Urinary metabolic profile of phenylketonuria in patients receiving total parenteral nutrition and medication

Nutrition and drugs are main environmental factors that affect metabolism. We performed metabolomics of urine from an 8‐year‐old patient (case 1) with epilepsy and an 11‐year‐old patient (case 2) with malignant lymphoma who was being treated with methotrexate. Both patients were receiving total parenteral nutrition (TPN). We used our diagnostic procedure consisting of urease pretreatment, partial adoption of stable isotope dilution, gas chromatography/mass spectrometry (GC/MS) measurement and target analysis for 200 analytes including organic acids and amino acids. Surprisingly, their metabolic profiles were identical to that of phenylketonuria. The neopterin level was markedly above normal in case 1, and both neopterin and biopterin were significantly above normal in case 2. Mutation analysis of genomic DNA from case 1 showed neither homozygosity nor heterozygosity for phenylalanine hydroxylase deficiency. The metabolic profiles of both cases were normal when they were not receiving TPN. TPN is presently prohibited for individuals who have inherited disorders that affect amino acid metabolism. Although the Phe content of the TPN was not the sole cause of the PKU profile, its effect, combined with other factors, e.g. specific medication or possibly underlying diseases, led to this metabolic abnormality. The present study suggests that GC/MS‐based metabolomics by target analysis could be important for assuring the safety of the treatments for patients receiving both TPN and methotrexate. Metabolomic profiling, both before and during TPN, is useful for determining the optimal nutritional formula not only for neonates, but also for young children who are known heterozygotes for metabolic disorders or whose status is unknown. Copyright © 2009 John Wiley & Sons, Ltd.     

Experimental evaluation of reflectance of surface plasmon polaritons at metal step barrier

We have proposed a way to evaluate the reflectance of surface plasmon polaritons (SPP) at a Ag step barrier from an experiment using the attenuated total reflection structure consisting of ultra-thin metal films sandwiched by dielectrics with nearly identical refractive index. At a wavelength of 632.8 nm, for a long-range SPP (L-SPP) excited in a Ag film of 5.7 nm in thickness, the reflectance at Ag step barriers of 766 nm in height was evaluated to be 7.9 × 10⁻².     

Isogeny formulas for the Picard modular form and a three terms arithmetic geometric mean

In this paper we study the Picard modular forms and show a new three terms arithmetic geometric mean (AGM) system. This AGM system is expressed via the Appell hypergeometric function of two variables. The Picard modular forms are expressed via the theta constants, and they give the modular function for the family of Picard curves. Our theta constants are “Neben type” modular forms of weight 1 defined on the complex 2-dimensional hyperball with respect to an index finite subgroup of the Picard modular group. We define a simultaneous 3-isogeny for the family of Jacobian varieties of Picard curves. Our main theorem shows the explicit relations between two systems of theta constants which are corresponding to isogenous Jacobian varieties. This relation induces a new three terms AGM which is a generalization of Borweins' cubic AGM.     

Errata to “Cyclic strength of imperfectly saturated sands and analysis of liquefaction”: [Proc. Jpn. Acad., Ser. B 80, No. 8, 372–391 (2004)]

The simplified method of analysis to assess liquefaction potential of a given sand deposit is briefly introduced in the first part of this paper. Then, recent advances in the laboratory testing for evaluating liquefaction resistance are described with a particular emphasis on the sand partly saturated with water. As a means to identify the degree of saturation which is applicable for both field deposits and laboratory samples, the use of the longitudinal wave (P-wave) is proposed based on a suite of data obtained from the triaxial tests in the laboratory. It is recommended that the non-destructive P-wave measurements be carried out first to determine the degree of saturation, and then the cyclic triaxial tests involving large destructive strains should be performed to determine the cyclic strength on the same sample of the sand. In order to demonstrate usefulness of the proposed approach, two sets of undisturbed samples were secured from two sites; one is located in Sakai-minato city which has suffered severe liquefaction at the time of the 2000 Tottoriken-Seibu earthquake and the other site is located in Koshigaya city, Saitama, where likelihood of liquefaction to occur in a future earthquake is of major concern. Penetration tests and in-situ velocity logging were also conducted at these two sites. By adjusting the P-wave velocity of the undisturbed samples in the laboratory so as to have the same velocity in the field, the in-situ state of saturation was reproduced in the laboratory samples. Then, the cyclic loading tests were conducted to determine the cyclic strength of intact samples. The results of the laboratory tests as above were incorporated into the simple method of liquefaction analysis described in the first section of this paper. The analysis seems to yield results which are in reasonably good agreement with what was observed at the time of the earthquake.     

New estimation methods of erase band width and track-edge noise in perpendicular magnetic recording

In order to realize higher track density, improving recording resolution and noise at track edge is one of the crucial issues. It has been considered that the erase band (EB), which appears at track-edge, can suppress the cross-talk noise from the adjacent track. On the other hand, the EB consists of a randomly magnetized area that may emanate track-edge noise. In this study, we estimated the accurate EB width by a newly proposed technique and derived analytical formula of the 747 curve with large EB noise. As a result, we found that the peak of track-edge noise was outside the EB and the EB was enough of a noise source at track edge and may be obstructive to the improvement of track density. A bump of 747 curve was produced in the case of little noise of EB. There is a close relationship between the shape of the 747 curve and the EB noise.