near infrared spectral range. Furthermore, these carbon nanoparticles also had excellent up-conversion fluorescent properties.

  14. Ultraporous superhydrophobic gas-permeable nano-layers by scalable solvent-free one-step self-assembly

    NASA Astrophysics Data System (ADS)

    Liu, Guanyu; Wong, William S. Y.; Nasiri, Noushin; Tricoli, Antonio

    2016-03-01

    Superhydrophobic materials with excellent humidity tolerance, high porosity and light transmittance are being investigated for numerous applications including moisture-sensitive catalysts and perovskite solar cells. Here, we report the one-step solvent-free synthesis of ultraporous superhydrophobic nano-layers by the on-the-fly functionalization of nanoparticle aerosols. Short exposure of surfaces to hot Mn3O4, ZnO and TiO2 aerosols results in ultraporous nanoparticle networks with repulsive dewetting state approaching ideal Cassie-Baxter superhydrophobicity. In addition to showcasing sliding angles of ca. 0° and very low contact angle hysteresis of 3° +/- 2°, these optimal nano-layers have up to 98% porosity and pore size of several micrometres, a key feature to enable efficient penetration of gases to the substrate surface. The stability of this ultraporous superhydrophobic morphology is demonstrated by rapidly applying Moses effect-functionality to substrates that parts water up to 5 mm high. This scalable synthesis method offers a flexible and rapid approach for the production of numerous moisture-resistant devices including gas sensors, catalysts and perovskite solar cells.Superhydrophobic materials with excellent humidity tolerance, high porosity and light transmittance are being investigated for numerous applications including moisture-sensitive catalysts and perovskite solar cells. Here, we report the one-step solvent-free synthesis of ultraporous superhydrophobic nano-layers by the on-the-fly functionalization of nanoparticle aerosols. Short exposure of surfaces to hot Mn3O4, ZnO and TiO2 aerosols results in ultraporous nanoparticle networks with repulsive dewetting state approaching ideal Cassie-Baxter superhydrophobicity. In addition to showcasing sliding angles of ca. 0° and very low contact angle hysteresis of 3° +/- 2°, these optimal nano-layers have up to 98% porosity and pore size of several micrometres, a key feature to enable efficient

  15. General transient solution of the one-step master equation in one dimension

    NASA Astrophysics Data System (ADS)

    Smith, Stephen; Shahrezaei, Vahid

    2015-06-01

    Exact analytical solutions of the master equation are limited to special cases and exact numerical methods are inefficient. Even the generic one-dimensional, one-step master equation has evaded exact solution, aside from the steady-state case. This type of master equation describes the dynamics of a continuous-time Markov process whose range consists of positive integers and whose transitions are allowed only between adjacent sites. The solution of any master equation can be written as the exponential of a (typically huge) matrix, which requires the calculation of the eigenvalues and eigenvectors of the matrix. Here we propose a linear algebraic method for simplifying this exponential for the general one-dimensional, one-step process. In particular, we prove that the calculation of the eigenvectors is actually not necessary for the computation of exponential, thereby we dramatically cut the time of this calculation. We apply our new methodology to examples from birth-death processes and biochemical networks. We show that the computational time is significantly reduced compared to existing methods.

  16. Operator Approach to the Master Equation for the One-Step Process

    NASA Astrophysics Data System (ADS)

    Hnatič, M.; Eferina, E. G.; Korolkova, A. V.; Kulyabov, D. S.; Sevastyanov, L. A.

    2016-02-01

    Background. Presentation of the probability as an intrinsic property of the nature leads researchers to switch from deterministic to stochastic description of the phenomena. The kinetics of the interaction has recently attracted attention because it often occurs in the physical, chemical, technical, biological, environmental, economic, and sociological systems. However, there are no general methods for the direct study of this equation. The expansion of the equation in a formal Taylor series (the so called Kramers-Moyal's expansion) is used in the procedure of stochastization of one-step processes. Purpose. However, this does not eliminate the need for the study of the master equation. Method. It is proposed to use quantum field perturbation theory for the statistical systems (the so-called Doi method). Results: This work is a methodological material that describes the principles of master equation solution based on quantum field perturbation theory methods. The characteristic property of the work is that it is intelligible for non-specialists in quantum field theory. Conclusions: We show the full equivalence of the operator and combinatorial methods of obtaining and study of the one-step process master equation.

  17. One step 'dip' and 'use' Ag nanostructured thin films for ultrahigh sensitive SERS Detection.

    PubMed

    Rajkumar, Kanakaraj; Jayram, Naidu Dhanpal; Mangalaraj, Devanesan; Rajendra Kumar, Ramasamy Thangavelu

    2016-11-01

    A simple one step galvanic displacement method which involves dipping of the silicon substrate in the AgNO3/HF solution and using it for SERS application without any further process is demonstrated. The size and shape of the Ag nanoparticles changes as the deposition time is increased. Initially the shape of the particles was nearly spherical and as it grows, becomes oblong and then coalesce to form a discontinuous film with vertically grown hierarchical Ag nanostructures. The sizes of the deposited particles were in the ranges from 30nm to a discontinuous film. It also demonstrated a highly sensitive chemical detection by surface-enhanced Raman scattering of rhodamine 6G dye, down to 10(-16)M concentration. Prepared samples were able to detect lower concentrations of Melamine. Discontinuous thin films with hierarchical Ag nanostructures were obtained for 5min Ag deposition. The formation of Hot spots between the discontinuous islands and also along the hierarchical structures is responsible for the high SERS enhancement. This simple one step, fast, non-lithographic and cost effective method can be applied for various label free detection of analytes of importance.

  18. One-step hydrotreatment of vegetable oil to produce high quality diesel-range alkanes.

    PubMed

    Wang, Congxin; Tian, Zhijian; Wang, Lei; Xu, Renshun; Liu, Qianhe; Qu, Wei; Ma, Huaijun; Wang, Bingchun

    2012-10-01

    A one-step hydrotreatment of vegetable oil combining deoxygenation and isomerization to directly produce low cloud point, high quality diesel is devised. The Pt/zeolite bifunctional catalysts prepared by using SAPO-11 and ZSM-22 zeolites as supports are used in this process. Catalytic reactions are conducted in a fixed-bed reactor under a hydrogen atmosphere. Over the bifunctional catalyst, 100 % conversion of soybean oil is obtained at 357 °C, 4 MPa, and 1 h(-1), and 80 % organic liquid yield is achieved, which is close to the maximum theoretical liquid yield. In the organic products, the alkanes selectivity is 100 % with an i-alkanes selectivity above 63 %. NH(3)-temperature programmed desorption (TPD), pyridine IR spectroscopy, and other characterization techniques are used to study the effect of the support acidity on the reaction pathway. Over the Pt/zeolite bifunctional catalyst with less strong Lewis acid sites, the reaction proceeds via the decarboxylation plus decarbonylation pathway. This one-step method provides a new strategy to produce low cloud point, high quality diesel from biomass feedstock in a more economic and attractive way. PMID:22764086

  19. General transient solution of the one-step master equation in one dimension.

    PubMed

    Smith, Stephen; Shahrezaei, Vahid

    2015-06-01

    Exact analytical solutions of the master equation are limited to special cases and exact numerical methods are inefficient. Even the generic one-dimensional, one-step master equation has evaded exact solution, aside from the steady-state case. This type of master equation describes the dynamics of a continuous-time Markov process whose range consists of positive integers and whose transitions are allowed only between adjacent sites. The solution of any master equation can be written as the exponential of a (typically huge) matrix, which requires the calculation of the eigenvalues and eigenvectors of the matrix. Here we propose a linear algebraic method for simplifying this exponential for the general one-dimensional, one-step process. In particular, we prove that the calculation of the eigenvectors is actually not necessary for the computation of exponential, thereby we dramatically cut the time of this calculation. We apply our new methodology to examples from birth-death processes and biochemical networks. We show that the computational time is significantly reduced compared to existing methods.

  20. One step 'dip' and 'use' Ag nanostructured thin films for ultrahigh sensitive SERS Detection.

    PubMed

    Rajkumar, Kanakaraj; Jayram, Naidu Dhanpal; Mangalaraj, Devanesan; Rajendra Kumar, Ramasamy Thangavelu

    2016-11-01

    A simple one step galvanic displacement method which involves dipping of the silicon substrate in the AgNO3/HF solution and using it for SERS application without any further process is demonstrated. The size and shape of the Ag nanoparticles changes as the deposition time is increased. Initially the shape of the particles was nearly spherical and as it grows, becomes oblong and then coalesce to form a discontinuous film with vertically grown hierarchical Ag nanostructures. The sizes of the deposited particles were in the ranges from 30nm to a discontinuous film. It also demonstrated a highly sensitive chemical detection by surface-enhanced Raman scattering of rhodamine 6G dye, down to 10(-16)M concentration. Prepared samples were able to detect lower concentrations of Melamine. Discontinuous thin films with hierarchical Ag nanostructures were obtained for 5min Ag deposition. The formation of Hot spots between the discontinuous islands and also along the hierarchical structures is responsible for the high SERS enhancement. This simple one step, fast, non-lithographic and cost effective method can be applied for various label free detection of analytes of importance. PMID:27524085

  1. Transparent, superhydrophobic surfaces from one-step spin coating of hydrophobic nanoparticles.

    PubMed

    Xu, Lebo; Karunakaran, Raghuraman G; Guo, Jia; Yang, Shu

    2012-02-01

    We study the nonwettability and transparency from the assembly of fluorosilane modified silica nanoparticles (F-SiO(2) NPs) via one-step spin-coating and dip-coating without any surface postpassivation steps. When spin-coating the hydrophobic NPs (100 nm in diameter) at a concentration ≥ 0.8 wt % in a fluorinated solvent, the surface exhibited superhydrophobicity with an advancing water contact angle greater than 150° and a water droplet (5 μL) roll-off angle less than 5°. In comparison, superhydrophobicity was not achieved by dip-coating the same hydrophobic NPs. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images revealed that NPs formed a nearly close-packed assembly in the superhydrophobic films, which effectively minimized the exposure of the underlying substrate while offering sufficiently trapped air pockets. In the dip-coated films, however, the surface coverage was rather random and incomplete. Therefore, the underlying substrate was exposed and water was able to impregnate between the NPs, leading to smaller water contact angle and larger water contact angle hysteresis. The spin-coated superhydrophobic film was also highly transparent with greater than 95% transmittance in the visible region. Further, we demonstrated that the one-step coating strategy could be extended to different polymeric substrates, including poly(methyl methacrylate) and polyester fabrics, to achieve superhydrophobicity.

  2. One-step solution immersion process to fabricate superhydrophobic surfaces on light alloys.

    PubMed

    Ou, Junfei; Hu, Weihua; Xue, Mingshan; Wang, Fajun; Li, Wen

    2013-10-23

    A simple and universal one-step process bas been developed to render light alloys (including AZ91D Mg alloy, 5083 Al alloy, and TC4 Ti alloy) superhydrophobic by immersing the substrates in a solution containing low-surface-energy molecules of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS, 20 μL), ethanol (10 mL), and H2O (10 mL for Al and Mg alloy)/H2O2 (15%, 10 mL for Ti alloy). Field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and water contact angle measurements have been performed to characterize the morphological features, chemical composition, and wettability of the surfaces, respectively. The results indicate that the treated light alloys are rough-structured and covered by PFOTS molecules; consequently, the surfaces show static contact angles higher than 150° and sliding angles lower than 10°. This research reveals that it is feasible to fabricate superhydrophobic surfaces (SHS) easily and effectively without involving the traditional two-step processes. Moreover, this one-step process may find potential application in the field of industrial preparation of SHS because of its simplicity and universality.

  3. One-step fabrication of near superhydrophobic aluminum surface by nanosecond laser ablation

    NASA Astrophysics Data System (ADS)

    Jagdheesh, R.; García-Ballesteros, J. J.; Ocaña, J. L.

    2016-06-01

    Inspired by the micro and nano structures of biological surface such as lotus leaf, rice leaves, etc. a functional near superhydrophobic surface of pure aluminum has been fabricated using one-step nanosecond laser processing. Thin aluminum sheets are micro-patterned with ultraviolet laser pulses to create near superhydrophobic surface in one-step direct laser writing technique. The impact of number of pulses/microhole with respect to the geometry and static contact angle measurements has been investigated. The microstructure shows the formation of blind microholes along with the micro-wall by laser processing, which improves the composite interface between the three phases such as water, air and solid, thus enhance the wetting property of the surface. The geometrical changes are supported by the chemical changes induced on the surface for improving the degree of hydrophobicity. Laser processed microholes exhibited near superhydrophobic surface with SCA measurement of 148 ± 3°. The static contact angle values are very consistent for repeated measurement at same area and across the laser patterned surface.

  4. One-step synthesis of nitrogen-iron coordinated carbon nanotube catalysts for oxygen reduction reaction

    NASA Astrophysics Data System (ADS)

    Choi, Woongchul; Yang, Gang; Kim, Suk Lae; Liu, Peng; Sue, Hung-Jue; Yu, Choongho

    2016-05-01

    Prohibitively expensive precious metal catalysts for oxygen reduction reaction (ORR) have been one of the major hurdles in a wide use of electrochemical cells. Recent significant efforts to develop precious metal free catalysts have resulted in excellent catalytic activities. However, complicated and time-consuming synthesis processes have negated the cost benefit. Moreover, detailed analysis about catalytically active sites and the role of each element in these high-performance catalysts containing nanomaterials for large surface areas are often lacking. Here we report a facile one-step synthesis method of nitrogen-iron coordinated carbon nanotube (CNT) catalysts without precious metals. Our catalysts show excellent long-term stability and onset ORR potential comparable to those of other precious metal free catalysts, and the maximum limiting current density from our catalysts is larger than that of the Pt-based catalysts. We carry out a series of synthesis and characterization experiments with/without iron and nitrogen in CNT, and identify that the coordination of nitrogen and iron in CNT plays a key role in achieving the excellent catalytic performances. We anticipate our one-step process could be used for mass production of precious metal free electrocatalysts for a wide range of electrochemical cells including fuel cells and metal-air batteries.

  5. Ratiometric electrochemical proximity assay for sensitive one-step protein detection

    NASA Astrophysics Data System (ADS)

    Ren, Kewei; Wu, Jie; Yan, Feng; Ju, Huangxian

    2014-03-01

    This work proposes the concept of ratiometric electrochemical proximity assay (REPA), which can be used for one-step, highly sensitive and selective detection of protein. The assay strategy was achieved on a sensing interface that was formed by hybridization of methylene blue (MB)-labeled antibody-DNA probe (MB-DNA1-Ab1) with ferrocene (Fc)-labeled DNA capture probe (Fc-P) modified gold electrode. On the interface the target protein could trigger the formation of immunocomplex between MB-DNA1-Ab1 and detection antibody-DNA probe (Ab2-DNA2) and subsequently the proximity hybridization of DNA1-DNA2, which led to the departure of MB-DNA1-Ab1 from the interface. The remained Fc-P could form a hairpin structure to take Fc group to electrode surface. Therefore, the recognition of target protein to Ab1 and Ab2 resulted in both the ``signal-off'' of MB and the ``signal-on'' of Fc for dual-signal electrochemical ratiometric readout. The proposed REPA could be carried out in one-step with 40-min duration and showed a wide detection range from 0.05 to 100 ng/mL with pg/mL limit of detection, displaying great potential for convenient point-of-care testing and commercial application.

  6. One-step electrodeposition of graphene loaded nickel oxides nanoparticles for acetaminophen detection.

    PubMed

    Liu, Gui-Ting; Chen, Hui-Fen; Lin, Guo-Ming; Ye, Ping-ping; Wang, Xiao-Ping; Jiao, Ying-Zhi; Guo, Xiao-Yu; Wen, Ying; Yang, Hai-Feng

    2014-06-15

    An electrochemical sensor of acetaminophen (AP) based on electrochemically reduced graphene (ERG) loaded nickel oxides (Ni2O3-NiO) nanoparticles coated onto glassy carbon electrode (ERG/Ni2O3-NiO/GCE) was prepared by a one-step electrodeposition process. The as-prepared electrode was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The electrocatalytic properties of ERG/Ni2O3-NiO modified glassy carbon electrode toward the oxidation of acetaminophen were analyzed via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrodes of Ni2O3-NiO/GCE, ERG/GCE, and Ni2O3-NiO deposited ERG/GCE were fabricated for the comparison and the catalytic mechanism understanding. The studies showed that the one-step prepared ERG/Ni2O3-NiO/GCE displayed the highest electro-catalytic activity, attributing to the synergetic effect derived from the unique composite structure and physical properties of nickel oxides nanoparticles and graphene. The low detection limit of 0.02 μM (S/N=3) with the wide linear detection range from 0.04 μM to 100 μM (R=0.998) was obtained. The resulting sensor was successfully used to detect acetaminophen in commercial pharmaceutical tablets and urine samples.

  7. Statistical analysis of cellular detonation dynamics from numerical simulations: one-step chemistry

    NASA Astrophysics Data System (ADS)

    Sharpe, G. J.; Radulescu, M. I.

    2011-10-01

    In this paper, two methods are developed for statistically analysing the nonlinear cellular dynamics from numerical simulations of gaseous detonations, one use of which is the systematic determination of detonation cell sizes from such simulations. Both these methods rely on signed vorticity records in which the individual families of transverse waves are captured independently. The first method involves an automated extraction of the main triple-point tracks from the vorticity records, allowing statistical analysis of the spacings between neighbouring tracks. The second method uses the autocorrelation function to spectrally analyse the vorticity records. These methods are then employed for a preliminary analysis of the cellular dynamics of the standard, idealized one-step chemistry model. Evidence is found for 'cell size doubling' bifurcations in the one-step model as the cellular dynamics become more irregular (e.g. as the activation is increased). It is also shown that the statistical models converge slowly due to systematic 'shot-to-shot' variation in the cellular dynamics for fixed parameters with different initial perturbations. Instead, it appears that a range of equally probable cell sizes can be obtained for given parameters.

  8. A simple one-step chemistry model for partially premixed hydrocarbon combustion

    SciTech Connect

    Fernandez-Tarrazo, Eduardo; Sanchez, Antonio L.; Linan, Amable; Williams, Forman A.

    2006-10-15

    This work explores the applicability of one-step irreversible Arrhenius kinetics with unity reaction order to the numerical description of partially premixed hydrocarbon combustion. Computations of planar premixed flames are used in the selection of the three model parameters: the heat of reaction q, the activation temperature T{sub a}, and the preexponential factor B. It is seen that changes in q with equivalence ratio f need to be introduced in fuel-rich combustion to describe the effect of partial fuel oxidation on the amount of heat released, leading to a universal linear variation q(f) for f>1 for all hydrocarbons. The model also employs a variable activation temperature T{sub a}(f) to mimic changes in the underlying chemistry in rich and very lean flames. The resulting chemistry description is able to reproduce propagation velocities of diluted and undiluted flames accurately over the whole flammability limit. Furthermore, computations of methane-air counterflow diffusion flames are used to test the proposed chemistry under nonpremixed conditions. The model not only predicts the critical strain rate at extinction accurately but also gives near-extinction flames with oxygen leakage, thereby overcoming known predictive limitations of one-step Arrhenius kinetics. (author)

  9. Parallel p-n junctions across nanowires by one-step ex situ doping.

    PubMed

    Hazut, Ori; Huang, Bo-Chao; Pantzer, Adi; Amit, Iddo; Rosenwaks, Yossi; Kohn, Amit; Chang, Chia-Seng; Chiu, Ya-Ping; Yerushalmi, Roie

    2014-08-26

    The bottom-up synthesis of nanoscale building blocks is a versatile approach for the formation of a vast array of materials with controlled structures and compositions. This approach is one of the main driving forces for the immense progress in materials science and nanotechnology witnessed over the past few decades. Despite the overwhelming advances in the bottom-up synthesis of nanoscale building blocks and the fine control of accessible compositions and structures, certain aspects are still lacking. In particular, the transformation of symmetric nanostructures to asymmetric nanostructures by highly controlled processes while preserving the modified structural orientation still poses a significant challenge. We present a one-step ex situ doping process for the transformation of undoped silicon nanowires (i-Si NWs) to p-type/n-type (p-n) parallel p-n junction configuration across NWs. The vertical p-n junctions were measured by scanning tunneling microscopy (STM) in concert with scanning tunneling spectroscopy (STS), termed STM/S, to obtain the spatial electronic properties of the junction formed across the NWs. Additionally, the parallel p-n junction configuration was characterized by off-axis electron holography in a transmission electron microscope to provide an independent verification of junction formation. The doping process was simulated to elucidate the doping mechanisms involved in the one-step p-i-n junction formation.

  10. One-step synthesis of hierarchically porous carbons for high-performance electric double layer supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhang, Haitao; Zhang, Lei; Chen, Jun; Su, Hai; Liu, Fangyan; Yang, Weiqing

    2016-05-01

    With plenty of unique porous structure at micro-/nano scale, hierarchically porous carbons (HPCs) are promising for usage in advanced electric double layer supercapacitors (EDLCs) as the electrode materials. However, wide-range adoption of HPC for practical application is largely shadowed by its extremely complex synthesis process with considerably low production efficiency. Herein we reported a simple template-free, one-step sintering method, to massively produce the HPCs for high-performance EDLCs. Resorting to the 3D structure modification of the wide pore size distribution, high surface area of HPCs (up to 3000 m2 g-1) was achieved. By using 1 M Na2SO4 as electrolyte, the as-fabricated HPCs based EDLCs can be operated reversibly over a wide voltage window of 1.6 V with superior specific capacitance of 240 F g-1 under a current density of 0.5 A g-1. In the meanwhile, the EDLCs exhibit excellent rate capability (high power density of 16 kW kg-1 at 10.2 Wh kg-1) and long-term cycling stability with 9% loss of its initial capacitance after 2000 cycles. This output performance distinguished itself among most of the carbon-based EDLCs with neutral aqueous electrolyte. Thus, the template-free one-step sintering method produced HPCs for EDLCs represents a new approach for high-performance energy storage.

  11. Development of one-step real-time PCR assay for titrating trivalent live attenuated influenza vaccines.

    PubMed

    Zang, Yang; Du, Dongchuan; Ge, Peng; Xu, Yongqing; Liu, Xintao; Zhang, Yan; Su, Weiheng; Kiseleva, Irina; Rudenko, Larisa; Xu, Fei; Kong, Wei; Jiang, Chunlai

    2014-01-01

    Traditionally, infectivity of a trivalent live attenuated influenza vaccines (LAIVs) is titrated by determining the 50% egg infectious dose assay (EID50) or plaque forming units (PFU), which requires specific monoclonal antibodies to neutralize 2 strains while estimating the titer of the non-neutralized strain. Compared to this time-consuming, laborious, subjective and variable process, reverse transcription-quantitative real-time PCR (RT-qPCR) technology has advantages of rapidity, sensitivity, reproducibility and reduced contamination, thus has been applied widely for detecting pathogens and measuring viral titers. In this study, the critical harvest time was determined to be 18 h post-infection (hpi) for type A influenza and 12 hpi for type B influenza, but no significant difference between titers at 12 hpi and 18 hpi for the type B strain was observed. In conclusion, trivalent LAIVs can be titrated simultaneously within 24 h by this one-step RT-qPCR assay, which yielded titers comparable to those obtained by the traditional EID50 assay. Therefore, the RT-qPCR assay may be used as a highly specific, sensitive, precise and rapid alternative to the EID50 assay for titering LAIVs.

  12. Ultraporous superhydrophobic gas-permeable nano-layers by scalable solvent-free one-step self-assembly.

    PubMed

    Liu, Guanyu; Wong, William S Y; Nasiri, Noushin; Tricoli, Antonio

    2016-03-21

    Superhydrophobic materials with excellent humidity tolerance, high porosity and light transmittance are being investigated for numerous applications including moisture-sensitive catalysts and perovskite solar cells. Here, we report the one-step solvent-free synthesis of ultraporous superhydrophobic nano-layers by the on-the-fly functionalization of nanoparticle aerosols. Short exposure of surfaces to hot Mn3O4, ZnO and TiO2 aerosols results in ultraporous nanoparticle networks with repulsive dewetting state approaching ideal Cassie-Baxter superhydrophobicity. In addition to showcasing sliding angles of ca. 0° and very low contact angle hysteresis of 3° ± 2°, these optimal nano-layers have up to 98% porosity and pore size of several micrometres, a key feature to enable efficient penetration of gases to the substrate surface. The stability of this ultraporous superhydrophobic morphology is demonstrated by rapidly applying Moses effect-functionality to substrates that parts water up to 5 mm high. This scalable synthesis method offers a flexible and rapid approach for the production of numerous moisture-resistant devices including gas sensors, catalysts and perovskite solar cells.

  13. Simple, specific molecular typing of dengue virus isolates using one-step RT-PCR and restriction fragment length polymorphism.

    PubMed

    Ortiz, Alma; Capitan, Zeuz; Mendoza, Yaxelis; Cisneros, Julio; Moreno, Brechla; Zaldivar, Yamitzel; Garcia, Mariana; Smith, Rebecca E; Motta, Jorge; Pascale, Juan Miguel

    2012-10-01

    A one-step RT-PCR and one-enzyme RFLP was used to detect and distinguish among flaviviruses, including the four serotypes of dengue and the St. Louis Encephalitis, West Nile and Yellow Fever viruses in cultured virus samples or acute-phase human serum. Using a previously described RT-PCR, but novel RFLP procedure, results are obtained in 24 h with basic PCR and electrophoresis equipment. There is 95% agreement between RT-PCR/RFLP results and those achieved by indirect immunofluorescence assays, and 100% agreement between RT-PCR/RFLP results and gene sequencing. This method is more rapid than tests of cytopathic effect based on virus isolation in tissue culture, and simpler than real-time PCR. It does not require specialized equipment, radioisotopes or computer analysis and is a method that can be applied widely in the developing world. It allows for prompt determination of whether a flavivirus is the cause of illness in a febrile patient, rapid identification of dengue serotypes in circulation, and improved patient management in cases where prior dengue exposure make dengue hemorrhagic fever or dengue shock syndrome a risk.

  14. Microwave Enabled One-Pot, One-Step Fabrication and Nitrogen Doping of Holey Graphene Oxide for Catalytic Applications.

    PubMed

    Patel, Mehulkumar; Feng, Wenchun; Savaram, Keerthi; Khoshi, M Reza; Huang, Ruiming; Sun, Jing; Rabie, Emann; Flach, Carol; Mendelsohn, Richard; Garfunkel, Eric; He, Huixin

    2015-07-15

    The unique properties of a holey graphene sheet, referred to as a graphene sheet with nanoholes in its basal plane, lead to wide range of applications that cannot be achieved by its nonporous counterpart. However, the large-scale solution-based production requires graphene oxide (GO) or reduced GO (rGO) as the starting materials, which take hours to days for fabrication. Here, an unexpected discovery that GO with or without holes can be controllably, directly, and rapidly (tens of seconds) fabricated from graphite powder via a one-step-one-pot microwave assisted reaction with a production yield of 120 wt% of graphite is reported. Furthermore, a fast and low temperature approach is developed for simultaneous nitrogen (N) doping and reduction of GO sheets. The N-doped holey rGO sheets demonstrate remarkable electrocatalytic capabilities for the electrochemical oxygen reduction reaction. The existence of the nanoholes provides a "short cut" for efficient mass transport and dramatically increases edges and surface area, therefore, creates more catalytic centers. The capability of rapid fabrication and N-doping as well as reduction of holey GO can lead to development of an efficient catalyst that can replace previous coin metals for energy generation and storage, such as fuel cells and metal-air batteries. PMID:25683019

  15. Microwave Enabled One-Pot, One-Step Fabrication and Nitrogen Doping of Holey Graphene Oxide for Catalytic Applications.

    PubMed

    Patel, Mehulkumar; Feng, Wenchun; Savaram, Keerthi; Khoshi, M Reza; Huang, Ruiming; Sun, Jing; Rabie, Emann; Flach, Carol; Mendelsohn, Richard; Garfunkel, Eric; He, Huixin

    2015-07-15

    The unique properties of a holey graphene sheet, referred to as a graphene sheet with nanoholes in its basal plane, lead to wide range of applications that cannot be achieved by its nonporous counterpart. However, the large-scale solution-based production requires graphene oxide (GO) or reduced GO (rGO) as the starting materials, which take hours to days for fabrication. Here, an unexpected discovery that GO with or without holes can be controllably, directly, and rapidly (tens of seconds) fabricated from graphite powder via a one-step-one-pot microwave assisted reaction with a production yield of 120 wt% of graphite is reported. Furthermore, a fast and low temperature approach is developed for simultaneous nitrogen (N) doping and reduction of GO sheets. The N-doped holey rGO sheets demonstrate remarkable electrocatalytic capabilities for the electrochemical oxygen reduction reaction. The existence of the nanoholes provides a "short cut" for efficient mass transport and dramatically increases edges and surface area, therefore, creates more catalytic centers. The capability of rapid fabrication and N-doping as well as reduction of holey GO can lead to development of an efficient catalyst that can replace previous coin metals for energy generation and storage, such as fuel cells and metal-air batteries.

  16. Development of a chamber system for rapid, high yield and cost-effective purification of deoxyribonucleic acid fragments from agarose gel

    PubMed Central

    Eslami, Gilda; Salehi, Rasoul

    2014-01-01

    Background: There are several methods commonly practicing for deoxyribonucleic acid (DNA) purification from agarose gel. In most laboratories, especially in developing countries, present methods for recovering of DNA fragments from the gel are mostly involved organic solvents. However, manual purification using organic solvents are toxic, labor intensive, time consuming and prone to contamination owing to several handling steps. The above mentioned burdens as well as cost and long time to import them, especially in developing countries, prompted us to design and develop a chamber system for rapid, non-toxic, cost-effective and user friendly device for polymerase chain reaction (PCR) products purification from agarose gel. Materials and Methods: The device was made from plexiglass plates. After amplification of two fragments of 250 and 850 bp, PCR products were electrophoresed. Subsequently, the desired bands were excised and purified with three method: HiPer Mini chamber, phenol extraction method and spin column procedure. To assess the suitability of the purified DNAs, restriction digestion was applied. Results: Results showed that the yield of recovered DNA in our method was above 95%, whereas the yields obtained with conventional phenol extraction and spin column methods were around 60%. Conclusion: In conclusion, the current method for DNA elution is quick, inexpensive and robust and it does not require the use of toxic organic solvents. In addition, the purified DNA was well has suited for further manipulations such as restriction digestion, ligation, cloning, sequencing and hybridization. PMID:24761386

  17. Facile One-Step Strategy for Highly Boosted Microbial Extracellular Electron Transfer of the Genus Shewanella.

    PubMed

    Wang, Yuan; Lv, Meiling; Meng, Qingan; Ding, Chunmei; Jiang, Lei; Liu, Huan

    2016-06-28

    High performance of bacterial extracellular electron transfer (EET) is essentially important for its practical applications in versatile bioelectric fields. We developed a facile one-step approach to dramatically boost the bacterial EET activity 75-fold by exogenous addition of ethylenediamine tetraacetic acid disodium salt (EDTA-2Na, 1 mM) into the electrochemical cells, where the anodic process of microbial EET was monitored. We propose that EDTA-2Na enables both the alternation of the local environment around the c-type cytochromes located on the outer membrane channels (OMCs), which therefore changes the redox behavior of OMCs in mediating the EET process, and the formation of densely packed biofilm that can further facilitate the EET process. As a synergistic effect, the highly boosted bacterial EET activity was achieved. The method shows good generality for versatile bioelectrical bacteria. We envision that the method is also applicable for constructing various bioelectric devices. PMID:27196945

  18. Fluorinated alkyne-derived monolayers on oxide-free silicon nanowires via one-step hydrosilylation

    NASA Astrophysics Data System (ADS)

    Nguyen Minh, Quyen; Pujari, Sidharam P.; Wang, Bin; Wang, Zhanhua; Haick, Hossam; Zuilhof, Han; van Rijn, Cees J. M.

    2016-11-01

    Passivation of oxide-free silicon nanowires (Si NWs) by the formation of high-quality fluorinated 1-hexadecyne-derived monolayers with varying fluorine content has been investigated. Alkyl chain monolayers (C16H30-xFx) with a varying number of fluorine substituents (x = 0, 1, 3, 9, 17) were attached onto hydrogen-terminated silicon (Sisbnd H) surfaces with an effective one-step hydrosilylation. This surface chemistry gives well-defined monolayers on nanowires that have a cylindrical core-shell structure, as characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and static contact angle (SCA) analysis. The monolayers were stable under acidic and basic conditions, as well as under extreme conditions (such as UV exposure), and provide excellent surface passivation, which opens up applications in the fields of field effect transistors, optoelectronics and especially for disease diagnosis.

  19. One-step preparation of multiwall carbon nanotube/silicon hybrids for solar energy conversion

    NASA Astrophysics Data System (ADS)

    Lobiak, Egor V.; Bychanok, Dzmitry S.; Shlyakhova, Elena V.; Kuzhir, Polina P.; Maksimenko, Sergey A.; Bulusheva, Lyubov G.; Okotrub, Alexander V.

    2016-03-01

    The hybrid material consisting of a thin layer of multiwall carbon nanotubes (MWCNTs) on an n-doped silicon wafer was obtained in one step using an aerosol-assisted catalytic chemical vapor deposition. The MWCNTs were grown from a mixture of acetone and ethanol with ˜0.2 wt.% of iron polyoxomolybdate nanocluster of the keplerate-type structure. The samples produced at 800°C and 1050°C were tested as a solar energy converter. It was shown that photoresponse of the hybrid material significantly depends on the presence of structural defects in MWCNTs, being much higher in the case of more defective nanotubes. This is because defects lead to p-doping of nanotubes, whereas the p-n heterojunction between MWCNTs and silicon provides a high efficiency of the solar cell.

  20. One step sintering of homogenized bauxite raw material and kinetic study

    NASA Astrophysics Data System (ADS)

    Gao, Chang-he; Jiang, Peng; Li, Yong; Sun, Jia-lin; Zhang, Jun-jie; Yang, Huan-ying

    2016-10-01

    A one-step sintering process of bauxite raw material from direct mining was completed, and the kinetics of this process was analyzed thoroughly. The results show that the sintering kinetics of bauxite raw material exhibits the liquid-phase sintering behavior. A small portion of impurities existed in the raw material act as a liquid phase. After X-ray diffraction analyses, scanning electron microscopy observations, and kinetics calculations, sintering temperature and heating duration were determined as the two major factors contributing to the sintering process and densification of bauxite ore. An elevated heating temperature and longer duration favor the densification process. The major obstacle for the densification of bauxite material is attributed to the formation of the enclosed blowhole during liquid-phase sintering.

  1. Thread-like supercapacitors based on one-step spun nanocomposite yarns.

    PubMed

    Meng, Qinghai; Wang, Kai; Guo, Wei; Fang, Jin; Wei, Zhixiang; She, Xilin

    2014-08-13

    Thread-like electronic devices have attracted great interest because of their potential applications in wearable electronics. To produce high-performance, thread-like supercapacitors, a mixture of stable dispersions of single-walled carbon nanotubes and conducting polyaniline nanowires are prepared. Then, the mixture is spun into flexible yarns with a polyvinyl alcohol outer sheath by a one-step spinning process. The composite yarns show excellent mechanical properties and high electrical conductivities after sufficient washing to remove surfactants. After applying a further coating layer of gel electrolyte, two flexible yarns are twisted together to form a thread-like supercapacitor. The supercapacitor based on these two yarns (SWCNTs and PAniNWs) possesses a much higher specific capacitance than that based only on pure SWCNTs yarns, making it an ideal energy-storage device for wearable electronics. PMID:24729355

  2. One-step semisynthesis of oleacein and the determination as a 5-lipoxygenase inhibitor.

    PubMed

    Vougogiannopoulou, Konstantina; Lemus, Christelle; Halabalaki, Maria; Pergola, Carlo; Werz, Oliver; Smith, Amos B; Michel, Sylvie; Skaltsounis, Leandros; Deguin, Brigitte

    2014-03-28

    The dialdehydes oleacein (2) and oleocanthal (4) are closely related to oleuropein (1) and ligstroside (3), the two latter compounds being abundant iridoids of Olea europaea. By exploiting oleuropein isolated from the plant leaf extract, an efficient procedure has been developed for a one-step semisynthesis of oleacein under Krapcho decarbomethoxylation conditions. Highlighted is the fact that 5-lipoxygenase is a direct target for oleacein with an inhibitory potential (IC50: 2 μM) more potent than oleocanthal (4) and oleuropein (1). This enzyme catalyzes the initial steps in the biosynthesis of pro-inflammatory leukotrienes. Taken together, the methodology presented here offers an alternative solution to isolation or total synthesis for the procurement of oleacein, thus facilitating the further development as a potential anti-inflammatory agent. PMID:24568174

  3. Cellulose acetate from oil palm empty fruit bunch via a one step heterogeneous acetylation.

    PubMed

    Wan Daud, Wan Rosli; Djuned, Fauzi Muhammad

    2015-11-01

    Acetone soluble oil palm empty fruit bunch cellulose acetate (OPEFB-CA) of DS 2.52 has been successfully synthesized in a one-step heterogeneous acetylation of OPEFB cellulose without necessitating the hydrolysis stage. This has only been made possible by the mathematical modeling of the acetylation process by manipulating the variables of reaction time and acetic anhydride/cellulose ratio (RR). The obtained model was verified by experimental data with an error of less than 2.5%. NMR analysis showed that the distribution of the acetyl moiety among the three OH groups of cellulose indicates a preference at the C6 position, followed by C3 and C2. XRD revealed that OPEFB-CA is highly amorphous with a degree of crystallinity estimated to be ca. 6.41% as determined from DSC. The OPEFB-CA films exhibited good mechanical properties being their tensile strength and Young's modulus higher than those of the commercial CA. PMID:26256348

  4. One-step hydrothermal synthesis of carboxyl-functionalized upconversion phosphors for bioapplications.

    PubMed

    Yang, Jianping; Shen, Dengke; Li, Xiaomin; Li, Wei; Fang, Yin; Wei, Yong; Yao, Chi; Tu, Bo; Zhang, Fan; Zhao, Dongyuan

    2012-10-22

    In this paper, we report a facile one-step hydrothermal method to synthesize phase-, size-, and shape-controlled carboxyl-functionalized rare-earth fluorescence upconversion phosphors by using a small-molecule binary acid, such as malonic acid, oxalic acid, succinic acid, or tartaric acid as capping agent. The crystals, from nano- to microstructures with diverse shapes that include nanospheres, microrods, hexagonal prisms, microtubes, microdisks, polygonal columns, and hexagonal tablets, can be obtained with different reaction times, reaction temperatures, molar ratios of capping agent to sodium hydroxide, and by varying the binary acids. Fourier transform infrared, thermogravimetric analysis, and upconversion luminescence spectra measurements indicate that the synthesized NaYF(4):Yb/Er products with hydrophilic carboxyl-functionalized surface offer efficient upconversion luminescent performance. Furthermore, the antibody/secondary antibody conjugation can be realized by the carboxyl-functionalized surfaces of the upconversion phosphors, thus indicating the potential bioapplications of these kinds of materials.

  5. Efficient hydrogen evolution in transition metal dichalcogenides via a simple one-step hydrazine reaction

    PubMed Central

    Cummins, Dustin R.; Martinez, Ulises; Sherehiy, Andriy; Kappera, Rajesh; Martinez-Garcia, Alejandro; Schulze, Roland K.; Jasinski, Jacek; Zhang, Jing; Gupta, Ram K.; Lou, Jun; Chhowalla, Manish; Sumanasekera, Gamini; Mohite, Aditya D.; Sunkara, Mahendra K.; Gupta, Gautam

    2016-01-01

    Hydrogen evolution reaction is catalysed efficiently with precious metals, such as platinum; however, transition metal dichalcogenides have recently emerged as a promising class of materials for electrocatalysis, but these materials still have low activity and durability when compared with precious metals. Here we report a simple one-step scalable approach, where MoOx/MoS2 core-shell nanowires and molybdenum disulfide sheets are exposed to dilute aqueous hydrazine at room temperature, which results in marked improvement in electrocatalytic performance. The nanowires exhibit ∼100 mV improvement in overpotential following exposure to dilute hydrazine, while also showing a 10-fold increase in current density and a significant change in Tafel slope. In situ electrical, gate-dependent measurements and spectroscopic investigations reveal that hydrazine acts as an electron dopant in molybdenum disulfide, increasing its conductivity, while also reducing the MoOx core in the core-shell nanowires, which leads to improved electrocatalytic performance. PMID:27282871

  6. Corrosion Properties of Polydopamine Coatings Formed in One-Step Immersion Process on Magnesium.

    PubMed

    Singer, Ferdinand; Schlesak, Magdalena; Mebert, Caroline; Höhn, Sarah; Virtanen, Sannakaisa

    2015-12-01

    Polydopamine layers were polymerized directly from Tris(hydroxymethyl)aminomethane-buffered solution in a one-step immersion process onto magnesium surface. Scanning electron microscopy showed successful formation of a ∼1 μm thick layer. ASTM D3359-09 "Tape test" revealed excellent adhesion of the layer. X-ray induced photoelectron spectroscopy and Fourier transform infrared spectroscopy verified the presence of polydopamine on the surface. Corrosion measurements were performed in 0.1 M NaCl solution investigating the influence of coating parameters: dopamine concentration, immersion time, solution pH, and immersion angle. Tafel analysis revealed strong improvement of corrosion behavior compared to bare magnesium. Polydopamine layers prepared with optimized coating procedure showed promising corrosion properties in Dulbecco's modified Eagle medium. In summary, polydopamine coatings offer a simple treatment for magnesium to improve the corrosion behavior and could further act as intermediate layer for further surface functionalization. PMID:26561489

  7. Facile one-step photolithographic method for engineering hierarchically nano/microstructured transparent superamphiphobic surfaces.

    PubMed

    Li, Tingjie; Paliy, Maxim; Wang, Xiaolong; Kobe, Brad; Lau, Woon-Ming; Yang, Jun

    2015-05-27

    It is of great value to develop a simple, controllable, and scalable method of making superamphiphobic surfaces. Here we present a facile one-step photolithographic method to engineer superamphiphobic surfaces consisting of photoresist micropillars decorated with nanoparticles of the same photoresist. The surface or coating is optically transparent and versatile, and can be fabricated on a broad range of substrates including stretchable elastomers. During the development of the micropillar array, photoresist nanoparticles are spontaneously grown on the micropillars by a well-controlled emulsification process of the un-cross-linked residual photoresist. This creates a hierarchical structure with a re-entrant and convex morphology which is the key for superoleophobicity. The chemical bonding between the nanoparticles and the micropillars is strong producing a robust and durable coating. This facile method is scalable and industry-applicable for a variety of applications such as self-cleaning, antifouling, and deicing/antifrosting.

  8. One-step in situ biosynthesis of graphene oxide-bacterial cellulose nanocomposite hydrogels.

    PubMed

    Si, Hongjuan; Luo, Honglin; Xiong, Guangyao; Yang, Zhiwei; Raman, Sudha R; Guo, Ruisong; Wan, Yizao

    2014-10-01

    Graphene oxide-bacterial cellulose (GO/BC) nanocomposite hydrogels with well-dispersed GO in the network of BC are successfully developed using a facile one-step in situ biosynthesis by adding GO suspension into the culture medium of BC. During the biosynthesis process, the crystallinity index of BC decreases and GO is partially reduced. The experimental results indicate that GO nanosheets are uniformly dispersed and well-bound to the BC matrix and that the 3D porous structure of BC is sustained. This is responsible for efficient load transfer between the GO reinforcement and BC matrix. Compared with the pure BC, the tensile strength and Young's modulus of the GO/BC nanocomposite hydrogel containing 0.48 wt% GO are significantly improved by about 38 and 120%, respectively. The GO/BC nanocomposite hydrogels are promising as a new material for tissue engineering scaffolds.

  9. Feature Extraction of One-step Ahead Daily Maximum Load with Regression Tree

    NASA Astrophysics Data System (ADS)

    Mori, Hiroyuki; Sakatani, Yoshinori; Fujino, Tatsurou; Numa, Kazuyuki

    In this paper, a new efficient feature extraction method is proposed to handle the one-step ahead daily maximum load forecasting. In recent years, power systems become more complicated under the deregulated and competitive environment. As a result, it is not easy to understand the cause and effect of short-term load forecasting with a bunch of data. This paper analyzes load data from a standpoint of data mining. By it we mean a technique that finds out rules or knowledge through large database. As a data mining method for load forecasting, this paper focuses on the regression tree that handles continuous variables and expresses a knowledge rule as if-then rules. Investigating the variable importance of the regression tree gives information on the transition of the load forecasting models. This paper proposes a feature extraction method for examining the variable importance. The proposed method allows to classify the transition of the variable importance through actual data.

