High performance liquid chromatographic studies of erythrocytes haem biosynthetic enzyme activities in alcoholic macrocytosis

The activities of 5-aminolaevulinate dehydrase (ALA-D), hydroxymethylbilane synthase (HMB-S), uroporphyrinogen III synthase (URO-S) and uroporphyrinogen decarboxylase (URO-D) in the erythrocytes of alcoholics were assayed and compared with those in controls and abstaining alcoholics. The HMB-S and URO-S activities in alcoholics were significantly higher than the controls and there were significant correlations between enzyme activities and mean corpuscular volume (MCV). Alcoholics abstaining from alcohol over a nine-month period showed a return to normal enzyme activities in parallel with the normalization of their MCV. Abstaining alcoholics thus all had normal HMB-S and URO-S activities. The ALA-D and URO-D activities of alcoholics were not significantly different from controls or from abstaining alcoholics. Alcohol appears to have a selective effect on the haem biosynthetic enzymes in the erythron.     

A conjecture involving generalized matrix functions

This paper resolves the following conjecture of R. Merris: Let d^G_λ be the generalized matrix function determined by a subgroup G of the symmetric group S_m and an irreducible complex character λ of G. If A, B, and A?B are m-square positive semidefinite hermitian m-square matrices and d^G_λ(A)=d^G_λ(B)≠0, then A=B.     

High‐modulus,high‐strength,thick polypropylene monofilament production: Response surface analysis approach

Response surface analysis was used in optimizing spinning and drawing conditions for the production of a high‐modulus, high‐strength, thick polypropylene (PP) monofilament. Rotatable octagonal central composite design was adopted with two independent variables (take‐up velocity and draw ratio), and variations in the diameter, tensile modulus, and tenacity of the PP monofilament were observed. Quadratic response surface functions described the variations in those properties with quite high correlation coefficients. Canonical analysis combined with contour plots revealed the variation sensitivity: the diameter varied more markedly with the take‐up velocity, and the tensile modulus varied somewhat equally with the two variables, whereas the tenacity varied more markedly with the draw ratio. From such contour plots, the optimum processing conditions for desired properties were predicted without intensive structural analysis. Case studies showed that under the suggested processing conditions, the PP monofilament fulfilled the property requirements, such as a tensile modulus of 10.4 GPa and a tenacity of 672 MPa with a diameter still above 400 μm. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1175–1182, 2003     

Determination of inorganic anions in natural water by microcolumn ion chromatography with on-column enrichment.

An on-column enrichment method was developed for the rapid determination of inorganic anions in natural water. The system was assembled from a syringe pump, a six-port switching valve with a sample-enrichment loop, a separation column and a UV detector. The enrichment efficiency of the system was tested by using inorganic anions as samples. The limits of detection were between 0.6 and 7.7 microg/L. The system was applied to the determination of anions in river and pond-water samples.     

Stochastic quantisation of a gauge field in the spatial axial gauge

The stochastic quantisation method of Nelson can be applied to quantise an Abelian gauge field in the spatial axial gauge.     

Towards a definitive assay of creatinine in serum and in urine: separation by high-performance liquid chromatography

A fast and sensitive method for the separation of serum and urinary creatinine is described. For the preliminary purification of serum and urine, a cation-exchange column is used to remove protein, anions and neutral compounds prior to isolation of creatinine by high-performance liquid chromatography. A reversed-phase system with 0.01 M ammonium acetate solution as the mobile phase can separate creatinine in 7.5 min at a flow-rate of 1 ml/min. The purity of the separated creatinine is proved by derivatization using trifluoracetic anhydride, followed by gas chromatography and mass spectrometry. Although this method of purification was designed for incorporation into a definitive assay, the ease and speed of analysis makes is very attractive for routine clinical use.     

Spectral linewidth of light quasi-elastically scattered from xenon along the coexistence curve near the critical point

We have measured the linewidth of the central component of light scattered from xenon in both the liquid and vapor phases from 1 to 900 mK below the critical point, and compared our results with the predictions of the mode-mode coupling theory. By taking proper account of the “noncritical” background, using independent measurements of all parameters in both the singular and background parts of the theoretical linewidth, we find satisfactory agreement for 0.03<qξ<6.     

Coproporphyrinogen oxidase, protoporphyrinogen oxidase and ferrochelatase activities in iron-overloaded and ethanol-treated rats

The activities of coproporphyrinogen oxidase, protoporphyrinogen oxidase and ferrochelatase in liver homogenates of iron-overloaded and acutely or chronically ethanol-treated rats were assayed by high performance liquid chromatographic methods. Decreased coproporphyrinogen oxidase activity was found in chronically carbonyliron-fed rats while the activities of protoporphyrinogen oxidase and ferrochelatase remained unchanged. Coproporphyrinogen oxidase and protoporphyrinogen oxidase activities in both chronically and acutely ethanol-treated animals were not significantly different from controls. In chronically ethanol-fed rats normal ferrochelatase activity was found.     

Preferred shapes and modes of internal motion in a five-boson system

A five-body system is studied using harmonic-oscillator basis functions and through suitably-defined shape-density functions which are based on its wave functions, we are able to ascribe dominant shapes and modes of internal motion to a number of its low-lying 0⁺ states.Research supported in part by NSF Grant No. PHY-8712229 and Grant No. PHY-8945627