Home About us Contact
|
Home About us Contact | ||
|
|
||
Direct Preparation (direct + preparation)
Selected AbstractsDirect Preparation of N-Glycosidic Bond-Linked Nonionic Carbohydrate-Based Surfactant (NICBS) via Ritter Reaction,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2007Zerong Daniel Wang Abstract The Ritter reaction has been successfully extended to the direct preparation of N-glycosidic bond-linked nonionic carbohydrate-based surfactants from carbohydrates and nitriles in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and silver perchlorate (AgClO4) on a high-speed mechanical shaker. The new surfactant molecules have the features of low toxicity, environmental compatibility and biodegradability. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Direct Preparation of 7-Allyl- and 7-ArylindolinesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Daniele Leonori Abstract Addition of allyl halides to the organolithium species derived from lithiation of N - tert -butoxycarbonylindoline with sec -butyllithium (sec -BuLi) and tetramethylethylenediamine (TMEDA) occurs regioselectively by SN2 allylation. In contrast, the organolithium species can be transmetalated to the mixed zinc cuprate that undergoes regioselective SN2, allylations. Transmetalation to the organozinc chloride allows a Negishi-type cross-coupling reaction with aryl bromides using palladium catalysis with triphenylphosphine (PPh3) as ligand. The chemistry was applied to a very short synthesis of 7-prenylindole and of the alkaloid vasconine. [source] Direct Preparation of Nanoscale Thin Films of Poly(vinylidene fluoride) Containing , -Crystalline Phase by Heat-Controlled Spin CoatingMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 24 2008Subramaniyan Ramasundaram Abstract Nanoscale thin films of PVDF containing the , -crystalline phase were directly prepared by heat-controlled spin coating without the influence of external stimuli either in the form of additives or post-treatments. Sample preparation was carried out at different temperatures, ranging from 10 to 70,°C. At elevated temperatures (40, 50, 60 and 70,°C), PVDF was crystallized into the , -phase, while at near-ambient conditions (20 and 30,°C) it was crystallized into the , -phase. Some samples exhibited a phase-segregated morphology, with varying particle sizes depending on the preparation temperature. The ferroelectric nature of a typical sample, prepared at 40,°C, was visualized by piezoresponse imaging studies. [source] ChemInform Abstract: 2-Pyridyl and 3-Pyridylzinc Bromides: Direct Preparation and Coupling Reaction.CHEMINFORM, Issue 41 2010Seung-Hoi Kim Abstract 2-Pyridyl and 3-pyridylzinc bromides are readily prepared from the corresponding pyridylbromides and Rieke zinc. [source] ChemInform Abstract: Direct Preparation of Primary Amides by Reaction of Carboxylic Acids and Ammonia in Alcohols Using DMT-MM.CHEMINFORM, Issue 18 2009Tsukasa Mizuhara Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Palladium-Catalyzed sp3 C,H Activation of Simple Alkyl Groups: Direct Preparation of Indoline Derivatives from N-Alkyl-2-bromoanilines.CHEMINFORM, Issue 37 2008Toshiaki Watanabe Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Efficient Method for the Direct Preparation of Amides from Carboxylic Acids Using Tosyl Chloride under Solvent-Free Conditions.CHEMINFORM, Issue 3 2006Ali Khalafi-Nezhad Abstract For Abstract see ChemInform Abstract in Full Text. [source] Heteroaryl Manganese Reagents: Direct Preparation and Reactivity Studies.CHEMINFORM, Issue 49 2005Reuben D. Rieke Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Direct Preparation of Functionalized Aryl and Heteroaryl Disulfides from Functionalized Zinc Organometallics by Using Sulfur Monochloride (S2Cl2).CHEMINFORM, Issue 41 2005Tobias J. Korn No abstract is available for this article. [source] Direct Preparation of Allylic Indium(III) Reagents from Allylic Alcohols via a Reductive Transmetalation of ,-Allylnickel(II) with Indium(I) Iodide.CHEMINFORM, Issue 47 2004Tsunehisa Hirashita Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A Direct Preparation of Silyl Oxazoles: A Dramatic Chemoselectivity Difference Between R3SiOTf and R3SiCl.CHEMINFORM, Issue 23 2002Ross A. Miller Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] The selective