  10. Optimizing Simplified One-Step Chemical Models for High Speed Reacting Flows

    NASA Astrophysics Data System (ADS)

    Ozgen, Alp; Houim, Ryan W.; Oran, Elaine S.

    2015-11-01

    One of the most important and difficult parts of constructing a multidimensional numerical simulation of a hydrocarbon reacting flow is finding a reliable and affordable model of the chemical and diffusive properties. Full detailed chemical models of these systems contain too many reactions and chemical species to be practical for realistic scenarios. The objective of our work is to create the simplest model possible that can reproduce the time-dependence of the energy input and the conversion from fuel to products. To that end, we are developing a procedure optimizing parameters in the most simplified ``one-step'' model. An important requirement of this model is that it reproduces known flame and detonation properties. Multidimensional numerical simulations using the new model are compared to deflagration-to-detonation experiments in channels containing ethylene and oxygen.

  11. Simple glucose reduction route for one-step synthesis of copper nanofluids

    NASA Astrophysics Data System (ADS)

    Shenoy, U. Sandhya; Shetty, A. Nityananda

    2014-01-01

    One-step method has been employed in the synthesis of copper nanofluids. Copper nitrate is reduced by glucose in the presence of sodium lauryl sulfate. The synthesized particles are characterized by X-ray diffraction technique for the phase structure; electron diffraction X-ray analysis for chemical composition; transmission electron microscopy and field emission scanning electron microscopy for the morphology; Fourier-transform infrared spectroscopy and ultraviolet-visible spectroscopy for the analysis of ingredients of the solution. Thermal conductivity, sedimentation and rheological measurements have also been carried out. It is found that the reaction parameters have considerable effect on the size of the particle formed and rate of the reaction. The techniques confirm that the synthesized particles are copper. The reported method showed promising increase in the thermal conductivity of the base fluid and is found to be reliable, simple and cost-effective method for preparing heat transfer fluids with higher stability.

  12. Hollow Block Copolymer Nanoparticles through a Spontaneous One-Step Structural Reorganization

    PubMed Central

    Petzetakis, Nikos; Robin, Mathew P.; Patterson, Joseph P.; Kelley, Elizabeth G.; Cotanda, Pepa; Bomans, Paul H. H.; Sommerdijk, Nico A. J. M.; Dove, Andrew P.; Epps, Thomas H.; O'Reilly, Rachel K.

    2013-01-01

    The spontaneous one-step synthesis of hollow nanocages and nanotubes from spherical and cylindrical micelles based on poly(acrylic acid)-b-polylactide (P(AA)-b-P(LA)) block copolymers (BCPs) has been achieved. This structural reorganization, which occurs simply upon drying of the samples, was elucidated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). We show that it was necessary to use stain-free imaging to examine these nanoscale assemblies, as the hollow nature of the particles was obscured by application of a heavy metal stain. Additionally, the internal topology of the P(AA)-b-P(LA) particles could be tuned by manipulating the drying conditions to give solid or compartmentalized structures. Upon re-suspension, these reorganized nanoparticles retain their hollow structure and can be display significantly enhanced loading of a hydrophobic dye compared to the original cylinders. PMID:23391297

  13. The use of enhanced polymer one-step staining reagents for immunoenzyme double-labelling.

    PubMed

    Van der Loos, C M; Naruko, T; Becker, A E

    1996-10-01

    The newly developed peroxidase-labelled Enhanced Polymer One-Step (EPOS) reagents were applied, together with an unlabelled primary mouse antibody, in a multistep double-labelling protocol. Enzyme label reporter combinations consisted of either peroxidase and alkaline phosphatase in red and blue, respectively, or beta-galactosidase and alkaline phosphatase in turquoise and red, respectively. The latter enzyme combination was introduced using a rabbit antiperoxidase antibody and an enzyme-labelled anti-rabbit immunoglobulin antibody. The multistep procedure was tested using five different antibody combinations on cryostat and Carnoy- or formalin-fixed, paraffin-embedded sections. In each instance, clear and distinct labelling was obtained, either with the two antigens at separate sites, or with an overlap in distribution. In the latter situation, the sites of co-localization were marked by mixed colours, which were distinct and readily discriminated from the two basic colours.

  14. Boron nitride colloidal solutions, ultralight aerogels and freestanding membranes through one-step exfoliation and functionalization

    NASA Astrophysics Data System (ADS)

    Lei, Weiwei; Mochalin, Vadym N.; Liu, Dan; Qin, Si; Gogotsi, Yury; Chen, Ying

    2015-11-01

    Manufacturing of aerogels and membranes from hexagonal boron nitride (h-BN) is much more difficult than from graphene or graphene oxides because of the poor dispersibility of h-BN in water, which limits its exfoliation and preparation of colloidal solutions. Here, a simple, one-step mechano-chemical process to exfoliate and functionalize h-BN into highly water-dispersible, few-layer h-BN containing amino groups is presented. The colloidal solutions of few-layer h-BN can have unprecedentedly high concentrations, up to 30 mg ml-1, and are stable for up to several months. They can be used to produce ultralight aerogels with a density of 1.4 mg cm-3, which is ~1,500 times less than bulk h-BN, and freestanding membranes simply by cryodrying and filtration, respectively. The material shows strong blue light emission under ultraviolet excitation, in both dispersed and dry state.

  15. One-step chemical synthesis of samarium telluride thin films and their supercapacitive properties

    NASA Astrophysics Data System (ADS)

    Kumbhar, V. S.; Lokhande, A. C.; Gaikwad, N. S.; Lokhande, C. D.

    2016-02-01

    The letter reports synthesis of samarium telluride (Sm2Te3) thin films through a one-step chemical route. The formation of Sm2Te3 is confirmed by X-ray diffraction and X-ray photoelectron spectroscopy studies. The surface morphological study is carried out using field emission scanning electron microscopy and contact angle measurement techniques. The film shows barley-like microstructure with an average length of barley of about 5 μm and diameter of about 300 nm. The Sm2Te3 film surface exhibits lyophilic nature with contact angle of 21.3° for propylene carbonate electrolyte. Cyclic voltammetry results revealed specific capacitance of 207 F g-1 with power density of 14.18 kW kg-1 in LiClO4-propylene carbonate electrolyte.

  16. One-step synthesis of magnetic chitosan for controlled release of 5-hydroxytryptophan

    NASA Astrophysics Data System (ADS)

    Santos Menegucci, Jucély dos; Santos, Mac-Kedson Medeiros Salviano; Dias, Diego Juscelino Santos; Chaker, Juliano Alexandre; Sousa, Marcelo Henrique

    2015-04-01

    In this work, nanoparticles of chitosan embedded with 25% (w/w) of iron oxide magnetic nanoparticles (magnetite/maghemite) with narrow size-distribution and with a loading efficiency of about 80% for 5-hydroxytryptophan (5-HTP), which is a chemical precursor in the biosynthesis of important neurotransmitters as serotonin, were synthesized with an initial mass ratio of 5-HTP/magnetic chitosan=1.2, using homogeneous precipitation by urea decomposition, in an efficient one-step procedure. Characterization of morphology, structure and surface were performed by XRD, TEM, FTIR, TGA, magnetization and zeta potential measurements, while drug loading and drug releasing were investigated using UV-vis spectroscopy. Kinetic drug release experiments under different pH conditions revealed a pH-sensitivecontrolled-release system, ruled by polymer swelling and/or particle dissolution.

  17. Facile fabrication of superhydrophobic surfaces on wood substrates via a one-step hydrothermal process

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Qing, Yan; Wu, Yiqiang; Liang, Jin; Luo, Sha

    2015-03-01

    Superhydrophobic nanocomposite surfaces were successfully fabricated on wood substrates via a one-step hydrothermal process. The morphology of the nanocomposite surfaces was characterized using scanning electron microscopy (SEM), and the elemental composition was determined via energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) analysis, and Fourier transform infrared (FTIR) spectroscopy. The results indicated that the crystallization of the anatase phase of TiO2 was prevented because of the presence of vinyltriethoxysilane [VTES, CH2CHSi(OC2H5)3] during the hydrothermal process. In addition, the nanocomposite contained Ti/Si particles with diameters ranging from 50 to 100 nm that thoroughly covered the wood substrate. Furthermore, the roughness coupled with the presence of low surface free energy groups led to superhydrophobicity; the static water contact angle (WCA) was as high as 153°, and the sliding angle was very low.

  18. One-step electro-spinning/netting technique for controllably preparing polyurethane nano-fiber/net.

    PubMed

    Hu, Juanping; Wang, Xianfeng; Ding, Bin; Lin, Jinyou; Yu, Jianyong; Sun, Gang

    2011-11-01

    Electro-spinning/netting (ESN) as a cutting-edge technique evokes much interest because of its ability in the one-step preparation of versatile nano-fiber/net (NFN) membranes. Here, a controllable fabrication of polyurethane (PU) NFN membranes with attractive structures, consisting of common electrospun nanofibers and two-dimensional (2D) soap bubble-like structured nano-nets via an ESN process is reported. The unique nanoscaled NFN architecture can be finely controlled by regulating the solution properties and several ESN process parameters. The versatile PU nano-nets comprising interlinked nanowires with ultrathin diameters (5-40 nm) mean that the NFN structured membranes possess several excellent characteristics, such as an extremely large specific surface area, high porosity and large stacking density, which would be particularly useful for applications in ultrafiltration, special protective clothing, ultrasensitive sensors, catalyst support and so on. PMID:21858891

  19. Microfluidic one-step synthesis of Fe₃O₄-chitosan composite particles and their applications.

    PubMed

    Yang, Chih-Hui; Wang, Chih-Yu; Huang, Keng-Shiang; Kung, Chao-Pin; Chang, Yi-Ching; Shaw, Jei-Fu

    2014-03-25

    This paper demonstrates a simple and easy approach for the one-step synthesis of Fe₃O₄-chitosan composite particles with tadpole-like shape. The length and diameter of the particles were adjustable from 638.3 μm to ca. 798 μm (length), and from 290 μm to 412 μm (diameter) by varying the flow rate of the dispersed phase. Mitoxantrone was used as the model drug in the drug release study. The encapsulation rate of the drug was 71% for chitosan particles, and 69% for magnetic iron oxide-chitosan particles, respectively. The iron oxide-chitosan composite particles had a faster release rate (up to 41.6% at the third hour) than the chitosan particles (about 24.6%). These iron oxide-chitosan composite particles are potentially useful for biomedical applications, such as magnetic responsive drug carriers, magnetic resonance imaging (MRI) enhancers, in the future.

  20. One-step electrochemical fabrication of bilayered MgO/polymer coating on magnesium alloy

    NASA Astrophysics Data System (ADS)

    Liang, Jun; Zhang, Ren-Hui; Peng, Zhen-Jun; Liu, Bai-Xing

    2014-09-01

    This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion (SAE) with pulsed DC voltage. The morphologies, XRD and FTIR results show that the bilayer coating consists of an inner oxide layer and an outer polyaniline (PANI)/SAE composite layer. It is believed that the bilayered structure achieved results from a hybrid process combining electropolymerization (EPM) of aniline, electrophoretic deposition (EPD) of SAE and plasma electrolyte oxidation (PEO) of magnesium alloy substrate. Electrochemical corrosion tests indicate that the bilayer coating can provide superior corrosion protection to the magnesium alloy substrate in 3.5 wt.% NaCl solution.

  1. One-step integration of multiple genes into the oleaginous yeast Yarrowia lipolytica.

    PubMed

    Gao, Shuliang; Han, Linna; Zhu, Li; Ge, Mei; Yang, Sheng; Jiang, Yu; Chen, Daijie

    2014-12-01

    Yarrowia lipolytica is an unconventional yeast, and is generally recognized as safe (GRAS). It provides a versatile fermentation platform that is used commercially to produce many added-value products. Here we report a multiple fragment assembly method that allows one-step integration of an entire β-carotene biosynthesis pathway (~11 kb, consisting of four genes) via in vivo homologous recombination into the rDNA locus of the Y. lipolytica chromosome. The highest efficiency was 21%, and the highest production of β-carotene was 2.2 ± 0.3 mg per g dry cell weight. The total procedure was completed in less than one week, as compared to a previously reported sequential gene integration method that required n weeks for n genes. This time-saving method will facilitate synthetic biology, metabolic engineering and functional genomics studies of Y. lipolytica. PMID:25216641

  2. One-step surface modification of polyurethane using affinity binding peptides for enhanced fouling resistance.

    PubMed

    Wang, Yibing; Yu, Yong; Zhang, Liting; Qin, Peng; Wang, Ping

    2015-01-01

    Affinity binding peptides were examined for surface fabrication of synthetic polymeric materials. Peptides possessing strong binding affinities toward polyurethane (PU) were discovered via biopanning of M13 phage peptide library. The apparent binding constant (K(app)) was as high as 2.68 × 10(9) M(-1) with surface peptide density exceeded 1.8 μg/cm(2). Structural analysis showed that the ideal peptide had a high content (75%) of H-donor amino acid residues, and that intensified hydrogen bond interaction was the key driving force for the highly stable binding of peptides on PU. PU treated with such affinity peptides promises applications as low-fouling materials, as peptides increased its wettability and substantially reduced protein adsorption and cell adhesion. These results demonstrated a facile but highly efficient one-step strategy for surface property modification of polymeric materials for biotechnological applications. PMID:25732121

  3. One-step electro-spinning/netting technique for controllably preparing polyurethane nano-fiber/net.

    PubMed

    Hu, Juanping; Wang, Xianfeng; Ding, Bin; Lin, Jinyou; Yu, Jianyong; Sun, Gang

    2011-11-01

    Electro-spinning/netting (ESN) as a cutting-edge technique evokes much interest because of its ability in the one-step preparation of versatile nano-fiber/net (NFN) membranes. Here, a controllable fabrication of polyurethane (PU) NFN membranes with attractive structures, consisting of common electrospun nanofibers and two-dimensional (2D) soap bubble-like structured nano-nets via an ESN process is reported. The unique nanoscaled NFN architecture can be finely controlled by regulating the solution properties and several ESN process parameters. The versatile PU nano-nets comprising interlinked nanowires with ultrathin diameters (5-40 nm) mean that the NFN structured membranes possess several excellent characteristics, such as an extremely large specific surface area, high porosity and large stacking density, which would be particularly useful for applications in ultrafiltration, special protective clothing, ultrasensitive sensors, catalyst support and so on.

  4. Preparation of Reduced-Graphene Nanoribbons via One-Step Solvothermal Process.

    PubMed

    Wu, Xiang-Feng; Sun, Yang; Zhang, Jie; Li, Jing; Zhao, Yong-Ke; Zhao, Ze-Hua; Fu, Shi-Da; Yu, Xiao-Ying; Zheng, Sen-Sen

    2016-04-01

    Carbon nanotubes were unzipped to become reduced-graphene nanoribbons via one-step solvothermal process in a Teflon-lined autoclave. The samples were characterized by X-ray diffraction, thermo-gravimetric analysis and transmission electrical microscopy, respectively. Results showed that the solvothermal reaction temperature played an important role in the structure of the samples. When it was 75 °C, carbon nanotubes were completely cutted into graphene oxide nanoribbons. Moreover, when it was 155 °C, they were become reduced-graphene nanoribbons. Furthermore, the as-prepared reduced-graphene nanoribbons could improve mechanical strength of the phenolic resin/hollow glass beads foamed composites. When the reduced-graphene nanoribbons loading was 0.4 wt%, the tensile and compressive strength of the composites were increased by 19.7% and 21.3%, respectively. PMID:27451785

  5. Ionic liquid-stabilized non-spherical gold nanofluids synthesized using a one-step method

    PubMed Central

    2012-01-01

    Ionic liquid (IL)-stabilized non-spherical gold nanofluids have been synthesized by a one-step method in aqueous solution. The whole reaction proceeded in room temperature. In the presence of amino-functionalized ionic liquids, gold nanofluids with long-wave surface plasmon resonance (SPR) absorption (>600 nm) could be obtained by adopting tannic acid as the reductant. The specific SPR absorption was related to the non-spherical gold nanoparticles including gold triangle, decahedra, and icosahedra nanocrystals. All the nanocrystals were observed by transmission electron microscopy. It was deduced that the formation of non-spherical gold nanofluids was related to the hydroxyls in tannic acid while IL acted as the synthesis template. PMID:23092303

  6. One-Step Generation of Multifunctional Polyelectrolyte Microcapsules via Nanoscale Interfacial Complexation in Emulsion (NICE).

    PubMed

    Kim, Miju; Yeo, Seon Ju; Highley, Christopher B; Burdick, Jason A; Yoo, Pil J; Doh, Junsang; Lee, Daeyeon

    2015-08-25

    Polyelectrolyte microcapsules represent versatile stimuli-responsive structures that enable the encapsulation, protection, and release of active agents. Their conventional preparation methods, however, tend to be time-consuming, yield low encapsulation efficiency, and seldom allow for the dual incorporation of hydrophilic and hydrophobic materials, limiting their widespread utilization. In this work, we present a method to fabricate stimuli-responsive polyelectrolyte microcapsules in one step based on nanoscale interfacial complexation in emulsions (NICE) followed by spontaneous droplet hatching. NICE microcapsules can incorporate both hydrophilic and hydrophobic materials and also can be induced to trigger the release of encapsulated materials by changes in the solution pH or ionic strength. We also show that NICE microcapsules can be functionalized with nanomaterials to exhibit useful functionality, such as response to a magnetic field and disassembly in response to light. NICE represents a potentially transformative method to prepare multifunctional nanoengineered polyelectrolyte microcapsules for various applications such as drug delivery and cell mimicry. PMID:26172934

  7. One-step Double-layer Thermal Evaporation Method for Organic Light Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Kee, Y. Y.; Yong, T. K.; Ong, D. S.; Tou, T. Y.

    2011-03-01

    A new one-step double-layer thermal evaporation method was used to fabricate organic light emitting diodes (OLEDs) with device structure of: ITO (anode)/N,N_-diphenyl-N,N_-bis(3-methylphenyl)-1,1_-diphenyl-4,4_-diamine (TPD) /tris-(8-hydroxyquinoline)aluminum(3) (Alq3)/Al (cathode). These OLEDs were fabricated in cleanroom on the ITO-coated glass with a sheet resistivity of 20Ω/sq and an optical transmittance of 90%. The I-V and brightness characteristic showed that the new method could produce better performance achieving lower turn-on voltage (-2V), higher peak current efficiency (+29%) and higher brightness (+36%).

  8. Cellulose acetate from oil palm empty fruit bunch via a one step heterogeneous acetylation.

    PubMed

    Wan Daud, Wan Rosli; Djuned, Fauzi Muhammad

    2015-11-01

    Acetone soluble oil palm empty fruit bunch cellulose acetate (OPEFB-CA) of DS 2.52 has been successfully synthesized in a one-step heterogeneous acetylation of OPEFB cellulose without necessitating the hydrolysis stage. This has only been made possible by the mathematical modeling of the acetylation process by manipulating the variables of reaction time and acetic anhydride/cellulose ratio (RR). The obtained model was verified by experimental data with an error of less than 2.5%. NMR analysis showed that the distribution of the acetyl moiety among the three OH groups of cellulose indicates a preference at the C6 position, followed by C3 and C2. XRD revealed that OPEFB-CA is highly amorphous with a degree of crystallinity estimated to be ca. 6.41% as determined from DSC. The OPEFB-CA films exhibited good mechanical properties being their tensile strength and Young's modulus higher than those of the commercial CA.

  9. One-step fabrication of nanowire-grid polarizers using liquid-bridge-mediated nanotransfer molding

    PubMed Central

    2012-01-01

    Ag nanowire-grid polarizers (NWGPs) were prepared by a one-step fabrication method, called liquid-bridge-mediated nanotransfer molding (LB-nTM). LB-nTM is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. We fabricated NWGPs with Ag nanowire arrays (81 nm parallel lines and 119 nm spaces) on 2.5 in. transparent substrates by LB-nTM using an Ag nanoparticle solution. The maximum and minimum transmittances of the Ag NWGP at 800 nm were 80% and 10%, respectively. PMID:22738252

  10. Shape-control and characterization of iron nanocrystals prepared via a one-step solvothermal method

    NASA Astrophysics Data System (ADS)

    Fan, Junmei; Cao, Yuebin; Yuan, Fangli

    2015-12-01

    In the present work, iron nanocubes, nanorods and nanowires are successfully synthesized by one-step reduction approach in a solvothermal environment. It is analyzed that the iron nanocubes, nanorods and nanowires belong to the pure body-centered cubic structure of α-Fe. Effects of additive sort and the amount of Anionic Gemini surfactant 12-4-12 on the morphology evolution of Fe are discussed based on SEM and TEM images. The possible formation mechanisms of iron nanocubes, nanorods and nanowires are proposed. The Anionic Gemini surfactant 12-4-12 regarded as template plays an important role in the formation of iron nanocrystals. The microwave electromagnetic (EM) (80 wt% Fe) and calculated microwave-absorbing (0.5 mm thickness) properties in 2-18 GHz of the iron nanocubes, nanorods and nanowires are studied systematically. Results show that iron nanowires are superior to nanorods and nanocubes, which indicates the potential to be a super-thin microwave absorber.

  11. ABS polymer electroless plating through a one-step poly(acrylic acid) covalent grafting.

    PubMed

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Mesnage, Alice; Jégou, Pascale; Nekelson, Fabien; Roussel, Sébastien; Palacin, Serge

    2010-04-01

    A new, efficient, palladium- and chromium-free process for the electroless plating of acrylonitrile-butadiene-styrene (ABS) polymers has been developed. The process is based on the ion-exchange properties of poly(acrylic acid) (PAA) chemically grafted onto ABS via a simple and one-step method that prevents using classical surface conditioning. Hence, ABS electroless plating can be obtained in three steps, namely: (i) the grafting of PAA onto ABS, (ii) the copper Cu(0) seeding of the ABS surface, and (iii) the nickel or copper metallization using commercial-like electroless plating bath. IR, XPS, and SEM were used to characterize each step of the process, and the Cu loading was quantified by atomic absorption spectroscopy. This process successfully compares with the commercial one based on chromic acid etching and palladium-based seed layer, because the final metallic layer showed excellent adhesion with the ABS substrate. PMID:20361751

  12. One-step synthesis of graphene-Pt nanocomposites by gamma-ray irradiation

    NASA Astrophysics Data System (ADS)

    Tokai, Akihiro; Okitsu, Kenji; Hori, Fuminobu; Mizukoshi, Yoshiteru; Iwase, Akihiro

    2016-06-01

    We developed a one-step gamma-ray irradiation method to synthesize nanocomposites composed of graphene and Pt nanoparticles from aqueous solution containing graphene and Pt(IV) complex ions in the presence of 2-propanol (IPA) or sodium dodecyl sulfate (SDS). It was confirmed that gamma-ray irradiation provided carbonyl groups on graphene and Pt nanoparticles formed from the radiolytic reduction of Pt(IV) complex ions were deposited onto the carbonyl modified graphene. In the presence of IPA, small Pt nanoparticles were deposited on graphene, but large Pt nanoparticles were deposited in the presence of SDS: the size of Pt nanoparticles formed was larger in the presence of SDS than IPA. Based on the results, formation and deposition mechanisms of Pt nanoparticles were proposed.

  13. Cytotoxic effects of one-step self-etching adhesives on an odontoblast cell line.

    PubMed

    Lee, Yoon; An, So-Youn; Park, Yoon-Jung; Yu, Frank H; Park, Joo-Cheol; Seo, Deog-Gyu

    2016-01-01

    The aim of this study was to evaluate the cytotoxic effects of one-step self-etching adhesives. Cells from an immortalized mouse odontoblast cell line (MDPC-23) were cultured with six different dental adhesive systems (diluted to concentrations of 0.5% for 4 h): Adper Easy Bond (EB), Xeno V (XV), iBond (IB), AdheSE One (AO), Clearfil SE primer (CS), and Adper Single Bond 2 (SB). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometric apoptosis assays were used to evaluate cell viability and the rate of apoptosis. The odontoblasts were also examined under a scanning electron microscope. While all of the cultures with adhesives showed reduced viability, the viabilities in the IB and SB groups were not significantly different from the control group. Although increased apoptosis rates were observed in all of the cultures with adhesives, the rate in the SB group was not significantly different from the rate in the control. The control group showed the lowest apoptosis rate followed by the SB, AO, IB, EB, XV, and CS groups. When examined under a scanning electron microscope, control odontoblasts and the SB group exhibited relatively large cytoplasmic extensions. In contrast, in the EB and CS groups, fewer fibroblasts remained adhered to the plate surface. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, all cultures with one-step self-etching adhesives showed increased apoptotic activity. SB, an etch-and-rinse adhesive, was comparable to the control group, and CS and EB showed the lowest odontoblast viabilities according to the MTT assay. PMID:26186405

  14. One-step reduced kinetics for lean hydrogen-air deflagration

    SciTech Connect

    Fernandez-Galisteo, D.; Sanchez, A.L.; Linan, A.; Williams, F.A.

    2009-05-15

    A short mechanism consisting of seven elementary reactions, of which only three are reversible, is shown to provide good predictions of hydrogen-air lean-flame burning velocities. This mechanism is further simplified by noting that over a range of conditions of practical interest, near the lean flammability limit all reaction intermediaries have small concentrations in the important thin reaction zone that controls the hydrogen-air laminar burning velocity and therefore follow a steady state approximation, while the main species react according to the global irreversible reaction 2H{sub 2} + O{sub 2} {yields} 2H{sub 2}O. An explicit expression for the non-Arrhenius rate of this one-step overall reaction for hydrogen oxidation is derived from the seven-step detailed mechanism, for application near the flammability limit. The one-step results are used to calculate flammability limits and burning velocities of planar deflagrations. Furthermore, implications concerning radical profiles in the deflagration and reasons for the success of the approximations are clarified. It is also demonstrated that adding only two irreversible direct recombination steps to the seven-step mechanism accurately reproduces burning velocities of the full detailed mechanism for all equivalence ratios at normal atmospheric conditions and that an eight-step detailed mechanism, constructed from the seven-step mechanism by adding to it the fourth reversible shuffle reaction, improves predictions of O and OH profiles. The new reduced-chemistry descriptions can be useful for both analytical and computational studies of lean hydrogen-air flames, decreasing required computation times. (author)

  15. One-step synthesis of hydrothermally stable mesoporous aluminosilicates with strong acidity

    SciTech Connect

    Yang Dongjiang; Xu Yao Wu Dong; Sun Yuhan

    2008-09-15

    Using tetraethylorthosilicate (TEOS), polymethylhydrosiloxane (PMHS) and aluminium isopropoxide (AIP) as the reactants, through a one-step nonsurfactant route based on PMHS-TEOS-AIP co-polycondensation, hydrothermally stable mesoporous aluminosilicates with different Si/Al molar ratios were successfully prepared. All samples exclusively showed narrow pore size distribution centered at 3.6 nm. To assess the hydrothermal stability, samples were subjected to 100 deg. C distilled water for 300 h. The boiled mesoporous aluminosilicates have nearly the same N{sub 2} adsorption-desorption isotherms and the same pore size distributions as those newly synthesized ones, indicating excellent hydrothermal stability. The {sup 29}Si MAS NMR spectra confirmed that PMHS and TEOS have jointly condensed and CH{sub 3} groups have been introduced into the materials. The {sup 27}Al MAS NMR spectra indicated that Al atoms have been incorporated in the mesopore frameworks. The NH{sub 3} temperature-programmed desorption showed strong acidity. Due to the existence of large amount of CH{sub 3} groups, the mesoporous aluminosilicates obtained good hydrophobicity. Owing to the relatively large pore and the strong acidity provided by the uniform four-coordinated Al atoms, the excellent catalytic performance for 1,3,5-triisopropylbenzene cracking was acquired easily. The materials may be a profitable complement for the synthesis of solid acid catalysts. - Graphical abstract: Based on the nonsurfactant method, a facile one-step synthesis route has been developed to prepare methyl-modified mesoporous aluminosilicates that possessed hydrothermal stability and strong acidity.

  16. Shear bond strength of one-step self-etch adhesives: pH influence

    PubMed Central

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2015-01-01

    Background: The aim of this study was to compare the shear bond strength of four one-step self-etch adhesives with different pH values to enamel and dentin. Materials and Methods: In this in vitro study, 200 bovine permanent mandibular incisors were used. Four one-step self-etch adhesives with different pH values were tested both on enamel and on dentin: Adper™ Easy Bond Self-Etch Adhesive (pH = 0.8-1), Futurabond NR (pH=2), G-aenial Bond (pH = 1.5), Clearfil S3 Bond (pH = 2.7). After adhesive systems application, a nanohybrid composite resin was inserted into the bonded surface. The specimens were placed in a universal testing machine. The shear bond strength was performed at a cross-head speed of 1 mm/min until the sample rupture. The shear bond strength values (MPa) of the different groups were compared with analysis of variance after that Kolmogorov and Smirnov tests were applied to assess normality of distributions. P < 0.05 was considered as significant. Results: In enamel shear bond strength, the highest shear bond strength values were reported with Futurabond NR (P < 0.01); however, no significant differences were found with Clearfil S3 Bond. The others adhesive systems showed lower shear bond strength values with significant differences between them (P < 0.05). When comparing the dentin shear bond strength, the lowest shear bond strength values were reported with Clearfil S3 Bond (P < 0.05), while there were no significant differences among the other three products (P > 0.05). Conclusion: The pH values of adhesive systems did not influence significantly their shear bond strength to enamel or dentin. PMID:26005459

  17. One step beyond lethal equivalents: characterization of deleterious loci in the rapid cycling Brassica rapa L. base population.

    PubMed

    Lascoux, M; Lee, J K

    1998-10-01

    The total number of lethal equivalents as defined by Morton, Crow and Muller (1956) is a function of three parameters: M, the number of loci at which deleterious mutations can occur, q, the frequency of the deleterious alleles at each locus, and s, their selective value. A new approach based on multi-generation inbreeding data is outlined and used to infer these three parameters as well as the dominance coefficient, h, in a self-incompatible species, Brassica rapa L. Germination and flowering data from thirty bud-selfed lines of fast-cycling B.rapa were assessed over three generations. Germination and flowering were significantly postponed by inbreeding but germination and flowering success were not so strongly decreased. Estimates of the average s values were obtained but it was not possible to get separate estimates of M and q. For both characters, the average dominance coefficient was particularly low. The number of lethal equivalents at the zygotic level was around two for germination and three for flowering, which, owing to the self-incompatibility of B.rapa, is an unexpectedly low value. These results may be explained by past biparental inbreeding which in turn may have increased self-compatibility thus allowing the purging of more deleterious alleles than under strict self-incompatibility.

  18. One step electrodeposition of dendritic gold nanostructures on β-lactoglobulin-functionalized reduced graphene oxide for glucose sensing.

    PubMed

    Du, Xin; Zhang, Zhenguo; Miao, Zhiying; Ma, Min; Zhang, Yanyan; Zhang, Cong; Wang, Weizhen; Han, Bingkai; Chen, Qiang

    2015-11-01

    Dendritic gold nanostructures (AuNDs) were successfully synthesized by one step electrodeposition on reduced graphene oxide (rGO) functionalized by a globular protein, β-lactoglobulin (BLG), for the first time. Owing to its sulfhydryl groups, water-soluble BLG-rGO provided a superb platform for the growth of AuNDs. Scanning electron microscopy, Raman spectroscopy and X-ray spectroscopy analysis were used to investigate the as prepared BLG-rGO-AuNDs nanocomposite. Electrocatalytic ability of the nanocomposite was evaluated by cyclic voltammetry and chronoamperometric method. In order to prove the superiority of BLG-rGO-AuNDs, we developed a novel glucose biosensor on the nanocomposite modified glassy carbon electrode (GCE) through a cross-linking method. The biosensor exhibited a remarkable sensitivity of 46.2 μA mM(-1) cm(-2), a wide linear range of 0.05-6 mM glucose, a low detection limit of 22.9 µM (S/N=3), and a rapid response time (within 6 s). The prepared biosensor also used to detect glucose in human serum and statistical analysis in the respect of reproducibility was done. PMID:26452896

  19. One-step multiplex quantitative RT-PCR for the simultaneous detection of viroids and phytoplasmas of pome fruit trees.

    PubMed

    Malandraki, Ioanna; Varveri, Christina; Olmos, Antonio; Vassilakos, Nikon

    2015-03-01

    A one-step multiplex real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) based on TaqMan chemistry was developed for the simultaneous detection of Pear blister canker viroid and Apple scar skin viroid along with universal detection of phytoplasmas, in pome trees. Total nucleic acids (TNAs) extraction was performed according to a modified CTAB protocol. Primers and TaqMan MGB probes for specific detection of the two viroids were designed in this study, whereas for phytoplasma detection published universal primers and probe were used, with the difference that the later was modified to carry a MGB quencher. The pathogens were detected simultaneously in 10-fold serial dilutions of TNAs from infected plant material into TNAs of healthy plant up to dilutions 10(-5) for viroids and 10(-4) for phytoplasmas. The multiplex real-time assay was at least 10 times more sensitive than conventional protocols for viroid and phytoplasma detection. Simultaneous detection of the three targets was achieved in composite samples at least up to a ratio of 1:100 triple-infected to healthy tissue, demonstrating that the developed assay has the potential to be used for rapid and massive screening of viroids and phytoplasmas of pome fruit trees in the frame of certification schemes and surveys.

  20. One-step in situ synthesis of graphene–TiO{sub 2} nanorod hybrid composites with enhanced photocatalytic activity

    SciTech Connect

    Sun, Mingxuan Li, Weibin; Sun, Shanfu; He, Jia; Zhang, Qiang; Shi, Yuying

    2015-01-15

    Chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with superior dispersity were synthesized by a one-step in situ hydrothermal method using graphene oxide (GO) and TiO{sub 2} (P25) as the starting materials. The as-prepared samples were characterized by XRD, XPS, TEM, FE-SEM, EDX, Raman, N{sub 2} adsorption, and UV–vis DRS techniques. Enhanced light absorption and a red shift of absorption edge were observed for the composites in the ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS). Their effective photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light irradiation. An enhancement of photocatalytic performance was observed over graphene/TiO{sub 2} nanorod hybrid composite photocatalysts, as 3.7 times larger than that of pristine TiO{sub 2} nanorods. This work demonstrated that the synthesis of TiO{sub 2} nanorods and simultaneous conversion of GO to graphene “without using reducing agents” had shown to be a rapid, direct and clean approach to fabricate chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with enhanced photocatalytic performance.

  1. Homology-integrated CRISPR-Cas (HI-CRISPR) system for one-step multigene disruption in Saccharomyces cerevisiae.

    PubMed

    Bao, Zehua; Xiao, Han; Liang, Jing; Zhang, Lu; Xiong, Xiong; Sun, Ning; Si, Tong; Zhao, Huimin

    2015-05-15

    One-step multiple gene disruption in the model organism Saccharomyces cerevisiae is a highly useful tool for both basic and applied research, but it remains a challenge. Here, we report a rapid, efficient, and potentially scalable strategy based on the type II Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR associated proteins (Cas) system to generate multiple gene disruptions simultaneously in S. cerevisiae. A 100 bp dsDNA mutagenizing homologous recombination donor is inserted between two direct repeats for each target gene in a CRISPR array consisting of multiple donor and guide sequence pairs. An ultrahigh copy number plasmid carrying iCas9, a variant of wild-type Cas9, trans-encoded RNA (tracrRNA), and a homology-integrated crRNA cassette is designed to greatly increase the gene disruption efficiency. As proof of concept, three genes, CAN1, ADE2, and LYP1, were simultaneously disrupted in 4 days with an efficiency ranging from 27 to 87%. Another three genes involved in an artificial hydrocortisone biosynthetic pathway, ATF2, GCY1, and YPR1, were simultaneously disrupted in 6 days with 100% efficiency. This homology-integrated CRISPR (HI-CRISPR) strategy represents a powerful tool for creating yeast strains with multiple gene knockouts.

  2. One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and magnetic separation.

    PubMed

    Yin, Binfeng; Wang, Yu; Dong, Mingling; Wu, Jing; Ran, Bei; Xie, Mengxia; Joo, Sang Woo; Chen, Yiping

    2016-12-15

    A rapid and multiplexed immunosensor was developed based on a quantum dot (QD)-reverse assaying strategy (RAS) and immuno-magnetic beads (IMBs) for one-step and simultaneous detection of Escherichia coli O157: H7 and Salmonella. In a conventional QD-based immunosensor, the fluorescence signal of the "IMBs-target-QD" immunoconjugate is directly used as the assaying readout. However, the fluorescence signal is affected by IMBs due to light scattering and the "IMBs-target-QD" immunoconjugate needs multiple washing and re-suspension steps. To address these problems, we use the surplus QD-antibody conjugate as signal readout in the RAS, which prevents interference from the IMBs, increases the fluorescence signal, and avoids complex operations. Compared with conventional QD-based immunosensor, the sensitivity of QD-RSA immunosensor for detection of Escherichia coli O157: H7 has been improved fifty-fold, and whole analysis procedure can be finished within 1h. Therefore, this RSA strategy is promising for improving the performance of QD-based immunosensors and could greatly broaden their applications.

  3. Simple and Green Fabrication of a Superhydrophobic Surface by One-Step Immersion for Continuous Oil/Water Separation.

    PubMed

    Zhu, Jingfang; Liu, Bin; Li, Longyang; Zeng, Zhixiang; Zhao, Wenjie; Wang, Gang; Guan, Xiaoyan

    2016-07-21

    In this paper, stainless steel meshes with superhydrophobic and superoleophilic surfaces were fabricated by rapid and simple one-step immersion in a solution containing hydrochloric acid and stearic acid. The apparent contact angles were tested by a video contact angle measurement system (CA). Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were conducted to characterize the surface topographies and chemical compositions. The SEM results showed that mesh surfaces were covered by ferric stearate (Fe[CH3(CH2)16COO]2) with low surface energy. The CA test results showed that the mesh had a maximum apparent contact angle of 160 ± 1.0° and a sliding angle of less than 5.0° for the water droplet, whereas the apparent contact angle for the oil droplet was zero. Ultrasound oscillation and exposure tests at atmospheric conditions and immersion tests in 3.5 wt % NaCl aqueous solution were conducted to confirm the mesh with excellent superhydrophobic and superoleophilic properties. On the basis of the superhydrophobic mesh, a miniature separation device pump was designed to collect pure oil from the oil/water mixture. It showed that the device was easier and convenient. The techniques and materials presented in this work are promising for application to wastewater and oil spill treatment.

  4. One-step multiplexed detection of foodborne pathogens: Combining a quantum dot-mediated reverse assaying strategy and magnetic separation.

    PubMed

    Yin, Binfeng; Wang, Yu; Dong, Mingling; Wu, Jing; Ran, Bei; Xie, Mengxia; Joo, Sang Woo; Chen, Yiping

    2016-12-15

    A rapid and multiplexed immunosensor was developed based on a quantum dot (QD)-reverse assaying strategy (RAS) and immuno-magnetic beads (IMBs) for one-step and simultaneous detection of Escherichia coli O157: H7 and Salmonella. In a conventional QD-based immunosensor, the fluorescence signal of the "IMBs-target-QD" immunoconjugate is directly used as the assaying readout. However, the fluorescence signal is affected by IMBs due to light scattering and the "IMBs-target-QD" immunoconjugate needs multiple washing and re-suspension steps. To address these problems, we use the surplus QD-antibody conjugate as signal readout in the RAS, which prevents interference from the IMBs, increases the fluorescence signal, and avoids complex operations. Compared with conventional QD-based immunosensor, the sensitivity of QD-RSA immunosensor for detection of Escherichia coli O157: H7 has been improved fifty-fold, and whole analysis procedure can be finished within 1h. Therefore, this RSA strategy is promising for improving the performance of QD-based immunosensors and could greatly broaden their applications. PMID:27498327

  5. Simple and Green Fabrication of a Superhydrophobic Surface by One-Step Immersion for Continuous Oil/Water Separation.

    PubMed

    Zhu, Jingfang; Liu, Bin; Li, Longyang; Zeng, Zhixiang; Zhao, Wenjie; Wang, Gang; Guan, Xiaoyan

    2016-07-21

    In this paper, stainless steel meshes with superhydrophobic and superoleophilic surfaces were fabricated by rapid and simple one-step immersion in a solution containing hydrochloric acid and stearic acid. The apparent contact angles were tested by a video contact angle measurement system (CA). Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were conducted to characterize the surface topographies and chemical compositions. The SEM results showed that mesh surfaces were covered by ferric stearate (Fe[CH3(CH2)16COO]2) with low surface energy. The CA test results showed that the mesh had a maximum apparent contact angle of 160 ± 1.0° and a sliding angle of less than 5.0° for the water droplet, whereas the apparent contact angle for the oil droplet was zero. Ultrasound oscillation and exposure tests at atmospheric conditions and immersion tests in 3.5 wt % NaCl aqueous solution were conducted to confirm the mesh with excellent superhydrophobic and superoleophilic properties. On the basis of the superhydrophobic mesh, a miniature separation device pump was designed to collect pure oil from the oil/water mixture. It showed that the device was easier and convenient. The techniques and materials presented in this work are promising for application to wastewater and oil spill treatment. PMID:27328269

  6. Differential determinants of cancer cell insensitivity to anti-mitotic drugs discriminated by a one-step cell imaging assay

    PubMed Central

    Tang, Yangzhong; Xie, Tiao; Florian, Stefan; Moerke, Nathan; Shamu, Caroline; Benes, Cyril; Mitchison, Timothy J.

    2013-01-01

    Cancer cells can be drug resistant due to genetic variation at multiple steps in the drug response pathway, including drug efflux pumping, target mutation and blunted apoptotic response. These are not discriminated by conventional cell survival assays. Here, we report a rapid and convenient high content cell-imaging assay that measures multiple physiological changes in cells responding to anti-mitotic small-molecule drugs. Our one-step, no-wash assay uses three dyes to stain living cells and is much more accurate for scoring weakly adherent mitotic and apoptotic cells than conventional antibody-based assays. We profiled responses of 33 cell lines to 8 anti-mitotic drugs at multiple concentrations and time points using this assay, and deposited our data and assay protocols into a public database (http://lincs.hms.harvard.edu/). Our data discriminated between alternative mechanisms that compromise drug sensitivity to Paclitaxel, and revealed an unexpected bell-shaped dose-response curve for BI2536, a highly selective inhibitor of Polo-like kinases. Our approach can be generalized, is scalable and should therefore facilitate identification of molecular biomarkers for mechanisms of drug insensitivity in high-throughput screens and other assays. PMID:23788527

  7. One step electrodeposition of dendritic gold nanostructures on β-lactoglobulin-functionalized reduced graphene oxide for glucose sensing.

    PubMed

    Du, Xin; Zhang, Zhenguo; Miao, Zhiying; Ma, Min; Zhang, Yanyan; Zhang, Cong; Wang, Weizhen; Han, Bingkai; Chen, Qiang

    2015-11-01

    Dendritic gold nanostructures (AuNDs) were successfully synthesized by one step electrodeposition on reduced graphene oxide (rGO) functionalized by a globular protein, β-lactoglobulin (BLG), for the first time. Owing to its sulfhydryl groups, water-soluble BLG-rGO provided a superb platform for the growth of AuNDs. Scanning electron microscopy, Raman spectroscopy and X-ray spectroscopy analysis were used to investigate the as prepared BLG-rGO-AuNDs nanocomposite. Electrocatalytic ability of the nanocomposite was evaluated by cyclic voltammetry and chronoamperometric method. In order to prove the superiority of BLG-rGO-AuNDs, we developed a novel glucose biosensor on the nanocomposite modified glassy carbon electrode (GCE) through a cross-linking method. The biosensor exhibited a remarkable sensitivity of 46.2 μA mM(-1) cm(-2), a wide linear range of 0.05-6 mM glucose, a low detection limit of 22.9 µM (S/N=3), and a rapid response time (within 6 s). The prepared biosensor also used to detect glucose in human serum and statistical analysis in the respect of reproducibility was done.

