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One-step Procedure (one-step + procedure)
Selected AbstractsCationic and anionic lipid-based nanoparticles in CEC for protein separationELECTROPHORESIS, Issue 11 2010Christian Nilsson Abstract The development of new separation techniques is an important task in protein science. Herein, we describe how anionic and cationic lipid-based liquid crystalline nanoparticles can be used for protein separation. The potential of the suggested separation methods is demonstrated on green fluorescent protein (GFP) samples for future use on more complex samples. Three different CEC-LIF approaches for protein separation are described. (i) GFP and GFP N212Y, which are equally charged, were separated with high resolution by using anionic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (ii) High efficiency (800,000 plates/m) and peak capacity were demonstrated separating GFP samples from Escherichia coli with cationic nanoparticles suspended in the electrolyte and adsorbed to the capillary wall. (iii) Three single amino-acid-substituted GFP variants were separated with high resolution using an approach based on a physical attached double-layer coating of cationic and anionic nanoparticles combined with anionic lipid nanoparticles suspended in the electrolyte. The soft and porous lipid-based nanoparticles were synthesized by a one-step procedure based on the self-assembly of lipids, and were biocompatible with a large surface-to-volume ratio. The methodology is still under development and the optimization of the nanoparticle chemistry and separation conditions can further improve the separation system. In contrast to conventional LC, a new interaction phase is introduced for every analysis, which minimizes carry-over and time-consuming column regeneration. [source] Macrocyclic Cyclo[n]malonates , Synthetic Aspects and Observation of Columnar Arrangements by X-ray CrystallographyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 10 2006Nikos Chronakis Abstract A variety of achiral and chiral macrocyclic oligomalonates were synthesised in a one-step procedure through condensation of malonyl dichloride with ,,,-diols. We have investigated the applicability of this method by varying the length and type of the spacers in the diol. Product distribution analysis revealed that the preferential formation of monomeric, dimeric, or trimeric macrocyclic malonates can be controlled by choosing diols with specific spacers connecting the hydroxy groups. Of special interest are the macrocyclic bismalonates, as they show pronounced crystallisability and arrange into columnar motifs in the solid state. They feature distinctive dihedral angles: all ester moieties adopt anti conformations whereas the planes of the carboxy moieties of each malonate residue arrange in an approximately orthogonal fashion. The latter geometry is enforced by the macrocyclic structures, as revealed by a conformational search in the Cambridge Structural Database. The X-ray diffraction data show that C=O···H,C, and C,O···H,C hydrogen bonds stabilise the columnar arrangement of the dimeric rings with formation of tubular assemblies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Silicon Surface-Bound Redox-Active Conjugated Wires Derived From Mono- and Dinuclear Iron(II) and Ruthenium(II) Oligo(phenyleneethynylene) Complexes,ADVANCED MATERIALS, Issue 10 2008Nicolas Gauthier Electron-rich mononuclear Fe(II) or dinuclear Fe(II)/Ru(II) acetylide complexes are photochemically grafted onto hydrogenated silicon surfaces following a simple and mild one-step procedure. The monolayers of redox-active organometallics that are formed exhibit efficient electrical communication between their bound metallic centers and the silicon surface through interfacial SiC bonds. [source] In-Situ Coating of SBA-15 with MgO: Direct Synthesis of Mesoporous Solid Bases from Strong Acidic Systems,ADVANCED MATERIALS, Issue 22 2003Y.L. Wei Basic mesoporous materials (see Figure) are synthesized directly from a strong acidic solution for the first time. This is achieved by in-situ coating of SBA-15 with basic MgO by adding acetate salt into the initial mixture of raw materials for synthesis. The synthesis and modification is performed in a one-step procedure. The magnesium acetate not only acts as the precursor of MgO, but also leads to a better order in the mesostructure. [source] Oxazoline chemistry part III.JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2003-anilinyl)-2-oxazolines], Synthesis, characterisation of [2-(, some related compounds The syntheses and characterisation of a series of chiral and achiral 2-(aminophenyl)-2-oxazolines and some related compounds is reported. All of the derivatives have been produced by a one-step procedure involving the treatment of isatoic anhydride (i.e. [2H]-3, 1-benzoxazine-[1H -2,4-dione: 1) or its 5-chloro analogue with a slight excess of appropriate amino-alcohols. In most cases, anhydrous ZnCl2 is shown to be an effective Lewis acid catalyst for this reaction at reflux temperature in high boiling aromatic solvents (PhCl or PhMe). Oxazolines have been readily formed using rac -2-amino-1-butanol, (S)-phenylglycinol, 2-methyl-2-amino-1-propanol and (1S,2R) or (IR,2S)-cis - 1 -amino-2-indanol; yields range from 85% to 22%. The use of aminoalcohols such as 2-ethanolamine, (±)-2-amino-1-phenyl-1-propanol or 3-amino-1-propanol (to give the corresponding 4,5-dihydro-1,3-oxazine) results in poor yields. The use of other Lewis acid catalysts (silicic acid, Cd(acac)2·2H2O, CuCl2·2H2O, InCl3) or higher temperatures