Sample records for solid phase support

  1. Automated Solid-Phase Radiofluorination Using Polymer-Supported Phosphazenes

    Bente Mathiessen


    Full Text Available The polymer supported phosphazene bases PS-P2tBu and the novel PS-P2PEG allowed for efficient extraction of [18F]F− from proton irradiated [18O]H2O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic sulfonates (69% and bromides (42%; the total radiosynthesis time was 35–45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [18F]FLT and [18F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production of [18F]FDG. The combination of compact form factor, simplicity of [18F]F− recovery and processing, and column reusability can make solid phase radiofluorination an attractive radiochemistry platform for the emerging dose-on-demand instruments for bedside production of PET radiotracers.

  2. Solid-Phase Organic Chemistry: Synthesis of 2β-(HeterocyclylthiomethylPenam Derivatives on Solid Support

    Ernesto G. Mata


    Full Text Available The synthesis of 2β-(heterocyclylthiomethylpenam derivatives on solid support has been developed. Compounds are obtained in good to high yields (based on loading of the original resin. The key step is the solid-phase double rearrangement of the corresponding penicillin sulfoxide.

  3. A Long Chain Alcohol as Support in Solid Phase Organic Synthesis

    Nurlela, Yeni; Minnaard, Adrian J.; Achmad, Sadijah; Wahyuningrum, Deana


    The solid phase synthesis is a method by which organic compound synthesis are performed on a support. With this method, the purification can be carried out easily by simple filtration and washing procedures. Long-chain alcohol (C-100 alcohol) can be used as a support because of its insolubility in o

  4. Novel functionalized polymeric fabric and fiber material as solid support for solid-phase synthesis and biomedical applications

    Xiang, Bei

    The aim of the research is to develop novel polymer solid support by modifying or fabricating polymeric fibrous materials for peptide synthesis and biomedical applications. Originally chemical inert isotactic polypropylene (iPP) fabric was utilized and modified to serve as a functional flexible planar solid support for solid phase peptide synthesis. The modification was achieved through thermal initiated radical grafting polymerization using acrylic acid, poly (ethylene glycol) diacrylate as monomers, and benzoyl peroxide as radical initiator. The iPP fabric was successfully functionalized and possessing as high as 0.7mmol/g carboxylic acid groups. Peptide ligand LHPQF was successfully synthesized on the new functional planar support. Specific enzyme immobilization was fulfilled on the functional iPP fabric support. A commercially available ethylene-acrylic acid copolymer was made into ultrafine copolymer fiber bundles which are composed of nanofibers with diameters ranging from 200nm to 800nm. Various mixing ratios of copolymer/matrix materials were utilized to explore the effect on the final nanofiber physical properties including morphology and stability in solvents. The surface carboxylic acid groups were further converted to amino groups before the functional nanofibers can be applied in solid phase peptide synthesis. Two peptide ligands, LHPQF and HWRGWV, were also successfully synthesized on the nanofiber bundles. Streptavidin and human immunoglobulin G specific binding with the corresponding ligand which was anchored on the nanofibers was conducted successfully to illustrate the potential applications of the nanofiber materials in biomedical field. Further study on the dispersion of the ethylene-acrylic acid nanofiber bundles was pursued to take advantage of the super high active surface area of functional nanofibers. To manipulate the polymer nanofibers during synthesis and bio-assays, a technique was developed to controllably assemble and disperse the

  5. Silica supported Fe(3)O(4) magnetic nanoparticles for magnetic solid-phase extraction and magnetic in-tube solid-phase microextraction: application to organophosphorous compounds.

    Moliner-Martinez, Y; Vitta, Yosmery; Prima-Garcia, Helena; González-Fuenzalida, R A; Ribera, Antonio; Campíns-Falcó, P; Coronado, Eugenio


    This work demonstrates the application of silica supported Fe3O4 nanoparticles as sorbent phase for magnetic solid-phase extraction (MSPE) and magnetic on-line in-tube solid-phase microextraction (Magnetic-IT-SPME) combined with capillary liquid chromatography-diode array detection (CapLC-DAD) to determine organophosphorous compounds (OPs) at trace level. In MSPE, magnetism is used as separation tool while in Magnetic-IT-SPME, the application of an external magnetic field gave rise to a significant improvement of the adsorption of OPs on the sorbent phase. Extraction efficiency, analysis time, reproducibility and sensitivity have been compared. This work showed that Magnetic-IT-SPME can be extended to OPs with successful results in terms of simplicity, speed, extraction efficiency and limit of detection. Finally, wastewater samples were analysed to determine OPs at nanograms per litre.

  6. Isolation of genomic DNA using magnetic nanoparticles as a solid-phase support

    Saiyed, Z. M.; Ramchand, C. N.; Telang, S. D.


    In recent years, techniques employing magnetizable solid-phase supports (MSPS) have found application in numerous biological fields. This magnetic separation procedure offers several advantages in terms of subjecting the analyte to very little mechanical stress compared to other methods. Secondly, these methods are non-laborious, cheap, and often highly scalable. The current paper details a genomic DNA isolation method optimized in our laboratory using magnetic nanoparticles as a solid-phase support. The quality and yields of the isolated DNA from all the samples using magnetic nanoparticles were higher or equivalent to the traditional DNA extraction procedures. Additionally, the magnetic method takes less than 15 min to extract polymerase chain reaction (PCR) ready genomic DNA as against several hours taken by traditional phenol-chloroform extraction protocols. Moreover, the isolated DNA was found to be compatible in PCR amplification and restriction endonuclease digestion. The developed procedure is quick, inexpensive, robust, and it does not require the use of organic solvents or sophisticated instruments, which makes it more amenable to automation and miniaturization.

  7. Case report: solid-phase platelet crossmatching to support the alloimmunized patient.

    O'Connell, B A


    Platelet crossmatching by a solid-phase red cell adherence assay was used to provide compatible platelets for two alloimmunized patients with leukemia. In this study, a successful platelet transfusion was defined as giving a corrected count increment (CCI) of >7,500 in a posttransfusion sample. For patient A, a total of 205 random platelet concentrates (PCs) were crossmatched. Eleven were considered compatible. These 11 PCs were transfused during five transfusion episodes. Four of the five transfusions produced CCIs of >7,500 and were considered successful. Individually, eight of the eleven units were considered in vivo compatible, and five of the eight donors of these units agreed to become apheresis donors. Platelets from three of these five apheresis donors gave CCIs of >7,500. For patient B, 1,074 random PCs were crossmatched, and 332 were considered compatible. These units were administered during 78 different transfusions. Seventy-one of these transfusion episodes resulted in CCIs of >7,500. In addition, 19 apheresis donors were identified by platelet crossmatching, and they provided platelets for 38 of 39 successful transfusions for Patient B. Platelet crossmatching should therefore be considered when a blood bank is called upon to support a refractory thrombocytopenic patient.

  8. Solid Phase Synthesis of 1, 4-Disubstituted 1, 2, 3-Triazole from Polystyrene-supported Selenium Resin

    Wei Ming XU; Lu Ling WU; Xian HUANG


    We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimination, which ensures the purity of the products.

  9. Matrix supported tailored polymer for solid phase extraction of fluoride from variety of aqueous streams

    Thakur, Neha; Kumar, Sanjukta A.; Wagh, D.N. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Das, Sadananda; Pandey, Ashok K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kumar, Sangita D., E-mail: [Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Reddy, A.V.R. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)


    Highlights: Black-Right-Pointing-Pointer Th complexed with poly (bis[2-(methacryloyloxy)-ethyl]phosphate) as tailored polymer membranes. Black-Right-Pointing-Pointer Membranes offered high capacity and selectivity for fluoride in aqueous media. Black-Right-Pointing-Pointer Quantitative uptake (80 {+-} 5%) of fluoride. Black-Right-Pointing-Pointer Fast sorption kinetics. Black-Right-Pointing-Pointer Reusability of polymer membranes. - Abstract: Fluoride related health hazards (fluorosis) are a major environmental problem in many regions of the world. It affects teeth; skeleton and its accumulation over a long period can lead to changes in the DNA structure. It is thus absolutely essential to bring down the fluoride levels to acceptable limits. Here, we present a new inorganic-organic hybrid polymer sorbent having tailored fixed-sites for fluoride sorption. The matrix supported poly (bis[2-(methacryloyloxy)-ethyl]phosphate) was prepared by photo-initiator induced graft-polymerization in fibrous and microporous (sheet) host poly(propylene) substrates. These substrates were conditioned for selective fluoride sorption by forming thorium complex with phosphate groups on bis[2-methacryloyloxy)-ethyl] phosphate (MEP). These tailored sorbents were studied for their selectivity towards fluoride in aqueous media having different chemical conditions. The fibrous sorbent was found to take up fluoride with a faster rate (15 min for Almost-Equal-To 76% sorption) than the sheet sorbent. But, the fluoride loading capacity of sheet sorbent (4320 mg kg{sup -1}), was higher than fibrous and any other sorbent reported in the literature so far. The sorbent developed in the present work was found to be reusable after desorption of fluoride using NaOH solution. It was tested for solid phase extraction of fluoride from natural water samples.

  10. Liquid-phase benzene isopropylation using alumina solid lewis superacid-supported platinum catalyst

    Yamada, K.; Honda, K.; Kitahara, D.; Miyamoto, M.; Shiga, M.; Ayame, A. [Muroran Inst. of Tech., Hokkaido (Japan)


    Supporting platinum on alumina solid Lewis superacid (AmLSA; J. C. S., Chem. Commun., 645 (1989)) was prepared by using of the in situ CVD technique at 773 K with Ar{sup +}-sputtered platinum fine particles and dry chlorine, followed by reduction with hydrogen at 673 K. The AmLSA-supported platinum catalyst (Pt/AmLSA) was applied to isopropylation of benzene with propene in the hydrogen stream at ambient temperature, using a semibatch reactor. Products were mono-, di-, tri-, and tetra-isopropylbenzenes. Conversion of propene to propane was below 1 %, and a trace amount of cyclohexane from benzene was also observed. Deactivation of AmLSA due to strong adsorption of poly-substituted benzenes and/or propene oligomers was remarkably depressed by supporting platinum and supplying hydrogen into the propene stream. Consequently, the activity of Pt/AmLSA catalyst had increased almost 1.5 times that of AmLSA. At the same level of benzene conversion, the product distribution f isopropyl-substituted benzenes obtained on Pt/AmLSA was identical to that on AmLSA, and had shifted slightly into the mono-substituted benzene side compared with the result on AmLSA in the absence of hydrogen. In the isopropylation of benzene with 2-chloropropane, the results quite similar to those described above were obtained. From the above observations, synergetic effects of platinum supporting and hydrogen supplying were considered to be due to the presence of hydrogen atoms spilled over from the platinum surface to the strong Lewis acid sites. (author)

  11. Peptide-based affinity media for solid-phase extraction of Ochratoxin A from wine samples: Effect of the solid support on binding properties.

    Giovannoli, Cristina; Passini, Cinzia; Volpi, Giorgio; Di Nardo, Fabio; Anfossi, Laura; Baggiani, Claudio


    A suitable sample clean up is a key point in the development of an analytical method. Peptide-based affinity media have recently gained attention in the selective extraction of defined target analytes from complex samples. In this paper we investigated the thermodynamic and kinetic binding properties of different stationary phases (Amberlite IRC-50, Lewatit CNP105, Toyopearl CM-650 M, porous silica gel beads and micrometric glass beads) functionalized with a hexapeptide sequence binding the Ochratoxin A. The highest values of the equilibrium binding constant (Keq) and binding site concentration (Bmax) were obtained for Lewatit CNP105 (Keq: 98.1×10(6) M(-1), Bmax: 30.8 μmol/g), followed by Toyopearl and micrometric glass beads, whereas the worst performances were obtained with Amberlite IRC-50 and porous silica gel beads. Also kinetic performances show the same trend. These results highlight that the surface chemical nature has a key role in the binding properties of solid supports used as affinity media for the selective extraction of well-defined target molecules. Finally, Lewatit CNP105 was compared with Amberlite IRC-50 as solid support in SPE extraction of OTA from 14 wine samples fortified with OTA at 2 and 4 μg l(-1) levels. The extracts were analyzed by HPLC with fluorescence detection (λexc 333 nm, λem 460 nm) showing no significant matrix effects, with a LOD and LOQ of 0.45 and 1.5 μgl(-1), respectively, and good recoveries between 71% and 108% for Amberlite IRC-50 and 91% and 101% for Lewatit CNP105. While both supports showed a statistically comparable extraction accuracy, a statistically significant difference was found in terms of extraction precision, confirming that the solid phase based on Lewatit CNP105 performs better than the solid phase based on Amberlite IRC-50.

  12. Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction

    Msagati, Titus A. M.; Mamba, Bhekie B.

    The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

  13. Supported liquid membrane-protected molecularly imprinted beads for micro-solid phase extraction of sulfonamides in environmental waters.

    Díaz-Álvarez, M; Barahona, F; Turiel, E; Martín-Esteban, A


    In this work, molecularly imprinted polymer (MIP) beads have been prepared and evaluated for the development of a supported liquid membrane-protected micro-solid phase extraction method for the analysis of sulfonamides (SAs) in aqueous samples. The performance of MIP beads was firstly evaluated in cartridges by conventional solid-phase extraction for the simultaneous analysis of SAs. Afterward, beads were packed into a polypropylene hollow fiber protected by an organic solvent immobilized in the pores of the capillary wall. During the process, the analytes were extracted from the aqueous sample to the immobilized organic solvent and then selectively retained by the MIP beads located inside the capillary. The effect of various experimental parameters as sample pH, time and stirring-rate among others, were studied for the establishment of optimum rebinding conditions. Relative recoveries for all sulfonamides tested in river and reservoir water samples by the proposed method using 100mL water sample spiked with 50μg L-1 of each sulfonamide were within 70-120%, with a relative standard deviation (RSD) <10% (n=3). The detection limits (LODs) were within 0.2-3μgL(-1), depending upon the sulfonamide and the type of water used.

  14. Solid phase transformations II

    Čermák, J


    This topical volume includes ten invited papers that cover selected areas of the field of solid phase transformations. The first two contributions represent a burgeoning branch; that of the computer simulation of physical phenomena. The following three articles deal with the thermodynamics of phase transformations as a basic theory for describing the phenomenology of phase changes in matter. The next paper describes the interconnections between structural stability and the electronic structure of phases. Two further articles are devoted to displacive transformations; a field where there are ma

  15. Towards automated solid phase radiofluorination for dose-on-demand PET: retention of activity by solid support

    Ingemann Mathiessen, Bente; Severin, Gregory; Zhuravlev, Fedor


    On-column [18F]fluoride trapping and radiofluorination of 2-(naphthalen-1-yl)ethyl-4-methylbenzenesulfonate (C10H7(CH2)2OTs), performed on polystyrene supported phosphazene base PS-PtBu2 yielded [18F]1-(2-fluoroethyl)naphthalene ([18F]C10H7(CH2)2F) in 50% radiochemical yield but left up to 43% of...

  16. Solid-phase Synthesis of α-Haloaldehydes from Polymer-supported 4-(Phenylseleno)morpholine


    Polystyrene-supported 4-(phenylseleno)morpholine was synthesized and could be used as an efficient α-selenenylating agent for saturated aldehydes.α-Haloaldehydes were prepared by reaction of polystyrene-supported α-selenoaldehydes with bromine or sulfuryl chloride in good yield and high purity.

  17. Solid-phase microextraction

    Nilsson, Torben

    The objective of this study has been to develop new analytical methods using the rapid, simple and solvent-free extraction technique solid-phase microextraction (SPME) for the quantitative analysis of organic pollutants at trace level in drinking water and environmental samples. The dynamics...

  18. Evaluation of alternative environmentally friendly matrix solid phase dispersion solid supports for the simultaneous extraction of 15 pesticides of different chemical classes from drinking water treatment sludge.

    Soares, Karina Lotz; Cerqueira, Maristela Barnes Rodrigues; Caldas, Sergiane Souza; Primel, Ednei Gilberto


    This study describes the development, optimization and validation of a method for the extraction of 15 pesticides of different chemical classes in drinking water treatment sludge (DWTS) by vortex-assisted Matrix Solid Phase Dispersion (MSPD) with determination by gas chromatography coupled to mass spectrometry. It focused on the application of alternative and different solid supports to the extraction step of the MSPD. The main parameters that influenced the extraction were studied in order to obtain better recovery responses. Recoveries ranged from 70 to 120% with RSD below 20% for all analytes. Limits of quantification (LOQ) of the method ranged from 5 to 500 μg kg(-1) whereas the analytical curves showed correlation coefficients above 0.997. The method under investigation used low volume of solvent (5 mL), low sample mass (1.5 g) and low mass of chitin (0.5 g), an environmentally friendly support. It has advantages, such as speed, simplicity and low cost material, over other methods. When the method was applied, 4 out of 15 pesticides were detected in the DWTS samples in concentrations below the LOQ. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Polymer-support Selenium-induced Electrophilic Cyclization: Solid-phase Synthesis of Flavonoids

    Jian CAO; E TANG; Xuan HUANG; Lu Ling WU; Xian HUANG


    The Lewis acid mediated polystyrene supported selenium induced intramolecular cyclization of chalcones and oxidative cleavage of selenium resins gave the corresponding flavonoids in good yields and purities have been reported.

  20. Solid phases of tenoxicam.

    Cantera, Rodrigo G; Leza, María G; Bachiller, Carmen M


    In this report we describe the preparation and characterization of four polymorphic forms of tenoxicam; they are, three 1:1 stoichiometric solvates with acetonitrile, dioxane, and N,N-dimethylformamide, and an amorphous phase obtained by recrystallization in various solvents. Polymorph IV and solvates with dioxane and N,N-dimethylformamide are reported for the first time in this paper. In addition, three solvates were crystallized in acetone, ethyl acetate, and isopropyl alcohol. These solid forms were characterized by X-ray powder diffraction, differential scanning calorimetry, infrared spectroscopy, thermogravimetry, optical microscopy, and elemental analysis. Solid-state properties, intrinsic dissolution rate, and dissolution kinetics from formulated tablets are also provided.

  1. Solid phase transformations

    Čermák, J


    This special-topic book, devoted to ""Solid Phase Transformations"" , covers a broad range of phenomena which are of importance in a number of technological processes. Most commercial alloys undergo thermal treatment after casting, with the aim of imparting desired compositions and/or optimal morphologies to the component phases. In spite of the fact that the topic has lain at the center of physical metallurgy for a long time, there are numerous aspects which are wide open to potential investigative breakthroughs. Materials with new structures also stimulate research in the field, as well as n

  2. Fabrication and characterization of anode-supported micro-tubular solide oxide fuel cell by phase inversion method

    Ren, Cong

    Nowadays, the micro-tubular solid oxide fuel cells (MT-SOFCs), especially the anode supported MT-SOFCs have been extensively developed to be applied for SOFC stacks designation, which can be potentially used for portable power sources and vehicle power supply. To prepare MT-SOFCs with high electrochemical performance, one of the main strategies is to optimize the microstructure of the anode support. Recently, a novel phase inversion method has been applied to prepare the anode support with a unique asymmetrical microstructure, which can improve the electrochemical performance of the MT-SOFCs. Since several process parameters of the phase inversion method can influence the pore formation mechanism and final microstructure, it is essential and necessary to systematically investigate the relationship between phase inversion process parameters and final microstructure of the anode supports. The objective of this study is aiming at correlating the process parameters and microstructure and further preparing MT-SOFCs with enhanced electrochemical performance. Non-solvent, which is used to trigger the phase separation process, can significantly influence the microstructure of the anode support fabricated by phase inversion method. To investigate the mechanism of non-solvent affecting the microstructure, water and ethanol/water mixture were selected for the NiO-YSZ anode supports fabrication. The presence of ethanol in non-solvent can inhibit the growth of the finger-like pores in the tubes. With the increasing of the ethanol concentration in the non-solvent, a relatively dense layer can be observed both in the outside and inside of the tubes. The mechanism of pores growth and morphology obtained by using non-solvent with high concentration ethanol was explained based on the inter-diffusivity between solvent and non-solvent. Solvent and non-solvent pair with larger Dm value is benefit for the growth of finger-like pores. Three cells with different anode geometries was

  3. Solid phase syntheses of oligoureas

    Burgess, K.; Linthicum, D.S.; Russell, D.H.; Shin, H.; Shitangkoon, A.; Totani, R.; Zhang, A.J.; Ibarzo, J. [Texas A& M Univ., College Station, TX (United States)


    Isocyanates 7 were formed from monoprotected diamines 3 or 6, which in turn can be easily prepared from commercially available N-BOC- or N-FMOC-protected amino acid derivatives. Isocyanates 7, formed in situ, could be coupled directly to a solid support functionalized with amine groups or to amino acids anchored on resins using CH{sub 2}Cl{sub 2} as solvent and an 11 h coupling time at 25 {degree}C. Such couplings afforded peptidomimetics with an N-phthaloyl group at the N-terminus. The optimal conditions identified for removal of the N-phthaloyl group were to use 60% hydrazine in DMF for 1-3 h. Several sequences of amino acids coupled to ureas (`peptidic ureas`) and of sequential urea units (`oligoureas`) were prepared via solid phase syntheses and isolated by HPLC. Partition coefficients were measured for two of these peptidomimetics, and their water solubilities were found to be similar to the corresponding peptides. A small library of 160 analogues of the YGGFL-amide sequence was prepared via Houghten`s tea bag methodology. This library was tested for binding to the anti-{beta}-endorphin monoclonal antibody. Overall, this paper describes methodology for solid phase syntheses of oligourea derivatives with side chains corresponding to some of the protein amino acids. The chemistry involved is ideal for high-throughput syntheses and screening operations. 51 refs., 3 figs., 2 tabs.

  4. Sodium dodecyl sulfate coated poly (vinyl) chloride: an alternative support for solid phase extraction of some transition and heavy metals.

    Marahel, Farzaneh; Ghaedi, Mehrorang; Shokrollahi, Ardeshir; Montazerozohori, Morteza; Davoodi, Shahnaz


    A simple and relatively fast approach for developing a solid phase extraction has been described and used for determination of trace quantities of some heavy and transition metal ions with sodium dodecyl sulfate (SDS)-coated poly vinyl chloride (PVC) modified with bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) ligand. The adsorbed ions were stripped from the solid phase by 10 mL of 3M nitric acid as eluent. The eluting solution was analyzed for metals content (cadmium, chromium, cobalt, copper, lead and zinc) by flame atomic absorption spectrometry (FAAS). The main factors such as pH, amount of ligand and PVC, amount and type of surfactant, and condition of eluting solutions on the sorption recovery of metal ions have been investigated in detail. The relative standard deviation was found in the range of 1.0-3.2% for 0.2 microg mL(-1)of metals ions. After optimization of the extraction condition and the instrumental parameters, a detection limit was found to be in the range of 1.2-3.1 microg L(-1), with enrichment factor of 50 was achieved. The method was successfully applied for the determination of these metals contents in real samples with satisfactory results.

  5. Extraction of Genomic DNA Using Magnetic Nanoparticles (Fe3O4 as a Solid-Phase Support

    Z. M. Saiyed


    Full Text Available Magnetic separation technology, using magnetic particles, is quick and easy method for sensitive and reliable captures of specific proteins, genetic material and other biomolecules. The current paper describes a universal genomic DNA extraction method optimized in our laboratory using magnetic nanoparticles as a solid phase adsorbent. The yields of the isolated DNA with magnetic method were higher or equivalent to the conventional procedures in all the samples tested. Additionally, the magnetic method takes less than 15 minutes to extract DNA as against several hours taken by conventional protocols. Furthermore, the isolated DNA was found to function satisfactorily in PCR amplification and restriction endonuclease digestion. The developed procedure is simple, quick, cheap, robust and does not require the use of organic solvents or sophisticated equipments; thereby making it more amenable to automation.

  6. Core-Shell Diamond as a Support for Solid-Phase Extraction and High-Performance Liquid Chromatography

    Saini, Gaurav; Jensen, David S.; Wiest, Landon A.; Vail, Michael A.; Dadson, Andrew; Lee, Milton L.; Shutthanandan, V.; Linford, Matthew R.


    We report the formation of core-shell diamond particles for solid phase extraction (SPE) and high performance liquid chromatography (HPLC) made by layer-by-layer (LbL) deposition. Their synthesis begins with the amine functionalization of microdiamond by its immersion in an aqueous solution of a primary amine-containing polymer (polyallylamine (PAAm)). The amine-terminated microdiamond is then immersed in an aqueous suspension of nanodiamond, which leads to adsorption of the nanodiamond. Alternating (self-limiting) immersions in the solutions of the amine-containing polymer and the suspension of nanodiamond are continued until the desired number of nanodiamond layers is formed around the microdiamond. Finally, the core-shell particles are cross-linked with 1,2,5,6-diepoxycyclooctane or reacted with 1,2-epoxyoctadecane. Layer-by-layer deposition of PAAm and nanodiamond is also studied on planar Si/SiO2 surfaces, which were characterized by SEM, Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Core-shell particles are characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), environmental scanning electron microscopy (ESEM), and Brunauer Emmett Teller (BET) surface area and pore size measurements. Larger (ca. 50 μm) core-shell diamond particles have much higher surface areas, and analyte loading capacities in SPE than nonporous solid diamond particles. Smaller (ca. 3 μm), normal and reversed phase, core-shell diamond particles have been used for HPLC, with 36,300 plates per meter for mesitylene in a separation of benzene and alkyl benzenes on a C18 adsorbent, and 54,800 plates per meter for diazinon in a similar separation of two pesticides.

  7. Preparation of metal wire supported solid-phase microextraction fiber coated with multi-walled carbon nanotubes.

    Feng, Juanjuan; Sun, Min; Xu, Lili; Li, Jubai; Liu, Xia; Jiang, Shengxiang


    Multi-walled carbon nanotubes-coated solid-phase microextraction fiber was prepared by a novel protocol involving mussel-adhesive-protein-inspired polydopamine film. The polydopamine was used as binding agent to immobilize amine-functionalized multi-walled carbon nanotubes onto the surface of the stainless steel wire via Michael addition or Schiff base reaction. Surface properties of the fiber were characterized by field emission scanning electron microscope and X-ray photoelectron spectroscope. Six phenols in aqueous solution were used as model compounds to investigate the extraction performance of the fiber and satisfactory results were obtained. Limit of detection was 0.10 μg/L for 2-methylphenol (2-MP) and 4-methylphenol (4-MP), and 0.02 μg/L for 2-ethylphenol (2-EP), 4-ethylphenol (4-EP), 2-tert-butylphenol (2-t-BuP), and 4-tert-butylphenol (4-t-BuP), which were much lower than commercial fiber and fibers made in laboratory. RSDs for one unique fiber are in the range of 1.92-7.00%. Fiber-to-fiber (n=3) reproducibility ranges from 4.44 to 8.41%. It also showed very high stability and durability to acid, alkali, organic solvent, and high temperature. Real water sample from Yellow river was applied to test the reliability of the established solid-phase microextraction (SPME)-GC method and recoveries with addition level at 5 and 100 μg/L were in the range from 81.5 to 110.0%.

  8. Molecular Modeling of Solid Fluid Phase Behavior

    Peter A. Monson


    This report gives a summary of the achievements under DOE contract No. DOE/ER/14150 during the period September 1, 1990 to December 31, 2007. This project was concerned with the molecular modeling of solid-fluid equilibrium. The focus was on understanding how solid-fluid and solid-solid phase behavior are related to molecular structure, and the research program made a seminal contribution in this area. The project led to 34 journal articles, including a comprehensive review article published in Advances in Chemical Physics. The DOE funding supported the work of 5 Ph.D. students, 2 M.S. students and 5 postdoctoral researchers.

  9. Solid-Phase Random Glycosylation

    Agoston, K.; Kröger, Lars; Dekany, Gyula


    Two different approaches were employed to study solid phase random glycosylations to obtain oligosaccharide libraries. In approach I, Wang resin esters were attached to the acceptors structures. Following their glycosylation and resin cleavage, the peracetylated components of the oligosaccharide ...

  10. Sodium dodecyl sulfate coated γ-alumina support modified by a new Schiff base for solid phase extraction and flame-AAS determination of lead and copper ions

    Ardeshir Shokrollahi


    Full Text Available A simple and fast approach for solid phase extraction is herein described, and used to determine trace amounts of Pb2+ and Cu2+ metal ions. The solid phase support is sodium dodecyl sulfate (SDS-coated γ-alumina modified with bis(2-hydroxy acetophenone-1,6-hexanediimine (BHAH ligand. The adsorbed ions were stripped from the solid phase by 6 mL of 4 M nitric acid as eluent. The eluting solution was analyzed by flame atomic absorption spectrometry (FAAS. The sorption recovery of metal ions was investigated with regard to the effects of pH, amount of ligand, γ-alumina and surfactant and the amount and type of eluent. Complexation of BHAH with Pb2+ or Cu2+ ions was examined via spectrophotometry using the HypSpec program. The detection limit for Cu2+ was 7.9 µg L-1 with a relative standard deviation of 1.67%, while that for Pb2+ was 6.4 µg L-1 with a relative standard deviation of 1.64%. A preconcentration factor of 100 was achieved for these ions. The method was successfully applied to determine analyte concentrations in samples of liver, parsley, cabbage, and water.

  11. Metal-organic framework mixed-matrix disks: Versatile supports for automated solid-phase extraction prior to chromatographic separation.

    Ghani, Milad; Font Picó, Maria Francesca; Salehinia, Shima; Palomino Cabello, Carlos; Maya, Fernando; Berlier, Gloria; Saraji, Mohammad; Cerdà, Víctor; Turnes Palomino, Gemma


    We present for the first time the application of metal-organic framework (MOF) mixed-matrix disks (MMD) for the automated flow-through solid-phase extraction (SPE) of environmental pollutants. Zirconium terephthalate UiO-66 and UiO-66-NH2 MOFs with different size (90, 200 and 300nm) have been incorporated into mechanically stable polyvinylidene difluoride (PVDF) disks. The performance of the MOF-MMDs for automated SPE of seven substituted phenols prior to HPLC analysis has been evaluated using the sequential injection analysis technique. MOF-MMDs enabled the simultaneous extraction of phenols with the concomitant size exclusion of molecules of larger size. The best extraction performance was obtained using a MOF-MMD containing 90nm UiO-66-NH2 crystals. Using the selected MOF-MMD, detection limits ranging from 0.1 to 0.2μgL(-1) were obtained. Relative standard deviations ranged from 3.9 to 5.3% intra-day, and 4.7-5.7% inter-day. Membrane batch-to-batch reproducibility was from 5.2 to 6.4%. Three different groundwater samples were analyzed with the proposed method using MOF-MMDs, obtaining recoveries ranging from 90 to 98% for all tested analytes.

  12. Solid-phase peptide synthesis

    Jensen, Knud Jørgen


    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective.......This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....



    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin isreported. 2-Polystyrylsuifonamidoethanol resin 1 was reacted with acryloyl chloride to afford2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominatedaldoximes by [3+2] cycioaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6mol/L HCI solution to obtain isoxazolines in good yield and purity.

  14. Multiple solid-phase microextraction

    Koster, EHM; de Jong, GJ


    Theoretical aspects of multiple solid-phase microextraction are described and the principle is illustrated with the extraction of lidocaine from aqueous solutions. With multiple extraction under non-equilibrium conditions considerably less time is required in order to obtain an extraction yield that

  15. Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

    José A. Rodríguez


    Full Text Available A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P<0.05.

  16. Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages

    Rodríguez, José A.; Escamilla-Lara, Karen A.; Guevara-Lara, Alfredo; Miranda, Jose M.


    A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P < 0.05). PMID:25873965

  17. Application of an activated carbon-based support for magnetic solid phase extraction followed by spectrophotometric determination of tartrazine in commercial beverages.

    Rodríguez, José A; Escamilla-Lara, Karen A; Guevara-Lara, Alfredo; Miranda, Jose M; Páez-Hernández, Ma Elena


    A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L(-1), with a limit of detection of 1 mg L(-1). The method was validated by comparing the results with those obtained by HPLC. A precision of <5.0% was obtained in all cases and no significant differences were observed (P < 0.05).


    SUNWeimin; LUOJuntao; 等


    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported.2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylate resin 2,which was further reacted with brominated aldoximes by [3+2] cycloaddition to give isoxazoline resin 4.Resin 4 was treated with aqueous 6 mol/L HCl solution to obtain isoxazolines in good yield and purity.

  19. Determination of nerve agent metabolites in human urine by isotope-dilution gas chromatography-tandem mass spectrometry after solid phase supported derivatization.

    Lin, Ying; Chen, Jia; Yan, Long; Guo, Lei; Wu, Bidong; Li, Chunzheng; Feng, Jianlin; Liu, Qin; Xie, Jianwei


    A simple and sensitive method has been developed and validated for determining ethyl methylphosphonic acid (EMPA), isopropyl methylphosphonic acid (IMPA), isobutyl methylphosphonic acid (iBuMPA), and pinacolyl methylphosphonic acid (PMPA) in human urine using gas chromatography-tandem mass spectrometry (GC-MS/MS) coupled with solid phase derivatization (SPD). These four alkyl methylphosphonic acids (AMPAs) are specific hydrolysis products and biomarkers of exposure to classic organophosphorus (OP) nerve agents VX, sarin, RVX, and soman. The AMPAs in urine samples were directly derivatized with pentafluorobenzyl bromide on a solid support and then extracted by liquid-liquid extraction. The analytes were quantified with isotope-dilution by negative chemical ionization (NCI) GC-MS/MS in a selected reaction monitoring (SRM) mode. This method is highly sensitive, with the limits of detection of 0.02 ng/mL for each compound in a 0.2 mL sample of human urine, and an excellent linearity from 0.1 to 50 ng/mL. It is proven to be very suitable for the qualitative and quantitative analyses of degradation markers of OP nerve agents in biomedical samples.

  20. A Rational Solid-State Synthesis of Supported Au-Ni Bimetallic Nanoparticles with Enhanced Activity for Gas-Phase Selective Oxidation of Alcohols.

    Yi, Wuzhong; Yuan, Wentao; Meng, Ye; Zou, Shihui; Zhou, Yuheng; Hong, Wei; Che, Jianwei; Hao, Mengjia; Ye, Bin; Xiao, Liping; Wang, Yong; Kobayashi, Hisayoshi; Fan, Jie


    A facile confined solid-state seed-mediated alloying strategy is applied for the rational synthesis of supported Au-Ni bimetallic nanoparticles (BMNPs). The method sequentially deposits nickel salts and AuNP seeds into the ordered array of extra-large mesopores (EP-FDU-12 support) followed by a high-temperature annealing process. The size, structure, and composition of the AuNi BMNPs can be well tuned by varying the AuNP seeds, annealing temperature, and feeding ratio of metal precursors. Kinetic studies and DFT calculations suggest that the introduction of the Ni component can significantly prompt the O2 activation on AuNPs, which is critical for the selective alcohol oxidation using molecular O2 as the oxidant. The optimal Au-Ni BMNP catalyst showed the highest turnover frequency (TOF) (59 000 h(-1), 240 °C) and highest space-time yield (STY) of benzyl aldehyde (BAD) productivity (9.23 kg·gAu(-1)·h(-1)) in the gas-phase oxidation of benzyl alcohol (BA), which is at least about 5-fold higher than that of other supported Au catalysts.

  1. PEG encapsulated by porous triamide-linked polymers as support for solid-liquid phase change materials for energy storage

    Andriamitantsoa, Radoelizo S.; Dong, Wenjun; Gao, Hongyi; Wang, Ge


    A series of porous triamide-linked polymers labeled as PTP were prepared by condensation of 1,3,5-benzenetricarbonyl trichloride with benzene-1,4-diamine (A), 4,4‧-methylenediamine (B) and 1,3,5-triazine-2,4,6-triamine (C) respectively. The as-synthesized polymers exhibit permanent porosity and high surface areas which guarantee to hold polyethylene glycol (PEG) molecules in their network for shape-stabilized phase change materials. They possess different effects on the phase change properties of the composite due to their different porosities. PTP-A have intrinsic well-ordered morphology, microstructure and good enough pores to keep the PCMs compared to PTP-B and PTP-C. PEG 2000 used as PCMs could be retained up to 85 wt% in PTP-A polymer materials and these composites were defined as form-stable composite PCMs without the leakage of melted PCM. The thermal study revealed a good storage effect of encapsulated polymer and the enthalpy of melting increases in the order PTP-C storage capacity. The latent heats for melting and freezing was found to be 155 and 141.7 kJ/kg with a peak appearing at around 53.13 and 29.67 °C respectively. The study suggests that pore size is important for the preparation of shape-stabilized PCMs.

  2. Solid Phase Characterization of Solids Recovered from Failed Sluicer Arm

    Cooke, Gary A. [Hanford Site (HNF), Richland, WA (United States)


    The Enclosure to this memo discusses the solid phase characterization of a solid sample that was retrieved from the single-shell Tank 241-C-111 extended reach sluicer #2. This sluicer, removed from riser #3 on September 25, 2014, was found to have approximately 0.4 gallons of solid tank waste adhering to the nozzle area.

  3. Facile and fast preparation of low-cost silica-supported graphitic carbon nitride for solid-phase extraction of fluoroquinolone drugs from environmental waters.

    Speltini, Andrea; Maraschi, Federica; Govoni, Roberta; Milanese, Chiara; Profumo, Antonella; Malavasi, Lorenzo; Sturini, Michela


    The analytical application of silica-supported graphitic carbon nitride (g-C3N4@silica) for solid-phase extraction (SPE) of fluoroquinolone (FQ) pollutants from water is presented for the first time. g-C3N4@silica was easily and quickly prepared by one-pot thermal condensation of dicyandiamide and characterized by powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and surface area measurements. The novel composite was applied as sorbent for SPE of FQs from water prior high-performance liquid chromatography with fluorescence detection. The extraction efficiency of g-C3N4 was tested in tap and surface waters at actual concentrations (10-100ngL(-1)). Quantitative adsorption was achieved using 100mg sorbent (20wt% g-C3N4) for pre-concentration of 50-500mL sample, at the native pH (∼7.5-8). Elution was performed with 25mM H3PO4 aqueous solution-acetonitrile (80:20), obtaining recoveries in the range 70-114%, enrichment factors up to 500 and inter-day RSDs≤12%. The batch-to-batch reproducibility was assessed on three independently synthesized g-C3N4@silica preparations (RSD 6-12%). g-C3N4 supported on silica microparticles proved to be of easy preparation, inexpensive, reusable for at least 4 extractions of raw surface waters, and suitable for determination in real matrices. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Solid phase sequencing of biopolymers

    Cantor, Charles R.; Hubert, Koster


    This invention relates to methods for detecting and sequencing target nucleic acid sequences, to mass modified nucleic acid probes and arrays of probes useful in these methods, and to kits and systems which contain these probes. Useful methods involve hybridizing the nucleic acids or nucleic acids which represent complementary or homologous sequences of the target to an array of nucleic acid probes. These probes comprise a single-stranded portion, an optional double-stranded portion and a variable sequence within the single-stranded portion. The molecular weights of the hybridized nucleic acids of the set can be determined by mass spectroscopy, and the sequence of the target determined from the molecular weights of the fragments. Probes may be affixed to a solid support such as a hybridization chip to facilitate automated molecular weight analysis and identification of the target sequence.

  5. Solid phase sequencing of biopolymers

    Cantor, Charles (Del Mar, CA); Koster, Hubert (La Jolla, CA)


    This invention relates to methods for detecting and sequencing target nucleic acid sequences, to mass modified nucleic acid probes and arrays of probes useful in these methods, and to kits and systems which contain these probes. Useful methods involve hybridizing the nucleic acids or nucleic acids which represent complementary or homologous sequences of the target to an array of nucleic acid probes. These probes comprise a single-stranded portion, an optional double-stranded portion and a variable sequence within the single-stranded portion. The molecular weights of the hybridized nucleic acids of the set can be determined by mass spectroscopy, and the sequence of the target determined from the molecular weights of the fragments. Nucleic acids whose sequences can be determined include DNA or RNA in biological samples such as patient biopsies and environmental samples. Probes may be fixed to a solid support such as a hybridization chip to facilitate automated molecular weight analysis and identification of the target sequence.

  6. A comparison of observables for solid-solid phase transitions

    Smilowitz, Laura B [Los Alamos National Laboratory; Henson, Bryan F [Los Alamos National Laboratory; Romero, Jerry J [Los Alamos National Laboratory


    The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries. Bulk generation of SHG is allowed by symmetry only in noncentrosymmetric crystallographic space groups. For the organic energetic nitramine octahydro-1,3 ,5,7 -tetranitro-1,3 ,5,7 -tatrazocine (HMX), the beta phase is centro symmetric (space group P2{sub 1}/c) and the delta phase iS noncentrosymmetric (space group P6{sub 1}22) making SHG an extremely sensitive, essentially zero background probe of the phase change progress. We have used SHG as a tool to follow the progress of the transformation from beta to delta phase during the solid-solid transformation. However, kinetic models of the transformation derived using different observables from several other groups have differed, showing later onset for the phase change and faster progression to completion. In this work, we have intercompared several techniques to understand these differences. The three techniques discussed are second harmonic generation, Raman spectroscopy, and differential scanning calorimetry (DSC). The progress of the beta to delta phase transition in HMX observed with each of these different probes will be discussed and advantages and disadvantages of each technique described. This paper compares several different observables for use in measuring the kinetics of solid-solid phase transitions. Relative advantages and disadvantages for each technique are described and a direct comparison of results is made for the beta to delta polymorphic phase transition of the energetic nitramine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tatrazocine.

  7. Solid phase microextraction device using aerogel

    Miller, Fred S.; Andresen, Brian D.


    A sample collection substrate of aerogel and/or xerogel materials bound to a support structure is used as a solid phase microextraction (SPME) device. The xerogels and aerogels may be organic or inorganic and doped with metals or other compounds to target specific chemical analytes. The support structure is typically formed of a glass fiber or a metal wire (stainless steel or kovar). The devices are made by applying gel solution to the support structures and drying the solution to form aerogel or xerogel. Aerogel particles may be attached to the wet layer before drying to increase sample collection surface area. These devices are robust, stable in fields of high radiation, and highly effective at collecting gas and liquid samples while maintaining superior mechanical and thermal stability during routine use. Aerogel SPME devices are advantageous for use in GC/MS analyses due to their lack of interfering background and tolerance of GC thermal cycling.

  8. Nanoporous array anodic titanium-supported co-polymeric ionic liquids as high performance solid-phase microextraction sorbents for hydrogen bonding compounds.

    Jia, Jing; Liang, Xiaojing; Wang, Licheng; Guo, Yong; Liu, Xia; Jiang, Shengxiang


    A nanoporous array anodic titanium-supported co-polymeric ionic liquids (NAAT/PILs) solid-phase microextraction (SPME) fiber was prepared in situ on the titanium wire. NAAT was selected as the substrate, in view of its high surface-to-volume ratio, easy preparation, mechanical stability, and rich titanol groups on its surface which can anchor silica coupling agent containing vinyl and then introduce ionic liquid copolymers as sorbents. In this work, 1-vinyl-3-nonanol imidazolium bromide ([C9OHVIm]Br) and 1,4-di(3-vinylimidazolium) butane dibromide ([(VIM)2C4]2[Br]) were synthesized and used as monomer and crosslinker, respectively. Extraction properties of the NAAT/PILs fiber for polar alcohols and volatile fatty acids (VFAs) in aqueous matrix were examined using gaseous sampling-SPME (GS-SPME) and headspace SPME (HS-SPME) mode, respectively. Combining the superior properties of NAAT substrate and the strong hydrogen bond interaction of PILs to polar compounds, the NAAT/PILs SPME fiber showed much higher adsorption affinity to aliphatic alcohols than bare NAAT and pure PILs fibers. The detection limits (LOD) of established GS-SPME-GC-FID method are in the range of 0.35-17.30ngL(-1) with a linear range from 0.01 to 500ngmL(-1). Also, it showed high extraction performance toward volatile fatty acids (VFAs) compounds from aqueous matrix. Under the optimized SPME conditions, wide linear ranges were obtained with correlation coefficients (R(2)) greater than 0.99 and limits of detection were in the range of 0.85-8.74ngL(-1). Moreover, real-world samples were analyzed and good results were obtained.

  9. Combinatorial Solid-Phase Synthesis of Balanol Analogues

    Nielsen, John; Lyngsø, Lars Ole


    The natural product balanol has served as a template for the design and synthesis of a combinatorial library using solid-phase chemistry. Using a retrosynthetic analysis, the structural analogues have been assembled from three relatively accessible building blocks. The solid-phase chemistry inclu...... including MSNT-mediated esterification of both support-bound alcohols and carboxylic acids has been implemented successfully. Copyright (C) 1996 Elsevier Science Ltd....

  10. Combinatorial Solid-Phase Synthesis of Balanol Analogues

    Nielsen, John; Lyngsø, Lars Ole


    The natural product balanol has served as a template for the design and synthesis of a combinatorial library using solid-phase chemistry. Using a retrosynthetic analysis, the structural analogues have been assembled from three relatively accessible building blocks. The solid-phase chemistry inclu...... including MSNT-mediated esterification of both support-bound alcohols and carboxylic acids has been implemented successfully. Copyright (C) 1996 Elsevier Science Ltd....

  11. Solid-solid phase transitions via melting in metals

    Pogatscher, S.; Leutenegger, D.; Schawe, J. E. K.; Uggowitzer, P. J.; Löffler, J. F.


    Observing solid-solid phase transitions in-situ with sufficient temporal and spatial resolution is a great challenge, and is often only possible via computer simulations or in model systems. Recently, a study of polymeric colloidal particles, where the particles mimic atoms, revealed an intermediate liquid state in the transition from one solid to another. While not yet observed there, this finding suggests that such phenomena may also occur in metals and alloys. Here we present experimental evidence for a solid-solid transition via the formation of a metastable liquid in a `real' atomic system. We observe this transition in a bulk glass-forming metallic system in-situ using fast differential scanning calorimetry. We investigate the corresponding transformation kinetics and discuss the underlying thermodynamics. The mechanism is likely to be a feature of many metallic glasses and metals in general, and may provide further insight into phase transition theory.

  12. Binary Solid-Liquid Phase Equilibria

    Ellison, Herbert R.


    Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

  13. Molecular phospholipid films on solid supports

    Czolkos, Ilja; Jesorka, Aldo; Orwar, Owe


    Phospholipid membranes are versatile structures for mimicking biological surfaces. Bilayer and monolayer membranes can be formed on solid supports, leading to enhanced stability and accessibility of the biomimetic molecular film. This has facilitated functional studies of membrane proteins...... stable lipid membranes. In this review, the current state of the art of molecularly thin lipid layer fabrication is presented with an emphasis on support materials, film formation mechanisms, characterisation methods, and applications....

  14. Measurements of solids concentration and axial solids velocity in gas-solid two-phase flows.

    Nieuwland, J.J.; Meijer, R.; Kuipers, J.A.M.; Swaaij, van W.P.M.


    Several techniques reported in the literature for measuring solids concentration and solids velocity in (dense) gas-solid two-phase flow have been briefly reviewed. An optical measuring system, based on detection of light reflected by the suspended particles, has been developed to measure local soli

  15. Graphene and graphene oxide modified by deep eutectic solvents and ionic liquids supported on silica as adsorbents for solid-phase extraction

    Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho [Dept. of Chemistry and Chemical Engineering, Inha University, Incheon (Korea, Republic of)


    A novel deep eutectic solvent (DES) and ionic liquid (IL)-modified graphene (G) and graphene oxide (GO) were synthesized and used as effective adsorbents for the preconcentration of three chlorophenols (CPs), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP), in environmental water samples prior to high-performance liquid chromatography (HPLC). The new materials were characterized by scanning electron microscopy (S-4200) and Fourier-transform infrared spectrometry. The prepared functionalized GO@silica shows remarkable adsorption capacity toward CPs. When used as solid-phase extraction (SPE) sorbents, a superior recovery (88.49–89.70%) could be obtained compared to commercial sorbents, such as silica and aminosilica. Based on this, a method for the analysis of CPs in water samples was established by coupling SPE with HPLC. These results highlight the potential new role of DES and IL-modified GO in the preparation of analytical samples.

  16. Solid Phase Synthesis of Ethyl β-Substituted Indolepropionates

    刘占祥; 阮秀秀; 黄宪


    A facile solid phase synthesis of ethyl β-substituted indolepropionates is reported. Condensation between indole, polymer-supported cyclic malonic acid ester and aldehyde yielded the trimolecular adducts, which was cleaved by pyridine/EtOH to release the final products in good yield with high purity.

  17. Synbeads porous-rigid methacrylic support: application to solid phase peptide synthesis and characterization of the polymeric matrix by FTIR microspectroscopy and high resolution magic angle spinning NMR.

    Sinigoi, Loris; Bravin, Paola; Ebert, Cynthia; D'Amelio, Nicola; Vaccari, Lisa; Ciccarelli, Laura; Cantone, Sara; Basso, Alessandra; Gardossi, Lucia


    Porous and rigid methacrylic Synbeads were optimized and applied efficiently to the solid phase peptide synthesis with the objective of improving significantly volumetric yields (0.33 mol/L calculated on the basis of maximum chemical accessibility, i.e. the maximum number of functional groups that can be acylated by FmocCl) as compared to swelling commercial polymers (from 0.06 to 0.12 mol/L). The effects of the density of functional groups and spacer length were investigated obtaining a chemical accessibility of the functional groups up to 1 mmol/g(dry). High resolution magic angle spinning (HR-MAS) was exploited to evidence the presence of "solution-like" flexible linkers anchored on the rigid methacrylic backbone of Synbeads and to study the degree of functionalization by the Wang linker. To demonstrate the efficiency of the optimized Synbeads, the peptides Somatostatin and Terlipressin were synthesized. In the case of Somatostatin, final synthetic yields of 45 and 60% were achieved by following the HCTU/DIPEA and DIC/HOBt routes respectively, with the HPLC purity always higher than 83%. In the case of Terlipressin, the synthesis was carried out in parallel on Synbeads and also on TentaGel, ChemMatrix, and PS-DVB for comparison (DIC/HOBt route). The profiles describing the synthetic efficiency demonstrated that Synbeads leads to synthetic efficiency (86%) comparable to PS-DVB (96%) or ChemMatrix (84%). In order to gain a more precise picture of chemical and morphological features of Synbeads, their matrix was also characterized by exploiting innovative approaches based on FTIR microspectroscopy with a conventional source and with synchrotron radiation. A uniform distribution of the functional groups was evidenced through a detailed chemical mapping.

  18. Multiplexed Colorimetric Solid-Phase Extraction

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.


    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  19. Solid support resins and affinity purification mass spectrometry.

    Havis, Spencer; Moree, Wilna J; Mali, Sujina; Bark, Steven J


    Co-affinity purification-mass spectrometry (CoAP-MS) is a primary technology for elucidating the protein-protein interactions that form the basis of all biological processes. A critical component of CoAP-MS is the affinity purification (AP) of the bait protein, usually by immobilization of an antibody to a solid-phase resin. This Minireview discusses common resins, reagents, tagging methods, and their consideration for successful AP of tagged proteins. We discuss our experiences with different solid supports, their impact in AP experiments, and propose areas where chemistry can advance this important technology.

  20. Phase 2, Solid waste retrieval strategy

    Johnson, D.M.


    Solid TRU retrieval, Phase 1 is scheduled to commence operation in 1998 at 218W-4C-T01 and complete recovery of the waste containers in 2001. Phase 2 Retrieval will recover the remaining buried TRU waste to be retrieved and provide the preliminary characterization by non-destructive means to allow interim storage until processing for disposal. This document reports on researching the characterization documents to determine the types of wastes to be retrieved and where located, waste configurations, conditions, and required methods for retrieval. Also included are discussions of wastes encompassed by Phase 2 for which there are valid reasons to not retrieve.