  8. Simple one-step ultrasonic synthesis of anatase titania/polypyrrole nanocomposites.

    PubMed

    Arenas, M C; Rodríguez-Núnez, L Fernando; Rangel, Domingo; Martínez-Álvarez, Omar; Martínez-Alonso, Claudia; Castaño, V M

    2013-03-01

    In this work, hybrid nanocomposites based on anatase titania:polypyrrole (TiO(2):PPy) were directly obtained from a simple, one-step, ultrasonic (UT)-assisted synthesis. The properties of these crystalline nanocomposites were compared with those of others fabricated using cold (Cold)-assisted synthesis without any UT assistance, which required a hydrothermal treatment (HT) to yield crystalline anatase titania in the nanocomposite (TiO(2):PPy) at low temperature (130°C) and in a short time (3h). The SEM results demonstrated that the UT-assisted synthesis is a feasible method to obtain anatase TiO(2):PPy nanocomposites with controlled morphology using low energy. The Fourier transform infrared (FT-IR) bands of the crystalline nanocomposites exhibited a shift with respect to neat components, which was attributed to the strong interaction between the secondary amine groups (N-H) of PPy and the oxygen from TiO(2). The acceptable absorption in the visible region (λ(max)=670nm) indicates that these nanocomposites are good candidates for harvesting energy in solar cells. Devices based on these nanocomposites were built to evaluate their electrical properties. An increase in the photocurrent was observed for the devices prepared with the nanocomposites from the UT-assisted synthesis.

  9. Self-Stratified Antimicrobial Acrylic Coatings via One-Step UV Curing.

    PubMed

    Zhao, Jie; Millians, William; Tang, Saide; Wu, Tiehang; Zhu, Lei; Ming, Weihua

    2015-08-26

    We designed and synthesized a novel quaternary ammonium methacrylate compound (QAC-2) bearing a perfluoroalkyl tail on one end and an acrylic moiety on the other. Via one-step UV curing of QAC-2 and methyl methacrylate (MMA) with ethylene glycol dimethacrylate (EGDMA) as the cross-linker, we obtained cross-linked coatings with excellent antimicrobial property, as demonstrated by the total kill against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus epidermidis (S. epidermidis) at a QAC-2 concentration as low as ∼0.06 mol % (∼0.4 wt %) relative to MMA, which was substantially lower than the QAC amount needed in the coatings containing QACs with a hydrocarbon tail. A zone of inhibition test confirmed that the antimicrobial effect was on the basis of contact killing and there was no leaching of antimicrobial species from the cross-linked coating. The high antimicrobial potency in QAC-2-containing films was the consequence of strong surface enrichment of the fluorinated QAC, as confirmed by X-ray photoelectron spectroscopy (XPS). PMID:26226193

  10. One step enzyme linked immunosorbent assay for direct estimation of serum testosterone.

    PubMed

    Shrivastav, Tulsidas G; Basu, Anupam; Kariya, Kiran P

    2003-01-01

    One step competitive enzyme linked immunosorbent assay (ELISA) for direct estimation of testosterone in human serum is described. Testosterone-3-O-carboxymethyl-oxime-bovine serum albumin (testosterone-3-O-CMO-BSA), was used as immunogen and testosterone-3-O-carboxymethyl-oxime-adipic-acid dihydrazide-horseradish peroxidase (testosterone-3-O-CMO-ADH-HRP) was used as tracer. To the testosterone antibody coated microtiter wells, standard or serum samples (100 microL), along with testosterone-3-O-CMO-ADH-HRP conjugate (100 microL) were incubated for 1 h at 37 degrees C. Bound enzyme activity was measured by using tetra methyl benzidine/hydrogen peroxide (TMB/H2O2) as a substrate. In this new strategy, charcoal stripped pooled human serum spiked with non-cross reactive C18, C19, C21, and C27 steroids, used for preparing the standards and blocking the sex hormone binding globulin (SHBG)/and other steroid binding globulins (SBG). The sensitivity of the assay was 0.015 ng/mL. The intra-assay and inter-assay coefficients of variation (CVs) were ranged from 7.8 to 11.8 and 4.8 to 10.4, respectively. The serum testosterone values, obtained by this method, were correlated well with those obtained by radioimmunoassay r = .98 (n = 100). PMID:12778972

  11. Characterization of Conventional One-Step Sodium Thiosulfate Facilitated Gold Nanoparticle Synthesis

    NASA Astrophysics Data System (ADS)

    Saverot, Scott-Eugene; Reese, Laura M.; Cimini, Daniela; Vikesland, Peter J.; Bickford, Lissett Ramirez

    2015-05-01

    Gold-gold sulfide nanoparticles are of interest for drug delivery, biomedical imaging, and photothermal therapy applications due to a facile synthesis method resulting in small particles with high near-infrared (NIR) absorption efficiency. Previous studies suggest that the NIR sensitivity of these nanoparticles was due to hexagonally shaped metal-coated dielectric nanoparticles that consist of a gold sulfide core and gold shell. Here, we illustrate that the conventional synthesis procedure results in the formation of polydisperse samples of icosahedral gold particles, gold nanoplates, and small gold spheres. Importantly, through compositional analysis, via UV/vis absorption spectrophotometry, transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS), we show that all of the nanoparticles exhibit identical face center cubic (FCC) gold crystalline structures, thus suggesting that sulfide is not present in the final fabricated nanoparticles. We show that icosahedrally shaped nanoparticles result in a blue-shifted absorbance, with a peak in the visible range. Alternatively, the nanoplate nanoparticles result in the characteristic NIR absorbance peak. Thus, we report that the NIR-contributing species in conventional gold-gold sulfide formulations are nanoplates that are comprised entirely of gold. Furthermore, polydisperse gold nanoparticle samples produced by the traditional one-step reduction of HAuCl4 by sodium thiosulfate show increased in vitro toxicity, compared to isolated and more homogeneous constituent samples. This result exemplifies the importance of developing monodisperse nanoparticle formulations that are well characterized in order to expedite the development of clinically beneficial nanomaterials.

  12. One-step synthesis of iron oxide polypyrrole nanoparticles encapsulating ketoprofen as model of hydrophobic drug.

    PubMed

    Attia, Mohamed F; Anton, Nicolas; Khan, Ikram Ullah; Serra, Christophe A; Messaddeq, Nadia; Jakhmola, Anshuman; Vecchione, Raffaele; Vandamme, Thierry

    2016-07-11

    This study reports a novel one-step synthesis of hybrid iron oxide/polypyrrole multifunctional nanoparticles encapsulating hydrophobic drug and decorated with polyethylene glycol. The overall process is based on the in situ chemical oxidative polymerization of pyrrole along with the reduction of ferric chloride (FeCl3) in the presence of ketoprofen as model drug and PEGylated surfactants. The final product is a nanocomposite composed of polypyrrole and a mixture of FeO/Fe2O3. Different concentrations of ketoprofen were encapsulated in the nanocomposite, and were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Encapsulation efficiency of the final product was measured by absorption, which can reach up to 98%. The release experiments confirmed complete drug release after about 3h in PBS solution. Morphological characterization of the nanocomposites was performed by electron microscopy (scanning and transmission electron microscopy) which confirmed the spherical geometry and opaque nature of nanoparticles with average particle size well below 50 nm. The final product is multifunctional system, which could act both as a nanocarrier for drug molecules as well as a contrasting agent. Magnetic relaxometry studies confirmed their possible applications as potential contrast agent in the field of magnetic resonance imaging (MRI). PMID:27163525

  13. One-step electrolytic preparation of Si-Fe alloys as anodes for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Hailong; Sun, Diankun; Song, Qiqi; Xie, Wenqi; Jiang, Xu; Zhang, Bo

    2016-06-01

    One-step electrolytic formation of uniform crystalline Si-Fe alloy particles was successfully demonstrated in direct electro-reduction of solid mixed oxides of SiO2 and Fe2O3 in molten CaCl2 at 900∘C. Upon constant voltage electrolysis of solid mixed oxides at 2.8V between solid oxide cathode and graphite anode for 5h, electrolytic Si-Fe with the same Si/Fe stoichimetry of the precursory oxides was generated. The firstly generated Fe could function as depolarizers to enhance reduction rate of SiO2, resulting in the enhanced reduction kinetics to the electrolysis of individual SiO2. When evaluated as anode for lithium ion batteries, the prepared SiFe electrode showed a reversible lithium storage capacity as high as 470mAh g‑1 after 100 cycles at 200mA g‑1, promising application in high-performance lithium ion batteries.

  14. nanoparticles via a facile one-step solvothermal process for adsorption of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Shen, Mao; Yu, Yujing; Fan, Guodong; Chen, Guang; Jin, Ying min; Tang, Wenyuan; Jia, Wenping

    2014-06-01

    Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization.

  15. Facile fabrication of HDPE-g-MA/nanodiamond nanocomposites via one-step reactive blending

    PubMed Central

    2012-01-01

    In this letter, nanocomposites based on maleic anhydride grafted high density polyethylene (HDPE-g-MA) and amine-functionalized nanodiamond (ND) were fabricated via one-step reactive melt-blending, generating a homogeneous dispersion of ND, as evidenced by transmission electron microscope observations. Thermal analysis results suggest that addition of ND does not affect significantly thermal stability of polymer matrix in nitrogen. However, it was interestingly found that incorporating pure ND decreases the thermal oxidation degradation stability temperature, but blending amino-functionalized ND via reactive processing significantly enhances it of HDPE in air condition. Most importantly, cone tests revealed that both ND additives and reactive blending greatly reduce the heat release rate of HDPE. The results suggest that ND has a potential application as flame retardant alternative for polymers. Tensile results show that adding ND considerably enhances Young’s modulus, and reactive blending leads to further improvement in Young’s modulus while hardly reducing the elongation at break of HDPE. PMID:22747773

  16. One-Step, Non-Contact Pattern Transfer by Direct-Current Plasma Immersion Ion Implantation

    NASA Astrophysics Data System (ADS)

    Kwok, Dixon T. K.; Chu, Paul K.

    2009-10-01

    A one-step non-contact pattern transferring method is demonstrated. Clear non-identical images with well-defined boundaries are simultaneously transferred to a substrate by -15 kV plasma immersion ion implantation through a patterned metal mask. The metal mask is 6 cm away from the substrate and no lens system is necessary for the pattern transfer. To avoid diversification of compensating ions, the electric field must be smoothed out by the fine mesh overlapping on top of the metal mask. Complex patterns with micrometer size line-widths can be transferred onto a silicon wafer by placing the metal masks 4 mm away from the wafer. Scanning electron microscopy (SEM) discloses that by negatively biasing the metal mask, ions coming from a hole with a diameter of 200 micrometers in the mask can be confined to a smaller region of 100 micrometers. The ion focusing effect is confirmed by two-dimensional multiple grid particle-in-cell (PIC) simulation.

  17. Open-sandwich enzyme immunoassay for one-step noncompetitive detection of corticosteroid 11-deoxycortisol.

    PubMed

    Ihara, Masaki; Suzuki, Tatsuya; Kobayashi, Norihiro; Goto, Junichi; Ueda, Hiroshi

    2009-10-15

    A noncompetitive immunoassay has the potential for improved sensitivity and working range compared with corresponding competitive assays. However, monovalent antigens with less than 1000 in molecular weight are not susceptible to sandwich assays due to their small size. As a noncompetitive immunoassay that can be performed with a clone of an antibody, an open-sandwich immunoassay (OS-IA) based on the antigen-dependent stabilization of the antibody variable region (V(H) + V(L)) was applied to the quantification of 11-deoxycortisol (11-DC; M(r) 346.5), a corticosteroid serving as a diagnostic index for pituitary-adrenal function, as a model target hapten. By one step OS-IA detection of enzyme-labeled V(H) fragment bound to immobilized V(L) in the presence of sample in microplate wells, 11-DC was measured with a femtomolar detection limit and the working range was wider than that with corresponding competitive assay. In addition, the selectivity against analogues was found almost identical to that of conventional assays. The effect of the mutagenesis of a V(H) residue at the V(H)/V(L) interface to reduce background signal was also shown, implying the wider application of OS-IA in small molecule analyses.

  18. One-step preparation of pharmaceutical nanocrystals using ultra cryo-milling technique in liquid nitrogen.

    PubMed

    Niwa, Toshiyuki; Nakanishi, Yasuo; Danjo, Kazumi

    2010-09-11

    A novel micronization technique for pharmaceutical powders has been established using liquid nitrogen (LN2). Different from the conventional dry milling while cooling the milling pot by LN2, the materials were directly suspended in LN2 together with hard small spherical balls, called beads, and broken down by agitating intensively. The present beads milling in LN2 was named "ultra cryo-milling" in this paper. The operational conditions including the size/amount of beads made of zirconia and agitation speed were optimized to obtain the finer particles. It was found that the original crystals were effectively broken down into submicron particles, and the ultra cryo-milled particles were much finer and more uniform in size and shape than the conventional jet-milled particles. Dried powder was recovered continuously after milling process because LN2 was spontaneously evaporated at ambient temperature/pressure. Further, it was shown that this technique is applicable to the drugs with wide range of physicochemical features including heat-sensitive and water-soluble drugs. However, the resultant fine particles intrinsically tended to form the agglomerated masses. The crystalline analysis indicated that the both crystal form and crystallinity of the original bulk drugs completely remained after ultra cryo-milling process. The results demonstrated that the ultra cryo-milling would be a fundamental technique to produce the pharmaceutical nanocrystals by one step. PMID:20621640

  19. Chitosan-Coated Magnetic Nanoparticles Prepared in One Step by Reverse Microemulsion Precipitation

    PubMed Central

    López, Raúl G.; Pineda, María G.; Hurtado, Gilberto; de León, Ramón Díaz; Fernández, Salvador; Saade, Hened; Bueno, Darío

    2013-01-01

    Chitosan-coated magnetic nanoparticles (CMNP) were obtained at 70 °C and 80 °C in a one-step method, which comprises precipitation in reverse microemulsion in the presence of low chitosan concentration in the aqueous phase. X-ray diffractometry showed that CMNP obtained at both temperatures contain a mixture of magnetite and maghemite nanoparticles with ≈4.5 nm in average diameter, determined by electron microscopy, which suggests that precipitation temperature does not affect the particle size. The chitosan coating on nanoparticles was inferred from Fourier transform infrared spectrometry measurements; furthermore, the carbon concentration in the nanoparticles allowed an estimation of chitosan content in CMNP of 6%–7%. CMNP exhibit a superparamagnetic behavior with relatively high final magnetization values (≈49–53 emu/g) at 20 kOe and room temperature, probably due to a higher magnetite content in the mixture of magnetic nanoparticles. In addition, a slight direct effect of precipitation temperature on magnetization was identified, which was ascribed to a possible higher degree of nanoparticles crystallinity as temperature at which they are obtained increases. Tested for Pb2+ removal from a Pb(NO3)2 aqueous solution, CMNP showed a recovery efficacy of 100%, which makes them attractive for using in heavy metals ion removal from waste water. PMID:24084716

  20. Boron nitride colloidal solutions, ultralight aerogels and freestanding membranes through one-step exfoliation and functionalization

    PubMed Central

    Lei, Weiwei; Mochalin, Vadym N.; Liu, Dan; Qin, Si; Gogotsi, Yury; Chen, Ying

    2015-01-01

    Manufacturing of aerogels and membranes from hexagonal boron nitride (h-BN) is much more difficult than from graphene or graphene oxides because of the poor dispersibility of h-BN in water, which limits its exfoliation and preparation of colloidal solutions. Here, a simple, one-step mechano-chemical process to exfoliate and functionalize h-BN into highly water-dispersible, few-layer h-BN containing amino groups is presented. The colloidal solutions of few-layer h-BN can have unprecedentedly high concentrations, up to 30 mg ml−1, and are stable for up to several months. They can be used to produce ultralight aerogels with a density of 1.4 mg cm−3, which is ∼1,500 times less than bulk h-BN, and freestanding membranes simply by cryodrying and filtration, respectively. The material shows strong blue light emission under ultraviolet excitation, in both dispersed and dry state. PMID:26611437

  1. One-step synthesis and functionalization of hydroxyl-decorated magnetite nanoparticles.

    PubMed

    Mondini, Sara; Cenedese, Simone; Marinoni, Giorgio; Molteni, Giorgio; Santo, Nadia; Bianchi, Claudia L; Ponti, Alessandro

    2008-06-01

    Magnetite nanoparticles covered by a layer of omega-hydroxycarboxylic acid were synthesized in one step by high-temperature decomposition of iron(III) omega-hydroxycarboxylates in tri- and tetra-ethylene glycol. The nanoparticles were characterized by TEM, XRD, IR, XPS and NMR techniques in order to show that they comprise a crystalline magnetite core and actually bear on the outer surface terminal hydroxy groups. The latter ones are convenient "handles" for further functionalization as opposed to the chemically-inert aliphatic chains which cover conventionally synthesized nanoparticles. This was shown by several examples in which the hydroxy groups on the nanoparticle surface were easily transformed in other functional groups or reacted with other molecules. For instance, the hydroxyl-decorated nanoparticles were made water soluble by esterification with a PEGylated acetic acid. The reactive behavior of the surfactant monolayer was monitored by degrading the nanoparticles with aqueous acid and isolating the surfactant for NMR characterization. In general, the reactivity of the terminal hydroxyl groups on the nanoparticle surface parallels that observed in the free surfactants. The reported hydroxyl-decorated magnetite nanoparticles can be thus considered as pro-functional nanoparticles, i.e., a convenient starting material to functionalized magnetic nanoparticles.

  2. One-step controllable fabrication of superhydrophobic surfaces with special composite structure on zinc substrates.

    PubMed

    Ning, Tao; Xu, Wenguo; Lu, Shixiang

    2011-09-01

    Stable superhydrophobic platinum surfaces have been effectively fabricated on the zinc substrates through one-step replacement deposition process without further modification or any other post-treatment procedures. The fabrication process was controllable, which could be testified by various morphologies and hydrophobic properties of different prepared samples. By conducting SEM and water CA analysis, the effects of reaction conditions on the surface morphology and hydrophobicity of the resulting surfaces were carefully studied. The results show that the optimum condition of superhydrophobic surface fabrication depends largely on the positioning of zinc plate and the concentrations of reactants. When the zinc plate was placed vertically and the concentration of PtCl(4) solution was 5 mmol/L, the zinc substrate would be covered by a novel and interesting composite structure. The structure was composed by microscale hexagonal cavities, densely packed nanoparticles layer and top micro- and nanoscale flower-like structures, which exhibit great surface roughness and porosity contributing to the superhydrophobicity. The maximal CA value of about 171° was obtained under the same reaction condition. The XRD, XPS and EDX results indicate that crystallite pure platinum nanoparticles were aggregated on the zinc substrates in accordance with a free deposition way.

  3. One-step electrophoretic deposition for the preparation of superhydrophobic silica particle/trimethylsiloxysilicate composite coatings.

    PubMed

    Ogihara, Hitoshi; Katayama, Takafumi; Saji, Tetsuo

    2011-10-15

    SiO(2) particle/silicone resin (trimethylsiloxysilicate (TMSS)) composite coatings were prepared by electrophoretic deposition (EPD), and their wettability was examined. SiO(2) coatings prepared by EPD baths without TMSS were hydrophilic, while superhydrophobicity was observed for SiO(2)/TMSS composite coatings. IR spectra and EDS analyses revealed that not only SiO(2) particles but also TMSS electrophoretically moved toward a cathode; as a result, hydrophilic SiO(2) particles turned into superhydrophobic composite coatings by one-step EPD. SEM and AFM images of the superhydrophobic SiO(2)/TMSS composite coatings showed the presence of both nanometer- and micrometer-sized roughness in their surfaces. Particle size of SiO(2) had a great influence on the wettability of the composite coatings. The superhydrophobic SiO(2)/TMSS composite coatings showed excellent water repellency; they repelled running water continuously. In addition, by controlling the amount of deposited SiO(2) particles and TMSS, transparent superhydrophobic SiO(2)/TMSS composite coatings were prepared.

  4. One-step synthesis of iron oxide polypyrrole nanoparticles encapsulating ketoprofen as model of hydrophobic drug.

    PubMed

    Attia, Mohamed F; Anton, Nicolas; Khan, Ikram Ullah; Serra, Christophe A; Messaddeq, Nadia; Jakhmola, Anshuman; Vecchione, Raffaele; Vandamme, Thierry

    2016-07-11

    This study reports a novel one-step synthesis of hybrid iron oxide/polypyrrole multifunctional nanoparticles encapsulating hydrophobic drug and decorated with polyethylene glycol. The overall process is based on the in situ chemical oxidative polymerization of pyrrole along with the reduction of ferric chloride (FeCl3) in the presence of ketoprofen as model drug and PEGylated surfactants. The final product is a nanocomposite composed of polypyrrole and a mixture of FeO/Fe2O3. Different concentrations of ketoprofen were encapsulated in the nanocomposite, and were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Encapsulation efficiency of the final product was measured by absorption, which can reach up to 98%. The release experiments confirmed complete drug release after about 3h in PBS solution. Morphological characterization of the nanocomposites was performed by electron microscopy (scanning and transmission electron microscopy) which confirmed the spherical geometry and opaque nature of nanoparticles with average particle size well below 50 nm. The final product is multifunctional system, which could act both as a nanocarrier for drug molecules as well as a contrasting agent. Magnetic relaxometry studies confirmed their possible applications as potential contrast agent in the field of magnetic resonance imaging (MRI).

  5. One-step Solution Processing of Ag, Au and Pd@MXene Hybrids for SERS.

    PubMed

    Satheeshkumar, Elumalai; Makaryan, Taron; Melikyan, Armen; Minassian, Hayk; Gogotsi, Yury; Yoshimura, Masahiro

    2016-01-01

    We report on one-step hybridization of silver, gold and palladium nanoparticles from solution onto exfoliated two-dimensional (2D) Ti3C2 titanium carbide (MXene) nanosheets. The produced hybrid materials can be used as substrates for surface-enhanced Raman spectroscopy (SERS). An approximate analytical approach is also developed for the calculation of the surface plasmon resonance (SPR) frequency of nanoparticles immersed in a medium, near the interface of two dielectric media with different dielectric constants. We obtained a good match with the experimental data for SPR wavelengths, 440 nm and 558 nm, respectively for silver and gold nanoparticles. In the case of palladium, our calculated SPR wavelength for the planar geometry was 160 nm, demonstrating that non-spherical palladium nanoparticles coupled with 2D MXene yield a broad, significanlty red-shifted SPR band with a peak at 230 nm. We propose a possible mechanism of the plasmonic hybridization of nanoparticles with MXene. The as-prepared noble metal nanoparticles on MXene show a highly sensitive SERS detection of methylene blue (MB) with calculated enhancement factors on the order of 10(5). These findings open a pathway for extending visible-range SERS applications of novel 2D hybrid materials in sensors, catalysis, and biomedical applications. PMID:27557838

  6. One-step electrolytic preparation of Si-Fe alloys as anodes for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Hailong; Sun, Diankun; Song, Qiqi; Xie, Wenqi; Jiang, Xu; Zhang, Bo

    2016-06-01

    One-step electrolytic formation of uniform crystalline Si-Fe alloy particles was successfully demonstrated in direct electro-reduction of solid mixed oxides of SiO2 and Fe2O3 in molten CaCl2 at 900∘C. Upon constant voltage electrolysis of solid mixed oxides at 2.8V between solid oxide cathode and graphite anode for 5h, electrolytic Si-Fe with the same Si/Fe stoichimetry of the precursory oxides was generated. The firstly generated Fe could function as depolarizers to enhance reduction rate of SiO2, resulting in the enhanced reduction kinetics to the electrolysis of individual SiO2. When evaluated as anode for lithium ion batteries, the prepared SiFe electrode showed a reversible lithium storage capacity as high as 470mAh g-1 after 100 cycles at 200mA g-1, promising application in high-performance lithium ion batteries.

  7. [One-step PCR sequencing]. Final report, July 1, 1994--August 31, 1997

    SciTech Connect

    Shaw, B.R.

    1997-12-31

    The author explored the use of a novel class of boronated nucleic acids, the boranophosphates, as an alternative, but complementary method to dideoxysequencing. Boranophosphates can be used to directly amplify and sequence single- or double-stranded DNA. Fragments are derived not from truncations during polymerase synthesis, but from insertion and digestion back to a boronated marker or delimiter that was incorporated during exponential amplification. The method, which the author calls Boronated One-Step PCR Sequencing, is unique in that it employs a new class of {alpha}-P-boronated 2{prime}-deoxynucleoside 5{prime}-triphosphates first synthesized in the laboratory. These boronated triphosphates exhibit useful properties: (a) they are heat stable, (b) they can be base-specifically incorporated into DNA during the polymerase chain reaction, and (c) once incorporated, the boranophosphate nucleotide (marker) blocks the action of exonuclease. Thus, the positions of the stably-incorporated boronated markers can be revealed by a simple exonuclease digestion, producing a series of fragments--each of which is terminated base-specifically at the boronated markers--and thereby defining the sequence of the PCR product.

  8. Low temperature one-step synthesis of cobalt nanowires encapsulated in carbon

    NASA Astrophysics Data System (ADS)

    Majewska, Justyna; Michalkiewicz, Beata

    2013-06-01

    The one-step method of carbon nanotubes filled with continuous cobalt nanowires (CoF-CNT) synthesis is presented. Co/ZSM-5 (8 wt% Co) was used as catalyst for CoF-CNT production by methane decomposition at the temperature of 400 °C and 800 °C at atmospheric pressure in a conventional gas-flow system. The average diameter of the CoF-CNT is about 25 and 40 nm for products obtained at 400 °C and at 800 °C, respectively. The average size of coherently scattering domains along the normal to graphite layers L c , the interlayer spacing d 002, the graphitization degree of carbon, and the relative intensities of the G and D bands in Raman spectroscopy were determined to characterize the quality of carbon. It was proved that cobalt-filled carbon nanotubes can be produced by a simple method. The results of XRD, FE-SEM, and TEM show that CoF-CNT can be obtained even at 400 °C by catalytic decomposition of methane. On the basis of XRD, TEM, Raman spectroscopy was found that at a temperature of 800 °C, a better quality of carbon was produced.

  9. Directed mutagenesis in Candida albicans: one-step gene disruption to isolate ura3 mutants

    SciTech Connect

    Kelly, R.; Miller, S.M.; Kurtz, M.B.; Kirsch, D.R.

    1987-01-01

    A method for introducing specific mutations into the diploid Candida albicans by one-step gene disruption and subsequent UV-induced recombination was developed. The cloned C. albicans URA3 gene was disrupted with the C. albicans ADE2 gene, and the linearized DNA was used for transformation of two ade2 mutants, SGY-129 and A81-Pu. Both an insertional inactivation of the URA3 gene and a disruption which results in a 4.0-kilobase deletion were made. Southern hybridization analyses demonstrated that the URA3 gene was disrupted on one of the chromosomal homologs in 15 of the 18 transformants analyzed. These analyses also revealed restriction site dimorphism of EcoRI at the URA3 locus which provides a unique marker to distinguish between chromosomal homologs. This enabled us to show that either homolog could be disrupted and that disrupted transformants of SGY-129 contained more than two copies of the URA3 locus. The A81-Pu transformants heterozygous for the ura3 mutations were rendered homozygous and Ura- by UV-induced recombination. The homozygosity of a deletion mutant and an insertion mutant was confirmed by Southern hybridization. Both mutants were transformed to Ura+ with plasmids containing the URA3 gene and in addition, were resistant to 5-fluoro-orotic acid, a characteristic of Saccharomyces cerevisiae ura3 mutants as well as of orotidine-5'-phosphate decarboxylase mutants of other organisms.

  10. One-Step Ligation on RNA Amplification for the Detection of Point Mutations.

    PubMed

    Zhang, Lei; Wang, Jingjing; Coetzer, Mia; Angione, Stephanie; Kantor, Rami; Tripathi, Anubhav

    2015-11-01

    The detection of point mutations is required in the diagnosis of many human diseases. The conformal specificity of DNA ligases was elegantly used to distinguish single-nucleotide mismatches. However, to detect point mutations in RNA retroviruses, conventional ligase-mediated approaches require the reverse transcription of viral genomes before separate ligation and amplification steps. We developed one-step ligation on RNA amplification (LRA) for the direct detection of RNA point mutations. The process combines the ligase-mediated joining of two oligonucleotides and subsequent hot start amplification into a single-tube reaction. We report that modifications to the structure of the oligonucleotide ligation probes improve the rate of ligation and the specificity of mutation detection on RNA. We applied LRA to the detection of a common, clinically relevant HIV-1 reverse transcriptase drug-resistant point mutation, K103N, and compared it with allele-specific PCR and pyrosequencing. LRA achieved a limit of specific quantitation of 1:100 (1%), and a limit of specific detection for mutant K103N RNA transcripts among excess wild-type strands of 1:10,000 (0.01%). LRA also exhibited good detection threshold of 5 × 10(2) copies/μL K103N RNA transcripts. LRA is a novel point mutation detection method, with potential utilization in HIV drug resistance detection and early diagnostics of genetic disorders associated with other infectious diseases and cancer. PMID:26322949

  11. One-Step Deposition of Photovoltaic Layers Using Iodide Terminated PbS Quantum Dots.

    PubMed

    Kim, Sungwoo; Noh, Jaehong; Choi, Hyekyoung; Ha, Heonseok; Song, Jung Hoon; Shim, Hyung Cheoul; Jang, Jihoon; Beard, Matthew C; Jeong, Sohee

    2014-11-20

    We present a one-step layer deposition procedure employing ammonium iodide (NH4I) to achieve photovoltaic quality PbS quantum dot (QD) layers. Ammonium iodide is used to replace the long alkyl organic native ligands binding to the QD surface resulting in iodide terminated QDs that are stabilized in polar solvents such as N,N-dimethylformamide without particle aggregation. We extensively characterized the iodide terminated PbS QD via UV-vis absorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), FT-IR transmission spectroscopy, and X-ray photoelectron spectroscopy (XPS). Finally, we fabricated PbS QD photovoltaic cells that employ the iodide terminated PbS QDs. The resulting QD-PV devices achieved a best power conversion efficiency of 2.36% under ambient conditions that is limited by the layer thickness. The PV characteristics compare favorably to similar devices that were prepared using the standard layer-by-layer ethandithiol (EDT) treatment that had a similar layer thickness.

  12. One-step synthesis of magnetic hollow silica and their application for nanomedicine

    NASA Astrophysics Data System (ADS)

    Wu, W.; Decoster, M. A.; Daniel, B. M.; Chen, J. F.; Yu, M. H.; Cruntu, D.; O'Connor, C. J.; Zhou, W. L.

    2006-04-01

    Magnetic nanoparticles are usually present in the form of magnetic carriers and used in nanomedicine and biosystem. In this paper, magnetic hollow silica (MHS) nanoparticles were fabricated by a one-step synthesis of Fe3O4 nanoparticles and then coating of silica on nanosized spherical calcium carbonate under alkaline conditions, in which nanosized calcium carbonate (CaCO3, 25-60 nm) was used as a scarified template, tetraethoxysilane as a precursor, and Fe3O4 nanoparticles (~5 nm), formed in the initial reaction stage, as magnetic agents. The as-synthesized nanoparticles were immersed in a weak acetic acidic solution to remove CaCO3, forming MHS carriers. The nanostructures of the MHS carriers were characterized by scanning electron microscope, transmission electron microscope, and x-ray diffraction. Superconducting quantum interference device measurement exhibited that the MHS nanoparticles were superparamagnetic. Toxicity was tested for MHS carriers using rat brain microvascular endothelial cells. The cells treated with concentration lower than 50 μg/ml of the MHS nanoparticles showed no significant toxicity. After modification by silane coupling agent, the MHS carriers have strong absorption for ibuprofen in nanomedicine field.

  13. One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining.

    PubMed

    Bae, Won Gyu; Song, Ki Young; Rahmawan, Yudi; Chu, Chong Nam; Kim, Dookon; Chung, Do Kwan; Suh, Kahp Y

    2012-07-25

    We present a direct one-step method to fabricate dual-scale superhydrophobic metallic surfaces using wire electrical discharge machining (WEDM). A dual-scale structure was spontaneously formed by the nature of exfoliation characteristic of Al 7075 alloy surface during WEDM process. A primary microscale sinusoidal pattern was formed via a programmed WEDM process, with the wavelength in the range of 200 to 500 μm. Notably, a secondary roughness in the form of microcraters (average roughness, Ra: 4.16 to 0.41 μm) was generated during the exfoliation process without additional chemical treatment. The low surface energy of Al 7075 alloy (γ = 30.65 mJ/m(2)) together with the presence of dual-scale structures appears to contribute to the observed superhydrophobicity with a static contact angle of 156° and a hysteresis less than 3°. To explain the wetting characteristics on dual-scale structures, we used a simple theoretical model. It was found that Cassie state is likely to present on the secondary roughness in all fabricated surfaces. On the other hand, either Wenzel or Cassie state can present on the primary roughness depending on the characteristic length of sinusoidal pattern. In an optimal condition of the serial cutting steps with applied powers of ∼30 and ∼8 kW, respectively, a stable, superhydrophobic metallic surface was created with a sinusoidal pattern of 500 μm wavelength.

  14. On-demand one-step synthesis of monodisperse functional polymeric microspheres with droplet microfluidics.

    PubMed

    Yu, Xu; Cheng, Gong; Zhou, Ming-Da; Zheng, Si-Yang

    2015-04-01

    A simple and robust method for one-step synthesis of monodisperse functional polymeric microspheres was established by generation of reversed microemulsion droplets in aqueous phase inside microfluidic chips and controlled evaporation of the organic solvent. Using this method, water-soluble nanomaterials can be easily encapsulated into biodegradable Poly(D,L-lactic-co-glycolic acid) (PLGA) to form functional microspheres. By controlling the flow rate of microemulsion phase, PLGA polymeric microspheres with narrow size distribution and diameters in the range of ∼50-100 μm were obtained. As a demonstration of the versatility of the approach, high-quality fluorescent CdTe:Zn(2+) quantum dots (QDs) of various emission spectra, superparamagnetic Fe3O4 nanoparticles, and water-soluble carbon nanotubes (CNTs) were used to synthesize fluorescent PLGA@QDs, magnetic PLGA@Fe3O4, and PLGA@CNTs polymeric microspheres, respectively. In order to show specific applications, the PLGA@Fe3O4 were modified with polydopamine (PDA), and then the silver nanoparticles grew on the surfaces of the PLGA@Fe3O4@PDA polymeric microspheres by reducting the Ag(+) to Ag(0). The as-prepared PLGA@Fe3O4@PDA-Ag microspheres showed a highly efficient catalytic reduction of the 4-nitrophenol, a highly toxic substance. The monodisperse uniform functional PLGA polymeric microspheres can potentially be critically important for multiple biomedical applications.

  15. One-step Solution Processing of Ag, Au and Pd@MXene Hybrids for SERS

    NASA Astrophysics Data System (ADS)

    Satheeshkumar, Elumalai; Makaryan, Taron; Melikyan, Armen; Minassian, Hayk; Gogotsi, Yury; Yoshimura, Masahiro

    2016-08-01

    We report on one-step hybridization of silver, gold and palladium nanoparticles from solution onto exfoliated two-dimensional (2D) Ti3C2 titanium carbide (MXene) nanosheets. The produced hybrid materials can be used as substrates for surface-enhanced Raman spectroscopy (SERS). An approximate analytical approach is also developed for the calculation of the surface plasmon resonance (SPR) frequency of nanoparticles immersed in a medium, near the interface of two dielectric media with different dielectric constants. We obtained a good match with the experimental data for SPR wavelengths, 440 nm and 558 nm, respectively for silver and gold nanoparticles. In the case of palladium, our calculated SPR wavelength for the planar geometry was 160 nm, demonstrating that non-spherical palladium nanoparticles coupled with 2D MXene yield a broad, significanlty red-shifted SPR band with a peak at 230 nm. We propose a possible mechanism of the plasmonic hybridization of nanoparticles with MXene. The as-prepared noble metal nanoparticles on MXene show a highly sensitive SERS detection of methylene blue (MB) with calculated enhancement factors on the order of 105. These findings open a pathway for extending visible-range SERS applications of novel 2D hybrid materials in sensors, catalysis, and biomedical applications.

  16. One-step synthesis of platinum nanoparticles loaded in alginate bubbles.

    PubMed

    Yang, Chih-Hui; Wang, Wei-Ting; Grumezescu, Alexandru Mihai; Huang, Keng-Shiang; Lin, Yung-Sheng

    2014-01-01

    Composite particles with multifunctions have been extensively utilized for various applications. Bubble particles can be applied for ultrasound-mediated imaging, drug delivery, absorbers, cell culture, etc. This study proposes a one-step strategy to obtain Pt nanoparticles loaded in alginate bubbles. A needle-based droplet formation was used to generate uniform alginate particles about 2 mm in diameter. The hydrolysis reaction of NaBH4 was utilized to produce gaseous hydrogen and then trapped within alginate particles to form bubbles. The Pt(4+) mixed with alginate solution was dropped into the reservoir to react with reducing NaBH4 and hardening CaCl2 to form Pt nanoparticles-alginate composite bubbles. Results indicate that the size of bubbles decreases with the CaCl2 concentration (1% ~ 20%), and size of bubbles increases with the NaBH4 concentration (1 ~ 20 mM). The advantages for the present approach include low cost, easy operation, and effective production of Pt nanoparticles-alginate composite bubbles.

  17. A one-step-ahead pseudo-DIC for comparison of Bayesian state-space models.

    PubMed

    Millar, R B; McKechnie, S

    2014-12-01

    In the context of state-space modeling, conventional usage of the deviance information criterion (DIC) evaluates the ability of the model to predict an observation at time t given the underlying state at time t. Motivated by the failure of conventional DIC to clearly choose between competing multivariate nonlinear Bayesian state-space models for coho salmon population dynamics, and the computational challenge of alternatives, this work proposes a one-step-ahead DIC, DICp, where prediction is conditional on the state at the previous time point. Simulations revealed that DICp worked well for choosing between state-space models with different process or observation equations. In contrast, conventional DIC could be grossly misleading, with a strong preference for the wrong model. This can be explained by its failure to account for inflated estimates of process error arising from the model mis-specification. DICp is not based on a true conditional likelihood, but is shown to have interpretation as a pseudo-DIC in which the compensatory behavior of the inflated process errors is eliminated. It can be easily calculated using the DIC monitors within popular BUGS software when the process and observation equations are conjugate. The improved performance of DICp is demonstrated by application to the multi-stage modeling of coho salmon abundance in Lobster Creek, Oregon.

  18. The production of oxygenated polycrystalline graphene by one-step ethanol-chemical vapor deposition

    PubMed Central

    Paul, Rajat K.; Badhulika, Sushmee; Niyogi, Sandip; Haddon, Robert C.; Boddu, Veera M.; Costales-Nieves, Carmen; Bozhilov, Krassimir N.; Mulchandani, Ashok

    2012-01-01

    Large-area mono- and bilayer graphene films were synthesized on Cu foil (~ 1 inch2) in about 1 min by a simple ethanol-chemical vapor deposition (CVD) technique. Raman spectroscopy and high resolution transmission electron microscopy revealed the synthesized graphene films to have polycrystalline structures with 2–5 nm individual crystallite size which is a function of temperature up to 1000°C. X-ray photoelectron spectroscopy investigations showed about 3 atomic% carboxylic (COOH) functional groups were formed during growth. The field-effect transistor devices fabricated using polycrystalline graphene as conducting channel (Lc=10 μm; Wc=50 μm) demonstrated a p-type semiconducting behavior with high drive current and Dirac point at ~35 V. This simple one-step method of growing large area polycrystalline graphene films with semiconductor properties and easily functionalizable groups should assist in the realization of potential of polycrystalline graphene for nanoelectronics, sensors and energy storage devices. PMID:22408276

  19. One-step Solution Processing of Ag, Au and Pd@MXene Hybrids for SERS

    PubMed Central

    Satheeshkumar, Elumalai; Makaryan, Taron; Melikyan, Armen; Minassian, Hayk; Gogotsi, Yury; Yoshimura, Masahiro

    2016-01-01

    We report on one-step hybridization of silver, gold and palladium nanoparticles from solution onto exfoliated two-dimensional (2D) Ti3C2 titanium carbide (MXene) nanosheets. The produced hybrid materials can be used as substrates for surface-enhanced Raman spectroscopy (SERS). An approximate analytical approach is also developed for the calculation of the surface plasmon resonance (SPR) frequency of nanoparticles immersed in a medium, near the interface of two dielectric media with different dielectric constants. We obtained a good match with the experimental data for SPR wavelengths, 440 nm and 558 nm, respectively for silver and gold nanoparticles. In the case of palladium, our calculated SPR wavelength for the planar geometry was 160 nm, demonstrating that non-spherical palladium nanoparticles coupled with 2D MXene yield a broad, significanlty red-shifted SPR band with a peak at 230 nm. We propose a possible mechanism of the plasmonic hybridization of nanoparticles with MXene. The as-prepared noble metal nanoparticles on MXene show a highly sensitive SERS detection of methylene blue (MB) with calculated enhancement factors on the order of 105. These findings open a pathway for extending visible-range SERS applications of novel 2D hybrid materials in sensors, catalysis, and biomedical applications. PMID:27557838

  20. One-step large-scale deposition of salt-free DNA origami nanostructures

    PubMed Central

    Linko, Veikko; Shen, Boxuan; Tapio, Kosti; Toppari, J. Jussi; Kostiainen, Mauri A.; Tuukkanen, Sampo

    2015-01-01

    DNA origami nanostructures have tremendous potential to serve as versatile platforms in self-assembly -based nanofabrication and in highly parallel nanoscale patterning. However, uniform deposition and reliable anchoring of DNA nanostructures often requires specific conditions, such as pre-treatment of the chosen substrate or a fine-tuned salt concentration for the deposition buffer. In addition, currently available deposition techniques are suitable merely for small scales. In this article, we exploit a spray-coating technique in order to resolve the aforementioned issues in the deposition of different 2D and 3D DNA origami nanostructures. We show that purified DNA origamis can be controllably deposited on silicon and glass substrates by the proposed method. The results are verified using either atomic force microscopy or fluorescence microscopy depending on the shape of the DNA origami. DNA origamis are successfully deposited onto untreated substrates with surface coverage of about 4 objects/mm2. Further, the DNA nanostructures maintain their shape even if the salt residues are removed from the DNA origami fabrication buffer after the folding procedure. We believe that the presented one-step spray-coating method will find use in various fields of material sciences, especially in the development of DNA biochips and in the fabrication of metamaterials and plasmonic devices through DNA metallisation. PMID:26492833

  1. Biocompatible gold nanorods: one-step surface functionalization, highly colloidal stability, and low cytotoxicity.

    PubMed

    Liu, Kang; Zheng, Yuanhui; Lu, Xun; Thai, Thibaut; Lee, Nanju Alice; Bach, Udo; Gooding, J Justin

    2015-05-01

    The conjugation of gold nanorods (AuNRs) with polyethylene glycol (PEG) is one of the most effective ways to reduce their cytotoxicity arising from the cetyltrimethylammonium bromide (CTAB) and silver ions used in their synthesis. However, typical PEGylation occurs only at the tips of the AuNRs, producing partially modified AuNRs. To address this issue, we have developed a novel, facile, one-step surface functionalization method that involves the use of Tween 20 to stabilize AuNRs, bis(p-sulfonatophenyl)phenylphosphine (BSPP) to activate the AuNR surface for the subsequent PEGylation, and NaCl to etch silver from the AuNRs. This method allows for the complete removal of the surface-bound CTAB and the most active surface silver from the AuNRs. The produced AuNRs showed far lower toxicity than other methods to PEGylate AuNRs, with no apparent toxicity when their concentration is lower than 5 μg/mL. Even at a high concentration of 80 μg/mL, their cell viability is still four times higher than that of the tip-modified AuNRs. PMID:25874503

  2. Responsive hybrid microcapsules by the one-step interfacial thiol-ene photopolymerization.

    PubMed

    Liu, Dandan; Yu, Bing; Jiang, Xuesong; Yin, Jie

    2013-04-30

    We here demonstrated a general, convenient, and robust method to fabricate the hybrid microcapsules through the one-step thiol-ene photopolymerization at the interface between toluene and water. In the presence of amphiphilic polyhedral oligomeric silsesquioxane (POSS) containing thiol groups (PTPS) as reactive surfactants and trimethylolpropane triacrylate (TMPTA) as a cross-linker, the wall of hybrid microcapsules can be photo-cross-linked. The obtained hybrid microcapsules (HMCs) were well-characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM). The results revealed that the obtained HMCs are uniform with the tunable size in diameter (2-4 μm) and wall thickness (55-120 nm). The size of HMCs increased with the increasing content of toluene. The wall thickness of HMCs decreased with the increasing content of toluene, while the wall thickness of HMCs increased with the increasing content of cross-linker TMPTA. Furthermore, HMCs are thermoresponsive in aqueous solution, can encapsulate both hydrophobic and dydrophilic dyes, and can be used in the controlled dispersion of dyes in different mediums. It is believed that this simple, robust, and general method to fabricate the hybrid microcapsules will extend the potential application fields of microcapsules, such as in the controlled dispersion and drug delivery.