did not improve the yields with these latter two substrates. Benzoxazoles and N-substituted benzoxazoles can also be obtained in reasonable yields from 1 using 2-aminophenol (36%) or 2-amino-3-hydroxypyridine (45%). [source] Genetic evaluation of dairy cattle using a simple heritable genetic groundJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2010Josef Pribyl Abstract The evaluation of an animal is based on production records, adjusted for environmental effects, which gives a reliable estimation of its breeding value. Highly reliable daughter yield deviations are used as inputs for genetic marker evaluation. Genetic variability is explained by particular loci and background polygenes, both of which are described by the genomic breeding value selection index. Automated genotyping enables the determination of many single-nucleotide polymorphisms (SNPs) and can increase the reliability of evaluation of young animals (from 0.30 if only the pedigree value is used to 0.60 when the genomic breeding value is applied). However, the introduction of SNPs requires a mixed model with a large number of regressors, in turn requiring new algorithms for the best linear unbiased prediction and BayesB. Here, we discuss a method that uses a genomic relationship matrix to estimate the genomic breeding value of animals directly, without regressors. A one-step procedure evaluates both genotyped and ungenotyped animals at the same time, and produces one common ranking of all animals in a whole population. An augmented pedigree,genomic relationship matrix and the removal of prerequisites produce more accurate evaluations of all connected animals. Copyright © 2010 Society of Chemical Industry [source] Anisotropic Particle Synthesis Inside Droplet Templates on Superhydrophobic SurfacesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 2 2010Vinayak Rastogi Abstract We demonstrate how droplet templates dispensed on superhydrophobic substrates can be used to fabricate both shape-anisotropic ("doughnut") and composition-anisotropic ("patchy magnetic") supraparticles. The macroscopic shape of the closely-packed particle assemblies is guided by the droplet meniscus. Aqueous droplets of monodisperse microsphere suspensions dispensed on the substrates initially acquire near-spherical shape due to a high contact angle. During the solvent evaporation, however, silica suspension droplets undergo shape transitions (concaving) guiding the structure of the final assemblies into doughnut supraparticles. Composition anisotropy is achieved by drying a droplet containing a mixed suspension of latex and magnetic nanoparticles, while exposing it to magnetic field gradients. Depending on the pattern of the magnetic fields, the magnetic nanoparticles segregate into single, bilateral, or trilateral, patched spherical supraparticles. The physical effects leading to the development of anisotropy are discussed. Unlike the conventional wet self-assembly (WSA) methods where the final structures need to be extracted from the liquid environment, this efficient one-step procedure produces ready to use "dry" supraparticles. [source] Segmented polymer networks containing amino-dendrimersPOLYMER INTERNATIONAL, Issue 2 2003Leen M Tanghe Abstract Polymer networks in which poly(propylene imine) dendrimers (AstramolÔ) are connected to each other by linear polytetrahydrofuran (polyTHF) segments, were prepared by two methods. The first method was a one-step procedure in which bifunctionally living polyTHF, obtained by initiation of the THF polymerization with trifluoromethane sulfonic anhydride (triflic anhydride), was reacted with an amino-dendrimer. This reaction was very fast but did not allow formation of the end products. The second method was a two-step procedure. In a first step, living polyTHF, prepared with acryloyloxybutyl triflate as initiator, was grafted on an amino-dendrimer, to form a star-like, acrylate-terminated polyTHF multi-macromonomer with the dendrimer as core. In a second step, networks were obtained by Michael addition between the acrylate end-groups and unreacted amino-groups of the dendrimer. This cross-linking reaction occurred spontaneously upon heating of the solution of the multi-macromonomer with gelation times varying from a few minutes to a few hours, depending on the temperature and the composition of the prepolymers. With this method it was possible to prepare networks in the form of coatings or films. © 2003 Society of Chemical Industry [source] Vitrification of In Vitro -produced Bovine Embryos by Addition of Ethylene Glycol in One-stepREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2006DJ Walker Contents The objective of this study was to simplify two-step addition of cryoprotectant for vitrification of bovine embryos by developing a one-step procedure. Survival was calculated as a percentage of non-vitrified controls developed from the same batch of oocytes. In experiment 1, bovine blastocysts were vitrified following one- or two-step addition of cryoprotectant. Exposure of embryos to cryoprotectant in one-step resulted in survival rates not significantly lower (p > 0.1) than those obtained by two-step addition (85% vs 98%, respectively). Based on these results, experiments 2,4 were designed to test one-step addition of cryoprotectant more rigorously. Experiment 2 exposed day 7 blastocysts to 6, 7 or 8 m ethylene glycol for 2.5 or 3.5 min. At 24 h post-vitrification, survival of embryos was similar, irrespective of ethylene glycol concentration or exposure time (6 m 38%, 7 m 51%, 8 m 59%; 2.5 min 54%, 3.5 min 45%). In experiment 