use of rapid aneuploidy screening in prenatal diagnosisAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2009Jan E. DICKINSON Aims: To evaluate the diagnostic utility and costing of the selective use of rapid aneuploidy screening (RAS) for chorion villus sampling (CVS) and amniocentesis specimens. Methods: CVS and amniocenteses performed between 2000 and 2006 were identified. Cases were subdivided into two groups: (i) RAS in addition to long-term culture and (ii) long-term chromosome culture alone. The frequency of RAS, the proportion of abnormal results and the cytogenetic costings were reviewed. Results: A total of 3315 procedures were performed: 730 CVS and 2585 amniocenteses. An abnormal karyotype culture was present in 366 of 3315 (11%). For CVS an abnormal culture was present in 164 (22.5%). RAS (short-term culture/direct preparation) was selectively used in 399 cases (54.6%) with an abnormal result in 128 (32% of RAS). For amniocentesis, 206 chromosome abnormalities were present (8.0% of specimens). RAS (interphase FISH) was selectively used in 580 amniocenteses (22.4%). FISH was requested in 95 (66.4%) of the 143 abnormal cases potentially detectable with standard probes. There was a progressive increase in utilisation of RAS for amniocentesis (8.9% in 2000 to 43.3% of cases in 2006, P < 0.001). CVS RAS was stable. This liberalisation resulted in a fourfold increase in expenditure for FISH and cost/abnormality detected ($A970 per abnormal result in 2000 to $A4015 per abnormal result in 2006). Conclusion: The selective use of prenatal RAS results in a reasonably high detection rate for chromosomal anomalies. Liberalisation of RAS, however, is an expensive cytogenetic model. An approach based on some predictive level of risk combined with resource funding levels may be a more pragmatic approach. [source] Direct Preparation of N-Glycosidic Bond-Linked Nonionic Carbohydrate-Based Surfactant (NICBS) via Ritter Reaction,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2007Zerong Daniel Wang Abstract The Ritter reaction has been successfully extended to the direct preparation of N-glycosidic bond-linked nonionic carbohydrate-based surfactants from carbohydrates and nitriles in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and silver perchlorate (AgClO4) on a high-speed mechanical shaker. The new surfactant molecules have the features of low toxicity, environmental compatibility and biodegradability. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] CdS-Nanoparticle/Polymer Composite Shells Grown on Silica Nanospheres by Atom-Transfer Radical Polymerization,ADVANCED FUNCTIONAL MATERIALS, Issue 3 2005T. Cui Abstract In this paper we describe the combined use of surface-initiated atom transfer radical polymerization (ATRP) and a gas/solid reaction in the direct preparation of CdS-nanoparticle/block-copolymer composite shells on silica nanospheres. The block copolymer, consisting of poly(cadmium dimethacrylate) (PCDMA) and poly(methyl methacrylate) (PMMA), is obtained by repeatedly performing the surface-initiated ATRP procedures in N,N -dimethylformamide (DMF) solution at room temperature, using cadmium dimethacrylate (CDMA) and methyl methacrylate (MMA) as the monomers. CdS nanoparticles with an average size of about 3,nm are generated in situ by exposing the silica nanospheres coated with block-copolymer shells to H2S gas. These synthetic core,shell nanospheres were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), diffuse reflectance UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). These composite nanospheres exhibit strong red photoluminescence in the solid state at room temperature. [source] A Direct Amine-Palladium Acetate Cocatalyzed Saegusa Oxidation Reaction of Unmodified Aldehydes to ,,,-Unsaturated AldehydesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Jin Zhu Abstract A direct preparation of synthetically useful ,,,-unsaturated aldehydes from readily available aldehydes has been developed. The process is effectively cocatalyzed by an amine-palladium acetate to give rise to ,,,-unsaturated aldehydes in moderate to good yields (41,62%). The reaction features the use of unmodified aldehydes rather than enol silyl ethers, which are used in a typical Saegusa oxidation reaction. [source] Caregiver Understanding of