  3. A one-step-ahead pseudo-DIC for comparison of Bayesian state-space models.

    PubMed

    Millar, R B; McKechnie, S

    2014-12-01

    In the context of state-space modeling, conventional usage of the deviance information criterion (DIC) evaluates the ability of the model to predict an observation at time t given the underlying state at time t. Motivated by the failure of conventional DIC to clearly choose between competing multivariate nonlinear Bayesian state-space models for coho salmon population dynamics, and the computational challenge of alternatives, this work proposes a one-step-ahead DIC, DICp, where prediction is conditional on the state at the previous time point. Simulations revealed that DICp worked well for choosing between state-space models with different process or observation equations. In contrast, conventional DIC could be grossly misleading, with a strong preference for the wrong model. This can be explained by its failure to account for inflated estimates of process error arising from the model mis-specification. DICp is not based on a true conditional likelihood, but is shown to have interpretation as a pseudo-DIC in which the compensatory behavior of the inflated process errors is eliminated. It can be easily calculated using the DIC monitors within popular BUGS software when the process and observation equations are conjugate. The improved performance of DICp is demonstrated by application to the multi-stage modeling of coho salmon abundance in Lobster Creek, Oregon. PMID:25370730

  4. In situ biosynthesis of bacterial nanocellulose-CaCO3 hybrid bionanocomposite: One-step process.

    PubMed

    Mohammadkazemi, Faranak; Faria, Marisa; Cordeiro, Nereida

    2016-08-01

    In this work, a simple and green route to the synthesis of the bacterial nanocellulose-calcium carbonate (BNC/CaCO3) hybrid bionanocomposites using one-step in situ biosynthesis was studied. The CaCO3 was incorporated in the bacterial nanocellulose structure during the cellulose biosynthesis by Gluconacetobacter xylinus PTCC 1734 bacteria. Hestrin-Schramm (HS) and Zhou (Z) culture media were used to the hybrid bionanocomposites production and the effect of ethanol addition was investigated. Attenuated total reflection Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, inverse gas chromatography and thermogravimetric analysis were used to characterize the samples. The experimental results demonstrated that the ethanol and culture medium play an important role in the BNC/CaCO3 hybrid bionanocomposites production, structure and properties. The BNC/CaCO3 biosynthesized in Z culture medium revealed higher O/C ratio and amphoteric surface character, which justify the highest CaCO3 content incorporation. The CaCO3 was incorporated into the cellulosic matrix decreasing the bacterial nanocellulose crystallinity. This work reveals the high potential of in situ biosynthesis of BNC/CaCO3 hybrid bionanocomposites and opens a new way to the high value-added applications of bacterial nanocellulose. PMID:27157766

  5. One-step fermentative production of poly(lactate-co-glycolate) from carbohydrates in Escherichia coli.

    PubMed

    Choi, So Young; Park, Si Jae; Kim, Won Jun; Yang, Jung Eun; Lee, Hyuk; Shin, Jihoon; Lee, Sang Yup

    2016-04-01

    Poly(lactate-co-glycolate) (PLGA) is a widely used biodegradable and biocompatible synthetic polymer. Here we report one-step fermentative production of PLGA in engineered Escherichia coli harboring an evolved polyhydroxyalkanoate (PHA) synthase that polymerizes D-lactyl-CoA and glycolyl-CoA into PLGA. Introduction of the Dahms pathway enables production of glycolate from xylose. Deletion of ptsG enables simultaneous utilization of glucose and xylose. An evolved propionyl-CoA transferase converts D-lactate and glycolate to D-lactyl-CoA and glycolyl-CoA, respectively. Deletion of adhE, frdB, pflB and poxB prevents by-product formation. We also demonstrate modulation of the monomer fractions in PLGA by overexpressing ldhA and deleting dld to increase the proportion of D-lactate or by deleting aceB, glcB, glcD, glcE, glcF and glcG to increase the proportion of glycolate. Incorporation of 2-hydroxybutyrate is prevented by deleting ilvA or feeding strains with L-isoleucine. The utility of our approach for generating diverse forms of PLGA is shown by the production of copolymers containing 3-hydroxybutyrate, 4-hydroxybutyrate or 2-hydroxyisovalerate. PMID:26950748

  6. Hetero-oligonucleotide nanoscale tiles capable of two-dimensional lattice formation as testbeds for a rapid, affordable purification methodology.

    PubMed

    Lukeman, Philip S

    2013-06-21

    New nanoscale hetero-oligonucleotide tiles are assembled from DNA, RNA and morpholino oligos and purified using size exclusion filtration. Homo-oligonucleotide tiles assembled from RP-cartridge processed DNA oligos are purified by nondenaturing gel electrophoresis. These tiles' purity and homogeneity are demonstrated by gel electrophoresis and their incorporation into two-dimensional arrays visualized by AFM. This purification methodology increases throughput and decreases costs for researchers who wish to screen multiple tiles for utilization in structural or analytical studies.

  7. Rapid isolation and purification of 1-cyano-2-hydroxy-3-butene (crambene) from Crambe abyssinica seed meal using immiscible solvent extraction and high-performance liquid chromatography.

    PubMed

    Niedoborski, T E; Klein, B P; Wallig, M A

    2001-08-01

    1-Cyano-2-hydroxy-3-butene (crambene) is a nitrile found in cruciferous vegetables that causes significant upregulation of quinone reductase and glutathione S-transferases in vivo and in vitro, making it a likely candidate as a cancer chemopreventive compound. To investigate further the putative anticarcinogenic mechanisms of crambene, a compound of the highest possible purity is vital. Therefore, a rapid and effective method of purification of crambene is necessary to continue studies of its beneficial health effects. A rapid method to isolate and purify natural crambene from either Crambe abyssinica (crambe) seed or commercially processed crambe seed meal was developed using immiscible solvent extraction followed by high-performance liquid chromatography. Use of this methodology eliminated the need for time-consuming and relatively inefficient column chromatography, improved extraction efficiency, and resulted in higher purity than previously used methodologies. Elimination of trace amounts of fatty acid residues, unachievable with previous methodologies, also was accomplished.

  8. Quantification of Hantaan virus with a SYBR green I-based one-step qRT-PCR assay.

    PubMed

    Jiang, Wei; Yu, Hai-tao; Zhao, Ke; Zhang, Ye; Du, Hong; Wang, Ping-zhong; Bai, Xue-fan

    2013-01-01

    Hantaan virus (HTNV) is a major zoonotic pathogen that causes hemorrhagic fever with renal syndrome (HFRS) in Asia, especially in China. Shaanxi province, which is located in northwest of China, is one of the areas in China most severely afflicted with HFRS epidemics annually. This study aims to establish a quantitative RT-PCR (qRT-PCR) assay to detect HTNV both in cell culture and clinical serum samples. We established a SYBR Green I-based one-step qRT-PCR assay that targets the S segment of the HTNV genome for rapid detection and quantification. The HTNV cRNA standards were constructed by in vitro transcription, and the copy numbers of the HTNV cRNA were quantified. Standard curve was generated by determining the mean cycle threshold (Ct) values versus 10-fold serial dilutions of the HTNV cRNA over a range of 1 × 10(8) to 1 × 10(3) copies/μl. The standard curve had a reaction efficiency of 102.1%, a correlation coefficient (R(2)) of 0.998, and a slope of -3.273. The coefficient of variation (CV) of the intra- and inter-assays ranged from 0.68% to 3.00% and from 0.86% to 3.21%, respectively. The cycle intervals of the qRT-PCR assay between each dilution ranged from 2.9 to 3.8 cycles, and the lowest detection limit of the qRT-PCR assay was 10 copies/μl. The assay exhibited high specificity that was confirmed by melting curve analysis, and no cross reaction with the Seoul virus (SEOV) and other viruses (HBV, HCV and HIV) was observed. HTNV RNA was also detected in the 27 serum samples of clinical HFRS patients using the assay, and the HTNV RNA viral load ranged from 2.06 × 10(1) to 1.95 × 10(5) copies/μl. The SYBR Green I-based one-step qRT-PCR assay is a sensitive, specific, reproducible, and simple method for detecting and quantifying HTNV in cell culture and clinical samples.

  9. Quantification of Hantaan virus with a SYBR green I-based one-step qRT-PCR assay.

    PubMed

    Jiang, Wei; Yu, Hai-tao; Zhao, Ke; Zhang, Ye; Du, Hong; Wang, Ping-zhong; Bai, Xue-fan

    2013-01-01

    Hantaan virus (HTNV) is a major zoonotic pathogen that causes hemorrhagic fever with renal syndrome (HFRS) in Asia, especially in China. Shaanxi province, which is located in northwest of China, is one of the areas in China most severely afflicted with HFRS epidemics annually. This study aims to establish a quantitative RT-PCR (qRT-PCR) assay to detect HTNV both in cell culture and clinical serum samples. We established a SYBR Green I-based one-step qRT-PCR assay that targets the S segment of the HTNV genome for rapid detection and quantification. The HTNV cRNA standards were constructed by in vitro transcription, and the copy numbers of the HTNV cRNA were quantified. Standard curve was generated by determining the mean cycle threshold (Ct) values versus 10-fold serial dilutions of the HTNV cRNA over a range of 1 × 10(8) to 1 × 10(3) copies/μl. The standard curve had a reaction efficiency of 102.1%, a correlation coefficient (R(2)) of 0.998, and a slope of -3.273. The coefficient of variation (CV) of the intra- and inter-assays ranged from 0.68% to 3.00% and from 0.86% to 3.21%, respectively. The cycle intervals of the qRT-PCR assay between each dilution ranged from 2.9 to 3.8 cycles, and the lowest detection limit of the qRT-PCR assay was 10 copies/μl. The assay exhibited high specificity that was confirmed by melting curve analysis, and no cross reaction with the Seoul virus (SEOV) and other viruses (HBV, HCV and HIV) was observed. HTNV RNA was also detected in the 27 serum samples of clinical HFRS patients using the assay, and the HTNV RNA viral load ranged from 2.06 × 10(1) to 1.95 × 10(5) copies/μl. The SYBR Green I-based one-step qRT-PCR assay is a sensitive, specific, reproducible, and simple method for detecting and quantifying HTNV in cell culture and clinical samples. PMID:24278449

  10. A Novel One-Step Fabricated, Droplet-Based Electrochemical Sensor for Facile Biochemical Assays.

    PubMed

    Yao, Yong; Zhang, Chunsun

    2016-01-01

    A simple, novel concept for the one-step fabrication of a low-cost, easy-to-use droplet-based electrochemical (EC) sensor is described, in which the EC reagents are contained in a droplet and the droplet assay is operated on a simple planar surface instead of in a complicated closed channel/chamber. In combination with an elegant carbon electrode configuration, screen-printed on a widely available polyethylene terephthalate (PET) substrate, the developed sensor exhibits a stable solution-restriction capacity and acceptable EC response, and thus can be used directly for the detection of different analytes (including ascorbic acid (AA), copper ions (Cu(2+)), 2'-deoxyguanosine 5'-triphosphate (dGTP) and ferulic acid (FA)), without any pretreatment. The obtained, acceptable linear ranges/detection limits for AA, Cu(2+), dGTP and FA are 0.5-10/0.415 mM, (0.0157-0.1574 and 0.1574-1.5736)/0.011 mM, 0.01-0.1/0.008 mM and 0.0257-0.515/0.024 mM, respectively. Finally, the utility of the droplet-based EC sensor was demonstrated for the determination of AA in two commercial beverages, and of Cu(2+) in two water samples, with reliable recovery and good stability. The applicability of the droplet-based sensor demonstrates that the proposed EC strategy is potentially a cost-effective solution for a series of biochemical sensing applications in public health, environmental monitoring, and the developing world. PMID:27527176

  11. One-step high-efficiency CRISPR/Cas9-mediated genome editing in Streptomyces.

    PubMed

    Huang, He; Zheng, Guosong; Jiang, Weihong; Hu, Haifeng; Lu, Yinhua

    2015-04-01

    The RNA-guided DNA editing technology CRISPRs (clustered regularly interspaced short palindromic repeats)/Cas9 had been used to introduce double-stranded breaks into genomes and to direct subsequent site-specific insertions/deletions or the replacement of genetic material in bacteria, such as Escherichia coli, Streptococcus pneumonia, and Lactobacillus reuteri. In this study, we established a high-efficiency CRISPR/Cas9 genome editing plasmid pKCcas9dO for use in Streptomyces genetic manipulation, which comprises a target-specific guide RNA, a codon-optimized cas9, and two homology-directed repair templates. By delivering pKCcas9dO series editing plasmids into the model strain Streptomyces coelicolor M145, through one-step intergeneric transfer, we achieved the genome editing at different levels with high efficiencies of 60%-100%, including single gene deletion, such as actII-orf4, redD, and glnR, and single large-size gene cluster deletion, such as the antibiotic biosynthetic clusters of actinorhodin (ACT) (21.3 kb), undecylprodigiosin (RED) (31.6 kb), and Ca(2+)-dependent antibiotic (82.8 kb). Furthermore, we also realized simultaneous deletions of actII-orf4 and redD, and of the ACT and RED biosynthetic gene clusters with high efficiencies of 54% and 45%, respectively. Finally, we applied this system to introduce nucleotide point mutations into the rpsL gene, which conferred the mutants with resistance to streptomycin. Notably, using this system, the time required for one round of genome modification is reduced by one-third or one-half of those for conventional methods. These results clearly indicate that the established CRISPR/Cas9 genome editing system substantially improves the genome editing efficiency compared with the currently existing methods in Streptomyces, and it has promise for application to genome modification in other Actinomyces species.

  12. Durability of solvent-free one-step self-etch adhesive under simulated intrapulpal pressure

    PubMed Central

    2015-01-01

    Background There are different solvents presented in simplified adhesives. Bond-1 SF has been developed, which contains neither water nor organic solvents, in order to eliminate technical issues in terms of evaporation of solvents and concerns for the durability of resin-dentin bond. Thus this study was conducted to evaluate the microtensile bond strength (?TBS) of solvent-free and ethanol-based one-step self-etch adhesives to dentin under simulated intrapulpal pressure (IPP). Material and Methods Occlusal surfaces of human molars were prepared to expose mid-dentin depth. Bond-1SF Solvent-Free SE [SF] and AdperTM easy one adhesives [AE] were applied on dentin specimens. Resin composite build up was done in increments. Then specimens were stored under simulated IPP 20 mmHg, immersed in artificial saliva at 37 ºC for 24 hours (24h) and 6 months (6m). Specimens were sectioned into sticks of (1 mm²) to be tested for (?TBS) using a universal testing machine. Both fractured sections of each stick were inspected using a stereomicroscope at 40× magnification to determine the mode of failure. Data were statistically analyzed by Two-way ANOVA of Variance. Results There was no statistically significant difference between the mean ?TBS of both [SF] and [AE] adhesives at both aging periods, 24h and 6m (p< 0.1103) and (p< 0.7148) respectively. Only for [AE] there was statistical significance for aging periods (p< 0.0057*). The most represented modes of failure were adhesive failure at tooth side. Conclusions Under simulated IPP solvent-free adhesive [SF] had comparable performance as ethanol-based adhesive [AE] when bonded to dentin substrate. Key words:Bond strength, dentin, simulated intrapulpal pressure, self-etch adhesives, solvents. PMID:26535091

  13. One-Step Synthesis of Zeolite Membranes Containing Catalytic Metal Nanoclusters.

    PubMed

    Kim, Seok-Jhin; Tan, Shuai; Taborga Claure, Micaela; Briones Gil, Laura; More, Karren L; Liu, Yujun; Moore, Jason S; Dixit, Ravindra S; Pendergast, John G; Sholl, David S; Jones, Christopher W; Nair, Sankar

    2016-09-21

    Metal-loaded zeolitic membranes are promising candidates as catalytic membrane reactors. We report a one-step synthesis method to synthesize zeolite membranes containing metal nanoclusters, that has advantages in comparison to multistep methods such as impregnation and ion exchange. Pure-silica MFI zeolite-Pt hybrid membranes were prepared by hydrothermal synthesis with addition of 3-mercaptopropyl-trimethoxysilane (MPS) and a platinum precursor. Composition analysis and mapping by energy-dispersive X-ray spectroscopy (EDX) reveal that Pt ions/clusters are uniformly distributed along the membrane cross-section. High-magnification scanning transmission electron microscopy (STEM) analysis shows that Pt metal clusters in the hybrid zeolite membrane have a diameter distribution in the range of 0.5-2.0 nm. In contrast, a pure-silica MFI membrane synthesized from an MPS-free solution shows negligible incorporation of Pt metal clusters. To characterize the properties of the hybrid (zeolite/metal) membrane, it was used as a catalytic membrane reactor (CMR) for high-temperature propane dehydrogenation (PDH) at 600 °C and 1 atm. The results indicate that Pt metal clusters formed within the MFI zeolite membrane can serve as effective catalysts for high-temperature PDH reaction along with H2 removal via membrane permeation, thereby increasing both conversion and selectivity in relation to a conventional membrane reactor containing an equivalent amount of packed Pt catalyst in contact with an MFI membrane. The hybrid zeolite-Pt CMR also showed stable conversion and selectivity upon extended high-temperature operation (12 h), indicating that encapsulation in the zeolite allowed thermal stabilization of the Pt nanoclusters and reduced catalyst deactivation. PMID:27574979

  14. Magnetic studies of mesoporous nanostructured iron oxide materials synthesized by one-step soft-templating.

    PubMed

    Jin, Jing; Hines, William A; Kuo, Chung-Hao; Perry, David M; Poyraz, Altug S; Xia, Yan; Zaidi, Taha; Nieh, Mu-Ping; Suib, Steven L

    2015-07-14

    A combined magnetization and (57)Fe spin-echo nuclear magnetic resonance (NMR) study has been carried out on mesoporous nanostructured materials consisting of the magnetite (Fe3O4) and maghemite (γ-Fe2O3) phases. Two series of samples were synthesized using a recently developed one-step soft-templating approach with systematic variations in calcination temperature and reaction atmosphere. Nuclear magnetic resonance has been shown to be a valuable tool for distinguishing between the two magnetic iron oxide spinel phases, Fe3O4 and γ-Fe2O3, on the nanoscale as well as monitoring phase transformation resulting from oxidation. For the Fe3O4 and γ-Fe2O3 phases, peaks in the NMR spectra are attributed to Fe in the tetrahedral (A) sites and octahedral (B) sites. The magnetic field dependence of the peaks was observed and confirmed the site assignments. Fe3O4 on a nanoscale readily oxidizes to form γ-Fe2O3 and this was clearly evident in the NMR spectra. As evidenced by transmission electron microscope (TEM) images, the porous mesostructure for the iron oxide materials is formed by a random close-packed aggregation of nanoparticles; correspondingly, superparamagnetic behavior was observed in the magnetic measurements. Although X-ray diffraction (XRD) shows the spinel structure for the Fe3O4 and γ-Fe2O3 phases, unlike NMR, it is difficult to distinguish between the two phases with XRD. Nitrogen sorption isotherms characterize the mesoporous structures of the materials, and yield BET surface area values and limited BJH pore size distribution curves.

  15. Technical note on probabilistic assessment of one-step-ahead rainfall variation by Split Markov Process

    NASA Astrophysics Data System (ADS)

    Maity, R.; Prasad, D.

    2011-01-01

    In this paper, Split Markov Process (SMP) is developed to assess one-step-ahead variation of daily rainfall at a rain gauge station. SMP is an advancement of general Markov Process (MP) and specially developed for probabilistic assessment of change in daily rainfall magnitude. The approach is based on a first-order Markov chain to simulate daily rainfall variation at a point through state/sub-state Transitional Probability Matrix (TPM). The state/sub-state TPM is based on the historical transitions from a particular state to a particular sub-state, which is the basic difference between SMP and general MP. In MP, the transition from a particular state to another state is investigated. However, in SMP, the daily rainfall magnitude is categorized into different states and change in magnitude from one temporal step to another is categorized into different sub-states for the probabilistic assessment of rainfall variation. The cumulative state/sub-state TPM is represented in a contour plot at different probability levels. The developed cumulative state/sub-state TPM is used to assess the possible range of rainfall in next time step, in a probabilistic sense. Application of SMP is investigated for daily rainfall at Khandwa station in the Nimar district of Madhya Pradesh, India. Eighty years of daily monsoon rainfall is used to develop the state/sub-state TPM and twenty years data is used to investigate its performance. It is observed that the predicted range of daily rainfall captures the actual observed rainfall with few exceptions. Overall, the assessed range, particularly the upper limit, provides a quantification possible extreme value in the next time step, which is very useful information to tackle the extreme events, such flooding, water logging etc.

  16. A novel one-step, highly sensitive fluorometric assay to evaluate cell-mediated cytotoxicity.

    PubMed

    Nociari, M M; Shalev, A; Benias, P; Russo, C

    1998-04-15

    In this study, a fluorometric method using alamarBlue has been developed for detecting cell-mediated cytotoxicity in vitro. AlamarBlue is a non-toxic metabolic indicator of viable cells that becomes fluorescent upon mitochondrial reduction. Specific lysis of targets by effector cells is quantified by comparing the total number of viable cells in wells containing effector and targets together, with wells where target and effector cells were separately seeded. Cell-mediated cytotoxic activity by alloreactive T cells and natural killer cells has been detected using a novel application of the alamarBlue technique. The assay that we have developed to detect cell-mediated cytotoxicity is extremely sensitive and specific and requires a significant lower number of effector cells than the standard 51Cr assay. Since alamarBlue reagent is non-toxic to cells and the assay can be performed under sterile conditions, effector cells may be recovered at the end for further analysis or cell expansion, if desired. Direct comparison of cell-mediated cytotoxicity measured by the alamarBlue method with the standard 51Cr release assay revealed that the former method is as specific and more sensitive than the conventional assay. Moreover, very small inter and intra-assay variations have been observed for alamarBlue cytotoxicity assays. In conclusion, this study shows that the alamarBlue assay is an extremely sensitive, economical, simple and non-toxic procedure to evaluate cell-mediated cytotoxicity that yields accurate results using a limited number of effector cells. Furthermore, since this assay is a one-step procedure, and does not involve any risk for the personnel, it may be useful to analyze automatically cell-mediated cytotoxicity in a large number of samples.

  17. A Novel One-Step Fabricated, Droplet-Based Electrochemical Sensor for Facile Biochemical Assays

    PubMed Central

    Yao, Yong; Zhang, Chunsun

    2016-01-01

    A simple, novel concept for the one-step fabrication of a low-cost, easy-to-use droplet-based electrochemical (EC) sensor is described, in which the EC reagents are contained in a droplet and the droplet assay is operated on a simple planar surface instead of in a complicated closed channel/chamber. In combination with an elegant carbon electrode configuration, screen-printed on a widely available polyethylene terephthalate (PET) substrate, the developed sensor exhibits a stable solution-restriction capacity and acceptable EC response, and thus can be used directly for the detection of different analytes (including ascorbic acid (AA), copper ions (Cu2+), 2′-deoxyguanosine 5′-triphosphate (dGTP) and ferulic acid (FA)), without any pretreatment. The obtained, acceptable linear ranges/detection limits for AA, Cu2+, dGTP and FA are 0.5–10/0.415 mM, (0.0157–0.1574 and 0.1574–1.5736)/0.011 mM, 0.01–0.1/0.008 mM and 0.0257–0.515/0.024 mM, respectively. Finally, the utility of the droplet-based EC sensor was demonstrated for the determination of AA in two commercial beverages, and of Cu2+ in two water samples, with reliable recovery and good stability. The applicability of the droplet-based sensor demonstrates that the proposed EC strategy is potentially a cost-effective solution for a series of biochemical sensing applications in public health, environmental monitoring, and the developing world. PMID:27527176

  18. One-Step Synthesis of Zeolite Membranes Containing Catalytic Metal Nanoclusters.

    PubMed

    Kim, Seok-Jhin; Tan, Shuai; Taborga Claure, Micaela; Briones Gil, Laura; More, Karren L; Liu, Yujun; Moore, Jason S; Dixit, Ravindra S; Pendergast, John G; Sholl, David S; Jones, Christopher W; Nair, Sankar

    2016-09-21

    Metal-loaded zeolitic membranes are promising candidates as catalytic membrane reactors. We report a one-step synthesis method to synthesize zeolite membranes containing metal nanoclusters, that has advantages in comparison to multistep methods such as impregnation and ion exchange. Pure-silica MFI zeolite-Pt hybrid membranes were prepared by hydrothermal synthesis with addition of 3-mercaptopropyl-trimethoxysilane (MPS) and a platinum precursor. Composition analysis and mapping by energy-dispersive X-ray spectroscopy (EDX) reveal that Pt ions/clusters are uniformly distributed along the membrane cross-section. High-magnification scanning transmission electron microscopy (STEM) analysis shows that Pt metal clusters in the hybrid zeolite membrane have a diameter distribution in the range of 0.5-2.0 nm. In contrast, a pure-silica MFI membrane synthesized from an MPS-free solution shows negligible incorporation of Pt metal clusters. To characterize the properties of the hybrid (zeolite/metal) membrane, it was used as a catalytic membrane reactor (CMR) for high-temperature propane dehydrogenation (PDH) at 600 °C and 1 atm. The results indicate that Pt metal clusters formed within the MFI zeolite membrane can serve as effective catalysts for high-temperature PDH reaction along with H2 removal via membrane permeation, thereby increasing both conversion and selectivity in relation to a conventional membrane reactor containing an equivalent amount of packed Pt catalyst in contact with an MFI membrane. The hybrid zeolite-Pt CMR also showed stable conversion and selectivity upon extended high-temperature operation (12 h), indicating that encapsulation in the zeolite allowed thermal stabilization of the Pt nanoclusters and reduced catalyst deactivation.

  19. Lumicyano™: a new fluorescent cyanoacrylate for a one-step luminescent latent fingermark development.

    PubMed

    Prete, Cosimo; Galmiche, Laurent; Quenum-Possy-Berry, Fifonsi-Gwladys; Allain, Clémence; Thiburce, Nicolas; Colard, Thomas

    2013-12-10

    Latent fingermarks developed by cyanoacrylate fuming often lack contrast; therefore further enhancement is required, such as dye staining. This second step is part of the conventional detection sequences performed by forensics practitioners. Dye-staining or powder dusting aims at improving contrast and at increasing the legibility of details, yet their use may at times be limited. Indeed powder dusting may not be effective due to unexpected adherence to the background, and poor affinity to the cyanoacrylate. In the same way staining processes can dye a whole semi-porous surface or may wash the marks. To avoid that second step, a new luminescent cyanoacrylate (Lumicyano™) which allows one-step development without changing the fuming chamber settings (80% humidity rate, 120°C fuming temperature) was developed and assessed. This study aimed at comparing Lumicyano™ to a conventional two-step process. A detailed sensitivity study was conducted on glass slides, as well as the processing of various non-porous and semi-porous substrates, usually considered as problematic for a dye staining step. The results indicate that Lumicyano™ detects fingermarks with equal or better sensitivity and ridge details than currently used cyanoacrylate. Secondly in luminescent mode, good ridges clarity and excellent contrast are observed, even if Lumicyano™ is sometimes less bright than the two-step process. Furthermore, conventional enhancement can still be carried out if needed. As a conclusion, Lumicyano™ makes it possible to avoid an enhancement step which can be detrimental to further examinations, particularly on rough or semi-porous surfaces.

  20. Luminescent transition metal dichalcogenide nanosheets through one-step liquid phase exfoliation

    NASA Astrophysics Data System (ADS)

    Mar Bernal, M.; Álvarez, Lidia; Giovanelli, Emerson; Arnáiz, Adriana; Ruiz-González, Luisa; Casado, Santiago; Granados, Daniel; Pizarro, Ana M.; Castellanos-Gomez, Andres; Pérez, Emilio M.

    2016-09-01

    Liquid phase exfoliation (LPE) from the bulk is an adequate method for the mass-production of thin nanosheets of transition metal dichalcogenides (TMDCs). However, making suspensions in which the extraordinary properties of mechanically exfoliated TMDCs are observable remains a challenge. We describe a mild LPE method to produce luminescent suspensions of MoS2 and WS2 in N-methylpyrrolidone or isopropanol/water mixtures, without the need for a purification step. The key differences in our experimental procedure compared to previously reported LPE methods are the use of mild bath sonication at controlled temperature and the low initial concentration of the parent TMDC. Spectroscopic and AFM data confirm that an overwhelming majority of the sample is composed of ultrathin nanosheets. HREM data support the formation of the luminescent 2H polytype. The ultrathin nanosheets can be transferred to pure water and cell culture medium. Confocal fluorescence microscopy experiments on MCF-7 breast cancer cells exposed to LPE WS2 show that the cells are viable and the photoluminescence of the nanosheets is detectable.

  1. Hetero-oligonucleotide nanoscale tiles capable of two-dimensional lattice formation as testbeds for a rapid, affordable purification methodology.

    PubMed

    Lukeman, Philip S

    2013-06-21

    New nanoscale hetero-oligonucleotide tiles are assembled from DNA, RNA and morpholino oligos and purified using size exclusion filtration. Homo-oligonucleotide tiles assembled from RP-cartridge processed DNA oligos are purified by nondenaturing gel electrophoresis. These tiles' purity and homogeneity are demonstrated by gel electrophoresis and their incorporation into two-dimensional arrays visualized by AFM. This purification methodology increases throughput and decreases costs for researchers who wish to screen multiple tiles for utilization in structural or analytical studies. PMID:23676891

  2. One-Step Fabrication of Stretchable Copper Nanowire Conductors by a Fast Photonic Sintering Technique and Its Application in Wearable Devices.

    PubMed

    Ding, Su; Jiu, Jinting; Gao, Yue; Tian, Yanhong; Araki, Teppei; Sugahara, Tohru; Nagao, Shijo; Nogi, Masaya; Koga, Hirotaka; Suganuma, Katsuaki; Uchida, Hiroshi

    2016-03-01

    Copper nanowire (CuNW) conductors have been considered to have a promising perspective in the area of stretchable electronics due to the low price and high conductivity. However, the fabrication of CuNW conductors suffers from harsh conditions, such as high temperature, reducing atmosphere, and time-consuming transfer step. Here, a simple and rapid one-step photonic sintering technique was developed to fabricate stretchable CuNW conductors on polyurethane (PU) at room temperature in air environment. It was observed that CuNWs were instantaneously deoxidized, welded and simultaneously embedded into the soft surface of PU through the one-step photonic sintering technique, after which highly conductive network and strong adhesion between CuNWs and PU substrates were achieved. The CuNW/PU conductor with sheet resistance of 22.1 Ohm/sq and transmittance of 78% was achieved by the one-step photonic sintering technique within only 20 μs in air. Besides, the CuNW/PU conductor could remain a low sheet resistance even after 1000 cycles of stretching/releasing under 10% strain. Two flexible electronic devices, wearable sensor and glove-shaped heater, were fabricated using the stretchable CuNW/PU conductor, demonstrating that our CuNW/PU conductor could be integrated into various wearable electronic devices for applications in food, clothes, and medical supplies fields.

  3. Capillary-driven multiparametric microfluidic chips for one-step immunoassays.

    PubMed

    Gervais, Luc; Hitzbleck, Martina; Delamarche, Emmanuel

    2011-09-15

    Here we present a capillary-driven microfluidic chip for "one-step" immunoassays. The chip allows for easy modification of several assay parameters such as the flow rates of sample, the volumes of samples for tests, and the type of reagents and receptors for detecting analytes. We therefore term such a chip a multiparametric chip and illustrate this concept with the integration and release of anti-C-reactive protein (CRP) detection antibodies (dAbs) together with splitting flow of samples containing CRP across lines of anti-CRP capture antibodies (cAbs). The microfluidic chip is fabricated in Si and is sealed with polydimethylsiloxane (PDMS) patterned with cAbs. The microfluidic chip is ∼1.7×3.4 cm(2) and is capable of analyzing 20 μL of human serum in 6 parallel flow paths with a range of flow rates from 3.3 nL s(-1) to 0.46 nL s(-1). An inkjet spotter was used to deposit 10.6 nL of dAb solution in a structure vicinal to the main flow path of the chip. The consequent asymmetric release of dAbs in a stream of human serum is compensated by a Dean flow mixer having 9 mixing loops and a footprint of 2.8 mm × 0.78 mm. The quantity of dAb present in the half of the flow path close to the spotting region decreases from 83% at the entrance of the mixer to 52% in the region after the mixer. The sample is then equally split into 6 reaction chambers and proceeds via connecting channels to 2 μL capillary pumps. The hydraulic resistance of the connecting channels is designed to vary flow rates, and therefore the kinetics of capture of CRP-dAb complexes, from 10 min to 72 min. The increased incubation time leads to a fourfold increase in detection signal in the reaction chamber with the longer incubation time. The concept presented here is flexible and suited for implementing various surface fluorescence immunoassays on a capillary-driven microfluidic chip.

  4. One-step synthesis and stabilization of gold nanoparticles and multilayer film assembly

    SciTech Connect

    Bao Yayan; Bi Lihua; Wu Lixin

    2011-03-15

    Au nanoparticles (NPs) were synthesized in the one-pot procedure in water at room temperature with the wheel-shaped V{sup V}-V{sup IV} mixed-valence tungstovanadate [P{sub 8}W{sub 48}O{sub 184{l_brace}}V{sub 4}{sup V}V{sub 2}{sup IV}O{sub 12}(H{sub 2}O){sub 2{r_brace}2}]{sup 32-} (V12) acting as both reducing and stabilizing agents. The V12 stabilized Au NPs (Au-V12 NPs) were characterized by SEM, TEM, DLS, UV-vis spectroscopy, XPS, and XRD analyses and the negatively charged surface of the Au-V12 NPs was proved by the zeta potential analysis. Based on the layer-by-layer assembly (LbL), the Au-V12 NPs-containing multilayer films have been fabricated on ITO-coated glass slide and quartz substrates with poly(ethyleneimine) (PEI). The regular growth of the multilayer films was monitored by UV-vis spectroscopy and cyclic voltammetry, the composition was characterized by XPS. The Au-V12 NPs based composite films showed electrocatalytic activities towards the reduction of dioxygen and the oxidation of methanol. This approach is expected to open the way towards procedures aimed at the one-step fabrication of Au NPs and polyoxometalates (POMs) into the multilayer films. -- Graphical abstract: The wheel-shaped V{sup V}-V{sup IV} mixed-valence tungstovanadate [P{sub 8}W{sub 48}O{sub 184{l_brace}}V{sub 4}{sup V}V{sub 2}{sup IV}O{sub 12}(H{sub 2}O){sub 2{r_brace}2}]{sup 32-} (V12) stabilized Au nanoparticles (Au-V12 NPs) have been synthesized and characterized. The multilayer films containing Au-V12 NPs were fabricated and their electrocatalytic properties were studied. Display Omitted Research highlights: {yields} Au core-V12 shell nanostructures, Au-V12 NPs, were synthesized and characterized. {yields} The negatively charged Au NPs were fabricated and catalytic properties were studied. {yields} This study opens the way to the fabrication of multifunctional thin-film materials.

  5. Hetero-oligonucleotide nanoscale tiles capable of two-dimensional lattice formation as testbeds for a rapid, affordable purification methodology

    NASA Astrophysics Data System (ADS)

    Lukeman, Philip S.

    2013-05-01

    New nanoscale hetero-oligonucleotide tiles are assembled from DNA, RNA and morpholino oligos and purified using size exclusion filtration. Homo-oligonucleotide tiles assembled from RP-cartridge processed DNA oligos are purified by nondenaturing gel electrophoresis. These tiles' purity and homogeneity are demonstrated by gel electrophoresis and their incorporation into two-dimensional arrays visualized by AFM. This purification methodology increases throughput and decreases costs for researchers who wish to screen multiple tiles for utilization in structural or analytical studies.New nanoscale hetero-oligonucleotide tiles are assembled from DNA, RNA and morpholino oligos and purified using size exclusion filtration. Homo-oligonucleotide tiles assembled from RP-cartridge processed DNA oligos are purified by nondenaturing gel electrophoresis. These tiles' purity and homogeneity are demonstrated by gel electrophoresis and their incorporation into two-dimensional arrays visualized by AFM. This purification methodology increases throughput and decreases costs for researchers who wish to screen multiple tiles for utilization in structural or analytical studies. Electronic supplementary information (ESI) available: Experimental procedures, gel electrophoresis and AFM data. See DOI: 10.1039/c3nr01551c

  6. Rapid purification of cell encapsulated hydrogel beads from oil phase to aqueous phase in a microfluidic device.

    PubMed

    Deng, Yuliang; Zhang, Nangang; Zhao, Libo; Yu, Xiaolei; Ji, Xinghu; Liu, Wei; Guo, Shishang; Liu, Kan; Zhao, Xing-Zhong

    2011-12-01

    In this paper, we demonstrate a new type of microfluidic chip that can realize continuous-flow purification of hydrogel beads from a carrier oil into aqueous solution by using a laminar-like oil/water interface. The microfluidic chip is composed by two functional components: (1) a flow-focusing bead generation module that can control size and shape of beads, (2) a bead extraction module capable of purifying hydrogel beads from oil into aqueous solution. This module is featured with large branch channels on one side and small ones on the opposite side. Water is continuously infused into the bead extraction module through the large branch channels, resulting in a laminar-like oil/water interface between the branch junctions. Simulation and experimental data show that the efficiency of oil depletion is determined by the relative flow rates between infused water and carrier oil. By using such a microfluidic device, viable cells (HCT116, colon cancer cell line) can be encapsulated in the hydrogel beads and purified into a cell culture media. Significantly improved cell viability was achieved compared to that observed by conventional bead purification approaches. This facile microfluidic chip could be a promising candidate for sample treatment in lab-on-a-chip applications.

  7. High-performance hollow sulfur nanostructured battery cathode through a scalable, room temperature, one-step, bottom-up approach

    PubMed Central

    Li, Weiyang; Zheng, Guangyuan; Yang, Yuan; Seh, Zhi Wei; Liu, Nian; Cui, Yi

    2013-01-01

    Sulfur is an exciting cathode material with high specific capacity of 1,673 mAh/g, more than five times the theoretical limits of its transition metal oxides counterpart. However, successful applications of sulfur cathode have been impeded by rapid capacity fading caused by multiple mechanisms, including large volume expansion during lithiation, dissolution of intermediate polysulfides, and low ionic/electronic conductivity. Tackling the sulfur cathode problems requires a multifaceted approach, which can simultaneously address the challenges mentioned above. Herein, we present a scalable, room temperature, one-step, bottom-up approach to fabricate monodisperse polymer (polyvinylpyrrolidone)-encapsulated hollow sulfur nanospheres for sulfur cathode, allowing unprecedented control over electrode design from nanoscale to macroscale. We demonstrate high specific discharge capacities at different current rates (1,179, 1,018, and 990 mAh/g at C/10, C/5, and C/2, respectively) and excellent capacity retention of 77.6% (at C/5) and 73.4% (at C/2) after 300 and 500 cycles, respectively. Over a long-term cycling of 1,000 cycles at C/2, a capacity decay as low as 0.046% per cycle and an average coulombic efficiency of 98.5% was achieved. In addition, a simple modification on the sulfur nanosphere surface with a layer of conducting polymer, poly(3,4-ethylenedioxythiophene), allows the sulfur cathode to achieve excellent high-rate capability, showing a high reversible capacity of 849 and 610 mAh/g at 2C and 4C, respectively. PMID:23589875

  8. One-step synthesis of magnetite core/zirconia shell nanocomposite for high efficiency removal of phosphate from water

    NASA Astrophysics Data System (ADS)

    Wang, Zhe; Xing, Mingchao; Fang, Wenkan; Wu, Deyi

    2016-03-01

    A self-assembled magnetite core/zirconia shell (Fe3O4@ZrO2) nanoparticle material was fabricated by the one-step co-precipitation method to capture phosphate from water. Fe3O4@ZrO2 with different Fe/Zr molar ratios were obtained and characterized by XRD, TEM, BET surface area and magnetization. It was shown that, with the decreasing of Fe/Zr molar ratio, magnetization decreased whereas surface area and adsorption capacity of phosphate increased. Fe3O4@ZrO2 with the ratio of higher than 4:1 had satisfactory magnetization property (>23.65 emu/g), enabling rapid magnetic separation from water and recycle of the spent adsorbent. The Langmuir adsorption capacity of Fe3O4@ZrO2 reached 27.93-69.44 mg/g, and the adsorption was fast (90% of phosphate removal within 20 min). The adsorption decreases with increasing pH, and higher ionic strength caused slight increase in adsorption at pH > about 5.5. The presence of chloride, nitrate and sulfate anions did not bring about significant changes in adsorption. As a result, Fe3O4@ZrO2 performed well to remove phosphate from real wastewater. These results were interpreted by the ligand exchange mechanism, i.e., the direct coordination of phosphate onto zirconium by replacement of hydroxyl groups. Results suggested that phosphate reacted mainly with surface hydroxyl groups but diffusion into interior of zirconia phase also contributed to adsorption. The adsorbed phosphate could be desorbed with a NaOH treatment and the regenerated Fe3O4@ZrO2 could be repeatedly used.

  9. Methods for rapid and effective PCR-based detection of 'Candidatus Liberibacter solanacearum' from the insect vector Bactericera cockerelli: streamlining the DNA extraction/purification process.

    PubMed

    Lévy, Julien; Hancock, Joseph; Ravindran, Aravind; Gross, Dennis; Tamborindeguy, Cecilia; Pierson, Elizabeth

    2013-06-01

    This study provides a protocol for rapid DNA isolation from psyllid vectors (Bactericera cockerelli and Diaphorina citri) that can be used directly with DNA-based methods for the detection of 'Candidatus (Ca.) Liberibacter solanacearum,' the bacterial causal agent of potato zebra chip disease and eventually for 'Ca. Liberibacter asiaticus' the causal agent of huanglongbing disease in citrus. The fast DNA extraction protocol was designed to work with conventional polymerase chain reaction (cPCR) DNA amplification as well as Loop mediated PCR DNA amplification. Direct cPCR of the psyllid 28S rDNA gene from samples prepared using the fast DNA extraction method was as reliable as from samples prepared using standard DNA purification (> 97% from live insects) as tested in B. cockerelli. However, samples prepared using the fast DNA extraction method had to be diluted 1:100 in sterile water for reliable amplification, presumably to dilute PCR inhibitors in the crude extract. Similarly, both cPCR and loop mediated PCR DNA amplification detected 'Ca. Liberibacter' in psyllids infected with either the zebra chip or huanglongbing pathogen equally well from diluted samples prepared using the fast DNA extraction method or from samples prepared using a DNA purification step. In addition to being reliable, the time required to complete the fast DNA extraction for 10 samples was on average approximately 5 min and required no special reagents or laboratory equipment. Thus, the fast DNA extraction method shows strong promise as a rapid, reliable, and expedient method when coupled with PCR-based analyses for detection of 'Ca. Liberibacter' pathogens in psyllids. PMID:23865212

  10. One-step Real-time Food Quality Analysis by Simultaneous DSC-FTIR Microspectroscopy.

    PubMed

    Lin, Shan-Yang; Lin, Chih-Cheng

    2016-01-01

    This review discusses an analytical technique that combines differential scanning calorimetry and Fourier-transform infrared (DSC-FTIR) microspectroscopy, which simulates the accelerated stability test and detects decomposition products simultaneously in real time. We show that the DSC-FTIR technique is a fast, simple and powerful analytical tool with applications in food sciences. This technique has been applied successfully to the simultaneous investigation of: encapsulated squid oil stability; the dehydration and intramolecular condensation of sweetener (aspartame); the dehydration, rehydration and solidification of trehalose; and online monitoring of the Maillard reaction for glucose (Glc)/asparagine (Asn) in the solid state. This technique delivers rapid and appropriate interpretations with food science applications.

  11. One-step immunochromatography assay kit for detecting antibodies to canine parvovirus.

    PubMed

    Oh, Jin-Sik; Ha, Gun-Woo; Cho, Young-Shik; Kim, Min-Jae; An, Dong-Jun; Hwang, Kyu-Kye; Lim, Yoon-Kyu; Park, Bong-Kyun; Kang, BoKyu; Song, Dae-Sub

    2006-04-01

    This study was performed to determine the feasibility of using whole serum to detect antibodies to canine parvovirus (CPV) under nonlaboratory conditions and to evaluate the performance characteristics of an immunochromatography assay kit. Precise detection of levels of antibody against CPV in puppies can be used to determine a vaccination schedule, because maternal antibodies frequently result in the failure of protective vaccination, and can also be used to determine the antibody levels of infected puppies. Several methods for the titration of CPV antibodies have been reported, including the hemagglutination inhibition (HI) assay, which is considered the "gold standard." These methods, however, require intricate and time-consuming procedures. In this study, a total of 386 serum specimens were tested. Compared to the HI assay, the rapid assay had a 97.1% sensitivity and a 76.6% specificity (with a cutoff HI titer of 1:80). This single-step assay could be performed rapidly and easily without special equipment. The kit provides a reliable method for detection of anti-CPV antibody where laboratory support and personnel are limited.