  1. Megabar pressure phases of solid hydrogen

    Chen, Nancy Hueling

    The behavior of solid Hsb2, Dsb2, and HD at low temperatures high pressures was investigated. The experimental data were obtained by combining high pressure diamond anvil cell apparatus with cryogenic and spectroscopic techniques. Megabar pressures (1 bar = 10sp5 Pa) and liquid helium temperatures were accessible. The observed phases and phase lines are discussed with respect to orientational order, crystal structure, and electronic properties. The orientational order-disorder phase transition in HD was studied by Raman spectroscopy. Due to the distinguishability of the nuclei in an HD molecule, the observed phase line exhibits surprising behavior relative to that expected for the homonuclear molecules Hsb2 and Dsb2. The megabar pressure phase diagram of solid Dsb2 was investigated by infrared and Raman spectroscopy. The broken symmetry phase (BSP) transition line and the D-A phase line were observed to meet at a triple point. The relative arrangement of phase lines in P-T space, combined with group theoretical analysis of observed infrared and Raman spectra within the phases, sets symmetry restrictions on the allowed crystal structures. The electronic properties of the high pressure H-A and D-A phases were examined, since these recently discovered phases were suspected of being metallic. Acquired broadband infrared absorption spectra extending to 10 mum were analyzed in terms of the Drude model for metals. No evidence indicating metallic behavior was found. Refinements in high pressure techniques were explored, in order to increase the maximum pressures attainable. A method of extending ruby fluorescence pressure measurements to multimegabar pressures was developed, which involved excitation of ruby fluorescence with red, rather than blue or green laser light.

  2. Recent Approaches Toward Solid Phase Synthesis of β-Lactams

    Mandal, Bablee; Ghosh, Pranab; Basu, Basudeb

    Since the discovery of penicillin in 1929, β-lactam antibiotics have been recognized as potentially chemotherapeutic drugs of incomparable effectiveness, conjugating a broad spectrum of activity with very low toxicity. The primary motif azetidin-2-one ring (β-lactam) has been considered as specific pharmacophores and scaffolds. With the advent of combinatorial chemistry and automated parallel synthesis coupled with ample interests from the pharmaceutical industries, recent trends have been driven mostly by adopting solid phase techniques and polymer-supported synthesis of β-lactams. The present survey will present an overview of the developments on the polymer-supported and solid phase techniques for the preparation of β-lactam ring or β-lactam containing antibiotics published over the last decade. Both unsubstituted and substitutions with different functional groups at various positions of β-lactams have been synthesized using solid phase technology. However, Wang resin and application of Staudinger [2+2] cycloaddition reaction have remained hitherto the major choice. It may be expected that other solid phase approaches involving different resins would be developed in the coming years.

  3. Dosing of Reagents and Solid Supports as Tablets

    T. Ruhland; P. Holm; K Andersen


    @@ 1Introduction During the latest decade, the intensive investigation into the solid-phase synthesis of small organic molecules, as well as the use of polymer-supported reagents and catalysts for solution-phase organic synthesis has lead to paradigm shifts in many areas of chemistry. This has particularly been the case within the fields of biological and medicinal chemistry where the parallel synthesis of discrete molecules (in series or larger libraries), either by manual or automated methods, has been implemented as a key technology/methodology in the preparation of compounds for biological evaluation[1a-c].

  4. Solid phase synthesis of bifunctional antibodies.

    DeSilva, B S; Wilson, G S


    Bifunctional antibodies were prepared using the principle of solid-phase synthesis. The two Fab' fragments were chemically linked together via a bismaleimide crosslinking reagent. The F(ab')2 fragments from intact IgG were prepared using an immobilized pepsin column. Goat, mouse and human antibodies were digested completely within 4 h. The F(ab')2 fragments thus produced did not contain any IgG impurities. The Fab' fragments were produced by reducing the inter-heavy chain disulfide bonds using 2-mercaptoethylamine. The use of the solid-phase reactor in the preparation of the bifunctional antibodies eliminated many of the time-consuming separation steps between the fragmentation and conjugation steps. This procedure facilitates the automation of the bifunctional antibody preparation and the rapid optimization of reaction conditions.

  5. [Solid phase techniques in blood group serology].

    Uthemann, H; Sturmfels, L; Lenhard, V


    As alternatives to hemagglutination, solid-phase red blood cell adherence assays are of increasing importance. The adaptation of the new techniques to microplates offers several advantages over hemagglutination. Using microplates the assays may be processed semiautomatically, and the results can be read spectrophotometrically and interpreted by a personal computer. In this paper, different red blood cell adherence assays for AB0 grouping, Rh typing, Rh phenotyping, antibody screening and identification, as well as crossmatching will be described.

  6. Recent advances in solid phase peptide synthesis

    White, P.D.


    Since its introduction by Merrifield half a century ago, solid phase peptide synthesis has evolved to become the enabling technology for the development of peptide therapeutics. Using modern methods, 100 - 1000s of peptides can be routinely synthesised in parallel for screening as leads for drug development and peptide APIs are produced in ton scale. In this talk I consider the state of art and report on recent advances to overcome remaining issues such as aspartimide formation, racemisation ...

  7. Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

    Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael


    The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative

  8. Development of headspace solid-phase microextraction method for ...

    ... solid-phase microextraction method for the analysis of pesticide residues in fruit and ... Journal of Applied Sciences and Environmental Management ... interface temperature) and solid phase microextraction parameters (fiber coating type, ...

  9. Reliable characterization of coffee bean aroma profiles by automated headspace solid phase microextraction-gas chromatography-mass spectrometry with the support of a dual-filter mass spectra library.

    Mondello, Luigi; Costa, Rosaria; Tranchida, Peter Quinto; Dugo, Paola; Lo Presti, Maria; Festa, Saverio; Fazio, Alessia; Dugo, Giovanni


    This investigation is based on the automated solid phase microextraction GC-MS analysis of the volatile fraction of a variety of coffee bean matrices. Volatile analytes were extracted by headspace (HS)-SPME which was achieved with the support of automated instrumentation. The research was directed towards various important aspects relating to coffee aroma analysis: monitoring of the volatile fraction formation during roasting; chromatographic differentiation of the two main coffee species (Arabica and Robusta) and of a single species from different geographical origins; evaluation of the influence of specific industrial treatments prior to roasting. Reliable peak assignment was carried out through the use of a recently laboratory-constructed "flavour and fragrance" library and a dual-filter MS spectral search procedure. Further emphasis was placed on the automated SPME instrumentation and on its ability to supply highly repeatable chromatographic data.

  10. Wax Precipitation Modeled with Many Mixed Solid Phases

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan


    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows sub...

  11. Complement fixation by solid phase immune complexes. Reduced capacity in SLE sera

    Baatrup, G; Jonsson, H; Sjöholm, A


    We describe an ELISA for assessment of complement function based on the capacity of serum to support fixation of complement components to solid phase immune complexes (IC). Microplates were coated with aggregated bovine serum albumin (BSA) followed by rabbit anti-BSA IgG. The solid phase IC were ...

  12. Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope

    Shirish Patil; Abhijit Dandekar; Santanu Khataniar


    The medium-heavy oil (viscous oil) resources in the Alaska North Slope are estimated at 20 to 25 billion barrels. These oils are viscous, flow sluggishly in the formations, and are difficult to recover. Recovery of this viscous oil requires carefully designed enhanced oil recovery processes. Success of these recovery processes is critically dependent on accurate knowledge of the phase behavior and fluid properties, especially viscosity, of these oils under variety of pressure and temperature conditions. This project focused on predicting phase behavior and viscosity of viscous oils using equations of state and semi-empirical correlations. An experimental study was conducted to quantify the phase behavior and physical properties of viscous oils from the Alaska North Slope oil field. The oil samples were compositionally characterized by the simulated distillation technique. Constant composition expansion and differential liberation tests were conducted on viscous oil samples. Experiment results for phase behavior and reservoir fluid properties were used to tune the Peng-Robinson equation of state and predict the phase behavior accurately. A comprehensive literature search was carried out to compile available compositional viscosity models and their modifications, for application to heavy or viscous oils. With the help of meticulously amassed new medium-heavy oil viscosity data from experiments, a comparative study was conducted to evaluate the potential of various models. The widely used corresponding state viscosity model predictions deteriorate when applied to heavy oil systems. Hence, a semi-empirical approach (the Lindeloff model) was adopted for modeling the viscosity behavior. Based on the analysis, appropriate adjustments have been suggested: the major one is the division of the pressure-viscosity profile into three distinct regions. New modifications have improved the overall fit, including the saturated viscosities at low pressures. However, with the limited

  13. Parallel solid-phase synthesis of diaryltriazoles

    Matthias Wrobel


    Full Text Available A series of substituted diaryltriazoles was prepared by a solid-phase-synthesis protocol using a modified Wang resin. The copper(I- or ruthenium(II-catalyzed 1,3-cycloaddition on the polymer bead allowed a rapid synthesis of the target compounds in a parallel fashion with in many cases good to excellent yields. Substituted diaryltriazoles resemble a molecular structure similar to established terphenyl-alpha-helix peptide mimics and have therefore the potential to act as selective inhibitors for protein–protein interactions.

  14. Solid-phase synthesis of molecularly imprinted nanoparticles.

    Canfarotta, Francesco; Poma, Alessandro; Guerreiro, Antonio; Piletsky, Sergey


    Molecularly imprinted polymers (MIPs) are synthetic materials, generally based on acrylic or methacrylic monomers, that are polymerized in the presence of a specific target molecule called the 'template' and capable of rebinding selectively to this target molecule. They have the potential to be low-cost and robust alternatives to biomolecules such as antibodies and receptors. When prepared by traditional synthetic methods (i.e., with free template in solution), their usefulness has been limited by high binding site heterogeneity, the presence of residual template and the fact that the production methods are complex and difficult to standardize. To overcome some of these limitations, we developed a method for the synthesis of MIP nanoparticles (nanoMIPs) using an innovative solid-phase approach, which relies on the covalent immobilization of the template molecules onto the surface of a solid support (glass beads). The obtained nanoMIPs are virtually free of template and demonstrate high affinity for the target molecule (e.g., melamine and trypsin in our published work). Because of an affinity separation step performed on the solid phase after polymerization, poor binders and unproductive polymer are removed, so the final product has more uniform binding characteristics. The overall protocol, starting from the immobilization of the template onto the solid phase and including the purification and characterization of the nanoparticles, takes up to 1 week.

  15. Studies in Solid Phase Peptide Synthesis: A Personal Perspective

    Mitchell, A R


    By the early 1970s it had became apparent that the solid phase synthesis of ribonuclease A could not be generalized. Consequently, virtually every aspect of solid phase peptide synthesis (SPPS) was reexamined and improved during the decade of the 1970s. The sensitive detection and elimination of possible side reactions (amino acid insertion, N{sup {alpha}}-trifluoroacetylation, N{sup {alpha}{var_epsilon}}-alkylation) was examined. The quantitation of coupling efficiency in SPPS as a function of chain length was studied. A new and improved support for SPPS, the 'PAM-resin', was prepared and evaluated. These and many other studies from the Merrifield laboratory and elsewhere increased the general acceptance of SPPS leading to the 1984 Nobel Prize in Chemistry for Bruce Merrifield.

  16. Density-functional theory for fluid-solid and solid-solid phase transitions

    Bharadwaj, Atul S.; Singh, Yashwant


    We develop a theory to describe solid-solid phase transitions. The density functional formalism of classical statistical mechanics is used to find an exact expression for the difference in the grand thermodynamic potentials of the two coexisting phases. The expression involves both the symmetry conserving and the symmetry broken parts of the direct pair correlation function. The theory is used to calculate phase diagram of systems of soft spheres interacting via inverse power potentials u (r ) =ɛ "close="1 /n )">σ /r n , where parameter n measures softness of the potential. We find that for 1 /n ≥0.154 the body-centred-cubic (bcc) structure is preferred. The bcc structure transforms into the fcc structure upon increasing the density. The calculated phase diagram is in good agreement with the one found from molecular simulations.

  17. Solid-Phase Organic Synthesis and Catalysis: Some Recent Strategies Using Alumina, Silica, and Polyionic Resins

    Basudeb Basu; Susmita Paul


    Solid-phase organic synthesis (SPOS) and catalysis have gained impetus after the seminal discovery of Merrifield’s solid-phase peptide synthesis and also because of wide applicability in combinatorial and high throughput chemistry. A large number of organic, inorganic, or organic-inorganic hybrid materials have been employed as polymeric solid supports to promote or catalyze various organic reactions. This review article provides a concise account on our approaches involving the use of (i) al...

  18. Studies on solid-solid phase transitions of polyols by infrared spectroscopy

    Feng, H.; Liu, X.; He, S.; Wu, K.; Zhang, J. [Department of Chemistry, Hebei Normal University, Shijiazhuang (China)


    This paper chiefly deals with the properties of polyols - a kind of energy storage material, by IR spectra. A series of infrared spectra at various temperatures were obtained for pentaerythritol (PE), pentaglycerine (PG), neopentylglycol (NPG) and their mixture NPG/PG. The experimental results (the shifts of -OH absorption band in IR spectra) support the solid-solid phase transition mechanism, which involves the reversible breaking of nearest-neighbor hydrogen bonds in the molecular crystals at transformation temperature. The correlation between the wave number shifts and the temperatures of phase transition is proposed in this paper. Finally, by means of infrared spectroscopy experiments, it is shown that aging has a great influence on the thermal properties of polyol mixtures.

  19. A Novel, One-Step Palladium and Phenylsilane Activated Amidation from Allyl Ester on Solid Support

    Zheming Ruan


    Full Text Available The direct conversion of solid-supported carboxylic acid allyl esters to carboxamides through the use of phenylsilane and catalytic Pd(PPh34 under mild reaction conditions is reported. The use of this methodology for the generation of a 48 compound solid-phase array is described herein.

  20. Solid Phase Synthesis of Polymacromer and Copolymacromer Brushes


    REPORT Solid Phase Synthesis of Polymacromer and Copolymacromer Brushes 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: We report a novel solid phase...form poly-macromer brushes wherein macromonomers are linked via triazole groups. After each addition step, the terminal alkyne group can be deprotected...Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Solid Phase Synthesis , polymers and copolymers Hernán R. Rengifo, Cristian Grigoras, Benjamin I

  1. Solid-Phase Purification of Synthetic DNA Sequences.

    Grajkowski, Andrzej; Cieslak, Jacek; Beaucage, Serge L


    Although high-throughput methods for solid-phase synthesis of DNA sequences are currently available for synthetic biology applications and technologies for large-scale production of nucleic acid-based drugs have been exploited for various therapeutic indications, little has been done to develop high-throughput procedures for the purification of synthetic nucleic acid sequences. An efficient process for purification of phosphorothioate and native DNA sequences is described herein. This process consists of functionalizing commercial aminopropylated silica gel with aminooxyalkyl functions to enable capture of DNA sequences carrying a 5'-siloxyl ether linker with a "keto" function through an oximation reaction. Deoxyribonucleoside phosphoramidites functionalized with the 5'-siloxyl ether linker were prepared in yields of 75-83% and incorporated last into the solid-phase assembly of DNA sequences. Capture of nucleobase- and phosphate-deprotected DNA sequences released from the synthesis support is demonstrated to proceed near quantitatively. After shorter than full-length DNA sequences were washed from the capture support, the purified DNA sequences were released from this support upon treatment with tetra-n-butylammonium fluoride in dry DMSO. The purity of released DNA sequences exceeds 98%. The scalability and high-throughput features of the purification process are demonstrated without sacrificing purity of the DNA sequences.

  2. 3-D graphene-supported mesoporous SiO2 @Fe3 O4 composites for the analysis of pesticides in aqueous samples by magnetic solid-phase extraction with high-performance liquid chromatography.

    Wang, Xuemei; Wang, Huan; Lu, Muxin; Ma, Xiaomin; Huang, Pengfei; Lu, Xiaoquan; Du, Xinzhen


    Three-dimensional graphene-supported mesoporous silica@Fe3 O4 composites (mSiO2 @Fe3 O4 -G) were prepared by modifying mesoporous SiO2 -coated Fe3 O4 onto hydrophobic graphene nanosheets through a simple adsorption co-condensation method. The obtained composites possess unique properties of large surface area (332.9 m(2) /g), pore volume (0.68 cm(3) /g), highly open pore structure with uniform pore size (31.1 nm), as well as good magnetic separation properties. The adsorbent (mSiO2 @Fe3 O4 -G) was used for the magnetic solid-phase extraction of seven pesticides with benzene rings in different aqueous samples before high-performance liquid chromatography. The main parameters affecting the extraction such as adsorbent amount, volume of elution solvent, time of extraction and desorption, salt effect, oscillation rate were investigated. Under the optimal conditions, this method provided low limits of detection (S/N = 3, 0.525-3.30 μg/L) and good linearity (5.0-1000 μg/L, R(2) > 0.9954). Method validation proved the feasibility of the developed adsorbent, which has a high extraction efficiency and excellent enhancement performance for pesticides in this study. The proposed method was successfully applied to real aqueous samples, and satisfactory recoveries ranging from 77.5 to 113.6% with relative standard deviations within 9.7% were obtained.

  3. Supported ionic liquid-phase (SILP) catalysis

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.


    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  4. Stable solid-phase Rh antigen.

    Yared, M A; Moise, K J; Rodkey, L S


    Numerous investigators have attempted to isolate the Rh antigens in a stable, immunologically reactive form since the discovery of the Rh system over 56 years ago. We report here a successful and reproducible approach to solubilizing and adsorbing the human Rh antigen(s) to a solid-phase matrix in an antigenically active form. Similar results were obtained with rabbit A/D/F red blood cell antigens. The antigen preparation was made by dissolution of the red blood cell membrane lipid followed by fragmentation of the residual cytoskeleton in an EDTA solution at low ionic strength. The antigenic activity of the soluble preparations was labile in standard buffers but was stable in zwitterionic buffers for extended periods of time. Further studies showed that the antigenic activity of these preparations was enhanced, as was their affinity for plastic surfaces, in the presence of acidic zwitterionic buffers. Adherence to plastic surfaces at low pH maintained antigenic reactivity and specificity for antibody was retained. The data show that this approach yields a stable form of antigenically active human Rh D antigen that could be used in a red blood cell-free assay for quantitative analysis of Rh D antibody and for Rh D antibody immunoadsorption and purification.

  5. Preparation of Ion Exchange Films for Solid-Phase Spectrophotometry and Solid-Phase Fluorometry

    Hill, Carol M.; Street, Kenneth W.; Tanner, Stephen P.; Philipp, Warren H.


    Atomic spectroscopy has dominated the field of trace inorganic analysis because of its high sensitivity and selectivity. The advantages gained by the atomic spectroscopies come with the disadvantage of expensive and often complicated instrumentation. Solid-phase spectroscopy, in which the analyte is preconcentrated on a solid medium followed by conventional spectrophotometry or fluorometry, requires less expensive instrumentation and has considerable sensitivity and selectivity. The sensitivity gains come from preconcentration and the use of chromophore (or fluorophore) developers and the selectivity is achieved by use of ion exchange conditions that favor the analyte in combination with speciative chromophores. Little work has been done to optimize the ion exchange medium (IEM) associated with these techniques. In this report we present a method for making ion exchange polymer films, which considerably simplify the solid-phase spectroscopic techniques. The polymer consists of formaldehyde-crosslinked polyvinyl alcohol with polyacrylic acid entrapped therein. The films are a carboxylate weak cation exchanger in the calcium form. They are mechanically sturdy and optically transparent in the ultraviolet and visible portion of the spectrum, which makes them suitable for spectrophotometry and fluorometry.

  6. Investigation of binary solid phases by calorimetry and kinetic modelling

    Matovic, M.


    The traditional methods for the determination of liquid-solid phase diagrams are based on the assumption that the overall equilibrium is established between the phases. However, the result of the crystallization of a liquid mixture will typically be a non-equilibrium or metastable state of the solid

  7. Method of fabricating lipid bilayer membranes on solid supports

    Cho, Nam-Joon (Inventor); Frank, Curtis W. (Inventor); Glenn, Jeffrey S. (Inventor); Cheong, Kwang Ho (Inventor)


    The present invention provides a method of producing a planar lipid bilayer on a solid support. With this method, a solution of lipid vesicles is first deposited on the solid support. Next, the lipid vesicles are destabilized by adding an amphipathic peptide solution to the lipid vesicle solution. This destabilization leads to production of a planar lipid bilayer on the solid support. The present invention also provides a supported planar lipid bilayer, where the planar lipid bilayer is made of naturally occurring lipids and the solid support is made of unmodified gold or titanium oxide. Preferably, the supported planar lipid bilayer is continuous. The planar lipid bilayer may be made of any naturally occurring lipid or mixture of lipids, including, but not limited to phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinsitol, cardiolipin, cholesterol, and sphingomyelin.

  8. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Liu, Han [Waltham, MA; LaConti, Anthony B [Lynnfield, MA; Mittelsteadt, Cortney K [Natick, MA; McCallum, Thomas J [Ashland, MA


    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  9. Solid-solid phase transitions determined by differential scanning calorimetry.

    Murrill, E.; Whitehead, M. E.; Breed, L.


    Data are presented to show that tris(hydroxymethyl)acetic acid, monochloropentaerythritol, monofluoropentaerythritol, difluoropentaerythritol, monoaminopentaerythritol, and diaminopentaerythritol exhibit solid-state transitions to a plastic crystalline state. Transitional enthalpies in many of these substances are lower than might be expected by analogy with related structures, suggesting that some configurational contributions to their entropy increments have been inhibited.

  10. Solid-solid phase transitions determined by differential scanning calorimetry.

    Murrill, E.; Whitehead, M. E.; Breed, L.


    Data are presented to show that tris(hydroxymethyl)acetic acid, monochloropentaerythritol, monofluoropentaerythritol, difluoropentaerythritol, monoaminopentaerythritol, and diaminopentaerythritol exhibit solid-state transitions to a plastic crystalline state. Transitional enthalpies in many of these substances are lower than might be expected by analogy with related structures, suggesting that some configurational contributions to their entropy increments have been inhibited.

  11. Metallocene supported core@LDH catalysts for slurry phase ethylene polymerisation.

    Buffet, Jean-Charles; Byles, Coral F H; Felton, Ryan; Chen, Chunping; O'Hare, Dermot


    We report the synthesis of solid catalysts based on a zirconocene supported on either silica@AMO-LDH or zeolite@AMO-LDH for the slurry phase polymerisation of ethylene. The hybrid catalysts demonstrate synergistic effects in which the polymerisation activity is up to three times higher than the zirconocene supported on analogous single phase silica or zeolite supports.



    Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction,then general equations of velocities of solid phase and liquid phase were founded in twophase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham's rheology equation of liquid phase and Bagnold's testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.

  13. A High-Throughput Process for the Solid-Phase Purification of Synthetic DNA Sequences.

    Grajkowski, Andrzej; Cieślak, Jacek; Beaucage, Serge L


    An efficient process for the purification of synthetic phosphorothioate and native DNA sequences is presented. The process is based on the use of an aminopropylated silica gel support functionalized with aminooxyalkyl functions to enable capture of DNA sequences through an oximation reaction with the keto function of a linker conjugated to the 5'-terminus of DNA sequences. Deoxyribonucleoside phosphoramidites carrying this linker, as a 5'-hydroxyl protecting group, have been synthesized for incorporation into DNA sequences during the last coupling step of a standard solid-phase synthesis protocol executed on a controlled pore glass (CPG) support. Solid-phase capture of the nucleobase- and phosphate-deprotected DNA sequences released from the CPG support is demonstrated to proceed near quantitatively. Shorter than full-length DNA sequences are first washed away from the capture support; the solid-phase purified DNA sequences are then released from this support upon reaction with tetra-n-butylammonium fluoride in dry dimethylsulfoxide (DMSO) and precipitated in tetrahydrofuran (THF). The purity of solid-phase-purified DNA sequences exceeds 98%. The simulated high-throughput and scalability features of the solid-phase purification process are demonstrated without sacrificing purity of the DNA sequences. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  14. Analysis of solid-liquid phase change heat transfer enhancement

    张寅平; 王馨


    Solid-liquid phase change processes have two important features: the process is an approximately isothermal process and the heat of fusion of phase change material tends to be much greater than its specific heat. Therefore, if any phase change material adjacent to a hot or cold surface undergoes phase change, the heat transfer rate on the surface will be noticeably enhanced. This paper presents a novel insight into the mechanisms of heat transfer enhancement induced by solid-liquid phase change based on the analogy analysis for heat conduction with an internal heat source and solid-liquid phase change heat transfer. Three degrees of surface heat transfer enhancement for different conditions are explored, and corresponding formulae are written to describe them. The factors influencing the degrees of heat transfer enhancement are clarified and their effects quantitatively analyzed. Both the novel insight and the analysis contribute to effective application of phase change heat transfer enhancement technique.

  15. A review on solid phase extraction of actinides and lanthanides with amide based extractants.

    Ansari, Seraj A; Mohapatra, Prasanta K


    Solid phase extraction is gaining attention from separation scientists due to its high chromatographic utility. Though both grafted and impregnated forms of solid phase extraction resins are popular, the later is easy to make by impregnating a given organic extractant on to an inert solid support. Solid phase extraction on an impregnated support, also known as extraction chromatography, combines the advantages of liquid-liquid extraction and the ion exchange chromatography methods. On the flip side, the impregnated extraction chromatographic resins are less stable against leaching out of the organic extractant from the pores of the support material. Grafted resins, on the other hand, have a higher stability, which allows their prolong use. The goal of this article is a brief literature review on reported actinide and lanthanide separation methods based on solid phase extractants of both the types, i.e., (i) ligand impregnation on the solid support or (ii) ligand functionalized polymers (chemically bonded resins). Though the literature survey reveals an enormous volume of studies on the extraction chromatographic separation of actinides and lanthanides using several extractants, the focus of the present article is limited to the work carried out with amide based ligands, viz. monoamides, diamides and diglycolamides. The emphasis will be on reported applied experimental results rather than on data pertaining fundamental metal complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane

    A. G. Gaikwad


    Full Text Available Transport of carbonate ions was explored through fiber supported solid membrane. A novel fiber supported solid membrane was prepared by chemical modification of cellulose fiber with citric acid, 2′2-bipyridine and magnesium carbonate. The factors affecting the permeability of carbonate ions such as immobilization of citric acid-magnesium metal ion -2′2-bipyridine complex (0 to 2.5 mmol/g range over cellulose fiber, carbon-ate ion concentration in source phase and NaOH concentration in receiving phase were investigated. Ki-netic of carbonate, sulfate, and nitrate ions was investigated through fiber supported solid membrane. Transport of carbonate ions with/without bubbling of CO2 (0 to 10 ml/min in source phase was explored from source to receiving phase. The novel idea is to explore the adsorptive transport of CO2 from source to receiving phase through cellulose fiber containing magnesium metal ion organic framework. Copyright © 2012 BCREC UNDIP. All rights reserved.Received: 25th November 2011; Revised: 17th December 2011; Accepted: 19th December 2011[How to Cite: A.G. Gaikwad. (2012. Transport of Carbonate Ions by Novel Cellulose Fiber Supported Solid Membrane. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 49– 57.  doi:10.9767/bcrec.7.1.1225.49-57][How to Link / DOI: ] | View in 

  17. Electrostatic levitation studies of supercooled liquids and metastable solid phases

    Rustan, Gustav Errol

    A new laboratory has been developed at Iowa State University (ISU) to be used for the study of high temperature liquids and solids, with particular focus on the supercooling of liquids and their metastable solidification products. This new laboratory employs the electrostatic levitation (ESL) technique, in which a charged sample is suspended between a set of electrodes to achieve non-contact handling. Owing to the elimination of a crucible, high temperature processing of samples can be achieved with reduced levels of contamination and heterogeneous nucleation. Because of the reduction in heterogeneous nucleation, samples can be supercooled well below their equilibrium melting temperature, opening the door to a wide range of measurements on supercooled liquids. Measurements methods have been implemented for the characterization of thermophysical properties such as: volume/density, ratio of specific heat to total hemispherical emissivity, surface tension, viscosity, electrical resistivity, and magnetic susceptibility. For measurements of electrical resistivity and magnetic susceptibility, a new method has been developed at ISU based on the tunnel diode oscillator (TDO) technique. The TDO technique uses the negative differential resistance of a tunnel diode to drive an LC tank circuit into self-sustained oscillation at the resonant LC frequency. The LC tank is inductively coupled to the samples under study, and changes in the electrical resistivity or magnetic susceptibility of the sample are manifested as changes in the resonant frequency. By measuring the frequency shifts of the TDO, insights can be made into changes in the material's electrical and magnetic properties. This method has been validated by performing resistivity measurements on a sample of high purity Zr, and by performing measurements on the ferromagnetic transition in a low-carbon steel ball bearing. In addition to the development of the laboratory and its supporting instrumentation, an effort has

  18. Automated solid-phase synthesis of oligosaccharides containing sialic acids

    Chian-Hui Lai


    Full Text Available A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.


    B. S. Chandravanshi

    cation exchange-solid phase extraction (SCX-SPE) was investigated as an .... Stock solutions, with a concentration of 1.00 mg/mL were prepared ... Johannesburg, South Africa) connected to a vacuum pump (Vacuubrand, GMBH, Germany).

  20. Proteome analysis of vaccinia virus IHD-W-infected HEK 293 cells with 2-dimensional gel electrophoresis and MALDI-PSD-TOF MS of on solid phase support N-terminally sulfonated peptides

    Bartel Sebastian


    Full Text Available Abstract Background Despite the successful eradication of smallpox by the WHO-led vaccination programme, pox virus infections remain a considerable health threat. The possible use of smallpox as a bioterrorism agent as well as the continuous occurrence of zoonotic pox virus infections document the relevance to deepen the understanding for virus host interactions. Since the permissiveness of pox infections is independent of hosts surface receptors, but correlates with the ability of the virus to infiltrate the antiviral host response, it directly depends on the hosts proteome set. In this report the proteome of HEK293 cells infected with Vaccinia Virus strain IHD-W was analyzed by 2-dimensional gel electrophoresis and MALDI-PSD-TOF MS in a bottom-up approach. Results The cellular and viral proteomes of VACV IHD-W infected HEK293 cells, UV-inactivated VACV IHD-W-treated as well as non-infected cells were compared. Derivatization of peptides with 4-sulfophenyl isothiocyanate (SPITC carried out on ZipTipμ-C18 columns enabled protein identification via the peptides' primary sequence, providing improved s/n ratios as well as signal intensities of the PSD spectra. The expression of more than 24 human proteins was modulated by the viral infection. Effects of UV-inactivated and infectious viruses on the hosts' proteome concerning energy metabolism and proteins associated with gene expression and protein-biosynthesis were quite similar. These effects might therefore be attributed to virus entry and virion proteins. However, the modulation of proteins involved in apoptosis was clearly correlated to infectious viruses. Conclusions The proteome analysis of infected cells provides insight into apoptosis modulation, regulation of cellular gene expression and the regulation of energy metabolism. The confidence of protein identifications was clearly improved by the peptides' derivatization with SPITC on a solid phase support. Some of the identified proteins

  1. The Structural Phase Transition in Solid DCN

    Dietrich, O. W.; Mackenzie, Gordon A.; Pawley, G. S.


    Neutron scattering measurements on deuterated hydrogen cyanide have shown that the structural phase change from a tetragonal to an orthorhombic form at 160K is a first-order transition. A transverse acoustic phonon mode, which has the symmetry of the phase change, was observed at very low energies...... and showed 'softening' as the transition temperature was approached from above....

  2. Magnetic Solid Phase Extraction Applied to Food Analysis

    Israel S. Ibarra


    Full Text Available Magnetic solid phase extraction has been used as pretreatment technique for the analysis of several compounds because of its advantages when it is compared with classic methods. This methodology is based on the use of magnetic solids as adsorbents for preconcentration of different analytes from complex matrices. Magnetic solid phase extraction minimizes the use of additional steps such as precipitation, centrifugation, and filtration which decreases the manipulation of the sample. In this review, we describe the main procedures used for synthesis, characterization, and application of this pretreatment technique which were applied in food analysis.

  3. Fuel spill identification using solid-phase extraction and solid-phase microextraction. 1. Aviation turbine fuels.

    Lavine, B K; Brzozowski, D M; Ritter, J; Moores, A J; Mayfield, H T


    The water-soluble fraction of aviation jet fuels is examined using solid-phase extraction and solid-phase microextraction. Gas chromatographic profiles of solid-phase extracts and solid-phase microextracts of the water-soluble fraction of kerosene- and nonkerosene-based jet fuels reveal that each jet fuel possesses a unique profile. Pattern recognition analysis reveals fingerprint patterns within the data characteristic of fuel type. By using a novel genetic algorithm (GA) that emulates human pattern recognition through machine learning, it is possible to identify features characteristic of the chromatographic profile of each fuel class. The pattern recognition GA identifies a set of features that optimize the separation of the fuel classes in a plot of the two largest principal components of the data. Because principal components maximize variance, the bulk of the information encoded by the selected features is primarily about the differences between the fuel classes.

  4. Symmetrical, bi-electrode supported solid oxide fuel cell

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)


    The present invention is a symmetrical bi-electrode supported solid oxide fuel cell comprising a sintered monolithic framework having graded pore electrode scaffolds that, upon treatment with metal solutions and heat subsequent to sintering, acquire respective anodic and cathodic catalytic activity. The invention is also a method for making such a solid oxide fuel cell. The graded pore structure of the graded pore electrode scaffolds in achieved by a novel freeze casting for YSZ tape.

  5. Passive Supporters of Terrorism and Phase Transitions

    August, Friedrich; Delitzscher, Sascha; Hiller, Gerald; Krueger, Tyll


    We discuss some social contagion processes to describe the formation and spread of radical opinions. The dynamics of opinion spread involves local threshold processes as well as mean field effects. We calculate and observe phase transitions in the dynamical variables resulting in a rapidly increasing number of passive supporters. This strongly indicates that military solutions are inappropriate.

  6. N-Acyliminium Intermediates in Solid-Phase Synthesis

    Quement, Sebastian Thordal le; Petersen, Rico; Meldal, M.


    N-Acyliminium ions are powerful intermediates in synthetic organic chemistry. Examples of their use are numerous in solution-phase synthesis, but there are unmerited few reports on these highly reactive electrophiles in solid-phase synthesis. The present review covers the literature to date and i...

  7. Solid phase extraction method for determination of mitragynine in ...

    mitragynine in urine and its application to mitragynine excretion ... Purpose: To develop a solid phase extraction (SPE) method that utilizes reverse-phase high performance .... solution of MG (1 mg/mL) which was further ... Facility, Prince of Songkla University and carried ..... d), which permit unrestricted use, distribution,.

  8. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Liu, Han; LaConti, Anthony B.


    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  9. Heterogeneous Ferroelectric Solid Solutions Phases and Domain States

    Topolov, Vitaly


    The book deals with perovskite-type ferroelectric solid solutions for modern materials science and applications, solving problems of complicated heterophase/domain structures near the morphotropic phase boundary and applications to various systems with morphotropic phases. In this book domain state–interface diagrams are presented for the interpretation of heterophase states in perovskite-type ferroelectric solid solutions. It allows to describe the stress relief in the presence of polydomain phases, the behavior of unit-cell parameters of coexisting phases and the effect of external electric fields. The novelty of the book consists in (i) the first systematization of data about heterophase states and their evolution in ferroelectric solid solutions (ii) the general interpretation of heterophase and domain structures at changing temperature, composition or electric field (iii) the complete analysis of interconnection domain structures, unit-cell parameters changes, heterophase structures and stress relief.

  10. Anisotropic kinetics of solid phase transition from first principles: alpha-omega phase transformation of Zr.

    Guan, Shu-Hui; Liu, Zhi-Pan


    Structural inhomogeneity is ubiquitous in solid crystals and plays critical roles in phase nucleation and propagation. Here, we develop a heterogeneous solid-solid phase transition theory for predicting the prevailing heterophase junctions, the metastable states governing microstructure evolution in solids. Using this theory and first-principles pathway sampling simulation, we determine two types of heterophase junctions pertaining to metal α-ω phase transition at different pressures and predict the reversibility of transformation only at low pressures, i.e. below 7 GPa. The low-pressure transformation is dominated by displacive Martensitic mechanism, while the high-pressure one is controlled by the reconstructive mechanism. The mechanism of α-ω phase transition is thus highly pressure-sensitive, for which the traditional homogeneous model fails to explain the experimental observations. The results provide the first atomic-level evidence on the coexistence of two different solid phase transition mechanisms in one system.

  11. The Structural Phase Transition in Solid DCN

    Dietrich, O. W.; Mackenzie, Gordon A.; Pawley, G. S.


    Neutron scattering measurements on deuterated hydrogen cyanide have shown that the structural phase transition from a tetragonal to an orthorhombic form at 160 K is a first order transition. A transverse acoustic phonon mode, which has the symmetry of the transition was observed at very low energ...... energies and showed “softening” as the transition was approached from above.......Neutron scattering measurements on deuterated hydrogen cyanide have shown that the structural phase transition from a tetragonal to an orthorhombic form at 160 K is a first order transition. A transverse acoustic phonon mode, which has the symmetry of the transition was observed at very low...

  12. Development and characterization of cation exchange sorbent of St - DVB copolymer support for solid-phase extraction%St-DVB基质阳离子交换固相萃取填料的研制及应用

    申书昌; 李媛媛; 柏叶春


    以玉米淀粉为分散剂,偶氮二异丁腈 (AIBN)为引发剂,二乙烯基苯(DVB)为交联剂,在在氮气保护下,用悬浮聚合法制备了交联苯乙烯-二乙烯苯(St-DVB )高分子微球,用浓硫酸进行磺化,制成了以St-DVB为基质的阳离子交换固相萃取填料.考察了搅拌速度对交联聚苯乙烯微球粒径大小及分布的影响.分别用TEM,SEM/EDS和傅里叶红外光谱法对填料进行了形貌及结构分析,测定了磺化物的磺化度.自制阳离子交换固相萃取小柱,对水中的莠去津进行了应用试验,考察了性能.%In this paper, used eom-starch as dispersing agent, 2,2-azobisisobutyronitrile as initiator of polymerization, divinyl benzene as cross-linking agent,polystyrene-divinyl benzene microspheres were prepared by suspension polymerization under nitrogen.The polystyrene-divinyl benzene microspheres were sulfonated by concentrated sulfuric acid, the polystyrene-divinyl benzene sulphonic acid material as a cation exchange sorbent for solid phase extraction packing. stirring speed were investigated to cress-linked polystyrene partiele size and distribution. The form , structure and composition of the polystyrene-divinyl benzene and the polystyrene -divinyl benzene sulphonie acid mierospheres were characterized by means of transmission electron mieraseope , scanning electron microscope/energy dispersive X-ray spectrometer and fourier transform infrared spectroscopy measurement respectively the sulfonate sulfonation degree was Determinated by acid-soda titration method. The cation exchange solid phase extraction column made using the self-made and a plastic syringe. The atrazine in water was detected by solid phase extraetion-HPLC

  13. First application of supported ionic liquid phase (SILP) catalysis for continuous methanol carbonylation

    Riisager, Anders; Jørgensen, Betina; Wasserscheid, Peter


    A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation.......A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation....

  14. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong


    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen.

  15. Phase coexistence in ferroelectric solid solutions: Formation of monoclinic phase with enhanced piezoelectricity

    Xiaoyan Lu


    Full Text Available Phase morphology and corresponding piezoelectricity in ferroelectric solid solutions were studied by using a phenomenological theory with the consideration of phase coexistence. Results have shown that phases with similar energy potentials can coexist, thus induce interfacial stresses which lead to the formation of adaptive monoclinic phases. A new tetragonal-like monoclinic to rhombohedral-like monoclinic phase transition was predicted in a shear stress state. Enhanced piezoelectricity can be achieved by manipulating the stress state close to a critical stress field. Phase coexistence is universal in ferroelectric solid solutions and may provide a way to optimize ultra-fine structures and proper stress states to achieve ultrahigh piezoelectricity.

  16. Structural control of Fe-based alloys through diffusional solid/solid phase transformations in a high magnetic field.

    Ohtsuka, Hideyuki


    A magnetic field has a remarkable influence on solid/solid phase transformations and it can be used to control the structure and function of materials during phase transformations. The effects of magnetic fields on diffusional solid/solid phase transformations, mainly from austenite to ferrite, in Fe-based alloys are reviewed. The effects of magnetic fields on the transformation temperature and phase diagram are explained thermodynamically, and the transformation behavior and transformed structures in magnetic fields are discussed.

  17. Strength of Anode‐Supported Solid Oxide Fuel Cells

    Faes, A.; Frandsen, Henrik Lund; Kaiser, Andreas


    Nickel oxide and yttria doped zirconia composite strength is crucial for anode‐supported solid oxide fuel cells, especially during transient operation, but also for the initial stacking process, where cell curvature after sintering can cause problems. This work first compares tensile and ball......‐on‐ring strength measurements of as‐sintered anodes support. Secondly, the strength of anode support sintered alone is compared to the strength of a co‐sintered anode support with anode and electrolyte layers. Finally, the orientation of the specimens to the bending axis of a co‐sintered half‐cell is investigated...

  18. Microwave-Assisted Hydantoins Synthesis on Solid Support

    Coursindel, Thibault; Martinez, Jean; Parrot, Isabelle


    In this laboratory activity, students are introduced to a three-step synthesis of hydantoin (imidazolidine-2,4-dione), a moiety that is found in many biologically active compounds. Using a microwave oven and solid-support technology, this synthetic experiment is designed for masters-degree candidates working in organic chemistry or upper-level…

  19. Solid-phase techniques in blood transfusion serology.

    Beck, M L; Plapp, F V; Sinor, L T; Rachel, J M


    For nearly a century, erythrocyte agglutination has persisted as the most widely used method for the demonstration of antigen-antibody reaction in immunohematology. So far, no other system has been developed which can match its simplicity, versatility, and general reliability. The major disadvantage of agglutination reactions is the lack of an objective endpoint, which has severely hindered attempts to automate routine pretransfusion tests. To overcome this problem, we have designed a series of solid-phase assays for ABO and Rh grouping, antibody screening, compatibility, and hepatitis tests. Each of these solid-phase assays shares a common endpoint of red cell adherence, which is easily interpreted visually or spectrophotometrically. Computer interface permits the automatic interpretation and recording of results. We believe this solid-phase system should finally bring the blood bank laboratory into the age of automation.

  20. A Discovery-Oriented Approach to Solid-Phase Peptide Synthesis

    Bockman, Matthew R.; Miedema, Christopher J.; Brennan, Brian B.


    In this discovery-oriented laboratory experiment, students use solid-phase synthesis techniques to construct a dipeptide containing an unknown amino acid. Following synthesis and cleavage from the polymeric support, electrospray ionization-mass spectrometry is employed to identify the unknown amino acid that was used in the peptide coupling. This…


    Yu-ying Li; Jia-song He


    Solid phase transition of the a form crystals to the β form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the α form crystals to the β form crystals.

  2. Stability of phases in (Ba, Gd)MnO3 solid solution system

    Migaku Kobayashi; Hidenori Tamura; Hiromi Nakano; Hirohisa Satoh; Naoki Kamegashira


    The existing phases in BaxGd1-xMnO3 solid solution system (0≦x≦1) were studied by analyzing the detailed crystal structure of each composition from the results of the Rietveld method using powder X-ray diffraction data. For a small substitution of Ba for Gd (0≦x<0.1), the orthorhombic phase with a perovskite type structure (Pnma space group) was stably formed and this fact was supported by the electron diffraction data. There existed an intermediate phase of Ba0.33Gd0.67MnO3, which was characterized as the tetragonal phase with perovskite structure. The composition range of this phase was narrow and almost line compound. Between the regions of these phases, there existed two-phase region. There was also a two-phase region between the intermediate tetragonal phase and BaMnO3. Measurement of electrical conductivities of these orthorhombic solid solutions and tetragonal phases showed semiconducting behaviors for both phases and the existence of the phase transition at high temperature for the orthorhombic phase. The transition temperature decreased as the Ba content increased.

  3. Laser-induced solid-solid phase transition in As under pressure: a theoretical prediction

    Zijlstra, Eeuwe S; Huntemann, Nils; Garcia, Martin E [Theoretische Physik, Universitaet Kassel, Heinrich-Plett-Strasse 40, 34132 Kassel (Germany)], E-mail:


    In arsenic, a pressure-induced solid-solid phase transition from the A7 into the simple cubic structure has been experimentally demonstrated (Beister et al 1990 Phys. Rev. B 41 5535). In this paper, we present calculations, which predict that this phase transition can also be induced by an ultrashort laser pulse in As under pressure. In addition, calculations for the pressure-induced phase transition are presented. Using density functional theory in the generalized gradient approximation, we found that the pressure-induced phase transition takes place at 26.3 GPa and is accompanied by a volume change {delta}V=0.5 a{sub 0}{sup 3} atom{sup -1}. The laser-induced phase transition is predicted for an applied pressure of 23.8 GPa and an absorbed laser energy of 2.8 mRy atom{sup -1}.

  4. All solid-state SBS phase conjugate mirror

    Dane, C.B.; Hackel, L.A.


    A stimulated Brillouin scattering (SBS) phase conjugate laser mirror uses a solid-state nonlinear gain medium instead of the conventional liquid or high pressure gas medium. The concept has been effectively demonstrated using common optical-grade fused silica. An energy threshold of 2.5 mJ and a slope efficiency of over 90% were achieved, resulting in an overall energy reflectivity of >80% for 15 ns, 1 um laser pulses. The use of solid-state materials is enabled by a multi-pass resonant architecture which suppresses transient fluctuations that would otherwise result in damage to the SBS medium. This all solid state phase conjugator is safer, more reliable, and more easily manufactured than prior art designs. It allows nonlinear wavefront correction to be implemented in industrial and defense laser systems whose operating environments would preclude the introduction of potentially hazardous liquids or high pressure gases. 8 figs.

  5. Binding of properdin to solid-phase immune complexes

    Junker, A; Baatrup, G; Svehag, S E


    The capacity of serum to support deposition of C3, properdin and factor B was studied by enzyme-linked immunosorbent assay using solid-phase immune complexes (IC) for activation of complement. Deposition of C3 and properdin occurred in fairly dilute normal human serum (NHS), but factor B uptake...... was hardly detectable. Alternative pathway-mediated deposition of C3 with slow kinetics was demonstrated in C2-deficient serum and in NHS depleted of C1q, factor D and properdin (C1qDP-depleted serum) after reconstitution with factor D and properdin. Efficient uptake of properdin required a functional...... classical pathway, in the presence of which C3 and properdin were rapidly deposited onto the IC. Judging from findings in C3-deficient serum, factor I-deficient serum, and C1qDPB-depleted serum, the uptake of properdin was strictly C3-dependent, and did not require the presence of factors B and D. Thus, C3b...

  6. Stereochemistry Control in Direct 1α-Hydroxylation of 5,6-trans-Vitamin D3 by Solid Support

    Yong Bin HAN; Jin Ping CHEN; Bai Ning LIU; Guo Qiang YANG; Yi LI


    A solid-phase synthesis of 1α-hydroxylation of 5,6-trans-vitamin D3 8 is described.The solid phase resin acts as a special protecting group, which gives a higher stereoselectivity in oxidation step than classical protecting groups. The stereochemistry control is favored by using high crosslinkage polymer support in a poor solvent. This work may be of benefit to the synthesis of vitamin D system.

  7. Solid-phase oligosaccharide and glycopeptide synthesis using glycosynthases

    Tolborg, Jakob Fjord; Petersen, Lars; Jensen, Knud Jørgen;


    Enzymatic approaches for the preparation of oligosaccharides are interesting alternatives to traditional chemical synthesis, the main advantage being the regio- and stereoselectivity offered without the need for protecting groups. The use of solid-phase techniques offers easy workup procedures an...

  8. Solid and solution phase combinatorial synthesis of ureas

    Nieuwenhuijzen, JW; Conti, PGM; Ottenheijm, HCJ; Linders, JTM


    An efficient parallel synthesis of ureas based on amino acids is described, both in solution and on solid phase. 1,1'-Carbonylbisbenzotriazole 2 is used as the coupling reagent. The ureas 5 and 10 were obtained in high yield (80-100%) and purity (71-97%). (C) 1998 Elsevier Science Ltd. All rights re

  9. Solid-phase synthesis of 3-amino-2-pyrazolines

    Lyngsø, Lars O.; Nielsen, John


    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to α,β-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2- pyrazolines....

  10. Solid-phase synthesis of 3-amino-2-pyrazolines

    Nielsen, John


    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to alpha,beta-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2...

  11. Solid-phase synthesis of complex and pharmacologically interesting heterocycles

    Nielsen, Thomas Eiland


    Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...

  12. Solid-phase synthesis of 3-amino-2-pyrazolines

    Lyngsø, Lars O.; Nielsen, John


    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to α,β-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2- pyrazolines....

  13. Solid-phase synthesis of complex and pharmacologically interesting heterocycles

    Nielsen, Thomas Eiland


    Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...

  14. Solid-phase microextraction for the analysis of biological samples

    Theodoridis, G; Koster, EHM; de Jong, GJ


    Solid-phase microextraction (SPME) has been introduced for the extraction of organic compounds from environmental samples. This relatively new extraction technique has now also gained a lot of interest in a broad field of analysis including food, biological and pharmaceutical samples. SPME has a num

  15. Solid Phase Characterization of Tank 241-C-105 Grab Samples

    Ely, T. M. [Washington River Protection Solutions LLC, Richland, WA (United States); LaMothe, M. E. [Washington River Protection Solutions LLC, Richland, WA (United States); Lachut, J. S. [Washington River Protection Solutions LLC, Richland, WA (United States)


    The solid phase characterization (SPC) of three grab samples from single-shell Tank 241-C-105 (C-105) that were received at the laboratory the week of October 26, 2015, has been completed. The three samples were received and broken down in the 11A hot cells.

  16. Sensitive and fast mutation detection by solid phase chemical cleavage

    Hansen, Lise Lotte; Justesen, Just; Kruse, Torben A


    We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly...

  17. Effective Liquid-phase Nitration of Benzene Catalyzed by a Stable Solid Acid Catalyst: Silica Supported Cs{sub 2.5}H{sub 0.5}PMo{sub 12}O{sub 40}

    Gong, Shu-wen; Liu, Li-jun; Zhang, Qian; Wang, Liang-yin [Liaocheng University, Liaocheng (China)


    Silica supported Cs{sub 2.5}H{sub 0.5}PMo{sub 12}O{sub 40} catalyst was prepared through sol-gel method with ethyl silicate-40 as silicon resource and characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen adsorption-desorption and potentiometric titration methods. The Cs{sub 2.5}H{sub 0.5}PMo{sub 12}O{sub 40} particles with Keggin-type structure well dispersed on the surface of silica, and the catalyst exhibited high surface area and acidity. The catalytic performance of the catalysts for benzene liquid-phase nitration was examined with 65% nitric acid as nitrating agent, and the effects of various parameters were tested, which including temperature, time and amount of catalyst, reactants ratio, especially the recycle of catalyst was emphasized. Benzene was effectively nitrated to mononitro-benzene with high conversion (95%) in optimized conditions. Most importantly, the supported catalyst was proved has excellent stability in the nitration progress, and there were no any other organic solvent and sulfuric acid were used in the reaction system, so the liquid-phase nitration of benzene that we developed was an eco-friendly and attractive alternative for the commercial technology

  18. DARPA DTN Phase 3 Core Engineering Support

    Torgerson, J. Leigh; Richard Borgen, Richard; McKelvey, James; Segui, John; Tsao, Phil


    This report covers the initial DARPA DTN Phase 3 activities as JPL provided Core Engineering Support to the DARPA DTN Program, and then further details the culmination of the Phase 3 Program with a systematic development, integration and test of a disruption-tolerant C2 Situation Awareness (SA) system that may be transitioned to the USMC and deployed in the near future. The system developed and tested was a SPAWAR/JPL-Developed Common Operating Picture Fusion Tool called the Software Interoperability Environment (SIE), running over Disruption Tolerant Networking (DTN) protocols provided by BBN and MITRE, which effectively extends the operational range of SIE from normal fully-connected internet environments to the mobile tactical edges of the battlefield network.