3, blastocysts were exposed to 7 m ethylene glycol for shorter times (30 or 60 s); 30 s exposure resulted in decreased survival (8% vs 31%, p < 0.05). Experiment 4 concerned one-step addition of cryoprotectant to day 6 bovine morulae, exposed to 7 m ethylene glycol for 1 or 1.5 min. There was no difference in survival between exposure times of 1 or 1.5 min (28% vs 45%, respectively; p > 0.1). It is unclear why many embryos survive vitrification with one-step addition of cryoprotectant, but others do not. Although, one-step addition of cryoprotectant simplifies the vitrification procedure, survival rates were inadequate for routine cryopreservation of in vitro -produced bovine embryos. [source] Argon Plasma Coagulation (APC) in Palliative Surgery of Head and Neck MalignanciesTHE LARYNGOSCOPE, Issue 7 2002Ulrich Hauser MD Abstract Objectives Surgical reduction of bulky disease is an important treatment option in patients with incurable head and neck malignancies. In general, conventional tumor ablation is associated with significant hemorrhage, and the resulting tumorous wound surface entails aftercare problems. Argon plasma coagulation (APC) represents a novel technique providing effective hemostasis and wound sealing. Thus, APC features requirements of particular interest in palliative surgery of the head and neck. Study Design Using APC, we performed 18 palliative tumor resections in a series of 8 consecutive patients with recurrent head and neck lesions. Five patients received repeated APC treatment up to five times. Methods APC as non-contact, high-frequency electrosurgery under inert argon plasma atmosphere allows dissection, hemostasis, and desiccation of tumor tissue in a one-step procedure. In consideration of the limited and heterogeneous group of patients, results are interpreted descriptively. Results In every case of palliative surgery, APC caused efficient hemostasis, which helped significantly to reduce both time exposure of the operation and intraoperative loss of blood. Only one APC-unrelated complication occurred (transient rhino-liquorrhea), and none of the patients developed postoperative hemorrhage. Finally, APC produced dry and clean wound surfaces facilitating surgical aftercare. The achieved esthetic and functional improvements strengthened the patient's autonomy and social acceptance. Conclusion APC is highly recommended for palliative surgery of head and neck malignancies. [source] Intraoperative frozen section examination of axillary sentinel lymph nodes in breast cancer,APMIS, Issue 1 2005D. A. GRABAU The study presents the results from intraoperative frozen section assessment of axillary sentinel lymph nodes (SLNs) in breast cancer. Routine histological frozen sections from one level were used, two sections stained with haematoxylin and eosin. Immunohistochemistry for cytokeratins was applied to the permanent SLN paraffin sections only. Axillary dissection was performed on all SLN-positive cases regardless of the size of the metastatic deposits. With a detection rate of 83%, 272 patients entered the study over a period of 46 months. A total of 61 cases were SLN positive by frozen section analysis. The paraffin sections gave an additional 23 SLN-positive cases. The false-negative rate for frozen sections was then 27% (23/84). Micrometastases were found in 28 of 84 cases, and macrometastases in 56. The false-negative rate of frozen sections for micrometastases was 71% (20/28), and for macrometastases 5% (3/56). A total of 73% (61/84) of the patients underwent axillary surgery as a one-step procedure. [source] Regimes of Multiple Emulsions of W1/O/W2 and O1/W/O2 Type in the Continuous Couette-Taylor Flow ContactorCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 1 2010E. Dluska Abstract The flow regimes of multiple emulsions in the continuous Couette-Taylor flow (CTF) contactor and characterization of the dispersion state are reported. The proposed method of multiple emulsion preparation is a one-step procedure on the contrary to the classical two-step procedure. The effect of operating parameters in the CTF contactor on multiple emulsion appearance, structure (drop size and packing), and rheological behavior is discussed. The key factors affecting multiple emulsion preparation in the CTF apparatus were the phases ratio, the rotational flow, and an annular gap width. The influence of an axial flow was more significant in the range of small rotational rates. The operating conditions were optimized to find the best characteristic multiple emulsions (largest interfacial area). The paper presents the same exemplary data of using W1/O/W2 emulsions as emulsion liquid membranes (ELMs) in the extraction process and O1/W/O2 for control active agent (drug) release. [source] Synthesis of new 3-(trifluoromethyl)-1H -indoles by reduction of trifluoromethyloxoindolesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2008Moônica M. Bastos This work describes the synthesis of new 3-trifluoromethylindoles. Different isatins were trifluoromethylated using (trifluoromethyl) trimethylsilane (Me3SiCF3) as a nucleophilic agent giving new 3-hydroxy-3-(trifluoromethyl)indolin-2-one. Different "one-step" procedures to transform the latter compounds into the reduced indoles were attempted, but failed. For the synthesis of the new trifluoromethylindoles the corresponding 2-oxo-3-(trifluoromethyl)indoles were reduced using borane/THF complex to furnish 3-(trifluoromethyl)indolin-3-ol that additionally were dehydrated using thionyl chloride in pyridine to give excellent yields of the desired products. [source] | ||||||||||||||||