  12. A new mid-Silurian aquatic scorpion—one step closer to land?

    PubMed Central

    Waddington, Janet; Rudkin, David M.; Dunlop, Jason A.

    2015-01-01

    One of the oldest known fossil scorpions, a new species from the mid-Silurian Eramosa Formation (430 myr) of Ontario, Canada, exhibits several surprising features. The depositional environment and associated biota indicate a marine habitat; however, the leg morphology of this scorpion, which has a short tarsus in common with all Recent scorpions, suggests that a key adaptation for terrestrial locomotion, the ability to support its weight on a subterminal ‘foot’, appeared remarkably early in the scorpion fossil record. Specimens are preserved intact and undisturbed in a splayed posture typical of moults rather than carcasses. We postulate that these animals were aquatic, but occasionally ventured into extremely shallow water, or onto a transient subaerially exposed surface while moulting, before returning to deeper water. Shed exuviae were preserved in situ by rapid overgrowth of bacterial biofilm. PMID:25589484

  13. A new mid-Silurian aquatic scorpion-one step closer to land?

    PubMed

    Waddington, Janet; Rudkin, David M; Dunlop, Jason A

    2015-01-01

    One of the oldest known fossil scorpions, a new species from the mid-Silurian Eramosa Formation (430 myr) of Ontario, Canada, exhibits several surprising features. The depositional environment and associated biota indicate a marine habitat; however, the leg morphology of this scorpion, which has a short tarsus in common with all Recent scorpions, suggests that a key adaptation for terrestrial locomotion, the ability to support its weight on a subterminal 'foot', appeared remarkably early in the scorpion fossil record. Specimens are preserved intact and undisturbed in a splayed posture typical of moults rather than carcasses. We postulate that these animals were aquatic, but occasionally ventured into extremely shallow water, or onto a transient subaerially exposed surface while moulting, before returning to deeper water. Shed exuviae were preserved in situ by rapid overgrowth of bacterial biofilm.

  14. LDRD final report on microencapsulated immunoreagents for development of one-step ELISA

    SciTech Connect

    Henderson, C.C.; Singh, A.K.

    1997-08-01

    Microencapsulation of biological macromolecules was investigated as a method for incorporating the necessary immunoreagents into an improved enzyme-linked immunosorbant assay (ELISA) package that would self-develop. This self-contained ELISA package would eliminate the need for a trained technician to perform multiple additions of immunoreagent to the assay. Microencapsulation by insolution drying was selected from the many available microencapsulation methods, and two satisfactory procedures for microencapsulation of proteins were established. The stability and potential for rapid release of protein from these microencapsulates was then evaluated. The results suggest that the chosen method for protein entrapment produces microcapsules with a considerable amount of protein in the walls making these particular microcapsules unsuitable for their intended use.

  15. One-step microwave-assisted asymmetric cyclisation/hydrogenation of citronellal to menthols using supported nanoparticles on mesoporous materials.

    PubMed

    Balu, Alina Mariana; Campelo, Juan Manuel; Luque, Rafael; Romero, Antonio Angel

    2010-06-21

    The selective conversion of citronellal to menthols, with good diastereoselectivities to (-)-menthol for the case of (+)-citronellal as starting material, can effectively be carried out in a one-step reaction under microwave irradiation catalysed by supported nanoparticles on mesoporous materials. 2% Pt/Ga-MCM-41 was found to be the optimum catalyst for the reaction, with a quantitative conversion of starting material and selectivities above 85% to menthols obtained in short reaction times (typically 15 min). These results constitute the first report of a simple microwave-assisted one-step cyclisation/hydrogenation process for the production of menthols.

  16. Rapid Purification of a New P-I Class Metalloproteinase from Bothrops moojeni Venom with Antiplatelet Activity

    PubMed Central

    de Queiroz, Mayara R.; Mamede, Carla C. Neves; Fonseca, Kelly C.; de Morais, Nadia C. G.; de Sousa, Bruna B.; Santos-Filho, Norival A.; Beletti, Marcelo E.; Arantes, Eliane C.; Stanziola, Leonilda; de Oliveira, Fábio

    2014-01-01

    The present study aimed to evaluate the proteolytic and biological activities of a new metalloproteinase from B. moojeni venom. The purification of BmooMPα-II was carried out through two chromatographic steps (ion-exchange and affinity). BmooMPα-II is a monomeric protein with an apparent molecular mass of 22.5 kDa on SDS-PAGE 14% under nonreducing conditions. The N-terminal sequence (FSPRYIELVVVADHGMFTKYKSNLN) revealed homology with other snake venom metalloproteinases, mainly among P-I class. BmooMPα-II cleaves Aα-chain of fibrinogen followed by Bβ-chain, and does not show any effect on the γ-chain. Its optimum temperature and pH for the fibrinogenolytic activity were 30–50°C and pH 8, respectively. The inhibitory effects of EDTA and 1,10-phenantroline on the fibrinogenolytic activity suggest that BmooMPα-II is a metalloproteinase. This proteinase was devoid of haemorrhagic, coagulant, or anticoagulant activities. BmooMPα-II caused morphological alterations in liver, lung, kidney, and muscle of Swiss mice. The enzymatically active protein yet inhibited collagen, ADP, and ristocetin-induced platelet aggregation in a concentration-dependent manner. Our results suggest that BmooMPα-II contributes to the toxic effect of the envenomation and that more investigations to elucidate the mechanisms of inhibition of platelet aggregation may contribute to the studies of snake venom on thrombotic disorders. PMID:24982866

  17. Defining gene-phenotype relationships in Acinetobacter baumannii through one-step chromosomal gene inactivation.

    PubMed

    Tucker, Ashley T; Nowicki, Emily M; Boll, Joseph M; Knauf, Gregory A; Burdis, Nora C; Trent, M Stephen; Davies, Bryan W

    2014-01-01

    Rates of infection with hospital-acquired Acinetobacter baumannii have exploded over the past decade due to our inability to limit persistence and effectively treat disease. A. baumannii quickly acquires antibiotic resistance, and its genome encodes mechanisms to tolerate biocides and desiccation, which enhance its persistence in hospital settings. With depleted antibiotic options, new methods to treat A. baumannii infections are desperately needed. A comprehensive understanding detailing A. baumannii cellular factors that contribute to its resiliency at genetic and mechanistic levels is vital to the development of new treatment options. Tools to rapidly dissect the A. baumannii genome will facilitate this goal by quickly advancing our understanding of A. baumannii gene-phenotype relationships. We describe here a recombination-mediated genetic engineering (recombineering) system for targeted genome editing of A. baumannii. We have demonstrated that this system can perform directed mutagenesis on wide-ranging genes and operons and is functional in various strains of A. baumannii, indicating its broad application. We utilized this system to investigate key gene-phenotype relationships in A. baumannii biology important to infection and persistence in hospitals, including oxidative stress protection, biocide resistance mechanisms, and biofilm formation. In addition, we have demonstrated that both the formation and movement of type IV pili play an important role in A. baumannii biofilm. Importance: Acinetobacter baumannii is the causative agent of hospital-acquired infections, including pneumonia and serious blood and wound infections. A. baumannii is an emerging pathogen and has become a threat to public health because it quickly develops antibiotic resistance, making treatment difficult or impossible. While the threat of A. baumannii is well recognized, our understanding of even its most basic biology lags behind. Analysis of A. baumannii cellular functions to

  18. One-step assay for detecting influenza virus using dynamic light scattering and gold nanoparticles.

    PubMed

    Driskell, Jeremy D; Jones, Cheryl A; Tompkins, S Mark; Tripp, Ralph A

    2011-08-01

    Herein we detail the development of a simple, rapid, and sensitive method for quantitative detection of influenza A virus using dynamic light scattering (DLS) and gold nanoparticle (AuNP) labels. Influenza-specific antibodies are conjugated to AuNPs, and aggregation of the AuNP probes is induced upon addition of the target virus. DLS is used to measure the extent of aggregation and the mean hydrodynamic diameter is correlated to virus concentration. The effects of nanoparticle concentration and size on the analytical performance of the assay were systematically investigated. It was determined that decreasing the AuNP probe concentration improves the detection limit while the effect of changing the AuNP size is minimal. Optimization of the assay provided a detection limit of <100 TCID(50)/mL which is 1-2 orders of magnitude improved over commercial diagnostic kits without increasing the assay time or complexity. Additionally, this assay was demonstrated to perform equivalently for influenza virus prepared in different biological matrices.

  19. A novel, one-step amplification and oligonucleotide ligation procedure for multiplex genetic typing

    SciTech Connect

    Eggerding, F.A.

    1994-09-01

    A new technique, coupled amplification and oligonucleotide ligation (CAL), has been developed for simultaneous multiplex amplification and genotyping of DNA. CAL is a biphasic method which combines in one assay DNA amplification by the polymerase chain reaction (PCR) with DNA genotyping by the oligonucleotide ligation assay (OLA). By virtue of a difference in the melting temperatures of PCR primer-target DNA and OLA probe-target DNA hybrids, the method allows preferential amplification of DNA during stage I and oligonucleotide ligation during stage II of the reaction. In stage I target DNA is amplified using high-melting primers in a two-step PCR cycle that employs a 72{degrees}C anneal-elongation step. In stage II genotyping of PCR products by competitive oligonucleotide ligation with oligonucleotide probes located between PCR primers is accomplished by several cycles of denaturation at 94{degrees}C followed by anneal-ligation at 55{degrees}C. Ligation products are fluorochrome-labeled at their 3{prime}-ends and analyzed electrophoretically on a fluorescent DNA sequencer. The CAL procedure has been used for multiplex detection of 30 cystic fibrosis mutations and for analysis of ras gene point mutations. Because mutation detection occurs concurrently with target amplification, the technique is rapid, highly sensitive and specific, easily automatable, and requires minimal sample processing.

  20. Silver nanoparticle enhanced immunoassays: one step real time kinetic assay for insulin in serum.

    PubMed

    Lochner, Nina; Lobmaier, Christina; Wirth, Michael; Leitner, Alfred; Pittner, Fritz; Gabor, Franz

    2003-11-01

    Silver nanoparticle enhanced fluorescence is introduced as an alternative method to surface plasmon resonance techniques for real time monitoring of biorecognitive interactions or immunoassays. This method relies on the phenomenon that an electromagnetic near field is generated upon illumination on the surface of silver nanoparticles. The interaction of this field with nearby fluorophores results in fluorescence enhancement. Thus, fluorophores in the bulk solution can be discriminated from surface bound fluorophores. Anti-insulin-antibodies were immobilized on the surface of silver colloids in the following order: A ready to use microplate was prepared by bottom up coating with layers of aminosilane, silver nanoparticles, Fc-recognizing F(ab)(2)-fragments and anti-insulin-antibodies. At equilibrium conditions fluorescein-labeled insulin could only be detected in the presence of the colloid; the detection limit was 250 nM, and a fourfold increase in fluorescence was observed upon real time monitoring. The competitive assay of labeled and unlabeled insulin revealed a working range of 10-200 nM insulin in serum. The rapid single step immunoassay is easy to perform even in microplate format, its sensitivity is comparable to ELISA techniques, and offers broad application for real time monitoring of molecular recognitive processes.

  1. Preparation of hybrid molecularly imprinted polymer with double-templates for rapid simultaneous purification of theophylline and chlorogenic acid in green tea.

    PubMed

    Tang, Weiyang; Li, Guizhen; Row, Kyung Ho; Zhu, Tao

    2016-05-15

    A novel double-templates technique was adopted for solid-phase extraction packing agent, and the obtained hybrid molecularly imprinted polymers with double-templates (theophylline and chlorogenic acid) were characterized by fourier transform infrared and field emission scanning electron microscope. The molecular recognition ability and binding capability for theophylline and chlorogenic acid of polymers was evaluated by static absorption and dynamic adsorption curves. A rapid and accurate approach was established for simultaneous purification of theophylline and chlorogenic acid in green tea by coupling hybrid molecularly imprinted solid-phase extraction with high performance liquid chromatography. With optimization of SPE procedure, a reliable analytical method was developed for highly recognition towards theophylline and chlorogenic acid in green tea with satisfactory extraction recoveries (theophylline: 96.7% and chlorogenic acid: 95.8%). The limit of detection and limit of quantity of the method were 0.01 μg/mL and 0.03 μg/mL for theophylline, 0.05 μg/mL and 0.17 μg/mL for chlorogenic acid, respectively. The recoveries of proposed method at three spiked levels analysis were 98.7-100.8% and 98.3-100.2%, respectively, with the relative standard deviation less than 1.9%. Hybrid molecularly imprinted polymers with double-templates showed good performance for two kinds of targets, and the proposed approach with high affinity of hybrid molecularly imprinted polymers might offer a novel method for the purification of complex samples.

  2. Direct construction of predictive models for describing growth Salmonella enteritidis in liquid eggs – a one-step approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to develop a new approach using a one-step approach to directly construct predictive models for describing the growth of Salmonella Enteritidis (SE) in liquid egg white (LEW) and egg yolk (LEY). A five-strain cocktail of SE, induced to resist rifampicin at 100 mg/L, ...

  3. Nanofabrication of spin-transfer torque devices by a polymethylmethacrylate mask one step process: Giant magnetoresistance versus single layer devices

    NASA Astrophysics Data System (ADS)

    Parge, Anne; Niermann, Tore; Seibt, Michael; Münzenberg, Markus

    2007-05-01

    We present a method to prepare magnetic spin torque devices of low specific resistance in a one step lithography process. The quality of the pillar devices is demonstrated for a standard magnetic double layer device. For single layer devices, we found hysteretic switching and a more complex dynamical excitation pattern in higher fields. A simple model to explain the resistance spikes is presented.

  4. One-step synthesis of amine-functionalized hollow mesoporous silica nanoparticles as efficient antibacterial and anticancer materials

    PubMed Central

    Hao, Nanjing; Jayawardana, Kalana W.; Chen, Xuan; De Zoysa, Thareendra

    2015-01-01

    In this study, amine-functionalized hollow mesoporous silica nanoparticles with an average diameter of ~100 nm and shell thickness of ~20 nm were prepared by an one-step process. This new nanoparticulate system exhibited excellent killing efficiency against mycobacterial (M. smegmatis strain mc2 651) and cancer cells (A549). PMID:25562524

  5. One-Step Multiplex PCR Assay for Differentiating Proposed New Species “Clostridium neonatale” from Closely Related Species

    PubMed Central

    Ferraris, Laurent; Schönherr, Sophia; Bouvet, Philippe; Dauphin, Brunhilde; Popoff, Michel; Butel, Marie Jose

    2015-01-01

    “Clostridium neonatale” sp. nov., previously involved in an outbreak of neonatal necrotizing enterocolitis, was recently proposed as a new species of the Clostridium genus sensu stricto. We developed a one-step multiplex colony PCR for C. neonatale identification and investigated C. neonatale intestinal colonization frequency in healthy preterm neonates. PMID:26292306

  6. A Novel and Efficient One-Step Parallel Synthesis of Dibenzopyranones via Suzuki-Miyaura Cross Coupling

    PubMed Central

    Vishnumurthy, Kodumuru; Makriyannis, Alexandros

    2010-01-01

    Microwave promoted novel and efficient one-step parallel synthesis of dibenzopyranones and heterocyclic analogues from bromo arylcarboxylates and o-hydroxyarylboronic acids via Suzuki-Miyaura cross coupling reaction is described. Spontaneous lactonization gave dibenzopyranones and heterocyclic analogues bearing electron donating and withdrawing groups on both aromatic rings in good to excellent yields. PMID:20831265

  7. Block Copolymer Nanocomposites with High Refractive Index Contrast for One-Step Photonics.

    PubMed

    Song, Dong-Po; Li, Cheng; Li, Wenhao; Watkins, James J

    2016-01-26

    Photonic crystals (PhCs) prepared using the self-assembly of block copolymers (BCPs) offer the potential for simple and rapid device fabrication but typically suffer from low refractive index contrast (Δn ≤ 0.1) between the phase-segregated domains. Here, we report the simple fabrication of BCP-based photonic nanocomposites with large differences in refractive index (Δn > 0.27). Zirconium oxide (ZrO2) nanoparticles coated with gallic acid are used to tune the optical constants of the target domains of self-assembled (polynorbornene-graft-poly(tert-butyl acrylate))-block-(polynorbornene-graft-poly(ethylene oxide)) (PtBA-b-PEO) brush block copolymers (BBCPs). Strong hydrogen-bonding interactions between the ligands on ZrO2 and PEO brushes of the BBCPs enable selective incorporation and high loading of up to 70 wt % (42 vol %) of the ZrO2 nanoparticles within the PEO domain, resulting in a significant increase of refractive index from 1.45 to up to 1.70. Consequently, greatly enhanced reflection at approximately 398 nm (increases of ∼250%) was observed for the photonic nanocomposites (domain spacing = 137 nm) relative to that of the unmodified BBCPs, which is consistent with numeric modeling results using transfer matrix methods. This work provides a simple strategy for a wide range tuning of optical constants of BCP domains, thereby enabling the design and creation of high-performance photonic coatings for various applications. The large refractive index contrast enables high reflectivity while simultaneously reducing the coating thickness necessary, compared to pure BCP systems.

  8. Bringing large-scale multiple genome analysis one step closer: ScalaBLAST and beyond

    SciTech Connect

    Oehmen, Christopher S.; Sofia, Heidi J.; Baxter, Douglas; Szeto, Ernest; Hugenholtz, Philip; Kyrpides, Nikos; Markowitz, Victor; Straatsma, Tjerk P.

    2007-06-01

    Genome sequence comparisons of exponentially growing data sets form the foundation for the comparative analysis tools provided by community biological data resources such as the Integrated Microbial Genome (IMG) system at the Joint Genome Institute (JGI). We present an example of how ScalaBLAST, a high-throughput sequence analysis program harnesses increasingly critical high-performance computing to perform sequence analysis which is a critical component of maintaining a state-of-the-art sequence data repository. The Integrated Microbial Genomes (IMG) system1 is a data management and analysis platform for microbial genomes hosted at the JGI. IMG contains both draft and complete JGI genomes integrated with other publicly available microbial genomes of all three domains of life. IMG provides tools and viewers for interactive analysis of genomes, genes and functions, individually or in a comparative context. Most of these tools are based on pre-computed pairwise sequence similarities involving millions of genes. These computations are becoming prohibitively time consuming with the rapid increase in the number of newly sequenced genomes incorporated into IMG and the need to refresh regularly the content of IMG in order to reflect changes in the annotations of existing genomes. Thus, building IMG 2.0 (released on December 1st 2006) entailed reloading from NCBI's RefSeq all the genomes in the previous version of IMG (IMG 1.6, as of September 1st, 2006) together with 1,541 new public microbial,viral and eukaryal genomes, bringing the total of IMG genomes to 2,301. A critical part of building IMG 2.0 involved using PNNL ScalaBLAST software for computing pairwise similarities for over 2.2 million genes in under 26 hours on 1,000 processors, thus illustrating the impact that new generation bioinformatics tools are poised to make in biology. The BLAST algorithm2, 3 is a familiar bioinformatics application for computing sequence similarity, and has become a workhorse in large

  9. One-step synthesis of large-scale graphene film doped with gold nanoparticles at liquid-air interface for electrochemistry and Raman detection applications.

    PubMed

    Zhang, Panpan; Huang, Ying; Lu, Xin; Zhang, Siyu; Li, Jingfeng; Wei, Gang; Su, Zhiqiang

    2014-07-29

    We demonstrated a facile one-step synthesis strategy for the preparation of a large-scale reduced graphene oxide multilayered film doped with gold nanoparticles (RGO/AuNP film) and applied this film as functional nanomaterials for electrochemistry and Raman detection applications. The related applications of the fabricated RGO/AuNP film in electrochemical nonenzymatic H2O2 biosensor, electrochemical oxygen reduction reaction (ORR), and surface-enhanced Raman scattering (SERS) detection were investigated. Electrochemical data indicate that the H2O2 biosensor fabricated by RGO/AuNP film shows a wide linear range, low limitation of detection, high selectivity, and long-term stability. In addition, it was proved that the created RGO/AuNP film also exhibits excellent ORR electrochemical catalysis performance. The created RGO/AuNP film, when serving as SERS biodetection platform, presents outstanding performances in detecting 4-aminothiophenol with an enhancement factor of approximately 5.6 × 10(5) as well as 2-thiouracil sensing with a low concentration to 1 μM. It is expected that this facile strategy for fabricating large-scale graphene film doped with metallic nanoparticles will spark inspirations in preparing functional nanomaterials and further extend their applications in drug delivery, wastewater purification, and bioenergy. PMID:25015184

  10. Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s.

    PubMed

    Jones, Gavin O; Yuen, Alexander; Wojtecki, Rudy J; Hedrick, James L; García, Jeannette M

    2016-07-12

    It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.

  11. Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s.

    PubMed

    Jones, Gavin O; Yuen, Alexander; Wojtecki, Rudy J; Hedrick, James L; García, Jeannette M

    2016-07-12

    It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers. PMID:27354514

  12. Classification and purification of proteins of heterogeneous nuclear ribonucleoprotein particles by RNA-binding specificities

    SciTech Connect

    Swanson, M.S.; Dreyfuss, G.

    1988-05-01

    Several proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) particles display very high binding affinities for different ribonucleotide homopolymers. The specificity of some of these proteins at high salt concentrations and in the presence of heparin allows for their rapid one-step purification from HeLa nucleoplasm. The authors show that the hnRNP proteins are poly(U)-binding proteins and compare their specificity to that of the previously described cytoplasmic poly(A)-binding protein. These findings provide a useful tool for the classification and purification of hnRNP proteins from various tissues and organisms and indicate that different hnRNP proteins have different RNA-binding specificities.

  13. Functionalized liposome purification via Liposome Extruder Purification (LEP).

    PubMed

    Alves, Nathan J; Cusick, William; Stefanick, Jared F; Ashley, Jonathan D; Handlogten, Michael W; Bilgicer, Basar

    2013-09-01

    Liposome Extruder Purification (LEP) allows for the rapid purification of diverse liposome formulations using the same extrusion apparatus employed during liposome formation. The LEP process provides a means for purifying functionalized liposomes from non-conjugated drug or protein contaminants with >93% liposome recovery and >93% contaminant removal in a single step.

  14. Anti-idiotypic nanobody-alkaline phosphatase fusion proteins: Development of a one-step competitive enzyme immunoassay for fumonisin B1 detection in cereal.

    PubMed

    Shu, Mei; Xu, Yang; Liu, Xing; Li, Yanping; He, Qinghua; Tu, Zhui; Fu, Jinheng; Gee, Shirley J; Hammock, Bruce D

    2016-06-14

    A rapid and sensitive one-step competitive enzyme immunoassay for the detection of FB1 was developed. The anti-idiotypic nanobody-alkaline phosphatase (Ab2β-Nb-AP) was validated by the AP enzyme activity and the properties of bounding to anti-FB1-mAb (3F11) through colorimetric and chemiluminescence analyses. The 50% inhibitory concentration and the detection limit (LOD) of colorimetric enzyme-linked immunosorbent assay (ELISA) for FB1 were 2.69 and 0.35 ng mL(-1), respectively, with a linear range of 0.93-7.73 ng mL(-1). The LOD of the chemiluminescence ELISA (CLIA) was 0.12 ng mL(-1), and the IC50 was 0.89 ± 0.09 ng mL(-1) with a linear range of 0.29-2.68 ng mL(-1). Compared with LC-MS/MS, the results of this assay indicated the reliability of the Ab2β-Nb-AP fusion protein based one-step competitive immunoassay for monitoring FB1 contamination in cereals. The Ab2β-Nb-AP fusion proteins have the potential to replace chemically-coupled probes in competitive enzyme immunoassay systems.

  15. A simple one-step synthesis of melanin-originated red shift emissive carbonaceous dots for bioimaging.

    PubMed

    Hu, Chuan; Liu, Yongmei; Chen, Jiantao; He, Qin; Gao, Huile

    2016-10-15

    Carbonaceous dots (CDs) are superior nanomaterials owing to their promising luminescence properties and good biocompatibility. However, most CDs have relatively short excitation/emission, which restrict their application in bioimaging. In this study, a simple one-step procedure was developed for synthesis of melanin-originated CDs (MNPs). The MNPs showed two long red shift emissions at 570nm and 645nm with broad absorptions from 200nm to 400nm and 500nm to 700nm, suggesting the great potential of MNPs in bioimaging. Besides, several experiments indicated that MNPs possessed good serum stability and well blood compatibility. In vitro, MNPs could be taken up by C6 cell in a concentration- and time-dependent manner with endosomes involved. In conclusion, MNPs were prepared using a simple one-step method with unique optical and good biological properties and could be used for bioimaging.

  16. Comparing two independent groups: a test based on a one-step M-estimator and bootstrap-t.

    PubMed

    Özdemir, A Fırat

    2013-05-01

    A new test is proposed for the problem of comparing two independent groups in terms of some measure of location. The proposed test () uses a one-step M-estimator and a bootstrap-t method with the procedure proposed by Özdemir and Kurt (2006). Eight methods were compared in terms of actual Type I error and power when the underlying distributions differ in skewness and kurtosis under heterogeneity of variances. For the 21 theoretical distributions, the Yuen test with the bootstrap-t method was the most favourable, followed by test. For the five real data sets, the proposed test and percentile bootstrap method with the one-step M-estimator performed best.

  17. Investigation of a one-step spectral CT reconstruction algorithm for direct inversion into basis material images

    NASA Astrophysics Data System (ADS)

    Gilat Schmidt, Taly; Sidky, Emil Y.

    2015-03-01

    Photon-counting detectors with pulse-height analysis have shown promise for improved spectral CT imaging. This study investigated a novel spectral CT reconstruction method that directly estimates basis-material images from the measured energy-bin data (i.e., `one-step' reconstruction). The proposed algorithm can incorporate constraints to stabilize the reconstruction and potentially reduce noise. The algorithm minimizes the error between the measured energy-bin data and the data estimated from the reconstructed basis images. A total variation (TV) constraint was also investigated for additional noise reduction. The proposed one-step algorithm was applied to simulated data of an anthropomorphic phantom with heterogeneous tissue composition. Reconstructed water, bone, and gadolinium basis images were compared for the proposed one-step algorithm and the conventional `two-step' method of decomposition followed by reconstruction. The unconstrained algorithm provided a 30% to 60% reduction in noise standard deviation compared to the two-step algorithm. The fTV =0.8 constraint provided a small reduction in noise (˜ 1%) compared to the unconstrained reconstruction. Images reconstructed with the fTV =0.5 constraint demonstrated 77% to 94% standard deviation reduction compared to the two-step reconstruction, however with increased blurring. There were no significant differences in the mean values reconstructed by the investigated algorithms. Overall, the proposed one-step spectral CT reconstruction algorithm provided three-material-decomposition basis images with reduced noise compared to the conventional two-step approach. When using a moderate TV constraint factor (fTV = 0.8), a 30%-60% reduction in noise standard deviation was achieved while preserving the edge profile for this simulated phantom.

  18. One-step electrochemical synthesis of ultrathin graphitic carbon nitride nanosheets and their application to the detection of uric acid.

    PubMed

    Lu, Qiujun; Deng, Jianhui; Hou, Yuxin; Wang, Haiyan; Li, Haitao; Zhang, Youyu

    2015-08-01

    Ultrathin graphitic carbon nitride nanosheets (g-C3N4) with a thickness of about 2 nm were synthesized by a one-step electrochemical method for the first time. The possible mechanism of the electrochemical synthesis was discussed. This as-synthesized g-C3N4 showed intrinsic peroxidase-like activity and was successfully applied for the detection of uric acid.

  19. A One-Step System for Convenient and Flexible Assembly of Transcription Activator-Like Effector Nucleases (TALENs).

    PubMed

    Zhao, Jinlong; Sun, Wenye; Liang, Jing; Jiang, Jing; Wu, Zhao

    2016-09-01

    Transcription activator-like effector nucleases (TALENs) are powerful tools for targeted genome editing in diverse cell types and organisms. However, the highly identical TALE repeat sequences make it challenging to assemble TALEs using conventional cloning approaches, and multiple repeats in one plasmid are easily catalyzed for homologous recombination in bacteria. Although the methods for TALE assembly are constantly improving, these methods are not convenient because of laborious assembly steps or large module libraries, limiting their broad utility. To overcome the barrier of multiple assembly steps, we report a one-step system for the convenient and flexible assembly of a 180 TALE module library. This study is the first demonstration to ligate 9 mono-/dimer modules and one circular TALEN backbone vector in a one step process, generating 9.5 to 18.5 repeat sequences with an overall assembly rate higher than 50%. This system makes TALEN assembly much simpler than the conventional cloning of two DNA fragments because this strategy combines digestion and ligation into one step using circular vectors and different modules to avoid gel extraction. Therefore, this system provides a convenient tool for the application of TALEN-mediated genome editing in scientific studies and clinical trials. PMID:27604899

  20. One-Step Targeted Minimum Loss-based Estimation Based on Universal Least Favorable One-Dimensional Submodels

    PubMed Central

    van der Laan, Mark; Gruber, Susan

    2016-01-01

    Consider a study in which one observes n independent and identically distributed random variables whose probability distribution is known to be an element of a particular statistical model, and one is concerned with estimation of a particular real valued pathwise differentiable target parameter of this data probability distribution. The targeted maximum likelihood estimator (TMLE) is an asymptotically efficient substitution estimator obtained by constructing a so called least favorable parametric submodel through an initial estimator with score, at zero fluctuation of the initial estimator, that spans the efficient influence curve, and iteratively maximizing the corresponding parametric likelihood till no more updates occur, at which point the updated initial estimator solves the so called efficient influence curve equation. In this article we construct a one-dimensional universal least favorable submodel for which the TMLE only takes one step, and thereby requires minimal extra data fitting to achieve its goal of solving the efficient influence curve equation. We generalize these to universal least favorable submodels through the relevant part of the data distribution as required for targeted minimum loss-based estimation. Finally, remarkably, given a multidimensional target parameter, we develop a universal canonical one-dimensional submodel such that the one-step TMLE, only maximizing the log-likelihood over a univariate parameter, solves the multivariate efficient influence curve equation. This allows us to construct a one-step TMLE based on a one-dimensional parametric submodel through the initial estimator, that solves any multivariate desired set of estimating equations. PMID:27227728

  1. A One-Step System for Convenient and Flexible Assembly of Transcription Activator-Like Effector Nucleases (TALENs)

    PubMed Central

    Zhao, Jinlong; Sun, Wenye; Liang, Jing; Jiang, Jing; Wu, Zhao

    2016-01-01

    Transcription activator-like effector nucleases (TALENs) are powerful tools for targeted genome editing in diverse cell types and organisms. However, the highly identical TALE repeat sequences make it challenging to assemble TALEs using conventional cloning approaches, and multiple repeats in one plasmid are easily catalyzed for homologous recombination in bacteria. Although the methods for TALE assembly are constantly improving, these methods are not convenient because of laborious assembly steps or large module libraries, limiting their broad utility. To overcome the barrier of multiple assembly steps, we report a one-step system for the convenient and flexible assembly of a 180 TALE module library. This study is the first demonstration to ligate 9 mono-/dimer modules and one circular TALEN backbone vector in a one step process, generating 9.5 to 18.5 repeat sequences with an overall assembly rate higher than 50%. This system makes TALEN assembly much simpler than the conventional cloning of two DNA fragments because this strategy combines digestion and ligation into one step using circular vectors and different modules to avoid gel extraction. Therefore, this system provides a convenient tool for the application of TALEN-mediated genome editing in scientific studies and clinical trials. PMID:27604899

  2. One-step leapfrog ADI-FDTD method for simulating electromagnetic wave propagation in general dispersive media.

    PubMed

    Wang, Xiang-Hua; Yin, Wen-Yan; Chen, Zhi Zhang David

    2013-09-01

    The one-step leapfrog alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is reformulated for simulating general electrically dispersive media. It models material dispersive properties with equivalent polarization currents. These currents are then solved with the auxiliary differential equation (ADE) and then incorporated into the one-step leapfrog ADI-FDTD method. The final equations are presented in the form similar to that of the conventional FDTD method but with second-order perturbation. The adapted method is then applied to characterize (a) electromagnetic wave propagation in a rectangular waveguide loaded with a magnetized plasma slab, (b) transmission coefficient of a plane wave normally incident on a monolayer graphene sheet biased by a magnetostatic field, and (c) surface plasmon polaritons (SPPs) propagation along a monolayer graphene sheet biased by an electrostatic field. The numerical results verify the stability, accuracy and computational efficiency of the proposed one-step leapfrog ADI-FDTD algorithm in comparison with analytical results and the results obtained with the other methods. PMID:24103929

  3. One-step leapfrog ADI-FDTD method for simulating electromagnetic wave propagation in general dispersive media.

    PubMed

    Wang, Xiang-Hua; Yin, Wen-Yan; Chen, Zhi Zhang David

    2013-09-01

    The one-step leapfrog alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is reformulated for simulating general electrically dispersive media. It models material dispersive properties with equivalent polarization currents. These currents are then solved with the auxiliary differential equation (ADE) and then incorporated into the one-step leapfrog ADI-FDTD method. The final equations are presented in the form similar to that of the conventional FDTD method but with second-order perturbation. The adapted method is then applied to characterize (a) electromagnetic wave propagation in a rectangular waveguide loaded with a magnetized plasma slab, (b) transmission coefficient of a plane wave normally incident on a monolayer graphene sheet biased by a magnetostatic field, and (c) surface plasmon polaritons (SPPs) propagation along a monolayer graphene sheet biased by an electrostatic field. The numerical results verify the stability, accuracy and computational efficiency of the proposed one-step leapfrog ADI-FDTD algorithm in comparison with analytical results and the results obtained with the other methods.

  4. One-step Melt Synthesis of Water Soluble, Photoluminescent, Surface-Oxidized Silicon Nanoparticles for Cellular Imaging Applications

    PubMed Central

    Manhat, Beth A.; Brown, Anna L.; Black, Labe A.; Ross, J.B. Alexander; Fichter, Katye; Vu, Tania; Richman, Erik

    2012-01-01

    We have developed a versatile, one-step melt synthesis of water-soluble, highly emissive silicon nanoparticles using bi-functional, low-melting solids (such as glutaric acid) as reaction media. Characterization through transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy shows that the one-step melt synthesis produces nanoscale Si cores surrounded by a silicon oxide shell. Analysis of the nanoparticle surface using FT-IR, zeta potential, and gel electrophoresis indicates that the bi-functional ligand used in the one-step synthesis is grafted onto the nanoparticle, which allows for tuning of the particle surface charge, solubility, and functionality. Photoluminescence spectra of the as-prepared glutaric acid-synthesized silicon nanoparticles show an intense blue-green emission with a short (ns) lifetime suitable for biological imaging. These nanoparticles are found to be stable in biological media and have been used to examine cellular uptake and distribution in live N2a cells. PMID:23139440

  5. One Step Beyond

    ERIC Educational Resources Information Center

    De Wyngaert, Laura

    1975-01-01

    Students learned to use mathematics to understand the importance of measurement, graphing and a simplified version of conic section and parabola. Through the development of the concept of line from which curve forms were created art and mathematics became intertwined while students accomplished far greater flexibility and mastery of an artistic…

  6. Development of a combined technique using a rapid one-step immunochromatographic assay and indirect competitive ELISA for the rapid detection of baicalin.

    PubMed

    Paudel, Madan Kumar; Putalun, Waraporn; Sritularak, Boonchoo; Morinaga, Osamu; Shoyama, Yukihiro; Tanaka, Hiroyuki; Morimoto, Satoshi

    2011-09-01

    A colloidal gold conjugated anti-baicalin monoclonal antibody (anti-BA MAb) was prepared and used in an immunochromatographic assay (ICA) for BA in Scutellariae Radix and Kampo medicines. This competitive ICA uses an anti-BA MAb which shows a high specificity for BA and baicalein. Its advantages include a short assay time (15 min), no dependence on any instrumental systems, and it can detect BA in plant materials and Kampo medicines. The limit of detection for the ICA was found to be around 0.6 μg mL(-1)of baicalin. Moreover, the usefulness of the combination of indirect competitive ELISA and the ICA using anti-BA MAb as a quality control method was confirmed for analysis of BA in Scutellariae Radix and Kampo medicines with a sufficient sensitivity (200 ng mL(-1) to 2 μg mL(-1)), obtainable in an easy and timely manner.

  7. Rapid and efficient purification of chrysophanol in Rheum Palmatum LINN by supercritical fluid extraction coupled with preparative liquid chromatography in tandem.

    PubMed

    Lo, Tiffany Chien-Ting; Nian, Hung-Chi; Chiu, Kong-Hwa; Wang, Ai-Yih; Wu, Ben-Zen

    2012-04-15

    Chrysophanol has high pharmaceutical values. However, it was difficult to use the traditional extraction method to extract high-concentration chrysophanol. Therefore, the purpose of this study is to purify and separate chrysophanol in traditional herb, Rheum Palmatum LINN, by using supercritical fluid extraction (SFE) and preparative high-performance liquid chromatography (P-HPLC) for rapid and large-scale isolation. The method is efficient for selective extraction of chrysophanol from the herbs, which have complex compositions. The extraction efficiency of chrysophanol with SFE is 25 × higher than that of boiled water extraction under the same extraction time. The optimal conditions for SFE were 210 atm and 85 °C for 30 min; for P-HPLC, a C18 column was used with a gradient elution of methanol and 1% acetic acid at a flow rate of 10 mL/min. According to (1)H NMR and LC-MS analyses, the purity of the isolated chrysophanol was as high as 99%. The recovery for chrysophanol in Rheum after SPE/PHPLC processing was in the range of 88-91.5%. Compared with other extraction and purification methods, the sequential system (SFE/P-HPLC) achieved the highest amount of extracted chrysophanol from Rheum Palmatum LINN (0.38 mg/g) and the shortest run time (3h). Hence, this rapid and environmentally friendly method can separate compounds based on polarity with high efficiencies and, coupled with P-HPLC, it may be applicable in the large-scale production of foods and medicines in the future.

  8. Application of an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum.

    PubMed

    Chen, Tao; Liu, Yongling; Zou, Denglang; Chen, Chen; You, Jinmao; Zhou, Guoying; Sun, Jing; Li, Yulin

    2014-01-01

    This study presents an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid-liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe-emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high-speed counter-current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe-emodin, physcione, and chrysophanol.

  9. One-step Preparation of Nanoarchitectured TiO2 on Porous Al as Integrated Anode for High-performance Lithium-ion Batteries

    PubMed Central

    Du, Xianfeng; Wang, Qianwen; Feng, Tianyu; Chen, Xizi; Li, Liang; Li, Long; Meng, Xiangfei; Xiong, Lilong; Sun, Xiaofei; Lu, Lu; Xu, Youlong

    2016-01-01

    Titanium dioxide (TiO2) is an attractive anode material for energy storage devices due to its low-volume-change and high safety. However, TiO2 anodes usually suffer from poor electrical and ionic conductivity, thus causing dramatic degradation of electrochemical performance at rapid charge/discharge rates, which has hindered its use in energy storage devices. Here, we present a novel strategy to address this main obstacle via using nanoarchitectured TiO2 anode consisting of mesoporous TiO2 wrapped in carbon on a tunnel-like etched aluminum substrate prepared by a simple one-step approach. As a result of this nanoarchitecture arrangement, the anode exhibits excellent rate performance and superior cyclability. A rate up to 100 C is achieved with a high specific capacity of about 95 mA h g−1, and without apparent decay after 8,000 cycles. PMID:26841711

  10. Development of a duplex one-step RT-qPCR assay for the simultaneous detection of Apple scar skin viroid and plant RNA internal control.

    PubMed

    Khan, Subuhi; Mackay, John; Liefting, Lia; Ward, Lisa

    2015-09-01

    Apple scar skin viroid (ASSVd) is an important quarantine pathogen for international movement of pome germplasm as it can cause significant damage to pip fruit. A one-step real-time RT-PCR assay was developed for the rapid and sensitive detection of ASSVd. The assay was able to detect a wide range of ASSVd isolates and was highly specific compared to a published conventional RT-PCR. The detection limit of the new assay was estimated to be about 100 copies of the ASSVd target. The assay can be run as a duplex with the nad5 internal control primers and probe to simultaneously check the PCR competency of the samples therefore reducing the risk of false negatives. It is expected that this real-time RT-PCR assay will facilitate efficient testing for ASSVd by regulatory services, and will also have a wider use for the general detection of ASSVd in a range of pip fruit.

  11. One-step Preparation of Nanoarchitectured TiO2 on Porous Al as Integrated Anode for High-performance Lithium-ion Batteries

    NASA Astrophysics Data System (ADS)

    Du, Xianfeng; Wang, Qianwen; Feng, Tianyu; Chen, Xizi; Li, Liang; Li, Long; Meng, Xiangfei; Xiong, Lilong; Sun, Xiaofei; Lu, Lu; Xu, Youlong

    2016-02-01

    Titanium dioxide (TiO2) is an attractive anode material for energy storage devices due to its low-volume-change and high safety. However, TiO2 anodes usually suffer from poor electrical and ionic conductivity, thus causing dramatic degradation of electrochemical performance at rapid charge/discharge rates, which has hindered its use in energy storage devices. Here, we present a novel strategy to address this main obstacle via using nanoarchitectured TiO2 anode consisting of mesoporous TiO2 wrapped in carbon on a tunnel-like etched aluminum substrate prepared by a simple one-step approach. As a result of this nanoarchitecture arrangement, the anode exhibits excellent rate performance and superior cyclability. A rate up to 100 C is achieved with a high specific capacity of about 95 mA h g‑1, and without apparent decay after 8,000 cycles.

  12. PCR Duplication: A One-Step Cloning-Free Method to Generate Duplicated Chromosomal Loci and Interference-Free Expression Reporters in Yeast

    PubMed Central

    Huber, Florian; Meurer, Matthias; Bunina, Daria; Kats, Ilia; Maeder, Céline I.; Štefl, Martin; Mongis, Cyril; Knop, Michael

    2014-01-01

    Here, we report on a novel PCR targeting-based strategy called ‘PCR duplication’ that enables targeted duplications of genomic regions in the yeast genome using a simple PCR-based approach. To demonstrate its application we first duplicated the promoter of the FAR1 gene in yeast and simultaneously inserted a GFP downstream of it. This created a reporter for promoter activity while leaving the FAR1 gene fully intact. In another experiment, we used PCR duplication to increase the dosage of a gene in a discrete manner, from 1× to 2x. Using TUB4, the gene encoding for the yeast γ-tubulin, we validated that this led to corresponding increases in the levels of mRNA and protein. PCR duplication is an easy one-step procedure that can be adapted in different ways to permit rapid, disturbance-free investigation of various genomic regulatory elements without the need for ex vivo cloning. PMID:25493941

  13. Development of a duplex one-step RT-qPCR assay for the simultaneous detection of Apple scar skin viroid and plant RNA internal control.

    PubMed

    Khan, Subuhi; Mackay, John; Liefting, Lia; Ward, Lisa

    2015-09-01

    Apple scar skin viroid (ASSVd) is an important quarantine pathogen for international movement of pome germplasm as it can cause significant damage to pip fruit. A one-step real-time RT-PCR assay was developed for the rapid and sensitive detection of ASSVd. The assay was able to detect a wide range of ASSVd isolates and was highly specific compared to a published conventional RT-PCR. The detection limit of the new assay was estimated to be about 100 copies of the ASSVd target. The assay can be run as a duplex with the nad5 internal control primers and probe to simultaneously check the PCR competency of the samples therefore reducing the risk of false negatives. It is expected that this real-time RT-PCR assay will facilitate efficient testing for ASSVd by regulatory services, and will also have a wider use for the general detection of ASSVd in a range of pip fruit. PMID:25962536

  14. [Rapid determination of 137Cs in environmental samples--purification of 137Cs by ammonium molybdophosphate column separation].