  19. Peptide Synthesis Method and Solid Support for Use in the Method


    or proteins in a parallel and substantially simultaneous fashion. Preferred embodiments of a solid support for performing the synthesis are prepared from thin polyethylene sheet or film which has been grafted with polystyrene chains in a radical-initiated process in which the polyethylene sheet or film......A method for the solid-phase synthesis of peptides or proteins in high yield and high purity uses a solid support consisting of a functionalized polystyrene-grafted polymer substrate, the grafted polystyrene chains being substantially non-cross-linked and having a chain molecular weight......, not including optional non-reactive substituents, of at least 200,000, preferably in the range of 600,000-1,200,000. Particularly suitable polymer substrates are substrates of a polyolefin such as polyethylene. The method is particularly well-suited to the compartmentalized synthesis of a multitude of peptides...

  20. Fabrication of anode supported PEN for solid oxide fuel cell

    谢淑红; 崔崑; 夏风; 肖建中


    Fabrication process for anode supported planar PEN of intermediate temperature solid oxide fuel cell (SOFC) was introduced, in which tape casting and screen printing methods were used. Gd2O3 doped CeO2(GDC) powders were prepared by solid reaction method. Anode tape was produced by tape casting. Electrolyte and cathode were produced by screen printing. The GDC powder's component, thermal expand coefficient, the porosity, density and microstructure of anode and electrolyte were investigated . It was shown that an bi-layer with dense thin electrolyte film and porous anode support and with good coherency of the electrolyte film to the anode could be realized after co-sintering the green tape at 1 350℃ by optimizing the power characteristics of the starting materials in the slurry.

  1. Solid-supported biomimetic membranes based on amphiphilic block copolymers

    Kowal, Justyna


    Planar artificial membranes based on amphiphilic block copolymers are of high interest due to their potential applications in catalysis, drug screening, sensing, etc. Such polymeric membranes can successfully mimic biological membranes, providing high robustness and stability, which makes them good candidates to be developed in direction of applications. Even though solid-supported polymer membranes have been already investigated to a certain extent, it is still an emerging area. This thesis ...

  2. Phase field modeling of flexoelectricity in solid dielectrics

    Chen, H. T.; Zhang, S. D.; Soh, A. K.; Yin, W. Y.


    A phase field model is developed to study the flexoelectricity in nanoscale solid dielectrics, which exhibit both structural and elastic inhomogeneity. The model is established for an elastic homogeneous system by taking into consideration all the important non-local interactions, such as electrostatic, elastic, polarization gradient, as well as flexoelectric terms. The model is then extended to simulate a two-phase system with strong elastic inhomogeneity. Both the microscopic domain structures and the macroscopic effective piezoelectricity are thoroughly studied using the proposed model. The results obtained show that the largest flexoelectric induced polarization exists at the interface between the matrix and the inclusion. The effective piezoelectricity is greatly influenced by the inclusion size, volume fraction, elastic stiffness, and the applied stress. The established model in the present study can provide a fundamental framework for computational study of flexoelectricity in nanoscale solid dielectrics, since various boundary conditions can be easily incorporated into the phase field model.

  3. Distribution of Dechlorinating Bacteria between the Aqueous and Solid Phases

    Cápiro, N. L.; Hatt, J. K.; Wang, Y.; Loeffler, F. E.; Pennell, K. D.


    Microbial monitoring of aquifers relies on nucleic acid biomarker analysis, which is typically performed with biomass recovered from groundwater samples; however, it is unclear what fraction of the target population(s) is associated with groundwater (i.e., planktonic cells) or is attached to solid phases (i.e., biofilms). Understanding how the titer of target organism(s) in groundwater correlates with the true cell titers of the target organism in the aquifer (i.e., planktonic plus attached cells) is critical for a meaningful interpretation of the data, the prediction of bioremediation performance, and the implementation of site management strategies. To evaluate the distribution of active cells between resident solid phase and the aqueous phase, one-dimensional columns were packed under water-saturated conditions with Bio-Dechlor INOCULUM, a PCE-to ethene-dechlorinating bacterial consortium containing both multiple Dehalococcoides (Dhc) strains and Geobacter lovleyi strain SZ (GeoSZ). The columns were packed with two distinct solid matrices: a low organic content sandy Federal Fine Ottawa soil or Appling soil with higher organic matter content. Influent reduced mineral salts medium supplied at a groundwater pore-water velocity of 0.3 m/day contained both 10 mM lactate as electron donor and 0.33 mM PCE as electron acceptor. Routine collection of biomass from column side ports and effluent samples measured the titers of target cells in the aqueous phase and determined when steady state conditions had been reached. A second set of column experiments evaluated delivery and filtration effects by the solid matrix (i.e., Federal Fine Ottawa sand versus Appling soil) under the same conditions except that electron donor or acceptor were omitted (no growth conditions). Quantitative real-time PCR (qPCR) analysis using Dhc and GeoSZ 16S rRNA gene-targeted primer and probe sets determined the planktonic cell counts, and destructive sampling of the columns allowed measurement

  4. Solid-Phase Synthesis of PEGylated Lipopeptides Using Click Chemistry

    Jølck, Rasmus Irming; Berg, Rolf Henrik; Andresen, Thomas Lars


    A versatile methodology for efficient synthesis of PEGylated lipopeptides via CuAAC “Click” conjugation between alkyne-bearing solid-supported lipopeptides and azido-functionalized PEGs is described. This new and very robust method offers a unique platform for synthesizing PEGylated lipopeptides...

  5. Observation of Solid-Solid Phase Transitions in Ramp-Compressed Aluminum

    Polsin, D. N.; Boehly, T. R.; Delettrez, J. A.; Gregor, M. C.; McCoy, C. A.; Henderson, B.; Fratanduono, D. E.; Smith, R.; Kraus, R.; Eggert, J. H.; Collins, R.; Coppari, F.; Celliers, P. M.


    We present results of experiments using x-ray diffraction to study the crystalline structure of solid aluminum compressed up to 500 GPa. Aluminum is of interest because it is frequently used as a standard material in high-pressure compression experiments. At ambient pressure and temperature, Al is a face-centered cubic close-packed crystal and has been observed to transform to hexagonal close-packed (hcp) when compressed to 200GPa in a diamond anvil cell. It is predicted to transform from hcp to body-centered cubic when compressed to 315GPa. Laser-driven ramp waves will be used to compress Al to various constant-pressure states. The goal is to investigate the Al phase diagram along its isentrope, i.e., at temperatures 1000K and pressures ranging from 200 to 500 GPa. X-ray diffraction will be used to measure the crystalline structure of the compressed Al and observe the transformations that occur at various pressures. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  6. Modeling the solid-liquid phase transition in saturated triglycerides

    Pink, David A.; Hanna, Charles B.; Sandt, Christophe; MacDonald, Adam J.; MacEachern, Ronald; Corkery, Robert; Rousseau, Dérick


    We investigated theoretically two competing published scenarios for the melting transition of the triglyceride trilaurin (TL): those of (1) Corkery et al. [Langmuir 23, 7241 (2007)], in which the average state of each TL molecule in the liquid phase is a discotic "Y" conformer whose three chains are dynamically twisted, with an average angle of ˜120° between them, and those of (2) Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid-state conformation of the TL molecule in the liquid phase is a nematic h∗-conformer whose three chains are in a modified "chair" conformation. We developed two competing models for the two scenarios, in which TL molecules are in a nematic compact-chair (or "h") conformation, with extended, possibly all-trans, chains at low-temperatures, and in either a Y conformation or an h∗ conformation in the liquid state at temperatures higher than the phase-transition temperature, T∗=319 K. We defined an h-Y model as a realization of the proposal of Corkery et al. [Langmuir 23, 7241 (2007)], and explored its predictions by mapping it onto an Ising model in a temperature-dependent field, performing a mean-field approximation, and calculating the transition enthalpy ΔH. We found that the most plausible realization of the h-Y model, as applied to the solid-liquid phase transition in TL, and likely to all saturated triglycerides, gave a value of ΔH in reasonable agreement with the experiment. We then defined an alternative h-h∗ model as a realization of the proposal of Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid phase exhibits an average symmetry breaking similar to an h conformation, but with twisted chains, to see whether it could describe the TL phase transition. The h-h∗ model gave a value of ΔH that was too small by a factor of ˜3-4. We also predicted the temperature dependence of the 1132 cm-1 Raman band for both models, and performed measurements of the ratios of three TL Raman

  7. Three-dimensional graphene aerogel-supported iron oxide nanoparticles as an efficient adsorbent for magnetic solid phase extraction of organophosphorus pesticide residues in fruit juices followed by gas chromatographic determination.

    Mahpishanian, Shokouh; Sereshti, Hassan


    In this research, a magnetic three dimensional-graphene nanocomposite (3D-G-Fe3O4) was prepared, characterized and used as an effective nanoadsorbent in magnetic solid-phase extraction (MSPE) of eight organophosphorus pesticides (OPPs) from juice samples prior to gas chromatography-nitrogen phosphorous detection (GC-NPD). The properties and morphology of 3D-G-Fe3O4 were characterized by scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM). The main experimental parameters affecting extraction recoveries including extraction time, amount of adsorbent, pH of sample solution, salt concentration and desorption conditions were carefully studied and optimized. The results showed wide linear concentration ranges with determination coefficients between 0.9973 and 0.9999. The limits of detection (S/N=3) of the method and limits of quantification (S/N=10) were from 1.2 to 5.1 ng L(-1) and 3.4-17.0 ng L(-1), respectively. The intra-day and inter-day RSDs were 2.6-5.1% and 3.5-6.9%, respectively. The method was successfully applied to the analysis of OPPs in fruit juices (apple, orange, grape, sour-cherry and apricot) with recoveries in range of 86.6-107.5%. The GC-NPD results were confirmed by gas chromatography-mass spectrometry (GC-MS). The results demonstrated that with combination of highly interconnected 3D network structure and magnetism property of adsorbent, 3D-G-Fe3O4 aerogel exhibited exceptional extraction ability towards the OPPs.

  8. Determining the solid phases hosting arsenic in Mekong Delta sediments

    Wucher, M.; Stuckey, J. W.; McCurdy, S.; Fendorf, S.


    The major river systems originating from the Himalaya deposit arsenic bearing sediment into the deltas of South and Southeast Asia. High rates of sediment and organic carbon deposition combined with frequent flooding leads to anaerobic processes that release arsenic into the pore-water. Arsenic concentrations in the groundwater of these sedimentary basins are often above the World Health Organization drinking water standard of 10 μg As L-1. As a result, 150 million people are at risk of chronic arsenic poisoning through water and rice consumption. The composition of the iron bearing phases hosting the arsenic in these deltaic sediments is poorly understood. Here we implemented a suite of selective chemical extractions to help constrain the types of arsenic bearing solid phases, which were complimented with synchrotron-based X-ray absorption spectroscopy and X-ray diffraction analyses to define the arsenic and iron mineralogy of the system. Sediment cores were collected in triplicate from a seasonally-inundated wetland in Cambodia at depths of 10, 50, 100, and 150 centimeters. We hypothesize that (i) arsenic will be predominantly associated with iron oxides, and (ii) the ratio of crystalline to amorphous iron oxides will increase with sediment depth (and age). We performed four selective extractions in parallel to quantify the various pools of arsenic. First, 1 M MgCl2 was used to extract electrostatically-bound arsenic (labile forms) from the sediment. Second, 1 M NaH2PO4 targeted strongly adsorbed arsenic. Third, 1 M HCl was used to liberated arsenic coprecipitated with amorphous Fe/Mn oxides, carbonates, and acid-volatile sulfides. Finally, a dithionite extraction was used to account for arsenic associated with reducible Fe/Mn oxides. Through this work, we identified the composition of the phases hosting arsenic at various depths through the soil profile, improving our understanding of how arsenic persists in the aquifer. In addition, defining the arsenic and

  9. Transport of Indium, Gallium and Thallium Metal Ions Through Chromatographic Fiber Supported Solid Membrane in Acetylacetone Containing Mixed Solvents

    Abaji Gaikwad


    The transport of metal ions of indium, gallium and thallium from source solution to receiving phase through the chromatographic fiber supported solid membrane in the acetylacetone (HAA) containing mixed solvent system has been explored. The fibers supported solid membranes were prepared with chemical synthesis from cellulose fibers and citric acid with the carboxylic acid ion exchange groups introduced. The experimental variables, such as concentration of metal ions (10^-2 to 10^-4 mol.L^-1) in the source solution, mixed solvent composition [for exampl, e, acetylacetone, (2,4-pentanedione), (HAA) 20% (by volume), 1,4-dioxane 10% to 60% and HC1 0.25 to 2 mol.L^-1] in the receiving phase and stirring speed (50-130 r.min ) of the bulk source and receiving phase, were explored. The efficiency of mixed solvents for the transport of metal ions from the source to receiving phase through the fiber supported solid membrane was evaluated. The combined ion exchange solvent extraction (CIESE) was observed effective for the selective transport of thallium, indium and gallium metal ions through fiber supported solid membrane in mixed solvents. The oxonium salt formation in the receiving phase enhances thallium, indium and gallium metal ion transport through solid membrane phase. The selective transport of thallium metal ions from source phase was observed from indium and gallium metal ions in the presence of hydrochloric acid in organic solvents in receiving phase. The separation of thallium metal ions from the binary mixtures of Be(II), Ti(IV), AI(III) Ca(II), Mg(II), K (I), La(III) and Y(III) was carried out in the mixed solvent system using cellulose fiber supported solid membrane.

  10. Solid-Phase Organic Synthesis and Catalysis: Some Recent Strategies Using Alumina, Silica, and Polyionic Resins

    Basudeb Basu


    Full Text Available Solid-phase organic synthesis (SPOS and catalysis have gained impetus after the seminal discovery of Merrifield’s solid-phase peptide synthesis and also because of wide applicability in combinatorial and high throughput chemistry. A large number of organic, inorganic, or organic-inorganic hybrid materials have been employed as polymeric solid supports to promote or catalyze various organic reactions. This review article provides a concise account on our approaches involving the use of (i alumina or silica, either having doped with metal salts or directly, and (ii polyionic resins to either promote various organic reactions or to immobilize reagents/metal catalysts for subsequent use in hydrogenation and cross-coupling reactions. The reaction parameters, scopes, and limitations, particularly in the context of green chemistry, have been highlighted with pertinent approaches by other groups.

  11. Advances in automatic, manual and microwave-assisted solid-phase peptide synthesis.

    Sabatino, Giuseppina; Papini, Anna M


    Solid-phase strategies speed up the production of both short- and long-sequence peptides compared with solution methodologies. Therefore, solid-phase peptide synthesis (SPPS), proposed by Merrifield in the early 1960s, contributed to the 'Peptide Revolution' in the fields of diagnostics, and drug and vaccine development. Since then, peptide chemistry research has aimed to optimize these synthetic procedures, focusing on areas such as amide bond formation (the coupling step), solid supports and automation. Particular attention was devoted to the environmental impact of SPPS: the requirement for large amounts of organic solvents meant high costs for industrial peptide manufacturing that needed to be reduced. SPPS, alone or in hybrid technologies, has become strategic for the production of peptides as active pharmaceutical ingredients on a commercial scale.

  12. Entransy dissipation minimization for liquid-solid phase change processes


    The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes.

  13. Semi-automated microwave assisted solid-phase peptide synthesis

    Pedersen, Søren Ljungberg

    with microwaves for SPPS has gained in popularity as it for many syntheses has provided significant improvement in terms of speed, purity, and yields, maybe especially in the synthesis of long and "difficult" peptides. Thus, precise microwave heating has emerged as one new parameter for SPPS, in addition...... to coupling reagents, resins, solvents etc. We have previously reported on microwave heating to promote a range of solid-phase reactions in SPPS. Here we present a new, flexible semi-automated instrument for the application of precise microwave heating in solid-phase synthesis. It combines a slightly modified...... Biotage Initiator microwave instrument, which is available in many laboratories, with a modified semi-automated peptide synthesizer from MultiSynTech. A custom-made reaction vessel is placed permanently in the microwave oven, thus the reactor does not have to be moved between steps. Mixing is achieved...

  14. Indigenous microbial capability in solid manure residues to start-up solid-phase anaerobic digesters.

    Yap, S D; Astals, S; Jensen, P D; Batstone, D J; Tait, S


    Batch solid-phase anaerobic digestion is a technology for sustainable on-farm treatment of solid residues, but is an emerging technology that is yet to be optimised with respect to start-up and inoculation. In the present study, spent bedding from two piggeries (site A and B) were batch digested at total solids (TS) concentration of 5, 10 and 20% at mesophilic (37°C) and thermophilic (55°C) temperatures, without adding an external inoculum. The results showed that the indigenous microbial community present in spent bedding was able to recover the full methane potential of the bedding (140±5 and 227±6L CH4 kgVSfed(-1) for site A and B, respectively), but longer treatment times were required than for digestion with an added external inoculum. Nonetheless, at high solid loadings (i.e. TS level>10%), the digestion performance was affected by chemical inhibition due to ammonia and/or humic acid. Thermophilic temperatures did not influence digestion performance but did increase start-up failure risk. Further, inoculation of residues from the batch digestion to subsequent batch enhanced start-up and achieved full methane potential recovery of the bedding. Inoculation with liquid residue (leachate) was preferred over a solid residue, to preserve treatment capacity for fresh substrate. Overall, the study highlighted that indigenous microbial community in the solid manure residue was capable of recovering full methane potential and that solid-phase digestion was ultimately limited by chemical inhibition rather than lack of suitable microbial community. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Hyperdoping silicon with selenium: solid vs. liquid phase epitaxy

    Zhou, Shengqiang; Liu, Fang; Prucnal, S.; Gao, Kun; Khalid, M.; Baehtz, C.; Posselt, M.; Skorupa, W.; Helm, M


    Chalcogen-hyperdoped silicon shows potential applications in silicon-based infrared photodetectors and intermediate band solar cells. Due to the low solid solubility limits of chalcogen elements in silicon, these materials were previously realized by femtosecond or nanosecond laser annealing of implanted silicon or bare silicon in certain background gases. The high energy density deposited on the silicon surface leads to a liquid phase and the fast recrystallization velocity allows trapping o...

  16. Chromatography, solid-phase extraction, and capillary electrochromatography with MIPs.

    Tóth, Blanka; Horvai, George


    Most analytical applications of molecularly imprinted polymers are based on their selective adsorption properties towards the template or its analogs. In chromatography, solid phase extraction and electrochromatography this adsorption is a dynamic process. The dynamic process combined with the nonlinear adsorption isotherm of the polymers and other factors results in complications which have limited the success of imprinted polymers. This chapter explains these problems and shows many examples of successful applications overcoming or avoiding the problems.

  17. Oscillatory burning of solid propellants including gas phase time lag.

    T'Ien, J. S.


    An analysis has been performed for oscillatory burning of solid propellants including gas phase time lag. The gaseous flame is assumed to be premixed and laminar with a one-step overall chemical reaction. The propellant is assumed to decompose according to the Arrenhius Law, with no condensed phase reaction. With this model, strong gas phase resonance has been found in certain cases at the characteristic gas-phase frequencies, but the peaking of the acoustic admittance is in the direction favoring the damping of pressure waves. At still higher frequencies, moderate wave-amplifying ability was found. The limit of low frequency response obtained previously by Denison and Baum was recovered, and the limitations of the quasi-steady theory were investigated.

  18. Simulating confined swirling gas-solid two phase jet

    金晗辉; 夏钧; 樊建人; 岑可法


    A k-ε-kp multi-fluid model was used to simulate confined swirling gas-solid two phase jet comprised of particle-laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. After considering the drag force between the two phases and gravity, a series of numerical simulations of the two-phase flow of 30μm, 45μm, 60μm diameter particles were performed on a x×r=50×50 mesh grid respectively. The results showed that the k-ε-kp multi-fluid model can be applied to predict moderate swirling multi-phase flow. When the particle diameter is large, the collision of the particles with the wall will influence the prediction accuracy. The bigger the diameter of the particles, the stronger the collision with the wall, and the more obvious the difference between measured and calculated results.

  19. Oscillatory burning of solid propellants including gas phase time lag.

    T'Ien, J. S.


    An analysis has been performed for oscillatory burning of solid propellants including gas phase time lag. The gaseous flame is assumed to be premixed and laminar with a one-step overall chemical reaction. The propellant is assumed to decompose according to the Arrenhius Law, with no condensed phase reaction. With this model, strong gas phase resonance has been found in certain cases at the characteristic gas-phase frequencies, but the peaking of the acoustic admittance is in the direction favoring the damping of pressure waves. At still higher frequencies, moderate wave-amplifying ability was found. The limit of low frequency response obtained previously by Denison and Baum was recovered, and the limitations of the quasi-steady theory were investigated.

  20. Exploring solid-phase approaches for the preparation of new beta-lactams from amino acids.

    Gerona-Navarro, Guillermo; Royo, Miriam; García-López, Ma Teresa; Albericio, Fernando; González-Muñiz, Rosario


    Two solid-phase approaches, involving the base-assisted intramolecular alkylation of N-chloroacetyl-Phe derivatives anchored to appropriate solid supports, were investigated for the preparation of novel beta-lactams. When a BAL-type strategy was used, the resin-bound azetidinones were easily formed, as established by MAS-NMR, but final compounds could not be removed from the resin, unless a suitable two linkers system was used. In the second approach, in which the Phe residue is anchored to a Wang-type resin through the carboxylate group, the corresponding 1,4,4-trisubstituted 2-azetidinone was obtained in moderate to good yield and high purity.

  1. Two phase continuous digestion of solid manure on-farm

    Schaefer, W.; Lehto, M. [MTT Agrifood Research Finland, Vihti (Finland). Animal Production Research; Evers, L.; Granstedt, A. [Biodynamic Research Inst., Jaerna (Sweden)


    Present commercially available biogas plants are mainly suitable for slurry and co-substrates. Cattle, horse and poultry farms using a solid manure chain experience a crucial competitive disadvantage, because conversion to slurry technology requires additional investments. Based on the technological progress of anaerobic digestion of municipal solid waste, so called 'dry fermentation' prototype plants were developed for anaerobic digestion of organic material containing 15-50% total solids (Hoffman, 2001). These plants show added advantages compared to slurry digestion plants: Less reactor volume, less process energy, less transport capacity, less odour emissions. On-farm research (Gronauer and Aschmann, 2004; Kusch and Oechsner, 2004) and prototype research (Linke, 2004) on dry fermentation in batch reactors show that loading and discharging of batch reactors remains difficult and/or time-consuming compared to slurry reactors. Additionally a constant level of gas generation requires offset operation of several batch reactors. Baserga et al. (1994) developed a pilot plant of 9.6 m{sup 3} capacity for continuous digestion of solid beef cattle manure on-farm. However, on-farm dry fermentation plants are not common and rarely commercially available. We assume that lack of tested technical solutions and scarceness of on-farm research results are the main reason for low acceptance of dry fermentation technology on-farm. We report about an innovative two phase farm-scale biogas plant. The plant continuously digests dairy cattle manure and organic residues of the farm and the surrounding food processing units. The two phase reactor technology was chosen for two reasons: first it offers the separation of a liquid fraction and a solid fraction for composting after hydrolysis and secondly the methanation of the liquid fraction using fixed film technology results in a very short hydraulic retention time, reduction in reactor volume, and higher methane content of the

  2. Phase field modeling and simulation of three-phase flow on solid surfaces

    Zhang, Qian; Wang, Xiao-Ping


    Phase field models are widely used to describe the two-phase system. The evolution of the phase field variables is usually driven by the gradient flow of a total free energy functional. The generalization of the approach to an N phase (N ≥ 3) system requires some extra consistency conditions on the free energy functional in order for the model to give physically relevant results. A projection approach is proposed for the derivation of a consistent free energy functional for the three-phase Cahn-Hilliard equations. The system is then coupled with the Navier-Stokes equations to describe the three-phase flow on solid surfaces with moving contact line. An energy stable scheme is developed for the three-phase flow system. The discrete energy law of the numerical scheme is proved which ensures the stability of the scheme. We also show some numerical results for the dynamics of triple junctions and four phase contact lines.

  3. R. Bruce Merrifield and Solid-Phase Peptide Synthesis: A Historical Assessment

    Mitchell, A R


    Bruce Merrifield, trained as a biochemist, had to address three major challenges related to the development and acceptance of solid-phase peptide synthesis (SPPS). The challenges were (1) to reduce the concept of peptide synthesis on a insoluble support to practice, (2) overcome the resistance of synthetic chemists to this novel approach, and (3) establish that a biochemist had the scientific credentials to effect the proposed revolutionary change in chemical synthesis. How these challenges were met is discussed in this article.

  4. Solid-Phase Organic Synthesis of Aryl Vinyl Ethers Using Sulfone-Linking Strategy

    余腊妹; 汤妮; 盛寿日; 陈茹冰; 刘晓玲; 蔡明中


    A novel facile solid-phase organic synthesis of aryl vinyl ethers by reaction of polystyrene-supported 2-phenylsulfonylethanol with phenols under Mitsunobu conditions and subsequent elimination reaction with DBU has been developed. The advantages of this method include straightforward operation, good yield and high purity of the products. Alternatively, a typical example of Suzuki coupling reaction on-resin was further applied to prepare 4-phenylphenyl vinyl ether for extending this method.

  5. Determination of formaldehyde in Brazilian alcohol fuels by flow-injection solid phase spectrophotometry

    Teixeira, Leonardo Sena Gomes; Leão, Elsimar S.; Dantas,Alailson Falcão; Pinheiro, Heloísa Lúcia C.; Costa, Antonio Celso Spinola; Andrade,Jailson Bittencourt de


    p. 711–715 In thiswork, a solid phase spectrophotometric method in association with flowinjection analysis for formaldehyde determination has been developed with direct measurement of light-absorption in C18 material. The 3,5-diacetyl-1,4-dihydrolutidine produced from the reaction between formaldehyde and fluoral P was quantitatively retained on C18 support and the spectrophotometric detection was performed simultaneously at 412 nm. The retained complex was quickly eluted from C18 mater...

  6. Solid-Phase Preparation and Characterization of Chitosan

    GaoLe-ping; DuYu-min; ZhangDao-bin; ShiXiao-wen; ZhanHuai-yu; SongWen-hua


    Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carborr13 magnetic resonance sperctroscopy (13C NMR). Chitosan with a deacetylation degree (DD) of 76. 1% was obtained at a mass ratio 0.2 : 1 : 1 for H20/chitin/NaOH at 160℃ for 12 mirL Compared to conventional solution method(usually 1 : 10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,M. 1.54 X 10s ) was lower than that obtained by suspension method(Y2,Mw3. 34×105). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitirL It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13C NMR showed that structures of chitosans prepared by solid-phase method were not changed.

  7. Thermodynamic phase behavior of API/polymer solid dispersions.

    Prudic, Anke; Ji, Yuanhui; Sadowski, Gabriele


    To improve the bioavailability of poorly soluble active pharmaceutical ingredients (APIs), these materials are often integrated into a polymer matrix that acts as a carrier. The resulting mixture is called a solid dispersion. In this work, the phase behaviors of solid dispersions were investigated as a function of the API as well as of the type and molecular weight of the carrier polymer. Specifically, the solubility of artemisinin and indomethacin was measured in different poly(ethylene glycol)s (PEG 400, PEG 6000, and PEG 35000). The measured solubility data and the solubility of sulfonamides in poly(vinylpyrrolidone) (PVP) K10 and PEG 35000 were modeled using the perturbed-chain statistical associating fluid theory (PC-SAFT). The results show that PC-SAFT predictions are in a good accordance with the experimental data, and PC-SAFT can be used to predict the whole phase diagram of an API/polymer solid dispersion as a function of the kind of API and polymer and of the polymer's molecular weight. This remarkably simplifies the screening process for suitable API/polymer combinations.

  8. Novel solidsolid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

    Wojda Marta


    Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.

  9. Solid Phase Peptide Synthesis of Fusukang for AIDS

    甘一如; 戴琦; 张雪竹; 高晨昊


    A 36-residue peptide is designed to cure acquired immunodeficiency syndrome(AIDS), and is synthesized by the manual solid phase peptide synthesis technique. Different reaction conditions of the synthesis process were discussed. Stirring efficiency of mechanics and nitrogen was compared. The mechanical method displays a predominant performance. Although the coupling efficiencies of diisopropylcarbodiimide(DIC) and dicyclohexylcarbodiimide(DCC) are virtually identical, DIC offers several advantages over DCC in practice due to different physical characters. Wash conditions after deprotection and coupling were investigated to monitor washing efficiency. 0.369 2 g crude peptide was obtained.

  10. Solid-phase colorimetric method for the quantification of fucoidan.

    Lee, Jung Min; Shin, Z-U; Mavlonov, Gafurjon T; Abdurakhmonov, Ibrokhim Y; Yi, Tae-Hoo


    We described the simple, selective, and rapid method for determination of fucoidans using methylene blue staining of sulfated polysaccharides, immobilized into filter paper and consequent optic density (at A (663) nm) measurement of the eluted dye from filter paper. This solid-phase method allows selective determination of 1-20 μg fucoidan in presence of potentially interfering compounds (alginic acid, DNA, salts, proteins, and detergents). Further, we demonstrated the alternative way of using image processing software for fucoidan quantification without extraction of methylene blue dye from stained spots of fucoidan-dye complex.


    E.Q. Xie; W.W. Wang; N. Jiang; D.Y. He


    Manganese silicide MnSi2-x thin films have been prepared on n-type silicon substratesthrough solid phase reaction. The heterostructures were analyzed by X-ray diffraction,Rutherford backscattering spectroscopy, Fourier transform infrared transmittance spec-troscopy and the four-point probe technique. The results show that two manganese sili-cides have been formed sequentially via the reaction of thin layer Mn with Si substrateat different irradiation annealing stages, i.e., MnSi at 450℃ and MnSi1.73 at 550℃.MnSi1.73 phase exhibits preferred growth after irradiation with infrared. In situ four-point probe measurements of sheet resistance during infrared irradiation annealingshow that nucleation of MnSi and phase transformation of MnSi to MnSi1. 73 occur at410℃ and 530℃, respectively; the MnSi phase shows metallic behavior, while MnSi1.73exhibits semiconducting behavior. Characteristic phonon bands of MnSi2-x silicides,which can be used for phase identification along with conventional XRD techniques,have been observed by FTIR spectroscopy.


    Ning Yang; Wei Wang; Wei Ge; Jinghai Li


    @@ Introduction Gas-solid two-phase flow is often encountered in chemical reactors for the process industry. For industrial users, design, scale-up, control and optimization for these reactors require a good understanding of the hydrodynamics of gas-solid two-phase flow. For researchers, exploration and prediction of the complex phenomena call for a good comprehension of the heterogeneous structure and of the dominant mechanisms of gas-solid and solid-solid interactions.

  13. The contribution of solid-state chemistry in the determination of multicomponent phase diagrams

    Jean Claude Tedenac; Franck Gascoin; Didier Ravot


    For a long period of time, the determination of phase diagrams was only supported by experiments related to thermal effects or thermodynamic measurements: thermal analysis, calorimetric measurements, vapor pressures, and EMF measurements. As a matter of fact, solid-solid transformations were not so accurately determined and could not be taken into account in the system's analysis. First, X-ray diffraction methods were used as a support for the thermal analysis. Sec ond, the implementation of novel tools in structural analysis (for example, the Rietveld method) has permitted to increase the knowledge of phase stability. Finally, modeling the phases using a Calphad method needed increasingly more structural results to determine and better understand the phase diagrams. On the other hand, the Calphad method has been widely developed for metallic systems, for oxide systems, and in the past 10 years, for some semi-conductor systems, for example,gallium arsenide, cadmium telluride, and lead telluride systems. In such applications, it is very important to bring point defects in the modeling of the phases to map the defects as a function of the chemical composition. Owing to its complexity,this characteristic, the knowledge of which is crucial for the understanding and the control of potential physical applications, was ignored in the previous assessment of semi-conductor systems.

  14. Nucleation of the diamond phase in aluminium-solid solutions

    Hornbogen, E.; Mukhopadhyay, A. K.; Starke, E. A., Jr.


    Precipitation was studied from fcc solid solutions with silicon, germanium, copper and magnesium. Of all these elements only silicon and germanium form diamond cubic (DC) precipitates in fcc Al. Nucleation of the DC structure is enhanced if both types of atom are dissolved in the fcc lattice. This is interpreted as due to atomic size effects in the prenucleation stage. There are two modes of interference of fourth elements with nucleation of the DC phase in Al + Si, Ge. The formation of the DC phase is hardly affected if the atoms (for example, copper) are rejected from the (Si, Ge)-rich clusters. If additional types of atom are attracted by silicon and/or germanium, DC nuclei are replaced by intermetallic compounds (for example Mg2Si).

  15. Powder metallurgy: Solid and liquid phase sintering of copper

    Sheldon, Rex; Weiser, Martin W.


    Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

  16. Solid Phase Characterization of Tank 241-C-108 Residual Waste Solids Samples

    Cooke, Gary A.; Pestovich, John A.; Huber, Heinz J.


    This report presents the results for solid phase characterization (SPC) of solid samples removed from tank 241-C-108 (C-108) on August 12-13,2012, using the off-riser sampler. Samples were received at the 222-S Laboratory on August 13 and were described and photographed. The SPC analyses that were performed include scanning electron microscopy (SEM) using the ASPEX(R)l scanning electron microscope, X-ray diffraction (XRD) using the Rigaku(R) 2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon(R) 3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information. Gary A. Cooke conducted the SEM analysis, John A. Pestovich performed the XRD analysis, and Dr. Heinz J. Huber performed the PLM examination. The results of these analyses are presented here.

  17. The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides

    Woo, Y; Mitchell, A R; Camarero, J A


    Since Merrifield introduced the concept of solid phase synthesis in 1963 for the rapid preparation of peptides, a large variety of different supports and resin-linkers have been developed that improve the efficiency of peptide assembly and expand the myriad of synthetically feasible peptides. The aryl hydrazide is one of the most useful resin-linkers for the synthesis of chemically modified peptides. This linker is completely stable during Boc- and Fmoc-based solid phase synthesis and yet it can be cleaved under very mild oxidative conditions. The present article reviews the use of this valuable linker for the rapid and efficient synthesis of C-terminal modified peptides, head-to-tail cyclic peptides and lipidated peptides.

  18. Application of matrix solid-phase dispersion and high-performance liquid chromatography for determination of sulfonamides in honey.

    Zou, Qiong-Hui; Wang, Jin; Wang, Xiang-Feng; Liu, Yuan; Han, Jie; Hou, Feier; Xie, Meng-Xia


    A novel method for simultaneous determination of 8 sulfonamide residues (sulfathiazole, sulfapyridine, sulfadiazine, sulfamerazine, sulfamonome-thoxine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxine) in honey samples by high-performance liquid chromatography (HPLC) has been developed on the basis of precolumn derivatization with 9-fluorenylmethyl-chloroformate (FMOC-Cl). Sulfonamide residues in honey samples were extracted and purified by matrix solid-phase dispersion with C18 as the solid support. The residues were derivatized by FMOC-CI, and the FMOC-sulfonamide derivatives were further purified by solid-phase extraction with silica gel as the solid support prior to HPLC analysis. The average recoveries for most sulfonamide compounds at different spiking levels (from 10 to 250 microg/kg) were > 70% with relative standard deviations < 16%, and their limits of detection were 4.0 microg/kg. The established analytical method has high sensitivity and repeatability and can be applicable for determining the sulfonamide residues in various honey matrixes.

  19. Hyperdoping silicon with selenium: solid vs. liquid phase epitaxy.

    Zhou, Shengqiang; Liu, Fang; Prucnal, S; Gao, Kun; Khalid, M; Baehtz, C; Posselt, M; Skorupa, W; Helm, M


    Chalcogen-hyperdoped silicon shows potential applications in silicon-based infrared photodetectors and intermediate band solar cells. Due to the low solid solubility limits of chalcogen elements in silicon, these materials were previously realized by femtosecond or nanosecond laser annealing of implanted silicon or bare silicon in certain background gases. The high energy density deposited on the silicon surface leads to a liquid phase and the fast recrystallization velocity allows trapping of chalcogen into the silicon matrix. However, this method encounters the problem of surface segregation. In this paper, we propose a solid phase processing by flash-lamp annealing in the millisecond range, which is in between the conventional rapid thermal annealing and pulsed laser annealing. Flash lamp annealed selenium-implanted silicon shows a substitutional fraction of ~ 70% with an implanted concentration up to 2.3%. The resistivity is lower and the carrier mobility is higher than those of nanosecond pulsed laser annealed samples. Our results show that flash-lamp annealing is superior to laser annealing in preventing surface segregation and in allowing scalability.

  20. Energetics of the Phase Transition in Free-Standing versus Supported Lipid Membranes.

    Mangiarotti, Agustín; Wilke, Natalia


    We compared the thermodynamic behavior of supported and free-standing films of phospholipids with different chain length and showed that the change in free energy for the phase transition to a denser state was greater in free-standing than in supported membranes, with the differences being independent of the chain length. The presence of the support promoted a decrease in the energy gap between the coexisting phases of 1.7 kJ mol(-1), and this was a long-range effect affecting both leaflets, probably related with the impediment of out-of-plane motion of the film by the solid surface.

  1. The role of solid-solid phase transitions in mantle convection

    Faccenda, Manuele; Dal Zilio, Luca


    With changing pressure and temperature conditions, downwelling and upwelling crustal and mantle rocks experience several solid-solid phase transitions that affect the mineral physical properties owing to structural changes in the crystal lattice and to the absorption or release of latent heat. Variations in density, together with phase boundary deflections related to the non-null reaction slope, generate important buoyancy forces that add to those induced by thermal perturbations. These buoyancy forces are proportional to the density contrast between reactant and product phases, their volume fraction, the slope and the sharpness of the reaction, and affect the style of mantle convection depending on the system composition. In a homogeneous pyrolitic mantle there is little tendency for layered convection, with slabs that may stagnate in the transition zone because of the positive buoyancy caused by post-spinel and post-ilmenite reactions, and hot plumes that are accelerated by phase transformations in the 600-800 km depth range. By adding chemical and mineralogical heterogeneities as on Earth, phase transitions introduce bulk rock and volatiles filtering effects that generate a compositional gradient throughout the entire mantle, with levels that are enriched or depleted in one or more of these components. Phase transitions often lead to mechanical softening or hardening that can be related to a different intrinsic mechanical behaviour and volatile solubility of the product phases, the heating or cooling associated with latent heat, and the transient grain size reduction in downwelling cold material. Strong variations in viscosity would enhance layered mantle convection, causing slab stagnation and plume ponding. At low temperatures and relatively dry conditions, reactions are delayed due to the sluggish kinetics, so that non-equilibrium phase aggregates can persist metastably beyond the equilibrium phase boundary. Survival of low-density metastable olivine

  2. Studies of phase transitions in the aripiprazole solid dosage form.

    Łaszcz, Marta; Witkowska, Anna


    Studies of the phase transitions in an active substance contained in a solid dosage form are very complicated but essential, especially if an active substance is classified as a BCS Class IV drug. The purpose of this work was the development of sensitive methods for the detection of the phase transitions in the aripiprazole tablets containing initially its form III. Aripiprazole exhibits polymorphism and pseudopolymorphism. Powder diffraction, Raman spectroscopy and differential scanning calorimetry methods were developed for the detection of the polymorphic transition between forms III and I as well as the phase transition of form III into aripiprazole monohydrate in tablets. The study involved the initial 10 mg and 30 mg tablets, as well as those stored in Al/Al blisters, a triplex blister pack and HDPE bottles (with and without desiccant) under accelerated and long term conditions. The polymorphic transition was not observed in the initial and stored tablets but it was visible on the DSC curve of the Abilify(®) 10 mg reference tablets. The formation of the monohydrate was observed in the diffractograms and Raman spectra in the tablets stored under accelerated conditions. The monohydrate phase was not detected in the tablets stored in the Al/Al blisters under long term conditions. The results showed that the Al/Al blisters can be recommended as the packaging of the aripiprazole tablets containing form III.

  3. Phase transition of solid bismuth under high pressure

    Chen, Hai-Yan; Xiang, Shi-Kai; Yan, Xiao-Zhen; Zheng, Li-Rong; Zhang, Yi; Liu, Sheng-Gang; Bi, Yan


    As a widely used pressure calibrator, the structural phase transitions of bismuth from phase I, to phase II, to phase III, and then to phase V with increasing pressure at 300 K have been widely confirmed. However, there are different structural versions for phase III, most of which are determined by x-ray diffraction (XRD) technology. Using x-ray absorption fine structure (XAFS) measurements combined with ab initio calculations, we show that the proposed incommensurate composite structure of bismuth of the three configurations is the best option. An abnormal continuous increase of the nearest-neighbor distance of phase III with elevated pressure is also observed. The electronic structure transformation from semimetal to metal is responsible for the complex behavior of structure transformation. Project supported by the National Natural Science Foundation of China (Grant Nos. 10904133, 11304294, 11274281, 11404006, and U1230201), the Development Foundation of China Academy of Engineering Physics (Grant Nos. 2015B0101004, 2013B0401062, and 2012A0101001), the Research Foundation of the Laboratory of Shock Wave and Detonation, China (Grant No. 9140C670201140C67282).

  4. Solid-phase staudinger ligation from a novel core-shell-type resin: a tool for facile condensation of small peptide fragments.

    Kim, Hanyoung; Cho, Jin Ku; Aimoto, Saburo; Lee, Yoon-Sik


    [reaction: see text] Solid-phase Staudinger ligation of small peptides was performed on a novel core-shell-type resin. Solid-phase Staudinger ligation was mediated by synthetic solid-supported phosphinothiol, which was readily prepared by a straightforward synthetic route. This protocol afforded final peptide products in excellent yields and purities and thus could provide the opportunity to facilitate a simple manipulation for condensation of peptide fragments. In particular, the resulting resin could be recycled in a successful manner.

  5. Solid-phase synthesis of lidocaine and procainamide analogues using backbone amide linker (BAL) anchoring.

    Shannon, Simon K; Peacock, Mandy J; Kates, Steven A; Barany, George


    New solid-phase strategies have been developed for the synthesis of lidocaine (1) and procainamide (2) analogues, using backbone amide linker (BAL) anchoring. Both sets were prepared starting from a common resin-bound intermediate, followed by four general steps: (i) attachment of a primary aliphatic or aromatic amine to the solid support via reductive amination (as monitored by a novel test involving reaction of 2,4-dinitrophenylhydrazine with residual aldehyde groups); (ii) acylation of the resultant secondary amine; (iii) displacement of halide with an amine; and (iv) trifluoroacetic acid-mediated release from the support. A manual parallel strategy was followed to provide 60 novel compounds, of which two dozen have not been previously described. In most cases, initial crude purities were >80%, and overall isolated yields were in the 40-88% range.

  6. Solid-supported synthesis of cryptand-like macrobicyclic peptides.

    Virta, Pasi; Lönnberg, Harri


    A straightforward method for the solid-supported synthesis of cryptand-like bicyclic peptides (1-5) on a backbone amide linker has been described. For the branching, two novel easily available building blocks, viz. N-(4-methoxytrityl)-N-(2-nitrobenzenesulfonyl)-protected N,N-bis(2-aminoethyl)-beta-alanine (6) and N-(9-fluorenylmethoxycarbonyl) protected iminodiacetic acid monoallyl ester (7), have been employed. The key steps of the synthesis are as follows: (i) stepwise coupling of one amino acid and 6 to the secondary amino group of the linker; (ii) removal of the 2-nitrobenzenesulfonyl group and SPPS by the Fmoc chemistry, using 7 as the penultimate and tert-butoxycarbonyl (Boc) protected glycine as the last amino acid; (iii) removal of the 4-methoxytrityl protection and subsequent SPPS by the Fmoc chemistry; (iv) removal of the allyl and Fmoc groups, followed by cyclization; and (v) removal of the Boc and tert-butyl groups, followed by cyclization. Final cleavage from the support and removal of benzyl-derived protecting groups gives the desired bicyclic products.

  7. Solid state NMR investigation of silica aerogel supported Fischer-Tropsch catalysts

    Ma, Zhiru; Dunn, Brian C.; Turpin, Gregory C.; Eyring, Edward M.; Ernst, Richard D.; Pugmire, Ronald J. [Department of Chemistry, University of Utah, Salt Lake City, UT 84112 (United States)


    The Fischer-Tropsch (F-T) catalyst is the critical component for the F-T synthesis of a variety of hydrocarbons from syngas. Fischer-Tropsch cobalt, iron and ruthenium catalysts supported on silica aerogel have been prepared using a combination of sol-gel chemistry and vapor phase deposition methods. Solid state NMR spectroscopy, a very powerful technique for analyzing the structure and dynamics of various materials, was employed in the study of these F-T catalyst systems. The silica aerogel supported F-T catalysts have been investigated using both solid state {sup 29}Si and {sup 13}C NMR methods. The silica aerogel's tetrahedral sub-unit structure and the influence of the loaded metal compounds have been observed. Three types of Si(O{sub 1/2}){sub 4} tetrahedral unit structure (Q{sub 2}, Q{sub 3} and Q{sub 4}) are clearly resolved in the silica aerogel samples. The calcining process and the loading of metal compounds produce line broadening in the {sup 29}Si spectra sufficient to prevent clear resolution of the three distinct Q{sub n} spectral lines, but the broadened spectra indicate that the three Q sub-unit structures are still present. The ferrocene and ruthenocene molecules used in the vapor phase deposition method exhibit a rapid exchange within the silica aerogel support similar to what one would expect in the gas or liquid state. (author)

  8. Critical Regimes of Two-Phase Flows with a Polydisperse Solid Phase

    Barsky, Eugene


    This book brings to light peculiarities of the formation of critical regimes of two-phase flows with a polydisperse solid phase. A definition of entropy is formulated on the basis of statistical analysis of these peculiarities. The physical meaning of entropy and its correlation with other parameters determining two-phase flows are clearly defined. The interrelations and main differences between this entropy and the thermodynamic one are revealed. The main regularities of two-phase flows both in critical and in other regimes are established using the notion of entropy. This parameter serves as a basis for a deeper insight into the physics of the process and for the development of exhaustive techniques of mass exchange estimation in such flows. The book is intended for graduate and postgraduate students of engineering studying two-phase flows, and to scientists and engineers engaged in specific problems of such fields as chemical technology, mineral dressing, modern ceramics, microelectronics, pharmacology, po...

  9. Phases management for advanced life support processes

    Eckhard, F.; Brunink, J.A.J.; Tuinstra, B.; Assink, J.W.; Ten Asbroek, N.; Backx, V.; Klaassen, A.; Waters, G.; Stasiak, M.A.; Dixon, M.; Ordoñez-Inda, L.


    For a planetary base, a reliable life support system including food and water supply, gas generation and waste management is a condition sine qua non. While for a short-term period the life support system may be an open loop, i.e. water, gases and food provided from the Earth, for long-term missions

  10. Detecting Lesch-Nyhan syndrome by solid phase primer extension

    Shumaker, J.M.; Caskey, C.T. [Baylor College of Medicine, Houston, TX (United States); Metspalu, A.


    A mutation detection method based upon the wild type human HPRT sequence is presented for identification of Lesch Nyhan syndrome. The technique consists of performing a biotinlyated PCR amplification of the region of interest, followed by isolation and purification of single stranded template using magnetic separation. Allele-specific primers are annealed adjacent to the potential mutation site on the template. A terminal fluorescent deoxynucleotide addition is performed with a DNA template-dependent polymerase to distinguish between the mutant and wild-type sequence. The products are purified from unincorporated ddNTPs, eluted and finally analyzed on an ABI 373 to identify the mutation. The length of an extension primer is used as a position signature for mutations. The fidelity of nucleotide incorporation provides an excellent signal-to-noise ratio for the detection of nine HPRT mutations within eight cell lines. This method should detect all types of mutations except for repeated sequences that are longer than the primers. Moreover, the method is being extended to a solid support assay, whereby the extension primers are attached to a two-dimensional glass surface. Following extension, the solid support is analyzed for radioactive incorporation. We have shown the sequence determination of a five base region of a wild-type sequence and two different HPRT mutations. As more dense oligonucleotide arrays are produced, this method could be extended to sequence the complete coding region of HPRT.

  11. Pentaerythrityltetramine scaffolds for solid-phase combinatorial chemistry.

    Virta, Pasi; Leppänen, Marika; Lönnberg, Harri


    Straightforward synthesis for two pentaerythrityltetramine precursors, 2,2-bis(azidomethyl)propane-1,3-diamine (1) and 2-[N-(allyloxycarbonyl)aminomethyl]-2-azidomethylpropane-1,3-diamine (2), has been described. Both propane-1,3-diamines have been attached by reductive amination to a solid-supported backbone amide linker derived from 4-(4-formyl-3,5-dimethoxyphenoxy)butyric acid. The presence of the two methoxy substituents on the linker is essential to avoid cross-linking between two linkers. The remaining free primary amino group of the propane-1,3-diamine moiety may then be selectively acylated with an appropriately protected amino acid using conventional N,N-dicyclohexylcarbodiimide/1-hydroxybenzotriazole (DCC/HOBt) activation without any interference by the secondary amino function. The latter group may be subsequently acylated by an anhydride method. Sequential reduction of the azido group and removal of the allyloxycarbonyl protection from 2 allow further coupling of two different amino acids, and hence, this handle may be utilized in construction of branched structures containing four different amino acids or peptides. Solid-supported 1 may, in turn, be used for the synthesis of similar constructs containing two identical branches. It is worth noting that no acid-labile protecting groups are required in this approach, and hence, this dimension may be saved for the cleavage of the linker. The applicability of the scaffolds to library synthesis has been demonstrated by preparation of 11 pentaerythrityl-branched tetra- and octapeptides.

  12. Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

    Knepper, Kerstin; Vanderheiden, Sylvia


    Summary The synthesis of diverse substituted indole structures on solid supports is described. The immobilization of nitrobenzoic acid onto Merrifield resin and the subsequent treatment with alkenyl Grignard reagents delivered indole carboxylates bound to solid supports. In contrast to results in the liquid phase, ortho,ortho-unsubstituted nitroarenes also delivered indole moieties in good yields. Subsequent palladium-catalyzed reactions (Suzuki, Heck, Sonogashira, Stille) delivered, after cleavage, the desired molecules in moderate to good yields over four steps. The scope and limitations are presented. PMID:23019447

  13. Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

    Kerstin Knepper


    Full Text Available The synthesis of diverse substituted indole structures on solid supports is described. The immobilization of nitrobenzoic acid onto Merrifield resin and the subsequent treatment with alkenyl Grignard reagents delivered indole carboxylates bound to solid supports. In contrast to results in the liquid phase, ortho,ortho-unsubstituted nitroarenes also delivered indole moieties in good yields. Subsequent palladium-catalyzed reactions (Suzuki, Heck, Sonogashira, Stille delivered, after cleavage, the desired molecules in moderate to good yields over four steps. The scope and limitations are presented.

  14. Density functional theory study of phase IV of solid hydrogen

    Pickard, Chris J.; Martinez-Canales, Miguel; Needs, Richard J.


    We have studied solid hydrogen up to pressures of 300 GPa and temperatures of 350 K using density functional theory methods and have found “mixed structures” that are more stable than those predicted earlier. Mixed structures consist of alternate layers of strongly bonded molecules and weakly bonded graphene-like sheets. Quasiharmonic vibrational calculations show that mixed structures are the most stable at room temperature over the pressure range 250-295 GPa. These structures are stabilized with respect to strongly bonded molecular phases at room temperature by the presence of lower frequency vibrational modes arising from the graphene-like sheets. Our results for the mixed structures are consistent with the experimental Raman data [M. I. Eremets and I. A. Troyan, Nat. Mater.1476-112210.1038/nmat3175 10, 927 (2011) and R. T. Howie , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.108.125501 108, 125501 (2012)]. We find that mixed phases are reasonable structural models for phase IV of hydrogen.