Adolescent Development in Residential TreatmentJOURNAL OF CHILD AND ADOLESCENT PSYCHIATRIC NURSING, Issue 4 2002Susan Kools PhD PROBLEM Caretaker knowledge and understanding of adolescent development and its application to clinical practice with severely emotionally disturbed adolescents in residential treatment. METHODS Twenty child-care workers and registered nurses participated in semistructured interviews analyzed using dimensional analysis, a grounded theory method. FINDINGS Three distinct categories of caregivers were identified based on level of expertise and engagement in developmentally appropriate treatment practices: inexperienced, party-liners, and transcenders. Developmental issues identified included lack of resident preparation for puberty and staff discomfort with adolescent sexuality. CONCLUSIONS Caregiver, institutional, and social barriers to developmentally sensitive practice were identified. Practice recommendations include direct preparation of children and adolescents in residential treatment for pubertal changes and sexual development, and carefkl discernment of age-appropriate and psycho-pathological adolescent behaviors. [source] A direct preparation of silica shell on polystyrene microspheres prepared by dispersion polymerization with polyvinylpyrrolidoneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2008Jinho Hong PS/silica core/shell structured microspheres were easily prepared in a simple process. Because of the acid-base interaction between the TEOS and seed particles prepared by dispersion polymerization, uniform silica shell was formed on the PVP-stabilized PS particles without additional PVP-coating process. [source] Synthesis and Characterization of Nanoscaled Cerium (IV) Oxide via a Solid-State Mechanochemical MethodJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2006Jun Lu Solid-state reactions have the potential for direct preparation of ceramic powders and offer a low-temperature and low-cost alternative to conventional techniques for production of oxide powders. This paper describes a simple and effective mechanochemical method based on solid-state reactions during ball milling for synthesis of nanoscaled ceria (CeO2) particles. By using an organic base instead of an inorganic base, metal-ion-free nanoscaled CeO2 can also be made. The effects of annealing temperature on particle sizes and lattice strain are investigated. The results show that the average particle sizes of the particles increases and the average crystal lattice distortion decreases with the annealing temperature. Transmission electron microscopy examinations demonstrate that the CeO2 particles synthesised by this method are near-spherical shaped. [source] On-plate digestion of proteins using novel trypsin-immobilized magnetic nanospheres for MALDI-TOF-MS analysisPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 20 2007Yan Li Abstract In this study, a novel method of on-plate digestion using trypsin-immobilized magnetic nanospheres was developed followed by MALDI-TOF-MS for rapid and effective analysis and identification of proteins. We utilized a facile one-pot method for the direct preparation of amine-functionalized magnetic nanospheres with highly magnetic properties and the amino groups on the outer surface. Through the reaction of the aldehyde groups with amine groups, trypsin was simply and stably immobilized onto the magnetic nanospheres. The obtained trypsin-linked magnetic nanospheres were then applied for on-plate digestion of sample proteins (myoglobin and Cytochrome c). Moreover, after digestion, the trypsin-linked nanospheres could be easily removed from the plate due to their magnetic property, which would avoid causing contamination on the ion source chamber in MS. The effects of the temperature and incubation time on the digestion efficiency were characterized. Within only 5,min, proteins could be efficiently digested with the peptide sequence coverage higher than or equal to that of the traditional in-solution digestion for 12,h. Furthermore, RPLC fractions of rat liver extract were also successfully processed using this novel method. These results suggested that our improved on-plate digestion protocol for MALDI-MS may find further application in automated analysis of large sets of proteins. [source] | ||||||||||||||||