    PubMed

    Nonaka, N; Sato, K; Higuchi, H; Hamaguchi, H

    1976-10-01

    A rapid method for the determination of 137Cs in environmental samples was proposed. The principal technic employed in this study is based on column separation of 137Cs using ammonium molybdophosphate mixed with glass fiber to eliminate contribution of natural radionuclides such as 40K and 87Rb. The separation of cesium from potassium and rubidium was performed by the elution with 0.5m ammonium nitrate solution. The time required for separation of cesium was five hours as compared with the conventional cation exchange separation which required thirteen hours. The chemical yield of cesium carrier was normally more than 90 percent. The results obtained were compared with that by the conventional methods using Bio-Rex cation exchange separation and the good agreement between the two methods was obtained. PMID:1037401

  15. Mixed stimuli-responsive magnetic and gold nanoparticle system for rapid purification, enrichment, and detection of biomarkers.

    PubMed

    Nash, Michael A; Yager, Paul; Hoffman, Allan S; Stayton, Patrick S

    2010-12-15

    A new diagnostic system for the enrichment and detection of protein biomarkers from human plasma is presented. Gold nanoparticles (AuNPs) were surface-modified with a diblock copolymer synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. The diblock copolymer contained a thermally responsive poly(N-isopropylacrylamide) (pNIPAAm) block, a cationic amine-containing block, and a semi-telechelic PEG₂-biotin end group. When a mixed suspension of 23 nm pNIPAAm-modified AuNPs was heated with pNIPAAm-coated 10 nm iron oxide magnetic nanoparticles (mNPs) in human plasma, the thermally responsive pNIPAAm directed the formation of mixed AuNP/mNP aggregates that could be separated efficiently with a magnet. Model studies showed that this mixed nanoparticle system could efficiently purify and strongly enrich the model biomarker protein streptavidin in spiked human plasma. A 10 ng/mL streptavidin sample was mixed with the biotinylated pNIPAAm-modified AuNPs and magnetically separated in the mixed nanoparticle system with pNIPAAm mNPs. The aggregates were concentrated into a 50-fold smaller fluid volume at room temperature where the gold nanoparticle reagent redissolved with the streptavidin target still bound. The concentrated gold-labeled streptavidin could be subsequently analyzed directly using lateral flow immunochromatography. This rapid capture and enrichment module thus utilizes the mixed stimuli-responsive nanoparticle system to achieve concentration of a gold-labeled biomarker that can be directly analyzed using lateral flow or other rapid diagnostic strategies. PMID:21070026

  16. A Mixed Stimuli-Responsive Magnetic and Gold Nanoparticle System for Rapid Purification, Enrichment, and Detection of Biomarkers

    PubMed Central

    Nash, Michael A.; Yager, Paul; Hoffman, Allan S.; Stayton, Patrick S.

    2010-01-01

    A new diagnostic system for the enrichment and detection of protein biomarkers from human plasma is presented. Gold nanoparticles (AuNPs) were surface-modified with a diblock copolymer synthesized using reversible addition fragmentation chain transfer (RAFT) polymerization. The diblock copolymer contained a thermally-responsive poly(N-isopropylacrylamide) (pNIPAAm) block, a cationic amine-containing block, and a semi-telechelic PEG2-biotin end group. When a mixed suspension of 23 nm pNIPAAm-modified AuNPs was heated with pNIPAAm-coated 10 nm iron oxide magnetic nanoparticles (mNPs) in human plasma, the thermally-responsive pNIPAAm directed the formation of mixed AuNP/mNP aggregates that could be separated efficiently with a magnet. Model studies showed that this mixed nanoparticle system could efficiently purify and strongly enrich the model biomarker protein streptavidin in spiked human plasma. A 10 ng/mL streptavidin sample was mixed with the biotinylated and pNIPAAm modified AuNP and magnetically separated in the mixed nanoparticle system with pNIPAAm mNPs. The aggregates were concentrated into a 50-fold smaller fluid volume at room temperature where the gold nanoparticle reagent redissolved with the streptavidin target still bound. The concentrated gold-labeled streptavidin could be subsequently analyzed directly using lateral flow immunochromatography. This rapid capture and enrichment module thus utilizes the mixed stimuli-responsive nanoparticle system to achieve direct concentration of a gold-labeled biomarker that can be directly analyzed using lateral flow or other rapid diagnostic strategies. PMID:21070026

  17. A sensitive one-step method for quantitative detection of α-amylase in serum and urine using a personal glucose meter.

    PubMed

    Wang, Qing; Wang, Hui; Yang, Xiaohai; Wang, Kemin; Liu, Rongjuan; Li, Qing; Ou, Jinqing

    2015-02-21

    Assays of α-amylase (AMS) activity in serum and urine constitute the important indicator for the diagnosis of acute pancreatitis, mumps, renal disease and abdominal disorders. Since these diseases confer a heavy financial burden on the health care system, AMS detection in point-of-care is fundamental. Here, a one-step assay for direct determination of the AMS activity was developed using a portable personal glucose meter (PGM). In this assay, maltopentaose was used as a substrate for sensitive detection of AMS with the assistance of α-glucosidase. In the presence of AMS, maltopentaose can be readily hydrolyzed to form maltotriose and maltose quickly. With the enzymatic hydrolysis of α-glucosidase, maltotriose and maltose can be turned into glucose rapidly, which can be quantitatively measured using a portable PGM. This assay did not require any cumbersome and time consuming operations, such as surface modification, synthesis of invertase conjugate, washing and centrifugation. Detection of AMS can be achieved using only a one-step mixture, and the limit of detection was 20 U L(-1) which was lower than the clinical cutoff for AMS. More importantly, this sensitive and selective assay was also used for the detection of AMS in human serum/urine samples. The results showed that the recovery of AMS from human serum/urine samples was 91-107%. The rapid and easy-to-operate assay may have potential application in the fields of point-of-care (POC) clinical diagnosis, particularly in rural and remote areas where lab equipment may be limited. PMID:25516912

  18. One-step formation of a single atomic-layer transistor by the selective fluorination of a graphene film.

    PubMed

    Ho, Kuan-I; Liao, Jia-Hong; Huang, Chi-Hsien; Hsu, Chang-Lung; Zhang, Wenjing; Lu, Ang-Yu; Li, Lain-Jong; Lai, Chao-Sung; Su, Ching-Yuan

    2014-03-12

    In this study, the scalable and one-step fabrication of single atomic-layer transistors is demonstrated by the selective fluorination of graphene using a low-damage CF4 plasma treatment, where the generated F-radicals preferentially fluorinated the graphene at low temperature (<200 °C) while defect formation was suppressed by screening out the effect of ion damage. The chemical structure of the C-F bonds is well correlated with their optical and electrical properties in fluorinated graphene, as determined by X-ray photoelectron spectroscopy, Raman spectroscopy, and optical and electrical characterizations. The electrical conductivity of the resultant fluorinated graphene (F-graphene) was demonstrated to be in the range between 1.6 kΩ/sq and 1 MΩ/sq by adjusting the stoichiometric ratio of C/F in the range between 27.4 and 5.6, respectively. Moreover, a unique heterojunction structure of semi-metal/semiconductor/insulator can be directly formed in a single layer of graphene using a one-step fluorination process by introducing a Au thin-film as a buffer layer. With this heterojunction structure, it would be possible to fabricate transistors in a single graphene film via a one-step fluorination process, in which pristine graphene, partial F-graphene, and highly F-graphene serve as the source/drain contacts, the channel, and the channel isolation in a transistor, respectively. The demonstrated graphene transistor exhibits an on-off ratio above 10, which is 3-fold higher than that of devices made from pristine graphene. This efficient transistor fabrication method produces electrical heterojunctions of graphene over a large area and with selective patterning, providing the potential for the integration of electronics down to the single atomic-layer scale.

  19. One-step immunoassay for tetrabromobisphenol a using a camelid single domain antibody-alkaline phosphatase fusion protein.

    PubMed

    Wang, Jia; Majkova, Zuzana; Bever, Candace R S; Yang, Jun; Gee, Shirley J; Li, Ji; Xu, Ting; Hammock, Bruce D

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is a ubiquitous brominated flame retardant, showing widespread environmental and human exposures. A variable domain of the heavy chain antibody (VHH), naturally occurring in camelids, approaches the lower size limit of functional antigen-binding entities. The ease of genetic manipulation makes such VHHs a superior choice to use as an immunoreagent. In this study, a highly selective anti-TBBPA VHH T3-15 fused with alkaline phosphatase (AP) from E. coli was expressed, showing both an integrated TBBPA-binding capacity and enzymatic activity. A one-step immunoassay based on the fusion protein T3-15-AP was developed for TBBPA in 5% dimethyl sulfoxide (DMSO)/phosphate buffered saline (PBS, pH 7.4), with a half-maximum signal inhibition concentration (IC50) of 0.20 ng mL(-1). Compared to the parental VHH T3-15, T3-15-AP was able to bind to a wider variety of coating antigens and the assay sensitivity was slightly improved. Cross-reactivity of T3-15-AP with a set of important brominated analogues was negligible (<0.1%). Although T3-15-AP was susceptible to extreme heat (90 °C), much higher binding stability at ambient temperature was observed in the T3-15-AP-based assay for at least 70 days. A simple pretreatment method of diluting urine samples with DMSO was developed for a one-step assay. The recoveries of TBBPA from urine samples via this one-step assay ranged from 96.7% to 109.9% and correlated well with a high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS) method. It is expected that the dimerized fusion protein, VHH-AP, will show promising applications in human exposure and environmental monitoring.

  20. One-step Immunoassay for Tetrabromobisphenol A Using a Camelid Single Domain Antibody-Alkaline Phosphatase Fusion Protein

    PubMed Central

    Wang, Jia; Majkova, Zuzana; Bever, Candace R. S.; Yang, Jun; Gee, Shirley J.; Li, Ji; Xu, Ting; Hammock, Bruce D.

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is a ubiquitous brominated flame retardant, showing widespread environment and human exposures. A variable domain of the heavy chain antibody (VHH), naturally occurring in camelids, approaches the lower size limit of functional antigen-binding entities. Ease of genetic manipulation makes such VHHs a superior choice to use as an immunoreagent. In this study, a highly selective anti-TBBPA VHH T3-15 fused with alkaline phosphatase (AP) from E. coli was expressed, showing both an integrated TBBPA-binding capacity and enzymatic activity. A one-step immunoassay based on the fusion protein T3-15-AP was developed for TBBPA in 5% dimethyl sulfoxide (DMSO)/phosphate buffered saline (PBS, pH 7.4), with a half-maximum signal inhibition concentration (IC50) of 0.20 ng mL−1. Compared to the parental VHH T3-15, T3-15-AP was able to bind to a wider variety of coating antigens and the assay sensitivity was slightly improved. Cross-reactivity of T3-15-AP with a set of important brominated analogs was negligible (<0.1%). Although T3-15-AP was susceptible to extreme heat (90 °C), much higher binding stability at ambient temperature was observed in the T3-15-AP based assay for at least 70 days. A simple pretreatment method of diluting urine samples with DMSO was developed for a one-step assay. The recoveries of TBBPA from urine samples by this one-step assay ranged from 96.7–109.9% and correlated well with an HPLC-MS/MS method. It is expected that the dimerized fusion protein, VHH-AP, will show promising applications in human exposure and environmental monitoring. PMID:25849972

  1. One-step Maskless Fabrication and Optical Characterization of Silicon Surfaces with Antireflective Properties and a White Color Appearance

    PubMed Central

    Schneider, Ling; Feidenhans’l, Nikolaj A.; Telecka, Agnieszka; Taboryski, Rafael J.

    2016-01-01

    We report a simple one-step maskless fabrication of inverted pyramids on silicon wafers by reactive ion etching. The fabricated surface structures exhibit excellent anti-reflective properties: The total reflectance of the nano inverted pyramids fabricated by our method can be as low as 12% without any anti-reflective layers, and down to only 0.33% with a silicon nitride coating. The results from angle resolved scattering measurements indicate that the existence of triple reflections is responsible for the reduced reflectance. The surfaces with the nano inverted pyramids also exhibit a distinct milky white color. PMID:27725703

  2. One-step fabrication of intense red fluorescent gold nanoclusters and their application in cancer cell imaging

    NASA Astrophysics Data System (ADS)

    Bian, Pingping; Zhou, Jing; Liu, Yueying; Ma, Zhanfang

    2013-06-01

    A one-step method for successfully fabrication of water-soluble and alkanethiol-stabilized Au nanoclusters (NCs) was demonstrated. The novel and facile method was based on simply placing histidine (His), HAuCl4 and 11-mercaptoundcanoic acid (MUA) together at room temperature. The resulting Au NCs were exclusively composed of Au17MUA4His22 (AMH), as demonstrated by the photoluminescence, UV-Vis absorption, electrospray ionization mass and X-ray photoelectron spectroscopy. AMH exhibited intense red fluorescence (λem = 600 nm), a long fluorescence lifetime (7.11 μs), considerable stability, and a large Stoke's shift (320 nm). Based on the excellent properties of the AMH, cell experiments were conducted. Cytotoxicity studies showed that the Au NCs exhibited negligible effects in altering cell proliferation or triggering apoptosis. Cancer cell imaging of HeLa cell lines indicated that the obtained AMH could serve as a promising fluorescent bioprobe for bioimaging. This strategy, based on the one-step method, may offer a novel approach to fabricate other water-soluble and alkanethiol-stabilized metal nanoclusters for application in biolabelling and bioimaging.A one-step method for successfully fabrication of water-soluble and alkanethiol-stabilized Au nanoclusters (NCs) was demonstrated. The novel and facile method was based on simply placing histidine (His), HAuCl4 and 11-mercaptoundcanoic acid (MUA) together at room temperature. The resulting Au NCs were exclusively composed of Au17MUA4His22 (AMH), as demonstrated by the photoluminescence, UV-Vis absorption, electrospray ionization mass and X-ray photoelectron spectroscopy. AMH exhibited intense red fluorescence (λem = 600 nm), a long fluorescence lifetime (7.11 μs), considerable stability, and a large Stoke's shift (320 nm). Based on the excellent properties of the AMH, cell experiments were conducted. Cytotoxicity studies showed that the Au NCs exhibited negligible effects in altering cell proliferation or

  3. One-step synthesis of collagen hybrid gold nanoparticles and formation on Egyptian-like gold-plated archaeological ivory.

    PubMed

    Spadavecchia, Jolanda; Apchain, Emilande; Albéric, Marie; Fontan, Elisabeth; Reiche, Ina

    2014-08-01

    A one-step method is reported to synthesize hybrid gold nanoparticles (AuNPs) by reduction of HAuCl4 in acetic solution in the presence of collagen (Col), dicarboxylic acid-terminated polyethylene glycol (PEG), and cetyltetrammonium bromide (CTAB) mixed with hydoxyapatite (HAP) as surfactants. Such formation process of AuNPs was shown to be responsible for purple stains naturally formed on Egyptianizing archaeological gilded ivories from 8th BC Syria. The understanding of this formation mechanism, which most likely involves a step with hybrid AuNPs, allows the establishing of an authenticity marker of ancient gold-plated ivories.

  4. Bonded cylindrical Terfenol-D-epoxy/PZT magnetoelectric composites prepared by the one-step compression molding

    NASA Astrophysics Data System (ADS)

    Song, Yang; Pan, De'an; Wang, Jiao; Zuo, Zhijun; Zhang, Shengen; Liu, Bo; Volinsky, Alex A.

    2015-03-01

    Magnetoelectric composites with bonded Terfenol-D-epoxy (TDE) and PZT cylindrical ceramics were prepared by the one-step compression molding at room temperature. The PZT cylindrical ceramics not only provided the piezoelectric phase, but also acted as a mold for TDE. The axial ME voltage coefficient of the cylindrical composites, αE,A, was studied. By contrast, the new structure has a larger ME voltage coefficient compared with the effective planar laminated composites due to the self-bound state. This study decreases the ME composite dimensions, making it a promising candidate for the magnetic field sensor applications.

  5. Changing Safety Culture, One Step at a Time: The Value of the DOE-VPP Program at PNNL

    SciTech Connect

    Wright, Patrick A.; Isern, Nancy G.

    2005-02-01

    The primary value of the Pacific Northwest National Laboratory (PNNL) Voluntary Protection Program (VPP) is the ongoing partnership between management and staff committed to change Laboratory safety culture one step at a time. VPP enables PNNL's safety and health program to transcend a top-down, by-the-book approach to safety, and it also raises grassroots safety consciousness by promoting a commitment to safety and health 24 hours a day, 7 days a week. PNNL VPP is a dynamic, evolving program that fosters innovative approaches to continuous improvement in safety and health performance at the Laboratory.

  6. One-step Maskless Fabrication and Optical Characterization of Silicon Surfaces with Antireflective Properties and a White Color Appearance

    NASA Astrophysics Data System (ADS)

    Schneider, Ling; Feidenhans’L, Nikolaj A.; Telecka, Agnieszka; Taboryski, Rafael J.

    2016-10-01

    We report a simple one-step maskless fabrication of inverted pyramids on silicon wafers by reactive ion etching. The fabricated surface structures exhibit excellent anti-reflective properties: The total reflectance of the nano inverted pyramids fabricated by our method can be as low as 12% without any anti-reflective layers, and down to only 0.33% with a silicon nitride coating. The results from angle resolved scattering measurements indicate that the existence of triple reflections is responsible for the reduced reflectance. The surfaces with the nano inverted pyramids also exhibit a distinct milky white color.

  7. One-step synthesis of CdS-reduced graphene oxide composites based on high-energy radiation technique

    NASA Astrophysics Data System (ADS)

    Liu, Xuqiang; Zeng, Guang; Jiang, Shubin

    2016-02-01

    In this paper, we introduced a novel 60Co-ray-irradiation-based one-step synthesis method of nano-CdS-reduced graphene oxide composites (CdS/RGO) in aqueous solution. The synthesis approach is simple and green and may be applied in the synthesis of other RGO-metal-sulfide nanocomposites. Sodium thiosulfate was used as a sulfur source. Triethanolamine and glycerol were respectively used as the colloidal stabilizer and radical scavenger. The compositional distribution of the particles in the samples was demonstrated by X-ray diffractometry, Raman spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy.

  8. The amphiphilic hydrophobin Vmh2 plays a key role in one step synthesis of hybrid protein-gold nanoparticles.

    PubMed

    Politi, Jane; De Stefano, Luca; Longobardi, Sara; Giardina, Paola; Rea, Ilaria; Methivier, Christophe; Pradier, Claire-Marie; Casale, Sandra; Spadavecchia, Jolanda

    2015-12-01

    We report a simple and original method to synthesize gold nanoparticles in which a fungal protein, the hydrophobin Vmh2 from Pleurotus ostreatus and dicarboxylic acid-terminated polyethylene-glycol (PEG) has been used as additional components in a one step process, leading to hybrid protein-metal nanoparticles (NPs). The nanoparticles have been characterized by ultra-violet/visible, infrared and X-ray photoelectron spectroscopies, dynamic light scattering and also by electron microscopy imaging. The results of these analytical techniques highlight nanometric sized, stable, hybrid complexes of about 12 nm, with outer surface rich in functional chemical groups. Interaction with protein and antibodies has also been exploited. PMID:26402419

  9. One-step green synthesis of high uniform SERS substrate based on Au nanoparticles grown on Ge wafer

    NASA Astrophysics Data System (ADS)

    Zhou, Juhong; Zhu, Feng; Wang, Yan; Wang, Tao

    2015-05-01

    Highly sensitive, large-area and uniform surface-enhanced Raman scattering (SERS) substrates based on gold nanoparticles grown on Ge wafer have been fabricated by a one-step green reaction. The results showed that these substrates exhibited admirable performance in the low concentration detection (1 × 10-7 M) of Rhodamine 6G with the enhancement factor of 4.5 × 106 and remarkable uniformity with relative standard deviation less than 8%. The uniform enhancement was also obtained in the aqueous detection of malachite green. During the experiments, the Raman spectra were recorded in the solution to pursue the uniformity, reproducibility and stability of signals.

  10. One-step growth of lanthanoid metal-organic framework (MOF) films under solvothermal conditions for temperature sensing.

    PubMed

    Liu, Xue; Fu, Wentian; Bouwman, Elisabeth

    2016-05-25

    A one-step direct solvothermal synthesis of an Ln metal-organic framework (MOF) film is reported. The LnHL (Ln = Tb and Gd) films that were deposited on a Gd2O3 subtrate are continuous and smooth. The Gd0.9Tb0.1HL film can be used as a ratiometric thermometer, showing good linear behaviour in the temperature range of 110-250 K with a sensitivity up to 0.8% K(-1). PMID:27147478

  11. Fabrication of twisted nematic structure and vector grating cells by one-step exposure on photocrosslinkable polymer liquid crystals.

    PubMed

    Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2012-03-15

    We present a simple yet efficient method to automatically fabricate the twisted nematic structure by one-step exposure on an empty glass cell coated with photocrosslinkable polymer liquid crystal (PCLC) films. The resultant photoalignment directions of two substrates can be orthogonal to each other by controlling the difference between the exposure energy for upper and lower PCLC films and the twisted nematic (TN) structure can be automatically fabricated. The vector grating liquid crystalline cell with TN structure was also fabricated by means of a developed method, and the diffraction properties were well explained by the theoretical calculation on the basis of Jones calculus. PMID:22446243

  12. Use of Strep-tag II for rapid detection and purification of Mycobacterium tuberculosis recombinant antigens secreted by Streptomyces lividans.

    PubMed

    Ayala, Julio C; Pimienta, Elsa; Rodríguez, Caridad; Anné, Jozef; Vallín, Carlos; Milanés, María T; King-Batsios, Emmanuel; Huygen, Kris; Van Mellaert, Lieve

    2013-09-01

    Recent results with respect to the secretory production of bio-active Mycobacterium tuberculosis proteins in Streptomyces have stimulated the further exploitation of this host as a bacterial cell factory. However, the rapid isolation of a recombinant protein by conventional procedures can be a restrictive step. A previous attempt to isolate recombinant antigens fused to the widely used 6His-tag was found to be relatively incompatible with secretory production in the Streptomyces host. As an alternative, the eight-residue Strep-tag® II (WSHPQFEK), displaying intrinsic binding affinity towards streptavidin, was evaluated for the secretory production of two M. tuberculosis immunodominant antigens in Streptomyces lividans and their subsequent downstream processing. Therefore, the genes ag85A (Rv3804c, encoding the mycolyl-transferase Ag85A) and Rv2626c (encoding hypoxic response protein 1), were equipped with a 3'-Strep-tag® II-encoding sequence and placed under control of the Streptomyces venezuelae CBS762.70 subtilisin inhibitor (vsi) transcriptional, translational and signal sequences. Strep-tagged Ag85A and Rv2626c proteins were detected in the spent medium of recombinant S. lividans cultures at 48h of growth, and purified using a Strep-Tactin Superflow® matrix. Recombinant Ag85A appeared as a 30-kDa protein of which the N-terminal amino acid sequence was identical to the expected one. Rv2626c was produced in two forms of 17 and 37kDa respectively, both with the same predicted N-terminal sequence, suggesting that the 37-kDa product is an Rv2626c dimer. The obtained results indicate that the Strep-tagII is proteolytically stable in Streptomyces and does not interfere with the membrane translocation of Ag85A and Rv2626c. A comparison of reactivity of serum from tuberculosis patients versus healthy persons by ELISA showed that both S. lividans-derived antigens were recognized by sera of individuals infected with M. tuberculosis, indicating that they remained

  13. Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine

    SciTech Connect

    Sochman, Jan Peregrin, Jan H.; Rocek, Miloslav; Timmermans, Hans A.; Pavcnik, Dusan; Roesch, Josef

    2006-02-15

    Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.

  14. One-step room temperature synthesis of very small γ-Fe{sub 2}O{sub 3} nanoparticles

    SciTech Connect

    Moscoso-Londoño, O.; Carrião, M.S.; Cosio-Castañeda, C.; Bilovol, V.; Sánchez, R. Martínez; Lede, E.J.; Socolovsky, L.M.; Martínez-García, R.

    2013-09-01

    Graphical abstract: - Highlights: • One-step synthesis of 3 nm maghemite nanoparticles is reported. • Maghemite nanoparticles can be synthesized from a ferric solution. • γ-Fe{sub 2}O{sub 3} NPs can be obtained if the precursor has Fe(III) in tetrahedral interstices. • HR-TEM, Mössbauer, XAFS and magnetometry analysis proved the maghemite existence - Abstract: Very small maghemite nanoparticles (∼3 nm) are obtained through a one-step synthesis at room temperature. The fast neutralization reaction of a ferric solution in a basic medium produces an intermediate phase, presumably two-line ferrihydrite, which in oxidizing conditions is transformed to maghemite nanoparticles. The synthesis of maghemite, as final product of the reaction, was characterized by High-Resolution Transmission Electron Microscopy (HR-TEM), X-ray Absorption Fine Structure (XAFS), Mössbauer spectroscopy, and magnetometry. The XAFS technique allowed the analysis of the crystallographic variations into maghemite nanoparticles as a result of modification in its surface/volume ratio. Mössbauer spectroscopy at low temperature (4.2 K) confirms the presence of Fe(III) in tetrahedral and octahedral interstices, in the stoichiometry corresponding to maghemite. The specific magnetization, M vs H (3 K and 300 K, up to 7 T) and temperature dependence of the magnetization (50 Oe by ZFC mode, 2 K ≤ T ≤ 300 K) indicate that maghemite nanoparticles of 3 nm are in superparamagnetic state with a blocking temperature close to 36 K.

  15. The energy expenditure of stair climbing one step and two steps at a time: estimations from measures of heart rate.

    PubMed

    Halsey, Lewis G; Watkins, David A R; Duggan, Brendan M

    2012-01-01

    Stairway climbing provides a ubiquitous and inconspicuous method of burning calories. While typically two strategies are employed for climbing stairs, climbing one stair step per stride or two steps per stride, research to date has not clarified if there are any differences in energy expenditure between them. Fourteen participants took part in two stair climbing trials whereby measures of heart rate were used to estimate energy expenditure during stairway ascent at speeds chosen by the participants. The relationship between rate of oxygen consumption ([Formula: see text]) and heart rate was calibrated for each participant using an inclined treadmill. The trials involved climbing up and down a 14.05 m high stairway, either ascending one step per stride or ascending two stair steps per stride. Single-step climbing used 8.5±0.1 kcal min(-1), whereas double step climbing used 9.2±0.1 kcal min(-1). These estimations are similar to equivalent measures in all previous studies, which have all directly measured [Formula: see text] The present study findings indicate that (1) treadmill-calibrated heart rate recordings can be used as a valid alternative to respirometry to ascertain rate of energy expenditure during stair climbing; (2) two step climbing invokes a higher rate of energy expenditure; however, one step climbing is energetically more expensive in total over the entirety of a stairway. Therefore to expend the maximum number of calories when climbing a set of stairs the single-step strategy is better. PMID:23251455

  16. One-step synthesis and characterization of polyaniline nanofiber/silver nanoparticle composite networks as antibacterial agents.

    PubMed

    Poyraz, Selcuk; Cerkez, Idris; Huang, Tung Shi; Liu, Zhen; Kang, Litao; Luo, Jujie; Zhang, Xinyu

    2014-11-26

    Through a facile and effective seeding polymerization reaction via a one-step redox/complexation process, which took place in aqueous medium at ambient temperature, silver nanoparticles (Ag NPs) embedded polyaniline nanofiber (PANI NF) networks were synthesized as antibacterial agents. During the reaction, not only NF morphology formation of the resulting conducting polymers (CPs) but also amplification of the aqueous silver nitrate (AgNO3) solutions' oxidative potentials were managed by vanadium pentoxide (V2O5) sol-gel nanofibers, which acted as well-known nanofibrous seeding agents and the auxiliary oxidative agent at the same time. The PANI/Ag nanocomposites were proven to exhibit excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Antibacterial property performance and average life span of the nanocomposite network were optimized through the homogeneous distribution/embedment of Ag NPs within one-dimensional (1-D) PANI NF matrix. The antibacterial efficacy tests and nanocomposite material characterization results further indicated that the sole components of PANI/Ag have a synergistic effect to each other in terms of antibacterial property. Thus, this well-known catalytic seeding approach via a one-step oxidative polymerization reaction can be considered as a general methodology and a substantial fabrication tool to synthesize Ag NP decorated nanofibrillar PANI networks as advanced antibacterial agents.

  17. One-Step Transformation from Hierarchical-Structured Superhydrophilic NF Membrane into Superhydrophobic OSN Membrane with Improved Antifouling Effect.

    PubMed

    Guo, Hongxia; Ma, Yiwen; Qin, Zhenping; Gu, Zhaoxiang; Cui, Suping; Zhang, Guojun

    2016-09-01

    The hierarchical-structured superhydrophilic poly(ethylenimine)/poly(acrylic acid) (PEI/PAA)calcium silicate hydrate (CSH) multilayered membranes (PEI/PAA-CSH)n were prepared as aqueous nanofiltration (NF) membrane, and then they were transformed into superhydrophobic organic solvent nanofiltration (OSN) membranes by one-step modification of trimethylperfluorinatedsilane (PFTS). Investigation on surface structures and properties of these multilayered membranes (PEI/PAA-CSH)n indicated that the hierarchical-structured (PEI/PAA-CSH)n multilayered membrane produced by in situ incorporation of CSH aggregates into PEI/PAA multilayers facilitated its one-step transformation from superhydrophilicity into superhydrophobicity. Both of the superwetting membranes showed better nanofiltration performances for retention of dyes of water and ethanol solution, respectively. Moreover, the long-term performance and antifouling behaviors, investigated by retention of methyl blue (MB), bovine serum albumin (BSA), and humic acid (HA) aqueous water solution and nonaqueous ethanol solution indicated that both of the superhydrophilic and superhydrophobic membrane showed higher stability and excellent antifouling property.

  18. Fabrication and characterization of metal-packaged fiber Bragg grating sensor by one-step ultrasonic welding

    NASA Astrophysics Data System (ADS)

    Zhang, Yumin; Zhu, Lianqing; Luo, Fei; Dong, Mingli; Ding, Xiangdong; He, Wei

    2016-06-01

    A metallic packaging technique of fiber Bragg grating (FBG) sensors is developed for measurement of strain and temperature, and it can be simply achieved via one-step ultrasonic welding. The average strain transfer rate of the metal-packaged sensor is theoretically evaluated by a proposed model aiming at surface-bonded metallic packaging FBG. According to analytical results, the metallic packaging shows higher average strain transfer rate compared with traditional adhesive packaging under the same packaging conditions. Strain tests are performed on an elaborate uniform strength beam for both tensile and compressive strains; strain sensitivities of approximately 1.16 and 1.30 pm/μɛ are obtained for the tensile and compressive situations, respectively. Temperature rising and cooling tests are also executed from 50°C to 200°C, and the sensitivity of temperature is 36.59 pm/°C. All the measurements of strain and temperature exhibit good linearity and stability. These results demonstrate that the metal-packaged sensors can be successfully fabricated by one-step welding technique and provide great promise for long-term and high-precision structural health monitoring.

  19. One-step green synthesis of non-hazardous dicarboxyl cellulose flocculant and its flocculation activity evaluation.

    PubMed

    Zhu, Hangcheng; Zhang, Yong; Yang, Xiaogang; Liu, Hongyi; Shao, Lan; Zhang, Xiumei; Yao, Juming

    2015-10-15

    The waste management of used flocculants is a thorny issue in the field of wastewater treatment. To natural cellulose based flocculants, utilization of hazardous cellulose solvent and simplification of synthetic procedure are the two urgent problems needing to be further improved. In this work, a series of natural dicarboxyl cellulose flocculants (DCCs) were one-step synthesized via Schiff-base route. The cellulose solvent (NaOH/Urea solution) was utilized during the synthesis process. The full-biodegradable flocculants avoid causing secondary pollution to environment. The chemical structure and solution property of the DCC products were characterized by FT-IR, (1)H NMR, (13)C NMR, TGA, FESEM, charge density and ζ-potential. Kaolin suspension and effluent from paper mill were selected to evaluate the flocculation activity of the DCCs. Their flocculation performance was compared with that of commercial cationic polyacrylamide and poly aluminium chloride flocculants. The positive results showed that the NaOH/Urea solvent effectively promoted the dialdehyde cellulose (DAC) conversion to DCC in the one-step synthesis reaction. The DCCs with the carboxylate content more than 1 mmol/g exhibited steady flocculation performance to kaolin suspension in the broad pH range from 4 to 10. Its flocculation capacity to the effluent from paper mill also showed excellent.

  20. One-Step Transformation from Hierarchical-Structured Superhydrophilic NF Membrane into Superhydrophobic OSN Membrane with Improved Antifouling Effect.

    PubMed

    Guo, Hongxia; Ma, Yiwen; Qin, Zhenping; Gu, Zhaoxiang; Cui, Suping; Zhang, Guojun

    2016-09-01

    The hierarchical-structured superhydrophilic poly(ethylenimine)/poly(acrylic acid) (PEI/PAA)calcium silicate hydrate (CSH) multilayered membranes (PEI/PAA-CSH)n were prepared as aqueous nanofiltration (NF) membrane, and then they were transformed into superhydrophobic organic solvent nanofiltration (OSN) membranes by one-step modification of trimethylperfluorinatedsilane (PFTS). Investigation on surface structures and properties of these multilayered membranes (PEI/PAA-CSH)n indicated that the hierarchical-structured (PEI/PAA-CSH)n multilayered membrane produced by in situ incorporation of CSH aggregates into PEI/PAA multilayers facilitated its one-step transformation from superhydrophilicity into superhydrophobicity. Both of the superwetting membranes showed better nanofiltration performances for retention of dyes of water and ethanol solution, respectively. Moreover, the long-term performance and antifouling behaviors, investigated by retention of methyl blue (MB), bovine serum albumin (BSA), and humic acid (HA) aqueous water solution and nonaqueous ethanol solution indicated that both of the superhydrophilic and superhydrophobic membrane showed higher stability and excellent antifouling property. PMID:27537337

  1. Influence of preliminary etching on the stability of bonds created by one-step self-etch bonding systems.

    PubMed

    Taschner, Michael; Nato, Fernando; Mazzoni, Annalisa; Frankenberger, Roland; Falconi, Mirella; Petschelt, Anselm; Breschi, Lorenzo

    2012-06-01

    We evaluated the effects of preliminary etching of dentine on the stability of the bond created by one-step self-etch adhesives under different storage conditions. Adper Easy Bond (3M ESPE) and iBond Self-Etch (iBond SE; Heraeus Kulzer) were applied with an etch-and-rinse (i.e. after preliminary phosphoric acid etching for 15 s) or a self-etch approach. Resin-dentine bonded specimens were sectioned perpendicularly to the adhesive interface according to the 'non-trimming technique'. Beams were stored in artificial saliva for 24 h, 6 months, or 1 yr at 37°C, or in 10% NaOCl for 5 h at room temperature, and then stressed until failure; the microtensile bond strengths were calculated. Interfacial nanoleakage of additional teeth was evaluated using light microscopy or transmission electron microscopy. Adper Easy Bond showed higher bond strength than iBond SE, regardless of the dentine treatment. Similar microtensile bond strength results were obtained for teeth subjected to artificial ageing in 10% NaOCl for 5 h at room temperature and for teeth stored in artificial saliva for 6 months at 37°C. The additional etching step increased the microtensile bond strength for Adper Easy Bond and iBond SE. This study supports the use of one-step adhesives on etched dentine because of the increased bond strength compared with their application onto smear-layer-covered dentine, regardless of storage conditions. PMID:22607341

  2. One-step green synthesis of cuprous oxide crystals with truncated octahedra shapes via a high pressure flux approach

    SciTech Connect

    Li Benxian; Wang Xiaofeng; Xia Dandan; Chu Qingxin; Liu Xiaoyang; Lu Fengguo; Zhao Xudong

    2011-08-15

    Cuprous oxide (Cu{sub 2}O) was synthesized via reactions between cupric oxide (CuO) and copper metal (Cu) at a low temperature of 300 deg. C. This progress is green, environmentally friendly and energy efficient. Cu{sub 2}O crystals with truncated octahedra morphology were grown under high pressure using sodium hydroxide (NaOH) and potassium hydroxide (KOH) with a molar ratio of 1:1 as a flux. The growth mechanism of Cu{sub 2}O polyhedral microcrystals are proposed and discussed. - Graphical Abstract: The Cu{sub 2}O crystals with truncated octahedral shape were one-step synthesized in high yield via high pressure flux method for the first time, which is green and environmentally friendly. The mechanisms of synthesis and crystal growth were discussed in this paper. Highlights: > Cuprous oxide was one-step green synthesized by high pressure flux method. > The approach was based on the reverse dismutation reactions between cupric oxide and copper metal. > This progress is green, environmentally friendly and energy efficient. > The synthesized Cu2O crystals were of truncated octahedra morphology.

  3. One-step synthesis of hybrid inorganic-organic nanocomposite coatings by novel laser adaptive ablation deposition technique

    NASA Astrophysics Data System (ADS)

    Serbezov, Valery; Sotirov, Sotir

    2013-03-01

    A novel approach for one-step synthesis of hybrid inorganic-organic nanocomposite coatings by new modification of Pulsed Laser Deposition technology called Laser Adaptive Ablation Deposition (LAAD) is presented. Hybrid nanocomposite coatings including Mg- Rapamycin and Mg- Desoximetasone were produced by UV TEA N2 laser under low vacuum (0.1 Pa) and room temperature onto substrates from SS 316L, KCl and NaCl. The laser fluence for Mg alloy was 1, 8 J/cm2 and for Desoximetasone 0,176 J/cm2 and for Rapamycin 0,118 J/cm2 were respectively. The threedimensional two-segmented single target was used to adapt the interaction of focused laser beam with inorganic and organic material. Magnesium alloy nanoparticles with sizes from 50 nm to 250 nm were obtained in organic matrices. The morphology of nanocomposites films were studied by Bright field / Fluorescence optical microscope and Scanning Electron Microscope (SEM). Fourier Transform Infrared (FTIR) spectroscopy measurements were applied in order to study the functional properties of organic component before and after the LAAD process. Energy Dispersive X-ray Spectroscopy (EDX) was used for identification of Mg alloy presence in hybrid nanocomposites coatings. The precise control of process parameters and particularly of the laser fluence adjustment enables transfer on materials with different physical chemical properties and one-step synthesis of complex inorganic- organic nanocomposites coatings.

  4. High-performance, nanostructure LiMnPO4/C composites synthesized via one-step solid state reaction

    NASA Astrophysics Data System (ADS)

    Zheng, Jugong; Ni, Liang; Lu, Yanwen; Qin, Cancan; Liu, Panxing; Wu, Tongfu; Tang, Yuefeng; Chen, Yanfeng

    2015-05-01

    LiMnPO4 is proposed as more promising cathode material as LiFePO4, while poor electronic conductivity and Jahn-Teller effects during charge/discharge processes hinder the electrochemical performance. To overcome these problems, one-step solid state reaction method is developed to synthesize LiMnPO4/C composites, which is with nanostructure, high crystallinity and good carbon coating. Manganese oxide sources and calcination temperature are investigated as factors for preparing high-performance LiMnPO4/C for Li-ion batteries. The results show that the LiMnPO4/C composites prepared with mixed manganese oxide deliver a superior initial capacity of 153 mAh g-1 at 0.05 C and high rate performance with discharge capacities of 123 mAh g-1 at 1 C and 103 mAh g-1 at 2 C. And the LiMnPO4/C composites synthesized at 600 °C can retain 94% of the initial capacity after 200 cycles at 1 C, revealing a stable cycling stability. Therefore, one-step solid state reaction brings to light the synthesis of high performance LiMnPO4/C cathode materials and is suitable for large scale production.

  5. Humidity-Sensing Properties of One-Step Hydrothermally Synthesized Tin Dioxide-Decorated Graphene Nanocomposite on Polyimide Substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Dongzhi; Chang, Hongyan; Liu, Runhua

    2016-08-01

    This paper demonstrates the one-step hydrothermal synthesis of a tin dioxide (SnO2)-decorated reduced graphene oxide (RGO) hybrid nanocomposite, which was drop-casted on a polyimide substrate as a humidity sensor. The as-synthesized hybrid was characterized in terms of its nanostructural, morphological and compositional features by SEM, XRD and nitrogen sorption. The humidity sensing properties of the presented RGO/SnO2 hybrid nanocomposite, such as repeatability, stability, response-recovery characteristics, were investigated by exposing it to a broad humidity range of 11-97% RH at room temperature. As a result, the sensor demonstrated a high sensitivity, a good repeatability, an acceptable linearity, a fast response/recovery characteristic and high long-term stability over a full humidity range measurement, indicating the unique advantages of one-step hydrothermal synthesis for sensor fabrication. The possible and proposed sensing mechanism for the sensor is mainly attributed to a humidity-induced transfer of charge carriers occuring at the interfaces and the swelling effect of RGO.

  6. Establishment and validation of two duplex one-step real-time RT-PCR assays for diagnosis of foot-and-mouth disease.

    PubMed

    Gorna, K; Relmy, A; Romey, A; Zientara, S; Blaise-Boisseau, S; Bakkali-Kassimi, L

    2016-09-01

    Two duplex one-step TaqMan-based RT-PCR protocols for detection of foot-and-mouth disease virus (FMDV) were established and validated. Each RT-PCR test consists of a ready-to-use master mix for simultaneous detection of the well established 3D or IRES FMDV targets and incorporates the host β-actin mRNA as an internal control target, in a single-tube assay. The two real-time RT-PCR 3D/β-actin and IRES/β-actin tests are highly sensitive and able to detect up to 7TCID50/ml of FMDV and 10 copies/1μl of viral RNA. In field epithelium samples, the diagnostic sensitivity was 100% (95% CI; 91-100%) for the 3D/β-actin test and 97% (95% CI; 87-100%) for the IRES/β-actin test. The diagnostic specificity was 100% (95% CI; 95-100%) for both RT-PCRs. In addition, the two protocols proved to be robust, showing inter-assay coefficients of variation ranging from 1.94% to 6.73% for the IRES target and from 2.33% to 5.42% for the 3D target for different RNA extractions and different RT-PCR conditions. The internally controlled one-step real-time RT-PCR protocols described in this study provide a rapid, effective and reliable method for the detection of FMDV and thus may improve the routine diagnosis for foot-and-mouth disease. PMID:27317973

  7. A real-time one-step reverse transcriptase-polymerase chain reaction method to quantify c-erbB-2 expression in human breast cancer.

    PubMed

    Pawlowski, V; Révillion, F; Hornez, L; Peyrat, J P

    2000-01-01

    We developed a real-time one-step reverse transcriptase-polymerase chain reaction (RT-PCR) method for the routine quantification of c-erbB-2 oncogene expression in breast cancer, using a 7700 ABI PRISM Sequence Detector System (Perkin Elmer-Applied Biosystems, Courtaboeuf, France). The real-time quantification of the polymerase chain reaction products is based on the TaqMan 5' nuclease assay. The optimal experimental conditions we determined were as follows: 6 mM MgCl2, 200 nM of fluorogenic probe, 200 nM of each primer, and 12.5 units MuLV reverse transcriptase. The GAPDH housekeeping gene was used for normalization of c-erbB-2 expression. In human breast cancer cell lines, the normalized expression of c-erbB-2 ranged from 8 x 10(-6) to 2,600 x 10(-6), the two highest values corresponding to the c-erbB-2 overexpressing cells MDA-MB-453 and SK-BR-3. In a series of 100 breast cancer samples, c-erbB-2 normalized expression was found to range from 0.4 x 10(-6) to 350 x 10(-6). A close correlation was observed between this real-time one-step quantitative RT-PCR method and both semiquantitative conventional RT-PCR (N = 22; r = 0.8543; P < .0001) and c-erbB-2 protein expression (p185) quantified by an enzyme immunoassay (EIA) (N = 27; r = 0.71; P < .0001). The current realtime RT-PCR assay is rapid, sensitive, and reproducible and appears particularly suitable to quantify gene expression in large series of samples.