  15. Vapour phase synthesis of salol over solid acids via transesterification

    S Z Mohamed Shamshuddin; N Nagaraju


    The transesterification of methyl salicylate with phenol has been studied in vapour phase over solid acid catalysts such as ZrO2, MoO3 and SO$^{2-}_{4}$ or Mo(VI) ions modified zirconia. The catalytic materials were prepared and characterized for their total surface acidity, BET surface area and powder XRD patterns. The effect of mole-ratio of the reactants, catalyst bed temperature, catalyst weight, flowrate of reactants, WHSV and time-on-stream on the conversion (%) of phenol and selectivity (%) of salol has been investigated. A good yield (up to 70%) of salol with 90% selectivity was observed when the reactions were carried out at a catalyst bed temperature of 200°C and flow-rate of 10 mL/h in presence of Mo(VI)/ZrO2 as catalyst. The results have been interpreted based on the variation of acidic properties and powder XRD phases of zirconia on incorporation of SO$^{2-}_{4}$ or Mo(VI) ions. The effect of poisoning of acid sites of SO$^{2-}_{4}$ or Mo(VI) ions modified zirconia on total surface acidity, powder XRD phases and catalytic activity was also studied. Possible reaction mechanisms for the formation of salol and diphenyl ether over acid sites are proposed.

  16. Solid phase epitaxial regrowth of (001) anatase titanium dioxide

    Barlaz, David Eitan; Seebauer, Edmund G., E-mail: [Department of Chemical and Biomolecular Engineering, University of Illinois, 600 S Mathews Ave., Urbana, Illinois 61801 (United States)


    The growing interest in metal oxide based semiconductor technologies has driven the need to produce high quality epitaxial films of one metal oxide upon another. Largely unrecognized in synthetic efforts is that some metal oxides offer strongly polar surfaces and interfaces that require electrostatic stabilization to avoid a physically implausible divergence in the potential. The present work examines these issues for epitaxial growth of anatase TiO{sub 2} on strontium titanate (001). Solid phase epitaxial regrowth yields only the (001) facet, while direct crystalline growth by atomic layer deposition yields both the (112) and (001). The presence of amorphous TiO{sub 2} during regrowth may provide preferential stabilization for formation of the (001) facet.

  17. Nanoscale doping of compound semiconductors by solid phase dopant diffusion

    Ahn, Jaehyun, E-mail:; Koh, Donghyi; Roy, Anupam; Banerjee, Sanjay K., E-mail: [Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Chou, Harry [Materials Science and Engineering Program, University of Texas at Austin, Austin, Texas 78712 (United States); Kim, Taegon [Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Semiconductor R& D Center, Samsung Electronics Corporation, 1 Samsungjeonja-ro, Hwasung, Kyounggi 445-330 (Korea, Republic of); Song, Jonghan [Advanced Analysis Center, Korea Institute of Science and Technology, Cheongryang, P.O. Box 131, Seoul 130-650 (Korea, Republic of)


    Achieving damage-free, uniform, abrupt, ultra-shallow junctions while simultaneously controlling the doping concentration on the nanoscale is an ongoing challenge to the scaling down of electronic device dimensions. Here, we demonstrate a simple method of effectively doping ΙΙΙ-V compound semiconductors, specifically InGaAs, by a solid phase doping source. This method is based on the in-diffusion of oxygen and/or silicon from a deposited non-stoichiometric silicon dioxide (SiO{sub x}) film on InGaAs, which then acts as donors upon activation by annealing. The dopant profile and concentration can be controlled by the deposited film thickness and thermal annealing parameters, giving active carrier concentration of 1.4 × 10{sup 18 }cm{sup −3}. Our results also indicate that conventional silicon based processes must be carefully reviewed for compound semiconductor device fabrication to prevent unintended doping.

  18. A rapid easy—to—perform solid phase digoxin radioimmunoassay

    LiBin; ZhouMei-Ying; 等


    A solid-phase-radioimmunoassay(SPRIA) for the monitoring of blood digoxin level has been developed,in which a secondary antibody-coated polystyrene tubes are used.This noval method seems to be simple to use and only takes about an half hour.The standard curve is linear from 0.25to 4μg/L.The sensitivity of the detection is 0.1μg/L.Reproducibility studies with 3 control sera of 0.5-2.5μg/L give intraassay CV<5% and interassay CV<10%.The specimens are measured and compared with those of the conventional radioimmunoassay and the values are well correlated(r=0.96,Y=1.022X+0.04μg/L)。

  19. Solid-phase synthesis of siRNA oligonucleotides.

    Beaucage, Serge L


    Since the discovery of RNA interference (RNAi) as a means to silence the expression of specific genes, small interfering RNA (siRNA) oligonucleotides have been recognized as powerful tools for targeting therapeutically important mRNAs and eliciting their destruction. This discovery has created a high demand for synthetic oligoribonucleotides as potential therapeutics and has spurred a renaissance in the development of rapid, efficient methods for solid-phase RNA synthesis. The design and implementation of 2'-hydroxyl protecting groups that provide ribonucleoside phosphoramidites with coupling kinetics and coupling efficiencies comparable to those of deoxyribonucleoside phosphoramidites are key to the production of RNA oligonucleotides in sufficient quantity and purity for pharmaceutical applications. In this context, various siRNAs were chemically modified to identify the biophysical and biochemical parameters necessary for effective and stable RNAi-mediated gene-silencing activities.

  20. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes


    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. New methods and materials for solid phase extraction and high performance liquid chromatography

    Dumont, Philip John [Iowa State Univ., Ames, IA (United States)


    This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.

  2. Comparative solution and solid-phase glycosylations toward a disaccharide library

    Agoston, K.; Kröger, Lars; Agoston, Agnes


    A comparative study on solution-phase and solid-phase oligosaccharide synthesis was performed. A 16-member library containing all regioisomers of Glc-Glc, Glc-Gal, Gal-Glc, and Gal-Gal disaccharides was synthesized both in solution and on solid phase. The various reaction conditions for different...

  3. Steady-state diffusion regime in solid-phase micro extraction kinetics

    Benhabib, K.; Laak, ter T.L.; Leeuwen, van H.P.


    The temporal evolution of diffusion-controlled analyte accumulation in solid-phase microextraction (SPME) is critically discussed in terms of the various aspects of steady-state diffusion in the two phases under conditions of fast exchange of the analyte at the solid phase film/water interface. For

  4. Glycosylation efficiencies on different solid supports using a hydrogenolysis-labile linker

    Mayeul Collot


    Full Text Available Automated oligosaccharide assembly requires suitable linkers to connect the first monosaccharide to a solid support. A new hydrogenolysis-labile linker that is stable under both acidic and basic conditions was designed, synthesized and coupled to different resins. Glycosylation and cleavage efficiencies on these functionalized solid supports were investigated, and restrictions for the choice of solid support for oligosaccharide synthesis were found.

  5. Development of novel solid-phase protein formulations

    Montalvo Ortiz, Brenda Liz

    Proteins are the next-generation drugs for the treatment of several diseases. However, the number of protein drugs is still limited due to the physical or chemical instability of proteins during processing, formulation, storage, and delivery. The formulation of proteins at the solid state has advantages over liquid state, such as improved stability during long-term storage and delivery and decreases transportation costs. In this dissertation, we developed new solid-phase protein formulations in which the integrity of the protein was not compromised. The long term goal of this research was to use these protein formulations to improve protein stability in drug delivery devices, such as poly(lactic-co-glycolic) acid (PLGA). The first solid-phase protein formulation developed in this investigation was named "glassification". We proposed glassification as an alternative protein dehydration technique to the common used one, lyophilization, because this last method involves a series of steps which are detrimental to protein structure and stability. The glassification method consisted on protein dehydration by the use of organic solvents. As a result of the glassification process a small (micrometer size range) protein solid bead was obtained. The proteins used to study the glassification process were lysozyme (LYS), alpha-chymotrypsin (CHYMO) and horseradish peroxidase (HRP). These studies revealed that the glassification process itself did not alter protein structure and the activity was preserved. Ethyl acetate was the most effective organic solvent for protein glassification because it led to the highest protein residual activity, no insoluble aggregate formation and is a relatively non-toxic solvent, which allow the incorporation of these protein microparticles in PLGA microspheres. The incorporation of spherical HRP microparticles into PLGA microspheres resulted in superior properties when compared with encapsulated lyophilized HRP powder, such as improved release

  6. Phase diagrams and kinetics of solid-liquid phase transitions in crystalline polymer blends

    Matkar, Rushikesh A.

    A free energy functional has been formulated based on an order parameter approach to describe the competition between liquid-liquid phase separation and solid-liquid phase separation. In the free energy description, the assumption of complete solvent rejection from the crystalline phase that is inherent in the Flory diluent theory was removed as solvent has been found to reside in the crystalline phase in the form of intercalates. Using this approach, we have calculated various phase diagrams in binary blends of crystalline and amorphous polymers that show upper or lower critical solution temperature. Also, the discrepancy in the chi values obtained from different experimental methods reported in the literature for the polymer blend of poly(vinylidenefluoride) and poly(methylmethacrylate) has been discussed in the context of the present model. Experimental phase diagram for the polymer blend of poly(caprolactone) and polystyrene has also been calculated. Of particular importance is that the crystalline phase concentration as a function of temperature has been calculated using free energy minimization methods instead of assuming it to be pure. In the limit of complete immiscibility of the solvent in the crystalline phase, the Flory diluent theory is recovered. The model is extended to binary crystalline blends and the formation of eutectic, peritectic and azeotrope phase diagrams has been explained on the basis of departure from ideal solid solution behavior. Experimental eutectic phase diagram from literature of a binary blend of crystalline polymer poly(caprolactone) and trioxane were recalculated using the aforementioned approach. Furthermore, simulations on the spatio temporal dynamics of crystallization in blends of crystalline and amorphous polymers were carried out using the Ginzburg-Landau approach. These simulations have provided insight into the distribution of the amorphous polymer in the blends during the crystallization process. The simulated results

  7. Solid Phase Formylation of N-Terminus Peptides

    Anna Lucia Tornesello


    Full Text Available Formylation of amino groups is a critical reaction involved in several biological processes including post-translational modification of histones. The addition of a formyl group (CHO to the N-terminal end of a peptide chain generates biologically active molecules. N-formyl-peptides can be produced by different methods. We performed the N-formylation of two chemotactic hexapetides, Met1-Leu2-Lys3-Leu4-Ile5-Val6 and Met1-Met2-Tyr3-Ala4-Leu5-Phe6, carrying out the reaction directly on peptidyl-resin following pre-activation of formic acid with N,N-dicyclohexylcarbodiimmide (DCC in liquid phase. The overnight incubation at 4 °C resulted in a significant increase in production yields of formylated peptides compared to the reaction performed at room temperature. The method is consistently effective, rapid, and inexpensive. Moreover, the synthetic strategy can be applied for the formylation of all primary amines at N-terminus of peptide chains or amino groups of lysine side-chains in solid phase.

  8. Reducing the sulfur-dioxide binding power of sweet white wines by solid-phase extraction.

    Saidane, Dorra; Barbe, Jean-Christophe; Birot, Marc; Deleuze, Hervé


    The high sulfur-dioxide binding power of sweet white wines may be reduced by extracting the naturally present carbonyl compounds from wine that are responsible for carbonyl bisulphites formation. The carbonyl compounds mainly responsible for trapping SO2 are acetaldehyde, pyruvic acid, and 2-oxoglutaric acid. The method employed was selective solid phase extraction, using phenylsulfonylhydrazine as a scavenging agent. The scavenging function was grafted onto a support prepared from raw materials derived from lignin. This approach is more acceptable to winemakers than the polymer media previously reported, as it reduces the possible contamination of wine to molecules already present in the wine making process.

  9. Solid-phase enolate chemistry investigated using HR-MAS NMR spectroscopy.

    Fruchart, Jean-Sébastien; Lippens, Guy; Kuhn, Cyrille; Gras-Masse, Hélène; Melnyk, Oleg


    Supported P4-t-Bu enolate chemistry of phenylacetyloxymethyl polystyrene (PS) resin was investigated using high-resolution magic angle spinning (HR-MAS) NMR spectroscopy. Direct analysis of the crude reaction suspensions through the use of a diffusion filter (DF) allowed a rapid selection of the optimal experimental conditions, but also the characterization of the enolate on the solid phase. Comparison with solution experiments and literature data allowed us to address partially the structure of the enolate. HR-MAS NMR spectra of the enolate revealed also a tight interaction of P4-t-Bu base with the polymer matrix.

  10. Immunochemical cross-reactivity between albumin and solid-phase adsorbed histamine

    Poulsen, L K; Nolte, H; Søndergaard, I


    For production of an antibody against histamine, this was coupled to human serum albumin (HSA) and used for immunization of rabbits. To test the antiserum, an immunoradiometric assay was developed comprising solid-phase bound histamine, antisera and radiolabelled protein A. Titration and inhibition...... experiments revealed that histamine adsorbed onto a solid-phase could bind the antiserum. However, neither free histamine nor histamine coupled to unrelated carriers could inhibit the binding of antiserum to the solid-phase histamine. Cross-reactivity was demonstrated between HSA and solid-phase bound...

  11. Size Dependence of a Temperature-Induced Solid-Solid Phase Transition in Copper(I) Sulfide

    Rivest, Jessy B; Fong, Lam-Kiu; Jain, Prashant K; Toney, Michael F; Alivisatos, A Paul


    Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics.

  12. From Polymer to Small Organic Molecules: A Tight Relationship between Radical Chemistry and Solid-Phase Organic Synthesis

    Danilo Mirizzi


    Full Text Available Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual “in-solution” radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the development of methodologies for the synthesis of small molecules or potential libraries. The aim of this review is to put in perspective radical chemistry, moving it away from its origin as a synthetic means for solid supports, to becoming a useful tool for the synthesis of small molecules.

  13. From polymer to small organic molecules: a tight relationship between radical chemistry and solid-phase organic synthesis.

    Mirizzi, Danilo; Pulici, Maurizio


    Since Gomberg's discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual "in-solution" radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the development of methodologies for the synthesis of small molecules or potential libraries. The aim of this review is to put in perspective radical chemistry, moving it away from its origin as a synthetic means for solid supports, to becoming a useful tool for the synthesis of small molecules.

  14. Solid Phase Synthesis of 2-Substituted 1,3-Oxazin-6-ones Using Resin-bound Cyclic Malonic Acid Ester

    LIU, Zhan-Xiang(刘占祥); RUAN, Xiu-Xiu(阮秀秀); HUANG, Xian(黄宪)


    A facile solid phase synthesis of 2-substituted 1,3-oxazin-6-ones using polymer-supported Meldrum's acid has been reported. Reaction of the resin-bound cyclic malonic acid ester with triethyl orthoformate and subsequent double substitution with amide, afforded the corresponding polymer-supported acylaminomethylene cyclic malonic acid ester, which upon thermal treatment led to 1, 3-oxazin-6-ones in good yields and with high purity.

  15. Vacuum-assisted headspace solid phase microextraction of polycyclic aromatic hydrocarbons in solid samples.

    Yiantzi, Evangelia; Kalogerakis, Nicolas; Psillakis, Elefteria


    For the first time, Vacuum Assisted Headspace Solid Phase Microextraction (Vac-HSSPME) is used for the recovery of polycyclic aromatic hydrocarbons (PAHs) from solid matrices. The procedure was investigated both theoretically and experimentally. According to the theory, reducing the total pressure increases the vapor flux of chemicals at the soil surface, and hence improves HSSPME extraction kinetics. Vac-HSSPME sampling could be further enhanced by adding water as a modifier and creating a slurry mixture. For these soil-water mixtures, reduced pressure conditions may increase the volatilization rates of compounds with a low K(H) present in the aqueous phase of the slurry mixture and result in a faster HSSPME extraction process. Nevertheless, analyte desorption from soil to water may become a rate-limiting step when significant depletion of the aqueous analyte concentration takes place during Vac-HSSPME. Sand samples spiked with PAHs were used as simple solid matrices and the effect of different experimental parameters was investigated (extraction temperature, modifiers and extraction time). Vac-HSSPME sampling of dry spiked sand samples provided the first experimental evidence of the positive combined effect of reduced pressure and temperature on HSSPME. Although adding 2 mL of water as a modifier improved Vac-HSSPME, humidity decreased the amount of naphthalene extracted at equilibrium as well as impaired extraction of all analytes at elevated sampling temperatures. Within short HSSPME sampling times and under mild sampling temperatures, Vac-HSSPME yielded linear calibration curves in the range of 1-400 ng g(-1) and, with the exception of fluorene, regression coefficients were found higher than 0.99. The limits of detection for spiked sand samples ranged from 0.003 to 0.233 ng g(-1) and repeatability from 4.3 to 10 %. Finally, the amount of PAHs extracted from spiked soil samples was smaller compared to spiked sand samples, confirming that soil could bind target

  16. Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

    Reiss, Georg; Frandsen, Henrik Lund; Brandstätter, Wilhelm


    Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X-ray...

  17. Preparation of Pt/C Catalyst with Solid Phase Reaction Method


    The Pt/C catalyst was prepared with solid phase reaction method (Pt/C(S)) for the first time. Its performances were compared with that prepared by the traditional liquid phase reaction method. The results demonstrate that the electrocatalytic activity of Pt/C catalyst with solid phase reaction method for methanol oxidation is higher than that with liquid phase reaction method. XRD and TEM measurements indicate that the Pt/C(S) possesses low crystalline extent and small particle size.

  18. Molecularly imprinted solid phase extraction of fluconazole from pharmaceutical formulations.

    Manzoor, S; Buffon, R; Rossi, A V


    This work encompasses a direct and coherent strategy to synthesise a molecularly imprinted polymer (MIP) capable of extracting fluconazole from its sample. The MIP was successfully prepared from methacrylic acid (functional monomer), ethyleneglycoldimethacrylate (crosslinker) and acetonitrile (porogenic solvent) in the presence of fluconazole as the template molecule through a non-covalent approach. The non-imprinted polymer (NIP) was prepared following the same synthetic scheme, but in the absence of the template. The data obtained from scanning electronic microscopy, infrared spectroscopy, thermogravimetric and nitrogen Brunauer-Emmett-Teller plot helped to elucidate the structural as well as the morphological characteristics of the MIP and NIP. The application of MIP as a sorbent was demonstrated by packing it in solid phase extraction cartridges to extract fluconazole from commercial capsule samples through an offline analytical procedure. The quantification of fluconazole was accomplished through UPLC-MS, which resulted in LOD≤1.63×10(-10) mM. Furthermore, a high percentage recovery of 91±10% (n=9) was obtained. The ability of the MIP for selective recognition of fluconazole was evaluated by comparison with the structural analogues, miconazole, tioconazole and secnidazole, resulting in percentage recoveries of 51, 35 and 32%, respectively.

  19. Microwave heating in solid-phase peptide synthesis.

    Pedersen, Søren L; Tofteng, A Pernille; Malik, Leila; Jensen, Knud J


    The highly refined organic chemistry in solid-phase synthesis has made it the method of choice not only to assemble peptides but also small proteins - mainly on a laboratory scale but increasingly also on an industrial scale. While conductive heating occasionally has been applied to peptide synthesis, precise microwave irradiation to heat the reaction mixture during coupling and N(α)-deprotection has become increasingly popular. It has often provided dramatic reductions in synthesis times, accompanied by an increase in the crude peptide purity. Microwave heating has been proven especially relevant for sequences which might form β-sheet type structures and for sterically difficult couplings. The beneficial effect of microwave heating appears so far to be due to the precise nature of this type of heating, rather than a peptide-specific microwave effect. However, microwave heating as such is not a panacea for all difficulties in peptide syntheses and the conditions may need to be adjusted for the incorporation of Cys, His and Asp in peptides, and for the synthesis of, for example, phosphopeptides, glycopeptides, and N-methylated peptides. Here we provide a comprehensive overview of the advances in microwave heating for peptide synthesis, with a focus on systematic studies and general protocols, as well as important applications. The assembly of β-peptides, peptoids and pseudopeptides are also evaluated in this critical review (254 references).

  20. Ionic liquids in solid-phase microextraction: a review.

    Ho, Tien D; Canestraro, Anthony J; Anderson, Jared L


    Solid-phase microextraction (SPME) has undergone a surge in popularity within the field of analytical chemistry in the past two decades since its introduction. Owing to its nature of extraction, SPME has become widely known as a quick and cost-effective sample preparation technique. Although SPME has demonstrated extraordinary versatility in sampling capabilities, the technique continues to experience a tremendous growth in innovation. Presently, increasing efforts have been directed towards the engineering of novel sorbent material in order to expand the applicability of SPME for a wider range of analytes and matrices. This review highlights the application of ionic liquids (ILs) and polymeric ionic liquids (PILs) as innovative sorbent materials for SPME. Characterized by their unique physico-chemical properties, these compounds can be structurally-designed to selectively extract target analytes based on unique molecular interactions. To examine the advantages of IL and PIL-based sorbent coatings in SPME, the field is reviewed by gathering available experimental data and exploring the sensitivity, linear calibration range, as well as detection limits for a variety of target analytes in the methods that have been developed.

  1. Solid-phase microextraction and the human fecal VOC metabolome.

    Emma Dixon

    Full Text Available The diagnostic potential and health implications of volatile organic compounds (VOCs present in human feces has begun to receive considerable attention. Headspace solid-phase microextraction (SPME has greatly facilitated the isolation and analysis of VOCs from human feces. Pioneering human fecal VOC metabolomic investigations have utilized a single SPME fiber type for analyte extraction and analysis. However, we hypothesized that the multifarious nature of metabolites present in human feces dictates the use of several diverse SPME fiber coatings for more comprehensive metabolomic coverage. We report here an evaluation of eight different commercially available SPME fibers, in combination with both GC-MS and GC-FID, and identify the 50/30 µm CAR-DVB-PDMS, 85 µm CAR-PDMS, 65 µm DVB-PDMS, 7 µm PDMS, and 60 µm PEG SPME fibers as a minimal set of fibers appropriate for human fecal VOC metabolomics, collectively isolating approximately 90% of the total metabolites obtained when using all eight fibers. We also evaluate the effect of extraction duration on metabolite isolation and illustrate that ex vivo enteric microbial fermentation has no effect on metabolite composition during prolonged extractions if the SPME is performed as described herein.

  2. Phase I studies of porfiromycin (NSC--56410) in solid tumors.

    Grage, T B; Weiss, A J; Wilson, W; Reynolds, V


    Porfiromycin was given to a group of patients with a variety of solid tumors. Of 114 patients admitted to the study, 103 yielded evaluable data. The following dosage schedules were used to determine the toxicity of porfiromycin when given in multiple doses by intravenous injection: 0.2 mg/kg x 5 days, 0.3 mg/kg x 5 days, 0.35 mg/kg x 5 days, 0.4 mg/kg x 5 days, 0.24 mg/kg x 10 days and 0.6 mg/kg weekly. Toxic effects noted were mainly leukopenia, thrombocytopenia, and, when injected paravenously, local tissue necrosis. Biological effects were noted at all dosage levels and were more severe at the higher dosages. The data suggest that profiromycin administered intravenously at a dose of 0.35 mg/kg daily for 5 days results in moderate hermatological toxicity and clinical evaluation in a Phase II study at this dosage level is indicated.

  3. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Veronika Mäde


    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  4. Headspace solid-phase microextraction for wine volatile analysis.

    Azzi-Achkouty, Samar; Estephan, Nathalie; Ouaini, Naïm; Rutledge, Douglas N


    The most commonly used technique to prepare samples for the analysis of wine volatile is the headspace solid-phase microextraction (HS-SPME). This method has gained popularity in last few years, as it is a unique solventless preparation technique. In this paper, a summary of recently published studies using HS-SPME for the analysis of wine aromas, with special emphasis on the method developed, has been compiled. Several papers are discussed in detail, mainly with respect to the SPME conditions used. A brief summary of the reviews related to HS-SPME analysis is given and discussed. Several parameters affecting the HS-SPME, such as the salt concentration and the agitation conditions, are used in the same way as used in several papers. The HS-SPME extraction proved to be sufficiently sensitive to satisfy legislative requirements related to low detection and quantification limits as well as method accuracy and precision requirements. However, in order to achieve the best performance and precision, the protocol needs to be optimized for each case. The effect of different parameters must be well characterized to ensure correct extraction and desorption to ensure the transfer of extracted compounds into the analytical system. The operating parameters, such as time, temperature, and agitation, must then be kept constant for all the samples.

  5. DNA display III. Solid-phase organic synthesis on unprotected DNA.

    David R Halpin


    Full Text Available DNA-directed synthesis represents a powerful new tool for molecular discovery. Its ultimate utility, however, hinges upon the diversity of chemical reactions that can be executed in the presence of unprotected DNA. We present a solid-phase reaction format that makes possible the use of standard organic reaction conditions and common reagents to facilitate chemical transformations on unprotected DNA supports. We demonstrate the feasibility of this strategy by comprehensively adapting solid-phase 9-fluorenylmethyoxycarbonyl-based peptide synthesis to be DNA-compatible, and we describe a set of tools for the adaptation of other chemistries. Efficient peptide coupling to DNA was observed for all 33 amino acids tested, and polypeptides as long as 12 amino acids were synthesized on DNA supports. Beyond the direct implications for synthesis of peptide-DNA conjugates, the methods described offer a general strategy for organic synthesis on unprotected DNA. Their employment can facilitate the generation of chemically diverse DNA-encoded molecular populations amenable to in vitro evolution and genetic manipulation.

  6. An acid-stable tert-butyldiarylsilyl (TBDAS) linker for solid-phase organic synthesis.

    Diblasi, Christine M; Macks, Daniel E; Tan, Derek S


    [reaction: see text] A new, robust tert-butyldiarylsilyl (TBDAS) linker has been developed for solid-phase organic synthesis. This linker is stable to both protic and Lewis acidic reaction conditions, overcoming a significant limitation of previously reported silyl linkers. Solid-phase acetal deprotection, olefination, asymmetric allylation, and silyl protecting group deblocking reactions have been demonstrated with TBDAS-linked substrates.

  7. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.


    ... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Liquid, suspended particulate, and solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL...


    A. R. Koohpaei ، S. J. Shahtaheri ، M. R. Ganjali ، A. Rahimi Forushani


    Full Text Available Solid phase extraction is one of the major applications of molecularly imprinted polymers fields for clean-up of environmental and biological samples namely molecularly imprinted solid-phase extraction. In this study, solid phase extraction using the imprinted polymer has been optimized with the experimental design approach for a triazine herbicide, named atrazine with regard to the critical factors which influence the molecular imprinted solid phase extraction efficiency such as sample pH, concentration, flow-rate, volume, elution solvent, washing solvent and sorbent mass. Optimization methods that involve changing one factor at a time can be laborious. A novel approach for the optimization of imprinted solid-phase extraction using chemometrics is described. The factors were evaluated statistically and also validated with spiked water samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Also, in order to the evaluate efficiency of the optimized molecularly imprinted solid-phase extraction protocols, enrichment capacity, reusability and cross-reactivity of cartridges have been also evaluated. Finally, selective molecularly imprinted solid-phase extraction of atrazine was successfully demonstrated with a recovery above 90% for spiked drinking water samples. It was concluded that the chemometrics is frequently employed for analytical method optimization and based on the obtained results, it is believed that the central composite design could prove beneficial for aiding the molecularly imprinted polymer and molecularly imprinted solid-phase extraction development.

  9. Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

    Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.;


    Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formation...

  10. The Iron-Iron Carbide Phase Diagram: A Practical Guide to Some Descriptive Solid State Chemistry.

    Long, Gary J.; Leighly, H. P., Jr.


    Discusses the solid state chemistry of iron and steel in terms of the iron-iron carbide phase diagram. Suggests that this is an excellent way of introducing the phase diagram (equilibrium diagram) to undergraduate students while at the same time introducing the descriptive solid state chemistry of iron and steel. (Author/JN)

  11. Solid-state retrodirective phased array concepts for microwave power transmission from Solar Power Satellite

    Schroeder, K. G.; Petroff, I. K.


    Two prototype solid-state phased array systems concepts for potential use in the Solar Power Satellite are described. In both concepts, the beam is centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed is on-going solid-state amplifier development.

  12. Automated Solid-Phase Radiofluorination Using Polymer-Supported Phosphazenes

    Mathiessen, Bente; Zhuravlev, Fedor


    or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [18F]FLT and [18F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production...... sulfonates (69%) and bromides (42%); the total radiosynthesis time was 35–45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same...

  13. Micropatterning proteins and synthetic peptides on solid supports: a novel application for microelectronics fabrication technology.

    Britland, S; Perez-Arnaud, E; Clark, P; McGinn, B; Connolly, P; Moores, G


    In this paper, we describe a method for immobilizing proteins and synthesizing peptides in micrometer-dimension patterns on solid supports. Microelectronics fabrication technology was adapted and used to lithographically direct the location of immobilization of proteins on appropriately derivatized surfaces. As examples, we micropatterned the protein bovine serum albumin (BSA) and the enzyme horseradish peroxidase (HRP). The catalytic activity of HRP was shown to be retained after being cross-linked to the support. When coupled with solid-phase peptide synthesis, the technique allowed synthetic peptides to be constructed in patterns again having micrometer dimensions. Synthetic polypeptides, polylysine, were constructed in patterns with dimensions that approached the practical limit of resolution for optical lithography at 1-2 microns. The patterns of immobilized molecules and synthetic peptides were visualized using histochemical methods together with light and fluorescence microscopy. The protein and peptide patterning technique described here is an advance in the field of bioelectronics. In particular, it should now be possible to devise novel methods for interfacing with biological systems and constructing new devices for incorporation into miniaturized biosensors.

  14. Local Gas Phase Flow Characteristics of a Gas—Liquid—Solid Three—Phase Reversed Flow Jet Loop Reactor

    WENJianping; ChenYunlin; 等


    The local gas-phase flow characteristics such as local gas holdup (εg), local bubble velocity (Vb) and local bubble mean diameter(db) at a specified point in a gas-liquid-solid three-phase reversed flow jet loop reactor was experimentally investigated by a five-point conductivity probe. The effects of gas jet flow rate, liquid jet flow rate, solid loading, nozzle diameter and axial position on the local εg,Vb and db profiles were discussed. The presence of solids at low solid concentrations not only increased the local εg and Vb, but also decreased the local db. The optimum solid olading for the maximum local εg and Vb together with the minimum local db was 0.16×10-3m3, corresponding to a solid volume fraction,εS=2.5%.

  15. Inhibition of a solid phase reaction among excipients that accelerates drug release from a solid dispersion with aging.

    Mizuno, Masayasu; Hirakura, Yutaka; Yamane, Ikuro; Miyanishi, Hideo; Yokota, Shoji; Hattori, Munetaka; Kajiyama, Atsushi


    Hydrophobic drug substances can be formulated as a solid dispersion or solution using macromolecular matrices with high glass transition temperatures to attain satisfactory dissolution. However, very few marketed products have previously relied on solid dispersion technology due to physical and chemical instability problems, and processing difficulties. In the present study, a modified release product of a therapeutic drug for hypertension, Barnidipine hydrochloride, was developed. The drug product consisted of solid dispersion based on a matrix of carboxymethylethylcellulose (CMEC), which was produced using the spray-coating method. An enteric coat layer was sprayed on the surface of the solid dispersion to control drug release. Interestingly, the release rate accelerated as the drug product aged, while there were no indications of deceleration of the release rate which was due to crystallization of the drug substance. To prevent changes in the dissolution kinetics during storage periods, a variety of processing conditions were tried. It was found that not only use of non-aqueous solvents but also a reduction in coating temperatures consistently resulted in stable solid dispersions. The molecular bases of dissolution of the drug substance from those matrices were investigated. The molecular weight of CMEC was found to be a dominant factor that determined dissolution kinetics, which followed zero-order release, suggesting an involvement of an osmotic pumping mechanism. While dissolution was faster using a higher molecular weight CMEC, the molecular weight of CMEC in the drug product slowly increased with aging (solid phase reaction) depending on the processing conditions, causing the time-induced elevation of dissolution. While no crystalline components were found in the solid dispersion, the amorphous structure maintained a degree of non-equilibrium by nature. Plasticization by water in the coating solution relaxed the amorphous system and facilitated phase

  16. Novel materials and methods for solid-phase extraction and liquid chromatography

    Ambrose, Diana [Iowa State Univ., Ames, IA (United States)


    This report contains a general introduction which discusses solid-phase extraction and solid-phase micro-extraction as sample preparation techniques for high-performance liquid chromatography, which is also evaluated in the study. This report also contains the Conclusions section. Four sections have been removed and processed separately: silicalite as a sorbent for solid-phase extraction; a new, high-capacity carboxylic acid functionalized resin for solid-phase extraction; semi-micro solid-phase extraction of organic compounds from aqueous and biological samples; and the high-performance liquid chromatographic determination of drugs and metabolites in human serum and urine using direct injection and a unique molecular sieve.

  17. Lanthanide-Mediated Dephosphorylation Used for Peptide Cleavage during Solid Phase Peptide Synthesis

    Byunghee Yoo


    Full Text Available Lanthanide(III ions can accelerate the hydrolysis of phosphomonoesters and phosphodiesters in neutral aqueous solution. In this paper, lanthanide-mediated dephosphorylation has been applied in aqueous media as an orthogonal cleavage condition that can be employed in conventional solid phase peptide synthesis (SPPS. A phosphorylated polymeric support for SPPS was developed using Boc chemistry. The cleavage of resin-bound phosphates was investigated with the addition of Eu(III, Yb(III, acid or base, a mixture of solvents or different temperatures. To demonstrate the utility of this approach for SPPS, a peptide sequence was synthesized on a phosphorylated polymeric support and quantitatively cleaved with lanthanide ions in neutral aqueous media. The protecting groups for side chains were retained during peptide cleavage using lanthanide ions. This new methodology provides a mild orthogonal cleavage condition of phosphoester as a linker during SPPS.

  18. Pressure Effects on Solid State Phase Transformation of Aluminium Bronze in Cooling Process

    WANG Hai-Yan; CHEN Yan; LIU Yu-Wen; LI Fei; LIU Jian-Hua; PENG Gui-Rong; WANG Wen-Kui


    Effects of high pressure (6 GPa) on the solid state phase transformation kinetic parameters of aluminum bronze during the cooling process are investigated, based on the measurement and calculation of its solid state phase transformation temperature, duration and activation energy and the observation of its microstructures. The results show that high pressure treatment can reduce the solid phase transformation temperature and activation energy in the cooling process and can shorten the phase transformation duration, which is favorable when forming fine-grained aluminum bronze.

  19. Operating System Support for High-Performance Solid State Drives

    Bjørling, Matias

    The performance of Solid State Drives (SSD) has evolved from hundreds to millions of I/Os per second in the past three years. Such a radical evolution is transforming both the storage and the software industries. Indeed, software designed based on the assumption of slow IOs has become...

  20. The importance of screening solid-state phases of a racemic modification of a chiral drug: thermodynamic and structural characterization of solid-state phases of etiracetam.

    Herman, Christelle; Vermylen, Valérie; Norberg, Bernadette; Wouters, Johan; Leyssens, Tom


    In this contribution different solid-state forms of the racemic compound (RS)-2-(2-oxo-pyrrolidin-1yl)-butyramide are studied from a structural and thermal point of view. Three different solid-state phases were identified, including two polymorphs and one hydrate phase. Comparison is made with the structure of the (S)-enantiomer, for which only one solid-state phase is known. The basic structural motif found in both polymorphs of the racemic compound is similar, but the basic motif observed for the hydrate differs. These synthons could in principle be used in future polymorph prediction studies to screen for possible alternative forms of the enantiopure compound. Based on the structure of the hydrate, further efforts should therefore be made in order to identify a hydrate structure of the enantiopure compound. Studying the different phases of a racemic compound can therefore help to guide polymorphic screening of an enantiopure compound.

  1. Solid and liquid phase equilibria and solid-hydrate formation in binary mixtures of water with amines

    车冠全; 彭文烈; 黄良恩; 古喜兰; 车飙


    Solid and liquid phase diagrams have been constructed for {water+triethylamine,or+N,N-dimethylformamide(DMF) or+N,N-dimethlacetamide (DMA)} Solid-hydrates form with the empirical formulae N(C2H5)3 3H2O,DMF 3H2O,DMF 2H2O,DMA 3H2O and (DMA)2 3H2O.All are congruently melting except the first which melts incongruently.The solid-hydrate formation is attributed to hydrogen bond.The results are compared with the references

  2. Solid phase epitaxial regrowth of (100)GaAs

    Almonte, Marlene Isabel [California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering


    This thesis showed that low temperature (250°C) SPE of stoichiometrically balanced ion implanted GaAs layers can yield good epitaxial recovery for doses near the amorphization threshold. For 250°C anneals, most of the regrowth occurred in the first 10 min. HRTEM revealed much lower stacking fault density in the co-implanted sample than in the As-only and Ga-only samples with comparable doses. After low temp annealing, the nonstoichiometric samples had a large number of residual defects. For higher dose implants, very high temperatures (700°C) were needed to remove residual defects for all samples. The stoichiometrically balanced layer did not regrow better than the Ga-only and As-only samples. The co-implanted sample exhibited a thinner amorphous layer and a room temperature (RT) annealing effect. The amorphous layer regrew about 5 nm, suggesting that stoichiometrically balanced amorphous layers can regrow even at RT. Mechanisms for solid phase crystallization in (100)GasAs is discussed: nucleation and growth of randomly oriented crystallites and SPE. These two mechanisms compete in compound semiconductors at much lower temperatures than in Si. For the low dose As-only and Ga-only samples with low-temp anneals, both mechanisms are active. For this amorphization threshold dose, crystallites remain in the amorphous layer for all as-implants. 250°C annealing showed recrystallization from the surface and bulk for these samples; for the co-implant, the mechanism is not evident.

  3. Application of solid phase microextraction on dental composite resin analysis.

    Wang, Ven-Shing; Chang, Ta-Yuan; Lai, Chien-Chen; Chen, San-Yue; Huang, Long-Chen; Chao, Keh-Ping


    A direct immersion solid phase microextraction (DI-SPME) method was developed for the analysis of dentin monomers in saliva. Dentine monomers, such as triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA) and 2,2-bis-[4-(2-hydroxy-3-methacryloyloxypropoxy) phenyl]-propane (Bis-GMA), have a high molecular weight and a low vapor pressure. The polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber with a medium polarity was employed for DI-SPME, and 215 nm of detection wavelength was found to be optimum in the chromatogram of HPLC measurement. The calibration range for DI-SPME was 0.30-300 μg/mL with correlation coefficients (r) greater than 0.998 for each analyte. The DI-SPME method achieved good accuracy (recovery 96.1-101.2%) and precision (2.30-8.15% CV) for both intra- and inter-day assays of quality control samples for three target compounds. Method validation was performed on standards dissolved in blank saliva, and there was no significant difference (p>0.2) between the DI-SPME method and the liquid injection method. However, the detection limit of DI-SPME was as low as 0.03, 0.27 and 0.06 μg/mL for TEGDMA, UDMA and Bis-GMA, respectively. Real sample analyses were performed on commercial dentin products after curing for the leaching measurement. In summary, DI-SPME is a more sensitive method that requires less sample pretreatment procedures to measure the resin materials leached in saliva.

  4. Ultrarapid mutation detection by multiplex, solid-phase chemical cleavage

    Rowley, G.; Saad, S.; Giannelli, F.; Green, P.M. [Guy`s & St. Thomas`s Hospitals, London (United Kingdom)


    The chemical cleavage of mismatches in heteroduplexes formed by probe and test DNA detects and locates any sequence change in long DNA segments ({approximately}1.8 kb), and its efficiency has been well tested in the analysis of both average (e.g., coagulation factor IX) and large, complex genes (e.g., coagulation factor VIII and dystrophin). In the latter application RT/PCR products allow the examination of all essential sequences of the gene in a minimum number of reactions. We use two specific chemical reactants (hydroxylamine and osmium tetroxide) and piperidine cleavage of the above procedure to develop a very fast mutation screening method. This is based on: (1) 5{prime} or internal fluorescent labeling to allow concurrent screening of three to four DNA fragments and (2) solid-phase chemistry to use a microliter format and reduce the time required for the procedure, from amplification of sequence to gel loading inclusive, to one person-working-day. We test the two variations of the method, one entailing 5{prime} labeling of probe DNA and the other uniform labeling of both probe and target DNA, by detecting 114 known hemophilia B (coagulation factor IX) mutations and by analyzing 129 new patients. Uniform labeling of both probe and target DNA prior to formation of the heteroduplexes leads to almost twofold redundancy in the ability to detect mutations. Alternatively, the latter procedure may offer very efficient though less than 100% screening for sequence changes with only hydroxylamine. The full method with two chemical reactions (hydroxylamine and osmium tetroxide) should allow one person to screen with virtually 100% accuracy more than 300 kb of sequence in three ABI 373 gels in 1 day. 26 refs., 7 figs., 1 tab.

  5. Porous, High Capacity Coatings for Solid Phase Microextraction by Sputtering.

    Diwan, Anubhav; Singh, Bhupinder; Roychowdhury, Tuhin; Yan, DanDan; Tedone, Laura; Nesterenko, Pavel N; Paull, Brett; Sevy, Eric T; Shellie, Robert A; Kaykhaii, Massoud; Linford, Matthew R


    We describe a new process for preparing porous solid phase microextraction (SPME) coatings by the sputtering of silicon onto silica fibers. The microstructure of these coatings is a function of the substrate geometry and mean free path of the silicon atoms, and the coating thickness is controlled by the sputtering time. Sputtered silicon structures on silica fibers were treated with piranha solution (a mixture of concd H2SO4 and 30% H2O2) to increase the concentration of silanol groups on their surfaces, and the nanostructures were silanized with octadecyldimethylmethoxysilane in the gas phase. The attachment of this hydrophobic ligand was confirmed by X-ray photoelectron spectroscopy and contact angle goniometry on model, planar silicon substrates. Sputtered silicon coatings adhered strongly to their surfaces, as they were able to pass the Scotch tape adhesion test. The extraction time and temperature for headspace extraction of mixtures of alkanes and alcohols on the sputtered fibers were optimized (5 min and 40 °C), and the extraction performances of SPME fibers with 1.0 or 2.0 μm of sputtered silicon were compared to those from a commercial 7 μm poly(dimethylsiloxane) (PDMS) fiber. For mixtures of alcohols, aldehydes, amines, and esters, the 2.0 μm sputtered silicon fiber yielded signals that were 3-9, 3-5, 2.5-4.5, and 1.5-2 times higher, respectively, than those of the commercial fiber. For the heavier alkanes (undecane-hexadecane), the 2.0 μm sputtered fiber yielded signals that were approximately 1.0-1.5 times higher than the commercial fiber. The sputtered fibers extracted low molecular weight analytes that were not detectable with the commercial fiber. The selectivity of the sputtered fibers appears to favor analytes that have both a hydrophobic component and hydrogen-bonding capabilities. No detectable carryover between runs was noted for the sputtered fibers. The repeatability (RSD%) for a fiber (n = 3) was less than 10% for all analytes tested

  6. Solid rocket motor fire tests: Phases 1 and 2

    Chang, Yale; Hunter, Lawrence W.; Han, David K.; Thomas, Michael E.; Cain, Russell P.; Lennon, Andrew M.


    JHU/APL conducted a series of open-air burns of small blocks (3 to 10 kg) of solid rocket motor (SRM) propellant at the Thiokol Elkton MD facility to elucidate the thermal environment under burning propellant. The propellant was TP-H-3340A for the STAR 48 motor, with a weight ratio of 71/18/11 for the ammonium perchlorate, aluminum, and HTPB binder. Combustion inhibitor applied on the blocks allowed burning on the bottom and/or sides only. Burns were conducted on sand and concrete to simulate near-launch pad surfaces, and on graphite to simulate a low-recession surface. Unique test fixturing allowed propellant self-levitation while constraining lateral motion. Optics instrumentation consisted of a longwave infrared imaging pyrometer, a midwave spectroradiometer, and a UV/visible spectroradiometer. In-situ instrumentation consisted of rod calorimeters, Gardon gauges, elevated thermocouples, flush thermocouples, a two-color pyrometer, and Knudsen cells. Witness materials consisted of yttria, ceria, alumina, tungsten, iridium, and platinum/rhodium. Objectives of the tests were to determine propellant burn characteristics such as burn rate and self-levitation, to determine heat fluxes and temperatures, and to carry out materials analyses. A summary of qualitative results: alumina coated almost all surfaces, the concrete spalled, sand moisture content matters, the propellant self-levitated, the test fixtures worked as designed, and bottom-burning propellant does not self-extinguish. A summary of quantitative results: burn rate averaged 1.15 mm/s, thermocouples peaked at 2070 C, pyrometer readings matched MWIR data at about 2400 C, the volume-averaged plume temperatures were 2300-2400 C with peaks of 2400-2600 C, and the heat fluxes peaked at 125 W/cm2. These results are higher than other researchers' measurements of top-burning propellant in chimneys, and will be used, along with Phase 3 test results, to analyze hardware response to these environments, including General

  7. Oxidative homocoupling of alkynes using supported ionic liquid phase (SILP) catalysts--systematic investigation of the support influence.

    Szesni, Normen; Kaiser, Melanie; Putzien, Sophie; Fischer, Richard W


    Supported Ionic Liquid Phase (SILP) catalysts have been prepared by effective immobilization of [Cu(TMEDA)(OH)]Cl in a nano-metric film of an ionic liquid on various oxidic support materials. The catalysts were tested for the oxidative homocoupling of 1-alkynes to the corresponding diynes in in a combined high throughput and conventional batch reaction approach. Among the screened support materials silica based materials performed best. The results indicate that for the specific reaction the thickness of the ionic liquids layer and therefore the mobility of the homogeneous copper complex within the ionic liquid layer as deduced from solid state nmr measurements have major impact on the catalytic performance. The optimized catalysts could be recycled up to four times without any loss of activity.

  8. Revealing protein structures in solid-phase peptide synthesis by 13C solid-state NMR: evidence of excessive misfolding for Alzheimer's β.

    Wang, Songlin; Ishii, Yoshitaka


    Solid-phase peptide synthesis (SPPS) is a widely used technique in biology and chemistry. However, the synthesis yield in SPPS often drops drastically for longer amino acid sequences, presumably because of the occurrence of incomplete coupling reactions. The underlying cause for this problem is hypothesized to be a sequence-dependent propensity to form secondary structures through protein aggregation. However, few methods are available to study the site-specific structure of proteins or long peptides that are anchored to the solid support used in SPPS. This study presents a novel solid-state NMR (SSNMR) approach to examine protein structure in the course of SPPS. As a useful benchmark, we describe the site-specific SSNMR structural characterization of the 40-residue Alzheimer's β-amyloid (Aβ) peptide during SPPS. Our 2D (13)C/(13)C correlation SSNMR data on Aβ(1-40) bound to a resin support demonstrated that Aβ underwent excessive misfolding into a highly ordered β-strand structure across the entire amino acid sequence during SPPS. This approach is likely to be applicable to a wide range of peptides/proteins bound to the solid support that are synthesized through SPPS.

  9. Proposed method for controlling turbid particles in solid-phase bioluminescent toxicity measurement.

    Yeo, Seul-Ki; Park, Jun-Boum; Ahn, Joo-Sung; Han, Young-Soo


    In the recent half century, numerous methods have been developed to assess ecological toxicity. However, the presence of solid-particle turbidity sometimes causes such tests to end with questionable results. Many researchers focused on controlling this arbitrary turbidity effect when using the Microtox® solid-phase toxicity system, but there is not yet a standard method. In this study, we examined four solid-phase sample test methods recommended in the Microtox® manual, or proposed from the literature, and compared the existing methods with our proposed method (centrifuged basic solid-phase test, c-BSPT). Four existing methods use the following strategies to control turbid particles: complete separation of liquid and solid using 0.45-μm filtration before contacting solid samples and bacteria, natural settlement, moderate separation of large particles using coarser pore size filtration, and exclusion of light loss in the toxicity calculation caused by turbidity after full disturbance of samples. Our proposed method uses moderate centrifugation to separate out the heavier soil particles from the lighter bacteria after direct contact between them. Among the solid-phase methods tested, in which the bacteria and solid particles were in direct contact (i.e., the three existing methods and the newly proposed one, c-BSPT), no single method could be recommended as optimal for samples over a range of turbidity. Instead, a simple screening strategy for selecting a sample-dependent solid-phase test method was suggested, depending on the turbidity of the solid suspension. The results of this study highlight the importance of considering solid particles, and the necessity for optimal selection of test method to reduce errors in the measurement of solid-phase toxicity.

  10. Microwave spectroscopic observation of distinct electron solid phases in wide quantum wells.

    Hatke, A T; Liu, Yang; Magill, B A; Moon, B H; Engel, L W; Shayegan, M; Pfeiffer, L N; West, K W; Baldwin, K W


    In high magnetic fields, two-dimensional electron systems can form a number of phases in which interelectron repulsion plays the central role, since the kinetic energy is frozen out by Landau quantization. These phases include the well-known liquids of the fractional quantum Hall effect, as well as solid phases with broken spatial symmetry and crystalline order. Solids can occur at the low Landau-filling termination of the fractional quantum Hall effect series but also within integer quantum Hall effects. Here we present microwave spectroscopy studies of wide quantum wells that clearly reveal two distinct solid phases, hidden within what in d.c. transport would be the zero diagonal conductivity of an integer quantum-Hall-effect state. Explanation of these solids is not possible with the simple picture of a Wigner solid of ordinary (quasi) electrons or holes.

  11. Gallium-rich Pd-Ga phases as supported liquid metal catalysts

    Taccardi, N.; Grabau, M.; Debuschewitz, J.; Distaso, M.; Brandl, M.; Hock, R.; Maier, F.; Papp, C.; Erhard, J.; Neiss, C.; Peukert, W.; Görling, A.; Steinrück, H.-P.; Wasserscheid, P.


    A strategy to develop improved catalysts is to create systems that merge the advantages of heterogeneous and molecular catalysis. One such system involves supported liquid-phase catalysts, which feature a molecularly defined, catalytically active liquid film/droplet layer adsorbed on a porous solid support. In the past decade, this concept has also been extended to supported ionic liquid-phase catalysts. Here we develop this idea further and describe supported catalytically active liquid metal solutions (SCALMS). We report a liquid mixture of gallium and palladium deposited on porous glass that forms an active catalyst for alkane dehydrogenation that is resistant to coke formation and is thus highly stable. X-ray diffraction and X-ray photoelectron spectroscopy, supported by theoretical calculations, confirm the liquid state of the catalytic phase under the reaction conditions. Unlike traditional heterogeneous catalysts, the supported liquid metal reported here is highly dynamic and catalysis does not proceed at the surface of the metal nanoparticles, but presumably at homogeneously distributed metal atoms at the surface of a liquid metallic phase.

  12. Superfluid--Solid Quantum Phase Transitions and Landau-Ginzburg-Wilson Paradigm

    Kuklov, A. B.; Prokof'ev, N. V.


    We study superfluid (SF)--solid zero-temperature transitions in 2d lattice boson/spin models by Worm-Algorithm Monte Carlo simulations. The SF -- Valence Bond Solid (VBS) transition was recently argued to be generically of II order in violation of the Ginzburg-Landau- Wilson (GLW) paradigm [1]. We simulate the J-current model on lattices up to 64x64x64, and observe that SF- columnar VBS and SF-checkerboard solid transitions are typically weak I-order ones and in small systems they may be confused with the continuous or high-symmetry points [2]. Thus, in the simulated model, the SF-VBS transition proceeds in agreement with the GLW paradigm. We explain this by dominance of standard particle and hole excitations, as opposed to fractionalized (spinon) excitations [1]. We developed a technique based on tunneling events (instantons) in the insulating phase which reveals charges of the revelant long-wave modes. While in 1d systems spinons are clearly seen in tunneling events, in two spatial dimensions tunneling is solely controlled by particles and holes in our system. This work is supported by NSF grant ITR-405460001 and PSC-CUNY- 665560035. [1] T. Senthil, A. Vishwanath, L. Balents, S. Sachdev, and M.P.A. Fisher, Science 303, 1490 (2004); [2] A.B. Kuklov, N.V. Prokof'ev, B.V. Svistunov, condmat/0406061; PRL, to be published.

