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Well-known Procedure (well-known + procedure)
Selected AbstractsP-Chirogenic Benzo-Fused Phenoxaphosphane: Synthesis, Resolution and Study of the Stereochemical Properties of the Corresponding Palladium ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2008Franco Doro Abstract The synthesis and resolution of chiral phenoxaphosphane 3, with the stereogenic center at the phosphorus atom, is described. Compound 3 has been synthesized following a well-known procedure for trapping a phosphorus atom within a six-membered ring. The resolution of the racemic mixture of 3 was achieved through separation of its diastereomeric palladacycle derivatives 7a,b and 9a,b. The absolute configuration of enantiopure phosphanes 3a,b was assigned unequivocally by means of X-ray crystal structure determination for complex 9a and by combination of NOE(1H,1H)/COSY(1H,1H) spectroscopy and DFT calculations for complexes 7a,b, which in both cases led to identical results. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Cranioplasty in ancient Peru: a critical review of the evidence, and a unique case from the Cuzco areaINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2010J. W. Verano Abstract Cranioplasty is a well-known procedure in modern neurosurgery. Although some authors have claimed it was also performed by prehistoric trepanners in various parts of the world, there is little hard evidence to support this. Here we review various claims of cranioplasty in Peru, where trepanation was widely practised in Prehispanic times. We find little support for assertions that cranioplasty was common. One recently discovered burial from the Cuzco region, however, provides the first documented case of the reinsertion of a bone plug into a trepanation opening. Copyright © 2008 John Wiley & Sons, Ltd. [source] Duncan's model for X, -control charts: sensitivity analysis to input parametersQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 1 2010Cinzia Mortarino Abstract Duncan's model is a well-known procedure to build a control chart with specific reference to the production process it has to be applied to. Although many papers report true applications proving the procedure's noteworthy economic advantages over control charts set purely on the basis of standard statistical criteria, this method is often perceived only as an academic exercise. Perhaps the greater barrier preventing its practical application stems from the difficulty in making cost items explicit. In this paper a sensitivity analysis is proposed for misspecification in the cost parameters for optimal solutions of Duncan's model. While similar contributions published in the literature perform sensitivity analyses with a one-factor-at-a-time scheme, the original contribution of this paper is represented by the focus given on interactions among changes in values of different cost parameters. The results obtained here denote that all factors significantly affect optimal solutions through quite complicated interactions. This should not, in our opinion, discourage the implementation of Duncan's model, pointing conversely to its robust versions, already available in the current literature. Copyright © 2009 John Wiley & Sons, Ltd. [source] A European interlaboratory testing of three well-known procedures for immunocytochemical detection of epithelial cells in bone marrow.CYTOMETRY, Issue 6 2006Results from analysis of normal bone marrow Abstract Background: This investigation intended to study the unspecific background to be expected in normal bone marrow (BM), comparing three well recognized protocols for immunocytochemical detection of disseminated carcinoma cells. The interlaboratory variation in screening and evaluation of stained cells was analyzed and different screening methods were compared. Methods: BM mononuclear cells (BM MNC) from 48 normal BMs were immunostained in parallel by three participating laboratories. The protocols, based on three different anti-cytokeratin antibodies, have all been in common use for detection of disseminated carcinoma cells: the A45-B/B3 protocol (Hamburg), the CK2 protocol (Augsburg) and the AE1AE3 protocol (Oslo). For all protocols, the immunostained cells were visualized by the same alkaline-phosphatase (AP) detection system (APAAP) followed by detection of the cells by manual screening and by two different automated screening systems (ACIS from Chromavision and MDS1 from Applied Imaging). Detected AP-visualized cells were morphologically classified into unambiguous hematopoietic (Uhc) and questionable cells (Qc, potentially interpreted as tumor cells). Results: Seven of 48 BMs (15%) harbored ,1 AP-visualized cell(s) among 1 × 106 BM MNC, both for the A45-B/B3- and for the AE1AE3 protocol, while for CK2 a higher proportion of BMs (21 BMs; 44%) harbored AP-visualized cells (P < 0.01, McNemar's test). The number of Qc was, for all protocols, 1 log lower than the total number of AP-visualized cells. On average, the frequency of Qc was 0.04, 0.08, and 0.02 per 106 BM MNC with A45-B/B3, CK2 and AE1AE3, respectively, and the number of Qc-positive BMs 1, 4, and 1. The MDS1 screening sensitivity was similar to manual screening, while ACIS detected fewer cells (P < 0.001, McNemar's test). Conclusions: All protocols resulted in AP-visualization of occasional hematopoietic cells. However, morphological classification brings the specificity to a satisfactory high level. Approximately 10% of AP-visualized cells were categorized "questionable". The CK2 protocol turned out less specific than the A45-B/B3 and AE1AE3 protocols. © 2006 International Society for Analytical Cytology. [source] Molecular mechanics in the context of the finite element methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2009Jens Wackerfuß Abstract In molecular mechanics, the formalism of the finite element method can be exploited in order to analyze the behavior of atomic structures in a computationally efficient way. Based on the atom-related consideration of the atomic interactions, a direct correlation between the type of the underlying interatomic potential and the design of the related finite element is established. Each type of potential is represented by a specific finite element. A general formulation that unifies the various finite elements is proposed. Arbitrary diagonal- and cross-terms dependent on bond length, valence angle, dihedral angle, improper dihedral angle and inversion angle can also be considered. The finite elements are formulated in a geometrically exact setting; the related formulas are stated in detail. The mesh generation can be performed using well-known procedures typically used in molecular dynamics. Although adjacent elements overlap, a double counting of the element contributions (as a result of the assembly process) cannot occur a priori. As a consequence, the assembly process can be performed efficiently line by line. The presented formulation can easily be implemented in standard finite element codes; thus, already existing features (e.g. equation solver, visualization of the numerical results) can be employed. The formulation is applied to various interatomic potentials that are frequently used to describe the mechanical behavior of carbon nanotubes. The effectiveness and robustness of this method are demonstrated by means of several numerical examples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Matrix-assisted laser desorption/ionisation mass spectrometry in the study of polycondensation of Ti(OBun)4 in the presence of Si(OEt)4RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2003Roberta Seraglia The hydrolysis-polycondensation behaviour of alcoholic solutions containing Si(OEt)4 and Ti(OBun)4, in different molar ratios (Si/Ti,=,10,0.2), was analysed by laser desorption/ionisation (LDI) and matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry. The solutions were prepared using operating conditions usually employed in the sol-gel synthesis of SiO2 -TiO2 materials. In accord with the well-known procedures for controlling the different chemical reactivities of the alkoxides, the pre-hydrolysis of the slower reacting silicon ethoxide and the chelation by acetylacetone of the faster reacting titanium butoxide were performed before mass spectrometric analysis. While LDI-MS did not provide evidence for the presence of mixed Si-Ti species in samples obtained from these reactions, MALDI-MS of samples diluted with chloroform and using 2,5-dihydroxybenzoic acid (DHB) as matrix led to detection of various oligomers with different contents of Si and Ti atoms. The results suggest that the formation of Si-Ti mixed oligomers seems to be the favoured process, especially for solutions in which one of the two components is diluted. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||