Materials Literature
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The genes ptsI and ptsH, which encode, respectively, enzyme I and Hpr, cytoplasmic proteins involved in the phosphoenolpyruvate:sugar phosphotransferase system, were cloned from Bacillus subtilis. A plasmid containing a 4.1-kilobase DNA fragment was shown to complement Escherichia coli mutations affecting the ptsH and…
The binding of calcium and terbium to purified chick vitamin D-dependent intestinal calcium-binding protein was studied by terbium fluorescence, circular dichroism, and intrinsic protein fluorescence techniques. Calcium-binding protein bound, with high affinity, at least 3 mol of terbium/mol of protein; numerous low a…
An analysis has been developed to describe the rate of drainage of an axi-symmetric plane-parallel foam and emulsion films associated with bubble-bubble and drop-drop coalescence phenomena. The present analysis extends the earlier work of Zapryanov et al(1983) and of others which was limited to the diffusion controlle…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharacterization of large cationic transition-metal-gold clusters by fast atom bombardment mass spectroscopy (FABMS). New rhenium-gold and platinum-gold clusters: [Au4Re(H)4[P(p-tol)3]2(PPh3)4]+, [Au2Re2(H)6(PPh3)6]+, and [Au6Pt(PPh3)7]2+Paul D. Boyle, Brian J. Johnson, Bruc…
Abstract. A series of phthalocyanine (Pc) dyes were screened for their ability to photosensitise murine embryonic fibroblasts or fibrosarcoma cells. Cells were cultured in the presence of the dyes for 24 h. following which they were irradiated with either room light or red light and cultured for a further 72‐h period.…
Abstract The dynamic mechanical properties of homogeneous copolymers of ethylene with 1‐butene, 1‐octene, and 1‐octadecene prepared by means of a vanadium‐based catalyst system have been determined. The 1‐butene copolymers show α′ and α transitions in the 20–60°C temperature range, whereas the 1‐octene and 1‐octadecen…
Abstract To help make a good polymer blend by melt blending, the properties of polycarbonate (PC)/acrylonitrile‐butadiene‐styrene (ABS) systems with various compositions have been investigated. As ABS is blended into PC to form a binary system, Brabender torque is reduced, a phenomenon that results in Improved process…
Abstract Four soils (Cecil, Typic Hapludult; Davidson, Rhodic Paleudult; Dyke, Typic Rhodudult; and Townley, Typic Hapludult) from the Southern Piedmont in Georgia, which have received large applications of gypsum, as well as soils from control plots, have been characterized with respect to their surface charge proper…
Abstract The thermal oxidation of some hydrecarbon polymers differing by their degree of branching was studied simultaneously by chemiluminescence and infrared spectrophotometry. In the case of isotactic polypropylene, measurements were made at various temperatures ranging from 140 to 180°C. The other polymers—ethylen…
Abstract Poly(lactide) with narrow molecular weight distribution was obtained by the ring-opening polymerization of D-lactide with (5,10,15,20-tetraphenylporphinato)aluminum alkoxide as initiator. The polymerization was demonstrated to proceed via the ring-opening of lactide at the acyl-oxygen bond to give (porphinato…
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies…
Abstract The solubility of a series of para ‐linked, substituted phenyl, biphenyl, terphenyl, and quaterphenyl polyamides is reported. Most of these polymers are soluble in amide solvents without lithium chloride, and several are soluble in ethers and/or ketones. The results indicate that solubility in this class of p…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConformational variability of corrins. Some methods of analysisVirginia B. Pett, Michael N. Liebman, Peter Murray-Rust, Kamla Prasad, and Jenny P. GluskerCite this: J. Am. Chem. Soc. 1987, 109, 11, 3207–3215Publication Date (Print):May 1, 1987Publication History Published on…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic structure of low-spin ferric porphyrins: a single-crystal EPR and structural investigation of the influence of axial ligand orientation and the effects of pseudo-Jahn-Teller distortionRobert Quinn, Joan Selverstone Valentine, Marianne P. Byrn, and Charles E. Strou…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy of transesterification in poly(ethylene terephthalate) by small-angle neutron scatteringJ. Kugler, J. W. Gilmer, D. Wiswe, H. G. Zachmann, K. Hahn, and E. W. FischerCite this: Macromolecules 1987, 20, 5, 1116–1119Publication Date (Print):May 1, 1987Publication History…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNonlinear susceptibilities of finite conjugated organic polymersDavid N. Beratan, Jose Nelson. Onuchic, and Joseph W. PerryCite this: J. Phys. Chem. 1987, 91, 11, 2696–2698Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 M…
An overview of the method of surface differential reflectivity (SDR) for the study of semiconductor surfaces is presented. This includes the principles of the technique, the experimental apparatus, and some theoretical considerations concerning the connection of SDR data with the microscopic properties of the surface.…
Abstract— The photosensitized oxidation of L‐tryptophan by gallium phthalocyanines sulfonated to different degrees is studied as a function of both substrate and sensitizer concentrations in water and 50% MeOH‐H 2 O solutions. The maximum quantum yield of singlet oxygen was found to be nearly 0.5 for all sulfonated ga…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 enriched end groups of isotactic polypropylene and poly(1-butene) prepared in the presence of ethylenediindenyldimethyltitanium and methylalumoxanePasquale Longo, Alfonso Grassi, Claudio Pellecchia, and Adolfo ZambelliCite this: Macromolecules 1987, 20, 5, 1015–101…
Abstract A modified centrifugation technique for obtaining soil solutions was developed and compared to immiscible displacement technique using different immiscible liquids. Coefficients of variation and standard deviations for ionic composition of soil solutions obtained by the modified centrifugation method were con…