  13. Phase interface effects in the total enthalpy-based lattice Boltzmann model for solid-liquid phase change

    Huang, Rongzong; Wu, Huiying


    In this paper, phase interface effects, including the differences in thermophysical properties between solid and liquid phases and the numerical diffusion across phase interface, are investigated for the recently developed total enthalpy-based lattice Boltzmann model for solid-liquid phase change, which has high computational efficiency by avoiding iteration procedure and linear equation system solving. For the differences in thermophysical properties (thermal conductivity and specific heat) between solid and liquid phases, a novel reference specific heat is introduced to improve the total enthalpy-based lattice Boltzmann model, which makes the thermal conductivity and specific heat decoupled. Therefore, the differences in thermal conductivity and specific heat can be handled by the dimensionless relaxation time and equilibrium distribution function, respectively. As for the numerical diffusion across phase interface, it is revealed for the first time and found to be induced by solid-liquid phase change. To reduce such numerical diffusion, multiple-relaxation-time collision scheme is exploited, and a special value (one fourth) for the so-called "magic" parameter, a combination of two relaxation parameters, is found. Numerical tests show that the differences in thermophysical properties can be correctly handled and the numerical diffusion across phase interface can be dramatically reduced. Finally, theoretical analyses are carried out to offer insights into the roles of the reference specific heat and "magic" parameter in the treatments of phase interface effects.

  14. Solid phase extraction and determination of carbamate pesticides in water samples by reverse-phase HPLC

    Moreno-Tovar, J.; Santos-Delgado, M.J. [Departamento de Quimica Analitica, Facultad de ciencias Quimicas, Universidad Complutense de Madrid (Spain)


    Solid phase extraction. SPE. using C{sub 1}8 bonded silica cartridges for trace amounts determination of carbaryl, propoxur, thiram, propham and methiocarb in water samples was studied and the breakthrough volume of the cartridges was established. The high enrichment factor and large injection volume admissible in the isocratic reverse-phase HPLC system allows pesticides determination with UV detection at 22o nm even at a concentration lower than 0.05 mug/L. Purified tap natural and underground water samples were spiked with carbamate pesticides in the concentration range 0.16-16.0 mug/L. Large volumes of samples (up to 2L) were passed through available C{sub 1}8, cartridges and eluted with acetonitrile. The preconcentrated samples were analyzed by HPLC using a Spherisorb ODS column with a 42.58 acetonitrile-water mobile phase. From replicate samples, recovery for the pesticides ranged from 79.0 to 103.7% except for thiran which is not retained. Tehe relative standard deviation (n=4 at 0.16 to 1.61 mug/L concetration level) range from 1.1 to 6.8%. (Author) 14 refs.

  15. Shortcut access to peptidosteroid conjugates: building blocks for solid-phase bile acid scaffold decoration by convergent ligation.

    Verzele, Dieter; Figaroli, Sara; Madder, Annemieke


    We present three versatile solid-supported scaffold building blocks based on the (deoxy)cholic acid framework and decorated with handles for further derivatization by modern ligation techniques such as click chemistry, Staudinger ligation or native chemical ligation. Straightforward procedures are presented for the synthesis and analysis of the steroid constructs. These building blocks offer a new, facile and shorter access route to bile acid-peptide conjugates on solid-phase with emphasis on heterodipodal conjugates with defined spatial arrangements. As such, we provide versatile new synthons to the toolbox for bile acid decoration.

  16. Shortcut Access to Peptidosteroid Conjugates: Building Blocks for Solid-Phase Bile Acid Scaffold Decoration by Convergent Ligation

    Sara Figaroli


    Full Text Available We present three versatile solid-supported scaffold building blocks based on the (deoxycholic acid framework and decorated with handles for further derivatization by modern ligation techniques such as click chemistry, Staudinger ligation or native chemical ligation. Straightforward procedures are presented for the synthesis and analysis of the steroid constructs. These building blocks offer a new, facile and shorter access route to bile acid-peptide conjugates on solid-phase with emphasis on heterodipodal conjugates with defined spatial arrangements. As such, we provide versatile new synthons to the toolbox for bile acid decoration.

  17. Kinetic study of solid phase crystallisation of expanding thermal plasma deposited a-Si:H

    Law, F., E-mail: [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Hoex, B. [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Wang, J. [Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Luther, J. [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Sharma, K.; Creatore, M.; Van de Sanden, M.C.M. [Department of Applied Physics, Eindhoven University of Technology, Eindhoven (Netherlands)


    In-situ X-ray diffraction was used to study the dynamics of the solid phase crystallisation (SPC) of hydrogenated amorphous silicon (a-Si:H) films deposited by expanding thermal plasma technique. The Johnson-Mehl-Avrami-Kolmogorov model was used for the analysis of the dynamic data and the activation energy associated with the SPC process was 2.9 eV, which was lower than a-Si:H films deposited by other techniques. Relationships between the Avrami exponent n, the SPC process stability and the subsequent grain structure were demonstrated. Under certain conditions, the films exhibited columnar grain structure with indications of good grain quality, suggesting that these films are suitable to be further developed into solar cell devices. Structure of the grains and the SPC dynamics in this work lend support to prior work that vacancies decorated by hydrogen clusters are related to nucleation sites. - Highlights: Black-Right-Pointing-Pointer The crystallisation of expanding thermal plasma (ETP) deposited a-Si:H was studied. Black-Right-Pointing-Pointer Johnson-Mehl-Avrami-Kolmogorov model was used to model the crystallisation process. Black-Right-Pointing-Pointer Activation energy of the solid phase crystallisation process was 2.9 eV. Black-Right-Pointing-Pointer Vacancies decorated by hydrogen clusters are suggested nucleation sites. Black-Right-Pointing-Pointer ETP is promising in the fabrication process of pc-Si thin film solar cells.

  18. Optimized Solid Phase-Assisted Synthesis of Dendrons Applicable as Scaffolds for Radiolabeled Bioactive Multivalent Compounds Intended for Molecular Imaging

    Gabriel Fischer


    Full Text Available Dendritic structures, being highly homogeneous and symmetric, represent ideal scaffolds for the multimerization of bioactive molecules and thus enable the synthesis of compounds of high valency which are e.g., applicable in radiolabeled form as multivalent radiotracers for in vivo imaging. As the commonly applied solution phase synthesis of dendritic scaffolds is cumbersome and time-consuming, a synthesis strategy was developed that allows for the efficient assembly of acid amide bond-based highly modular dendrons on solid support via standard Fmoc solid phase peptide synthesis protocols. The obtained dendritic structures comprised up to 16 maleimide functionalities and were derivatized on solid support with the chelating agent DOTA. The functionalized dendrons furthermore could be efficiently reacted with structurally variable model thiol-bearing bioactive molecules via click chemistry and finally radiolabeled with 68Ga. Thus, this solid phase-assisted dendron synthesis approach enables the fast and straightforward assembly of bioactive multivalent constructs for example applicable as radiotracers for in vivo imaging with Positron Emission Tomography (PET.

  19. Characterization of interactions between soil solid phase and soil solution in the initial ecosystem development phase

    Zimmermann, Claudia; Schaaf, Wolfgang


    In the initial phase of soil formation interactions between solid and liquid phases and processes like mineral weathering, formation of reactive surfaces and accumulation of organic matter play a decisive role in developing soil properties. As part of the Transregional Collaborative Research Centre (SFB/TRR 38) 'Patterns and processes of initial ecosystem development' in an artificial catchment, these interactions are studied at the catchment 'Chicken Creek' (Gerwin et al. 2009). To link the interactions between soil solid phase and soil solution at the micro-scale with observed processes at the catchment scale, microcosm experiments under controlled laboratory conditions were carried out. Main objectives were to determine the transformation processes of C and N from litter decomposition within the gaseous, liquid and solid phase, the interaction with mineral surfaces and its role for the establishment of biogeochemical cycles. The microcosm experiments were established in a climate chamber at constant 10 ° C. In total 48 soil columns (diameter: 14.4 cm; height: 30 cm) were filled with two different quaternary substrates (sand and loamy sand) representing the textural variation within the catchment at a bulk density of 1.4-1.5 g*cm-3. The columns were automatically irrigated four times a day with 6.6 ml each (corresponding to 600 mm*yr-1). The gaseous phase in the headspace of the microcosms was analysed continuously for CO2 and N2O contents. C and N transformation processes were studied using 13C and 15N labelled litter of two different plant species occurring at the catchment (Lotus corniculatus, Calamagrostis epigejos) that was incorporated into the microcosm surface. All treatments including a control ran with four replicates over a period of 40 weeks. Two additional microcosms act as pure litter controls where substrate was replaced by glass pearls. Litter and substrate were analysed before and after the experiment. Percolate was continuously collected and

  20. The growth and tensile deformation behavior of the silver solid solution phase with zinc

    Wu, Jiaqi, E-mail: [Department of Electrical Engineering and Computer Science, University of California, Irvine, CA 92697-2660 (United States); Materials and Manufacturing Technology, University of California, Irvine, CA 92697-2660 (United States); Lee, Chin C. [Department of Electrical Engineering and Computer Science, University of California, Irvine, CA 92697-2660 (United States); Materials and Manufacturing Technology, University of California, Irvine, CA 92697-2660 (United States)


    The growth of homogeneous silver solid solution phase with zinc are conducted at two different compositions. X-ray diffraction (XRD) and Scanning electron microscope/Energy dispersive X-ray spectroscopy (SEM/EDX) are carried out for phase identification and chemical composition verification. The mechanical properties of silver solid solution phase with zinc are evaluated by tensile test. The engineering and true stress vs. strain curves are presented and analyzed, with those of pure silver in comparison. According to the experimental results, silver solid solution phase with zinc at both compositions show tempered yield strength, high tensile strength and large uniform strain compared to those of pure silver. Fractography further confirmed the superior ductility of silver solid solution phase with zinc at both compositions. Our preliminary but encouraging results may pave the way for the silver based alloys to be applied in industries such as electronic packaging and structure engineering.

  1. Separation of Flue Gas Components by SILP (Supported Ionic Liquid-Phase) Absorbers

    Thomassen, P.; Kunov-Kruse, Andreas Jonas; Mossin, Susanne L.


    -Phase (SILP) absorber materials. The use of solid SILP absorbers with selected ILs were found to significantly improve the absorption capacity and sorption dynamics at low flue gas concentration, thus making the applicability of ILs viable in technical, continuous flow processes for flue gas cleaning......Reversible absorption of the flue gas components CO2, NO, NO2 and SO2 has been tested for different ionic liquids (ILs) at different temperatures and flue gas compositions where porous, high surface area carriers have been applied as supports for the ionic liquids to obtain Supported Ionic Liquid....... The results show that CO2, NO and SO2 can be reversible and selective absorbed using different ILs and that Supported Ionic Liquid-Phase (SILP) absorbers are promising materials for industrial flue gas cleaning. Absorption/desorption dynamics can be tuned by temperature, pressure and gas concentration. © 2012...

  2. Accelerated creep in solid oxide fuel cell anode supports during reduction

    Frandsen, H. L.; Makowska, M.; Greco, F.; Chatzichristodoulou, C.; Ni, D. W.; Curran, D. J.; Strobl, M.; Kuhn, L. T.; Hendriksen, P. V.


    To evaluate the reliability of solid oxide fuel cell (SOFC) stacks during operation, the stress field in the stack must be known. During operation the stress field will depend on time as creep processes relax stresses. The creep of reduced Ni-YSZ anode support at operating conditions has been studied previously. In this work a newly discovered creep phenomenon taking place during the reduction is reported. This relaxes stresses at a much higher rate (∼×104) than creep during operation. The phenomenon was studied both in three-point bending and uniaxial tension. Differences between the two measurements could be explained by newly observed stress promoted reduction. Finally, samples exposed to a small tensile stress (∼0.004 MPa) were observed to expand during reduction, which is in contradiction to previous literature. These observations suggest that release of internal residual stresses between the NiO and the YSZ phases occurs during reduction. The accelerated creep should practically eliminate any residual stress in the anode support in an SOFC stack, as has previously been indirectly observed. This phenomenon has to be taken into account both in the production of stacks and in the simulation of the stress field in a stack based on anode supported SOFCs.

  3. High performance metal-supported solid oxide fuel cells with Gd-doped ceria barrier layers

    Klemensø, Trine; Nielsen, Jimmi; Blennow Tullmar, Peter


    Metal-supported solid oxide fuel cells are believed to have commercial advantages compared to conventional anode (Ni–YSZ) supported cells, with the metal-supported cells having lower material costs, increased tolerance to mechanical and thermal stresses, and lower operational temperatures. The im...

  4. Improved coupling of bacterial polysaccharides to macromolecules and solid supports


    The invention relates to a method of producing a polysaccharide-carrier conjugate comprising coupling a polysaccharide to a carrier, said polysaccharide comprising at least one monosaccharide unit comprising a keto-carboxy group according to the formula -C(=O)COOR, where R is either hydrogen or C1......-alkoxyamine group of the carrier with a keto-carboxy group of said polysaccharide to form a covalent amide bond between the carrier and the polysaccharide. Another aspect of the present invention relates to a compound or solid surface obtained when performing the method of the present invention. A third aspect...

  5. Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system

    Kobayashi, T.; Sasaki, T.; Takagi, I.; Moriyama, H. [Kyoto Univ. (Japan). Dept. of Nuclear Engineering


    The solubility-limiting solid phases in the ternary aqueous systems of Zr(IV)/OH/oxalate, Zr(IV)/OH/malonate, Th(IV)/OH/oxalate and Th(IV)/OH/malonate were characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis and differential thermal analysis. The ternary solid phase of M(IV)/OH/carboxylate was observed to form, even under acidic conditions, depending on the pH and the concentration of carboxylate ligand. In the presence of a large excess of carboxylic acid, however; the binary M(IV)-carboxylate solid phase formed. (orig.)

  6. Design and Synthesis of a Dual Linker for Solid Phase Synthesis of Oleanolic Acid Derivatives

    Shaorong Wang


    Full Text Available A hydrophilic amino-terminated poly(ethylene glycol-type dual linker for solid phase synthesis of oleanolic acid derivatives using trityl chloride resin was designed and synthesized for the first time. Model reactions in both liquid and solid phase were performed to show the feasibility of its selective cleavage at two different sites. The biological assay results indicated that the long and flexible alkyl ether functionality in the linker is less likely to be critical for the binding event. Following the successful solid-phase synthesis of model compounds, the potential of this dual linker in reaction monitoring and target identification is deemed worthy of further study.

  7. Solid-fluid and solid-solid equilibrium in hard sphere united atom models of n-alkanes: rotator phase stability.

    Cao, M; Monson, P A


    We present a study of the phase behavior for models of n-alkanes with chain lengths up to C(21) based on hard sphere united atom models of methyl and methylene groups, with fixed bond lengths and C-C-C bond angles. We extend earlier work on such models of shorter alkanes by allowing for gauche conformations in the chains. We focus particularly on the orientational order about the chain axes in the solid phase near the melting point, and our model shows how the loss of this orientational order leads to the formation of rotator phases. We have made extensive calculations of the thermodynamic properties of the models as well as order parameters for tracking the degree of orientational order around the chain axis. Depending on the chain length and whether the carbon number is even or odd, the model exhibits both a rotator phase and a more orientationally ordered solid phase in addition to the fluid phase. Our results indicate that the transition between the two solid phases is first-order with a small density change. The results are qualitatively similar to those seen experimentally and show that rotator phases can appear in models of alkanes without explicit treatment of attractive forces or explicit treatment of the hydrogen atoms in the chains.

  8. Saponification of esters of chiral alpha-amino acids anchored through their amine function on solid support.

    Cantel, Sonia; Desgranges, Stéphane; Martinez, Jean; Fehrentz, Jean-Alain


    Anchoring an alpha-amino acid residue by its amine function onto a solid support is an alternative to develop chemistry on its carboxylic function. This strategy can involve the use of amino-acid esters as precursors of the carboxylic function. A complete study on the Wang-resin was performed to determine the non racemizing saponification conditions of anchored alpha-amino esters. The use of LiOH, NaOH, NaOSi(Me)3, various solvents and temperatures were tested for this reaction. After saponification and cleavage from the support, samples were examined through their Marfey's derivatives by reversed phase HPLC to evaluate the percentage of racemization.

  9. Combinatorial Libraries on Rigid Scaffolds: Solid Phase Synthesis of Variably Substituted Pyrazoles and Isoxazoles

    Eduard R. Felder


    Full Text Available The synthesis of combinatorial compound libraries has become a powerful lead finding tool in modern drug discovery. The ability to synthesize rapidly, in high yield, new chemical entities with low molecular weight on a solid support has a recognized strategic relevance (“small molecule libraries”. We designed and validated a novel solid phase synthesis scheme, suitable to generate diversity on small heterocycles of the pyrazole and isoxazole type. Appropriate conditions were worked out for each reaction, and a variety of more or less reactive agents (building blocks was utilized for discrete conversions, in order to exploit the system’s breadth of applicability. Four sequential reaction steps were validated, including the loading of the support with an acetyl bearing moiety, a Claisen condensation, an a-alkylation and a cyclization of a b-diketone with monosubstituted hydrazines. In a second stage, the reaction sequence was applied in a split and mix approach, in order to prepare a combinatorial library built-up from 4 acetyl carboxylic acids (R1, 35 carboxylic esters (R2 and 41 hydrazines (R4 (and 1 hydroxylamine to yield a total of 11,760 compounds divided into 41 pyrazole sublibraries with 140 pairs of regioisomers and 1 isoxazole sublibrary of equal size.

  10. Methane production improvement by modulation of solid phase immersion in dry batch anaerobic digestion process: Dynamic of methanogen populations.

    André, L; Ndiaye, M; Pernier, M; Lespinard, O; Pauss, A; Lamy, E; Ribeiro, T


    Several 60L dry batch anaerobic digestion (AD) reactors were implemented with or without liquid reserve on cattle manure. The immersed part modulation of cattle manure increased the methane flow of about 13%. The quantitative real time PCR and the optimized DNA extraction were implemented and validated to characterize and quantify the methanogen dynamic in dry batch AD process. Final quantities of methanogens converged toward the same level in several inocula at the end of AD. Methanogen dynamic was shown by dominance of Methanosarcinaceae for acetotrophic methanogens and Methanobacteriales for the hydrogenotrophic methanogens. Overall, methanogens populations were stabilized in liquid phase, except Methanosaetaceae. Solid phase was colonized by Methanomicrobiales and Methanosarcinaceae populations giving a support to biofilm development. The methane increase could be explained by a raise of Methanosarcinaceae population in presence of a total contact between solid and liquid phases. Methanosarcinaceae was a bio-indicator of the methane production.

  11. Molecularly imprinted polymers based on SBA-15 for selective solid-phase extraction of baicalein from plasma samples.

    He, Hongliang; Gu, Xiaoli; Shi, Liying; Hong, Junli; Zhang, Hongjuan; Gao, Yankun; Du, Shuhu; Chen, Lina


    Highly selective molecularly imprinted mesoporous silica polymer (SBA-15@MIP) for baicalein (BAI) extraction was synthesized using a surface molecular imprinting technique on the SBA-15 supporter. Computational simulation was used to predict the optimal functional monomer for the rational design of SBA-15@MIP. Meanwhile, high adsorption capacity was obtained when a suitable yield of molecularly imprinted polymers (MIPs) layer was grafted onto the surface of SBA-15. Characterization and performance tests of the obtained polymer revealed that SBA-15@MIP possessed a highly ordered mesoporous structure, reached saturated adsorption within 60 min, and exhibited higher sorption capacity to the target molecule BAI compared with non-imprinted mesoporous silica polymer (SBA-15@NIP) and SBA-15. Finally, SBA-15@MIP was successfully applied to solid-phase extraction (SPE) coupled with high-performance liquid chromatography and ultraviolet detection (HPLC-UV) for the determination of trace BAI in plasma samples. Mean recoveries of BAI through the molecularly imprinted solid-phase extraction (MISPE) sorbent, non-imprinted solid-phase extraction (NISPE) sorbent, and SBA-15 solid-phase extraction (SBA-15-SPE) sorbent were 94.4, 22.7, and 10.7 %, respectively, and the relative standard deviations were 2.9, 2.6, and 3.6 %, respectively. These results reveal that SBA-15@MIP as a SPE sorbent has good applicability to selectively separate and enrich trace BAI from complex samples.

  12. Liquid phase sintering, II: Computer study of skeletal settling and solid phase extrication in a microgravity environment

    Nikolić Z.S.


    Full Text Available A two-dimensional numerical method based on the Brownian motion model and on the Densification model for simulation of liquid phase sintering in microgravity environment will be developed. Both models will be based on domain topology (two-dimensional particle representation and control volume methodology and on three submodels for domain translation, solid skeleton formation and domain extrication. This method will be tested in order to conduct a study of diffusion phenomena and microgravitational effects on microstructural evolution influenced by skeletal settling combined with solid-phase extrication during liquid phase sintering of porous W-Ni system.

  13. Traceless Azido Linker for the Solid-Phase Synthesis of NH-1,2,3-Triazoles via Cu-Catalyzed Azide-Alkyne Cycloaddition Reactions

    Cohrt, Anders Emil; Jensen, Jakob Feldthusen; Nielsen, Thomas Eiland


    A broadly useful acid-labile traceless azido linker for the solid-phase synthesis of NH-1,2,3-triazoles is presented. A variety of alkynes were efficiently immobilized on a range of polymeric supports by Cu(I)-mediated azide-alkyne cycloadditions. Supported triazoles showed excellent compatibility...

  14. The EPOS Implementation Phase: building thematic and integrated services for solid Earth sciences

    Cocco, Massimo; Epos Consortium, the


    The European Plate Observing System (EPOS) has a scientific vision and approach aimed at creating a pan-European infrastructure for Earth sciences to support a safe and sustainable society. To follow this vision, the EPOS mission is integrating a suite of diverse and advanced Research Infrastructures (RIs) in Europe relying on new e-science opportunities to monitor and understand the dynamic and complex Earth system. To this goal, the EPOS Preparatory Phase has designed a long-term plan to facilitate integrated use of data and products as well as access to facilities from mainly distributed existing and new research infrastructures for solid Earth Science. EPOS will enable innovative multidisciplinary research for a better understanding of the Earth's physical processes that control earthquakes, volcanic eruptions, ground instability and tsunami as well as the processes driving tectonics and Earth surface dynamics. Through integration of data, models and facilities EPOS will allow the Earth Science community to make a step change in developing new concepts and tools for key answers to scientific and socio-economic questions concerning geo-hazards and geo-resources as well as Earth sciences applications to the environment and to human welfare. Since its conception EPOS has been built as "a single, Pan-European, sustainable and distributed infrastructure". EPOS is, indeed, the sole infrastructure for solid Earth Science in ESFRI and its pan-European dimension is demonstrated by the participation of 23 countries in its preparatory phase. EPOS is presently moving into its implementation phase further extending its pan-European dimension. The EPOS Implementation Phase project (EPOS IP) builds on the achievements of the successful EPOS preparatory phase project. The EPOS IP objectives are synergetic and coherent with the establishment of the new legal subject (the EPOS-ERIC in Italy). EPOS coordinates the existing and new solid Earth RIs within Europe and builds the

  15. Solid-supported enzymatic synthesis of pectic oligogalacturonides and their analysis by MALDI-TOF mass spectrometry

    Guillaumie, Fanny; Sterling, J.D.; Jensen, K.J.;


    a disulfide-containing cleavable linker, were prepared. The OGAs (degrees of polymerization of 13 and 14) were efficiently immobilized through the reducing end via formation of an oxime linkage. These OGA-derivatized matrices were subsequently employed in novel solid-phase enzymatic reactions, with the pectin......Solid-phase biosynthetic reactions, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis (MALDI-TOF), was used to gain insight into the biosynthesis of pectin oligomers. Sepharose supports bearing long pectic oligogalacturonides (OGAs) anchored through...... in approximate to excess compared to immobilized (GalA)(13), OGAs up to the 16-mer were synthesized, confirming the non-processivity of the GalAT in vitro....

  16. Structure and dynamics of 1-butyl-3-methylimidazolium hexafluorophosphate phases on silica and laponite clay: from liquid to solid behavior.

    Castillo, M Rosa; Fraile, José M; Mayoral, José A


    Solid-state NMR experiments show that the behavior of supported 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid phases depends on the type of support and the phase thickness. A mobile nearly liquid phase is obtained on silica, on the basis of the line widths of the bands in (1)H, (31)P, and (13)C spectra. However, the mobility is somehow restricted, as shown by the possibility of using the cross-polarization technique, although with slow dynamics. On laponite clay, a layered material with a negatively charged surface, a truly solid phase is obtained at low coverage, whereas the increase in ionic liquid loading leads to a second liquid phase, as shown by the presence of two contributions with very different line widths. These two phases seem to coexist without exchange in the NMR time frame. Heteronuclear correlation experiments evidence different relative dispositions of the imidazolium-surface-PF(6) system, with only aromatic protons involved in all the interactions on silica but participation of the benzylic groups (N-CH(3) and/or N-CH(2)) in the case of laponite clay.

  17. Phase nucleation and evolution mechanisms in heterogeneous solids

    Udupa, Anirudh

    Phase nucleation and evolution is a problem of critical importance in many applications. As the length scales are reduced, it becomes increasingly important to consider interfacial and micro-structural effects that can be safely ignored at larger length scales owing to randomness. The theory of phase nucleation has been addressed usually by the classical nucleation theory, which was originally derived for single component fluid systems, after making an assumption of equilibrium. The criterion has not been rigorously derived for solids, which are far from equilibrium due to dissipation by multiple physical drivers. In this thesis, a thermodynamically sound nucleation criterion is derived for systems with multiple interacting physical phenomena and multiple dissipating mechanisms. This is done, using the tools of continuum mechanics, by determining the change in free energy upon the introduction of a new nucleus into the system. The developed theory is demonstrated to be a generalization of the classical nucleation theory (CNT). The developed theory is then applied to the problem of electromigration driven void nucleation, a serious reliability concern for the microelectronics industry. The void grows and eventually severs the line making the chip nonfunctional. There are two classes of theories at present in the electromigration literature to address the problem of void nucleation, the vacancy supersaturation theory and the entropic dissipation theory, both of which are empirical and based on intuition developed from experimental observations. When the developed theory was applied to the problem of electromigration, it was found to be consistent with the vacancy supersaturation theory, but provided the correct energetic quantity, the chemical potential, which has contribution from both the vacancy concentration as well as the hydrostatic stress. An experiment, consisting of electromigration tests on serpentine lines, was developed to validate the developed

  18. Solid-phase synthesis, characterization, and cellular activities of collagen-model nanodiamond-peptide conjugates.

    Knapinska, Anna M; Tokmina-Roszyk, Dorota; Amar, Sabrina; Tokmina-Roszyk, Michal; Mochalin, Vadym N; Gogotsi, Yury; Cosme, Patrick; Terentis, Andrew C; Fields, Gregg B


    Nanodiamonds (NDs) have received considerable attention as potential drug delivery vehicles. NDs are small (∼5 nm diameter), can be surface modified in a controllable fashion with a variety of functional groups, and have little observed toxicity in vitro and in vivo. However, most biomedical applications of NDs utilize surface adsorption of biomolecules, as opposed to covalent attachment. Covalent modification provides reliable and reproducible ND-biomolecule ratios, and alleviates concerns over biomolecule desorption prior to delivery. The present study has outlined methods for the efficient solid-phase conjugation of ND to peptides and characterization of ND-peptide conjugates. Utilizing collagen-derived peptides, the ND was found to support or even enhance the cell adhesion and viability activities of the conjugated sequence. Thus, NDs can be incorporated into peptides and proteins in a selective manner, where the presence of the ND could potentially enhance the in vivo activities of the biomolecule it is attached to.

  19. Emergence of a Metallic Quantum Solid Phase in a Rydberg-Dressed Fermi Gas.

    Li, Wei-Han; Hsieh, Tzu-Chi; Mou, Chung-Yu; Wang, Daw-Wei


    We examine possible low-temperature phases of a repulsively Rydberg-dressed Fermi gas in a three-dimensional free space. It is shown that the collective density excitations develop a roton minimum, which is softened at a wave vector smaller than the Fermi wave vector when the particle density is above a critical value. The mean field calculation shows that, unlike the insulating density wave states often observed in conventional condensed matters, a self-assembled metallic density wave state emerges at low temperatures. In particular, the density wave state supports a Fermi surface and a body-centered-cubic crystal order at the same time with the estimated critical temperature being about one tenth of the noninteracting Fermi energy. Our results suggest the emergence of a fermionic quantum solid that should be observable in the current experimental setup.

  20. Colorimetric monitoring of solid-phase aldehydes using 2,4-dinitrophenylhydrazine.

    Shannon, Simon K; Barany, George


    A simple and rapid method to achieve colorimetric monitoring of resin-bound aldehydes, based on ambient temperature reaction with 2,4-dinitrophenylhydrazine (DNPH) in the presence of dilute acid, has been developed as an adjunct to solid-phase organic synthesis and combinatorial chemistry. By this test, the presence of aldehydes is indicated by a red to dark-orange appearance, within a minute. Alternatively, resins that are free of aldehydes or in which aldehyde functions have reacted completely retain their original color. The DNPH test was demonstrated for poly(ethylene glycol)-polystyrene (PEG-PS), aminomethyl polystyrene (AMP), cross-linked ethoxylate acrylate resin (CLEAR), and acryloylated O,O'-bis(2-aminopropyl)poly(ethylene glycol) (PEGA) supports and gave results visible to the naked eye at levels as low as 18 micromol of aldehyde per gram of resin.

  1. Phase Change Permeation Technology For Environmental Control Life Support Systems

    Wheeler, Raymond M.


    Use of a phase change permeation membrane (Dutyion [Trademark]) to passively and selectively mobilize water in microgravity to enable improved water recovery from urine/brine for Environment Control and Life Support Systems (ECLSS) and water delivery to plans for potential use in microgravity.

  2. Utilizing ion-pairing hydrophilic interaction chromatography solid phase extraction for efficient glycopeptide enrichment in glycoproteomics

    Mysling, Simon; Palmisano, Giuseppe; Højrup, Peter;


    Glycopeptide enrichment is a prerequisite to enable structural characterization of protein glycosylation in glycoproteomics. Here we present an improved method for glycopeptide enrichment based on zwitter-ionic hydrophilic interaction chromatography solid phase extraction (ZIC-HILIC SPE...

  3. Study on New Sensitive Method of Determination of Phosphorus by Solid Phase Spectrophotometry


    The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate-fructose is described. The adsorption of the system on anion-exchange resin is reported.

  4. Recent Application of Solid Phase Based Techniques for Extraction and Preconcentration of Cyanotoxins in Environmental Matrices.

    Mashile, Geaneth Pertunia; Nomngongo, Philiswa N


    Cyanotoxins are toxic and are found in eutrophic, municipal, and residential water supplies. For this reason, their occurrence in drinking water systems has become a global concern. Therefore, monitoring, control, risk assessment, and prevention of these contaminants in the environmental bodies are important subjects associated with public health. Thus, rapid, sensitive, selective, simple, and accurate analytical methods for the identification and determination of cyanotoxins are required. In this paper, the sampling methodologies and applications of solid phase-based sample preparation methods for the determination of cyanotoxins in environmental matrices are reviewed. The sample preparation techniques mainly include solid phase micro-extraction (SPME), solid phase extraction (SPE), and solid phase adsorption toxin tracking technology (SPATT). In addition, advantages and disadvantages and future prospects of these methods have been discussed.

  5. Design and Solid-Phase Synthesis of Multiple Muramyl Dipeptide (MMD)


    As a non-specific modulator of macrophage, multiplied muramyl dipeptide (MMD) is solid-phase synthesized by application of standard Fmoc chemistry strategy. Tam's multiple antigen system (MAS) is used as our four branched-linker on Lysine.

  6. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    Zielinska, K.


    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid

  7. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    Zielinska, K.


    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid phas

  8. Solid-phase micro-extraction in bioanalysis, exemplified by lidocaine determination

    de Jong, GJ; Koster, EHM


    Solid-phase micro-extraction (SPME) is a never sample preparation technique that can be used for gaseous, liquid or solid samples in conjunction with GC, HPLC or CE (e.g. [1]). The use of SPME for the analysis of drugs in biofluids is also becoming popular (e.g. [2]). The principle is that a fused s

  9. Highly Selective Continuous Gas-Phase Methoxycarbonylation of Ethylene with Supported Ionic Liquid Phase (SILP) Catalysts

    Khokarale, Santosh Govind; Garcia Suárez, Eduardo José; Fehrmann, Rasmus


    Supported ionic liquid phase (SILP) technology was applied for the first time to the Pd-catalyzed continuous, gas-phase methoxycarbonylation of ethylene to selectively produce methyl propanoate (MP) in high yields. The influence of catalyst and reaction parameters such as, for example, ionic liqu...

  10. Continuous gas-phase hydroformylation of 1-butene using supported ionic liquid phase (SILP) catalysts

    Haumann, Marco; Dentler, Katharina; Joni, Joni;


    The concept of supported ionic liquid phase (SILP) catalysis has been extended to 1-butene hydroformylation. A rhodium-sulfoxantphos complex was dissolved in [BMIM][n-C8H17OSO3] and this solution was highly dispersed on silica. Continuous gas-phase experiments in a fixed-bed reactor revealed...

  11. Sparse Support Recovery with Phase-Only Measurements

    Liu, Yipeng


    Sparse support recovery (SSR) is an important part of the compressive sensing (CS). Most of the current SSR methods are with the full information measurements. But in practice the amplitude part of the measurements may be seriously destroyed. The corrupted measurements mismatch the current SSR algorithms, which leads to serious performance degeneration. This paper considers the problem of SSR with only phase information. In the proposed method, the minimization of the l1 norm of the estimated sparse signal enforces sparse distribution, while a nonzero constraint of the uncorrupted random measurements' amplitudes with respect to the reconstructed sparse signal is introduced. Because it only requires the phase components of the measurements in the constraint, it can avoid the performance deterioration by corrupted amplitude components. Simulations demonstrate that the proposed phase-only SSR is superior in the support reconstruction accuracy when the amplitude components of the measurements are contaminated.

  12. Solid supported reagents for effecting selective transformation in natural products

    V.P. Santhanakrishnan


    Full Text Available Polymer supported N-bromoacetamide resin can be easily prepared by the bromination of the acetamide resin and can be used for the transformation of furan ring in tetranortriterpenoids to butryolactone with excellent selectivity and in good yield in shorter time under microwave irradiation condition.

  13. Isostructural solid-solid phase transition in monolayers of soft core-shell particles at fluid interfaces: structure and mechanics.

    Rey, Marcel; Fernández-Rodríguez, Miguel Ángel; Steinacher, Mathias; Scheidegger, Laura; Geisel, Karen; Richtering, Walter; Squires, Todd M; Isa, Lucio


    We have studied the complete two-dimensional phase diagram of a core-shell microgel-laden fluid interface by synchronizing its compression with the deposition of the interfacial monolayer. Applying a new protocol, different positions on the substrate correspond to different values of the monolayer surface pressure and specific area. Analyzing the microstructure of the deposited monolayers, we discovered an isostructural solid-solid phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases corresponded to shell-shell and core-core inter-particle contacts, respectively; with increasing surface pressure the former mechanically failed enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore measured the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer. The interfaces always showed a strong elastic response, with a dip in the shear elastic modulus in correspondence with the melting of the shell-shell phase, followed by a steep increase upon the formation of a percolating network of the core-core contacts. These results demonstrate that the core-shell nature of the particles leads to a rich mechanical and structural behavior that can be externally tuned by compressing the interface, indicating new routes for applications, e.g. in surface patterning or emulsion stabilization.

  14. Solid Phase Equilibria in the Pi-Ga-As and Pt-Ga-Sb Systems


    OFFICE OF NAVAL RESEARCH Research Contract N00014-87-K-0014 R&T Code 413E026---01 AD-A 198 654 TECHNICAL REPORT No. 9 SOLID PHASE EQUILIBRIA IN THE...Classtcation) UNCLASSLFIED: Tech.Rept.#9 SOLID PHASE EQUILIBRIA IN T11: Pt-Ga-As AND Pt-Ga-Sb SYST’IS 12 PERSONAL AuTiOR(S) C.T. Tsai and R.S. Williats 13a TYPE

  15. Molecularly imprinted polymers: New molecular recognition materials for selective solid-phase extraction of organic compounds

    Martín Esteban, A.


    During the last few years molecularly imprinted polymers have appeared as new selective sorbents for solid-phase extraction of organic compounds in different samples. Molecular imprinting technology involves the preparation of a polymer with specific recognition sites for certain molecules. Once the polymer has been obtained, it can be used in solid-phase extraction protocols, where a careful selection of the most appropriate solvents to be used in the different steps (sample loading, washing...

  16. Expedient protocol for solid-phase synthesis of secondary and tertiary amines

    Olsen, Christian A; Witt, Matthias; Jaroszewski, Jerzy W


    [reaction: see text] An expedient solid-phase synthetic approach to secondary and tertiary amines was developed. The protocol employs conversion of resin-bound amino alcohols to the corresponding iodides, followed by iodide displacement with primary or secondary amines or with unprotected amino...... alcohols. This two-step procedure, affording products in good to excellent yields, is suitable for solid-phase synthesis of polyamines....

  17. Isotope effects in dense solid hydrogen - Phase transition in deuterium at 190 + or - 20 GPa

    Hemley, R. J.; Mao, H. K.


    Raman measurements of solid normal deuterium compressed in a diamond-anvil cell indicate that the material undergoes a structural phase transformation at 190 + or - 20 GPa and 77 K. Spectroscopically, the transition appears analogous to that observed in hydrogen at 145 + or - 5 GPa. The large isotope effect on the transition pressure suggests there is a significant vibrational contribution to the relative stability of the solid phases of hydrogen at very high densities.

  18. Multivariate Quantification of the Solid State Phase Composition of Co-Amorphous Naproxen-Indomethacin

    Beyer, Andreas; Grohganz, Holger; Löbmann, Korbinian


    regression approach that enables the simultaneous determination of up to four solid state fractions: crystalline naproxen, γ-indomethacin, α-indomethacin as well as co-amorphous naproxen-indomethacin. For this purpose, a calibration set that covers the whole range of possible combinations of the four...... four solid state phases, involving one co-amorphous phase, can be quantified with this XRPD data-based approach....

  19. Two-dimensional solid-phase extraction strategy for the selective enrichment of aminoglycosides in milk.

    Shen, Aijin; Wei, Jie; Yan, Jingyu; Jin, Gaowa; Ding, Junjie; Yang, Bingcheng; Guo, Zhimou; Zhang, Feifang; Liang, Xinmiao


    An orthogonal two-dimensional solid-phase extraction strategy was established for the selective enrichment of three aminoglycosides including spectinomycin, streptomycin, and dihydrostreptomycin in milk. A reversed-phase liquid chromatography material (C18 ) and a weak cation-exchange material (TGA) were integrated in a single solid-phase extraction cartridge. The feasibility of two-dimensional clean-up procedure that experienced two-step adsorption, two-step rinsing, and two-step elution was systematically investigated. Based on the orthogonality of reversed-phase and weak cation-exchange procedures, the two-dimensional solid-phase extraction strategy could minimize the interference from the hydrophobic matrix existing in traditional reversed-phase solid-phase extraction. In addition, high ionic strength in the extracts could be effectively removed before the second dimension of weak cation-exchange solid-phase extraction. Combined with liquid chromatography and tandem mass spectrometry, the optimized procedure was validated according to the European Union Commission directive 2002/657/EC. A good performance was achieved in terms of linearity, recovery, precision, decision limit, and detection capability in milk. Finally, the optimized two-dimensional clean-up procedure incorporated with liquid chromatography and tandem mass spectrometry was successfully applied to the rapid monitoring of aminoglycoside residues in milk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Municipal solid waste composition determination supporting the integrated solid waste management system in the island of Crete.

    Gidarakos, E; Havas, G; Ntzamilis, P


    A one-year survey was conducted in the greater region of Crete (located at the lower region of the Aegean Sea) for the purpose of identifying waste composition (including chemical and physical characterization), as well as any seasonal variation. The investigation was carried out repeatedly at seven landfills and one transfer station in Crete, in four phases. Each sampling phase corresponded to a season (autumn, winter, spring, summer). ASTM D5231-92(2003) standard method and RCRA Waste Sampling Draft Technical Guidance were used. Hand sorting was used for classifying the collected wastes into the following categories: plastics, paper, metals, aluminium, leather-wood-textiles-rubbers, organic wastes, non-combustibles and miscellaneous. Further analysis included proximate and ultimate analysis of combustible materials. Metals such as lead, cadmium and mercury were also investigated. The results show that there has been a significant decrease of organic wastes during the last decade due to the increase of packaging materials, as a result of a change in consumption patterns. Three main waste categories were determined: organic wastes, paper and plastics, which combined represent 76% of the total waste in Crete. Furthermore, a high fraction of glass and a seasonal variation of aluminium indicate a strong correlation of waste composition with certain human activities, such as tourism. There is also a variation between the municipal solid waste (MSW) composition in the region of Crete (2003-2004) and MSW composition suggested in the National Solid Waste Planning (2000) [National Solid Waste Planning, 2000. Completion and particularization of Common Ministerial Act 113944//1944/1997: National Solid Waste Planning, June 2000]. The results of this survey are to be utilized by the regional solid waste authorities in order to establish an integrated waste treatment site, capable of fulfilling the regional waste management demands.

  1. From waste biomass to solid support: lignosulfonate as a cost-effective and renewable supporting material for catalysis.

    Sun, Shaohuan; Bai, Rongxian; Gu, Yanlong


    Lignosulfonate (LS) is an organic waste generated as a byproduct of the cooking process in sulfite pulping in the manufacture of paper. In this paper, LS was used as an anionic supporting material for immobilizing cationic species, which can then be used as heterogeneous catalysts in some organic transformations. With this strategy, three lignin-supported catalysts were prepared including 1) lignin-SO3 Sc(OTf)2 , 2) lignin-SO3 Cu(OTf), and 3) lignin-IL@NH2 (IL=ionic liquid). These solid materials were then examined in many organic transformations. It was finally found that, compared with its homogeneous counterpart as well as some other solid catalysts that are prepared by using different supports with the same metal or catalytically active species, the lignin-supported catalysts showed better performance in these reactions not only in terms of activity but also with regard to recyclability.

  2. Interactions of Aqueous Imidazolium-Based Ionic Liquid Mixtures with Solid-Supported Phospholipid Vesicles

    Losada-Pérez, Patricia; Khorshid, Mehran; Renner, Frank Uwe


    Despite the environmentally friendly reputation of ionic liquids (ILs), their safety has been recently questioned given their potential as cytotoxic agents. The fundamental mechanisms underlying the interactions between ILs and cells are less studied and by far not completely understood. Biomimetic films are here important biophysical model systems to elucidate fundamental aspects and mechanisms relevant for a large range of biological interaction ranging from signaling to drug reception or toxicity. Here we use dissipative quartz crystal microbalance QCM-D to examine the effect of aqueous imidazolium-based ionic liquid mixtures on solid-supported biomimetic membranes. Specifically, we assess in real time the effect of the cation chain length and the anion nature on a supported vesicle layer of the model phospholipid DMPC. Results indicate that interactions are mainly driven by the hydrophobic components of the IL, which significantly distort the layer and promote vesicle rupture. Our analyses evidence the gradual decrease of the main phase transition temperature upon increasing IL concentration, reflecting increased disorder by weakening of lipid chain interactions. The degree of rupture is significant for ILs with long hydrophobic cation chains and large hydrophobic anions whose behavior is reminiscent of that of antimicrobial peptides. PMID:27684947

  3. A solid-phase extraction approach for the identification of pharmaceutical-sludge adsorption mechanisms

    Laurence Berthod; Gary Roberts; Graham A. Mills


    It is important to understand the adsorption mechanism of chemicals and active pharmaceu-tical ingredients (API) on sewage sludge since wastewater treatment plants are the last barrier before the release of these compounds to the environment. Adsorption models were developed considering mostly hydrophobic API-sludge interaction. They have poor predictive ability, especially with ionisable compounds. This work proposes a solid-phase extraction (SPE) approach to estimate rapidly the API-sludge interaction. Sludge-filled SPE cartridges could not be percolated with API spiked mobile phases so different powders were tested as SPE sludge supports. Polytetrafluoroethylene (PTFE) was selected and tested at different PTFE/sludge ratios under eight different adsorption conditions with three API ionisable compounds. The PTFE/sludge mixtures with 50% or less sludge could be used in SPE mode for API sorption studies with methanol/water liquid phases. The results gave insights into API-sludge interactions. It was found that π-π, hydrogen-bonding and charge-charge interactions were as important as hydrophobicity in the adsorption mechanism of charged APIs on sludge.

  4. Direct MD simulation of liquid-solid phase equilibria for two-component plasmas

    Schneider, A S; Horowitz, C J; Berry, D K


    We determine the liquid-solid phase diagram for carbon-oxygen plasma mixtures using two-phase MD simulations. We identified liquid, solid, and interface regions using a bond angle metric. To study finite size effects, we perform 55296 ion simulations and compare to earlier 27648 ion results. To help monitor non-equilibrium effects, we calculate diffusion constants $D_i$. We find that $D_O$ for oxygen ions in the solid is much smaller than $D_C$ for carbon ions and that both diffusion constants are 80 or more times smaller than diffusion constants in the liquid phase. There is excellent agreement between our phase diagram and that predicted by Medin and Cumming. This suggests that errors from finite size and non-equilibrium effects are small and that the carbon-oxygen phase diagram is now accurately known.

  5. Numerical Simulation of Erosion-Corrosion in the Liquid Solid Two-Phase Flow


    Erosion-corrosion of liquid-solid two-phase flow occurring in a pipe with sudden expansion in cross section is numerically simulated in this paper. The global model for erosion-corrosion process includes three main components: the liquid-solid two-phase flow model, erosion model and corrosion model. The Euierian-Lagranglan approach is used to simulate liquid-solid two-phase flow, while the stochastic trajectory model was adopted to obtain properties of particle phase. Two-way coupling effect between the fluid and the particle phase is considered in the model. The accuracy of the models is tested by the data in the reference. The comparison shows that the model is basically correct and feasible.

  6. Solid-phase synthesis of Biotin-S-Farnesyl-L-Cysteine, a surrogate substrate for isoprenylcysteine Carboxylmethyltransferase (ICMT).

    Stevenson, Graeme I; Yong, Sarah; Fechner, Gregory A; Neve, Juliette; Lock, Aaron; Avery, Vicky M


    Inhibition of isoprenylcysteine Carboxylmethyltransferase (ICMT) is of particular interest as a potential target for the development of cancer chemotherapeutic agents. Screening for inhibitors of ICMT utilises a scintillation proximity assay (SPA) in which Biotin-S-Farnesyl-L-Cysteine (BFC) acts as a surrogate substrate. A solid-phase synthesis protocol for the preparation of BFC using 2-chlorotrityl chloride resin as a solid support has been developed to provide sufficient supply of BFC for high throughput screening (HTS) and subsequent chemistry campaigns to target inhibitors of ICMT. The BFC prepared by this method can be produced quickly on large scale and is stable when stored at -20 °C as a solid, in solution, or on the resin.

  7. Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

    Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon


    We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

  8. Evaporation induced orientational order in soft solid phases of clays

    Lindbo Hansen, Elisabeth; Hemmen, Henrik; Dommersnes, Paul; Fossum, Jon Otto


    We demonstrate experimentally the possibility for promoting uniaxial orientational order in initially isotropic, soft solid dispersions of the synthetic clays Na-fluorohectorite and Laponite RD. We observe that strong orientational order can emerge from initially isotropic states when the samples are subjected to a slow concentration increase through evaporation of the dispersion water. During evaporation, there is a gradient in the order which, if evaporation is halted, slowly relaxes towards a uniform order throughout the samples. It is evident that the development of orientational order is not counterindicated by the viscoelastic nature of the samples, and that although the translational and likely also rotational diffusion of the particles is restricted in the soft solid state, the orientational degree of freedom can undergo a transition from a collectively random to an ordered state.

  9. New insights in Microbial Fuel Cells: novel solid phase anolyte

    Tommasi, Tonia; Salvador, Gian Paolo; Quaglio, Marzia


    For the development of long lasting portable microbial fuel cells (MFCs) new strategies are necessary to overcome critical issues such as hydraulic pump system and the biochemical substrate retrieval overtime to sustain bacteria metabolism. The present work proposes the use of a synthetic solid anolyte (SSA), constituted by agar, carbonaceous and nitrogen sources dissolved into diluted seawater. Results of a month-test showed the potential of the new SSA-MFC as a long lasting low energy consuming system.

  10. Solid-liquid phase diagram of disubstituted benzene systems

    黑恩成; 刘国杰


    The cooling curves of different compositions of the systems of ortho-chlorotoluene/para-chlorotoluene and ortho-nitrochlorobenzene/para-nitrochlorobenzene are carefully determined by the thermal analysis method. The crystals obtained are also tested. The conclusion that both systems are of simple eutectic diagram but not the solid solution diagram with a minimum melting point is confirmed. The characteristics of the diagram are explained according to the physical and thermodynarmc properties of the components.

  11. Supporting universal prevention programs: a two-phased coaching model.

    Becker, Kimberly D; Darney, Dana; Domitrovich, Celene; Keperling, Jennifer Pitchford; Ialongo, Nicholas S


    Schools are adopting evidence-based programs designed to enhance students' emotional and behavioral competencies at increasing rates (Hemmeter et al. in Early Child Res Q 26:96-109, 2011). At the same time, teachers express the need for increased support surrounding implementation of these evidence-based programs (Carter and Van Norman in Early Child Educ 38:279-288, 2010). Ongoing professional development in the form of coaching may enhance teacher skills and implementation (Noell et al. in School Psychol Rev 34:87-106, 2005; Stormont et al. 2012). There exists a need for a coaching model that can be applied to a variety of teacher skill levels and one that guides coach decision-making about how best to support teachers. This article provides a detailed account of a two-phased coaching model with empirical support developed and tested with coaches and teachers in urban schools (Becker et al. 2013). In the initial universal coaching phase, all teachers receive the same coaching elements regardless of their skill level. Then, in the tailored coaching phase, coaching varies according to the strengths and needs of each teacher. Specifically, more intensive coaching strategies are used only with teachers who need additional coaching supports, whereas other teachers receive just enough support to consolidate and maintain their strong implementation. Examples of how coaches used the two-phased coaching model when working with teachers who were implementing two universal prevention programs (i.e., the PATHS curriculum and PAX Good Behavior Game [PAX GBG]) provide illustrations of the application of this model. The potential reach of this coaching model extends to other school-based programs as well as other settings in which coaches partner with interventionists to implement evidence-based programs.

  12. Manufacturing and characterization of metal-supported solid oxide fuel cells

    Blennow Tullmar, Peter; Hjelm, Johan; Klemensø, Trine


    A metal-supported solid oxide fuel cell design offers competitive advantages, for example reduced material costs and improved robustness. This paper reports the performance and stability of a recently developed metal-supported cell design, based on a novel cermet anode, on a 25cm2 (1cm2/16cm2 act...

  13. Molecularly imprinted polymer/cryogel composites for solid-phase extraction of bisphenol A from river water and wine.