  8. Establishment and validation of two duplex one-step real-time RT-PCR assays for diagnosis of foot-and-mouth disease.

    PubMed

    Gorna, K; Relmy, A; Romey, A; Zientara, S; Blaise-Boisseau, S; Bakkali-Kassimi, L

    2016-09-01

    Two duplex one-step TaqMan-based RT-PCR protocols for detection of foot-and-mouth disease virus (FMDV) were established and validated. Each RT-PCR test consists of a ready-to-use master mix for simultaneous detection of the well established 3D or IRES FMDV targets and incorporates the host β-actin mRNA as an internal control target, in a single-tube assay. The two real-time RT-PCR 3D/β-actin and IRES/β-actin tests are highly sensitive and able to detect up to 7TCID50/ml of FMDV and 10 copies/1μl of viral RNA. In field epithelium samples, the diagnostic sensitivity was 100% (95% CI; 91-100%) for the 3D/β-actin test and 97% (95% CI; 87-100%) for the IRES/β-actin test. The diagnostic specificity was 100% (95% CI; 95-100%) for both RT-PCRs. In addition, the two protocols proved to be robust, showing inter-assay coefficients of variation ranging from 1.94% to 6.73% for the IRES target and from 2.33% to 5.42% for the 3D target for different RNA extractions and different RT-PCR conditions. The internally controlled one-step real-time RT-PCR protocols described in this study provide a rapid, effective and reliable method for the detection of FMDV and thus may improve the routine diagnosis for foot-and-mouth disease.

  9. Pyridine-containing block copolymer/silica core-shell nanoparticles for one-step preparation of superhydrophobic surfaces.

    PubMed

    Liang, Junyan; Wang, Li; He, Ling; Sun, Shaodong

    2013-07-14

    Two poly(4-vinylpyridine)-b-polystyrene diblock copolymer/silica core-shell nanoparticles (P4VP-b-PS/SiO2 NPs) are developed in this work. Confirmed by DLS analysis and TEM observation, one comprises a SiO2 core surrounded by a P4VP-b-PS shell and the other comprises a P4VP-b-PS core surrounded by a SiO2 shell, which is facilely prepared by the in situ hydrolysis of tetraethyl orthosilicate (TEOS) using cationic P4VP-b-PS micelles obtained in a THF-H2C2O4 (aq, 0.1 mol L(-1)) mixture and a DMF-H2C2O4 (aq, 0.01 mol L(-1)) mixture as template, respectively. The SCA, CAH, SA and SEM measurements reveal that one-step deposition of P4VP-b-PS/SiO2 NPs with SiO2 cores formed at a high level of TEOS creates a superhydrophobic surface with an SCA of 160°, a CAH of 2° and an SA of around 4° originating from the formation of a typical micro-nanoscale binary structure (MNBS). For the NPs with SiO2 cores formed at a low level of TEOS, the superhydrophobicity with a SCA of 151°, CAH of 3° and SA of around 5° can be induced by the transition of the surface microstructure from an uneven and discontinuous MNBS, created by a one-step deposition process, to the coexistence of MNBS and a nanoscale structure (NS) after annealing with toluene for 30 min. In contrast, one-step deposition of P4VP-b-PS/SiO2 NPs with P4VP-b-PS cores and SiO2 shells usually results in the inhomogeneous precipitation of SiO2 from bulk P4VP-b-PS along with the production of micro-cracks, with which is impossible to achieve surface superhydrophobicity.

  10. Highly Sensitive Detection of Melamine Using a One-Step Sample Treatment Combined with a Portable Ag Nanostructure Array SERS Sensor

    PubMed Central

    Cheng, Jie; Su, Xiao-Ou; Yao, Yue; Han, Caiqin; Wang, Shi; Zhao, Yiping

    2016-01-01

    There is an urgent need for rapid and reliable methods able to detect melamine in animal feed. In this study, a quick, simple, and sensitive method for the determination of melamine content in animal feed was developed using surface-enhanced Raman spectroscopy on fabricated Ag nanorod (AgNR) array substrates with a one-step sample extraction procedure. The AgNR array substrates washed by HNO3 solvent (10−7 M) and methanol and showed the good stability within 6 months. The Raman shift at △ν = 682 cm−1 was used as the characteristic melamine peak in the calculations. Sufficient linearity was obtained in the 2–200 μg·g−1 range (R2 = 0.926). The limits of detection and quantification were 0.9 and 2 μg·g−1, respectively. The recovery rates were 89.7–93.3%, with coefficients of variation below 2.02%. The method showed good accuracy compared with the tradition GC-MS analysis. This new protocol only need 2 min to fininsh the detection which could be developed for rapid onsite screening of melamine contamination in quality control and market surveillance applications. PMID:27120183

  11. One-step, room temperature, colorimetric melamine sensing using an in-situ formation of silver nanoparticles through modified Tollens process

    NASA Astrophysics Data System (ADS)

    Wang, Huiying; Chen, Dinglong; Yu, Longquan; Chang, Ming; Ci, Lijie

    2015-02-01

    We have developed a rapid, sensitive, one-step, and selective colorimetric detection method for melamine (MEL) in milk powder based upon an in-situ formation of silver nanoparticles (AgNPs) through modified Tollens process at room temperature. The triazine ring N atoms of MEL molecule were strategically designed to complex the Ag+ through electron donor-acceptor interaction. During the AgNPs formation procedure, the MEL molecule, which has been covalently bonded with the Ag+ ions, was adsorbed to the surface of as-prepared AgNPs, resulting in the aggregation of the adjacent AgNPs with detectable decreases of absorption signal. The concentration of MEL can be determined with the naked eye or a UV-vis spectrometer at which the yellow-to-brown color change associated with aggregate enhancement takes place. This method enables rapid (less than 30 min) and sensitive (limit of detection, LOD, 10 nM) detection, and it was also able to discriminate MEL from sixteen other milk relevant coexisting compounds. This assay does not utilize organic cosolvents, enzymatic reactions, light-sensitive dye molecules, lengthy protocols, or sophisticated instrumentation thereby overcoming some of the limitations of conventional methods.

  12. One-step kinetics-based immunoassay for the highly sensitive detection of C-reactive protein in less than 30 min.

    PubMed

    Vashist, Sandeep Kumar; Czilwik, Gregor; van Oordt, Thomas; von Stetten, Felix; Zengerle, Roland; Marion Schneider, E; Luong, John H T

    2014-07-01

    This article reveals a rapid sandwich enzyme-linked immunosorbent assay (ELISA) for the highly sensitive detection of human C-reactive protein (CRP) in less than 30 min. It employs a one-step kinetics-based highly simplified and cost-effective sandwich ELISA procedure with minimal process steps. The procedure involves the formation of a sandwich immune complex on capture anti-human CRP antibody-bound Dynabeads in 15 min, followed by two magnet-assisted washings and one enzymatic reaction. The developed sandwich ELISA detects CRP in the dynamic range of 0.3 to 81 ng ml(-1) with a limit of detection of 0.4 ng ml(-1) and an analytical sensitivity of 0.7 ng ml(-1). It detects CRP spiked in diluted human whole blood and serum with high analytical precision, as confirmed by conventional sandwich ELISA. Moreover, the results of the developed ELISA for the determination of CRP in the ethylenediaminetetraacetic acid plasma samples of patients are in good agreement with those obtained by the conventional ELISA. The developed immunoassay has immense potential for the development of rapid and cost-effective in vitro diagnostic kits.

  13. Purification of recombinant proteins from mammalian cell culture using a generic double-affinity chromatography scheme.

    PubMed

    Cass, Brian; Pham, Phuong Lan; Kamen, Amine; Durocher, Yves

    2005-03-01

    Transient transfection of mammalian cells has proven to be a useful technique for the rapid production of recombinant proteins because of its ability to produce milligram quantities within 2 weeks following cloning of their corresponding cDNA. This rapid production also requires a fast and efficient purification scheme that can be applied generically, typically through the use of affinity tags such as the polyhistidine-tag for capture by immobilized metal-affinity chromatography (IMAC) or the Strep-tag II, which binds to the StrepTactin affinity ligand. However, one-step purification using either of these tags has disadvantages in terms of yield, elution conditions, and purity. Here, we show that the addition of both Strep-tag-II and (His)(8) to the C-terminal of r-proteins allows efficient purification by consecutive IMAC and StrepTactin affinity. This approach has been successfully demonstrated using the intracellular protein DsRed, as well as two secreted proteins, secreted alkaline phosphatase (SEAP) and vascular endothelial growth factor (VEGF), all produced by transient transfection of HEK293-EBNA1 cells in medium supplemented with bovine calf serum. All proteins were purified to >99% homogeneity with yields varying from 29 to 81%. PMID:15721774

  14. One-step functionalization of multi-walled carbon nanotubes with Ag/polymer under γ-ray irradiation.

    PubMed

    Wu, Wei-Tai; Shi, Lei; Wang, Yusong; Pang, Wenmin; Zhu, Qingren

    2008-03-26

    We reported an easy strategy of using γ-ray irradiation to functionalize multi-walled carbon nanotubes (MWCNTs) without the use of aggressive acid treatment, all in a single processing step. In this paper, we tried to decorate MWCNTs with Ag nanoparticles relying on covalently bonded polymers, via one-step covalent grafting of the polymer to the surface of MWCNTs, and simultaneous reducing of Ag(+) ions to Ag which are then efficiently anchored onto the MWCNTs. Herein, the polymer involved was the commercially available polymer poly(vinyl alcohol) (PVA) and two of its derivatives, polyvinylacetone with ketalization degree D(H) = 0.22 and 0.53. It is envisioned that this simple but efficient method could be extended to fabricate other CNT-based hybrids for both theoretical study and applications in biological and technological fields. PMID:21817739

  15. Hybrid C-nanotubes/Si 3D nanostructures by one-step growth in a dual-plasma reactor

    NASA Astrophysics Data System (ADS)

    Toschi, Francesco; Orlanducci, Silvia; Guglielmotti, Valeria; Cianchetta, Ilaria; Magni, Corrado; Terranova, Maria Letizia; Pasquali, Matteo; Tamburri, Emanuela; Matassa, Roberto; Rossi, Marco

    2012-06-01

    Hybrid nanostructures consisting of Si polycrystalline nanocones, with an anemone-like termination coated with C-nanotubes bundles, have been generated on a (1 0 0) Si substrate in a dual mode microwave/radio-frequency plasma reactor. The substrate is both heated and bombarded by energetic H ions during the synthesis process. The nanocones growth is explained considering pull of the growing Si nanocrystalline phase along the lines of the electrical field, likely via a molten/recrystallization mechanism. The one-step building of the achieved complex 3D architectures is described in terms of dynamic competition between Si and C nanotubes growth under the peculiar conditions of kinetically driven processes.

  16. One-step synthesis of gold and silver hydrosols using poly(N-vinyl-2-pyrrolidone) as a reducing agent.

    PubMed

    Hoppe, Cristina E; Lazzari, Massimo; Pardiñas-Blanco, Iván; López-Quintela, M Arturo

    2006-08-01

    Synthesis of gold and silver hydrosols was carried out in a one-step process by reduction of aqueous solutions of metal salts using poly(N-vinyl-2-pyrrolidone) (PVP). Both kinds of metal nanoparticles were obtained without the addition of any other reducing agent, at low temperatures and using water as the synthesis solvent. Shape, size, and optical properties of the particles could be tuned by changing the employed PVP/metal salt ratio. It is proposed that PVP acts as the reducing agent suffering a partial degradation during the nanoparticles synthesis. Two possible mechanisms are proposed to explain the reduction step: direct hydrogen abstraction induced by the metal ion and/or reducing action of macroradicals formed during degradation of the polymer. Initial formation of the macroradicals might be associated with the metal-accelerated decomposition of low amounts of peroxides present in the commercial polymer.

  17. One-step fabrication of three-dimensional polydimethylsiloxane peel-off microwell array for cell trapping

    NASA Astrophysics Data System (ADS)

    Xue, Ning; Bleris, Leonidas; Lee, Jeong-Bong (JB)

    2015-01-01

    A three-dimensional polydimethylsiloxane (PDMS)-based microarray was one-step fabricated by releasing from an SU-8 mold for cell trapping. A human embryonic kidney-293 cell line was cultured on the PDMS microarray. By taking advantage of the chemical nature difference between PDMS surface released from oxidized silicon and released from SU-8 substrate, cells can only grow and be attached inside the PDMS microarray after 2 days of cell culture. To investigate the substantial nature of the cell adhesion and repellency on the PDMS substrate, atomic force microscopy, contact angle, and x-ray photoelectron spectroscopy methods have been carried out to analyze the physical and chemical properties of the PDMS material surfaces under different surface treatment circumstances.

  18. One-step hydrothermal synthesis of nitrogen-doped carbon nanotubes as an efficient electrocatalyst for oxygen reduction reactions.

    PubMed

    Chen, Lisong; Cui, Xiangzhi; Wang, Yongxia; Wang, Min; Cui, Fangming; Wei, Chenyang; Huang, Weimin; Hua, Zile; Zhang, Lingxia; Shi, Jianlin

    2014-10-01

    A high amount of heteroatom doping in carbon, although favorable for enhanced density of catalytically active sites, may lead to substantially decreased electroconductivity, which is necessary for the electrochemical oxygen reduction reaction. Herein, a relatively low amount of nitrogen was successfully doped into carbon nanotubes (CNTs) by a hydrothermal approach in one step, and the synthesized nitrogen-doped CNT (CNT-N) materials retained most of the original, excellent characteristics, such as the graphitic structure, tubular morphology, and high surface area, of CNTs. The resultant CNT-N materials, although containing a relatively low amount of nitrogen doping, exhibited high electrocatalytic ORR activity, comparable to that of 20 wt% Pt/C; long durability; and, more importantly, largely inhibited methanol crossover effect.

  19. One-step implementation of the 1->3 orbital state quantum cloning machine via quantum Zeno dynamics

    SciTech Connect

    Shao Xiaoqiang; Wang Hongfu; Zhang Shou; Chen Li; Zhao Yongfang; Yeon, Kyu-Hwang

    2009-12-15

    We present an approach for implementation of a 1->3 orbital state quantum cloning machine based on the quantum Zeno dynamics via manipulating three rf superconducting quantum interference device (SQUID) qubits to resonantly interact with a superconducting cavity assisted by classical fields. Through appropriate modulation of the coupling constants between rf SQUIDs and classical fields, the quantum cloning machine can be realized within one step. We also discuss the effects of decoherence such as spontaneous emission and the loss of cavity in virtue of master equation. The numerical simulation result reveals that the quantum cloning machine is especially robust against the cavity decay, since all qubits evolve in the decoherence-free subspace with respect to cavity decay due to the quantum Zeno dynamics.

  20. Cu2ZnSnS4 nanoflakes prepared by one step microwave irradiation technique: Effect of Cu concentration

    NASA Astrophysics Data System (ADS)

    Kandare, S. P.; Dhole, S. D.; Bhoraskar, V. N.; Dahiwale, S. S.

    2016-05-01

    Cu2ZnSnS4 (CZTS) nanoflakes were synthesized in one step by microwave irradiation method. Controlling the secondary phases in Copper Zinc Tin Sulfide (CZTS) material is critical, but it is necessary to control secondary phases in order to achieve the high efficiency solar cells made from CZTS. In the recent years, CZTS has shown its growing importance in thin film photovoltaic application because of its favorable optical and electrical properties. In this work, a systematic study has been carried out by properly controlling the copper concentration to get the pure phase of CZTS. X-ray diffraction shows the CZTS kesterite structure. Optical band gap estimated from UV-Visible spectroscopy was around 1.37eV. Systematic Raman study reveals the suppression of Cu2S peak with variation in copper concentration which otherwise was not clear from XRD and UV-visible data.

  1. One-step spray-coating process for the fabrication of colorful superhydrophobic coatings with excellent corrosion resistance.

    PubMed

    Li, Jian; Wu, Runni; Jing, Zhijiao; Yan, Long; Zha, Fei; Lei, Ziqiang

    2015-10-01

    A simple method was used to generate colorful hydrophobic stearate particles via chemical reactions between inorganic salts and sodium stearate. Colored self-cleaning superhydrophobic coatings were prepared through a facile one-step spray-coating process by spraying the stearate particle suspensions onto stainless steel substrates. Furthermore, the colorful superhydrophobic coating maintains excellent chemical stability under both harsh acidic and alkaline circumstances. After being immersed in a 3.5 wt % NaCl aqueous solution for 1 month, the as-prepared coatings remained superhydrophobic; however, they lost their self-cleaning property with a sliding angle of about 46 ± 3°. The corrosion behavior of the superhydrophobic coatings on the Al substrate was characterized by the polarization curve and electrochemical impedance spectroscopy (EIS). The electrochemical corrosion test results indicated that the superhydrophobic coatings possessed excellent corrosion resistance, which could supply efficient and long-term preservation for the bare Al substrate.

  2. Novel heterometallic metal-azido complex synthesized by "one-step" reaction: synthetic strategy and magnetic properties

    NASA Astrophysics Data System (ADS)

    Jiao, Yong-Kun; Li, Xiu-Ping; Zhao, Cui; Wang, Hai-Chao; Xue, Min; Zhao, Jiong-Peng; Liu, Fu-Chen

    2013-06-01

    A novel heterometallic complex, [Ni2Mn(N3)2(nic)4·(H2O)2]n (1) (nic=nicotinate), was obtained by assembling MnCl2·4H2O, Ni(NO3)2·6H2O, NaN3 and nicotinic acid with a "one step" synthetic strategy—hydrothermal reaction. The 3D structure of the complex can be described as end-on (EO) azido and syn,syn carboxylates mixed bridged by alternate Ni-Mn-Ni trimers linked by the nicotinate. Dominant ferromagnetic interactions were observed between the NiII and MnII ions in the trimer.

  3. Phase composition of Al-Ni-Mo catalysts for hydrotreatment prepared by one-step impregnation using different procedures

    SciTech Connect

    Gazimzyanov, N.R.; Mikhailov, V.I.; Volod`ko, V.V.

    1995-09-01

    X-ray diffraction, Raman and diffuse-reflectance (DR) spectroscopy, coupled with selective extraction of Mo and Ni, are applied to investigate the phase composition of Al-Ni-Mo catalysts prepared both by a conventional one-step impregnation with ammonia and phosphoric acid, and by a new method based on the use of nickel heteropolymolybdate. By comparing the data obtained by Raman and DR spectroscopy with the data on water extraction, it is shown that the phase removed on washing can be ascribed to heteropolymolybdates. Formation of these compounds is found to be favored by the use of the solution containing H{sub 3}PO{sub 4} to impregnate the catalyst with Mo and Ni.

  4. CIS(CIGS) thin films prepared for solar cells by one-step electrodeposition in alcohol solution

    NASA Astrophysics Data System (ADS)

    Long, Fei; Wang, Weiming; Du, Jingjing; Zou, Zhengguang

    2009-03-01

    The precursors of CIS and CIGS thin films were prepared by one-step electrodeposition in alcohol solution and then annealed in Ar atmosphere at 550°C for 30min. The influences of deposition potentials and salt concentrations on the morphology and composition of the thin films were studied in details. The films were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), and energy-dispersive X-ray spectroscopy(EDS). The results show that annealed films have pure CIS or CIGS phases with good crystallization and the morphology of the films are very uniform and dense. The high quality precursor films were obtained using optimized deposition parameters. Moreover the electrodeposition mechanism of CIS thin films was briefly discussed.

  5. One-step fabrication of inorganic/organic hybrid microspheres with tunable surface texture for controlled drug release application.

    PubMed

    Dong, Hua; Tang, Guannan; Ma, Ting; Cao, Xiaodong

    2016-01-01

    In this paper, we report one-step fabrication of poly(lactide-co-glycolic acid)/titanium oxide (PLGA/TiO2) hybrid microspheres with tunable surface texture via droplet-based microfluidics. Surface texture of microspheres can be continuously tuned by changing the mass ratio between titanium tetraisopropoxide (TTIP) and PLGA in the dispersed phase. The fast hydrolysis of TTIP on the droplet surface can generate a thin shell membrane, resulting in a wrinkled surface after extraction of organic solvent. In vitro drug release monitoring of tanshinone IIA-loaded PLGA/TiO2 hybrid microsphere reveals that surface texture can affect the drug release rate to a large extent without sacrificing the drug encapsulation efficiency. Our finding might benefit the sustained drug delivery where variable drug release rate and high drug encapsulation efficiency are both required. PMID:26610930

  6. Fabrication of non-flaking, superhydrophobic surfaces using a one-step solution-immersion process on copper foams

    NASA Astrophysics Data System (ADS)

    Xu, Jia; Xu, Jinliang; Cao, Yang; Ji, Xianbing; Yan, Yuying

    2013-12-01

    Non-flaking superhydrophobic surfaces were prepared using a simple one-step solution-immersion process on commercially obtained copper foam substrates. Copper foams were immersed in a 0.05 M ethanolic stearic acid solution at room temperature for several days. This formed coverage of copper stearate with micro- and nano-scale hierarchical surface morphology. The surface of the copper foam after 4 days of immersion demonstrates superhydrophobicity with a water contact angle of 156°. A sliding angel of 4° for a 5 μL droplet indicates excellent non-sticking behavior. Compared with a flat copper plate, the superhydrophobic surfaces based on copper foams are much more robust and mechanically stable. This work provides a promising strategy for scalable fabrication of superhydrophobic surfaces on 3D porous structures.

  7. A versatile cost-effective and one step process to engineer ZnO superhydrophobic surfaces on Al substrate

    NASA Astrophysics Data System (ADS)

    Siddaramanna, Ashoka; Saleema, N.; Sarkar, D. K.

    2014-08-01

    Multifunctional superhydrophobic surfaces based on photocatalytic material, ZnO have generated significant research interest from both fundamental and potential applications. Superhydrophobic ZnO surfaces are usually made in multi steps by creating rough surface and subsequent hydrophobization by low-surface-energy materials. Herein, a simple and one step chemical bath deposition has been developed to prepare superhydrophobic ZnO surfaces on aluminum substrate. The aluminum surfaces covered with randomly distributed ZnO particles can not only present multiscale surface roughness, but also readily coordinate with fatty acid, leading to special wettability. The contact angle of the resulting superhydrophobic surface reaches up to 165 ± 2° and contact angle hysteresis of 4°. The contact angle and contact angle hysteresis variation as a function of particle size has been discussed systematically based on surface morphology.

  8. Blazed vector grating liquid crystal cells with photocrosslinkable polymeric alignment films fabricated by one-step polarizer rotation method

    NASA Astrophysics Data System (ADS)

    Kawai, Kotaro; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

    2014-12-01

    Blazed vector grating liquid crystal (LC) cells, in which the directors of low-molar-mass LCs are antisymmetrically distributed, were fabricated by one-step exposure of an empty glass cell inner-coated with a photocrosslinkable polymer LC (PCLC) to UV light. By adopting a LC cell structure, twisted nematic (TN) and homogeneous (HOMO) alignments were obtained in the blazed vector grating LC cells. Moreover, the diffraction efficiency of the blazed vector grating LC cells was greatly improved by increasing the thickness of the device in comparison with that of a blazed vector grating with a thin film structure obtained in our previous study. In addition, the diffraction efficiency and polarization states of ±1st-order diffracted beams from the resultant blazed vector grating LC cells were controlled by designing a blazed pattern in the alignment films, and these diffraction properties were well explained on the basis of Jones calculus and the elastic continuum theory of nematic LCs.

  9. Graphene based soft nanoreactors for facile "one-step" glycan enrichment and derivatization for MALDI-TOF-MS analysis.

    PubMed

    Bai, Haihong; Pan, Yiting; Tong, Wei; Zhang, Wanjun; Ren, Xiaojun; Tian, Fang; Peng, Bo; Wang, Xin; Zhang, Yangjun; Deng, Yulin; Qin, Weijie; Qian, Xiaohong

    2013-12-15

    Protein glycosylation is involved in the control of many important biological processes and structural alterations of the N-linked glycans are correlated with various kinds of disease. High-throughput N-glycan profiling is a key technique for elucidating the functions of glycans in biological process and disease development as well as discovering new diagnostic biomarkers. However, the low abundance of glycans existing in living organism, the competition/suppression effect of other highly abundant biological molecules and the inherent lack of alkalinity and hydrophobicity of glycans leads to particularly poor detection sensitivity in MS analysis. Here, we demonstrated the first "one-step" approach for highly efficient glycan enrichment and derivatization using reduced graphene oxide as nanoreactors and 1-pyrenebutyric hydrazide for glycan capture and derivatization, which resulted in a 33-fold increase in the glycan detection sensitivity in MALDI-TOF-MS and the identification of 48N-glycoforms from human plasma.

  10. One-step large-scale synthesis of micrometer-sized silver nanosheets by a template-free electrochemical method

    PubMed Central

    2013-01-01

    We have synthesized micrometer-sized Ag nanosheets via a facile, one-step, template-free electrochemical deposition in an ultra-dilute silver nitrate aqueous electrolyte. The nanosheet growth was revealed to occur in three stages: (1) formation of polygonal Ag nuclei on a substrate, (2) growth of {112}-faceted nanowire from the nuclei, and (3) anisotropic growth of (111)-planar nanosheets, approximately 20 to 50 nm in thickness and 10 μm in width, in the <112>−direction. The vertical growth of the facet nanowire was induced by the strong interface anisotropy between the deposit and electrolyte due to the ultra-dilute concentration of electrolyte and high reduction potential. The thickness of Ag nanosheets was controllable by the adjustment of the reduction/oxidation potential and frequency of the reverse-pulse potentiodynamic mode. PMID:23692676

  11. One-step synthesis of graphene/SnO2 nanocomposites and its application in electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Li, Fenghua; Song, Jiangfeng; Yang, Huafeng; Gan, Shiyu; Zhang, Qixian; Han, Dongxue; Ivaska, Ari; Niu, Li

    2009-11-01

    A one-step method was developed to fabricate conductive graphene/SnO2 (GS) nanocomposites in acidic solution. Graphite oxides were reduced by SnCl2 to graphene sheets in the presence of HCl and urea. The reducing process was accompanied by generation of SnO2 nanoparticles. The structure and composition of GS nanocomposites were confirmed by means of transmission electron microscopy, x-ray photoelectron and Raman spectroscopy. Moreover, the ultracapacitor characteristics of GS nanocomposites were studied by cyclic voltammograms (CVs) and electrical impedance spectroscopy (EIS). The CVs of GS nanocomposites are nearly rectangular in shape and the specific capacitance degrades slightly as the voltage scan rate is increased. The EIS of GS nanocomposites presents a phase angle close to π/2 at low frequency, indicating a good capacitive behavior. In addition, the GS nanocomposites could be promisingly applied in many fields such as nanoelectronics, ultracapacitors, sensors, nanocomposites, batteries and gas storage.

  12. High-efficiency l-lactic acid production by Rhizopus oryzae using a novel modified one-step fermentation strategy.

    PubMed

    Fu, Yong-Qian; Yin, Long-Fei; Zhu, Hua-Yue; Jiang, Ru

    2016-10-01

    In this study, lactic acid fermentation by Rhizopus oryzae was investigated using the two different fermentation strategies of one-step fermentation (OSF) and conventional fermentation (CF). Compared to CF, OSF reduced the demurrage of the production process and increased the production of lactic acid. However, the qp was significantly lower than during CF. Based on analysis of μ, qs and qp, a novel modified OSF strategy was proposed. This strategy aimed to achieve a high final concentration of lactic acid, and a high qp by R. oryzae. In this strategy, the maximum lactic acid concentration and productivity of the lactic acid production stage reached 158g/l and 5.45g/(lh), which were 177% and 366% higher, respectively, than the best results from CF. Importantly, the qp and yield did not decrease. This strategy is a convenient and economical method for l-lactic acid fermentation by R. oryzae.

  13. One-step sub-10 μm patterning of carbon-nanotube thin films for transparent conductor applications.

    PubMed

    Fukaya, Norihiro; Kim, Dong Young; Kishimoto, Shigeru; Noda, Suguru; Ohno, Yutaka

    2014-04-22

    We propose a technique for one-step micropatterning of as-grown carbon-nanotube films on a plastic substrate with sub-10 μm resolution on the basis of the dry transfer process. By utilizing this technique, we demonstrated the novel high-performance flexible carbon-nanotube transparent conductive film with a microgrid structure, which enabled improvement of the performance over the trade-off between the sheet resistance and transmittance of a conventional uniform carbon-nanotube film. The sheet resistance was reduced by 46% at its maximum by adding the microgrid, leading to a value of 53 Ω/sq at a transmittance of 80%. We also demonstrated easy fabrication of multitouch projected capacitive sensors with 12 × 12 electrodes. The technique is quite promising for energy-saving production of transparent conductor devices with 100% material utilization. PMID:24689647

  14. One-step synthesis of 4-[(18) F]fluorobenzyltriphenylphosphonium cation for imaging with positron emission tomography.

    PubMed

    Zhang, Zhengxing; Zhang, Chengcheng; Lau, Joseph; Colpo, Nadine; Bénard, François; Lin, Kuo-Shyan

    2016-09-01

    4-[(18) F]Fluorobenzyltriphenylphosphonium cation ((18) F-FBnTP) is a promising negative membrane potential targeting positron emission tomography tracer. However, the reported multistep radiolabeling approach for the synthesis of (18) F-FBnTP poses a challenge for routine clinical applications. In this study, we demonstrated that (18) F-FBnTP can be prepared in good conversion yields (~60%, nondecay corrected) in just one step via a copper-mediated (18) F-fluorination reaction using a pinacolyl arylboronate precursor. In addition, our data suggest that (18) F-labeled (phosphonium) cations can be efficiently prepared via a copper-mediated (18) F-fluoronation by using triflate as the counterion.

  15. Nanobranched porous palladium-tin intermetallics: One-step synthesis and their superior electrocatalysis towards formic acid oxidation

    NASA Astrophysics Data System (ADS)

    Sun, Dandan; Si, Ling; Fu, Gengtao; Liu, Chang; Sun, Dongmei; Chen, Yu; Tang, Yawen; Lu, Tianhong

    2015-04-01

    Nanocrystalline intermetallics in bulk with high surface area hold enormous promise as an efficient catalyst for real fuel cell applications due to their unique electrocatalytic properties. In this work, a novel three-dimensional (3D) porous Pd-Sn intermetallics in network nanostructures (Pd-Sn-INNs) has been fabricated at relatively low temperature for the first time by one-step ethylene glycol-assisted hydrothermal reduction method. The structure characteristics of the Pd-Sn-INNs are confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), selected-area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-prepared 3D Pd-Sn-INNs exhibit remarkably improved electrocatalytic activity and stability towards formic acid oxidation reaction (FAOR) over commercially available Pd black.

  16. One-step fabrication of membraneless microbial fuel cell cathode by electropolymerization of polypyrrole onto stainless steel mesh.

    PubMed

    Feng, Chunhua; Wan, Qunyi; Lv, Zhisheng; Yue, Xianjun; Chen, Yanfeng; Wei, Chaohai

    2011-05-15

    A unique one-step method for fabrication of a membraneless microbial fuel cell (MFC) cathode was developed by coating a conductive polymer onto stainless steel mesh. The resulting polypyrrole/anthraquinone-2-sulfonate (PPy/AQS) film was synthesized via electropolymerization using AQS as the dopants. The scanning electron microscopy results indicated that the PPy/AQS film was uniformly formed on the metal mesh electrode without cracks on its surface and featuring a globular structure. Being equipped with such a cathode that was able to catalyze oxygen reduction and prevent water leakage, the membraneless MFC allowed power generation over 250 h and exhibited a maximum power density of 575 mW m(-2). Increasing film thickness seemed to result in a reduction in power performance due to the increased ohmic resistance of the cathode material and the enhanced difficulty for oxygen diffusion inside the cathode.

  17. One-step large-scale synthesis of micrometer-sized silver nanosheets by a template-free electrochemical method.

    PubMed

    Park, Sun Hwa; Son, Jin Gyeong; Lee, Tae Geol; Park, Hyun Min; Song, Jae Yong

    2013-01-01

    We have synthesized micrometer-sized Ag nanosheets via a facile, one-step, template-free electrochemical deposition in an ultra-dilute silver nitrate aqueous electrolyte. The nanosheet growth was revealed to occur in three stages: (1) formation of polygonal Ag nuclei on a substrate, (2) growth of {112}-faceted nanowire from the nuclei, and (3) anisotropic growth of (111)-planar nanosheets, approximately 20 to 50 nm in thickness and 10 μm in width, in the <112>-direction. The vertical growth of the facet nanowire was induced by the strong interface anisotropy between the deposit and electrolyte due to the ultra-dilute concentration of electrolyte and high reduction potential. The thickness of Ag nanosheets was controllable by the adjustment of the reduction/oxidation potential and frequency of the reverse-pulse potentiodynamic mode. PMID:23692676

  18. A one-step process for oil-in-water-in-oil double emulsion formation using a single surfactant.

    PubMed

    Pradhan, Mamata; Rousseau, Dérick

    2012-11-15

    A one-step double emulsification protocol using one surfactant was developed for oil-in-water-in-oil (O(1)/W/O(2)) double emulsions. Two n-alkane oils and three different surfactants were studied, with focus placed on a formulation containing mineral oil, glycerol monoleate (GMO) and deionized water. Phenomenologically, double emulsion formation and stability originate from the combined actions of phase inversion and interfacial charging of the oil/water interface during high shear homogenization. Based on the extent of double emulsion formation and stability, a critical emulsification zone dependent on the weight ratios of GMO to water was identified. Within this critical zone, enhanced O(1)/W/O(2) emulsion formation occurred at higher pH and lower salt concentrations, demonstrating the key role of interfacial charging on double emulsification. Overall, this novel approach provides a novel platform for the development of double emulsions with simple compositions and processing requirements.

  19. Identification of Veillonella Species in the Tongue Biofilm by Using a Novel One-Step Polymerase Chain Reaction Method.

    PubMed

    Mashima, Izumi; Theodorea, Citra Fragrantia; Thaweboon, Boonyanit; Thaweboon, Sroisiri; Nakazawa, Futoshi

    2016-01-01

    Six Veillonella species have been frequently isolated from human oral cavities including infectious sites. Recently, it was reported that diet, smoking, and possibly socioeconomic status can influence the bacterial profile in oral cavities. In addition, oral hygiene habits may also influence oral microbiota in terms of both numbers and diversity of microorganisms. In this study, the identification of Veillonella species in tongue biofilms of Thai children, divided into three groups dependent on their status of oral hygiene. For this, we used a novel one-step PCR method with species-specific primer sets based on sequences of the rpoB gene. As shown in the results, the number of isolates of Veillonella species was 101 strains from only 10 of 89 subjects. However, the total number of bacteria was high for all subjects. Since it was reported in previous studies that Veillonella species were easy to isolate in human tongue biofilms at high numbers, the results obtained in this study may suggest country- or age-specific differences. Moreover, Veillonella species were detected predominantly in subjects who had poor oral hygiene compared to those with good or moderate oral hygiene. From these results, there is a possibility that Veillonella species may be an index of oral hygiene status. Furthermore, V. rogosae was a predominant species in tongue biofilms of Thai children, whereas V. parvula and V. denticariosi were not isolated at all. These characteristics of the distribution and frequency of Veillonella species are similar to those reported in previous studies. Although further studies are needed in other countries, in this study, a successful novel one-step PCR method was established to detect Veillonella species in human oral cavities easily and effectively. Furthermore, this is the first report investigating the distribution and frequency of Veillonella species in tongue biofilms of Thai children.

  20. Identification of Veillonella Species in the Tongue Biofilm by Using a Novel One-Step Polymerase Chain Reaction Method

    PubMed Central

    Mashima, Izumi; Theodorea, Citra Fragrantia; Thaweboon, Boonyanit; Thaweboon, Sroisiri; Nakazawa, Futoshi

    2016-01-01

    Six Veillonella species have been frequently isolated from human oral cavities including infectious sites. Recently, it was reported that diet, smoking, and possibly socioeconomic status can influence the bacterial profile in oral cavities. In addition, oral hygiene habits may also influence oral microbiota in terms of both numbers and diversity of microorganisms. In this study, the identification of Veillonella species in tongue biofilms of Thai children, divided into three groups dependent on their status of oral hygiene. For this, we used a novel one-step PCR method with species-specific primer sets based on sequences of the rpoB gene. As shown in the results, the number of isolates of Veillonella species was 101 strains from only 10 of 89 subjects. However, the total number of bacteria was high for all subjects. Since it was reported in previous studies that Veillonella species were easy to isolate in human tongue biofilms at high numbers, the results obtained in this study may suggest country- or age-specific differences. Moreover, Veillonella species were detected predominantly in subjects who had poor oral hygiene compared to those with good or moderate oral hygiene. From these results, there is a possibility that Veillonella species may be an index of oral hygiene status. Furthermore, V. rogosae was a predominant species in tongue biofilms of Thai children, whereas V. parvula and V. denticariosi were not isolated at all. These characteristics of the distribution and frequency of Veillonella species are similar to those reported in previous studies. Although further studies are needed in other countries, in this study, a successful novel one-step PCR method was established to detect Veillonella species in human oral cavities easily and effectively. Furthermore, this is the first report investigating the distribution and frequency of Veillonella species in tongue biofilms of Thai children. PMID:27326455

  1. One-step hydrothermal synthesis, characterization and magnetic properties of orthorhombic PrCrO{sub 3} cubic particles

    SciTech Connect

    Zhang, Youjin Yao, Chengpeng; Fan, Yun; Zhou, Maozhong

    2014-11-15

    Highlights: • Orthorhombic PrCrO{sub 3} cubic particles were prepared by a simple and facile one-step hydrothermal method. • The possible formation mechanism of PrCrO{sub 3} cubic particles was proposed. • The as-synthesized PrCrO{sub 3} exhibited behaviors of magnetic transition and negative magnetization. - Abstract: Orthorhombic PrCrO{sub 3} cubic particles were synthesized by a simple and facile one-step hydrothermal method of processing temperature 280 °C for 7 days. The products prepared in this paper have been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM). The magnetic properties of the final sample are also studied. The XRD pattern shows the pure orthorhombic phase for PrCrO{sub 3} particles, the XPS and FTIR results further demonstrate the purity and composition of the product. FESEM images show cubic morphology for the PrCrO{sub 3} particles. The possible growth mechanism for PrCrO{sub 3} cubic particles is proposed. Through the investigation of magnetic properties, it can be seen that the orthorhombic PrCrO{sub 3} cubic particles exhibit behaviors of magnetic transition and negative magnetization. The Néel temperature is about 232 K and the magnetic hysteresis loop under 4 K shows that the coercivity (H{sub C}) and remanence (M{sub r}) is about 1728 Oe and 4.88 emu/g, respectively.

  2. Fabrication of p-type porous silicon nanowire with oxidized silicon substrate through one-step MACE

    SciTech Connect

    Li, Shaoyuan; Ma, Wenhui; Zhou, Yang; Chen, Xiuhua; Xiao, Yongyin; Ma, Mingyu; Wei, Feng; Yang, Xi

    2014-05-01

    In this paper, the simple pre-oxidization process is firstly used to treat the starting silicon wafer, and then MPSiNWs are successfully fabricated from the moderately doped wafer by one-step MACE technology in HF/AgNO{sub 3} system. The PL spectrum of MPSiNWs obtained from the oxidized silicon wafers show a large blue-shift, which can be attributed to the deep Q. C. effect induced by numerous mesoporous structures. The effects of HF and AgNO{sub 3} concentration on formation of SiNWs were carefully investigated. The results indicate that the higher HF concentration is favorable to the growth of SiNWs, and the density of SiNWs is significantly reduced when Ag{sup +} ions concentrations are too high. The deposition behaviors of Ag{sup +} ions on oxidized and unoxidized silicon surface were studied. According to the experimental results, a model was proposed to explain the formation mechanism of porous SiNWs by etching the oxidized starting silicon. - Graphical abstract: Schematic cross-sectional views of PSiNWs array formation by etching oxidized silicon wafer in HF/AgNO{sub 3} solution. (A) At the starting point; (B) during the etching process; and (C) after Ag dendrites remove. - Highlights: • Prior to etching, a simple pre-oxidation is firstly used to treat silicon substrate. • The medially doped p-type MPSiNWs are prepared by one-step MACE. • Deposition behaviors of Ag{sup +} ions on oxidized and unoxidized silicon are studied. • A model is finally proposed to explain the formation mechanism of PSiNWs.

  3. One-dimensional WO{sub 3} and its hydrate: One-step synthesis, structural and spectroscopic characterization

    SciTech Connect

    Iwu, Kingsley O.; Galeckas, Augustinas; Rauwel, Protima; Kuznetsov, Andrej Y.; Norby, Truls

    2012-01-15

    We report on a one-step hydrothermal growth of one-dimensional (1D) WO{sub 3} nanostructures, using urea as 1D growth-directing agent and a precursor free of metals other than tungsten. By decreasing the pH of the starting solution, the size of the nanostructures was reduced significantly, this development being accompanied by the realization of phase pure hexagonal WO{sub 3} nanorods (elimination of monoclinic impurity phase) and a red shift in optical absorption edge. Surface analyses indicated the presence of reduced tungsten species in the WO{sub 3} nanostructures, which increased two-fold in a hydrated WO{sub 3} phase obtained with further decrease in pH. We suggest that oxygen vacancies are responsible for this defect state in WO{sub 3}, while protons are responsible or contribute significantly to the same in the hydrated phase. - Graphical abstract: The figure illustrates the role of pH in morphological and absorption edge evolution of WO{sub 3} (hydrate) as well as the variation in the concentration of defect electrons between anhydrous and hydrated WO{sub 3}. Highlights: Black-Right-Pointing-Pointer WO{sub 3} nanorods prepared in a one step procedure. Black-Right-Pointing-Pointer HCl (aq) enables phase pure WO{sub 3} nanorods. Black-Right-Pointing-Pointer HCl (aq) induces significant reduction in dimension of and red shift in absorption edge of nanorods. Black-Right-Pointing-Pointer W{sup 5+} detected in hydrothermal WO{sub 3} phase, the concentration of which increases in the hydrated phase. Black-Right-Pointing-Pointer W{sup 5+} from the two phases due to different positive defects.

  4. One-step reconstruction with a 3D-printed, biomechanically evaluated custom implant after complex pelvic tumor resection.

    PubMed

    Wong, K C; Kumta, S M; Geel, N V; Demol, J

    2015-01-01

    Resection of a pelvic tumor is challenging because of its complex three-dimensional (3D) anatomy and deep-seated location with nearby vital structures. The resection is technically demanding if a custom implant is used for reconstruction of the bone defect as the surgeon needs to ensure the resection margin is sufficiently wide and the orientation of intended resection planes must match that of the custom implant. We describe a novel workflow of performing a partial acetabular resection in a patient with pelvic chondrosarcoma and reconstruction with a custom pelvic implant in a one-step operation. A multi-planar bone resection was virtually planned. A computer-aided design implant that both matched the bone defect and biomechanically evaluated was prefabricated with 3D printing technology. The 3D-printed patient-specific instruments (PSIs) were used to reproduce the same planned resection. The histology of the tumor specimen showed a clear resection margin. The errors of the achieved resection and implant position were deviating (1-4 mm) from the planned. The patient could walk unaided with a good hip function. No tumor recurrence and implant loosening were noted at 11 months after surgery. The use of this novel CT-based method for surgical planning, the engineering software for implant design and validation, together with 3D printing technology for implant and PSI fabrication makes it possible to generate a personalized, biomechanically evaluated implant for accurate reconstruction after a pelvic tumor resection in a one-step operation. Further study in a larger population is needed to assess the clinical efficacy of the workflow in complex bone tumor surgery.

  5. Purification of recombinant adeno-associated virus by iodixanol gradient ultracentrifugation allows rapid and reproducible preparation of vector stocks for gene transfer in the nervous system.

    PubMed

    Hermens, W T; ter Brake, O; Dijkhuizen, P A; Sonnemans, M A; Grimm, D; Kleinschmidt, J A; Verhaagen, J

    1999-07-20

    Recombinant adeno-associated virus (rAAV) vectors have become attractive tools for in vivo gene transfer. The production and purification of high-titer rAAV vector stocks for experimental and therapeutic gene transfer continue to undergo improvement. Standard rAAV vector purification protocols include the purification of the vector by cesium chloride (CsCl)-density gradient centrifugation followed by extensive desalination via dialysis against a physiological buffer for in vivo use. These procedures are extremely time consuming and frequently result in a substantial loss of the infectious vector titer. As an alternative to CsCl we have investigated the use of Iodixanol, an X-ray contrast solution, as the density-gradient medium. Purification of rAAV vectors by Iodixanol shortened the centrifugation period to 3 hr and resulted in reproducible concentration and purification of rAAV-vector stocks. We show that injection of rAAV derived from an Iodixanol gradient can be used for in vivo gene transfer applications in the brain and spinal cord without detectable cytopathic effects and directing stable transgene expression for at least 2 months.

  6. Three-phase partitioning as a rapid and easy method for the purification and recovery of catalase from sweet potato tubers (Solanum tuberosum).

