Ergot alkaloids in cereals--description of an analytical method

A method is described for the isolation, separation and quantitative determination of ergot alkaloids in cereals and cereal products.     

Crosstalk and switching characteristics in directional couplers

The normal mode approach is used to calculate the fundamental limits on crosstalk and switching characteristics in directional coupler switches of the stepped delta beta type. The normal modes are calculated numerically as well as analytically using a method for computing the eigenmodes of two coupled, identical waveguides with an antisymmetric index perturbation. The results of the two methods are compared to one another as well as to the results of coupled-mode theory. It is shown that the theoretical minimum for the crosstalk level is very low for the stepped delta beta structure. Nonzero crosstalk was found in some cases where coupled-mode theory predicts zero crosstalk. This is attributed to the improper handling of discontinuities in coupled-mode theory     

Decelerating growth and human breast cancer

BACKGROUND: Improved understanding of human breast cancer growth rates may have many clinical applications. Previous reports have used small numbers of patients and assumed an exponential growth rate. METHODS: The exponential equation and the most commonly used decelerating growth equations, the Gompertz equation and seven generalized forms of the logistic equation, were fitted to mammographic measurements of primary breast cancer using the least squares method. An average of 3.4 observations was made in 113 patients, whereas two measurements were made in another 335 patients. Tumors were assumed to originate as a single cell with the lethal tumor volume assumed to be 2(40) cells. RESULTS: All decelerating equations tested provided a better fit than the exponential, whereas a form of the logistic equation provided the best fit to the data. Limitations in the number of tumor measurements, the assumption of maximal tumor size, and biases inherent in the method of data collection are reviewed. These observations suggest families of curves that characterize breast cancer growth during the early period of clinical observation. CONCLUSIONS: Breast cancer growth in the early clinical period was modeled by a form of the logistic equation. The exponential equation fit the data least well.     

Particle induced X-ray emission (PIXE) analyses on metal samples with structured surfaces

The X-ray yields obtained in PIXE measurements from metal samples with bent or relief surface have been investigated experimentally and by a computer simulation. It was found, that in the fundamental parameter method correct analytical results will be obtained, if two conditions are fulfilled: (1) the inclination of the tangential plane of the bent surface at the point where the ion beam hits this surface has to be known; and (2) the radius of curvature of the surface structure must be larger than 3 to 4 times the ion beam radius used.     

An actively mode-locked/Q-switched Nd:phosphate glass laser oscillator

Good stability and reliability is achieved in the operation of a laser oscillator with Nd-doped phosphate glass that is actively mode-locked, as well as activelyQ-switched. It delivers a single pulse at 1.053 μm with an energy of 140μJ. Pulse duration is variable between 150 ps and 1.1 ns. The system offers a TTL trigger well related to the Single pulse.     

Cystic neuroblastoma in a newborn

A neuroblastoma that presented as an adrenal cyst in a newborn infant is described. This is an extremely unusual presentation for neuroblastoma; it emphasizes the need for a high degree of suspicion when evaluating any abdominal mass in the newborn.     

Complexation of uranyl ions by polypyrrole doped by sulfonated and phosphonated polyethyleneimine

Branched polyethyleneimine (PEI) was sulfonated by reaction with chloropropanesulfonylchloride and phosphonated by reaction with phosphorous acid and formaldehyde. The accordingly formed polyanions were used as doping agents for polypyrrole (PPy). The amount of doping polyanions into thin films of PPy was measured by Rutherford back‐scattering. These films were tested for their capacity to extract uranyl ions from liquid wastes of low level activity. The uranium content was determined by neutron activation analysis, autoradiography, and gravimetry of uranium oxide after calcination. The resistance against static and dynamic leachings was also estimated. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 352–359, 2003     

An early rise in urine N-telopeptide predicts the growth response of normal prepubertal short children to growth hormone therapy

The effects of growth hormone (GH) therapy on biochemical markers of bone turnover were investigated in 11 short prepubertal children without GH deficiency by measuring serum osteocalcin, a marker for bone formation, and urinary concentrations of pyridinium cross-linked amino acids of collagen (PCL), and the peptide-bound pyridinoline residue N-telopeptide (NT), which are specific markers for bone resorption. GH treatment for three months increased bone turnover in this group of children: urinary PCL concentrations increased from 69 +/- 6.2 to 114 +/- 9.3 nmol/mmol Cr (p < 0.01), and urinary NT levels increased from 512 +/- 65 to 766 +/- 74 pmol BCE/mumol Cr (p = 0.058). Serum osteocalcin concentrations increased from 13.64 +/- 2.57 ng/ml to 26.45 +/- 1.39 ng/ml (p < 0.01). The increment in 12-hour urinary concentrations of PCL was highly correlated with the increment in 12-hour urinary NT levels (r = 0.92, p < 0.01). Stepwise multiple regression analysis revealed that the urinary concentrations of NT after 3 months of GH therapy were the best predictor of growth after 12 months of treatment (r = 0.78, F = 7.9, p = 0.037).     

Downcomer and tie plate countercurrent flow in the Upper Plenum Test Facility (UPTF)

The limitation of vertical steam-water countercurrent flow, called flooding, is important for the operation of Emergency Core Cooling (ECC) Systems in Nuclear Reactors. The ECC water injection flooding behavior is scale dependent and the reactor size behavior cannot be extrapolated from small scale data.A new flooding correlation is presented, based on the classic flooding equation where the effects of gravity, interphase momentum exchange, and instability of the gas/liquid interface are considered. Development of a new correlation was necessary in order to correlate the reactor scale downcomer and upper tie plate countercurrent flow data gained in the Upper Plenum Test Facility (UPTF). The new correlation is an extension of the well-known Wallis-type and Kutateladze-type correlations. Each of the three correlations is valid for the experimental facilities on a certain scale. The range of applicability for each of the three correlations is defined for the case of downcomer and tie plate countercurrent flow.