    Baggiani, Claudio; Baravalle, Patrizia; Giovannoli, Cristina; Anfossi, Laura; Giraudi, Gianfranco


    Superporous monolithic hydrogels (cryogel monoliths) are elastic, sponge-like materials that can be prepared in an aqueous medium through a cryotropic gelation technique. These monoliths show interesting properties for the development of high-throughput solid-phase extraction supports to treat large volumes of aqueous samples. In this work, a cryogel-supported molecularly imprinted solid-phase extraction approach for the endocrine disruptor bisphenol A (BPA) from river water and wine samples is presented. An imprinted polymer with molecular recognition properties for BPA was prepared in acetonitrile by thermal polymerization of a mixture of 4,4'-dihydroxy-2,2-diphenyl-1,1,1,3,3,3-trifluoropropane as a mimic template of BPA, 4-vinylpyridine and trimethylolpropane trimethacrylate in a molar ratio of 1 + 6 + 6. Fine imprinted particles (extraction approach to recover BPA from dilute aqueous samples with minimum pre-loading work-up. The optimized extraction protocol resulted in a reliable MISPE method suitable to selectively extract and preconcentrate BPA from river water and red wine samples, demonstrating the practical feasibility of cryogel-trapped imprinted polymers as solid-phase extraction materials.

  14. Spectral and thermal studies of solid-phase thermochromism of Co(II) double metal complexes

    AL-Sha'alan, Noura H.


    Tetrahedral solid state structures of the blue potassium tris(aryloxo)cobaltate(II)-tetrahydrofurane complexes of the formula KCo(OAr) 3·2thf (OAr = o-chloro-, o-bromo-, m-chloro-, p-bromo, 2,6-dichloro-, 2,4-dichloro- or 2,4-dimethylphenoxide) undergo solid-phase thermal tetrahedral to octahedral transformation accompanied by change in their colours from blue to rose (one-step thermochromism). Magnetic moments, electronic and infrared spectral studies supported these results. Thermal treatment of theses complexes leads to the loss of the crystallized thf molecule yielding also blue tetrahedral complexes. However, further heating leads to the loss of the coordinated thf molecule and the formation of rose octahedral trimeric products. TG-DTA results showed that the, two solvated thf molecules were eliminated in two steps. Mass spectral studies and IR intensity measurements confirmed the trimeric behaviour of the rose octahedral geometry of thermal products. Conductance measurements of solutions of these complexes in thf indicated that they behave as non-electrolytes.

  15. [Determination of aflatoxins in hot chilli products by matrix solid-phase dispersion and liquid chromatography].

    Zheng, Ping; Sheng, Xuan; Yu, Xiaofeng; Hu, Yanyun


    A new method based on matrix solid-phase dispersion (MSPD) extraction with neutral alumina and co-column purification with graphitized carbon black has been developed to determine aflatoxins B1, B2, G1, G2 in hot chilli products. The method includes liquid chromatography and fluorescence detection with on-line post-column derivatization with bromine. Optimization of different parameters, such as the type of solid supports for matrix dispersion and co-column clean-up was carried out. The recoveries of aflatoxins B1, B2, G1 and G2 were 95.4%, 87.3%, 91.5% and 92.6%, respectively, with relative standard deviations ranging from 3.3% to 6.1%. The limits of detection were in the range of 0.10 ng/g (B2, G2) to 0.25 ng/g (B1, G1). In addition, the comparison of the extraction and purification effect of MSPD with immunity affinity column showed that, MSPD is a valid method to analyze aflatoxins in hot chilli products.

  16. Methylation and Release of Mercury From the Solid Phase. What Comes First?

    Regnell, O.


    It is a well-known fact that methylation leads to a dramatic increase in the bioavailability of mercury (Hg). All recent observations support the notion that Hg methylation is almost exclusively an anaerobic process. According to the reigning paradigm, methylation of Hg takes place in the cytoplasm of anaerobic bacteria, notably sulfate-reducing bacteria. It is believed that certain forms of inorganic divalent Hg (Hg(II)), can readily diffuse across the cell membrane. In addition, a recent study suggested that active uptake may occur when Hg is bound to low weight organic molecules. In the cytoplasm, cobalamin-dependent biochemical pathways, designed to methylate substrates other than Hg(II), are held responsible for the methylation of Hg(II). However, recent results from studies in a Swedish wetland (within the project "Svartsjoprojektet", aiming at understanding Hg dynamics in a Hg-polluted river-lake system) have led us to question whether Hg methylation does occur exclusively within cells. A provocative interpretation of our results is that methylation preceded the release of Hg from the solid phase, e.g. that Hg(II) sorbed to solid surfaces was methylated and subsequently released as methyl Hg to the sulfidic water. I will discuss this possibility in light of existing evidence that Hg methylation is an intra cellular process.

  17. Solid-phase cloning for high-throughput assembly of single and multiple DNA parts.

    Lundqvist, Magnus; Edfors, Fredrik; Sivertsson, Åsa; Hallström, Björn M; Hudson, Elton P; Tegel, Hanna; Holmberg, Anders; Uhlén, Mathias; Rockberg, Johan


    We describe solid-phase cloning (SPC) for high-throughput assembly of expression plasmids. Our method allows PCR products to be put directly into a liquid handler for capture and purification using paramagnetic streptavidin beads and conversion into constructs by subsequent cloning reactions. We present a robust automated protocol for restriction enzyme based SPC and its performance for the cloning of >60 000 unique human gene fragments into expression vectors. In addition, we report on SPC-based single-strand assembly for applications where exact control of the sequence between fragments is needed or where multiple inserts are to be assembled. In this approach, the solid support allows for head-to-tail assembly of DNA fragments based on hybridization and polymerase fill-in. The usefulness of head-to-tail SPC was demonstrated by assembly of >150 constructs with up to four DNA parts at an average success rate above 80%. We report on several applications for SPC and we suggest it to be particularly suitable for high-throughput efforts using laboratory workstations.

  18. Effect of shear stress in ferroelectric solid solutions with coexisting phases

    Lu, Xiaoyan; Zhang, Hangbo; Zheng, Limei; Cao, Wenwu


    One common feature of ferroelectric solid solutions with large piezoelectricity is the coexistence of two or more phases. Due to the strain mismatch among coexisting phases, adaptive structures near the interfaces or domain walls develop to maintain the atomic coherency. Shear stresses commonly exist, especially when the domain size is small. The effect of shear stresses on phase morphology in Pb(Zr1-xTix)O3 solid solutions with compositions within the morphotropic phase boundary region was studied within the framework of Landau phenomenological theory. Our results show that the coexisting rhombohedral (R) and tetragonal (T) phases can be modified to form stable or metastable R-like and/or T-like monoclinic phases under shear stresses. Large stresses may also induce first order or second order phase transitions.

  19. Temperature and phase dependence of positron lifetimes in solid cyclohexane

    Eldrup, Morten Mostgaard


    The temperature dependence of position lifetimes in both the brittle and plastic phases of cyclohaxane has been examined. Long-lived components in both phases are associated with the formation of positronium (Ps). Two long lifetimes attributable to ortho-Ps are resolvable in the plastic phase....... The longer of these (≈ 2.5 ns), which is temperature dependent, is ascribed to ortho-Ps trapped at vacancies. The shorter lifetime (≈ 0.9 ns), shows little temperature dependence. In contrast to most other plastic crystals, no sigmoidal behaviour of the average ortho-Ps lifetime is observed. A possibility...

  20. A comparison of hybridization efficiency between flat glass and channel glass solid supports.

    Betanzos-Cabrera, Gabriel; Harker, Brent W; Doktycz, Mitchel J; Weber, James L; Beattie, Kenneth L


    Two different solid supports, channel glass and flat glass, were compared for their affect on the sensitivity and efficiency of DNA hybridization reactions. Both solid supports were tested using a set of arrayed, synthetic oligonucleotides that are designed to detect short insertion/deletion polymorphisms (SIDPs). A total of 13 different human SIDPs were chosen for analysis. Capture probes, designed for this test set, were covalently immobilized on substrates. Hybridization efficiency was assessed using fluorescently labeled stacking probes which were preannealed to the target and then hybridized to the support-bound oligonucleotide array; the hybridization pattern was detected by fluorescence imaging. It was found that structural features of nucleic acid capture probes tethered to a solid support and the molecular basis of their interaction with targets in solution have direct implications on the hybridization process. Our results demonstrate that channel glass has a number of practical advantages over flat glass including higher sensitivity and a faster hybridization rate.

  1. Solid-liquid phase equilibria of the Gaussian core model fluid.

    Mausbach, Peter; Ahmed, Alauddin; Sadus, Richard J


    The solid-liquid phase equilibria of the Gaussian core model are determined using the GWTS [J. Ge, G.-W. Wu, B. D. Todd, and R. J. Sadus, J. Chem. Phys. 119, 11017 (2003)] algorithm, which combines equilibrium and nonequilibrium molecular dynamics simulations. This is the first reported use of the GWTS algorithm for a fluid system displaying a reentrant melting scenario. Using the GWTS algorithm, the phase envelope of the Gaussian core model can be calculated more precisely than previously possible. The results for the low-density and the high-density (reentrant melting) sides of the solid state are in good agreement with those obtained by Monte Carlo simulations in conjunction with calculations of the solid free energies. The common point on the Gaussian core envelope, where equal-density solid and liquid phases are in coexistence, could be determined with high precision.

  2. Study of solid solution strengthening of alloying element with phase structure factors


    Using the empirical electron theory of solids and molecules (EET), the phase structure factors, nA and nB, of the carbon-containing structural units with mass fraction of carbon (wC) below 0.8% and the mono-alloy structural units with wC at 0.2% in austenite and martensite are calculated. The solid solution strengthening brought by C-containing interstitial solid solution and alloy-substitutional solid solution in γ-Fe and α-Fe is discussed at electron structural level. The coefficient (s) of solid solution strengthening is advanced according to the bonding force between atoms. The study shows that when the criterion is applied to the carbonaceous or alloying element-containing solid solution the results of calculation will coincide with the experimental result very well.

  3. Determination of Roxarsone in feeds using solid phase extraction and liquid chromatography with ultraviolet detection.

    Sapp, R E; Davidson, S


    A method is presented for detection and quantitation of Roxarsone in poultry feed by liquid chromatography. The drug is extracted by phosphate buffer and determined by solid phase extraction and reversed-phase liquid chromatography. Recoveries of the sample spikes and fortified field samples agree closely with those obtained by the standard spectrophotometric method.


    TANG Xuelin; QIAN Zhongdong; WU Yulin


    The dense solid-phase governing equations for two-phase flows are obtained by using the kinetic theory of gas molecules. Assuming that the solid-phase velocity distributions obey the Maxwell equations, the collision term for particles under dense two-phase flow conditions is also derived.In comparison with the governing equations of a dilute two-phase flow, the solid-particle's governing equations are developed for a dense turbulent solid-liquid flow by adopting some relevant terms from the dilute two-phase governing equations. Based on Cauchy-Helmholtz theorem and Smagorinsky model,a second-order dynamic sub-grid-scale (SGS) model, in which the sub-grid-scale stress is a function of both the strain-rate tensor and the rotation-rate tensor, is proposed to model the two-phase governing equations by applying dimension analyses. Applying the SIMPLEC algorithm and staggering grid system to the two-phase discretized governing equations and employing the slip boundary conditions on the walls, the velocity and pressure fields, and the volumetric concentration are calculated. The simulation results are in a fairly good agreement with experimental data in two operating cases in a conduit with a rectangular cross-section and these comparisons imply that these models are practical.

  5. Traveling waves for models of phase transitions of solids driven by configurational forces

    Kawashima, Shuichi


    This article is concerned with the existence of traveling wave solutions, including standing waves, to some models based on configurational forces, describing respectively the diffusionless phase transformations of solid materials, e.g., Steel, and phase transitions due to interface motion by interface diffusion, e.g., Sintering. These models are recently proposed by Alber and Zhu. We consider both the order-parameter-conserved case and the non-conserved one, under suitable assumptions. Also we compare our results with the corresponding ones for the Allen-Cahn and the Cahn-Hilliard equations coupled with linear elasticity, which are models for diffusion-dominated phase transformations in elastic solids.

  6. Density-functional theory of a lattice-gas model with vapour, liquid, and solid phases

    Prestipino, S.; Giaquinta, P. V.


    We use the classical version of the density-functional theory in the weighted-density approximation to build up the entire phase diagram and the interface structure of a two-dimensional lattice-gas model which is known, from previous studies, to possess three stable phases -- solid, liquid, and vapour. Following the common practice, the attractive part of the potential is treated in a mean-field-like fashion, although with different prescriptions for the solid and the fluid phases. It turns o...

  7. Solid-phase microextraction for bioconcentration studies according to OECD TG 305

    Duering, Rolf-Alexander; Boehm, Leonard [Land Use and Nutrition (IFZ) Justus Liebig University Giessen, Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Giessen (Germany); Schlechtriem, Christian [Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg (Germany)


    An important aim of the European Community Regulation on chemicals and their safe use is the identification of (very) persistent, (very) bioaccumulative, and toxic substances. In other regulatory chemical safety assessments (pharmaceuticals, biocides, pesticides), the identification of such (very) persistent, (very) bioaccumulative, and toxic substances is of increasing importance. Solid-phase microextraction is especially capable of extracting total water concentrations as well as the freely dissolved fraction of analytes in the water phase, which is available for bioconcentration in fish. However, although already well established in environmental analyses to determine and quantify analytes mainly in aqueous matrices, solid-phase microextraction is still a rather unusual method in regulatory ecotoxicological research. Here, the potential benefits and drawbacks of solid-phase microextraction are discussed as an analytical routine approach for aquatic bioconcentration studies according to OECD TG 305, with a special focus on the testing of hydrophobic organic compounds characterized by log K{sub OW}> 5. (orig.)

  8. Solid-Supported Lipid Membranes: Formation, Stability and Applications

    Goh, Haw Zan

    This thesis presents a comprehensive investigation of the formation of supported lipid membranes with vesicle hemifusion, their stability under detergents and organic solvents and their applications in molecular biology. In Chapter 3, we describe how isolated patches of DOPC bilayers supported on glass surfaces are dissolved by various detergents (decyl maltoside, dodecyl maltoside, CHAPS, CTAB, SDS, TritonX-100 and Tween20) at their CMC, as investigated by fluorescence video microscopy. In general, detergents partition into distal leaflets of bilayers and lead to the expansion of the bilayers through a rolling motion of the distal over the proximal leaflets, in agreement with the first stage of the established 3-stage model of lipid vesicle solubilization by detergents. Subsequently, we study the partitioning of organic solvents (methanol, ethanol, isopropanol, propanol, acetone and chloroform) into isolated bilayer patches on glass in Chapter 4 with fluorescence microscopy. The area expansion of bilayers due to the partitioning of organic solvents is measured. From the titration of organic solvents, we measured the rate of area expansion as a function of the volume fraction of organic solvents, which is proposed to be a measure of strength of interactions between solvents and membranes. From the same experiments, we also measure the maximum expansion of bilayers (or the maximum binding stoichiometry between organic solvents and lipids) before structural breakdown, which depends on the depth of penetration of solvents to the membranes. In Chapter 5, we investigate the formation of sparsely-tethered bilayer lipid membranes (stBLMs) with vesicle hemifusion. In vesicle hemifusion, lipid vesicles in contact with a hydrophobic alkyl-terminated self-assembled monolayer (SAM) deposit a lipid monolayer to the SAM surface, thus completing the bilayer. Electrical Impedance Spectroscopy and Neutron Reflectivity are used to probe the integrity of stBLMs in terms of their

  9. Crystalline-to-plastic phase transitions in molecularly thin n-dotriacontane films adsorbed on solid surfaces

    Cisternas, Edgardo; Corrales, T. P.; del Campo, V.;


    Crystalline-to-rotator phase transitions have been widely studied in bulk hydrocarbons, in particular in normal alkanes. But few studies of these transitions deal with molecularly thin films of pure n-alkanes on solid substrates. In this work, we were able to grow dotriacontane (n-C32H66) films...... identify with a solid-solid phase transition. At higher coverages, we observed additional steps in the ellipsometric signal that we identify with a solid-solid phase transition in multilayer islands (similar to 333 K) and with the transition to the rotator phase in bulk crystallites (similar to 337 K...

  10. Rapidly Activated Dynamic Phase Transitions in Nonlinear Solids


    I Form Approv# edAD -A263 601 AiENTA11ON PAGE- f____________18 1. AGENCY USE ONLY (Lea"e blaWk 12. REPORT DATE 13. REPORT TYPE AND OATES COVEREO Feb...phase transforming media during high energy impact. Conversion of mechanical energy to thermal ener- gy has been studied by means of an extended theory...and Phase Structures in General Media , R. Fosdick, E. Dunn & M. Slemrod eds., IMA volume series, Springer- Verlag. Song, J. and T. L. Pence (1992

  11. Two-phase anaerobic digestion of vegetable market waste fraction of municipal solid waste and development of improved technology for phase separation in two-phase reactor.

    Majhi, Bijoy Kumar; Jash, Tushar


    Biogas production from vegetable market waste (VMW) fraction of municipal solid waste (MSW) by two-phase anaerobic digestion system should be preferred over the single-stage reactors. This is because VMW undergoes rapid acidification leading to accumulation of volatile fatty acids and consequent low pH resulting in frequent failure of digesters. The weakest part in the two-phase anaerobic reactors was the techniques applied for solid-liquid phase separation of digestate in the first reactor where solubilization, hydrolysis and acidogenesis of solid organic waste occur. In this study, a two-phase reactor which consisted of a solid-phase reactor and a methane reactor was designed, built and operated with VMW fraction of Indian MSW. A robust type filter, which is unique in its implementation method, was developed and incorporated in the solid-phase reactor to separate the process liquid produced in the first reactor. Experiments were carried out to assess the long term performance of the two-phase reactor with respect to biogas production, volatile solids reduction, pH and number of occurrence of clogging in the filtering system or choking in the process liquid transfer line. The system performed well and was operated successfully without the occurrence of clogging or any other disruptions throughout. Biogas production of 0.86-0.889m(3)kg(-1)VS, at OLR of 1.11-1.585kgm(-3)d(-1), were obtained from vegetable market waste, which were higher than the results reported for similar substrates digested in two-phase reactors. The VS reduction was 82-86%. The two-phase anaerobic digestion system was demonstrated to be stable and suitable for the treatment of VMW fraction of MSW for energy generation.

  12. Positronium in solid phases of n-alkane binary mixtures

    Zgardzińska, B.; Goworek, T.


    Highlights: • Rotator phase in even alkanes C{sub n}H{sub 2n+2} with n ⩽ 20 appears in mixed samples only. • Interlamellar gap width is the same for shorter chain alkane concentration x and 1 − x. • Excess electron trapping diminishes with broadening of alkane chain distribution Δn. - Abstract: Binary mixtures of even-numbered normal alkanes C{sub n}H{sub 2n+2} and C{sub n+2}H{sub 2n+6} with n ⩽ 18 were investigated by positron annihilation spectroscopy. Formation of the rotator phase was observed in mixed structures, while no such a phase in neat alkanes in this range of n was found. Phase diagrams for n = 18 and n = 16 are very similar to the diagrams for binary mixtures of odd-numbered alkanes. The effect of positronium formation with trapped excess electrons weakens with decreasing n, at low n values the time constant of Ps rise contains the component much shorter than 1 h.

  13. All rights reserved Development of Headspace Solid-Phase ...


    Pesticide Residues in Fruit and Vegetable Samples using OFAT Design. *. 1,2. LUKMAN BOLA ... phase microextraction parameters (fiber coating type, extraction temperature and time, pH, salt addition ... production of food (Bakırcı, et al. 2014 ...

  14. SANS study of phase separation in solid {sup 3}He-{sup 4}He

    Koster, J.P.; Nagler, S.E.; Adams, E.D. [Florida Univ., Gainesville, FL (United States). Dept. of Physics; Wignall, G.D. [Oak Ridge National Lab., TN (United States). Solid State Div.


    Small angle neutron scattering has been used to study phase separation in a quantum alloy, solid {sup 3}He{sub x}-{sup 4}He{sub 1{minus}x}. The onset of phase separation is marked by a dramatic increase in the measured scattering. A simple interpretation of the results suggests that the late-stage phase separation kinetics are dominated by an increase in the concentration of {sup 3}He atoms in preexisting precipitate regions.

  15. Multi-Phase CFD Modeling of Solid Sorbent Carbon Capture System

    Ryan, Emily M.; DeCroix, David; Breault, Ronald W.; Xu, Wei; Huckaby, E. D.; Saha, Kringan; Darteville, Sebastien; Sun, Xin


    Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian-Eulerian and Eulerian-Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian-Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian-Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian-Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.

  16. Multi-phase CFD modeling of solid sorbent carbon capture system

    Ryan, E. M.; DeCroix, D.; Breault, Ronald W. [U.S. DOE; Xu, W.; Huckaby, E. David [U.S. DOE


    Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian–Eulerian and Eulerian–Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian–Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian–Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian–Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.

  17. Thermoelastic properties of solid phases: C++ object oriented library “SolidEOS”

    Churakov, Sergey V.


    A new object-oriented C++ library (SolidEOS) for calculating the thermoelastic properties of solids is presented. The implementation is based on the Mie-Grüneisen-Debye equation of state (EOS) augmented by lowest order correction for anharmonicity. Several commonly used static EOS like Birch-Murnaghan and Vinet models are available. Although some widely used approximation for the Debye-Grüneisen parameter and static EOS are implemented, the final behaviour of the EOS can be easily modified by overloading predefined virtual functions. The article provides a basic physical background of the modern theory of high-pressure EOS. The detailed documentation of the class hierarchy is summarized in the appendix, which accompanies the source. Several examples of practical use are given in the appendix as well. The library is appropriate for applications in geophysics, petrology, material science or any other field where thermodynamic and elastic properties of solids are relevant. The source code is available from the Computers & Geoscience software archive.

  18. Theoretical study on phase coexistence in ferroelectric solid solutions near the tricritical point

    Lu, Xiaoyan, E-mail:, E-mail:; Li, Hui [Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, School of Civil Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zheng, Limei [Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150001 (China); Cao, Wenwu [Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150001 (China); Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)


    Phase coexistence in ferroelectric solid solutions near the tricritical point has been theoretically analyzed by using the Landau-Devonshire theory. Results revealed that different phases having similar potential wells could coexist in a narrow composition range near the tricritical point in the classical Pb(Zr{sub 1−x}Ti{sub x})O{sub 3} system. The potential barrier between potential wells increases with the decrease of temperature. Coexisting phases or different domains of the same phase can produce adaptive strains to maintain atomic coherency at the interfaces or domain walls. Such compatibility strains have influence on the energy potential as well as the stability of relative phases, leading to the appearance of energetically unfavorable monoclinic phases. Those competing and coexisting phases also construct an easy phase transition path with small energy barrier in between, so that very small stimuli can produce large response in compositions near the morphotropic phase boundary, especially near the tricritical point.

  19. Optimizing the solid-phase immunofiltration assay. A rapid alternative to immunoassays.

    IJsselmuiden, O E; Herbrink, P; Meddens, M J; Tank, B; Stolz, E; Van Eijk, R V


    The technical variables of the solid-phase immunofiltration assay (SPIA) for the detection of antibodies bound to antigens on a solid-phase filter have been investigated. The binding to solid-phase filters of 125I-labelled axial filament proteins derived from Treponema phagedenis and the optimal conditions for blocking non-specific protein binding were analysed. Axial filament was applied to nitrocellulose, Hybond Nylon and Zeta Probe. After extensive rinsing, the highest amount (68%) of axial filament was observed bound to Zeta Probe. However, blocking non-specific protein binding by pre-wetting the filter with rinsing buffer containing 0.5% Tween 20, prevented the binding of protein to the filter only when nitrocellulose was used as solid phase. Tween 20 (0.5%) in the rinsing and incubation solutions was found to be necessary for the reduction of non-specific binding of contaminants in turbid sera. However, the use of such solutions resulted in a substantial leakage of antigen (47%) during rinsing procedures. Binding of antigen-specific antibody was analysed using 125I-labelled protein A. The maximal possible binding of the antibody occurred within 5 min when the antibody solution was filtered. For optimal binding of 125I-labelled protein A an incubation time of 1 h was needed. It is suggested that solid-phase immunofiltration may provide a rapid alternative for radioimmunoassays or enzyme immunoassays for the detection of specific antibodies.

  20. Determination of melamine in aquaculture feed samples based on molecularly imprinted solid-phase extraction.

    Lian, Ziru; Liang, Zhenlin; Wang, Jiangtao


    This research highlights the application of highly efficient molecularly imprinted solid-phase extraction for the preconcentration and analysis of melamine in aquaculture feed samples. Melamine-imprinted polymers were synthesized employing methacrylic acid and ethylene glycol dimethacrylate as functional monomer and cross-linker, respectively. The characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted polymers showed an excellent adsorption ability for melamine and were applied as special solid-phase extraction sorbents for the selective cleanup of melamine. An off-line molecularly imprinted solid-phase extraction procedure was developed for the separation and enrichment of melamine from aquaculture feed samples prior to high-performance liquid chromatography analysis. Optimum molecularly imprinted solid-phase extraction conditions led to recoveries of the target in spiked feed samples in the range 84.6-96.6% and the relative standard deviation less than 3.38% (n = 3). The aquaculture feed sample was determined, and there was no melamine found. The results showed that the molecularly imprinted solid-phase extraction protocols permitted the sensitive, uncomplicated and inexpensive separation and pre-treatment of melamine in aquaculture feed samples.

  1. Phosphopeptide Enrichment by Covalent Chromatography after Derivatization of Protein Digests Immobilized on Reversed-Phase Supports

    Nika, Heinz; Nieves, Edward; Hawke, David H.; Angeletti, Ruth Hogue


    A rugged sample-preparation method for comprehensive affinity enrichment of phosphopeptides from protein digests has been developed. The method uses a series of chemical reactions to incorporate efficiently and specifically a thiol-functionalized affinity tag into the analyte by barium hydroxide catalyzed β-elimination with Michael addition using 2-aminoethanethiol as nucleophile and subsequent thiolation of the resulting amino group with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate. Gentle oxidation of cysteine residues, followed by acetylation of α- and ε-amino groups before these reactions, ensured selectivity of reversible capture of the modified phosphopeptides by covalent chromatography on activated thiol sepharose. The use of C18 reversed-phase supports as a miniaturized reaction bed facilitated optimization of the individual modification steps for throughput and completeness of derivatization. Reagents were exchanged directly on the supports, eliminating sample transfer between the reaction steps and thus, allowing the immobilized analyte to be carried through the multistep reaction scheme with minimal sample loss. The use of this sample-preparation method for phosphopeptide enrichment was demonstrated with low-level amounts of in-gel-digested protein. As applied to tryptic digests of α-S1- and β-casein, the method enabled the enrichment and detection of the phosphorylated peptides contained in the mixture, including the tetraphosphorylated species of β-casein, which has escaped chemical procedures reported previously. The isolates proved highly suitable for mapping the sites of phosphorylation by collisionally induced dissociation. β-Elimination, with consecutive Michael addition, expanded the use of the solid-phase-based enrichment strategy to phosphothreonyl peptides and to phosphoseryl/phosphothreonyl peptides derived from proline-directed kinase substrates and to their O-sulfono- and O-linked β-N-acetylglucosamine (O

  2. The synthesis and properties of the phases obtained by solid-solid reactions

    Blonska-Tabero A.


    Full Text Available The presented work encompasses the subject of the studies and the results obtained over the last years by the research workers of the Department of Inorganic Chemistry. They include mainly the studies on the reactivity of metal oxides, searching for new phases in binary and ternary systems of metal oxides as well as describing phase relations establishing in such systems. They also encompass works on the extensive characteristics of physico-chemical properties of the newly obtained compounds.

  3. Solid-Phase Parallel Synthesis of Phosphite Ligands

    Swennenhuis, Bert H.G.; Chen, Ruifang; Leeuwen, Piet W.N.M. van; Vries, Johannes G. de; Kamer, Paul C.J.


    Various routes for the synthesis of polymer-bound phosphites and phosphoramidites have been investigated. In the presence of a suitable activator the supported phosphoramidites react cleanly with alcohols to give the corresponding monodentate phosphite ligands in solution. We have applied this novel

  4. Immobilization of lambda exonuclease onto polymer micropillar arrays for the solid-phase digestion of dsDNAs.

    Oliver-Calixte, Nyoté J; Uba, Franklin I; Battle, Katrina N; Weerakoon-Ratnayake, Kumuditha M; Soper, Steven A


    The process of immobilizing enzymes onto solid supports for bioreactions has some compelling advantages compared to their solution-based counterpart including the facile separation of enzyme from products, elimination of enzyme autodigestion, and increased enzyme stability and activity. We report the immobilization of λ-exonuclease onto poly(methylmethacrylate) (PMMA) micropillars populated within a microfluidic device for the on-chip digestion of double-stranded DNA. Enzyme immobilization was successfully accomplished using 3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling to carboxylic acid functionalized PMMA micropillars. Our results suggest that the efficiency for the catalysis of dsDNA digestion using λ-exonuclease, including its processivity and reaction rate, were higher when the enzyme was attached to a solid support compared to the free solution digestion. We obtained a clipping rate of 1.0 × 10(3) nucleotides s(-1) for the digestion of λ-DNA (48.5 kbp) by λ-exonuclease. The kinetic behavior of the solid-phase reactor could be described by a fractal Michaelis-Menten model with a catalytic efficiency nearly 17% better than the homogeneous solution-phase reaction. The results from this work will have important ramifications in new single-molecule DNA sequencing strategies that employ free mononucleotide identification.

  5. Studies on solid phase synthesis,characterization and fluorescent property of the new rare earth complexes

    Shi, Jianwei; Xiaoxu TENG; Wang, Linling; Long, Rong


    Rare earth-β-diketone ligand complex luminescent material has stable chemical properties and excellent luminous property. Using europium oxide and (γ-NTA) as raw materials, novel rare earth-β-dione complexes are synthesized by solid state coordination chemistry. The synthesis temperature and milling time are discussed for optimization. Experimental results show that the suitable reaction situation is at 50 ℃ and 20 h for solid-phase synthesis. The compositions and structures of the complexes...

  6. Solid-phase PCR for rapid multiplex detection of Salmonella spp. at the subspecies level, with amplification efficiency comparable to conventional PCR.

    Chin, Wai Hoe; Sun, Yi; Høgberg, Jonas; Hung, Tran Quang; Wolff, Anders; Bang, Dang Duong


    Solid-phase PCR (SP-PCR) has attracted considerable interest in different research fields since it allows parallel DNA amplification on the surface of a solid substrate. However, the applications of SP-PCR have been hampered by the low efficiency of the solid-phase amplification. In order to increase the yield of the solid-phase amplification, we studied various parameters including the length, the density, as well as the annealing position of the solid support primer. A dramatic increase in the signal-to-noise (S/N) ratio was observed when increasing the length of solid support primers from 45 to 80 bp. The density of the primer on the surface was found to be important for the S/N ratio of the SP-PCR, and the optimal S/N was obtained with a density of 1.49 × 10(11) molecules/mm(2). In addition, the use of solid support primers with a short overhang at the 5' end would help improve the S/N ratio of the SP-PCR. With optimized conditions, SP-PCR can achieve amplification efficiency comparable to conventional PCR, with a limit of detection of 1.5 copies/μl (37.5 copies/reaction). These improvements will pave the way for wider applications of SP-PCR in various fields such as clinical diagnosis, high-throughput DNA sequencing, and single-nucleotide polymorphism analysis. Graphical abstract Schematic representation of solid-phase PCR.

  7. Solid solution, phase separation, and cathodoluminescence of GaP-ZnS nanostructures.

    Liu, Baodan; Bando, Yoshio; Dierre, Benjamin; Sekiguchi, Takashi; Golberg, Dmitri; Jiang, Xin


    Quaternary solid-solution nanowires made of GaP and ZnS have been synthesized through well-designed synthetic routines. The as-synthesized GaP-ZnS solid-solution nanowires exhibit decent crystallinity with the GaP phase as the host, while a large amount of twin structural defects are observed in ZnS-rich nanowires. Cathodoluminescence studies showed that GaP-rich solid-solution nanowires have a strong visible emission centered at 600 nm and the ZnS-rich solid-solution nanowires exhibited a weak emission peak in the UV range and a broad band in the range 400-600 nm. The formation mechanism, processes, and optical emissions of GaP-ZnS solid-solution nanowires were discussed in detail.

  8. The solid-liquid phase diagrams of binary mixtures of consecutive, even saturated fatty acids.

    Costa, Mariana C; Sardo, Mariana; Rolemberg, Marlus P; Coutinho, João A P; Meirelles, Antonio J A; Ribeiro-Claro, Paulo; Krähenbühl, M A


    For the first time, the solid-liquid phase diagrams of five binary mixtures of saturated fatty acids are here presented. These mixtures are formed of caprylic acid (C(8:0))+capric acid (C(10:0)), capric acid (C(10:0))+lauric acid (C(12:0)), lauric acid (C(12:0))+myristic acid (C(14:0)), myristic acid (C(14:0))+palmitic acid (C(16:0)) and palmitic acid (C(16:0))+stearic acid (C(18:0)). The information used in these phase diagrams was obtained by differential scanning calorimetry (DSC), X-ray diffraction (XRD), FT-Raman spectrometry and polarized light microscopy, aiming at a complete understanding of the phase diagrams of the fatty acid mixtures. All of the phase diagrams reported here presented the same global behavior and it was shown that this was far more complex than previously imagined. They presented not only peritectic and eutectic reactions, but also metatectic reactions, due to solid-solid phase transitions common in fatty acids and regions of solid solution not previously reported. This work contributes to the elucidation of the phase behavior of these important biochemical molecules, with implications in various industrial applications.

  9. Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

    Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko


    Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort.

  10. Mixed Model for Silt-Laden Solid-Liquid Two-Phase Flows

    唐学林; 徐宇; 吴玉林


    The kinetic theory of molecular gases was used to derive the governing equations for dense solid-liquid two-phase flows from a microscopic flow characteristics viewpoint by multiplying the Boltzmann equation for each phase by property parameters and integrating over the velocity space. The particle collision term was derived from microscopic terms by comparison with dilute two-phase flow but with consideration of the collisions between particles for dense two-phase flow conditions and by assuming that the particle-phase velocity distribution obeys the Maxwell equations. Appropriate terms from the dilute two-phase governing equations were combined with the dense particle collision term to develop the governing equations for dense solid-liquid turbulent flows. The SIMPLEC algorithm and a staggered grid system were used to solve the discretized two-phase governing equations with a Reynolds averaged turbulence model. Dense solid-liquid turbulent two-phase flows were simulated for flow in a duct. The simulation results agree well with experimental data.

  11. Study supporting the phasing out of environmentally harmful subsidies

    Withana, S.; Ten Brink, P.; Franckx, L.; Hirschnitz-Garbers, M.; Mayeres, I.; Oosterhuis, F.; Porsch, L.


    The need to reform ineffective or harmful public subsidies has long been recognised and has been a contentious point of discussion for several years. The EU has a long-standing commitment to removing or phasing out environmentally harmful subsidies (EHS). Most recently, the need to phase out EHS is reiterated in the 'Roadmap for a resource efficient Europe' which includes a milestone that 'by 2020 EHS will be phased out, with due regard to the impact on people in need'. Despite several commitments, progress has been slow and subsidies remain an issue in most EU countries. This study focuses specifically on EHS at the level of EU Member States; it identifies key types of EHS and examines cases of existing EHS across a range of environmental sectors and issues, including subsidies from non-action. The study also analyses examples of good practices in the reform of EHS in EU Member States and the lessons that can be learnt from these cases. Finally, based on this analysis, it develops practical recommendations on phasing out and reforming EHS to support the objectives of the Europe 2020 Strategy and the resource efficiency agenda. The study was carried out between January and October 2012 and is based on an analysis of literature and consultation with experts and policy makers. The sectoral cases studied are listed and discussed in the annexes report: agriculture, climate and energy, fisheries, food, forestry, materials, transport, waste, and water.

  12. Solid-Phase Synthesis of Amine/Carboxyl Substituted Prolines and Proline Homologues: Scope and Limitations.

    Zhou, Ziniu; Scott, William L; O'Donnell, Martin J


    A solid-phase procedure is used to synthesize racemic peptidomimetics based on the fundamental peptide unit. The peptidomimetics are constructed around proline or proline homologues variably substituted at the amine and carbonyl sites. The procedure expands the diversity of substituted peptidomimetic molecules available to the Distributed Drug Discovery (D3) project. Using a BAL-based solid-phase synthetic sequence the proline or proline homologue subunit is both constructed and incorporated into the peptidomimetic by an α-alkylation, hydrolysis and intramolecular cyclization sequence. Further transformations on solid-phase provide access to a variety of piperazine derivatives representing a class of molecules known to exhibit central nervous system activity. The procedure works well with proline cores, but with larger six- and seven-membered ring homologues the nature of the carboxylic acid acylating the cyclic amine can lead to side reactions and result in poor overall yields.

  13. In situ transmission electron microscopy of solid-liquid phase transition of silica encapsulated bismuth nanoparticles

    Hu, Jianjun; Hong, Yan; Muratore, Chris; Su, Ming; Voevodin, Andrey A.


    The solid-liquid phase transition of silica encapsulated bismuth nanoparticles was studied by in situ transmission electron microscopy (TEM). The nanoparticles were prepared by a two-step chemical synthesis process involving thermal decomposition of organometallic precursors for nucleating bismuth and a sol-gel process for growing silica. The microstructural and chemical analyses of the nanoparticles were performed using high-resolution TEM, Z-contrast imaging, focused ion beam milling, and X-ray energy dispersive spectroscopy. Solid-liquid-solid phase transitions of the nanoparticles were directly recorded by electron diffractions and TEM images. The silica encapsulation of the nanoparticles prevented agglomeration and allowed particles to preserve their original volume upon melting, which is desirable for applications of phase change nanoparticles with consistently repeatable thermal properties.

  14. Phase-amplitude coupling supports phase coding in human ECoG

    Watrous, Andrew J; Deuker, Lorena; Fell, Juergen; Axmacher, Nikolai


    Prior studies have shown that high-frequency activity (HFA) is modulated by the phase of low-frequency activity. This phenomenon of phase-amplitude coupling (PAC) is often interpreted as reflecting phase coding of neural representations, although evidence for this link is still lacking in humans. Here, we show that PAC indeed supports phase-dependent stimulus representations for categories. Six patients with medication-resistant epilepsy viewed images of faces, tools, houses, and scenes during simultaneous acquisition of intracranial recordings. Analyzing 167 electrodes, we observed PAC at 43% of electrodes. Further inspection of PAC revealed that category specific HFA modulations occurred at different phases and frequencies of the underlying low-frequency rhythm, permitting decoding of categorical information using the phase at which HFA events occurred. These results provide evidence for categorical phase-coded neural representations and are the first to show that PAC coincides with phase-dependent coding in the human brain. DOI: PMID:26308582

  15. Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

    Xu, Xinhua; Wang, Xiaogang; Wu, Meifen


    The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

  16. Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

    Xu, Xinhua; Wang, Xiaogang; Wu, Meifen


    The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

  17. Extraction of Pb2+ using Silica from Rice Husks Ash (RHA – Chitosan as Solid Phase

    Hanandayu Widwiastuti


    Full Text Available The existence of lead (Pb compounds in waters can be caused of waste pollution from industrial activities such as dye and battery industries. Lead has toxic characteristic and is able to causing deseases. The levels of Cr(VI can be decreased by methods such as electroplating, oxidation, reduction, and membrane separation. But this methods require high cost and produce a lot of waste. Furthermore, those methods cannot determine the small concentration of Pb2+. Therefore, solid phase extraction is used because it’s a simple method and can be used to preconcentrate Pb2+ ion. The aim of this study is to create solid phase from nature material as an alternative method to determine Pb2+ in water samples. The solid phase is silica from rice husks ash (RHA that was modified using chitosan. To achieve that aim, the optimization of silica : chitosan composition was done. The influence of Pb2+ concentration and citric acid concentration was studied to obtain optimum recovery of Pb2+. Interaction between Pb2+ ion and solid phase silica – chitosan could be estimated based on the result. The result showed the optimum composition of silica : chitosan is 65% silica : 35% chitosan with Cation Exchange Capacity (CEC 0.00455 mek/g. Mass Adsorbed Pb2+for 1 g silica : chitosan 65% is 9.715 mg/g. Optimum recovery of Pb2+ on solid phase extraction is reached at concentration of Pb2+ 10 ppm and citric acid concentration 0.05 M (88.25 % and 81.18 %. This result showed that solid phase extraction using silica – chitosan can be used as an alternative method to determine Pb2+ in water.

  18. A photolabile linker for the solid-phase synthesis of peptide hydrazides and heterocycles.

    Qvortrup, Katrine; Komnatnyy, Vitaly V; Nielsen, Thomas E


    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino acids, including those with side-chain protected residues at the C-terminal of the resulting peptide hydrazide, and are useful for the synthesis of dihydropyrano[2,3-c]pyrazoles. The linker is compatible with most commonly used coupling reagents and protecting groups for solid-phase peptide synthesis.

  19. Development of orthogonally protected hypusine for solid-phase peptide synthesis.

    Song, Aimin; Tom, Jeffrey; Yu, Zhiyong; Pham, Victoria; Tan, Dajin; Zhang, Dengxiong; Fang, Guoyong; Yu, Tao; Deshayes, Kurt


    An orthogonally protected hypusine reagent was developed for solid-phase synthesis of hypusinated peptides using the Fmoc/t-Bu protection strategy. The reagent was synthesized in an overall yield of 27% after seven steps from Cbz-Lys-OBzl and (R)-3-hydroxypyrrolidin-2-one. The side-chain protecting groups (Boc and t-Bu) are fully compatible with standard Fmoc chemistry and can be readily removed during the peptide cleavage step. The utility of the reagent was demonstrated by solid-phase synthesis of hypusinated peptides.

  20. Synthesis of indium tin oxide powder by solid-phase reaction with microwave heating

    Fukui, Kunihiro; Kanayama, Keiji; Katoh, Manabu; Yamamoto, Tetsuya; Yoshida, Hideto


    Indium tin oxide (ITO) powder was synthesized from indium oxide and tin oxide powders by a solid-phase method using microwave heating and conventional heating methods. Microwave heating could reduce the treatment time necessary for the completion of the solid-phase reaction by 1/30. This decrease was attributed to an increase in the diffusion rate of Sn at the local heat spot in the indium oxide formed by microwave irradiation. However, microwave heating also decreased the amount of ITO produ...

  1. Detection of ibuprofen and ciprofloxacin by solid-phase extraction and UV/Vis spectroscopy

    Zhou, Zhengwei; Jiang, Jia Qian


    A simple and economic solid-phase extraction coupled with UV/Vis spectrophotometric method is described for the analysis of ibuprofen and ciprofloxacin. Following solid-phase extraction from model wastewater samples containing standard ibuprofen or ciprofloxacin, elutes were analyzed by a UV/Vis spectrophotometer at 225 nm for ibuprofen and 280 nm for ciprofloxacin. The assay was linear for both compounds with good coefficients of correlation. This method shows good recoveries for both compounds with 101.0 ± 9.8% for ibuprofen and 99.4 ± 11.8% ciprofloxacin.

  2. A Photolabile Linker for the Solid-Phase Synthesis of Peptide Hydrazides and Heterocycles

    Qvortrup, Katrine; Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland


    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino adds, including those with side-cha......-chain protected residues at the C-terminal of the resulting peptide hydrazide, and are useful for the synthesis of dihydropyrano[2,3-c]pyrazoles. The linker is compatible with most commonly used coupling reagents and protecting groups for solid-phase peptide synthesis....

  3. CuAAC: An Efficient Click Chemistry Reaction on Solid Phase.

    Castro, Vida; Rodríguez, Hortensia; Albericio, Fernando


    Click chemistry is an approach that uses efficient and reliable reactions, such as Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), to bind two molecular building blocks. CuAAC has broad applications in medicinal chemistry and other fields of chemistry. This review describes the general features and applications of CuAAC in solid-phase synthesis (CuAAC-SP), highlighting the suitability of this kind of reaction for peptides, nucleotides, small molecules, supramolecular structures, and polymers, among others. This versatile reaction is expected to become pivotal for meeting future challenges in solid-phase chemistry.

  4. Free-Surface Optical Scattering as an Indicator of the Shock-Induced Solid-Liquid Phase Transition in Tin

    Stevens, G. D.; Lutz, S. S.; Marshall, B. R.; Turley, W. D.; Veeser, L. R.; Furlanetto, M. R.; Hixson, R. S.; Holtkamp, D. B.; Jensen, B. J.; Rigg, P. A.; Wilke, M. D.


    When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (pre-shock) to diffuse upon melting. A familiar manifestation of this phenomenon is the loss of signal light in VISAR measurements, which occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry, conductivity) that show relatively small (1%–10%) changes, the specularity of reflection provides a more sensitive and definitive indication of the solid-liquid phase transition. Data will be presented that support the hypothesis that specularity changes indicate melt in a way that can be measured easily and unambiguously.

  5. Highly durable anode supported solid oxide fuel cell with an infiltrated cathode

    Samson, Alfred Junio; Hjalmarsson, Per; Søgaard, Martin


    An anode supported solid oxide fuel cell with an La0.6Sr0.4Co1.05O3_δ (LSC) infiltrated-Ce0.9Gd0.1O1.95 (CGO) cathode that shows a stable performance has been developed. The cathode was prepared by screen printing a porous CGO backbone on top of a laminated and co-fired anode supported half cell,...

  6. "Active surfaces" formed by immobilization of enzymes on solid-supported polymer membranes.

    Draghici, Camelia; Kowal, Justyna; Darjan, Alina; Meier, Wolfgang; Palivan, Cornelia G


    In various domains ranging from catalysis to medical and environmental sciences, there is currently much focus on the design of surfaces that present active compounds at the interface with their environments. Here, we describe the design of "active surfaces" based on solid-supported monolayers of asymmetric triblock copolymers, which serve as templates for the attachment of enzymes. A group of poly(ethylene glycol)-block-poly(γ-methyl-ε-caprolactone)-block-poly[(2-dimethylamino) ethyl methacrylate] amphiphilic copolymers, with different hydrophilic and hydrophobic domains (PEG45-b-PMCLx-b-PDMAEMAy) was selected to generate solid-supported polymer membranes. The behavior of the copolymers in terms of their molecular arrangements at the air-water interface was established by a combination of Langmuir isotherms and Brewster angle microscopy. Uniform thin layers of copolymers were obtained by transferring films onto silica solid supports at optimal surface pressure. These solid-supported polymer membranes were characterized by assessing various properties, such as monolayer thickness, hydrophilic/hydrophobic balance, topography, and roughness. Laccase, used as an enzyme model, was successfully attached to copolymer membranes by stable interactions as followed by quartz crystal microbalance with dissipation measurements, and its activity was preserved, as indicated by activity assays. The interaction between the amphiphilic triblock copolymer films and immobilized enzymes represents a straightforward approach to engineer "active surfaces", with biomolecules playing the active role by their intrinsic bioactivity.

  7. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmy; Thydén, Karl Tor Sune


    The electrochemical performance and stability of the planar metal supported solid oxide fuel cells (MS-SOFC) with two different electrocatalytically active materials, namely, Ni:GDC and Ru:GDC were investigated. Ru:GDC with an ASR of 0.322 Ωcm2 performed better than Ni:GDC with an ASR of 0.453 Ωc...

  8. Synthesis of Dopamine and Serotonin Derivatives for Immobilization on a Solid Support

    Funder, Erik Daa; Jensen, Anne Bjørnskov; Tørring, Thomas;


    The two important neurotransmitters dopamine and serotonin are synthesized with short PEG tethers and immobilized on a magnetic solid support. The tether is attached to the aromatic moiety of the neurotransmitters to conserve their original functional groups. This approach causes minimal alterati...

  9. Solid-supported synthesis: From pharmacologically relevant heterocycles to biologically active surfaces

    Komnatnyy, Vitaly V.

    The present PhD thesis consists of an introduction part and two separate parts covering selected research projects during the PhD study. The introduction part describes the concept of solid-supported synthesis and combinatorial chemistry. The chapter covers recent achievements in materials...

  10. Alkene Isomerization Using a Solid Acid as Activator and Support for a Homogeneous Catalyst

    Seen, Andrew J.


    An upper-level undergraduate experiment that, in addition to introducing students to catalysis using an air sensitive transition-metal complex, introduces the use of a solid acid as an activator and support for the catalyst is developed. The increased stability acquired in the course of the process affords the opportunity to characterize the…

  11. Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction of herbicides in peanuts.

    Li, Na; Wang, Zhibing; Zhang, Liyuan; Nian, Li; Lei, Lei; Yang, Xiao; Zhang, Hanqi; Yu, Aimin


    Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction was developed and applied to the extraction of pesticides in high fatty matrices. The herbicides were ultrasonically extracted from peanut using ethyl acetate as extraction solvent. The separation of the analytes from a large amount of co-extractive fat was achieved by dispersive solid-phase extraction using MIL-101(Cr) as sorbent. In this step, the analytes were adsorbed on MIL-101(Cr) and the fat remained in bulk. The herbicides were separated and determined by high-performance liquid chromatography. The experimental parameters, including type and volume of extraction solvent, ultrasonication time, volume of hexane and eluting solvent, amount of MIL-101(Cr) and dispersive solid phase extraction time, were optimized. The limits of detection for herbicides range from 0.98 to 1.9 μg/kg. The recoveries of the herbicides are in the range of 89.5-102.7% and relative standard deviations are equal or lower than 7.0%. The proposed method is simple, effective and suitable for treatment of the samples containing high content of fat.

  12. Partition chromatography separation using trilaurylamine adsorbed on a solid support. Behaviour of the uranyl ion; Separations par chromatographie de partage au moyen de trilaurylamine adsorbee sur support solide comportement de l'ion uranyle

    Petit-Bromet, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires


    The extractive phase is made up of a TLA solution in cyclohexanol adsorbed on a solid poly-trifluorochloroethylene support (sold commercially as voltalef or KEL-F). The mixture obtained is homogeneous and can be used for partition chromatography. For a solution of hydrochloric acid stronger than 1 M, the amine is quantitatively in the form of the chlorohydrate. The partition curve for U(VI) between the 2 N hydrochloric acid aqueous phase and the organic TLA phase has two steps which can be explained by assuming that two complexes exist in the organic phase. The equilibrium constants for extraction have been determined. The homogeneity of the voltalef-amine mixture has made it possible to build up a column with reproducible characteristics. Under the operational conditions adopted, the height of the equivalent theoretical plate is about 3 mm. A plot of all the curves giving the variations in the partition function of U(VI), Fe(III), Cu(II), Sr(II) and Cs(I) as a function of the hydrochloric acid concentration makes it possible to predict the conditions under which these elements may be separated. [French] La phase extractive est constituee d'une solution de TLA dans le cyclohexanol adsorbe sur un support solide de polytrifluorochloroethylene (commercialise sous le nom de voltalef ou KEL-F). Le melange obtenu est homogene et peut etre utilise en chromatographie de partage. Pour une concentration d'acide chlorhydrique en solution superieure a 1 M, l'amine est quantitativement sous forme de chlorhydrate. La courbe de partage de U(VI) entre la phase aqueuse d'acide chlorhydrique 2 N et la phase organique de TLA presente deux paliers que l'on peut interpreter en admettant l'existence de deux complexes en phase organique. Les constantes des equilibres d'extraction ont ete determinees. L'homogeneite du melange voltalef-amine a permis de constituer une colonne.dont les caracteristiques sont reproductibles. Dans les conditions de

  13. Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.

    Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek


    Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees.

  14. A comparative study of solid and liquid non-aqueous phases for the biodegradation of hexane in two-phase partitioning bioreactors.