    PubMed

    Duman, Yonca Avcı; Kaya, Erdem

    2013-07-01

    Three-phase partitioning (TPP) was used to purify and recover catalase from potato crude extract. The method consists of ammonium sulfate saturation, t-butanol addition, and adjustment of pH, respectively. The best catalase recovery (262 %) and 14.1-fold purification were seen in the interfacial phase in the presence of 40 % (w/v) ammonium sulfate saturation with 1.0:1.0 crude extract/t-butanol ratio (v/v) at pH 7 in a single step. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the enzyme showed comparatively purification and protein molecular weight was nearly found to be 56 kDa. This study shows that TPP is a simple, economical, and quick method for the recovering of catalase and can be used for the purification process.

  7. Three-phase partitioning as a rapid and easy method for the purification and recovery of catalase from sweet potato tubers (Solanum tuberosum).

    PubMed

    Duman, Yonca Avcı; Kaya, Erdem

    2013-07-01

    Three-phase partitioning (TPP) was used to purify and recover catalase from potato crude extract. The method consists of ammonium sulfate saturation, t-butanol addition, and adjustment of pH, respectively. The best catalase recovery (262 %) and 14.1-fold purification were seen in the interfacial phase in the presence of 40 % (w/v) ammonium sulfate saturation with 1.0:1.0 crude extract/t-butanol ratio (v/v) at pH 7 in a single step. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the enzyme showed comparatively purification and protein molecular weight was nearly found to be 56 kDa. This study shows that TPP is a simple, economical, and quick method for the recovering of catalase and can be used for the purification process. PMID:23640263

  8. Comprehensive Multiplex One-Step Real-Time TaqMan qRT-PCR Assays for Detection and Quantification of Hemorrhagic Fever Viruses

    PubMed Central

    Li, Jiandong; Qu, Jing; He, Chengcheng; Zhang, Shuo; Li, Chuan; Zhang, Quanfu; Liang, Mifang; Li, Dexin

    2014-01-01

    Background Viral hemorrhagic fevers (VHFs) are a group of animal and human illnesses that are mostly caused by several distinct families of viruses including bunyaviruses, flaviviruses, filoviruses and arenaviruses. Although specific signs and symptoms vary by the type of VHF, initial signs and symptoms are very similar. Therefore rapid immunologic and molecular tools for differential diagnosis of hemorrhagic fever viruses (HFVs) are important for effective case management and control of the spread of VHFs. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assay is one of the reliable and desirable methods for specific detection and quantification of virus load. Multiplex PCR assay has the potential to produce considerable savings in time and resources in the laboratory detection. Results Primers/probe sets were designed based on appropriate specific genes for each of 28 HFVs which nearly covered all the HFVs, and identified with good specificity and sensitivity using monoplex assays. Seven groups of multiplex one-step real-time qRT-PCR assays in a universal experimental system were then developed by combining all primers/probe sets into 4-plex reactions and evaluated with serial dilutions of synthesized viral RNAs. For all the multiplex assays, no cross-reactivity with other HFVs was observed, and the limits of detection were mainly between 45 and 150 copies/PCR. The reproducibility was satisfactory, since the coefficient of variation of Ct values were all less than 5% in each dilution of synthesized viral RNAs for both intra-assays and inter-assays. Evaluation of the method with available clinical serum samples collected from HFRS patients, SFTS patients and Dengue fever patients showed high sensitivity and specificity of the related multiplex assays on the clinical specimens. Conclusions Overall, the comprehensive multiplex one-step real-time qRT-PCR assays were established in this study, and proved to be specific, sensitive

  9. 48 CFR 3036.104-90 - Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... turn-key design-build contracting for the United States Coast Guard (USCG). 3036.104-90 Section 3036... General 3036.104-90 Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG). The Head of the Contracting Activity (HCA) of the U.S. Coast Guard may use one-step...

  10. 48 CFR 3036.104-90 - Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... turn-key design-build contracting for the United States Coast Guard (USCG). 3036.104-90 Section 3036... General 3036.104-90 Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG). The Head of the Contracting Activity (HCA) of the U.S. Coast Guard may use one-step...

  11. 48 CFR 3036.104-90 - Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... turn-key design-build contracting for the United States Coast Guard (USCG). 3036.104-90 Section 3036... General 3036.104-90 Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG). The Head of the Contracting Activity (HCA) of the U.S. Coast Guard may use one-step...

  12. 48 CFR 3036.104-90 - Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-key design-build contracting for the United States Coast Guard (USCG). 3036.104-90 Section 3036.104-90... 3036.104-90 Authority for one-step turn-key design-build contracting for the United States Coast Guard (USCG). The Head of the Contracting Activity (HCA) of the U.S. Coast Guard may use one-step...

  13. Modeling soybean canopy resistance from micrometeorological and plant variables for estimating evapotranspiration using one-step Penman-Monteith approach

    NASA Astrophysics Data System (ADS)

    Irmak, Suat; Mutiibwa, Denis; Payero, Jose; Marek, Thomas; Porter, Dana

    2013-12-01

    Canopy resistance (rc) is one of the most important variables in evapotranspiration, agronomy, hydrology and climate change studies that link vegetation response to changing environmental and climatic variables. This study investigates the concept of generalized nonlinear/linear modeling approach of rc from micrometeorological and plant variables for soybean [Glycine max (L.) Merr.] canopy at different climatic zones in Nebraska, USA (Clay Center, Geneva, Holdrege and North Platte). Eight models estimating rc as a function of different combination of micrometeorological and plant variables are presented. The models integrated the linear and non-linear effects of regulating variables (net radiation, Rn; relative humidity, RH; wind speed, U3; air temperature, Ta; vapor pressure deficit, VPD; leaf area index, LAI; aerodynamic resistance, ra; and solar zenith angle, Za) to predict hourly rc. The most complex rc model has all regulating variables and the simplest model has only Rn, Ta and RH. The rc models were developed at Clay Center in the growing season of 2007 and applied to other independent sites and years. The predicted rc for the growing seasons at four locations were then used to estimate actual crop evapotranspiration (ETc) as a one-step process using the Penman-Monteith model and compared to the measured data at all locations. The models were able to account for 66-93% of the variability in measured hourly ETc across locations. Models without LAI generally underperformed and underestimated due to overestimation of rc, especially during full canopy cover stage. Using vapor pressure deficit or relative humidity in the models had similar effect on estimating rc. The root squared error (RSE) between measured and estimated ETc was about 0.07 mm h-1 for most of the models at Clay Center, Geneva and Holdrege. At North Platte, RSE was above 0.10 mm h-1. The results at different sites and different growing seasons demonstrate the robustness and consistency of the

  14. The effect of one-step polishing system on the surface roughness of three esthetic resin composite materials.

    PubMed

    Türkün, L S; Türkün, M

    2004-01-01

    Proper finishing of restorations is desirable not only for aesthetic considerations but also for oral health. The primary goal of finishing is to obtain a restoration that has good contour, occlusion, healthy embrasure forms and a smooth surface. This study investigated: 1) analyzing the surface roughness of three resin composites finished and polished with a new one-step and two conventional multi-step polishing systems and 2) evaluating the effectiveness of one-step polishing system and surface morphology using scanning electron microscope analysis (SEM). Specimens (N = 72) measuring 8-mm in diameter x 2-mm in thickness were fabricated in a plexiglass mold covered with a Mylar strip using three esthetic resin composites. After polymerization six specimens per resin composite received no finishing treatment and served as a control. Fifty-four specimens were randomly polished with Sof-Lex discs, Enhance disc with polishing paste or PoGo for 30 seconds after being ground wet with a 1200 grit silicon carbide paper. The average surface roughness of each polished specimen was determined with a profilometer (Surtronic 4). The data were analyzed using repeated measures ANOVA and Scheffe's post-hoc test of multiple comparisons (p < or = 0.01). Representative samples of the mentioned finishing procedures were selected and examined using a scanning electron microscope (SEM). There was no surface roughness in all resin composites tested against Mylar strip. The results showed no difference between the surfaces of Clearfil ST and Esthet-X polished with PoGo and the Mylar group (p > or = 0.01). Among all the polishing systems tested, PoGo exhibited the smoothest finish for all resin composites. The combination of Enhance and Prisma Gloss polishing paste exhibited the highest roughness values for Filtek A110 and Clearfil ST; however, it gave the same Ra values as PoGo for Esthet-X (p < or = 0.01). SEM analysis of Esthet-X samples confirmed the profilometer's results. The

  15. One-step solvothermal synthesis of highly water-soluble, negatively charged superparamagnetic Fe3O4 colloidal nanocrystal clusters

    NASA Astrophysics Data System (ADS)

    Gao, Jining; Ran, Xinze; Shi, Chunmeng; Cheng, Humin; Cheng, Tianmin; Su, Yongping

    2013-07-01

    Highly charged hydrophilic superparamagnetic Fe3O4 colloidal nanocrystal clusters with an average diameter of 195 nm have been successfully synthesized using a modified one-step solvothermal method. Anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium salt containing both sulfonate and carboxylate groups was used as the stabilizer. The clusters synthesized under different experimental conditions were characterized with transmission electron microscopy and dynamic light scattering; it was found that the size distribution and water dispersity were significantly affected by the concentration of the polyelectrolyte stabilizer and iron sources in the reaction mixtures. A possible mechanism involving novel gel-like large molecular networks that confined the nucleation and aggregation process was proposed and discussed. The colloidal nanocrystal clusters remained negatively charged in the experimental pH ranges from 2 to 11, and also showed high colloidal stability in phosphate buffered saline (PBS) and ethanol. These highly colloidal stable superparamagnetic Fe3O4 clusters could find potential applications in bioseparation, targeted drug delivery, and photonics.Highly charged hydrophilic superparamagnetic Fe3O4 colloidal nanocrystal clusters with an average diameter of 195 nm have been successfully synthesized using a modified one-step solvothermal method. Anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium salt containing both sulfonate and carboxylate groups was used as the stabilizer. The clusters synthesized under different experimental conditions were characterized with transmission electron microscopy and dynamic light scattering; it was found that the size distribution and water dispersity were significantly affected by the concentration of the polyelectrolyte stabilizer and iron sources in the reaction mixtures. A possible mechanism involving novel gel-like large molecular networks that confined the nucleation and

  16. Nitrogen Dioxide-Sensing Properties at Room Temperature of Metal Oxide-Modified Graphene Composite via One-Step Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Zhang, Dongzhi; Liu, Jingjing; Xia, Bokai

    2016-08-01

    A metal oxide/graphene composite film-based sensor toward room-temperature detection of ppm-level nitrogen dioxide (NO2) gas has been demonstrated. The sensor prototype was constructed on a PCB substrate with microelectrodes, and a tin oxide-reduced graphene oxide (SnO2-rGO) composite as sensing film was prepared by one-step hydrothermal synthesis of tin tetrachloride pentahydrate solution in the presence of graphene oxide (GO). The SnO2-rGO hybrid composite was examined by scanning electron microscope and x-ray diffraction (XRD). The gas sensing properties of the SnO2-rGO composite were investigated at room temperature by exposing it to a wide concentration ranging from 1 ppm to 2000 ppm toward NO2 gas. The experiment results showed that the sensor exhibited a high response, superior selectivity, good repeatability, rapid response/recovery characteristics and low detection limit of 1 ppm, which exceeded that of a pure rGO sensor. The gas sensing mechanisms of the proposed sensor toward NO2 were possibly attributed to the nano-hybrid structures and n- p heterojunctions created at the interface of the SnO2 nanocrystals and rGO nanosheets.

  17. One-Step Formation of Silicon-Graphene Composites from Silicon Sludge Waste and Graphene Oxide via Aerosol Process for Lithium Ion Batteries.

    PubMed

    Kim, Sun Kyung; Kim, Hyekyoung; Chang, Hankwon; Cho, Bong-Gyoo; Huang, Jiaxing; Yoo, Hyundong; Kim, Hansu; Jang, Hee Dong

    2016-01-01

    Over 40% of high-purity silicon (Si) is consumed as sludge waste consisting of Si, silicon carbide (SiC) particles and metal impurities from the fragments of cutting wire mixed in ethylene glycol based cutting fluid during Si wafer slicing in semiconductor fabrication. Recovery of Si from the waste Si sludge has been a great concern because Si particles are promising high-capacity anode materials for Li ion batteries. In this study, we report a novel one-step aerosol process that not only extracts Si particles but also generates Si-graphene (GR) composites from the colloidal mixture of waste Si sludge and graphene oxide (GO) at the same time by ultrasonic atomization-assisted spray pyrolysis. This process supports many advantages such as eco-friendly, low-energy, rapid, and simple method for forming Si-GR composite. The morphology of the as-formed Si-GR composites looked like a crumpled paper ball and the average size of the composites varied from 0.6 to 0.8 μm with variation of the process variables. The electrochemical performance was then conducted with the Si-GR composites for Lithium Ion Batteries (LIBs). The Si-GR composites exhibited very high performance as Li ion battery anodes in terms of capacity, cycling stability, and Coulombic efficiency. PMID:27646853

  18. One-Step Formation of Silicon-Graphene Composites from Silicon Sludge Waste and Graphene Oxide via Aerosol Process for Lithium Ion Batteries

    PubMed Central

    Kim, Sun Kyung; Kim, Hyekyoung; Chang, Hankwon; Cho, Bong-Gyoo; Huang, Jiaxing; Yoo, Hyundong; Kim, Hansu; Jang, Hee Dong

    2016-01-01

    Over 40% of high-purity silicon (Si) is consumed as sludge waste consisting of Si, silicon carbide (SiC) particles and metal impurities from the fragments of cutting wire mixed in ethylene glycol based cutting fluid during Si wafer slicing in semiconductor fabrication. Recovery of Si from the waste Si sludge has been a great concern because Si particles are promising high-capacity anode materials for Li ion batteries. In this study, we report a novel one-step aerosol process that not only extracts Si particles but also generates Si-graphene (GR) composites from the colloidal mixture of waste Si sludge and graphene oxide (GO) at the same time by ultrasonic atomization-assisted spray pyrolysis. This process supports many advantages such as eco-friendly, low-energy, rapid, and simple method for forming Si-GR composite. The morphology of the as-formed Si-GR composites looked like a crumpled paper ball and the average size of the composites varied from 0.6 to 0.8 μm with variation of the process variables. The electrochemical performance was then conducted with the Si-GR composites for Lithium Ion Batteries (LIBs). The Si-GR composites exhibited very high performance as Li ion battery anodes in terms of capacity, cycling stability, and Coulombic efficiency. PMID:27646853

  19. One-Step Formation of Silicon-Graphene Composites from Silicon Sludge Waste and Graphene Oxide via Aerosol Process for Lithium Ion Batteries

    NASA Astrophysics Data System (ADS)

    Kim, Sun Kyung; Kim, Hyekyoung; Chang, Hankwon; Cho, Bong-Gyoo; Huang, Jiaxing; Yoo, Hyundong; Kim, Hansu; Jang, Hee Dong

    2016-09-01

    Over 40% of high-purity silicon (Si) is consumed as sludge waste consisting of Si, silicon carbide (SiC) particles and metal impurities from the fragments of cutting wire mixed in ethylene glycol based cutting fluid during Si wafer slicing in semiconductor fabrication. Recovery of Si from the waste Si sludge has been a great concern because Si particles are promising high-capacity anode materials for Li ion batteries. In this study, we report a novel one-step aerosol process that not only extracts Si particles but also generates Si-graphene (GR) composites from the colloidal mixture of waste Si sludge and graphene oxide (GO) at the same time by ultrasonic atomization-assisted spray pyrolysis. This process supports many advantages such as eco-friendly, low-energy, rapid, and simple method for forming Si-GR composite. The morphology of the as-formed Si-GR composites looked like a crumpled paper ball and the average size of the composites varied from 0.6 to 0.8 μm with variation of the process variables. The electrochemical performance was then conducted with the Si-GR composites for Lithium Ion Batteries (LIBs). The Si-GR composites exhibited very high performance as Li ion battery anodes in terms of capacity, cycling stability, and Coulombic efficiency.

  20. A One-Step Real-Time RT-PCR Assay for the Detection and Quantitation of Sugarcane Streak Mosaic Virus

    PubMed Central

    Fu, Wei-Lin; Sun, Sheng-Ren; Fu, Hua-Ying; Chen, Ru-Kai; Su, Jin-Wei; Gao, San-Ji

    2015-01-01

    Sugarcane mosaic disease is caused by the Sugarcane streak mosaic virus (SCSMV; genus Poacevirus, family Potyviridae) which is common in some Asian countries. Here, we established a protocol of a one-step real-time quantitative reverse transcription PCR (real-time qRT-PCR) using the TaqMan probe for the detection of SCSMV in sugarcane. Primers and probes were designed within the conserved region of the SCSMV coat protein (CP) gene sequences. Standard single-stranded RNA (ssRNA) generated by PCR-based gene transcripts of recombinant pGEM-CP plasmid in vitro and total RNA extracted from SCSMV-infected sugarcane were used as templates of qRT-PCR. We further performed a sensitivity assay to show that the detection limit of the assay was 100 copies of ssRNA and 2 pg of total RNA with good reproducibility. The values obtained were approximately 100-fold more sensitive than those of the conventional RT-PCR. A higher incidence (68.6%) of SCSMV infection was detected by qRT-PCR than that (48.6%) with conventional RT-PCR in samples showing mosaic symptoms. SCSMV-free samples were verified by infection with Sugarcane mosaic virus (SCMV) or Sorghum mosaic virus (SrMV) or a combination of both. The developed qRT-PCR assay may become an alternative molecular tool for an economical, rapid, and efficient detection and quantification of SCSMV. PMID:26185758

  1. One-step highly sensitive florescence detection of T4 polynucleotide kinase activity and biological small molecules by ligation-nicking coupled reaction-mediated signal amplification.

    PubMed

    Chen, Feng; Zhao, Yongxi; Qi, Lin; Fan, Chunhai

    2013-09-15

    DNA phosphorylation, catalyzed by polynucleotide kinase (PNK), plays significant regulatory roles in many biological events. Herein, using T4 PNK as a model target, we describe a one-step, highly sensitive, simple and rapid fluorescence approach for monitoring its activity and inhibition. This innovative strategy is inspired by the great amplification capability of ligation-nicking coupled reaction-mediated signal amplification. In the presence of T4 PNK, one of two short oligonucleotides complementary to the loop sequence of molecular beacon (MB) are phosphorylated, and then ligated with the other by DNA ligase. Upon formation of the stable duplex between the ligated DNA and MB, the fluorescence is restored and further significantly amplified through nicking endonuclease assisted cleavage of multiple MBs. Meanwhile, the cleavage of MBs will also generate new nicks to initiate the ligation reaction. Eventually, a maximum fluorescence enhancement is obtained when the ligation and nicking process reached a dynamic equilibrium. As compared to those of the existing approaches except for the assay based on single nanoparticle counting, all limited to 1:1 signal transduction function, the sensitivity (0.00001U/mL) of the proposed strategy is 100-1700 times higher. The application of the sensing system in complex biological matrix and screening of T4 PNK inhibition are demonstrated with satisfactory results. Moreover, this approach is also successfully used to detect biological small molecules such as adenosine triphosphate (ATP), and can be further extended for nicotinamide adenine dinucleotide (NAD(+)) detection.

  2. Large-area one-step assembly of three-dimensional porous metal micro/nanocages by ethanol-assisted femtosecond laser irradiation for enhanced antireflection and hydrophobicity.

    PubMed

    Li, Guoqiang; Li, Jiawen; Zhang, Chenchu; Hu, Yanlei; Li, Xiaohong; Chu, Jiaru; Huang, Wenhao; Wu, Dong

    2015-01-14

    The capability to realize 2D-3D controllable metallic micro/nanostructures is of key importance for various fields such as plasmonics, electronics, bioscience, and chemistry due to unique properties such as electromagnetic field enhancement, catalysis, photoemission, and conductivity. However, most of the present techniques are limited to low-dimension (1D-2D), small area, or single function. Here we report the assembly of self-organized three-dimensional (3D) porous metal micro/nanocages arrays on nickel surface by ethanol-assisted femtosecond laser irradiation. The underlying formation mechanism was investigated by a series of femtosecond laser irradiation under exposure time from 5 to 30 ms. We also demonstrate the ability to control the size of micro/nanocage arrays from 0.8 to 2 μm by different laser pulse energy. This method features rapidness (∼10 min), simplicity (one-step process), and ease of large-area (4 cm(2) or more) fabrication. The 3D cagelike micro/nanostructures exhibit not only improved antireflection from 80% to 7% but also enhanced hydrophobicity from 98.5° to 142° without surface modification. This simple technique for 3D large-area controllable metal microstructures will find great potential applications in optoelectronics, physics, and chemistry.

  3. One-Step Formation of Silicon-Graphene Composites from Silicon Sludge Waste and Graphene Oxide via Aerosol Process for Lithium Ion Batteries.

    PubMed

    Kim, Sun Kyung; Kim, Hyekyoung; Chang, Hankwon; Cho, Bong-Gyoo; Huang, Jiaxing; Yoo, Hyundong; Kim, Hansu; Jang, Hee Dong

    2016-09-20

    Over 40% of high-purity silicon (Si) is consumed as sludge waste consisting of Si, silicon carbide (SiC) particles and metal impurities from the fragments of cutting wire mixed in ethylene glycol based cutting fluid during Si wafer slicing in semiconductor fabrication. Recovery of Si from the waste Si sludge has been a great concern because Si particles are promising high-capacity anode materials for Li ion batteries. In this study, we report a novel one-step aerosol process that not only extracts Si particles but also generates Si-graphene (GR) composites from the colloidal mixture of waste Si sludge and graphene oxide (GO) at the same time by ultrasonic atomization-assisted spray pyrolysis. This process supports many advantages such as eco-friendly, low-energy, rapid, and simple method for forming Si-GR composite. The morphology of the as-formed Si-GR composites looked like a crumpled paper ball and the average size of the composites varied from 0.6 to 0.8 μm with variation of the process variables. The electrochemical performance was then conducted with the Si-GR composites for Lithium Ion Batteries (LIBs). The Si-GR composites exhibited very high performance as Li ion battery anodes in terms of capacity, cycling stability, and Coulombic efficiency.

  4. Multilayered film microreactors fabricated by a one-step thermal bonding technique with high reproducibility and their applications.

    PubMed

    Min, Kyoung-Ik; Kim, Jin-Oh; Kim, Heejin; Im, Do Jin; Kim, Dong-Pyo

    2016-03-21

    We report the versatile uses of multilayered polyimide (PI) film microreactors with various functions including pressure tolerance, three-dimensional mixing and multistep membrane emulsification. Such PI film microreactors were fabricated by a simple one-step thermal bonding technique with high reproducibility. Upon bonding at 300 °C for 1 hour, the thin and flexible film microdevices could withstand pressure up to 8.6 MPa and 16.3 MPa with PI adhesive film or fluoropolymer adhesive, respectively, due to differences in wettability. The hydrophilic and hydrophobic microchannel devices were used to generate monodisperse oil-in-water (O/W) and water-in-oil (W/O) droplets, and polymer micro/nanoparticles at a high generation frequency. A monolithic and chemical resistant film microreactor with a three-dimensional serpentine microchannel was used for the selective reduction of ester to aldehyde by efficient mixing and quenching in a flash chemistry manner, within a several 10(1) millisecond time scale. Furthermore, a novel multilayered film microreactor for organic-aqueous biphasic interfacial reactions was devised by embedding a membrane layer to induce chaotic mixing in both the interface and emulsified phase by flowing through multiple numbers of meshed structures along the hydrophobic channel. This simple and economic fabrication technique significantly facilitates mass production of multilayered film devices that could be useful as a platform for various microfluidic applications in chemistry and biology.

  5. Characterization and in vivo evaluation of chitosan-hydroxyapatite bone scaffolds made by one step coprecipitation method.

    PubMed

    Danilchenko, Sergei N; Kalinkevich, Oksana V; Pogorelov, Maksim V; Kalinkevich, Aleksei N; Sklyar, Anatoly M; Kalinichenko, Tatyana G; Ilyashenko, Vyacheslav Y; Starikov, Vadim V; Bumeyster, Valentina I; Sikora, Vitaly Z; Sukhodub, Leonid F

    2011-03-15

    Chitosan/hydroxyapatite scaffolds could be used for bone regeneration in case the application of auto- or allografts is impossible. The objective of the present work was to characterize and study in vivo biodegradation of simple chitosan/hydroxyapatite scaffolds. For this purpose, a series of chitosan/hydroxyapatite composites has been synthesized in aqueous medium from chitosan solution and soluble precursor salts by a one step coprecipitation method. A study of in vivo behavior of the materials was then performed using model linear rats. Cylindrical-shaped rods made of the chitosan/hydroxyapatite composite material were implanted into tibial bones of the rats. After 5, 10, 15, and 24 days of implantation, histological and histo-morphometric analyses of decalcified specimens were performed to evaluate the stages of biodegradation processes. Calcified specimens were examined by scanning electron microscopy with X-ray microanalysis to compare elemental composition and morphological characteristics of the implant and the bone during integration. Porous chitosan/hydroxyapatite scaffolds have shown osteoconductive properties and have been replaced in the in vivo experiments by newly formed bone tissue. PMID:21268238

  6. Understanding bond formation in polar one-step reactions. Topological analyses of the reaction between nitrones and lithium ynolates.

    PubMed

    Roca-López, David; Polo, Victor; Tejero, Tomás; Merino, Pedro

    2015-04-17

    The mechanism of the reaction between nitrones and lithium ynolates has been studied using DFT methods at the M06-2X/cc-pVTZ/PCM=THF level. After the formation of a starting complex an without energy barrier, in which the lithium atom is coordinated to both nitrone and ynolate, the reaction takes place in one single kinetic step through a single transition structure. However, the formation of C-C and C-O bonds takes place sequentially through a typical two-stage, one-step process. A combined study of noncovalent interactions (NCIs) and electron localization function (ELFs) of selected points along the intrinsic reaction coordinate (IRC) of the reaction confirmed that, in the transition structure, only the C-C bond is being formed to some extent, whereas an electrostatic interaction is present between carbon and oxygen atoms previous to the formation of the C-O bond. Indeed, the formation of the second C-O bond only begins when the first C-C bond is completely formed without formation of any intermediate. Once the C-C bond is formed and before the C-O bond formation starts the RMS gradient norm dips, approaching but not reaching 0, giving rise to a hidden intermediate.

  7. Oxygen reduction reaction catalyzed by platinum nanonetwork prepared by template free one step synthesis for polymer electrolyte membrane fuel cells

    SciTech Connect

    Narayanamoorthy, B.; Kumar, B.V.V.S. Pavan; Eswaramoorthy, M.; Balaji, S.

    2014-07-01

    Highlights: • Supportless Pt nanonetwork (Pt NN) synthesized by novel template free one step method as per our earlier reported procedure. • Electrocatalytic activity of Pt NN studied taking oxygen reduction reaction in acid medium. • Kinetic and thermodynamic parameters were deduced under hydrodynamic conditions. • ORR mechanistic pathway was proposed based on kinetic rate constants. • ADT analysis found enhanced stability (5000 cycles) for Pt NN than Pt NN/VC and reported Pt/C. - Abstract: The reduction reaction of molecular oxygen (ORR) was investigated using supportless Pt nanonetwork (Pt NN) electrocatalyst in sulfuric acid medium. Pt NN was prepared by template free borohydride reduction. The transmission electron microscope images revealed a network like nano-architecture having an average cluster size of 30 nm. The electrochemical characterization of supportless and Vulcan carbon supported Pt NN (Pt NN/VC) was carried out using rotating disc and ring disc electrodes at various temperatures. Kinetic and thermodynamic parameters were estimated under hydrodynamic conditions and compared with Pt NN/VC and reported Pt/C catalysts. The accelerated durability test revealed that supportless Pt NN is quite stable for 5000 potential cycles with 22% reduction in electrochemical surface area (ECSA). While the initial limiting current density has in fact increased by 11.6%, whereas Pt NN/VC suffered nearly 55% loss in ECSA and 13% loss in limiting current density confirming an enhanced stability of supportless Pt NN morphology for ORR compared to conventional Pt/C ORR catalysts in acid medium.

  8. One-step synthesis of graphene/polypyrrole nanofiber composites as cathode material for a biocompatible zinc/polymer battery.

    PubMed

    Li, Sha; Shu, Kewei; Zhao, Chen; Wang, Caiyun; Guo, Zaiping; Wallace, Gordon; Liu, Hua Kun

    2014-10-01

    The significance of developing implantable, biocompatible, miniature power sources operated in a low current range has become manifest in recent years to meet the demands of the fast-growing market for biomedical microdevices. In this work, we focus on developing high-performance cathode material for biocompatible zinc/polymer batteries utilizing biofluids as electrolyte. Conductive polymers and graphene are generally considered to be biocompatible and suitable for bioengineering applications. To harness the high electrical conductivity of graphene and the redox capability of polypyrrole (PPy), a polypyrrole fiber/graphene composite has been synthesized via a simple one-step route. This composite is highly conductive (141 S cm(-1)) and has a large specific surface area (561 m(2) g(-1)). It performs more effectively as the cathode material than pure polypyrrole fibers. The battery constructed with PPy fiber/reduced graphene oxide cathode and Zn anode delivered an energy density of 264 mWh g(-1) in 0.1 M phosphate-buffer saline.

  9. One-step solvothermal synthesis of highly water-soluble, negatively charged superparamagnetic Fe3O4 colloidal nanocrystal clusters.

    PubMed

    Gao, Jining; Ran, Xinze; Shi, Chunmeng; Cheng, Humin; Cheng, Tianmin; Su, Yongping

    2013-08-01

    Highly charged hydrophilic superparamagnetic Fe3O4 colloidal nanocrystal clusters with an average diameter of 195 nm have been successfully synthesized using a modified one-step solvothermal method. Anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium salt containing both sulfonate and carboxylate groups was used as the stabilizer. The clusters synthesized under different experimental conditions were characterized with transmission electron microscopy and dynamic light scattering; it was found that the size distribution and water dispersity were significantly affected by the concentration of the polyelectrolyte stabilizer and iron sources in the reaction mixtures. A possible mechanism involving novel gel-like large molecular networks that confined the nucleation and aggregation process was proposed and discussed. The colloidal nanocrystal clusters remained negatively charged in the experimental pH ranges from 2 to 11, and also showed high colloidal stability in phosphate buffered saline (PBS) and ethanol. These highly colloidal stable superparamagnetic Fe3O4 clusters could find potential applications in bioseparation, targeted drug delivery, and photonics. PMID:23803791

  10. A label-free and sensitive fluorescent assay for one step detection of protein kinase activity and inhibition.

    PubMed

    Wang, Lei; Yan, Xu; Su, Xingguang

    2016-09-01

    In this paper, a label-free, highly sensitive and simple assay for one step detection of protein kinase (PKA) activity and inhibition that avoids the fluorescent dye process has been established. The detection was based on the fluorescence (FL) quenching of peptide-Ag nanoclusters (Ag NCs) caused by antibody modified Au nanoparticles (anti-Au NPs) via fluorescence resonance energy transfer (FRET). With PKA and adenosine 5'-triphosphate (ATP) introduced, the substrate peptide of Ag NCs could react with PKA via targeted phosphorylation, and followed by the linking interactions between peptide-Ag NCs and anti-Au NPs. According to the fluorescence quenching of Ag NCs, the activity of protein kinase can be facilely monitored in the range of 0.1-2000 mU/μL with high sensitivity. The detection limit for PKA is 0.039 mU/μL. We further explored the inhibitory effect of H-89 for protein kinase activity. The developed method was also applied to the investigation of drug-induced PKA activation in HeLa cells, which provides a promising means for screening of kinase-related drugs and the clinical diagnosis of disease. PMID:27543031

  11. Comparative studies on zirconia and graphene composites obtained by one-step and stepwise electrodeposition for deoxyribonucleic acid sensing.

    PubMed

    Yang, Tao; Guo, Xiuhong; Kong, Qianqian; Yang, Ruirui; Li, Qianhe; Jiao, Kui

    2013-07-01

    In this paper, the comparison of two kinds of electrochemically reduced graphene oxide (ERGNO) and zirconia composites, obtained by one-step (ZrO2-ERGNO) and stepwise (ZrO2/ERGNO) electrodeposition for DNA sensing, is systematically studied. The resulting composites were characterized by scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The results indicated that the ZrO2-ERGNO presented fine globular nanostructure. However, ZrO2/ERGNO presented agglomerate massive microstructure due to the absence of the oxygen-containing groups of graphene oxide, confirming the oxygen-containing groups provided a better affinity for the deposition of ZrO2. Due to the strong binding of the phosphate groups of DNA with the zirconia film, DNA probes were attached on the ZrO2-based composites. ZrO2-ERGNO/Au owning fine nanostructure presented larger surface area than microstructured ZrO2/ERGNO/Au. Moreover, compared with microstructured ZrO2/ERGNO, the nanostructured ZrO2-ERGNO provided more accessible space for immobilized DNA probe hybridization with target sequence, which consequently resulted in higher hybridization efficiency. Therefore, the ZrO2-ERGNO was chosen for fabricating DNA sensor with a limit of detection 1.21×10(-14) mol L(-1).

  12. One-step Conjugation of Glycyrrhetinic Acid to Cationic Polymers for High-performance Gene Delivery to Cultured Liver Cell

    PubMed Central

    Cong, Yue; Shi, Bingyang; Lu, Yiqing; Wen, Shihui; Chung, Roger; Jin, Dayong

    2016-01-01

    Gene therapies represent a promising therapeutic route for liver cancers, but major challenges remain in the design of safe and efficient gene-targeting delivery systems. For example, cationic polymers show good transfection efficiency as gene carriers, but are hindered by cytotoxicity and non-specific targeting. Here we report a versatile method of one-step conjugation of glycyrrhetinic acid (GA) to reduce cytotoxicity and improve the cultured liver cell -targeting capability of cationic polymers. We have explored a series of cationic polymer derivatives by coupling different ratios of GA to polypropylenimine (PPI) dendrimer. These new gene carriers (GA-PPI dendrimer) were systematically characterized by UV-vis,1H NMR titration, electron microscopy, zeta potential, dynamic light-scattering, gel electrophoresis, confocal microscopy and flow cytometry. We demonstrate that GA-PPI dendrimers can efficiently load and protect pDNA, via formation of nanostructured GA-PPI/pDNA polyplexes. With optimal GA substitution degree (6.31%), GA-PPI dendrimers deliver higher liver cell transfection efficiency (43.5% vs 22.3%) and lower cytotoxicity (94.3% vs 62.5%, cell viability) than the commercial bench-mark DNA carrier bPEI (25kDa) with cultured liver model cells (HepG2). There results suggest that our new GA-PPI dendrimer are a promising candidate gene carrier for targeted liver cancer therapy. PMID:26902258

  13. A novel enterovirus and parechovirus multiplex one-step real-time PCR-validation and clinical experience.

    PubMed

    Nielsen, Alex Christian Yde; Böttiger, Blenda; Midgley, Sofie Elisabeth; Nielsen, Lars Peter

    2013-11-01

    As the number of new enteroviruses and human parechoviruses seems ever growing, the necessity for updated diagnostics is relevant. We have updated an enterovirus assay and combined it with a previously published assay for human parechovirus resulting in a multiplex one-step RT-PCR assay. The multiplex assay was validated by analysing the sensitivity and specificity of the assay compared to the respective monoplex assays, and a good concordance was found. Furthermore, the enterovirus assay was able to detect 42 reference strains from all 4 species, and an additional 9 genotypes during panel testing and routine usage. During 15 months of routine use, from October 2008 to December 2009, we received and analysed 2187 samples (stool samples, cerebrospinal fluids, blood samples, respiratory samples and autopsy samples) were tested, from 1546 patients and detected enteroviruses and parechoviruses in 171 (8%) and 66 (3%) of the samples, respectively. 180 of the positive samples could be genotyped by PCR and sequencing and the most common genotypes found were human parechovirus type 3, echovirus 9, enterovirus 71, Coxsackievirus A16, and echovirus 25. During 2009 in Denmark, both enterovirus and human parechovirus type 3 had a similar seasonal pattern with a peak during the summer and autumn. Human parechovirus type 3 was almost invariably found in children less than 4 months of age. In conclusion, a multiplex assay was developed allowing simultaneous detection of 2 viruses, which can cause similar clinical symptoms.

  14. Preparation of stable superamphiphobic surfaces on Ti-6Al-4V substrates by one-step anodization

    NASA Astrophysics Data System (ADS)

    Sun, Yuwen; Wang, Lili; Gao, Yuze; Guo, Dongming

    2015-01-01

    Superamphiphobic surfaces on titanium alloy substrates were successfully fabricated via one-step anodization and subsequent fluoroalkylsilane modification. The prepared superamphiphobic titanium alloy surfaces display contact angles with water, glycerol and hexadecane are 166.4° ± 1.8°, 158.4° ± 2.1° and 152.5° ± 1.9°, respectively, corresponding sliding angles are all within 10°, which can be attributed to the combination of reentrant micro/nano structures with low surface energy modification. In order to obtain the optimal superamphiphobicity, the relationship between reaction time with wettability of the superamphiphobic surfaces is analyzed in detail. Furthermore, the robustness of the superamphiphobicity is also investigated by UV light test, immersion test and abrasion test, which show that the created superamphiphobic surfaces possess good stability under harsh conditions. The developed approach is simple and has potential to be applied into the commercial production of large-area superamphiphobic titanium alloy surface.

  15. One-step transfer and integration of multifunctionality in CVD graphene by TiO₂/graphene oxide hybrid layer.

    PubMed

    Jeong, Hee Jin; Kim, Ho Young; Jeong, Hyun; Han, Joong Tark; Jeong, Seung Yol; Baeg, Kang-Jun; Jeong, Mun Seok; Lee, Geon-Woong

    2014-05-28

    We present a straightforward method for simultaneously enhancing the electrical conductivity, environmental stability, and photocatalytic properties of graphene films through one-step transfer of CVD graphene and integration by introducing TiO2/graphene oxide layer. A highly durable and flexible TiO2 layer is successfully used as a supporting layer for graphene transfer instead of the commonly used PMMA. Transferred graphene/TiO2 film is directly used for measuring the carrier transport and optoelectronic properties without an extra TiO2 removal and following deposition steps for multifunctional integration into devices because the thin TiO2 layer is optically transparent and electrically semiconducting. Moreover, the TiO2 layer induces charge screening by electrostatically interacting with the residual oxygen moieties on graphene, which are charge scattering centers, resulting in a reduced current hysteresis. Adsorption of water and other chemical molecules onto the graphene surface is also prevented by the passivating TiO2 layer, resulting in the long term environmental stability of the graphene under high temperature and humidity. In addition, the graphene/TiO2 film shows effectively enhanced photocatalytic properties because of the increase in the transport efficiency of the photogenerated electrons due to the decrease in the injection barrier formed at the interface between the F-doped tin oxide and TiO2 layers. PMID:24578338

  16. One-Step Green Synthesis of Gold Nanoparticles Using Black Cardamom and Effect of pH on Its Synthesis.

    PubMed

    Singh, Ashwani Kumar; Srivastava, O N

    2015-12-01

    In the present article, an effective, one-step, and environmentally benign protocol for the synthesis of gold nanoparticles has been discussed. The black cardamom extract is used as a reducing agent for HAuCl4.3H2O. In order to synthesize gold nanoparticles, an aqueous solution of HAuCl4.3H2O was mixed with an optimized concentration of black cardamom extract where 1,8-cineole is the dominant component. Choosing black cardamom extract as a reducing agent can be justified under the light of the fact that it has a very fast reducing ability. Gold nanoparticles with different shapes and sizes were synthesized by varying the ratio of AuCl4 ions to black cardamom extract. Kinetics of reactions has been evaluated through monitoring of surface plasmon behavior of gold nanoparticles as a function of time. Based on Fourier transform infrared spectroscopy (FTIR) studies, a tentative mechanism of reduction of Au nanoparticles has also been proposed which includes oxidation of 1,8-cineole to 2-oxo-1,8-cineole. Further, a comprehensive study to investigate the effect of pH on the synthesis of Au nanoparticles has been carried out. PMID:26334545

  17. One-step separation of β-galactosidase from β-lactoglobulin using water-in-oil microemulsions.

    PubMed

    Mazı, Bekir G; Hamamcı, Haluk; Dungan, Stephanie R

    2012-05-01

    Solubilisation of β-galactosidase from Kluyveromyces lactis in Aerosol-OT water-in-isooctane microemulsions was measured as a function of buffer type and concentration, pH, and protein concentration. For buffer concentrations above ∼40mM, the enzyme was largely excluded from the droplets. Based on these results, a one-step separation was developed. A protein-containing aqueous feed was injected into an AOT/isooctane solution, with the feed volume slightly in excess of the predicted water solubility. Impurity proteins were entrapped inside the microemulsion droplets that then formed in the organic phase, while the high MW target protein was excluded and entered a newly formed, excess aqueous phase. The separation of β-galactosidase from the test protein β-lactoglobulin was most complete at 100mM KCl salt concentration, where the droplets were large enough to carry β-lactoglobulin but too small for β-galactosidase. At 100mM [KCl], 92% of the total enzyme activity was recovered in a concentrated and virtually pure form. PMID:26434297

  18. Understanding bond formation in polar one-step reactions. Topological analyses of the reaction between nitrones and lithium ynolates.

    PubMed

    Roca-López, David; Polo, Victor; Tejero, Tomás; Merino, Pedro

    2015-04-17

    The mechanism of the reaction between nitrones and lithium ynolates has been studied using DFT methods at the M06-2X/cc-pVTZ/PCM=THF level. After the formation of a starting complex an without energy barrier, in which the lithium atom is coordinated to both nitrone and ynolate, the reaction takes place in one single kinetic step through a single transition structure. However, the formation of C-C and C-O bonds takes place sequentially through a typical two-stage, one-step process. A combined study of noncovalent interactions (NCIs) and electron localization function (ELFs) of selected points along the intrinsic reaction coordinate (IRC) of the reaction confirmed that, in the transition structure, only the C-C bond is being formed to some extent, whereas an electrostatic interaction is present between carbon and oxygen atoms previous to the formation of the C-O bond. Indeed, the formation of the second C-O bond only begins when the first C-C bond is completely formed without formation of any intermediate. Once the C-C bond is formed and before the C-O bond formation starts the RMS gradient norm dips, approaching but not reaching 0, giving rise to a hidden intermediate. PMID:25803829

  19. Identification of Dobrava, Hantaan, Seoul, and Puumala viruses by one-step real-time RT-PCR.

    PubMed

    Aitichou, Mohamed; Saleh, Sharron S; McElroy, Anita K; Schmaljohn, C; Ibrahim, M Sofi

    2005-03-01

    We developed four assays for specifically identifying Dobrava (DOB), Hantaan (HTN), Puumala (PUU), and Seoul (SEO) viruses. The assays are based on the real-time one-step reverse transcriptase polymerase chain reaction (RT-PCR) with the small segment used as the target sequence. The detection limits of DOB, HTN, PUU, and SEO assays were 25, 25, 25, and 12.5 plaque-forming units, respectively. The assays were evaluated in blinded experiments, each with 100 samples that contained Andes, Black Creek Canal, Crimean-Congo hemorrhagic fever, Rift Valley fever and Sin Nombre viruses in addition to DOB, HTN, PUU and SEO viruses. The sensitivity levels of the DOB, HTN, PUU, and SEO assays were 98%, 96%, 92% and 94%, respectively. The specificity of DOB, HTN and SEO assays was 100% and the specificity of the PUU assay was 98%. Because of the high levels of sensitivity, specificity, and reproducibility, we believe that these assays can be useful for diagnosing and differentiating these four Old-World hantaviruses.

  20. One-step synthesis of CDTA coated magnetic nanoparticles for selective removal of Cu(II) from aqueous solution.

    PubMed

    Lü, Haixia; Wang, Xiaoming; Yang, Jingqi; Xie, Zenghong

    2015-01-01

    A novel 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) modified Fe3O4 magnetic nanoparticles (MNPs) was synthesized by one-step solvothermal method and used as solid phase extraction (SPE) material to preconcentrate trace copper coupled with flame atomic absorption spectrometry (FAAS). The synthesized adsorbents were characterized by field emission scanning electron microscopy and X-ray powder diffraction with a nanoscale. The optimum conditions for the absorption process were investigated on several commonly tested experimental parameters such as pH of the solution, ultrasound time, sample volume, concentration and volume of elution solution. The influences of some anions and cations on the recoveries of Cu(II) ions were also investigated, and no considerable interference was observed. The maximum adsorption capacity of Fe3O4 magnetic nanoparticles and CDTA modified Fe3O4 magnetic nanoparticles were found to be 27.50 mg/g and 78.24 mg/g for Cu(II). The developed method was applied to the determination of Cu(II) in tap and lake water samples with recoveries ranging from 96.4% to 99.1%. PMID:25858878