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31.
A biologically active peptide designated hLCP has been isolated and purified to homogeneity from human lung carcinoma by means of acidic extraction and successive chromatography on Sephadex G-50, Toyopearl HW-40 F and reverse-phase high performance liquid chromatography columns. Analysis showed that peptide consists of thirteen amino acids. Primary structure of hLCP has been deduced by double-coupling Edman degradation combined with enzyme digestion as H-Ser-Pro-Pro-Asp-Gly-Lys-Lys-Glx-Ser-Ala-Asp-Val-Lys-OH. hLCP possessed significant excitatory activity on an electrical stimulation induced contraction. No hLCP could be detected in normal lung tissue. The possibility of using hLCP as a biochemical marker in the clinic for the early detection of lung carcinoma is being investigated. 相似文献
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The effect of die flow variables on the stability of isothermal melt spinning has been studied, both theoretically and experimentally. A die flow analysis provides the boundary conditions for a differential treatment of the spinline, both as a steady flow problem and as a linear stability problem. From the latter, one can predict the onset of draw resonance as a function of draw ratio, certain rheological parameters, and the stresses in the die. The experimental materials were two commercial polypropylenes and the apparatus consisted of a short (1.5–6 cm) isothermal spinning chamber; the agreement with theory was quite satisfactory. In most cases, high shear rates in the die (and subsequent high die swells) decrease the spinline stability but the magnitude of this interaction depends on many variables. In general, there is a high propensity for draw resonance (or ductile breakage) when the spinline is operating under conditions of severe thinning in a rheological sense. 相似文献
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Brands KM Payack JF Rosen JD Nelson TD Candelario A Huffman MA Zhao MM Li J Craig B Song ZJ Tschaen DM Hansen K Devine PN Pye PJ Rossen K Dormer PG Reamer RA Welch CJ Mathre DJ Tsou NN McNamara JM Reider PJ 《Journal of the American Chemical Society》2003,125(8):2129-2135
An efficient stereoselective synthesis of the orally active NK(1) receptor antagonist Aprepitant is described. A direct condensation of N-benzyl ethanolamine with glyoxylic acid yielded a 2-hydroxy-1,4-oxazin-3-one which was activated as the corresponding trifluoroacetate. A Lewis acid mediated coupling with enantiopure (R)-1-(3,5-bis(trifluoromethyl)phenyl)ethan-1-ol afforded a 1:1 mixture of acetal diastereomers which was converted into a single isomer via a novel crystallization-induced asymmetric transformation. The resulting 1,4-oxazin-3-one was converted via a unique and highly stereoselective one-pot process to the desired alpha-(fluorophenyl)morpholine derivative. Interesting and unexpected [1,2]-Wittig and [1,3]-sigmatropic rearrangements were identified during the optimization of these key steps. In the final step, a triazolinone side chain was appended to the morpholine core. The targeted clinical candidate was thus obtained in 55% overall yield over the longest linear sequence. 相似文献
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The addition of Grignard reagents to chiral trifluoromethyl tert-butyl sulfinimine-ethanol adducts affords protected trifluoromethylamines in high yields with good to excellent diastereoselectivities. The stereochemical outcome of the addition is opposite to that expected via a chelation controlled transition state. 相似文献
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[reaction: see text] The chemical behavior of 1,2-bis-triisopropylsilanylsulfanyl alkenes 1 is relatively unexplored, and the weak sulfur-silicon bonds give rise to various transformations. Under acidic conditions (HCl) and in the presence of a Lewis acid at room temperature the bicyclic adduct 2 is obtained in good yield. The structure was confirmed by X-ray crystal analysis with R = benzyl. 相似文献
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Two novel methods named performance baseline and performance correspondence matrices are proposed to evaluate the performance of decision making units (DMUs) based on the techniques of singular value decomposition (SVD). The performance baseline matrix can be used to rank all the DMUs because it provides a common basis for performance comparison. The performance correspondence matrix can be used to conduct performance cluster analysis, with which to explore the structure of input/output variables that are associated with DMUs. The analysis can reveal the performance difference of the DMUs and the key input/output variables determining the efficiency of a certain DMU, and provides valuable quantitative information for adjusting variables to improve efficiency of the DMU. Three case studies are presented to demonstrate that the proposed methods in this work are effective and easy to use and can provide insights into proper selection of input/output variables for performance comparison to avoid over manipulating DEA models in practice. 相似文献