    Hernández, María; Quijano, Guillermo; Thalasso, Frédéric; Daugulis, Andrew J; Villaverde, Santiago; Muñoz, Raúl


    A comparative study of the performance of solid and liquid non-aqueous phases (NAPs) to enhance the mass transfer and biodegradation of hexane by Pseudomonas aeruginosa in two-phase partitioning bioreactors (TPPBs) was undertaken. A preliminary NAP screening was thus carried out among the most common solid and liquid NAPs used in pollutant biodegradation. The polymer Kraton G1657 (solid) and the liquid silicone oils SO20 and SO200 were selected from this screening based on their biocompatibility, resistance to microbial attack, non-volatility and high affinity for hexane (low partition coefficient: K = C(g)/C(NAP), where C(g) and C(NAP) represent the pollutant concentration in the gas phase and NAP, respectively). Despite the three NAPs exhibited a similar affinity for hexane (K approximately 0.0058), SO200 and SO20 showed a superior performance to Kraton G1657 in terms of hexane mass transfer and biodegradation enhancement. The enhanced performance of SO200 and SO20 could be explained by both the low interfacial area of this solid polymer (as a result of the large size of commercial beads) and by the interference of water on hexane transfer (observed in this work). When Kraton G1657 (20%) was tested in a TPPB inoculated with P. aeruginosa, steady state elimination capacities (ECs) of 5.6 +/- 0.6 g m(-3) h(-1) were achieved. These values were similar to those obtained in the absence of a NAP but lower compared to the ECs recorded in the presence of 20% of SO200 (10.6 +/- 0.9 g m(-3) h(-1)). Finally, this study showed that the enhancement in the transfer of hexane supported by SO200 was attenuated by limitations in microbial activity, as shown by the fact that the ECs in biotic systems were far lower than the maximum hexane transfer capacity recorded under abiotic conditions.

  15. Effects of the Use of Pore Formers on Performance of an Anode supported Solid Oxide Fuel Cell

    Haslam, J J; Pham, A; Chung, B W; DiCarlo, J F; Glass, R S


    The effects of amount of pore former used to produce porosity in the anode of an anode supported planar solid oxide fuel cell were examined. The pore forming material utilized was rice starch. The reduction rate of the anode material was measured by Thermogravimetric Analysis (TGA) to qualitatively characterize the gas transport within the porous anode materials. Fuel cells with varying amounts of porosity produced by using rice starch as a pore former were tested. The performance of the fuel cell was the greatest with an optimum amount of pore former used to create porosity in the anode. This optimum is believed to be related to a trade off between increasing gas diffusion to the active three-phase boundary region of the anode and the loss of performance due to the replacement of active three-phase boundary regions of the anode with porosity.

  16. Molecularly imprinted polymer grafted to porous polyethylene frits: a new selective solid-phase extraction format.

    Barahona, Francisco; Turiel, Esther; Martín-Esteban, Antonio


    In this paper, a novel format for selective solid-phase extraction based on a molecularly imprinted polymer (MIP) is described. A small amount of MIP has been synthesized within the pores of commercial polyethylene (PE) frits and attached to its surface using benzophenone (BP), a photo-initiator capable to start the polymerisation from the surface of the support material. Key properties affecting the obtainment of a proper polymeric layer, such as polymerisation time and kind of cross-linker were optimised. The developed imprinted material has been applied as a selective sorbent for cleaning extracts of thiabendazole (TBZ), as model compound, from citrus samples. The use of different solvents for loading the analyte in the imprinted frits was investigated, as well as the binding capacity of the imprinted polymer. Imprinted frits showed good selectivity when loads were performed using toluene and a linear relationship was obtained for the target analyte up to 1000 ng of loaded analyte. Prepared composite material was applied to the SPE of TBZ in real samples extracts, showing an impressive clean-up ability. Calibrations showed good linearity in the concentration range of 0.05-5.00 μg g(-1), referred to the original solid sample, and the regression coefficients obtained were greater than 0.996. The calculated detection limit was 0.016 μg g(-1), low enough to satisfactory analysis of TBZ in real samples. RSDs at different spiking levels ranged below 15% in all the cases and imprinted frits were reusable without loss in their performance.

  17. Microwave-Assisted Solid Phase Organic Synthesis.Application to Indole Library Construction

    DAI Wei-Min; SUN Li-Ping; GUO Dian-Shun; HUANG Xiang-Hong


    Microwave-assisted organic synthesis (MAOS) has attained increasing popularity due to recent advancement in the instrumentation of microwave technology. Now, MAOS can be performed under controlled temperature and pressure to yield reproducible results. For combinatorial chemistry,the dramatically increased reaction rate under microwave irradiation at high temperature provides an ideal solution to those sluggish reactions, in particular the combinatorial reactions carried out on solid supports. In this presentation, we describe our results on microwave-assisted solid-phase organic synthesis (MASPOS) applied to the construction of indole libraries such as 5. Compounds 4 were synthesized on the Rink amide resins using IRORI MicroKanTM reactors encoded with a radio-frequency (Rf) tag. The resin-bound terminal alkynes 2, prepared via the amide bond, were cross-coupled with the nitroaryl triflate under the conditions adopted from the solution reactions developed by us1,2. The nitro group of 3 was then reduced and sulfonylated to give 4. Ring closure reactions within 4 with Cu(OAc)2 were examined initially in refluxing DCE for 24 h, but no indole product was detected after cleavage from the resin. Therefore, the same reactions were carried out under microwave irradiation at 200 ℃ for 10 min on a Personal Chemistry Emrys Creator, the desired indoles 5 were obtained in 60-95% overall yields calculated from 1 and in >90% purities in most cases3. It is necessary to mention that the IRORI microreactors cannot tolerate the high temperature and the resin-bound 4 must be transferred to the reaction vials for the microwave-assisted ring closure reactions. A traceless synthesis of an indole library via MASPOS will be discussed as well.4

  18. Solid solution and amorphous phase in Ti–Nb–Ta–Mn systems synthesized by mechanical alloying

    Aguilar, C., E-mail: [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Guzman, P. [Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Lascano, S. [Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Parra, C. [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Bejar, L. [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia C.P. 58000, Michoacán (Mexico); Medina, A. [Facultad de Ingeniería Mecánica, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, C.P. 58000, Michoacán (Mexico); Guzman, D. [Departamento de Metalurgia, Universidad de Atacama, Av. España 485, Copiapó (Chile)


    This work discusses the formation of Ti–30Nb–13Ta–xMn (x: 2, 4 and 6 wt%) solid solution by mechanical alloying using a shaker mill. A solid solution was formed after 15 h of milling and an amorphous phase was formed after 30 h of milling, according to X-ray diffraction results. Disappearance of strongest X-ray diffraction peaks of Nb, Ta and Mn indicated the formation of solid solution, while, X-ray diffraction patterns of powders milled for 30 h showed an amorphous hump with crystalline peaks in the angular range of 35–45° in 2θ. TEM image analysis showed the presence of nanocrystalline intermetallic compounds embedded in an amorphous matrix. Mn{sub 2}Ti, MnTi and NbTi{sub 4} intermetallic compounds were detected and revealed crystallites with size ranging from 3 to 20 nm. The Gibbs free energy for the formation of solid solution and amorphous phase of three ternary systems (Ti–Nb–Ta, Ti–Nb–Mn and Ti–Ta–Mn) was calculated using extended Miedema's model. Experimental and thermodynamic data confirmed that solid solution was first formed in the alloy with 6wt% Mn followed by the formation of an amorphous phase as milling time increases. The presence of Mn promoted the formation of amorphous phase because the atomic radius difference between Mn with Ti, Nb and Ta. - Highlights: • Thermodynamics analysis of extension of solid solution of the Ti–Nb–Ta–Mn system. • Formation of amorphous phase and intermetallic compounds were observed. • Nanocrystalline intermetallic compounds were formed with the sizes between 3 and 20 nm.

  19. Optical manipulation of Berry phase in a solid-state spin qubit

    Yale, Christopher G; Zhou, Brian B; Auer, Adrian; Burkard, Guido; Awschalom, David D


    The phase relation between quantum states represents an essential resource for the storage and processing of quantum information. While quantum phases are commonly controlled dynamically by tuning energetic interactions, utilizing geometric phases that accumulate during cyclic evolution may offer superior robustness to noise. To date, demonstrations of geometric phase control in solid-state systems rely on microwave fields that have limited spatial resolution. Here, we demonstrate an all-optical method based on stimulated Raman adiabatic passage to accumulate a geometric phase, the Berry phase, in an individual nitrogen-vacancy (NV) center in diamond. Using diffraction-limited laser light, we guide the NV center's spin along loops on the Bloch sphere to enclose arbitrary Berry phase and characterize these trajectories through time-resolved state tomography. We investigate the limits of this control due to loss of adiabiaticity and decoherence, as well as its robustness to noise intentionally introduced into t...

  20. Bioproduction of benzaldehyde in a solid-liquid two-phase partitioning bioreactor using Pichia pastoris.

    Jain, Ashu N; Khan, Tanya R; Daugulis, Andrew J


    The bioproduction of benzaldehyde from benzyl alcohol using Pichia pastoris was examined in a solid-liquid two-phase partitioning bioreactor (TPPB) to reduce substrate and product inhibition. Rational polymer selection identified Elvax 40W as an effective sequestering phase, possessing partition coefficients for benzyl alcohol and benzaldehyde of 3.5 and 35.4, respectively. The use of Elvax 40W increased the overall mass of benzaldehyde produced by approx. 300% in a 5 l bioreactor, relative to a single phase biotransformation. The two-phase system had a molar yield of 0.99, indicating that only minor losses occurred. These results provide a promising starting point for solid-liquid TPPBs to enhance benzaldehyde production, and suggest that multiple, targeted polymers may provide relief for transformations characterized by multiple inhibitory substrates/product/by-products.

  1. Synthesis of biologically important neutral amylo-β peptide by using improved Fmoc solid-phase peptide synthetic strategy.

    Selvam, R; Sudha, E; Rajkumar, P R; Subashchandran, K P


    The 10 amino acid sequence of the biologically important neutral amylo-β peptide has equally hydrophilic and hydrophobic properties, which reduces the coupling efficiency during its synthesis and reduces the final yield of the peptide, and is therefore classified as a "difficult peptide sequence." The method presented here minimizes the synthetic problems by the introduction of improved Fmoc chemistry and effective hydroxybenzotriazole (HoBt), diisopropylcarbodiimide (DIC)-coupling and activation strategies. In addition, we developed a PS-TPGD resin as a solid support for the synthesis of specific neutral peptides, which is still a challenge to peptide chemistry. The most essential biologically active neutral amylo-β peptide (KVKRIILARS) was successfully synthesized, and some synthetic modification was performed using the Fmoc solid-phase peptide synthesis (SPPS) method for purity and yield improvement. Graphical abstractᅟ.

  2. Porous Silica-Supported Solid Lipid Particles for Enhanced Solubilization of Poorly Soluble Drugs.

    Yasmin, Rokhsana; Rao, Shasha; Bremmell, Kristen E; Prestidge, Clive A


    Low dissolution of drugs in the intestinal fluid can limit their effectiveness in oral therapies. Here, a novel porous silica-supported solid lipid system was developed to optimize the oral delivery of drugs with limited aqueous solubility. Using lovastatin (LOV) as the model poorly water-soluble drug, two porous silica-supported solid lipid systems (SSL-A and SSL-S) were fabricated from solid lipid (glyceryl monostearate, GMS) and nanoporous silica particles Aerosil 380 (silica-A) and Syloid 244FP (silica-S) via immersion/solvent evaporation. SSL particles demonstrated significantly higher rate and extent of lipolysis in comparison with the pure solid lipid, depending on the lipid loading levels and the morphology. The highest lipid digestion was observed when silica-S was loaded with 34% (w/w) solid lipid, and differential scanning calorimeter (DSC) analysis confirmed the encapsulation of up to 2% (w/w) non-crystalline LOV in this optimal SSL-S formulation. Drug dissolution under non-digesting intestinal conditions revealed a three- to sixfold increase in dissolution efficiencies when compared to the unformulated drug and a LOV-lipid suspension. Furthermore, the SSL-S provided superior drug solubilization under simulated intestinal digesting condition in comparison with the drug-lipid suspension and drug-loaded silica. Therefore, solid lipid and nanoporous silica provides a synergistic effect on optimizing the solubilization of poorly water-soluble compound and the solid lipid-based porous carrier system provides a promising delivery approach to overcome the oral delivery challenges of poorly water-soluble drugs.

  3. Homogenization of. beta. -solid solution during fast heating of two-phase titanium alloys

    Gridnev, V.N.; Zhuravlev, A.F.; Zhuravlev, B.F.; Ivasishin, O.M.; Markovskij, P.E. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)


    Using model alloy Ti-10%Mo as an example the homogenization of high-temperature ..beta..-phase during fast heating has been studied by calculational and experimental methods. The effect of heating rate and the initial structure disoersion on the homogenization is shown. A method is suggested for evaluation of the concentration state of ..beta..-solid solution depleted parts of commercial two-phase titanium alloys. The method has been used to study the homogenization process.

  4. Numerical investigation of confined swirling gas-solid two phase jet


    This paper presents a k-ε-kp multi-fluid model for simulating confined swirling gas-solid two phase jet comprised of particle-laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. A series of numerical simulations of the two-phase flow of 30 μm, 45 μm, 60 μm diameter particles respectively yielded results fitting well with published experimental data.

  5. Numerical Simulation of Swirling Gas-solid Two Phase Flow through a Pipe Expansion

    Jin Hanhui; Xia Jun; Fan Jianren; Cen Kefa


    A k- ε -kp multi-fluid model is stated and adopted to simulate swirling gas-solid two phase flow. A particle-laden flow from a center tube and a swirling air stream from the coaxial annular enter the test section. A series of numerical simulations of the two-phase flow are performed based on 30 μ m, 45 μ m, 60 μ m diameter particles respectively. The results fit well with published experimental data.

  6. Numerical investigation of confined swirling gas-solid two phase jet

    金晗辉; 夏钧; 樊建人; 岑可法


    This paper presents a k-e-kp multi-fluid model for simulating confined swirling gas-solid two phase jet comprised of particle-laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. A series of numerical simulations of the two-phase flow of 30μm, 45μm, 60μm diameter particles respectively yielded results fitting well with published experimental data.


    S. Manna


    Full Text Available High performance liquid chromatographic determination of organophosphorous compound has been done by reverse phase chromatography in goats. The goats were dying showing the symptoms of organophosphorous poisoning. The viscera and stomach contents sample were received from Project Co-Ordinator, Animal Disease Research Institute, Phulnakhara, Cuttack, Orissa. The analysis of samples by HPLC with UV detector after cleaning up in Solid Phase Extraction (SPE revealed presence of malathion that was later quantified.

  8. The 2D Alternative Binary L-J System: Solid-Liquid Phase Diagram

    ZHANG Zhi; CHEN Li-Rong


    The Lennard-Jones potential is introduced into the Collins model and is generalized to the two-dimensionalalternative binary system. The Gibbs free energy of the binary system is calculated. According to the thermodynamicconditions of solid-liquid equilibrium, the "cigar-type" phase diagram and the phase diagram with a minimum areobtained. The results are quite analogous to the behavior of three-dimensional substances.

  9. Direct molecular dynamics simulation of liquid-solid phase equilibria for a three-component plasma.

    Hughto, J; Horowitz, C J; Schneider, A S; Medin, Zach; Cumming, Andrew; Berry, D K


    The neutron-rich isotope ²²Ne may be a significant impurity in carbon and oxygen white dwarfs and could impact how the stars freeze. We perform molecular dynamics simulations to determine the influence of ²²Ne in carbon-oxygen-neon systems on liquid-solid phase equilibria. Both liquid and solid phases are present simultaneously in our simulation volumes. We identify liquid, solid, and interface regions in our simulations using a bond angle metric. In general we find good agreement for the composition of liquid and solid phases between our MD simulations and the semianalytic model of Medin and Cumming. The trace presence of a third component, neon, does not appear to strongly impact the chemical separation found previously for two-component carbon and oxygen systems. This suggests that small amounts of ²²Ne may not qualitatively change how the material in white dwarf stars freezes. However, we do find systematically lower melting temperatures (higher Γ) in our MD simulations compared to the semianalytic model. This difference seems to grow with impurity parameter Q_{imp} and suggests a problem with simple corrections to the linear mixing rule for the free energy of multicomponent solid mixtures that is used in the semianalytic model.

  10. The Solid Phase Curing Time Effect of Asbuton with Texapon Emulsifier at the Optimum Bitumen Content

    Sarwono, D.; Surya D, R.; Setyawan, A.; Djumari


    Buton asphalt (asbuton) could not be utilized optimally in Indonesia. Asbuton utilization rate was still low because the processed product of asbuton still have impracticable form in the term of use and also requiring high processing costs. This research aimed to obtain asphalt products from asbuton practical for be used through the extraction process and not requiring expensive processing cost. This research was done with experimental method in laboratory. The composition of emulsify asbuton were 5/20 grain, premium, texapon, HCl, and aquades. Solid phase was the mixture asbuton 5/20 grain and premium with 3 minutes mixing time. Liquid phase consisted texapon, HCl and aquades. The aging process was done after solid phase mixing process in order to reaction and tie of solid phase mixed become more optimal for high solubility level of asphalt production. Aging variable time were 30, 60, 90, 120, and 150 minutes. Solid and liquid phase was mixed for emulsify asbuton production, then extracted for 25 minutes. Solubility level of asphalt, water level, and asphalt characteristic was tested at extraction result of emulsify asbuton with most optimum ashphal level. The result of analysis tested data asphalt solubility level at extract asbuton resulted 94.77% on 120 minutes aging variable time. Water level test resulted water content reduction on emulsify asbuton more long time on occurring of aging solid phase. Examination of asphalt characteristic at extraction result of emulsify asbuton with optimum asphalt solubility level, obtain specimen that have rigid and strong texture in order that examination result have not sufficient ductility and penetration value.

  11. Preparation and application of zirconium sulfate supported on SAPO-34 molecular sieve as solid acid catalyst for esterification

    Xu, Dongyan, E-mail:; Ma, Hong; Cheng, Fei


    Graphical abstract: - Highlights: • SAPO-34 supported zirconium sulfate solid acid catalyst was prepared. • Esterification of acetic acid with ethanol can be catalyzed by ZS/SAPO-34. • The hydration of ZS is vital to the acidic property and catalytic performance. • The ZS/SAPO-34 catalyst treated at 200 °C shows good reusability. - Abstract: Zirconium sulfate (ZS) was supported on SAPO-34 molecular sieve by using an incipient wetness impregnation method with zirconium sulfate as the precursor. The as-prepared catalysts were used as solid acid catalyst for esterification reaction of acetic acid with ethanol. The influence of calcination temperature on the acidic property, catalytic activity, and reusability of ZS/SAPO-34 catalysts were mainly investigated. FT-IR, SEM, EDS and TG analysis have been carried out to demonstrate the characteristics of ZS/SAPO-34 catalysts. It was found that the 30 wt%ZS/SAPO-34 catalysts display the property of superacid irrespective of calcination temperature. The ZS/SAPO-34 catalyst treated at 200 °C can enhance the interaction between the supported ZS and SAPO-34 and keep the catalyst remaining substantially active after several reaction cycles. However, further increasing calcination temperature will cause the transfer of ZS from hydrate to anhydrous phase, and thus the decrease of activity.

  12. Direct molecular dynamics simulation of liquid-solid phase equilibria for two-component plasmas.

    Schneider, A S; Hughto, J; Horowitz, C J; Berry, D K


    We determine the liquid-solid phase diagram for carbon-oxygen and oxygen-selenium plasma mixtures using two-phase molecular dynamics simulations. We identify liquid, solid, and interface regions using a bond angle metric. To study finite-size effects, we perform 27,648- and 55,296-ion simulations. To help monitor nonequilibrium effects, we calculate diffusion constants D(i). For the carbon-oxygen system we find that D(O) for oxygen ions in the solid is much smaller than D(C) for carbon ions and that both diffusion constants are 80 or more times smaller than diffusion constants in the liquid phase. There is excellent agreement between our carbon-oxygen phase diagram and that predicted by Medin and Cumming. This suggests that errors from finite-size and nonequilibrium effects are small and that the carbon-oxygen phase diagram is now accurately known. The oxygen-selenium system is a simple two-component model for more complex rapid proton capture nucleosynthesis ash compositions for an accreting neutron star. Diffusion of oxygen, in a predominantly selenium crystal, is remarkably fast, comparable to diffusion in the liquid phase. We find a somewhat lower melting temperature for the oxygen-selenium system than that predicted by Medin and Cumming. This is probably because of electron screening effects.

  13. Regenerable mixed copper-iron-inert support oxygen carriers for solid fuel chemical looping combustion process

    Siriwardane, Ranjani V.; Tian, Hanjing


    The disclosure provides an oxygen carrier for a chemical looping cycle, such as the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The oxygen carrier is comprised of at least 24 weight % (wt %) CuO, at least 10 wt % Fe2O3, and an inert support, and is typically a calcine. The oxygen carrier exhibits a CuO crystalline structure and an absence of iron oxide crystalline structures under XRD crystallography, and provides an improved and sustained combustion reactivity in the temperature range of C. particularly for solid fuels such as carbon and coal.

  14. The Effects of Solid Phase Additives on Sintering Properties of Alumina Bioceramic

    WANG Xin-yu; LI Shi-pu; HE Jian-hua; JIANG Xin; LI Jian-hua


    In order to reduce the sintering temperature and improve the preparing conditions of alumina bioceramics,the Mg-Zr-Y composite solid phase additives were added into high purity Al2O3 micro-powder by chemical coprecipitation method.The powder was shaped under 200MPa cold isostatic pressure,and then the biscuits were sintered at 1600℃ under normal pressure.The sintered alumina materials were tested and the sintering mechanism was discussed.The results show that physical properties of the material were improved comparatively.The Mg-Zr-Y composite solid additives could promote the sintering of alumina bioceramics and the mechanism is solid phase sintering.

  15. The synthesis and chemical durability of Nd-doped single-phase zirconolite solid solutions

    Cai, Xin; Teng, Yuancheng; Wu, Lang; Zhang, Kuibao; Huang, Yi


    Nd-doped single-phase zirconolite solid solutions was synthesized by solid-state reaction and following two steps of acid treatment. The phase composition, microstructure, and chemical durability of the zirconolite solid solutions were investigated. About 15 at% Nd was successfully stabilized into the zirconolite. The element mapping images of Ca, Zr, Nd and Ti show that all the elements are almost distributed homogeneously in the zirconolite waste forms. Product Consistency Test (PCT) was conducted under different pH values (pH = 5, 7 and 9) to evaluate the chemical durability of the Nd-doped zirconolite waste forms. The normalized element release rate of Ca (LRCa) in pH = 5 medium is higher than that of pH = 7 and 9, while the LRNd value remains almost unchanged under different pH values. The LRNd value is as low as 10-5 g m-2 d-1 after 42 days.

  16. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Yu, Honglian; Merib, Josias; Anderson, Jared L


    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively.

  17. Cholesterol transport via ABCA1: new insights from solid-phase binding assay.

    Reboul, Emmanuelle; Dyka, Frank M; Quazi, Faraz; Molday, Robert S


    It is now well established that the ATP-binding cassette transporter A1 (ABCA1) plays a pivotal role in HDL metabolism, reverse cholesterol transport and net efflux of cellular cholesterol and phospholipids. We aimed to resolve some uncertainties related to the putative function of ABCA1 as a mediator of lipid transport by using a methodology developed in the laboratory to isolate a protein and study its interactions with other compounds. ABCA1 was tagged with the 1D4 peptide at the C terminus and expressed in human HEK 293 cells. Preliminary experiments showed that the tag modified neither the protein expression/localization within the cells nor the ability of ABCA1 to promote cholesterol cellular efflux to apolipoprotein A-I. ABCA1-1D4 was then purified and reconstituted in liposomes. ABCA1 displayed an ATPase activity in phospholipid liposomes that was significantly decreased by cholesterol. Finally, interactions with either cholesterol or apolipoprotein A-I were assessed by binding experiments with protein immobilized on an immunoaffinity matrix. Solid-phase binding assays showed no direct binding of cholesterol or apolipoprotein A-I to ABCA1. Overall, our data support the hypothesis that ABCA1 is able to mediate the transport of cholesterol from cells without direct interaction and that apo A-I primarily binds to membrane surface or accessory protein(s).

  18. Laboratory investigation of aluminum solubility and solid-phase properties following alum treatment of lake waters.

    Berkowitz, Jacob; Anderson, Michael A; Graham, Robert C


    Water samples from two southern California lakes adversely affected by internal nutrient loading were treated with a 20 mg/L dose of Al3+ in laboratory studies to examine Al solubility and solid-phase speciation over time. Alum [Al2(SO4)3 . 18 H2O] applications to water samples from Big Bear Lake and Lake Elsinore resulted in a rapid initial decrease in pH and alkalinity followed by a gradual recovery in pH over several weeks. Dissolved Al concentrations increased following treatment, reaching a maximum of 2.54 mg/L after 17 days in Lake Elsinore water and 0.91 mg/L after 48 days in Big Bear Lake water; concentrations in both waters then decreased to Lake Elsinore water. Surface areas also decreased over time as crystals reordered to form gibbsite/microcrystalline gibbsite species. DSC-TGA results suggested that the initially formed amorphous Al(OH)3 underwent transformation to >45% gibbsite. These results were supported by geochemical modeling using Visual MINTEQ, with Al solubility putatively controlled by amorphous Al(OH)3 shortly after treatment and approaching that of microcrystalline gibbsite after about 150 days. These findings indicate that Al(OH)3 formed after alum treatment undergoes significant chemical and mineralogical changes that may alter its effectiveness as a reactive barrier to phosphorus release from lake sediments.

  19. Altering the interfacial activation mechanism of a lipase by solid-phase selective chemical modification.

    López-Gallego, Fernando; Abian, Olga; Guisán, Jose Manuel


    This study presents a combined protein immobilization, directed mutagenesis, and site-selective chemical modification approach, which was used to create a hyperactivated semisynthetic variant of BTL2. Various alkane chains were tethered at three different positions in order to mimic the lipase interfacial activation exogenously triggered by detergents. Optimum results were obtained when a dodecane chain was introduced at position 320 by solid-phase site-selective chemical modification. The resulting semisynthetic variant showed a 2.5-fold higher activity than the wild-type nonmodified variant in aqueous conditions. Remarkably, this is the maximum hyperactivation ever observed for BTL2 in the presence of detergents such as Triton X-100. We present evidence to suggest that the endogenous dodecane chain hyperactivates the enzyme in a similar fashion as an exogenous detergent molecule. In this way, we also observe a faster irreversible enzyme inhibition and an altered detergent sensitivity profile promoted by the site-selective chemical modification. These findings are also supported by fluorescence studies, which reveal that the structural conformation changes of the semisynthetic variant are different to those of the wild type, an effect that is more pronounced in the presence of detergent. Finally, the optimal immobilized semisynthetic variant was successfully applied to the selective synthesis of oxiran-2-yl butyrate. Significantly, this biocatalyst is 12-fold more efficient than the immobilized wild-type enzyme, producing the S-enantiomer with higher enantiospecificity (ee = 92%).

  20. Preparation and characterization of porous carbon material-coated solid-phase microextraction metal fibers.

    Zhu, Fang; Guo, Jiaming; Zeng, Feng; Fu, Ruowen; Wu, Dingcai; Luan, Tiangang; Tong, Yexiang; Lu, Tongbu; Ouyang, Gangfeng


    Two kinds of porous carbon materials, including carbon aerogels (CAs), wormhole-like mesoporous carbons (WMCs), were synthesized and used as the coatings of solid-phase microextraction (SPME) fibers. By using stainless steel wire as the supporting core, six types of fibers were prepared with sol-gel method, direct coating method and direct coating plus sol-gel method. Headspace SPME experiments indicated that the extraction efficiencies of the CA fibers are better than those of the WMC fibers, although the surface area of WMCs is much higher than that of CAs. The sol-gel-CA fiber (CA-A) exhibited excellent extraction properties for non-polar compounds (BTEX, benzene, toluene, ethylbenzene, o-xylene), while direct-coated CA fiber (CA-B) presented the best performance in extracting polar compounds (phenols). The two CA fibers showed wide linear ranges, low detection limits (0.008-0.047μgL(-1) for BTEX, 0.15-5.7μgL(-1) for phenols) and good repeatabilities (RSDs less than 4.6% for BTEX, and less than 9.5% for phenols) and satisfying reproducibilities between fibers (RSDs less than 5.2% for BTEX, and less than 9.9% for phenols). These fibers were successfully used for the analysis of water samples from the Pearl River, which demonstrated the applicability of the home-made CA fibers.

  1. Determination of formaldehyde in Brazilian alcohol fuels by flow-injection solid phase spectrophotometry

    Teixeira, Leonardo S.G.; Leao, Elsimar S.; Dantas, Alailson F.; Pinheiro, Heloisa L.C.; Costa, Antonio C.S.; De Andrade, Jailson B. [Instituto de Quimica-Universidade Federal da Bahia, Campus Universitario de Ondina, 40.170-280-Salvador, Bahia (Brazil)


    In this work, a solid phase spectrophotometric method in association with flow injection analysis for formaldehyde determination has been developed with direct measurement of light-absorption in C{sub 18} material. The 3,5-diacetyl-1,4-dihydrolutidine produced from the reaction between formaldehyde and fluoral P was quantitatively retained on C{sub 18} support and the spectrophotometric detection was performed simultaneously at 412nm. The retained complex was quickly eluted from C{sub 18} material with the eluent stream consisting of a 50% (v/v) ethanol solution. The results showed that the proposed method is simple, rapid and the analytical response is linear in the concentration range of 0.050-1.5mgL{sup -1}. The limit of detection was estimated as 30{mu}mgL{sup -1} and the R.S.D. 2.2% using a sample volume of 625{mu}mL. The system presented an analytical throughput of 20 determinations per hour. The method was successfully applied in the determination of formaldehyde in ethanol fuel.

  2. Determination of formaldehyde in Brazilian alcohol fuels by flow-injection solid phase spectrophotometry.

    Teixeira, Leonardo S G; Leão, Elsimar S; Dantas, Alaílson F; Pinheiro, Heloísa L C; Costa, Antonio C S; de Andrade, Jailson B


    In this work, a solid phase spectrophotometric method in association with flow injection analysis for formaldehyde determination has been developed with direct measurement of light-absorption in C(18) material. The 3,5-diacetyl-1,4-dihydrolutidine produced from the reaction between formaldehyde and fluoral P was quantitatively retained on C(18) support and the spectrophotometric detection was performed simultaneously at 412nm. The retained complex was quickly eluted from C(18) material with the eluent stream consisting of a 50% (v/v) ethanol solution. The results showed that the proposed method is simple, rapid and the analytical response is linear in the concentration range of 0.050-1.5mgL(-1). The limit of detection was estimated as 30mugL(-1) and the R.S.D. 2.2% using a sample volume of 625muL. The system presented an analytical throughput of 20 determinations per hour. The method was successfully applied in the determination of formaldehyde in ethanol fuel.

  3. Understanding processing-induced phase transformations in erythromycin-PEG 6000 solid dispersions

    Mirza, Sabiruddin; Heinämäki, Jyrki; Miroshnyk, Inna


    Since the quality and performance of a pharmaceutical solid formulation depend on solid state of the drug and excipients, a thorough investigation of potential processing-induced transformations (PITs) of the ingredients is required. In this study, the physical phenomena taking place during...... formulation of erythromycin (EM) dihydrate solid dispersions with polyethylene glycol (PEG) 6000 by melting were investigated. PITs were monitored in situ using variable temperature X-ray powder diffraction (VT-XRPD), differential scanning calorimetry (DSC), and hot-stage microscopy (HSM). Possible...... intermolecular interactions between the drug and polymer in the solid state were further studied by Fourier transform infrared (FTIR) spectroscopy. While in the absence of PEG the dehydration was the only transformation observed, hot-melt processing with the polymer caused the drug to undergo multiple phase...

  4. Ni coarsening in the three-phase solid oxide fuel cell anode - a phase-field simulation study

    Chen, Hsun-Yi; Cronin, J Scott; Wilson, James R; Barnett, Scott A; Thornton, Katsuyo


    Ni coarsening in Ni-yttria stabilized zirconia (YSZ) solid oxide fuel cell anodes is considered a major reason for anode degradation. We present a predictive, quantative modeling framework based on the phase-field approach to systematically examine coarsening kinetics in such anodes. The initial structures for simulations are experimentally acquired functional layers of anodes. Sample size effects and error analysis of contact angles are examined. Three phase boundary (TPB) lengths and Ni surface areas are quantatively identified on the basis of the active, dead-end, and isolated phase clusters throughout coarsening. Tortuosity evolution of the pores is also investigated. We find that phase clusters with larger characteristic length evolve slower than those with smaller length scales. As a result, coarsening has small positive effects on transport, and impacts less on the active Ni surface area than the total counter part. TPBs, however, are found to be sensitive to local morphological features and are only i...

  5. Indirect solid-phase immunosorbent assay for detection of arenavirus antigens and antibodies

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A. (Institute of Poliomyelitis anU Viral Encephalities of the U.S.S.R. Academy of Medical Sciences, Moscow)


    Indirect enzyme-linked immunosorbent assay (ELISA) and solid phase radioimmunoassay (SPRIA) using either enti-human or anti-mouse IgG labelled with horseradish peroxidase and /sup 125/I, respectively, were developed for the detection of Junin, Machupo, Tacaribe, Amapari, Tamiami, Lassa and LCM arenaviruses. Both methods allow high sensitivity detection of arenavirus antigens and antibodies.

  6. Solid-phase synthesis of an apoptosis-inducing tetrapeptide mimicking the Smac protein

    Le Quement, Sebastian Thordal; Ishøy, Mette; Petersen, Mette Terp;


    An approach for the solid-phase synthesis of apoptosis-inducing Smac peptidomimetics is presented. Using a Rink linker strategy, tetrapeptides mimicking the N-4-terminal residue of the Smac protein [(N-Me)AVPF sequence] were synthesized on PEGA resin in excellent purities and yields. Following tw...

  7. Detection and specifity of class specific antibodies to whole bacteria cells using a solid phase radioimmunoassay

    Czerkinsky, C.; Rees, A.S.; Bergimeier, L.A.; Challacombe, S.J. (Guy' s Hospital Medical and Dental Schools, London (UK))


    A solid phase radioimmunoassay has been developed which can be used for the detection of isotype specific antibodies to whole bacteria and other particulate antigens, and is applicable to a variety of species. Bacteria are bound to the solid phase by the use either of antibodies, or of methyl glyoxal. Both methods result in a sensitive and reproducible assay, and bacteria do not appear to desorb from the solid phase. The specificity of antibodies to whole bacteria was examined by absorption of antisera with various species of bacteria and retesting, or by determining the binding of antisera to various bacteria bound to the solid phase. Both methods revealed specificity for the bacteria examined. Inhibition studies showed that antibodies to Streptococcus mutans whole cells could be inhibited by purified cell surface antigens glucosyltransferase and antigen I/II, but only minimally by lipoteichoic acid, c polysaccharide or dextran. In murine antisera antibodies of the IgG, IgM, and IgA classes could be detected at amounts of less than 1 ng/ml.

  8. New method for the preparation of solid-phase bound isocyanocarboxylic acids and Ugi reactions therewith

    Henkel, Bernd; Sax, Michael; Dömling, Alexander


    A novel method of synthesizing solid-phase bound isocyanocarboxylic acids is reported. The potassium salts of four different isocyanocarboxylic acids are coupled onto a brominated resin in DMF in good yields. 32 Ugi reactions were performed using these resins and 24 products were obtained in good to

  9. Solid Phase Extraction: Applications to the Chromatographic Analysis of Vegetable Oils and Fats

    Panagiotopoulout, P. M.; Tsimidou, M.


    Applications of solid-phase extraction for the isolation of certain lipid classes prior to chromatographic analysis are given. More information was found for sterols and related compounds, polar phenols and contaminants such as polycyclic aromatic hydrocarbons. Detailed analytical protocols are presented and discussed in many cases. (Author) 120 refs.

  10. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

    Lors, Christine [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France); Centre National de Recherche sur les Sites et Sols Pollues, 930 Boulevard Lahure, BP 537, 59505 Douai Cedex (France); Ponge, Jean-Francois, E-mail: [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Martinez Aldaya, Maite [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Damidot, Denis [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France)


    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. - Highlights: > Comparison of liquid- and solid-phase bioassays on contaminated soils, using ecoscores. > Complementarity of liquid- and solid-phase bioassays for the evaluation of environmental hazards. > Proposal for a restricted battery of 5 most sensitive tests. > Use of this restricted battery for a cost-effective assessment of polluted/remediated soils. - Aqueous and solid phases of contaminated soils give similar results in terms of toxicity but are complementary for the evaluation of environmental hazards by ecoscores.

  11. Solid-phase synthesis of polyfunctional polylysine dendrons using aldehyde linkers

    Svenssen, Daniel K.; Mirsharghi, Sahar; Boas, Ulrik


    A straightforward method for the solid-phase synthesis of C-terminally modified polylysine dendrons has been developed by applying bisalkoxybenzaldehyde and trisalkoxybenzaldehyde linkers. The method has been used for the synthesis of polylysine dendrons with a variety of C-terminal ‘tail groups’...

  12. Micro versus macro solid phase extraction for monitoring water contaminants: a preliminary study using trihalomethanes.

    Alexandrou, Lydon D; Spencer, Michelle J S; Morrison, Paul D; Meehan, Barry J; Jones, Oliver A H


    Solid phase extraction is one of the most commonly used pre-concentration and cleanup steps in environmental science. However, traditional methods need electrically powered pumps, can use large volumes of solvent (if multiple samples are run), and require several hours to filter a sample. Additionally, if the cartridge is open to the air volatile compounds may be lost and sample integrity compromised. In contrast, micro cartridge based solid phase extraction can be completed in less than 2 min by hand, uses only microlitres of solvent and provides comparable concentration factors to established methods. It is also an enclosed system so volatile components are not lost. The sample can also be eluted directly into a detector (e.g. a mass spectrometer) if required. However, the technology is new and has not been much used for environmental analysis. In this study we compare traditional (macro) and the new micro solid phase extraction for the analysis of four common volatile trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane and tribromomethane). The results demonstrate that micro solid phase extraction is faster and cheaper than traditional methods with similar recovery rates for the target compounds. This method shows potential for further development in a range of applications.

  13. Solid-phase oligosaccharide synthesis with tris(alkoxy)benzyl amine (BAL) safety-catch anchoring

    Tolborg, Jakob Fjord; Jensen, Knud Jørgen


    A tris(alkoxy)benzylamine (BAL) handle strategy was developed for safety-catch anchoring of D-glucosamine derivatives in solid-phase synthesis of oligosaccharides; the linkage between the BAL handle and the amine proved stable to conc. TFA and Lewis acids, but after N-acylation the amide could...

  14. A Solid Phase Synthesis of Chalcones by Claisen-Schmidt Condensations


    In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroquine-resistant strains of Plasmodium falclparum, a methodology for the solid phase synthesis of chalcone (l, 3-diphenyl-2-propen-l-one) analogues in reasonably high yields has been developed.

  15. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  16. Microwave-assisted solid-phase Ugi four-component condensations

    Nielsen, John


    An 18-member library was constructed from 2 isocyanides, 3 aldehydes and 3 carboxylic acids via microwave-assisted solid-phase Ugi reactions on TentaGel S RAM. Products of high purity were obtained in moderate to excellent yields after reaction times of 5 minutes or less (irradiation at 60W). (C...

  17. Determination of lidocaine in plasma by direct solid-phase microextraction combined with gas chromatography

    Koster, EHM; Wemes, C; Morsink, JB; de Jong, GJ


    Direct-immersion solid-phase microextraction (SPME) has been used to extract the local anesthetic lidocaine from human plasma. A simplified model shows the relationship between the total amount of drug in plasma and the amount of drug extracted. The model takes into account that the drug participate

  18. Side-chain-anchored N(alpha)-Fmoc-Tyr-OPfp for bidirectional solid-phase synthesis

    Olsen, Christian A; Jørgensen, Malene; Hansen, Steen H;


    [reaction: see text] A mild resin-immobilization strategy employing a readily prepared trityl bromide resin for anchoring building blocks via a phenol group has been developed. With N(alpha)-Fmoc-Tyr-OPfp as a starter building block, it was possible to prepare asymmetrically substituted hybrids o...... of spider- and wasp-type polyamine toxins using solid-phase peptide synthesis conditions....

  19. Speciation analysis of aqueous nanoparticulate diclofenac complexes by solid-phase microextraction

    Zielinska, K.; Leeuwen, van H.P.; Thibault, S.; Town, R.M.


    The dynamic sorption of an organic compound by nanoparticles (NPs) is analyzed by solid-phase microextraction (SPME) for the example case of the pharmaceutical diclofenac in dispersions of impermeable (silica, SiO(2)) and permeable (bovine serum albumin, BSA) NPs. It is shown that only the protonate

  20. Solid-phase synthesis of succinylhydroxamate peptides : Functionalized matrix metalloproteinase inhibitors

    Leeuwenburgh, MA; Geurink, PP; Klein, T; Kauffman, HF; van der Marel, GA; Bischoff, R; Overkleeft, HS


    A novel solid-phase synthesis strategy toward succinylhydroxamate peptides, using an appropriately protected hydroxamate building block, is described. Rapid and efficient access is gained to amine-functionalized peptides, which can be decorated with, for instance, a fluorescent label. In addition, w

  1. A convenient procedure for the solid-phase synthesis of hydroxamic acids on PEGA resins

    Nandurkar, Nitin Subhash; Petersen, Rico; Qvortrup, Katrine


    An efficient method for the solid-phase synthesis of hydroxamic acids is described. The method comprises the nucleophilic displacement of esters immobilized on PEGA resins with hydroxylamine/sodium hydroxide in isopropanol. The hydroxyaminolysis protocol is compatible with a broad range of PEGA-s...

  2. A Rapid Solid-phase Synthesis to Soluble Oligothiophene Molecular Wires


    A novel method for the preparation of oligothiophene molecular wires is described via a bi-directional solid-phase synthesis. Using an alternating sequence of bromination and Stille coupling reactions, oligomers were obtained up to the heptamer in excellent yield and purity.

  3. Linkers, resins, and general procedures for solid-phase peptide synthesis

    Shelton, Anne Pernille Tofteng; Jensen, Knud Jørgen


    and linkers for solid-phase synthesis is a key parameter for successful peptide synthesis. This chapter provides an overview of the most common and useful resins and linkers for the synthesis of peptides with C-terminal amides, carboxylic acids, and more. The chapter finishes with robust protocols for general...

  4. Total synthesis of human urotension-Ⅱ by microwave-assisted solid phase method


    Human urotension-Ⅱ was synthesized efficiently on Wang resin under microwave irradiation using Fmoc/tBu orthogonal protection strategy. Disulphide bridge was formed on solid phase with the irradiation of microwave, then the whole peptide was cleaved from the resin. The purity of crude peptide cyclized under microwave irradiation was higher than that under room temperature.

  5. Electrocatalytic phenomena in gas phase reactions in solid electrolyte electrochemical cells

    Gellings, P.J.; Koopmans, H.J.A.; Burggraaf, A.J.


    The recent literature on electrocatalysis and electrocatalytic phenomena occurring in gas phase reactions on solid, oxygen conducting electrolytes is reviewed. In this field there are a number of different subjects which are treated separately. These are: the use of electrochemical methods to study

  6. Solid-phase Synthesis of a Novel Kind of Hydroxylated Heterocyclic Ketene Aminals

    Tao PENG; Chu Yi YU; Zhi Tang HUANG


    An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.

  7. Fibers coated with molecularly imprinted polymers for solid-phase microextraction

    Koster, E.H M; Crescenzi, C; den Hoedt, W; Ensing, K; de Jong, G.J.


    The simplicity and flexibility of solid-phase microextraction have been combined with the selectivity of molecularly imprinted polymers (MIPs), Silica fibers were coated reproducible with a 75-mum layer of methacrylate polymer either nonimprinted or imprinted with clenbuterol to compare their extrac

  8. Dynamic speciation analysis of atrazine in aqueous latex nanoparticle dispersions using solid phase microextraction (SPME)

    Benhabib, K.; Town, R.M.; Leeuwen, van H.P.


    Solid phase microextraction (SPME) is applied in the dynamic speciation analysis of the pesticide atrazine in an aqueous medium containing sorbing latex nanoparticles. It is found that the overall rate of extraction of the analyte is faster than in the absence of nanoparticles and governed by the

  9. Investigating the Retention Mechanisms of Liquid Chromatography Using Solid-Phase Extraction Cartridges

    O'Donnell, Mary E.; Musial, Beata A.; Bretz, Stacey Lowery; Danielson, Neil D.; Ca, Diep


    Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase…

  10. Solid-Phase Synthesis of Smac Peptidomimetics Incorporating Triazoloprolines and Biarylalanines

    Le Quement, Sebastian T.; Ishoey, Mette; Petersen, Mette T.;


    -Me)AVPF sequence, peptides incorporating triazoloprolines and biarylalanines were synthesized by means of Cu(I)-catalyzed azide–alkyne cycloaddition and Pd-catalyzed Suzuki cross-coupling reactions. Solid-phase procedures were optimized to high efficiency, thus accessing all products in excellent crude purities...

  11. Highly Selective Liquid-Phase Benzylation of Anisole with Solid-Acid Zeolite Catalysts

    Poreddy, Raju; Shunmugavel, Saravanamurugan; Riisager, Anders


    Zeolites were evaluated as solid acid catalysts for the liquid-phase benzylation of anisole with benzyl alcohol, benzyl bromide, and benzyl chloride at 80 °C. Among the examined zeolites, H-mordenite-10 (H-MOR-10) demonstrated particular high activity (>99 %) and excellent selectivity (>96...

  12. Rapid and convenient semi-automated microwave-assisted solid-phase synthesis of arylopeptoids

    Rasmussen, Jakob Ewald; Boccia, Marcello Massimo; Nielsen, John


    A facile and expedient route to the synthesis of arylopeptoid oligomers (N-alkylated aminomethyl benz-amides) using semi-automated microwave-assisted solid-phase synthesis is presented. The synthesis was optimized for the incorporation of side chains derived from sterically hindered or unreactive...

  13. Solid-Phase Synthesis of Small Molecule Libraries using Double Combinatorial Chemistry

    Nielsen, John; Jensen, Flemming R.


    The first synthesis of a combinatorial library using double combinatorial chemistry is presented. Coupling of unprotected Fmoc-tyrosine to the solid support was followed by Mitsunobu O-alkylation. Introduction of a diacid linker yields a system in which the double combinatorial step can be demons......The first synthesis of a combinatorial library using double combinatorial chemistry is presented. Coupling of unprotected Fmoc-tyrosine to the solid support was followed by Mitsunobu O-alkylation. Introduction of a diacid linker yields a system in which the double combinatorial step can...... be demonstrated. The resulting library of model compounds was verified by LC-MS analysis. (C) 1997 Elsevier Science Ltd....

  14. Preparation of zeolite ANA crystal from zeolite Y by in situ solid phase iso-structure transformation.

    Wang, Yi; Li, Xuguang; Xue, Zhiyuan; Dai, Linsen; Xie, Songhai; Li, Quanzhi


    A new method has been explored to synthesize zeolite ANA crystals with regular icositetrahedron in aqueous media via transformation of zeolite Y under the conditions of low temperature, short reaction time, and without organic template. The products are perfect, almost 100% crystals. The samples prepared at different crystallization stages are measured by XRD, TEM, and SEM to investigate the transformation mechanism from zeolite Y to zeolite ANA. It has been demonstrated for the first time that the mechanism of forming a zeolite ANA polycrystal with sphere or shell morphologies is the in situ solid phase iso-structure transformation (Is-SPIST) of zeolite Y. The Is-SPIST mechanism is also supported by the results of steam-induced crystallization experiments and other assistant means, including the same Si/Al ratio, the same weight, the same particle size, and the same morphology before and after transformation of zeolite Y to zeolite ANA. It is also observed that a spherical or shell ANA polycrystal is constructed via the reconstruction from its exterior to interior, to form an ANA single crystal with a solid or hollow icositetrahedron. The main driving force of the reconstruction is considered to be the grain boundary energy existing between polycrystalline grains. This process also obeys the mechanism of in situ solid phase reconstruction (Is-SPR). Furthermore, the size and morphology of the zeolite ANA single crystal can be modified by surfactants.

  15. Determination of aflatoxins in rice samples by ultrasound-assisted matrix solid-phase dispersion.

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi


    This work describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and sample preparation approach for aflatoxins (B1, B2, G1 and G2) and subsequent determination of them by high-performance liquid chromatography-fluorescence detection. A Box-Behnken design in combination with response surface methodology was used to determine the affecting parameters on the extraction procedure. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent was investigated in the optimization study. C18, primary-secondary amine (PSA) and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The obtained optimized values were sample-to-dispersing phase ratio of 1 : 1, 60 mg of PSA, 11 min ultrasonication time, 30°C ultrasonication temperature and 4 mL acetonitrile. Under the optimal conditions, the limits of detection were ranged from 0.09 to 0.14 ng g(-1) and the precisions [relative standard deviation (RSD%)] were <8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 78 to 83% with RSD <10% in all cases. Finally, this method was successfully applied to the extraction of trace amounts of aflatoxins in rice samples. © The Author [2014]. Published by Oxford University Press. All rights reserved. For Permissions, please email:

  16. Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

    Reiss, Georg; Frandsen, Henrik Lund; Brandstätter, Wilhelm; Weber, André


    Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X-ray tomography and micro-structural modelling is presented in this work. The simulation technique comprises a novel treatment of the boundary conditions, which leads to more accurate effective transport parameters compared to those, which can be achieved with the conventional homogenisation procedures. Furthermore, the porosity distribution in the metal-support was determined, which provided information about the inhomogeneous nature of the material. In addition to that, transport parameters for two identified, different dense layers of the metal-support are evaluated separately. The results of the evaluation show three significant findings. Firstly, that the effective transport parameters are up to a factor of 20 lower compared to other SOFC anodes. Secondly, that the micro-structure can have regions, which are much denser, especially the first 100 μm of the interface between gas-channel and support-structure. Thirdly, that the calculation of the transport parameters depends on the correct application of boundary conditions.

  17. Solid polymer electrolyte composite membrane comprising a porous support and a solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide

    Liu, Han; Mittelsteadt, Cortney K; Norman, Timothy J; Griffith, Arthur E; LaConti, Anthony B


    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

  18. Profilometry of three-dimensional discontinuous solids by combining two-steps temporal phase unwrapping, co-phased profilometry and phase-shifting interferometry

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo; Gonzalez, Adonai


    In this work we review and combine two techniques that have been recently published for three-dimensional (3D) fringe projection profilometry and phase unwrapping, namely: co-phased profilometry and 2-steps temporal phase-unwrapping. By combining these two methods we get a more accurate, higher signal-to-noise 3D profilometer for discontinuous industrial objects. In single-camera single-projector (standard) profilometry, the camera and the projector must form an angle between them. The phase-sensitivity of the profilometer depends on this angle, so it cannot be avoided. This angle produces regions with self-occluding shadows and glare from the solid as viewed from the camera's perspective, making impossible the demodulation of the fringe-pattern there. In other words, the phase data is undefined at those shadow regions. As published recently, this limitation can be solved by using several co-phased fringe-projectors and a single camera. These co-phased projectors are positioned at different directions towards the object, and as a consequence most shadows are compensated. In addition to this, most industrial objects are highly discontinuous, which precludes the use of spatial phase-unwrappers. One way to avoid spatial unwrapping is to decrease the phase-sensitivity to a point where the demodulated phase is bounded to one lambda, so the need for phase-unwrapping disappears. By doing this, however, the recovered non-wrapped phase contains too much harmonic distortion and noise. Using our recently proposed two-step temporal phase-unwrapping technique, the high-sensitivity phase is unwrapped using the low-frequency one as initial gross estimation. This two-step unwrapping technique solves the 3D object discontinuities while keeping the accuracy of the high-frequency profilometry data. In scientific research, new art are derived as logical and consistent result of previous efforts in the same direction. Here we present a new 3D-profilometer combining these two recently

  19. CSBB-ConeExclusion, adapting structure based solution virtual screening to libraries on solid support.

    Shave, Steven; Auer, Manfred


    Combinatorial chemical libraries produced on solid support offer fast and cost-effective access to a large number of unique compounds. If such libraries are screened directly on-bead, the speed at which chemical space can be explored by chemists is much greater than that addressable using solution based synthesis and screening methods. Solution based screening has a large supporting body of software such as structure-based virtual screening tools which enable the prediction of protein-ligand complexes. Use of these techniques to predict the protein bound complexes of compounds synthesized on solid support neglects to take into account the conjugation site on the small molecule ligand. This may invalidate predicted binding modes, the linker may be clashing with protein atoms. We present CSBB-ConeExclusion, a methodology and computer program which provides a measure of the applicability of solution dockings to solid support. Output is given in the form of statistics for each docking pose, a unique 2D visualization method which can be used to determine applicability at a glance, and automatically generated PyMol scripts allowing visualization of protein atom incursion into a defined exclusion volume. CSBB-ConeExclusion is then exemplarically used to determine the optimum attachment point for a purine library targeting cyclin-dependent kinase 2 CDK2.



    In this paper, an energy equation of silt-laden water flow is educed based on the energy equation of continuum fluid flow. The dissipation functions of liquid phase and solid phase are presented respectively. Then the extremity law of energy dissipation rate is introduced for the research of the silt-laden water flow and a new mathematical model is developed. The corresponding procedure based on the finite difference method (FDM) is developed to calculate the two phase flow in hydraulic turbine. The method is applied to analyze the silt-laden water flow between stay vanes, and the numerical results are in good agreement with the experimental ones.

  1. Phase separation kinetics in amorphous solid dispersions upon exposure to water.

    Purohit, Hitesh S; Taylor, Lynne S


    The purpose of this study was to develop a novel fluorescence technique employing environment-sensitive fluorescent probes to study phase separation kinetics in hydrated matrices of amorphous solid dispersions (ASDs) following storage at high humidity and during dissolution. The initial miscibility of the ASDs was confirmed using infrared (IR) spectroscopy and differential scanning calorimetry (DSC). Fluorescence spectroscopy, as an independent primary technique, was used together with conventional confirmatory techniques including DSC, X-ray diffraction (XRD), fluorescence microscopy, and IR spectroscopy to study phase separation phenomena. By monitoring the emission characteristics of the environment-sensitive fluorescent probes, it was possible to successfully monitor amorphous-amorphous phase separation (AAPS) as a function of time in probucol-poly(vinylpyrrolidone) (PVP) and ritonavir-PVP ASDs after exposure to water. In contrast, a ritonavir-hydroxypropylmethylcellulose acetate succinate (HPMCAS) ASD, did not show AAPS and was used as a control to demonstrate the capability of the newly developed fluorescence method to differentiate systems that showed no phase separation following exposure to water versus those that did. The results from the fluorescence studies were in good agreement with results obtained using various other complementary techniques. Thus, fluorescence spectroscopy can be utilized as a fast and efficient tool to detect and monitor the kinetics of phase transformations in amorphous solid dispersions during hydration and will help provide mechanistic insight into the stability and dissolution behavior of amorphous solid dispersions.

  2. Cluster-based composition rule for Laves phase-related BCC solid solution hydrogen storage alloys

    WANG Qing; CHEN Feng; WU Jiang; QIANG Jianbing; DONG Chuang; ZHANG Yao; XU Fen; SUN Lixian


    A new cluster line approach for the composition rule of Laves phase-related BCC solid solution hydrogen-storage alloys was presented. The cluster line in a ternary phase diagram refers to a straight composition line linking a specific binary cluster to the third element. In the Laves phase-related BCC solid solution alloy system such as Ti-Cr-V, Ti-Cr tends to form binary Cr2Ti Laves phase while Ti-V and Cr-V to form solid solutions. This Laves phase is characterized by a close-packing icosahedral cluster Cr7Ti6. A cluster line Cr7Ti6-V is then constructed in this system. Alloy rods with a diameter of 3 mm of compositions along this line were prepared by copper-mould suction method. The alloy structure is found to vary with the V contents. Furthermore, the P-C-T measurements indicate that the cluster-line (Cr7Ti6)1-xVx alloys have large hydrogen storage capacities.

  3. Accelerated exploration of multi-principal element alloys with solid solution phases

    Senkov, O. N.; Miller, J. D.; Miracle, D. B.; Woodward, C.


    Recent multi-principal element, high entropy alloy (HEA) development strategies vastly expand the number of candidate alloy systems, but also pose a new challenge—how to rapidly screen thousands of candidate alloy systems for targeted properties. Here we develop a new approach to rapidly assess structural metals by combining calculated phase diagrams with simple rules based on the phases present, their transformation temperatures and useful microstructures. We evaluate over 130,000 alloy systems, identifying promising compositions for more time-intensive experimental studies. We find the surprising result that solid solution alloys become less likely as the number of alloy elements increases. This contradicts the major premise of HEAs—that increased configurational entropy increases the stability of disordered solid solution phases. As the number of elements increases, the configurational entropy rises slowly while the probability of at least one pair of elements favouring formation of intermetallic compounds increases more rapidly, explaining this apparent contradiction.

  4. Accelerated exploration of multi-principal element alloys with solid solution phases.

    Senkov, O N; Miller, J D; Miracle, D B; Woodward, C


    Recent multi-principal element, high entropy alloy (HEA) development strategies vastly expand the number of candidate alloy systems, but also pose a new challenge--how to rapidly screen thousands of candidate alloy systems for targeted properties. Here we develop a new approach to rapidly assess structural metals by combining calculated phase diagrams with simple rules based on the phases present, their transformation temperatures and useful microstructures. We evaluate over 130,000 alloy systems, identifying promising compositions for more time-intensive experimental studies. We find the surprising result that solid solution alloys become less likely as the number of alloy elements increases. This contradicts the major premise of HEAs--that increased configurational entropy increases the stability of disordered solid solution phases. As the number of elements increases, the configurational entropy rises slowly while the probability of at least one pair of elements favouring formation of intermetallic compounds increases more rapidly, explaining this apparent contradiction.

  5. A phase-field approach to nonequilibrium phase transformations in elastic solids via an intermediate phase (melt) allowing for interface stresses.

    Momeni, Kasra; Levitas, Valery I


    A phase-field approach for phase transformations (PTs) between three different phases at nonequilibrium temperatures is developed. It includes advanced mechanics, thermodynamically consistent interfacial stresses, and interface interactions. A thermodynamic Landau-Ginzburg potential developed in terms of polar order parameters satisfies the desired instability and equilibrium conditions for homogeneous phases. The interfacial stresses were introduced with some terms from large-strain formulation even though the small-strain assumption was utilized. The developed model is applied to study the PTs between two solid phases via a highly disordered intermediate phase (IP) or an intermediate melt (IM) hundreds of degrees below the melting temperature. In particular, the β ↔ δ PTs in HMX energetic crystals via IM are analyzed. The effects of various parameters (temperature, ratios of widths and energies of solid-solid (SS) to solid-melt (SM) interfaces, elastic energy, and interfacial stresses) on the formation, stability, and structure of the IM within a propagating SS interface are studied. Interfacial and elastic stresses within a SS interphase and their relaxation and redistribution with the appearance of a partial or complete IM are analyzed. The energy and structure of the critical nucleus (CN) of the IM are studied as well. In particular, the interfacial stresses increase the aspect-ratio of the CN. Although including elastic energy can drastically reduce the energy of the CN of the IM, the activation energy of the CN of the IM within the SS interface increases when interfacial tension is taken into account. The developed thermodynamic potential can also be modified to model other multiphase physical phenomena, such as multi-variant martensitic PTs, grain boundary and surface-induced pre-melting and PTs, as well as developing phase diagrams for IPs.

  6. Liquid Phase Hydrogenation of Nitrobenzene over Nickel Supported on Titania



    The catalytic hydrogenation of nitrobenzene to aniline employing nickel impregnated on rutile,anatase,and high surface area titania supports has been investigated.The nickel is present in elemental state as fcc phase on the catalyst as evidenced by X-ray diffraction results.The Ni crystallite size was found to be greater for Ni/anatase.The temperature-programmed reduction results suggest a greater metal-support interaction for Ni/rutile.The observed order of catalytic activity for the hydrogenation of nitrobenzene is Ni/rutile > Ni/anatase > Ni/TiO2.A conversion of 99% was observed for Ni/rutile at 140 ℃ and hydrogen pressure of 1.96 MPa.Interestingly,aniline is the only product formed which demonstrates the catalytic hydrogenation of nitrobenzene proceeds with atom economy.Both Ni/rutile and Ni/anatase exhibited a better stability than Ni/TiO2.The hydrogenation proceeds with the preferential adsorption of hydrogen on nickel present in the catalyst surface,possibly assisted by TiOx species.

  7. A Variational Model for Two-Phase Immiscible Electroosmotic Flow at Solid Surfaces

    Shao, Sihong


    We develop a continuum hydrodynamic model for two-phase immiscible flows that involve electroosmotic effect in an electrolyte and moving contact line at solid surfaces. The model is derived through a variational approach based on the Onsager principle of minimum energy dissipation. This approach was first presented in the derivation of a continuum hydrodynamic model for moving contact line in neutral two-phase immiscible flows (Qian, Wang, and Sheng, J. Fluid Mech. 564, 333-360 (2006)). Physically, the electroosmotic effect can be formulated by the Onsager principle as well in the linear response regime. Therefore, the same variational approach is applied here to the derivation of the continuum hydrodynamic model for charged two-phase immiscible flows where one fluid component is an electrolyte exhibiting electroosmotic effect on a charged surface. A phase field is employed to model the diffuse interface between two immiscible fluid components, one being the electrolyte and the other a nonconductive fluid, both allowed to slip at solid surfaces. Our model consists of the incompressible Navier-Stokes equation for momentum transport, the Nernst-Planck equation for ion transport, the Cahn-Hilliard phase-field equation for interface motion, and the Poisson equation for electric potential, along with all the necessary boundary conditions. In particular, all the dynamic boundary conditions at solid surfaces, including the generalized Navier boundary condition for slip, are derived together with the equations of motion in the bulk region. Numerical examples in two-dimensional space, which involve overlapped electric double layer fields, have been presented to demonstrate the validity and applicability of the model, and a few salient features of the two-phase immiscible electroosmotic flows at solid surface. The wall slip in the vicinity of moving contact line and the Smoluchowski slip in the electric double layer are both investigated. © 2012 Global-Science Press.

  8. Optical manipulation of the Berry phase in a solid-state spin qubit

    Yale, Christopher G.; Heremans, F. Joseph; Zhou, Brian B.; Auer, Adrian; Burkard, Guido; Awschalom, David D.


    Phase relations between quantum states represent a resource for storing and processing quantum information. Although quantum phases are commonly controlled dynamically by tuning energetic interactions, the use of geometric phases that accumulate during cyclic evolution may offer superior robustness to noise. To date, demonstrations of geometric phase in solid-state systems employ microwave fields that have limited spatial resolution. Here, we demonstrate an all-optical method to accumulate a geometric phase, the Berry phase, in an individual nitrogen-vacancy centre in diamond. Using stimulated Raman adiabatic passage controlled by diffraction-limited laser light, we loop the nitrogen-vacancy centre's spin around the Bloch sphere to enclose an arbitrary Berry phase. We investigate the limits of this control due to the loss of adiabaticity and decoherence, as well as its robustness to noise introduced into the experimental control parameters. These techniques set the foundation for optical geometric manipulation in photonic networks of solid-state qubits linked and controlled by light.

  9. A lab-on-a-chip device for rapid identification of avian influenza viral RNA by solid-phase PCR

    Yi, Sun; Dhumpa, Raghuram; Bang, Dang Duong


    This paper describes a lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid-phase PCR on a microfluidic chip.......This paper describes a lab-on-a-chip device for fast AIV screening by integrating DNA microarray-based solid-phase PCR on a microfluidic chip....

  10. A photolabile linker for the solid-phase synthesis of 4-substituted NH-1,2,3-triazoles

    Qvortrup, Katrine; Nielsen, Thomas Eiland


    A novel photolabile linker for solid-phase synthesis is presented. The linker displays an azido handle for copper-catalyzed azide–alkyne cycloaddition reactions with a variety of alkynes, remains intact under typical solid-phase reaction conditions, and enables a mild photolytic release of 4-subs...

  11. Direct MD simulation of liquid-solid phase equilibria for three-component plasma

    Hughto, J; Schneider, A S; Medin, Zach; Cumming, Andrew; Berry, D K


    The neutron rich isotope 22Ne may be a significant impurity in carbon and oxygen white dwarfs and could impact how the stars freeze. We perform molecular dynamics simulations to determine the influence of 22Ne in carbon-oxygen-neon systems on liquid-solid phase equilibria. Both liquid and solid phases are present simultaneously in our simulation volumes. We identify liquid, solid, and interface regions in our simulations using a bond angle metric. In general we find good agreement for the composition of liquid and solid phases between our MD simulations and the semi analytic model of Medin and Cumming. The trace presence of a third component, neon, does not appear to strongly impact the chemical separation found previously for two component carbon and oxygen systems. This suggests that small amounts of 22Ne may not qualitatively change how the material in white dwarf stars freezes. However, we do find systematically lower melting temperatures (higher Gamma) in our MD simulations compared to the semi analytic ...

  12. Phase Evolution and Mechanical Behavior of the Semi-Solid SIMA Processed 7075 Aluminum Alloy

    Behzad Binesh


    Full Text Available Microstructural and mechanical behaviors of semi-solid 7075 aluminum alloy were investigated during semi-solid processing. The strain induced melt activation (SIMA process consisted of applying uniaxial compression strain at ambient temperature and subsequent semi-solid treatment at 600–620 °C for 5–35 min. Microstructures were characterized by scanning electron microscope (SEM, energy dispersive spectroscopy (EDS, and X-ray diffraction (XRD. During the isothermal heating, intermetallic precipitates were gradually dissolved through the phase transformations of α-Al + η (MgZn2 → liquid phase (L and then α-Al + Al2CuMg (S + Mg2Si → liquid phase (L. However, Fe-rich precipitates appeared mainly as square particles at the grain boundaries at low heating temperatures. Cu and Si were enriched at the grain boundaries during the isothermal treatment while a significant depletion of Mg was also observed at the grain boundaries. The mechanical behavior of different SIMA processed samples in the semi-solid state were investigated by means of hot compression tests. The results indicated that the SIMA processed sample with near equiaxed microstructure exhibits the highest flow resistance during thixoforming which significantly decreases in the case of samples with globular microstructures. This was justified based on the governing deformation mechanisms for different thixoformed microstructures.


    Dulce A. Flores-Maltos


    Full Text Available Biological wastes contain several reusable substances of high value such as soluble sugars and fiber. Direct disposal of such wastes to soil or landfill causes serious environmental problems. Thus, the development of potential value-added processes for these wastes is highly attractive. These biological wastes can be used as support-substrates in Solid-State Fermentation (SSF to produce industrially relevant metabolites with great economical advantage. In addition, it is an environment friendly method of waste management. In this study were analyzed six different Mexican agro industrial residues to evaluate their suitability as support-substrate in SSF, between physicochemical properties that have included Water Absorption Index (WAI, Critical Moisture Point (CHP and Packing Density (PD. The selection of an appropriate solid substrate plays an important role in the development of an efficient SSF process. The results provided important knowledge about the characteristics of these materials revealing their potential for use in fermentation processes.

  14. Assaying the proton transport and regulation of UCP1 using solid supported membranes.

    Blesneac, Iulia; Ravaud, Stéphanie; Machillot, Paul; Zoonens, Manuela; Masscheylen, Sandrine; Miroux, Bruno; Vivaudou, Michel; Pebay-Peyroula, Eva


    The uncoupling protein 1 (UCP1) is a mitochondrial protein that carries protons across the inner mitochondrial membrane. It has an important role in non-shivering thermogenesis, and recent evidence suggests its role in human adult metabolism. Using rapid solution exchange on solid supported membranes, we succeeded in measuring electrical currents generated by the transport activity of UCP1. The protein was purified from mouse brown adipose tissue, reconstituted in liposomes and absorbed on solid supported membranes. A fast pH jump activated the ion transport, and electrical signals could be recorded. The currents were characterized by a fast rise and a slow decay, were stable over time, inhibited by purine nucleotides and activated by fatty acids. This new assay permits direct observation of UCP1 activity in controlled cell-free conditions, and opens up new possibilities for UCP1 functional characterization and drug screening because of its robustness and its potential for automation.

  15. Solid-Phase Synthesis of Small Molecule Libraries using Double Combinatorial Chemistry

    Nielsen, John; Jensen, Flemming R.


    The first synthesis of a combinatorial library using double combinatorial chemistry is presented. Coupling of unprotected Fmoc-tyrosine to the solid support was followed by Mitsunobu O-alkylation. Introduction of a diacid linker yields a system in which the double combinatorial step can...

  16. Solid-phase polyamine synthesis using piperazine and piperidine building blocks

    Olsen, Christian A; Witt, Matthias; Jaroszewski, Jerzy W;


    [reaction: see text]. Polyamines containing piperidine and piperazine moieties have been synthesized on solid support using SN2 alkylation of resin-bound secondary amines with 2-nitrobenzenesulfonates (nosylates). The effect of solvent on this alkylation was investigated. The methodology was empl...

  17. Synthesis of silicon carbide nanowires by solid phase source chemical vapor deposition

    NI Jie; LI Zhengcao; ZHANG Zhengjun


    In this paper,we report a simple approach to synthesize silicon carbide(SiC)nanowires by solid phase source chemical vapor deposition(CVD) at relatively low temperatures.3C-SiC nanowires covered by an amorphous shell were obtained on a thin film which was first deposited on silicon substrates,and the nanowires are 20-80 am in diameter and several μm in length,with a growth direction of[200].The growth of the nanowires agrees well on vapor-liquid-solid (VLS)process and the film deposited on the substrates plays an important role in the formation of nanowires.

  18. Study on blister of the coating on solid cantilevers of hydraulic supports for coal mining


    In this work, blister of the Cu-Sn plus Cr coating on solid cantilevers of hydraulic supports for coal mining was investigated by hydrogen-charging, Devanathan-Stachurski method and electrochemical impedance spectroscopy (EIS) measurement. It was found that the permeation hydrogen during the pickling process and the electroplating process was responsible for the blisters. The residual tensile stress due to the machining process would increase the permeation hydrogen amount during pickling and electroplating processes.

  19. Solvent-Controlled Chemoselectivity in the Photolytic Release of Hydroxamic Acids and Carboxamides from Solid Support.

    Qvortrup, Katrine; Petersen, Rico G; Dohn, Asmus O; Møller, Klaus B; Nielsen, Thomas E


    The synthetic utility and theoretical basis of a photolabile hydroxylamine-linker are presented. The developed protocols enable the efficient synthesis and chemoselective photolytic release of either hydroxamates or carboxamides from solid support. The bidetachable mode of the linker unit is uniquely dependent on the solvent. Hydroxamic acids are obtained by performing photolysis in protic solvents, whereas photolysis in aprotic solvents enables the selective release of carboxamides.

  20. Optimization of Solid-Supported Glaser-Hay Reactions in the Microwave

    Jessica S. Lampkowski


    Full Text Available The translation of organometallic reactions into a microwave reactor has numerous advantages. Herein, we describe the application of a previously developed solid-supported Glaser-Hay reaction to microwave conditions. Overall, an array of diynes has been prepared demonstrating the ability to conduct chemoselective reactions in the microwave within 20 min compared to the 16 h thermal conditions. Moreover, non-microwave transparent alkynes have been found to react more quickly, preventing catalyst quenching, and resulting in higher yields.

  1. Solid-supported synthesis: From pharmacologically relevant heterocycles to biologically active surfaces

    Komnatnyy, Vitaly V.

    The present PhD thesis consists of an introduction part and two separate parts covering selected research projects during the PhD study. The introduction part describes the concept of solid-supported synthesis and combinatorial chemistry. The chapter covers recent achievements in materials...... versatile amine -containing reagents. Subsequent applications in antimicrobial peptide synthesis, metal -catalysis, release from the surface, and polymer grafti ng, are also presented....

  2. Typical Mexican agroindustrial residues as supports for solid-state fermentation

    Flores-Maltos, Dulce A.; Mussatto, Solange Ines; Contreras Esquivel, Juan Carlos;


    . These biological wastes can be used as support-substrates in Solid-State Fermentation (SSF) to produce industrially relevant metabolites with great economical advantage. In addition, it is an environment friendly method of waste management. In this study were analyzed six different Mexican agro industrial residues...... process. The results provided important knowledge about the characteristics of these materials revealing their potential for use in fermentation processes....

  3. Rapid activation of the melibiose permease MelB immobilized on a solid-supported membrane.

    Garcia-Celma, Juan J; Dueck, Benjamin; Stein, Martin; Schlueter, Michela; Meyer-Lipp, Kerstin; Leblanc, Gerard; Fendler, Klaus


    Rapid solution exchange on a solid-supported membrane (SSM) is investigated using fluidic structures and a solid-supported membrane of 1 mm diameter in wall jet geometry. The flow is analyzed with a new technique based on specific ion interactions with the surface combined with an electrical measurement. The critical parameters affecting the time course of the solution exchange and the transfer function describing the time resolution of the SSM system are determined. The experimental data indicate that solution transport represents an intermediate situation between the plug flow and the Hagen-Poiseuille laminar flow regime. However, to a good approximation the rise of the surface concentration can be described by Hagen-Poiseuille flow with ideal mixing at the surface of the SSM. Using an improved cuvette design, solution exchange as fast as 2 ms was achieved at the surface of a solid-supported membrane. As an application of the technique, the rate constant of a fast electrogenic reaction in the melibiose permease MelB, a bacterial ( Escherichia coli) sugar transporter, is determined. For comparison, the kinetics of a conformational transition of the same transporter was measured using stopped-flow tryptophan fluorescence spectroscopy. The relaxation time constant obtained for the charge displacement agrees with that determined in the stopped-flow experiments. This demonstrates that upon sugar binding MelB undergoes an electrogenic conformational transition with a rate constant of k approximately 250 s (-1).

  4. EGDMA-cross-linked polystyrene resin: An efficient support for gel phase peptide synthesis

    P K Ajikumar; K S Devaky


    This article illustrates the application of a 2% ethyleneglycol dimethacrylate-cross-linked polystyrene support (EGDMA-PS) in manual solid phase peptide synthesis. This copolymer has been characterised and optimised for peptide synthesis by performing the synthesis of a few model peptides and two biologically important peptides. EGDMA-cross-linked polystyrene support was prepared by the suspension polymerisation of the monomers EGDMA and styrene. EGDMA-PS resin undergoes facile swelling in a variety of solvents, both polar and nonpolar, used in peptide synthesis. The polymer was functionalised by Friedel-Crafts chloromethylation reaction. Peptides were assembled on a 2% cross-linked chloromethyl polymer support of capacity 1.63 mmol Cl/g. The biological peptides synthesised are an 11-residue peptide ATP binding site of the CDC2 kinase and a difficult sequence-a nineresidue peptide 34-42 corresponding to a portion of the hydrophobic terminus of the-amyloid protein 1-42. After synthesis, the peptides were cleaved from the support by treating with neat TFA. Purity of the peptides obtained in good yield was checked by TLC and HPLC methods and found to be fairly high.

  5. Break‐down of Losses in High Performing Metal‐Supported Solid Oxide Fuel Cells

    Kromp, A.; Nielsen, Jimmi; Blennow Tullmar, Peter;


    in the metal support, the electrochemical fuel oxidation at the anode and the oxygen reduction in the mixed ionic electronic conducting cathode. An additional process with a rather high relaxation frequency was attributed to the formation of insulating interlayers at the cathode/electrolyte‐interface. Based...... on these results, selective measures to improve performance and stability, such as (i) PVD‐deposited CGO buffer layer preventing solid state reaction between cathode and the zirconia‐based electrolyte, (ii) LSC‐CGO based in‐situ sintered cathodes and (iii) reduced corrosion of the metal support, were adopted...

  6. Rheology of sludge from double phase anaerobic digestion of organic fraction of municipal solid waste.

    Battistoni, P; Pavan, P; Mata-Alvarez, J; Prisciandaro, M; Cecchi, F


    In this paper experimental results on the anaerobic digestion of sewage sludge and organic fraction of municipal solid waste (OFMSW) by using a double phase process are reported. The long-term experiment has been carried out on a pilot scale plant, performed in different sets of operative conditions, during which granulometric distributions of particles in sludges and rheological properties of sludges were monitored. A significant fluidification of sludge was evidenced in the meso-thermo process, especially taking into account the variation in sludge behaviour from the first to the second phase. In the thermo-thermo process a fluidification higher than that shown in meso-thermo conditions is not observed, this suggesting that better results in terms of sludge conditioning can be obtained in a long time spent in thermophilic anaerobic digestion. Total volatile solids (TVS) and total fixed solids (TFS) become the most important parameters when mathematical modelling is applied to these processes. In the acidogenic phase, hydraulic retention time (HRT) and temperature are used to determine rigidity coefficient (RC), while only temperature is needed for yield stress (YC). Organic loading rate (OLR) and specific gas production (SGP) exert an important role in methanogenic phase description.

  7. The isolation of soyasaponins by fractional precipitation, solid phase extraction, and low pressure liquid chromatography.

    Gurfinkel, D M; Reynolds, W F; Rao, A V


    Bioactive soyasaponins are present in soybean (Glycine max). In this study, the isolation of soyasaponins in relatively pure form (>80%) using precipitation, solid phase extraction and reverse phase low pressure liquid chromatography (RP-LPLC) is described. Soy flour soyasaponins were separated from non-saponins by methanol extraction and precipitation with ammonium sulphate. Acetylated group A soyasaponins were isolated first by solid phase extraction followed by RP-LPLC (solvent: ethanol-water). Soyasaponins, from a commercial preparation, were saponified and fractionated into deacetylated group A and group B soyasaponins by solid phase extraction (methanol-water). Partial hydrolysis of group B soyasaponins produced a mixture of soyasaponin III and soyasapogenol B monoglucuronide. RP-LPLC of deacetylated group A soyasaponins separated soyasaponin A1 and A2 (38% methanol); of group B soyasaponins isolated soyasaponin I (50% ethanol); and of the partial hydrolysate separated soyasaponin III from soyasapogenol B monoglucuronide (50% ethanol). This methodology provides soyasaponin fractions that are suitable for biological evaluation.

  8. Formation of organic solid phases in hydrocarbon reservoir fluids. Final report

    Andersen, S.I.; Lindeloff, N.; Stenby, E.H.


    The occurrence of solid phases during oil recovery is a potential problem. The present work has mainly been concerned with wax formation due to cooling of oils with a large paraffin content. 8 oils have been included in this project, although only a few of these have till now been subject to all the experimental techniques applied. The oils and wax fractions from these have been characterized using techniques such as GC-MS and Ftir. The goal has in part been to get a detailed description of the oil composition for use in model evaluation and development and in part to get a fundamental understanding of waxy oil properties and behaviour. A high pressure (200 bar) equipment has been developed for automatic detection of wax appearance using a filtration technique and laser light turbidimetry. The latter was found to be far superior to the filtration. The filtration was used to sample the incipient solid phase for characterization. However entrapment of liquid in the filters currently used have hampered this part. A number of model systems and one gas condensate have been investigated. The GC-MS procedure was found only to been able to detect molecules up to n-C45 and the group type analysis was not accurate enough for modelling purposes. Using Ftir it was obvious that incipient phases may contain very complex molecules (asphaltenes) which are not captured by GC-MS especially when fractionation is done using the acetone precipitation at elevated temperature. The latter fractionation procedure has been investigated thoroughly as a tool for understanding wax distribution etc. Within thermodynamic modelling a delta lattice parameter model has been developed which incorporates the non-ideality of the solid phases into the calculation of SLE. The non-ideality is estimated from pure component properties. A new algorithm for phase equilibria involving gas-liquid-solid has been developed. Currently both the model work and the experimental works are continued. (au)

  9. Numerical simulation of predicting and reducing solid particle erosion of solid-liquid two-phase flow in a choke

    Li Guomei; Wang Yueshe; He Renyang; Cao Xuewen; Lin Changzhi; Meng Tao


    Chokes are one of the most important components of downhole flow-control equipment. The particle erosion mathematical model, which considers particle-particle interaction, was established and used to simulate solid particle movement as well as particle erosion characteristics of the solid-liquid two-phase flow in a choke. The corresponding erosion reduction approach by setting ribs on the inner wall of the choke was advanced. This mathematical model includes three parts: the flow field simulation of the continuous carrier fluid by an Eulerian approach, the particle interaction simulation using the discrete particle hard sphere model by a Lagrangian approach and calculation of erosion rate using semi-empirical correlations. The results show that particles accumulated in a narrow region from inlet to outlet of the choke and the dominating factor affecting particle motion is the fluid drag force. As a result, the optimization of rib geometrical parameters indicates that good anti-erosion performance can be achieved by four ribs, each of them with a height (H) of 3 mm and a width (B) of 5 mm equaling the interval between ribs (L).

  10. Determination of multi-class herbicides in soil by liquid-solid extraction coupled with headspace solid phase microextraction method

    Đurović-Pejčev Rada


    Full Text Available A method is described for simultaneous determination of five herbicides (metribuzin, acetochlor, clomazone, oxyfluorfen and dimethenamid belonging to different pesticides groups in soil samples. Developed headspace solid phase microextraction method (HS-SPME in combination with liquid-solid sample preparation (LS was optimized and applied in the analysis of some agricultural samples. Optimization of microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl content was perfor-med using 100 μm polydimethyl-siloxane (PDMS fiber. The extraction effi-ciencies of methanol, methanol:acetone=1:1 and methanol:acetone:hexane= =2:2:1 and the optimum number of extraction steps during the sample prepa-ration, were tested, as well. Gas chromatography-mass spectrometry (GC-MS was used for detection and quantification, obtaining relative standard deviation (RSD below 13%, and recovery values higher than 83% for multiple analyses of soil samples fortified at 30 μg kg-1 of each herbicide. Limits of detection (LOD were less than 1.2 μg kg-1 for all the studied herbicides. [Projekat Ministarstva nauke Republike Srbije, br. TR31043 i br. III43005

  11. Deformability of adsorbents during adsorption and principles of the thermodynamics of solid-phase systems

    Tovbin, Yu. K.


    A microscopic theory of adsorption, based on a discrete continuum lattice gas model for noninert (including deformable) adsorbents that change their lattice parameters during adsorption, is presented. Cases of the complete and partial equilibrium states of the adsorbent are considered. In the former, the adsorbent consists of coexisting solid and vapor phases of adsorbent components, and the adsorbate is a mobile component of the vapor phase with an arbitrary density (up to that of the liquid adsorbate phase). The adsorptive transitioning to the bound state changes the state of the near-surface region of the adsorbent. In the latter, there are no equilibrium components of the adsorbent between the solid and vapor phases. The adsorbent state is shown to be determined by its prehistory, rather than set by chemical potentials of vapor of its components. Relations between the microscopic theory and thermodynamic interpretations are discussed: (1) adsorption on an open surface, (2) two-dimensional stratification of the adsorbate mobile phase on an open homogeneous surface, (3) small microcrystals in vacuum and the gas phase, and (4) adsorption in porous systems.

  12. Solid Waste Operations Complex W-113, Detail Design Report (Title II). Volume 2: Solid waste retrieval facilities -- Phase 1, detail design drawings



    The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. Volume 2 provides the complete set of the Detail Design drawings along with a listing of the drawings. Once approved by WHC, these drawings will be issued and baselined for the Title 3 construction effort.

  13. Computational model and simulations of gas-liquid-solid three-phase interactions

    Zhang, Lucy; Wang, Chu


    A computational technique to model three-phase (gas-liquid-solid) interactions is proposed in this study. This numerical algorithm couples a connectivity-free front-tracking method that treats gas-liquid multi-fluid interface to the immersed finite element method that treats fully-coupled fluid-solid interactions. The numerical framework is based on a non-boundary-fitted meshing technique where the background grid is fixed where no mesh-updating or re-meshing is required. An indicator function is used to identify the gas from the liquid, and the fluid (gas or liquid) from the solid. Several 2-D and 3-D validation cases are demonstrated to show the accuracy and the robustness of the method. Funding from NRC and CCNI computational facility at Rensselaer Polytechnic Institute are greatly acknowledged.

  14. Fluid dynamics of the unsteady two phase processes leading to DDT in granular solid propellants

    Krier, H.; Butler, P. B.; Lembeck, M. F.


    Deflagration to Detonation (DDT) was predicted to occur in porous beds of high-energy solid propellants by solving the unsteady fluid mechanical convective heat transfer from hot gas products, obtained from the rapid burning at high pressures, provides the impetus to develop a narrow combustion zone and a resulting strong shock. A parametric study clearly indicates that DDT occurs only when a combination of the solids loading fraction, the burning rate constants, the propellant chemical energy, and the particle size provide for critical energy and gas release to support a detonation wave. Predictions for the run-up length to detonation as a function of these parameters are presented.

  15. Numerical modeling of two-phase high speed jet with non-equilibrium solid phase crystallization

    Molchanov, A. M.; Yanyshev, D. S.; Bykov, L. V.


    The main purpose of the paper is to demonstrate that the Euler approach is fully applicable to the multiphase flows with discrete phase undergoing phase transitions. It is carried out using the example of a jet flow with aluminium oxide particles non-equilibrium crystallization. The jet is strongly underexpanded. The non-equilibrium molecular effects are being taken into account. The obtained results of the simulations are in good agreement with the works of the other authors. The developed Euler approach proved itself to be the most robust in flows with complex flow geometry.

  16. Technologies and decision support systems to aid solid-waste management: a systematic review.

    Vitorino de Souza Melaré, Angelina; Montenegro González, Sahudy; Faceli, Katti; Casadei, Vitor


    Population growth associated with population migration to urban areas and industrial development have led to a consumption relation that results in environmental, social, and economic problems. With respect to the environment, a critical concern is the lack of control and the inadequate management of the solid waste generated in urban centers. Among the challenges are proper waste-collection management, treatment, and disposal, with an emphasis on sustainable management. This paper presents a systematic review on scientific publications concerning decision support systems applied to Solid Waste Management (SWM) using ICTs and OR in the period of 2010-2013. A statistical analysis of the eighty-seven most relevant publications is presented, encompassing the ICTs and OR methods adopted in SWM, the processes of solid-waste management where they were adopted, and which countries are investigating solutions for the management of solid waste. A detailed discussion on how the ICTs and OR methods have been combined in the solutions was also presented. The analysis and discussion provided aims to help researchers and managers to gather insights on technologies/methods suitable the SWM challenges they have at hand, and on gaps that can be explored regarding technologies/methods that could be useful as well as the processes in SWM that currently do not benefit from using ICTs and OR methods.

  17. Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

    Houen, G.; Olsen, D.T.; Hansen, P.R.;


    A solid-phase conjugation method utilizing carrier protein bound to an ion exchange matrix was developed. Ovalbumin was adsorbed to an anion exchange matrix using a batch procedure, and the immobilized protein was then derivatized with iodoacetic acid N-hydroxysuccinimid ester. The activated......, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates...... of ovalbumin and various peptides were prepared in a similar manner and used for production of peptide antisera by direct immunization with the conjugates bound to the ion exchanger. Advantages of the method are its solid-phase nature, allowing fast and efficient reactions and intermediate washings...

  18. A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

    Hosanagara N. Harishkumar


    Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

  19. Silica-Based Solid Phase Extraction of DNA on a Microchip

    陈晓芳; 沈科跃; 刘鹏; 郭旻; 程京; 周玉祥


    Micro total analysis systems for chemical and biological analysis have attracted much attention.However,microchips for sample preparation and especially DNA purification are still underdeveloped.This work describes a solid phase extraction chip for purifying DNA from biological samples based on the adsorption of DNA on bare silica beads prepacked in a microchannel.The chip was fabricated with poly-dimethylsiloxane.The silica beads were packed in the channel on the chip with a tapered microchannel to form the packed bed.Fluorescence detection was used to evaluate the DNA adsorbing efficiency of the solid phase.The polymerase chain reaction was used to evaluate the quality of the purified DNA for further use.The extraction efficiency for the DNA extraction chip is approximately 50% with a 150-nL extraction volume.Successful amplification of DNA extracted from human whole blood indicates that this method is compatible with the polymerase chain reaction.

  20. Solid phase epitaxy amorphous silicon re-growth: some insight from empirical molecular dynamics simulation

    Krzeminski, Christophe; 10.1140/epjb/e2011-10958-7


    The modelling of interface migration and the associated diffusion mechanisms at the nanoscale level is a challenging issue. For many technological applications ranging from nanoelectronic devices to solar cells, more knowledge of the mechanisms governing the migration of the silicon amorphous/crystalline interface and dopant diffusion during solid phase epitaxy is needed. In this work, silicon recrystallisation in the framework of solid phase epitaxy and the influence on orientation effects have been investigated at the atomic level using empirical molecular dynamics simulations. The morphology and the migration process of the interface has been observed to be highly dependent on the original inter-facial atomic structure. The [100] interface migration is a quasi-planar ideal process whereas the cases [110] and [111] are much more complex with a more diffuse interface. For [110], the interface migration corresponds to the formation and dissolution of nanofacets whereas for [111] a defective based bilayer reor...

  1. Experimental setup for investigating silicon solid phase crystallization at high temperatures.

    Schmidt, Thomas; Gawlik, Annett; Schneidewind, Henrik; Ihring, Andreas; Andrä, Gudrun; Falk, Fritz


    An experimental setup is presented to measure and interpret the solid phase crystallization of amorphous silicon thin films on glass at very high temperatures of about 800 °C. Molybdenum-SiO(2)-silicon film stacks were irradiated by a diode laser with a well-shaped top hat profile. From the relevant thermal and optical parameters of the system the temperature evolution can be calculated accurately. A time evolution of the laser power was applied which leads to a temperature constant in time in the center of the sample. Such a process will allow the observation and interpretation of solid phase crystallization in terms of nucleation and growth in further work.

  2. 西仑吉肽的固相合成%Solid phase synthesis of cilengitide

    张波; 王卫国; 康武; 智小霞; 姚忠; 徐红岩


    Fully-protected linear peptide was synthesized by Fmoc solid phase peptide synthesis methods. The solid phase carrier was 2-chlorotrityl chloride resin. HATU/HOBt and HBTU/HOBt were used as the coupling reagents. The synthesis of fully-protected cyclic peptide used THF/DCM ( at a ratio of 1: 1 by volume) as the solvent and HATU/HOBt as the coupling reagents. Finally cilengitide could be obtained by deprotection reaction.%采用Fmoc固相合成法,选用2-氯三苯甲基氯树脂作为固相载,HBTU/HOBt和HATU/HOBt为缩合剂,合成全保护线性肽.以V(DCM)∶V(THF)= 1∶1为溶剂,HATU/HOBt为缩合剂,合成全保护环肽.最后脱除保护基得终产物西仑吉肽.

  3. Dense Pellicular Agarose-Glass Beads for Expanded Bed Application: Flow Hydrodynamics and Solid Phase Classifications

    周鑫; 史清洪; 白姝; 孙彦


    Two dense pellicular agarose-glass matrices of different sizes and densities, i.e., AG-S and AG-L, have been characterized for their bed expansion behavior, flow hydrodynamics and particle classifications in an expanded bed system. A 26 mm ID column with side ports was used for sampling the liquid-solid suspension during expanded bed operations. Measurements of the collected solid phase at different column positions yielded the particle size and density distribution data. It was found that the composite matrices showed particle size as well as density classifications along the column axis, i.e., both the size and density of each matrix decreased with increasing the axial bed height. Their axial classifications were expressed by a correlation related to both the particle size and density as a function of the dimensionless axial bed height. The correlation was found to fairly describe the solid phase classifications in the expanded bed system. Moreover, it can also be applied to other two commercial solid matrices designed for expanded bed applications.

  4. Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

    Helena Prosen


    Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

  5. Investigation of phase diagrams and physical stability of drug-polymer solid dispersions.

    Lu, Jiannan; Shah, Sejal; Jo, Seongbong; Majumdar, Soumyajit; Gryczke, Andreas; Kolter, Karl; Langley, Nigel; Repka, Michael A


    Solid dispersion technology has been widely explored to improve the solubility and bioavailability of poorly water-soluble compounds. One of the critical drawbacks associated with this technology is the lack of physical stability, i.e. the solid dispersion would undergo recrystallization or phase separation thus limiting a product's shelf life. In the current study, the melting point depression method was utilized to construct a complete phase diagram for felodipine (FEL)-Soluplus® (SOL) and ketoconazole (KTZ)-Soluplus® (SOL) binary systems, respectively, based on the Flory-Huggins theory. The miscibility or solubility of the two compounds in SOL was also determined. The Flory-Huggins interaction parameter χ values of both systems were calculated as positive at room temperature (25 °C), indicating either compound was miscible with SOL. In addition, the glass transition temperatures of both solid dispersion systems were theoretically predicted using three empirical equations and compared with the practical values. Furthermore, the FEL-SOL solid dispersions were subjected to accelerated stability studies for up to 3 months.

  6. Molecular simulation of homogeneous crystal nucleation of AB2 solid phase from a binary hard sphere mixture

    Bommineni, Praveen Kumar; Punnathanam, Sudeep N.


    Co-crystal formation from fluid-mixtures is quite common in a large number of systems. The simplest systems that show co-crystal (also called substitutionally ordered solids) formation are binary hard sphere mixtures. In this work, we study the nucleation of AB2 type solid compounds using Monte Carlo molecular simulations in binary hard sphere mixtures with the size ratio of 0.55. The conditions chosen for the study lie in the region where nucleation of an AB2 type solid competes with that of a pure A solid with a face-centered-cubic structure. The fluid phase composition is kept equal to that of the AB2 type solid. The nucleation free-energy barriers are computed using the seeding technique of Sanz et al. [J. Am. Chem. Soc. 135, 15008 (2013)]. Our simulation results show that the nucleation of the AB2 type solid is favored even under conditions where the pure A solid is more stable. This is primarily due to the similarity in the composition of the fluid phase and the AB2 type solid which in turn leads to much lower interfacial tension between the crystal nucleus and the fluid phase. This system is an example of how the fluid phase composition affects the structure of the nucleating solid phase during crystallization and has relevance to crystal polymorphism during crystallization processes.

  7. Thermodynamic Model Formulations for Inhomogeneous Solids with Application to Non-isothermal Phase Field Modelling

    Gladkov, Svyatoslav; Kochmann, Julian; Reese, Stefanie; Hütter, Markus; Svendsen, Bob


    The purpose of the current work is the comparison of thermodynamic model formulations for chemically and structurally inhomogeneous solids at finite deformation based on "standard" non-equilibrium thermodynamics [SNET: e. g. S. de Groot and P. Mazur, Non-equilibrium Thermodynamics, North Holland, 1962] and the general equation for non-equilibrium reversible-irreversible coupling (GENERIC) [H. C. Öttinger, Beyond Equilibrium Thermodynamics, Wiley Interscience, 2005]. In the process, non-isothermal generalizations of standard isothermal conservative [e. g. J. W. Cahn and J. E. Hilliard, Free energy of a non-uniform system. I. Interfacial energy. J. Chem. Phys. 28 (1958), 258-267] and non-conservative [e. g. S. M. Allen and J. W. Cahn, A macroscopic theory for antiphase boundary motion and its application to antiphase domain coarsening. Acta Metall. 27 (1979), 1085-1095; A. G. Khachaturyan, Theory of Structural Transformations in Solids, Wiley, New York, 1983] diffuse interface or "phase-field" models [e. g. P. C. Hohenberg and B. I. Halperin, Theory of dynamic critical phenomena, Rev. Modern Phys. 49 (1977), 435-479; N. Provatas and K. Elder, Phase Field Methods in Material Science and Engineering, Wiley-VCH, 2010.] for solids are obtained. The current treatment is consistent with, and includes, previous works [e. g. O. Penrose and P. C. Fife, Thermodynamically consistent models of phase-field type for the kinetics of phase transitions, Phys. D 43 (1990), 44-62; O. Penrose and P. C. Fife, On the relation between the standard phase-field model and a "thermodynamically consistent" phase-field model. Phys. D 69 (1993), 107-113] on non-isothermal systems as a special case. In the context of no-flux boundary conditions, the SNET- and GENERIC-based approaches are shown to be completely consistent with each other and result in equivalent temperature evolution relations.

  8. Investigation on Dynamic Calibration for an Optical-Fiber Solids Concentration Probe in Gas-Solid Two-Phase Flows

    Changsui Zhao; Liu Shen; Pan Xu; Xiaoping Chen; Daoyin Liu; Cai Liang; Guiling Xu


    This paper presents a review and analysis of the research that has been carried out on dynamic calibration for optical-fiber solids concentration probes. An introduction to the optical-fiber solids concentration probe was given. Different calibration methods of optical-fiber solids concentration probes reported in the literature were reviewed. In addition, a reflection-type optical-fiber solids concentration probe was uniquely calibrated at nearly full range of the solids concentration from 0...

  9. Design of indirect solid-phase immunosorbent methods for detecting arenavirus antigens and antibodies

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A.


    Specifications have been elaborated for formulating indirect solid-phase enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (SPRIA) methods that employ anti-human and anti-mice G class immunoglobulin (IgG), conjugated with horseradish peroxidase and /sup 125/I for detecting the arenaviruses Junin, Machupo, Tacaribe, Amalpari, Tamiami, Lassa, and LCM (lymphocytic choriomeningitis). These methods make it possible to identify with a high degree of sensitivity arenavirus antigens and antibodies in various kinds of material.

  10. Phase I Study of Continuous Weekly Dosing of Dimethylamino Benzoylphenylurea (BPU) in Patients with Solid Tumours

    Messersmith, Wells A.; Rudek, Michelle A.; Baker, Sharyn D.; Zhao, Ming; Collins, Connie; Colevas, A. Dimitrios; Donehower, Ross C.; Carducci, Michael A.; Wolff, Antonio C.


    A phase I study of Dimethylamino Benzoylphenylurea (BPU), a tubulin inhibitor, was performed using a weekly continuous schedule. Patients with refractory solid tumours received oral BPU once weekly without interruption at doses ranging from 5 to 320mg using an accelerated titration design. Nineteen subjects received 54 cycles of BPU. Early pharmacokinetic findings of decreased clearance with increasing dose and plasma accumulation led to the expansion of the 320mg dose level. Two subjects the...

  11. Determination of zinc in environmental samples by solid phase spectrophotometry: optimization and validation study

    Molina, Mar??a Francisca; Nechar, Mounir; Bosque-Sendra, Juan M.


    A simple and specific solid-phase spectrophotometric (SPS) determination of zinc in ??g dm-3 level has been developed based on the reaction of Zn(II) with 4-(2-pyridylazo)resorcinol (PAR) in the presence of potassium iodide; the product was then fixed on an anionic exchanger. The absorbance of the gel, packed in a 1 mm cell, is measured directly. PAR and KI concentrations were optimized simultaneously using response surface methodology (RSM) from sequential experimental Doehlert designs. The ...

  12. Zirconyl chloride promoted highly efficient solid phase synthesis of amide derivatives


    An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.

  13. Numerical study of light-induced phase behavior of smectic solids

    Chung, Hayoung; Park, Jaesung; Cho, Maenghyo


    By the chemical cross-linking of rigid molecules, liquid crystal polymer (LCP) has been envisaged as a novel heterogeneous material due to the fact that various optical and geometric states of the liquid crystalline (LC) phases are projected onto the polymeric constituents. The phase behavior, which refers to the macroscopic shape change of LCP under thermotropic phase change, is a compelling example of such optical-mechanical coupling. In this study, the photomechanical behavior, which broadly refers to the thermal- or light-induced actuation of smectic solids, is investigated using three-dimensional nonlinear finite element analysis (FEA). First, the various phases of LC are considered as well as their relation to polymeric conformation defined by the strain energy of the smectic polymer; a comprehensive constitutive equation that bridges the strong, optomechanical coupling is then derived. Such photomechanical coupling is incorporated in the FEA considering geometric nonlinearity, which is vital to understanding the large-scale light-induced bending behavior of the smectic solid.To demonstrate the simulation capability of the present model, numerous examples of photomechanical deformations are investigated parametrically, either by changing the operating conditions such as stimuli (postsynthesis) or the intrinsic properties (presynthesis). When compared to nematic solids, distinguished behaviors due to smectic substances are found herein and discussed through experiments. The quasisoftness that bidirectionally couples microscopic variables to mechanical behavior is also explained, while considering the effect of nonlinearity. In addition to providing a comprehensive measure that could deepen the knowledge of photomechanical coupling, the use of the proposed finite element framework offers an insight into the design of light-responsive actuating systems made of smectic solids.

  14. A New Molecularly Imprinted Polymer for Solid-phase Extraction of Cotinine from Human Urine

    Jun YANG; Xiao Lan ZHU; Ji Bao CAI; Qing De SU; Yun GAO; Liang ZHANG


    A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.

  15. Kinetics of solid state phase transformations: Measurement and modelling of some basic issues

    S Raju; E Mohandas


    A brief review of the issues involved in modelling of the solid state transformation kinetics is presented. The fact that apart from the standard thermodynamic parameters, certain path variables like heating or cooling rate can also exert a crucial influence on the kinetic outcome is stressed. The kinetic specialties that are intrinsic to phase changes proceeding under varying thermal history are enumerated. A simple and general modelling methodology for understanding the kinetics of non-isothermal transformations is outlined.

  16. Selective fiber used for headspace solid-phase microextraction of abused drugs in human urine

    Sunanta Wangkarn


    A sensitive and selective fiber for simultaneous analysis of three drugs of abuse (amphetamine, methamphetamine and ephedrine) in urine samples was explored using headspace solid phase microextraction and gas chromatography with flame ionization detection. Several parameters affecting extraction such as extraction time, extraction temperature, pH of solution and salt concentrations were investigated. Among five commercially available fibers, divinylbenzene/carboxen/ polydimethylsiloxane is th...

  17. Dynamics of Vibrio cholerae abundance in Austrian saline lakes, assessed with quantitative solid-phase cytometry


    International audience; In order to elucidate the main predictors of Vibrio cholerae dynamics and to estimate the risk of Vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (CARD-FISH/ SPC) was applied in comparison to cultivation for water samples from the lake Neusiedler See, Austria and three shallow alkaline lakes over a period of 20 months. Vibrio cholerae attached to crustacean zoo-plankto...

  18. Solid-phase cloning for high-throughput assembly of single and multiple DNA parts

    Lundqvist, Magnus; Edfors, Fredrik; Sivertsson, Åsa


    We describe solid-phase cloning (SPC) for high-throughput assembly of expression plasmids. Our method allows PCR products to be put directly into a liquid handler for capture and purification using paramagnetic streptavidin beads and conversion into constructs by subsequent cloning reactions. We...... at an average success rate above 80%. We report on several applications for SPC and we suggest it to be particularly suitable for high-throughput efforts using laboratory workstations....

  19. Fmoc solid-phase synthesis of peptide thioesters by masking as trithioortho esters

    Brask, Jesper; Albericio, F.; Jensen, Knud Jørgen


    Total chemical synthesis of proteins by chemoselective ligation relies on C-terminal peptide thioesters as building blocks. Their preparation by standard Fmoc solid-phase peptide synthesis is made difficult by the lability of thioesters to aminolysis by the secondary amines used for removal of th...... of the Fmoc group. Here we present a novel backbone amide linker (BAL) strategy for their synthesis in which the thioester functionality is masked as a trithioortho ester throughout the synthesis....

  20. Solid-phase microextraction for flavor analysis in Harari Khat (Catha edulis) stimulant

    AL-FLAHI Abdulsalam; ZOU Jian-kai (邹建凯); YIN Xue-feng (殷学锋)


    This research examined the typical flavor compounds in the commonest type of Khat called Harari Khat grown in the region of Ethiopia. Twenty-eight compounds, which includes 1,2-Propanedione, 1-Phenyl, Hexanol, Hexanal compounds, Limonene, Benzaldehyde with other flavors, were extracted by polydimethylsiloxane at room temperature for 30 min from Khat samples, and identified by solid-phase microextraction-gas chromatography-mass spectrometry (SPME- GC-MS). This method needs no organic solvents and required minimal sample.